One-way clutch and wheel drive unit

Abstract

The present application provides a one-way clutch and a wheel drive unit, which can disconnect a drive shaft from a hub bearing when a vehicle does not need driving power, thereby reducing friction and stirring energy loss of the drive shaft and the drive unit. The one-way clutch (1) includes: a first clutch member (2) having a clutch outer ring portion (6) and a first engagement portion (7) capable of transmitting torque and engaging with a driving member (43); a second clutch member (3) having a clutch inner ring portion (14), a shaft portion (15) inserted into a central hole (77) of a hub (68), and a second engagement portion (16) capable of transmitting torque and engaging with the hub; and a locking member (4). The locking member is arranged between the clutch outer ring portion and the clutch inner ring portion, and transmits torque between the clutch outer ring portion and the clutch inner ring portion only when the clutch outer ring portion rotates relative to the clutch inner ring portion in the same direction as the rotation direction of the driving wheel (33) when driving and the relative rotation speed is within a rated speed range.

Description

Technical Field

[0001] This disclosure relates to a one-way clutch for cutting off power to a drive wheel and a wheel drive unit having the one-way clutch, a hub unit bearing, and a drive component. Background Technology

[0002] Driven by the recent trend of reduced fossil fuel consumption, research on electric vehicles (EVs) and hybrid vehicles (HVs) has been continuously developing, with some projects already underway. Similar to engine-powered vehicles, electric and hybrid vehicles have been developed with various drive configurations, including front-wheel drive (FF), rear-wheel drive (FR), and four-wheel drive (4WD).

[0003] As described in Japanese Patent Application Publication No. 2021-027649, a four-wheel drive electric vehicle includes: a main drive unit for driving one of the front and rear wheels; and an auxiliary drive unit for driving the other of the front and rear wheels. The main drive unit and the auxiliary drive unit are each composed of components such as a motor, a countershaft, a differential gear, and a drive shaft.

[0004] As described in Japanese Patent Application Publication No. 2024-130402, the main drive wheel and the auxiliary drive wheel are supported by hub unit bearings and can rotate freely relative to the vehicle body. The main drive wheel and the auxiliary drive wheel are fixed to the hub that constitutes the hub unit bearing and rotate together with the hub. The hub is connected to drive components such as the drive shaft that constitute the drive device and is driven by rotation.

[0005] Existing technical documents

[0006] Patent documents

[0007] Patent Document 1: Japanese Patent Application Publication No. 2021-027649

[0008] Patent Document 2: Japanese Patent Application Publication No. 2024-130402 Summary of the Invention

[0009] The problem that the invention aims to solve

[0010] In low-load driving conditions, four-wheel drive electric vehicles sometimes operate by driving only the main drive wheels without driving the auxiliary drive wheels. That is, sometimes the auxiliary drive wheels are used like driven wheels. In this case, the auxiliary drive wheels passively rotate as the electric vehicle moves. This causes multiple components of the auxiliary drive system, including the hub where the auxiliary drive wheels are fixed and the drive shaft connected to the hub, to rotate. When these components rotate, frictional resistance caused by rotation and churning resistance of the lubricating oil are generated, resulting in energy loss in the auxiliary drive system.

[0011] The problem of energy loss that occurs when the drive wheels are passively rotated as the car moves is not unique to four-wheel drive electric vehicles.

[0012] Regardless of the type of power source or drive system, all automobiles, in order to improve fuel efficiency or electrical efficiency, deactivate the accelerator and rely on inertia while driving. However, during this inertial motion, the drive wheels passively rotate as the car moves. Therefore, energy loss occurs in the drive system used to rotate the drive wheels.

[0013] The purpose of this disclosure is to provide a one-way clutch and a wheel drive unit that can reduce energy loss when the drive wheels are passively rotated as the vehicle is moving.

[0014] Solution for solving the problem

[0015] One aspect of the present invention provides a one-way clutch comprising a first clutch component, a second clutch component, and a locking component.

[0016] The aforementioned first clutch component is connected to a drive component that is rotated by the vehicle's power source.

[0017] The second clutch component is coaxially arranged with the first clutch component and connected to the hub of the hub unit bearing that forms a hub unit bearing for rotatably supporting the drive wheel.

[0018] The aforementioned locking component transmits torque between the aforementioned first clutch component and the aforementioned second clutch component.

[0019] The aforementioned first clutch component includes: a clutch outer ring portion; and a first engagement portion that engages with the aforementioned drive component to transmit torque.

[0020] The second clutch component described above includes: a clutch inner ring portion disposed radially inside the clutch outer ring portion; a shaft portion inserted into the center hole of the hub; and a second engaging portion engaged relative to the hub to transmit torque.

[0021] The aforementioned locking component is disposed between the outer ring of the clutch and the inner ring of the clutch, and transmits torque between the outer ring of the clutch and the inner ring of the clutch only when the outer ring of the clutch is to rotate relative to the inner ring of the clutch in the same direction as the rotation direction of the drive wheel when the vehicle is moving forward, and the relative rotation speed is within the rated speed range.

[0022] One aspect of the present invention provides a one-way clutch that includes a support bearing disposed between the first clutch component and the second clutch component.

[0023] In this case, the aforementioned support bearing can be positioned to overlap radially with the outer ring portion of the clutch and the inner ring portion of the clutch, respectively.

[0024] In a one-way clutch according to one aspect of the present invention, the first clutch component may have a fitting sleeve portion disposed radially inside the inner ring portion of the clutch and externally fitted into the drive component, and the support bearing may be disposed between the inner ring portion of the clutch and the fitting sleeve portion, and axially positioned and locked by a nut at the end of the drive component.

[0025] In one embodiment of the present invention, the first engaging portion can be formed by an inner spline portion or an inner serrated portion formed on the inner peripheral surface of the engaging cylinder portion.

[0026] In one embodiment of the present invention, the first clutch component can have a sealing mounting portion for mounting a sealing device that seals the first clutch component with the steering knuckle constituting the suspension device.

[0027] In this case, the aforementioned sealing mounting portion can be fitted onto the outer ring portion of the aforementioned clutch.

[0028] In a one-way clutch according to one aspect of the present invention, the second engagement portion can be formed by an end face spline portion of the surface of the second clutch component that is axially opposite to the hub. The second clutch component has a threaded portion formed at the end opposite to the second engagement portion, and is locked to the hub in the axial direction by a nut.

[0029] One aspect of the present invention provides a wheel drive unit comprising: a one-way clutch according to the present invention; a drive component that is rotated and driven by a power source of the automobile; and a hub unit bearing for rotatably supporting the drive wheel.

[0030] The aforementioned drive component has a drive-side engagement portion that engages with the aforementioned first engagement portion to transmit torque.

[0031] The aforementioned hub unit bearing comprises: an outer ring having multiple rows of outer ring tracks on its inner circumference and fixed to the steering knuckle of the suspension device; a hub having multiple rows of inner ring tracks on its outer circumference, having a central hole extending axially through the radial center, and having a hub-side engaging portion capable of transmitting torque with the aforementioned second engaging portion; and a plurality of rolling elements that are freely arranged between the aforementioned multiple rows of outer ring tracks and the aforementioned multiple rows of inner ring tracks.

[0032] In the wheel drive unit of the present invention, the one-way clutch and the hub unit bearing can be lubricated by grease.

[0033] In the wheel drive unit of the present invention, the locking component setting space and the rolling element setting space can be interconnected. The locking component setting space exists between the inner peripheral surface of the outer ring of the clutch and the outer peripheral surface of the inner ring of the clutch, and the rolling element setting space exists between the inner peripheral surface of the outer ring and the outer peripheral surface of the wheel hub.

[0034] The wheel drive unit of the present invention can include: a hub-side sealing device that closes the opening on the axially outer side of the rolling element placement space; and a clutch-side sealing device that closes the space between the steering knuckle and the first clutch component.

[0035] The wheel drive unit of the present invention can include a wheel speed signal measuring component, which is mounted on the wheel hub.

[0036] In the wheel drive unit of the present invention, the wheel hub can have a cylindrical pilot portion at the axially outer end, and the pilot portion is covered.

[0037] The wheel drive unit of the present invention can have a rolling bearing disposed between the drive component and the second clutch component.

[0038] The wheel drive unit of the present invention can form the second engagement portion by an end face spline portion provided on the surface of the second clutch member that is axially opposite to the wheel hub, and the wheel hub side engagement portion by an end face spline portion provided on the surface of the wheel hub that is axially opposite to the second clutch member.

[0039] In this case, a nut that is threadedly engaged with the portion of the shaft that protrudes axially outward from the central hole is provided, and the second engaging portion is pressed axially relative to the hub-side engaging portion.

[0040] Invention Effects

[0041] According to one embodiment of the present disclosure, a one-way clutch and a wheel drive unit can disconnect the drive shaft from the wheel hub bearing when the vehicle does not require driving force, thereby reducing friction and agitation energy loss of the drive shaft and drive unit, thus reducing energy consumption and increasing driving range. Attached Figure Description

[0042] Figure 1 This is a cross-sectional view of a one-way clutch, representing a first example of an embodiment of this disclosure.

[0043] Figure 2 yes Figure 1 A schematic diagram of the AA-line cross section.

[0044] Figure 3This is a schematic diagram illustrating an example of a four-wheel drive electric vehicle equipped with the one-way clutch of the first example.

[0045] Figure 4 This is a schematic diagram illustrating an example of a drive system for an electric vehicle.

[0046] Figure 5 This is a cross-sectional view showing a wheel drive unit equipped with the first example of a one-way clutch.

[0047] Figure 6 yes Figure 5 A magnified view of a portion of the image.

[0048] In the picture:

[0049] 1—One-way clutch, 2—First clutch assembly, 3—Second clutch assembly, 4—Locking assembly, 5—Locking element (wedge), 6—Outer ring of clutch, 7—First engaging part, 8—Inner circumferential surface of outer ring, 9—Engaging cylinder part, 10—Connecting part, 11—Plate part, 12—Conical cylinder part, 13—Sealing mounting part, 14

[0050] 15—Clutch inner ring portion, 16—Shaft portion, 17—Second engagement portion, 18—Inner ring outer circumferential surface, 19—Locking component space, 20—External thread portion, 21—Engine surface, 22—Stepped surface, 23—Clutch retainer, 24—Force application component, 25—Support bearing, 26—Outer ring track, 27—Bearing outer ring, 28—Inner ring track, 29—Bearing inner ring, 30—Rolling element, 31—Electric vehicle, 32—Main drive wheel, 33—Auxiliary drive wheel, 34—Main drive unit, 35—Auxiliary drive Device, 36—Battery, 37—Hub unit bearing, 38—Motor, 39—Counter shaft, 40—Differential gear, 41—Drive shaft, 42—Constant velocity joint, 43—Drive component, 44—Wheel drive unit, 45—Drive side engaging part, 46—Matching shaft part, 47—Outer diameter changing part, 48—Support shaft part, 49—Step surface, 50—Matching surface, 51—Abutting surface, 52—Outer ring for joint, 53—Inner ring for joint, 54—Ball, 55—Outer engaging groove, 56—Inner engaging groove, 57—Intermediate shaft, 58 —Anti-slip component, 59—Spacer, 60—Rolling bearing, 61—Outer ring track, 62—Bearing outer ring, 63—Inner ring track, 64—Bearing inner ring, 65—Rolling element, 66—Retaining ring, 67—Outer ring, 68—Hub, 69a, 69b—Rolling elements, 70a, 70b—Outer ring track, 71—Steering knuckle, 72—Stationary flange, 73—Flange side support hole, 74—Support bolt, 75—Steering knuckle side support hole, 76a, 76b—Inner ring track, 77—Center hole, 78—Hub side engaging part, 79— Rolling element mounting space, 80—rotating flange, 81—pilot section, 82—mounting hole, 83—stud, 84—inner ring, 85—hub ring, 86—small diameter shaft section, 87—stepped surface, 88—riveting section, 89a, 89b—retainer, 90—nut, 91—steering knuckle center hole, 92—hub side sealing device, 93—clutch side sealing device, 94—sealing ring, 95—oil slinger ring, 96—sealing ring, 97—oil slinger ring, 98—steering knuckle cylinder section, 99—sealing component, 100—cover, 101—encoder. Detailed Implementation

[0051] [First example]

[0052] pass Figures 1-6 The one-way clutch 1 and the wheel drive unit 44 of the first embodiment of the present disclosure will be described.

[0053] In the following description, unless otherwise specified, axial, radial, and circumferential directions refer to the axial, radial, and circumferential directions of the first clutch component 2. The axial, radial, and circumferential directions of the first clutch component 2 are consistent with the axial, radial, and circumferential directions of the second clutch component 3, the outer ring 67 constituting the hub unit bearing 37 and the hub 68, and the drive component 43, respectively. Furthermore, axial outer side refers to the outer side of the vehicle in the width direction when the one-way clutch 1 is assembled in the vehicle, and axial inner side refers to the central side of the vehicle in the width direction when the one-way clutch 1 is assembled in the vehicle.

[0054] [Explanation of the construction of a one-way clutch]

[0055] The one-way clutch 1 includes a first clutch component 2, a second clutch component 3, and a locking component 4.

[0056] <First Clutch Component>

[0057] The first clutch component 2 is connected to the drive component 43, which is driven by the rotation of the vehicle's power source.

[0058] The first clutch component 2 is made of metal, is coaxially arranged with the drive component 43, and rotates synchronously with the drive component 43. That is, when the drive component 43 rotates, the first clutch component 2 rotates in the same direction as the drive component 43 and at the same speed as the drive component 43, and stops when the drive component 43 stops.

[0059] The first clutch component 2 includes a clutch outer ring portion 6 and a first engagement portion 7 that engages with the drive component 43 to transmit torque.

[0060] The outer ring 6 of the clutch is an element used to transmit torque between itself and the locking component 4.

[0061] The outer ring portion 6 of the clutch is disposed radially outward of the locking member 4. The outer ring portion 6 of the clutch has an inner circumferential surface 8 facing radially inward.

[0062] The inner circumferential surface 8 of the outer ring has a structure corresponding to the locking element 5 constituting the locking member 4. Specifically, when the locking element 5 of the locking member 4 is a wedge, the inner circumferential surface 8 of the outer ring is a cylindrical surface. When the locking element 5 of the locking member 4 is a roller, the inner circumferential surface 8 of the outer ring is a cylindrical surface or a cam surface. When the locking element 5 of the locking member 4 is a pawl member (latch), the inner circumferential surface 8 of the outer ring is either a gear-shaped concave-convex surface that engages with the radially outer end of the pawl member, or a support surface that supports the radially outer end of the pawl member so that it can rotate around a support shaft arranged parallel to the central axis of the first clutch member 2.

[0063] In this example, the locking element 5 of the locking component 4 is composed of a wedge, so the inner circumferential surface 8 of the outer ring is composed of a cylindrical surface.

[0064] In this example, the outer ring portion 6 of the clutch has an annular shape and constitutes the radially outer portion of the first clutch component 2. The outer ring portion 6 of the clutch has an axial dimension smaller than its outer diameter.

[0065] The first engaging part 7 is an element used to transmit torque between itself and the drive component 43.

[0066] The first engaging part 7 is provided on the surface that is radially or axially opposed to the driving member 43.

[0067] When the first engaging portion 7 is provided on a surface radially opposite to the drive member 43, the first engaging portion 7 can be composed of a plurality of teeth that protrude radially and are arranged circumferentially. In this case, the first engaging portion 7 can be composed of a spline portion composed of a plurality of spline teeth or a serrated portion composed of a plurality of serrated teeth. Alternatively, the first engaging portion 7 can also be composed of an outer or inner circumferential surface having a non-circular contour shape such as a side-width shape.

[0068] When the first engaging portion 7 is provided on a surface that is axially opposed to the drive member 43, the first engaging portion 7 can also be constructed by a plurality of teeth that protrude axially and are arranged in the circumferential direction. In this case, the first engaging portion 7 can be constructed by an end face spline portion composed of a plurality of spline teeth.

[0069] In this example, the first clutch component 2 has a fitting sleeve 9 that is externally or internally fitted into the drive component 43. The fitting sleeve 9 is an element for coaxially arranging the first clutch component 2 and the drive component 43.

[0070] The fitting cylinder portion 9 is coaxially arranged with the outer ring portion 6 of the clutch.

[0071] In this example, the engagement cylinder portion 9 is disposed radially inside the outer ring portion 6 of the clutch. This reduces the axial dimension of the first clutch component 2. The engagement cylinder portion 9 constitutes the radially inner portion of the first clutch component 2.

[0072] In this example, the fitting cylinder portion 9 is externally fitted into the drive member 43. The fitting cylinder portion 9 has a first engaging portion 7 on its inner circumferential surface that is radially opposed to the drive member 43. The first engaging portion 7 is composed of an inner spline portion or an inner serrated portion formed on the inner circumferential surface of the fitting cylinder portion 9.

[0073] However, the fitting cylinder portion 9 can also be embedded within the drive member 43. In this case, the fitting cylinder portion 9 may have a first engaging portion 7 on its outer peripheral surface that is radially opposite to the drive member 43. The first engaging portion 7 may be formed by an outer spline portion or an outer serrated portion formed on the outer peripheral surface of the fitting cylinder portion 9.

[0074] The first clutch component 2 includes a connecting portion 10 that connects the outer ring portion 6 of the clutch and the engagement cylinder portion 9. The connecting portion 10 forms the radial middle portion of the first clutch component 2.

[0075] In this example, the connecting portion 10 connects the axially inner end of the outer ring portion 6 of the clutch and the axially inner end of the fitting cylinder portion 9. Therefore, the first clutch component 2 has a transverse U-shaped cross-sectional shape.

[0076] The connecting portion 10 abuts against the drive member 43 in the axial direction, thereby enabling the first clutch member 2 to be positioned relative to the drive member 43 in the axial direction. Alternatively, the connecting portion 10 may also have a first engaging portion 7 formed by an end face spline on the surface opposite to the drive member 43 in the axial direction.

[0077] In this example, the connecting part 10 is composed of a flat plate part 11 and a conical cylinder part 12.

[0078] The flat plate portion 11 forms the radially outer portion of the connecting portion 10, extending radially inward from the axially inner end of the clutch outer ring portion 6. The axially inner surface of the flat plate portion 11 is formed by a flat surface orthogonal to the central axis of the first clutch component 2. In this example, the radially inner portion of the axially inner surface of the flat plate portion 11 abuts against the drive component 43 in the axial direction.

[0079] The conical cylinder portion 12 forms the radially inner portion of the connecting portion 10, extending from the axially inner end of the fitting cylinder portion 9 in a direction toward both the radially outer and axially inner sides. The conical cylinder portion 12 is provided to prevent interference between the connecting portion 10 and the outer diameter variation portion 47 of the drive member 43 (described later). Therefore, if it is not necessary to prevent interference between the connecting portion 10 and the drive member 43, the connecting portion 10 may be composed solely of the flat plate portion 11.

[0080] The first clutch component 2 has a sealing mounting portion 13 for mounting a clutch-side sealing device 93 that will seal between the clutch component and the steering knuckle 71 constituting the suspension device.

[0081] The sealing mounting part 13 is provided on the surface of the first clutch component 2 that is radially or axially opposed to the steering knuckle 71.

[0082] The sealing mounting portion 13 can be provided, for example, on the inner circumferential surface, outer circumferential surface, or axial end face of the outer ring portion 6 of the clutch.

[0083] In this example, the sealing mounting portion 13 is provided on the inner circumferential surface of the clutch outer ring portion 6. Specifically, the sealing mounting portion 13 is provided at the axially outer end of the inner circumferential surface of the clutch outer ring portion 6, which is offset axially outward from the inner circumferential surface 8 of the outer ring. The sealing mounting portion 13 is composed of a cylindrical surface.

[0084] <Second Clutch Component>

[0085] The second clutch component 3 is coaxially arranged with the first clutch component 2 and is connected to the hub 68, which constitutes the hub unit bearing 37 for rotatably supporting the drive wheel.

[0086] The second clutch component 3 is made of metal, is coaxially arranged with the hub 68, and rotates synchronously with the hub 68. That is, when the hub 68 rotates, the second clutch component 3 rotates in the same direction as the hub 68 and at the same speed as the hub 68, and stops when the hub 68 stops.

[0087] The second clutch component 3 includes: a clutch inner ring portion 14 disposed radially inside the clutch outer ring portion 6; a shaft portion 15 inserted into the center hole 77 of the hub 68; and a second engaging portion 16 capable of engaging with the hub 68 in a torque-transmitting manner.

[0088] The inner ring 14 of the clutch is an element used to transmit torque between itself and the locking component 4.

[0089] In this example, the clutch inner ring portion 14 is disposed radially inside the clutch outer ring portion 6 and radially outside the engagement cylinder portion 9. That is, the clutch inner ring portion 14 is radially disposed between the clutch outer ring portion 6 and the engagement cylinder portion 9. The clutch inner ring portion 14 constitutes the axial inner portion of the second clutch component 3.

[0090] The inner ring portion 14 of the clutch has an outer circumferential surface 17 facing radially outward and radially opposed to the inner circumferential surface 8 of the outer ring. An annular locking member space 18 is formed between the outer circumferential surface 17 of the inner ring and the inner circumferential surface 8 of the outer ring, in which a locking member 4 is disposed.

[0091] The outer peripheral surface 17 of the inner ring has a structure corresponding to the locking element 5 constituting the locking member 4. Specifically, when the locking element 5 of the locking member 4 is composed of a wedge, the outer peripheral surface 17 of the inner ring is composed of a cylindrical surface.

[0092] When the locking element 5 of the locking component 4 is made of a roller, the outer peripheral surface 17 of the inner ring is made of a surface that is different from the inner peripheral surface 8 of the outer ring, either a cam surface or a cylindrical surface. That is, when the inner peripheral surface 8 of the outer ring is made of a cylindrical surface, the outer peripheral surface 17 of the inner ring is made of a cam surface, and when the inner peripheral surface 8 of the outer ring is made of a cam surface, the outer peripheral surface 17 of the inner ring is made of a cylindrical surface.

[0093] When the locking element 5 of the locking component 4 is composed of a claw component, the inner circumferential surface 8 of the outer ring is either a gear-shaped concave-convex surface that engages with the radially inner end of the claw component, or a support surface that supports the radially inner end of the claw component so that it can rotate around a support shaft arranged parallel to the central axis of the second clutch component 3, which is different from the inner circumferential surface 8 of the outer ring. That is, when the inner circumferential surface 8 of the outer ring is composed of a gear-shaped concave-convex surface, the outer circumferential surface 17 of the inner ring is composed of a support surface, and when the inner circumferential surface 8 of the outer ring is composed of a support surface, the outer circumferential surface 17 of the inner ring is composed of a gear-shaped concave-convex surface.

[0094] In this example, the locking element 5 of the locking component 4 is composed of a wedge, so the outer circumferential surface 17 of the inner ring is composed of a cylindrical surface.

[0095] In this example, the inner ring portion 14 of the clutch has an annular shape and an inner diameter that is slightly larger than the outer diameter of the engagement cylinder portion 9. The inner ring portion 14 of the clutch has a smaller axial dimension than the outer ring portion 6 of the clutch.

[0096] Shaft 15 is a component used to fix the second clutch component 3 to the hub 68.

[0097] The shaft portion 15 forms the axial outer portion of the second clutch component 3. The shaft portion 15 can be inserted into the center hole 77 of the hub 68 without wobbling or loosely.

[0098] The shaft portion 15 has an axial dimension larger than the center hole 77 of the hub 68. Therefore, the axially outer end of the shaft portion 15 protrudes axially outward from the center hole 77 of the hub 68. The axially outer end of the shaft portion 15 is disposed inside the pilot portion 81 that constitutes the hub 68.

[0099] In this example, the nut 90 is threaded into the portion of the shaft 15 that protrudes axially outward from the center hole 77 of the hub 68. Therefore, an external thread 19 is formed on the portion of the shaft 15 that protrudes axially outward from the center hole 77 of the hub 68. However, a riveting portion can be formed in the shaft 15 instead of threading the nut into the shaft 15.

[0100] In this example, the shaft portion 15 is hollow. However, the shaft portion 15 can also be solid. When the shaft portion 15 has a second engaging portion 16 on its outer circumferential surface, it is preferable that the shaft portion 15 is solid to ensure rigidity.

[0101] The second engaging part 16 is a component used to transmit torque between itself and the hub 68.

[0102] The second engaging part 16 is provided on the surface that is radially or axially opposite to the hub 68.

[0103] When the second engaging portion 16 is provided on a surface that radially opposes the hub 68, the second engaging portion 16 can be composed of a plurality of teeth that each protrude radially and are arranged circumferentially. In this case, the second engaging portion 16 can be composed of a spline portion composed of a plurality of spline teeth or a serrated portion composed of a plurality of serrated teeth. Alternatively, the second engaging portion 16 can also be composed of an outer or inner circumferential surface having a non-circular profile shape such as a side-width shape.

[0104] When the second engaging portion 16 is provided on a surface opposite the hub 68 in the axial direction, the second engaging portion 16 can be composed of a plurality of teeth that protrude axially and are arranged in the circumferential direction. In this case, the second engaging portion 16 can be composed of an end face spline portion composed of a plurality of spline teeth.

[0105] In this example, the second engaging portion 16 is provided on the surface opposite to the hub 68 in the axial direction and is composed of an end face spline portion. Alternatively, the second engaging portion 16 may also be composed of an external spline portion or an external serrated portion formed on the outer peripheral surface of the shaft portion 15 which is radially opposite to the inner peripheral surface of the hub 68.

[0106] In this example, the second clutch component 3 has an engagement shaft portion 20 on a surface axially opposite to the hub 68, wherein a second engagement portion 16 is provided. The engagement shaft portion 20 has the second engagement portion 16 on its axially outer side.

[0107] In this example, the engaging shaft portion 20 constitutes the axial intermediate portion of the second clutch component 3 and is axially positioned between the clutch inner ring portion 14 and the shaft portion 15.

[0108] The engagement shaft portion 20 has an outer diameter larger than that of the shaft portion 15. In this example, the engagement shaft portion 20 has an outer diameter smaller than that of the clutch inner ring portion 14. However, the engagement shaft portion 20 may also have an outer diameter larger than that of the clutch inner ring portion 14, or it may have an outer diameter of the same size as that of the clutch inner ring portion 14.

[0109] In this example, the engaging shaft portion 20 is hollow. The axially outer end of the drive member 43 is disposed on the radially inner side of the engaging shaft portion 20. However, the engaging shaft portion 20 can also be solid.

[0110] In this example, the inner ring portion 14 of the clutch is annular, and the shaft portion 15 and the engaging shaft portion 20 are both hollow, so the second clutch component 3 is hollow as a whole. However, the second clutch component 3 may also be partially hollow, with the remaining portion being solid.

[0111] In this example, the second clutch component 3 has a cylindrical mating surface 21 and a stepped surface 22 on its inner circumferential surface. The mating surface 21 has an inner diameter smaller than that of the clutch inner ring portion 14. The stepped surface 22 is disposed adjacent to the axially outer side of the mating surface 21 and faces axially inward. The stepped surface 22 is formed by a flat surface orthogonal to the central axis of the second clutch component 3. In this example, the mating surface 21 and the stepped surface 22 are provided on the inner circumferential surface of the engaging shaft portion 20, but they could also be provided on the inner circumferential surface of the shaft portion 15.

[0112] <Locking component>

[0113] The locking component 4 transmits torque between the first clutch component 2 and the second clutch component 3.

[0114] The locking component 4 is disposed between the outer ring portion 6 of the clutch and the inner ring portion 14 of the clutch. It transmits torque between the outer ring portion 6 of the clutch and the inner ring portion 14 of the clutch only when the outer ring portion 6 of the clutch is to rotate relative to the inner ring portion 14 of the clutch in the same direction as the rotation of the drive wheel when the vehicle is moving forward.

[0115] The structure of the locking component 4 is arbitrary. For example, the locking element 5 of the locking component 4 can be composed of a wedge, a roller, or a pawl. When the locking element 5 of the locking component 4 is composed of a wedge, the one-way clutch 1 is a wedge clutch. When the locking element 5 of the locking component 4 is composed of a roller, the one-way clutch 1 is a roller clutch. When the locking element 5 of the locking component 4 is composed of a pawl, the one-way clutch 1 is a ratchet clutch.

[0116] When the locking member 4 is composed of locking elements 5 such as wedges or rollers, the one-way clutch 1 can include a clutch retainer and a force-applying member. The clutch retainer holds the locking elements 5 constituting the locking member 4 at equal intervals in the circumferential direction. The force-applying member is disposed between the locking elements 5 and the clutch retainer, and applies force to the locking elements 5 in the direction of engagement with the inner circumferential surface 8 of the outer ring and the outer circumferential surface 17 of the inner ring.

[0117] When the locking member 4 is composed of a locking element 5 such as a claw member, the one-way clutch 1 can have an elastic member. The elastic member is disposed between the locking element 5 constituting the locking member 4 and the support surface formed by the inner circumferential surface 8 of the outer ring or the outer circumferential surface 17 of the inner ring, and presses the other end of the locking element 5 toward the gear-shaped concave and convex surface formed by the inner circumferential surface 8 of the outer ring or the outer circumferential surface 17 of the inner ring.

[0118] The locking component 4 can be composed of multiple locking elements 5 or a single locking element 5.

[0119] In this example, such as Figure 2As shown, the locking component 4 is composed of multiple locking elements 5, i.e., wedges, and the one-way clutch 1 is a wedge clutch.

[0120] The one-way clutch 1 includes a clutch retainer 23 and a force-applying member 24. The clutch retainer 23 is annular in shape and is disposed in the locking member space 18. The clutch retainer 23 retains a plurality of locking elements (wedges) 5 of the locking member 4 at equal intervals in the circumferential direction, and is capable of pivotally retaining each locking element 5. The force-applying member 24 is disposed between each locking element 5 and the clutch retainer 23, and applies force to each locking element 5 in the direction of engagement with the inner circumferential surface 8 of the outer ring and the outer circumferential surface 17 of the inner ring, i.e., in the same direction of rotation of the drive wheels when the vehicle is moving forward. Figure 2 In the diagram, the X-arrow points in the same direction as the rotation of the drive wheels when the car is moving forward, and the Y-arrow points in the same direction as the rotation of the drive wheels when the car is moving backward.

[0121] In this example, the one-way clutch 1 includes a support bearing 25 disposed between the first clutch component 2 and the second clutch component 3. The support bearing 25 is a component for coaxially arranging the first clutch component 2 and the second clutch component 3.

[0122] The support bearing 25 is positioned to radially overlap with both the outer ring portion 6 and the inner ring portion 14 of the clutch. Therefore, the coaxiality of the outer ring portion 6 and the inner ring portion 14 of the clutch can be highly ensured. Furthermore, by providing the support bearing 25, the axial dimension of the one-way clutch 1 can be suppressed from increasing.

[0123] The support bearing 25 can be disposed between the inner ring portion 14 of the clutch and the engagement sleeve portion 9, and / or between the inner ring portion 14 of the clutch and the outer ring portion 6 of the clutch. When the support bearing 25 is disposed between the inner ring portion 14 of the clutch and the outer ring portion 6 of the clutch, the support bearing 25 can be disposed on the axial inner side of the locking member 4, and / or on the axial outer side of the locking member 4.

[0124] In this example, the support bearing 25 is positioned between the inner ring portion 14 of the clutch and the fitting cylinder portion 9.

[0125] The support bearing 25 has: an outer ring 27 having an outer ring track 26 on its inner circumferential surface; an inner ring 29 having an inner ring track 28 on its outer circumferential surface; and a plurality of rolling elements 30 disposed between the outer ring track 26 and the inner ring track 28.

[0126] In this example, the outer ring 27 of the bearing and the inner ring portion 14 of the clutch are integrally formed. Therefore, the inner ring portion 14 of the clutch has an outer ring track 26 directly on its inner circumferential surface. Furthermore, the inner ring 29 of the bearing and the fitting sleeve portion 9 are integrally formed. Therefore, the fitting sleeve portion 9 has an inner ring track 28 directly on its outer circumferential surface. This suppresses the increase in the number of components in the one-way clutch 1 and achieves miniaturization of the one-way clutch 1.

[0127] However, the outer bearing ring 27 constituting the support bearing and the inner clutch ring portion 14 may also be constructed separately, with the outer bearing ring 27 being embedded and fixed relative to the inner clutch ring portion 14. Alternatively / and, the inner bearing ring 29 constituting the support bearing and the fitting sleeve portion 9 may also be constructed separately, with the inner bearing ring 29 being embedded and fixed relative to the fitting sleeve portion 9.

[0128] Multiple rolling elements 30, made of steel or ceramic, are arranged at equal intervals in the circumferential direction between the outer raceway 26 and the inner raceway 28. In this example, needle rollers are used as the rolling elements 30. This reduces the radial dimension of the support bearing 25. However, ball or tapered rollers can also be used as the rolling elements 30. The support bearing 25 may also be equipped with a retainer to hold the rolling elements 30 at equal intervals in the circumferential direction and to allow for free rolling.

[0129] In this example, the support bearing 25 is composed of a single row of radial bearings capable of supporting radial loads, but it can also be composed of multiple rows of radial bearings, or it can be composed of bearings capable of supporting both radial and axial loads.

[0130] One-way clutch 1, when the outer ring 6 of the clutch is in the same direction as the rotation of the drive wheel when the vehicle is moving forward, i.e. Figure 2 When the arrow X rotates relative to the direction of the lock, the locking element 5 of the locking component 4 moves towards the direction of the lock. Figure 2 The direction indicated by the middle arrow α swings, resulting in a locked state where the locking element 5 of the locking member 4 engages with the inner circumferential surface 8 of the outer ring of the clutch outer ring portion 6 and the outer circumferential surface 17 of the inner ring of the clutch inner ring portion 14. Thus, the locking member 4 transmits torque between the outer ring portion 6 and the inner ring portion 14 of the clutch, thereby enabling torque transmission from the first clutch member 2 to the second clutch member 3.

[0131] In contrast, the one-way clutch 1, when the inner ring portion 14 of the clutch is in the same direction as the rotation of the drive wheel when the vehicle is moving forward, i.e., Figure 2 When the arrow X rotates relative to the direction of the lock, the locking element 5 of the locking component 4 moves towards the direction of the lock. Figure 2The swing in the direction indicated by the middle arrow β results in an overrunning state where the locking element 5 of the locking component 4 is disengaged from the inner circumferential surface 8 of the outer ring portion 6 of the clutch and the outer circumferential surface 17 of the inner ring portion 14 of the clutch. Consequently, the locking component 4 does not transmit torque between the outer ring portion 6 and the inner ring portion 14 of the clutch, and therefore torque transmission from the second clutch component 3 to the first clutch component 2 is impossible. That is, the second clutch component 3 idles relative to the first clutch component 2.

[0132] Therefore, in the one-way clutch 1, the torque of the drive component 43 when the vehicle is moving forward is transmitted to the hub 68, while the torque of the hub 68 when the drive wheel is passively rotated as the vehicle moves forward is not transmitted to the drive component 43. Thus, when the drive wheel is passively rotated as the vehicle moves forward, multiple components of the drive device, including the drive component 43, can be prevented from rotating. Therefore, frictional resistance caused by rotation and churning resistance of the lubricating oil can be suppressed, thereby suppressing energy loss.

[0133] Furthermore, in the one-way clutch 1, the torque of the drive component 43 relative to the reverse movement of the vehicle is not transmitted to the hub 68, but the torque of the hub 68 is transmitted to the drive component 43 when the drive wheel is passively rotated as the vehicle reverses. However, when the vehicle is reversed, the rotation speed is slow enough and the rotation time is short enough that the frictional resistance caused by rotation and the churning resistance of the lubricating oil are hardly a problem.

[0134] The one-way clutch 1 can be used in any type of automobile, regardless of the type of power source or drive mode, as long as it has drive wheels and a drive mechanism for rotating those drive wheels. The one-way clutch 1 can be used in any type of automobile, including engine-powered vehicles, hybrid vehicles, and electric vehicles. The one-way clutch 1 can be used in front-wheel-drive vehicles, rear-wheel-drive vehicles, and four-wheel-drive vehicles.

[0135] Next, the case of applying the one-way clutch 1 to a four-wheel drive electric vehicle 31 will be explained.

[0136] Figure 3 This represents an example of a four-wheel drive electric vehicle 31. The four-wheel drive electric vehicle 31 includes two main drive wheels 32, two auxiliary drive wheels 33, a main drive unit 34 for rotating the two main drive wheels 32, an auxiliary drive unit 35 for rotating the two auxiliary drive wheels 33, and a battery 36 for supplying power to the main drive unit 34 and the auxiliary drive unit 35.

[0137] The main drive wheel 32 is composed of one of the front wheels and one of the rear wheels. The auxiliary drive wheel 33 is composed of the other of the front wheels and one of the rear wheels. In this example, the main drive wheel 32 is composed of the front wheels, and the auxiliary drive wheel 33 is composed of the rear wheels.

[0138] The main drive wheel 32 and the auxiliary drive wheel 33 are supported by hub unit bearings 37 and can rotate freely.

[0139] For example, such as Figure 4 As shown, the main drive unit 34 and the auxiliary drive unit 35 are each composed of multiple components, including a motor 38 as a power source, a countershaft 39, a differential gear 40, a drive shaft 41, and bearings for rotating these components. The main drive unit 34 and the auxiliary drive unit 35 each have a drive component 43 at their downstream end in the power transmission direction.

[0140] The hub 68 of the hub unit bearing 37, which rotatably supports the main drive wheel 32, is directly connected to the drive component 43 of the main drive unit 34.

[0141] The hub 68, which forms the hub unit bearing 37 that rotatably supports the auxiliary drive wheel 33, is connected to the drive component 43 of the auxiliary drive device 35 via a one-way clutch 1. The hub unit bearing 37 that rotatably supports the auxiliary drive wheel 33, the drive component 43 that forms the auxiliary drive device 35, and the one-way clutch 1 constitute the wheel drive unit 44.

[0142] [Explanation of the structure of the wheel drive unit]

[0143] The wheel drive unit 44 includes a one-way clutch 1, a drive component 43 that is rotated and driven by the vehicle's power source, and a hub unit bearing 37 for rotatably supporting the drive wheels. The one-way clutch 1, the drive component 43, and the hub unit bearing 37 are arranged coaxially.

[0144] <Drive Components>

[0145] The drive component 43 is connected to the first clutch component 2 constituting the one-way clutch 1. The drive component 43 has a drive-side engagement portion 45, which engages with the first engagement portion 7 provided on the first clutch component 2 constituting the one-way clutch 1 in a torque-transmitting manner.

[0146] The drive-side engagement portion 45 is an element for transmitting torque between itself and the first clutch component 2. The torque transmitted to the drive component 43 is transmitted to the first clutch component 2 through the engagement portion of the drive-side engagement portion 45 and the first engagement portion 7.

[0147] The drive-side engagement portion 45 is provided on the surface that is radially or axially opposed to the first clutch component 2.

[0148] When the drive-side engagement portion 45 is provided on a surface radially opposite to the first clutch component 2, the drive-side engagement portion 45 can be composed of a plurality of teeth that protrude radially and are arranged circumferentially. In this case, the drive-side engagement portion 45 can be composed of a spline portion composed of a plurality of spline teeth or a serrated portion composed of a plurality of serrated teeth. Alternatively, the drive-side engagement portion 45 can also be composed of an outer or inner circumferential surface having a non-circular contour shape such as a side-width shape.

[0149] When the drive-side engagement portion 45 is provided on a surface that is axially opposed to the first clutch component 2, the drive-side engagement portion 45 can be composed of a plurality of teeth that protrude axially and are arranged in the circumferential direction. In this case, the drive-side engagement portion 45 can be composed of an end face spline portion composed of a plurality of spline teeth.

[0150] In this example, the drive component 43 has a mating shaft portion 46 that is fitted outside the mating cylinder portion 9 of the first clutch component 2. The mating shaft portion 46 has a drive-side engagement portion 45 on its outer peripheral surface that is radially opposite to the first clutch component 2. Therefore, the drive-side engagement portion 45 is composed of an outer spline portion or an outer serrated portion formed on the outer peripheral surface of the mating shaft portion 46. The mating cylinder portion 9 of the first clutch component 2 is splined or serratedly engaged with the mating shaft portion 46 of the drive component 43.

[0151] The portion of the engaging shaft portion 46 on its outer peripheral surface that has the drive-side engaging portion 45 has an outer diameter variation portion 47 that increases in size towards the axially inward side. The outer diameter variation portion 47 is provided to prevent stress concentration. The outer diameter variation portion 47 is located radially inward of the conical cylinder portion 12 that constitutes the first clutch component 2.

[0152] In this example, the fitting shaft portion 46 has an axial dimension that is the same as or slightly smaller than the axial dimension from the end face of the fitting cylinder portion 9 constituting the first clutch component 2 to the axial inner side of the connecting portion 10.

[0153] In this example, the drive member 43 has a support shaft portion 48 that is coaxially arranged with the engagement shaft portion 46 and located axially outward from the engagement shaft portion 46. The support shaft portion 48 is located radially inward from the engagement shaft portion 20 that constitutes the second clutch member 3.

[0154] In this example, the support shaft portion 48 has a smaller outer diameter than the mating shaft portion 46. The drive member 43 has a stepped surface 49 that connects the outer peripheral surface of the support shaft portion 48 and the outer peripheral surface of the mating shaft portion 46. The stepped surface 49 is formed by a flat surface orthogonal to the central axis of the drive member 43 and faces axially outward.

[0155] The support shaft portion 48 has a cylindrical mating surface 50 on its outer peripheral surface. The mating surface 50 and the mating surface 21 provided on the inner peripheral surface of the second clutch component 3 are arranged opposite each other in the radial direction.

[0156] The drive component 43 has an abutment surface 51 facing outward in the axial direction. The abutment surface 51 is formed by a flat surface orthogonal to the central axis of the drive component 43. The axially inner side of the connecting portion 10 of the first clutch component 2 constituting the one-way clutch 1 abuts against the abutment surface 51 in the axial direction.

[0157] In this example, the drive component 43 is constituted by the drive shaft 41. Specifically, the drive component 43 is constituted by a constant velocity joint 42 disposed at the axial end of the drive shaft 41. Therefore, the drive component 43 has an outer ring 52 for the joint, an inner ring 53 for the joint, and a plurality of balls 54. However, the drive component 43 may also be constituted by components other than the drive shaft 41.

[0158] The outer ring 52 of the connector is configured as a cup shape with an axially inward opening, and is integral with the fitting shaft portion 46. The abutting surface 51 is formed by the radially outer portion of the axially outer side surface of the outer ring 52 of the connector.

[0159] The outer ring 52 of the connector has outer engagement grooves 55 at multiple locations in the circumferential direction on the inner circumferential surface.

[0160] The inner ring 53 of the connector is disposed inside the outer ring 52 of the connector. The inner ring 53 of the connector has inner engagement grooves 56 at multiple locations in the circumferential direction of its outer circumferential surface. The inner ring 53 of the connector is externally and fixed to the axially outer end of the intermediate shaft 57 constituting the drive shaft 41 without relative rotation.

[0161] The ball 54 is rotatably disposed between the outer engagement groove 55 and the inner engagement groove 56.

[0162] The wheel drive unit 44 includes an anti-disengagement component 58, which is used to prevent the engagement cylinder portion 9 constituting the first clutch component 2 from disengaging axially outward from the engagement shaft portion 46 constituting the drive component 43.

[0163] The anti-detachment component 58 is mounted on the drive component 43. In this example, the anti-detachment component 58 is mounted on the support shaft portion 48 that constitutes the drive component 43.

[0164] The anti-detachment component 58 can be made of a nut or a retaining ring, etc. In this example, the anti-detachment component 58 is made of a nut. Therefore, the support shaft portion 48 has an external thread (not shown) on its outer peripheral surface that is threaded to engage with the anti-detachment component 58.

[0165] The anti-detachment component 58 can directly prevent the fitting cylinder portion 9 from detaching from the fitting shaft portion 46 axially outward, or it can indirectly prevent it via other components. In this example, the anti-detachment component 58 indirectly prevents the fitting cylinder portion 9 from detaching from the fitting shaft portion 46 axially outward via other components.

[0166] In this example, the anti-detachment component 58 indirectly prevents the fitting cylinder portion 9 from axially disengaging from the fitting shaft portion 46 via the spacer 59 and the rolling bearing 60.

[0167] The spacer 59 has an annular shape. The spacer 59 has an outer diameter larger than the outer diameter of the mating shaft portion 46 and smaller than the inner diameter of the clutch inner ring portion 14. The spacer 59 is externally fitted into the axially inner end of the support shaft portion 48, and its axially inner surface abuts or nearly opposes the axially outer end face of the mating cylinder portion 9. The spacer 59 can be a single spacer 59 or multiple spacers 59.

[0168] The rolling bearing 60 is axially positioned between the anti-disengagement member 58 and the spacer 59. The rolling bearing 60 not only prevents the fitting cylinder portion 9 from disengaging axially from the fitting shaft portion 46, but also prevents the second clutch component 3 from moving axially relative to the drive component 43.

[0169] The rolling bearing 60 has an outer ring 62 with an outer ring track 61 on its inner circumferential surface, an inner ring 64 with an inner ring track 63 on its outer circumferential surface, and a plurality of rolling elements 65 disposed between the outer ring track 61 and the inner ring track 63.

[0170] The outer ring 62 of the bearing is fitted into the mating surface 21 provided on the inner circumferential surface of the second clutch component 3. The axially outer end face of the outer ring 62 abuts against the stepped surface 22 provided on the inner circumferential surface of the second clutch component 3. In addition, in this example, a retaining ring 66 is provided between the outer circumferential surface of the outer ring 62 and the inner circumferential surface of the second clutch component 3. This prevents the outer ring 62 from moving axially inward relative to the second clutch component 3.

[0171] The bearing inner ring 64 is fitted onto the mating surface 50 provided on the outer peripheral surface of the support shaft portion 48. The bearing inner ring 64 is axially held between the anti-disengagement member 58 and the spacer 59.

[0172] Multiple rolling elements 65, made of steel or ceramic, are arranged at equal intervals in the circumferential direction between the outer raceway 61 and the inner raceway 63. In this example, balls are used as rolling elements 65. However, rollers (including needle rollers) can also be used as rolling elements 65. The rolling bearing 60 may also be equipped with a retainer to hold the rolling elements 65 at equal intervals in the circumferential direction and to allow them to roll freely.

[0173] In this example, the rolling bearing 60 is composed of a deep groove ball bearing capable of supporting radial loads and axial loads in both directions. However, the rolling bearing 60 can be composed of a multi-point contact ball bearing (four-point contact ball bearing), a multi-row deep groove ball bearing, a multi-row angular contact ball bearing, a tapered rolling bearing, a multi-row tapered roller bearing, etc., regardless of whether it is a single row or multiple rows, and can support radial and axial loads.

[0174] When connecting the one-way clutch 1 and the drive component 43, firstly, the engagement sleeve portion 9 of the first clutch component 2 is splined or serratedly engaged with the engagement shaft portion 46 of the drive component 43. Next, the spacer 59, the rolling bearing 60, and the anti-disengagement component 58 are sequentially installed relative to the support shaft portion 48 of the drive component 43. Thus, the first clutch component 2 is installed on the drive component 43. Then, the second clutch component 3, the locking component 4, and the support bearing 25 are assembled relative to the first clutch component 2. Thus, the one-way clutch 1 is assembled, and the one-way clutch 1 is connected to the drive component 43.

[0175] <Hub Unit Bearing>

[0176] The hub unit bearing 37 has an outer ring 67, a hub 68, and multiple rolling elements 69a and 69b.

[0177] The outer ring 67 has multiple rows of outer ring tracks 70a and 70b on its inner circumferential surface and is fixed to the steering knuckle 71 of the suspension device.

[0178] The outer ring 67 has a hollow shape. Specifically, the outer ring 67 has a roughly cylindrical shape. The outer ring 67 is made of a hard metal such as medium carbon steel.

[0179] The outer raceways 70a and 70b each have a generatrix shape corresponding to the shape of the multiple rolling elements 69a and 69b. When the multiple rolling elements 69a and 69b are composed of balls, the outer raceways 70a and 70b each have an arc-shaped generatrix shape; when the multiple rolling elements 69a and 69b are composed of tapered rollers, the outer raceways 70a and 70b each have a straight generatrix shape inclined relative to the central axis of the outer raceway 67. In this example, the multiple rolling elements 69a and 69b are composed of balls, therefore the outer raceways 70a and 70b each have an arc-shaped generatrix shape.

[0180] In this example, the outer ring 67 has a stationary flange 72 for fixing to the steering knuckle 71. The stationary flange 72 is provided on the outer peripheral surface of the outer ring 67. The stationary flange 72 has axially extending flange-side support holes 73 at multiple locations in the circumferential direction at its radial midpoint.

[0181] The outer ring 67 is supported and fixed relative to the steering knuckle 71 by inserting the support bolt 74 through one of the flange-side support hole 73 and the steering knuckle-side support hole 75 provided in the steering knuckle 71 and threading it into the other support hole.

[0182] The hub 68 has multiple rows of inner ring tracks 76a and 76b on its outer circumference, and has a center hole 77 that extends axially through the radial center, and a hub-side engaging portion 78 that engages with the second engaging portion 16 of the second clutch component 3 to transmit torque.

[0183] The hub 68 is arranged coaxially with the outer ring 67 on the radially inner side of the outer ring 67.

[0184] The inner raceways 76a and 76b each have a generatrix shape corresponding to the shape of the multiple rolling elements 69a and 69b. When the multiple rolling elements 69a and 69b are composed of balls, the inner raceways 76a and 76b each have an arc-shaped generatrix shape; when the multiple rolling elements 69a and 69b are composed of tapered rollers, the inner raceways 76a and 76b each have a straight generatrix shape inclined relative to the central axis of the hub 68. In this example, the multiple rolling elements 69a and 69b are composed of balls, therefore the inner raceways 76a and 76b each have an arc-shaped generatrix shape.

[0185] An annular rolling element placement space 79 is formed between the outer peripheral surface of the hub 68 and the inner peripheral surface of the outer ring 67, in which rolling elements 69a and 69b are arranged.

[0186] The shaft portion 15, constituting the second clutch component 3 of the one-way clutch 1, is inserted through the center hole 77 of the hub 68. In this example, the inner circumferential surface of the hub 68 is formed by a cylindrical surface that is radially opposed to the outer circumferential surface of the shaft portion 15. However, if the second engaging portion 16 is provided on the outer circumferential surface of the shaft portion 15, the hub 68 can have a hub-side engaging portion 78 on its inner circumferential surface. In this case, the center hole 77 of the hub 68 can be formed by a spline hole or a serrated hole.

[0187] The hub-side engaging portion 78 is provided on the surface that is radially or axially opposed to the second clutch component 3.

[0188] When the hub-side engaging portion 78 is provided on a surface radially opposite to the second clutch component 3, the hub-side engaging portion 78 can be composed of multiple teeth that protrude radially and are arranged circumferentially. In this case, the hub-side engaging portion 78 can be composed of a spline portion composed of multiple spline teeth or a serrated portion composed of multiple serrated teeth. Alternatively, the hub-side engaging portion 78 can also be composed of an outer or inner circumferential surface with a non-circular profile shape, such as a cross-side width shape.

[0189] When the hub-side engaging portion 78 is provided on a surface axially opposite to the second clutch component 3, the hub-side engaging portion 78 can also be composed of multiple teeth that protrude axially and are arranged circumferentially. In this case, the hub-side engaging portion 78 can be composed of an end face spline portion composed of multiple spline teeth.

[0190] In this example, the hub-side engaging portion 78 is provided on the surface opposite to the second clutch component 3 in the axial direction, and is composed of an end face spline portion. The hub-side engaging portion 78 is provided on the axially inner end face of the hub 68, which is axially opposite to the engaging shaft portion 20 of the second clutch component 3.

[0191] In this example, the hub 68 has a rotating flange 80 that protrudes radially outward from the outer ring 67 in the portion that protrudes axially outward, and has a cylindrical pilot portion 81 at the axially outward end.

[0192] The swivel flange 80 is a component used to fix the auxiliary drive wheel 33 and the braking rotating body to the hub 68. The swivel flange 80 has multiple axially penetrating mounting holes 82 at various locations along the circumference of its radial midpoint. The mounting holes 82 are either press-fit holes or threaded holes.

[0193] The pilot section 81 is a component used to coaxially arrange the auxiliary drive wheel 33 and the braking rotating body with the wheel hub 68. The wheel constituting the auxiliary drive wheel 33 and the braking rotating body such as the brake disc are respectively externally embedded in the pilot section 81.

[0194] When each mounting hole 82 is formed by a press-in hole, a stud 83 is pressed into each mounting hole 82 from the axial inside. The wheel constituting the auxiliary drive wheel 33 and the braking rotating body such as the brake disc are connected and fixed to the rotating flange 80 by inserting the stud 83, which is pressed into the mounting hole 82, into its respective through hole, and by threading a hub nut (not shown) onto the front end of the stud 83.

[0195] When the mounting holes 82 are each made of threaded holes, the wheel constituting the auxiliary drive wheel 33 and the brake disc and other braking rotating bodies are connected and fixed to the rotating flange 80 by inserting the pilot part 81 through the center hole provided at the center of each of them, and by threading the hub bolts that have been inserted through the through holes provided at each of them into the mounting holes 82 from the outer side of the axial direction.

[0196] In this example, the mounting holes 82 are each formed by a press-in hole, and studs 83 are press-in into each mounting hole 82.

[0197] In this example, the wheel hub 68 has an inner ring 84 and a wheel rim 85.

[0198] The inner ring 84 is made of hard metals such as bearing steel and is cylindrical.

[0199] The inner ring 84 has an inner ring track 76b on the inner side of the axial middle part of multiple rows of inner ring tracks 76a and 76b on the outer circumferential surface.

[0200] The hub ring 85 has an inner ring track 76a on the outer side of the axial middle part of multiple rows of inner ring tracks 76a and 76b on the outer circumferential surface.

[0201] The hub ring 85 has a rotating flange 80 on the axially outer portion of the inner ring track 76a, which is located on the axially outer side, and has a pilot portion 81 at the axially outer end.

[0202] Furthermore, the hub ring 85 has a small-diameter shaft portion 86 on the axially inner side of the inner ring track 76a, which has an outer diameter smaller than the outer diameter of the adjacent portion on the axially outer side. The hub ring 85 has a stepped surface 87 that connects the portion of the outer circumferential surface adjacent to the axially inner side of the inner ring track 76a on the axially outer side and the outer circumferential surface of the small-diameter shaft portion 86, and faces axially inner. The hub ring 85 also has a riveting portion 88, which is bent radially outward from the axially inner end of the small-diameter shaft portion 86, pressing against the axially inner end face of the inner ring 84.

[0203] Therefore, by having the inner ring 84 externally fitted into the small diameter shaft portion 86 of the hub ring 85, the inner ring 84 is clamped from both sides axially between the stepped surface 87 and the riveting portion 88, thereby fixing the inner ring 84 and the hub ring 85 together, thus forming the hub 68 of this example.

[0204] In this example, the axial inner surface of the riveted portion 88 in the hub 68 is axially opposed to the second clutch component 3. Therefore, the axial inner surface of the riveted portion 88 has a hub-side engaging portion 78 formed by an end face spline portion. The hub-side engaging portion 78 can engage with the second engaging portion 16 provided on the second clutch component 3 in a torque-transmitting manner.

[0205] The riveting portion 88 can be omitted from the axially inner end of the small diameter shaft portion 86 of the hub 68. In this case, the hub-side engaging portion 78 can also be formed on the axially inner side of the inner ring 84, and the inner ring 84 can be clamped from both sides axially between the stepped surface 87 provided on the hub 68 and the second clutch component 3, thereby fixing the inner ring 84 and the hub ring 85 together.

[0206] The wheel hub 85 is integrally constructed from a hard metal such as medium carbon steel. However, the wheel hub 85 can also be constructed by combining a hub spindle having a rotating flange 80 and a pilot portion 81 with other inner rings having an inner ring track 76a with an axially outward outer surface on the outer circumferential surface.

[0207] Between multiple rows of outer ring tracks 70a, 70b and multiple rows of inner ring tracks 76a, 76b, multiple rolling elements 69a, 69b are arranged in each row and can roll freely. In this example, between multiple rows of outer ring tracks 70a, 70b and multiple rows of inner ring tracks 76a, 76b, multiple rolling elements 69a, 69b are arranged in each row and are evenly spaced in the circumferential direction and can roll freely while being held by retainers 89a, 89b. The hub unit bearing 37 gives the multiple rows of rolling elements 69a, 69b a back-side combination type (DB type) contact angle to improve torque rigidity.

[0208] The rolling elements 69a and 69b are made of hard metals such as bearing steel or ceramics.

[0209] The rolling elements 69a and 69b are made of balls or tapered rollers. In this example, the rolling elements 69a and 69b are made of balls.

[0210] In this example, the hub unit bearing 37 has a so-called equal-diameter PCD type structure, in which the pitch circle diameters of the axially outer rolling element 69a and the axially inner rolling element 69b are equal. However, the hub unit bearing 37 may also have different pitch circle diameters for the axially outer and axially inner rolling elements.

[0211] The hub 68 of the hub unit bearing 37 and the second clutch component 3 of the one-way clutch 1 are connected by a nut 90 threaded into an externally threaded portion 19 of the portion protruding axially outward from the center hole 77 of the hub 68 in the shaft portion 15 of the second clutch component 3, thereby enabling torque transmission. As a result, the hub 68 is clamped from both axial sides between the axially inner surface of the nut 90 and the second engagement portion 16 of the second clutch component 3. Furthermore, the second engagement portion 16 of the second clutch component 3 is axially pressed against the hub-side engagement portion 78 of the hub 68. Consequently, the axial and circumferential backlashes in the engagement portions of the second engagement portion 16, which is composed of end-face splines, and the hub-side engagement portion 78, respectively, are reduced.

[0212] With the hub 68 and the second clutch component 3 connected, the engagement shaft portion 20 constituting the second clutch component 3 is disposed inside the steering knuckle center hole 91 of the steering knuckle 71, and the clutch inner ring portion 14 constituting the second clutch component 3 and the first clutch component 2 are disposed axially inside the steering knuckle 71.

[0213] In this example, the one-way clutch 1 and the hub unit bearing 37 are lubricated by grease. Therefore, the locking component space 18 of the one-way clutch 1 and the rolling element space 79 of the hub unit bearing 37 are filled with grease (not shown).

[0214] The hub unit bearing 37 of the wheel drive unit 44 in this example does not have the sealing device that closes the axially inner opening of the rolling element mounting space 79, which is common in hub unit bearings. Therefore, the locking member mounting space 18 and the rolling element mounting space 79 are in communication with each other. In this example, the locking member mounting space 18 and the rolling element mounting space 79 are filled with the same type of grease. Furthermore, in this example, an encoder 101 for measuring the rotational speed of the auxiliary drive wheel 33 is installed in the portion of the opening located axially inner to the rolling element mounting space 79 on the outer peripheral surface of the hub 68.

[0215] The wheel drive unit 44 has a hub-side sealing device 92 that closes the opening on the axially outer side of the rolling element space 79 and a clutch-side sealing device 93 that closes the steering knuckle 71 and the first clutch component 2 in order to prevent the grease filling the locking component space 18 and the rolling element space 79 from leaking and to prevent foreign objects from entering the locking component space 18 and the rolling element space 79 from the external space.

[0216] In this example, the hub-side sealing device 92 is composed of a combined sealing ring. Specifically, it consists of a sealing ring 94 fixed to the outer ring 67 and an oil slinger 95 fixed to the hub 68. The front end of the sealing lip provided on the sealing ring 94 contacts the surface of the oil slinger 95. However, the construction of the hub-side sealing device 92 is arbitrary. For example, the hub-side sealing device 92 may also consist solely of a sealing ring fixed to the outer ring 67 and having a sealing lip that allows the front end to directly contact the surface of the hub 68.

[0217] In this example, the clutch-side sealing device 93 is composed of a combined sealing ring. Specifically, it consists of a sealing ring 96 fixed to the first clutch component 2 and an oil slinger 97 fixed to the steering knuckle 71. The front end of the sealing lip provided on the sealing ring 96 contacts the surface of the oil slinger 97. However, the construction of the clutch-side sealing device 93 is arbitrary. For example, the clutch-side sealing device 93 may also consist solely of a sealing ring fixed to the first clutch component 2 and having a sealing lip that allows its front end to directly contact the surface of the steering knuckle 71.

[0218] In this example, the sealing ring 96 constituting the clutch-side sealing device 93 is mounted on the sealing mounting portion 13 provided in the first clutch component 2. Specifically, the sealing ring 96 is embedded and fixed in the sealing mounting portion 13 provided on the inner circumferential surface of the clutch outer ring portion 6. In contrast, the oil slinger 97 constituting the clutch-side sealing device 93 is externally fixed to the steering knuckle cylinder portion 98, which extends axially inward from the opening edge of the steering knuckle center hole 91 of the steering knuckle 71.

[0219] In this example, the wheel drive unit 44 is equipped with a sealing member 99 to prevent the grease filling the locking member space 18 and the rolling element space 79 from leaking through the gap between the drive member 43 and the first clutch member 2.

[0220] In this example, the sealing member 99 is composed of an elastic ring, such as an O-ring, that is elastically held between the outer peripheral surface of the mating shaft portion 46 constituting the drive member 43 and the inner peripheral surface of the mating cylinder portion 9 constituting the first clutch member 2. However, the sealing member 99 may also be composed of a sealing ring or the like, which is fixed to one of the drive member 43 and the first clutch member 2 and elastically contacts the surface of the other of the drive member 43 and the first clutch member 2.

[0221] In this example, the wheel drive unit 44 has a cover 100 that closes the guide portion 81 of the wheel hub 68 to prevent the grease filling the locking member space 18 and the rolling element space 79 from leaking through the gap between the wheel hub 68 and the second clutch member 3 and the inside of the second clutch member 3, and to prevent foreign objects from entering the locking member space 18 and the rolling element space 79 from the outside. The cover 100 is cup-shaped and is fixedly embedded in the guide portion 81.

[0222] In this example, the space between the outer peripheral surface of the fitting cylinder portion 9 and the inner peripheral surface of the clutch inner ring portion 14, as well as the space between the inner peripheral surface of the engaging shaft portion 20 and the outer peripheral surface of the support shaft portion 48 of the drive component 43, is also filled with the same type of grease as that filled in the locking component space 18 and the rolling element space 79. Therefore, the support bearing 25 and the rolling bearing 60 are also lubricated by grease lubrication.

[0223] When the four-wheel drive electric vehicle 31 is traveling on rough roads, the main drive unit 34 and the auxiliary drive unit 35 are operated separately. In this case, the drive component 43 in the auxiliary drive unit 35, which is located on the downstream side in the power transmission direction, is rotated and driven in the same direction as the rotation of the auxiliary drive wheel 33 when the electric vehicle 31 is traveling forward.

[0224] Therefore, the first clutch component 2, which is connected to the drive component 43 to transmit torque, rotates in the same direction as the drive component 43. In this case, the outer ring portion 6 of the clutch is in the same direction as the inner ring portion 14 of the clutch, which is the same direction as the rotation of the auxiliary drive wheel 33 when the vehicle is moving forward. Figure 2 The relative rotation is in the direction of arrow X in the diagram. Therefore, the locking element 5 of the locking component 4 rotates towards... Figure 2The one-way clutch oscillates in the direction indicated by the arrow α. As a result, the locking element 5 of the locking component 4 is engaged with the inner circumferential surface 8 of the outer ring of the outer ring portion 6 and the outer circumferential surface 17 of the inner ring of the inner ring portion 14, forming a locked state.

[0225] Therefore, the locking member 4 transmits torque between the outer ring portion 6 and the inner ring portion 14 of the clutch, thus enabling torque transmission from the first clutch member 2 to the second clutch member 3. As a result, the hub 68, which is connected to the second clutch member 3 to transmit torque, is driven to rotate in the same direction as the second clutch member 3, thereby driving the auxiliary drive wheel 33.

[0226] In contrast, when the four-wheel drive electric vehicle 31 is driving under low load, only the main drive unit 34 is operated, and the auxiliary drive unit 35 is not operated. In this case, the drive component 43 in the auxiliary drive unit 35, which is located on the downstream side in the direction of power transmission, does not rotate and remains stationary. As a result, the auxiliary drive wheel 33 passively rotates as the electric vehicle 31 moves forward.

[0227] Therefore, the first clutch component 2, which is connected to the drive component 43 to transmit torque, does not rotate, while the second clutch component 3, which is connected to the hub 68 to transmit torque, rotates in the same direction as the auxiliary drive wheel 33. In this case, the inner ring portion 14 of the clutch is in the same direction as the outer ring portion 6 of the clutch, i.e., the direction of rotation of the drive wheel when the vehicle is moving forward. Figure 2 The relative rotation is in the X direction of the arrow. Therefore, the locking element 5 of the locking component 4 rotates towards... Figure 2 The one-way clutch 1 swings in the direction indicated by the arrow β. As a result, the locking element 5 of the locking component 4 is in an over-engaged state relative to the inner circumferential surface 8 of the outer ring of the clutch outer ring portion 6 and the outer circumferential surface 17 of the inner ring of the clutch inner ring portion 14.

[0228] Therefore, the locking member 4 does not transmit torque between the outer ring portion 6 and the inner ring portion 14 of the clutch, and thus torque transmission from the second clutch member 3 to the first clutch member 2 is impossible. That is, the second clutch member 3 idles relative to the first clutch member 2. Therefore, the drive member 43 connected to the second clutch member 3 and the upstream component of the auxiliary drive device 35 in the power transmission direction relative to the drive member 43 can be prevented from rotating. Therefore, the frictional resistance caused by rotation and the churning resistance of the lubricating oil in the auxiliary drive device 35 can be suppressed, and thus energy loss can be suppressed.

[0229] The one-way clutch 1 is disposed between the drive component 43 constituting the auxiliary drive device 35 and the hub unit bearing 37. Therefore, when the auxiliary drive wheel 33 passively rotates as the electric vehicle 31 moves forward, all components constituting the auxiliary drive device 35 can be prevented from rotating. Thus, for example, compared to the case where the one-way clutch 1 is disposed between two components of the auxiliary drive device 35 located upstream of the drive component 43 in the power transmission direction, the number of components that do not transmit rotation of the auxiliary drive wheel 33 can be increased. Therefore, frictional resistance caused by rotation and churning resistance of the lubricating oil can be suppressed, and energy loss can be effectively suppressed.

[0230] In this example, by using the same type of grease as that used to lubricate the hub unit bearing 37 to lubricate the one-way clutch 1, the sealing device that closes the axial inner opening of the rolling element space 79, typical of hub unit bearings, is omitted, allowing the locking member space 18 and the rolling element space 79 to communicate with each other. Furthermore, the hub-side sealing device 92 and the clutch-side sealing device 93 prevent leakage of the grease filling the locking member space 18 and the rolling element space 79, and prevent foreign matter from entering the locking member space 18 and the rolling element space 79 from the outside. Therefore, compared to a typical hub unit bearing, the locking member space 18 and the rolling element space 79 are sealed without increasing the number of sealing devices. Thus, it is possible to prevent an increase in sliding resistance generated by the sealing devices.

[0231] Furthermore, the clutch-side sealing device 93 seals the space between the steering knuckle 71 and the first clutch component 2. When the auxiliary drive wheel 33 passively rotates as the electric vehicle 31 moves forward, the first clutch component 2 does not rotate. Therefore, when the auxiliary drive wheel 33 passively rotates as the electric vehicle 31 moves forward, no sliding resistance is generated in the clutch-side sealing device 93. Thus, energy loss can be effectively suppressed.

Claims

1. A one-way clutch, characterized in that, have: The first clutch component is connected to a drive component that is rotated by the power source of the automobile. A second clutch component, coaxially arranged with the first clutch component and connected to a hub constituting a hub unit bearing for rotatably supporting the drive wheel; and A locking component that transmits torque between the first clutch component and the second clutch component. The first clutch component includes: a clutch outer ring portion; and a first engagement portion capable of transmitting torque relative to the drive component. The second clutch component includes: an inner clutch ring portion disposed radially inside the outer clutch ring portion; a shaft portion inserted into a central hole of the hub; and a second engaging portion engaged relative to the hub to transmit torque. The locking component is disposed between the outer ring of the clutch and the inner ring of the clutch, and transmits torque between the outer ring of the clutch and the inner ring of the clutch only when the outer ring of the clutch wants to rotate relative to the inner ring of the clutch in the same direction as the rotation of the drive wheel when the vehicle is moving forward, and the relative rotation speed is within the rated speed range.

2. The one-way clutch according to claim 1, characterized in that, It includes a support bearing disposed between the first clutch component and the second clutch component.

3. The one-way clutch according to claim 2, characterized in that, The support bearing is positioned to overlap radially with both the outer ring of the clutch and the inner ring of the clutch.

4. The one-way clutch according to claim 3, characterized in that, The first clutch component has a fitting sleeve portion disposed radially inside the inner ring portion of the clutch and externally fitted into the drive component. The support bearing is disposed between the inner ring of the clutch and the fitting cylinder, and is axially positioned and locked by a nut at the end of the drive component.

5. The one-way clutch according to claim 4, characterized in that, The first engaging portion is composed of an inner spline portion or an inner serrated portion formed on the inner circumferential surface of the fitting cylinder portion.

6. The one-way clutch according to claim 1, characterized in that, The first clutch component has a sealing mounting portion for mounting a sealing device that seals the first clutch component with the steering knuckle constituting the suspension device.

7. The one-way clutch according to claim 6, characterized in that, The sealing mounting portion is provided on the outer ring portion of the clutch.

8. The one-way clutch according to claim 1, characterized in that, The second engaging portion is formed by an end face spline portion of the surface of the second clutch component that is axially opposite to the hub. The second clutch component has a threaded portion at the end opposite to the second engaging portion, and is locked to the hub in the axial direction by a nut.

9. A wheel drive unit, characterized in that, It comprises: a one-way clutch as described in any one of claims 1 to 8; a drive component that is rotary driven by the power source of the automobile; and a hub unit bearing for rotatably supporting the drive wheel. The drive component has a drive-side engagement portion that engages with the first engagement portion to transmit torque. The hub unit bearing has: The outer ring has multiple rows of outer ring tracks on its inner circumference and is fixed to the steering knuckle of the suspension device; A hub, having multiple rows of inner ring tracks on its outer circumference, a central hole extending axially through the radial center, and a hub-side engaging portion capable of transmitting torque with the second engaging portion; and Multiple rolling elements are freely arranged between the multiple outer ring tracks and the multiple inner ring tracks.

10. The wheel drive unit according to claim 9, characterized in that, The one-way clutch and the hub unit bearing are lubricated by grease.

11. The wheel drive unit according to claim 10, characterized in that, The locking component space and the rolling element space are interconnected. The locking component is positioned between the inner circumferential surface of the outer ring of the clutch and the outer circumferential surface of the inner ring of the clutch. The space for the rolling element exists between the inner circumferential surface of the outer ring and the outer circumferential surface of the hub.

12. The wheel drive unit according to claim 11, characterized in that, It includes: a hub-side sealing device that closes the opening on the axially outer side of the rolling element placement space; and a clutch-side sealing device that closes the space between the steering knuckle and the aforementioned first clutch component.

13. The wheel drive unit according to claim 9, characterized in that, It has a wheel speed signal measuring component, which is mounted on the wheel hub.

14. The wheel drive unit according to claim 9, characterized in that, The hub has a cylindrical pilot section at its axially outer end, which is covered.

15. The wheel drive unit according to claim 9, characterized in that, It has a rolling bearing disposed between the drive component and the second clutch component.

16. The wheel drive unit according to claim 9, characterized in that, The second engaging portion is formed by an end face spline portion provided on the surface of the second clutch component that is axially opposite to the hub, and the hub-side engaging portion is formed by an end face spline portion provided on the surface of the hub that is axially opposite to the second clutch component.

17. The wheel drive unit according to claim 16, characterized in that, A nut having a portion threadedly engaged with the portion of the shaft that protrudes axially outward from the central hole, wherein the second engaging portion is axially pressed against the hub-side engaging portion.

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