Motor

Abstract

To provide a motor capable of further suppressing temperature rise.SOLUTION: A motor includes a rotatable shaft, a motor magnet rotatable with the shaft, a non-rotatable motor stator including a motor coil, a position detector support member extending from the radially inner side to the radially outer side and rotatable together with the shaft, a position detector having a rotatable detection rotor provided on the position detector support member and a non-rotatable detection stator provided on the inner peripheral side of the detection rotor, and a housing. The detection rotor is provided at a position overlapping with the motor coil when viewed in the axial direction, and the detection stator is provided at a position overlapping with the motor magnet.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure relates to a motor. [Background technology]

[0002] An inner rotor type motor in which a rotating shaft is disposed at the radial center is known (see Patent Document 1). In the motor of Patent Document 1, a stator is disposed on the outer periphery of the rotating shaft, and a rotor is disposed on the outer periphery of the stator. The stator has a coil (winding). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-072537 A Summary of the Invention [Problem to be solved by the invention]

[0004] When a current flows through the stator coil, the coil heats up, which in turn increases the temperature of the motor. This increase in temperature can cause a decrease in the rotational torque of the motor.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and has an object to provide a motor that can further suppress temperature rise. [Means for solving the problem]

[0006] In order to achieve the above object, a motor according to one embodiment includes a shaft extending in the axial direction of a central axis and rotatable around the central axis, a motor magnet arranged on the outer periphery of the shaft and rotatable together with the shaft, a non-rotatable motor stator arranged facing the outer periphery of the motor magnet and including a motor coil, a position detector support member extending from the radially inner side to the radially outer side to a position overlapping with the motor coil when viewed from the axial direction and rotatable together with the shaft, a detection rotor provided on the position detector support member and rotatable together with the shaft, and a position detector having a detection stator arranged on the inner periphery of the detection rotor and non-rotatable, and a housing that accommodates the motor magnet, the motor stator, the position detector support member, and the position detector inwardly, wherein the detection rotor is arranged on one axial side of the motor coil and is arranged at a position overlapping with the motor coil when viewed from the axial direction, and the detection stator is arranged at a position overlapping with the motor magnet when viewed from the axial direction.

[0007] In this manner, in the motor of the present disclosure, a non-rotatable motor stator is disposed on the outer periphery of a rotatable motor magnet, and a rotatable detection rotor is disposed on the outer periphery of the non-rotatable detection stator. Also, when viewed from the axial direction, the motor coil and the detection rotor overlap, and the motor magnet and the detection stator overlap. Therefore, as the detection rotor rotates together with the position detector support member, the air inside the housing is disturbed, causing the air to flow turbulently. This air hits the motor coil, thereby cooling the motor coil. As the motor coil is cooled in this manner, the rated torque of the motor can be improved.

[0008] In the motor of the comparative example, in which a non-rotatable motor stator is arranged on the outer periphery of a rotatable motor magnet and a non-rotatable detection stator is arranged on the outer periphery of a rotatable detection rotor, a non-rotatable detection stator is arranged on one axial side of the non-rotatable motor stator. Therefore, in the motor of the comparative example, the turbulent flow caused by the disturbance of the air due to the rotation of the detection rotor is unlikely to hit the motor coil, and the motor coil is unlikely to be cooled, so it is difficult to improve the rated torque of the motor compared to the motor of the present disclosure. In addition, in the motor of the present disclosure, the air inside the housing is disturbed and the air becomes turbulent, so that the temperature rise of the entire motor is suppressed, and the torque decrease of the motor can be suppressed. In contrast, in the motor of the comparative example described above, turbulence caused by the disturbance of the air due to the rotation of the detection rotor is unlikely to occur, so it is difficult to suppress the temperature rise of the entire motor and it is difficult to suppress the torque decrease of the motor.

[0009] In a preferred embodiment, the housing includes a lower housing and an upper housing located on one axial side of the lower housing, the upper housing extends from the radially outer side to the radially inner side so as to cover the detection rotor and the detection stator from one axial side, and the detection stator is attached to the upper housing. Therefore, with a simple configuration of the upper housing, it is possible to establish a configuration in which the motor stator is disposed on the outer periphery of the motor magnet, and the detection rotor is disposed on the outer periphery of the detection stator.

[0010] In a preferred embodiment, the position detector support member is disposed between the position detector and the motor magnet and the motor stator. Therefore, the rotation of the position detector support member is not easily hindered by the position detector, the motor magnet, and the motor stator. That is, if the position detector support member is disposed in a position overlapping the motor magnet or the motor stator in a cross section including the central axis, there is a risk that the position detector support member may interfere with the motor magnet or the motor stator when it rotates. Therefore, by disposing the position detector support member between the position detector and the motor magnet and the motor stator, the position detector support member will not interfere with the motor magnet or the motor stator even when it rotates.

[0011] In a preferred embodiment, the upper housing is connected to an outer ring of a bearing, and the shaft is connected to an inner ring of the bearing, thereby allowing the shaft to rotate. This makes it possible to make the shaft rotatable with a simple structure.

[0012] In a preferred embodiment, the position detector support member has a first portion extending radially outward from the outer periphery of the shaft, a second portion extending from the first portion to one side in the axial direction, and a third portion extending radially outward from the second portion, and the detection rotor is fixed to the third portion.

[0013] Since the detection stator extends in the axial direction, when the position detector support member is formed in a flat shape extending along the radial direction, the detection stator needs to be positioned closer to one side in the axial direction than in the present disclosure. Therefore, in this case, the axial height of the motor is larger. Therefore, in the present disclosure, the axial height of the motor is smaller than when the position detector support member is formed in a flat shape along the radial direction.

[0014] In a preferred embodiment, the housing has a through hole, and a suction joint to which a suction device can be connected is fitted into the through hole. In this way, the air inside the housing can be sucked from the outside to exhaust the air from inside the motor. This makes it possible to further suppress the temperature rise of the motor and the decrease in torque of the motor.

[0015] In a preferred embodiment, the position detector support member is made of a non-magnetic material, which can reduce the effect of the magnetic flux of the motor magnet on the position detector and can prevent malfunction of the motor.

[0016] In a preferred embodiment, the shaft has a protruding portion that protrudes radially outward and to which the motor magnet is attached, a groove is provided on one axial side of the protruding portion, and in a cross section including the central axis, the groove accommodates a balancer that adjusts the balance when the shaft rotates, and the groove is covered by a support member for the position detector.

[0017] Since the protrusion rotates together with the shaft, the balancer is likely to fly off. Therefore, by covering the groove with the position detector support member, it is possible to prevent the balancer from flying off.

[0018] In a preferred embodiment, the detection stator and the detection rotor are disposed radially opposite to each other, so that the detection rotor is disposed radially outward, and thus turbulence caused by air disturbance due to rotation of the detection rotor is more likely to occur.

[0019] In a preferred embodiment, the detection stator and the detection rotor are arranged to face each other in the axial direction. With such an axial gap type position detector, the air inside the housing is stirred by the rotation of the position detector support member to which the detection rotor is attached, causing turbulence. This allows the motor coil of the motor stator to be cooled, thereby suppressing the temperature rise of the motor. Effect of the Invention

[0020] According to the present disclosure, a motor capable of further suppressing temperature rise is provided. [Brief description of the drawings]

[0021] [Figure 1] FIG. 1 is a cross-sectional view that illustrates a schematic overall configuration of a motor according to a first embodiment. [Diagram 2] FIG. 2 is an enlarged cross-sectional view of a portion of FIG. [Diagram 3] FIG. 3 is a cross-sectional view that illustrates a schematic overall configuration of a motor according to a second embodiment. [Figure 4] FIG. 4 is a cross-sectional view that illustrates the overall configuration of a motor according to a third embodiment. [Diagram 5] FIG. 5 is an enlarged cross-sectional view of a portion of FIG. [Figure 6] FIG. 6 is a cross-sectional view that illustrates the overall configuration of a motor according to a fourth embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] The following describes in detail the form (embodiment) for carrying out the present invention with reference to the drawings. The present invention is not limited to the contents described in the following embodiment. The components described below include those that a person skilled in the art can easily imagine and those that are substantially the same. Furthermore, the components described below can be appropriately combined.

[0023] [First embodiment] First, the first embodiment will be described. Fig. 1 is a cross-sectional view showing a schematic overall configuration of a motor according to a first embodiment. Fig. 2 is a cross-sectional view showing an enlarged portion of Fig. 1. As shown in Figs. 1 and 2, the motor 1 according to the first embodiment can transmit a rotational force directly to a rotor without using a reduction mechanism (e.g., a reduction gear, a transmission belt, etc.), and rotate the rotor. In this embodiment, an inner rotor type motor 1 is applied.

[0024] The motor 1 includes a housing 2, a motor stator 3, a position detector 4, a support member 5 for the position detector, a rotor 6, and a shaft 7. The motor 1 has an annular shape centered on a central axis Ax. In the embodiment, one side in the axial direction along the central axis Ax is the upper side, indicated as UP in the drawings. The other side in the axial direction is the lower side, indicated as LW in the drawings. However, the motor 1 is not limited to an aspect in which the central axis Ax is disposed along the up-down direction.

[0025] The housing 2 includes a lower housing 21 and upper housings 22 and 23. An accommodating section 24 is provided inside the lower housing 21, and an accommodating section 25 is provided inside the upper housing 22. The accommodating section 24 accommodates the motor stator 3. The accommodating section 25 accommodates the position detector 4. The housing 2 has an annular shape centered on the central axis Ax. The housing 2 can be made of a material such as aluminum, for example. Aluminum improves the heat dissipation properties of the housing 2.

[0026] The lower housing 21 includes a bottom plate 211, an inner peripheral side plate 212, and an outer peripheral side plate 213. The bottom plate 211 extends in a radial direction perpendicular to the central axis Ax. An inner peripheral side plate 212 protruding toward an upper side UP, which is one side in the axial direction, is provided at an inner peripheral end of the bottom plate 211. An outer peripheral side plate 213 protruding toward the upper side UP is provided at an outer peripheral end of the bottom plate 211. The axial height (height in the up-down direction) of the outer peripheral side plate 213 is greater than the axial height of the inner peripheral side plate 212.

[0027] The upper housing 22 includes an outer circumferential portion 221, a connecting portion 222, and an inner circumferential portion 223. The upper housing 22 is a lid-like member that covers an upper opening of the lower housing 21. An outer circumferential end portion of the outer circumferential portion 221 is fitted into a recess 213a in an upper portion of an outer circumferential side plate 213 of the lower housing 21, and is fixed to an upper portion of the outer circumferential side plate 213 via a bolt 110. The connecting portion 222 extends upward from the inner circumferential side of the outer circumferential portion 221. The inner circumferential portion 223 extends radially inward from an upper end portion of the connecting portion 222, i.e., in a direction approaching the central axis Ax.

[0028] The upper housing 23 has an inner peripheral portion 231, a connecting portion 232, and an outer peripheral portion 233. The inner peripheral portion 231 extends in the axial direction (the up-down direction in FIG. 1). An inner peripheral end portion of an inner peripheral portion 223 of the upper housing 22 is fixed to an upper end of the inner peripheral portion 231 via a bolt 114. A connecting portion 232 extends radially outward from a lower end of the inner peripheral portion 231. A outer peripheral portion 233 extends from a radially outer end of the connecting portion 232 toward the other axial side (the lower side LW in FIG. 1).

[0029] The shaft 7 extends in the axial direction (the vertical direction in FIG. 1). The shaft 7 has a cylindrical portion 71 and a protruding portion 72. The cylindrical portion 71 is a cylindrical member extending in the axial direction. A through hole 70 is provided inside the cylindrical portion 71. The through hole 70 penetrates the cylindrical portion 71 in the axial direction. The cylindrical portion 71 has a small diameter portion 711 and a large diameter portion 712. Since the outer diameter of the large diameter portion 712 is larger than the outer diameter of the small diameter portion 711, the upper surface of the large diameter portion 712 is exposed. The upper end surface of the shaft 7 is provided with holes 120 and 121 for mounting an object, and the lower end surface of the shaft 7 is provided with holes 122 and 123 for mounting an object. Bolts can be engaged with the mounted object mounting holes 120, 121, 122, and 123, and a mounted object such as an arm is attached to the mounted object mounting holes 120, 121, 122, and 123 via the bolts. Therefore, in the motor 1 of this embodiment, a mounted object can be attached to both one side (upper side) and the other side (lower side) in the axial direction of the shaft 7.

[0030] The protruding portion 72 is an annular member that protrudes radially outward from the outer circumferential surface of the cylindrical portion 71. A groove 73 is provided on the upper surface of the protruding portion 72. The groove 73 extends in the circumferential direction. The groove 73 has a rectangular shape in a cross section including the central axis Ax. A balancer 74 is housed in the groove 73. The balancer 74 adjusts the balance when the shaft 7 rotates. The balancer 74 is, for example, an epoxy resin. The motor magnet 61 of the rotor 6 is fixed to the outer circumferential side of the protruding portion 72. The motor magnet 61 is fixed to the protruding portion 72 by, for example, adhesion. The motor magnet 61 has an annular shape centered on the central axis Ax.

[0031] Here, the bearing 100 is a deep groove ball bearing having an inner ring 101, an outer ring 103, and a rolling element 102. The inner ring 101 and the outer ring 103 can rotate relative to each other via the spherical rolling element 102. In this embodiment, the bearings 100 are provided on the upper and lower sides. The inner ring 101 of the upper bearing 100 is placed on the upper surface of the large diameter portion 712. In addition, an annular spacer 45 and a wave washer 44 are sandwiched between the upper surface of the outer ring 103 and the lower surfaces of the inner peripheral portion 231 and the connecting portion 232 of the upper housing 23. The wave washer 44 is compressed by a compressive load in the axial direction (vertical direction) and a preload is applied, so that the outer ring 103 is fixed in the axial direction by the preload (elastic force) of the wave washer 44. As a result, the upper bearing 100 rotatably supports the axial center portion of the shaft 7 relative to the upper housing 23. Also, the inner ring 101 of the lower bearing 100 is fixed to the outer periphery of the shaft 7, and the outer ring 103 is fixed to the bottom plate 211 and the inner periphery plate 212. Therefore, the lower bearing 100 rotatably supports the other axial end portion (the end portion on the lower side LW) of the shaft 7 relative to the lower end portion of the lower housing 21.

[0032] The position detector support member 5 extends in the radial direction from the cylindrical portion 71 of the shaft 7 to the vicinity of the outer circumferential portion 221 of the upper housing 22. The position detector support member 5 is made of a non-magnetic material, and aluminum or stainless steel, for example, is applicable as the non-magnetic material. The position detector support member 5 has an annular shape centered on the central axis Ax, and is disposed so as to cover the upper opening of the lower housing 21. The position detector support member 5 has a shape in which two L-shaped members are connected in a cross section including the central axis Ax. Specifically, the position detector support member 5 has a first portion 51, a second portion 52, a third portion 53, and a fourth portion 54. The first portion 51 extends radially outward. The first portion 51 is fixed to an upper portion of the protruding portion 72 via a bolt 113. Since the protruding portion 72 is provided with a recessed groove 73, the upper side UP of the recessed groove 73 is sealed by the first portion 51. The second portion 52 extends from a radially outer end of the first portion 51 toward one side in the axial direction (upper side UP). The third portion 53 extends radially outward from an end of the second portion 52 on one side in the axial direction (end of the upper side UP). The fourth portion 54 extends from the radially outer end of the third portion 53 toward one side in the axial direction (upper side UP). The fourth portion 54 is disposed close to an inner circumferential surface of the outer circumferential portion 221 of the upper housing 22. The fourth portion 54 is disposed opposite to the inner circumferential surface of the outer circumferential portion 221.

[0033] The position detector 4 is also called a rotation sensor, and detects the rotation state (for example, the rotation angle) of the motor 1. Although various specifications are applicable as the position detector, the position detector 4 of the first embodiment will be described as an example of a radial gap type resolver. The position detector 4 makes it possible to rotate a load such as various works attached to the shaft 7 accurately by a predetermined angle and to position it at a target position with high accuracy. The position detector 4 includes a resolver stator (detection stator) 41 and a resolver rotor (detection rotor) 42. The resolver stator 41 and the resolver rotor 42 have an annular shape centered on the central axis Ax. The resolver stator 41 is fixed to the upper surface of the connecting portion 232 of the upper housing 23 via a bolt 112. The resolver stator 41 has a winding portion 411. The resolver rotor 42 is placed on the upper surface of the third portion 53 of the position detector support member 5 via a spacer 43. The resolver rotor 42 is disposed close to an inner circumferential surface of the fourth portion 54 of the position detector support member 5. The resolver rotor 42 is fixed to the third portion 53 via bolts 111 while being placed on the spacer 43. The resolver rotor 42 is disposed radially outward of the motor magnet 61. The resolver stator 41 and the resolver rotor 42 are positioned approximately in the same axial direction (up-down direction) and are disposed facing each other in the radial direction.

[0034] Furthermore, the upper housing 22 is provided with wiring holes 130, 131 for the position detector. The wiring hole 130 is disposed radially opposite to the winding portion 411 of the resolver stator 41. The wiring hole 130 passes through the inner periphery 223 of the upper housing 22 in the axial direction. The wiring hole 131 passes through the outer periphery 221 and the connecting portion 222 of the upper housing 22 in the axial direction.

[0035] The motor stator 3 has a stator core (iron core) 31 and a motor coil 32. The stator core 31 is formed, for example, by stacking a plurality of thin plates, such as a single annular electromagnetic steel plate or a cold-rolled steel plate, formed by punching in the axial direction. The motor coil 32 is wound around the stator core 31. The stator core 31 and the motor magnet 61 are located at substantially the same axial position. The stator core 31 is disposed facing the motor magnet 61 in the radial direction. The resolver rotor 42 is disposed overlapping the motor coil 32 when viewed from the axial direction. The position detector 4 is disposed on one side of the motor coil 32 in the axial direction.

[0036] As described above, the rotating parts of the motor 1 are the shaft 7, the rotor 6 including the motor magnet 61, the support member 5 for the position detector, and the resolver rotor 42. Moreover, the non-rotating parts of the motor 1 are the housing 2, the motor stator 3 including the motor coil 32, and the resolver stator 41. The rotating parts of the motor 1 are rotatable relative to the non-rotating parts via the two bearings 100, one above and one below.

[0037] As described above, the motor 1 includes the shaft 7 rotatable around the central axis Ax, the motor magnet 61 arranged on the outer periphery of the shaft 7 and rotatable together with the shaft 7, the non-rotatable motor stator 3 arranged facing the outer periphery of the motor magnet 61 and including the motor coil 32, the position detector support member 5 extending from the radially inner side to the radially outer side to a position overlapping with the motor coil 32 when viewed from the axial direction and rotatable together with the shaft 7, the position detector 4 including the resolver rotor (detection rotor) 42 provided on the position detector support member 5 and rotatable together with the shaft 7, and the resolver stator (detection stator) 41 arranged on the inner periphery of the resolver rotor (detection rotor) 42 and non-rotatable, and the housing 2 accommodating the motor magnet 61, the motor stator 3, the position detector support member 5, and the position detector 4 therein. The resolver rotor (detection rotor) 42 is disposed on one axial side of the motor coil 32, and is disposed at a position overlapping the motor coil 32 when viewed from the axial direction. The resolver stator (detection stator) 41 is disposed at a position overlapping the motor magnet 61 when viewed from the axial direction.

[0038] In this manner, the non-rotatable motor stator 3 is disposed on the outer periphery of the rotatable motor magnet 61, and the rotatable resolver rotor (detection rotor) 42 is disposed on the outer periphery of the non-rotatable resolver stator (detection stator) 41. When viewed from the axial direction, the motor coil 32 and the resolver rotor (detection rotor) 42 overlap, and the motor magnet 61 and the resolver stator (detection stator) 41 overlap. Therefore, the resolver rotor (detection rotor) 42 rotates together with the position detector support member 5, disturbing the air inside the housing 2 and causing the air to flow turbulently. This air hits the motor coil 32, and the motor coil 32 is cooled. In this manner, the motor coil 32 is cooled, and thus the rated torque of the motor 1 can be improved.

[0039] In addition, in the past, a non-rotatable motor stator was arranged on the outer periphery of a rotatable motor magnet, and a non-rotatable resolver stator (detection stator) was arranged on the outer periphery of a rotatable resolver rotor (detection rotor). That is, since the non-rotatable resolver stator (detection stator) is arranged on one axial side of the non-rotatable motor stator, the turbulent flow caused by the disturbance of the air due to the rotation of the resolver rotor (detection rotor) is unlikely to hit the motor coil, and the motor coil is unlikely to be cooled. For this reason, in the conventional motor, the turbulent flow caused by the disturbance of the air due to the rotation of the resolver rotor (detection rotor) is unlikely to hit the motor coil, and the motor coil is unlikely to be cooled, so that it is difficult to improve the rated torque of the motor compared to the motor of the present disclosure. Also, in the motor 1 of the present disclosure, the air inside the housing 2 is disturbed and the air becomes turbulent, so that it is possible to suppress the increase in temperature of the entire motor 1 and suppress the torque decrease of the motor 1. In contrast, in the conventional motor described above, turbulence caused by air disturbance due to the rotation of the resolver rotor (detection rotor) is unlikely to occur, making it difficult to suppress an increase in temperature of the entire motor and difficult to suppress a decrease in motor torque.

[0040] The housing 2 includes a lower housing 21 and upper housings 22, 23 located on one axial side of the lower housing 21. The upper housings 22, 23 extend from the radially outer side to the radially inner side so as to cover a resolver rotor (detection rotor) 42 and a resolver stator (detection stator) 41 from one axial side. The resolver stator (detection stator) 41 is attached to the upper housing 23.

[0041] Therefore, with the simple configuration of the upper housings 22, 23, it is possible to establish a configuration in which the motor stator 3 is arranged on the outer periphery of the motor magnet 61, and the resolver rotor (detection rotor) 42 is arranged on the outer periphery of the resolver stator (detection stator) 41.

[0042] The support member 5 for the position detector is disposed between the position detector 4 and the motor magnet 61 and the motor stator 3. Therefore, the rotation of the support member 5 for the position detector is not easily hindered by the position detector 4, the motor magnet 61, and the motor stator 3. That is, in the cross-sectional views of FIG. 1 and FIG. 2, if the support member 5 for the position detector is disposed at a position overlapping with the motor magnet 61 or the motor stator 3, the support member 5 for the position detector may interfere with the motor magnet 61 or the motor stator 3 when it rotates. Therefore, by disposing the support member 5 for the position detector between the position detector 4 and the motor magnet 61 or the motor stator 3, the support member 5 for the position detector does not interfere with the motor magnet 61 or the motor stator 3 even when it rotates.

[0043] The upper housing 23 is connected to the outer ring 103 of the bearing 100, and the shaft 7 is connected to the inner ring 101 of the bearing 100, thereby making the shaft 7 rotatable. This makes it possible to make the shaft 7 rotatable with a simple structure.

[0044] The position detector support member 5 has a first portion 51 extending radially outward from the outer periphery of the shaft 7, a second portion 52 extending from the first portion 51 to one side in the axial direction, and a third portion 53 extending radially outward from the second portion 52, and the resolver rotor (detection rotor) 42 is fixed to the third portion 53. If the position detector support member is formed in a flat shape along the radial direction, the resolver stator (detection stator) 41 needs to be positioned closer to one side in the axial direction with respect to the position detector support member 5 of the present disclosure, and this increases the axial height of the motor. Therefore, in the present disclosure, the axial height of the motor 1 is reduced.

[0045] Since the position detector support member 5 is a non-magnetic material, it is possible to reduce the effect of the magnetic flux of the motor magnet 61 on the position detector 4, and to suppress malfunctions of the motor 1. As a non-magnetic material, for example, aluminum is preferable in order to reduce the moment of inertia, and stainless steel is also applicable as long as it is a non-magnetic material.

[0046] The shaft 7 has a protruding portion 72 that protrudes radially outward and to which the motor magnet 61 is attached, and a groove 73 is provided on one axial side of the protruding portion 72, and in a cross section including the central axis Ax, the groove 73 houses a balancer 74 that adjusts the balance when the shaft 7 rotates, and the groove 73 is covered with a support member 5 for a position detector. Since the protruding portion 72 rotates together with the shaft 7, the balancer 74 is likely to fly off. Therefore, by covering the groove 73 with the support member 5 for a position detector, it is possible to prevent the balancer 74 from flying off.

[0047] The resolver stator (detection stator) 41 and the resolver rotor (detection rotor) 42 are disposed facing each other in the radial direction. Therefore, the resolver rotor (detection rotor) 42 is disposed further outward in the radial direction, so that turbulence due to air disturbance caused by the rotation of the resolver rotor (detection rotor) is more likely to occur.

[0048] [Second embodiment] Next, a second embodiment will be described, but the same reference numerals will be used to designate the same components as those in the first embodiment, and the description thereof will be omitted. Fig. 3 is a cross-sectional view showing a schematic overall configuration of a motor according to the second embodiment.

[0049] The motor 1A according to the second embodiment differs from the motor 1 according to the first embodiment in that a suction joint 300 is provided.

[0050] As shown in Fig. 3, a through hole 213b penetrating in the radial direction is provided in the outer peripheral side plate 213 of the lower housing 21. The through hole 213b is disposed axially opposite the motor coil 32 of the motor stator 3. A suction joint 300 is fitted into the radially outer end of the through hole 213b. A suction device (not shown) can be connected to the suction joint 300. The suction device includes, for example, a hose connected to the suction joint 300 and a suction pump connected to the hose. By operating the suction pump, air inside the housing 2 can be discharged to the outside of the housing 2 via the hose and the suction joint 300.

[0051] As described above, the lower housing 21 is provided with the through hole 213b, and the suction joint 300 to which a suction device can be connected is fitted into the through hole 213b. In this manner, the air inside the housing 2 is sucked from the outside, thereby making it possible to exhaust the high-temperature air inside the motor 1A. This makes it possible to further suppress the temperature rise of the motor 1A and the decrease in the torque of the motor 1A.

[0052] [Third embodiment] Next, a third embodiment will be described, but the same reference numerals will be used to designate parts having the same configuration as those of the first and second embodiments described above, and the description thereof will be omitted. Fig. 4 is a cross-sectional view showing a schematic overall configuration of a motor according to a third embodiment. Fig. 5 is a cross-sectional view showing an enlarged portion of Fig. 4.

[0053] A motor 1B according to the third embodiment differs from the motors 1 according to the first and second embodiments in a position detector 4A and an upper housing 23A.

[0054] 4 and 5, the upper housing 23A has an inner peripheral portion 231A, a connecting portion 232A, and an outer peripheral portion 233A. The connecting portion 232A is formed to have a longer axial length than the connecting portion 232 according to the first and second embodiments.

[0055] The position detector 4A of the third embodiment is an axial gap type position detector, and has a multi-pole magnetized position detector magnet 421A and a magnetic flux detection element 412A. The position detector 4A includes a stator 41A and a rotor 42A. The stator 41A and the rotor 42A have a disk shape centered on the central axis Ax. The stator 41A has a substrate 411A and a magnetic flux detection element 412A. The substrate 411A is fixed to an upper surface of the connecting portion 232A of the upper housing 23A via a bolt 112. The magnetic flux detection element 412A is fixed to a lower side (the other axial side) of a radially outer end of the substrate 411A.

[0056] The rotor 42A has a support plate 422A and a magnet for a position detector 421A. The support plate 422A is placed on the upper surface of the third part 53 of the support member for the position detector 5 via a spacer 43. The support plate 422A is disposed close to the inner circumferential surface of the fourth part 54 of the support member for the position detector 5 and extends radially inward. The support plate 422A is fixed to the third part 53 via a bolt 111 in a state where it is placed on the spacer 43. The magnet for a position detector 421A is fixed to the upper surface (one side surface in the axial direction) of the end part on the radial inner side of the support plate 422A. The magnet for a position detector 421A is fixed to the support plate 422A by, for example, adhesion. The magnetic flux detection element 412A is disposed facing the magnet for a position detector 421A in the axial direction.

[0057] As described above, in the third embodiment, the axial gap type position detector 4A is applied. In the position detector 4A, the magnetic flux detection element 412A of the stator 41A and the position detector magnet 421A of the rotor 42A are arranged to face each other in the axial direction. Even with such an axial gap type position detector 4A, the air inside the housing 2A is stirred by the rotation of the position detector support member 5 to which the rotor 42A is attached, causing a turbulent flow. Therefore, it is possible to cool the motor coil 32 of the motor stator 3 and suppress the temperature rise of the motor 1B. This makes it possible to suppress the decrease in the torque of the motor 1B.

[0058] [Fourth embodiment] Next, a fourth embodiment will be described, but the same reference numerals will be used to designate parts having the same configuration as those in the first to third embodiments described above, and the description thereof will be omitted. Fig. 6 is a cross-sectional view showing a schematic overall configuration of a motor according to the fourth embodiment.

[0059] The motor 1C according to the fourth embodiment differs from the motor 1B according to the third embodiment in that a suction joint 300 is provided.

[0060] As shown in Fig. 6, a through hole 213b penetrating in the radial direction is provided in the outer peripheral side plate 213 of the lower housing 21. The through hole 213b is disposed facing the motor coil 32 of the motor stator 3 in the axial direction. A suction joint 300 is fitted into the radially outer end of the through hole 213b. A suction device (not shown) can be connected to the suction joint 300. The suction device includes, for example, a hose connected to the suction joint 300 and a suction pump connected to the hose. By operating the suction pump, air inside the housing 2 can be discharged to the outside of the housing 2 via the hose and the suction joint 300.

[0061] As described above, in the motor 1C, similarly to the motor 1A, the lower housing 21 is provided with the through hole 213b, and the suction joint 300 to which a suction device can be connected is fitted into the through hole 213b. In this manner, the air inside the housing 2A is sucked from the outside, and the high-temperature air inside the motor 1C can be exhausted. This makes it possible to further suppress the temperature rise of the motor 1C and the decrease in the torque of the motor 1C. [Explanation of symbols]

[0062] 1, 1A, 1B, 1C motor 2, 2A housing 3 Motor stator 4, 4A Position Detector 5 Support member for position detector 6 Rotor 7 Shaft 21 Lower housing 22 Upper housing 23, 23A Upper housing 24, 25 Storage section 31 Stator core (iron core) 32 Motor coil 41 Resolver stator (detection stator) 41A Stator (detection stator) 42 Resolver rotor (detection rotor) 42A rotor (detection rotor) 43 Spacer 44 Wave washer 45 Spacer 51 Part 1 52 Part 2 53 Part 3 54 Part 4 61 Motor magnet 70 Through hole 71 Cylindrical part 72 Protrusion 73 Groove 74 Balancer 100 Bearings 101 Inner Circle 102 Rolling element 103 Outer Ring 110, 111, 112, 113, 114 volts 130, 131 Wiring holes 211 Bottom plate 212 Inner circumference side plate 213 Outer periphery plate 213b Through hole 221 Outer periphery 222 Connecting part 223 Inner circumference 231, 231A inner circumference 232, 232A connection part 233, 233A outer periphery 300 Suction joint 411 Winding section 411A Board 412A Magnetic flux detection element 421A Position Sensor Magnet 422A Support plate 711 Small diameter section 712 Large diameter section Ax center axis

Claims

1. A shaft extending in an axial direction of a central axis and rotatable in a direction around the central axis; a motor magnet disposed on an outer circumferential side of the shaft and rotatable together with the shaft; a non-rotatable motor stator disposed facing the outer periphery of the motor magnet and including a motor coil; a position detector support member that extends from a radially inner side toward a radially outer side to a position overlapping with the motor coil when viewed from the axial direction and is rotatable together with the shaft; a position detector including a detection rotor provided on the position detector support member and rotatable together with the shaft, and a detection stator disposed on an inner circumferential side of the detection rotor and non-rotatable; a housing that accommodates the motor magnet, the motor stator, the position detector support member, and the position detector therein, the detection rotor is disposed on one side of the motor coil in the axial direction and at a position overlapping the motor coil when viewed from the axial direction, the detection stator is disposed at a position overlapping with the motor magnet when viewed from the axial direction, the shaft has a protrusion that protrudes radially outward and to which the motor magnet is attached; A recessed groove is provided on one side of the protrusion in the axial direction, In a cross section including the central axis, a balancer that adjusts balance during rotation of the shaft is accommodated in the groove, and the groove is covered with the position detector support member. Motor.

2. The housing includes a lower housing and an upper housing located on one side of the lower housing in an axial direction, the upper housing extends from a radially outer side to a radially inner side so as to cover the detection rotor and the detection stator from one axial side, The detection stator is attached to the upper housing. The motor according to claim 1 .

3. The position detector support member is disposed between the position detector and the motor magnet and the motor stator; 3. The motor according to claim 1 or 2.

4. The upper housing is connected to an outer ring of a bearing, The shaft is coupled to the inner ring of the bearing, The shaft is rotatably mounted. The motor according to claim 2.

5. the position detector support member has a first portion extending radially outward from an outer periphery of the shaft, a second portion extending from the first portion to one side in the axial direction, and a third portion extending radially outward from the second portion, The detection rotor is fixed to the third portion. A motor according to any one of claims 1 to 4.

6. The housing has a through hole, and a suction joint to which a suction device can be connected is fitted into the through hole. A motor according to any one of claims 1 to 5.

7. The position detector support member is made of a non-magnetic material. A motor according to any one of claims 1 to 6.

8. The detection stator and the detection rotor are disposed opposite to each other in a radial direction. A motor according to any one of claims 1 to 7.

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