Vehicular power unit

Abstract

To provide a vehicular power unit which can suppress variation in motor torque or rotation of a wheel bearing.SOLUTION: A vehicular power unit PU comprises a wheel bearing 30 and a power generator GE. The wheel bearing 30 has: fixed rings 2, 3; and a rotary ring 1 which is supported via a rolling element 5 in a manner rotatable with respect to the fixed ring 2. A wheel of a vehicle is fitted to the rotary ring 1. The power generator GE has: a stator 9 fitted to the fixed ring 3 of the wheel bearing 30; and a rotor 12 fitted to the rotary ring 1 of the wheel bearing 30. An inner ring shaft 3 is inserted in an inner ring 2, which is the fixed ring, of the wheel bearing 30. The inner ring shaft 3 has: a flange part 3a which expands radially outside at an inboard-side end of the inner ring shaft; and a stator holding part 17 which axially extends from an outer diameter end of the flange part 3a to an outboard side. The stator 9 is fitted to the stator holding part 17.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a vehicle power plant that has a motor generator that performs driving and regenerative braking mounted on driving wheels that are mechanically connected to a main driving source of the vehicle or on non-driven wheels (driven wheels) that are not connected to the main driving source. [Background technology]

[0002] There is a vehicle power unit that includes an outer ring rotating type wheel bearing that is made up of an outer ring that is a rotating ring, an inner ring that is a fixed ring, and rolling elements interposed between the inner and outer rings, and a generator that can rotate the rotating ring (for example, Patent Document 1). In such a vehicle power unit, a stator holding part is mounted on an inner ring shaft that is connected to the fixed ring, and a stator of the generator is mounted on the stator holding part to hold the stator. In particular, in Patent Document 1, the stator holding part is fastened to a shaft part that protrudes from the inner ring to the inboard side by a nut, and further, the stator holding part is fastened to a knuckle by a bolt, making it possible to separate the wheel bearing, the generator rotor, and the generator stator without disassembling the wheel bearing. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-192998 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the vehicle power unit of Patent Document 1, the wheel bearing is held to the knuckle by a bolt via a stator holding portion fixed to the wheel bearing by a nut. Therefore, when a moment load or the like is applied when the vehicle turns, the wheel bearing and the stator holding portion are deformed differently, and the motor gap becomes uneven. This may cause fluctuations in the driving / regenerative torque of the motor and the rotation of the wheel bearing. As described above, since the wheel bearing is attached to the knuckle via the stator holding portion, errors during assembly may accumulate, causing the motor gap to become uneven, and as described above, there is a risk of torque and rotation fluctuations.

[0005] An object of the present invention is to provide a vehicle power unit capable of suppressing fluctuations in motor torque and rotation of wheel support bearings. [Means for solving the problem]

[0006] The vehicle power unit of the present invention comprises: a wheel bearing including a fixed ring and a rotating ring rotatably supported by the fixed ring via rolling elements, the rotating ring being provided with a hub flange to which a wheel of a vehicle is attached; A vehicle power unit including a generator having a stator attached to a fixed ring of the wheel bearing and a rotor attached to a rotating ring of the wheel bearing, An inner ring shaft is inserted into the inner ring of the wheel bearing which is the fixed ring, the inner ring shaft has a flange portion extending radially outward at an inboard end thereof, and a stator holding portion extending in the axial direction from an outer diameter end of the flange portion toward the outboard side, The stator is attached to the stator holder.

[0007] Here, the "inboard side" refers to the direction toward the center line of the vehicle body that extends in the front-to-rear direction of the vehicle when the vehicle power unit is attached to the vehicle body, and the "outboard side" refers to the direction away from the center line of the vehicle body when the vehicle power unit is attached to the vehicle body.

[0008] According to this configuration, the inner shaft has a stator holding portion that holds the stator. That is, the inner shaft and the stator holding portion are inseparably integrated. Therefore, when an external load is applied, the wheel support bearing and the generator deform as a unit. Therefore, it is possible to suppress the occurrence of fluctuations in the motor gap, and it is possible to suppress the occurrence of fluctuations in the motor torque and the rotation of the wheel support bearing. In addition, both the wheel support bearing and the generator are mounted on the suspension device by the inner shaft. Therefore, errors during assembly are not accumulated, and the motor gap is kept uniform. This makes it possible to suppress the occurrence of fluctuations in the motor torque and the rotation of the wheel support bearing. Furthermore, by integrating the stator holding portion and the inner shaft, it is possible to reduce the number of parts and the assembly man-hours.

[0009] In the present invention, the wheel bearing comprises: an outer ring having the hub flange on an outboard side and a double row outer ring rolling surface formed on an inner circumference thereof; a pair of inner rings each having an inner ring rolling surface formed on an outer periphery thereof opposite to the outer ring rolling surface; a double row of rolling elements interposed between the outer ring rolling surface and the inner ring rolling surface, the inner race shaft has an inner race fitting portion into which the inner race is fitted, and a male thread portion extending from the inner race fitting portion to the outboard side, The interference between the inner diameter of the inner ring and the outer diameter of the inner ring fitting portion is a negative clearance, The inner ring is sandwiched between the flange portion and a nut screwed onto the male thread portion, The flange may be attached to a suspension system of a vehicle by fastening a bolt to an internal thread provided in the flange.

[0010] In the device of the above-mentioned Patent Document 1, it is possible to separate the wheel bearing from the generator by loosening the nut fastened to the shaft portion protruding from the inner ring to the inboard side. Conventionally, the preload and internal clearance of the wheel bearing are managed and adjusted by the bearing manufacturer, and the wheel bearing is mounted on the vehicle by delivering it to the vehicle assembly manufacturer. However, in the device of Patent Document 1, the factor that determines the preload on the wheel bearing is the fastening force of the nut, and the vehicle assembly manufacturer adds man-hours to manage and adjust the preload of the wheel bearing. As a result, there is a risk that the vehicle assembly tact time will increase and that insufficient management of the preload will have a negative effect on the vehicle performance.

[0011] According to the above configuration, the wheel support bearing can be separated from the vehicle power unit simply by loosening the nut, improving maintainability. Moreover, since the wheel support bearing is a conventional second-generation type, the bearing manufacturer can manage and adjust the internal clearance. In addition, by using an interference fit between the inner ring and the inner ring shaft, creep can be prevented, and as a result, deterioration of the wheel support bearing can be prevented.

[0012] In the present invention, a rotation detector is further provided for detecting at least one of a rotation angle and a rotation speed of the rotating wheel relative to the fixed wheel, A brake rotor is attached to the hub flange, a part or whole of the stator and the rotor has a smaller diameter than a portion of the brake rotor against which a brake caliper is pressed; the entire generator, except for a portion attached to the hub flange, is located in an axial range between the hub flange and an outboard side surface of an undercarriage frame component of the vehicle; The rotation detector may be located radially inwardly of the rotor.

[0013] According to this configuration, the vehicle power unit including the rotation detector can be stored compactly.

[0014] In the present invention, a communication hole for leading out the wiring of the stator to the outside may be provided on the inboard end face of the stator holding part. According to this configuration, the wiring coming out of the inboard coil of the generator is led out from the communication hole radially inward from the stator. In other words, the wiring extends radially inward from the stator and then is led out to the inboard side. This ensures space on the inboard side of the stator, and this space can be effectively used for the motor winding coil. As a result, the desired motor output can be obtained.

[0015] In the present invention, a first notch may be provided at the inboard end of the stator holding portion, through which the wiring of the stator passes from the outer diameter side to the inner diameter side. With this configuration, the wiring coming out of the inboard coil of the generator can extend radially inward from the stator through the first notch. This ensures space on the inboard side of the stator, and this space can be effectively used for the motor winding coil. As a result, the desired motor output can be obtained.

[0016] In the present invention, the rotor may further include a rotation detector for detecting the rotation angle or rotation speed of the rotor relative to the fixed wheel, the sensing portion of the rotation detector being installed on the inboard side of the inner wheel shaft, and a second cutout portion may be provided on the inboard end face of the sensing portion of the rotation detector, through which the wiring of the stator passes from the outer diameter side to the inner diameter side of the rotation detector. With this configuration, the wiring coming out of the inboard coil of the generator can extend radially inward from the stator through the second cutout portion. This ensures space on the inboard side of the stator, and this space can be effectively used for the motor winding coil. As a result, the desired motor output can be obtained. Effect of the Invention

[0017] According to the vehicle power unit of the present invention, it is possible to suppress fluctuations in motor torque and in the rotation of the wheel support bearings. [Brief description of the drawings]

[0018] [Figure 1] 1 is a vertical cross-sectional view showing a vehicle power unit according to a first embodiment of the present invention. [Diagram 2] FIG. 2 is a cross-sectional view taken along line II-II in FIG. [Diagram 3] 2 is a perspective view showing a stator of a generator of the vehicle power plant. FIG. [Figure 4] FIG. 2 is a perspective view showing an inner shaft of the vehicle power unit. [Diagram 5] 5 is a perspective view of the inner shaft as viewed from an angle different from that in FIG. 4. [Figure 6] FIG. [Figure 7] FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0019] A preferred embodiment of the present invention will be described below with reference to the drawings. In the following description, the terms "axial direction", "radial direction" and "circumferential direction" refer to the "axial direction", "radial direction" and "circumferential direction" of the wheel bearing, respectively. In addition, in the axial direction, when the bearing is attached to the vehicle body, the direction toward the vehicle body centerline extending in the longitudinal direction of the vehicle, i.e., the vehicle body side, is called the "inboard side", and the direction away from the vehicle body centerline, i.e., the wheel side, is called the "outboard side". Furthermore, the radially inner side may be called the inner diameter side, and the radially outer side may be called the outer diameter side.

[0020] 1 shows a vehicle power unit PU according to a first embodiment of the present invention. The vehicle power unit PU of this embodiment includes a wheel bearing 30 and a generator GE. The wheel bearing 30 includes a fixed ring 2 and a rotating ring 1 rotatably supported by the fixed ring 2 via rolling elements 5. In this embodiment, steel balls are used as the rolling elements 5, but the rolling elements 5 are not limited thereto.

[0021] The wheel support bearing 30 of this embodiment is an outer ring rotating type, and is a so-called second generation wheel support bearing having an outer ring 1 which is a rotating ring and a double row inner ring 2 which is a fixed ring. An inner ring shaft 3 is inserted into the hollow part of the inner ring 2 and is integrated with the inner ring 2. In other words, the inner ring shaft 3 also constitutes a part of the fixed ring. From the inboard side, the inner ring shaft 3 has a large diameter flange portion 3a, an inner ring fitting portion 3b into whose outer circumferential surface the double row inner rings 2,2 are fitted, and a small diameter male thread portion 3c.

[0022] The inner rings 2, 2 are fitted onto the outer peripheral surface of the inner ring fitting portion 3b of the inner ring shaft 3 from the outboard side of the inner ring shaft 3. By tightening a nut 40 onto the male thread portion 3c of the inner ring shaft 3, the inner rings 2, 2 are sandwiched between the nut 40 and the flange portion 3a of the inner ring shaft 3, and a preload is applied to the wheel support bearing 30.

[0023] The fit between the outer peripheral surface of the inner ring fitting portion 3b of the inner ring shaft 3 and the inner peripheral surface of the inner ring 2, 2 is, for example, an interference fit. The inner ring shaft 3 is provided with an escape portion 3d having a smaller diameter than the inner ring fitting portion 3b with the inner ring 2. The escape portion 3d is formed between the inner ring fitting portion 3b and the male thread portion 3c. By providing the escape portion 3d, it is possible to prevent interference between the outer diameter of the inner ring shaft 3 and the inner diameter of the inner ring 2 when the nut is tightened, and it is possible to reliably manage the preload of the wheel bearing. However, the escape portion 3d is not essential.

[0024] Two outer ring rolling surfaces 1a are formed side by side in the axial direction on the inner peripheral surface of the outer ring 1. An inner ring rolling surface 2a is formed on the outer peripheral surface of each of the inner rings 2. Each of the inner ring rolling surfaces 2a faces the outer ring rolling surfaces 1a in the radial direction. A rolling element 5 is interposed between the outer ring rolling surface 1a and the inner ring rolling surface 2a.

[0025] A flange-shaped hub flange 1b extending radially is provided on the outboard side portion of the outer ring 1. A plurality of bolt insertion holes 1ba are formed in the hub flange 1b at intervals in the circumferential direction. The wheel and brake rotor 22 are attached to the hub flange 1b of the outer ring 1 by inserting hub bolts 4 into the bolt insertion holes 1ba and tightening with nuts (not shown). An outer ring cap 6 is fitted to the inner peripheral surface of the outboard end of the outer ring 1, closing the outboard side of the wheel bearing 30.

[0026] A plurality of female threads 21 are provided on the flange portion 3c at the inboard end of the inner shaft 3. In this embodiment, as shown in Fig. 2, six female threads 21 are provided, but the number of female threads 21 is not limited to this. The inner shaft 3 is attached to a suspension part of the vehicle, i.e., a suspension device 19, by fastening the bolts 18 shown in Fig. 1 to the female threads 21. In other words, the wheel bearing 30 is attached to the suspension device 19 of the vehicle by the bolts 18.

[0027] The radial position of the axis X1 of the bolt 18 is substantially the same as the radial position of the center O1 of the rolling element 5. Here, "the radial position of the axis X1 of the bolt 18" refers to the radial distance D1 between the axis AX of the wheel support bearing 30 and the axis X1 of the bolt 18. Meanwhile, "the radial position of the center O1 of the rolling element 5" refers to the radial distance D2 between the axis AX of the wheel support bearing 30 and the center O1 of the rolling element 5. In this embodiment, the radial positions of the axis X1 of the bolt 18 and the center O1 of the rolling element 5 are substantially the same (D1=D2), but the radial position of the axis X1 of the bolt 18 may be located radially inward relative to the radial position of the center O1 of the rolling element 5 (D1 <D2)。

[0028] The generator GE is supported by the wheel bearing 30, and generates a driving force and a regenerative braking force. The generator GE has a stator 9 attached to the fixed wheel 3 of the wheel bearing 30, and a rotor 12 attached to the rotating wheel 1 of the wheel bearing 30. The generator GE is installed in the brake rotor 22 while being supported by the wheel bearing 30.

[0029] In detail, the brake rotor 22 has an annular supported portion 22a, a cylindrical portion 22b extending axially from the radial outer end of the supported portion 22a toward the inboard side, and a gripped portion 22c extending radially outward from the inboard end of the cylindrical portion 22b. The supported portion 22a is flat and is clamped and bolted to the flange portion 1a of the outer ring 1 and the wheel. The gripped portion 22c constitutes the brake sliding portion 22c, which is a portion of the brake rotor 22 against which a brake caliper (not shown) is pressed. The generator GE is disposed radially inside the cylindrical portion 22b and the brake sliding portion 22c of the brake rotor 22.

[0030] A stator holding portion 17 is formed on the outer periphery of the inboard end of the inner shaft 3. The stator holding portion 17 is formed inseparably integral with the inner shaft 3. In this embodiment, the stator holding portion 17 has an annular portion 17a extending radially outward from the outer periphery surface of the flange portion 3a of the inner shaft 3, and a cylindrical portion 17b extending axially from the radial outer end of the annular portion 17a toward the outboard side.

[0031] The stator 9 is attached to the stator holding portion 17. The stator 9 has a cylindrical stator core 7 and a winding coil 8 for generating a magnetic force by passing a current through it. The winding coil 8 is attached to the stator core 7. The inner peripheral surface of the stator core 7 is fitted into the outer peripheral surface of the cylindrical portion 17b of the stator holding portion 17. In other words, the stator 9 is attached to the stator holding portion 17 which is integrally formed with the inboard end of the inner ring shaft 3.

[0032] A cylindrical rotor case 13 is attached by press fitting to the outer periphery of the hub flange 1b of the outer ring 1. In detail, the inner circumferential surface of a fitting portion 13a at the outboard end of the rotor case 13 is fitted to the outer periphery of the hub flange 1b of the outer ring 1. The rotor 12 is attached to the inner circumferential surface of a cylindrical portion 13b extending axially from the fitting portion 13a toward the inboard side. The rotor 12 has a rotor core 11 and permanent magnets 10, and is disposed radially outside the stator 9 so as to face the stator 9 in the radial direction.

[0033] In this embodiment, the rotor case 13 has a bottom portion 13c extending radially inward from the fitting portion 13a, and the bottom portion 13c is sandwiched between the hub flange 1b of the outer ring 1 and the supported portion 22a of the brake rotor 22 and fastened together by the hub bolt 4. However, if sufficient support strength can be ensured, the bottom portion 13c may be omitted.

[0034] The generator GE of this embodiment is accommodated radially inward of the brake sliding portion 22c of the brake rotor 22. Since the generator GE is disposed radially inward of the brake rotor 22 in this manner, when the generator GE is mounted on a vehicle, the mechanical structure from the generator GE to the axle AX is minimized, and an increase in weight can be suppressed. In this embodiment, the entire stator 9 and rotor 12 are configured to have a smaller diameter than the brake sliding portion 22c of the brake rotor 22, but it is sufficient that the stator 9 and part of the rotor 12 have a smaller diameter than the brake sliding portion 22c.

[0035] In addition, the entire generator GE, except for the mounting portion (fitting portion 13a and bottom portion 13c) to the hub flange 1b, is located in the axial range between the hub flange 1b and the outboard side of the vehicle suspension device 19 (suspension frame part).

[0036] Further, a seal unit 33 is press-fitted between the inner peripheral surface of the inboard end of the rotor case 13 and the outer peripheral surface of the inboard end of the stator holding part 17. In other words, the inboard end of the wheel bearing 30 is closed by the seal unit 33. The seal unit 33 has a seal holder 15 and a seal member 16.

[0037] The seal holder 15 is press-fitted into the inner circumferential surface of the inboard end of the rotor case 13 to close the inboard end of the wheel bearing 30. In detail, the seal holder 15 has an annular cover portion 15a that closes the inboard end of the wheel bearing 30, and a cylindrical fitting portion 15b that is press-fitted into the inner circumferential surface of the inboard end of the rotor case 13. The fitting portion 15b extends in the axial direction from the radially outer end of the cover portion 15a toward the outboard side.

[0038] A seal member 16 is interposed between the inner diameter surface of the cover portion 15a of the seal holder 15 and the outer diameter surface of the annular portion 17a of the stator holding portion 17 of the inner ring shaft 3. The seal member 16 prevents water, oil, etc. from entering the motor installation space inside the bearing from the external environment, and prevents leakage of lubricant (bearing grease) etc. sealed in the wheel bearing 30.

[0039] Although not shown, the gap between the rotor case 13 and the outer ring 1, and the gap between the rotor case 13 and the seal holder 15 are sealed with O-rings or the like to prevent the intrusion of dirt, oil, etc., and to prevent leakage of the lubricant (bearing grease) sealed in the wheel bearing 30.

[0040] [Removing the generator power line] A bus bar 14 is provided on the inboard end face of the stator core 7. The bus bar 14 is a conductor rod that connects a power source to the coil 8. A plurality of bus bars 14 are provided at the radially outer end of the inboard end face of the stator core 7, spaced apart in the circumferential direction, and protrude to the inboard side.

[0041] A power line 20 is connected to the bus bar 14. The power line 20 supplies power to the coil 8 of the stator 9 via the bus bar 14. In other words, the power line 20 constitutes the wiring 20 of the coil 8 of the stator 9. The power line 20 extends radially inward from the bus bar 14 to a position inside the inner diameter surface of the stator 9, and then extends in the axial direction toward the inboard side and is led out to the outside.

[0042] In detail, a communication hole 25 facing the axial direction is provided in the inboard end face of the stator holding portion 17, i.e., in a portion of the annular portion 17a of the stator holding portion 17 that is radially inward from the stator 9. The wiring (power line) 20 of the coil 8 of the stator 9 is led out to the outside through this communication hole 25. As shown in Fig. 2, the communication hole 25 in this embodiment is a groove-shaped through hole that is formed in the inboard end face of the stator holding portion 17 and extends in the circumferential direction.

[0043] In this way, by taking the power line 20 out from the communication hole 25 radially inside the stator 9, the space on the inboard side of the busbar 14 is increased, and the winding coil 8 can be wound more, thereby increasing the output of the generator (motor).

[0044] Also, by providing the communication hole 25 radially inward from the stator 9, the diameter of the seal member 16 attached to the outer diameter surface of the inboard end of the stator holding part 17 shown in Fig. 1 can be reduced. Furthermore, since the radial position of the axis X1 of the bolt 18 for mounting to the vehicle body is approximately the same as the radial position of the center O1 of the rolling element 5, the diameter of the seal member 16 can be further reduced. As a result, the seal peripheral speed during wheel rotation is reduced, and the seal member 16 can be expected to have a longer life.

[0045] In the above structure, the bus bar 14 is provided on the winding coil 8, and the power line 20 is taken out via the bus bar 14, but the power line 20 may be taken out directly from the winding coil 8 to the inner diameter side. In this case, the same effect can be obtained.

[0046] [Rotation detector] The vehicle power unit PU of this embodiment includes a rotation detector RD. The rotation detector RD detects the rotation angle or rotation speed of the rotating wheel 1 relative to the fixed wheel 3. Specifically, the rotation detector RD has a target 23 fixed to the rotating wheel 1, and a sensing unit 24 fixed to the fixed wheel 3 to detect the target 23. In this embodiment, the rotation detector RD is located radially inward of the rotor 12.

[0047] In this embodiment, a target 23 of the rotation detector RD is installed on the outer periphery of the inboard end of the outer ring 1, which is a rotating ring, and a sensing unit 24 of the rotation detector RD is installed on the inner periphery of the outboard end of the stator holding part 17. The target 23 is attached to the outer periphery of the outer ring 1 by, for example, press fitting. The sensing unit 24 is attached to the inner periphery of the stator holding part 17 by, for example, adhesive means. The target 23 and the sensing unit 24 are disposed opposite each other with a predetermined gap secured in the axial direction.

[0048] [Assembly of vehicle power unit] An exploded structural view of the vehicle power unit PU of this embodiment is shown in Fig. 6. As shown in the figure, the vehicle power unit PU of this embodiment is composed of a wheel bearing 30, a rotor unit 31, a stator unit 32, and a seal unit 33.

[0049] The rotor unit 31 has a rotor case 13 and a rotor 12 housed therein. The stator unit 32 has a stator holding portion 17 and a stator 9 held therein. The seal unit 33 has a seal holder 15 and a seal member 16 fitted to the inner diameter surface thereof.

[0050] 7 shows an exploded assembly view of the stator unit 32. As described above, the stator unit 32 has the inner ring shaft 3 including the stator holding portion 17, and the stator 9. The stator 9, the busbar 14, and the power lines 20 are integrally formed. A first cutout portion 45 is formed in a circumferential portion corresponding to the communication hole 25 on the outer circumferential surface of the stator holding portion 17. As shown in FIGS. 3, 4, and 5, the first cutout portion 45 is formed by cutting out a part of the peripheral wall of the cylinder.

[0051] In this embodiment, as shown in Fig. 7, the stator unit 32 further has a sensing portion 24 of a rotation detector RD. A second cutout portion 47 is provided at the inboard end of the sensing portion 24 of the rotation detector RD. The second cutout portion 47 is formed by cutting out a part of the peripheral wall of the cylinder. The first cutout portion 45 and the second cutout portion 47 are provided at the same position in the circumferential direction.

[0052] 7, the stator 9 is fitted to the outer peripheral surface of the stator holding portion 17 of the inner ring shaft 3, and the sensing portion 24 of the rotation detector RD is attached to the inner peripheral surface of the stator holding portion 17. At this time, the power line 20 protrudes toward the inner diameter side and extends in the axial direction, but passes radially through the first notch 45 of the stator holding portion 17 and the second notch 47 of the sensing portion 24, and is taken out in the axial direction from the communication hole 25 of the stator holding portion 17. Therefore, the stator 9 and the sensing portion 24 can be attached to the stator holding portion 17 without any problems, and the stator unit 32 is assembled.

[0053] As shown in Fig. 6, the inner peripheral surface of the inner ring 2 of the wheel support bearing 30 is fitted onto the outer peripheral surface of the inner ring shaft 3. This allows the wheel support bearing 30 and the stator unit 32 to be assembled. Also, the inner peripheral surface of the rotor case 13 of the rotor unit 31 is fitted onto the outer peripheral surface of the hub flange 1b of the outer ring 1 of the wheel support bearing 30, and the hub flange 1b and the rotor unit 31 are connected by the hub bolts 4. This allows the wheel support bearing 30 and the rotor unit 31 to be assembled.

[0054] Next, the outer peripheral surface of the seal holder 15 of the seal unit 33 is attached to the inner peripheral surface of the rotor case 13 of the rotor unit 31. At this time, the seal member 16 is held between the outer peripheral surface of the stator holding portion 17 of the inner shaft 3 and the inner peripheral surface of the seal holder 15 of the seal unit 33. In this way, the vehicle power unit PU is assembled.

[0055] Finally, the vehicle power unit PU is fixed to the vehicle suspension 19 by bolts 18. The vehicle power unit PU can be removed from the suspension 19 and disassembled by reversing the above steps. In this manner, the vehicle power unit PU in this embodiment has a structure that allows easy disassembly and assembly.

[0056] According to the above configuration, as shown in Fig. 1, the inner shaft 3 has a stator holding portion 17 that holds the stator 9. In other words, the inner shaft 3 and the stator holding portion 17 are configured as an inseparable unit. Therefore, when an external load is applied, the wheel support bearing 30 and the generator GE deform as a unit. This makes it possible to suppress fluctuations in the motor gap, and to suppress fluctuations in the motor torque and the rotation of the wheel support bearing 30.

[0057] In addition, both the wheel support bearing 30 and the generator GE are mounted on the suspension 19 by the inner shaft 3. Therefore, errors during assembly are not accumulated, and the motor gap is kept uniform. This makes it possible to suppress fluctuations in the motor torque and the rotation of the wheel support bearing 30, and does not adversely affect vehicle performance. Furthermore, by integrating the stator holding portion and the inner shaft, the number of parts can be reduced, and the number of assembly steps can be reduced.

[0058] Furthermore, according to the above configuration, only the wheel support bearing 30 can be separated from the vehicle power unit PU by simply loosening the nut 40, improving maintainability. Moreover, since the wheel support bearing 30 is a conventional second generation type, the bearing manufacturer can manage and adjust the internal clearance. Also, by making the fit between the inner ring 2 and the inner ring shaft 3 an interference fit, it is possible to prevent creep from occurring, and as a result, it is possible to prevent deterioration of the wheel support bearing 30. Furthermore, a relief portion 3d having a smaller diameter than the fit portion 3b of the inner ring shaft 3 is provided in a portion between the fit portion 3b and the male thread portion 3c of the inner ring shaft 3. This makes it possible to prevent interference between the outer diameter portion of the inner ring shaft 3 and the inner diameter portion of the inner ring 2 when the nut is fastened, and it is possible to reliably manage the preload of the wheel support bearing 30.

[0059] When it is not necessary to separate only the wheel support bearing 30 from the vehicle power unit PU, preload may be applied by crimping the outboard side of the inner shaft 3 instead of fastening with the nut 40 .

[0060] The stator 9 and rotor 12 have a smaller diameter than the portion of the brake rotor 22 against which the brake caliper is pressed, and the entire generator GE, except for the portion attached to the hub flange 1b, is located in the axial range between the hub flange 1b and the outboard side surface of the vehicle suspension frame component (suspension device) 19. This configuration allows the vehicle power unit PU, including the stator 9 and rotor 12 of the generator GE, to be arranged compactly. Furthermore, since the rotation detector RD is located radially inward of the rotor 12, the rotation detector RD can also be arranged compactly.

[0061] The wiring 20 coming out of the inboard coil 8 of the generator GE shown in Fig. 1 is led out from a communication hole 25 located radially inward of the stator 9. That is, the wiring 20 extends radially inward from the stator 9 and is then led out to the inboard side. This ensures space on the inboard side of the stator 9, and this space can be effectively used for the motor winding coil 8. As a result, the desired motor output can be obtained.

[0062] Additionally, the wiring 20 coming out from the coil 8 on the inboard side of the generator GE extends radially inward from the stator 9 through the first and second cutouts 45, 47. This ensures space on the inboard side of the stator 9, which can be effectively used for the motor winding coil 8. As a result, the desired motor output can be obtained.

[0063] The present invention is not limited to the above-described embodiment, and various additions, modifications, and deletions are possible without departing from the scope of the present invention. For example, in the above-described embodiment, the stator 9 is attached to the stator holding portion 17 by press-fitting, but the stator 9 may be fixed by fitting the stator 9 with a radial gap therebetween and deforming the stator holding portion 17 from the outboard side by crimping or the like.

[0064] Also, in the above embodiment, the second notch 47 is provided in the sensing portion 24 to avoid interference between the sensing portion 24 and the motor power line 20, but the sensing portion 24 may have a shape other than a ring shape, such as a semicircular ring, which can avoid interference. Furthermore, in the above embodiment, the rotation detection sensor RD is disposed on the inner diameter side of the stator 9, but it may be disposed at any position within the rotor case 13 as long as it is a position where the rotation of the rotating wheel 1 can be detected. Therefore, such a shape is also included in the scope of the present invention. [Explanation of symbols]

[0065] 1 Outer ring (rotating ring) 1a Outer ring raceway 1b Hub flange 2 Inner wheel (fixed wheel) 2a Inner raceway 3 Inner shaft (fixed wheel) 3a Flange 3b Inner ring fitting part 3c Male thread 5 Rolling elements 9 Stator 12 Rotor 17 Stator holder 18 Volts 19 Suspension system (suspension parts) 21 Female thread 22 Brake rotor 24 Sensing part of rotation detector 25 Communication hole 30 Wheel bearings 40 Nut 45 1st notch 47 Second notch GE Generators PU Vehicle power unit RD Rotation Detector

Claims

1. a wheel bearing including a fixed ring and a rotating ring rotatably supported by the fixed ring via rolling elements, the rotating ring being provided with a hub flange to which a wheel of a vehicle is attached; A vehicle power unit including a generator having a stator attached to a fixed ring of the wheel bearing and a rotor attached to a rotating ring of the wheel bearing, An inner ring shaft is inserted into the inner ring of the wheel bearing which is the fixed ring, the inner ring shaft has a flange portion extending radially outward at an inboard end thereof, and a stator holding portion extending in the axial direction from an outer diameter end of the flange portion toward the outboard side, The stator is attached to the stator holding portion.

2. 2. The vehicle power unit according to claim 1, wherein the wheel support bearing comprises: an outer ring having the hub flange on an outboard side and a double row outer ring rolling surface formed on an inner circumference thereof; a pair of inner rings each having an inner ring rolling surface formed on an outer periphery thereof opposite to the outer ring rolling surface; a double row of rolling elements interposed between the outer ring rolling surface and the inner ring rolling surface, the inner race shaft has an inner race fitting portion into which the inner race is fitted, and a male thread portion extending from the inner race fitting portion to the outboard side, The interference between the inner diameter of the inner ring and the outer diameter of the inner ring fitting portion is a negative clearance, The inner ring is sandwiched between the flange portion and a nut screwed onto the male thread portion, The vehicle power unit is attached to a suspension system of the vehicle by fastening a bolt to the female thread provided in the flange portion.

3. 3. The vehicle power unit according to claim 1, further comprising a rotation detector for detecting at least one of a rotation angle and a rotation speed of the rotating wheel relative to the fixed wheel, A brake rotor is attached to the hub flange, a part or whole of the stator and the rotor has a smaller diameter than a portion of the brake rotor against which a brake caliper is pressed; the entire generator, except for a portion attached to the hub flange, is located in an axial range between the hub flange and an outboard side surface of an undercarriage frame component of the vehicle; The vehicle power plant, wherein the rotation detector is located radially inward of the rotor.

4. 3. The vehicle power plant according to claim 1, wherein a communication hole for leading out wiring of the stator to the outside is provided on an inboard end face of the stator holding portion.

5. 3. The vehicle power plant according to claim 1, wherein a first cutout portion is provided at an inboard end of the stator holding portion, through which wiring of the stator passes from an outer diameter side to an inner diameter side.

6. 3. The vehicle power unit according to claim 1, further comprising a rotation detector for detecting a rotation angle or a rotation speed of the rotating wheel relative to the fixed wheel, a sensing portion of the rotation detector is installed on an inboard side of the inner ring shaft, A vehicle power unit, wherein a second cutout portion is provided on an inboard end face of the sensing portion of the rotation detector, through which wiring of the stator passes from the outer diameter side to the inner diameter side of the rotation detector.

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