This application claims the benefit of priority to Japanese Patent Application No. 2017-023491 filed on Feb. 10, 2017. The entire contents of this application are hereby incorporated herein by reference.
The present invention relates to a motor.
A motor has a substrate attached thereto. The substrate has, for example, a power conversion circuit mounted thereon. The power conversion circuit converts power supplied from a power source into a direct current. For example, in the motor described in Japanese Unexamined Utility Model Registration Application Publication No. 4-12777, a support piece is provided on an end plate attached to an end portion of a stator core. An engaging claw of the supporting piece engages with a notch in the outer periphery of a printed circuit board. In this manner, the printed circuit board is secured.
In general, a relatively large and heavy electronic component, such as an electrolytic capacitor, may be mounted on the circuit board as described above.
However, in the electric motor described in Japanese Unexamined Utility Model Registration Application Publication No. 4-12777, the sizes and arrangement of the electronic components mounted on the printed circuit board and, in addition, the resonance of the electric motor and the like are not taken into consideration. Consequently, the reliability against the vibration of the electric motor is not sufficient.
According to the present invention, an exemplary motor includes a bearing holder for holding a bearing that supports a rotary shaft extending in the vertical direction for rotation, a bracket for holding the bearing holder, a circuit board having electronic components mounted thereon, and a plurality of board fixing portions for fixing the circuit board to the bracket. The circuit board has a first region representing part of a mounting surface having the electronic components mounted thereon in the circumferential direction and a second region representing a region of the mounting surface other than the first region. The total weight of the electronic components mounted in the first region is greater than the total weight of the electronic components mounted in the second region. The number of the board fixing portions that fix the circuit board in the first region is greater than the number of the board fixing portions that fix the circuit board in the second region.
The exemplary motor according to the present invention can reduce or prevent resonance of the motor due to vibration of the circuit board.
The above and other elements, features, steps, characteristics and advantages of the present discloser will become more apparent from the following detailed description of the preferred embodiments with reference to the attached drawings.
Exemplary embodiments of the present invention are described below with reference to the accompanying drawings. As used herein, in regard to a motor 100, the direction in which the rotary shaft of a rotor 1 (refer to a shaft 11 in
The radial direction of the shaft 11 is simply referred to as a “radial direction”, and the circumferential direction around the shaft 11 is simply referred to as “circumferential direction”. In addition, in the radial direction, the direction extending towards the shaft 11 is simply referred to as an “inward” direction, and the direction extending away from the shaft 11 is simply referred to as an “outward” direction. Furthermore, among the surfaces of each of the constituent elements, the side surface facing in the inward radial direction is referred to as an “inside surface”, and the side surface facing in the outward radial direction is referred to as an “outside surface”.
In regard to an apparatus or a device including the motor 100, the direction of the air flow sent out by an air blowing device 200 is referred to as “air flow direction”. In addition, in the air flow direction, the direction from the upstream to downstream is simply referred to as a “forward” direction, and the direction from the downstream to upstream is simply referred to as a “backward” direction.
Note that the directions and surfaces mentioned and defined above do not indicate the positional relationship and the directions when the constituent elements are incorporated into an actual device.
According to the present embodiment, as illustrated in
The motor 100 is a drive unit that rotationally drives the impeller 101. The motor 100 is mounted in electrical equipment, such as a dryer 300 (refer to
As illustrated in
The rotor 1 is the rotor of the motor 100. The rotor 1 has the shaft 11, a rotor holder 12, and a magnet 13. The shaft 11 is a rotary shaft extending in both upward and downward axial directions. The rotor holder 12 is a member that holds the magnet 13 and is rotatable together with the shaft 11 and the impeller 101. The magnet 13 faces the stator 2.
The rotor holder 12 accommodates the rotor 1, the stator 2, and the bearing holder 4. The rotor holder 12 has a plate portion 121 and a cylindrical portion 122. The plate portion 121 is a disk-shaped member extending in an outward radial direction. The cylindrical portion 122 is a cylindrical member extending from the circumferential edge of the plate portion 121 in the axially downward direction. The peripheral wall member 101b of the impeller 101 is attached to the cylindrical portion 122 so as to be located radially outwardly of the cylindrical portion 122. The magnet 13 is held on the inside surface of the cylindrical portion 122
The stator 2 is an armature of the motor 100. The stator 2 is held on the outside surface of the bearing holder 4. The stator 2 faces the rotor 1 and drives the rotor 1. The stator 2 includes a stator core 21, a plurality of coil portions 22, and an insulator 23.
The stator core 21 is a laminated steel plate in which electromagnetic steel plates are stacked in the axial direction. The stator core 21 is provided radially outwardly of the bearing holder 4 and radially inwardly of the magnet 13.
As illustrated in
The insulator 23 is an insulating member made of, for example, a resin material. The insulator 23 covers the stator core 21. The insulator 23 electrically insulates the stator core 21 from the coil portion 22. In addition, the insulator 23 has a support member 3 for supporting the wire wrapping pin 6. The support member 3 protrudes from the lower end of the insulator 23 toward the circuit board 7. The support member 3 has terminal supporting portion 31 and a connection portion 32. The terminal supporting portion 31 supports one of the wire wrapping pins 6. The connection portion 32 connects the adjacent terminal supporting portions 31 with each other (refer to, for example,
The bearing holder 4 is a metal bearing holding portion for holding the bearings 41 and 42. The bearing holder 4 is provided radially outward of the shaft 11 and radially inward of the stator 2. The bearings 41 and 42 are bearings which support the shaft 11 for rotation. For example, ball bearings or sleeve bearings are used as the bearings 41 and 42.
The bearing holder 4 has a cylindrical portion 4a extending in the axial direction and a rectangular plate portion 4b. The bearings 41 and 42 are held inside the cylindrical portion 4a. The plate portion 4b extends radially outward from the lower circumference of the cylindrical portion 4a. In the axial direction, the position of the lower surface of part of the plate portion 4b close to the cylindrical portion 4a is the same as the position of the lower surface of the bracket 5. In addition, the upper surface and the lower surface of both end portions of the plate portion 4b in the long direction are clamped by the bracket 5. In this way, the bearing holder 4 is held by the bracket 5. According to the present embodiment, the plate portion 4b and the cylindrical portion 4a are separate members, but may be a single member. That is, the plate portion 4b may extend radially outward from the lower end of the cylindrical portion 4a.
The bracket 5 holds the bearing holder 4. As illustrated in
The cylindrical member 51 is provided radially outwardly of the rotor holder 12 and the peripheral wall member 101b of the impeller 101. The cylindrical member 51 accommodates the lower portions of the stator 2 and the bearing holder 4. The pair of motor fixing members 53 is provided on the outside surface of the cylindrical member 51. In addition, the three board supporting portions 54 and the two hook members 55 are provided at the lower end of the cylindrical member 51 in the axial direction (refer to, for example,
The holding member 52 holds the plate portion 4b. The holding member 52 has a portion extending in the long direction and a portion extending in the short direction. According to the present embodiment, the holding member 52 is a rectangular plate member. However, the holding member 52 is not limited to this example. The holding member 52 may have another shape, such as an oval shape. In a plan view as viewed from the axial direction, both ends in the long direction of the holding member 52 are joined to the cylindrical member 51 at two points where the pair of motor fixing members 53 are joined to the cylindrical member 51. Thus, two bracket openings 524 and 525 are formed in the holding member 52 between the cylindrical member 51 and the holding member 52 in the short direction of the holding member 52.
In the plan view as viewed from the axial direction, the long direction of the holding member 52 is parallel to, for example, a line segment extending between the middle of a portion of the circumferential edge of the lower end of the cylindrical member 51 to which one of the motor fixing members 53 is joined and the middle of a portion to which the other motor fixing member 53 is joined. That is, in the plan view as viewed from the axial direction, both ends in the long direction of the holding member 52 are respectively joined to the cylindrical member 51 at the above-mentioned two points. Since the holding member 52 is joined to the cylindrical member 51 at the above-mentioned two points at which the vibration of the motor 100 is easily transferred, the vibration of the motor 100 can be efficiently transferred to electrical equipment. In this manner, the eigenvalue (the vibration frequency) generated in the bracket 5 can be reduced. In addition, the mounting strength of the motor 100 attached to the electrical equipment can be increased.
As illustrated in
The pair of motor fixing members 53 is attached to the electrical equipment having the air blowing device 200 mounted thereon (for example, the dryer 300 described below). When the pair of motor fixing members 53 is attached, the motor 100 is fixed to the electrical equipment. In a plan view as viewed from the axial direction, the two motor fixing members 53 are respectively joined to the cylindrical member 51 at two points of the circumferential edge of the lower end of the cylindrical member 51, where the two points are across from each other with the shaft 11 therebetween.
The board supporting portions 54 are provided on the circumferential edge of the lower end of the cylindrical member 51. Each of the board supporting portions 54 has a stopper portion 541 and a pillar portion 542 (refer to
The hook members 55 are provided on the circumferential edge of the lower end of the cylindrical member 51. Each of the hook members 55 has an extension portion 551 and a claw portion 552 (refer to
The bracket 5 is formed by injection molding using a resin material, for example. The holding member 52, the cylindrical member 51, the motor fixing member 53, the board supporting portion 54, and the hook member 55 are parts of the bracket 5. That is, the holding member 52 is the same resin member as the cylindrical member 51, the motor fixing member 53, the board supporting portion 54, and the hook member 55. The holding member 52 is provided around the plate portion 4b (in particular, both end portions in the long direction) of the bearing holder 4. Consequently, the number of parts and the assembling steps can be reduced more than in the case where the holding member 52 is a member different from the cylindrical member 51, the motor fixing member 53, the board supporting portion 54, and the hook member 55. As a result, the manufacturing cost can also be reduced.
The circuit board 7 is, for example, a disk-shaped board made of a resin material, such as epoxy. The circuit board 7 is fixed to the bracket 5 at a position away from the holding member 52 in the downward axial direction. In this manner, for example, the need for providing a circuit board having electronic components mounted thereon between the stator 2 and the bracket 5 is eliminated. As a result, the size of the motor 100 can be reduced.
As illustrated in
As illustrated in
The electronic components 71 include circuits not illustrated in
The position detection circuit is a detection unit that detects the position (that is, the rotation angle) of the rotor 1 on the basis of the induced voltages generated in the coil portions 22 of the stator 2 due to the rotation of the rotor 1. Note that the induced voltages are voltages generated in the coil portions 22 by the magnetic force of the magnet 13 when the rotor 1 rotates. For example, the position detection circuit detects the induced voltage generated in each of the coil portions 22 and detects the zero cross of the detected voltage. That is, the position detection circuit further detects the time at which the detected voltage exceeds 0 [V] and the tendency of the voltage increase/decrease at this time. Thereafter, the position detection circuit detects the rotation angle of the rotor 1 on the basis of the result of detection.
If the electronic components 71 described above are mounted on the lower surface of the circuit board 7, the shortest distance between the stator 2 and the circuit board 7 can be made shorter than when the electronic components 71 are mounted on the upper surface of the circuit board 7. In addition, the shortest distance between the stator 2 and the circuit board 7 is not influenced by the size of the electronic component 71 mounted on the circuit board 7 in the axial direction. As a result, even when an element having a relatively large size in, in particular, the axial direction (e.g., the electrolytic capacitor 71a used in the AC/DC converter) is mounted on the circuit board 7, the shortest distance between the stator 2 and the circuit board 7 need not be increased. In this way, the occurrence of breaking of a wire (in particular, the lead wire 221) between the stator 2 and the circuit board 7 can be reduced or prevented.
If the electronic components 71 including the AC/DC converter, the inverter, the control circuit, the position detection circuit, and the like are mounted on the same circuit board 7, the number of parts (for example, the total number of circuit boards 7) of the motor 100 can be reduced and, thus, the manufacturing cost can be reduced.
A specific structure of the support member 3 is described below.
The support member 3 is a support member for supporting the wire wrapping pins 6. The support member 3 protrudes from the lower end of the insulator 23. The wire wrapping pins 6 are stably supported by the support member 3. As a result, the occurrence of breaking of the wires (in particular, the lead wire 221) between the coil portion 22 and the circuit board 7 due to the vibration of the motor 100 can be reduced or prevented more effectively.
The support member 3 is disposed in the connection opening 521 in a plan view as viewed from the axial direction (refer to
The support member 3 has three terminal supporting portions 31 and two connection portions 32. Note that the present invention is not limited to this example, and the number of the terminal supporting portions 31 may be any plural number other than three. Each of the terminal supporting portions 31 is a member for supporting the wire wrapping pin 6 and protrudes from the insulator 23 toward the circuit board 7. Each of the connection portions 32 connects the adjacent terminal supporting portions 31. In the radial direction, the radial width of the connection portion 32 is smaller than the radial width of the terminal supporting portion 31. As a result, in a plan view as viewed from the axial direction, the inside surface of the connection portion 32 forms a recess 33 together with the inside surfaces of the two adjacent terminal supporting portions 31, as illustrated in
In the holding member 52, the first protrusions 522 and the second protrusions 523 are provided on the circumferential edge of the connection opening 521. The first protrusions 522 protrude from the circumferential edge of the connection opening 521 in the outward radial direction and are in contact with the support member 3. The second protrusions 523 protrude from the circumferential edge of the connection opening 521 in the outward radial direction and are in contact with the support member 3. More specifically, as illustrated in
In this manner, the displacement of the support member 3 in both the inward radial direction and outward radial direction is suppressed. Consequently, a decrease in the strength of the support member 3 due to the vibration of the motor 100 can be reduced or prevented. In addition, the vibration of the motor 100 transferred from the holding member 52 via the first protrusions 522 and the second protrusions 523 can be reduced by the connection portion 32 and, thus, the vibration is less likely to be transferred to the terminal supporting portion 31. As a result, a decrease in the strength of the wire (in particular, the lead wire 221) between the coil portion 22 and the circuit board 7 due to the vibration of the wire wrapping pins 6 can be reduced.
The holding member 52 having the first protrusions 522 and the second protrusions 523 is a resin member. Consequently, even when the first protrusions 522 and the second protrusions 523 push the support member 3 due to the vibration of the motor 100, the force that pushes the support member 3 is reduced due to the elasticity of the holding member 52 having the first protrusions 522 and the second protrusions 523. As a result, a decrease in the strength of the support member 3 due to the vibration of the motor 100 can be reduced or prevented.
Note that it is desirable that in a plan view as viewed from the axial direction, the first protrusions 522 and the second protrusions 523 be in point contact with the inside surface and the outside surface of the connection portion 32, respectively. In addition, in a plan view as viewed from the axial direction, the points of the inside surface of the connection portion 32 with which the first protrusion 522 is in contact may be single. However, it is more desirable that the points be plural. For example, in
Referring back to
The electronic components 71 that are relatively large and heavy are mounted in the first region. According to the present embodiment, the electrolytic capacitor 71a and the choke coil 71b which are relatively large and heavy electronic components 71 are mounted in the first region. Although not illustrated in
At least part of the first region overlaps the bracket opening 524 in a plan view as viewed from the axial direction. In addition, the electronic components 71 mounted on at least part of the first region that overlaps the bracket opening 524 include the choke coil 71b. According to the present embodiment, as illustrated in
Note that the other electronic components 71 need not be mounted in the second region. Alternatively, at least one electronic component 71 may be mounted in each of the first region and the second region. However, when electronic components 71 are mounted in each of the regions, the total weight of all the electronic components mounted in the first region is greater than the total weight of all the electronic components mounted in the second region.
According to the mounting distribution of the electronic components as described above, in the plan view as viewed from the axial direction, the center of gravity 7a of the circuit board 7 having the electronic components 71 mounted thereon is located inside of the first region. The center of gravity 7a is shifted from the shaft 11 toward the electronic components 71 on the first region, as illustrated in
The electronic components 71 having a height more than or equal to a predetermined height are mounted in the first region, and the electronic components 71 having a height less than the predetermined height are mounted in the second region. In this way, the electronic components 71 having the predetermined height or more (for example, the electrolytic capacitor 71a and the choke coil 71b) are not mounted in the second region. Consequently, when the motor 100 is assembled, the work space is available in the second region.
The packaging density of the electronic components in the first region may be higher than the packaging density of the electronic components in the second region. If the packaging density of the electronic components 71 in the first region increases, the total weight of the electronic components 71 mounted in the first region may be greater than the total weight of the electronic components 71 mounted in the second region. Thus, the center of gravity 7a of the circuit board 7 may be shifted in a direction from the shaft 11 toward the first region. Even in such a case, the board fixing portions can fix the circuit board 7 at a position closer to the center of gravity 7a of the circuit board 7. Consequently, when the motor 100 is driven, the force couple acting on the circuit board 7 about the center of gravity 7a is reduced, and backrush of the circuit board 7 and the natural vibration of the circuit board 7 can be reduced.
The structure of the board fixing portions is described with reference to
The board supporting portion 54 is a second fixing member fixed to the second hole 73 of the circuit board 7. According to the present embodiment, when the circuit board 7 is fixed to the bracket 5, the board supporting portion 54 is press-fitted into the second hole 73. More specifically, the pillar portion 542 of each of the board supporting portions 54 is press-fitted into one of the second holes 73 until the upper surface of the circuit board 7 is brought into contact with the lower end of the stopper portion 541. Thus, the mounting position of the circuit board 7 relative to the bracket 5 in the axial direction is determined. Furthermore, the board supporting portion 54 fixes the circuit board 7 to the bracket 5 by the press-fit structure for press-fitting the board supporting portion 54 into the second hole 73. Note that the present invention is not limited to the above-described examples of the present embodiment. The board supporting portion 54 may be fixed to the second hole 73 by using another fixing part, such as a screw. In this case, the board supporting portion 54 has a screw hole, and the screw is fixed to the screw hole through the second hole 73. Thus, the circuit board 7 can be firmly fixed to the bracket 5. In addition to press-fitting the pillar portion 542 of the board supporting portion 54, the circuit board 7 and the bracket 5 may be fixed by crushing the pillar portion 542 against the surface of the circuit board 7.
According to the present embodiment, three board supporting portions 54 and three second holes 73 are provided. In a plan view as viewed from the axial direction, the board supporting portions 54 are provided at three positions on the circumferential edge of the lower end of the cylindrical member 51. More specifically, the board supporting portions 54 are provided at the positions that equally divide the circumferential edge of the lower end of the cylindrical member 51 into three in the circumferential direction. In a plan view as viewed from the axial direction, the second holes 73 are provided at three positions on the peripheral portion of the circuit board 7 and, in particular, are provided at the positions that substantially equally divide the peripheral portion of the circuit board 7 into three. In a plan view as viewed from the axial direction, the board supporting portions 54 fix the circuit board 7 by the press-fit structure with which the board supporting portions 54 are press-fitted into the second holes 73 at two positions in the first region. In this way, the circuit board 7 can be fixed and three-point supported by the board supporting portions 54 at positions that substantially equally divide the peripheral portion of the circuit board 7 into three in the circumferential direction. As a result, backlash of the circuit board 7 fixed by the board supporting portions 54 can be further reduced and, thus, the circuit board 7 can be more stably fixed.
In addition, at one of two positions in the first region, the board supporting portion 54 secures the circuit board 7 by using a press-fit structure in the vicinity of the snap-fit structure of the hook member 55.
The present invention is not limited to the examples of the present embodiment. The number of each of the board supporting portions 54 and the second holes 73 may be any plural number other than three. In this case, in the plan view as viewed from the axial direction, the board supporting portions 54 are provided at a plurality of positions on the circumferential edge of the lower end of the cylindrical member 51. The second holes 73 are provided at a plurality of positions on the peripheral portion of the circuit board 7. The board supporting portions 54 press-fitted into the second holes 73 fix the circuit board 7 at a plurality of positions on the peripheral portion of the circuit board 7. The first region of the mounting surface includes some of the plurality of positions. Even in such a case, at a plurality of positions in the peripheral portion of the circuit board 7, the circuit board 7 can be fixed by the press-fit structure of the board supporting portions 54. Furthermore, in a plan view as viewed from the axial direction, it is desirable that the number of press-fit structures of the board supporting portion 54 provided in the first region be greater than the number of press-fit structures of the board supporting portion 54 provided in the second region.
The hook member 55 is a first fixing member for fixing the circumferential edge of the circuit board 7. When the circuit board 7 is fixed to the bracket 5, the hook member 55 is caught by the notch 74 while pushing the outside surface of the circuit board 7. More specifically, in the notch 74, the inside surface of the extension portion 551 pushes the outside surface of the circuit board 7, and the claw portion 552 is caught by the edge portion of the notch 74. By providing such a snap-fit structure at least at two positions across from each other, the circuit board 7 is fixed to the bracket 5.
According to the present embodiment, a pair of the hook members 55 and a pair of the notches 74 are provided (that is, two hook members 55 and two notches 74 are provided). In a plan view as viewed from the axial direction, the hook members 55 are provided on the circumferential edge of the lower end of the cylindrical member 51 at two positions across from each other in the radial direction. In a plan view as viewed from the axial direction, the notches 74 are provided on the peripheral edge of the circuit board 7 at two positions across from each other in the radial direction.
In a plan view as viewed from the axial direction, one of the hook members 55 fixes the circumferential edge of the circuit board 7 at a first position within the first region by using the snap-fit structure of the notch 74. In addition, the one hook member 55 fixes the circumferential edge of the circuit board 7 in the vicinity of the electrolytic capacitor 71a and the choke coil 71b. Furthermore, the other hook member 55 fixes the circumferential edge of the circuit board 7 at a second position opposed with respect to the first position with the shaft 11 interposed therebetween by using the snap-fit structure of the notch 74.
In this way, the circumferential edge of the circuit board 7 is fixed at two positions across from each other with the shaft 11 therebetween. Consequently, it is possible to reduce a force couple acting on the circuit board 7 about the radial direction perpendicular to the line segment passing through the shaft 11 and connecting the first position with the second position. As a result, backlash and the natural vibration of the circuit board 7 can be reduced.
It should be noted that the present invention is not limited to the examples of the present embodiment. Three or more hook members 55 and three or more notches 74 may be provided. In such a case, in a plan view as viewed from the axial direction, the hook members 55 are provided at a plurality of positions on the circumferential edge of the lower end of the cylindrical member 51. The notches 74 are provided at a plurality of positions on the circumferential edge of the circuit board 7. Note that the plurality of positions at which the hook members 55 are provided include at least two positions across from each other with the shaft 11 therebetween, and the plurality of positions at which the notches 74 are provided include at least two positions across from each other with the shaft 11 therebetween. The hook members 55 snap-fitted to the respective notches 74 fix the circuit board 7 at the plurality of positions on the circumferential edge of the circuit board 7. Some of the plurality of hook members 55 fix the circumferential edge of the circuit board 7 at the first positions in the first region. The other hook members 55 fix the circumferential edge of the circuit board 7 at the second positions opposed with respect to the respective first positions with the shaft 11 interposed therebetween. In addition, in a plan view as viewed from the axial direction, it is desirable that the number of snap-fit structures provided in the first region be greater than the number of snap-fit structures provided in the second region.
The first hole 72 of the circuit board 7 is provided in the first region of the mounting surface in a plan view as viewed from the axial direction. In addition, the first holes 72 are provided in the vicinity of the electronic components 71, such as the electrolytic capacitor 71a and the choke coil 71b. When the circuit board 7 is fixed, the wire wrapping pin 6 is inserted into the first hole 72 and passes through the first hole 72. Thereafter, the wire wrapping pin 6 is soldered to the circuit board 7. By using the soldering structure of the wire wrapping pin 6, the wire wrapping pin 6 is electrically connected to a wiring portion (not illustrated) of the circuit board 7 and, in addition, the circuit board 7 is fixed to the bracket 5.
Relatively heavy electronic components 71, such as an electrolytic capacitor 71a and a choke coil 71b, are mounted in part of the first region of the mounting surface of the circuit board 7 in the circumferential direction. Accordingly, the total weight of the electronic components 71 mounted in the first region is greater than the total weight of the electronic components 71 mounted in the second region. Accordingly, the board fixing portion particularly fixes the circuit board 7 in the vicinity of the electronic components 71 mounted in the first region of the mounting surface of the circuit board 7. That is, the board fixing portion particularly fixes the circuit board 7 in the vicinity of the relatively large and heavy electronic components 71, such as the electrolytic capacitor 71a and the choke coil 17b. Accordingly, the number of board fixing portions for fixing the circuit board 7 in the first region is greater than the number of board fixing portions for fixing the circuit board 7 in the second region. For example, as illustrated in
This configuration can reduce the natural vibration of the circuit board 7 caused by vibration of the relatively heavy electronic components 71 when the motor 100 is driven. Furthermore, it is possible to prevent overlapping of the natural frequency of the circuit board 7 with the vibration frequency of the portion of the motor 100 other than the circuit board 7. As a result, the occurrence of the resonance of the motor 100 caused by the vibration of the circuit board 7 can be reduced or prevented.
In addition, in a plan view as viewed from the axial direction, the plurality of board fixing portions fix the circuit board 7 in the middle of the first region in the circumferential direction. For example, according to the present embodiment, as illustrated in
Furthermore, the board fixing portions fix the circuit board 7 in the vicinity of the center of gravity 7a (hatching in
Subsequently, the dryer 300 is described below. The dryer 300 is an example of application of the electrical equipment having the air blowing device 200 including the above-described motor 100 according to the present embodiment.
The dryer 300 is electrical equipment for blowing out hot air. The dryer 300 rotates the impeller 101 of the air blowing device 200 by using the rotary drive of the motor 100 and sends an air flow frontward in the air blowing direction. The dryer 300 heats the air flow sent in the forward air blowing direction with a heater and discharges the heated air flow (that is, hot air) to the outside. The dryer 300 is used as, for example, a hairdryer for home or business use that dries hair. However, the dryer according to the present disclosure may be a dryer for drying or heating something other than hair, such as an industrial dryer.
As illustrated in
The dryer housing 301 is a casing of the dryer 300. The dryer housing 301 includes an air inlet 301a, an air outlet 301b, and an internal space 301c. The air inlet 301a is disposed in a rear portion of the dryer housing 301 in the air blowing direction. The air outlet 301b is provided in a front portion of the dryer housing 301 in the air blowing direction. The air inlet 301a and the air outlet 301b communicate with the internal space 301c of the dryer housing 301. The air blowing device 200 using the motor 100, the flow rectifier member, and the heater are disposed in the internal space 301c.
The impeller 101 of the air blowing device 200 is disposed in the rear portion in the air blowing direction, and the motor 100 is disposed in the front portion in the air blowing direction. The axial direction of the air blowing device 200 is parallel to the air blowing direction of the dryer 300. The upward axial direction corresponds to a direction opposite to the air blowing direction. The downward axial direction corresponds to the air blowing direction.
The flow rectifier member has a plurality of stator vanes (not illustrated) arranged in the circumferential direction of the motor. Each of the stator vanes is provided radially outward of the motor 100, that is, between the motor 100 and the dryer housing 301.
The heater is provided between the air blowing device 200 and the air outlet 301b. The heater is a heating member for heating an air flow. The heater has a heating wire, such as a nichrome wire, which generates heat by passing an electric current therethrough.
When the power switch (not illustrated) of the dryer 300 is switched on, the air blowing device 200 is activated. By rotation of the impeller 101, the air blowing device 200 generates an air flow flowing from the outside of the dryer housing 301 into the internal space 301c through the air inlet 301a. The air flow flowing into the internal space 301c is sent from the air blowing device 200 in the outward radial direction by the rotation of the impeller 101. The air flow is guided to between the plurality of stator vanes by the inner surface of the internal space 301c and is sent toward the heater. The air flow flowing around the heater is heated by the heater. Thereafter, the heated air flow is blown out from the air outlet 301b.
The embodiments of the present invention have been described above. It should be noted that the scope of the present disclosure is not limited to the above-described embodiments. The present disclosure can be implemented with various modifications without departing from the spirit and scope of the disclosure. Furthermore, the above-described embodiments can be combined in any way as appropriate.
In addition to the dryer (refer to
Features of the above-described preferred embodiments and the modifications thereof may be combined appropriately as long as no conflict arises.
While preferred embodiments of the present invention have been described above, it is to be understood that variations and modifications will be apparent to those skilled in the art without departing from the scope and spirit of the present invention. The scope of the present invention, therefore, is to be determined solely by the following claims.
Number | Date | Country | Kind |
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2017-023491 | Feb 2017 | JP | national |