Differential with disconnect mechanism

Abstract

To provide a structure which can easily switch the adaptability of torque transmission between drive wheels and a power transmission mechanism.SOLUTION: One drive shaft 5a out of a pair of drive shafts 5a, 5b is constituted by combining a first shaft 28 which is connected and fixed to a side gear 9a and a second shaft 29 for supporting drive wheels 6 via a reverse input block clutch 30. When a rotation number of the first shaft 28 is larger than a prescribed value, the reverse input block clutch 30 integrally rotates the first shaft 28 and the second shaft 29, and when the rotation number of the first shaft 28 is equal to or smaller than the prescribed value, the reverse input block clutch makes the first shaft 28 and the second shaft 29 idle with respect to each other.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a differential device for distributing power from a drive source to a pair of drive wheels. [Background technology]

[0002] In an automobile drive system, the torque of a drive source such as an engine or a drive motor is transmitted to a differential device (differential gear) via a power transmission mechanism such as a reduction mechanism including a transmission and a propeller shaft, and then distributed to a pair of drive wheels by the differential device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-46065 A [Patent Document 2] JP 2020-8124 A Summary of the Invention [Problem to be solved by the invention]

[0004] The above-mentioned automotive drive system has room for improvement in terms of improving fuel economy or power consumption. That is, when the accelerator is released while a vehicle equipped with the above-mentioned automotive drive system is running and coasting is attempted, losses occur in the meshing parts of the reduction gear mechanism, the drive source, etc., and this may shorten the travel distance by coasting.

[0005] JP 2020-46065 A (Patent Document 1) describes a differential device (differential device) equipped with a clutch device (disconnecting portion) between a differential case and a side gear. With such a differential device, the clutch device can be disconnected during coasting to separate the drive wheels from the power transmission mechanism, thereby increasing the travel distance by coasting. As a result, the fuel efficiency or power consumption of the vehicle can be improved.

[0006] However, the differential device described in JP 2020-46065 A has the following problems.

[0007] In other words, in the differential device described in JP 2020-46065 A, the clutch device uses a meshing clutch (dog clutch) that has engaging uneven portions on a pair of opposing axial side surfaces, each of which has engaging uneven portions formed by alternating concave and convex portions arranged in the circumferential direction, and is connected by engaging (meshing) the engaging uneven portions with each other.

[0008] Therefore, when an attempt is made to connect the clutch device when the relative rotational speed between the differential case and the side gear is faster than a predetermined speed, the convex portion that constitutes one of the engaging uneven portions is repelled by the convex portion that constitutes the other engaging uneven portion, preventing engagement with the concave portion of the other engaging uneven portion.

[0009] On the other hand, when the rotation speed of the differential case and the rotation speed of the side gears are completely the same, if the engaging uneven parts are brought close to each other to connect the clutch device, the tip surface of the convex part constituting one engaging uneven part may come into contact with the tip surface of the convex part constituting the other engaging uneven part. In this case, the engaging uneven parts may not be able to be engaged with each other, and the clutch device may not be able to be connected.

[0010] Therefore, in the differential device described in JP 2020-46065 A, the clutch device needs to be connected in a state where the relative rotation speed between the differential case and the side gear is equal to or lower than a predetermined speed. In other words, the timing for connecting the clutch device needs to be strictly adjusted, which may make the control complicated.

[0011] As a technique related to the present invention, JP 2020-8124 A (Patent Document 2) describes a free-type reverse input cutoff clutch. In the reverse input cutoff clutch described in JP 2020-8124 A, the radial movement of the engagement element is controlled by the rotation of the input member and the force applied by the force application member, and it is possible to switch between a locked state in which rotational torque can be transmitted from the input member to the output member, and a free state in which the rotational torque reversely input to the output member is cut off.

[0012] The present invention has been made to solve the above-mentioned problems, and aims to provide a differential gear with a disconnect mechanism that can easily switch between enabling and disabling torque transmission between the drive wheels and the power transmission mechanism. [Means for solving the problem]

[0013] A differential with a disconnect mechanism according to one aspect of the present invention includes a differential case, at least one pinion gear, a pair of side gears, and a pair of drive shafts. The differential case has a torque input portion, which may be constituted by a ring gear that meshes with a gear, a pulley for passing a belt around, a sprocket for passing a chain around, or the like. The pinion gear is supported relative to the differential case so as to be rotatable about an axis perpendicular to the central axis of the differential case. The pair of side gears are supported coaxially with a central axis of the differential case so as to be capable of relative rotation with respect to the differential case, and mesh with the pinion gears. The pair of drive shafts have their respective base ends fixedly coupled to the pair of side gears.

[0014] In particular, in the differential with disconnect mechanism according to one aspect of the present invention, one of the pair of drive shafts has a first shaft, a second shaft, and a reverse input cutoff clutch. The first shaft has a base end portion fixedly coupled to one of the pair of side gears. The second shaft is disposed coaxially with the first shaft. The reverse input cut-off clutch rotates the first shaft and the second shaft together when the rotation speed (rotational speed) of the first shaft is greater than a predetermined value (rotational speed), whereas it causes the first shaft and the second shaft to rotate freely relative to each other when the rotation speed of the first shaft is equal to or less than the predetermined value (including a state in which the first shaft is not rotating).

[0015] In the differential device with disconnect mechanism according to one aspect of the present invention, the reverse input cutoff clutch can include an output portion, an input portion, an engagement element, and a force application member. The output portion has a pressed surface on its inner circumferential surface, and rotates integrally with the second shaft. The input portion has a cam portion disposed radially inside the pressed surface, and rotates integrally with the first shaft. The engagement piece has a pressing surface that faces the pressed surface, and is disposed between the pressed surface and the cam portion in the radial direction. The force application member applies a force to the engagement element in a direction in which the pressing surface moves away from the pressed surface. When the force acting on the engaging element in the direction of bringing the pressing surface closer to the pressed surface due to the rotation of the input part and the rotation of the engaging element is greater than the force applied to the engaging element by the force application member, the engaging element moves radially in the direction of bringing the pressing surface closer to the pressed surface, frictionally engaging the pressing surface with the pressed surface, thereby rotating the input part and the output part as a unit, whereas when the input part is not rotating or the force acting on the engaging element in the direction of bringing the pressing surface closer to the pressed surface due to the rotation of the input part and the engaging element is less than the force applied to the engaging element by the force application member, a gap is formed between the pressed surface and the pressing surface based on the force applied to the engaging element by the force application member, thereby causing the input part and the output part to rotate freely relative to each other.

[0016] In addition, the force acting on the engaging element in the direction of moving the pressing surface closer to the pressed surface in response to the input of rotational torque to the input portion is the resultant force of the force that attempts to move the engaging element radially in the direction of moving the pressing surface closer to the pressed surface based on the engagement of the engaging element with the cam portion, and the centrifugal force acting on the engaging element.

[0017] In the disconnect mechanism-equipped differential according to one aspect of the present invention, the engagement element may have a pair of the pressing surfaces that are spaced apart from each other in the circumferential direction.

[0018] In a differential with a disconnect mechanism according to one aspect of the present invention, the input portion may have an input portion-side guide portion, and the engaging element may have an engaging element-side guide portion. In this case, in a state in which the gap is formed between the pressed surface and the pressing surface based on the force applied by the force application member to the engaging element, the input portion-side guide portion and the engaging element-side guide portion engage with each other without any rattling in a first direction that is a direction in which the pressing surface approaches or moves away from the pressed surface, and in a second direction that is perpendicular to the central axis of the input portion.

[0019] The disconnect mechanism-equipped differential according to one aspect of the present invention may include a pair of the engagement elements so as to sandwich the cam portion from radially outside. In this case, the force application member may be provided so as to span between the pair of engagement elements.

[0020] In the differential gear with disconnect mechanism according to one aspect of the present invention, the force application member can be made of an elastic member such as a spring or rubber.

[0021] In a differential device with a disconnect mechanism according to one embodiment of the present invention, the minimum value of the circumscribing circle diameter of the cam portion can be made larger than the outer diameter of the portion of the first shaft that is fixedly connected to the one of the side gears. Alternatively, the minimum value of the circumscribing circle diameter of the cam portion may be equal to or smaller than the outer diameter of the portion of the first shaft that is fixedly coupled to the one side gear. Effect of the Invention

[0022] According to the differential device of one aspect of the present invention, it is possible to easily switch between enabling and disabling torque transmission between the drive wheels and the power transmission mechanism. [Brief description of the drawings]

[0023] [Figure 1] FIG. 1 is a schematic diagram showing an example of a drive device for an electric vehicle incorporating a differential device according to an embodiment. [Diagram 2] FIG. 2 is a cross-sectional view showing a differential gear according to one embodiment. [Diagram 3] FIG. 3 is an exploded perspective view showing a reverse input cutoff clutch taken out from a differential device according to one embodiment. [Figure 4] FIG. 4 is a perspective view showing the reverse input cutoff clutch with some parts omitted. [Diagram 5] FIG. 5 is a cross-sectional view taken along line XX in FIG. 2, showing the reverse input cutoff clutch with some parts omitted. [Figure 6] FIG. 6 is a view similar to FIG. 5 showing the reverse input disconnect clutch when the vehicle is not coasting. [Figure 7] FIG. 7 is a view similar to FIG. 5 showing the reverse input disconnect clutch when the vehicle is coasting at high speed. [Figure 8] FIG. 8 is a view similar to FIG. 5 showing the reverse input disconnect clutch when the vehicle is coasting at low speed. [Figure 9] 9(A) is an enlarged view of the center portion of FIG. 6, FIG. 9(B) is an enlarged view of the center portion of FIG. 7, and FIG. 9(C) is an enlarged view of the center portion of FIG. [Figure 10] FIG. 10 is a perspective view showing the input portion taken out of the reverse input cutoff clutch with the small diameter shaft portion omitted. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] An example of an embodiment of the present invention will be described with reference to Figs. 1 to 10. Fig. 1 shows an electric vehicle drive device 2 incorporating a differential device 1 of this embodiment. In the electric vehicle drive device 2, the output torque of a drive motor 3 is increased by a power transmission mechanism 4, then transmitted to the differential device 1, and distributed to a pair of drive shafts 5a, 5b by the differential device 1. As a result, drive wheels 6 supported on the tips of the pair of drive shafts 5a, 5b via suspensions (not shown) are rotated and driven.

[0025] In this example, the power transmission mechanism 4 is configured by a gear-type reducer. The power transmission mechanism 4 includes a drive gear 4a, an intermediate shaft 4b, an intermediate gear 4c, and a final reduction gear (final gear) 4d. The drive gear 4a is supported and fixed to the output shaft 3a of the drive motor 3. The intermediate shaft 4b is supported in parallel to the output shaft 3a of the drive motor 3 so as to be rotatable with respect to a vehicle body (not shown). The intermediate gear 4c has a number of teeth greater than the number of teeth of the drive gear 4a, and is supported and fixed to the intermediate shaft 4b. The final reduction gear 4d has a number of teeth less than the number of teeth of the intermediate gear 4c, and is supported and fixed to the intermediate shaft 4b.

[0026] The power transmission mechanism 4 may also include a transmission such as an automatic transmission (AT), a belt-type or toroidal-type continuously variable transmission (CVT), an automated manual transmission (AMT), a dual clutch transmission (DCT), or a manual transmission (MT) and a propeller shaft. The power transmission mechanism 4 may also be configured with, for example, a belt-type or chain-type power transmission mechanism and / or a friction roller reducer instead of or in addition to a gear-type reducer.

[0027] The differential device 1 of this example includes a differential case 7, a pinion gear 8, a pair of side gears 9a, 9b, and a pair of drive shafts 5a, 5b.

[0028] In addition, unless otherwise specified, the axial direction, circumferential direction, and radial direction of the differential device 1 refer to the axial direction, circumferential direction, and radial direction of the differential case 7. In addition, the axial direction, circumferential direction, and radial direction of the differential case 7 coincide with the axial direction, circumferential direction, and radial direction of the pair of side gears 9a, 9b, and also coincide with the axial direction, circumferential direction, and radial direction of the pair of drive shafts 5a, 5b. In addition, one side in the axial direction refers to the right side in Figures 1 and 2, and the other side in the axial direction refers to the left side in Figures 1 and 2.

[0029] The differential case 7 has a ring gear 10 that constitutes a torque input portion. The ring gear 10 is formed of a helical gear, and meshes with the final reduction gear 4d of the power transmission mechanism 4. In this example, the differential case 7 includes a stepped cylindrical case member 11 and a gear member 12.

[0030] The case member 11 includes, in order from one axial end, a small diameter cylindrical portion 13a, a connecting portion 14a, a large diameter cylindrical portion 15, a connecting portion 14b, and a small diameter cylindrical portion 13b.

[0031] The small diameter cylindrical portion 13a has a cylindrical shape.

[0032] The connecting portion 14a has a generally hollow circular plate shape, and connects an end portion on the other axial side of the small diameter cylindrical portion 13a on one axial side to an end portion on one axial side of the large diameter cylindrical portion 15. That is, a radially inner end portion of the connecting portion 14a is connected to an end portion on the other axial side of the small diameter cylindrical portion 13a, and a radially outer end portion of the connecting portion 14a is connected to an end portion on one axial side of the large diameter cylindrical portion 15.

[0033] The large diameter cylindrical portion 15 has a substantially cylindrical shape. The large diameter cylindrical portion 15 has a circular hole 16 that opens to the inner peripheral surface at at least one circumferential position (two radially opposite positions in the illustrated example), and has a hollow circular plate-like outward flange portion 17 that protrudes radially outward from an axially intermediate portion. A base end portion of a support shaft 18 for supporting a pinion gear 8, which will be described later, is fitted and fixed into each circular hole 16. The large diameter cylindrical portion 15 has an opening window at at least one circumferential position (for example, two radially opposite positions). When assembling the differential device 1, the pinion gear 8 and the side gears 9a, 9b are arranged inside the large diameter cylindrical portion 15 through the opening window.

[0034] The connecting portion 14b has a generally hollow circular plate shape, and connects the other axial end of the large diameter cylindrical portion 15 to one axial end of the other small diameter cylindrical portion 13b. That is, the radially outer end of the connecting portion 14b is connected to the other axial end of the large diameter cylindrical portion 15, and the radially inner end of the connecting portion 14b is connected to the one axial end of the small diameter cylindrical portion 13b.

[0035] The small diameter cylindrical portion 13b has a cylindrical shape.

[0036] The case member 11 is rotatably supported by a pair of tapered roller bearings 19a, 19b having a face-to-face duplex (DF) type contact angle with respect to a fixed part 20 that does not rotate even during use. Specifically, the tapered roller bearing 19a on one axial side is disposed between the outer peripheral surface of the small diameter cylindrical part 13a on one axial side and the inner peripheral surface of the fixed part 20, and the tapered roller bearing 19b on the other axial side is disposed between the outer peripheral surface of the small diameter cylindrical part 13b on the other axial side and the inner peripheral surface of the fixed part 20. In this way, the case member 11 is rotatably supported inside the fixed part 20.

[0037] The gear member 12 includes a cylindrical portion 21 having the ring gear 10 on its outer circumferential surface, and a hollow circular plate-like inward flange portion 22 that protrudes radially inward from an axially intermediate portion of the cylindrical portion 21 .

[0038] The case member 11 and the gear member 12 are connected and fixed by a plurality of bolts 23. That is, each bolt 23 is inserted through a through hole provided in the inward flange portion 22 of the gear member 12 and screwed into a screw hole provided in the outward flange portion 17 of the case member 11, thereby connecting and fixing the case member 11 and the gear member 12 to form the differential case 7.

[0039] The pinion gear 8 is aligned with the central axis O of the differential case 7. 7 The pinion gears 8 are supported with respect to the differential case 7 so as to be rotatable about an axis perpendicular to the differential case 7. In this example, a pair of pinion gears 8 is provided, and each pinion gear 8 is configured with a bevel gear. That is, the pinion gears 8 have a substantially truncated cone shape and have a plurality of teeth on their outer circumferential surface. Furthermore, the pinion gears 8 have a center hole 24 at their center that penetrates the pinion gears 8 in the axial direction. The pinion gears 8 are rotatably supported via a radial bearing 25 around the tip end of a support shaft 18 that is fitted and fixed to the large diameter cylindrical portion 15 of the differential case 7.

[0040] The pair of side gears 9a, 9b are aligned with the central axis O of the differential case 7. 7 The side gears 9a and 9b are supported coaxially with the differential case 7 so as to be capable of relative rotation with respect to the differential case 7, and mesh with the pinion gear 8. Each of the side gears 9a and 9b is formed of a bevel gear. That is, the side gears 9a and 9b have a substantially truncated cone shape, and have a plurality of teeth on their outer circumferential surfaces that mesh with the teeth of the pinion gear 8. Furthermore, the side gears 9a and 9b have a spline hole 26 penetrating in the axial direction at their centers. The side gears 9a and 9b are disposed inside the large diameter cylindrical portion 15 of the differential case 7, and are coupled and fixed to the base ends of the drive shafts 5a and 5b so as to be capable of transmitting torque. That is, the male spline portion 27 provided on the outer circumferential surfaces of the base ends of the drive shafts 5a and 5b is spline-engaged with the female spline portion provided on the inner circumferential surfaces of the spline hole 26.

[0041] Of the pair of drive shafts 5a, 5b, the drive shaft 5a on one axial side has a first shaft 28, a second shaft 29, and a reverse input cutoff clutch 30.

[0042] The first shaft 28 has a base end (the other axial end) coupled and fixed to the side gear 9a on one axial side of the pair of side gears 9a, 9b. That is, the first shaft 28 has a male spline portion 27 on the outer circumferential surface of the base end.

[0043] The second shaft 29 is supported coaxially with the first shaft 28 and capable of relative rotation with respect to the first shaft 28. The driving wheel 6 is supported on the tip end (one end on one axial side) of the second shaft 29 via a suspension.

[0044] The reverse input cutoff clutch 30 is a free-type (idling type) reverse input cutoff clutch. That is, the reverse input cutoff clutch 30 rotates the first shaft 28 and the second shaft 29 integrally when the rotational speed (rotational speed) of the first shaft 28 is greater than a predetermined value (faster than the predetermined rotational speed), whereas the reverse input cutoff clutch 30 rotates the first shaft 28 and the second shaft 29 idly relative to each other when the rotational speed of the first shaft 28 is equal to or less than the predetermined value (equal to or less than the predetermined rotational speed). In this example, the reverse input cutoff clutch 30 includes a housing 31, an output portion 32, an input portion 33, a pair of engagement members 34, and a pair of force application members 35.

[0045] The housing 31 is configured in a stepped cylindrical shape. In this example, the housing 31 has a hollow circular plate-like side plate portion 36, a large diameter cylindrical portion 37 that protrudes from a radially outer portion of the side plate portion 36 toward one axial side over the entire circumference, and a small diameter cylindrical portion 38 that is bent from a radially inner end portion of the side plate portion 36 toward the other axial side over the entire circumference. Furthermore, the housing 31 has an inward flange portion 39 that is bent from the other axially side end portion of the small diameter cylindrical portion 38 toward the radially inner side over the entire circumference, and has through holes 40 that penetrate in the axial direction at multiple locations in the circumferential direction of the side plate portion 36 that protrudes radially outward from the outer circumferential surface of the large diameter cylindrical portion 37.

[0046] The housing 31 is supported and fixed to the fixed part 20 by screwing a bolt 41 inserted into the through hole 40 into a threaded hole 77 opening on one axial side of the fixed part 20, which does not rotate even during use, and further tightening the bolt.

[0047] The output section 32 has an output shaft section 42, a cylindrical section 43, and a side plate section 44. In this example, the output section 32 is provided integrally with the base end section (the other axial end section) of the second shaft 29. Alternatively, when carrying out the present invention, the second shaft can be configured by coupling and fixing the output section to a shaft main body whose tip section is connected to a suspension so as to be integrally rotatable.

[0048] The output shaft portion 42 has a columnar small diameter portion 45 arranged on one axial side and a cylindrical large diameter portion 46 arranged on the other axial side. The output shaft portion 42 is provided integrally with the base end portion of the second shaft 29. The large diameter portion 46 has a stepped cylindrical inner circumferential surface formed by connecting a small diameter cylindrical surface portion 47 on one axial side and a large diameter cylindrical surface portion 48 on the other axial side by a step portion 49 facing the other axial side.

[0049] The cylindrical portion 43 has a pressed surface 50, which is a cylindrical concave surface, on its inner circumferential surface over the entire circumference, and is disposed on the other axial side of the output shaft portion .

[0050] The side plate portion 44 is configured in a hollow circular plate shape, and connects the other axial end of the output shaft portion 42 (large diameter portion 46 ) and one axial side portion of the cylindrical portion 43 .

[0051] In the reverse input cutoff clutch 30 of this example, the cylindrical portion 43 of the output portion 32 is rotatably supported on the radial inside of the large diameter cylindrical portion 37 of the housing 31 via a radial needle bearing 51. That is, an outer ring 52 formed by bending a metal plate into a substantially U-shaped cross section is tightly fitted into the large diameter cylindrical portion 37, and a plurality of needles 54 held by a cage 53 are rollably disposed between the inner peripheral surface of the outer ring 52 and the outer peripheral surface of the cylindrical portion 43 to form the radial needle bearing 51. In this way, the output portion 32 is rotatably supported relative to the housing 31.

[0052] In this example, an opening on one axial side of the cylindrical space that exists between the inner peripheral surface of the large-diameter tube portion 37 and the outer peripheral surface of the cylindrical portion 43 and in which the radial needle bearing 51 is installed is closed by a seal member 55. This prevents the grease sealed in the cylindrical space from leaking to the external space and prevents foreign matter such as moisture from entering the cylindrical space.

[0053] The input portion 33 has, in order from the other axial side, a large diameter shaft portion 56, a cam portion 57, and a small diameter shaft portion 58. The large diameter shaft portion 56, the cam portion 57, and the small diameter shaft portion 58 are all arranged coaxially and in series. In this example, the input portion 33 is provided integrally with the tip portion (the end portion on one axial side) of the first shaft 28. However, when carrying out the present invention, the first shaft can also be configured by integrally connecting and fixing the input portion to a shaft main body having a male spline portion on the outer peripheral surface of the base end portion.

[0054] The large diameter shaft portion 56 is formed in a cylindrical shape and is provided integrally with the tip portion of the first shaft 28. The large diameter shaft portion 56 has an outward flange portion 59 that protrudes radially outward at one end portion in the axial direction.

[0055] The cam portion 57 has an end face shape of a substantially rectangle including four corners of an arc or elliptical shape when viewed from the axial direction. That is, the outer peripheral surface of the cam portion 57 is composed of a pair of first flat surface portions 60 arranged on both sides in the short axis direction (up and down direction in FIG. 5), a pair of second flat surface portions 61 arranged on both sides in the long axis direction (left and right direction in FIG. 5), and a connecting surface portion 62 having an arc or elliptical cross section that connects the long axis end portion of the first flat surface portion 60 and the short axis end portion of the second flat surface portion 61. Therefore, the central axis O of the input portion 33 (the rotation center of the cam portion 57) is axially inclined. 33 The distance from the end of the first flat surface portion 60 to the outer circumferential surface of the cam portion 57 varies in the circumferential direction. The width dimension of the cam portion 57 in the major axis direction decreases toward the end in the minor axis direction. The ends of the first flat surface portion 60 and the connecting surface portion 62 are smoothly connected in the tangential direction.

[0056] The small diameter shaft portion 58 is formed in a cylindrical shape.

[0057] The input portion 33 rotatably supports the large diameter shaft portion 56 radially inside the small diameter cylindrical portion 38 of the housing 31 via a radial rolling bearing 63a, and rotatably supports the small diameter shaft portion 58 radially inside the large diameter portion 46 of the output portion 32 via a radial rolling bearing 63b. In this state, the cam portion 57 is disposed radially inside the pressed surface 50.

[0058] That is, the radial rolling bearing 63a on the other axial side has an outer ring fitted inside the small diameter cylindrical portion 38, an inner ring fitted outside the large diameter shaft portion 56, and a plurality of rolling elements arranged to roll freely between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring. The outer ring is sandwiched from both axial sides between one axial side of the inward flange portion 39 and a retaining ring 67a engaged with the inner peripheral surface of one axial end of the small diameter cylindrical portion 38. The inner ring is sandwiched from both axial sides between the other axial side of the outward flange portion 59 and a retaining ring 67b engaged with the outer peripheral surface of an axial middle portion of the large diameter shaft portion 56.

[0059] The radial rolling bearing 63b on one axial side has an outer ring fitted on the large diameter cylindrical surface portion 48 provided on the inner peripheral surface of the large diameter portion 46, an inner ring fitted on the small diameter shaft portion 58, and a plurality of rolling elements arranged to roll freely between the inner peripheral surface of the outer ring and the outer peripheral surface of the inner ring. The outer ring is sandwiched from both axial sides between the step portion 49 and a snap ring 67c engaged with the end portion on the other axial side of the large diameter cylindrical surface portion 48. The inner ring is sandwiched from both axial sides between an end face on one axial side of the cam portion 57 and a snap ring 67d engaged with the outer peripheral surface of the end portion on one axial side of the small diameter shaft portion 58.

[0060] In this example, the radial rolling bearings 63a and 63b are radial ball bearings that use balls as rolling elements. However, the radial rolling bearings 63a and 63b can also be radial tapered roller bearings that use tapered rollers as rolling elements or radial roller bearings that use cylindrical rollers (including needle rollers).

[0061] The pair of engaging elements 34 has an end face shape that is approximately semicircular (approximately arch-shaped) when viewed from the axial direction. The pair of engaging elements 34 is disposed between the pressed surface 50 of the output portion 32 and the cam portion 57 of the input portion 33 so as to sandwich the cam portion 57 from both sides in the short axis direction of the cam portion 57. The pair of engaging elements 34 are identical parts made to have the same shape and size.

[0062] The pair of engaging elements 34 are arranged such that their radially outer surfaces corresponding to the arcs face opposite each other and their radially inner surfaces corresponding to the chords face each other, and are capable of moving their radially outer surfaces in a first direction (direction indicated by α in FIG. 5) that is a direction in which the radially outer surfaces are moved toward or away from the pressed surface 50. In other words, the inner diameter of the pressed surface 50 and the radial dimension of the engaging elements 34 are regulated so that, with the pair of engaging elements 34 arranged between the pressed surface 50 and the cam portion 57, the radially outer surfaces of the engaging elements 34 can move in the first direction relative to the pressed surface 50.

[0063] Each of the pair of engaging elements 34 has a pair of pressing surfaces 68 on its radially outer surface, each of which faces the pressed surface 50 and is spaced apart from each other in the circumferential direction. Each of the pressing surfaces 68 is configured as a partially cylindrical convex curved surface having a radius of curvature smaller than the radius of curvature of the pressed surface 50. Note that, of the radially outer surfaces of each of the pair of engaging elements 34, a portion that is circumferentially deviated from the pair of pressing surfaces 68 is aligned with the central axis O of the input portion 33 when viewed in the axial direction. 33 The pair of pressing surfaces 68 are located radially inward of an imaginary circle having the pair of pressing surfaces 68 as its center and tangent to the pair of pressing surfaces 68. In other words, when the pair of pressing surfaces 68 are in contact with the pressed surface 50, the portions of the radially outer side surfaces of the pair of engaging elements 34 that are deviated from the pair of pressing surfaces 68 in the circumferential direction do not come into contact with the pressed surface 50.

[0064] It is preferable that each pressing surface 68 has a surface property that has a larger coefficient of friction with the pressed surface 50 than the other portions of the engaging element 34. Also, each pressing surface 68 may be formed integrally with the other portions of the engaging element 34, or may be formed of a friction material fixed to the other portions of the engaging element 34 by adhesion or bonding. of It can also be formed on the surface.

[0065] The pair of engagement pieces 34 are arranged on the radially inner surface thereof so as to face in the first direction and the central axis O of the output portion 32. 32 5. The recess 69 has a generally trapezoidal shape at its center in a second direction (the direction indicated by β in FIG. 5) perpendicular to the first direction.

[0066] The engagement recess 69 engages with the short axis direction end of the cam portion 57 of the input portion 33 without any rattling in the second direction when the reverse input cutoff clutch 30, which will be described later, is in a free state. That is, in this example, the short axis direction end of the cam portion 57 constitutes the input portion side guide portion, and the engagement recess 69 constitutes the engager side guide portion. The inner surface of the engagement recess 69 is composed of a bottom surface 70 and a pair of side surface portions 71.

[0067] The bottom surface 70 is configured of a flat surface perpendicular to the first direction. The length dimension of the bottom surface 70 (length dimension in the second direction) is the same as the length dimension of the first flat surface portion 60 of the cam portion 57 or slightly longer than the length dimension of the first flat surface portion 60.

[0068] The pair of side portions 71 are disposed on both sides of the inner surface of the engagement recess 69 in the second direction, and face each other in the second direction. In this example, the pair of side portions 71 are formed of concave curved surfaces inclined in a direction in which the distance between them increases toward the radial inside of the engagement piece 34, that is, toward the direction away from the pressed surface 50 in the first direction. Therefore, the width dimension of the engagement recess 69 in the second direction increases toward the opening side. The pair of side portions 71 have a radius of curvature equal to or slightly larger than the radius of curvature of the connection surface 62 of the cam portion 57. The bottom surface 70 and the side portion 71 smoothly connect their ends in the tangential direction.

[0069] Therefore, when the reverse input cutoff clutch 30 is in a free state, the bottom surface 70 is in surface contact with the first flat surface portion 60, and the pair of side surface portions 71 are in surface contact with the connecting surface portions 62.

[0070] Furthermore, each pair of engaging members 34 has semi-elliptical cutout portions 72 on both sides of the radially inner surface that sandwich the engaging recess 69 in the second direction, and has an axially penetrating engagement hole 73 in a portion located radially outward of the cutout portions 72.

[0071] The pair of force applying members 35 apply force to the pair of engaging elements 34 in a direction in which the pair of pressing surfaces 68 move away from the pressed surface 50. In this example, the pair of force applying members 35 apply elastic force to the pair of engaging elements 34 in a direction in which they move toward each other. For this reason, in this example, the pair of force applying members 35 are configured with tension coil springs. That is, the pair of force applying members 35 include a coil portion 74 formed by bending an elastic metal wire into a spiral shape, and a pair of locking arms 75 bent into a substantially L-shape from both end portions of the coil portion 74.

[0072] Each force applying member 35 is bridged between the pair of engaging elements 34 by engaging (inserting) the engaging arm portion 75 with the engaging hole 73, and applies an elastic force to the pair of engaging elements 34 in a direction in which they approach each other. As a result, the engaging recesses 69 of the pair of engaging elements 34 elastically hold the cam portion 57 of the input portion 33 from both radial sides. Specifically, the bottom surface 70 is elastically pressed against the first flat surface portion 60, and the side surface portion 71 is elastically pressed against the connection surface portion 62. Then, in the free state of the reverse input cutoff clutch 30, the attitude (rotation phase) of the cam portion 57 is regulated so that the major axis direction of the cam portion 57 is approximately parallel to the radial inner side surface of the engaging element 34, and a gap 79 is formed between the pressed surface 50 and the pair of pressing surfaces 68.

[0073] In addition, when the pair of force-applying members 35 are stretched between the pair of engaging members 34, both longitudinal side portions of the coil portion 74 and the pair of locking arm portions 75 are positioned inside the cutout portion 72.

[0074] The reverse input cut-off clutch 30 switches between a locked state in which the input section 33 and the output section 32 rotate integrally, and a free state in which the input section 33 and the output section 32 rotate freely relative to each other, depending on the magnitude of the force F acting on the engaging section 34 in a direction that brings a pair of pressing surfaces 68 closer to the pressed surface 50 as the input section 33 and the engaging section 34 rotate.

[0075] When a rotational torque is input to the input portion 33, as shown in Fig. 6, the cam portion 57 tries to rotate inside the pair of engaging recesses 69 in the rotation direction of the input portion 33 (clockwise in the example of Fig. 6). Then, the connection surface portion 62 of the cam portion 57 presses the bottom surface 70 of the engaging recess 69. At this time, based on the connection surface portion 62 pressing the bottom surface 70, a force that tries to move the pair of engaging elements 34 radially outward in a direction to bring the pair of pressing surfaces 68 closer to the pressed surface 50 and a force that tries to move the pair of engaging elements 34 radially outward in a direction to bring the pair of pressing surfaces 68 closer to the pressed surface 50 are generated. 33When the resultant force F of the centrifugal force acting on the pair of engagement members 34 as the pair of engagement members 34 rotates around the center becomes larger than the force f applied to the pair of engagement members 34 by the pair of force applying members 35 (F>f), the pair of engagement members 34 move radially outward in a direction that brings the pair of pressing surfaces 68 closer to the pressed surface 50. Then, the pair of pressing surfaces 68 are pressed against the pressed surface 50 to cause frictional engagement, and the pair of engagement members 34 are stretched between the cam portion 57 and the pressed surface 50. This switches the reverse input cutoff clutch 30 to a locked state in which the input portion 33 and the output portion 32 rotate integrally. As a result, the rotational torque input to the input portion 33 is transmitted to the output portion 32 via the pair of engagement members 34.

[0076] When the resultant force F is greater than the force f applied by the pair of force application members 35 to the pair of engagement members 34, the reverse input cutoff clutch 30 moves the pair of engagement members 34 in a direction approaching the pressed surface 50 in the first direction, regardless of the rotational direction of the input part 33. Then, the input part 33 and the output part 32 rotate integrally via the pair of engagement members 34.

[0077] In contrast, when a resultant force F of a force that causes the pair of engaging elements 34 to move the pair of pressing surfaces 68 radially outward in a direction to approach the pressed surface 50 in association with the rotation of the input portion 33 and the engaging elements 34, and a centrifugal force acting on the pair of engaging elements 34, is equal to or less than the force f applied to the engaging elements 34 by the pair of force application members 35 (F≦f), including when the input portion 33 is not rotating, a gap 76 is formed between the pressed surface 50 and the pair of pressing surfaces 68 based on the force f applied to the engaging elements 34 by the pair of force application members 35. As a result, the reverse input cutoff clutch 30 switches to a free state in which the input portion 33 and the output portion 32 rotate idly relative to each other.

[0078] When the resultant force F is less than or equal to the force f applied by the pair of force application members 35 to the pair of engagement members 34, the reverse input cut-off clutch 30 causes the input portion 33 and the output portion 32 to rotate freely relative to each other, regardless of the rotational direction of the input portion 33 and the output portion 32.

[0079] The magnitude of the force (elastic force) applied by the pair of force application members 35 to the pair of engagement members 34 is appropriately set according to the vehicle running speed (vehicle speed) at which the pair of drive wheels 6 should be separated from the drive motor 3 and the power transmission mechanism 4 after the accelerator is released, as described below. However, the force applied by the pair of force application members 35 to the pair of engagement members 34 is set to be smaller than the force acting on the pair of engagement members 34 in a direction that brings the pair of pressing surfaces 68 closer to the pressed surface 50 as a result of input of a rotational torque to the input unit 33, which is based on outputting from the drive motor 3 a torque sufficient to start the vehicle.

[0080] In a vehicle equipped with the electric vehicle drive device 2 of this embodiment, the reverse input cutoff clutch 30 is switched between a locked state and a free state depending on the running state.

[0081] <When the vehicle is not coasting> When the accelerator is operated (the accelerator pedal is depressed) with the shift lever switched to the drive range (D range or R range), torque is output from the drive motor 3. The torque output from the drive motor 3 is amplified by the power transmission mechanism 4 and then transmitted to the differential case 7.

[0082] When the differential case 7 rotates, a pair of pinion gears 8 are aligned with the central axis O of the differential case 7. 7 The pinion gear 8 rotates (revolves) around the center axis O of the differential case 7, and the pair of side gears 9a, 9b rotates around the center axis O of the differential case 7 based on the meshing of the teeth of the pinion gear 8 with the teeth of the side gears 9a, 9b. 7 It rotates around its own central axis, which is coaxial with the

[0083] When the side gear 9a on one axial side of the pair of side gears 9a, 9b rotates, the first shaft 28 coupled and fixed to the side gear 9a rotates. Then, when the force F acting on the engagement elements 34 in a direction in which the pair of pressing surfaces 68 approach the pressed surface 50 as the input portion 33 rotates becomes greater than the force f applied to the pair of engagement elements 34 by the pair of force application members 35, the reverse input cutoff clutch 30 switches to a locked state. As a result, the rotational torque transmitted to the first shaft 28 is transmitted to the second shaft 29, and the drive wheel 6 on one axial side supported on the tip of the second shaft 29 is rotationally driven.

[0084] On the other hand, when the side gear 9b on the other axial direction of the pair of side gears 9a, 9b rotates, the drive shaft 5b on the other axial direction which is connected and fixed to the side gear 9b is rotated, and further the drive wheel 6 on the other axial direction which is supported at the tip of the drive shaft 5b is rotated.

[0085] <When the vehicle is coasting at high speed> When the accelerator is released while the vehicle is traveling at high speed, immediately after that, due to the effect of inertia, the pair of engagement members 34 move toward the center axis O of the input portion 33 while keeping the pair of pressing surfaces 68 in contact with the pressed surface 50, as shown in Figs. 33 7, the bottom surface 70 of the engagement recess 69 presses against the connection surface 62 of the cam portion 57 on the opposite side in the longitudinal direction to the connection surface 62 that pressed against the bottom surface 70 when the drive torque was being transmitted from the drive motor 3.

[0086] On the other hand, after the transmission of the drive torque from the drive motor 3 stops with the accelerator being released, drag resistance acts on the input portion 33 based on the regenerative torque caused by the drive motor 3 operating as a generator, meshing resistance at the meshing portion of the differential device 1 and the power transmission mechanism 4, and the like. For this reason, a force in a direction that brings the pair of pressing surfaces 68 closer to the pressed surface 50 is applied to the pair of engagement elements 34 from the cam portion 57 as a reaction force against the bottom surface 70 of the engagement recess 69 pressing the connection surface portion 62. While the resultant force F of this force and the centrifugal force acting on the pair of engagement elements 34 is larger than the force f applied by the pair of force application members 35 to the pair of engagement elements 34, the reverse input cutoff clutch 30 is in a locked state as shown in FIG. 7, and the first shaft 28 rotates integrally with the second shaft 29 via the pair of engagement elements 34. Therefore, the rotational torque of the first shaft 28 (the drive shaft 5a on one axial side) and the drive shaft 5b on the other axial side is transmitted to the output shaft 3a of the drive motor 3 via the side gears 9a, 9b, the pinion gear 8, the differential case 7, and the power transmission mechanism 4. Then, the drive motor 3 operates as a generator, thereby performing regenerative braking.

[0087] In addition, when the vehicle is not coasting and is coasting at high speed, the difference in rotational speed between a pair of drive wheels 6 that occurs when cornering, etc. is absorbed by the pair of pinion gears 8 rotating (spinning) around the support shaft 18.

[0088] <When the vehicle is coasting at low speed> When the vehicle speed decreases due to regenerative braking, the centrifugal force acting on the pair of engaging elements 34 and the force acting from the cam portion 57 on the pair of engaging elements 34 to move the pair of pressing surfaces 68 radially outward in a direction to bring them closer to the pressed surface 50 become smaller. As a result, when the resultant force F becomes equal to or less than the force f applied by the pair of force application members 35 to the pair of engaging elements 34, the reverse input cutoff clutch 30 enters a free state as shown in FIG. 8. In this free state, the first shaft 28 and the second shaft 29 rotate freely relative to each other. In short, the driving wheel 6 on one axial side is disconnected from the driving motor 3 and the power transmission mechanism 4.

[0089] On the other hand, the rotation of the drive wheel 6 on the other axial side is transmitted to the pinion gear 8 through the meshing portion between the side gear 9b on the other axial side and the pinion gear 8, and the pinion gear 8 rotates (spins) around the support shaft 18. The rotation (spin) of the pinion gear 8 is transmitted to the side gear 9a on one axial side through the meshing portion between the pinion gear 8 and the side gear 9a on one axial side. Then, the first shaft 28 to which the side gear 9a on one axial side is fixedly coupled rotates idly relative to the second shaft 29 supporting the drive wheel 6 on one axial side. In this way, the first shaft 28 rotates idly relative to the second shaft 29, so that the drive wheel 6 on the other axial side is allowed to rotate, and the differential case 7 does not rotate. In short, the drive wheel 6 on the other axial side is disconnected from the drive motor 3 and the power transmission mechanism 4.

[0090] As described above, according to the differential gear 1 of this embodiment, when coasting at low speed (when the accelerator is off and the vehicle is traveling at low speed), the pair of drive wheels 6 can be separated from the power transmission mechanism 4 and the drive motor 3. This makes it possible to extend the distance traveled by coasting. In other words, it is possible to make the speed decrease during coasting more gradual. As a result, it is possible to improve the electric power consumption performance of a vehicle (electric vehicle) equipped with the differential gear 1.

[0091] In particular, in this example, one (one axial side) drive shaft 5a of the pair of drive shafts 5a, 5b is configured by combining a first shaft 28 and a second shaft 29 via a reverse input cutoff clutch 30. This makes it easy to switch between enabling and disabling torque transmission between the pair of drive wheels 6 and the power transmission mechanism 4 and drive motor 3. The reason for this will be explained below.

[0092] In the differential device 1 of this example, during non-coast running in which the pair of drive wheels 6 are rotationally driven based on torque output from the drive motor 3 by operating the accelerator, the reverse input cutoff clutch 30 switches to a locked state, and the first shaft 28 and the second shaft 29 rotate integrally. As a result, the torque from the drive motor 3 is transmitted to the pair of drive wheels 6 via the power transmission mechanism 4 and the differential device 1.

[0093] In contrast, during coasting with the accelerator released, the reverse input cutoff clutch 30 switches between connected and disconnected states depending on the rotational speed of the drive wheels 6 .

[0094] Specifically, while the rotation speed of the drive wheels 6 is high and a resultant force F of a force acting on the pair of engagement elements 34 based on the drag resistance of the input portion 33 in a direction that brings the pair of pressing surfaces 68 closer to the pressed surfaces 50 and a centrifugal force acting on the pair of engagement elements 34 is greater than a force f applied to the pair of engagement elements 34 by the pair of force application members 35. Therefore, the rotation torque of the pair of drive wheels 6 is transmitted to the output shaft 3a of the drive motor 3 via the power transmission mechanism 4, and regenerative braking is performed by the drive motor 3 operating as a generator.

[0095] On the other hand, the rotation speed of the drive wheel 6 slows down, and the resultant force F However, when the force applied by the pair of force application members 35 to the pair of engagement members 34 falls below the force f, the reverse input cutoff clutch 30 switches to a free state, and the first shaft 28 and the second shaft 29 rotate freely relative to each other. This disconnects the pair of drive wheels 6 from the drive motor 3 and the power transmission mechanism 4. This makes it possible to reduce losses at the meshing portions of the drive motor 3 and the power transmission mechanism 4, and to increase the distance traveled by coasting.

[0096] As described above, in the differential device 1 of this example, the reverse input cutoff clutch 30 is switched between on and off depending on the change in the rotation speed of the drive wheels 6 during coasting, thereby switching between the possibility of torque transmission between the pair of drive wheels 6 and the power transmission mechanism 4 and drive motor 3. Therefore, unlike the differential device described in JP 2020-46065 A, there is no need to strictly adjust the timing of connecting the clutch device. In short, it is possible to easily switch between the possibility of torque transmission between the pair of drive wheels 6 and the power transmission mechanism 4 and drive motor 3.

[0097] In the reverse input cutoff clutch 30 incorporated in the differential device 1 of this example, the pair of engagement members 34 have pressing surfaces 68 at two locations spaced apart in the circumferential direction on the radially outer surface. Therefore, according to the reverse input cutoff clutch 30 of this example, the frictional engagement force between the pressed surface 50 and the pair of pressing surfaces 68 can be increased by the wedge effect, compared to the reverse input cutoff clutch described in JP 2020-8124 A, in which one pressing surface is frictionally engaged with the pressed surface. Therefore, when the frictional engagement force between the output portion 32 and the engagement members 34 is the same, the reverse input cutoff clutch 30 of this example can have a smaller outer diameter dimension and / or axial dimension than the reverse input cutoff clutch described in JP 2020-8124 A.

[0098] In addition, in the reverse input cutoff clutch described in JP 2020-8124 A, the dimension in the second direction of the bottom surface of the engagement recess (input engagement recess) formed on the radially inner surface of the engagement element is made larger than the dimension in the major axis direction of the cam portion (input engagement cam) of the input member. Therefore, in a free state in which the input member and the output member rotate freely relative to each other, the engagement element may shift in the second direction relative to the input member. For this reason, it is necessary to ensure that the radial dimension of the gap between the pressed surface and the pressing surface in the free state is relatively large.

[0099] In contrast, in the reverse input cutoff clutch 30 of this example, in the free state, the short axis direction end of the cam portion 57 of the input portion 33 and the engagement recesses 69 of the pair of engagement members 34 are engaged in the second direction without rattling. Therefore, in the free state, the pair of engagement members 34 can be prevented from shifting in the second direction relative to the input portion 33. Therefore, the radial dimension of the gap 76 between the pressed surface 50 and the pair of pressing surfaces 68 in the free state can be reduced. From this perspective, the reverse input cutoff clutch 30 of this example is easier to further miniaturize than the reverse input cutoff clutch described in JP 2020-8124 A.

[0100] In the reverse input cutoff clutch 30 of this embodiment, the width dimension of the cam portion 57 in the major axis direction is made smaller toward the end in the minor axis direction, and the width dimension of the engagement recess 69 in the second direction is made larger toward the opening side. Therefore, as shown in FIG. 6 (or FIG. 7)→FIG. 8 and FIG. 9(A) (or FIG. 9(B))→FIG. 9(C), when the reverse input cutoff clutch 30 switches from the locked state to the free state, the pair of side portions 71 located on both sides of the engagement recess 69 in the second direction are guided by the pair of connection surface portions 62 located on both sides of the major axis direction of the minor axis end of the cam portion 57, thereby restricting the pair of engagement pieces 34 from moving in the second direction. Therefore, even when the minor axis direction end of the cam portion 57 of the input portion 33 and the engagement recess 69 of the pair of engagement pieces 34 are engaged with each other without rattling in the second direction in the free state, the switch from the locked state to the free state can be made smoothly.

[0101] In the differential device 1 of this example, the minimum value of the circumscribing circle diameter of the cam portion 57 of the first shaft 28 (the distance between the pair of first flat surface portions 60) is smaller than the portion of the first shaft 28 that is joined and fixed to the side gear 9a on one axial side (the outer diameter of the male spline portion 27). However, although not shown in the drawings, when implementing the present invention, the minimum value of the circumscribing circle diameter of the cam portion can also be made larger than the portion of the first shaft that is joined and fixed to the side gear.

[0102] In addition, the reverse input cutoff clutch 30 of this example has one pair (two pieces) of the engagers 34, but when implementing the present invention, the number of engagers constituting the reverse input cutoff clutch can be one or three or more. In addition, the engagement structure between the input part and the output part and the engagers is not limited to the structure shown in the embodiment. As long as the rotation of the input part can be converted into the radial movement of the engagers, various conventionally known structures can be adopted. In addition, the force applying member can be of various structures as long as it is a structure that can apply force to the engagers so that a pair of pressing surfaces move away from the pressed surface. In addition, the number of force applying members incorporated in the reverse input cutoff clutch device is not limited to two, and may be one, or three or more. When only one force applying member is provided, the force applying member can be disposed in a through hole formed in the cam part.

[0103] Furthermore, when implementing the differential with disconnect mechanism of the present invention, the reverse input cutoff clutch can be of any structure as long as it rotates the first shaft and the second shaft together when the rotation speed of the first shaft is greater than a predetermined value, and causes the first shaft and the second shaft to rotate freely relative to each other when the rotation speed of the first shaft is equal to or less than the predetermined value. For example, instead of the reverse input cutoff clutch 30 of this example, the reverse input cutoff clutch described in JP 2020-8124 A can also be used.

[0104] In addition, the differential with disconnect mechanism of the present invention is not limited to the drive device of an electric vehicle (EV) using a drive motor as a drive source, but can also be used in the drive device of a fossil fuel vehicle using an engine as a drive source, or in a hybrid vehicle using a drive motor and an engine as a drive source. stomach The present invention can also be applied to drive units for hybrid vehicles (HVs). [Explanation of symbols]

[0105] 1 Differential device 2. Electric vehicle drive system 3 Drive motor 3a Output shaft 4 Power transmission mechanism 4a Drive gear 4b Intermediate shaft 4c intermediate gear 4d final reduction gear 5a, 5b Drive shaft 6 Drive wheels 7 Differential Case 8 Pinion gear 9a, 9b Side gear 10 Ring gear 11 Case material 12 Gear parts 13a, 13b Small diameter cylinder part 14a, 14b Connection 15 Large diameter cylinder 16 circular hole 17 Outward flange 18 Support shaft 19a, 19b Tapered roller bearings 20 Fixed part 21 Cylindrical part 22 Inward flange 23 Volts 24 Center hole 25 Radial bearing 26 Spline hole 27 Male spline part 28 1st Shaft 29 Second Shaft 30 Reverse input cutoff clutch 31 Housing 32 Output section 33 Input section 34 Engagement element 35 Force applying member 36 Side plate part 37 Large diameter cylinder 38 Small diameter cylinder part 39 Inward flange 40 through hole 41 Volts 42 Output shaft 43 Cylindrical section 44 Side plate part 45 Small diameter section 46 Large diameter section 47 Small diameter cylindrical surface part 48 Large diameter cylindrical surface 49 Step 50 Pressed surface 51 Radial needle bearing 52 Outer ring 53 Cage 54 Needle 55 Sealing material 56 Large diameter shaft 57 Cam section 58 Small diameter shaft 59 Outward flange 60 1st flat surface section 61 2nd flat surface part 62 Connection surface 63a, 63b Radial rolling bearings 67a, 67b, 67c, 67d Retaining ring 68 Pressing surface 69 Engagement recess 70 Bottom 71 Side part 72 Cutout 73 Locking hole 74 Coil section 75 Locking arm 76 Gap 77 Screw hole

Claims

1. A differential case having a torque input portion; At least one pinion gear supported on the differential case so as to be rotatable about an axis perpendicular to the central axis of the differential case; A pair of side gears that are supported coaxially with a central axis of the differential case so as to be capable of rotating relative to the differential case and mesh with the pinion gears; a pair of drive shafts, each having a base end portion fixedly coupled to the pair of side gears; Equipped with One of the pair of drive shafts is a first shaft having a base end portion fixedly coupled to one of the pair of side gears; A second shaft arranged coaxially with the first shaft; a reverse input cutoff clutch connecting the first shaft and the second shaft; It has the reverse input cutoff clutch rotates the first shaft and the second shaft integrally when the rotation speed of the first shaft is greater than a predetermined value, whereas the reverse input cutoff clutch rotates the first shaft and the second shaft idly relative to each other when the rotation speed of the first shaft is equal to or less than the predetermined value; The reverse input cutoff clutch is an output portion having a pressed surface on an inner circumferential surface thereof and rotating integrally with the second shaft; an input portion having a cam portion disposed radially inside the pressed surface and rotating integrally with the first shaft; an engaging element having a pressing surface facing the pressed surface and disposed between the pressed surface and the cam portion in a radial direction; a force applying member that applies a force to the engaging element in a direction in which the pressing surface moves away from the pressed surface; Equipped with When a force acting on the engaging element in a direction bringing the pressing surface closer to the pressed surface due to the rotation of the input portion and the rotation of the engaging element is greater than the force applied to the engaging element by the force application member, the engaging element moves radially in a direction bringing the pressing surface closer to the pressed surface, frictionally engaging the pressing surface with the pressed surface, and causing the input portion and the output portion to rotate integrally. On the other hand, when the input portion is not rotating or a force acting on the engaging element in a direction bringing the pressing surface closer to the pressed surface due to the rotation of the input portion and the rotation of the engaging element is equal to or less than the force applied to the engaging element by the force application member, a gap is formed between the pressed surface and the pressing surface based on the force applied to the engaging element by the force application member, thereby causing the input portion and the output portion to rotate freely relative to each other. The input portion has an input portion-side guide portion, and the engaging element has an engaging element-side guide portion, In a state in which the gap is formed between the pressed surface and the pressing surface based on the force applied by the force application member to the engaging element, the input portion side guide portion and the engaging element side guide portion engage with each other without any rattling in a first direction which is a direction in which the pressing surface approaches or approaches the pressed surface and a second direction which is perpendicular to the central axis of the input portion. Differential with disconnect mechanism.

2. The engaging element has a pair of pressing surfaces spaced apart from each other in the circumferential direction.

2. The differential with disconnect mechanism according to claim 1.

3. A pair of the engaging members are provided so as to sandwich the cam portion from the radially outer side.

3. The differential with disconnect mechanism according to claim 1 or 2.

4. The force application member is provided so as to span between the pair of engagement elements.

4. The differential with disconnect mechanism according to claim 3.

5. The force application member is made of an elastic member.

5. The differential with disconnect mechanism according to claim 1.

6. a minimum value of a circumscribing circle diameter of the cam portion is larger than an outer diameter of a portion of the first shaft that is fixedly coupled to the one side gear; 6. The differential with disconnect mechanism according to claim 1.

Images