In-wheel motor unit

Abstract

To secure flexibility of mounting of a unit including a motor and a brake and avoid the size increase of the unit.SOLUTION: An in-wheel motor unit is provided within a wheel of a vehicle wheel and includes: a motor having a rotor disposed at the radial outer side of a stator; a brake disposed at the inner side of the motor; and a housing which houses the motor and the brake. The housing has a cylindrical partition part which partitions a space for housing the motor from a space for housing the brake in a radial direction. The stator is fixed to an outer peripheral surface of the partition part. The brake is fixed to the housing at a fixing part included in the brake in a state in which the brake is disposed at the inner periphery side of the partition part.SELECTED DRAWING: Figure 2

Description

[Technical field]

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

[0002] Patent Document 1 discloses an in-wheel motor unit equipped with a brake and a motor. The configuration described in Patent Document 1 includes a motor with a rotor disposed radially inside a stator, and a drum brake having a structure in which a drum portion is formed in part of the rotor and the rotor is pressed from the inside by a lining. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 05-278476 Summary of the Invention [Problem to be solved by the invention]

[0004] In the configuration described in Patent Document 1, by placing the drum brake inside the rotor, the axial dimension of the unit is reduced and mountability is improved; however, the lining must be placed in a position where it can come into contact with the inner surface of the rotor, leaving room for improvement in terms of freedom of mounting.

[0005] The present invention has been made in consideration of the above circumstances, and aims to provide an in-wheel motor unit that can avoid enlargement while ensuring freedom of mounting for a unit including a motor and a brake. [Means for solving the problem]

[0006] The present invention is an in-wheel motor unit provided within a wheel of a vehicle, comprising a motor having a rotor arranged radially outside a stator, a brake arranged inside the motor, and a housing that accommodates the motor and the brake, wherein the housing has a cylindrical partition that radially separates a space that accommodates the motor from a space that accommodates the brake, the stator is fixed to the outer peripheral surface of the partition, and the brake is arranged on the inner peripheral side of the partition, with a fixing part included in the brake being fixed to the housing.

[0007] According to this configuration, for an in-wheel motor having a motor with a rotor disposed radially outside a stator, the axial dimension of the unit can be reduced by disposing the brake radially inside the stator. In addition, by fixing the fixing parts of the stator and the brake to a common housing, the number of housings can be reduced to one, thereby reducing the number of housings. This allows the overall unit to be made smaller while ensuring the freedom of mounting.

[0008] The vehicle may further include a reducer provided in a power transmission path between the motor and the wheel, which reduces the rotation of the rotor and outputs it to the wheel, and the brake applies a braking force to the wheel via the reducer, and the reducer may be arranged at least partially inside the wheel while being axially aligned with the motor.

[0009] With this configuration, the axial dimension can be reduced by placing the reducer inside the wheel. Also, because the brake is connected to the wheel via the reducer, the torque required by the brake can be reduced, allowing the brake to be made smaller. This allows the entire unit to be made smaller.

[0010] The present invention may further include a manual release mechanism capable of manually releasing the activated state of the brake, the brake being an electromagnetic brake that is activated without excitation, and the manual release mechanism may be capable of applying a force in the release direction to the armature of the electromagnetic brake when no current is flowing through the electromagnetic brake.

[0011] With this configuration, even if there is no power supplied to the non-excitation-activated electromagnetic brake, the brake can be manually released by the manual release mechanism, allowing the wheels to rotate in a non-excitation state.

[0012] In addition, the wiring of the motor may be brought out axially to the outside of the housing, and the wiring of the electromagnetic brake may be brought out axially to the outside of the housing, and the manual release mechanism may have a movable part that moves inside the housing to apply a force in the release direction to the armature, and an operating part that extends axially outward from the housing while connected to the movable part, and accepts a release operation to apply a force in the release direction to the armature, and the operating part may be positioned outside the housing, vertically lower than the wiring of the motor and the wiring of the electromagnetic brake.

[0013] With this configuration, the operation part of the manual release mechanism is located below the wiring of the motor and the wiring of the electromagnetic brake, so that the operability of the operation part can be ensured. Also, since the wiring of the motor and the wiring of the electromagnetic brake are located relatively far from the ground, the risk of these wirings being cut can be reduced. Effect of the Invention

[0014] In the present invention, for an in-wheel motor having a motor with a rotor disposed radially outside a stator, the axial dimension of the unit can be reduced by disposing the brake radially inside the stator. In addition, by fixing the fixing parts of the stator and the brake to a common housing, the number of housings can be reduced to one, thereby reducing the number of housings. This allows the overall unit to be made smaller while ensuring the freedom of mounting. [Brief description of the drawings]

[0015] [Figure 1] FIG. 1 is a diagram illustrating an in-wheel motor unit according to the first embodiment. [Diagram 2] FIG. 2 is a diagram showing a structure of the in-wheel motor unit in the first embodiment. [Diagram 3] FIG. 3 is a diagram for explaining the structure of the disc brake in the first embodiment. [Figure 4] FIG. 4 is a diagram showing a modified example of the reducer in the first embodiment. [Diagram 5] FIG. 5 is a diagram illustrating an in-wheel motor unit according to the second embodiment. [Figure 6] FIG. 6 is a diagram for explaining the structure of the electromagnetic brake in the second embodiment. [Figure 7] FIG. 7 is a schematic diagram showing an electromagnetic brake according to the second embodiment as viewed from the axial direction. [Figure 8] FIG. 8 is a diagram illustrating an in-wheel motor unit according to the third embodiment. [Figure 9] FIG. 9 is a diagram showing a schematic view of a vehicle equipped with an in-wheel motor unit according to the third embodiment, as viewed from outside the vehicle. [Figure 10] FIG. 10 is a schematic view of the A arrow in FIG. [Figure 11] FIG. 11 is a diagram illustrating a modified example of the third embodiment. [Figure 12]FIG. 12 is a diagram for explaining a modified example of the third embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0016] Hereinafter, an in-wheel motor unit according to an embodiment of the present invention will be described in detail with reference to the drawings. Note that the present invention is not limited to the embodiment described below.

[0017] (First embodiment) FIG. 1 is a diagram showing a schematic diagram of an in-wheel motor unit in a first embodiment. The in-wheel motor unit 1 is a unit capable of driving a wheel 10 and braking the wheel 10. The wheel 10 is a driving wheel including a wheel 11 and a tire 12, and is provided on both the left and right sides of a vehicle. The in-wheel motor unit 1 is provided inside the wheel 11. Note that FIG. 1 shows the right wheel of the wheels 10 provided on both the left and right sides, as viewed from the rear side of the vehicle. The direction parallel to the central axis of rotation of the wheel 10 is referred to as the axial direction.

[0018] The in-wheel motor unit 1 includes a motor 2, a reduction gear 3, a brake 4, a housing 5, a rotating shaft 6, and an output member 7.

[0019] The motor 2 is an in-wheel motor that drives the wheels 10. The motor 2 is a three-phase motor, and is electrically connected to a power supply device mounted on the vehicle. During power running, the motor 2 generates power torque using power supplied from the power supply device to drive the wheels 10. During regeneration, the motor 2 is rotated by the rotational force of the wheels 10 to generate power, and supplies the generated power to the power supply device.

[0020] This motor 2 is an outer rotor type motor in which a rotor 21 is disposed radially outside a stator 22.

[0021] The rotor 21 is attached to a rotating member 23 and rotates integrally with the rotating member 23. The rotating member 23 is a member formed in a cup shape, and has a cylindrical portion 23a and a disk portion 23b.

[0022] The cylindrical portion 23a extends along the axial direction, and the rotor 21 is fixed to its inner peripheral surface. The disk portion 23b extends radially inward from one axial end of the cylindrical portion 23a, and its inner peripheral portion is connected to the rotating shaft 6. For example, the inner peripheral portion of the disk portion 23b is spline-fitted with the outer peripheral portion of the rotating shaft 6. The rotating member 23 rotates integrally with the rotating shaft 6.

[0023] The rotating shaft 6 is a rotating shaft connected to the reducer 3. The rotor 21 is connected to the reducer 3 via the rotating shaft 6. Therefore, this rotating shaft 6 functions as an input shaft of the reducer 3 when transmitting the power of the motor 2 to the wheels 10. Since the motor 2 is connected to the wheels 10 via the reducer 3 so as to be capable of transmitting power, the power output from the motor 2 is transmitted to the wheels 10 via the reducer 3.

[0024] The stator 22 includes a stator core and a stator coil wound around the stator core. The stator coil is electrically connected to a power supply device via motor wiring. The stator 22 is fixed to the housing 5.

[0025] The housing 5 is a non-rotating member that accommodates the motor 2 and the brake 4. The housing 5 has a cylindrical partition portion 51 that radially divides a space that accommodates the motor 2 (motor chamber) and a space that accommodates the brake 4 (brake chamber).

[0026] The partition portion 51 is a cylindrical portion extending in the axial direction. Within the housing 5, the motor 2 is disposed on the outer circumferential side of the partition portion 51, and the brake 4 is disposed on the inner circumferential side of the partition portion 51. On the outer circumferential side of the partition portion 51, the stator 22 is fixed to the outer circumferential surface of the partition portion 51. On the inner circumferential side of the partition portion 51, a fixed portion included in the brake 4 is fixed to the housing 5. The fixed portion included in the brake 4 is a non-rotating member among the members constituting the brake 4. In this way, in the in-wheel motor unit 1, the housing that houses the motor 2 and the housing that houses the brake 4 are shared by a single housing 5.

[0027] Further, a cover 8 is attached to the housing 5 so as to axially partition a space (brake chamber) that accommodates the brakes 4. The cover 8 is fixed to the housing 5 so as to close an opening on one axial side of the partition portion 51 (an opening on the vehicle inner side). For example, the cover 8 is fixed to the housing 5 by bolting.

[0028] The brake 4 is a device that applies a braking force to the wheel 10. The brake 4 is fixed to the housing 5 while being disposed inside the motor 2. In the in-wheel motor unit 1, the output member 7, rotor 21, stator 22, housing 5, brake 4, and rotating shaft 6 are disposed in this order from the radial outside to the radial inside within the wheel 11. The rotating shaft 6 is disposed on the central axis of rotation of the wheel 10. The rotating shaft 6 is rotatably supported with respect to the housing 5 and the cover 8 by bearings 61 and 62. The bearing 61 is a rolling bearing in which an outer ring is attached to the housing 5 and an inner ring is attached to the rotating shaft 6. The bearing 62 is a rolling bearing in which an outer ring is attached to the cover 8 and an inner ring is attached to the rotating shaft 6.

[0029] The brake 4 is a friction engagement device that selectively fixes the rotating shaft 6 to the housing 5. In the in-wheel motor unit 1, the rotating shaft 6 is provided in front of the reducer 3 (upstream of the reducer 3 in the power transmission path), so the brake 4 brakes the rotating shaft 6 to apply a braking force to the wheels 10 via the reducer 3. Therefore, the braking torque generated by the brake 4 is amplified by the reducer 3 and transmitted to the wheels 10. This amplification effect is the same when the motor 2 is powered or regenerated. During powering, the powering torque generated by the motor 2 is amplified by the reducer 3 and transmitted to the wheels 10. During regeneration, the regenerative torque generated by the motor 2 is amplified by the reducer 3 and transmitted to the wheels 10. The motor 2 functions as a regenerative brake and can apply a braking force to the wheels 10.

[0030] The reduction gear 3 is a power transmission mechanism provided in a power transmission path between the motor 2 and the wheel 10. The reduction gear 3 is arranged alongside the motor 2 in the axial direction, and at least a portion of the reduction gear 3 is arranged inside the wheel 11. The reduction gear 3 and the brake 4 are arranged in a position where they overlap in the axial direction. Regarding the positional relationship between the motor 2 and the reduction gear 3, the motor 2 is arranged relatively on the inner side of the vehicle, and the reduction gear 3 is arranged relatively on the outer side of the vehicle.

[0031] When transmitting the power of the motor 2 to the wheel 10, the reducer 3 reduces the rotation of the motor 2 and outputs it to the output member 7. The output member 7 is connected to a rotating member (output element) on the output side of the reducer 3, and functions as the output member of the reducer 3. This output member 7 is connected to the wheel 11 so as to rotate integrally with the wheel 11. The output member 7 and the wheel 11 are fastened and integrated with each other by a plurality of bolts 9. Furthermore, the output member 7 has a hollow shaft portion, and is disposed inside the rim portion of the wheel 11. This output member 7 is disposed along the central axis of rotation of the wheel 10, and is rotatably supported with respect to the housing 5 by the bearing 63. The bearing 63 is a rolling bearing in which an outer ring is attached to the output member 7 and an inner ring is attached to the housing 5. The motor 2, the reducer 3, and the brake 4 are disposed inside the output member 7.

[0032] Here, a detailed structure of the in-wheel motor unit 1 will be described with reference to Figures 2 and 3. In the first embodiment, the speed reducer 3 is configured by a compound planetary gear mechanism, and the brake 4 is configured by a disc brake.

[0033] 2, the reducer 3 includes a sun gear S, a carrier C, a stepped pinion gear P, a fixed ring gear R1, and an output ring gear R2. In this compound planetary gear mechanism, when transmitting power from the rotating shaft 6 to the output member 7, the sun gear S serves as an input element, the fixed ring gear R1 serves as a fixed element, and the output ring gear R2 serves as an output element.

[0034] The sun gear S is connected to the sun gear shaft 31 so as to rotate integrally with it. The sun gear shaft 31 is a rotating shaft arranged coaxially with the rotating shaft 6, and is connected to rotate integrally with the rotating shaft 6. For example, the rotating shaft 6 and the sun gear shaft 31 are spline-fitted. In addition, the sun gear shaft 31 is supported by a bearing 64 and a bearing 65 so as to be rotatable relative to the carrier C.

[0035] The carrier C supports the stepped pinion gear P so that it can rotate and revolve. The carrier C is rotatably supported by a bearing 66 relative to the fixed member 32. The fixed member 32 is a non-rotating member that functions as a housing that accommodates the reduction gear 3. As shown in FIG. 2, the fixed member 32 is disposed axially outside the vehicle relative to the wheel 11. The fixed member 32 is connected to the housing 5 via a connecting member (not shown) and is integrated with the housing 5. For example, the connecting member extends from the fixed member 32 so as to cover the upper side of the wheel 10 and is connected to the housing 5.

[0036] The stepped pinion gear P has a first pinion gear P1 that meshes with the sun gear S and the fixed ring gear R1, and a second pinion gear P2 that meshes with the output ring gear R2. The first pinion gear P1 is a smaller diameter gear than the second pinion gear P2, and rotates integrally with the second pinion gear P2.

[0037] The fixed ring gear R1 is fixed to a non-rotating member, that is, a fixed member 32. As shown in FIG.

[0038] The output ring gear R2 is connected to the output member 7 so as to rotate integrally with the output member 7. As shown in Fig. 2, the output ring gear R2 is attached to the inner peripheral portion of the output member 7. The output member 7 is rotatably supported with respect to the fixed member 32 by a bearing 67, and is supported with respect to the carrier C by a bearing 68 so as to be rotatable relative to the carrier C.

[0039] As shown in FIGS. 2 and 3, the brake 4 includes a rotating disc 41, an inner pad 42, an outer pad 43, a pressing device 44, and a support 45.

[0040] The rotating disc 41 is connected to the rotating shaft 6 via the hub 46. The rotating disc 41 rotates integrally with the hub 46 and the rotating shaft 6. The brake 4 can apply a brake to the rotating disc 41 to suppress the rotation of the wheel 10.

[0041] The inner pad 42 and the outer pad 43 are brake pads arranged on either side of the rotating disc 41. The inner pad 42 is arranged on the inner side of the rotating disc 41, and the outer pad 43 is arranged on the outer side of the rotating disc 41.

[0042] The pressing device 44 is a device that sandwiches the rotating disk 41 from both sides between the inner pad 42 and the outer pad 43. The pressing device 44 has a caliper 44a and a cylinder portion 44b.

[0043] The caliper 44a supports the inner pad 42 and is movable in the axial direction. The cylinder portion 44b is an actuator that activates the brake 4. A piston 44c is housed in a cylinder formed inside the cylinder portion 44b. The piston 44c moves in the axial direction by a force generated by the actuator and presses the outer pad 43 against the rotating disc 41. Furthermore, after the outer pad 43 is pressed against the rotating disc 41, the caliper 44a moves in the axial direction and presses the inner pad 42 against the rotating disc 41. This allows the inner pad 42 and the outer pad 43 to sandwich the rotating disc 41 from both sides.

[0044] The support 45 is a member that holds the cylinder portion 44b of the pressing device 44. The support 45 is provided with a bolt hole through which a bolt 47 is inserted. The support 45 is located on the outer periphery of the rotating shaft 6, and is formed into a shape having a predetermined length in the circumferential direction of the rotating shaft 6. The support 45 is fixed to the housing 5 by a plurality of bolts 47.

[0045] The housing 5 has an inner circumferential side disc portion 52 extending radially inward from one axial end of the partition portion 51, and an outer circumferential side disc portion 53 extending radially outward from the other axial end of the partition portion 51.

[0046] The inner disk portion 52 extends radially inside the motor 2. A support 45 is fastened to the disk portion 52 with a bolt. A bolt 47 is inserted into a bolt hole of the support 45 and screwed into the disk portion 52. A bearing 61 is attached to the inner peripheral portion of the disk portion 52.

[0047] The disk portion 53 on the outer periphery extends along the radial direction at a position facing the motor 2 in the axial direction. As shown in Fig. 2, the disk portion 53 extends along the radial direction outside the cover 8 in the radial direction. A bearing 63 is attached to the outer periphery of this disk portion 53. The bearing 63 and the cover 8 are disposed in a position where they overlap in the axial direction.

[0048] As described above, according to the first embodiment, for an in-wheel motor unit 1 including a motor 2 in which a rotor 21 is disposed radially outside a stator 22, the axial dimension of the unit can be reduced by disposing the brake 4 radially inside the stator 22. Furthermore, a common housing 5 can be used to fix the stator 22 and the housing 5 to fix a fixed portion of the brake 4, so the number of housings can be reduced to one. This increases the degree of freedom in mounting and allows the overall unit to be made more compact.

[0049] Furthermore, by disposing the brake 4 upstream of the reducer 3, the braking torque is amplified by the reducer 3 and transmitted to the wheel 10. This makes it possible to reduce the torque required by the brake 4. This allows the radial dimension of the brake 4 to be reduced, thereby enabling the miniaturization of the brake 4 and therefore the overall unit. Furthermore, since an existing brake can be used as the brake 4, versatility is increased and costs can be reduced.

[0050] In the first embodiment, an example in which the brake 4 is configured as a disc brake has been described, but the present invention is not limited to this. For example, the brake 4 can be configured as a drum brake. In short, the brake 4 may be a friction engagement device that switches between an engaged state in which the rotating shaft 6 is fixed so as not to rotate and a released state in which the rotating shaft 6 is released so as to be freely rotatable.

[0051] Furthermore, the actuator of the brake 4 may be either a hydraulic actuator or an electric actuator. For example, if the actuator of the brake 4 is a hydraulic actuator, hydraulic pressure is supplied from a hydraulic supply source mounted on the vehicle to the hydraulic actuator to operate the brake 4. If the actuator of the brake 4 is an electric actuator, electric power is supplied from a power supply device mounted on the vehicle to the electric actuator to operate the brake 4.

[0052] In the first embodiment, a configuration including the reduction gear 3 has been described, but the present invention is not limited to this. That is, the in-wheel motor unit 1 does not need to include the reduction gear 3. In this case, the motor 2 is connected to the wheel 10 so as to be capable of transmitting power without the reduction gear 3. Similarly, the brake 4 is connected to apply a braking force to the wheel 10 without the reduction gear 3.

[0053] In the first embodiment, an example in which the reducer 3 is configured by a compound planetary gear mechanism having a stepped pinion gear P has been described, but the present invention is not limited thereto. For example, as shown in FIG. 4, the reducer 3 can be configured by a planetary gear mechanism having a pinion gear P3 meshing with a sun gear S and a ring gear R. This reducer 3 includes a sun gear S, a ring gear R, and a carrier C that holds the pinion gear P3 meshing with the sun gear S and the ring gear R so as to be rotatable and revolvable. The carrier C is attached to a fixed member 32. The ring gear R is connected to an output member 7 so as to rotate integrally therewith. In this planetary gear mechanism, when power is transmitted from the rotating shaft 6 to the output member 7, the sun gear S is an input element, the carrier C is a fixed element, and the ring gear R is an output element.

[0054] Second embodiment 5 is a diagram showing a schematic diagram of an in-wheel motor unit according to a second embodiment. Unlike the first embodiment, the brake in the second embodiment is configured by an electromagnetic brake 100. In the explanation of the second embodiment, explanations of the same configurations as those in the first embodiment will be omitted and the same reference numerals will be used.

[0055] The in-wheel motor unit 1 of the second embodiment includes an electromagnetic brake 100 disposed inside the motor 2 and fixed to the housing 5 as a brake.

[0056] The electromagnetic brake 100 is a non-excitation actuation type electromagnetic brake. The non-excitation actuation type electromagnetic brake 100 is in an actuated state where it brakes the rotating shaft 6 when not energized, and in a released state where it releases the rotating shaft 6 to rotate by utilizing the magnetic attraction force generated when energized. The electromagnetic brake 100 is a normally closed brake. As shown in Figs. 5 and 6, the electromagnetic brake 100 includes a rotating disk 101, an electromagnetic coil 102, a yoke 103, a spring 104, an armature 105, a fixed plate 106, and a brake wiring 107.

[0057] The rotating disk 101 is connected to the rotating shaft 6 so as to rotate integrally with the rotating shaft 6. The rotating disk 101 is connected to the rotating shaft 6 via a hub 108. The rotating disk 101, the hub 108, and the rotating shaft 6 rotate integrally.

[0058] The electromagnetic coil 102 is excited when a current is passed through it. The electromagnetic coil 102 is electrically connected to a power supply device via a brake wiring 107. The power supply device is a power supply device shared with the motor 2.

[0059] The yoke 103 is a member that holds the electromagnetic coil 102. The yoke 103 has a U-shaped cross section and is formed into an annular shape as a whole. As shown in Fig. 6, the yoke 103 is provided with a bolt hole 110 through which a bolt 109 is inserted. The yoke 103 is fixed to the housing 5 by the bolt 109 with the electromagnetic coil 102 accommodated in the U-shaped portion.

[0060] The spring 104 is disposed between the yoke 103 and the armature 105, and applies a biasing force to the armature 105. This biasing force is a force in the engagement direction. The axial movement of the spring 104 is restricted by a portion on the inner periphery side of the yoke 103.

[0061] Armature 105 is a disk-shaped plate member, and is disposed between rotating disk 101 and electromagnetic coil 102. One surface of armature 105 faces electromagnetic coil 102 and yoke 103 in the axial direction, and the other surface of armature 105 faces rotating disk 101 in the axial direction. A force is applied to armature 105 by spring 104, pushing it towards rotating disk 101.

[0062] For example, when the electromagnetic coil 102 is energized, the magnetic attraction force generated by the energization attracts the armature 105 toward the electromagnetic coil 102 against the biasing force of the spring 104, and moves in the axial direction. When the electromagnetic coil 102 is not energized, no magnetic attraction force is generated, and the armature 105 is pushed in the engagement direction by the biasing force of the spring 104 and pressed against the rotating disk 101. In this non-excited state, the rotating disk 101 is sandwiched between the armature 105 and the fixed plate 106 by the biasing force of the spring 104, and the electromagnetic brake 100 is activated.

[0063] The fixed plate 106 is an annular plate member fixed to the yoke 103, and functions as a brake plate that brakes the rotating disk 101. As shown in FIG. 6, the fixed plate 106 is fixed to the yoke 103 by a screw 111 and a collar 112. The screw 111 is inserted into the collar 112 and is screwed into the yoke 103. The collar 112 restricts the fixed plate 106 from moving in the axial direction, and supports the armature 105. The armature 105 is supported by the collar 112 so as to be movable relative to the yoke 103 in the axial direction, and is fixed unrotatably by the screw 111. The fixed plate 106 is prevented from moving in the axial direction by the collar 112, and is fixed unrotatably by the screw 111.

[0064] The brake wiring 107 is connected to the electromagnetic coil 102 and extends outside the cover 8. The brake wiring 107 is led out from the inside of a brake chamber defined by the housing 5 and the cover 8 to the outside of the brake chamber at a position above the rotation center of the rotating shaft 6.

[0065] In the in-wheel motor unit 1, the motor 2 and the electromagnetic brake 100 are controlled by a common control unit 302 (shown in FIG. 9). This control unit 302 can control the motor 2 and the electromagnetic brake 100 by a common voltage command.

[0066] As shown in FIG. 7, in the electromagnetic brake 100, the brake wiring 107 is taken out from one location on the fixed plate 106. Three screws 111 are attached to the fixed plate 106 at positions equally spaced apart in the circumferential direction. The position from which the brake wiring 107 is taken out on the fixed plate 106 is a position vertically above the center of rotation of the wheel 10. In the example shown in FIG. 7, the position from which the brake wiring 107 is taken out is the same position as one of the screws 111 in the circumferential direction and is below the screw 111 in the vertical direction. Also, the yoke 103 is provided with three bolt holes 110 at positions different from the three screws 111 in the circumferential direction. That is, the yoke 103 is provided with the three bolt holes 110 at positions equally spaced apart in the circumferential direction. Note that the armature 105 and the rotating disk 101 are omitted in the diagram shown in FIG. 7.

[0067] In a vehicle equipped with the in-wheel motor unit 1 configured in this manner, the electromagnetic brake 100 is released by exciting the electromagnetic coil 102 while the vehicle is running. If the system fails, voltage is no longer applied to the electromagnetic brake 100, and the brake is put into a non-excitation state. Since the electromagnetic brake 100 is of a non-excitation operation type, the brake is activated when a system abnormality occurs (when a system failure occurs), making it possible to brake and stop the vehicle. This makes it possible to safely stop the vehicle.

[0068] As described above, according to the second embodiment, the brake is constituted by the electromagnetic brake 100, so that the space required for disposing the brake can be reduced, thereby enabling the size of the entire unit to be reduced.

[0069] Furthermore, according to the second embodiment, it is possible to reduce the size of the unit compared to, for example, a case in which the brake is configured as a hydraulic brake. By employing the electromagnetic brake 100, the vehicle system can be simplified compared to a hydraulic brake or the like. The electrical system is already constructed as a system for driving the motor, and adding a new hydraulic system separately from this leads to an increase in costs. Therefore, according to the second embodiment, by providing the electromagnetic brake 100, it is possible to suppress the increase in costs.

[0070] Furthermore, because the electromagnetic brake 100 is of the non-excitation operation type, it is possible to brake the wheels 10 when there is no power supply from the vehicle's power supply device to the electromagnetic brake 100. For example, if the vehicle is an electric vehicle, the rotation of the wheels 10 can be stopped with the vehicle's power supply shut down. This makes it possible to keep the electric vehicle stationary without requiring power to operate the brake.

[0071] In the second embodiment, the structure of the reducer 3 is not particularly limited. The reducer 3 in the second embodiment may be, for example, a reducer 3 configured with a compound planetary gear mechanism as shown in Fig. 2, or may be a reducer 3 configured with a planetary gear mechanism as shown in Fig. 4.

[0072] The electromagnetic brake of the second embodiment is not limited to a non-excitation actuation type, and may be an excitation actuation type. As a modification of the second embodiment, the in-wheel motor unit 1 can be provided with an excitation actuation type electromagnetic brake instead of the non-excitation actuation type electromagnetic brake 100. The excitation actuation type electromagnetic brake is in an actuated state in which the rotating shaft 6 is braked by utilizing a magnetic attraction force generated by energization, and in a released state in which the rotating shaft 6 is rotatably released when not energized. This excitation actuation type electromagnetic brake is a normally open brake. In a vehicle equipped with the in-wheel motor unit 1 of this modification, the electromagnetic brake can be released without exciting the electromagnetic coil while traveling. Then, when braking is required, the electromagnetic brake can be activated by exciting the electromagnetic coil. This eliminates the need for power to release the brake while traveling, and reduces energy consumption. In addition, the rotating disc is released to be rotatable by the force of the spring (biasing force acting in the release direction).

[0073] Third embodiment 8 is a schematic diagram of an in-wheel motor unit according to a third embodiment. In addition to the components of the second embodiment, the third embodiment includes a manual release mechanism 200 that allows the electromagnetic brake 100 to be manually released from its activated state. In the description of the third embodiment, the same components as those of the second embodiment will not be described and their reference numerals will be used instead.

[0074] The in-wheel motor unit 1 of the third embodiment includes a manual release mechanism 200 that enables the electromagnetic brake 100 to be manually released from its activated state.

[0075] The manual release mechanism 200 has a movable part 201 and an operating part 202 .

[0076] The movable part 201 is a part that comes into contact with the armature 105. The movable part 201 is located in a space defined by the housing 5 and the cover 8, and is disposed between the armature 105 and the fixed plate 106. The movable part 201 also has a first part that is disposed radially outward of the fixed plate 106, and a second part that extends radially inward from the first part and is disposed at a position facing the armature 105. The first part comes into contact with the armature 105 during manual release and presses the armature 105 in the release direction. The second part supports the first part that presses the armature 105.

[0077] The operating unit 202 is connected to the movable unit 201, and is located outside the brake chamber. The operating unit 202 is a portion that receives a release operation on the outside of the cover 8, and extends so as to protrude outside the cover 8. The operating unit 202 is configured, for example, by an operating lever, and is configured so as to be operable by human force from outside the vehicle.

[0078] When the operating unit 202 is operated, the movable unit 201 moves in accordance with the operation. When the operating unit 202 is operated to manually release the electromagnetic brake 100 from its activated state, the movable unit 201 applies a force to the armature 105 in the release direction against the biasing force of the spring 104. Since the electromagnetic brake 100 is connected to the wheel 10 via the reducer 3, the torque required for the brake can be reduced and the size can be made small, so that the required spring load can be reduced. In other words, the force required by the manual release mechanism 200 at the time of release can be reduced. Then, the movable unit 201 moves the armature 105 in the engagement direction to release the rotating disk 101 so that it can rotate, and the electromagnetic brake 100 in the activated state is released.

[0079] Regarding the positional relationship between the manual release mechanism 200 and the brake wiring 107, the manual release mechanism 200 is disposed vertically below the brake wiring 107 on the outside of the cover 8. When the wheel 10 and the in-wheel motor unit 1 are viewed from the axial direction, the manual release mechanism 200 is disposed below the brake wiring 107, as shown in Fig. 9. The wheel 10 is supported rotatably relative to a vehicle frame 301. A control unit 302 that controls the motor 2 and the electromagnetic brake 100 is mounted on the vehicle frame 301.

[0080] The motor wiring 24 is arranged above the brake wiring 107. The motor wiring 24 is connected to the stator 22, and is electrically connected to a power supply device mounted on the vehicle. In the in-wheel motor unit 1, the motor wiring 24, the brake wiring 107, and the manual release mechanism 200 are arranged in this order from top to bottom in the vertical direction, as shown in Figs. 9 and 10.

[0081] As described above, according to the third embodiment, by providing the manual release mechanism 200 capable of releasing the actuated state of the non-excitation actuated electromagnetic brake 100, it becomes possible to manually release the electromagnetic brake 100 even if the power supply from the power supply device is cut off.

[0082] For example, in the case of the de-energized electromagnetic brake 100, when the power supply of the power supply device runs out, the power supply is cut off, so the brake is activated and the wheels 10 are braked. To transport the vehicle in this braked state, it is necessary to lift the vehicle and move it. In contrast, in the third embodiment, the brake is released by the manual release mechanism 200 in the de-energized state, so it becomes possible to transport the vehicle by rolling the wheels 10.

[0083] Moreover, according to the in-wheel motor unit 1, the operability of the operation part 202 of the manual release mechanism 200 is improved. Since the vehicle body is attached to the upper side of the in-wheel motor unit 1, this structure needs to be considered from the viewpoint of improving the operability of the manual release mechanism 200 when releasing the brake. Furthermore, it is also necessary to consider the brake wiring 107 and the motor wiring 24. In consideration of these, the manual release mechanism 200 is arranged below the brake wiring 107 and the motor wiring 24. If the brake wiring 107 and the motor wiring 24 are arranged below the manual release mechanism 200, it becomes difficult to operate the operation part 202 of the manual release mechanism 200. For example, in the case where the vehicle is a dolly, it becomes difficult to approach the operation part 202 from the upper side of the dolly. Therefore, the operability is improved by positioning the operation part 202 below the brake wiring 107 and the motor wiring 24. In other words, the vehicle on which the in-wheel motor unit 1 is provided is not particularly limited to a vehicle on which a person can ride, a vehicle that runs unmanned, or an unmanned dolly that transports luggage. Furthermore, it is not limited to a four-wheeled vehicle.

[0084] In addition, the risk of the wiring being cut can be reduced by routing the motor wiring 24 and the brake wiring 107 at a position relatively far from the ground 400. Furthermore, the wiring can be easily routed because the attachment destinations of the motor wiring 24 and the brake wiring 107 are located above the in-wheel motor unit 1.

[0085] As a modification of the third embodiment, the position at which the operating unit 202 protrudes on the outside of the cover 8 can be changed. For example, as shown in FIG. 11, the operating unit 202 can be disposed at a position tilted from the vertical direction. When the operating unit 202 is disposed at a position tilted from the vertical direction, the tilt angle is calculated by {360° / (number of bolts 109 fixing the brake)} / 2. In this modification, the circumferential position of the operating unit 202 can be determined according to the number of bolts 109 fixing the electromagnetic brake 100 and the arrangement of the bolts 109. FIG. 11 shows the in-wheel motor unit 1 as viewed from the inside of the vehicle.

[0086] Specifically, in the example shown in Fig. 11, since there are three bolts 109 that secure the brake, the inclination angle from the vertical direction is "{360° / 3} / 2=60°". Therefore, the circumferential position (phase) with the upper vertical side as the starting point (0°) is 120° or 240°. Since the lower vertical side is a circumferential position of 180°, 120° and 240° are obtained as positions inclined in the circumferential direction by an inclination angle of 60° from this 180° position. Therefore, the operation unit 202 of the manual release mechanism 200 is disposed at this circumferential position.

[0087] At that time, consideration is given to whether the wheel 10 is a rear wheel or a front wheel. In order to make it easier to approach the operation unit 202, if the wheel 10 is a rear wheel, the operation unit 202 is disposed at a position tilted toward the rear of the vehicle from the vertical direction, and if the wheel 10 is a front wheel, the operation unit 202 is disposed at a position tilted toward the front of the vehicle from the vertical direction. In addition, the tilt direction from the vertical direction changes depending on whether the wheel 10 is a left wheel or a right wheel.

[0088] For example, if the wheel 10 is a rear right wheel, the manual release mechanism 200 is disposed at a position 120° from the vertical upper side as a starting point, as shown in Fig. 11. This positions the operation unit 202 for the right rear wheel toward the rear of the vehicle. If the wheel 10 is a rear left wheel, the manual release mechanism 200 is disposed at a position 240° from the vertical upper side as a starting point, as shown in Fig. 12. This positions the operation unit 202 for the left rear wheel toward the rear of the vehicle.

[0089] This modification improves the reliability of the in-wheel motor unit 1 and reduces costs by standardizing parts. The manual release mechanism 200 is structured such that foreign matter such as water remains on the operating portion 202. When the manual release mechanism 200 is turned on or off, the foreign matter may enter the unit. The manual release mechanism 200 is arranged at a position tilted at a predetermined angle from a vertically downward position, so that water and the like are less likely to accumulate. Furthermore, by determining the installation angle (phase) of the manual release mechanism 200 based on the number of bolts 109 that secure the electromagnetic brake 100 to the housing 5, the electromagnetic brake 100 can be standardized, which reduces costs.

[0090] 11 and 12, the wheel 10 is a rear wheel, but if the wheel 10 is a front wheel, the operation unit 202 of the manual release mechanism 200 can be disposed at a position tilted from the lower vertical side toward the front of the vehicle. Therefore, if the wheel 10 is a front right wheel, the manual release mechanism 200 is disposed at a position 240° from the upper vertical side as a starting point. If the wheel 10 is a front left wheel, the manual release mechanism 200 is disposed at a position 120° from the upper vertical side as a starting point.

[0091] Furthermore, the number of bolts 109 is not limited to three. The number of bolts 109 can be three or more. For example, when there are four bolts 109, the inclination angle from the vertical direction is 45°, so the phase at which the operating unit 202 of the manual release mechanism 200 is positioned is 135° or 225°. [Explanation of symbols]

[0092] 1 In-wheel motor unit 2 Motors 3 Reducer 4. Brakes 5. Housing 6 Rotation Axis 7 Output member 8 Cover 9 Volts 10 wheels 11 Wheels 12 Tires 23 Rotating parts 51 Partition 52,53 Disc section 100 Electromagnetic brake 200 Manual release mechanism

Claims

1. An in-wheel motor unit provided in a wheel of a vehicle, A motor having a rotor disposed radially outside a stator; a rotating shaft that is disposed on a rotational center axis of the wheel and rotates integrally with the rotor; A brake disposed radially inside the stator; a housing that is a non-rotating member that accommodates the motor and the brake; a cover attached to the housing so as to axially define a space for accommodating the brake; Equipped with The housing includes: a partition portion formed in a cylindrical shape extending in an axial direction and radially dividing a space that houses the motor and a space that houses the brake; an inner circumferential side disk portion extending radially inward from one axial end of the partition portion; and an outer circumferential disk portion extending radially outward from the other axial end of the partition portion, the cover is disposed at a position overlapping with the disk portion on the outer circumferential side in the axial direction, and is attached to the housing so as to close an opening on one axial side of the partition portion, the outer circumferential disk portion extends radially outside the cover and faces the stator and the rotor in the axial direction; the rotating shaft is rotatably supported with respect to the housing by a first bearing, and is rotatably supported with respect to the cover by a second bearing; The stator is fixed to an outer circumferential surface of the partition portion, The brake is disposed on the inner periphery side of the partition and attached to the inner periphery side disk portion. An in-wheel motor unit comprising:

2. An output member disposed inside a rim portion of the wheel and aligned along a central axis of rotation of the wheel and integrated with the wheel; a reducer that is provided in a power transmission path between the motor and the wheels and that reduces the rotation speed of the rotor and outputs the reduced rotation speed to the output member; a third bearing that rotatably supports the output member with respect to the housing; Further equipped with the output member includes a cylindrical portion extending axially along an inner circumferential surface of the rim portion, the third bearing is disposed at a position overlapping with the cover in the axial direction and is attached to the disk portion on the outer circumferential side, The brake applies a braking force to the wheel via the reduction gear, the rotating shaft functions as an input shaft of the reduction gear when transmitting the power of the motor to the wheels; the reduction gear is arranged in line with the motor in the axial direction, and at least a portion of the reduction gear is arranged inside the wheel; The output member, the rotor, the stator, the partition, the brake, and the rotating shaft are arranged in this order from the radially outer side to the radially inner side within the wheel. The in-wheel motor unit according to claim 1 .

3. A manual release mechanism is further provided to manually release the applied state of the brake, The brake is a non-excitation type electromagnetic brake, The electromagnetic brake is A rotating disk connected to the rotating shaft so as to rotate integrally with the rotating shaft; An electromagnetic coil that is excited when current is passed through it; A yoke for holding the electromagnetic coil; an armature, which is a disk-shaped plate member disposed between the rotating disk and the electromagnetic coil; a spring disposed between the yoke and the armature and applying a biasing force to the armature; a fixed plate which is a disk-shaped plate member fixed to the yoke; a brake wiring connected to the electromagnetic coil and extending outside the cover, The brake wiring is taken out from one location of the fixed plate, The manual release mechanism is capable of applying a force in a releasing direction to the armature when the electromagnetic brake is not energized.

3. The in-wheel motor unit according to claim 1 or 2.

4. Wiring of the motor is taken out from the housing in the axial direction; The brake wiring is taken out to the outside of the housing in the axial direction, The manual release mechanism includes: a movable part that moves inside the housing so as to apply a force in the release direction to the armature; an operation portion that is connected to the movable portion and extends from the housing in the axial direction outward, and receives a release operation that applies a force in the release direction to the armature, The operating unit is disposed outside the housing and vertically below the motor wiring and the brake wiring. The in-wheel motor unit according to claim 3 .

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