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 radially inside a stator around which a coil is wound. In this type of motor device, a rotor in which a plurality of permanent magnets are 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 formed 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 constructed by stacking multiple steel plates in the axial direction. Therefore, the shape of the multiple steel plates constituting the rotor core is difficult to stabilize 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 that can stabilize the shape of the steel plates constituting the rotor core. [Means for solving the problem]

[0008] To solve the above problems, the rotor according to the present invention employs the following configuration. That is, in a first aspect of the present invention, the rotor comprises a rotor core made of a plurality of steel plates stacked in the axial direction along the axis of rotation, a plurality of permanent magnets arranged on the outer circumference of the rotor core, a magnet cover covering the radially outer side of the rotor core and the plurality of permanent magnets, and a pair of load-bearing blocks arranged at one end and the other end of the rotor core in the axial direction, wherein the rotor core has a substantially cylindrical core body and a plurality of salient poles projecting radially from the outer circumference of the core body, and the permanent magnets are arranged between adjacent salient poles The load-receiving block is positioned such that it has an annular portion that is placed on top of the axial core end face of the core body, a plurality of legs that protrude radially from the outer circumferential surface of the annular portion and are placed on top of the axial salient pole end faces of each salient pole, and an end wall that is integrally connected to the axial outer side of the annular portion and the legs and extends radially outward from the annular portion, wherein the annular portion has a plurality of recesses that protrude at a low height from the end wall, and each of the recesses is located between the base ends of adjacent legs in the circumferential direction of the annular portion.

[0009] In a second aspect of the present invention, the rotor of the first aspect is characterized in that the annular portion has a plurality of protrusions provided between each of the adjacent recesses in the circumferential direction, each leg portion is provided protruding from the outer circumferential surface of each protrusion, the axially inward end face of each protrusion abuts against the core end face, and the axially inward end face of each leg portion abuts against the axially outward salient pole end face of each salient pole.

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

[0011] In a fourth aspect of the present invention, in any one of the rotors of the first to third aspects, the end wall The end wall has confirmation holes provided between each adjacent leg portion, and the confirmation holes are formed at positions facing the axial magnet end faces of each permanent magnet when the load-receiving block is assembled in the magnet cover together with the permanent magnets and the rotor core. [Effects of the Invention]

[0012] According to the present invention, the shape of the steel plates constituting the rotor core can be stabilized. [Brief explanation of the drawing]

[0013] [Figure 1] This is a perspective view of the motor device of the embodiment. [Figure 2] This is a cross-sectional view of the motor device of the embodiment along the line II-II in Figure 1. [Figure 3] This is a longitudinal cross-sectional view of the rotor of the embodiment. [Figure 4] This is a perspective view of the rotor of the embodiment. [Figure 5] This is an exploded perspective view of the rotor of the embodiment. [Figure 6]Perspective view of the rotor of an embodiment with the magnet cover removed. [Figure 7] Plan view of the rotor of an embodiment with the magnet cover removed. [Figure 8] Perspective view of the load-bearing block of an embodiment. [Figure 9] Enlarged cross-sectional view at IX in FIG. 3 of the rotor of an embodiment.

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described based on 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 reduction unit 3 that reduces and outputs the rotation of the motor 2, and a controller 4 that performs drive control 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", the 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 provided rotatably 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 separable 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 reduction part 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] Also, outer flange portions 16, 17 that project outward in the radial direction 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 abutting 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 main body portion 21 and a plurality (for example, six) of teeth 22 that project radially inward from the inner peripheral portion of the core main body portion 21. The inner peripheral surface of the core main 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 positioned radially inward of the stator 8 with a small gap between them. The rotor 9 comprises a rotating shaft 31, a substantially cylindrical rotor core 32 in which the rotating shaft 31 is press-fitted and fixed to the inner circumference, and four permanent magnets 33 (see Figures 3, 5, 6, etc.) assembled to the outer circumference of the rotor core 32. In this embodiment, the rotating shaft 31 is formed integrally with the worm shaft 44 that constitutes the reduction gear 3. However, the worm shaft 44 is not limited to this and may be formed separately from the rotating shaft 31 and connected to the end of the rotating shaft 31. The rotating shaft 31 and the worm shaft 44 are rotatably supported in the gear case 40 (casing) via bearings 46 and 47. The rotating shaft 31 and the worm shaft 44 rotate around the axis of rotation (axis C). For example, ferrite magnets are used as the permanent magnets 33. However, the permanent magnet 33 is not limited to this; neodymium bonded magnets, neodymium sintered magnets, and the like can also be used. The detailed structure of rotor 9 will be explained later.

[0021] (Deceleration part) The reduction unit 3 comprises a gear case 40 integrated with the motor case 5, and a reduction mechanism 41 housed within the gear case 40. The gear case 40 is made of a metal material with excellent heat dissipation properties, such as an aluminum alloy. The gear case 40 is formed in a box shape with an opening 40a on one side. The gear case 40 has a gear housing section 42 that houses the reduction mechanism 41 inside. In addition, an opening 43 is formed in the side wall 40b of the gear case 40 where the first motor case 6 is integrally formed, connecting the through hole of the first motor case 6 to the gear housing section 42.

[0022] A roughly cylindrical bearing boss 49 is provided protruding from the bottom wall 40c of the gear case 40. The bearing boss 49 is for rotatably supporting the output shaft 48 of the reduction mechanism 41, and a sliding bearing (not shown) is arranged on its inner circumference. An O-ring (not shown) is fitted to the inside of the tip of the bearing boss 49. In addition, multiple ribs 52 are provided protruding from the outer circumference of the bearing boss 49 to ensure rigidity.

[0023] The reduction mechanism 41 housed in the gear housing 42 consists of a worm shaft 44 and a worm wheel 45 that meshes with the worm shaft 44. The worm shaft 44 is rotatably supported at both axial ends by the gear case 40 via bearings 46 and 47. The worm shaft 44 is coaxially and integrally mounted with the motor 2's rotation shaft 31. The output shaft 48 of the reduction mechanism 41 is coaxially and integrally mounted on the worm wheel 45. The rotation axes of the worm wheel 45 and the output shaft 48 are arranged so as to be approximately perpendicular to the rotation axis (axis center C) of the worm shaft 44 (motor 2's rotation shaft 31). The output shaft 48 protrudes to the outside via a bearing boss 49 of the gear case 40. A spline 48a is formed at the protruding tip of the output shaft 48, which can be connected to an object to be driven by the motor.

[0024] Furthermore, the worm wheel 45 is equipped with a sensor magnet (not shown). The position of this sensor magnet is detected by a magnetic detection element 61 provided in the controller 4, which will be described later. In other words, 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 a magnetic detection element 61 is mounted. The controller board 62 is positioned within an 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] The controller board 62 is connected to the terminals of multiple coils 24 drawn from the stator core 20. The controller board 62 is also electrically connected to the terminals of the connector 11 (see Figure 1) provided on the cover 63. In addition to the magnetic detection element 61, the controller board 62 is equipped with a power module (not shown) consisting of switching elements such as FETs (Field Effect Transistors) that control the drive voltage supplied to the coils 24, and capacitors (not shown) that smooth the voltage.

[0027] (Detailed rotor structure) Figure 3 is a longitudinal cross-sectional view of the rotor 9, and Figure 4 is a perspective view of the rotor 9. Figure 5 is an exploded perspective view of the rotor 9. As shown in these figures, the rotor 9 comprises a rotor core 32 that can rotate together with the rotation shaft 31 around the axis of rotation (axis C), a rotation shaft 31 with 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 circumference of the rotor core 32, a pair of load-bearing blocks 70 arranged on one end and the other end of the rotor core 32 in the axial direction, and a metal magnet cover 71 that covers the rotor core 32, the permanent magnets 33 and the pair of load-bearing blocks 70 from the outside in the axial and radial directions.

[0028] Figure 6 is a perspective view of the rotor 9 with the magnet cover 71 removed, and Figure 7 is a plan view of the rotor 9 with the magnet cover 71 removed. The rotor core 32 is constructed by stacking multiple 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 that protrude radially from the outer circumference of the core body portion 32A.

[0029] The four salient poles 32B protrude from the outer circumference of the core body 32A at equal intervals in the circumferential direction. In this embodiment, the outer surface of the core body 32A is formed in a substantially circular shape centered on the axis C (rotation axis) of the rotor 9. The side surface of each salient pole 32B facing the rotor core 32 in the circumferential direction is made of a flat surface. Permanent magnets 33 are assembled between adjacent salient poles 32B in the circumferential direction of the rotor core 32.

[0030] In this embodiment, the permanent magnet 33 is formed in a substantially arc shape when viewed in the axial direction. However, the inner circumference of the permanent magnet 33 is formed in a substantially arc shape centered on the axis C (axis of rotation) of the rotor 9 (a substantially arc shape that almost coincides with the outer surface of the core body 32A), while the outer circumference of the permanent magnet 33 is formed in a circular arc shape with a smaller radius of curvature than the inner circumference. Each salient pole 32B of the rotor core 32 is formed such that the distance from the axis C (axis of rotation) of the rotor 9 to its radially outer end is approximately the same as the distance from the axis C (axis of rotation) of the rotor 9 to the maximum bulge on the outer surface of the permanent magnet 33.

[0031] As shown in Figure 3, the axial length of each permanent magnet 33 is formed to be longer than the axial length of the rotor core 32. In this embodiment, when assembled to the rotor core 32, each permanent magnet 33 is set to protrude approximately the same length in the axial direction from one end and the other end relative to the salient pole 32B.

[0032] Furthermore, as shown in Figure 5, the inner circumferential surface of the rotor core 32 has four arcuate surfaces 72 centered on the axis C (rotation axis) of the rotor 9, and relief grooves 73 extending radially outward from between adjacent arcuate surfaces 72. Each relief groove 73 extends radially outward by the same length, and its end in the extension direction is an arcuate engaging portion 73a. The locking claws 74 (core restricting portion) of the load-receiving block 70, which will be described later, are fitted into the engaging portion 73a of each relief groove 73. The rotating shaft 31 of the motor 2 is press-fitted and fixed into the four arcuate surfaces 72 on the inner circumference of the rotor core 32. The four arcuate surfaces 72 on the inner circumference of the rotor core 32 constitute the axial center hole 69 into which the rotating shaft 31 is fitted (fixed in an inserted state).

[0033] The magnet cover 71 has a cylindrical peripheral wall portion 71a and a pair of flange portions 71b and 71c that bend radially inward from one axial end and the other end of the peripheral wall portion 71a, respectively. Inside the peripheral wall portion 71a, the rotor core 32 and permanent magnets 33 are arranged together with a pair of load-bearing blocks 70. At least one of the pair of flange portions 71b and 71c is a crimped flange formed by plastically deforming the end of the peripheral wall portion 71a by crimping. In the following description, one flange portion 71c is pre-bent, and the other flange portion 71b is formed by crimping after the rotor core 32 and the like are installed.

[0034] Figure 8 is a perspective view of the load-bearing block 70. Figure 8(A) is a view of the load-bearing block 70 from a first direction, and Figure 8(B) is a view of the load-bearing block 70 from a second direction. The load-bearing blocks 70, which are positioned on the first and second direction sides of the rotor core 32, are identical in shape, and are assembled to the rotor core 32 with their front and back reversed. The load-bearing block 70 has an annular portion 70A that is positioned on top of the axial end face of the core body portion 32A of the rotor core 32, four leg portions 70B that protrude radially from the outer circumferential surface of the annular portion 70A and are positioned on top of the axial end faces of each salient pole 32B of the rotor core 32, and a perforated disc-shaped end wall 70C that is integrally connected to the axial outer side of the annular portion 70A and the leg portions 70B and protrudes radially outward from the annular portion 70A. The four leg portions 70B protrude at equal intervals on the outer circumferential surface of the annular portion 70A. The load-bearing block 70 is formed of, for example, a hard resin. The load-bearing 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 positioned to overlap the axial end face of the core body portion 32A of the rotor core 32.

[0035] Each load-bearing block 70 is positioned on top of the axial end face of the rotor core 32, with its radially outer region positioned between the end face of the rotor core 32 and the flange portions 71b and 71c of the magnet cover 71. In this embodiment, the upper flange portion 71b in Figure 3 becomes a crimping flange, and during the crimping operation of the flange portion 71b, the crimping load is received by the leg portion 70B of the upper load-bearing block 70 through the flange portion 71b.

[0036] The four legs 70B of the load-bearing block 70 are positioned to overlap the axial end faces of each salient pole 32B of the rotor core 32. The end walls 70C are formed in the shape of a disc (perforated disc) with a radius approximately equal to the length from the axis C of the rotor core 32 to the tip of the leg 70B. The end walls 70C close the space between adjacent legs 70B in the circumferential direction at the axially outer position of the leg 70B.

[0037] A locking claw 74 is integrally formed on the inner peripheral edge of the annular portion 70A of the load-bearing block 70, at a position on the extension of each leg portion 70B, projecting toward the rotor core 32 side substantially along the axial direction. The locking claw 74 is formed in a substantially semicircular cross-section and is designed to fit into the relief groove 73 (engagement portion 73a) on the inner circumference of the rotor core 32 when the load-bearing block 70 is assembled to the end face of the rotor core 32. The relative radial displacement of the load-bearing block 70 with respect to the rotor core 32 is restricted by the fitting of each locking claw 74 into the corresponding relief groove 73 (engagement portion 73a).

[0038] Furthermore, a pair of press-fit protrusions 76 are formed on the side surface near the base of each leg portion 70B of the load-bearing block 70. Each press-fit protrusion 76 extends along the axial direction and is formed such that its bulge height gradually decreases toward the side closer to the rotor core 32. When a load-bearing block 70 is assembled to a rotor core 32 on which permanent magnets 33 are arranged around its outer circumference, the ends of each permanent magnet 33 are inserted between adjacent legs 70B of the load-bearing block 70. At this time, the contact surfaces of the permanent magnets 33 come into contact with the press-fit projections 76. This restricts the circumferential displacement of the permanent magnets 33.

[0039] Circular inspection holes 57 are formed on the end wall 70C between adjacent leg portions 70B. The inspection holes 57 are formed opposite the axial end faces of each permanent magnet 33 so that the position of each permanent magnet 33 can be visually confirmed from outside the rotor 9 when the load-bearing block 70 is assembled inside the magnet cover 71 together with the rotor core 32 that holds the permanent magnets 33. In this embodiment, four inspection holes 57 are provided so that there is a one-to-one correspondence with each permanent magnet 33.

[0040] In the rotor 9 of this embodiment, the axially outer end of the load-bearing block 70 is covered by a substantially disc-shaped end wall 70C. Therefore, when the load-bearing block 70 is inserted into the magnet cover 71 together with the rotor core 32 holding the permanent magnet 33, and the ends of the magnet cover 71 (flange portions 71b, 71c) are crimped in this state, the ends of the magnet cover 71 are crimped and fixed to the end wall 70C so as to cover the entire outer circumference of the end wall 70C.

[0041] The end wall 70C of the load-bearing block 70 is formed with a flat axial outer surface so that when the end of the magnet cover 71 is crimped, the crimping load is applied uniformly to the entire outer circumference of the end wall 70C (see Figure 8(A)). In contrast, the axial inner surface of the end wall 70C is provided with multiple reinforcing ribs 58 extending radially, as shown in Figure 8(B).

[0042] Furthermore, the annular portion 70A of the load-bearing block 70 has multiple recesses 59 formed therein, which protrude from the end wall 70C at a low height. Each recess 59 is located between the base ends of adjacent legs 70B in the circumferential direction of the annular portion 70A.

[0043] Furthermore, when the load-bearing block 70 is assembled inside the magnet cover 71, the portion indicated by the dots in Figure 8(B) (the area of ​​the axially inner end face of the annular portion 70A excluding the recess 59, and the axially inner end face of each leg portion 70B) contacts the core body portion 32A of the rotor core 32 and the axial end faces of the salient poles 32B. In this embodiment, the region of the load-bearing block 70 that protrudes axially inward is separated into four blocks in the circumferential direction, with the recess 59 in between. This makes it easy to adjust the mold to ensure that the end face of each block precisely contacts the axial end face of the rotor core 32.

[0044] Figure 9 is an enlarged cross-sectional view of section IX of the rotor 9 shown in Figure 3. As shown in the figure, a small-diameter portion 70Cb is formed at the axially outer end of the end wall 70C of the load-bearing block 70, with an outer diameter slightly smaller than that of the other parts (hereinafter referred to as the "general portion 70Ca"). 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 area between the general portion 70Ca and the inclined surface 70Cc is formed by an obtuse-angled corner portion 64a. Furthermore, the axially outer end of the small-diameter portion 70Cb (the axially outer end of the end wall 70C) is formed by an arc-shaped curved surface portion 64b.

[0045] The corner portion 64a and the curved portion 64b on the outer circumference of the end wall 70C serve as two crimping starting points when the axial end (flange portion 71b) of the magnet cover 71 is crimped to the load-receiving block 70. In other words, the corner portion 64a becomes the first crimping starting point when a crimping load is applied to the axial end of the magnet cover 71, and the curved portion 64b becomes the second crimping starting point when a crimping load is applied to the axial end of the magnet cover 71. Therefore, by adopting this configuration, the stress acting from the magnet cover 71 to the load-bearing block 70 during crimping of the axial end of the magnet cover 71 can be relieved, preventing deterioration and damage to the load-bearing block 70.

[0046] (Rotor assembly) When assembling the rotor 9, first, the permanent magnets 33 are placed on the outer circumference of the rotor core 32, and then the load-bearing blocks 70 are temporarily assembled to each axial end face of the rotor core 32, and then the assembly is inserted into the magnet cover 71. At this time, one flange portion 71c of the magnet cover 71 is formed in advance by bending. Next, from this state, the other axial edge (second direction side) of the magnet cover 71 is crimped to form a flange portion 71b (crimped flange) by plastic deformation, and the flange portion 71b is pressed against the end faces of each leg portion 70B of the load-bearing 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-bearing block 70.

[0047] (Rotor and rotating shaft) As described above, the rotor 9 is fixed integrally with the rotor core 32 by fitting the end of the rotating shaft 31 opposite to the worm shaft 44 side (one end) into the axial hole 69 of the rotor core 32. The rotating shaft 31 is fixed to the rotor core 32 with the end on the worm shaft 44 side (the other end) protruding from the rotor core 32 in a second direction. The rotating shaft 31 is fixed to the gear case 40 by bearings 46 and 47 attached to the other end. As a result, the rotor 9 is cantilevered to the gear case 40 with the other end of the rotating shaft 31 (the second direction side) as the fixed end and the rotor core 32 side (the 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 with its end face 31e facing the first direction (hereinafter referred to as "rotating shaft end face 31e") stopped at a predetermined position within the axial hole 69. Specifically, as shown in Figure 3, the rotating shaft 31 is positioned such that its end face 31e is on the second direction side of the end face of the rotor core 32 facing the first direction (hereinafter referred to as "rotor core end face 32s"), and on the first direction side of the axial intermediate position P (intermediate position in the stacking direction) of the rotor core 32.

[0048] (Effects of the embodiment) In this embodiment, the motor device 1 has a rotating shaft end face 31e facing a first direction of the rotating shaft 31 positioned on the second direction side of the rotor core end face 32s facing a first direction of the rotor core 32. Therefore, even when increasing the number of layers of steel plates in the rotor core 32 to increase the motor output, the motor output can be increased without increasing the axial length of the rotating shaft 31, and the weight can be reduced accordingly. Furthermore, in the motor device 1 of this embodiment, the end face 31e of the rotating shaft is positioned on the first direction side (opposite side of the reduction unit 3) from the intermediate position P in the axial direction (stacking direction) of the rotor core 32. As a result, the center of gravity of the rotor core 32, which is a heavy object, is always fixed to the rotating shaft 31. Therefore, the motor device 1 of this embodiment has a structure in which the other axial end of the rotating shaft 31 protruding from the rotor core 32 is cantilevered to the casing (gear case 40) via bearings 46 and 47, while suppressing the wobble of the rotor 9, thereby improving output and reducing weight. Furthermore, if the positional relationship between the end face 31e of the rotating shaft 31 and the rotor core 32 satisfies the above relationship, a common rotating shaft 31 can be used for multiple types of motor devices with different numbers of steel plate layers in the rotor core 32 (and thus different motor outputs). In this case, production efficiency at the production site can be increased.

[0049] Furthermore, in the motor device 1 of this embodiment, a reduction mechanism 41 equipped with a worm shaft 44 provided on the rotating shaft 31 and a worm wheel 45 that meshes with the worm shaft 44 is housed in a casing (gear case 40), and both ends of the worm shaft 44 along the axial direction are supported by the casing (gear case 40) via bearings 46 and 47. In the structure in which the worm shaft 44 is provided on the rotating shaft 31 of the motor 2, a reaction force is generated from the worm wheel 45 to the worm shaft 44 that causes the worm shaft 44 to tilt when power is output. However, in the motor device 1 of this embodiment, since the rotor 9 is supported on the rotating shaft 31 at the center of gravity of the heavy rotor core 32, the wobble of the rotor 9 on the rotating shaft 31 of the motor 2 can be reduced.

[0050] Furthermore, in the motor device 1 of this embodiment, the rotor core 32 has a core body portion 32A having an axial hole 69 into which the rotating shaft 31 is inserted and fixed, and a plurality of salient poles 32B protruding radially from the outer circumference of the core body portion 32A. The rotor 9 includes permanent magnets 33 positioned between adjacent salient poles 32B, and a magnet cover 71 that covers the outside of the rotor core 32 and the permanent magnets 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 magnets 33, and flange portions 71b and 71c that are bent radially inward from the axial end of the peripheral wall portion 71a. Therefore, in the motor device 1 of this embodiment, the plurality of steel plates of the rotor core 32, which are stacked in the axial direction, are covered by the magnet cover 71 together with the permanent magnets 33. Consequently, when the motor device 1 of this embodiment is adopted, even if some of the plurality of steel plates of the rotor core 32 are not directly fixed to the rotating shaft 31, the displacement of those steel plates can be suppressed by the magnet cover 71.

[0051] Furthermore, in this embodiment, the motor device 1 has a load-bearing block 70 positioned between the axial end face of the rotor core 32 and the flange portions 71b and 71c of the magnet cover 71, so that the axial end face of the rotor core 32 and the flange portions 71b and 71c are in contact with the load-bearing block 70. Therefore, when the rotor 9 is manufactured, the rotor core 32 and permanent magnets 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 crimped, and the crimping load can be received by the load-bearing block 70. As a result, the crimping load does not directly act on the permanent magnets 33 inside the magnet cover 71, making it possible to prevent damage or deterioration of the permanent magnets 33 during the manufacture of the rotor 9.

[0052] It should be noted that the present invention is not limited to the embodiments described above, and various design modifications are possible without departing from the spirit of the invention. [Explanation of Symbols]

[0053] 1…Motor device 9…Rotor 32...Rotor core 32A... Core body 32B…Salient pole 33…Permanent magnets 57…Confirmation hole 59…recess 70... Load-bearing block 70A... Ring section 70B…legs 70C…End wall 71…Magnetic cover 71a...peripheral wall part 71b, 71c... Flange section 74… Locking claw

Claims

1. A rotor core consisting of multiple steel plates stacked in the axial direction along the axis of rotation, Multiple permanent magnets arranged on the outer circumference of the rotor core, A magnet cover that covers the rotor core and the radially outer side of the plurality of permanent magnets, A pair of load-bearing blocks are arranged at one end and the other end of the rotor core in the axial direction, A rotor equipped with, The rotor core is A roughly cylindrical core body, Multiple salient poles protruding radially from the outer circumference of the core body, It has, The permanent magnet is positioned between a plurality of adjacent salient poles, The aforementioned load-bearing block is An annular portion is arranged to overlap the axial core end face of the core body, A plurality of legs project radially from the outer surface of the annular portion and are arranged to overlap the axial end faces of each of the salient poles, The annular portion and the leg portion are integrally connected on the axially outward side, and the end wall extends radially outward from the annular portion, It has, The annular portion has a plurality of recesses that protrude from the end wall at a low height, Each of the aforementioned recesses is located between the base ends of adjacent legs in the circumferential direction of the annular portion. A rotor characterized by the following features.

2. In the rotor according to claim 1, The annular portion has a plurality of protrusions provided between each of the recesses adjacent to each other in the circumferential direction, Each of the aforementioned legs is provided protruding from the outer circumferential surface of each of the aforementioned protrusions, The end face of each of the aforementioned protrusions on the axially inward side is in contact with the core end face, The axially inner end face of each leg portion is in contact with the axially outer end face of each salient pole. A rotor characterized by the following features.

3. In the rotor according to claim 2, The annular portion has locking claws that protrude axially inward from each of the end faces of the protrusions and are provided on the extension line along the radial direction of the leg portion. The rotor is characterized in that the locking claws are locked to the inner circumferential surface of the core body.

4. In the rotor according to any one of claims 1 to 3, The end wall has confirmation holes provided between each of the adjacent legs on the end wall, The confirmation holes are formed at positions facing the axial end faces of each permanent magnet when the load-receiving block is assembled within the magnet cover together with the permanent magnets and the rotor core. A rotor characterized by the following features.

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