Rotor and method for manufacturing the same

Abstract

To provide a rotor capable of reducing the number of components, improving performance, and being easily manufactured, and a method for manufacturing the same.SOLUTION: A rotor core 32 includes a cylindrical core main body 32a with an inner peripheral portion fixed to a rotary shaft 31, and four salient poles 32b in total that are provided on an outer peripheral portion of the core main body 32a, protrude outward in a radial direction of the core main body 32a, and is disposed at equal intervals (90-degree intervals) in a circumferential direction of the core main body 32a. A magnet 33 has a first end portion 33a that abuts against one salient pole 32b of the salient poles 32b adjacent to each other in the circumferential direction of the core main body 32a, and a second end portion 33b that faces the other salient pole 32b of the salient poles 32b adjacent to each other in the circumferential direction of the core main body 32a via a first gap G1. In a shaft direction of the rotary shaft 31, a length dimension of the rotor core 32 is longer than that of the magnet 33, and one side in the shaft direction of the rotor core 32 is exposed from one side in the shaft direction of the magnet 33.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a rotor for use in an electric motor and a method for manufacturing the same. [Background technology]

[0002] For example, Patent Document 1 describes a rotor including a rotor core, a magnet provided on the outer periphery of the rotor core, a magnet cover supporting the outer periphery of the magnet, and resin holders provided on both axial sides of the rotor core. Specifically, the magnet is disposed between a plurality of salient poles provided on the outer periphery of the rotor core, and is brought close to one of the adjacent salient poles by a pair of holders. The magnet cover covers the rotor core and the magnet, including the pair of holders, from the radial outside. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2022-146185 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, the technology described in Patent Document 1 has problems in that the pair of holders occupy a large proportion of the axial dimension of the rotor, resulting in a small output torque relative to the size and a large number of parts.In addition, because the resin holders are disposed on both axial sides of the rotor, there is a problem in that the position of the assembled rotor varies when it is set in the magnetizing device.

[0005] An object of the present invention is to provide a rotor which can be easily manufactured while reducing the number of parts and improving performance, and a manufacturing method thereof. [Means for solving the problem]

[0006] The rotor of the present invention comprises a rotor core that rotates integrally with a rotating shaft, a plurality of magnets provided on the outer periphery of the rotor core and arranged circumferentially of the rotor core, and a magnet holder that supports the outer periphery of the magnets and prevents the magnets from falling off from the rotor core, wherein the rotor core has a cylindrical core body whose inner periphery is fixed to the rotating shaft, and a plurality of salient poles provided on the outer periphery of the core body, protruding radially outward from the core body, and arranged at equal intervals in the circumferential direction of the core body, and the magnets have a first end that abuts against one of the salient poles adjacent to each other in the circumferential direction of the core body, and a second end that faces the other of the salient poles adjacent to each other in the circumferential direction of the core body, via a gap, and the length dimension of the rotor core is longer than the length dimension of the magnets in the axial direction of the rotating shaft, and one axial side of the rotor core is exposed from one axial side of the magnets.

[0007] In the method for manufacturing a rotor of the present invention, a rotor is manufactured including a rotor core which rotates integrally with a rotating shaft, a plurality of magnets provided on an outer periphery of the rotor core and arranged in a circumferential direction of the rotor core, and a magnet holder which supports the outer periphery of the magnets and prevents the magnets from falling off the rotor core, the method including a rotor core setting step of setting the rotor core to which the rotating shaft is fixed on a base, a magnet material arrangement step of arranging a magnet material to become the magnets between a plurality of salient poles provided on the radial outside of a core body of the rotor core, and a magnet holder for supporting the magnets. the magnet material is abutted against one of the salient poles adjacent to each other in the circumferential direction of the core body by rotating a turntable having support claws for supporting a rotor core relative to the base; the magnet holder mounting process is a process for mounting the magnet holder on the outer periphery of the magnet material while the magnet material is abutted against one of the salient poles; and the magnet material magnetizing process is a process for magnetizing the magnet material by setting an exposed portion of the rotor core exposed from one axial side of the magnet material in a magnetizing device in the axial direction of the rotating shaft. Effect of the Invention

[0008] According to the present invention, it is possible to realize a rotor that can be easily manufactured while reducing the number of parts and improving performance, and a manufacturing method thereof. [Brief description of the drawings]

[0009] [Figure 1] FIG. 4 is a perspective view showing the output gear side of the sunroof motor. [Diagram 2] FIG. 2 is a cross-sectional view of the sunroof motor taken along the axial direction of the rotating shaft. [Diagram 3] FIG. 2 is a perspective view showing the rotor assembly alone. [Figure 4] FIG. 3 is a cross-sectional view of the rotor assembly taken along line AA in FIG. 2. [Diagram 5] FIG. 2 is a cross-sectional view of the rotor assembly taken along the axial direction of the rotating shaft. [Figure 6] FIG. 4 is a diagram illustrating an assembly procedure (1) of the rotor assembly. [Figure 7] 1A to 1C are diagrams illustrating a procedure (1) for mounting magnets to a rotor core. [Figure 8] 13A to 13C are diagrams illustrating a procedure (2) for mounting magnets to a rotor core. [Figure 9] 13A to 13C are diagrams illustrating a procedure (2) for mounting magnets to a rotor core. [Figure 10] FIG. 11 is a diagram illustrating the rotor assembly assembly procedure (2). DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings.

[0011] Figure 1 is an oblique view showing the output gear side of the sunroof motor, Figure 2 is a cross-sectional view of the sunroof motor along the axial direction of the rotating shaft, Figure 3 is an oblique view showing the rotor assy alone, Figure 4 is a cross-sectional view of the rotor assy along line AA in Figure 2, and Figure 5 is a cross-sectional view of the rotor assy along the axial direction of the rotating shaft.

[0012] [Outline of Sunroof Motor] 1 and 2 is used as a drive source for a sunroof device (not shown) that opens and closes a roof panel provided in a vehicle. Therefore, the sunroof motor 10 adopts a thin structure so that it can be mounted in a narrow space (not shown) inside the roof of the vehicle. The output gear GR of the sunroof motor 10 rotates forward and backward, so that the roof panel moves in the front-rear direction of the vehicle.

[0013] The sunroof motor 10 is a motor device with a speed reduction mechanism, and includes an electric motor section 20 and a speed reduction mechanism section 40. The electric motor section 20 and the speed reduction mechanism section 40 are fixed to each other by a total of three fixing screws S.

[0014] [Electric motor section] The electric motor section 20 employs a brushless motor and has a motor case 21 formed into a cylindrical shape with a bottom by deep drawing a steel plate or the like. The motor case 21 forms the outer shell of the electric motor section 20 and has a side wall section 21a formed into a substantially regular hexagonal cross section. One axial side of the side wall section 21a (the right side in FIG. 2) is closed by a stepped bottom wall section 21b.

[0015] [Stator] 2, a stator 22 is housed inside the motor case 21. The stator 22 has a stator core 22a formed by laminating a plurality of thin steel plates. The stator core 22a is fixed to the motor case 21 and has a total of six teeth 22b (not shown in detail). Three-phase coils CL consisting of U-phase, V-phase, and W-phase are wound around each of the teeth 22b via insulators 22c.

[0016] [Rotor assembly] 2 to 5, the rotor assembly 30 is rotatably provided on the radial inside of the stator 22 via a predetermined air gap AG. The rotor assembly 30 has a rotating shaft 31 and a rotor section RO. The rotor section RO is formed of a rotor core 32 that rotates integrally with the rotating shaft 31, a total of four magnets 33 that are provided on the outer periphery of the rotor core 32 and aligned in the circumferential direction of the rotor core 32, and a magnet holder 34 that supports the outer periphery of the magnets 33 and prevents the magnets 33 from falling off the rotor core 32.

[0017] The rotor portion RO corresponds to the rotor in this invention.

[0018] Rotation Axis The rotating shaft 31 is made of a round steel bar to ensure sufficient strength, and a rotor core 32 is fixed to the outer periphery of the rotating shaft 31 by press fitting.

[0019] One axial side (right side in FIG. 2) of the rotating shaft 31 is housed inside the motor case 21 and rotatably supported by a first plain bearing B1 attached to the bottom wall portion 21b of the motor case 21. Meanwhile, the other axial side (left side in FIG. 2) of the rotating shaft 31 is housed inside a housing 41 that forms the reduction mechanism portion 40 and rotatably supported by a second plain bearing B2 attached to a worm accommodating portion 49 of the housing 41.

[0020] Moreover, a worm 35 forming the speed reduction mechanism SD is provided integrally on the other axial side of the rotating shaft 31. That is, the worm 35 is also made of a round steel bar. This increases the rigidity of the worm 35, and the worm 35 does not bend, and thus meshes reliably with the worm wheel 46.

[0021] [Rotor core] 4, rotor core 32 is formed by laminating a plurality of thin steel plates, and has a cylindrical core body 32a whose inner periphery is fixed to rotating shaft 31 by press fitting, and a total of four salient poles 32b that are integrally formed on the outer periphery of core body 32a and protrude at a predetermined height radially outward from core body 32a. Each steel plate forming rotor core 32 is manufactured with high dimensional precision by pressing or the like.

[0022] Here, the total of four salient poles 32b are disposed at equal intervals (90 degree intervals) in the circumferential direction of the core body 32a, and the protruding height is approximately 1 / 2 the thickness dimension T of the magnet 33 in the radial direction of the rotor core 32.

[0023] 5, in the axial direction of the rotating shaft 31, the length dimension L1 of the rotor core 32 is longer than the length dimension L2 of the magnet 33 (L1>L2). Furthermore, in the axial direction of the rotating shaft 31, the other axial side of the rotor core 32 (upper side in FIG. 5) and the other axial side of the magnet 33 (upper side in FIG. 5) are disposed at the same position so as to be flush with each other. Therefore, one axial side of the rotor core 32 is exposed from one axial side of the magnet 33.

[0024] In this way, by making the length dimension L1 of the rotor core 32 in the axial direction of the rotating shaft 31 longer than the length dimension L2 of the magnet 33 in the axial direction of the rotating shaft 31, the rotation torque of the rotor assembly 30 can be increased compared to the inverse dimensional relationship (L2>L1), thereby improving the performance of the sunroof motor 10.

[0025] Here, the exposed portion 32c of the rotor core 32 exposed from the magnet 33 in the axial direction of the rotating shaft 31 is a portion supported by the work set portion WS of the magnetizing device MD, and the exposed amount L is L1-L2. This allows the rotor portion RO to which the rotating shaft 31 is fixed to be set in the work set portion WS of the magnetizing device MD without any rattling, and therefore allows the magnetizing operation by the magnetizing device MD to be performed with high precision.

[0026] Specifically, as shown in Fig. 5, the magnetizing device MD includes a workpiece setting part WS formed in a substantially cylindrical shape, and a cylindrical air-core coil AC arranged coaxially with the workpiece setting part WS. By gripping the exposed part 32c with the workpiece setting part WS, the rotor part RO before magnetization is positioned with high accuracy in the axial and radial directions with respect to the air-core coil AC. This makes it possible to magnetize the pre-magnetized magnet material MM (see Fig. 6) without variation between products.

[0027] [magnet] 4 and 5, the magnet 33 has a substantially arc-shaped cross section in a direction perpendicular to the axial direction of the rotating shaft 31. The length dimension of the magnet 33 in the axial direction of the rotating shaft 31 is L2. A total of four magnets 33 are arranged at equal intervals (90 degree intervals) in the circumferential direction of the core body 32a. Specifically, the magnets 33 are arranged between adjacent salient poles 32b in the circumferential direction of the core body 32a.

[0028] A first end 33a is provided on one side of the magnet 33 in the circumferential direction of the rotating shaft 31, and a second end 33b is provided on the other side of the magnet 33 in the circumferential direction of the rotating shaft 31. When the rotor part RO is assembled, the first end 33a of the magnet 33 abuts against one of the salient poles 32b adjacent in the circumferential direction of the core body 32a at an abutment part CP. Meanwhile, the second end 33b of the magnet 33 faces the other of the salient poles 32b adjacent in the circumferential direction of the core body 32a via a first gap G1.

[0029] The first gap G1 corresponds to the gap according to the present invention.

[0030] That is, the magnets 33 are mounted between the adjacent salient poles 32b with a dimensional margin. This is because in this embodiment, the magnets 33 are ferrite magnets made by sintering iron oxide powder, and there is a risk of damage due to the large load applied when the magnets are fitted in place. Of course, magnets of other types may be used instead of ferrite magnets.

[0031] On the other hand, if the position of the magnets 33 is shifted in the circumferential direction of the rotor core 32 between the adjacent salient poles 32b, the arrangement angle of the adjacent magnets 33 becomes, for example, 88 degrees or 92 degrees, and it becomes difficult to arrange them precisely at 90 degree intervals. In this case, when the electric motor unit 20 is in operation, this causes the generation of motor operating noise of a specific frequency. In particular, in this embodiment, the sunroof motor 10 is arranged above the heads of the driver and passengers. Therefore, it is desirable to improve quietness.

[0032] Therefore, in the circumferential direction of the rotor core 32, the first ends 33a of the magnets 33 on the same side are abutted against the salient poles 32b as shown by dashed arrows DR (see FIG. 4), and the magnets 33 are positioned in the circumferential direction of the core body 32a with the abutment parts CP as a reference. Here, the salient poles 32b are precisely arranged at 90 degree intervals in the circumferential direction of the core body 32a. Therefore, the magnets 33 positioned at the first ends 33a with the salient poles 32b (abutment parts CP) as a reference are also precisely arranged at 90 degree intervals in the circumferential direction of the core body 32a.

[0033] When assembling the rotor section RO, the magnet material MM (see FIG. 6) before magnetization is attached to the rotor core 32, so it will not stick to other parts due to magnetic force and assembly will not be impaired.

[0034] [Magnet holder] 4 and 5, the outer periphery of each magnet 33 fixed to rotor core 32 is supported by a magnet holder 34 formed into a generally cylindrical shape from a thin stainless steel plate or the like. The magnet holder 34 prevents the magnets 33 from falling off from rotor core 32. As a result, even if the rotor part RO rotates at high speed, the magnets 33 will not come off the rotor core 32 due to the centrifugal force generated at that time.

[0035] Here, an inner peripheral wall 33c is provided on the radial inside of the magnet 33, and an outer peripheral wall 33d is provided on the radial outside of the magnet 33. A central portion C1 of the inner peripheral wall 33c in the circumferential direction of the rotor part RO is in contact with the core body 32a of the rotor core 32. A central portion C2 of the outer peripheral wall 33d in the circumferential direction of the rotor part RO is pressed radially inward by the magnet holder 34.

[0036] As a result, the center of the magnet 33 in the circumferential direction of the rotor part RO, i.e., the portion corresponding to the center portions C1 and C2, is sandwiched between the rotor core 32 and the magnet holder 34. This makes it possible to reduce the load acting in a direction that curves the magnet 33, and thus effectively prevent damage to the magnet 33 (ferrite magnet).

[0037] [Ball bearings] 2 and 3, a ball bearing 36 is attached to the axial center of the rotating shaft 31. That is, the ball bearing 36 rotatably supports the axial center of the rotating shaft 31. The rotor core 32 to which the magnet 33 is fixed and the ball bearing 36 are aligned in the axial direction of the rotating shaft 31, and the rotor core 32 to which the magnet 33 is fixed is disposed between the ball bearing 36 and the first sliding bearing B1.

[0038] The ball bearing 36, like the first plain bearing B1 and the second plain bearing B2, rotatably supports the rotating shaft 31, and includes an inner race 36a and an outer race 36b. A plurality of steel balls 36c are provided between the inner race 36a and the outer race 36b. The inner race 36a is fixed to the rotating shaft 31 by press fitting, and rotates together with the rotating shaft 31.

[0039] [Sensor magnet unit] A sensor magnet unit 37 is provided between the worm 35 and the ball bearing 36 in the axial direction of the rotating shaft 31. The sensor magnet unit 37 has a cylindrical bracket member 37a that is fixed to the rotating shaft 31 by press-fitting, and a sensor magnet 37b that is held by the bracket member 37a. The sensor magnet 37b is used to detect the rotation state (rotation direction, rotation speed, etc.) of the rotating shaft 31 (rotor assembly 30).

[0040] The sensor magnet unit 37 also rotates together with the rotary shaft 31 in the same manner as the inner race 36 a of the ball bearing 36 .

[0041] [Adjustment parts] Furthermore, an adjustment member 38 used to adjust the rotational balance of the rotor assembly 30 is provided between the ball bearing 36 and the rotor core 32 (magnet 33) in the axial direction of the rotating shaft 31. The adjustment member 38 is formed into a substantially cylindrical shape by laminating a plurality of thin steel plates, and is fixed to the rotating shaft 31 by press fitting. The adjustment member 38 is disposed between the ball bearing 36 and the rotor core 32 in the axial direction of the rotating shaft 31.

[0042] The adjustment member 38 has a function of suppressing rotational runout of the rotor assembly 30 caused by minute distortion of the rotating shaft 31, which differs from product to product, and minute positional deviation between the center of rotation of the rotating shaft 31 and the center of rotation of the rotor core 32. Specifically, when assembling the rotor assembly 30, the outer periphery of the adjustment member 38 is cut while the rotor assembly 30 is rotating, thereby optimizing the rotational balance of the rotor assembly 30.

[0043] This also makes it possible to reduce the operating noise of the sunroof motor 10 and improve quietness.

[0044] [Bearing support member] 2, the electric motor unit 20 includes a bearing support member 39. The bearing support member 39 is formed into a predetermined shape from a resin material such as plastic, and includes a support body 39a formed into a substantially flat plate shape, and a wall portion 39b that fits into the housing 41. In other words, the bearing support member 39 is a component that is attached to the housing 41.

[0045] An annular support portion 39c is integrally provided on a support body 39a of the bearing support member 39. The annular support portion 39c supports the entire circumference of one axial side (right side in FIG. 2) of an outer race 36b that forms the ball bearing 36. The other axial side (left side in FIG. 2) of the outer race 36b is supported by a bearing mounting portion 50 provided on the housing 41.

[0046] In this way, the outer race 36b of the ball bearing 36 is sandwiched between the housing 41 and the bearing support member 39 in the axial direction of the rotating shaft 31. Here, the bearing support member 39 is fixed inside the housing 41 without rattling by fixing the motor case 21 to the housing 41 with a total of three fixing screws S.

[0047] Further, a plurality of conductive members EP (only one is shown in the figure) are attached to the support body 39a in correspondence with the three-phase coils CL. These conductive members EP are formed in a generally rod-like shape from brass or the like having excellent conductivity, and one longitudinal side (the right side in FIG. 2) is electrically connected to each of the three-phase coils CL. In contrast, the other longitudinal side (the left side in FIG. 2) of the conductive member EP is electrically connectable to a connection terminal (not shown) of an external connector provided on the vehicle side.

[0048] As a result, a driving current is supplied from an on-board controller or the like to the three-phase coils CL of the sunroof motor 10, and thus the rotating shaft 31 is rotated in the forward and reverse directions.

[0049] [Deceleration mechanism section] 2, the speed reduction mechanism 40 includes a housing 41 that accommodates the speed reduction mechanism SD. The housing 41 is made of a resin material such as plastic and has a generally flat rectangular parallelepiped shape, and includes a first wall 42, a second wall 43, and a third wall 44.

[0050] A worm wheel accommodating portion 45 is provided inside the housing 41. The worm wheel accommodating portion 45 is disposed in a portion close to the third wall portion 44. A worm wheel 46 forming the speed reduction mechanism SD is rotatably accommodated inside the worm wheel accommodating portion 45. The worm wheel 46 is made of a resin material such as plastic, and is provided with teeth 46a. The teeth 46a are engaged with the worm 35 inside the housing 41.

[0051] That is, the reduction mechanism SD is a worm reducer that can obtain a relatively large reduction ratio. Specifically, in this embodiment, the reduction ratio of the reduction mechanism SD is "1 / 67." That is, the reduction ratio is such that the worm wheel 46 finally rotates once every 67 rotations of the worm 35. Of course, it is also possible to set another reduction ratio.

[0052] The axial base end of an output shaft 47 made of a round steel bar is fixed to the center of rotation of the worm wheel 46. On the other hand, an output gear GR (see FIG. 1) is integrally provided on the axial tip end of the output shaft 47. Thus, the high-speed rotation of the rotating shaft 31 is reduced in speed by the reduction gear SD, and the reduced, high-torque rotational force is output from the output shaft 47 to the output gear GR. The reduction gear SD is formed by the worm 35 and the worm wheel 46.

[0053] 2, a worm accommodating portion 49 is provided inside the housing 41. The worm accommodating portion 49 is disposed in a portion closer to the second wall portion 43. The worm accommodating portion 49 is disposed in the vicinity of the worm wheel accommodating portion 45, and the insides of these accommodating portions 49, 45 communicate with each other. This allows the worm 35 and the tooth portion 46a to mesh with each other.

[0054] The worm accommodating portion 49 extends in the axial direction of the rotating shaft 31, and a second sliding bearing B2 is accommodated on the other axial side of the worm accommodating portion 49 (left side in Figure 2) to rotatably support the other axial side of the rotating shaft 31.

[0055] Furthermore, a bearing mounting portion 50 is provided inside the housing 41. The bearing mounting portion 50 is disposed on one axial side (the right side in FIG. 2) of the worm accommodating portion 49, and opens toward the motor case 21. The ball bearing 36 is accommodated inside the bearing mounting portion 50, and the entire circumference of the other axial side (the left side in FIG. 2) of the outer race 36b is supported by the bearing mounting portion 50.

[0056] In this way, the rotating shaft 31 is supported at three points by the first plain bearing B1, the second plain bearing B2, and the ball bearing 36. Therefore, when the sunroof motor 10 is in operation, the worm 35 is prevented from coming off the teeth 46a of the worm wheel 46 (disengagement from each other), and sufficient transmission efficiency [%] is obtained.

[0057] Additionally, an inner race 36a is fixed to the rotating shaft 31, and an outer race 36b is sandwiched between a bearing mounting portion 50 and a bearing support member 39. Therefore, the rotating shaft 31 does not move in its axial direction. This eliminates the need to provide thrust bearings on both axial sides of the rotating shaft 31, thereby reducing the number of parts.

[0058] [Metal jacket] 1 and 2, a metal jacket 60 formed by bending a thin steel plate is partially attached to the outside of the housing 41. The metal jacket 60 has the function of preventing electrical noise generated inside the housing 41 from radiating to the outside of the housing 41. This prevents electrical noise from reaching a car audio system (not shown) mounted in the vehicle, suppressing the generation of radio noise and the like.

[0059] [Assembly Instructions] Next, an assembly procedure (manufacturing method) for the rotor assembly 30 formed as above will be described in detail with reference to the drawings.

[0060] Figure 6 is a diagram explaining the rotor assembly assembly procedure (1), Figure 7 is a diagram explaining the procedure for attaching magnets to the rotor core (1), Figure 8 is a diagram explaining the procedure for attaching magnets to the rotor core (2), Figure 9 is a diagram explaining the procedure for attaching magnets to the rotor core (2), and Figure 10 is a diagram explaining the rotor assembly assembly procedure (2).

[0061] [Preparation] As shown in Figs. 6 and 10, in assembling the rotor assembly 30, the rotating shaft 31, the rotor core 32, the magnet material MM before magnetization, the magnet holder 34, the adjustment member 38, the ball bearings 36 and the sensor magnet unit 37 are prepared.

[0062] [Rotor core press-fit] First, the rotor core 32 is press-fitted onto the rotating shaft 31. Specifically, as shown by arrow M1 in Fig. 6, the rotor core 32 is press-fitted onto the rotating shaft 31 from the other axial side of the rotating shaft 31, i.e., the worm 35 side. Then, the rotor core 32 is disposed at a specified position in the axial direction of the rotating shaft 31. This completes the process of fixing the rotor core 32 to the rotating shaft 31.

[0063] [Magnetic material attached] Next, the magnet material MM before magnetization is fixed to the radial outside of the rotor core 32 fixed to the rotating shaft 31. Specifically, a magnet positioning device MP shown in Figs. 7 to 9 is used.

[0064] The magnet positioning device MP has a base part BS on which a rotating shaft 31 to which a rotor core 32 is fixed can be fixed, centered on a central axis C. The magnet positioning device MP also has a turntable TT that is disposed coaxially with the base part BS and is rotatable relative to the base part BS.

[0065] The base portion BS corresponds to the base in this invention.

[0066] A total of four support claws SC are provided on the turntable TT so as to be movable in radial directions around the central axis C. Specifically, the total of four support claws SC are disposed at 90 degree intervals around the circumferential direction of the turntable TT, and each support claw SC corresponds to a total of four magnet materials MM attached to the outer periphery of the rotor core 32.

[0067] Further, the support claws SC are provided with a magnet holder PB formed in a substantially rod shape so as to be able to swing about a pivot pin P. Here, the magnet holder PB has a function of moving the magnet material MM arranged on the outer periphery of the core body 32a toward one of the salient poles 32b adjacent to each other in the circumferential direction of the core body 32a as the turntable TT rotates.

[0068] A return spring RP is provided on the base end side of the magnet presser PB to return the magnet presser PB (see FIG. 9) that has swung when the magnet material MM is pressed to its original state (see FIG. 8).

[0069] Then, the rotor core 32 to which the rotating shaft 31 is fixed is set on the base part BS of the magnet positioning device MP. Here, the process of setting the rotor core 32 to which the rotating shaft 31 is fixed on the base part BS of the magnet positioning device MP corresponds to the "rotor core setting process" in this invention.

[0070] Next, each magnet material MM is set on the outer periphery of the rotor core 32 (core body 32a) as shown by the arrow M2 in Fig. 6. At this time, the magnet materials MM are arranged between a total of four salient poles 32b provided on the radial outside of the core body 32a of the rotor core 32 as shown in Fig. 7.

[0071] The process of arranging the magnet material MM between the total of four salient poles 32b provided on the radially outer side of the core body 32a of the rotor core 32 corresponds to the "magnet material arranging process" in this invention.

[0072] Since the magnet material MM has not yet been magnetized, it does not have magnetic force, and the magnet material MM can be easily set in the core body 32a.

[0073] Thereafter, as shown by the arrow M3 in FIG. 7, the four support claws SC are driven to move toward the central axis C. As a result, as shown in FIG. 8, each support claw SC is able to support the corresponding magnet material MM. Here, a second gap G2 (approximately 0.1 mm) of approximately 0.1 mm is provided between the magnet material MM and the support claws SC. This prevents a large load from being applied to the magnet material MM, and therefore prevents the magnet material MM from being damaged. At this time, the tip of the magnet presser PB is in contact with the corner CN of the magnet material MM with a light force.

[0074] 9, the turntable TT is driven to rotate the turntable TT by "about 5 degrees" with respect to the base portion BS. Then, the magnet presser PB presses the corner portion CN of the magnet material MM with a pressing force F, and the magnet material MM is rotated relative to the rotor core 32. As a result, the side of the magnet material MM opposite to the corner portion CN in the circumferential direction of the rotor core 32 (the portion corresponding to the first end portion 33a) is brought close to and abuts against one of the salient poles 32b adjacent in the circumferential direction of the core body 32a.

[0075] At this time, the magnet presser PB swings around the pivot pin P as shown by the arrow M5, compressing the return spring RP. In other words, the pressing force F pressing the magnet material MM is obtained by the spring force of the return spring RP and is not very large, so the magnet material MM is not damaged.

[0076] In addition, the process of rotating the turntable TT having support claws SC that support the magnet material MM relative to the base portion BS and abutting the magnet material MM against one of the adjacent salient poles 32b in the circumferential direction of the core body 32a corresponds to the ``magnet material abutment process'' in this invention.

[0077] [Magnetic holder attached] Thereafter, as shown by arrow M6 in Fig. 6, with the magnet material MM abutting against one of the salient poles 32b, the magnet holder 34 is attached to the outer periphery of the magnet material MM attached to the rotor core 32. Specifically, the magnet holder 34 is attached from one axial side of the rotating shaft 31 (the lower side in Fig. 6). Then, the magnet holder 34 is disposed at a specified position in the axial direction of the rotating shaft 31, i.e., at a position that completely covers the outer periphery of the magnet material MM.

[0078] The process of mounting the magnet holder 34 on the outer periphery of the magnet material MM in a state in which the magnet material MM is abutted against one salient pole 32b corresponds to the "magnet holder mounting process" in this invention.

[0079] [Balance adjustment work] 10, the adjustment member 38 is press-fitted and fixed to the rotating shaft 31. Specifically, the adjustment member 38 is press-fitted into the rotating shaft 31 from the worm 35 side of the rotating shaft 31 in the axial direction.

[0080] Thereafter, the rotating shaft 31 to which the magnet holder 34 and the adjustment member 38 are attached is set in a balance adjustment device (not shown in detail), and the rotating shaft 31 is rotated as shown by the arrow RT in Fig. 10. At this time, as shown by the arrow M8 in Fig. 10, a pair of support arms AM provided on the balance adjustment device are inserted between the magnet holder 34 and the adjustment member 38, and the rotating shaft 31 is supported by the pair of support arms AM.

[0081] Next, while rotating the rotating shaft 31, as shown by the arrow M9 in Fig. 10, the cutting blade CB of the balance adjustment device is moved while abutting against the adjustment member 38, to partially cut the outer periphery of the adjustment member 38. This suppresses rotational runout of the rotor assembly 30 caused by minute distortion of the rotating shaft 31 that differs from product to product, minute positional deviation between the rotation center of the rotating shaft 31 and the rotation center of the rotor core 32, etc.

[0082] [Magnetization work] After the balance adjustment is completed, the magnetization is performed as shown in Fig. 10. Specifically, the rotor assembly 30 after the balance adjustment is set in the magnetization device MD. At this time, the exposed portion 32c (see Fig. 5) of the rotor core 32 exposed from the magnet 33 in the axial direction of the rotating shaft 31 is supported by the work setting part WS of the magnetization device MD. As a result, a total of four magnet materials MM (see Fig. 5) are set with high precision, with minute gaps interposed between them, on the radial inside of the air-core coil AC that forms the magnetization device MD.

[0083] Thereafter, a magnetizing current is passed through the air-core coil AC to generate a magnetic field MF (see the outlined arrow in FIG. 10) in the radially inner direction thereof, whereby each of the magnetic materials MM (see FIG. 6) is magnetized to become a magnet 33 (see FIG. 2) having magnetic force.

[0084] In addition, the process of setting the exposed portion 32c of the rotor core 32 exposed from one axial side of the magnet material MM in the magnetizing device MD in the axial direction of the rotating shaft 31 and magnetizing the magnet material MM corresponds to the "magnet material magnetizing process" in this invention.

[0085] [Other parts installed] 10, the ball bearing 36 and the sensor magnet unit 37 are attached to the rotating shaft 31 from the worm 35 side of the rotating shaft 31. The ball bearing 36 and the sensor magnet unit 37 are both fixed to the rotating shaft 31 by press-fitting.

[0086] The ball bearings 36 are general-purpose high-precision ball bearings, and the sensor magnet unit 37 is small in diameter and lightweight. Therefore, even after balance adjustment, the rotational balance of the rotor assembly 30 is not lost. Thus, the rotor section RO and other parts (ball bearings 36 and sensor magnet unit 37) are attached to the rotating shaft 31, and the rotor assembly 30 is finally completed.

[0087] As described above in detail, according to this embodiment, the rotor core 32 has a cylindrical core body 32a whose inner periphery is fixed to the rotating shaft 31, and a total of four salient poles 32b that are provided on the outer periphery of the core body 32a, protrude radially outward from the core body 32a, and are arranged at equal intervals (90 degree intervals) in the circumferential direction of the core body 32a. The magnet 33 has a first end 33a that abuts against one of the salient poles 32b adjacent to each other in the circumferential direction of the core body 32a, and a second end 33b that faces the other of the salient poles 32b adjacent to each other in the circumferential direction of the core body 32a, via a first gap G1. In the axial direction of the rotating shaft 31, the length dimension L1 of the rotor core 32 is longer than the length dimension L2 of the magnet 33, and one axial side of the rotor core 32 is exposed from one axial side of the magnet 33.

[0088] This makes it possible to reduce the number of parts compared to the conventional method, and since the length dimension L1 of the rotor core 32 is longer than the length dimension L2 of the magnet 33, it is possible to increase the rotational torque of the rotor assembly 30 compared to the conventional method, thereby improving the performance of the sunroof motor 10. Also, the exposed portion 32c on one axial side of the rotor core 32 exposed from one axial side of the magnet 33 can be set in the work set part WS of the magnetizing device MD without any rattling, making it possible to easily and accurately perform the magnetizing operation by the magnetizing device MD.

[0089] Furthermore, according to this embodiment, the other axial side of the rotor core 32 and the other axial side of the magnet 33 are arranged at the same position in the axial direction of the rotating shaft 31, so that it is possible to further increase the rotational torque of the rotor assembly 30 and improve the performance of the sunroof motor 10.

[0090] Furthermore, according to this embodiment, the magnet 33 has a cross section in a direction perpendicular to the axial direction of the rotating shaft 31 that is arc-shaped, and the central portion of the magnet 33 in the circumferential direction (the portion corresponding to the central portions C1 and C2) is sandwiched between the rotor core 32 and the magnet holder 34. This makes it possible to reduce the load acting in the direction that curves the magnet 33, and in turn makes it possible to effectively prevent damage to the magnet 33 (ferrite magnet).

[0091] Furthermore, according to this embodiment, the rotor assembly 30 including the rotor portion RO can be easily and accurately assembled through five processes, namely, the "rotor core setting process," the "magnet material placement process," the "magnet material butting process," the "magnet holder mounting process," and the "magnet material magnetization process."

[0092] Furthermore, according to the present embodiment, as described above, the number of parts can be reduced and the product can be easily manufactured, which makes it possible to reduce the energy required for manufacturing. This makes 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).

[0093] The present invention is not limited to the above-mentioned embodiment, and it goes without saying that various modifications can be made without departing from the gist of the present invention. In the above-mentioned embodiment, the present invention is applied to the sunroof motor 10, but the present invention is not limited to this, and can be applied to, for example, rotors of vehicle-mounted motors used in slide door devices, power window devices, wiper devices, etc. mounted on vehicles.

[0094] Furthermore, the material, shape, size, number, installation location, etc. of each component in the above-described embodiment may be arbitrary as long as it achieves the present invention, and is not limited to the above-described embodiment. [Explanation of symbols]

[0095] 10: sunroof motor, 20: electric motor section, 21: motor case, 21a: side wall section, 21b: bottom wall section, 22: stator, 22a: stator core, 22b: teeth, 22c: insulator, 30: rotor assembly, 31: rotating shaft, 32: rotor core, 32a: core body, 32b: salient pole, 32c: exposed section, 33: magnet, 33a: first end section, 33b: second end section, 33c: inner peripheral wall ,33d: outer wall, 34: magnet holder, 35: worm, 36: ball bearing, 36a: inner race, 36b: outer race, 36c: steel ball, 37: sensor magnet unit, 37a: bracket member, 37b: sensor magnet, 38: adjustment member, 39: bearing support member, 39a: support body, 39b: wall portion, 39c: annular support portion, 40: reduction mechanism portion, 41: Housing, 42: First wall, 43: Second wall, 44: Third wall, 45: Worm wheel housing, 46: Worm wheel, 46a: Teeth, 47: Output shaft, 49: Worm housing, 50: Bearing mounting section, 60: Metal jacket, AC: Air core coil, AG: Air gap, AM: Support arm, B1: First plain bearing, B2: Second plain bearing, BS: Base (base), CB: Cutting blade, CL: Coil, CN: Corner, CP: Abutment, EP: Conductive material, G1: First gap (gap), G2: Second gap, GR: Output gear, MD: Magnetizing device, MF: Magnetic field, MM: Magnet material, MP: Magnet positioning device, P: Rotating pin, RO: Rotor, RP: Return spring, S: Fixing screw, SC: Support claw, SD: Reduction mechanism, TT: Turntable, WS: Work set section

Claims

1. A rotor core that rotates integrally with the rotating shaft; A plurality of magnets are provided on an outer periphery of the rotor core and arranged in a circumferential direction of the rotor core; a magnet holder that supports an outer periphery of the magnet and prevents the magnet from falling off the rotor core; A rotor comprising: The rotor core is A cylindrical core body having an inner circumferential portion fixed to the rotating shaft; a plurality of salient poles provided on an outer periphery of the core body, protruding radially outward from the core body, and arranged at equal intervals in a circumferential direction of the core body; having The magnet is a first end portion abutting against one of the salient poles adjacent to each other in the circumferential direction of the core body; a second end portion opposed to the other salient pole of the salient poles adjacent to each other in the circumferential direction of the core body, with a gap therebetween; Equipped with In the axial direction of the rotating shaft, a length dimension of the rotor core is longer than a length dimension of the magnet, and one axial side of the rotor core is exposed from one axial side of the magnet. Rotor.

2. In the axial direction of the rotating shaft, the other axial side of the rotor core and the other axial side of the magnet are disposed at the same position. The rotor of claim 1 .

3. The magnet has a cross section in a direction perpendicular to the axial direction of the rotation shaft that is arc-shaped, and a central portion of the magnet in a circumferential direction is sandwiched between the rotor core and the magnet holder. A rotor according to claim 1 or 2.

4. A rotor core that rotates integrally with the rotating shaft; A plurality of magnets are provided on an outer periphery of the rotor core and arranged in a circumferential direction of the rotor core; a magnet holder that supports an outer periphery of the magnet and prevents the magnet from falling off the rotor core; A method for manufacturing a rotor comprising: a rotor core setting process of setting the rotor core to which the rotating shaft is fixed on a base; a magnet material arrangement process of arranging a magnet material to be the magnets between a plurality of salient poles provided on the radially outer side of a core body of the rotor core; a magnet material abutting process of rotating a turntable having support claws that support the magnet material relative to the base, and abutting the magnet material against one of the salient poles adjacent to each other in the circumferential direction of the core body; a magnet holder mounting step of mounting the magnet holder on an outer periphery of the magnet material in a state where the magnet material is abutted against one of the salient poles; a magnet material magnetizing process of setting an exposed portion of the rotor core exposed from one axial side of the magnet material in a magnetizing device in an axial direction of the rotating shaft, and magnetizing the magnet material; A method for manufacturing a rotor having the above structure.

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