Motor

Abstract

To provide a motor capable of significantly suppressing vibration and abnormal noise while rotating.SOLUTION: A motor includes: a rotatable shaft; a first rotating member fixed on one side in the axial direction of the shaft, a second rotating member fixed on the other side in the axial direction of the shaft; a motor magnet; a motor stator; and a housing storing the motor stator and having a motor fixing part for fixing the motor. A first radial-direction distance between the motor fixing part and a central axis is larger than a second radial-direction distance between a radial-direction outer end of the first rotating member and the central axis and is larger than a third radial-direction distance between the radial-direction outer end of the second rotating member and the central axis.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] The disk drive device disclosed in Patent Document 1 includes a turntable that is rotated by a motor. If the center of gravity of the rotor in the motor is misaligned with respect to the rotation axis, vibration or abnormal noise may occur when the motor rotates. Therefore, the motor in Patent Document 1 is provided with a balancer (steel balls) to correct the imbalance of rotation. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-203472 A Summary of the Invention [Problem to be solved by the invention]

[0004] It is desirable to further reduce the vibrations and abnormal noise that occur when the motor rotates.

[0005] The present disclosure has been made in consideration of the above-mentioned problems, and has an object to provide a motor that is capable of further suppressing vibrations and abnormal noise during rotation. [Means for solving the problem]

[0006] In order to achieve the above-mentioned object, a motor according to one embodiment includes a shaft extending in the axial direction of a central axis and rotatable in a direction around the central axis, a first rotating member fixed to one side of the shaft in the axial direction, a second rotating member fixed to the other side of the shaft in the axial direction, a motor magnet arranged on the outer periphery of the shaft and rotatable together with the shaft, a non-rotatable motor stator arranged opposite the outer periphery of the motor magnet and including a motor coil, and a housing that accommodates the motor stator and has a motor fixing portion that fixes the motor, wherein a first radial distance between the motor fixing portion and the central axis is greater than a second radial distance between a radial outer end of the first rotating member and the central axis, and is greater than a third radial distance between a radial outer end of the second rotating member and the central axis.

[0007] Thus, the motor of the present disclosure is a so-called inner rotor type motor in which the shaft located at the radial center rotates. That is, the housing is fixed to the mounting body via the motor fixing part, and the shaft located on the radial inner side of the housing rotates relative to the housing. The first rotating member and the second rotating member rotate together with the shaft. Therefore, for example, if the first rotating member and the second rotating member rotate with the center of gravity of the first rotating member and the second rotating member shifted from the central axis, the central axis of the shaft may tilt with respect to the central axis when the shaft is not rotating, which is called whirling, and this whirling may cause vibration or abnormal noise of the motor.

[0008] Here, since the first radial distance is greater than the second radial distance and the third radial distance, the motor fixing part is located radially outward of the radial outer ends of the first rotating member and the second rotating member, and therefore, even if the shaft whirls, the housing can be fixed to the mounting base more firmly against the whirling than when the motor fixing part is located radially inward of the radial outer ends of the first rotating member and the second rotating member.

[0009] As described above, according to the present disclosure, a motor is provided that is capable of further suppressing vibrations and abnormal noise during rotation.

[0010] In a preferred embodiment, at least one of the first rotating member and the second rotating member is provided with a groove capable of accommodating a balancer. By accommodating the balancer in the groove, the center of gravity of the first rotating member or the second rotating member is brought closer to the central axis, thereby further suppressing vibrations and abnormal noises during rotation of the motor.

[0011] In a preferred embodiment, the recessed groove is located at a radially outer end of the first rotating member or the second rotating member.

[0012] Providing the balancer as far outward as possible in the radial direction allows for a greater adjustment of the center of gravity of the first rotating member or the second rotating member, and therefore a greater amount of balance correction. Therefore, according to the present disclosure, vibrations and abnormal noises during rotation can be further suppressed.

[0013] In a preferred embodiment, the housing comprises a first housing located on one side in the axial direction and a second housing located on the other side in the axial direction relative to the first housing, the first rotating member is arranged on one side in the axial direction relative to the first housing, the first housing has an extension portion extending along a radial direction and a bent portion bent at a radially outer end of the extension portion to extend to the other side in the axial direction, the first rotating member has a plate-shaped portion extending along the extension portion and a first flange bent at a radially outer end of the plate-shaped portion to extend along the bent portion, a first gap extending in the radial direction is provided between the extension portion and the plate-shaped portion, a second gap extending in the axial direction is provided between the first flange and the bent portion, and a labyrinth is formed at the intersection of the first gap and the second gap.

[0014] In this manner, in the present disclosure, a labyrinth is provided between the first housing and the first rotating member, and the labyrinth can prevent foreign matter from entering the interior of the motor and particles from scattering from the interior of the motor.

[0015] In a preferred embodiment, the extension portion of the first housing has a recess that is recessed toward the other side in the axial direction, and the plate-shaped portion of the first rotating member has a convex portion that protrudes toward the other side in the axial direction and is inserted into the recess, and a gap is provided between these convex portions and the recesses, and a labyrinth is formed by the gap.

[0016] Since this labyrinth is formed by the gaps between the recesses and protrusions, it has a more intricate structure and the so-called labyrinth effect is also enhanced, which further prevents foreign matter from entering the motor and particles from scattering from the inside of the motor.

[0017] In a preferred embodiment, the second rotating member is arranged on the other side of the axial direction than the second housing, the second housing has an extension portion extending along a radial direction and a bent portion bent at a radially outer end of the extension portion to extend to one side in the axial direction, the second rotating member has a plate-shaped portion extending along the extension portion and a second flange bent at a radially outer end of the plate-shaped portion to extend along the bent portion, a third gap extending in the radial direction is provided between the extension portion and the plate-shaped portion, a fourth gap extending in the axial direction is provided between the second flange and the bent portion, and a labyrinth is formed at the intersection of the third gap and the fourth gap.

[0018] In this manner, in the present disclosure, a labyrinth is provided between the second housing and the second rotating member, and the labyrinth can prevent foreign matter from entering the interior of the motor and particles from scattering from the interior of the motor.

[0019] In a preferred embodiment, the extension portion of the second housing has a recess that is recessed toward one side in the axial direction, and the plate-shaped portion of the second rotating member has a convex portion that protrudes toward one side in the axial direction and is inserted into the concave portion, and a gap is provided between these convex portions and the concave portions, and a labyrinth is formed by the gap.

[0020] Since this labyrinth is formed by the gaps between the recesses and protrusions, it has a more intricate structure and the so-called labyrinth effect is also enhanced, which further prevents foreign matter from entering the motor and particles from scattering from the inside of the motor. Effect of the Invention

[0021] According to the present disclosure, a motor is provided that is capable of further suppressing vibrations and abnormal noise during rotation. [Brief description of the drawings]

[0022] [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 an enlarged cross-sectional view of a portion of FIG. [Diagram 5] FIG. 5 is a cross-sectional view that illustrates a schematic overall configuration of a motor according to a third embodiment. [Figure 6] FIG. 6 is an enlarged cross-sectional view of a portion of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0023] 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.

[0024] [First embodiment] First, a first embodiment will be described. Fig. 1 is a cross-sectional view showing a schematic overall configuration of a motor according to the 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.

[0025] 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, a shaft 7, a first rotating member 500, and a second rotating member 600. The motor 1 has an annular shape centered on a central axis Ax. In the embodiment, one side in the axial direction of the central axis Ax is the upper side, which is indicated as UP in the drawings. The other side in the axial direction is the lower side, which is 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.

[0026] The housing 2 includes a lower housing (second 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.

[0027] The lower housing 21 includes an extension portion 211, an inner circumferential side plate 212, a bent portion 214, and an outer circumferential side plate 213. The extension portion 211 extends in a radial direction perpendicular to the central axis Ax. An inner circumferential side plate 212 is provided at an inner circumferential end of the extension portion 211, protruding toward an upper side UP, which is one side in the axial direction. A bent portion 214 is provided at an outer circumferential end of the extension portion 211, protruding toward the upper side UP. The extension portion 211 and the outer circumferential side plate 213 are connected via the bent portion 214. The outer circumferential side plate 213 is provided above the bent portion 214. In other words, the extension portion 211 extends radially outward, and is bent at a radially outer end of the extension portion 211 to form the bent portion 214 extending upward (one side in the axial direction). The axial height (height in the vertical direction) of the outer circumferential side plate 213 is greater than the axial height of the inner circumferential side plate 212. Housing mounting holes (motor fixing portion) 124, 125 are provided in the lower portion of the outer circumferential side plate 213. The motor 1 can be mounted to a mounting target body via the housing mounting holes (motor fixing portion) 124, 125.

[0028] The upper housing (first housing) 22 includes an outer peripheral portion 221, a bent portion 222, and an extended portion 223. The upper housing (first housing) 22 is a lid-like member that covers an upper opening of the lower housing 21. An outer peripheral end portion of the outer peripheral portion 221 is fitted into a recess 213a at an upper portion of an outer peripheral side plate 213 of the lower housing 21, and is fixed to an upper portion of the outer peripheral side plate 213 via a bolt 110. The bent portion 222 extends upward from an inner peripheral side of the outer peripheral portion 221. An extended portion 223 extends radially inward from an upper end portion of the bent portion 222, that is, in a direction approaching the central axis Ax. In other words, the extended portion 223 extends radially outward along the radial direction, and is bent at a radially outer end of the extended portion 223 to extend downward (the other side in the axial direction).

[0029] The upper housing 23 has an inner circumferential portion 231, a connecting portion 232, and an outer circumferential portion 233. The inner circumferential portion 231 extends in the axial direction (the up-down direction in FIG. 1). An inner circumferential end portion of the extension portion 223 of the upper housing 22 is fixed to an upper end of the inner circumferential portion 231 via a bolt 114. A connecting portion 232 extends radially outward from a lower end of the inner circumferential portion 231. A outer circumferential 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).

[0030] 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 a bolt hole 121, and the lower end surface of the shaft 7 is provided with a bolt hole 123. A female thread is formed on the inner peripheral surface of the bolt holes 121 and 123, and the female thread meshes with a male thread on the outer periphery of the bolts 115 and 116.

[0031] A first rotating member 500 is attached to an upper surface 71a of the cylindrical portion 71. The first rotating member 500 has a cylindrical shape that extends in the circumferential direction around the central axis Ax.

[0032] The first rotating member 500 includes an annular portion 510, a plate-shaped portion 520, and a first flange 530. The annular portion 510 has an upper surface 511, a lower surface 512, an inner circumferential surface 513, and an outer circumferential surface 514. The upper surface 511 and the lower surface 512 overlap with the upper surface 71a of the cylindrical portion 71 when viewed from above. The annular portion 510 is provided with a through hole 515. The bolt 115 passes through the through hole 515 and engages with the bolt hole 121. As a result, the first rotating member 500 is fastened to the upper surface 71a of the cylindrical portion 71. The inner circumferential surface 513 is flush with the inner circumferential surface 71c of the cylindrical portion 71. The inner circumferential surface 513 and the outer circumferential surface 514 are cylindrical surfaces extending in the circumferential direction around the central axis Ax. Lower surface 512 abuts against upper surface 71a. An object mounting hole (mounting portion) 120 that opens upward is provided in annular portion 510. A bolt can be engaged with object mounting hole 120, and the object is mounted to object mounting hole 120 via the bolt. The object is, for example, a polishing machine of a semiconductor manufacturing device.

[0033] The plate-like portion 520 has an upper surface 521, a lower surface 522, an inner peripheral surface 523, and an outer peripheral surface 524. The upper surface 521 is located lower than the upper surface 511. A groove 525 recessed downward (in the axial direction of the central axis Ax) is provided at the radially outer end of the upper surface 521. A balancer 526 is housed in the groove 525. The balancer 526 adjusts the center of gravity of the first rotating member 500 to correct the balance when the shaft 7 rotates. The balancer 526 is, for example, an epoxy resin. The inner peripheral surface 523 and the outer peripheral surface 524 are cylindrical surfaces extending in the circumferential direction around the central axis Ax. The inner peripheral surface 523 abuts against the outer peripheral surface of the upper end of the small diameter portion 711.

[0034] The first flange 530 extends downward from a radially outer end of the plate-shaped portion 520. The first flange 530 is cylindrical and extends in the circumferential direction around the central axis Ax. The first flange 530 has a lower surface 532, an inner peripheral surface 533, and an outer peripheral surface 534. The lower surface 532 is parallel to the upper surface 521 and the lower surface 522 of the plate-shaped portion 520. The inner peripheral surface 533 of the first flange 530 is disposed opposite to the outer peripheral surface 222a of the bent portion 222.

[0035] Here, a first gap 540 is provided between an upper surface 223a of the extension portion 223 of the upper housing 22 and a lower surface 522 of the plate-shaped portion 520. In addition, a second gap 541 is provided between an outer peripheral surface 222a of the bent portion 222 and an inner peripheral surface 533 of the first flange 530. The first gap 540 and the second gap 541 communicate with each other via an intersection portion 542. The first gap 540 extends along the radial direction, and the second gap 541 extends along the axial direction, and a labyrinth 543 is formed at the intersection portion 542.

[0036] A second rotating member 600 is attached to a lower surface 71b of the cylindrical portion 71. The second rotating member 600 has a cylindrical shape that extends in the circumferential direction around the central axis Ax.

[0037] The second rotating member 600 includes an annular portion 610, a plate-shaped portion 620, and a second flange 630. The annular portion 610 has a lower surface 611, an upper surface 612, an inner circumferential surface 613, and an outer circumferential surface 614. The lower surface 611 and the upper surface 612 overlap with the lower surface 71b of the cylindrical portion 71 when viewed from below. The annular portion 610 is provided with a through hole 615. The bolt 116 passes through the through hole 615 and engages with the bolt hole 123. As a result, the second rotating member 600 is fastened to the lower surface 71b of the cylindrical portion 71. The inner circumferential surface 613 is flush with the inner circumferential surface 71c of the cylindrical portion 71. The inner circumferential surface 613 and the outer circumferential surface 614 are cylindrical surfaces extending in the circumferential direction around the central axis Ax. The upper surface 612 abuts against the lower surface 71b. An object mounting hole (mounting portion) 122 that opens downward is provided in the annular portion 610. A bolt can be engaged with the object mounting hole 122, and the object is mounted to the object mounting hole 122 via the bolt.

[0038] The plate-shaped portion 620 has a lower surface 621, an upper surface 622, an inner peripheral surface 623, and an outer peripheral surface 624. The lower surface 621 is located above the lower surface 611. A groove 525A is provided on the radially inner side of the radially outer end of the plate-shaped portion 620. The groove 525A opens to the outer peripheral surface 624. A balancer 526 is housed in the groove 525A. The balancer 526 adjusts the center of gravity of the second rotating member 600 to correct the balance when the shaft 7 rotates.

[0039] The recessed groove 525A provided in the second rotating member 600 may be in the form of the recessed groove 525 provided in the first rotating member 500. Also, the recessed groove 525 provided in the first rotating member 500 may be in the form of the recessed groove 525A provided in the second rotating member 600. Furthermore, the recessed groove and the balancer may be provided in only one of the first rotating member 500 and the second rotating member 600.

[0040] The inner peripheral surface 623 and the outer peripheral surface 624 are cylindrical surfaces extending in the circumferential direction around the central axis Ax. The inner peripheral surface 623 abuts against the outer peripheral surface of the upper end portion of the small diameter portion 711. The second flange 630 extends upward from a radially outer end of the plate-shaped portion 620. The second flange 630 is cylindrical and extends in the circumferential direction around the central axis Ax. The second flange 630 has an upper surface 632, an inner peripheral surface 633, and an outer peripheral surface 634. The upper surface 632 is parallel to the lower surface 621 and the upper surface 622 of the plate-shaped portion 620. The inner peripheral surface 633 of the second flange 630 is disposed opposite to the outer peripheral surface 214a of the bent portion 214.

[0041] Here, a third gap 640 is provided between a lower surface 211a of the extension portion 211 of the lower housing 21 and an upper surface 622 of the plate-like portion 620. In addition, a fourth gap 641 is provided between an outer peripheral surface 214a of the bent portion 214 and an inner peripheral surface 633 of the second flange 630. The third gap 640 and the fourth gap 641 communicate with each other via an intersection portion 642. The third gap 640 extends along the radial direction, and the fourth gap 641 extends along the axial direction, and a labyrinth 643 is formed at the intersection portion 642.

[0042] 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.

[0043] Here, as shown in FIG. 2, the distance along the radial direction between the housing mounting holes 124, 125 and the central axis Ax is defined as the first radial distance L1. In FIG. 2, the distance along the radial direction from the radial center of the housing mounting hole 124 to the central axis Ax is defined as the first radial distance L1, but the distance along the radial direction from the radial center of the housing mounting hole 125 to the central axis Ax is also defined as the first radial distance L1. In addition, the distance along the radial direction between the outer circumferential surface 524 (radial outer end) of the plate-shaped portion 520 of the first rotating member 500 and the central axis Ax is defined as the second radial distance L2, and the distance along the radial direction between the outer circumferential surface 624 (radial outer end) of the plate-shaped portion 620 of the second rotating member 600 and the central axis Ax is defined as the third radial distance L3. Then, the first radial distance L1 is greater than the second radial distance L2 and the third radial distance L3.

[0044] 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. 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 extension portion 211 and the inner periphery side 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.

[0045] 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.

[0046] 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.

[0047] 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. The axial distance between the center of the motor magnet 61 in the axial direction (vertical direction) and the center of the plate-shaped portion 620 of the second rotating member 600 in the axial direction (vertical direction) is smaller than the axial distance between the center of the motor magnet 61 in the axial direction (vertical direction) and the center of the plate-shaped portion 520 of the first rotating member 500 in the axial direction (vertical direction). In other words, the second rotating member 600 is provided at a position closer to the motor magnet 61 in the axial direction than the first rotating member 500.

[0048] 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, the resolver rotor 42, the first rotating member 500, and the second rotating member 600. 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.

[0049] As described above, the motor 1 according to the first embodiment includes the shaft 7 extending in the axial direction of the central axis Ax and rotatable in the direction around the central axis Ax, the first rotating member 500 fixed to the upper side (upper side (one side in the axial direction)) of the shaft 7 and provided with the mount attachment hole (mounting portion) 120 for attaching an object to be mounted, the second rotating member 600 fixed to the lower side (the other side in the axial direction) of the shaft 7 and provided with the mount attachment hole (mounting portion) 122 for attaching an object to be mounted, and the motor 600 disposed on the outer circumferential side of the shaft 7 and rotatable together with the shaft 7. The motor comprises a magnet 61, a non-rotatable motor stator 3 arranged opposite the outer periphery of the motor magnet 61 and including a motor coil 32, and a housing which accommodates the motor stator 3 and has housing mounting holes (motor fixing portion) 124, 125 for fixing the motor 1, wherein a first radial distance L1 between the housing mounting holes (motor fixing portion) 124, 125 and the central axis Ax is greater than a second radial distance L2 between the radial outer end of the first rotating member 500 and the central axis Ax, and is also greater than a third radial distance L3 between the radial outer end of the second rotating member 600 and the central axis Ax.

[0050] Thus, the motor 1 of this embodiment is a so-called inner rotor type motor in which the shaft 7 on the radial center side rotates. That is, the housing 2 is fixed to a mounting body via the housing mounting holes (motor fixing portion) 124, 125, and the shaft 7 located on the radial inside of the housing 2 rotates. The first rotating member 500 and the second rotating member 600 rotate together with the shaft 7. Therefore, for example, if the first rotating member 500 and the second rotating member 600 rotate in a state in which the center of gravity of the first rotating member 500 and the second rotating member 600 is shifted from the central axis, the central axis Ax of the shaft 7 may tilt with respect to the central axis Ax when the shaft 7 is not rotating, that is, a so-called whirling may occur, and this whirling may cause vibration or abnormal noise of the motor 1.

[0051] Here, because the first radial distance L1 is greater than the second radial distance L2 and the third radial distance L3, the housing mounting holes (motor fixing portion) 124, 125 are located radially outward from the radial outer ends of the first rotating member 500 and the second rotating member 600. Therefore, even if the shaft 7 whirls, the housing 2 can be fixed to the mounting base more firmly against the whirling than in a case where the housing mounting holes (motor fixing portion) 124, 125 are located radially inward from the radial outer ends of the first rotating member 500 and the second rotating member 600.

[0052] As described above, according to this embodiment, a motor 1 is provided that is capable of further suppressing vibrations and abnormal noise during rotation.

[0053] The first rotating member 500 and the second rotating member 600 are provided with grooves 525, 525A capable of accommodating the balancer 526. By accommodating the balancer 526 in the grooves 525, 525A, vibrations and abnormal noises of the motor 1 during rotation can be further suppressed.

[0054] The grooves 525, 525A are located at the radially outer end of the first rotating member 500 or the second rotating member 600. Providing the balancer 526 as far outward as possible in the radial direction increases the amount of adjustment of the center of gravity of the entire motor 1, i.e., the amount of balance correction. This therefore makes it possible to further suppress vibrations and abnormal noise during rotation.

[0055] The housing 2 includes an upper housing (first housing) 22 located on the upper side (one side in the axial direction) and a lower housing (second housing) 21 located on the lower side (the other side in the axial direction) relative to the upper housing (first housing) 22. The first rotating member 500 is disposed on the upper side (one side in the axial direction) of the upper housing (first housing) 22. The upper housing (first housing) 22 includes an extension portion 223 extending along a radial direction and a lower housing (second housing) 21 bent at a radially outer end of the extension portion 223 to extend downward (toward the axis of the shaft). The first rotating member 500 has a plate-shaped portion 520 extending along the extension portion 223, and a first flange 530 bent at a radially outer end of the plate-shaped portion 520 and extending along the bent portion 222, a first gap 540 extending in the radial direction is provided between the extension portion 223 and the plate-shaped portion 520, and a second gap 541 extending in the axial direction is provided between the first flange 530 and the bent portion 222, and a labyrinth 543 is formed at an intersection 542 of the first gap 540 and the second gap 541.

[0056] In this manner, in this embodiment, a labyrinth 543 is provided between the upper housing (first housing) 22 and the first rotating member 500, and the labyrinth 543 can prevent foreign matter from entering the interior of the motor 1 and particles from scattering from the interior of the motor 1.

[0057] The housing 2 includes an upper housing (first housing) 22 located on the upper side (one side in the axial direction) and a lower housing (second housing) 21 located on the lower side (the other side in the axial direction) relative to the upper housing (first housing) 22. The second rotating member 600 is disposed below the lower housing (second housing) 21 (the other side in the axial direction). The lower housing (second housing) 21 includes an extension portion 211 extending along the radial direction and a radially outer end of the extension portion 211 bent to extend upward (in the axial direction). The second rotating member 600 has a plate-shaped portion 620 extending along the extension portion 211, and a second flange 630 bent at a radially outer end of the plate-shaped portion 620 and extending along the bent portion 214, a third gap 640 extending in the radial direction is provided between the extension portion 211 and the plate-shaped portion 620, and a fourth gap 641 extending in the axial direction is provided between the second flange 630 and the bent portion 214, and a labyrinth 643 is formed at an intersection 642 between the third gap 640 and the fourth gap 641.

[0058] In this manner, in this embodiment, a labyrinth 643 is provided between the lower housing (second housing) 21 and the second rotating member 600, and the labyrinth 643 can prevent foreign matter from entering the interior of the motor 1 and particles from scattering from the interior of the motor 1.

[0059] Moreover, the first rotating member 500 is attached to the upper part of the shaft 7 from above (one side in the axial direction) and then fastened with bolts 115. The second rotating member 600 is attached to the lower part of the shaft 7 from below (the other side in the axial direction) and then fastened with bolts 116. In this way, the first rotating member 500 and the second rotating member 600 are attached to the shaft 7 from the axial direction, making them easy to assemble. Then, balance adjustment is performed using the balancer 526 on the first rotating member 500, and balance adjustment is also performed using the balancer 526 on the second rotating member 600. In this manner, in this embodiment, balance adjustment is performed by two-surface correction on one side and the other side in the axial direction of the shaft 7, so that vibrations and abnormal noises during rotation of the motor 1 can be further suppressed.

[0060] [Second embodiment] Next, a second embodiment will be described with a focus on the first and second rotating members. Fig. 3 is a cross-sectional view showing a schematic overall configuration of a motor according to the second embodiment. Fig. 4 is a cross-sectional view showing an enlarged portion of Fig. 3.

[0061] The first rotating member 500A and the second rotating member 600A according to the second embodiment are different from the first rotating member 500 and the second rotating member 600 according to the first embodiment in that they do not have a first flange 530 and a second flange 630. This will be described in detail below.

[0062] 3 and 4, a first rotating member 500A according to the second embodiment is attached to an upper surface 71a of a cylindrical portion 71. The first rotating member 500A has a cylindrical shape extending in the circumferential direction around the central axis Ax.

[0063] The first rotating member 500A includes an annular portion 510 and a plate-shaped portion 520A.

[0064] The plate-shaped portion 520A has an upper surface 521A, a lower surface 522A, an inner peripheral surface 523A, and an outer peripheral surface 524A. The upper surface 521A is located lower than the upper surface 511. A groove 525 recessed downward (in the axial direction of the central axis Ax) is provided at the radially outer end of the plate-shaped portion 520A. A balancer 526 is housed in the groove 525. The inner peripheral surface 523A and the outer peripheral surface 524A are cylindrical surfaces extending in the circumferential direction around the central axis Ax. The inner peripheral surface 523A abuts against the outer peripheral surface of the upper end of the small diameter portion 711.

[0065] Here, a first gap 540 is provided between an upper surface 223a of the extension portion 223 of the upper housing 22 and a lower surface 522A of the plate-shaped portion 520A.

[0066] The second rotating member 600A is attached to the lower surface 71b of the cylindrical portion 71. The second rotating member 600A has a cylindrical shape that extends in the circumferential direction around the central axis Ax.

[0067] The second rotating member 600A includes an annular portion 610 and a plate-shaped portion 620A.

[0068] The plate-shaped portion 620A has a lower surface 621A, an upper surface 622A, an inner peripheral surface 623A, and an outer peripheral surface 624A. The lower surface 621A is located above the lower surface 611. A groove 525A is provided on the radially inner side of the radially outer end of the plate-shaped portion 620A. The groove 525A opens on the outer peripheral surface 624A side. A balancer 526 is housed in the groove 525A. The balancer 526 adjusts the balance when the shaft 7 rotates. The balancer 526 is, for example, an epoxy resin.

[0069] The recessed groove 525A provided in the second rotating member 600A may be in the form of the recessed groove 525 provided in the first rotating member 500A. Also, the recessed groove 525 provided in the first rotating member 500A may be in the form of the recessed groove 525A provided in the second rotating member 600A.

[0070] The inner peripheral surface 623A and the outer peripheral surface 624A are cylindrical surfaces extending in the circumferential direction around the central axis Ax. The inner peripheral surface 623A abuts against the outer peripheral surface of the upper end portion of the small diameter portion 711.

[0071] Here, a third gap 640 is provided between the lower surface 211a of the extension portion 211 of the lower housing 21 and the upper surface 622A of the plate-like portion 620A.

[0072] Here, as shown in FIG. 4, the distance along the radial direction between the housing mounting holes 124, 125 and the central axis Ax is defined as the first radial distance L1. In FIG. 4, the distance along the radial direction from the radial center of the housing mounting hole 124 to the central axis Ax is defined as the first radial distance L1, but the distance along the radial direction from the radial center of the housing mounting hole 125 to the central axis Ax is also defined as the first radial distance L1. In addition, the distance along the radial direction between the outer circumferential surface 524A (radial outer end) of the plate-shaped portion 520A of the first rotating member 500A and the central axis Ax is defined as the second radial distance L2, and the distance along the radial direction between the outer circumferential surface 624A (radial outer end) of the plate-shaped portion 620 of the second rotating member 600A and the central axis Ax is defined as the third radial distance L3. Then, the first radial distance L1 is greater than the second radial distance L2 and the third radial distance L3.

[0073] As described above, the motor 1A according to the second embodiment can also provide the same effects as the motor 1 according to the first embodiment. Note that the first rotating member 500A and the second rotating member 600A do not have the first flange 530 and the second flange 630 compared to the first rotating member 500 and the second rotating member 600, and therefore the weight and size of the motor 1A can be further reduced.

[0074] [Third embodiment] Next, a third embodiment will be described with a focus on the first and second rotating members. Fig. 5 is a cross-sectional view showing a schematic overall configuration of a motor according to the third embodiment. Fig. 6 is a cross-sectional view showing an enlarged portion of Fig. 5.

[0075] The first rotating member 500B and the second rotating member 600B according to the second embodiment are different from the first rotating member 500 and the second rotating member 600 according to the first embodiment in that they are provided with convex portions 545, 645. This will be described in detail below.

[0076] The first rotating member 500B is attached to an upper surface 71a of the cylindrical portion 71. The first rotating member 500B has a cylindrical shape that extends in the circumferential direction around the central axis Ax.

[0077] The first rotating member 500B includes a circular ring portion 510, a plate-shaped portion 520B, and a first flange 530.

[0078] The plate-like portion 520B has an upper surface 521B, a lower surface 522B, an inner peripheral surface 523B, and an outer peripheral surface 524B. The upper surface 521B is located lower than the upper surface 511. A groove 525 recessed downward (in the axial direction of the central axis Ax) is provided at the radially outer end of the upper surface 521B. A balancer 526 is housed in the groove 525. The inner peripheral surface 523B and the outer peripheral surface 524B are cylindrical surfaces extending in the circumferential direction around the central axis Ax. The inner peripheral surface 523B abuts against the outer peripheral surface of the upper end of the small diameter portion 711.

[0079] The lower surface 522B is provided with a convex portion 545 that protrudes downward. The convex portion 545 is rectangular in a cross section including the central axis Ax. The convex portion 545 is an annular body extending along the circumferential direction around the central axis Ax. The extension portion 223 of the upper housing 22 is provided with a concave portion 546 that is concave downward. The concave portion 546 is formed by concaving the upper surface 223a of the extension portion 223 downward. The concave portion 546 is rectangular in a cross section including the central axis Ax. The convex portion 545 is inserted into the concave portion 546. When the convex portion 545 is inserted into the concave portion 546, a gap is formed between the convex portion 545 and the concave portion 546. The gap between the convex portion 545 and the concave portion 546 forms a labyrinth 544.

[0080] Alternatively, a labyrinth may be formed by providing a recess in plate-like portion 520B, providing a protrusion in extension portion 223, and inserting the protrusion into the recess.

[0081] The first flange 530 extends downward from the radially outer end of the plate-shaped portion 520B.

[0082] The second rotating member 600B is attached to the lower surface 71b of the cylindrical portion 71. The second rotating member 600B has a cylindrical shape that extends in the circumferential direction around the central axis Ax.

[0083] The second rotating member 600B includes a circular ring portion 610, a plate-shaped portion 620B, and a second flange 630.

[0084] Plate-shaped portion 620B has lower surface 621B, upper surface 622B, inner peripheral surface 623B, and outer peripheral surface 624B. Lower surface 621B is located above lower surface 611. A groove 525A is provided on the radially inner side of the radially outer end of plate-shaped portion 620B. Groove 525A opens to the outer peripheral surface 624B side. Balancer 526 is housed in groove 525A.

[0085] The recessed groove 525A provided in the second rotating member 600B may be in the form of the recessed groove 525 provided in the first rotating member 500B. Also, the recessed groove 525 provided in the first rotating member 500B may be in the form of the recessed groove 525A provided in the second rotating member 600B. The inner peripheral surface 623B and the outer peripheral surface 624B are cylindrical surfaces extending in the circumferential direction around the central axis Ax. The inner peripheral surface 623B abuts against the outer peripheral surface of the upper end portion of the small diameter portion 711.

[0086] The upper surface 622B is provided with a convex portion 645 that protrudes upward. The convex portion 645 is rectangular in a cross section including the central axis Ax. The convex portion 645 is an annular body extending along the circumferential direction around the central axis Ax. The extension portion 211 of the lower housing 21 is provided with a concave portion 646 that is concave upward. The concave portion 646 is formed by concaving the lower surface 211a of the extension portion 211 upward. The concave portion 646 is rectangular in a cross section including the central axis Ax. The convex portion 645 is inserted into the concave portion 646. When the convex portion 645 is inserted into the concave portion 646, a gap is formed between the convex portion 645 and the concave portion 646. The gap between the convex portion 645 and the concave portion 646 forms a labyrinth 644.

[0087] Alternatively, a labyrinth may be formed by providing a recess in plate-like portion 620B, providing a protrusion in extension portion 211, and inserting the protrusion into the recess.

[0088] The second flange 630 extends upward from the radially outer end of the plate-shaped portion 620B.

[0089] Here, as shown in FIG. 6, the distance along the radial direction between the housing mounting holes 124, 125 and the central axis Ax is defined as the first radial distance L1. In FIG. 6, the distance along the radial direction from the radial center of the housing mounting hole 124 to the central axis Ax is defined as the first radial distance L1, but the distance along the radial direction from the radial center of the housing mounting hole 125 to the central axis Ax is also defined as the first radial distance L1. In addition, the distance along the radial direction between the outer circumferential surface 524B (radial outer end) of the plate-shaped portion 520B of the first rotating member 500B and the central axis Ax is defined as the second radial distance L2, and the distance along the radial direction between the outer circumferential surface 624B (radial outer end) of the plate-shaped portion 620 of the second rotating member 600B and the central axis Ax is defined as the third radial distance L3. Then, the first radial distance L1 is greater than the second radial distance L2 and the third radial distance L3.

[0090] As described above, in the motor 1B of the third embodiment, the extension portion 223 of the upper housing (first housing) 22 has a recess 546 recessed downward (the other axial side), and the plate-shaped portion 520 of the first rotating member 500 has a convex portion 545 that protrudes downward (the other axial side) and is inserted into the recess 546, and a gap is provided between these convex portions 545 and the recess 546, and the gap forms a labyrinth 544. Since this labyrinth 544 is formed by the gap between the recessed portion 546 and the protruding portion 545, it has a more complicated structure and the so-called labyrinth effect is also enhanced. Therefore, it is possible to further suppress the intrusion of foreign matter into the inside of the motor 1B and the scattering of particles from the inside of the motor 1B.

[0091] The extension portion 211 of the lower housing (second housing) 21 has a recess 646 that is recessed toward the upper side (one side in the axial direction), and the plate-shaped portion 620 of the second rotating member 600 has a protrusion 645 that protrudes toward the upper side (one side in the axial direction) and is inserted into the recess 646, and a gap is provided between these protrusions 645 and recesses 646, and a labyrinth 644 is formed by this gap.

[0092] In this manner, in this embodiment, labyrinth 644 formed by the gap between recessed portion 646 and protruding portion 645 has a more intricate structure, and the so-called labyrinth effect is also enhanced. Therefore, it is possible to further suppress the intrusion of foreign matter into motor 1B and the scattering of particles from inside motor 1B. [Explanation of symbols]

[0093] 1, 1A, 1B motor 2. Housing 3 Motor stator 4 Position detector 5 Support member for position detector 6 Rotor 7 Shaft 21 Lower housing (second housing) 22 Upper housing (first housing) 23 Upper housing 24, 25 Storage section 31 Stator core (iron core) 32 Motor coil 41 Resolver stator (detection stator) 42 Resolver 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 71a Top side 71b Bottom side 71c Inner surface 72 Protrusion 73 Groove 74 Balancer 100 Bearings 101 Inner Circle 102 Rolling element 103 Outer Ring 110, 111, 112, 113, 114, 115, 116 Volts 120, 122 Mounting hole (mounting part) 121, 123 Bolt holes 124, 125 Housing mounting holes (motor fixing part) 211 Extension section 211a Bottom side 212 Inner circumference side plate 213 Outer periphery plate 213a Depression 214 Bend 214a Outer surface 221 Outer periphery 222 Bend 222a Outer surface 223 Extension section 223a Top side 231 Inner circumference 232 Connecting part 233 Outer periphery 411 Winding section 500, 500A, 500B First rotating member 510 Ring 511 Top surface 512 Bottom surface 513 Inner surface 514 Outer surface 515 Through hole 520, 520A, 520B Plate-shaped part 521, 521A, 521B top surface 522, 522A, 522B bottom side 523, 523A, 523B inner surface 524, 524A, 524B outer surface 525, 525A groove 526 Balancer 530 First flange 532 Bottom surface 533 Inner surface 534 Outer surface 540 1st gap 541 2nd gap 542 Intersection 543 Labyrinth 544 Labyrinth 545 Convex 546 Recess 600, 600A, 600B Second rotating member 610 Circular Ring 611 Bottom surface 612 Top 613 Inner surface 614 Outer surface 615 Through hole 620 Plate-shaped part 621 Bottom surface 622 Top 623 Inner surface 624 Outer surface 630 Second flange 632 Top surface 633 Inner surface 634 Outer surface 640 Third gap 641 4th gap 642 Intersection 643 Labyrinth 644 Labyrinth 645 Convex 646 Recess 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 first rotating member fixed to one side of the shaft in the axial direction; a second rotating member fixed to the other side of the shaft in the axial direction; 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 housing that accommodates the motor stator and has a motor fixing portion that fixes the motor, A first radial distance between the motor fixing portion and the central axis is a second radial distance between the radially outer end of the first rotating member and the central axis, and a third radial distance between the radially outer end of the second rotating member and the central axis, At least one of the first rotating member and the second rotating member is provided with a recessed groove capable of accommodating a balancer, The groove is located at a radially outer end of the first rotating member or the second rotating member. Motor.

2. the housing includes a first housing located on one side in the axial direction and a second housing located on the other side in the axial direction relative to the first housing, the first rotating member being disposed on the one side in the axial direction relative to the first housing, The first housing has an extension portion extending along a radial direction and a bent portion bent at a radially outer end of the extension portion to extend to the other side in the axial direction, The first rotating member has a plate-like portion extending along the extension portion, and a first flange bent at a radially outer end of the plate-like portion and extending along the bent portion, A first gap extending in the radial direction is provided between the extension portion and the plate-shaped portion, A second gap extending in the axial direction is provided between the first flange and the bent portion, A labyrinth is formed at an intersection of the first gap and the second gap. The motor according to claim 1 .

3. The extension portion of the first housing has a recess that is recessed toward the other side in the axial direction, the plate-shaped portion of the first rotating member has a protrusion that protrudes toward the other side in the axial direction and is inserted into the recess, A gap is provided between the protrusion and the recess, and the gap forms a labyrinth. The motor according to claim 2.

4. the second rotating member is disposed on the other side of the second housing in the axial direction, The second housing has an extension portion extending along a radial direction and a bent portion bent at a radially outer end of the extension portion to extend to one side in the axial direction, The second rotating member has a plate-like portion extending along the extension portion, and a second flange bent at a radially outer end of the plate-like portion and extending along the bent portion, A third gap extending in the radial direction is provided between the extension portion and the plate-shaped portion, A fourth gap extending in the axial direction is provided between the second flange and the bent portion, A labyrinth is formed at an intersection of the third gap and the fourth gap.

4. The motor according to claim 2 or 3.

5. The extension portion of the second housing has a recess that is recessed toward one side in the axial direction, the plate-shaped portion of the second rotating member has a protrusion that protrudes to one side in the axial direction and is inserted into the recess, A gap is provided between the protrusion and the recess, and the gap forms a labyrinth.

5. The motor according to claim 4.

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