Reducer and motor with reducer

Abstract

The invention provides a speed reducer and a motor with the speed reducer, which can restrain unnecessary deformation load from being input to a crankshaft. The speed reducer comprises a box body, a crankshaft (10) and a speed reducer body. The crankshaft (10) is provided with a rotation supporting part which is freely supported on the box body in a rotatable manner and an eccentric part (20) which is eccentric relative to the rotation supporting part, and receives rotation force from the outside to rotate. The speed reducer body is provided with a clamping part which is clamped on the peripheral surface of the eccentric part (20), and the swing rotation of the eccentric part received by the clamping part is decelerated and output to the outside. The crankshaft (10) is provided with a flange portion (12) protruding radially outward from the end portion of the eccentric portion side of the rotation support portion and abutting against the axial end face of the engagement portion. The flange portion (12) is formed such that the center of the flange portion (12) in the direction orthogonal to the axial direction coincides with the center of the eccentric portion in the direction orthogonal to the axial direction.

Description

Technical Field

[0001] The invention relates to a reducer and a motor with the reducer. Background Art

[0002] Conventionally, there is known a motor with a reducer, which reduces the rotation of the motor by the reducer to obtain a high rotational torque. As a reducer used in the motor with a reducer, there are reducers of various mechanisms, but as one of the mechanisms, the following mechanism is known: the rotation of the motor is converted into the swing rotation of the crankshaft, and the swing rotation is reduced by a planetary gear mechanism or the like (for example, refer to Patent Document 1).

[0003] The reducer described in Patent Document 1 includes a housing, a crankshaft rotatably supported on the housing, and a reducer body that reduces the swinging rotation of the eccentric portion of the crankshaft. The crankshaft has a rotation support portion rotatably supported on the housing and an eccentric portion eccentric to the rotation support portion. The crankshaft rotates by receiving the rotation of the output shaft of the motor. The reducer body includes: an eccentric portion bearing, which is engaged with the outer peripheral surface of the eccentric portion of the crankshaft; and a swing gear, which is rotatably supported on the eccentric portion via the eccentric portion bearing and has internal teeth and external teeth. In addition, the reducer body includes: a fixed gear, which is fixed to the housing and has internal teeth that mesh with the external teeth of the swing gear; and an output gear, which is rotatably held in the housing and has external teeth that mesh with the internal teeth of the swing gear. The internal teeth of the fixed gear and the external teeth of the output gear are formed concentrically with the central axis of the crankshaft.

[0004] In the above-mentioned speed reducer, when the crankshaft rotates by receiving the rotation of the output shaft of the motor, the eccentric part of the crankshaft causes the swing gear to swing and rotate via the eccentric part bearing. At this time, the swing gear rotates while the external teeth of the swing gear mesh with the internal teeth of the fixed gear, and the rotation component is transmitted to the output gear through the meshing part between the internal teeth of the swing gear and the external teeth of the output gear. As a result, the output gear outputs the rotation reduced to a predetermined reduction ratio to an external device.

[0005] In addition, the crankshaft of the reducer is provided with a flange portion protruding radially outward from the end portion of the eccentric portion side of the rotating support portion. The flange portion is formed in a circular ring shape concentrically with the rotating support portion. The end surface of the flange portion facing the eccentric portion side abuts against the end surface of the eccentric portion bearing (engaging portion) engaged with the eccentric portion. When the torque is transmitted to the external machine, the flange portion receives the reverse thrust (reaction force in the tilting direction) acting on the eccentric portion bearing.

[0006] [Prior art literature]

[0007] [Patent Document]

[0008] [Patent Document 1] Japanese Patent No. 6838849 Summary of the invention

[0009] [Problems to be solved by the invention]

[0010] The reducer described in Patent Document 1 is configured as follows: the reverse thrust acting on the eccentric bearing is supported by the annular flange of the crankshaft. However, the eccentric bearing is supported on the outer peripheral surface of the eccentric portion of the crankshaft, and the center in the direction orthogonal to the axial direction is set to be concentric with the eccentric portion. Therefore, the axis of the flange of the crankshaft is offset in the radial direction relative to the axis of the eccentric bearing.

[0011] As a result, the end face of the eccentric bearing abuts against the end face of the opposite flange in a non-concentric state (displaced in the radial direction). Therefore, the thrust load (load in the tilting direction) acting on the flange from the eccentric bearing will act unevenly around the center of the flange. Therefore, in the reducer described in Patent Document 1, when the reverse thrust acting on the eccentric bearing increases, a large deformation load is likely to act on the entire area of ​​the flange or the crankshaft.

[0012] Therefore, the present invention intends to provide a speed reducer and a motor with a speed reducer which can suppress input of an unnecessary deformation load to a crankshaft.

[0013] [Technical means to solve the problem]

[0014] In order to solve the above-mentioned problems, the speed reducer and the motor with speed reducer of the present invention adopt the following structures.

[0015] That is, the first form of the reducer of the present invention includes: a housing; a crankshaft, having a rotating support portion rotatably supported on the housing and an eccentric portion eccentric relative to the rotating support portion, which receives a rotating force from the outside and rotates; and a reducer body, having an engaging portion engaged with the outer peripheral surface of the eccentric portion, which reduces the swinging rotation of the eccentric portion received by the engaging portion and outputs it to the outside, and a flange portion is provided on the crankshaft, which protrudes radially outward from the end portion on the eccentric portion side of the rotating support portion and abuts against the axial end face of the engaging portion, and the flange portion is formed so that the center in a direction perpendicular to the axial direction coincides with the center of the eccentric portion in a direction perpendicular to the axial direction.

[0016] In the first form of the reducer, the center of the flange in the direction perpendicular to the axial direction and the center of the eccentric portion in the direction perpendicular to the axial direction are formed with respect to the crankshaft. Therefore, the engaging portion of the reducer body engaged with the outer peripheral surface of the eccentric portion abuts against the flange in a concentric state. Therefore, the thrust load acting on the flange of the crankshaft from the engaging portion of the reducer body becomes uniform in the surrounding area, and it is difficult for a biased deformation load to act on the flange.

[0017] A speed reducer according to a second aspect of the present invention is the speed reducer according to the first aspect, wherein the flange portion is formed in an annular shape in which a distance between an outer peripheral surface and the eccentric portion is uniform in a circumferential direction.

[0018] At this time, the engagement portion of the speed reducer body that engages with the outer peripheral surface of the eccentric portion is easy to abut against the end surface of the flange portion more evenly in the circumferential direction. In addition, in this structure, since the flange portion is annular, the flange portion can be further reduced in size and weight.

[0019] The third form of the reducer of the present invention is based on the reducer of the first form or the second form, wherein the reducer body includes: a bearing serving as the engaging portion; a swing gear, which is rotatably supported on the eccentric portion of the crankshaft via the bearing and has a first internal tooth and a first external tooth; a fixed gear, which is fixed to the housing and has a second internal tooth, the second internal tooth engages with the first external tooth of the swing gear and is concentric with the central axis of the rotating support portion of the crankshaft; and an output gear, having a second external tooth, the second external tooth engages with the first internal tooth of the swing gear and is concentric with the central axis.

[0020] At this time, when the crankshaft receives rotational force from the outside and rotates, the eccentric portion of the crankshaft swings and rotates accordingly, and the swing gear swings and rotates via the bearing engaged with the outer peripheral surface of the eccentric portion. At this time, the swing gear rotates in a state where the first external teeth are engaged with the second internal teeth of the fixed gear. Moreover, at this time, the output rotating body is engaged with the second internal teeth of the swing gear in the second external teeth, and thus rotates in response to the self-rotation of the swing gear. The rotation of the output rotating body is output to an external device.

[0021] When the reducer of this structure transmits power to an external machine, a reaction force is input from the external machine through the output rotating body. The reaction force is input to the crankshaft through the output rotating body, the swing rotating body and the bearing. At this time, a part of the reaction force acts on the flange of the crankshaft as a thrust load (load in the tipping direction). Since the flange is set to a shape that is consistent with the radial center of the bearing, the thrust load acting on the flange from the bearing becomes uniform in the surrounding area centered on the center of the flange.

[0022] Furthermore, a motor with a speed reducer according to a first aspect of the present invention is characterized by including: the speed reducer according to any one of the first to third aspects; and a motor unit connected to the crankshaft of the speed reducer.

[0023] [Effects of the Invention]

[0024] In the reducer and the motor with the reducer of the present invention, the engaging portion of the reducer body engaging with the outer peripheral surface of the eccentric portion of the crankshaft abuts against the flange portion in a concentric state. Therefore, the thrust load acts evenly from the engaging portion of the reducer body to the flange portion of the crankshaft in the circumferential direction, and it is difficult for a biased deformation load to act on the flange portion.

[0025] Therefore, when the speed reducer or the motor with speed reducer of the present invention is used, it is possible to suppress input of unnecessary deformation load to the crankshaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a perspective view of a motor with a speed reducer according to an embodiment.

[0027] Figure 2 The motor with a speed reducer according to the embodiment Figure 1 Cross-sectional view of line II-II.

[0028] Figure 3 The motor with a speed reducer according to the embodiment Figure 2 Cross-sectional view along line III-III.

[0029] Figure 4 It is a side view of the crankshaft of the embodiment.

[0030] Figure 5 The crankshaft of the embodiment Figure 4 IV arrow diagram.

[0031] [Explanation of Symbols]

[0032] 1: Motor with reducer

[0033] 2: Motor

[0034] 3: Control Department

[0035] 4: Reducer

[0036] 5: Cabinet

[0037] 5A: Box body

[0038] 5B: Control unit cover

[0039] 5C: Ring Block

[0040] 6: Partition wall

[0041] 7: Bearing seat

[0042] 8: Bearings

[0043] 8i: Inner wheel

[0044] 10: Crankshaft

[0045] 11: Reducer body

[0046] 12: Flange

[0047] 12f: End face

[0048] 12s: End face

[0049] 16: Fixed gear

[0050] 16b: Internal teeth

[0051] 17: External gear ring

[0052] 17a: External teeth

[0053] 20: Eccentric part

[0054] 21: Bearings

[0055] 22a: Rotation support part

[0056] 22b: Rotation support part

[0057] 24: Bearings

[0058] 24i: Inner wheel

[0059] 24o: Outer wheel

[0060] 25: Swing gear

[0061] 26: Bearings

[0062] 27: Output gear

[0063] 28: Fastening hole

[0064] 29: Bolt

[0065] 30: Stator

[0066] 31: Rotor

[0067] 32: stator core

[0068] 33: Coil

[0069] 34: Rotor core

[0070] 35: Ring magnet

[0071] 40: Connecting flange

[0072] 50: Control board

[0073] 51: Harness

[0074] 52: Harness

[0075] 53: Base wall

[0076] 54: Bearing seat

[0077] 55: Tooth wall

[0078] 55a: External teeth

[0079] 55b: Internal teeth

[0080] 56: Base wall

[0081] 57: Bearing receiving recess

[0082] L: Center axis

[0083] O: Center axis DETAILED DESCRIPTION

[0084] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0085] Figure 1 It is a perspective view of the motor 1 with a reduction gear according to the present embodiment. Figure 2 It is along Figure 1 Cross-sectional view of line II-II.

[0086] The motor 1 with a speed reducer of this embodiment is used, for example, in a wheel drive unit of a vehicle such as a two-wheeled vehicle. Figure 1 , Figure 2 As shown, the motor 1 with a speed reducer includes: a flat motor part 2, which is a so-called direct current (DC) brushless motor; a control part 3, which controls the drive of the motor part 2; a speed reducer 4, which reduces the rotational power of the motor part 2 and transmits the power to an external device; and a housing 5, which accommodates these parts. The housing 5 includes: a housing body 5A with a short axis and a cylindrical housing 5A, an axial end portion ( Figure 2 The control unit cover 5B is mounted on the right end of the housing body 5A in the axial direction. Figure 2 Annular block 5C at the left end of the block.

[0087] In addition, the motor axis (rotation axis) of the motor unit 2 is consistent with the central axis L of the crankshaft 10 described later of the reducer 4. In the following description, the direction along the motor axis (central axis L) is sometimes referred to as the axial direction, the direction around the motor axis is sometimes referred to as the circumferential direction, and the direction orthogonal to the motor axis and the circumferential direction is sometimes referred to as the radial direction.

[0088] The motor with a speed reducer 1 includes a control unit 3 , a motor unit 2 , and a speed reducer 4 arranged in order from one end side toward the other end side in the axial direction inside a housing 5 .

[0089] The housing body 5A is integrally formed with a partition wall 6 extending radially inward from a substantially central position in the axial direction. The interior of the housing body 5A is provided as a motor accommodation portion on the control unit 3 side with the partition wall 6 sandwiched therein, and a speed reducer accommodation portion is provided on the opposite side of the control unit 3 with the partition wall 6 sandwiched therein. Furthermore, a substantially cylindrical bearing seat (bearing housing) 7 is integrally formed on the radial inner side of the partition wall 6. In the bearing seat 7, a bearing 8 (ball bearing) is retained, and the bearing 8 is used to rotatably support one end side of a crankshaft 10 described later of the speed reducer 4.

[0090] The outer peripheral portion of the box body 5A at one end side in the axial direction is provided with a connecting flange 40 extending outward in the radial direction. The connecting flange 40 is connected to the control unit cover 5B covering the outer side of the control unit 3. In the box body 5, the box body 5A part can be fixed to the wheel support part of the vehicle, etc. Moreover, the outer peripheral surface of the box body 5A is stepped from one end side in the axial direction to the other end side. An annular block 5C is installed at the end of the box body 5A at the other end side in the axial direction where the diameter is most reduced.

[0091] <Motor 2>

[0092] The motor unit 2 is accommodated in a motor housing portion in the housing body 5A. The motor unit 2 includes a stator 30 having a perforated disk shape and a rotor 31 rotatably disposed radially inside the stator 30 .

[0093] The stator 30 has a stator core 32 formed by laminating a plurality of electromagnetic steel plates or press-molding soft magnetic powder. The outer peripheral edge of the stator core 32 is fastened and fixed to one axial end surface of the housing body 5A by a plurality of bolts 29 .

[0094] In addition, a plurality of teeth (symbols omitted) protruding radially inward are formed in the inner circumference of the stator core 32 in a circumferential direction. Coils 33 are wound around each of these teeth. A three-phase alternating current is supplied from a power supply circuit (not shown) to the coils 33 wound around each of the teeth. The stator 30 thus generates a rotating magnetic field.

[0095] The rotor 31 includes: a circular annular rotor core 34, the inner periphery of which is externally fixed to one axial end of the crankshaft 10 of the reducer 4; and a ring magnet (ring magnet) 35 (permanent magnet) fixed to the outer periphery of the rotor core 34. The inner periphery of the rotor core 34 is arranged adjacent to one axial end of the bearing 8 held by the bearing seat 7. The ring magnet 35 is magnetized so that different magnetic poles (N pole and S pole) are alternately arranged along the circumferential direction on the outer surface side. The rotor 31 rotates by the attraction and repulsion between the rotating magnetic field generated on the stator 30 side and the ring magnet 35.

[0096] Furthermore, the permanent magnets arranged on the outer peripheral portion of the rotor core 34 are not limited to the annular magnets 35 , and may be a plurality of magnet pieces divided in the circumferential direction.

[0097] <Control Department>

[0098] The control unit 3 includes a bottomed cylindrical control unit cover 5B and a control substrate 50 fixed to one of the axial end surfaces of the housing body 5A on the inner side of the control unit cover 5B. A control circuit for controlling the motor unit 2 or a sensor for detecting the rotation of the rotor 31 is mounted on the control substrate 50. In addition, a wiring harness 51 (see FIG. 1 ) for connecting to an external battery or the like is connected to the control substrate 50. Figure 1 ) and a signal system harness 52 connected to an external control device (see Figure 1 ).

[0099] <Reduction gear>

[0100] Figure 3 The motor 1 with a reducer is Figure 2 Cross-sectional view along line III-III. Figure 4 is a side view of the crankshaft 10, Figure 5 It is the crankshaft 10 Figure 4 IV arrow diagram.

[0101] The speed reducer 4 includes a housing 5 (housing body 5A), a crankshaft 10 that rotates by receiving a rotational force from the motor unit 2, and a speed reducer body 11 that reduces the rotation of the eccentric portion 20 of the crankshaft 10 and outputs it to the outside (wheels of the vehicle). The speed reducer 4 of this embodiment is configured as a hypocycloid speed reduction mechanism.

[0102] The speed reduction mechanism of the speed reducer 4 is not limited to the hypocycloid speed reduction mechanism, and may be another mechanism as long as it can reduce the speed of the rotation of the eccentric portion 20 of the crankshaft 10 and output it to the outside.

[0103] The crankshaft 10 includes: a pair of rotating support parts 22a and 22b, which are rotatably supported on the housing 5 via bearings 8 and bearings 21; and an eccentric part 20, which is eccentric with respect to the central axis L (rotation axis) of the rotating support parts 22a and 22b. The rotating support parts 22a and 22b are both formed in a cylindrical shape, and are coaxially formed in a manner that the central axis L of each other is consistent. The rotating support parts 22a and 22b are respectively arranged on one end side and the other end side of the axial direction of the crankshaft 10. The eccentric part 20 is formed in a cylindrical shape, and the ends on both sides of the axial direction are connected to the rotating support parts 22a and 22b. The outer peripheral surface of the eccentric part 20 is set as a cylindrical surface centered on the central axis O spaced radially from the central axis L of the rotating support parts 22a and 22b. When the rotation support parts 22 a and 22 b receive the rotation force from the motor part 2 and rotate, the eccentric part 20 swings and rotates with a constant radius around the central axis L.

[0104] A pair of bearings 24 (eccentric bearings including ball bearings) are arranged axially on the outer peripheral surface of the eccentric portion 20. These bearings 24 rotatably support the inner peripheral portion of the swing gear 25 described later of the reducer body 11. In the present embodiment, these bearings 24 constitute an engaging portion engaged with the outer peripheral surface of the eccentric portion 20. Each bearing 24 has an inner wheel 24i engaged with the outer peripheral surface of the eccentric portion 20 and an outer wheel 24o engaged with the inner peripheral surface of the swing gear 25.

[0105] Arranged on one end side of the crankshaft 10 in the axial direction ( Figure 2 , Figure 3 The rotation support portion 22a (right side in the middle) is rotatably supported by the partition wall 6 of the case body 5A via the bearing 8. Figure 2 , Figure 3 The rotation support portion 22b (left side in the figure) is rotatably supported by an output gear 27 described later of the speed reducer 4 via a bearing 21. The output gear 27 is rotatably supported by an annular block 5C of the casing 5 via another bearing 26. Therefore, the rotation support portion 22b on the other end side of the crankshaft 10 in the axial direction is rotatably supported by the annular block 5C (casing 5).

[0106] like Figure 2 , Figure 4 , Figure 5As shown, at the end of the eccentric portion 20 side of the rotating support portion 22a on the motor portion 2 side, a flange portion 12 is integrally formed so as to protrude radially outward from the outer peripheral surface of the rotating support portion 22a. The flange portion 12 is set to have a circular outer surface shape, but it is not a circular shape concentric with the rotating support portion 22a, but is set to have a circular shape concentric with the eccentric portion 20 adjacent in the axial direction. Therefore, the flange portion 12 is formed so that the center in the direction orthogonal to the axial direction coincides with the center of the eccentric portion 20 in the direction orthogonal to the axial direction (a point passing through the central axis O of the eccentric portion 20).

[0107] The end faces 12f and 12s on both sides of the flange 12 in the axial direction are formed by flat surfaces orthogonal to the axial direction. One end face 12f of the flange 12 stands radially outward from the outer peripheral surface of the rotation support 22a, and the other end face 12s of the flange 12 stands radially outward from the outer peripheral surface of the eccentric portion 20.

[0108] like Figure 2 As shown, one end face 12f of the flange portion 12 abuts against the end face of the inner race 8i of the bearing 8 supporting the rotation support portion 22a. The flange portion 12 thereby restricts positional deviation of the bearing 8 toward the other end side in the axial direction.

[0109] Moreover, if Figure 2 As shown, the other end face 12s of the flange portion 12 abuts against the end face of the inner race 24i of one of the bearings 24 that is engaged with the outer peripheral surface of the eccentric portion 20. The flange portion 12 thereby limits the position deviation of the bearing 24 toward one axial end side and resists the reverse thrust (load in the tilting direction) acting on the bearing 24 through the reducer body 11.

[0110] like Figure 5 As shown, the flange portion 12 is formed into an annular shape with an outer peripheral surface having a uniform distance from the eccentric portion 20 in the circumferential direction. Therefore, the end surface of the inner race 24i of the bearing 24 abuts against the end surface 12s of the flange portion 12 uniformly in the circumferential direction.

[0111] in addition, Figure 5 In FIG. 1 , a dot is indicated in a region of the end surface 12 s of the flange portion 12 with which the end surface of the inner race 24 i of the bearing 24 abuts.

[0112] Moreover, the reducer body 11 includes: the pair of bearings 24 mentioned above, which are embedded in the eccentric portion 20 of the crankshaft 10; a swing gear 25, which has a pair of bearings 24 fixed on the inner periphery and is provided with internal teeth 55b (first internal teeth) and external teeth 55a (first external teeth) in the outer peripheral area; a fixed gear 16, which has internal teeth 16b (second internal teeth) that mesh with the external teeth 55a of the swing gear 25; and an output gear 27, which has external teeth 17a (second external teeth) that mesh with the internal teeth 55b of the swing gear 25.

[0113] The swing gear 25 includes: a base wall 53 in the shape of an open circular plate extending in the radial direction; a substantially cylindrical bearing seat 54 protruding from the radially inner end of the base wall 53 toward the side opposite to the motor unit 2; and a substantially cylindrical tooth wall 55 connected to the radially outer end of the base wall 53. A substantially cylindrical recessed portion opening toward the side opposite to the motor unit 2 is formed between the tooth wall 55 and the bearing seat 54. The outer wheels 24o of the bearing 24 are fitted and fixed to the inner peripheral surface of the bearing seat 54. The tooth wall 55 of the swing gear 25 has external teeth 55a formed on the outer peripheral surface side and internal teeth 55b formed on the inner peripheral surface side.

[0114] The fixed gear 16 is formed in an annular shape as a whole. The fixed gear 16 is fixed to the inner peripheral portion of the housing body 5A. Internal teeth 16b are formed on the inner peripheral surface of the fixed gear 16. The fixed gear 16 is arranged on the outer peripheral side of the tooth wall 55 of the swing gear 25, and the internal teeth 16b on the inner peripheral surface can mesh with the external teeth 55a of the tooth wall 55.

[0115] The internal teeth 16b of the fixed gear 16 are formed so as to be concentric with the central axis L of the rotation support parts 22a and 22b of the crankshaft 10 when the fixed gear 16 is fixed to the case body 5A. The outer diameter of the external teeth 55a of the swing gear 25 is formed to be smaller than the inner diameter of the internal teeth 16b of the fixed gear 16. Moreover, the number of teeth of the external teeth 55a of the swing gear 25 and the number of teeth of the internal teeth 16b of the fixed gear 16 are set to be different. Therefore, when the swing gear 25 receives the swing rotation of the crankshaft 10 and swings, the swing gear 25 receives the reaction force from the external teeth 55a while meshing with the internal teeth 16b of the fixed gear 16 and rotates in a predetermined direction. The rotation speed thereof is reduced to a predetermined reduction ratio relative to the swing rotation of the crankshaft 10.

[0116] The output gear 27 includes a disc-shaped base wall 56 extending in the radial direction, and a substantially cylindrical outer gear ring 17 protruding from the radially outer portion of the base wall 56 toward the motor unit 2. The outer peripheral surface of the base wall 56 is rotatably supported on the inner peripheral surface of the annular block 5C of the housing 5 via a bearing 26. The output gear 27 is a member that outputs the rotation of the motor unit 2 decelerated by the reducer body 11 to an external device. A fastening hole 28 is provided on the outer end surface of the base wall 56 for fastening and fixing the output gear 27 to an external device (wheel of a vehicle).

[0117] Furthermore, a bearing receiving recess 57 is formed on the surface of the motor unit 2 side of the base wall 56. The bearing receiving recess 57 is provided in the radial center region of the base wall 56. The bearing 21 for axially supporting the rotation support portion 22b of the crankshaft 10 is held in the bearing receiving recess 57.

[0118] The outer gear ring 17 is inserted into the annular recess between the bearing seat 54 and the tooth wall 55 of the swing gear 25 when the output gear 27 is held in the annular block 5C (casing 5). The outer gear ring 17 has outer teeth 17a that can mesh with the inner teeth 55b of the swing gear 25 formed on its outer peripheral surface.

[0119] In addition, in the present embodiment, the outer gear ring 17 is configured as follows: an independent annular member having external teeth 17a is fixed to a cylindrical portion formed integrally with the base wall 56. However, the configuration of the outer gear ring 17 is not limited thereto. The outer gear ring 17 may be entirely formed of a member integrally with the base wall 56.

[0120] The outer teeth 17a of the outer gear ring 17 are formed so as to be concentric with the central axis L of the rotation support parts 22a and 22b of the crankshaft 10 when the output gear 27 is held in the annular block 5C (casing 5). The outer diameter of the outer teeth 17a of the outer gear ring 17 is formed to be smaller than the inner diameter of the inner teeth 55b of the swing gear 25. Moreover, the number of teeth of the outer teeth 17a of the outer gear ring 17 and the number of teeth of the inner teeth 55b of the swing gear 25 are set to be the same. With these structures, when the swing gear 25 receives the swing rotation of the crankshaft 10 and swings, only the rotation of the swing gear 25 is transmitted to the output gear 27. Therefore, the rotational power of the motor part 2 reduced by the speed reducer 4 is output to the external machine (wheels of the vehicle) through the output gear 27.

[0121] <Effects of implementation>

[0122] In the speed reducer 4 (motor 1 with speed reducer) of the present embodiment, the flange portion 12 of the crankshaft 10 is formed so that the center of the flange portion 12 in the direction orthogonal to the axial direction coincides with the center (central axis O) of the eccentric portion 20. Therefore, the inner race 24i (engaging portion) of the bearing 24 of the speed reducer body 11 abuts against the flange portion 12 of the crankshaft 10 in a concentric state. As a result, the thrust load acts evenly on the flange portion 12 of the crankshaft 10 from the inner race 24i of the bearing 24 in the circumferential direction, and it is difficult for a biased deformation load to act on the flange portion 12.

[0123] Therefore, when the speed reducer 4 (motor with speed reducer 1 ) of the present embodiment is adopted, it is possible to suppress input of unnecessary deformation load to the crankshaft 10 during use.

[0124] Therefore, by adopting the reducer 4 (motor 1 with reducer) of this embodiment, it is possible to contribute to Goal 7 of the Sustainable Development Goals (SDGs) led by the United Nations, "ensuring access to affordable, reliable, sustainable and modern energy for all."

[0125] Furthermore, in the speed reducer 4 (motor 1 with speed reducer) of the present embodiment, the flange portion 12 of the crankshaft 10 is formed into an annular shape whose outer peripheral surface is spaced apart from the eccentric portion 20 at a uniform distance in the circumferential direction. Therefore, the inner ring 24i of the bearing 24 is easily brought into contact with the end surface 12s of the flange portion 12 of the crankshaft 10 more evenly in the circumferential direction.

[0126] Therefore, when this structure is adopted, it is possible to further suppress the input of unnecessary deformation load to the crankshaft 10 during use. In addition, in this structure, since the outer periphery of the flange portion 12 is circular, the flange portion 12 can be made more compact and lightweight compared to the case where the outer periphery of the flange portion 12 is polygonal.

[0127] In the reducer 4 (motor 1 with reducer) of the present embodiment, the reducer body includes a bearing 24, a swing gear 25, a fixed gear 16, and an output gear 27, the bearing 24 is held on the inner periphery of the swing gear 25, and an inner tooth 55b (first inner tooth) and an outer tooth 55a (second outer tooth) are provided on the outer peripheral region of the swing gear 25. In addition, the fixed gear 16 is fixed to the housing 5 and includes an inner tooth 16b (second inner tooth) that meshes with the outer tooth 55a of the swing gear 25 and is concentric with the central axis L of the crankshaft 10. In addition, the output gear 27 includes an outer tooth (second outer tooth) that meshes with the inner tooth 55b of the swing gear 25 and is concentric with the central axis L.

[0128] Therefore, when this structure is adopted, the power of the motor part can be decelerated with good efficiency and output to the external device, and on the other hand, a part of the reaction force from the external device is easy to act as a large load that presses the bearing 24 in the tilting direction. However, in the present embodiment, the flange portion 12 of the crankshaft 10 is formed so that the center of the flange portion 12 in the direction orthogonal to the axial direction coincides with the center (central axis O) of the eccentric portion 20, so that the input of unnecessary deformation load to the crankshaft 10 can be effectively suppressed.

[0129] In addition, the present invention is not limited to the above-mentioned embodiments, and various design changes can be made within the scope of the main purpose. For example, in the above-mentioned embodiments, the motor 1 with a reducer is applied to the wheel drive part of the vehicle, but the application of the motor 1 with a reducer is not limited to this. The motor 1 with a reducer can be applied to various other machines as long as it is a machine that reduces the power of the motor and uses it.

[0130] Furthermore, in the above-described embodiment, the flange portion 12 provided on the crankshaft 10 is formed into a circular shape (annular shape), but the shape of the flange portion 12 is not limited thereto. The flange portion 12 may be, for example, a polygonal shape when viewed in the axial direction. In this case, the flange portion 12 only needs to be formed so that the center in the direction perpendicular to the axial direction coincides with the center of the eccentric portion 20 in the direction perpendicular to the axial direction.

Claims

1. A reducer, characterized in that: include: Box; A crankshaft having a rotation support portion rotatably supported by the housing and an eccentric portion eccentric to the rotation support portion, and receiving a rotational force from the outside to rotate; as well as The reducer body has an engaging portion engaged with the outer peripheral surface of the eccentric portion, and reduces the swing rotation of the eccentric portion received by the engaging portion and outputs it to the outside. The crankshaft is provided with a flange portion, which protrudes radially outward from an end portion of the rotation support portion on the eccentric portion side and abuts against an axial end surface of the engagement portion. The flange portion is formed so that the center in the direction perpendicular to the axial direction coincides with the center in the direction perpendicular to the axial direction of the eccentric portion.

2. The reducer according to claim 1, characterized in that: The flange portion is formed in an annular shape whose outer peripheral surface is spaced apart from the eccentric portion at a uniform distance in the circumferential direction.

3. The reducer according to claim 1, characterized in that: The reducer body comprises: A bearing as the engaging portion; a swing gear rotatably supported by the eccentric portion of the crankshaft via the bearing and having first internal teeth and first external teeth; a fixed gear fixed to the housing and having second internal teeth, the second internal teeth meshing with the first external teeth of the swing gear and being concentric with a central axis of the rotation support portion of the crankshaft; and The output gear has second external teeth, wherein the second external teeth are engaged with the first internal teeth of the swing gear and are concentric with the central axis.

4. A motor with a reducer, characterized in that: include: The reducer according to any one of claims 1 to 3; as well as The motor unit is connected to the crankshaft of the speed reducer.

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