Rotor

Abstract

To provide a rotor capable of stabilizing the shapes of steel plates that make up a rotor core.SOLUTION: A rotor 9 includes a rotor core 32, a plurality of permanent magnets 33, a magnet cover 71, and a pair of load receiving blocks 70 arranged at one end side and the other end side of the rotor core 32 in an axial direction. Each of the load receiving blocks 70 has an annular portion 70A arranged overlapping a rotor core end face 32s of a core body portion 32A in the axial direction, a plurality of leg portions 70B protruding in a radiation direction from the outer circumferential surface of the annular portion 70A and arranged overlapping an end face of each salient pole 32B in the axial direction, and an end wall 70C integrally connected to the outside of the annular portion 70A and the leg portions 70B in the axial direction and protruding radially outward from the annular portion 70A. The annular portion 70A has a plurality of recesses 59 with a low protruding height from the end wall 70C, and each recess 59 is arranged between the base ends of the leg portions 70B adjacent to each other in the circumferential direction of the annular portion 70A.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present invention relates to a rotor.

Background Art

[0002] As a motor device used in a wiper device of a vehicle or the like, there is one in which a rotor is disposed inside the diameter direction of a stator around which a coil is wound. In this type of motor device, a rotor having a plurality of permanent magnets held on the outer periphery of a rotor core is used, and a rotating shaft is attached to the axial center portion of the rotor core (see, for example, Patent Document 1).

[0003] In the motor device described in Patent Document 1, the rotor core is configured by laminating a plurality of steel plates (magnetic steel plates) in the axial direction. An axial center hole is formed in the axial center portion of the rotor core, and a rotating shaft is press-fitted and fixed in the axial center hole.

[0004] Further, this motor device is a motor device with a speed reducer, and a speed reduction mechanism is also housed inside a casing that houses a stator and a rotor. The speed reduction mechanism has a worm shaft that is an input rotating body and a worm wheel that is an output rotating body, and the worm shaft is coaxially connected to the rotating shaft on the rotor side. Both axial side portions of the worm shaft are rotatably supported by the casing via bearings. In addition, in this motor device, the rotating shaft fixed to the axial center portion of the rotor core is supported by the casing via a bearing on the speed reduction mechanism side in a cantilever state.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0006] The rotor used in the motor device described in Patent Document 1 has a rotor core formed by laminating a plurality of steel plates in the axial direction. Therefore, the shapes of the plurality of steel plates constituting the rotor core are liable to be unstable after assembly. For this reason, stabilization of the shape of the steel plates constituting the rotor core is desired.

[0007] Therefore, the present invention aims to provide a rotor capable of stabilizing the shape of the steel plates constituting the rotor core.

Means for Solving the Problems

[0008] In order to solve the above problems, the rotor according to the present invention employs the following configuration. That is, in a first aspect according to the present invention, the rotor includes a rotor core composed of a plurality of steel plates laminated in the axial direction along the rotation axis, a plurality of permanent magnets disposed on the outer peripheral portion of the rotor core, a magnet cover covering the radially outer sides of the rotor core and the plurality of permanent magnets, and a pair of load receiving blocks respectively disposed on one end side and the other end in the axial direction of the rotor core, wherein the rotor core has a substantially cylindrical core body portion and a plurality of salient poles protruding radially from the outer periphery of the core body portion, the permanent magnets are disposed between adjacent ones of the plurality of salient poles, the load receiving block has an annular portion disposed overlapping the core end face of the core body portion in the axial direction, a plurality of leg portions protruding radially from the outer peripheral surface of the annular portion and disposed overlapping the salient pole end faces of the respective salient poles in the axial direction, and an end wall integrally connected to the outer sides in the axial direction of the annular portion and the leg portions and protruding radially outward from the annular portion, the annular portion has a plurality of recesses with a low protruding height from the end wall, and each of the recesses is disposed between the base end portions of the respective leg portions adjacent to each other in the circumferential direction in the annular portion.

[0009] In a second aspect of the present invention, in the rotor of the first aspect, the annular portion has a plurality of convex portions provided between the concave portions adjacent to each other in the circumferential direction, each of the leg portions is provided so as to project from the outer peripheral surface of each of the convex portions, and the convex portion end surface on the inner side in the axial direction of each of the convex portions is in contact with the core end surface, and the leg portion end surface on the inner side in the axial direction of each of the leg portions is in contact with the salient pole end surface on the outer side in the axial direction of each of the salient poles.

[0010] In a third aspect of the present invention, in the rotor of the second aspect, the annular portion has locking claws that project inward in the axial direction from each of the convex portion end surfaces and are provided on the extension line along the radial direction of each of the leg portions, and the locking claws are locked to the inner peripheral surface of the core main body portion.

[0011] In a fourth aspect of the present invention, in the rotor according to any one of the first to third aspects, the annular portion has confirmation holes provided between the adjacent leg portions on the end wall, and the confirmation holes are formed at positions facing the magnet end surfaces in the axial direction of the permanent magnets when the load receiving block is assembled into the magnet cover together with the permanent magnets and the rotor core.

Advantages of the Invention

[0012] According to the present invention, it is possible to stabilize the shape of the steel plate constituting the rotor core.

Brief Description of the Drawings

[0013]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Figure 8

Figure 9

Mode for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0015] (Motor device) FIG. 1 is a perspective view of a motor device 1 used in a vehicle. FIG. 2 is a cross-sectional view of the motor device 1 taken along line II-II in FIG. 1. The motor device 1 is used, for example, as a drive source for a wiper device of a vehicle. As shown in FIGS. 1 and 2, the motor device 1 includes a motor 2, a speed reduction unit 3 that reduces and outputs the rotation of the motor 2, and a controller 4 that controls the drive of the motor 2. In the following description, when simply referring to the "axial direction", it means the direction along the rotation axis direction of the rotation axis 31 of the motor 2, and when simply referring to the "circumferential direction", it means the circumferential direction of the rotation axis 31. Also, when simply referring to the "radial direction", it means the radial direction of the rotation axis 31. Further, in the "axial direction", one end side of the rotation axis 31 (the side where the arrow points to D1 in FIGS. 2 and 3) is referred to as the "first direction", and the other end side of the rotation axis 31 (the side where the arrow points to D2 in FIGS. 2 and 3) is referred to as the "second direction".

[0016] (Motor) The motor 2 includes a motor case 5, a substantially cylindrical stator 8 housed in the motor case 5, and a rotor 9 disposed on the radially inner side of the stator 8 and rotatably provided with respect to the stator 8. The motor 2 of the present embodiment is a so-called brushless motor that does not require a brush when supplying power to the stator 8.

[0017] (Motor case) The motor case 5 is formed of a material with excellent heat dissipation properties such as an aluminum alloy. The motor case 5 is composed of a first motor case 6 and a second motor case 7 that are configured to be divisible in the axial direction. The first motor case 6 and the second motor case 7 are each formed in a bottomed cylindrical shape. The first motor case 6 is integrally formed with the gear case 40 such that the bottom 10 is connected to the gear case 40 of the speed reduction unit 3. A through hole through which the rotating shaft 31 of the motor 2 can be inserted is formed substantially at the center in the radial direction of the bottom 10. In this embodiment, the motor case 5 and the gear case 40 constitute the casing of the motor device 1.

[0018] In addition, outer flange portions 16, 17 that project radially outward are respectively formed at the openings 6a, 7a of the first motor case 6 and the second motor case 7. The motor case 5 forms an internal space by butting the outer flange portions 16, 17 against each other. A stator 8 and a rotor 9 are arranged in the internal space of the motor case 5. The stator 8 is press-fitted and fixed to a stepped portion formed on the inner peripheral surface of the first motor case 6.

[0019] (Stator) The stator 8 includes a stator core 20 made of laminated steel plates (electromagnetic steel plates) and a plurality of coils 24 wound around the stator core 20. The stator core 20 has an annular core body portion 21 and a plurality (for example, six) of teeth 22 that project radially inward from the inner peripheral portion of the core body portion 21. The inner peripheral surface of the core body portion 21 and each tooth 22 are covered with a resin insulator 23. The coil 24 is wound around the corresponding predetermined tooth 22 from above the insulator 23. Each coil 24 generates a magnetic field for rotating the rotor 9 by power supply from the controller 4.

[0020] (Rotor) The rotor 9 is rotatably disposed inside the stator 8 with a minute clearance therebetween in the radial direction. The rotor 9 includes a rotating shaft 31, a substantially cylindrical rotor core 32 having the rotating shaft 31 press-fitted and fixed to the inner peripheral portion thereof, and four permanent magnets 33 (see FIGS. 3, 5, 6, etc.) assembled to the outer peripheral portion of the rotor core 32. In the present embodiment, the rotating shaft 31 is integrally formed with the worm shaft 44 constituting the speed reduction unit 3. However, the worm shaft 44 is not limited thereto, and may be formed separately from the rotating shaft 31 and connected to the end portion of the rotating shaft 31. The rotating shaft 31 and the worm shaft 44 are rotatably supported by bearings 46 and 47 in a gear case 40 (casing). The rotating shaft 31 and the worm shaft 44 rotate about the rotation axis (axis C). As the permanent magnet 33, for example, a ferrite magnet is used. However, the permanent magnet 33 is not limited thereto, and a neodymium bonded magnet, a neodymium sintered magnet, or the like may also be applied. The detailed structure of the rotor 9 will be described later.

[0021] (Speed reduction unit) The speed reduction unit 3 includes a gear case 40 integrated with the motor case 5 and a speed reduction mechanism 41 housed in the gear case 40. The gear case 40 is formed of a metal material having excellent heat dissipation properties such as an aluminum alloy. The gear case 40 is formed in a box shape having an opening 40a on one side. The gear case 40 has a gear housing portion 42 for housing the speed reduction mechanism 41 therein. Further, an opening 43 communicating the through hole of the first motor case 6 and the gear housing portion 42 is formed at a location where the first motor case 6 is integrally formed on the side wall 40b of the gear case 40.

[0022] A substantially cylindrical bearing boss 49 protrudes from the bottom wall 40c of the gear case 40. The bearing boss 49 is for rotatably supporting the output shaft 48 of the speed reduction mechanism 41, and a sliding bearing (not shown) is disposed on the inner peripheral side thereof. An O-ring (not shown) is mounted inside the tip of the bearing boss 49. Further, a plurality of ribs 52 for ensuring rigidity protrude from the outer peripheral surface of the bearing boss 49.

[0023] The speed reduction mechanism 41 housed in the gear housing 42 is composed of a worm shaft 44 and a worm wheel 45 meshed with the worm shaft 44. Both axial ends of the worm shaft 44 are rotatably supported by the gear case 40 via bearings 46 and 47. Note that the worm shaft 44 is provided coaxially and integrally with the rotating shaft 31 of the motor 2. An output shaft 48 of the speed reduction mechanism 41 is provided coaxially and integrally with the worm wheel 45. The worm wheel 45 and the output shaft 48 are arranged such that their rotation axes are substantially orthogonal to the rotation axis (axis center C) of the worm shaft 44 (the rotating shaft 31 of the motor 2). The output shaft 48 projects outward through a bearing boss 49 of the gear case 40. A spline 48a connectable to an article to be driven by the motor is formed at the protruding tip of the output shaft 48.

[0024] In addition, a sensor magnet (not shown) is provided on the worm wheel 45. The position of this sensor magnet is detected by a magnetic detection element 61 provided on a controller 4 described later. That is, the rotational position of the worm wheel 45 is detected by the magnetic detection element 61 of the controller 4.

[0025] (Controller) The controller 4 has a controller board 62 on which the magnetic detection element 61 is mounted. The controller board 62 is arranged in the opening 40a of the gear case 40 such that the magnetic detection element 61 faces the sensor magnet of the worm wheel 45. The opening 40a of the gear case 40 is closed by a cover 63.

[0026] A plurality of terminal portions of coils 24 drawn from the stator core 20 are connected to the controller board 62. Further, terminals of a connector 11 (see FIG. 1) provided on the cover 63 are electrically connected to the controller board 62. In addition to the magnetic detection element 61, a power module (not shown) composed of a switching element such as an FET (Field Effect Transistor) that controls the drive voltage supplied to the coil 24, a capacitor (not shown) that smoothes the voltage, etc. are mounted on the controller board 62.

[0027] (Detailed Structure of Rotor) FIG. 3 is a longitudinal sectional view of the rotor 9, FIG. 4 is a perspective view of the rotor 9, and FIG. 5 is an exploded perspective view of the rotor 9. As shown in these figures, the rotor 9 includes a rotor core 32 rotatable about a rotation axis (axis C) together with the rotation axis 31, a rotation axis 31 having one end fixed to the rotor core 32 and the other end protruding axially from the rotor core 32, four permanent magnets 33 arranged on the outer peripheral portion of the rotor core 32, a pair of load receiving blocks 70 respectively arranged on one axial end side and the other end side of the rotor core 32, and a metal magnet cover 71 that covers the rotor core 32, the permanent magnets 33, and the pair of load receiving blocks 70 from the outside in the axial and radial directions.

[0028] FIG. 6 is a perspective view of the rotor 9 with the magnet cover 71 removed, and FIG. 7 is a plan view of the rotor 9 with the magnet cover 71 removed. The rotor core 32 is formed by laminating a plurality of steel plates (electromagnetic steel plates) of substantially the same shape in the axial direction. The rotor core 32 has a substantially cylindrical core body portion 32A and four salient poles 32B protruding radially from the outer periphery of the core body portion 32A.

[0029] The four salient poles 32B project from the outer periphery of the core main body 32A at equal intervals in the circumferential direction. In the present embodiment, the outer peripheral surface of the core main body 32A is formed in a substantially circular shape centered on the axis C (rotation axis) of the rotor 9. The side surfaces of each salient pole 32B facing the circumferential direction of the rotor core 32 are constituted by flat surfaces. A permanent magnet 33 is assembled between the adjacent salient poles 32B in the circumferential direction of the rotor core 32.

[0030] In the present embodiment, the permanent magnet 33 is formed in a substantially arc shape when viewed in the axial direction. However, the inner peripheral side of the permanent magnet 33 is formed in a substantially arc shape (substantially coinciding with the outer peripheral surface of the core main body 32A) centered on the axis C (rotation axis) of the rotor 9, while the outer peripheral side of the permanent magnet 33 is formed in an arc shape with a smaller radius of curvature than the inner peripheral side. Each salient pole 32B of the rotor core 32 is formed such that the distance from the axis C (rotation axis) of the rotor 9 to the radially outer end is substantially the same as the distance from the axis C (rotation axis) of the rotor 9 to the maximum bulging portion of the outer peripheral surface of the permanent magnet 33.

[0031] As shown in FIG. 3, the axial length of each permanent magnet 33 is formed to be longer than the axial length of the rotor core 32. In the case of the present embodiment, each permanent magnet 33 is set to protrude by substantially the same length on one end side and the other end side in the axial direction with respect to the salient pole 32B in the state of being assembled to the rotor core 32.

[0032] Further, as shown in FIG. 5, on the inner peripheral surface of the rotor core 32, four arc surfaces 72 centered on the axis C (rotation axis) of the rotor 9 and relief grooves 73 extending radially outward from between the adjacent arc surfaces 72 are formed. Each relief groove 73 extends by the same length radially outward, and the end portion in the extending direction is an arc-shaped engaging portion 73a. A locking claw 74 (core restricting portion) of a load receiving block 70 described later is fitted into the engaging portion 73a of each relief groove 73. Further, the rotating shaft 31 of the motor 2 is press-fitted and fixed to the four arc surfaces 72 on the inner periphery of the rotor core 32. The four arc surfaces 72 on the inner periphery of the rotor core 32 constitute a shaft core hole 69 into which the rotating shaft 31 is fitted (fixed in the inserted state).

[0033] The magnet cover 71 has a cylindrical peripheral wall portion 71a, and a pair of flange portions 71b and 71c that extend radially inward by bending from one axial end portion and the other end portion of the peripheral wall portion 71a, respectively. Inside the peripheral wall portion 71a, the rotor core 32 and the permanent magnet 33 are arranged together with a pair of load receiving blocks 70. At least one of the pair of flange portions 71b and 71c is a caulked flange formed by plastically deforming the end portion of the peripheral wall portion 71a by caulking. Hereinafter, one flange portion 71c is formed by bending in advance, and the other flange portion 71b will be described as being formed by caulking after loading the rotor core 32 and the like.

[0034] FIG. 8 is a perspective view of the load receiving block 70. FIG. 8(A) is a view of the load receiving block 70 as seen from the first direction, and FIG. 8(B) is a view of the load receiving block 70 as seen from the second direction. The load receiving blocks 70 arranged on the first direction side and the second direction side of the rotor core 32 have the same shape, and both are assembled to the rotor core 32 with their front and back reversed. The load receiving block 70 has an annular portion 70A that is arranged to overlap the axial end face of the core main body portion 32A of the rotor core 32, four leg portions 70B that project radially from the outer peripheral surface of the annular portion 70A and are arranged to overlap the axial end faces of the respective salient poles 32B of the rotor core 32, and an end wall 70C that is integrally connected to the outside in the axial direction of the annular portion 70A and the leg portions 70B and projects radially outward from the annular portion 70A and has a perforated disc shape. The four leg portions 70B project at equal intervals on the outer periphery of the annular portion 70A. The load receiving block 70 is formed of, for example, a hard resin. The load receiving block 70 is formed in a shape that substantially overlaps the rotor core 32 when viewed in the axial direction. The annular portion 70A is arranged to overlap the axial end face of the core main body portion 32A of the rotor core 32.

[0035] Each load receiving block 70 is arranged so as to overlap with the axial end face of the rotor core 32, and the radially outer region is arranged between the end face of the rotor core 32 and the flange portions 71b, 71c of the magnet cover 71. In the present embodiment, the upper flange portion 71b in FIG. 3 serves as a caulking flange, and when caulking the flange portion 71b, the caulking load is received by the leg portion 70B of the upper load receiving block 70 through the flange portion 71b.

[0036] The four leg portions 70B of the load receiving block 70 are arranged so as to overlap with the axial end faces of the respective salient poles 32B of the rotor core 32. The end wall 70C is formed in a disk shape (a disk shape with a hole) having a radius substantially the same as the length from the axis C of the rotor core 32 to the tip end portion of the leg portion 70B. The end wall 70C closes the space between the adjacent leg portions 70B in the circumferential direction at a position outside the axial direction of the leg portion 70B.

[0037] On the position along the extension of each leg portion 70B of the inner peripheral edge portion of the annular portion 70A of the load receiving block 70, a locking claw 74 that projects toward the rotor core 32 substantially along the axial direction is integrally formed. The locking claw 74 is formed with a substantially semicircular cross section, and is adapted to be fitted into the relief groove 73 (engagement portion 73a) on the inner periphery of the rotor core 32 when the load receiving block 70 is assembled to the end face of the rotor core 32. The load receiving block 70 is restricted from relative displacement in the radial direction with respect to the rotor core 32 by fitting each locking claw 74 into the corresponding relief groove 73 (engagement portion 73a).

[0038] Also, a pair of press-fitting protrusions 76 are formed on the side surface near the base of each leg portion 70B of the load receiving block 70. Each press-fitting protrusion 76 extends along the axial direction, and is formed such that the bulging height gradually decreases toward the side close to the rotor core 32. When the load receiving block 70 is assembled to the rotor core 32 having the permanent magnets 33 arranged on the outer peripheral portion, the ends of the respective permanent magnets 33 are inserted and arranged between the adjacent leg portions 70B of the load receiving block 70. At this time, the contact surface of the permanent magnet 33 contacts the press-fitting protrusion 76. Thereby, the circumferential displacement of the permanent magnet 33 is restricted.

[0039] At a position between adjacent leg portions 70B on the end wall 70C, a circular confirmation hole 57 is formed. The confirmation hole 57 is formed at a position facing the axial end surfaces of the permanent magnets 33 so that when the load receiving block 70 is assembled into the magnet cover 71 together with the rotor core 32 holding the permanent magnets 33, the positions of the permanent magnets 33 can be visually confirmed from the outside of the rotor 9. In the case of this embodiment, four confirmation holes 57 are provided so as to correspond one-to-one with the permanent magnets 33.

[0040] In the case of the rotor 9 of this embodiment, the outer axial end of the load receiving block 70 is covered by a substantially disk-shaped end wall 70C. For this reason, when the load receiving block 70 is inserted into the magnet cover 71 together with the rotor core 32 holding the permanent magnets 33 and the ends (flange portions 71b, 71c) of the magnet cover 71 are caulked in that state, the ends of the magnet cover 71 are caulked and fixed to the end wall 70C so as to cover the entire outer periphery of the end wall 70C.

[0041] The end wall 70C of the load receiving block 70 is formed with a flat outer axial surface so that a caulking load acts uniformly over the entire outer periphery of the end wall 70C when the end of the magnet cover 71 is caulked (see Fig. 8(A)). On the other hand, a plurality of reinforcing ribs 58 extending in the radial direction are provided protruding from the inner axial surface of the end wall 70C as shown in Fig. 8(B).

[0042] In addition, a plurality of recesses 59 with a low protruding height from the end wall 70C are formed at a plurality of locations in the annular portion 70A of the load receiving block 70. Each recess 59 is arranged between the base ends of adjacent leg portions 70B in the circumferential direction in the annular portion 70A.

[0043] Further, when the load receiving block 70 is assembled into the magnet cover 71, the portion shown with dots in Fig. 8(B) (the region excluding the recesses 59 in the inner axial end surface of the annular portion 70A and the inner axial end surfaces of the leg portions 70B) abuts against the axial end surfaces of the core main body portion 32A and the salient poles 32B of the rotor core 32. In this embodiment, the region protruding axially inward of the load receiving block 70 is separated into four blocks in the circumferential direction with the recess 59 interposed therebetween. Therefore, it is possible to easily adjust a mold for accurately bringing the end face of each block into contact with the axially end face of the rotor core 32.

[0044] FIG. 9 is an enlarged cross-sectional view of part IX of the rotor 9 shown in FIG. 3. As shown in this figure, a small-diameter portion 70Cb having an outer diameter slightly smaller than that of other portions (hereinafter referred to as “general portion 70Ca”) is formed at the axially outer end of the end wall 70C of the load receiving block 70. The general portion 70Ca and the small-diameter portion 70Cb are connected by an inclined surface 70Cc that tapers from the general portion 70Ca toward the small-diameter portion 70Cb. The general portion 70Ca and the inclined surface 70Cc are constituted by an angular portion 64a forming an obtuse angle. Further, the axially outer end of the small-diameter portion 70Cb (the axially outer end of the end wall 70C) is constituted by an arcuate curved surface portion 64b.

[0045] The angular portion 64a and the curved surface portion 64b on the outer periphery of the end wall 70C serve as two caulking starting points when caulking the axially end portion (flange portion 71b) of the magnet cover 71 to the load receiving block 70. That is, the angular portion 64a becomes the first caulking starting point (the first caulking starting point) when a caulking load is applied to the axially end portion of the magnet cover 71, and the curved surface portion 64b becomes the next caulking starting point (the second caulking starting point) when a caulking load is applied to the axially end portion of the magnet cover 71. Therefore, when this configuration is adopted, the stress acting on the load receiving block 70 from the magnet cover 71 can be relaxed during caulking of the axially end portion of the magnet cover 71, and deterioration and damage of the load receiving block 70 can be prevented.

[0046] (Assembly of Rotor) When assembling the rotor 9, first, a permanent magnet 33 is arranged on the outer peripheral portion of the rotor core 32. In this state, load receiving blocks 70 are temporarily assembled to each end face in the axial direction of the rotor core 32, and in this state, the assembly is inserted into the magnet cover 71. At this time, one flange portion 71c of the magnet cover 71 is formed by being bent in advance. Next, caulking is performed on the edge on the other (second direction side) in the axial direction of the magnet cover 71 from this state, and a flange portion 71b (caulking flange) is formed by plastic deformation, and the flange portion 71b is pressed against the end faces of the respective leg portions 70B of the load receiving block 70. As a result, the rotor core 32 and the permanent magnet 33 are fixed inside the magnet cover 71 together with the load receiving block 70.

[0047] (Rotor and Rotating Shaft) In the rotor 9 configured as described above, an end portion (one end portion) on the side opposite to the worm shaft 44 side of the rotating shaft 31 is fitted into the axial center hole 69 of the rotor core 32, and thereby it is fixed integrally with the rotating shaft 31. The rotating shaft 31 is fixed to the rotor core 32 in a state where the end portion (the other end portion) on the worm shaft 44 side protrudes from the rotor core 32 in the second direction. The rotating shaft 31 is fixed to the gear case 40 by bearings 46 and 47 attached to the other end portion. Thereby, the rotor 9 is fixed to the gear case 40 in a cantilever manner with the other end portion side (second direction side) of the rotating shaft 31 as the fixed end and the rotor core 32 side (first direction side) as the free end. The rotating shaft 31 does not completely penetrate the rotor core 32 in the axial direction, and is fixed in a state where the end face 31e facing the first direction (hereinafter referred to as the "rotating shaft end face 31e") stops at a predetermined position inside the axial center hole 69. Specifically, as shown in FIG. 3, the rotating shaft 31 is arranged on the second direction side of the end face of the rotor core 32 facing the first direction (hereinafter referred to as the "rotor core end face 32s") and on the first direction side of the intermediate position P (intermediate position in the stacking direction) in the axial direction of the rotor core 32.

[0048] (Effects of the Embodiment) In the motor device 1 of the present embodiment, a rotary shaft end face 31e facing the first direction of the rotary shaft 31 is disposed on the second direction side with respect to a rotor core end face 32s facing the first direction of the rotor core 32. Therefore, even when increasing the number of stacked steel plates of the rotor core 32 to increase the motor output, the motor output can be increased without increasing the axial length of the rotary shaft 31, and accordingly, weight reduction can be achieved. Furthermore, in the motor device 1 of the present embodiment, the rotary shaft end face 31e is disposed on the first direction side (the position opposite to the speed reduction unit 3) with respect to an intermediate position P in the axial direction (stacking direction) of the rotor core 32. For this reason, in the rotor 9, the center of gravity position of the rotor core 32, which is a heavy object, is always fixed to the rotary shaft 31. Therefore, the motor device 1 of the present embodiment has a structure in which the other end portion in the axial direction of the rotary shaft 31 protruding from the rotor core 32 is cantilever supported by a casing (gear case 40) via bearings 46 and 47, and while suppressing the wobbling of the rotor 9, the output can be improved and the weight can be reduced. Note that if the positional relationship between the rotary shaft end face 31e of the rotary shaft 31 and the rotor core 32 satisfies the above relationship, a common rotary shaft 31 can be used in a plurality of types of motor devices having different numbers of stacked steel plates of the rotor core 32 (different motor outputs). In this case, the production efficiency at the production site can be increased.

[0049] Also, in the motor device 1 of the present embodiment, a speed reduction mechanism 41 including a worm shaft 44 provided on the rotary shaft 31 and a worm wheel 45 meshing with the worm shaft 44 is housed in a casing (gear case 40), and both end portions along the axial direction of the worm shaft 44 are supported by the casing (gear case 40) via bearings 46 and 47. In the case of a structure in which the worm shaft 44 is provided on the rotary shaft 31 of the motor 2, a reaction force that tilts the worm shaft 44 is generated from the worm wheel 45 to the worm shaft 44 during power output. However, in the motor device 1 of the present embodiment, since the rotor 9 is supported by the rotary shaft 31 at the center of gravity position of the rotor core 32, which is a heavy object, the wobbling of the rotor 9 in the rotary shaft 31 of the motor 2 can be further reduced.

[0050] Further, in the motor device 1 of the present embodiment, the rotor core 32 has a core main body portion 32A having a shaft core hole 69 fixed with the rotation shaft 31 inserted therein, and a plurality of salient poles 32B protruding in the radial direction from the outer periphery of the core main body portion 32A. The rotor 9 includes a permanent magnet 33 disposed between adjacent salient poles 32B, and a magnet cover 71 that covers the outside of the rotor core 32 and the permanent magnet 33. The magnet cover 71 has a peripheral wall portion 71a that covers the radially outer side of the rotor core 32 and the permanent magnet 33, and flange portions 71b and 71c that are bent radially inward from the axial end portions of the peripheral wall portion 71a. Therefore, in the motor device 1 of the present embodiment, the plurality of steel plates of the rotor core 32 laminated in the axial direction are covered by the magnet cover 71 together with the permanent magnet 33. Accordingly, when the motor device 1 of the present embodiment is adopted, even if some of the plurality of steel plates of the rotor core 32 are not directly fixed to the rotation shaft 31, the displacement of the steel plates can be suppressed by the magnet cover 71.

[0051] Furthermore, in the motor device 1 of the present embodiment, a load receiving block 70 is disposed between the axial end surface of the rotor core 32 and the flange portions 71b and 71c of the magnet cover 71, and the axial end surface of the rotor core 32 and the flange portions 71b and 71c are in contact with the load receiving block 70. For this reason, when the rotor core 32 and the permanent magnet 33 are set inside the peripheral wall portion 71a of the magnet cover 71 and the flange portions 71b and 71c of the magnet cover 71 are caulked during the manufacture of the rotor 9, the caulking load can be received by the load receiving block 70. As a result, the caulking load does not directly act on the permanent magnet 33 in the magnet cover 71, and it becomes possible to prevent damage and deterioration of the permanent magnet 33 during the manufacture of the rotor 9.

[0052] Note that the present invention is not limited to the above-described embodiment, and various design changes are possible without departing from the gist thereof.

Description of Reference Numerals

[0053] 1... Motor device 9... Rotor 32… Rotor core 32A… Core main body 32B… Pole projection 33… Permanent magnet 57… Confirmation hole 59… Recess 70… Load receiving block 70A… Annular part 70B… Leg part 70C… End wall 71… Magnet cover 71a… Peripheral wall part 71b, 71c… Flange part 74… Locking claw

Claims

1. a rotor core made of a plurality of steel plates laminated in an axial direction along a rotation axis; A plurality of permanent magnets arranged on an outer periphery of the rotor core; a magnet cover for covering the rotor core and the radially outer sides of the permanent magnets; A pair of load-receiving blocks are respectively arranged at one end side and the other end of the rotor core in the axial direction; A rotor comprising: The rotor core is A substantially cylindrical core body portion; A plurality of salient poles protruding in a radial direction from an outer periphery of the core body portion; having The permanent magnet is disposed between adjacent ones of the salient poles, The load-receiving block is an annular portion disposed on a core end surface of the core body portion in the axial direction; a plurality of legs protruding in a radial direction from an outer circumferential surface of the annular portion and arranged to overlap with salient pole end surfaces in the axial direction of each of the salient poles; an end wall integrally connected to the annular portion and the leg portion on the axially outer side thereof and extending radially outward from the annular portion; having The annular portion has a plurality of recesses each having a low protruding height from the end wall, Each of the recesses is disposed between base ends of the legs adjacent to each other in the circumferential direction of the annular portion. A rotor characterized by:

2. 2. The rotor according to claim 1, the annular portion has a plurality of protruding portions provided between the recessed portions adjacent to each other in the circumferential direction, Each of the legs is provided so as to protrude from an outer circumferential surface of each of the protrusions, The axially inner convex end surface of each of the convex portions abuts against the core end surface, The leg end surface on the inner side in the axial direction of each of the legs abuts against the salient pole end surface on the outer side in the axial direction of each of the salient poles. A rotor characterized by:

3. 3. The rotor according to claim 2, The annular portion has a locking claw protruding inward in the axial direction from each of the protruding end faces and provided on an extension line of the leg portion along the radial direction, The locking claw is locked to the inner circumferential surface of the core body. A rotor characterized by:

4. The rotor according to any one of claims 1 to 3, the annular portion has a viewing hole disposed between adjacent legs on the end wall; The confirmation hole is formed at a position facing a magnet end face of each of the permanent magnets in the axial direction when the load receiving block is assembled in the magnet cover together with the permanent magnets and the rotor core. A rotor characterized by:

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