Motor device

Abstract

To make it possible to reduce the size and improve a layout of an object to be fixed.SOLUTION: A cross-sectional shape of a motor case 21 along a radial direction of a rotor 40 is formed in a square shape including first to fourth corner portions 24a to 24d, and a stator 30 includes a cylindrical core main body 32, first to fourth core protruding portions 33a to 33d that abut against the first to fourth corner portions 24a to 24d, a plurality of teeth 34, and coils wound around a plurality of teeth 34 for each phase. The rotor 40 includes a rotating shaft and a ring magnet provided on an outer peripheral portion of the rotating shaft, and U-phase, V-phase, and W-phase connection terminals Tu, Tv, and Tw electrically connected to coils provided for respective phases are disposed between the rotor 40 and the first to third corner portions 24a to 24c and on first to third line segments L1 to L3 connecting a rotation center C of the rotor 40 and the first to third corner portions 24a to 24c in the radial direction of the rotor 40.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] The present invention relates to a motor device having a stator and a rotor. [Background technology]

[0002] For example, Patent Document 1 describes a brushless motor that includes a stator fixed to a housing and a rotor that rotates relative to the stator. The brushless motor described in Patent Document 1 also includes molded bus bars formed by molding three bus bars with resin, as well as a terminal holder with a connector portion and a cover. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2023-125684 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the brushless motor described in Patent Document 1, relatively thick molded bus bars are stacked in the axial direction of the stator, making it difficult to further reduce the axial length of the brushless motor and make it more compact. Also, because the connectors on the terminal holder and cover partially protrude in the radial direction of the housing, the layout flexibility of the brushless motor relative to the object to which it is fixed is poor.

[0005] An object of the present invention is to provide a motor device that can be further miniaturized and that can be more easily laid out relative to an object to which it is fixed. [Means for solving the problem]

[0006] In one aspect of the motor device, the motor device has a stator fixed to the inside of a motor case and a rotor that rotates relative to the stator, wherein the cross-sectional shape of the motor case along the radial direction of the rotor is formed as a polygon with multiple corners, the stator has a cylindrical core body, a core protrusion provided on the outer periphery of the core body and abutting against the corners, a multiple of teeth provided on the inner periphery of the core body, and coils wound around the multiple teeth for each phase, the rotor has a rotating shaft that drives the object to be driven and a magnet provided on the outer periphery of the rotating shaft, and connection terminals electrically connected to each of the coils provided for each phase are arranged between the rotor and the corners and on a first line connecting the center of rotation of the rotor and the corners in the radial direction of the rotor. [Effects of the Invention]

[0007] According to the present invention, it is possible to realize a motor device that can be further miniaturized and that can be more easily laid out relative to an object to which it is fixed. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view showing a seat motor mounted on a vehicle. [Figure 2] 2 is a cross-sectional view taken along the axial direction of the rotation shaft of the seat motor of FIG. 1. FIG. [Figure 3] FIG. 3 is a cross-sectional view taken along line AA in FIG. 2. [Figure 4] 3 is a view taken along the arrow B in FIG. 2, showing a state in which a cover member has been removed. [Figure 5] FIG. 2 is a perspective view of the cover body as seen from the wiring unit side. [Figure 6] FIG. 2 is a perspective view of the cover body as seen from the sensor board side. [Figure 7] FIG. 2 is an exploded perspective view showing a rotor and first and second planetary gear reducers. [Figure 8] FIG. 2 is a perspective view showing a wiring unit. [Figure 9]10 is a diagram illustrating the layout of U-phase, V-phase, and W-phase connection terminals and a sensor connector connection portion. FIG. [Figure 10] FIG. [Figure 11] FIG. 10 is a diagram illustrating a power-on test of the electric motor unit. [Figure 12] FIG. 2 is a perspective view showing an electric motor unit, a wiring unit, and a cover member. [Figure 13] 10A to 10C are diagrams illustrating a procedure for connecting a wiring unit to an electric motor unit. [Figure 14] 10A to 10C are diagrams illustrating a procedure for connecting the reduction mechanism to the electric motor. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0010] Figure 1 is a perspective view showing a seat motor mounted on a vehicle, Figure 2 is a cross-sectional view along the axial direction of the rotation shaft of the seat motor in Figure 1, Figure 3 is a cross-sectional view along line AA in Figure 2, Figure 4 is a view taken along arrow B in Figure 2 showing the state with the cover member removed, Figure 5 is a perspective view of the cover main body seen from the wiring unit side, Figure 6 is a perspective view of the cover main body seen from the sensor board side, Figure 7 is an exploded perspective view showing the rotor and first and second planetary gear reducers, Figure 8 is a perspective view of the wiring unit, and Figure 9 is a diagram explaining the arrangement of the U-phase, V-phase, and W-phase connection terminals and the sensor connector connection part.

[0011] <Outline of the electric seat> The seat motor 10 shown in Fig. 1 is a drive source built into an electric seat installed in a vehicle such as an automobile. Specifically, the seat motor 10 drives a reclining mechanism for the backrest, a sliding mechanism that moves the electric seat back and forth, and a lifting mechanism that raises and lowers the seat. This allows the driver to adjust the posture and position of the electric seat to their preferred driving position by operating an operation switch located, for example, on the side of the electric seat.

[0012] The seat motor 10 has a wiring unit 90 equipped with a connector connection portion 91. The connector connection portion 91 is electrically connected to the in-vehicle controller CR, and a power supply wiring 92 and a signal wiring 93 are arranged between the connector connection portion 91 and the electric motor section 20 that forms the seat motor 10. Here, the power supply wiring 92 supplies a drive current to the electric motor section 20, and the signal wiring 93 sends a sensor signal indicating the rotation state of the electric motor section 20 to the in-vehicle controller CR.

[0013] This allows the in-vehicle controller CR to store multiple driving positions (electric seat positions) corresponding to drivers of different physiques, and the driver can then call up the stored driving position according to his or her preference.

[0014] The seat motor 10 corresponds to the motor device in the present invention.

[0015] <Seat motor> 1 to 9, the seat motor 10 includes an electric motor unit 20, a speed reduction mechanism unit 50, and a wiring unit 90. Specifically, the electric motor unit 20 and the speed reduction mechanism unit 50 are arranged coaxially. When connected to each other (as shown in FIGS. 1 and 2), the electric motor unit 20 and the speed reduction mechanism unit 50 are formed in the shape of a short, rectangular rod.

[0016] <Electric motor section> The electric motor unit 20 has a motor case 21 that forms the outer shell of the electric motor unit 20. The motor case 21 is formed into a cylindrical shape with a bottom by deep drawing a steel plate, and as shown in Fig. 3, the cross section along the direction perpendicular to the longitudinal direction is formed into a substantially square shape.

[0017] Specifically, a bottom wall 22 is provided on the side (left side in FIG. 2) where the speed reduction mechanism 50 is provided in the longitudinal direction of the motor case 21. As shown in FIGS. 3, 4, and 9, the motor case 21 also includes first, second, third, and fourth side walls 23a, 23b, 23c, and 23d.

[0018] First side wall portion 23a and second side wall portion 23b are connected to each other via first corner portion 24a, and second side wall portion 23b and third side wall portion 23c are connected to each other via second corner portion 24b. Furthermore, third side wall portion 23c and fourth side wall portion 23d are connected to each other via third corner portion 24c, and fourth side wall portion 23d and first side wall portion 23a are connected to each other via fourth corner portion 24d.

[0019] In this way, the cross section of the motor case 21 along the radial direction of the rotor 40 is formed into a regular polygon (a square in this embodiment) with a total of four corners, that is, the first to fourth corners 24a to 24d. The first to fourth corners 24a to 24d correspond to the corners in the present invention.

[0020] Here, the first to fourth corners 24a to 24d are all arc-shaped, forming part of a circle of the same size centered on the rotation center C of the rotor 40. In other words, when the motor case 21 is viewed from the axial direction of the rotor 40, the first to fourth corners 24a to 24d are all formed in an arc-shaped shape. The tip portions of the first, second, third, and fourth core protrusions 33a, 33b, 33c, and 33d that form the outer periphery of the stator core 31 abut against the arc-shaped inner peripheries on the inside of the first to fourth corners 24a to 24d, respectively.

[0021] Here, the stator core 31 and the motor case 21 only contact each other at four locations, namely the tip ends of the first to fourth core protrusions 33a to 33d. A small gap (not shown in detail) is formed in other areas between the stator core 31 and the motor case 21. This prevents the press-fit load of the stator core 31 into the motor case 21 from becoming too large, improving the ease of assembly of the electric motor section 20. The strength of the fixation of the stator core 31 to the motor case 21 is sufficiently ensured by a certain level of press-fit load between the stator core 31 and the motor case 21.

[0022] 2, a bearing support cylinder 22a is integrally provided in the center of the bottom wall portion 22 that forms the motor case 21. An outer ring 11a of the first ball bearing 11 is fixed to the bearing support cylinder 22a of the bottom wall portion 22 by press fitting.

[0023] Specifically, approximately two-thirds of the axial portion of the first ball bearing 11 on the side where the electric motor unit 20 is provided (the right side in FIG. 2) is press-fitted into the bearing support cylinder 22a. Also, approximately one-third of the axial portion of the first ball bearing 11 on the side where the speed reduction mechanism unit 50 is provided is exposed (protrudes) from the bearing support cylinder 22a toward the side where the speed reduction mechanism unit 50 is provided.

[0024] Here, first ball bearing 11 rotatably supports the side of rotating shaft 41 in the axial direction where speed reduction mechanism 50 is provided, and inner ring 11b of first ball bearing 11 is attached to the side of rotating shaft 41 where speed reduction mechanism 50 is provided. Specifically, inner ring 11b of first ball bearing 11 is attached to rotating shaft 41 so as to be movable only in the axial direction of rotating shaft 41.

[0025] 2, a plurality of steel balls 11c are arranged between an outer ring 11a arranged on the radially outer side and an inner ring 11b arranged on the radially inner side of the first ball bearing 11. This allows the outer ring 11a and the inner ring 11b to rotate smoothly relative to each other via the steel balls 11c.

[0026] Here, in the axial direction of the rotating shaft 41 (rotor 40), the side where the wiring unit 90 of the seat motor 10 is arranged (right side in Figure 2) is defined as the "one axial (longitudinal) side," and the side where the reduction mechanism part 50 of the seat motor 10 is arranged (left side in Figure 2) is defined as the "other axial (longitudinal) side."

[0027] 2, a pair of screw holes 22b (only one is shown in the figure) is provided in the bottom wall portion 22. Specifically, the pair of screw holes 22b are arranged opposite each other with the bearing support cylinder 22a at the center. A fixing screw S (see FIG. 14) for fixing the speed reduction mechanism portion 50 to the electric motor portion 20 is screwed into each screw hole 22b.

[0028] 2, an opening 25 is provided on one axial side of motor case 21, i.e., on the side opposite to bottom wall portion 22. Stator 30 and rotor 40 are fitted inside motor case 21 through this opening 25.

[0029] <Stator> 2 to 4 and 9, a stator 30 is fixed inside the motor case 21. Specifically, the stator 30 includes a stator core 31 formed into a generally cylindrical shape by laminating thin steel plates made of a ferromagnetic material. The stator core 31 is fixed inside the motor case 21 by being press-fitted.

[0030] 3 and 9, the stator core 31 includes a cylindrical core body 32. When viewed from the axial direction of the core body 32, a first core protrusion 33a, a second core protrusion 33b, a third core protrusion 33c, and a fourth core protrusion 33d (four in total) are integrally formed on the outer periphery of the core body 32, each of which is formed in a substantially triangular shape.

[0031] The first to fourth core protrusions 33a to 33d correspond to the core protrusions of the present invention.

[0032] The tip portions of these first to fourth core protrusions 33a to 33d abut against the inner circumferential portions of the first to fourth corners 24a to 24d, respectively. Specifically, the tip portions of the first to fourth core protrusions 33a to 33d are in surface contact with the inner arc-shaped inner circumferential portions of the first to fourth corners 24a to 24d.

[0033] This prevents the inner circumferential portions of the first to fourth corner portions 24a to 24d from being damaged, such as by being scraped off, when the stator core 31 is press-fitted and fixed into the motor case 21. At the same time, it is possible to ensure a sufficient level of fixing strength of the stator core 31 to the motor case 21. Note that in Figures 3 and 9, dashed lines (reference lines) are drawn at the boundaries between the core body 32 and the first to fourth core protrusions 33a to 33d.

[0034] Here, the stator 30 including the stator core 31 is assembled through the opening 25 of the motor case 21, and an automatic assembly machine (not shown) is used for this assembly work. Therefore, the stator 30 is positioned at a specified position with high precision in the axial direction of the motor case 21.

[0035] Furthermore, the first to fourth core projections 33a to 33d are each provided with a boss BS for lamination fixation. That is, the laminated thin steel plates that form the stator core 31 are firmly fixed to one another by a total of four bosses BS. In this way, when the stator core 31 is viewed from the axial direction, the bosses BS for lamination fixation are disposed on the first to fourth core projections 33a to 33d, which have a relatively large area and are close to the outer periphery of the stator core 31. Furthermore, as shown in FIG. 9, the total of four bosses BS are disposed on the first to fourth line segments L1 to L4. This prevents distortion of the core body 32 and the teeth 34 when the bosses BS are formed, i.e., when the stator core 31 is assembled.

[0036] 3, a plurality of teeth 34 projecting toward the rotor 40 are integrally formed on the radially inner side, i.e., the inner periphery, of the core body 32. The number of teeth 34 is equal to the number of slots in the stator core 31, and is six in this embodiment. Of course, the number of teeth 34 can be set arbitrarily in accordance with the specifications of the electric motor unit 20.

[0037] An insulator 35 made of a resin material such as plastic is attached to each of the six teeth 34. A coil 36 is wound around each tooth 34 with the insulator 35 interposed therebetween. Coils 36 of the same phase are wound around each pair of teeth 34 that are arranged opposite each other with the rotor 40 at the center. That is, the coils 36 are arranged at equal intervals (60-degree intervals) around the circumferential direction of the stator 30 in the order of U-phase, V-phase, W-phase, U-phase, V-phase, and W-phase. In this way, each tooth 34 is wound with a coil 36 for each phase.

[0038] 4, the two coils 36 corresponding to each of the U, V, and W phases are electrically connected via crossover wires WT to U-phase connection terminals Tu, V-phase connection terminals Tv, and W-phase connection terminals Tw, which are provided corresponding to the U, V, and W phases, respectively. These U-phase, V-phase, and W-phase connection terminals Tu, Tv, and Tw are formed into a generally plate shape from brass or other material with excellent conductivity, and are disposed on one axial side of the stator 30. In other words, the U-phase, V-phase, and W-phase connection terminals Tu, Tv, and Tw are disposed near the opening 25 in the longitudinal direction of the motor case 21.

[0039] The U-phase, V-phase, and W-phase connection terminals Tu, Tv, and Tw correspond to the connection terminals in the present invention.

[0040] 9, the U-phase connecting terminal Tu is arranged on one axial side of the core body 32 in the axial direction of the rotor 40 so as to overlap with the core body 32. The U-phase connecting terminal Tu is also arranged between the rotor 40 and the first corner portion 24a in the radial direction of the rotor 40 (radial region AR1). The U-phase connecting terminal Tu is also arranged on a first line segment L1 that connects the rotation center C of the rotor 40 and the circumferential center of the first corner portion 24a of the motor case 21 in the radial direction of the rotor 40.

[0041] The V-phase connecting terminal Tv is also arranged on one axial side of the core body 32 in the axial direction of the rotor 40 so as to overlap with the core body 32. The V-phase connecting terminal Tv is also arranged between the rotor 40 and the second corner portion 24b in the radial direction of the rotor 40 (in a region having the same width dimension as the radial region AR1). Furthermore, the V-phase connecting terminal Tv is arranged on a second line segment L2 that connects the rotation center C of the rotor 40 and the circumferential center of the second corner portion 24b of the motor case 21 in the radial direction of the rotor 40.

[0042] The W-phase connecting terminal Tw is also arranged on one axial side of the core body 32 in the axial direction of the rotor 40 so as to overlap with the core body 32. The W-phase connecting terminal Tw is also arranged between the rotor 40 and the third corner 24c in the radial direction of the rotor 40 (in a region having the same width as the radial region AR1). The W-phase connecting terminal Tw is also arranged on a third line segment L3 that connects the rotation center C of the rotor 40 and the circumferential center of the third corner 24c of the motor case 21 in the radial direction of the rotor 40.

[0043] The first, second, and third line segments L1, L2, and L3, on which the U-phase, V-phase, and W-phase connecting terminals Tu, Tv, and Tw are respectively arranged, correspond to the first line segment in the present invention. Also, in Fig. 9, only the motor case 21 (dark hatching) and the stator core 31 (light hatching) are shown.

[0044] The U-phase, V-phase, and W-phase connecting terminals Tu, Tv, and Tw extend from one axial side of the stator 30 toward the wiring unit 90, and the U-phase power line UL, V-phase power line VL, and W-phase power line WL (see FIG. 8) that form the power supply wiring 92 are electrically connected to the wiring unit 90 sides of the U-phase, V-phase, and W-phase connecting terminals Tu, Tv, and Tw. Specifically, the U-phase, V-phase, and W-phase connecting terminals Tu, Tv, and Tw and the U-phase, V-phase, and W-phase power lines UL, VL, and WL are electrically connected to each other by soldering (see FIG. 13).

[0045] 4 and 9, assembly jig introduction spaces SP1, SP2, and SP3 are formed between the U-phase connecting terminal Tu and the first corner 24a, between the V-phase connecting terminal Tv and the second corner 24b, and between the W-phase connecting terminal Tw and the third corner 24c, respectively, in the radial direction of the rotor 40. Specifically, these assembly jig introduction spaces SP1, SP2, and SP3 face the first core protrusion 33a, the second core protrusion 33b, and the third core protrusion 33c in the axial direction of the stator 30.

[0046] 13, the assembly jig introduction spaces SP1, SP2, and SP3 are designed to allow a soldering iron TL to enter as an assembly jig when assembling the seat motor 10. In this way, the assembly jig introduction spaces SP1, SP2, and SP3 have the function of making it easy to solder (connect) the U-phase, V-phase, and W-phase connection terminals Tu, Tv, and Tw and the U-phase, V-phase, and W-phase power supply wires UL, VL, and WL, respectively.

[0047] 9, a portion of the sensor connector connection portion CN (see FIG. 5) mounted on the sensor board SB (see FIG. 6) is disposed between the rotor 40 and the fourth corner 24d in the radial direction of the rotor 40 (a region having the same width as the radial region AR1) and on a fourth line segment L4 connecting the rotation center C of the rotor 40 and the fourth corner 24d of the motor case 21. Furthermore, the sensor connector connection portion CN faces the fourth core protrusion 33d in the axial direction of the stator 30. That is, the sensor connector connection portion CN is disposed near the fourth corner 24d of the motor case 21. Therefore, the sensor connector connection portion CN can be disposed in the same axial position as the U-phase, V-phase, and W-phase connection terminals Tu, Tv, and Tw of the rotor 40, thereby preventing an increase in the axial dimension of the seat motor 10.

[0048] The fourth line segment L4 on which a part of the sensor connector connection portion CN is arranged corresponds to the second line segment in the present invention.

[0049] <Rotor> As shown in Figures 2 to 4 and 7, a rotor 40 is rotatably provided radially inside the stator 30 via a small gap (air gap). That is, the rotor 40 rotates relative to the stator 30. The rotor 40 includes a rotating shaft 41 made of a stepped round steel bar. Specifically, a small diameter portion 41a is integrally provided on the other axial side of the rotating shaft 41 (the left side in Figure 2), and a first sun gear 71 that forms the first planetary gear reducer 70 of the reduction mechanism 50 is fixed to the small diameter portion 41a. That is, the rotating shaft 41 drives the first planetary gear reducer 70.

[0050] One axial side of the rotating shaft 41 (the right side in FIG. 2) is rotatably supported by the second ball bearing 12, and the other axial side of the rotating shaft 41 is rotatably supported by the first ball bearing 11. In other words, the rotating shaft 41 is rotatably supported by the first ball bearing 11 and the second ball bearing 12 fixed to the motor case 21 and the cover member 13.

[0051] Furthermore, a rotor core 42 made of a plurality of laminated steel plates made of a ferromagnetic material is attached to the outer periphery of the rotating shaft 41. Specifically, the rotating shaft 41 is press-fitted into a fixing hole 42a of the rotor core 42, so that the rotor core 42 is firmly fixed to the rotating shaft 41 at a specified position in the axial direction.

[0052] Furthermore, a ring magnet 43 is fixed to the outer periphery of the rotor core 42 via an adhesive (not shown). That is, the ring magnet 43 is provided on the outer periphery of the rotating shaft 41 and is, for example, a neodymium magnet formed in a substantially cylindrical shape. The ring magnet 43 is also magnetized so that south poles, north poles, south poles, and north poles (a total of four poles) are arranged alternately in the circumferential direction. In other words, the electric motor unit 20 is a four-pole, six-slot brushless motor. Of course, the number of poles of the ring magnet 43 can be set arbitrarily according to the specifications of the electric motor unit 20.

[0053] The ring magnet 43 corresponds to the magnet in the present invention.

[0054] 2, the other axial side of ring magnet 43 abuts against abutting member 44 fixed to rotating shaft 41. On the other hand, one axial side of ring magnet 43 abuts against opposing member 45 fixed to rotating shaft 41. As a result, ring magnet 43 is accurately positioned at a specified position between abutting member 44 and opposing member 45 in the axial direction of rotating shaft 41.

[0055] Here, the other axial side of abutting member 44 abuts against inner ring 11b of first ball bearing 11. In other words, the axial position of rotating shaft 41 to which abutting member 44 is fixed is determined by first ball bearing 11. Furthermore, in addition to ring magnet 43, the other axial side of rotor core 42 also abuts against one axial side of abutting member 44. Therefore, the axial positions of rotor core 42 and ring magnet 43 are determined by first ball bearing 11 via abutting member 44.

[0056] On the other hand, an opposing member 45 is fixed to one axial side of the rotating shaft 41, and the opposing member 45 is disposed between the second ball bearing 12 and the ring magnet 43 in the axial direction of the rotating shaft 41. A coil spring SP is disposed on one axial side of the opposing member 45, and the coil spring SP is disposed in a state where an initial load is applied between the opposing member 45 and the inner ring 12b of the second ball bearing 12.

[0057] As a result, the rotor 40 and the coil spring SP are arranged so as to be tensioned between the inner ring 11b of the first ball bearing 11 and the inner ring 12b of the second ball bearing 12. This prevents the inner rings 11b and 12b of the first and second ball bearings 11 and 12 from rattling in the axial direction relative to their respective outer rings 11a and 12a. In other words, the spring force of the coil spring SP has the function of suppressing axial rattle of the first and second ball bearings 11 and 12, thereby reducing the operating noise of the seat motor 10.

[0058] <Cover material> 2, opening 25 of motor case 21 is closed by cover member 13. This prevents dust and other particles from entering the inside of motor case 21. Specifically, cover member 13 includes cover main body 14 and lid member 18.

[0059] 5 and 6, cover body 14 is formed in a substantially square bowl shape from a resin material such as plastic. Cover body 14 includes a substantially square cover bottom wall 15, and first, second, third, and fourth cover side walls 16a, 16b, 16c, and 16d that are integral with cover bottom wall 15.

[0060] When the electric motor unit 20 is assembled, the first cover side wall 16a is aligned with the first side wall portion 23a (see Figure 4) in the axial direction of the rotor 40, the second cover side wall 16b is aligned with the second side wall portion 23b (see Figure 4) in the axial direction of the rotor 40, the third cover side wall 16c is aligned with the third side wall portion 23c (see Figure 4) in the axial direction of the rotor 40, and the fourth cover side wall 16d is aligned with the fourth side wall portion 23d (see Figure 4) in the axial direction of the rotor 40.

[0061] The first cover side wall 16a and the second cover side wall 16b are connected to each other via the first cover corner 17a, the second cover side wall 16b and the third cover side wall 16c are connected to each other via the second cover corner 17b, the third cover side wall 16c and the fourth cover side wall 16d are connected to each other via the third cover corner 17c, and the fourth cover side wall 16d and the first cover side wall 16a are connected to each other via the fourth cover corner 17d.

[0062] Here, the first cover side wall 16a and the third cover side wall 16c, which are arranged opposite each other with the second ball bearing 12 at the center, are each provided with an engagement recess 14a. As shown in Fig. 4, two of the four engagement claws 21a of the motor case 21 are engaged with these engagement recesses 14a. Therefore, the cover main body 14 (cover member 13) is prevented from coming off the motor case 21 without any rattle.

[0063] 5, a bearing retaining cylinder 15a is integrally provided in the center of the cover bottom wall 15 of the cover main body 14, and the bearing retaining cylinder 15a extends in the axial direction of the rotor 40. The outer ring 12a (see FIG. 2) of the second ball bearing 12 is fixed by press fitting inside the bearing retaining cylinder 15a. In other words, the cover member 13 is provided with the bearing retaining cylinder 15a, and the bearing retaining cylinder 15a holds the second ball bearing 12 at its inner periphery.

[0064] The second ball bearing 12 rotatably supports one axial side of the rotating shaft 41, and an inner ring 12b of the second ball bearing 12 is attached to one axial side of the rotating shaft 41. Specifically, the inner ring 12b of the second ball bearing 12 is attached to the rotating shaft 41 so as to be movable only in the axial direction of the rotating shaft 41.

[0065] Here, in the radial direction of the second ball bearing 12, a plurality of steel balls 12c are arranged between the outer ring 12a, which is arranged radially outward, and the inner ring 12b, which is arranged radially inward. This allows the outer ring 12a and the inner ring 12b to rotate smoothly relative to each other via the steel balls 12c. Note that the first ball bearing 11 and the second ball bearing 12 are both general-purpose products, and the same parts are used. This makes it possible to simplify parts management and improve assembly efficiency.

[0066] In this way, cover member 13 that closes opening 25 supports second ball bearing 12 and corresponds to the bearing holder in the present invention. Also, second ball bearing 12 held by cover member 13 corresponds to the bearing in the present invention.

[0067] As shown in Fig. 5, a total of three power line retaining claws 15b are integrally provided on one axial side (the right side in Fig. 2) of the bearing retaining cylinder 15a. These power line retaining claws 15b protrude at a predetermined height radially outward from the bearing retaining cylinder 15a on that axial side of the bearing retaining cylinder 15a. In other words, a total of three power line retaining claws 15b are provided on the outer periphery of the bearing retaining cylinder 15a.

[0068] The three power line retaining claws 15b have the function of retaining the U-phase, V-phase, and W-phase power lines UL, VL, and WL (see FIG. 8) that are provided along the outer periphery of the bearing retaining cylinder 15a. Specifically, each power line retaining claw 15b has the function of restricting the U-phase, V-phase, and W-phase power lines UL, VL, and WL from moving in the axial direction of the bearing retaining cylinder 15a.

[0069] 2, when second ball bearing 12 held inside bearing retaining cylinder 15a is viewed from the radial direction of rotor 40, the U-phase, V-phase, and W-phase power supply lines UL, VL, and WL and portions of sensor connector connection portion CN overlap second ball bearing 12. In other words, portions of U-phase, V-phase, and W-phase power supply lines UL, VL, and WL and sensor connector connection portion CN are inside axial region AR2 of second ball bearing 12.

[0070] In this way, the second ball bearing 12, the U-phase, V-phase, and W-phase power supply lines UL, VL, and WL, and the sensor connector connection portion CN are each efficiently positioned at predetermined locations on the cover body 14, thereby suppressing an increase in the axial dimension of the cover body 14.

[0071] 5 and 6, the cover bottom wall 15 of the cover main body 14 is provided with a U-phase terminal insertion hole Hu, a V-phase terminal insertion hole Hv, and a W-phase terminal insertion hole Hw, through which the U-phase, V-phase, and W-phase connecting terminals Tu, Tv, and Tw (see FIG. 4) are inserted, respectively, in the axial direction of the rotor 40. The U-phase, V-phase, and W-phase terminal insertion holes Hu, Hv, and Hw are each formed in a substantially rectangular shape. In the radial direction of the rotor 40, the U-phase terminal insertion hole Hu is disposed between the bearing retaining tube 15a and the first cover corner 17a, the V-phase terminal insertion hole Hv is disposed between the bearing retaining tube 15a and the second cover corner 17b, and the W-phase terminal insertion hole Hw is disposed between the bearing retaining tube 15a and the third cover corner 17c.

[0072] Furthermore, a connector insertion hole Hc is provided in the cover bottom wall 15 of the cover main body 14, through which the sensor connector connection portion CN is inserted in the axial direction of the rotor 40. Like the U-phase, V-phase, and W-phase terminal insertion holes Hu, Hv, and Hw, the connector insertion hole Hc is also formed in a substantially rectangular shape. In the radial direction of the rotor 40, the connector insertion hole Hc is disposed between the bearing retaining cylinder 15a and the fourth cover side wall 16d and the fourth cover corner portion 17d.

[0073] As shown in Fig. 6, a sensor board SB is fixed to the cover bottom wall 15 on the side where the electric motor unit 20 is provided (the left side in Fig. 2). Specifically, the sensor board SB is fixed to the cover bottom wall 15 via board fixing screws SC. A through hole 26 through which one axial side of the rotating shaft 41 passes is provided in the center of the sensor board SB, and a total of three Hall elements 27a, 27b, and 27c corresponding to the U phase, V phase, and W phase are arranged near the through hole 26 so as to surround the periphery of the through hole 26. These Hall elements 27a, 27b, and 27c are arranged at equal intervals (120-degree intervals) around the circumferential direction of the through hole 26.

[0074] Furthermore, the three Hall elements 27a, 27b, and 27c in total face one axial side of the ring magnet 43 (see FIG. 2) in the axial direction of the rotor 40. As a result, each of the Hall elements 27a, 27b, and 27c generates a square wave signal at a respective timing in response to a change in magnetic pole accompanying the rotation of the ring magnet 43 (rotor 40).

[0075] Here, the three Hall elements 27a, 27b, and 27c are electrically connected to five sensor terminals ST that form the sensor connector connection portion CN. The sensor connector connection portion CN of the sensor board SB is electrically connected to a wiring connector 94 (see FIG. 8) of the wiring unit 90. As a result, square wave signals generated by the Hall elements 27a, 27b, and 27c are sent to the in-vehicle controller CR (see FIG. 1) via five sensor lines SW (see FIG. 8) that form the signal wiring 93. Therefore, the in-vehicle controller CR can grasp the rotation state of the rotor 40 and control the rotation direction and rotation speed of the rotor 40, as well as the stopping position of the rotor 40.

[0076] In this way, the sensor board SB having the Hall elements 27a, 27b, and 27c that detect the rotation state of the rotating shaft 41 (rotor 40) and the sensor connector connection part CN to which the on-board controller CR is connected is attached to the cover body 14 of the cover member 13. The Hall elements 27a, 27b, and 27c correspond to the rotation sensor in the present invention, the on-board controller CR corresponds to the controller in the present invention, and the sensor connector connection part CN corresponds to the controller connection part in the present invention.

[0077] <Deceleration mechanism section> 2, the speed reduction mechanism 50 includes a reducer case 51. The reducer case 51 is formed into a cylindrical shape with a bottom by deep drawing a steel plate, and the cross section along the direction perpendicular to the longitudinal direction thereof is substantially square.

[0078] An annular bottom wall 52 is provided on one axial side of the reducer case 51, and abuts against the bottom wall portion 22 of the motor case 21 in the axial direction of the rotating shaft 41. A fitting cylinder 52a into which the bearing support cylinder 22a of the motor case 21 is fitted is integrally provided in the center of the annular bottom wall 52. As a result, the reducer case 51 is arranged coaxially with the motor case 21.

[0079] The annular bottom wall 52 is provided with a pair of screw insertion holes HS (see FIG. 14) through which fixing screws S are inserted for fixing the reduction mechanism unit 50 to the electric motor unit 20. Specifically, the pair of screw insertion holes HS are opposed to a pair of screw holes 22b formed in the bottom wall portion 22 of the motor case 21 in the axial direction of the rotating shaft 41, respectively.

[0080] An opening 53 is provided on the other axial side of the reducer case 51, i.e., on the opposite side to the annular bottom wall 52. The planetary gear reducer 60 is fitted inside the reducer case 51 through this opening 53. An engagement shoulder SH is provided on the other axial side of the planetary gear reducer 60, and an engagement claw 51a of the reducer case 51 engages with this engagement shoulder SH. This prevents the planetary gear reducer 60 from rattling and coming off the reducer case 51.

[0081] The planetary gear reducer 60 is formed in a generally box shape and includes a gearbox 61 with an internal gear 61a formed on its radially inner side. The gearbox 61 is made of a resin material such as plastic and includes a large-diameter portion 61b and a small-diameter portion 61c. Specifically, the large-diameter portion 61b is located on one axial side of the gearbox 61, and the small-diameter portion 61c is located on the other axial side of the gearbox 61. The internal gear 61a is provided across the entire axial area of ​​the large-diameter portion 61b.

[0082] On the other hand, a third ball bearing 62 having an outer ring 62a, an inner ring 62b, and steel balls 62c is housed inside the small diameter portion 61c. Specifically, the outer ring 62a of the third ball bearing 62 is fixed by press fitting inside the small diameter portion 61c, and the inner ring 62b of the third ball bearing 62 rotatably supports an output shaft 84 that forms the second planetary gear reducer 80.

[0083] An annular closing member 63 that closes a box opening 61d of the gear box 61 is provided on one axial side of the gear box 61. The closing member 63 is fixed to the box opening 61d by press fitting. A through hole 63a is provided in the center of the closing member 63, and the through hole 63a is fitted into approximately one-third of the first ball bearing 11 on one axial side.

[0084] This causes the axis of the closing member 63 (planetary gear reducer 60) and the axis of the first ball bearing 11 to coincide with each other without any misalignment. Therefore, the driving force of the rotating shaft 41, which is rotatably supported by the first ball bearing 11, is efficiently transmitted to the planetary gear reducer 60. Inside the gear box 61 and the closing member 63, there are housed a first planetary gear reducer 70 arranged on the input side (the side where the electric motor unit 20 is provided) and a second planetary gear reducer 80 arranged on the output side (the side where the reclining mechanism and the like are provided).

[0085] Specifically, the first planetary gear reducer 70 and the second planetary gear reducer 80 are arranged in the axial direction of the rotating shaft 41 so as to be able to transmit power to each other, and the planetary gear reducer 60 performs two-stage reduction. This allows the diameter of the planetary gear reducer 60 to be reduced.

[0086] <First planetary gear reducer> 2 and 7, first planetary gear reducer 70 has a first sun gear 71 that is attached to small diameter portion 41a of rotating shaft 41 and functions as an input portion of first planetary gear reducer 70. First sun gear 71 is rotated by rotating shaft 41, is press-fitted and fixed to small diameter portion 41a, and is precisely positioned coaxially with small diameter portion 41a.

[0087] The first planetary gear reducer 70 also includes three first planetary gears 72 (only two are shown in FIG. 7 ) that are meshed with both the internal gear 61 a provided in the gearbox 61 and the first sun gear 71 and roll around the first sun gear 71. These first planetary gears 72 are each rotatably supported by a first carrier 73 that forms the first planetary gear reducer 70. Specifically, the three first planetary gears 72 are arranged at equal intervals (at 120-degree intervals) around the circumferential direction of the first carrier 73.

[0088] Furthermore, a second sun gear 81 is integrally provided on the other axial side of first carrier 73. The second sun gear 81 functions as an output portion of first planetary gear reducer 70 and also functions as an input portion of second planetary gear reducer 80. Second sun gear 81 is hollow, and is disposed at the axis of first carrier 73.

[0089] <Second planetary gear reducer> As shown in FIGS. 2 and 7, the second planetary gear reducer 80 has a second sun gear 81 that is provided integrally with the first carrier 73 of the first planetary gear reducer 70.

[0090] The second planetary gear reducer 80 also includes three second planetary gears 82 (only two are shown in FIG. 7 ) that are meshed with both the internal gear 61 a provided in the gearbox 61 and the second sun gear 81 and roll around the second sun gear 81. These second planetary gears 82 are each rotatably supported by a second carrier 83 that forms the second planetary gear reducer 80. Specifically, the three second planetary gears 82 are arranged at equal intervals (at 120-degree intervals) around the circumferential direction of the second carrier 83.

[0091] Furthermore, an output shaft 84 that functions as an output portion of the second planetary gear reducer 80 is integrally provided on the other axial side of the second carrier 83. Here, the output shaft 84 is rotatably supported by the inner ring 62b of the third ball bearing 62, and is connected to a reclining mechanism or the like (not shown) so as to be capable of transmitting power.

[0092] Here, the other axial side of the support pin PN is attached to the axial center of the second carrier 83. Meanwhile, one axial side of the support pin PN is attached to the axial center of the first carrier 73. The support pin PN aligns the axial center of the first carrier 73 (second sun gear 81) with the axial center of the second carrier 83 (output shaft 84), and supports them so that they can rotate relative to each other.

[0093] In this way, the planetary gear reducer 60 performs two-stage reduction using the first and second planetary gear reducers 70, 80 arranged on the same axis, reducing the rotational speed of the rotor 40 (rotating shaft 41), which rotates at high speed, to a predetermined rotational speed, and the reduced, high-torque rotational force is output from the output shaft 84 to a reclining mechanism or the like (not shown).

[0094] The planetary gear reducer 60 is driven by the rotary shaft 41 and corresponds to the driven object in the present invention.

[0095] <Wiring unit> 8, the wiring unit 90 has a connector connection part 91 that is connected to a connector (not shown) of the in-vehicle controller CR (see FIG. 1). The wiring unit 90 also has a power supply wiring 92 and a signal wiring 93, and one longitudinal side (the right side in FIG. 8) of the power supply wiring 92 and the signal wiring 93 is connected to the connector connection part 91. On the other hand, the other longitudinal side (the left side in FIG. 8) of the power supply wiring 92 and the signal wiring 93 is connected to the cover member 13.

[0096] The power supply wiring 92 has a sheath 92a made of flame-retardant vinyl or the like, and a total of three U-phase, V-phase, and W-phase power supply wires UL, VL, and WL arranged inside the sheath 92a. As shown in Fig. 8, the other longitudinal sides of the U-phase, V-phase, and W-phase power supply wires UL, VL, and WL are stripped, and the exposed other longitudinal sides of the U-phase, V-phase, and W-phase power supply wires UL, VL, and WL are electrically connected by soldering to U-phase, V-phase, and W-phase connecting terminals Tu, Tv, and Tw (see Fig. 4).

[0097] In this way, the U-phase, V-phase, and W-phase power supply lines UL, VL, and WL are electrically connected to the U-phase, V-phase, and W-phase connecting terminals Tu, Tv, and Tw, respectively, and supply drive currents to the coils 36. The U-phase, V-phase, and W-phase power supply lines UL, VL, and WL correspond to the power supply lines in the present invention.

[0098] The signal wiring 93 also has a sheath 93a similar to that of the power supply wiring 92, and a total of five sensor wires SW are provided inside the sheath 93a. As shown in Fig. 8, the other longitudinal ends of the total of five sensor wires SW are connected to a wiring connector 94. This makes it possible to easily electrically connect each sensor wire SW to the sensor board SB (see Fig. 5) simply by inserting the wiring connector 94 into the sensor connector connection portion CN (see Fig. 5).

[0099] <Assembly procedure for seat motor> Next, the assembly procedure for the seat motor 10 formed as above will be described in detail with reference to the drawings.

[0100] Figure 10 is an exploded oblique view of the electric motor unit, Figure 11 is a diagram explaining the energization test of the electric motor unit, Figure 12 is an oblique view showing the electric motor unit, wiring unit and cover member, Figure 13 is a diagram showing the procedure for connecting the wiring unit to the electric motor unit, and Figure 14 is a diagram showing the procedure for connecting the reduction mechanism unit to the electric motor unit.

[0101] <Assembling the electric motor> First, as shown in Fig. 10, the stator assembly SA, rotor 40, and cover body 14, which are assembled in separate assembly processes, are prepared. Also, a first sun gear 71 that forms a first planetary gear reducer 70 (see Fig. 7) is prepared.

[0102] Then, the rotor 40 is attached to the inside of the stator assembly SA along the dashed line in the figure. At this time, the side of the rotor 40 where the abutment member 44 is provided, i.e., the side where the small diameter portion 41a of the rotating shaft 41 is provided, faces the opening 25 of the motor case 21. Thereafter, the other axial side of the rotating shaft 41 that forms the rotor 40 is inserted into the first ball bearing 11 (see FIG. 2) fixed to the bearing support cylinder 22a.

[0103] This completes the attachment of the rotor 40 to the stator assembly SA. The stator assembly SA refers to the motor case 21 to which the first ball bearing 11 (see FIG. 2) and the stator 30 are fixed.

[0104] Next, the cover body 14 on which the sensor board SB is mounted is attached to the opening 25 of the motor case 21 along the dashed line in the figure. At this time, with the side of the cover body 14 on which the sensor board SB is mounted facing the opening 25, one axial side of the rotating shaft 41 is inserted into the second ball bearing 12 mounted inside the bearing retaining cylinder 15a.

[0105] Then, engagement claws 21a of motor case 21 are engaged with engagement recesses 14a of cover body 14. This completes the attachment of cover body 14 to motor case 21. Thereafter, first sun gear 71 is press-fitted and fixed onto small diameter portion 41a of rotating shaft 41 protruding from bottom wall portion 22 (see FIG. 2) of motor case 21.

[0106] Note that, before cover body 14 is attached to opening 25, first sun gear 71 may be press-fitted and fixed to small diameter portion 41a.

[0107] This completes the assembly of the electric motor unit 20.

[0108] <Electric motor operation test> Next, a check is made to see if the assembled electric motor unit 20 operates normally, that is, an operation test (power-on test) is performed on the electric motor unit 20. Specifically, as shown in Fig. 11, a test device TEST is connected to the electric motor unit 20 to perform the operation test.

[0109] Then, the U-phase, V-phase, and W-phase wiring U, V, and W provided in the test device TEST are connected to the U-phase, V-phase, and W-phase connection terminals Tu, Tv, and Tw of the electric motor unit 20 using connection clips or the like (not shown). In addition, the sensor wiring SNSR (with connector) provided in the test device TEST is connected to the sensor connector connection portion CN of the electric motor unit 20.

[0110] Thereafter, the test device TEST is operated in test mode to check the driving state of the electric motor unit 20 and determine whether the electric motor unit 20 is good or bad (pass / fail). In this way, in this embodiment, the relatively compact electric motor unit 20 can be easily tested alone before the wiring unit 90 (see FIG. 8) is connected. The fact that the electric motor unit 20 can be tested alone in this way is due to the fact that the U-phase, V-phase, and W-phase connection terminals Tu, Tv, and Tw are exposed inside the cover body 14 and the sensor connector connection portion CN is also located inside the cover body 14.

[0111] This completes the operation test of the electric motor unit 20.

[0112] <Connection of wiring unit> Next, as shown in Figure 12, the wiring unit 90 is electrically connected to the electric motor section 20. First, the wiring unit 90 assembled in a separate assembly process is prepared, along with the lid member 18. Then, the wiring unit 90 is connected to the electric motor section 20 along the dashed dotted lines in the figure, and the lid member 18 is attached to the cover body 14.

[0113] 13, the U-phase, V-phase, and W-phase power supply wires UL, UV, and UW of the wiring unit 90 are soldered to the U-phase, V-phase, and W-phase connecting terminals Tu, Tv, and Tw, respectively. Note that Fig. 13 only shows the soldering of the U-phase power supply wire UL to the U-phase connecting terminal Tu. The V-phase and W-phase power supply wires UV and UW are also soldered to the V-phase and W-phase connecting terminals Tv and Tw, similar to the U-phase power supply wire UL.

[0114] Specifically, the stripped tip of the U-phase power wire UL is attached to the U-phase connecting terminal Tu, and in this state, a soldering iron TL is inserted into the assembly jig introduction space SP1 as shown by the solid arrow M1, thereby soldering the U-phase power wire UL and the U-phase connecting terminal Tu together and electrically connecting them.

[0115] Next, as shown by dashed arrow M2, the U-phase power line UL is routed so that it is hooked onto the power line holding claws 15b and wound around the bearing holder cylinder 15a. Note that the V-phase and W-phase power lines UV, UW are also routed so that they are disposed around the bearing holder cylinder 15a in the same manner as the U-phase power line UL.

[0116] Thereafter, as indicated by the dashed-dotted arrow M3, the wiring connector 94 of the wiring unit 90 is inserted into the sensor connector connection portion CN to electrically connect it, thereby completing the electrical connection of the wiring unit 90 to the electric motor unit 20.

[0117] 12, when the lid member 18 is attached to the cover main body 14, the U-phase, V-phase, and W-phase power supply lines UL, VL, and WL and a total of five sensor lines SW (see FIG. 13) are pulled out to the outside through cutouts 18a provided in the lid member 18. The lid member 18 is fixed to the cover main body 14 by hooking a plurality of hooking claws 18b provided on the lid member 18 onto hooking portions 14b (see FIG. 13) of the cover main body 14.

[0118] <Connection of the reduction mechanism> Next, as shown in Figure 14, the work of connecting the reduction mechanism unit 50 to the electric motor unit 20 is performed. First, the planetary gear reducer 60 assembled in a separate assembly process is prepared, along with the reducer case 51 and a pair of fixing screws S. Then, the annular bottom wall 52 of the reducer case 51 is abutted against the bottom wall portion 22 of the motor case 21 (see Figure 2) along the dashed dotted line in the figure. At this time, the fitting cylinder 52a is fitted into the bearing support cylinder 22a (see Figure 2).

[0119] Thereafter, a pair of fixing screws S are inserted into the pair of screw insertion holes HS from inside the reducer case 51 and screwed into a pair of screw holes 22b (see FIG. 2) provided in the bottom wall portion 22 of the motor case 21. This completes the process of fixing the reducer case 51 to the electric motor unit 20.

[0120] Next, the planetary gear reducer 60 is fitted into the reducer case 51 through the opening 53 (see FIG. 2) of the reducer case 51. At this time, the side of the planetary gear reducer 60 on which the blocking member 63 is provided faces the opening 53. Also, in the axial direction of the rotor 40, the position of the engagement shoulder portion SH of the planetary gear reducer 60 is aligned with the position of the engagement pawl 51a of the reducer case 51. Furthermore, the first sun gear 71 (see FIG. 7) fixed to the small diameter portion 41a is meshed with the three first planetary gears 72 (see FIG. 7) that form the first planetary gear reducer 70.

[0121] Then, the engagement claw 51a of the reducer case 51 is engaged with the engagement shoulder SH of the planetary gear reducer 60. This completes the connection of the reduction mechanism unit 50 to the electric motor unit 20, and the assembly of the seat motor 10 is completed.

[0122] As described above in detail, according to this embodiment, the cross section of the motor case 21 along the radial direction of the rotor 40 is formed into a square having the first to fourth corners 24a to 24d, and the stator 30 includes a cylindrical core body 32, first to fourth core protrusions 33a to 33d provided on the outer periphery of the core body 32 and abutting against the first to fourth corners 24a to 24d, a plurality of teeth 34 provided on the inner periphery of the core body 32, and coils 36 wound for each phase around the plurality of teeth 34. The rotor 40 includes a rotating shaft 41 that drives the planetary gear reducer 60 and a ring magnet 43 provided on the outer periphery of the rotating shaft 41, and U-phase, V-phase, and W-phase connection terminals Tu, Tv, and Tw that are electrically connected to the coils 36 provided for each phase are arranged between the rotor 40 and the first to third corner portions 24a to 24c in the radial direction of the rotor 40 and on first to third line segments L1 to L3 that connect the rotation center C of the rotor 40 and the first to third corner portions 24a to 24c.

[0123] This eliminates the need to overlap molded bus bars in the axial direction of the rotor 40 as in the past, making it possible to reduce the axial dimension of the seat motor 10. As a result, the seat motor 10 can be made even more compact.

[0124] Furthermore, the power supply wiring 92 (U-phase, V-phase, and W-phase power supply wires UL, VL, and WL) and the signal wiring 93 (a total of five sensor wires SW) can be arranged while being electrically connected within the radial range of the motor case 21. This eliminates portions of the motor case 21 that partially protrude in the radial direction, improving the layout flexibility relative to a fixed object.

[0125] Furthermore, in the radial direction of the rotor 40, assembly jig introduction spaces SP1, SP2, and SP3 can be formed between the U-phase connecting terminal Tu and the first corner 24a, between the V-phase connecting terminal Tv and the second corner 24b, and between the W-phase connecting terminal Tw and the third corner 24c, respectively, which makes it easier to electrically connect the U-phase, V-phase, and W-phase connecting terminals Tu, Tv, and Tw and the U-phase, V-phase, and W-phase power supply wires UL, VL, and WL using a soldering iron TL (improved assembly).

[0126] Furthermore, according to this embodiment, arc-shaped inner circumferential portions are provided inside the first to fourth corner portions 24a to 24d, and the first to fourth core protrusions 33a to 33d are in surface contact with these inner circumferential portions.

[0127] This makes it possible to prevent the inner circumferential portions of the first to fourth corners 24a to 24d from being damaged, such as by being scraped off, when the stator core 31 is press-fitted and fixed into the motor case 21. Furthermore, it is possible to ensure a sufficient fixing strength of the stator core 31 to the motor case 21.

[0128] Furthermore, according to this embodiment, the motor case 21 is provided with an opening 25 that is closed by a cover member 13 that holds the second ball bearing 12 that rotatably supports the rotating shaft 41, and U-phase, V-phase, and W-phase connection terminals Tu, Tv, and Tw are arranged near the opening 25, and the cover member 13 is equipped with a sensor board SB that has Hall elements 27a, 27b, and 27c that detect the rotational state of the rotating shaft 41, and a sensor connector connection portion CN to which the on-board controller CR is connected.

[0129] This allows the electronic components that make up the seat motor 10 to be concentrated on the side of the motor case 21 where the opening 25 is provided in the longitudinal direction, facilitating electrical connection work, thereby also improving the ease of assembly of the seat motor 10.

[0130] Furthermore, according to this embodiment, at least a portion of the sensor connector connection portion CN is positioned between the rotor 40 and the fourth corner portion 24d, and on the fourth line segment L4 connecting the rotation center C of the rotor 40 and the fourth corner portion 24d.

[0131] This allows the sensor connector connection portion CN to be located near the fourth corner portion 24d, and therefore allows the sensor connector connection portion CN to be located in the same position as the U-phase, V-phase, and W-phase connection terminals Tu, Tv, and Tw in the axial direction of the rotor 40. This also makes it possible to prevent an increase in the axial dimension of the seat motor 10.

[0132] Furthermore, according to this embodiment, the cover member 13 is provided with a bearing retaining cylinder 15a that retains the second ball bearing 12 on its inner periphery, and the bearing retaining cylinder 15a is provided with a total of three power line retaining claws 15b on its outer periphery that are electrically connected to the U-phase, V-phase, and W-phase connecting terminals Tu, Tv, and Tw and that retain the U-phase, V-phase, and W-phase power lines UL, VL, and WL that supply drive current to the coil 36.

[0133] This makes it possible to accommodate the U-phase, V-phase, and W-phase power lines UL, VL, and WL within the axial range of the bearing retaining cylinder 15a, thereby preventing the cover member 13 from increasing in size in the axial direction.

[0134] Furthermore, according to this embodiment, when the second ball bearing 12 is viewed from the radial direction of the rotor 40, at least a portion of the U-phase, V-phase, and W-phase power supply lines UL, VL, and WL and the sensor connector connection portion CN overlaps with the second ball bearing 12.

[0135] This allows the U-phase, V-phase, and W-phase power supply lines UL, VL, and WL and the sensor connector connection portion CN to be efficiently positioned at predetermined locations on the cover body 14 that forms the cover member 13, thereby also making it possible to suppress an increase in the axial dimension of the cover member 13.

[0136] Furthermore, according to this embodiment, the electric motor unit 20 that forms the seat motor 10 can be easily tested for operation as a single unit. This eliminates the need to disassemble the seat motor 10 and replace only the electric motor unit 20 after assembling the seat motor 10. This reduces the amount of energy required for manufacturing, making it possible to achieve the Sustainable Development Goals (SDGs) established by the United Nations, particularly Goal 7 (Ensure access to affordable, reliable, sustainable and modern energy for all) and Goal 13 (Take urgent action to combat climate change and its impacts).

[0137] The present invention is not limited to the above-described embodiment, and various modifications are possible without departing from the spirit and scope of the present invention. For example, in the above-described embodiment, the cross-sectional shape of the motor case 21 in the radial direction of the rotor 40 is a square (regular polygon) having first to fourth corners 24a to 24d, but the present invention is not limited to this. In other words, as long as the U-phase, V-phase, and W-phase connecting terminals Tu, Tv, and Tw and the U-phase, V-phase, and W-phase power lines UL, VL, and WL can be easily soldered to each other, the regular polygon may be an equilateral triangle, a regular pentagon, a regular hexagon, or the like.

[0138] In the above embodiment, when assembling the seat motor 10, the wiring unit 90 is first connected to the electric motor section 20, and then the speed reduction mechanism section 50 is connected, but the present invention is not limited to this. That is, the speed reduction mechanism section 50 may be connected to the electric motor section 20 first, and then the wiring unit 90 may be connected.

[0139] Furthermore, in the above embodiment, the seat motor 10 is shown as an example of a motor device, but the present invention is not limited to this and can also be applied to other in-vehicle devices, such as drive sources for power window devices and sunroof devices.

[0140] Furthermore, the material, shape, size, number, installation location, etc. of each component in the above-described embodiments are arbitrary as long as they can achieve the present invention, and are not limited to the above-described embodiments. [Explanation of symbols]

[0141] 10: seat motor (motor device), 11: first ball bearing, 11a: outer ring, 11b: inner ring, 11c: steel ball, 12: second ball bearing (bearing), 12a: outer ring, 12b: inner ring, 12c: steel ball, 13: cover member (bearing holder), 14: cover body, 14a: engagement recess, 14b: hook portion, 15: cover bottom wall, 15a: bearing retaining tube, 15b: power line retaining claw, 16a: first cover side wall, 16b: second cover side wall, 16c: third cover side wall, 16d: fourth cover side wall, 17a: first cover corner portion, 17b: second cover corner portion, 17c: third cover corner part, 17d: fourth cover corner part, 18: cover member, 18a: notch part, 18b: hooking claw, 20: electric motor part, 21: motor case, 21a: engaging claw, 22: bottom wall part, 22a: bearing support cylinder, 22b: screw hole, 23a: first side wall part, 23b: second side wall part, 23c: third side wall part, 23d: fourth side wall part, 24a: first corner part (corner part), 24b: second corner part (corner part), 24c: third corner part (corner part), 24d: fourth corner part (corner part), 25: opening part, 26: through hole, 27a, 27b, 27c: hall element (rotation sensor), 30: stator, 31: stator core, 32: core body, 33a: first core protrusion (core protrusion), 33b: second core protrusion (core protrusion), 33c: third core protrusion (core protrusion), 33d: fourth core protrusion (core protrusion), 34: teeth, 35: insulator, 36: coil, 40: rotor, 41: rotating shaft, 41a: small diameter portion, 42: rotor core, 42a: fixing hole, 43: ring magnet (magnet), 44: abutting member, 45: opposing member, 50: reduction mechanism, 51: reducer case, 51a: engaging claw, 52: annular bottom wall, 52a: fitting cylinder, 53: opening, 60: planetary gear reducer (driven object), 61: gear box, 61a: Internal gear, 61b: large diameter portion, 61c: small diameter portion, 61d: box opening, 62: third ball bearing, 62a: outer ring, 62b: inner ring, 62c: steel ball, 63: blocking member, 63a: through hole, 70: first planetary gear reducer, 71: first sun gear, 72: first planetary gear, 73: first carrier, 80: second planetary gear reducer, 81: second sun gear, 82: second planetary gear, 83: second carrier, 84: output shaft, 90: wiring unit, 91: connector connection part, 92: power supply wiring, 92a: sheath, 93: signal wiring, 93a: sheath, 94: wiring connector,BS: boss for fixing stacked layers, C: center of rotation of rotor, CN: connector connection for sensor (controller connection), CR: on-board controller (controller), HS: screw insertion hole, Hc: connector insertion hole, Hu: U-phase terminal insertion hole, Hv: V-phase terminal insertion hole, Hw: W-phase terminal insertion hole, L1: first line segment (first line segment), L2: second line segment (first line segment), L3: third line segment (first line segment), L4: fourth line segment (second line segment), PN: support pin, S: fixing screw, SA: stator assembly, SB: sensor Circuit board, SC: Circuit board fixing screw, SH: Engagement shoulder, SNSR: Sensor wiring, SP: Coil spring, SP1, SP2, SP3: Assembly jig introduction space, ST: Sensor terminal, SW: Sensor wire, TEST: Test equipment, Tu: U-phase connection terminal (connection terminal), Tv: V-phase connection terminal (connection terminal), Tw: W-phase connection terminal (connection terminal), U: U-phase wiring, V: V-phase wiring, W: W-phase wiring, UL: U-phase power line (power line), VL: V-phase power line (power line), WL: W-phase power line (power line), WT: Crossover wire

Claims

1. a stator fixed to the inside of the motor case; a rotor that rotates relative to the stator; A motor device having a cross-sectional shape of the motor case along the radial direction of the rotor is formed into a polygon having a plurality of corners, The stator includes: A cylindrical core body; a core protrusion provided on an outer periphery of the core body and abutting against the corner; a plurality of teeth provided on an inner peripheral portion of the core body; a coil wound around each of the plurality of teeth for each phase; and The rotor is a rotation shaft that drives the driven object; a magnet provided on the outer periphery of the rotating shaft; Equipped with In the radial direction of the rotor, connection terminals electrically connected to the coils provided for each phase are arranged between the rotor and the corner portion and on a first line segment connecting the center of rotation of the rotor and the corner portion. Motor device.

2. An arc-shaped inner periphery is provided inside the corner, The core protrusion is in surface contact with the inner peripheral portion. The motor device according to claim 1 .

3. 3. The motor device according to claim 1, the motor case is provided with an opening that is closed by a bearing holder that holds a bearing that rotatably supports the rotary shaft, The connection terminal is disposed near the opening, a sensor board having a rotation sensor that detects the rotation state of the rotating shaft and a controller connection portion to which a controller is connected is mounted on the bearing holder; Motor device.

4. at least a part of the controller connection portion is disposed on a second line segment that is located between the rotor and the corner portion and that connects the center of rotation of the rotor and the corner portion in the radial direction of the rotor; The motor device according to claim 3 .

5. 4. The motor device according to claim 3, The bearing holder is provided with a bearing retaining cylinder that retains the bearing at its inner periphery, a power line holding claw for holding a power line electrically connected to the connection terminal and supplying a drive current to the coil is provided on the outer periphery of the bearing holding cylinder; Motor device.

6. When the bearing is viewed from a radial direction of the rotor, at least a portion of the power supply line and the controller connection portion overlap with the bearing. The motor device according to claim 5 .

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