In-wheel motor

Abstract

To provide an in-wheel motor capable of improving reliability.SOLUTION: An in-wheel motor includes: a supporting structure that forms a cylindrical shape extending in an axial direction and is attached to a vehicle body on one side in the axial direction; a wheel that has a cylinder portion surrounding the supporting structure from an outer peripheral side, and a disk portion blocking the other side in the axial direction of the cylinder portion; a bearing that supports the wheel with respect to the supporting structure so as to relatively rotate; a casing that is fitted in an inner peripheral surface of the supporting structure; a drive device that is stored inside the casing so as to be driven to rotate around an axis, and has an output shaft projecting out from the casing to the other side in the axial direction; a key member that connects the output shaft and the disc portion so as not to relatively rotate and so as to relatively move in the axial direction; and a regulating member that regulates relative movement in the axial direction of the output shaft and the disc portion to be within a predetermined range.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to an in-wheel motor. [Background technology]

[0002] In the electric wheel of Patent Document 1, a stator of a motor (drive device) is attached to the vehicle body, and the wheel, which rotates due to the rotational force of the drive device, is connected to the vehicle body via bearings or the like. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2013-23202 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the electric wheel described in Patent Document 1, when the wheel receives a thrust load, most of the thrust load is transmitted to the drive unit via the vehicle body. If the thrust load transmitted to the drive unit becomes large, breakdowns and failures become more likely to occur, and reliability decreases.

[0005] The present disclosure has been made to solve the above-mentioned problems, and has an object to provide an in-wheel motor that can improve reliability. [Means for solving the problem]

[0006] In order to solve the above-mentioned problems, the in-wheel motor of the present disclosure includes a support structure that is cylindrical and extends in the axial direction and has one axial side attached to a vehicle body, a wheel that has a cylindrical portion that surrounds the support structure from the outer periphery and a disk portion that closes the other axial side of the cylindrical portion, a bearing that supports the wheel so that it can rotate relative to the support structure about the axis, a casing fitted to the inner circumferential surface of the support structure, and a drive device that is housed inside the casing and can be driven to rotate about the axis and has an output shaft that protrudes from the casing on the other axial side, a key member that connects the output shaft and the disk portion so that they cannot rotate relative to each other but can move relative to each other in the axial direction, and a restricting member that restricts the relative movement in the axial direction between the output shaft and the disk portion within a predetermined range. [Effects of the Invention]

[0007] According to the in-wheel motor of the present disclosure, reliability can be improved. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a configuration diagram of an in-wheel motor according to a first embodiment of the present disclosure; [Figure 2] FIG. 2 is a detailed view of the wheel support bearing according to the first embodiment of the present disclosure. [Figure 3] 10A and 10B are diagrams illustrating assembly of a casing according to the first embodiment of the present disclosure. [Figure 4] 1 is a diagram showing a peripheral portion of an output shaft according to a first embodiment of the present disclosure; [Figure 5] FIG. 10 is a configuration diagram of an in-wheel motor according to a second embodiment of the present disclosure. [Figure 6] FIG. 10 is a view of a disk portion of a wheel according to a second embodiment of the present disclosure, viewed from the axial direction. [Figure 7] FIG. 10 is a view of a pressing member according to a second embodiment of the present disclosure, as viewed from the axial direction. [Figure 8] FIG. 10 is a configuration diagram of an in-wheel motor according to a third embodiment of the present disclosure. [Figure 9] FIG. 11 is a view of a disk portion of a wheel according to a third embodiment of the present disclosure, viewed from the axial direction. [Figure 10] FIG. 11 is a view of a disk portion of a wheel according to a modified example of the third embodiment of the present disclosure, viewed from the axial direction. [Figure 11] FIG. 11 is a cross-sectional view of a disk portion of a wheel according to a modified example of the third embodiment of the present disclosure, viewed from the radial direction. DETAILED DESCRIPTION OF THE INVENTION

[0009] First Embodiment An in-wheel motor 1 according to a first embodiment of the present disclosure will be described below with reference to FIGS.

[0010] (in-wheel motor) The in-wheel motor 1 of this embodiment is mounted on a vehicle and rotates a tire 2 of the vehicle.

[0011] As shown in Figure 1, the in-wheel motor 1 includes a support structure 10, a wheel 20, a wheel support bearing 4 (an example of a bearing provided between the support structure 10 and the wheel 20), a first retaining portion 5 (see Figure 2), a second retaining portion 6 (see Figure 2), a drive unit 7, a key member 8, and a regulating member 9.

[0012] (Support structure) The support structure 10 has a cylindrical shape extending in the direction of the axis O. Hereinafter, the axis O of the support structure 10 will be simply referred to as the "axis O." Furthermore, the radial direction about the axis O will be simply referred to as the "radial direction," and the circumferential direction about the axis O will be simply referred to as the "circumferential direction." One side of the support structure 10 in the direction of the axis O is attached to the vehicle body 3.

[0013] In this embodiment, the inner circumferential surface 10a of the support structure 10 is formed in a stepped shape that is positioned radially outward from one side to the other side in the direction of the axis O. The inner circumferential surface 10a of the support structure 10 has a first inner circumferential surface 11, a second inner circumferential surface 12, and a third inner circumferential surface 13. The first inner circumferential surface 11 is located on one side of the support structure 10 in the direction of the axis O. The second inner circumferential surface 12 is located at the center of the support structure 10 in the direction of the axis O. The second inner circumferential surface 12 is located radially outward of the first inner circumferential surface 11. An edge of the second inner circumferential surface 12 on one side in the direction of the axis O is connected to an edge of the first inner circumferential surface 11 on the other side in the direction of the axis O by a step surface 14 perpendicular to the direction of the axis O. The third inner circumferential surface 13 is located on the other side of the support structure 10 in the direction of the axis O. The third inner circumferential surface 13 is located radially outward of the second inner circumferential surface 12. An edge of the third inner circumferential surface 13 on one side in the direction of the axis O is connected to an edge of the second inner circumferential surface 12 on the other side in the direction of the axis O by a step surface 15 perpendicular to the direction of the axis O. A groove 16 is formed in the third inner circumferential surface 13. The groove 16 extends in the direction of the axis O from an open end of the support structure 10 on the other side in the direction of the axis O. The groove 16 is a spline groove or a key groove.

[0014] (wheel) The wheel 20 has a cylindrical portion 21 and a disk portion 22 . The cylindrical portion 21 surrounds the outer periphery of the support structure 10. The central axis of the cylindrical portion 21 is along the axis O. The tire 2 is mounted on the outer periphery of the cylindrical portion 21.

[0015] The disk portion 22 closes the other side of the cylindrical portion 21 in the direction of the axis O. The disk portion 22 is formed in a disk shape with the axis O as the central axis. The disk portion 22 has a wheel insertion hole 23 and a key groove 24 .

[0016] A plurality of wheel insertion holes 23 are formed in a radially inner portion of the disk portion 22. The wheel insertion holes 23 penetrate the disk portion 22 in the axial O direction.

[0017] The key groove 24 is formed on one surface of the disk portion 22 in the direction of the axis O. The key groove 24 extends linearly in one direction. For example, in the example shown in FIG. 1, the key groove 24 extends in the depth direction of the page. A cross section of the key groove 24 perpendicular to the longitudinal direction is formed into a rectangular shape.

[0018] (Wheel support bearing) The wheel support bearing 4 supports the wheel 20 so as to be rotatable relative to the support structure 10 about the axis O. Two wheel support bearings 4 are provided, spaced apart in the direction of the axis O. As shown in FIG. 2, the wheel support bearing 4 has an outer ring 4a, an inner ring 4b, and rolling elements 4c (balls, rollers, etc.). The outer ring 4a is attached to the inner circumferential surface of the cylindrical portion 21. The outer ring 4a is attached to the cylindrical portion 21 by fitting (for example, interference fit). The inner ring 4b is attached to an outer peripheral surface 10b of the support structure 10. The inner ring 4b is attached to the support structure 10 by fitting (for example, a loose fit). The rolling element 4c is provided, for example, between the inner ring 4b and the outer ring 4a. The rolling element 4c is rotatably installed between the inner ring 4b and the outer ring 4a.

[0019] (1st holding part, 2nd holding part) The first retaining portion 5 and the second retaining portion 6 sandwich the wheel support bearing 4 from both sides in the direction of the axis O. One first retaining portion 5 and one second retaining portion 6 are provided for each wheel support bearing 4. The first retaining portion 5, wheel support bearing 4, and second retaining portion 6 are aligned in this order in the direction of the axis O, and form a stepped structure located radially outward from the first retaining portion 5 toward the second retaining portion 6.

[0020] Specifically, the first retaining portion 5 is fixed to the outer peripheral surface 10b of the support structure 10. The first retaining portion 5 is arranged near the inner ring 4b of the wheel support bearing 4. The first retaining portion 5 and the inner ring 4b are slightly spaced apart in the direction of the axis O. In other words, there is play between the first retaining portion 5 and the inner ring 4b. The second retaining portion 6 is fixed to the inner peripheral surface of the cylindrical portion 21. The second retaining portion 6 abuts against the outer ring 4a of the wheel support bearing 4. The first holding portion 5 and the second holding portion 6 are, for example, bearing nuts, retaining rings, or the like.

[0021] In this embodiment, the two first retaining portions 5 are disposed between the two wheel support bearings 4. Furthermore, the two second retaining portions 6 are disposed so as to sandwich the set of two wheel support bearings 4 from both sides in the direction of the axis O.

[0022] (Drive unit) Returning to FIG. 1, the drive device 7 includes a casing 30, a mounting member 50, a motor 60, a fixing portion 70, and a reducer 80.

[0023] (Casing) The casing 30 is fitted onto the inner peripheral surface 10a of the support structure 10. The casing 30 has a motor casing 31 and a reducer casing 32.

[0024] (Motor casing) The motor casing 31 constitutes one side of the casing 30 in the direction of the axis O. The motor casing 31 accommodates the motor 60, which will be described later. The motor casing 31 has a side wall portion 33 , a bottom portion 34 , and a flange 35 .

[0025] The side wall portion 33 is formed in a cylindrical shape extending in the direction of the axis O. The central axis of the side wall portion 33 is along the axis O. The side wall portion 33 is fitted into the second inner circumferential surface 12 of the support structure 10.

[0026] The bottom portion 34 closes an opening on one side of the side wall portion 33 in the direction of the axis O. The bottom portion 34 is formed in a disk shape. The central axis of the bottom portion 34 is along the axis O. The bottom portion 34 abuts against the step surface 14 of the casing 30 from the other side in the direction of the axis O. The bottom portion 34 has a through hole 36 and an annular wall portion 37.

[0027] The through hole 36 penetrates the bottom portion 34 along the axis O. The through hole 36 has a small diameter hole 36a and a large diameter hole 36b. The small diameter hole 36a constitutes the other side of the through hole 36 in the direction of the axis O. The large diameter hole 36b constitutes one side of the through hole 36 in the direction of the axis O. The radius of the large diameter hole 36b is larger than the radius of the small diameter hole 36a. The large diameter hole 36b communicates with the small diameter hole 36a.

[0028] The annular wall portion 37 is provided on the surface of the bottom portion 34 facing the other side in the direction of the axis O. The annular wall portion 37 rises from the bottom portion 34 to the other side in the direction of the axis O and is provided so as to surround the small diameter hole 36a of the through hole 36 from the outer periphery side. The annular wall portion 37 is provided at a position spaced radially outward from the small diameter hole 36a.

[0029] The flange 35 is provided at the end of the side wall portion 33 on the other side in the direction of the axis O. The flange 35 protrudes radially outward from the outer peripheral surface of the side wall portion 33. The flange 35 abuts against the step surface 15 of the support structure 10 from the other side in the direction of the axis O.

[0030] (Reduction gear casing) The reducer casing 32 constitutes the other side of the casing 30 in the direction of the axis O. The reducer casing 32 accommodates a reducer 80, which will be described later. The reducer casing 32 has a side wall portion 38 , a first bottom portion 39 , a second bottom portion 40 , and a flange 41 .

[0031] The central axis of the side wall portion 38 is aligned with the axis O. The side wall portion 38 is surrounded from the outer periphery by the third inner circumferential surface 13 of the support structure 10. In addition, an annular inner toothed ring 38a is provided around the entire inner circumferential surface of the side wall portion 38.

[0032] The first bottom portion 39 closes an opening on one side of the side wall portion 38 in the direction of the axis O. The first bottom portion 39 has a base portion 42 and a fitting portion 43. The base 42 is formed in a disk shape. The central axis of the base 42 is aligned with the axis O. The fitting portion 43 is provided on one surface of the base portion 42 in the direction of the axis O. The fitting portion 43 is formed in a disk shape. The central axis of the fitting portion 43 is along the axis O. The radius of the fitting portion 43 is smaller than the radius of the base portion 42. The fitting portion 43 is fitted into an opening in the side wall portion 33 of the motor casing 31.

[0033] From another perspective, the first bottom portion 39 has a through hole 44 and an annular wall portion 45. The through-hole 44 penetrates the first bottom portion 39 along the axis O. The through-hole 44 has a small diameter hole 44a and a large diameter hole 44b. The small diameter hole 44a constitutes one side of the through hole 44 in the direction of the axis O. The large diameter hole 44b constitutes the other side of the through hole 44 in the direction of the axis O. The radius of the large diameter hole 44b is larger than the radius of the small diameter hole 44a. The large diameter hole 44b is in communication with the small diameter hole 44a.

[0034] The annular wall portion 45 is provided on a surface of the first bottom portion 39 facing one side in the direction of the axis O. The annular wall portion 45 rises from the bottom portion 34 to one side in the direction of the axis O and is provided so as to surround the small diameter hole 44a of the through hole 44 from the outer periphery. The annular wall portion 45 is provided at a position spaced radially outward from the small diameter hole 44a.

[0035] The second bottom portion 40 closes the opening on the other side of the side wall portion 38 in the direction of the axis O. The second bottom portion 40 is formed in a disk shape. The central axis of the second bottom portion 40 is along the axis O. The second bottom portion 40 has a through hole 46.

[0036] The through-hole 46 penetrates the first bottom portion 39 along the axis O. The through-hole 46 has a small diameter hole 46a and a large diameter hole 46b. The small diameter hole 46a constitutes the other side of the through hole 46 in the direction of the axis O. The large diameter hole 46b constitutes one side of the through hole 46 in the direction of the axis O. The radius of the large diameter hole 46b is larger than the radius of the small diameter hole 46a. The large diameter hole 46b communicates with the small diameter hole 46a.

[0037] The flange 41 is provided at one end of the side wall portion 38 in the direction of the axis O. The flange 41 protrudes radially outward from the outer peripheral surface of the side wall portion 38. The flange 41 of the reducer casing 32 abuts against the flange 35 of the motor casing 31 from the other side in the direction of the axis O.

[0038] (mounting material) The mounting member 50 mounts the casing 30 to the support structure 10. As shown in FIG. The bolt 51 penetrates the flange 35 of the motor casing 31 and the flange 41 of the reducer casing 32 in the direction of the axis O to fasten them together. As a result, the motor casing 31 and the reducer casing 32 are integrated to form the casing 30. Furthermore, the tip 51c of the bolt 51 penetrates into the support structure 10. As a result, the casing 30 is fastened and fixed to the support structure 10.

[0039] The elastic body 52 covers the outer periphery of the threaded portion 51a of the bolt 51. The elastic body 52 is provided from the head 51b of the bolt 51 to the inside of the flange 35 of the motor casing 31. The elastic body 52 is made of, for example, rubber.

[0040] The torque support ring 53 is fixed to the casing 30 by the bolt 51. The torque support ring 53 is provided between the head 51b of the bolt 51 and the flange 41 of the reducer casing 32. The torque support ring 53 covers the threaded portion 51a of the bolt 51 together with the elastic body 52 from the outer periphery side. The torque support ring 53 is fitted into a groove portion 16 formed in the third inner circumferential surface 13 of the support structure 10. The torque support ring 53 is, for example, a spline or a key.

[0041] (Motor) The motor 60 is housed in the motor casing 31. The motor 60 includes a stator 61 and a rotor 62. The stator 61 is provided in an annular shape around the entire inner circumferential surface of the motor casing 31. The stator 61 has a stator core 63 fixed to the inner circumferential surface of the motor casing 31 and a coil 64 attached to the stator core 63.

[0042] The rotor 62 is provided inside the stator 61. The rotor 62 has a rotor shaft 65 and a rotor core 66. The rotor shaft 65 is a hollow shaft formed in a cylindrical shape that extends along the axis O. Both ends of the rotor shaft 65 in the direction of the axis O are rotatably supported by bearings 67. The bearing 67 on one side in the direction of the axis O is attached to the inner circumferential surface of the annular wall portion 37 of the motor casing 31. The bearing 67 on the other side in the direction of the axis O is attached to the inner circumferential surface of the annular wall portion 45 of the reducer casing 32.

[0043] The rotor core 66 is provided at the center of the rotor shaft 65 in the direction of the axis O. The rotor core 66 protrudes radially outward from the rotor shaft 65 in a flange-like shape.

[0044] The rotor 62 described above is fixed to the reducer 80 by a fixing portion 70. The fixing portion 70 transmits rotational torque from the rotor 62 to the reducer 80. The detailed configuration of the fixing portion 70 will be described later.

[0045] (reducer) The reducer 80 is housed in the reducer casing 32. The reducer 80 has a sun shaft 81, a planetary gear 82, a carrier 83, and an output shaft 84.

[0046] (Sun axis) The sun shaft 81 has a shaft portion 85 and a sun gear 86 .

[0047] The shaft portion 85 extends along the axis O. The shaft portion 85 protrudes from the through-hole 46 of the reducer casing 32 to one side in the direction of the axis O. Furthermore, the shaft portion 85 is inserted into the rotor shaft 65 from the other side in the direction of the axis O. The shaft portion 85 is fixed to the rotor shaft 65 by the fixing portion 70.

[0048] The fixing portion 70 is provided at one end of the shaft portion 85 in the direction of the axis O. The fixing portion 70 has a torque receiving portion 71, a bolt 72, and a washer 73.

[0049] The torque receiving portion 71 is formed on the inner peripheral surface of the rotor shaft 65 and the outer peripheral surface of the shaft portion 85 of the sun shaft 81. The torque receiving portion 71 has a structure such as a spline or a key. The torque receiving portion 71 receives the rotational torque of the rotor 62 and transmits it to the shaft portion 85. The bolt 72 is threaded into the shaft portion 85 from one side in the direction of the axis O. The washer 73 is disposed between the head of the bolt 72 and the shaft portion 85 and is inserted into the bolt 72. The positions of the motor 60 and the reducer 80 in the direction of the axis O are fixed by the bolt 72 and the washer 73.

[0050] The sun gear 86 is provided at the other end of the shaft portion 85 in the direction of the axis O. The sun gear 86 is disposed inside the reducer casing 32.

[0051] (planetary gear) A plurality of planetary gears 82 are provided on the outer periphery of the sun gear 86. The planetary gears 82 are meshed with the sun gear 86. The planetary gears 82 have insertion holes 87. The insertion holes 87 penetrate the planetary gears 82 in the direction of the axis O. From another perspective, the planetary gears 82 have a first gear 82a and a second gear 82b. The first gear 82a constitutes one side of the planetary gears 82 in the direction of the axis O. The first gear 82a is engaged with the internal tooth ring 38a. The second gear 82b constitutes the other side of the planetary gears 82 in the direction of the axis O. The radius of the second gear 82b is smaller than the radius of the first gear 82a.

[0052] (Career) The carrier 83 supports the planetary gear 82. The carrier 83 has a first carrier body 89, a second carrier body 90, and a carrier shaft 91. The first carrier body 89 and the second carrier body 90 sandwich the planetary gear 82 from both sides in the axis O direction.

[0053] The first carrier body 89 is provided on one side in the direction of the axis O with respect to the planetary gear 82. The first carrier body 89 has a cylindrical portion 89a and a flange 389b. The cylindrical portion 89a extends along the axis O. The cylindrical portion 89a has an insertion hole 89c. The insertion hole 89c extends along the axis O. The shaft portion 85 of the sun shaft 81 is inserted into the insertion hole 89c. The insertion hole 89c is formed with a larger diameter than the shaft portion 85. The cylindrical portion 89a is rotatably supported by a bearing 92. The bearing 92 is attached to the inner circumferential surface of the large diameter hole 44b of the through hole 44 of the reducer casing 32. The flange 89b is provided at the other end of the columnar portion 89a in the direction of the axis O. The flange 89b protrudes radially outward from the outer circumferential surface of the columnar portion 89a.

[0054] The second carrier body 90 is provided on the other side in the direction of the axis O with respect to the planetary gear 82. The second carrier body 90 is located on the other side in the direction of the axis O with respect to the sun gear 86. The second carrier body 90 has a cylindrical portion 90a and a flange 90b. The cylindrical portion 90a extends along the axis O. The flange 90b is provided at one end of the columnar portion 90a in the direction of the axis O. The flange 90b protrudes radially outward from the outer circumferential surface of the columnar portion 90a.

[0055] The carrier shaft 91 connects the flange 89b of the first carrier body 89 and the flange 90b of the second carrier body 90 in the direction of the axis O. The carrier shaft 91 is inserted through an insertion hole 87 of the planetary gear 82. A bearing 88 is provided on the outer circumferential surface of the carrier shaft 91.

[0056] (output shaft) The output shaft 84 is housed inside the casing 30 and is provided so as to be rotatable about the axis O. The rotational force of the rotor 62 is transmitted to the output shaft 84 via the sun shaft 81 and the planetary gears 82. The output shaft 84 protrudes from the casing 30 to the other side in the direction of the axis O. The output shaft 84 has an output shaft body 93 and a connecting portion 94 . The output shaft body 93 is formed in a cylindrical shape extending in the direction of the axis O. The output shaft body 93 is inserted into the through hole 46 of the second bottom portion 40 from one side in the direction of the axis O and protrudes from the casing 30 to the other side in the direction of the axis O. The output shaft body 93 is supported by a bearing 95 so as to be rotatable around the axis O. The bearing 95 is attached to the inner circumferential surface of the large-diameter hole 46b of the through hole 46 of the second bottom portion 40. The output shaft body 93 also has a groove 93a that opens toward one side in the direction of the axis O. The groove 93a is formed in the radial center of the output shaft body 93. A bearing 96 is attached to the inner circumferential surface of the groove 93a. The cylindrical portion 90a of the second carrier body 90 is inserted into this bearing 96.

[0057] The connecting portion 94 is provided on one side of the output shaft body 93 in the direction of the axis O. The connecting portion 94 has a flange 94a, a wall portion 94b, and internal teeth 94c. The flange 94a extends radially outward from the outer peripheral surface of the output shaft body 93. The wall portion 94b extends in the direction of the axis O from the surface of one side of the flange 94a in the direction of the axis O. The internal teeth 94c are provided at the end of the wall portion 94b on one side in the direction of the axis O. The internal teeth 94c are in mesh with the second gear 82b of the planetary gear 82.

[0058] (Key parts) The key member 8 connects the output shaft 84 and the disk portion 22 so that they cannot rotate relative to each other but can move relative to each other in the direction of the axis O. In this embodiment, the key member 8 is attached to the surface of the output shaft main body 93 on the other side in the direction of the axis O. The key member 8 protrudes from the output shaft 84 to the other side in the direction of the axis O. The key member 8 is fitted into the key groove 24 with a gap therebetween in the direction of the axis O. This gap-like fit between the key member 8 and the key groove 24 allows the disk portion 22 to move relative to the key member 8 in the direction of the axis O. The key also transmits torque from the output shaft 84 to the wheel 20.

[0059] (Regulatory member) The restricting member 9 restricts the relative movement between the output shaft 84 and the disk portion 22 in the direction of the axis O within a predetermined range.

[0060] Here, if the range of play in the axial direction of the wheel support bearing 4 is Δ1 and the range of relative movement in the axial direction of the output shaft 84 and the disk portion 22, which is regulated by the regulating member 9, is Δ2, Δ2 is larger than Δ1.

[0061] In this embodiment, the restricting member 9 includes a bolt 17 and a spring 18 . The bolt 17 is inserted into the wheel insertion hole 23 of the wheel 20. The bolt 17 has a threaded portion 17a, a head portion 17b, and a tip portion 17c. The threaded portion 17a extends in the direction of the axis O. The head portion 17b is slightly spaced from the disk portion 22 of the wheel 20 on the other side in the direction of the axis O. The tip portion 17c is fastened to the disk portion 22. The springs 18 are provided on both sides of the disk portion 22 in the direction of the axis O. The spring 18 on one side in the direction of the axis O is sandwiched in the direction of the axis O between the output shaft 84 and the wheel 20, and the spring 18 on the other side in the direction of the axis O is sandwiched in the direction of the axis O between the wheel 20 and the head 17b of the bolt 17. Each spring 18 is compressed in the direction of the axis O when assembled.

[0062] A space in the axial direction O (hereinafter, this space will be referred to as backlash in the axial direction O) is provided between the head 17b of the bolt 17 and the disk portion 22 of the wheel 20, and between the disk portion 22 of the wheel 20 and the output shaft 84. The spring 18 is disposed within this backlash in the axial direction O. Note that, in this embodiment, the spring 18 does not necessarily have to be provided within this backlash in the axial direction O.

[0063] (Action and effect) The in-wheel motor 1 of this embodiment provides the following advantageous effects.

[0064] In this embodiment, the in-wheel motor 1 includes a support structure 10, a wheel 20, a drive unit 7, a key member 8, and a restricting member 9. The support structure 10 is cylindrical and extends in the direction of the axis O, with one side in the direction of the axis O attached to the vehicle body 3. The wheel 20 has a cylindrical portion 21 that surrounds the support structure 10 from the outer periphery, and a disk portion 22 that closes the other side in the direction of the axis O of the cylindrical portion 21. The wheel support bearing 4 supports the wheel 20 relative to the support structure 10 so that it can rotate about the axis O. The drive unit 7 includes a casing 30 and an output shaft 84. The casing 30 is fitted into an inner circumferential surface 10a of the support structure 10. The output shaft 84 is housed inside the casing 30 and is rotatable about the axis O, and protrudes from the casing 30 on the other side in the direction of the axis O. The key member 8 connects the output shaft 84 and the disk portion 22 so that they cannot rotate relative to each other but can move relative to each other in the direction of the axis O. The restricting member 9 restricts the relative movement between the output shaft 84 and the disk portion 22 in the direction of the axis O within a predetermined range.

[0065] For example, when the wheel 20 is steered, a thrust load F acts on the wheel 20 from the road surface. According to this embodiment, when the wheel 20 receives the thrust load F from the road surface or the like, the thrust load F is transmitted from the wheel 20 to the vehicle body 3 via the wheel support bearing 4 and the support structure 10. Furthermore, the key member 8 causes the output shaft 84 and the disk portion 22 to move relatively in the direction of the axis O. This relative movement between the output shaft 84 and the disk portion 22 absorbs the thrust load F directed toward the drive unit 7. This makes it easier for the thrust load F to be transmitted to the support structure 10, avoiding the drive unit 7. This prevents the thrust load F from acting on the drive unit 7. This prevents malfunctions and failures from occurring, improving reliability.

[0066] Furthermore, the output shaft 84 is disposed between the drive unit 7 and the disk portion 22 of the wheel 20. Therefore, the output shaft 84 is disposed in the space within the cylindrical portion 21 of the wheel 20. This makes it possible to utilize the available space, thereby making it possible to make the in-wheel motor 1 compact. Furthermore, since the output shaft 84 is disposed near the wheel 20, it becomes easy to arrange the output shaft 84 and the reducer 80 having the output shaft 84.

[0067] In this embodiment, the disk portion 22 has a key groove 24 that fits into the key member 8 with a gap therebetween in the direction of the axis O. The disk portion 22 is provided so as to be movable relative to the key member 8 in the direction of the axis O.

[0068] This allows the disk portion 22 of the wheel 20 to move in the direction of the axis O along the key member 8. This movement of the disk portion 22 in the direction of the axis O makes it easier for the thrust load F to be transmitted to the support structure 10, avoiding the drive unit 7. This further reduces the thrust load F from acting on the drive unit 7.

[0069] In addition, in this embodiment, a space (backlash) is provided in the direction of the axis O between the head 17b of the bolt 17 of the regulating member 9 and the disk portion 22 of the wheel 20, and between the disk portion 22 of the wheel 20 and the output shaft 84.

[0070] As a result, the thrust load F acting from the road surface or the like avoids the drive device 7 and is reliably transmitted to the support structure 10. Therefore, the thrust load F is further prevented from acting on the drive device 7.

[0071] In this embodiment, the in-wheel motor 1 further includes a first retaining portion 5 and a second retaining portion 6 that sandwich the wheel support bearing 4 from both sides in the direction of the axis O. The first retaining portion 5 is fixed to the outer peripheral surface 10b of the support structure 10, and the second retaining portion 6 is fixed to the inner peripheral surface of the cylindrical portion 21.

[0072] This allows the first retaining portion 5 and the second retaining portion 6 to retain the wheel support bearing 4 at the same position in the direction of the axis O. Therefore, deviation of the wheel support bearing 4 in the direction of the axis O is suppressed.

[0073] In this embodiment, an elastic body 52 is provided around the bolt 51 for fixing the torque support ring 53 .

[0074] As a result, the elastic body 52 absorbs any positional deviation of the drive device 7. Therefore, deviation (eccentricity) between the support structure 10 and the drive device 7 is alleviated, which reduces the occurrence of breakdowns and failures and improves reliability.

[0075] Second Embodiment An in-wheel motor 201 according to a second embodiment of the present disclosure will be described below mainly with reference to Figures 5 to 7. Configurations similar to those in the above-described embodiment will be given the same names and reference numerals, and descriptions thereof will be omitted as appropriate.

[0076] As shown in Figure 5, in this embodiment, the in-wheel motor 201 includes a support structure 10, a wheel 220, a wheel support bearing 4, a first holding portion 5 (see Figure 2), a second holding portion 6 (see Figure 2), a drive unit 7, a key member 8, a regulating member 209, and a pressing member 210.

[0077] The wheel 220 has a cylindrical portion 21 and a disk portion 222. The disk portion 222 has a wheel insertion hole 223 and a key groove 24.

[0078] As shown in Fig. 6, four wheel insertion holes 223 are provided lined up in the circumferential direction so as to surround the axis O. Each wheel insertion hole 223 is an elongated hole extending in the circumferential direction. All four wheel insertion holes 223 have the same circumferential length.

[0079] As shown, the pressing member 210 is disposed between the output shaft 84 and the disk portion 222. The pressing member 210 is formed in a disk shape extending in a direction perpendicular to the axis O. The pressing member 210 is formed from a friction material. The pressing member 210 has a key member 8 on its surface facing the disk portion 222. The pressing member 210 has an insertion hole 211.

[0080] The insertion hole 211 penetrates the pressing member 210 in the direction of the axis O. The insertion hole 211 is formed at a position overlapping with the wheel insertion hole 223 in the direction of the axis O. 7, four insertion holes 211 are provided lined up in the circumferential direction so as to surround the axis O. Each insertion hole 211 is an elongated hole extending in the circumferential direction. The four insertion holes 87, 89c, 211 all have the same circumferential length.

[0081] The restricting member 209 is provided so as to be movable relative to the disk portion 222 . The restricting member 209 includes a bolt 217 and a spring 218 . The bolt 217 is inserted through the wheel insertion hole 223 and the insertion hole 211 of the pressing member 210. The bolt 217 has a threaded portion 217a, a head portion 217b, and a tip portion 217c. The threaded portion 217a extends in the direction of the axis O. The head portion 217b is slightly spaced from the disk portion 222 of the wheel 220 on the other side in the direction of the axis O. The tip portion 217c is fastened to the disk portion 222. The wheel insertion hole 223 and the insertion hole 211 of the pressing member 210 are so-called countersunk holes. That is, the wheel insertion hole 223 and the insertion hole 211 of the pressing member 210 are formed with a larger diameter than the threaded portion 217a. However, the wheel insertion hole 223 and the insertion hole 211 of the pressing member 210 are formed with a smaller diameter than the head portion 217b.

[0082] The springs 218 are provided on both sides of the disk portion 222 in the direction of the axis O. The spring 218 on one side in the direction of the axis O is sandwiched in the direction of the axis O between the pressing member 210 and the wheel 220, and the spring 218 on the other side in the direction of the axis O is sandwiched in the direction of the axis O between the wheel 220 and the head 217b of the bolt 217. Each spring 218 is compressed in the direction of the axis O when assembled. The spring 218 on one side in the direction of the axis O presses the pressing member 210 against the output shaft 84 in the direction of the axis O. This generates a frictional force between the pressing member 210 and the output shaft 84 that is strong enough to withstand the rotational force of the output shaft 84. The spring 218 is, for example, a coil spring, a disc spring, a leaf spring, or the like.

[0083] (Action and effect) According to the in-wheel motor 201 of this embodiment, the following effects are achieved.

[0084] In this embodiment, the in-wheel motor 201 further includes a pressing member 210. The pressing member 210 is arranged between the output shaft 84 and the disk portion 222. A key member 8 is provided on the surface of the pressing member 210 facing the disk portion 222. The restricting member 209 is provided so as to be able to move relatively to the disk portion 222. The restricting member 209 has a spring 218 that presses the pressing member 210 against the output shaft 84 in the direction of the axis O.

[0085] According to this embodiment, the rotational force of the drive unit 7 is transmitted to the wheel 220 by the frictional force between the output shaft 84 and the pressing member 210. Therefore, when an unexpected disturbance acts on the wheel 220, the output shaft 84 and the pressing member 210 become misaligned, thereby preventing the disturbance from acting on the drive unit 7. This prevents the occurrence of breakdowns or failures due to disturbances. In this way, the pressing member 210 functions as a safety mechanism, further improving reliability.

[0086] In this embodiment, the pressing member 210 is made of a friction material.

[0087] Thus, by selecting the material of the friction material that constitutes the pressing member 210, the friction force between the output shaft 84 and the pressing member can be adjusted.

[0088] Third Embodiment An in-wheel motor 301 according to a third embodiment of the present disclosure will be described below mainly with reference to Figures 8 and 9. Configurations similar to those in the above-described embodiments will be given the same names and reference numerals, and descriptions thereof will be omitted as appropriate.

[0089] As shown in Figure 8, in this embodiment, the in-wheel motor 301 includes a support structure 10, a wheel 320, a wheel support bearing 4, a first holding portion 5 (see Figure 2), a second holding portion 6 (see Figure 2), a drive unit 7, a key member 8, a regulating member 209, and a pressing member 210.

[0090] The wheel 320 has a cylindrical portion 21 and a disk portion 322 .

[0091] The disk portion 322 has a wheel insertion hole 223 and a key groove 24. From another perspective, the disk portion 322 has a disk portion main body 322a, an annular portion 322b, and elastic structures 310, 310A.

[0092] The disk body 322a overlaps with the output shaft 84 in the direction of the axis O. The disk body 322a is provided with a wheel insertion hole 223 and a key groove 24. The disk body 322a is provided with a restricting member 209.

[0093] The annular portion 322b is provided around the entire circumference of the edge on the other side in the direction of the axis O of the cylindrical portion 21. The annular portion 322b surrounds the outer periphery of the disk portion main body 322a. The annular portion 322b is provided at a distance from the disk portion main body 322a. In this embodiment, the surface of the annular portion 322b on the other side in the direction of the axis O is located on one side in the direction of the axis O than the surface of the disk portion main body 322a on the other side in the direction of the axis O.

[0094] 8 and 9, elastic structure 310 connects disk portion main body 322a and annular portion 322b. Elastic structure 310 is elastically deformable in a direction intersecting with the direction of axis O. Elastic structure 310 is provided around the entire circumference of disk portion main body 322a.

[0095] The elastic structure 310 of this embodiment has a bellows portion 311 and an attachment portion 312 . The bellows portion 311 is provided between the surface of the annular portion 322b on the other side in the direction of the axis O and the surface of the disk portion main body 322a on the other side in the direction of the axis O. The bellows portion 311 is a cylindrical member extending in the direction of the axis O. The bellows portion 311 has a bellows structure in which multiple plates are stacked in the direction of the axis O. The bellows portion 311 covers the disk portion main body 322a from the outer periphery.

[0096] The mounting portions 312 are provided on both ends of the bellows portion 311 in the direction of the axis O. The mounting portion 312 on one side in the direction of the axis O is fixed to the surface of the annular portion 322b on the other side in the direction of the axis O by, for example, a bolt 217. The mounting portion 312 on the other side in the direction of the axis O is fixed to the surface of the disc portion main body 322a on the other side in the direction of the axis O by, for example, a bolt.

[0097] (Action and effect) According to the in-wheel motor 301 of this embodiment, the following effects are achieved.

[0098] In this embodiment, the disk portion 322 has a disk portion main body 322a, an annular portion 322b, and an elastic structure 310. The disk portion main body 322a overlaps with the output shaft 84 in the direction of the axis O. A restricting member 209 is provided on the disk portion main body 322a. The annular portion 322b surrounds the outer periphery of the disk portion main body 322a and is provided at a distance from the disk portion main body 322a. The elastic structure 310 connects the disk portion main body 322a and the annular portion 322b, and is elastically deformable in a direction intersecting the direction of the axis O.

[0099] For example, when an external force acting on the wheel 320 intersects with the direction of the axis O, the elastic structure 310 elastically deforms in a direction intersecting with the direction of the axis O. This allows the elastic structure 310 to absorb this external force. This reduces misalignment (eccentricity) between the wheel 320 and the output shaft 84. The elastic structure 310 also functions as a suspension, mitigating disturbances input in the vertical direction. This reduces the occurrence of breakdowns and failures, further improving reliability.

[0100] (Modification of the third embodiment) A modification of the third embodiment will be described with reference to FIGS. 10 and 11, in this modification, the surface of the annular portion 322b on the other side in the direction of axis O is at the same position in the direction of axis O as the surface of the disk portion main body 322a on the other side in the direction of axis O. Also, the elastic structure 310A in this modification is a plurality of leaf springs 313 that surround the disk portion main body 322a from the outer periphery.

[0101] The multiple leaf springs 313 are arranged at equal intervals in the circumferential direction. Each leaf spring 313 is connected to the outer peripheral surface 10b of the disk main body 322a and the outer peripheral surface 10b of the annular portion 322b in the axial direction O. The leaf spring 313 has a leaf spring main body 313a and an attachment portion 313b. The leaf spring main body 313a is formed in a V-shape protruding in the circumferential direction when viewed from the axial direction O. The attachment portions 313b are provided at both radial ends of the leaf spring main body 313a. The radially inner attachment portion 313b is fixed to the disk main body 322a by, for example, a bolt. The radially outer attachment portion 313b is fixed to the annular portion 322b by, for example, a bolt.

[0102] (Other embodiments) The above describes in detail the embodiments of the present disclosure with reference to the drawings, but the specific configuration is not limited to this embodiment, and design changes and the like are also included within the scope that does not deviate from the gist of the present disclosure.

[0103] In the above embodiment, the rotor shaft 65 is a hollow shaft, and the shaft portion 85 of the sun shaft 81 is inserted into the rotor shaft 65 and fixed by the fixing portion 70. However, this is not limiting. For example, the rotor shaft 65 and the shaft portion 85 of the sun shaft 81 may be connected by a joint.

[0104] In the above embodiment, the pressing member 210 is made of a friction material, but this is not limiting. The pressing member 210 may be made of a material other than a friction material.

[0105] <Additional Notes> The in-wheel motors 1, 201, and 301 described in the respective embodiments can be understood, for example, as follows.

[0106] (1) The in-wheel motor 1, 201, 301 according to the first aspect includes a support structure 10 having a cylindrical shape extending in the direction of an axis O and attached to a vehicle body 3 at one side in the direction of the axis O; a wheel 20, 220, 320 having a cylindrical portion 21 surrounding the support structure 10 from the outer periphery and a disk portion 22, 222, 322 closing the other side in the direction of the axis O of the cylindrical portion 21; a bearing supporting the wheel 20, 220, 320 relative to the support structure 10 so as to be rotatable about the axis O; and an inner peripheral surface 10a of the support structure 10. a casing 30 fitted into the disk portion 22, 222, 322; a drive unit 7 housed inside the casing 30 and capable of rotating about the axis O and having an output shaft 84 protruding from the casing 30 to the other side in the direction of the axis O; a key member 8 connecting the output shaft 84 and the disk portion 22, 222, 322 so that they cannot rotate relative to each other but can move relative to each other in the direction of the axis O; and a restricting member 9, 209 restricting the relative movement of the output shaft 84 and the disk portion 22, 222, 322 in the direction of the axis O within a predetermined range. An example of the bearing is the wheel support bearing 4 of the above embodiment.

[0107] According to this aspect, for example, when the wheel 20, 220, 320 receives a thrust load F from the road surface or the like, the thrust load F is transmitted from the wheel 20, 220, 320 to the vehicle body 3 via the bearing and the support structure 10. Furthermore, the key member 8 causes the output shaft 84 and the disk portion 22, 222, 322 to move relatively in the direction of the axis O. This relative movement between the output shaft 84 and the disk portion 22, 222, 322 absorbs the thrust load F directed toward the drive unit 7. This makes it easier for the thrust load F to be transmitted to the support structure 10, avoiding the drive unit 7. Therefore, the thrust load F is prevented from acting on the drive unit 7.

[0108] (2) The in-wheel motor 1, 201, 301 of the second aspect is the in-wheel motor 1, 201, 301 of (1), wherein the disk portion 22, 222, 322 has a key groove 24 that engages with the key member 8 with a gap in the direction of the axis O, and the disk portion 22, 222, 322 may be arranged to be movable relative to the key member 8 in the direction of the axis O.

[0109] This allows the disk portions 22, 222, 322 of the wheels 20, 220, 320 to move in the direction of the axis O along the key member 8. The movement of the disk portions 22, 222, 322 in the direction of the axis O makes it easier for the thrust load F to be transmitted to the support structure 10, bypassing the drive device 7.

[0110] (3) The in-wheel motor 1, 201, 301 of the third aspect is the in-wheel motor 1, 201, 301 of (1) or (2), and further includes a first retaining portion 5 and a second retaining portion 6 that sandwich the bearing from both sides in the direction of the axis O, and the first retaining portion 5 is fixed to the outer peripheral surface 10b of the support structure 10, and the second retaining portion 6 is fixed to the inner peripheral surface of the cylindrical portion 21.

[0111] According to this aspect, the first holding portion 5 and the second holding portion 6 can hold the bearing at the same position along the axis O. Therefore, deviation of the bearing along the axis O is suppressed.

[0112] (4) The in-wheel motor 201, 301 of the fourth aspect is the in-wheel motor 201, 301 of any of (1) to (3), and further comprises a pressing member 210 arranged between the output shaft 84 and the disk portion 222, 322, with the key member 8 provided on the surface of the disk portion 222, 322 side, and the regulating member 209 is arranged so as to be movable relative to the disk portion 222, 322, and the regulating member 209 may have a spring 218 that presses the pressing member 210 against the output shaft 84 in the direction of the axis O.

[0113] According to this aspect, the rotational force of the drive unit 7 is transmitted to the wheels 220, 320 by the frictional force between the output shaft 84 and the pressing member 210. Therefore, when an unexpected disturbance acts on the wheels 220, 320, the output shaft 84 and the pressing member 210 are misaligned, thereby preventing the disturbance from acting on the drive unit 7.

[0114] (5) The in-wheel motor 301 of a fifth aspect is the in-wheel motor 301 of any one of (1) to (4), wherein the disk portion 322 may have a disk portion main body 322a that overlaps with the output shaft 84 in the direction of the axis O and on which the regulating member 209 is provided, a circular ring portion 322b that surrounds the outer periphery of the disk portion main body 322a and is provided at a distance from the disk portion main body 322a, and elastic structures 310, 310A that connect the disk portion main body 322a and the circular ring portion 322b and are elastically deformable in a direction intersecting the direction of the axis O.

[0115] For example, when an external force acting on the wheel 320 intersects with the direction of the axis O, the elastic structures 310, 310A elastically deform in the direction intersecting with the direction of the axis O. This allows the external force to be absorbed by the elastic structures 310, 310A. Therefore, misalignment (eccentricity) between the wheel 320 and the output shaft 84 is suppressed. [Explanation of symbols]

[0116] DESCRIPTION OF SYMBOLS 1...in-wheel motor 2...tire 3...vehicle body 4...wheel support bearing (bearing) 4a...outer ring 4b...inner ring 4c...rolling element 5...first retaining portion 6...second retaining portion 7...drive device 8...key member 9...regulating member 10...support structure 10a...inner circumferential surface 10b...outer circumferential surface 11...first inner circumferential surface 12...second inner circumferential surface 13...third inner circumferential surface 14...step surface 15...step surface 16...groove portion 17...bolt 17a...threaded portion 17b...head portion 17c...tip portion 18...spring 20...wheel 21...cylindrical portion 22...disk portion 23...wheel insertion hole 24...key groove 30...casing 31...motor casing 32...reduction gear casing 33...side wall portion 34...bottom portion 35...flange 36...Through hole 36a...Small diameter hole 36b...Large diameter hole 37...Annular wall portion 38...Side wall portion 38a...Internal tooth ring 39...First bottom portion 40...Second bottom portion 41...Flange 42...Base portion 43...Fitting portion 44...Through hole 44a...Small diameter hole 44b...Large diameter hole 45...Annular wall portion 46...Through hole 46a...Small diameter hole 46b...Large diameter hole 50...Mounting member 51...Bolt 51a...Threaded portion 51b...Head portion 51c...Tip portion 52...Elastic body 53...Torque support ring 60...Motor 61...Stator 62...Rotor 63...Stator core 64...Coil 65...Rotor shaft 66...Rotor core 67...Bearing 70...Fixed portion 71...Torque receiving portion 72...Bolt 73...Washer 80...Reduction gear 81...Sun shaft 82...Planetary gear 82a...First gear 82b...Second gear 83...Carrier 84...Output shaft 85...Shaft portion 86...Sun gear 87...Insertion hole 88...Bearing 89...First carrier body 89a...Cylindrical portion 89b...Flange 89c...Insertion hole 90...Second carrier body 90a...Cylindrical portion 90b...Flange 91...Carrier shaft 92...Bearing 93...Output shaft body 93a...Groove portion 94...Connecting portion 94a...Flange 94b...Wall portion 94c...Internal teeth 95...Bearing 96...Bearing 201...In-wheel motor 209...Restricting member 217...Bolt 217a...Threaded portion 217b...Head portion 217c...Tip portion 218...Spring 210...Pressing member 211...insertion hole 220...wheel 222...disk portion 223...wheel insertion hole 301...in-wheel motor 310...elastic structure 310A...elastic structure 313...leaf spring 313a...leaf spring main body 313b...mounting portion 311...bellows portion312...Mounting portion 320...Wheel 322...Disk portion 322a...Disk portion main body 322b...Annular portion F...Thrust load O...Axis

Claims

1. a support structure having a cylindrical shape extending in an axial direction and one side in the axial direction attached to a vehicle body; a wheel having a cylindrical portion surrounding the support structure from an outer periphery side and a disk portion closing the other side of the cylindrical portion in the axial direction; a bearing that supports the wheel relative to the support structure so as to be rotatable about the axis; a casing fitted to an inner peripheral surface of the support structure; and a drive device housed inside the casing and rotatably driven about the axis, the drive device having an output shaft protruding from the casing toward the other side in the axial direction; a key member that connects the output shaft and the disk portion so as to be non-rotatable relative to each other and movable relative to each other in the axial direction; a restricting member that restricts relative movement between the output shaft and the disk portion in the axial direction within a predetermined range; Equipped with In-wheel motor.

2. the disk portion has a key groove that fits into the key member with a gap therebetween in the axial direction, The disk portion is provided so as to be movable relative to the key member in the axial direction. The in-wheel motor according to claim 1 .

3. a first holding portion and a second holding portion that sandwich the bearing from both sides in the axial direction, the first holding portion is fixed to an outer peripheral surface of the support structure, The second holding portion is fixed to an inner circumferential surface of the cylindrical portion. The in-wheel motor according to claim 1 or 2.

4. a pressing member disposed between the output shaft and the disk portion, the pressing member having the key member provided on a surface facing the disk portion; the restricting member is provided so as to be movable relative to the disk portion, The restricting member has a spring that presses the pressing member against the output shaft in the axial direction. The in-wheel motor according to claim 1 or 2.

5. The disk portion is a disk main body that overlaps with the output shaft in the axial direction and on which the restricting member is provided; a ring portion that surrounds the outer periphery of the disk portion main body and is spaced apart from the disk portion main body; an elastic structure that connects the disk body and the annular portion and is elastically deformable in a direction intersecting the axial direction; having The in-wheel motor according to claim 1 or 2.

Images