Patent Application
20240405623
Embodiments of the disclosure relate to appliances having surface permanent magnet synchronous motors (SPMSM).
Generally, washing machines use a motor to rotate a washing tub. As a motor, a surface permanent magnet synchronous motor (SPMSM) has been commonly adopted. When a washing machine is in operation, the motor is driven over a wide range of rotation speeds from a low rotation speed (e.g., 45 revolutions per minute (RPM)) during washing to a high rotation speed (e.g., 1200 RPM) during spinning. At high rotation speeds, noise generated by the SPMSM an integer multiple of a rotation speed may be undesirably loud.
One of the causes for noise is cogging torque (equivalent to a magnetic attractive force generated when rotating a rotor in a demagnetized state). Therefore, to address the noise problem, the cogging torque is suppressed by designing the shape of a magnet or core and the like differently. However, in mass-produced SPMSMs, noise may be caused due to small gaps during manufacturing, and the cause for noise is unclear.
Therefore, there is a need for a method of suppressing an increase in harmonic components of cogging torque, which causes noise in SPMSMs.
According to an embodiment of the disclosure, a washing machine including a motor with an annular magnetic pole body is provided. According to one embodiment of the disclosure, the washing machine may include a casing, a laundry inlet configured to load laundry on a top or side of the casing, a door attached to the laundry inlet, a stationary tub capable of storing water for washing the laundry, a rotary tub formed as a container within the stationary tub and configured to be rotatable, and a motor configured to rotate the rotary tub. According to an embodiment of the disclosure, the motor of the washing machine may include a rotor configured to rotate about a rotation axis. According to an embodiment of the disclosure, the motor of the washing machine may include a stator configured to face the rotor with an air gap therebetween. According to an embodiment of the disclosure, in the motor of the washing machine, the rotor may include an annular magnetic pole body in which a plurality of magnets having an arc-shaped cross-section are arranged in a circumferential direction of the rotor. According to an embodiment of the disclosure, the annular magnetic pole body included in the motor of the washing machine may include two or more types of magnets having different numbers of magnetic poles.
According to an embodiment of the disclosure, a home appliance including a motor with an annular magnetic pole body is provided. According to an embodiment of the disclosure, the motor of the home appliance may include a rotor configured to rotate about a rotation axis. According to an embodiment of the disclosure, the motor of the home appliance may include a stator facing the rotor with an air gap therebetween. According to an embodiment of the disclosure, in the motor of the home appliance, the rotor may include an annular magnetic pole body in which a plurality of magnets having an arc-shaped cross-section are arranged in a circumferential direction of the rotor. According to an embodiment of the disclosure, the annular magnetic pole body included in the motor of the home appliance may include two or more types of magnets having different numbers of magnetic poles.
It should be understood that various embodiments of the disclosure in this document and terms used therein are not intended to limit the technical features described herein to particular embodiments of the disclosure and that the disclosure includes various modifications, equivalents, or substitutions of the embodiments of the disclosure.
With regard to the description of the drawings, like reference numerals may be used to represent like or related elements.
A singular form of a noun corresponding to an item may include one or a plurality of the items unless the context clearly indicates otherwise.
As used herein, each of the phrases such as “A or B,” “at least one of A and B, “at least one of A or B,” “A, B, or C,” “at least one of A, B, and C,” and “at least one of A, B, or C” may include any one of the items listed together in a corresponding one of the phrases, or all possible combinations thereof.
The term “and/or” includes any combination of a plurality of associated elements listed, or any one of the plurality of associated listed elements.
Terms such as “first,” “second,” etc. may be used simply to distinguish an element from other elements and do not limit the elements in any other respect (e.g., importance or order).
It will be understood that when an element (e.g., a first element) is referred to, with or without the term “functionally” or “communicatively”, as being “coupled” or “connected” to another element (e.g., a second element), the element may be coupled to the other element directly (e.g., by wire), wirelessly, or via a third element.
The terms such as “comprise,” “include,” or “have” are intended to specify the presence of stated features, numbers, steps, operations, elements, components, or combinations thereof, but do not preclude the presence or addition of one or more other features, numbers, steps, operations, elements, components, or combinations thereof.
It will also be understood that when an element is referred to as “connected,” “coupled,” “supported,” or “in contact” with another element, this includes not only when the elements are directly connected, coupled, supported, or in contact, but also when they are indirectly connected, coupled, supported, or in contact via a third element.
It will also be understood that when an element is referred to as being “on” another element, the element may be directly on the other element, or intervening elements may also be present therebetween.
An embodiment of the disclosure will now be described more fully hereinafter with reference to the accompanying drawings so that the embodiment of the disclosure may be easily implemented by one of ordinary skill in the art. However, an embodiment of the disclosure may be implemented in different forms and should not be construed as being limited to the embodiment of the disclosure set forth herein. In addition, parts not related to descriptions of the disclosure are omitted to clearly explain an embodiment of the disclosure in the drawings, and like reference numerals denote like elements throughout.
According to an embodiment of the disclosure, a home appliance including a motor is provided. Home appliances may include electrical apparatuses and machines used at home. According to an embodiment of the disclosure, a home appliance may include a device that is fixedly placed within a home or a device that is movable within the home. As used herein, a ‘home’ may refer to not only a house but also an indoor space such as an office. For example, the home appliance may include a television, a digital video disk (DVD) player, audio equipment, a refrigerator, an air conditioner, a vacuum cleaner, an oven, a microwave, a washing machine, an air purifier, a set-top box, a home automation control panel, a security control panel, a media box (e.g., Samsung HomeSync™), a game console, an electronic dictionary, a camcorder, an electronic picture frame, a speaker, an e-book reader, a desktop PC, a laptop PC, a netbook computer, a workstation, a server, a personal digital assistant (PDA), a portable multimedia player (PMP), an MP3 player, a medical device, a camera, etc. According to an embodiment of the disclosure, the home appliance may include, in particular, a home appliance that drives a motor.
According to an embodiment of the disclosure, a home appliance may include at least one of a washing machine, an air conditioner, a vacuum cleaner, or a refrigerator that includes a motor.
Hereinafter, the disclosure is described in detail. However, the following description is essentially only an example.
The disclosure relates to a surface permanent magnet synchronous motor (also hereinafter simply referred to as a motor).
The motor includes a rotor that rotates about a rotation axis, and a stator that faces the rotor with an air gap therebetween.
The stator has a stator core having a plurality of teeth extending in a diameter direction, and a plurality of coils formed by inserting electric wires into slots formed between adjacent teeth. The rotor has an annular magnetic pole body, which is formed by arranging a plurality of magnets with an arc-shaped cross-section in a circumferential direction, on a side opposite to the stator. Furthermore, each of the plurality of magnets has two or more magnetic poles arranged in the circumferential direction, and the annular magnetic pole body is composed of a combination of two or more types of the magnets with different numbers of magnetic poles.
Because the motor according to an embodiment of the disclosure uses multipolar magnets, the number of magnets may be reduced, thereby reducing the cost of components. In addition, by combining two or more types of the magnets with different numbers of magnetic poles to produce an annular magnetic pole body, the force acting on each magnetic pole, which constitutes a harmonic component of cogging torque, may be distributed.
A magnetic flux is likely to decrease at a magnetic pole located at an end of each magnet upon magnetization. Accordingly, harmonic components of the cogging torque may be cancelled out by arranging these magnetic poles so that the harmonic components are out of phase with each other. As a result, even when magnetization imbalance occurs, an increase in the harmonic components of the cogging torque may be suppressed.
When the number of magnetic poles of the rotor is p and the number of slots in the stator is n, the magnets consist of a magnet having a number A of magnetic poles equal to p/|p−n| (where p/|p−n| is a natural number), and a magnet having a number A+1 of magnetic poles. When the annular magnetic pole body is manufactured with a configuration of these different types of magnets, harmonic components of the cogging torque may be effectively suppressed with a relatively small number of magnets.
When the number of magnetic poles of the rotor is p and the number of slots in the stator is n, there are pole-slot combinations where a value of a magnetic pole pitch (β) expressed as p/|p−n| is 2N (N is a natural number) or 4N. In this case, an n-th or 2n-th order harmonic component of the cogging torque may be suppressed more effectively.
In such a case, when a magnetic pole located at an end of the same side of each magnet among magnetic poles of each magnet is a specific magnetic pole, the magnetic poles of the annular magnetic body are periodically classified into groups having numbers ranging from 1 to the value of the magnetic pole pitch (β). Also, when differences between numbers of specific magnetic poles respectively included in each combination of two groups, whose group numbers have a difference equal to the natural number N, are summed together, and the sum is less than or equal to half a total number of magnets constituting the annular magnetic pole body, problems related to harmonic components do not occur.
By using the above-described method, even when magnetization imbalance occurs in the annular magnetic pole body, harmonic components of the cogging torque may be suppressed, and even when some harmonic components of the cogging torque remain, noise that is practically problematic may be prevented.
According to an embodiment of the disclosure, the rotor may be located on an outside of the stator so that a surface of the rotor facing the stator constitutes an inner circumferential surface of the rotor.
Therefore, when the motor is of an outer rotor type, an area occupied by magnets may be increased, and thus, high torque may be achieved. Furthermore, even when a centrifugal force acts on each magnet, the magnet may be prevented from popping out of the rotor. Therefore, the outer rotor type motor is advantageous for high-speed rotation.
The motor according to an embodiment of the disclosure may be a motor installed in a washing machine to rotationally drive a washing tub of the washing machine. Because the motor used in the washing machine has a wide rotation area, a relatively large diameter, and a large number of magnetic poles or slots, the motor according to the disclosure is effective for use in the washing machine.
A home appliance according to an embodiment of the disclosure may be a washing machine 1. For example, the washing machine 1 may be configured to automatically execute a washing process consisting of washing, rinsing, spinning, and drying cycles. According to an embodiment of the disclosure, the washing machine 1 may be a front loader washing machine (e.g., a drum-type washing machine) with a laundry inlet located on the front or a top loader washing machine (e.g., Tongdori washing machine) with a laundry inlet located on the top, and the washing machine 1 may include a dryer.
As illustrated in
The casing 2 is a box-shaped container composed of panels or a frame, and forms an outer portion of the washing machine 1. A laundry inlet 2a for loading laundry is located on a front of the casing 2, and a door 2b having a transparent window is attached to the laundry inlet 2a so that the laundry inlet 2a may be opened and closed by the door 2b. A manipulation part 2c may be provided above the laundry inlet 2a so that the user may manipulate the washing machine 1.
The stationary tub 3 includes a cylindrical container capable of storing water, and is installed inside the casing 2 with one opening connected to the laundry inlet 2a. The stationary tub 3 is supported by a damper (not shown) provided inside the casing 2 to be stabilized with a center axis J (rotation axis) inclined as indicated by a dotted line in
The rotary tub 4 includes a cylindrical container having a diameter smaller than that of the stationary tub 3, and is accommodated in the stationary tub 3 so that a central axis thereof is aligned with the central axis of the stationary tub 3. According to the embodiment of the disclosure shown in
The rotary tub 4 is provided with a number of spinning holes 4b over the entire side surface thereof (only a part of the entire side surface is shown in
The water supply device 5 is provided above the stationary tub 3 and may include a water supply pipe 5a, a water supply valve 5b, and a detergent container 5c. An upstream end of the water supply pipe 5a is connected to an external water supply source (not shown), and a downstream end of the water supply pipe 5a is connected to a water supply port 3a of the stationary tub 3. The water supply valve 5b and the detergent container 5c may be sequentially installed in the middle of the water supply pipe 5a from an upstream side of the water supply pipe 5a. The detergent container 5c may hold a detergent, a fabric softener, etc. and introduce them into the stationary tub 3 together with water.
The drain pump 6 is provided below the stationary tub 3 and may be connected to the stationary tub 3 via a drain port 3b. The drain pump 6 serves to drain unnecessary water from the stationary tub 3 to outside of the washing machine 1 via a drain pipe 6a.
The driving unit 7 is attached to a bottom of the stationary tub 3, and may include a unit base 7a, a shaft 7b, and a motor 7c.
The unit base 7a is located at the bottom of the stationary tub 3 and may include a disk-shaped metal or resin member according to an embodiment of the disclosure. The unit base 7a may be provided at the center thereof with a shaft insertion hole formed in a cylindrical shape and extending along the center axis J, and a pair of ball bearings (not shown) are mounted at both ends of the shaft insertion hole.
The shaft 7b is rotatably supported on the unit base 7a. In the embodiment of the disclosure shown in
According to an embodiment of the disclosure, the center axis J is aligned with a center line of the stationary tub 2, a center line of the rotary tub 4, and an axial line of the shaft 7b. Furthermore, the rotation axis J is arranged to be inclined with respect to a horizontal direction or in the horizontal direction.
The motor 7c rotationally drives the rotary tub 4. According to an embodiment of the disclosure, the motor 7c rotates the shaft 7b fixed to the rotary tub 4, and the rotary tub 4 rotates due to the rotation of the shaft 7b. Furthermore, the number of revolutions per unit time of the motor 7c may be variable.
The controller 10 of the washing machine 1 may be located inside the washing machine 1, and comprehensively controls operations of the washing machine 1. For example, the controller 10 may be in the form of a processor or the like mounted on a printed circuit board (PCB). The controller 10 may include hardware, such as a processor (or a microprocessor controller (MICOM)) or a memory, and software, such as a control program, etc. The controller 10 may include an algorithm for controlling operations of components in the washing machine 1, at least one memory storing data in the form of a program, and at least one processor performing the above-described operations by using the data stored in the memory. The memory and the processor may be implemented as separate chips. The processor may include one or two or more processor chips or include one or two or more processing cores. The memory may include one or two or more memory chips or include one or two or more memory blocks. In addition, the memory and the processor may be implemented as a single chip.
According to the disclosure, there is provided a surface permanent magnet synchronous motor that allows for easy adjustment of cogging torque. Cogging torque is a rotational force generated by a phase difference in magnetic poles of magnets included in a rotor of a motor and due to a magnetic attractive force between the rotor and a stator of the motor. In a rotor of a surface permanent magnet synchronous motor, there are an equal number of north (N)-pole magnets and south(S)-pole magnets with the same surface magnetic flux distribution and magnetic flux amount. The N-pole magnets may be classified into two groups with different surface magnetic flux distributions and magnetic flux amounts.
In a surface permanent magnet synchronous motor, permanent magnets with an arc-shaped cross-section are sometimes arranged all around a surface of a rotor.
In addition, a permanent magnet is created by magnetizing a magnetic material, and the greater the number of magnetic materials, the higher the costs of elements. Therefore, in order to suppress the cost of elements, the number of magnetic materials may be reduced by allowing one magnetic material to be magnetized with a plurality of magnetic poles.
However, in this case, there is a gap between adjacent magnetic materials, and thus, the gap acts as a pitch of the plurality of magnetic poles. Due to the effect of the gap, in mass production of a surface permanent magnet synchronous motor, the phase may deviate from an ideal state during magnetization, resulting in magnetization imbalance. Even when the gap is within a tolerance range for mass production, noise may occur because harmonic components of the cogging torque increase due to the magnetization imbalance. Therefore, the disclosure provides a method that enables suppression of the increase in harmonic components of the cogging torque even when magnetization imbalance occurs.
In exemplary embodiments, the increase in harmonic components of the cogging torque may be suppressed even when magnetization imbalance occurs. As a result, noise occurring in the surface permanent magnet synchronous motor may also be reduced or prevented.
The conventional motor 100 is used in household fully automatic washing machines, such as drum-type washing machines and top-loading washing machines, to rotate the washing machine.
The drive shaft of the conventional motor 100 may be directly connected to the washing machine without going through a transmission or the like (direct drive). Thus, the conventional motor 100 is rotationally driven over a wide range from high torque low rotation during washing to low torque high rotation during spinning.
The conventional motor 100 includes a rotor 110 and a stator 120.
The stator 120 consists of a stator core 121, a plurality of coils 122, etc. The stator core 121 includes a core base 121a with an annular cross-section and a plurality of teeth 121b arranged radially on the core base 121a. In one example conventional motor 100, the number of the teeth 121b is 36. The teeth 121b are arranged equidistantly on an outer circumferential surface of the core base 121a and extend radially outward in the diameter direction. In addition, although not shown, the stator core 121 is coated with an insulator.
Thirty-six (36) spaces (slots 123) are formed between adjacent teeth 121b. The plurality of coils 122 are formed by inserting electric wires into the slots 123 and respectively winding the electric wires around the teeth 121b (concentrated windings). There is also distributed winding where an electric wire is wound around at least two teeth 121b. The plurality of coils 122 include coil groups of three phases, i.e., a U phase, a V phase, and a W phase.
The rotor 110 is located outside the stator 120 (outer rotor type) and faces the stator 120 with a small air gap 102 therebetween.
The rotor 110 includes a motor case 111 made of metal and including a bottom wall 111a having a disk shape and a peripheral wall 111b having a cylindrical shape and connected from a circumference of the bottom wall 111a, and an annular magnetic pole body 112. A shaft hole 113 is formed in a center of the motor case 111. A shaft (not shown) is inserted into the shaft hole 113. As a result, the motor case 111 is rotatable about a rotation axis (Jr).
A plurality of magnets 115 having an arc-shaped cross-section are attached to an inner surface (an opposite surface 111c) of the peripheral wall 111b that inwardly and outwardly faces the stator 120. Because the opposite surface 111c is configured as an inner circumferential surface of the rotor 110, there is no risk that the magnets 115 will pop out even when a centrifugal force acts on the magnets 115. Therefore, motors configured as above are suitable for high-speed rotation.
In the case of the conventional motor 100, the number of magnets 115 can be 12. For example, the magnets 115 may include a ferrite magnet. The annular magnetic pole body 112 is formed by arranging the magnets 115 in a circumferential direction. In addition, as described later, an inter-magnet gap 116 (about 1 mm) between two adjacent magnets 115 may be present.
This annular magnetic pole body 112 faces the stator 120. Alternating current periodically flows through coil groups of each phase in the stator 120. In this way, a magnetic field between the stator 120 and the rotor 110 changes, causing the rotor 110 to rotate.
In order to reduce element costs, the conventional motor 100 may be configured so that one of the magnets 115 has two or more poles (Mp).
In detail, each of the magnets 115 has four magnetic poles (Mp) consisting of two N poles and two S poles arranged alternately in the circumferential direction. Accordingly, the rotor 110 has 48 magnetic poles (Mp). Therefore, a pole-slot combination of the conventional motor 100 is a 48-pole 36-slot (48p36n).
Throughout the disclosure, the annular magnetic pole body 112 of the related art may be referred to as a ‘conventional annular magnetic pole body 112’, and an improved annular magnetic pole body 2 according to an embodiment of the disclosure may be referred to simply as an ‘annular magnetic pole body 2’.
Referring to
For magnetization, a predetermined magnetizing yoke 130 corresponding to the conventional motor 100 is used. A magnetizing yoke 130 may include coils 131, teeth 132, etc. like the stator 120. For the magnetizing yoke 130, there are 48 coils 131 and 48 teeth 132 corresponding to the 48 poles.
The magnetizing yoke 130 needs to be set at a predetermined position in the circumferential direction relative to the annular magnetic pole body 112. Accordingly, a positioning hole 114 may be formed in the bottom wall 111a. The magnetizing yoke 130 is aligned with the motor case 111 based on the positioning hole 114. In this way, the current flows in the coils 131 of the magnetizing yoke 130.
In this way, as enlarged and shown in
When the annular magnetic pole body 112 is properly magnetized, cogging torque may be suppressed, and thus, the conventional motor 100 may be designed so that problematic noise does not occur.
However, as described above, a small gap (the inter-magnet gap 116) may be present between the two adjacent magnets 115. Therefore, when attaching the magnetic materials 115a to the peripheral wall 111b, a positional misalignment may occur in arrangement of the magnets 115. In addition, even when the magnetizing yoke 130 is set on the motor case 111, a positional misalignment may occur in the arrangement of the magnetizing yoke 130 and the annular magnetic pole body 112 due to the precision of the positioning hole 114.
When such a positional misalignment occurs during magnetization, a surface magnetic flux density may differ between the magnetic poles (Mp) of one or more magnets 115 due to the inter-magnet gap 116.
On the other hand, as indicated by an arrow Y2, a positional misalignment can occur in the arrangement of the magnetization yoke 130 and the annular magnetic pole body 112, such that central positions of magnetic flux at the magnetic poles (Mp) move toward a second end side (next to the magnetic pole Mp4) in the circumferential direction. Accordingly, a central position at which the magnetic material 115a is magnetized with each magnetic pole (Mp) is also misaligned in the circumferential direction, and thus, the surface magnetic flux density at the magnetic pole Mp4 decreases, as shown in graph (b) of
As this magnetization imbalance occurs, the magnitude of the cogging torque changes.
Graphs (a) and (b) of
A scale of the cogging torque shown on the vertical axis of graphs (a) and (b) of
When there is no magnetization imbalance, cogging torque is small and does not fluctuate significantly. On the other hand, when there is a magnetization imbalance, the cogging torque has periodic fluctuations that are different from those when there is no magnetization imbalance, and the magnitude of the cogging torque changes.
On the other hand, at the 1.5th order (1.5f) and the 3rd order (3f), the magnitude of the cogging torque is very small when there is no magnetization imbalance, but because the sensitivity to misalignment is very large, the magnitude of the cogging torque also increases significantly as the degree of magnetization imbalance increases. Therefore, when fixing the magnetizing yoke 130 to the positioning hole 114 for magnetization, a large cogging torque may occur with even a slight angular misalignment caused due to a clearance for ensuring manufacturability.
In addition, the harmonic order herein is expressed in an electrical angle (f). An order expressed based on a mechanical angle is an order expressed based on an electrical angle, which is multiplied by the pair number of the magnetic poles. For example, when the number of magnetic poles is 48, the pair number of the magnetic poles is 24, so 1.5f is a 36th order (36×) in the mechanical angle. In the disclosure, the order expressed by an electrical angle is denoted by f, and the order expressed by a mechanical angle is denoted without a symbol.
As the harmonic components of the cogging torque increase, the sound and vibration increase accordingly. When the magnitude of the harmonic components of the cogging torque exceeds an allowable range, these are perceived as a strange sound, and the resultant noise becomes a problem. Therefore, when the above-described magnetization imbalance occurs, the harmonic components of the cogging torque increase, resulting in noise. In the related art, additional components such as vibration damping materials were sometimes required to mitigate the noise produced.
Hereinafter, a motor (a motor 1000 of
In addition, the basic components of the motor 1000, including the stator 120, are the same as those of the conventional motor 100 described above. Accordingly, the motor 1000 according to an embodiment of the disclosure is described in detail with respect to components different from those of the conventional motor 100, and the same components are represented using the same reference numerals or symbols as in the conventional motor 100, and descriptions thereof are simplified or omitted below.
The disclosure may be applied to motors with different slot/plot combinations as described later, but the motor 1000 with the same slot/plot combination as the conventional motor 100 is first described.
In the motor 1000 according to an embodiment of the disclosure, the configuration of the annular magnetic pole body 112 of the rotor 110 is as follows. In detail, each of the magnets 115 has two or more magnetic poles (Mp), and the annular magnetic pole body 2 (also hereinafter referred to as the improved annular magnetic pole body 2) is composed of a combination of two or more types of magnets 115 with different numbers of magnetic poles.
The motor 1000 is the same as the conventional motor 100 in that each of the magnets 115 of the motor 1000 has two or more magnetic poles (Mp) (multi-polarization). As a result, the cost of elements may be reduced.
The motor 1000 according to the embodiment of the disclosure is different from the conventional motor 100 in that the annular magnetic pole body 112 includes a combination of two or more types of magnets 115 with different numbers of magnetic poles (hybridization).
The first pattern consists of 8 magnets 115 with 5 magnetic poles (Mp) (5-pole magnets 5a) and 2 magnets 115 with 4 magnetic poles (Mp) (4-pole magnets 5b). While the annular magnetic pole body 112 of the conventional motor 100 is composed of 12 magnets 115, the first pattern of the improved annular magnetic pole body 2 is composed of 10 magnets 115.
Here, in the first pattern of the improved annular magnetic pole body 2, the 10 magnets 115 are arranged in the circumferential direction in the order of the 5-pole magnet 5a, 5-pole magnet 5a, 5-pole magnet 5a, 5-pole magnet 5a, 5-pole magnet 5a, 5-pole magnet 5a, 5-pole magnet 5a, 4-pole magnet 5b, 5-pole magnet 5a, and 4-pole magnet 5b. In addition, as described below, the arrangement of the magnets 115 in the first pattern is not limited thereto. In other words, the relative positions of the eight 5-pole magnets 5a and the two 4-pole magnets 5b may be varied. For example, the 10 magnets 115 may be arranged in the order of the 5-pole magnet 5a, 5-pole magnet 5a, 4-pole magnet 5b, 5-pole magnet 5a, 5-pole magnet 5a, 5-pole magnet 5a, 5-pole magnet 5a, 4-pole magnet 5b, 5-pole magnet 5a, and 5-pole magnet 5b.
The second pattern of the improved annular magnetic pole body 2(1) consists of 9 magnets 115 with 4 magnetic poles (Mp) (4-pole magnets 5b) and 4 magnets 115 with 3 magnetic poles (Mp) (3-pole magnets 5c). Unlike in the conventional motor 100, the second pattern is composed of 13 magnets 115.
In the second pattern of the improved annular magnetic pole body 2(1) shown in
When p is the number of magnetic poles of the rotor 110 and n is the number of slots in the stator 120, the first pattern and the second pattern each consist of a first magnet having a number A of magnetic poles (Mp) equal to p/|p-n| (where p/|p-n| is a natural number) and a magnet(s) having a number A+1 of magnetic poles (Mp). To distinguish the magnet from the first magnet, a magnet with a number A+1 of magnetic poles (Mp) may be referred to as a second magnet, and a magnet with a number A−1 of magnetic poles (Mp) may be referred to as a third magnet.
In detail, the magnets 115 in the first pattern include a first magnet, i.e., a 4-pole magnet 5b, having a number A of magnetic pole (Mp) equal to 48/|48−36| (A=4), and a second magnet, i.e., a 5-pole magnet 5a, having a number A+1 of magnetic poles (Mp). Similarly, the magnets 115 in the second pattern include the first magnet, i.e., the 4-pole magnet 5b, having a number A of magnetic poles (Mp) equal to 48/|48−36| (A=4), and a third magnet, i.e., a 3-pole magnets 5c, having a number A−1 of magnetic poles (Mp).
According to these patterns, harmonic components of the cogging torque are found at the 1.5th order (1.5f), 3rd order (3f), and 6th order (6f). As seen on
Therefore, when the improved annular magnetic pole body 2 to which the first pattern or the second pattern is applied is used, an increase in the harmonic components of the cogging torque that occurs due to magnetization imbalance may be suppressed.
Next, the mechanism of cogging torque is described with reference to
Cogging torque is obtained by ‘summing forces acting on each of a total number of poles’. Accordingly, the cogging torque (Tcog (0)) of the rotor 110 with the number of magnetic poles being p may be expressed via Equation (1) where θ is an angle (a mechanical angle) of the rotor 110 with respect to the stator 120, and Fi(θ) is a force acting on one pole.
In the motor 1000, the magnetic poles (Mp) of the rotor 110 are equidistantly arranged in the circumferential direction, and the slots 123 in the stator 120 are also equidistantly arranged in the circumferential direction. As a result, cogging torques corresponding to adjacent magnetic poles (Mp) occur due to a phase difference (positional relationship in the circumferential direction) therebetween.
Therefore, with respect to a magnetic pole (Mp) at an arbitrary position as a reference magnetic pole, the cogging torque (Tcog(θ)) of the rotor 110 may be expressed via Equation (2). In Equation (2), δ is a phase difference, N is the number of slots as described above, F1 is the cogging torque of the reference magnetic pole (Mp), and αi is an amplitude ratio for F1 caused by a difference in magnetic force acting on each magnetic pole (Mp).
When F1 is represented as a Fourier series expansion, it may be expressed via Equation (3). Then, substituting Equation (3) into Equation (2), the cogging torque (Tcog(θ)) of the rotor 110 may be expressed via Equation (4).
From Equation (2), it can be seen that the force acting on the one pole has a phase difference of δ from the adjacent magnetic pole. In other words, the force acting on the one pole is periodic with a magnetic pole pitch (hereinafter, pole pitch) being β=2π/n|δ|, which is a slot pitch (2π/n) divided by the phase difference (δ) from an adjacent magnetic pole.
Also, from Equation (4), it can be seen that an n-th harmonic component (j=1) of the force acting on the one pole has an out of phase relationship at a pitch of β/2. Similarly, a 2n-th harmonic component (j=2), of the force acting on one pole has an out of phase relationship at a pitch of β/4 (the pitches of β/2 and β/4 are also referred to as out-of-phase pitches). Cogging torque may be considered as the remaining force that is not canceled out when forces acting on each of a total number of poles.
That is, for the n-th harmonic component of the cogging torque, there is a cogging torque component that is cancelled out with an out-of-phase pitch of β/2. Similarly, for the 2n-th harmonic component of the cogging torque, there is a cogging torque component that is cancelled out with an out-of-phase pitch of β/4.
The magnetization imbalance of the magnet 115 occurs when a pole (Mp) has a small magnetic flux at a pole pitch (β), i.e., at one end of each of the magnets 115. Thus, for magnetic poles (Mp) having a small magnetic flux located at the ends of the respective magnets 115, when a pole-slot combination in which harmonic components of the cogging torque are out of phase is selected, the harmonic components of the cogging torque that occur may be canceled out, and thus, and an increase in the harmonic components of the cogging torque may be effectively suppressed.
Referring to
At the top of the table, a pole-slot combination is shown. Below the plot-slot combinations, the pole pitch (β) corresponding to one period is shown. Furthermore, below the pole pitch (β), out-of-phase pitches at an n-th (a mechanical angle, the same below) harmonic component and a 2n-th harmonic component are shown.
For example, in the pole-slot combination of 48p36n, because the pole pitch (β) is 4, the force acting on one pole has a periodicity of being in phase, for example, at a first magnetic pole (Mp) and a fifth magnetic pole (Mp) in either circumferential direction. Furthermore, in the same combination, because a 36-th harmonic component of the cogging torque has an out-of-phase pitch of 2, the force acting on one pole has a periodicity of being out of phase, for example, at a first magnetic pole (Mp) and a third magnetic pole (Mp) in either circumferential direction.
Thus, in such a predetermined harmonic component, by selecting a plot-slot combination in which the force acting on one pole is periodically out of phase and by positioning magnetic poles (Mp) with a small magnetic flux located at the ends of the individual magnets 115 accordingly, the increase in the harmonic component of the cogging torque may be effectively suppressed.
On the other hand, for example, in the pole-slot combination of 44p36n, the pole pitch (β) is 5.5, and an appropriate out-of-phase pitch is not found in the n-th and 2n-th harmonic components of the cogging torque.
At least in the n-th harmonic component of the cogging torque, a pole-slot combination in which an out-of-phase pitch is a natural number is desirable. In detail, pole-slot combinations where the pole pitch (β) is 2N (where N is a natural number), which are shaded in the table in
As described above, according to the disclosure, an increase in harmonic components of the cogging torque may be suppressed by selecting desirable specific plot-slot combinations and hybridizing the magnets 115, each having multiple poles.
As a comparative example, the conventional motor 100 is described.
When the force acting on each of the magnetic poles (Mp) is F1 or the like, the cogging torque is the sum of forces acting on each of the total number of poles. Also, in this case, the pole pitch (β) is 4 (48/|48−36|=4), so the conventional motor 100 exhibits a periodicity with one period of 4 poles. Therefore, in the example shown in
The lower left diagram of
Unlike
In this case as well, the pole pitch (β) is 4, so a periodicity of one period with 4 poles appears. Therefore, F1=F5=F45, F2=F6=F46, F3=F7=F47, F4=F8=F48. Likewise, four pole groups are formed, each with the same phase of force acting on one pole.
The lower left diagram of
As a result, problematic noise occurs. Also, for comparison, the lower right diagram of
As illustrated by
In this case, for magnetic poles (Mp) for which magnetization is appropriate, four pole groups s are F1=F5=F13=F17=F21=F25=F29=F37=F41=F45 (first group), F2=F6=F10=F22=F26=F30=F34=F42=f46 (second group), F3=F7=F11=F15=F19=F27=F31=F35=F39=F47 (third group), and F8=F12=F16=F20=F24=F32=F36=F40=F44 (fourth group).
On the other hand, for magnetic poles (Mp) with reduced magnetic flux, for which magnetization is inappropriate, four pole groups are F9=F33 (first group), F14=F18=F38 (second group), F23=F43 (third group), F4=F28=F48 (fourth group).
Among these groups, the force F9 in the first group and the force F23 in the third group are out of phase with each other and cancel each other out. In addition, the force F14 in the second group and the force F4 in the fourth group are out of phase with each other and cancel each other out. Therefore, even when there is a magnetization imbalance, some of the forces that cause it are canceled out, so an increase in the 36th harmonic component of the cogging torque may be suppressed.
In this way, because the hybridization may cancel out the forces that cause magnetization imbalance, an increase in the harmonic component of the cogging torque may be suppressed. As a result, problematic noise can be reduced or prevented. In addition, even when arrangement of the magnets 115 is different from that in the above example, the effect of suppressing the increase in the harmonic component of the cogging torque may be obtained although a different degree of effects are achieved. The same applies to the second pattern.
The first and second patterns described above are provide as examples. In an annular magnetic pole body 2 according to an embodiment of the disclosure, each of the magnets 115 included therein may be multipolar. In addition, because hybridization may be achieved by combining two or more types of magnets 115 with different numbers of magnetic poles, it is not limited to the two types, and three or more types of magnets 115 may be combined. The number of magnets 115 may also be selected depending on a pole-slot combination.
A method of determining such a combination of magnets 115 is described below. First, a combination of magnets 115 in the conventional motor 100 is described as a comparative example.
The configuration table consists of pole numbers (rows) and pole groups (columns). A pole number is a number that identifies a magnetic pole (Mp) constituting the annular magnetic pole body 112. Pole numbers are assigned in the order from an arbitrary magnetic pole (Mp) in the circumferential direction. For the conventional motor 100, the number of magnetic poles is 48, so there are magnetic poles (Mp) numbered 1 to 48.
Pole groups are formed by classifying the magnetic poles (Mp) based on the pole pitch (β). In the case of the conventional motor 100, the pole pitch (β) is 4, so the magnetic poles (Mp) are classified into four pole groups (first group to fourth group).
The configuration table is shaded for each magnet. A cell containing ┌0┘ or ┌1┘ shown under each pole number corresponds to a pole group corresponding to the corresponding pole number. For example, a magnetic pole (Mp) with the pole number 1 belongs to the first group, and a magnetic pole (Mp) with the pole number 2 (Mp) belongs to the second group.
┌0┘ indicates that magnetization is appropriate, and ┌1┘ indicates that magnetization may be inappropriate. That is, ┌1┘ indicates a magnetic pole (Mp) (specific magnetic pole Mps) at an end of each magnet 115 where a magnetic flux is likely to be reduced due to magnetization imbalance. Here, a magnetic pole (Mp) at the end of each magnet 115 located on a side with a larger pole number is set as a specific magnetic pole (Mps) (a magnetic pole (Mp) on the opposite side may be set as such). Throughout the disclosure, a magnetic pole (Mp) at an end of each magnet 115 may be referred to as a specific magnetic pole (Mps) or a peculiar magnetic pole Mps.
For each pole group, the number of specific magnetic poles (Mps) (i.e., the number of ┌1┘'s) may be counted. The number is shown in the total of the configuration table.
In the case of this pole-slot combination, as described above, the 36th harmonic components of the cogging torque are out of phase between pole groups whose group numbers have a difference equal to the pole pitch β/2 (i.e., 4/2=2).
In detail, the 36th harmonic components of the cogging torque are out of phase with each other between the first and third groups, and are out of phase in anti-phase with each other between the second and fourth groups. Therefore, a difference between the numbers of specific magnetic poles (Mps) in these two groups corresponds to an extent to which the 36th harmonic component of the cogging torque remains without being canceled out.
Therefore, the smaller the sum of differences in the number of specific magnetic poles (Mps) in these two groups, the more the 36th harmonic component of the cogging torque is suppressed. When a sum of the differences is 0, the 36th harmonic component of the cogging torque does not occur.
Even when the sum is not 0, i.e., even when the harmonic component of the cogging torque is present to some extent, this is allowable as long as it does not cause problematic noise. In detail, regardless of the order of the harmonic component, when the sum is less than or equal to half the number of magnets 115 constituting the annular magnetic pole body 112, this is an allowable condition.
In the case of the conventional motor 100 in which there are the 12 magnets 115, the allowable condition is that the sum is 6 or less.
In this case, the number of specific magnetic pole (Mps) in the first group is 0, and the number of specific magnetic poles (Mps) in the third group is also 0, so a difference between these numbers is 0. On the other hand, the number of specific magnetic poles (Mps) in the second group is 0, but the number of specific magnetic poles (Mps) in the fourth group is 12, so a difference between these numbers is 12 (>6).
In other words, the 36th harmonic components of the cogging torque are increased rather than canceled out. Also, the sum of the differences is 12, which exceeds the allowable condition. That is, problematic noise occurs.
Also, as described above, in the case of the same pole-slot combination, the 72nd harmonic components of the cogging torque are out of phase between pole groups whose group numbers have a difference equal to the pole pitch β/4 (i.e., 4/4=1).
In detail, the 72nd harmonic components of the cogging torque are out of phase with each other between the first and second groups, and are out of phase with each other between the third and fourth groups. Therefore, the smaller the sum of differences in the number of specific magnetic poles (Mps) in these two groups, the more the increase in the 72nd harmonic component of the cogging torque may be suppressed. When the sum of the differences is 0, the 72nd harmonic component of the cogging torque does not occur.
And, even when the sum is not 0, as described above, when the sum is less than or equal to half the number of magnets 115 constituting the annular magnetic pole body 112, the allowable condition is satisfied.
In this case, because the number of specific magnetic poles (Mps) in each of the first to third groups is 0, and the number of specific magnetic poles (Mps) in the fourth group is 12, a difference between the numbers of specific magnetic poles (Mps) in the first and second groups is 0, but a difference between the numbers of specific magnetic poles (Mps) in the third and fourth groups is 12.
Thus, the 72nd harmonic components of the cogging torque are increased rather than canceled out. Also, in this case as well, the sum of the differences is 12, which exceeds the allowable condition. That is, problematic noise occurs.
A pole-slot combination according to
Due to the difference, the specific magnetic poles (Mps) (┌1┘'s) may be dispersed and classified into different magnetization groups. As a result, the number of specific magnetic poles (Mps) in each of first and second groups is 2, and the number of specific magnetic poles (Mps) in each of third and fourth groups is 3.
A difference between the numbers of specific magnetic poles (Mps) in the first and third groups is 1 (|2−3|=1), and a difference between the numbers of specific magnetic poles (Mps) in the second and fourth groups is also 1 (|2−3|=1). Therefore, a sum of the differences in the number of specific magnetic poles (Mps) in these two groups is 2.
Therefore, compared to the conventional motor 100, an increase in the 36th harmonic component of the cogging torque is suppressed. Furthermore, although there is some 36th harmonic component in the cogging torque, problematic noise does not occur because the sum satisfies the allowable condition (the sum is 5 or less).
Also, a difference between the numbers of specific magnetic poles (Mps) in the first and second groups is 0 (|2−2|=0), and a difference between the numbers of specific magnetic poles (Mps) in the third and fourth groups is also 0 (|3−3|=0). And, a sum of the differences in the number of specific magnetic poles (Mps) in these two groups is 0.
Thus, the 72nd harmonic components of the cogging torque cancel out and are not generated. Accordingly, no problematic noise occurs.
A pole-slot combination of
Due to the difference, the specific magnetic poles (Mps) (┌1┘'s) are dispersed and classified into different magnetization groups. As a result, the number of specific magnetic poles (Mps) in each of first and second groups is 3, and the number of specific magnetic poles (Mps) in a fourth group is 4.
A difference between the numbers of specific magnetic poles (Mps) in the first and third groups is 0 (|3−3|=0), and a difference between the numbers of specific magnetic poles (Mps) in the second and fourth groups is 1 (|3−4|=1). Therefore, a sum of the differences in the number of specific magnetic poles (Mps) in these two groups is 1.
Therefore, compared to the conventional motor 100, an increase in the 36th harmonic component of the cogging torque is suppressed. Furthermore, although there is some 36th harmonic component in the cogging torque, problematic noise does not occur because the sum satisfies the allowable condition (the sum is 6.5 or less).
Also, a difference between the numbers of specific magnetic poles (Mps) in the first and second groups is 0 (|3−3|=0), and a difference between the numbers of specific magnetic poles (Mps) in the third and fourth groups is 1 (|3−4|=1). Therefore, a sum of the differences in the number of specific magnetic poles (Mps) in these two groups is 1.
Therefore, compared to the conventional motor 100, an increase in the 72nd harmonic component of the cogging torque is suppressed. Furthermore, although there is some 72nd harmonic component in the cogging torque, problematic noise does not occur because the sum satisfies the allowable condition (the sum is 6.5 or less).
A pole-slot combination in
Due to the difference, the specific magnetic poles (Mps) (┌1┘'s) are dispersed and classified into different magnetization groups. As a result, the total number of specific magnetic poles (Mps) in each of the first and third groups is 2, and the total number of specific magnetic poles (Mps) in each of the second and fourth groups is 3.
A difference between the numbers of specific magnetic poles (Mps) in the first and third groups is 0 (|2−2|=0), and a difference between the numbers of specific magnetic poles (Mps) in the second and fourth groups is also 0 (|3−3|=0). Therefore, a sum of the differences in the number of specific magnetic poles (Mps) in these two groups is 0.
Thus, the 36th harmonic components of the cogging torque cancel out and are not generated. Accordingly, no problematic noise occurs.
Also, a difference between the numbers of specific magnetic poles (Mps) in the first and second groups is 1 (|2−3|=1), and a difference between the numbers of specific magnetic poles (Mps) in the third and fourth groups is also 1 (|2−3|=1). Therefore, a sum of the differences in the number of specific magnetic poles (Mps) in these two groups is 2.
Therefore, compared to the conventional motor 100, an increase in the 72nd harmonic component of the cogging torque is suppressed. Furthermore, although there is some 72nd harmonic component in the cogging torque, problematic noise does not occur because the sum satisfies the allowable condition (the sum is 5 or less).
A pole-slot combination (24p36n) in
Due to the difference, the specific magnetic poles (Mps) (┌1┘'s) are dispersed and classified into different magnetization groups. As a result, the number of specific magnetic poles (Mps) in the first group is 3, and the number of specific magnetic poles (Mps) in the second group is also 3. Also, a difference between the numbers of specific magnetic poles (Mps) in the first group and the second group is 0 (|3−3|=0).
Thus, the 36th harmonic components of the cogging torque cancel out and are not generated. Accordingly, no problematic noise occurs.
In
A pole-slot combination (32p36n) in
Due to the difference, the specific magnetic poles (Mps) (┌1┘'s) are dispersed and classified into different magnetization groups.
In the case of this pole-slot combination, a difference between pole group numbers where the 36th harmonic components of the cogging torque are out of phase is 4 (8/2=4). Therefore, combinations of groups with such a relationship are the first group and the fifth group, the second group and the sixth group, the third group and the seventh group, and the fourth group and the eighth group.
And, differences between the numbers of specific magnetic poles (Mps) in each combination of the two groups are 0 (|1−1|=0), 0 (|1−1|−=0), 0 (|1−1|=0), and 1 (|0−1|=1), respectively. Therefore, a sum of the differences in the number of specific magnetic poles (Mps) in these groups is 1.
Therefore, cancellation due to out-of-phase occurs in the 36th harmonic component of the cogging torque, and an increase in the harmonic component is suppressed. Furthermore, although there is some 36th harmonic component in the cogging torque, problematic noise does not occur because the sum satisfies an allowable condition (the sum is 3.5 (=7/2) or less).
Also, for this pole-slot combination, a difference between pole group numbers where the 72nd harmonic components of the cogging torque are out of phase is 2 (8/4=2). Therefore, combinations of groups with such a relationship are the first group and the third group, the second group and the fourth group, the third group and the fifth group, and the sixth group and the eighth group.
And, differences between the numbers of specific magnetic poles (Mps) in each combination of the two groups are 0 (|1−1|=0), 1 (|1−0|=1), 0 (|1−1|=0), and 0 (|1−1|=0), respectively. Therefore, a sum of the differences in the number of specific magnetic poles (Mps) in these groups is 1.
Therefore, cancellation due to out-of-phase occurs in the 72nd harmonic component of the cogging torque, and an increase in the harmonic component is suppressed. Furthermore, although there is some 72nd harmonic component in the cogging torque, problematic noise does not occur because the sum satisfies the allowable condition (the sum is 3.5 (=7/2) or less).
In
A pole-slot combination (40p36n) in
Due to the difference, the specific magnetic poles (Mps) (┌1┘'s) are dispersed and classified into different magnetization groups.
In the case of this pole-slot combination, a difference between pole group numbers where the 36th harmonic components of the cogging torque are out of phase is 5 (10/2=5). Therefore, combinations of groups with such a relationship are the first group and the sixth group, the second group and the seventh group, the third group and the eighth group, and the fifth group and the tenth group.
And, differences between the numbers of specific magnetic poles (Mps) in each combination of the two groups are 0 (|1−1|=0), 0 (|1−1|=0), 0 (|1−1|=0), and 1 (|0−1|=1), respectively. Therefore, a sum of the differences in the number of specific magnetic poles (Mps) in these groups is 1.
In other words, in this case, cancellation due to out-of-phase occurs in the 36th harmonic component of the cogging torque, and an increase in the harmonic component is suppressed. Furthermore, although there is some 36th harmonic component in the cogging torque, problematic noise does not occur because the sum satisfies an allowable condition (the sum is 4.5 (=9/2) or less).
A pole-slot combination according to
Due to the difference, the specific magnetic poles (Mps) (┌1┘'s) may be dispersed and classified into different magnetization groups. As a result, the number of specific magnetic poles (Mps) in each of first and four groups is 4, and the number of specific magnetic poles (Mps) in each of second and third groups is 2.
A difference between the numbers of specific magnetic poles (Mps) in the first and third groups is 2 (|4−2|=2), and a difference between the numbers of specific magnetic poles (Mps) in the second and fourth groups is also 2 (|2−4|=2). Therefore, a sum of the differences in the number of specific magnetic poles (Mps) in these two groups is 4.
In other words, in this case, compared to the conventional motor 100, an increase in the 36th harmonic component of the cogging torque is suppressed. Furthermore, although there is some 36th harmonic component in the cogging torque, problematic noise does not occur because the sum satisfies the allowable condition (the sum is 6 or less).
Also, a difference between the numbers of specific magnetic poles (Mps) in the first and second groups is 2 (|4−2|−2), and a difference between the numbers of specific magnetic poles (Mps) in the third and fourth groups is also 2 (|2−4|=2). And, a sum of the differences in the number of specific magnetic poles (Mps) in these two groups is 4.
Therefore, compared to the conventional motor 100, an increase in the 72nd harmonic component of the cogging torque is suppressed. Furthermore, although there is some 72nd harmonic component in the cogging torque, problematic noise does not occur because the sum satisfies the allowable condition (the sum is 6 or less).
While the disclosure has been described mainly with respect to the case where the motor 1000 including the improved annular magnetic pole body 2 according to an embodiment of the disclosure is used in a washing machine 1, the motor 1000 including the improved annular magnetic pole body 2 according to an embodiment of the disclosure is not limited to use in the washing machine 1, but may be used in a variety of home appliances, such as a refrigerator 2000, that include a motor.
According to an embodiment of the disclosure, the refrigerator 2000 may include a body 2100.
The body 2100 may include an inner case, an outer case provided outside the inner case, and an insulation material provided between the inner case and the outer case.
The “inner case” may include a case, a plate, a panel, or a liner forming a storage compartment. The inner case may be formed as a single body or may be formed by assembling a plurality of plates. The “outer case” may form an exterior of the body 2100 and may be coupled to an outside of the inner case so that the insulation material is provided between the inner case and the outer case.
The “insulation material” may insulate an inside of the storage compartment and an outside of the storage compartment so that a temperature inside the storage compartment may be maintained at a set appropriate temperature without being affected by an environment outside the storage compartment. According to an embodiment of the disclosure, the insulation material may include a foam insulation material. After fixing the inner case and the outer case with a jig, etc., the foam insulation material may be molded by injecting and foaming a urethane foam in which polyurethane and a foaming agent are mixed between the inner case and the outer case.
According to an embodiment of the disclosure, the insulation material may include a vacuum insulation material in addition to the foam insulation material, or may include only the vacuum insulation material instead of the foam insulation material. The vacuum insulation material may include a core material and an outer covering material that accommodates the core material and seals an interior to a vacuum or a pressure close to the vacuum. The vacuum insulation material may further include an adsorbent that adsorbs gas and moisture to stably maintain a vacuum state. However, the insulation material is not limited to the foam insulation material or vacuum insulation material described above and may include various materials that may be used for insulation.
According to an embodiment of the disclosure, the refrigerator 2000 may include a cold air supply device provided to supply cold air to the storage compartment.
The “cold air supply device” may include a machine, a device, an electronic device, and/or a system that is a combination thereof that are capable of producing cold air and guiding the cold air to cool the storage compartment.
According to an embodiment of the disclosure, the cold air supply device may produce cold air through a refrigeration cycle including compression, condensation, expansion, and evaporation of a refrigerant. To this end, the cold air supply device may include a refrigeration cycle system having a compressor, a condenser, an expansion device, and an evaporator capable of driving a refrigeration cycle.
According to an embodiment of the disclosure, the refrigerator 2000 may include a machine compartment in which at least some components belonging to the cold air supply device are arranged.
The “machine compartment” may be separated and insulated from the storage compartment to prevent heat generated in components arranged in the machine compartment from being transferred to the storage compartment. The inside of the machine compartment may be configured to communicate with the outside of the body 2100 so as to dissipate heat from components inside the machine compartment.
The refrigerator 2000 is a type of home appliance that supplies cold air generated by the compressor of the cold air supply device to the storage compartment to freshly preserve various foods for a long period of time. In addition to this long-term preservation function, the refrigerator 2000 has various other functions added, and representative functions include a communication function that allows the refrigerator 2000 to be connected to an Internet of Things (IoT) network and a function of outputting sound via a speaker built into the refrigerator 2000.
Referring to
According to an embodiment of the disclosure, the refrigerator 2000 may include the doors 2300 configured to open and close one open side of the storage compartment.
The refrigerator 2000 of
The doors 2300 may be configured to seal the storage compartment 2200 when the doors 2300 are closed. The doors 2300 may include an insulation material like in the body 2100 to insulate the storage compartment when the doors 2300 are closed.
Referring to
The storage compartment 2200 may include a space defined by the inner case. The storage compartment 2200 may further include an inner compartment defining the space. The storage compartment 2200 may have at least one side opened to put in or take out the foods. The storage compartment 2200 may be provided to store food. The food includes food that can be eaten or drunk, and specifically, may include meat, fish, seafood, fruits, vegetables, water, ice, beverages, kimchi, or alcoholic beverages such as wine. However, in addition to the food, medicines and cosmetics may also be stored in the storage compartment 2200, and there is no limitation on items that may be stored in the storage compartment 2200.
The refrigerator 2000 may include one or more storage compartments 2200. When two or more storage compartments 2200 are provided in the refrigerator 2000, each of the storage compartments 2200 may have a different purpose and may be maintained at a different temperature. To this end, the storage compartments 2200 may be separated from each other by a partition wall including an insulation material. According to an embodiment of the disclosure, the partition wall may be a portion of the body 2100. According to an embodiment of the disclosure, the partition wall may be a separate partition that is provided separately from the body 2100 and assembled to the body 2100.
The storage compartment 2200 may be provided to be maintained in an appropriate temperature range depending on its use, and include a refrigeration compartment 2200a, a freezer compartment 2200b, or a “variable temperature compartment” differentiated according to its use and/or temperature range. The refrigeration compartment 2200a may be maintained at a temperature suitable for refrigerating food, and the freezer compartment 2200b may be maintained at a temperature suitable for freezing food. “Refrigeration” may mean cooling food without freezing the food, and for example, the refrigeration compartment 2200a may be maintained in a range between 0° C. and 7° C. “Freezing” may mean freezing food or cooling the food so that it remains frozen, and for example, the freezer compartment 2200b may be maintained in a range between −20° C. and −1° C. The variable temperature compartment may be used as either the refrigeration compartment 2200a or the freezer compartment 2200b based on or regardless of a user's selection. According to an embodiment of the disclosure, one storage compartment 2200 may be provided such that a portion thereof is used as the refrigeration compartment 2200a and a portion thereof is used as the freezer compartment 2200b.
The storage compartment 2200 may be referred to as various names, such as a “vegetable compartment”, a “fresh compartment”, a “cooling compartment”, and an “ice-making compartment” in addition to names such as the refrigeration compartment 2200a, the freezer compartment 2200b, and the variable temperature compartment, and as used herein, the terms “refrigeration compartment”, “freezer compartment”, and “variable temperature compartment” should be understood to each encompass the storage compartment 2200 having a corresponding use and a corresponding temperature range.
When the compressor of the refrigerator 2000 operates, the motor 1000 that drives the compressor plays an important role. The compressor of the refrigerator 2000 may be driven by the motor 1000 including the improved annular magnetic pole body 2 according to an embodiment of the disclosure. As a motor used not only in the compressor but also within the refrigerator 2000, the motor 1000 including the improved annular magnetic pole body 2 according to an embodiment of the disclosure may be used.
According to an embodiment of the disclosure, to cool a space to be air-conditioned, the air conditioner 3000 may absorb heat from an air-conditioning space (hereinafter referred to as “an indoor space”) and release heat to the outside of the air-conditioning space (hereinafter referred to as “an outdoor space”). Furthermore, for heating the indoor space, the air conditioner 3000 may absorb heat from the outdoor space and release heat to the indoor space.
The air conditioner 3000 may include one or two or more outdoor units 3100 installed outdoors and one or two or more indoor units 3200 installed indoors. The outdoor unit 3100 may be electrically connected to the indoor unit 3200. For example, a user may input information (or commands) for controlling the indoor unit 3200 via a user interface, and the outdoor unit 3100 may operate in response to a user input from the indoor unit 3200.
The outdoor unit 3100 may be fluidly coupled to the indoor unit 3200 through a refrigerant pipe.
The outdoor unit 3100 is located outdoors. The outdoor unit 3100 may perform heat exchange between a refrigerant and outdoor air by using a phase change (e.g., evaporation or condensation) of the refrigerant. In this case, the heat exchange may be performed via an outdoor heat exchanger included in the outdoor unit 3100. For example, the refrigerant may release heat into the outdoor air during condensation of the refrigerant in the outdoor unit 3100. The refrigerant may absorb heat from the outdoor air during evaporation of the refrigerant in the outdoor unit 3100.
The indoor unit 3200 is installed indoors. The indoor unit 3200 may perform heat exchange between a refrigerant and indoor air by using a phase change (e.g., evaporation or condensation) of the refrigerant. In this case, the heat exchange may be performed via an indoor heat exchanger included in the indoor unit 3200. For example, while the refrigerant evaporates in the indoor unit 3200, the refrigerant may absorb heat from the indoor air, and the indoor space may be cooled. While a refrigerant condenses in the indoor unit 3200, the refrigerant may release heat into the indoor air, and the indoor space may be heated. The air conditioner 3000 may include the compressor, the outdoor heat exchanger, the expansion device, and the indoor heat exchanger. The air conditioner may include a refrigerant pipe connecting the compressor, the outdoor heat exchanger, the expansion device, and the indoor heat exchanger.
The refrigerant may circulate, via the refrigerant pipe, through the compressor, the outdoor heat exchanger, the expansion device, and the indoor heat exchanger in the stated order, or through the compressor, the indoor heat exchanger, the expansion device, and the outdoor heat exchanger in the stated order.
The compressor, the outdoor heat exchanger, and the expansion device may be located in the outdoor unit 3100. The indoor heat exchanger may be installed in the indoor unit 3200. The location of the expansion device is not limited to the outdoor unit 3100, and may be located in the indoor unit 3200 as needed.
The compressor may suck in refrigerant gas through a suction port and compress the refrigerant gas. The compressor may discharge high-temperature, high-pressure refrigerant gas via a discharge port. According to an embodiment of the disclosure, the compressor may perform a compression operation via the motor 1000 including the improved annular magnetic pole body 2.
The air conditioner 3000 may further include a flow path diverter valve. The flow path diverter valve may include, for example, a 4-way valve. The flow path diverter valve may determine a path of circulation of the refrigerant depending on an operating mode of the air conditioner 3000 (e.g., cooling operation or heating operation). The flow path diverter valve may be connected to the discharge port of the compressor.
The air conditioner 3000 may include an accumulator. The accumulator may be connected to the suction port of the compressor. Low-temperature, low-pressure refrigerant evaporated from the indoor heat exchanger or an outdoor heat exchanger may flow into the accumulator. When a mixture of refrigerant liquid and refrigerant gas flows into the accumulator, the accumulator may separate the refrigerant liquid from the refrigerant gas and provide the refrigerant gas from which the refrigerant liquid has been separated to the compressor.
In the outdoor heat exchanger, heat exchange may occur between the refrigerant and the outdoor air. For example, during cooling operation, high-pressure, high-temperature refrigerant may condense in the outdoor heat exchanger, and while the refrigerant condenses, the refrigerant may release heat into the outdoor air. During heating operation, low-pressure, low-temperature refrigerant may evaporate in the outdoor heat exchanger, and while the refrigerant evaporates, the refrigerant may absorb heat from the outdoor air.
An outdoor fan may be provided in the vicinity of the outdoor heat exchanger. The outdoor fan may blow outdoor air into the outdoor heat exchanger to facilitate heat exchange between the refrigerant and the outdoor air.
The expansion device may lower the pressure and temperature of the refrigerant condensed in the outdoor heat exchanger during cooling operation, and may lower the pressure and temperature of the refrigerant condensed in the indoor heat exchanger during heating operation.
For example, the expansion device may lower the temperature and pressure of the refrigerant by using a throttling effect. The expansion device may include an orifice capable of reducing a cross-sectional area of a flow path. The temperature and pressure of the refrigerant that passes through the orifice may be lowered.
For example, the expansion device may be implemented as an electronic expansion valve capable of adjusting an opening ratio (a ratio of a cross-sectional area of a flow path in a valve in a partially open state to a cross-sectional area of a flow path in the valve in a fully open state). The amount of refrigerant passing through the expansion device may be controlled depending on the opening ratio of the electronic expansion valve.
The indoor unit 3200 of the air conditioner 3000 may include a housing, a blower that circulates air inside or outside the housing, and an indoor heat exchanger that exchanges heat with air flowing into the housing.
The housing may include an air inlet. Indoor air may be drawn into the housing via the air inlet.
The indoor unit 3200 of the air conditioner 3000 may include a filter provided to filter out foreign substances from the air drawn into the housing via the air inlet.
The housing may include an air outlet. Air flowing inside the housing may be discharged from the housing via the air outlet.
The indoor unit 3200 of the air conditioner 3000 may include an airflow guide that guides a direction of air discharged through the air outlet. For example, the airflow guide may include a blade located on the air outlet. For example, the airflow guide may include an auxiliary fan for regulating an exhaust airflow. However, the disclosure is not limited thereto, and the airflow guide may be omitted.
The indoor unit 3200 of the air conditioner 3000 may include a flow path connecting the air inlet and the air outlet. The flow path may be provided so that air drawn in via the air inlet flows toward the air outlet. The blower and the indoor heat exchanger may be provided on the flow path.
The blower may include an indoor fan and a fan motor. For example, indoor fans may include an axial fan, a diagonal fan, a crossflow fan, and a centrifugal fan.
The indoor heat exchanger may be placed between the blower and the air outlet, or between the air inlet and the blower. The indoor heat exchanger may absorb heat from air drawn in through the air inlet or transfer heat to air drawn in through the air inlet. The indoor heat exchanger may include a heat exchange tube in which a refrigerant flows, and heat exchange fins provided to increase the heat transfer area.
The indoor unit 3200 of the air conditioner 3000 may include a drain tray located below the indoor heat exchanger to collect condensate water generated in the indoor heat exchanger. The condensate water collected in the drain tray may be drained to the outside via a drain hose. The drain tray may be provided to support the indoor heat exchanger.
The indoor unit 3200 of the air conditioner 3000 may include a first controller for controlling components of the indoor unit 3200, including the blower. The outdoor unit 3100 of the air conditioner 3000 may include a second controller for controlling components of the outdoor unit 3100, including the compressor and the like. The first controller may communicate with the second controller.
The first controller may obtain a user input via a user device including a mobile device, etc. or a remote controller, and the indoor unit 3200 may include a communication interface or infrared receiver capable of communicating with the user device or remote controller.
The first controller may control the components of the indoor unit 3200, including the blower, etc., in response to the received user input. The first controller may transmit information about the received user input to the second controller of the outdoor unit 3100. The second controller may control the components of the outdoor unit 3100, including the compressor, etc., based on the information about the user input received from the indoor unit 3200.
The first controller and the second controller may each include a processor and a memory. The first controller and the second controller may provide control signals to the compressor, the flow diverter valve, the expansion device, the outdoor fan, and the blower to drive the air conditioner 3000 in response to a user input.
The indoor unit 3200 of the air conditioner 3000 may include a display that displays operation information of the air conditioner 3000. The display may receive information about an operation of the air conditioner 3000 from the first controller and display information corresponding to the received information.
The display may include an indicator that show the type of an operation of the air conditioner 3000 selected by the user or whether the indoor unit 3200 is turned on or off. The indicator may include, for example, a liquid crystal display (LCD) panel, a light emitting diode panel (LED) panel, an organic LED (OLED) panel, a micro LED panel, and a plurality of LEDs.
In the air conditioner 3000, the motor 1000 including the improved annular magnetic pole body 2 may be used to operate the compressor.
Referring to
The outdoor unit 3100 includes an outdoor unit body 3101 that forms an exterior of the outdoor unit 3100, and an outdoor unit fan 3102 provided on one side of the outdoor unit body 3101 to discharge heat-exchanged air.
The indoor unit 3200 may include an indoor unit body 3201 that forms an exterior of the indoor unit 3200, an indoor unit outlet 3202 provided on a front of the indoor unit body 3201 to discharge heat-exchanged air, an input interface 3220 that receives operation commands for the air conditioner 3000, and an output interface 3210 that displays operation information of the air conditioner 3000.
Referring to
According to an embodiment of the disclosure, the vacuum cleaner 4000 may be a stick-type cleaner including a cleaner main body 4100, a brush device 4200, and an extension pipe 4300. However, all of the components shown in
The vacuum cleaner 4000 may include a user interface 4400. The user interface 4400 allows the user to selectively enter a cleaning intensity during cleaning, and a display including the user interface 4400 may indicate a charging status or cleaning mode.
The suction motor 4500 included in the main body 4100 of the vacuum cleaner 4000 performs an operation of sucking in dust during cleaning. As the suction motor 4500, the motor 1000 including the improved annular magnetic pole body 2 according to an embodiment of the disclosure may be used.
According to an embodiment of the disclosure, a washing machine 1 of
The processor 1001 may control all operations of the washing machine 1. The processor 1001 is a hardware device that controls all operations of the washing machine 1. The processor 1001 is a hardware chip including an integrated circuit with integrated electrical circuits thereon.
The processor 1001 may include various processing circuits and/or a plurality of processors. For example, the term “processor” as used herein, including that in the claims, may include various processing circuits, including at least one processor. One or more processors in the at least one processor may be configured to perform various functions described herein, individually and/or collectively, in a distributed manner. As used herein, “processor,” “at least one processor,” and “one or more processors” may be configured to perform various functions. However, these terms cover, without limitation, situations where one processor performs some of the functions and another processor (other processors) performs other functions, and situations where a single processor may perform all of the functions. Furthermore, the at least one processor may include a combination of processors that perform various functions described herein in a distributed manner. The at least one processor may execute program instructions to achieve or perform various functions. The processor 1001 may execute programs stored in the memory 1400 to control the washing machine 1.
According to an embodiment of the disclosure, the washing machine 1 may be equipped with an artificial intelligence (AI) processor. The AI processor may be manufactured in the form of a dedicated hardware chip for AI, or be manufactured as part of an existing general-purpose processor (e.g., a central processing unit (CPU) or application processor (AP)) or a dedicated graphics processor (e.g., a graphics processing unit (GPU)) and mounted on the washing machine 1.
According to an embodiment of the disclosure, the processor 1001 may include at least one of a CPU, a GPU, an accelerated processing unit (APU), a Many Integrated Core (MIC), a digital signal processor (DSP), or a neural processing unit (NPU). The processor 1001 may be implemented in the form of an integrated system on a chip (SoC) including one or more electronic components. When the processor 1001 includes a plurality of processors, each of the processors may be implemented as a separate piece of hardware (H/W). The processor 1001 may also be referred to as a MICOM, a microprocessor unit (MPU), a microcontroller unit (MCU), or the like. The processor 1001 according to the disclosure may be implemented as a single-core processor or as a multi-core processor.
The washing machine 1 may selectively include a communication interface 1100 for communicating with an external device. For example, the washing machine 1 may communicate with an external server (not shown) and/or a user terminal (not shown) via the communication interface 1100. In this case, the communication interface 1100 may communicate with the server by using a first communication method (e.g., a Wi-Fi communication method) and with the user terminal by using a second communication method (e.g., a Bluetooth Low Energy (BLE) communication method).
The communication interface 1100 may include a short-range wireless communication interface 1110, a long-range wireless communication interface 1120, etc. The short-range communication interface 1110 may include, but is not limited to, a Bluetooth communication interface, a BLE communication interface, a near field communication (NFC) interface, wireless local area network (WLAN) (or Wi-Fi) communication interface, a ZigBee communication interface, an Infrared Data Association (IrDA) communication interface, a Wi-Fi Direct (WFD) communication interface, an ultra-wideband (UWB) communication interface, an Ant+ communication interface, etc. The long-range communication interface 1120 may be used by the washing machine 1 to remotely communicate with the server or user terminal. The long-range communication interface may include the Internet, a computer network (e.g., a LAN or a wide area network (WAN)), and a mobile communication interface. The mobile communication interface may include, but is not limited to, a third generation (3G) module, a fourth generation (4G) module, a fifth generation (5G) module, a long-term evolution (LTE) module, a narrowband IoT (NB-IoT) module, an LTE machine (LTE-M) module, etc.
The communication interface 1100 may transmit data to the processor 1001 by using, for example, a universal asynchronous receiver/transmitter (UART) protocol which is an asynchronous communication protocol, but the communication method is not limited thereto.
The user interface 1200 of the washing machine 1 may include an output interface 1210 and an input interface 1220. The input interface 1220 may be a device via which the user may input commands to the washing machine 1. The input interface 1220 may include, but is not limited to, a touch screen, voice input, or physical buttons. The input interface 1220 may include a washing start button, a drying start button, a mode selection button, etc. The output interface 1210 may include a display such as an LED, a LCD, a touch screen, or the like. The output interface 1210 may further include a voice output device, but is not limited thereto. The output interface 1210 may display software update progress information, operation event information, overheating information, information about at which point overheating occurs, etc., but is not limited thereto.
The memory 1400 of the washing machine 1 may store a program (e.g., one or more instructions) for the processor 1001 to control all operations of the washing machine 1, and pieces of input/output data. For example, the memory 1400 of the washing machine 1 may store, but is not limited to, software related to control of the washing machine 1, overheating status data, overheating history data, overheating location information data, error occurrence data (failure history data), and types of operation events. The memory 1400 may store data received from an external user terminal.
The memory 1400 may include at least one type of storage medium, i.e., at least one of a flash memory-type memory, a hard disk-type memory, a multimedia card micro-type memory, a card-type memory (e.g., an Secure Digital (SD) card or an extreme Digital (XD) memory), random access memory (RAM), static RAM (SRAM), read-only memory (ROM), electrically erasable programmable ROM (EEPROM), PROM, a magnetic memory, a magnetic disc, or an optical disc. Programs stored in the memory 1400 may be classified into a plurality of modules according to their functions.
The motor driving device 250 may include an inverter capable of driving the motor 1000 via pulse width modulation (PWM) switching of a direct current (DC) voltage obtained by rectifying input alternating current (AC) power. The motor driving device 250 may include a converter that converts a DC voltage to a different level of DC voltage. The motor driving device 250 may include not only a switch element but also a gate driver for switching the switch element, and may include dead-time compensation and overheating prevention functions.
The motor 1000 is a motor driven by the motor driving device 250 and may include the annular magnetic pole body 2 according to an embodiment of the disclosure. The annular magnetic pole body 2 may include the annular magnetic pole bodies of the disclosure described above with reference to
Home appliances according to an embodiment of the disclosure may include not only the washing machine 1 but also various other home appliances that operate by driving the motor 1000. According to an embodiment of the disclosure, the home appliances according to an embodiment of the disclosure may include an air conditioner, a vacuum cleaner, a refrigerator, etc.
All of the components shown in
Furthermore, the disclosure is not limited to the above-described embodiments of the disclosure, and includes various other configurations. For example, the pole-slot combinations and magnet arrangements in the embodiments of the disclosure may be appropriately modified according to the specifications of the motor 1000 within the scope to which the disclosure is applicable. In addition, in an embodiment of the disclosure, an outer rotor type motor in which the rotor 110 is located outside the stator 120 is illustrated, but the motor may be an inner rotor type motor where the rotor 110 is located inside the stator 120. The magnets may be rare earth magnets or plastic magnets.
According to an embodiment of the disclosure, a washing machine including a motor with an annular magnetic pole body is provided. According to one embodiment of the disclosure, the washing machine may include a casing, a laundry inlet configured to load laundry on a top or side of the casing, a door attached to the laundry inlet, a stationary tub capable of storing water for washing the laundry, a rotary tub composed of a container within the stationary tub and configured to be rotatable, and a motor configured to rotate the rotary tub. According to an embodiment of the disclosure, the motor of the washing machine may include a rotor configured to rotate about a rotation axis. According to an embodiment of the disclosure, the motor of the washing machine may include a stator facing the rotor with an air gap therebetween. According to an embodiment of the disclosure, in the motor of the washing machine, the rotor may include an annular magnetic pole body in which a plurality of magnets having an arc-shaped cross-section are arranged in a circumferential direction of the rotor. According to an embodiment of the disclosure, the annular magnetic pole body included in the motor of the washing machine may include two or more types of magnets having different numbers of magnetic poles.
According to an embodiment of the disclosure, in the motor of the washing machine, when p is the number of magnetic poles of the rotor and n is the number of slots in the stator, a first magnet among the plurality of magnets may have a number A (where A=p/|p−n| and is a natural number) of magnetic poles, and a second magnet among the plurality of magnets may have a number A+1 of magnetic poles.
According to the embodiment of the disclosure, in the motor of the washing machine, when p=48 and n=36, the number of first magnets with four magnetic poles may be 2, and the number of second magnets with five magnetic poles may be 8.
According to an embodiment of the disclosure, in the motor of the washing machine, when p is the number of magnetic poles of the rotor and n is the number of slots in the stator, a first magnet among the plurality of magnets may have a number A (where A=p/|p−n| and is a natural number) of magnetic poles, and a third magnet among the plurality of magnets may have a number A-1 of magnetic poles.
According to the embodiment of the disclosure, in the motor of the washing machine, when p=48 and n=36, the number of first magnets with four magnetic poles may be 9, and the number of third magnets with three magnetic poles may be 4.
According to an embodiment of the disclosure, in the motor of the washing machine, when p is the number of magnetic poles of the rotor and n is the number of slots in the stator is n, a first magnet among the plurality of magnets may have a number A (where A=p/|p−n| and is a natural number) of magnetic poles, a second magnet among the plurality of magnets may have a number A+1 of magnetic poles, and a third magnet among the plurality of magnets may have a number A-1 of magnetic poles.
According to the embodiment of the disclosure, in the motor of the washing machine, when p=48 and n=36, the number of first magnets with four magnetic poles may be 4, the number of second magnets with five magnetic poles may be 4, and the number of third magnets with three magnetic poles may be 4.
According to the embodiment of the disclosure, when p is the number of magnetic poles of the rotor and n is the number of slots in the stator, the motor of the washing machine may have a pole-slot combination such that a value of a magnetic pole pitch (β) is 2N (where β=p/|p−n| and N is a natural number).
According to an embodiment of the disclosure, in the motor of the washing machine, when the number p of magnetic poles in the rotor is 24 and the number n of slots in the stator is 36, the plurality of magnets may include three 5-pole magnets and three 3-pole magnets.
According to an embodiment of the disclosure, in the motor of the washing machine, when the number p of magnetic poles in the rotor is 32 and the number n of slots in the stator is 36, the plurality of magnets may include three 4-pole magnets and four 5-pole magnets.
According to an embodiment of the disclosure, in the motor of the washing machine, when the number p of magnetic poles in the rotor is 40 and the number n of slots in the stator is 36, the plurality of magnets may include five 4-pole magnets and four 5-pole magnets.
According to the embodiment of the disclosure, in the motor of the washing machine, when the number of magnetic poles of the rotor is p and the number of slots in the stator is n, the motor may have a slot combination such that a value of a magnetic pole pitch (β) is 2N (where β=p/|p−n| and N is a natural number).
According to an embodiment of the disclosure, in the motor of the washing machine, magnetic poles in each of the plurality of magnets may include a specific magnet pole located at an end of the same side of each magnet. According to an embodiment of the disclosure, in the motor of the washing machine, magnetic poles in the plurality of magnets may be sequentially classified into a plurality of groups including a first group to a β-th group corresponding to the value of the magnetic pole pitch (β), and when differences between numbers of specific magnetic poles included in each pair of two groups whose group numbers have a difference equal to N are summed together, the sum of the differences may be less than or equal to half the number of the plurality of magnets.
According to the embodiment of the disclosure, in the motor of the washing machine, when p is the number of magnetic poles of the rotor and n is the number of slots in the stator, the motor may have a slot combination such that the value of the magnetic pole pitch (β) is 4N (where β=p/|p−n| and N is a natural number). According to an embodiment of the disclosure, in the motor of the washing machine, magnetic poles in each of the plurality of magnets may include a specific magnet pole located at an end of the same side of each magnet, and magnetic poles in the plurality of magnets may be sequentially classified into a plurality of groups including a first group to a β-th group corresponding to the value of the magnetic pole pitch (β), and when differences between numbers of specific magnetic poles included in each pair of two groups whose group numbers have a difference equal to N are summed together, the sum of the differences may be less than or equal to half the number of the plurality of magnets.
According to an embodiment of the disclosure, a home appliance including a motor with an annular magnetic pole body is provided. According to an embodiment of the disclosure, the motor of the home appliance may include a rotor configured to rotate about a rotation axis. According to an embodiment of the disclosure, the motor of the home appliance may include a stator facing the rotor with an air gap therebetween. According to an embodiment of the disclosure, in the motor of the home appliance, the rotor may include an annular magnetic pole body in which a plurality of magnets having an arc-shaped cross-section are arranged in a circumferential direction of the rotor. According to an embodiment of the disclosure, the annular magnetic pole body included in the motor of the home appliance may include two or more types of magnets having different numbers of magnetic poles.
According to an embodiment of the disclosure, there is provided a home appliance including a motor with an annular magnetic pole body including at least two types of magnets having different numbers of magnetic poles. According to an embodiment of the disclosure, the motor is a surface permanent magnet synchronous motor, and may include a rotor rotating about a rotation axis and a stator facing the rotor with an air gap therebetween. According to an embodiment of the disclosure, in the motor, the stator may include a stator core having a plurality of teeth extending in a diameter direction, and a plurality of coils formed by inserting electric wires into slots formed between adjacent teeth. According to an embodiment of the disclosure, in the motor, the rotor may include an annular magnetic pole body, which is formed by arranging a plurality of magnets with an arc-shaped cross-section in a circumferential direction, on a side opposite to the stator. According to an embodiment of the disclosure, in the motor, each of the plurality of magnets may include two or more magnetic poles arranged in the circumferential direction, and the annular magnetic pole body may be composed of a combination of two or more types of the magnets with different numbers of magnetic poles.
According to an embodiment of the disclosure, when p is the number of magnetic poles of the rotor and n is the number of slots in the stator, the motor with the annular magnetic pole body including the at least two types of the magnets with different numbers of magnetic poles may include a magnet having a number A of magnetic poles equal to p/|p−n| (where p/|p−n| is a natural number), and a magnet having a number A+1 of magnetic poles.
According to an embodiment of the disclosure, when p is the number of magnetic poles of the rotor and n is the number of slots in the stator, the motor with the annular magnetic pole body including the at least two types of the magnets with different numbers of magnetic poles may have a pole-slot combination such that a value of a magnetic pole pitch (β) expressed as p/|p−n| is 2N (where N a natural number).
According to an embodiment of the disclosure, the motor with the annular magnetic pole body including the at least two types of the magnets with different numbers of magnetic poles may be configured so that, when magnetic poles in each of the magnets may include a specific magnet pole located at an end of the same side of each magnet, magnetic poles in the annular magnetic pole body are periodically classified into groups having numbers ranging from 1 to the value of the magnetic pole pitch (β), and when differences between numbers of specific magnetic poles respectively included in each combination of two groups, whose group numbers have a difference equal to the natural number N, are summed together, the sum of the differences is less than or equal to half the number of the magnets.
According to an embodiment of the disclosure, when p is the number of magnetic poles of the rotor and n is the number of slots in the stator, the motor with the annular magnetic pole body including the at least two types of the magnets with different numbers of magnetic poles may have a pole-slot combination such that the value of the magnetic pole pitch (β) expressed as p/|p−n| is 4N (where N a natural number).
According to an embodiment of the disclosure, the motor with the annular magnetic pole body including the at least two types of the magnets with different numbers of magnetic poles may be configured so that, when magnetic poles in each of the magnets may include a specific magnet pole located at an end of the same side of each magnet, magnetic poles in the annular magnetic pole body are periodically classified into groups having numbers ranging from 1 to the value of the magnetic pole pitch (β), and when differences between numbers of specific magnetic poles respectively included in each combination of two groups, whose group numbers have a difference equal to the natural number N, are summed together, the sum of the differences is less than or equal to half the number of the magnets.
According to an embodiment of the disclosure, in the motor with the annular magnetic pole body including the at least two types of the magnets with different numbers of magnetic poles, the rotor may be located outside the stator so that a surface of the rotor facing the stator may constitute an inner circumferential surface of the rotor.
According to an embodiment of the disclosure, the motor with the annular magnetic pole body including the at least two types of the magnets with different numbers of magnetic poles may be installed in a washing machine and rotationally drive a washing tub of the washing machine.
A method according to an embodiment of the disclosure may be implemented in the form of program commands executable by various types of computers and may be recorded on computer-readable recording media. The computer-readable recording media may include program commands, data files, data structures, etc. either alone or in combination. The program commands recorded on the computer-readable recording media may be designed and configured specially for the disclosure or may be known to and be usable by those of skill in the art of computer software. Examples of the computer-readable recording media include magnetic media such as hard disks, floppy disks, and magnetic tapes, optical media such as compact disk ROM (CD-ROM) and digital versatile disks (DVDs), magneto-optical media such as floptical disks, and hardware devices that are specially configured to store and perform program commands, such as ROM, RAM, flash memory, etc. Examples of program commands include not only machine code such as that created by a compiler but also high-level language code that may be executed by a computer using an interpreter or the like.
Some embodiments of the disclosure may also be implemented in the form of recording media including instructions executable by a computer, such as a program module executed by the computer. The computer-readable recording media may be any available media that are accessible by a computer and include both volatile and nonvolatile media and both removable and non-removable media. Furthermore, the computer-readable recording media may include both computer storage media and communication media. The computer storage media include both volatile and nonvolatile, removable and non-removable media implemented using any method or technology for storage of information such as computer-readable instructions, data structures, program modules, or other data. The communication media typically embody computer-readable instructions, data structures, program modules, other data in a modulated data signal such as a carrier wave, or other transmission mechanism, and may include any information transmission media. Furthermore, some embodiments of the disclosure may also be implemented as a computer program product or computer program including instructions executable by a computer.
A machine-readable storage medium may be provided in the form of a non-transitory storage medium. In this regard, the term ‘non-transitory storage medium’ only means that the storage medium does not include a signal (e.g., an electromagnetic wave) and is a tangible device, and the term does not differentiate between where data is semi-permanently stored in the storage medium and where the data is temporarily stored in the storage medium. For example, the ‘non-transitory storage medium’ may include a buffer for temporarily storing data.
According to an embodiment of the disclosure, methods according to the embodiments of the disclosure may be included in a computer program product when provided. The computer program product may be traded, as a product, between a seller and a buyer. The computer program product may be distributed in the form of a machine-readable storage medium (e.g., CD-ROM) or distributed (e.g., downloaded or uploaded) on-line via an application store or directly between two user devices (e.g., smartphones). For online distribution, at least a part of the computer program product (e.g., a downloadable app) may be at least transiently stored or temporally generated in the machine-readable storage medium such as a memory of a server of a manufacturer, a server of an application store, or a relay server.
| Number | Date | Country | Kind |
|---|---|---|---|
| 2023-091914 | Jun 2023 | JP | national |
This application is a continuation application, claiming priority under § 365 (c), of International Application No. PCT/KR2024/007256, filed on May 28, 2024, which is based on and claims the benefit of Japanese Patent Application No. 2023-091914 filed on Jun. 2, 2023, in the Japan Patent Office, the disclosures of which are incorporated by reference herein in their entireties.
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/KR2024/007256 | May 2024 | WO |
| Child | 18680521 | US |
