This application claims foreign priority under 35 USC § 119 to Brazilian Patent Application No. BR102018073558-6 filed Nov. 14, 2018, and the entire disclosure of said application is hereby expressly incorporated by reference into the present application.
The present invention refers to a linear motor. More specifically, the present invention refers to a topology applied to a linear motor and that provides an increase in the magnetic flow variation generated by the linear motor.
Linear motors are commonly used in cooling systems for driving compressors (linear), either in the ambit of refrigerators (refrigerators/freezers) or in the cooling of environments (acclimatization).
More specifically, a linear compressor normally consists of a piston that moves inside a cylinder. Suction and gas discharge valves, which regulate the intake of low pressure gas and the output of high pressure gas from inside the cylinder, are positioned on the head of this cylinder. In valid modalities, the suction valve may be disposed directly on the piston of the linear motor. The axial movement of the piston inside the cylinder of the linear compressor compresses the gas taken in through the suction valve, increasing the pressure thereof, and letting it out through the discharge valve to a high pressure zone.
Said piston is coupled to at least one magnetic body (magnet), such that the displacement of the piston causes a corresponding displacement of the magnet, and vice-versa. In a linear motor, the displacement of the magnetic body occurs in a region referred to as air gap.
Therefore, the movement of the magnet in a certain region (air gap) cause the movement of the piston and consequently a suction and compression of the cooling gas, thus initiating a cooling cycle.
Basically, there is a constant search by an optimal point in the design/manufacture of linear motors, considering three main factors: (i) performance parameters, (ii) cost of the motor and (iii) its sizing.
Obviously the linear motor must be designed to have adequate efficiency, low energy consumption, be absent of noise or trepidation, also having reduced sizing and manufacturing costs.
There are various models of linear motors currently known in the state of the art, wherein differences between such models may be related to the disposition and arrangement of the stator and rotor, such as stator simples, double stator, short stator and short rotor, quantity of existing magnetic bodies, among others. The teachings of the present invention can be applied to any one of these models.
One of the known topologies of a linear motor refers to the topology wherein the stator is U-shaped, in this case, what is basically used is a single magnet that moves through the air gap portion (basically the magnet moves between the two legs of said “U”).
One of the problems found in this topology refers to the low magnetic flow variation generated by the movement of the magnet, thus requiring an increase in size of the motor so that it can achieve a certain power.
One of the ways of increasing the magnetic flow variation generated in the motor consists of using two magnetic bodies in its air gap, and as such commonly uses an E-shaped stator. However, and considering that the main costs of a motor arise from its magnet, said arrangement becomes unfeasible in financial terms (manufacturing costs), even if they enable a compacted motor to be achieved.
Therefore, there is a constant search in the state of the art for ways of increasing the magnetic flow variation of a linear motor having flat topology, also satisfying the motor efficiency parameters and maintaining its sizing and reduced costs.
As already mentioned, it is not enough for the proposed linear motor to comprise a greater quantity of magnets, which ultimately increases its manufacturing (and sales) costs.
Therefore, the present invention proposes a linear motor having flat topology, wherein the air gap area comprises just one magnetic body, but which provides flow variations similar to those obtained when using more than one magnet.
Accordingly, the topology proposed herein makes use of a high magnetic permeability element disposed in the air gap area and adjacently to the magnetic body, wherein said magnetically permeable element moves in accordance with the movement of the magnetic body, that is, both have cooperative movement, as better described ahead.
An objective of the present invention is to provide a linear motor having flat topology.
An additional objective of the present invention is the proposal of a linear motor endowed with a magnetically permeable element disposed in the air gap area, and adjacently to a magnetic body.
An additional objective of the present invention consists of the fact that the magnetically permeable element has movement cooperative to the movement of the magnetic body.
A further objective of the present invention is the arrangement of the magnetically permeable element into two segments, wherein each segment is disposed at opposite ends of the magnetic body of the linear motor.
An additional objective of the present invention consists of the formation of a linear motor wherein the two segments of the magnetically permeable element are formed by ferromagnetic materials.
Another objective of the present invention is the proposal that at least one of the first and the second segments is made of iron.
Also proposed is a linear compressor endowed with the linear motor proposed in the present invention, in addition to cooling equipment that makes use of said linear compressor.
Another objective of the present invention is the proposal of a stator applicable in a linear motor.
Objectives of the present invention are achieved by way of a linear motor which comprises: a stator defining at least an air gap area, at least one reel (coil) associated to the stator, wherein a magnetic flow moves over at least one portion of the stator and over a portion of the air gap area, wherein the linear motor comprises a magnetic body disposed in the air gap area, wherein a movement parameter of the magnetic body in the air gap area causes movement of a piston of the linear motor.
The linear motor further comprising: at least one magnetically permeable element disposed in the air gap area and adjacently to the magnetic body, wherein the movement parameter of the magnetic body is cooperative to the movement parameter of the magnetically permeable element.
The present invention will now be described in greater detail based on an example of an embodiment represented in the drawings. The drawings show:
The present invention refers to a linear motor 1, and more specifically to a linear motor 1 capable of being used in a linear compressor 30 of a cooling system.
Cooling system is understood to be any system wherein a certain cooling gas is used to cool/acclimatize a certain environment or product. In this arrangement of the present invention, cooling system can be understood to be cooling equipment (such as a freezer or refrigerator) or air-conditioning equipment.
Therefore, and as known by those persons skilled in the art, the linear compressor 30 comprises a cylinder 31, which presents a board of valves at its uppermost end, also called valve head. This board of valves comprises a suction valve 32 that lets gas at low pressure into the cylinder 31, and a discharge gas valve 33 that lets gas at high pressure out of the cylinder 31.
The linear compressor 30 further comprises a piston 34 that moves inside the cylinder 31, constituting therewith a resonant set. Inside the cylinder 31, the piston 34 carries out an alternative linear movement, performing action of compression on the gas taken inside the cylinder 31 by the suction valve 32, up to the point at which this gas can be discharged to the high pressure side by way of the discharge valve 33.
It is also noted in
The linear compressor 30, and more specifically its linear motor 1, further comprises a stator 2 associated to a coil 3, and said coil 3 should be electrically powered so as to produce a magnetic field responsible for operating the linear motor 1. Also noted is an air gap area 10 disposed next to the stator 2 in which said magnetic body 5 should move so as to enable the due operation of the linear motor.
It is worth emphasizing that
With regards to the magnet 5 of the linear compressor 30, and as already addressed previously, it should move through the air gap area 10 so as to provide the movement of the piston 34 of the compressor 30. Therefore, it is understood that the magnet 5 (magnetic body) establishes a movement parameter in the air gap area 10. In other words, the movement parameter of the magnet 5 should be understood as the movement (displacement) of the magnet 5 in the air gap 10.
In this sense,
More specifically,
Accordingly,
Therefore,
In this sense,
The elements previously described when addressing
It is noted that
The teachings of the present invention provide an increase in the magnetic flow variation when compared to the teachings of the state of the art. Accordingly, the disposition of at least one magnetically permeable element 20 in the air gap area 10 is proposed, as shown in
Accordingly, it is noted that this arrangement of the present invention proposes the use of two magnetically permeable elements 20, each of them disposed on one of the sides of the magnet 5, as represented in
In a preferred and valid arrangement of the present invention, both the first segment 20A and the second segment 20B are made of one and the same material, being iron.
In other fully valid modalities, the first segment 20A can be made in a first magnetically permeable material and the second segment 20B in a second magnetically permeable material.
Obviously, it is understood that the first and second magnetically permeable materials should be ones that facilitate the passage of the lines of magnetic flow on the surface of this material.
In this sense, persons skilled in the art are aware of the fact that the materials can be classified according to their magnetic permeability, that is: diamagnetic materials (have lesser permeability than that of vacuum), paramagnetic materials (have slightly greater permeability than that of vacuum) and ferromagnetic materials (have permeability of hundreds and even thousands of times greater than that of vacuum).
More specifically, it should be understood the first magnetically permeable material and the second magnetically permeable material as ferromagnetic materials, such as: iron, nickel, steel, cobalt and their respective alloys.
Therefore, a valid and non-limitative arrangement of the present invention consists of the formation of the first segment 20A made of iron and of the second segment 20B made of nickel.
A preferred form of fastening the magnetically permeable element 20 in the linear motor 1 is represented in
Therefore, the displacer 18 acts as a support (mold) for the set formed by the magnetically permeable element 20 and the magnetic body 5. Accordingly, it is understood that during the operation of the linear motor 1, the displacer 18 moves jointly with the magnetically permeable element 20 and the magnetic body 5.
In one modality, the displacer 18 can be made of aluminum. In any case, this should not be considered as a limitative characteristic of the present invention.
As known by persons skilled in the art, the displacer 18 of a linear motor 1 should be understood as the active part of the motor, equivalent to the rotor (mobile part) of a conventional motor.
Additionally, a fully valid arrangement of the present invention proposes that the magnetically permeable element 20 is formed by a plurality of steel blades 25, like the steel blades 25 used in manufacturing electric motors. Further, it is proposed that the steel blades 25 are sequentially arranged along the element 20, such as represented in
Therefore, the disposition of the magnetically permeable element 20 as proposed herein decreases the resistance of the magnetic flow lines which move through the air gap 10, in other words, the magnetically permeable element 20 will make the flow lines be attracted, whereby boosting the magnetic flow variation, as illustrated in the graph of
Based on the teachings of the present invention, that is, with the disposition of the magnetically permeable element 20, there is obtained a magnetic flow variation rate similar to the one obtained with the linear motor that comprises a pair of magnets in its air gap 10 (such as the motor illustrated in
It is thus understood that the teachings of the present invention are preferably beneficial for the linear motor that comprises U-shaped topology, and which thus makes use of just one magnetic body in its air gap.
According to the teachings of the present invention and as illustrated in
In other words, and taking the representation of
Therefore, and considering the illustration in
In this situation, the adjacent segment, that is, the second segment 20B of the magnetically permeable element 20 is mostly disposed in the air gap area 10, that is, the second segment 20B is mostly disposed in the region defined by the boundary limits A and A′.
By mostly disposed, it is understood that the second segment 20B will have its outer wall 21 disposed exactly on the boundary limit A′, such as represented in
The outermost point of the movement parameter of the magnetic body 5 is understood to mean the maximum displacement of the magnet 5 before its change of direction, such as the situation represented in
In line with that previously described for
By mostly disposed, it is understood that the first segment 20A will have its outer wall 21 disposed exactly on the boundary limit A, such as represented in
Further in relation to the sizing of the magnetic body 5, it is proposed that at the outermost point of the movement parameter of the magnet 5, a first surface 5A of the magnetic body will be disposed on the boundary limit A, whereas a second surface 5B is disposed on an air gap shaft C′, as shown in
In accordance with the description set out in the preceding paragraph, at the point opposite that represented in
It is thus understood that each one of the air gap shafts C and C′ of the linear motor 1 is respectively defined by inner surfaces 2C and 2C′ of the stator 2, as represented in
In addition to the representation of
Further in relation to the sizing of the magnetically permeable element 20 and of the magnetic body 5, and with specific reference to
In other words, it is understood that the first distance D1 is equal to or less than thickness E of the magnet 5, according to representation 11. Therefore, it is understood that D1≤E.
As represented in
Therefore,
Obviously, applying the present invention is not limited to the stator 2 represented in
Whatever the topology of the linear motor, it is understood to be fully possible to apply the modality wherein the segments 20A and 20B have equal or different sizing, as already addressed herein.
There is thus described a linear motor 1 endowed with a magnetically permeable element 20, wherein the movement parameter of the magnetically permeable element 20 is cooperative to the movement parameter of the magnetic body 5 (magnet) of the linear motor 1.
The teachings of the present invention provide an increase in the magnetic flow variation that circulates through the stator 2 and air gap 10, providing, for example, that a linear motor endowed with a single magnetic body has a similar flow variation rate to a motor that comprises a pair of magnets.
In harmony with that previously described, the present invention further addresses a compressor endowed with a linear motor 1 according to the teachings of the present invention. In one modality, said compressor is used in cooling equipment, such as a freezer/refrigerator or air-conditioning equipment.
Therefore, the present invention further proposes cooling equipment that comprises the linear motor defined herein.
In harmony with the description previously set out, a stator 2 applicable to a linear motor 1 is also proposed.
Lastly, the arrangement of the present invention wherein the magnetically permeable element 20 is made of Sheet Molding Compound (SMC) is fully valid.
Having described one example of a preferred embodiment, it should be understood that the scope of the present invention covers other possible variations, being limited solely by the content of the accompanying claims, potential equivalents being included therein.
Number | Date | Country | Kind |
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BR102018073558-6 | Nov 2018 | BR | national |