Differential limiting device

Abstract

[Problem] The purpose of the present invention is to provide a differential restriction device capable of suppressing relative rotation of a pair of output rotation members of a differential device and suppressing an increase in the length of a rod portion of a coupling member connected to one of the output rotation members. [Solution] A differential device (11) has a differential case (112) and a pair of side gears (115, 116), and a differential restriction device (10) suppresses relative rotation of the pair of side gears (115, 116). A differential restriction device (10) is provided with: a joint member (910) of a constant velocity universal joint (91) connected to one side gear (116) so as not to rotate relative thereto; a clutch mechanism (2) having a clutch (20) that suppresses relative rotation between the joint member (910) and the differential case (112); and an operation mechanism (3) for operating the clutch mechanism (2). The coupling member (910) has a cup part (911) formed in a bottomed cylindrical shape and a shaft-shaped rod part (912) connected to the half axle gear (116), and a clutch (20) is disposed on the outer periphery of the cup part (912).

Description

Technical Field

[0001] This invention relates to a differential limiting device mounted on a vehicle. Background Technology

[0002] Conventionally, vehicles are equipped with differential devices positioned between the left and right wheels, allowing the driving force of a drive source to be distributed differentially to the left and right wheels. Among such differential devices, there are, for example, differential devices with a differential limiting function that improves driving stability by suppressing differential rotation of the left and right wheels during low-μ road conditions.

[0003] The differential device described in Patent Documents 1 and 2 includes: a differential housing that transmits the driving force of a drive source such as an engine; a pinion shaft that is held in the differential housing; a plurality of pinions that are supported by the pinion shaft; a pair of left and right half-shaft gears that mesh with the plurality of pinions; and a differential limiting mechanism that suppresses the relative rotation between the half-shaft gear of one of the left and right half-shaft gears and the differential housing.

[0004] In the differential device described in Patent Document 1, the differential limiting mechanism is configured to have a multi-plate clutch and a hydraulic actuator. In the differential device described in Patent Document 2, the differential limiting mechanism is configured to have an engaging clutch and an electromagnetic actuator. In the differential devices described in Patent Documents 1 and 2, the differential limiting mechanism is disposed on the outer periphery of a shaft-shaped rod portion in a constant velocity universal joint that is connected to one half-shaft gear in a manner that prevents relative rotation.

[0005] Furthermore, the differential assembly is typically connected to the wheels via a drive shaft, for example, the structure described in Patent Document 3. The drive shaft described in Patent Document 3 has a constant velocity universal joint on the differential side, which is driven to connect with the differential assembly; a constant velocity universal joint on the wheel side, which is driven to connect with the wheels; and an intermediate shaft that connects these constant velocity universal joints in a swivel manner. The constant velocity universal joint on the differential side is a three-ball-pin type, having a coupling member and a three-ball-pin member. The coupling member integrally has a bottomed cylindrical cup portion and a shaft-shaped rod portion. The three-ball-pin member is disposed inside the cup portion, and the rod portion is connected to one half-shaft gear of the differential assembly in a non-rotatable manner. The constant velocity universal joint on the wheel side is a ball-cage type constant velocity universal joint that uses multiple balls held in a cage to connect the outer and inner rings in a manner capable of transmitting driving force. The constant velocity universal joints on the differential side and the constant velocity universal joints on the wheel side are positioned differently relative to the road surface in terms of height, and the intermediate shaft is axially inclined relative to the constant velocity universal joints on the differential side and the wheel side respectively.

[0006] Existing technical documents

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 11-201261

[0009] Patent Document 2: Japanese Patent Application Publication No. 2020-46065

[0010] Patent Document 3: Japanese Patent Application Publication No. 2019-11786 Summary of the Invention

[0011] In the differential gear device described in Patent Documents 1 and 2, a differential limiting mechanism is arranged on the outer periphery of the shaft-shaped rod in the coupling component, thus increasing the axial length of the rod. When the rod length increases, the distance in the vehicle width direction between the two constant velocity universal couplings at both ends of the drive shaft decreases, and the tilt angle of the intermediate shaft relative to the axial direction of the two constant velocity universal couplings increases. If the tilt angle of the intermediate shaft increases, wear is more likely to occur at the sliding parts of the two constant velocity universal couplings, easily reducing durability.

[0012] Therefore, the object of the present invention is to provide a differential limiting device, which is combined with a differential device that distributes and outputs the driving force of a vehicle input to an input rotating member to a pair of output rotating members, suppressing the relative rotation of the pair of output rotating members, wherein the increase in the length of the rod portion of the coupling member connected to one of the output rotating members is suppressed.

[0013] Methods for solving problems

[0014] To achieve the above-mentioned objective, the present invention provides a differential limiting device, combined with a differential device, to suppress the relative rotation of a pair of output rotating members. The differential device distributes and outputs the driving force of a vehicle input to an input rotating member to the pair of output rotating members. The differential limiting device comprises: a coupling member of a constant velocity universal joint, connected to one of the output rotating members of the pair in a manner that prevents relative rotation; a clutch mechanism having a clutch that suppresses relative rotation between the input rotating member and the coupling member, or relative rotation between the other output rotating member of the pair of output rotating members and the coupling member; and a working mechanism for operating the clutch mechanism. The coupling member has a cup portion formed as a bottomed cylindrical shape and a shaft-shaped rod portion extending axially from the cup portion, the rod portion being connected to one of the output rotating members, and the clutch being disposed on the outer periphery of the cup portion.

[0015] Invention Effects

[0016] According to the differential limiting device of the present invention, it is possible to suppress the increase in the length of the rod portion of the coupling member connected to one of the output rotating members. Attached Figure Description

[0017] Figure 1 This is a schematic structural diagram illustrating a general structural example of a vehicle equipped with a differential limiting device according to the first embodiment of the present invention.

[0018] Figure 2 This is a cross-sectional view showing a structural example of a differential limiting device and a differential device.

[0019] Figure 3 It is an enlarged representation Figure 2 A magnified view of a portion of it.

[0020] Figure 4 It is a sectional view of a constant velocity universal coupling and its connecting components.

[0021] Figure 5 This is a schematic structural diagram illustrating a general structural example of a vehicle equipped with a differential limiting device according to the second embodiment of the present invention. Detailed Implementation

[0022] [First Implementation Method]

[0023] Reference Figures 1 to 4 The first embodiment of the present invention will be described. It should be noted that the embodiments described below are specific examples of preferred embodiments for carrying out the present invention, and there are also parts that specifically illustrate various technically preferred aspects, but the technical scope of the present invention is not limited to this specific approach.

[0024] Figure 1 This is a schematic structural diagram illustrating a general structural example of a vehicle 1 equipped with the differential limiting device 10 of the first embodiment of the present invention. Figure 2 This is a cross-sectional view showing a structural example of the differential limiting device 10 and the differential device 11 adjacent to the differential limiting device 10. Figure 3 It is an enlarged representation Figure 2 A magnified view of a portion of it.

[0025] Vehicle 1 includes: a differential limiting device 10; a differential device 11, which incorporates the differential limiting device 10; a drive source 12 that generates driving force; a drive shaft 13, a cross coupling 14, and a pinion shaft 15 that transmit the driving force of the drive source 12 to the differential device 11; left and right wheels 16 and 17; and left and right wheel hub units 161 and 171, respectively, which are provided corresponding to the left and right wheels 16 and 17. Additionally, vehicle 1 has a left drive shaft 8 connected to the left wheel hub unit 161 and a right drive shaft 9 connected to the right wheel hub unit 171. The differential limiting device 10 and the differential device 11 are arranged between the left and right wheels 16 and 17 in the width direction of vehicle 1.

[0026] The drive source 12 is, for example, an engine or an electric motor, which generates driving force for the movement of the vehicle 1. The driving force of the drive source 12 is transmitted from the drive shaft 13 to the differential device 11 via the cross coupling 14 and the pinion shaft 15, and distributed to the left and right wheels 16 and 17 via the left and right drive shafts 8 and 9 and the wheel hub units 161 and 171.

[0027] The left drive shaft 8 has an intermediate shaft 80 and constant velocity universal joints 81 and 82 disposed at both ends of the intermediate shaft 80. The constant velocity universal joint 81 on the differential device 11 side is a sliding constant velocity universal joint capable of absorbing changes in the distance between the constant velocity universal joints 81 and 82 associated with the vertical movement of the vehicle 1 during travel. The constant velocity universal joint 82 on the left wheel 16 side is a fixed constant velocity universal joint where the position of the end of the intermediate shaft 80 relative to the constant velocity universal joint 82 in the direction of rotation of the left wheel 16 remains unchanged even if the operating angle changes.

[0028] Similarly, the right-side drive shaft 9 has an intermediate shaft 90 and constant velocity universal couplings 91 and 92 disposed at both ends of the intermediate shaft 90. The constant velocity universal coupling 91 on the differential device 11 side is a sliding constant velocity universal coupling, while the constant velocity universal coupling 92 on the right wheel 17 side is a fixed constant velocity universal coupling. In this embodiment, the constant velocity universal couplings 81 and 91 on the differential device 11 side are three-ball-pin type constant velocity universal couplings, while the constant velocity universal couplings 82 and 92 on the left wheel 16 and right wheel 17 sides are ball-cage type constant velocity universal couplings. The intermediate shafts 80 and 90 are normally inclined relative to the horizontal direction such that the end on the differential device 11 side is vertically higher than the ends on the left and right wheel 16 and 17 sides.

[0029] The differential device 11 includes: a gear ring 111 that meshes with a pinion shaft 15; a differential housing 112 that rotates integrally with the gear ring 111; a pinion shaft 113 that is fixed to the differential housing 112; a pair of pinions 114 that are supported on the pinion shaft 113; a pair of left and right half-shaft gears 115 and 116 that mesh with the pair of pinions 114; and a housing 117 that houses the gear ring 111, the differential housing 112, and a portion of the pinion shaft 15 together.

[0030] like Figure 2As shown, the pinion shaft 15 is supported on the housing 117 by a bearing 151 held in the housing 117. The left and right ends of the differential housing 112 are supported by bearings 118, allowing them to rotate relative to the housing 117. Differential oil is sealed inside the housing 117, lubricating the meshing of the pinion shaft 15 with the ring gear 111 and the meshing of the pinion 114 with the half-shaft gear 115. Oil seals 119 are respectively provided between the left and right ends of the differential housing 112 and the housing 117 to prevent differential oil leakage. Additionally, an O-ring 110 is provided between the right end of the differential housing 112 and the clutch mechanism 2 (described later) to prevent differential oil leakage.

[0031] The driving force is input to the differential housing 112 via the pinion shaft 15 and the ring gear 111. The differential device 11 distributes the driving force input to the differential housing 112 and outputs it to a pair of half-shaft gears 115 and 116. The coupling member 810 of the constant velocity universal coupling 81 of one of the left drive shafts 8 is connected to the left half-shaft gear 115 in a non-rotatable manner. The coupling member 910 of the constant velocity universal coupling 91 of one of the right drive shafts 9 is connected to the right half-shaft gear 116 in a non-rotatable manner. In this embodiment, the differential housing 112 corresponds to the input rotating member of the present invention, and the half-shaft gears 115 and 116 correspond to the output rotating member of the present invention.

[0032] The differential limiting device 10 suppresses the relative rotation of the left and right half-shaft gears 115 and 116 by suppressing the relative rotation of the differential housing 112 with the right half-shaft gear 116 and the coupling component 910. By suppressing the relative rotation of the differential housing 112 with the right half-shaft gear 116, the rotation of a pair of pinions 114 around the pinion shaft 113 is suppressed, thus suppressing the relative rotation of the left and right half-shaft gears 115 and 116, thereby suppressing the differential rotation of the left wheel 16 and the right wheel 17 and improving the straight-line stability of the vehicle 1.

[0033] Next, the structure of the differential limiting device 10 will be described in detail. The differential limiting device 10 is configured as a coupling member 910 including the constant velocity universal joint 91 in the drive shaft 9 on the right side. Furthermore, in this embodiment, the case where the differential limiting device 10 is arranged on the right side of the differential device 11 in the vehicle width direction will be described, but the differential limiting device 10 may also be arranged on the left side of the differential device 11.

[0034] The differential limiting device 10 includes: a coupling member 910 of a constant velocity universal coupling 91; a clutch mechanism 2 having a clutch 20 that inhibits relative rotation between the differential housing 112 and the coupling member 910; a working mechanism 3 for operating the clutch mechanism 2; an electric motor 30 as a power source for the working mechanism 3; a reduction mechanism 4 for reducing the output rotation of the electric motor 30 and transmitting it to the working mechanism 3; a housing 5 for housing at least a portion of the clutch mechanism 2; first to fourth bearings 61 to 64; and first to seventh sealing members 71 to 77.

[0035] The coupling component 910 of the constant velocity universal coupling 91 integrally has a cup portion 911 formed as a bottomed cylindrical shape and a shaft-shaped rod portion 912. The cup portion 911 opens horizontally toward the right wheel 17. The rod portion 912 is located closer to the differential device 11 than the cup portion 911, and a portion of it protrudes into the housing 117 of the differential device 11. At least a portion of the cup portion 911 is received within the housing 5.

[0036] A splined engagement portion 912a is provided at the front end of the rod portion 912, which spline-engages with the engagement hole 116a formed in the center of the half-shaft gear 116 of the differential device 11. The coupling member 910 is connected to the half-shaft gear 116 in a non-rotatable manner by spline engagement of the splined engagement portion 912a of the rod portion 912 with the engagement hole 116a of the half-shaft gear 116.

[0037] Furthermore, the coupling component 810 of the constant velocity universal coupling 81 of one of the drive shafts 8 on the left side also integrally has a cup portion 811 and a rod portion 812 in the same manner as described above. The spline fitting portion 812a provided at the front end of the rod portion 812 splines into the fitting hole 115a of the half shaft gear 115 on the left side, thereby connecting with the half shaft gear 115 in a manner that prevents relative rotation.

[0038] The coupling member 810 of the constant velocity universal coupling 81 in the drive shaft 8 on the left and the coupling member 910 of the constant velocity universal coupling 91 in the drive shaft 9 on the right can rotate relative to each other about a common axis of rotation O. Hereinafter, the direction parallel to the axis of rotation O will be referred to as the axial direction. The rod portion 812 of the coupling member 810 extends axially from the bottom of the cup portion 811 toward the half-shaft gear 115. The rod portion 912 of the coupling member 910 extends axially from the bottom of the cup portion 911 toward the half-shaft gear 116.

[0039] The clutch mechanism 2 includes: a clutch 20; a connecting rotating member 21 connected to the differential housing 112 in a manner that prevents relative rotation; a coupling connecting member 22 disposed on the outer periphery of the coupling member 910, which restricts relative rotation with respect to the coupling member 910 and axial movement relative to the coupling member 910; and a pressing plate 23 and a support plate 24 that clamp the clutch 20 axially.

[0040] Clutch 20 is disposed on the outer periphery of the cup portion 911 of coupling member 910. In this embodiment, clutch 20 is a multi-plate clutch having a plurality of outer clutch plates 201 and a plurality of inner clutch plates 202 arranged axially. The frictional sliding between the plurality of outer clutch plates 201 and the plurality of inner clutch plates 202 is lubricated by clutch oil. Clutch oil and differential oil have different characteristics. Clutch oil is a low-viscosity lubricating oil with lower viscosity than differential oil, and additives suitable for their respective uses are added to both clutch oil and differential oil.

[0041] The working mechanism 3 presses the clutch 20 axially, causing friction between the multiple outer clutch plates 201 and the multiple inner clutch plates 202. This friction becomes a differential limiting force that inhibits the relative rotation of the left and right half-shaft gears 115 and 116.

[0042] The rotating connecting member 21 integrally comprises: a connecting portion 211, which is connected to the differential housing 112 in a manner that prevents relative rotation; a small-diameter cylindrical portion 212 disposed on the outer periphery of the rod portion 912 of the coupling member 910; a large-diameter cylindrical portion 213 disposed on the outer periphery of the cup portion 911 of the coupling member 910; and a disc portion 214 between the small-diameter cylindrical portion 212 and the large-diameter cylindrical portion 213. The clutch 20 is arranged side by side with the large-diameter cylindrical portion 213 in a radial direction perpendicular to the axial direction.

[0043] The connecting portion 211 of the connecting rotating member 21 engages with the end spline of the differential limiting device 10 in the differential housing 112. The inner diameter of the small-diameter cylindrical portion 212 is larger than the outer diameter of the rod portion 912, forming an annular space between the small-diameter cylindrical portion 212 and the rod portion 912. A first bearing 61 and first and second sealing members 71 and 72 are disposed between the inner circumferential surface 212a of the small-diameter cylindrical portion 212 and the outer circumferential surface 912b of the rod portion 912. The first bearing 61 is a radial roller bearing and is positioned closer to the differential device 11 than the first sealing member 71.

[0044] A through hole 212c is formed in the small-diameter cylindrical portion 212, opening between the first sealing member 71 and the second sealing member 72, passing through the inner circumferential surface 212a and the outer circumferential surface 212b. The first sealing member 71 suppresses leakage of differential oil from the differential device 11. The second sealing member 72 keeps the space between the large-diameter cylindrical portion 213 and the disc portion 214 connecting the rotating member 21 and the cup portion 911 of the coupling member 910 fluidly sealed, suppressing leakage of clutch oil.

[0045] The large-diameter cylindrical portion 213 is formed such that its inner diameter is larger than the outer diameter of the small-diameter cylindrical portion 212 and the outer diameter of the cup portion 911. A second bearing 62 is disposed between the large-diameter cylindrical portion 213 and the cup portion 911. A spline engagement portion 213a is formed in the large-diameter cylindrical portion 213 for engaging multiple internal clutch plates 202 in a manner that allows axial movement but prevents relative rotation.

[0046] The coupling connecting member 22 includes: a connecting portion 221 that is connected to the cup portion 911 of the coupling member 910 in a manner that prevents relative rotation; an engaging portion 222 for engaging a plurality of external clutch plates 201 in a manner that prevents relative rotation; a side wall portion 223 between the connecting portion 221 and the engaging portion 222; a disc portion 224 that extends radially inward from the end of the engaging portion 222 on the differential device 11 side; and a cylindrical portion 225 that extends axially from the end of the disc portion 224 on the inner diameter side toward the differential device 11 side.

[0047] Both the connecting portion 221 and the engaging portion 222 are cylindrical and arranged axially around the outer periphery of the cup portion 911 of the coupling member 910. The diameter of the engaging portion 222 is larger than that of the connecting portion 221, and it is located on the differential device 11 side closer to the connecting portion 221. The pressing plate 23 and the supporting plate 24 are connected to the engaging portion 222 in a manner that allows axial movement but prevents relative rotation. The pressing plate 23 is disposed between the side wall portion 223 and the clutch 20, and the supporting plate 24 is disposed between the disc portion 224 and the clutch 20.

[0048] To facilitate the assembly of the clutch 20, the pressure plate 23, and the support plate 24, the coupling connecting component 22 is composed of two parts, a side wall portion 223 and an engaging portion 222, which are welded together. Furthermore, the welding location is not limited to between the side wall portion 223 and the engaging portion 222; for example, it could be between the engaging portion 222 and the disc portion 224. Additionally, it is not limited to welding; for example, the two components can be joined by bolts.

[0049] Figure 4 This is a cross-sectional view of the constant velocity universal joint 91 and the coupling connecting member 22 in a section perpendicular to the axis of rotation O. The constant velocity universal joint 91 has a three-ball pin member 913 as an inner member disposed inside the coupling member 910, and three roller units 914 mounted on the three-ball pin member 913. The three-ball pin member 913 and the three roller units 914, together with a part of the intermediate shaft 90, are received in a receiving hole 911a formed in the cup portion 911 of the coupling member 910. Figure 2 As shown, a protective cover 900 made of resin with a corrugated structure is mounted between the front end of the cup portion 911 and the intermediate shaft 90.

[0050] The three-ball pin component 913 integrally has a boss portion 913a for engaging with the intermediate shaft 90 in a non-rotatable manner and three foot shafts 913b extending radially from the boss portion 913a. Each roller unit 914 has: a cylindrical inner roller 914a, which is externally fitted into the foot shaft 913b in a swingable manner; an outer roller 914b, which is capable of rotating relative to the inner roller 914a on the same axis; and a plurality of rolling elements 914c disposed between the inner roller 914a and the outer roller 914b.

[0051] On the inner surface of the receiving hole 911a, a raceway surface 911b is formed extending axially for the outer roller 914b to roll. When the three-ball pin member 913 is displaced axially relative to the coupling member 910, the outer roller 914b rolls on the raceway surface 911b. The length of the raceway surface 911b is formed such that even if the right wheel 17 moves up and down relative to the vehicle body 1, it will not impede the axial movement of the three-ball pin member 913 relative to the coupling member 910.

[0052] If the coupling member 910 and the intermediate shaft 90 rotate while the intermediate shaft 90 is tilted relative to the rotation axis O, the three-ball pin member 913 oscillates relative to the roller unit 914. During this oscillation, the foot axle 913b slides on the inner surface of the inner roller 914a. The tilt angle of the intermediate shaft 90 relative to the rotation axis O, i.e., the working angle, is, for example, 10° to 15° when mounted on the vehicle 1. Furthermore, in Figures 2 to 4 The diagram shows the state where the working angle is 0°.

[0053] The connecting portion 221 of the coupling member 22 has a concave-convex shape on its inner circumferential surface that engages with a concave-convex shape on the outer circumferential surface of the cup portion 911, thereby restricting relative rotation with the coupling member 910. The outer circumferential surface of the cup portion 911 in a section perpendicular to the axis of rotation O is approximately hexagonal, forming six concave portions 911c and convex portions 911d. Similarly, the inner circumferential surface of the connecting portion 221 of the coupling member 22 in this section is also approximately hexagonal, forming six concave portions 221a and convex portions 221b. The connecting portion 221 engages with the six concave portions 911c of the cup portion 911 via the six convex portions 221b, and the six concave portions 221a engage with the six convex portions 911d of the cup portion 911, thereby restricting relative rotation with the coupling member 910.

[0054] Alternatively, the connecting portion 221 of the coupling connecting member 22 and the cup portion 911 corresponding to the inner side of the connecting portion 221 can be formed into a cylindrical shape, and a plurality of spline protrusions extending axially can be formed on the inner surface of the connecting portion 221 and the outer surface of the cup portion 911. The relative rotation between the coupling connecting member 22 and the coupling member 910 can be restricted by spline engagement between the cup portion 911 and the connecting portion 221.

[0055] The axial movement of the coupling connecting member 22 relative to the coupling member 910 is restricted. As a structure to restrict the axial movement of the coupling connecting member 22 relative to the coupling member 910, a portion of the connecting part 221 can be riveted to the cup part 911, or the connecting part 221 can be welded to the cup part 911. Alternatively, the axial movement of the coupling connecting member 22 relative to the coupling member 910 can be restricted by pressing the cup part 911 into the connecting part 221.

[0056] A third sealing member 73 is disposed between the connecting rotating member 21 and the coupling connecting member 22 to provide a fluid-tight seal for the clutch 20. The third sealing member 73 is installed inside the cylindrical portion 225 of the coupling connecting member 22 and is in elastic contact with the outer peripheral surface 212b of the small-diameter cylindrical portion 212. In addition, a fourth sealing member 74 is disposed between the connecting portion 221 of the coupling connecting member 22 and the cup portion 911 of the coupling member 910 to provide a fluid-tight seal for the clutch 20.

[0057] The clutch 20 is disposed between the engagement portion 222 of the coupling connecting member 22 and the large-diameter cylindrical portion 213 of the connecting rotating member 21. The engagement portion 222 has a spline engagement portion 222a for engaging multiple external clutch plates 201, pressing plates 23 and support plates 24 in a manner that allows axial movement but prevents relative rotation.

[0058] The housing 5 has a housing body 51 that opens towards the differential 11 and a housing cover 52 that is provided to block the opening of the housing body 51. The housing body 51 and the housing cover 52 are mounted to the housing 117 of the differential 11 by a plurality of bolts 53. By loosening the plurality of bolts 53, the differential limiting device 10 can be removed from the differential 11 together with the drive shaft 9. That is, the differential limiting device 10 can be attached to and detached relative to the differential 11.

[0059] The housing 5 houses the electric motor 30. Figure 1 As shown, the motor 30 has a motor body 301 fixed to the housing body 51, an output shaft 302 rotatable relative to the motor body 301, and an output gear 303 disposed at the front end of the output shaft 302. Current is supplied to the motor body 301 from the control device 100.

[0060] The reduction mechanism 4 consists of a reduction gear 40 supported on the housing 5. The reduction gear 40 has a large-diameter gear portion 41 and a small-diameter gear portion 42, and a connecting shaft 43 that connects the large-diameter gear portion 41 and the small-diameter gear portion 42 in a manner that allows them to rotate integrally. The large-diameter gear portion 41 meshes with the output gear 303 of the motor 30. One axial end of the connecting shaft 43 is supported on the housing body 51, and the other axial end is supported on the housing cover 52. The large-diameter gear portion 41 and the small-diameter gear portion 42 are disposed between the two ends of the connecting shaft 43. The rotation of the connecting shaft 43 and the meshing of the large-diameter gear portion 41 and the small-diameter gear portion 42 are lubricated by grease sealed within the housing 5.

[0061] The working mechanism 3 includes: a fixed cam member 31 that is anti-rotating relative to the housing 5; a rotating cam member 32 that rotates relative to the fixed cam member 31 by means of the torque of the motor 30 transmitted by the reduction mechanism 4; a plurality of cam balls 33 disposed between the fixed cam member 31 and the rotating cam member 32; a piston 34 that pushes the clutch 20; a bearing 35 disposed between the rotating cam member 32 and the piston 34; a return spring 36 that applies force to the piston 34 in the direction of disengagement from the clutch 20; and an anti-rotation pin 37 that engages with the fixed cam member 31 to prevent the fixed cam member 31 from rotating.

[0062] Multiple cam grooves 31a and 32a are formed on the fixed cam member 31 and the rotating cam member 32, respectively, for rolling of multiple cam balls 33. The cam grooves 31a and 32a are arc-shaped with the rotation axis O as the center, and are inclined grooves whose axial depth gradually changes according to the rolling position of the cam balls 33. The rotating cam member 32 has a gear portion 321 that meshes with the small-diameter gear portion 42 of the reduction gear 40, and rotates by the torque of the motor 30 amplified by the reduction mechanism 4. When the rotating cam member 32 rotates relative to the fixed cam member 31, the cam balls 33 roll in the cam grooves 31a and 32a, and the rotating cam member 32 moves axially relative to the fixed cam member 31.

[0063] The piston 34 has a disc-shaped base portion 341 centered on the rotation axis O and a plurality of boss portions 342 provided in an axially projecting manner from the base portion 341. The boss portions 342 are inserted into through holes 223a formed in the side wall portion 223 of the coupling connecting member 22, with their front ends facing the pressing plate 23. If the rotating cam member 32 rotates and moves away from the fixed cam member 31, its thrust is transmitted to the piston 34 via the bearing 35, and the plurality of boss portions 342 of the piston 34 press the clutch 20 via the pressing plate 23. The boss portions 342 are cylindrical, and sealing members 343, preventing clutch oil from leaking out of the through holes 223a, are installed on the outer periphery of each boss portion 342.

[0064] The working mechanism 3 is disposed on the outer periphery of the connecting portion 221 of the coupling connecting member 22. In other words, the connecting portion 221 of the coupling connecting member 22 and the working mechanism 3 are arranged side by side in the radial direction perpendicular to the axis of rotation O. This ensures the length of the connecting portion 221 in the axial direction and prevents the housing 5 and the coupling member 910 from becoming too large. The clutch 20 and the working mechanism 3 are arranged side by side in the axial direction on the outer periphery of the cup portion 911, with the clutch 20 being closer to the rod portion 912 than the working mechanism 3.

[0065] The fixed cam member 31 has an engagement portion 311 that engages with the anti-rotation pin 37. The anti-rotation pin 37 is pressed into a fitting hole 511 formed in the housing body 51. Additionally, the fixed cam member 31 has a cylindrical protrusion 312 extending toward a side opposite to the rotating cam member 32. A third bearing 63 is disposed between the protrusion 312 and the connection portion 221 of the coupling connecting member 22. The third bearing 63 supports the coupling member 910 for rotation via the connection portion 221 of the coupling connecting member 22. The axial movement of the third bearing 63 relative to the coupling connecting member 22 is limited by a retaining ring 25 fitted into the connection portion 221.

[0066] The housing 5 houses the coupling connecting member 22 and a portion of the cup portion 911 of the coupling member 910 together. The housing cover 52 has a cylindrical bearing retainer 521 that is radially opposed to the cylindrical portion 225 of the coupling connecting member 22, and a fourth bearing 64 is held between the bearing retainer 521 and the cylindrical portion 225 of the coupling connecting member 22. The fourth bearing 64 is held by the bearing retainer 521 and rotatably supports the coupling member 910 via the coupling connecting member 22.

[0067] The fourth bearing 64 is restricted from axial movement away from the differential device 11 by the locking protrusion 521a provided in the bearing retaining portion 521, and is restricted from axial movement toward the differential device 11 by the retaining ring 26 mounted on the cylindrical portion 225 of the coupling connecting member 22. That is, the axial relative movement of the coupling member 910 with respect to the housing 5 is restricted by the fourth bearing 64.

[0068] The third bearing 63 and the fourth bearing 64 are ball bearings with spherical rolling elements 633 and 643 arranged between the outer rings 631 and 641 and the inner rings 632 and 642, and are sealed bearings with seals 634 and 644 arranged between the outer rings 631 and 641 and the inner rings 632 and 642. Because the third bearing 63 and the fourth bearing 64 are sealed bearings, leakage of lubricating grease from the housing 5 is suppressed. Furthermore, leakage of lubricating grease from the housing 5 is also suppressed by a fifth sealing member 75 disposed between the protrusion 312 of the fixed cam member 31 and the housing body 51, a sixth sealing member 76 disposed between the outer ring 631 of the third bearing 63 and the protrusion 312 of the fixed cam member 31, and a seventh sealing member 77 disposed between the inner ring 632 of the third bearing 63 and the connection portion 221 of the coupling connecting member 22.

[0069] According to the first embodiment described above, by configuring the clutch 20 on the outer periphery of the cup portion 911 of the coupling member 910, compared to the case where, for example, the differential limiting mechanism is configured on the outer periphery of the rod portion in the coupling member of the constant velocity universal coupling as described in Patent Documents 1 and 2, the axial length of the coupling member 910 can be shortened. As a result, the operating angle of the intermediate shaft 90 can be reduced, wear on the sliding parts within the constant velocity universal coupling 91 during vehicle 1 operation can be decreased, and durability can be improved.

[0070] That is, if we assume that the coupling member 910 becomes longer, the distance between the pair of constant velocity universal couplings 91 and 92 provided at both ends of the drive shaft 9 becomes shorter, and the inclination of the intermediate shaft 90 relative to the axial direction of the coupling member 910 becomes larger. As a result, the foot shaft 913b of the three ball pin member 913, which is the inner member of the constant velocity universal coupling 91, swings significantly relative to the inner roller 914a. Wear is easily generated due to the sliding that oscillates. However, according to the first embodiment, the increase in the length of the coupling member 910 can be suppressed, and thus wear can be suppressed.

[0071] Furthermore, according to the first embodiment, the space where the clutch 20 is disposed can be fluidly sealed by the second and third sealing members 72 and 73 and the sealing member 343 disposed on the outer periphery of the boss portion 342 of the piston 34. Therefore, clutch oil with lubricating properties suitable for the multiple outer clutch plates 201 and inner clutch plates 202 can be used, thereby improving the durability and friction characteristics of the clutch 20.

[0072] Furthermore, according to the first embodiment, the axial relative movement of the coupling member 910 relative to the housing 5 is restricted by the fourth bearing 64, so the differential limiting device 10 and the drive shaft 9 can be easily installed and removed relative to the differential device 11.

[0073] In addition, according to the first embodiment, a working mechanism 3 is arranged axially parallel to the clutch 20 on the outer periphery of the cup portion 911 of the coupling member 910, so the increase in the length of the cup portion 911 caused by the arrangement of the working mechanism 3 can also be suppressed.

[0074] Furthermore, according to the first embodiment, the working mechanism 3 is disposed on the outer periphery of the connecting portion 221 of the coupling connecting member 22, thus ensuring the length of the connecting portion 221 sufficiently and improving the coaxiality between the coupling member 910 and the coupling connecting member 22. Additionally, the protrusions and concave surfaces of the connecting portion 221 of the coupling connecting member 22 engage with the protrusions and concave surfaces of the cup portion 911 on its outer periphery, restricting relative rotation with the coupling member 910. Therefore, even if the differential limiting force increases, the installation rigidity of the coupling connecting member 22 to the coupling member 910 can be sufficiently ensured.

[0075] [Second Implementation]

[0076] Next, refer to Figure 5 A second embodiment of the present invention will be described. In the second embodiment, the structure of the differential device 18 combined with the differential limiting device 10 differs from that of the differential device 11 in the first embodiment. Figure 5 In this text, for components, etc., corresponding to the components described in the first embodiment, the labels are... Figure 1 The same labels are used for the same labels, and detailed explanations are omitted.

[0077] In the first embodiment, the differential device 11 was described as having a differential housing 112 as an input rotating member and a pair of half-shaft gears 115 and 116 as output rotating members. However, the differential device 18 in the second embodiment has a differential housing 182 as an input rotating member that rotates integrally with the gear ring 181 meshing with the pinion shaft 15, a pair of planet carriers 183 and a sun gear 184 as output rotating members. The coupling member 810 of the constant velocity universal coupling 81 is connected to the planet carrier 183 in a non-rotatable manner. The coupling member 910 of the constant velocity universal coupling 91 is connected to the sun gear 184 in a non-rotatable manner.

[0078] Additionally, the differential 18 has multiple pinion sets 185. Each pinion set 185 has meshing outer planetary gears 186 and inner planetary gears 187. The planet carrier 183 supports the outer planetary gears 186 and inner planetary gears 187 of each pinion set 185 so that they can rotate. The outer planetary gears 186 mesh with an internal gear 182a formed on the inner circumference of the differential housing 182, and the inner planetary gears 187 mesh with a sun gear 184. Furthermore, in Figure 5In the diagram, the outer planetary gear 186 and the inner planetary gear 187 are shown side by side in the vertical direction, but the outer planetary gear 186 and the inner planetary gear 187 are arranged in a manner that partially follows the circumference of the planet carrier 183 between the internal gear 182a and the sun gear 184.

[0079] The planetary carrier 183, together with a plurality of pinion gear sets 185, is housed in the differential housing 182. The ring gear 181 and the differential housing 182 are housed in a housing 188 supported by the body of the vehicle 1.

[0080] When vehicle 1 is traveling straight with its left wheel 16 and right wheel 17 rotating at the same speed, the outer planetary gear 186 and inner planetary gear 187 do not rotate on their own axes but rotate as part of the planet carrier 183. The driving force input to the differential housing 182 is output from the planet carrier 183 and the sun gear 184. When a speed difference is generated between the left wheel 16 and the right wheel 17, the outer planetary gear 186 and inner planetary gear 187 transmit driving force while rotating on their own axes. The driving force input to the differential housing 182 is output from the planet carrier 183 and the sun gear 184.

[0081] The planetary carrier 183 has a first sidewall portion 183a disposed on one axial side of the plurality of pinion gear sets 185 and a second sidewall portion 183b disposed on the other axial side of the plurality of pinion gear sets 185. The coupling member 810 of the constant velocity universal coupling 81 is engaged with the first sidewall portion 183a in a manner that prevents relative rotation. The connecting rotating member 21 of the clutch mechanism 2 in the differential limiting device 10 is engaged with the second sidewall portion 183b in a manner that prevents relative rotation.

[0082] When the clutch 20 is pressed by the working mechanism 3 and friction is generated, the relative rotation of the coupling member 910 of the constant velocity universal coupling 91 connected to the sun gear 184 and the planet carrier 183 connected to the connecting rotating member 21 is suppressed. That is, in this embodiment, the relative rotation of the output rotating member, i.e., the sun gear 184, which is connected to the coupling member 910 in a manner that cannot rotate relative to each other, and the output rotating member, i.e., the planet carrier 183, which is connected to the connecting rotating member 21 in a manner that cannot rotate relative to each other, is suppressed by the friction of the clutch 20.

[0083] According to this second embodiment, the same effect as the first embodiment can also be obtained.

[0084] (Postscript)

[0085] The present invention has been described above based on the first and second embodiments, but these embodiments do not limit the invention as defined in the claims. Furthermore, it should be noted that the combinations of features described in the embodiments are not necessarily all necessary means to solve the problems of the invention. Additionally, the present invention can be implemented with appropriate modifications, such as omitting parts of the structure, adding or replacing structures, without departing from its spirit; for example, it can be modified as described below.

[0086] In the above embodiment, the case where the rotation of the motor 30 is reduced by the reduction mechanism 4, and the cam mechanism consisting of the fixed cam member 31, the rotating cam member 32, and a plurality of cam balls 33 is activated to press the clutch 20 is described. However, this is not the only possibility; for example, the clutch 20 can also be pressed hydraulically. In this case, the working mechanism consists of a piston that presses the clutch 20 and a hydraulic cylinder that applies hydraulic pressure to the piston.

[0087] Furthermore, in the above embodiment, the case where the clutch 20 is a multi-plate clutch has been described, but it is not limited to this; a meshing clutch that engages a pair of meshing members can also be used. When the clutch mechanism is composed of a meshing clutch, when the clutch is engaged, the left wheel 16 and the right wheel 17 are in a differential lock state where they cannot rotate relative to each other.

[0088] Label Explanation

[0089] 1…vehicles

[0090] 10…Differential limiting device

[0091] 11…Differential device

[0092] 112… Differential housing (input rotating component)

[0093] 115, 116… Half-shaft gears (output rotating components)

[0094] 183… Planetary Carrier (Output Rotating Component)

[0095] 184…Sun Gear (Output Rotating Component)

[0096] 2…Clutch mechanism

[0097] 20… Clutch

[0098] 201… External clutch plate

[0099] 202…Inner clutch plate

[0100] 21…Connecting rotating components

[0101] 211…Connecting Section

[0102] 212…Small diameter cylindrical section

[0103] 213…Large Diameter Cylindrical Section

[0104] 22…Coupling connecting components

[0105] 221…Connection Section

[0106] 222…Kahebu

[0107] 3…Work unit

[0108] 5…shell

[0109] 64… Fourth Bearing

[0110] 72-74…Second to Fourth Sealing Components

[0111] 91…Constant velocity universal coupling

[0112] 910…Coupling components

[0113] 911…cup section

[0114] 912…pole section Claims (as amended under Article 19 of the Treaty) 1. A differential limiting device, incorporated in a differential mechanism, suppressing relative rotation of a pair of output rotating members, the differential mechanism distributing and outputting a vehicle driving force input to an input rotating member to the pair of output rotating members, wherein, The differential limiting device comprises: a coupling member of a constant velocity universal joint, connected to the output rotating member of one of the pair of output rotating members in a manner that prevents relative rotation; a clutch mechanism having a clutch that inhibits relative rotation between the input rotating member and the coupling member or relative rotation between the output rotating member of the other of the pair of output rotating members and the coupling member; and a working mechanism for operating the clutch mechanism. The coupling component has a cup portion formed as a bottomed cylindrical shape and a shaft-shaped rod portion extending axially from the cup portion. The rod is connected to the output rotating component of one of the components. The clutch is disposed on the outer periphery of the cup portion. The clutch mechanism has a connecting rotating member, which is connected to either the input rotating member or the output rotating member of the other. The connecting rotating member includes: a connecting portion that is connected to the input rotating member or the output rotating member of the other party in a manner that prevents relative rotation; a small-diameter cylindrical portion disposed on the outer periphery of the rod portion; and a large-diameter cylindrical portion disposed on the outer periphery of the cup portion. The clutch and the large-diameter cylindrical portion are arranged side by side in the radial direction. A sealing member is disposed between the small-diameter cylindrical portion and the rod portion, and the sealing member liquid-tightly maintains the space between the cup portion and the large-diameter cylindrical portion. 2. The differential limiting device according to claim 1, wherein, The clutch mechanism has a coupling connecting member disposed on the outer periphery of the coupling member, and the relative rotation with respect to the coupling member and the axial movement relative to the coupling member are restricted. The clutch is disposed between the coupling connecting member and the large-diameter cylindrical portion of the connecting rotating member. 3. The differential limiting device according to claim 2, wherein, A sealing member is disposed between the coupling connecting member and the connecting rotating member to fluidly seal the clutch. 4. The differential limiting device according to claim 1, wherein, The clutch is a multi-plate clutch having multiple clutch plates arranged axially. The working mechanism presses the clutch axially, thereby generating friction between the plurality of clutch plates. The clutch and the working mechanism are arranged axially side by side on the outer periphery of the cup portion, with the clutch positioned on the side of the lever portion closer to the working mechanism than the working mechanism. 5. The differential limiting device according to claim 4, wherein, The clutch mechanism has a coupling connecting member disposed on the outer periphery of the coupling member, and the relative rotation with respect to the coupling member and the axial movement relative to the coupling member are restricted. The coupling connecting member has: a connecting portion that connects to the cup portion of the coupling component in a manner that prevents relative rotation; and an engaging portion that engages with a portion of the plurality of clutch discs in a manner that prevents relative rotation. The working mechanism is arranged on the outer periphery of the connecting part. 6. The differential limiting device according to claim 5, wherein, The concave and convex shapes on the inner circumferential surface of the connecting portion of the coupling connecting member engage with the concave and convex shapes on the outer circumferential surface of the cup portion, thereby restricting the relative rotation between the connecting portion of the coupling connecting member and the coupling component. 7. The differential limiting device according to claim 5 or 6, wherein, The clutch mechanism has a connecting rotating member that is connected to the input rotating member or the output rotating member of the other in a manner that prevents relative rotation. The connecting rotating member has a large-diameter cylindrical portion disposed on the outer periphery of the cup portion, and the clutch is disposed between the large-diameter cylindrical portion and the engaging portion of the coupling connecting member. 8. The differential limiting device according to any one of claims 1 to 3, wherein, The differential limiting device includes: a housing that accommodates at least a portion of the clutch mechanism and at least a portion of the cup portion together; and a bearing that is held in the housing and supports the coupling member so that it can rotate relative to the housing. The axial relative movement of the coupling component with respect to the housing is restricted by the bearing.

Claims

1. A differential limiting device, incorporated in a differential mechanism, suppressing relative rotation of a pair of output rotating members, the differential mechanism distributing and outputting a vehicle driving force input to an input rotating member to the pair of output rotating members, wherein, The differential limiting device comprises: a coupling member of a constant velocity universal joint, connected to the output rotating member of one of the pair of output rotating members in a manner that prevents relative rotation; a clutch mechanism having a clutch that inhibits relative rotation between the input rotating member and the coupling member or relative rotation between the output rotating member of the other of the pair of output rotating members and the coupling member; and a working mechanism for operating the clutch mechanism. The coupling component has a cup portion formed as a bottomed cylindrical shape and a shaft-shaped rod portion extending axially from the cup portion. The rod is connected to the output rotating component of one of the components. The clutch is disposed on the outer periphery of the cup portion.

2. The differential limiting device according to claim 1, wherein, The clutch mechanism has a connecting rotating member, which is connected to either the input rotating member or the output rotating member of the other. The connecting rotating member includes: a connecting portion that is connected to the input rotating member or the output rotating member of the other party in a manner that prevents relative rotation; a small-diameter cylindrical portion disposed on the outer periphery of the rod portion; and a large-diameter cylindrical portion disposed on the outer periphery of the cup portion. The clutch and the large-diameter cylindrical portion are arranged side by side in the radial direction. A sealing member is disposed between the small-diameter cylindrical portion and the rod portion, and the sealing member liquid-tightly maintains the space between the cup portion and the large-diameter cylindrical portion.

3. The differential limiting device according to claim 2, wherein, The clutch mechanism has a coupling connecting member disposed on the outer periphery of the coupling member, and the relative rotation with respect to the coupling member and the axial movement relative to the coupling member are restricted. The clutch is disposed between the coupling connecting member and the large-diameter cylindrical portion of the connecting rotating member.

4. The differential limiting device according to claim 3, wherein, A sealing member is disposed between the coupling connecting member and the connecting rotating member to fluidly seal the clutch.

5. The differential limiting device according to claim 1, wherein, The clutch is a multi-plate clutch having multiple clutch plates arranged axially. The working mechanism presses the clutch axially, thereby generating friction between the plurality of clutch plates. The clutch and the working mechanism are arranged axially side by side on the outer periphery of the cup portion, with the clutch positioned on the side of the lever portion closer to the working mechanism than the working mechanism.

6. The differential limiting device according to claim 5, wherein, The clutch mechanism has a coupling connecting member disposed on the outer periphery of the coupling member, and the relative rotation with respect to the coupling member and the axial movement relative to the coupling member are restricted. The coupling connecting member has: a connecting portion that connects to the cup portion of the coupling component in a manner that prevents relative rotation; and an engaging portion that engages with a portion of the plurality of clutch discs in a manner that prevents relative rotation. The working mechanism is arranged on the outer periphery of the connecting part.

7. The differential limiting device according to claim 6, wherein, The concave and convex shapes on the inner circumferential surface of the connecting portion of the coupling connecting member engage with the concave and convex shapes on the outer circumferential surface of the cup portion, thereby restricting the relative rotation between the connecting portion of the coupling connecting member and the coupling component.

8. The differential limiting device according to claim 6 or 7, wherein, The clutch mechanism has a connecting rotating member that is connected to the input rotating member or the output rotating member of the other in a manner that prevents relative rotation. The connecting rotating member has a large-diameter cylindrical portion disposed on the outer periphery of the cup portion, and the clutch is disposed between the large-diameter cylindrical portion and the engaging portion of the coupling connecting member.

9. The differential limiting device according to any one of claims 1 to 4, wherein, The differential limiting device includes: a housing that accommodates at least a portion of the clutch mechanism and at least a portion of the cup portion together; and a bearing that is held in the housing and supports the coupling member so that it can rotate relative to the housing. The axial relative movement of the coupling component with respect to the housing is restricted by the bearing.

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