CN107448504B

CN107448504B - Differential gear

Info

Publication number: CN107448504B
Application number: CN201710223872.8A
Authority: CN
Inventors: 神谷康宪; 鬼武稔; 吉坂正; 金鹤
Original assignee: JTEKT Corp
Current assignee: JTEKT Corp
Priority date: 2016-04-07
Filing date: 2017-04-07
Publication date: 2020-06-16
Anticipated expiration: 2037-04-07
Also published as: CN107435722A; CN107448504A; DE102017107218A1; DE102017107217A1; CN107435723A; CN107435723B; DE102017107219A1

Abstract

The invention provides a differential device. The differential device includes a differential mechanism, a differential case accommodating the differential mechanism, and a clutch mechanism transmitting a driving force between the differential case and the differential mechanism. The clutch mechanism includes a sliding member and an actuator that are movable in an axial direction within a differential case. The slide member has a first engagement portion at one end portion in the axial direction, and is movable in the axial direction relative to the differential mechanism and is not rotatable relative thereto. The differential case is formed by joining first and second case members, and the first case member integrally has a second meshing portion and a flange portion that connects the ring gear. When the actuator is operated, the first engagement portion engages with the second engagement portion, and the differential case and the slide member are connected so as to be incapable of relative rotation.

Description

Differential gear

Technical Field

The present invention relates to a differential device that outputs an input driving force from a pair of output members in a manner allowing a differential operation.

Background

Conventionally, a differential device that outputs an input driving force from a pair of output members so as to allow a differential operation is used, for example, as a differential device of a vehicle. Such a differential device has a structure capable of blocking transmission of an input driving force to an output member. For example, refer to Japanese patent laid-open No. 2015-87015.

The differential device described in japanese patent laid-open publication No. 2015-87015 includes: a differential mechanism having 2 differential gears and 2 sideshaft gears supported by shaft-like journals; a differential case (housing) that houses the differential mechanism; a carrier element rotatably housed in the differential case; a second clutch portion fixed to the carrier element; a first clutch portion engageable with the second clutch portion; and an actuator for moving the first clutch part in the axial direction relative to the second clutch part. Driving force is input to the differential case from a drive gear fixed to the outer peripheral surface by welding or bolting. The carrier element is provided with 2 bores, and a journal is inserted into the bores and fixed by fixing pins.

The first clutch portion has an annular portion and a plurality of axial projections projecting from the annular portion in the axial direction, and a toothed annular segment meshing with the second clutch portion is provided at the tip of the axial projections. The annular portion of the first clutch portion is disposed outside the differential case, and the axial projecting portion is inserted through an axial hole formed in a side wall of the differential case. Thus, the first clutch part is connected to the differential case so as to be relatively movable in the axial direction and relatively non-rotatable.

When the first clutch part moves axially toward the second clutch part by the operation of the actuator, the toothed annular segment of the axial protrusion engages with the second clutch part, and the carrier element rotates integrally with the differential case. Thus, the driving force input from the drive gear to the differential case is transmitted to the differential gear via the first clutch portion, the second clutch portion, and the carrier element.

On the other hand, when the actuator is in the non-operating state, the first clutch part is disengaged from the second clutch part by the return spring to release the engagement thereof, and the carrier element is rotatable relative to the differential case. Thereby, transmission of the driving force from the differential case to the differential mechanism is blocked.

In the differential device described in japanese patent application laid-open publication No. 2015-87015, the driving force input to the differential case is transmitted to the first clutch portion via the side wall. However, since the side wall is formed with a plurality of axial holes for inserting the axial protrusions, it is structurally difficult to ensure strength. That is, in order to transmit sufficient driving force to the first clutch part while ensuring the strength of the side wall, the thickness of the differential case must be increased, which leads to an increase in weight and size.

Disclosure of Invention

An object of the present invention is to provide a differential device capable of turning on or off the transmission of drive force and suppressing an increase in weight and size of a differential case.

A differential device according to an aspect of the present invention includes:

a differential mechanism that distributes a driving force input to an input member to a pair of output members in a manner that allows differentiation;

a differential case that houses the differential mechanism; and

a clutch mechanism that transmits the driving force between the differential case and the input member of the differential mechanism, wherein,

the clutch mechanism includes: a slide member disposed in the differential case so as to be relatively movable and relatively non-rotatable with respect to the differential mechanism in a center axis direction along a rotation axis of the differential case; and an actuator that applies a moving force to the slide member in the central axis direction, wherein the slide member has a first engagement portion that is provided at one end in the central axis direction and that has a plurality of engagement teeth, the differential case is formed by coupling a plurality of case members, and a first case member of the plurality of case members includes: a second engaging portion formed at a position opposite to the first engaging portion in the center axis direction and having a plurality of engaging teeth; and an engagement portion that is engaged with an input gear that rotates integrally with the differential case, and that switches between a connected state in which the first engagement portion and the second engagement portion are engaged in the circumferential direction and the slide member and the differential case are connected so as to be relatively non-rotatable, and a disconnected state in which the slide member and the differential case are relatively rotatable, by operation and non-operation of the actuator.

According to the differential device of the above aspect, the drive force transmission can be turned on or off while suppressing an increase in the weight and size of the differential case.

Drawings

The foregoing and other features and advantages of the invention will be apparent from the following description of the preferred embodiments, as illustrated in the accompanying drawings in which like reference characters refer to the same parts throughout the several views.

Fig. 1 is a sectional view showing an example of a configuration of a differential device according to a first embodiment of the present invention.

Fig. 2 is an exploded perspective view of the differential device.

Fig. 3 is a perspective view showing a slide member of the differential device.

Fig. 4 is a perspective view showing a differential mechanism of the differential device.

Fig. 5 is an exploded perspective view of the differential mechanism.

Fig. 6 is an enlarged cross-sectional view of a part of the differential device.

Fig. 7A is an explanatory diagram illustrating an operation of the differential device, and illustrates a state in which the actuator does not operate.

Fig. 7B is an explanatory diagram illustrating the operation of the differential device, and illustrates a state in which the actuator operates.

Fig. 8 is an exploded perspective view showing a differential mechanism according to a second embodiment of the present invention together with a slide member.

Fig. 9 is a partial cross-sectional view showing the cross sections of the first to third pinion shafts, the first support member, and the second support member of the differential mechanism.

Fig. 10 is a configuration diagram showing the pinion support member as the input member of the differential mechanism of the present embodiment.

Detailed Description

A first embodiment of the present invention will be described with reference to fig. 1 to 7B.

Fig. 1 is a sectional view showing an example of a configuration of a differential device according to a first embodiment of the present invention. Fig. 2 is an exploded perspective view of the differential device. Fig. 3 is a perspective view showing a slide member of the differential device. Fig. 4 is a perspective view showing a differential mechanism of the differential device. Fig. 5 is an exploded perspective view of the differential mechanism. Fig. 6 is an enlarged cross-sectional view of a part of the differential device. Fig. 7A is an explanatory diagram illustrating an operation of the differential device, and illustrates a state in which the actuator does not operate. Fig. 7B is an explanatory diagram illustrating the operation of the differential device, and illustrates a state in which the actuator operates.

The differential device 1 is used to distribute the driving force of a driving source such as an engine of a vehicle to a pair of output shafts so as to allow a differential motion. More specifically, the differential device 1 of the present embodiment is mounted on a four-wheel drive vehicle having a pair of left and right main drive wheels (for example, front wheels) to which the drive force of a drive source is constantly transmitted and a pair of left and right auxiliary drive wheels (for example, rear wheels) to which the drive force of the drive source is transmitted according to a traveling state, and is used as a differential device that distributes the drive force to the left and right auxiliary drive wheels. When the driving force is transmitted only to the main driving wheels, the vehicle is in a two-wheel drive state, and when the driving force is transmitted to the main driving wheels and the auxiliary driving wheels, the vehicle is in a four-wheel drive state. The differential device 1 distributes the input driving force to the right and left drive shafts on the auxiliary drive wheel side in the four-wheel drive state.

The differential device 1 includes: a differential case 2 rotatably supported by a differential carrier not shown; a differential mechanism 3 housed in the differential case 2; a clutch mechanism 4 that can transmit a driving force between the differential case 2 and the differential mechanism 3 in an on-off manner. Lubricating oil for lubricating the differential mechanism 3 is introduced into the differential case 2.

The differential mechanism 3 includes a pinion shaft 30 as an input member, a plurality of (4) pinion wheels 31 supported rotatably about the rotation axis O of the differential case 2, and a pair of side gears 32 as a pair of output members. The pinion 31 and the pair of side gears 32 are formed by bevel gears, and the pinion shafts are orthogonal to each other and mesh with each other. The left and right drive shafts are connected to the pair of side gears 32 so as to be relatively non-rotatable. Although a plurality of pinion teeth are formed on the pinion 31 and the side gear 32, these pinion teeth are not shown in fig. 2, 4, and 5.

The differential mechanism 3 outputs the drive power input to the pinion shaft 30 to the pair of drive shafts so as to allow differential motion. In this embodiment, the differential mechanism 3 has a pair of

pinion shafts

30, 2 of the 4 pinion 31 are supported on one pinion shaft 30, and the other 2 pinion 31 are supported on the other pinion shaft 30.

As shown in fig. 5, each pinion shaft 30 integrally has a pair of engaged portions 301 that engage with a slide member 5 of a clutch mechanism 4 described later, a pair of pinion supports 302 that pass through the pinion 31, and a connection portion 303 that connects the pair of pinion supports 302, and is formed in a shaft shape as a whole. The pair of engaged portions 301 are provided at both ends of the pinion shaft 30, and the connection portion 303 is provided at the axial center of the pinion shaft 30. The pair of pinion support portions 302 are provided between each of the pair of engaged portions 301 and the connection portion 303, and support the pinion 31.

The pair of pinion shafts 30 are engaged with each other at the axial center portions thereof. Specifically, the connection 303 of the other pinion 30 is fitted in the recess 300 formed between the pair of pinion supports 302 of the one pinion 30, and the connection 303 of the one pinion 30 is fitted in the recess 300 formed between the pair of pinion supports 302 of the other pinion 30. The pinion shafts 30 are orthogonal to each other when viewed along the rotation axis O of the differential case 2.

The clutch mechanism 4 includes a slide member 5 movable in a center axis direction along the rotation axis O of the differential case 2, an actuator 6 that applies a moving force in the center axis direction to the slide member 5, and a pressing member 7 disposed between the slide member 5 and the actuator 6. The slide member 5 is disposed inside the differential case 2. The actuator 6 is disposed outside the differential case 2. The pressing member 7 transmits the moving force of the actuator 6 to the slide member 5. The slide member 5 is pushed and moved in the center axis direction by the pushing member 7.

The slide member 5 is a cylindrical member having a central axis that coincides with the rotation axis O of the differential case 2, and is arranged to be relatively movable and relatively non-rotatable with respect to the differential mechanism 3 in a central axis direction along the rotation axis O of the differential case 2. The sliding member 5 is formed by forging a steel material, and as shown in fig. 3, integrally includes: a first engaging portion 51 provided at one end portion in the central axis direction and having a plurality of engaging teeth 510; an annular inner flange portion 52 provided to protrude inward of the first engagement portion 51; and a cylindrical section 53 having an engagement section 530 that engages with the pinion shaft 30 in the circumferential direction. The first engagement portion 51 engages with a second engagement portion 211 (described later) provided in the differential case 2 in the circumferential direction. The engaging portion 530 is a groove extending along the central axis direction of the slide member 5 and penetrates between the inner and outer circumferential surfaces of the cylindrical portion 53.

The engaged portions 301 provided at both ends of the pinion shaft 30 engage with the engaging portions 530. By engaging the engaged portion 301 of the pinion shaft 30 with the engaging portion 530 of the slide member 5, the slide member 5 is relatively movable in the central axis direction and relatively non-rotatable with respect to the plurality of pinion 31 supported on the pinion shaft 30. The pinion 31 rotates (revolves) around the rotation axis O of the differential case 2 together with the slide member 5. In the present embodiment, 4 engaging portions 530 are formed in the cylindrical portion 53 so that the engaged portions 301 provided at both ends of the pinion shafts 30 engage with the slide members 5.

As shown in fig. 7A and 7B, the washer 33 is disposed between the rear surface 31a of the pinion 31 and the inner peripheral surface 53a of the cylindrical portion 53 of the slide member 5. The inner surface 33a of the washer 33 facing the rear surface 31a of the pinion 31 is partially spherical, and the outer surface 33b facing the inner peripheral surface 53a of the cylindrical portion 53 of the slide member 5 is planar. When the pinion 31 rotates (turns) about the pinion shaft 30, the rear surface 31a of the pinion 31 slides on the inner surface 33a of the washer 33. When the slide member 5 moves in the central axis direction with respect to the pinion shaft 30, the inner peripheral surface 53a of the cylindrical portion 53 of the slide member 5 slides on the outer surface 33b of the washer 33.

Further, a plurality of openings 531 for flowing the lubricating oil are formed in the cylindrical portion 53 of the sliding member 5. In the present embodiment, the 4 openings 531 are formed at equal intervals in the circumferential direction of the cylindrical portion 53. The opening 531 penetrates the cylindrical portion 53 in the radial direction, and opens to the other end portion on the opposite side of the first engagement portion 51. However, the shape and the number of the openings 531 are not limited to this, and the shape may be changed as appropriate to increase or decrease the number.

The inner flange portion 52 of the slide member 5 has an annular receiving surface 52a that receives the biasing force of the biasing member 81 described later. Further, a plurality of fitting portions 520 to be fitted to a plurality of projections 821 (see fig. 2) of the holding member 82 holding the biasing member 81 are formed in the inner flange portion 52. The fitting portion 520 is formed inside the receiving surface 52 a.

The pressing member 7 has: an annular portion 71 abutting against an axial end surface 53b of the cylindrical portion 53 of the slide member 5 on the opposite side of the first engagement portion 51; and a plurality of shaft portions 72 extending from the annular portion 71 in parallel with the rotation axis O of the differential case 2. In the present embodiment, the pressing member 7 is provided with 3 shaft portions 72. The pressing member 7 is formed by pressing a steel plate, and a tip end portion (an end portion opposite to a base end portion on the side of the annular portion 71) of the shaft portion 72 is bent inward.

The actuator 6 includes: an annular electromagnet 61 having a coil winding 611 and a molded resin portion 612 for molding the coil winding 611; a yoke 62 serving as a magnetic path of the magnetic flux of the electromagnet 61 generated by the energization of the coil winding 611; and an armature 63 that is guided in the direction of the rotation axis O of the differential case 2 in sliding contact with the molded resin portion 612. The cross-sectional shape of the molded resin portion 612 along the rotation axis O is a rectangular shape. The armature 63 moves the slide member 5 in a direction in which the first engagement portion 51 engages with the second engagement portion 211 of the differential case 2 by a magnetic force generated by energization to the coil winding 611. The slide member 5 causes the first engagement portion 51 to engage with the second engagement portion 211 by the moving force of the actuator 6 transmitted via the pressing member 7.

An excitation current is supplied to the coil winding 611 via an electric wire 610 (see fig. 2) from a control device (not shown). The actuator 6 operates by supplying an excitation current to the coil winding 611. Since the actuator 6 is disposed outside the differential case 2, the current can be supplied to the coil winding 611 relatively easily. The yoke 62 is made of a soft magnetic metal such as mild steel, and integrally includes a cylindrical portion 621 covering the inner circumferential surface 612b of the mold resin portion 612 from the inside, and a flange portion 622 protruding outward from one end portion in the axial direction of the cylindrical portion 621 and covering the axial end surface 612c of the mold resin portion 612, as shown in fig. 6. The inner diameter of the cylindrical portion 621 is formed slightly larger than the outer diameter of the differential case 2 at the portion facing the inner circumferential surface 621a of the cylindrical portion 621.

An annular recess 620 is formed in an inner circumferential surface 621a of the cylindrical portion 621, and the annular recess 620 is fitted into a plurality of (3 in the present embodiment) plates 84 made of a non-magnetic material fixed to the differential case 2 by press-fitting pins 83. The yoke 62 is restricted from moving in the axial direction relative to the differential case 2 by fitting the plate 84 into the annular recess 620. The axial width of the annular recess 620 is formed larger than the thickness of the plate 84 to avoid the generation of rotational resistance with the yoke 62 when the differential case 2 rotates.

A stopper ring 64 is fixed to an end of the cylindrical portion 621 of the yoke 62 opposite to the flange portion 622. The stopper ring 64 is made of a nonmagnetic metal such as austenitic stainless steel, and integrally includes an annular portion 641 fixed to the yoke 62, a pair of protrusions 642 protruding from the annular portion 641 in the axial direction at two circumferential positions, and a folded portion 643 folded back at an acute angle from a distal end portion of the protrusion 642. The pair of protrusions 642 of the stopper ring 64 is locked to a differential carrier, not shown, and is prevented from rotating. The annular portion 641 is fixed to the yoke 62 by welding, for example.

The armature 63 is made of soft magnetic metal such as mild steel, and integrally includes an annular outer ring portion 631 disposed on the outer periphery of the electromagnet 61 and a side plate portion 632 axially opposed to the electromagnet 61. The outer ring 631 is cylindrical and covers the electromagnet 61 from the outer periphery. The side plate portion 632 protrudes inward from one end portion in the axial direction of the outer ring portion 631. The side plate portion 632 axially faces an axial end surface 612d of the mold resin portion 612 (an end surface on the opposite side of the axial end surface 612c facing the flange portion 622 of the yoke 62), the annular portion 641 of the stopper ring 64, and an axial end surface 621b of the cylindrical portion 621 of the yoke 62.

The inner peripheral surface 631a of the outer ring portion 631 of the armature 63 is supported by the electromagnet 61 in contact with the outer peripheral surface 612a of the molded resin portion 612. When the armature 63 moves in the axial direction, the inner peripheral surface 631a of the outer ring portion 631 slides on the outer peripheral surface 612a of the molded resin portion 612.

As shown in fig. 2, an engagement hole 632a that engages with the protrusion 642 of the stopper ring 64, a wire insertion hole 632b through which the wire 610 is inserted, and a plurality of (9 in the example shown in fig. 2) oil holes 632c through which the lubricating oil flows are formed in the side plate portion 632 of the armature 63. The tip end of the shaft portion 72 of the pressing member 7 abuts against the inner peripheral end of the side plate portion 632. The armature 63 is prevented from falling off the stopper ring 64 by the folded-back portion 643 of the stopper ring 64, and is prevented from rotating relative to the differential carrier by the projection 642 engaging with the engagement hole 632 a. The protrusion 642 of the stopper ring 64 is inserted through the engagement hole 632a and locked to the differential carrier.

The differential case 2 couples the first case member 21 and the second case member 22 juxtaposed in the direction of the rotation axis O. Annular plate-shaped washers 34 are disposed between the pair of side gears 32 of the differential mechanism 3 and the first and

second case members

21 and 22, respectively.

The second case member 22 is a bottomed cylindrical shape that houses the differential mechanism 3 and the slide member 5, and integrally has a cylindrical portion 221 that is cylindrical, a wall portion 222 that protrudes inward from one end portion of the cylindrical portion 221 on the side opposite to the end portion on the first case member 21 side, and a flange portion 223 that protrudes outward from the other end portion of the cylindrical portion 221. The electromagnet 61 and the yoke 62 are disposed at a corner between the cylindrical portion 221 and the wall portion 222.

The cylindrical portion 221 is formed with a plurality of oil holes 221a through which lubricating oil flows. The wall portion 222 is formed with a plurality of (3) insertion holes 222a for transmitting the moving force of the actuator 6 to the slide member 5, and a shaft insertion hole 222b into which a drive shaft coupled to one side gear 32 of the pair of side gears 32 is inserted so as to be relatively non-rotatable. The plurality of shaft portions 72 of the pressing member 7 are inserted into the insertion holes 222a, respectively. The plurality of insertion holes 222a and the shaft insertion holes 222b penetrate the wall portion 222 in a direction parallel to the rotation axis O.

The first case member 21 is formed by forging, for example, and has a disk shape covering the opening of the second case member 22, and integrally includes a second engagement portion 211 and a flange portion 212, the second engagement portion 211 having a plurality of engagement teeth 210, and the flange portion 212 abutting against the flange portion 223 of the second case member 22. The second engagement portion 211 is formed at a position facing the first engagement portion 51 along the central axis direction of the slide member 5. The slide member 5 is disposed between the second engagement portion 211 of the first housing member 21 and the wall portion 222 of the second housing member 22. The first housing member 21 is formed with a shaft insertion hole 21a into which a drive shaft coupled to the other side gear 32 of the pair of side gears 32 is inserted so as to be relatively non-rotatable.

A driving force is input to the differential case 2 from the ring gear 23 (see fig. 1) as an input gear fixed to the

flange portions

212 and 223 of the first and

second case members

21 and 22. The

flange portions

212, 223 function as joint portions to which the ring gear 23 is joined. In the present embodiment, the ring gear 23 is fixed so as to rotate integrally with the differential case 2 by the plurality of coupling bolts 24 that are inserted through the plurality of bolt insertion holes 212a formed in the flange portion 212 of the first case member 21 and the plurality of bolt insertion holes 223a formed in the flange portion 223 of the second case member 22. The head portion 241 of the coupling bolt 24 abuts against the flange portion 212 of the first housing member 21, and the shaft portion 242 formed with the male screw is inserted into the

bolt insertion holes

212a, 223a and screwed into the screw hole 23a of the ring gear 23.

The means for fixing the ring gear 23 to the differential case 2 is not limited to bolting, and the ring gear 23 may be fixed to the first case member 21 by welding, for example. In this case, the portion of the first housing member 21 to which the ring gear 23 is welded serves as a joint portion.

The first case member 21 and the second case member 22 are coupled by a plurality of coupling bolts 25 (see fig. 2). In the present embodiment, the first casing member 21 and the second casing member 22 are joined by the 4 joining bolts 25 before the ring gear 23 is joined. In fig. 2, 3 of the coupling bolts 25 are illustrated. The coupling bolt 25 is inserted into a bolt insertion hole 223b formed in the flange portion 223 of the second case member 22 and is screwed into the screw hole 212b formed in the first case member 21.

An urging member 81 made of an elastic body and a holding member 82 for holding the urging member 81 are disposed between the first housing member 21 and the inner flange portion 52 of the slide member 5. The holding member 82 has an annular

main body portion

820 and 3 protrusions 821 projecting from the main body portion 820 toward the wall portion 222 of the second case member 22. The holding member 82 is prevented from rotating with respect to the slide member 5 by the projection 821 engaging with the engaging portion 520 formed in the inner flange portion 52 of the slide member 5.

The urging member 81 is compressed in the central axis direction of the slide member 5 by the operation of the actuator 6. The slide member 5 is biased toward the wall portion 222 of the second housing member 22 by the restoring force (biasing force) of the biasing member 81. The urging member 81 is formed of, for example, a coil spring, but is not limited thereto, and the urging member 81 may be formed of rubber. In the present embodiment, the biasing member 81 is in the form of a ring disposed between the differential mechanism 3 and the cylindrical portion 221 of the second casing member 22, but is not limited to this, and may be disposed at a plurality of locations facing the inner flange portion 52 of the slide member 5.

The differential device 1 switches between a coupled state in which the first engagement portion 51 and the second engagement portion 211 are engaged in the circumferential direction and the slide member 5 and the differential case 2 are coupled so as to be relatively non-rotatable, and an uncoupled state in which the slide member 5 and the differential case 2 are relatively rotatable, by the operation and the non-operation of the actuator 6.

Fig. 7A is a partial cross-sectional view showing the differential device 1 when the actuator 6 is not operated. Fig. 7B is a partial cross-sectional view showing the differential device 1 when the actuator 6 is operated.

When the actuator 6, to which the exciting current is not supplied to the coil winding 611 of the electromagnet 61, is not operated, the slide member 5 moves toward the wall portion 222 of the second housing member 22 by the restoring force of the urging member 81, and the engagement between the first engagement portion 51 and the second engagement portion 211 is released. When the electromagnet 61 is not energized, the armature 63 returns to the initial position separated from the wall portion 222 by the restoring force of the biasing member 81 transmitted through the sliding member 5 and the pressing member 7.

When the actuator 6 is not operated, the differential case 2 and the slide member 5 are relatively rotatable, and therefore transmission of the driving force from the differential case 2 to the differential mechanism 3 is blocked. Thus, the driving force input from the ring gear 23 to the differential case 2 is not transmitted to the drive shaft, and the vehicle is in a two-wheel drive state.

When a field current is supplied to the coil winding 611 of the electromagnet 61, the armature 63 is moved in the axial direction by the magnetic force of the electromagnet 61 so that the side plate portion 632 of the armature 63 approaches the axial end surface 621b of the cylindrical portion 621 of the yoke 62 (see fig. 6). Thereby, the pressing member 7 presses the slide member 5 toward the first housing member 21, and the first engagement portion 51 engages with the second engagement portion 211. Specifically, the pressing member 7 receives the moving force of the armature 63 from the distal end portion of the shaft portion 72, and presses the slide member 5 toward the first housing member 21 by the moving force. At this time, the annular portion 71 of the pressing member 7 abuts against the axial end surface 53b of the cylindrical portion 53 of the sliding member 5 on the opposite side of the first engagement portion 51.

When the first engagement part 51 and the second engagement part 211 engage with each other, the drive power input from the ring gear 23 to the first case member 21 of the differential case 2 is transmitted to the drive shaft via the slide member 5, the pair of pinion shafts 30, 4 pinion 31, and the pair of side gears 32 of the differential mechanism 3, and the vehicle is in a four-wheel drive state.

The axial position of the armature 63 is detected by the position sensor 10, and a detection signal thereof is sent to the control device. The position sensor 10 includes a contact 11 and a support body 12 that supports the contact 11. The contact 11 is movable forward and backward relative to the support body 12 in parallel with the rotation axis O of the differential case 2, and its tip end portion elastically contacts the side plate portion 632 of the armature 63. The support body 12 is fixed to the differential carrier. The control device can recognize the position of the armature 63 by the detection signal of the position sensor 10, and thereby can determine whether or not the first engagement portion 51 and the second engagement portion 211 are engaged.

When the actuator 6 is switched from the non-operating state to the operating state, the control device supplies the electromagnet 61 with an excitation current having a large current value that can rapidly move the slide member 5, and then, when it is determined that the first engagement portion 51 is engaged with the second engagement portion 211, reduces the current value of the excitation current to a relatively small current value to such an extent that the engaged state of the first engagement portion 51 and the second engagement portion 211 can be maintained. This can reduce power consumption.

According to the first embodiment described above, the differential case 2 is formed by joining the first case member 21 and the second case member 22, and the first case member 21 integrally has the flange portion 212 that connects the ring gear 23 and the second engagement portion 221 that engages with the first engagement portion 51 of the slide member 5. Thus, the drive power input from the ring gear 23 is transmitted to the slide member 5 only through the first casing member 21 of the first and

second casing members

21, 22, and is transmitted from the slide member 5 to the pinion shaft 30 of the differential mechanism 3. Therefore, the wall portion 222 of the second casing member 22, in which the plurality of insertion holes 222a through which the plurality of shaft portions 72 of the pressing member 7 are inserted, is not included in the transmission path of the driving force. This can suppress an increase in the weight and size of the differential case 2, and can turn on or off the drive force transmission by the axial movement of the slide member 5.

Next, a differential device according to a second embodiment of the present invention will be described with reference to fig. 8 and 9. The differential device of the present embodiment is configured in the same manner as the differential device 1 of the first embodiment except that the configuration of the input member of the differential mechanism is different from that of the first embodiment, and therefore, the different portions thereof will be described. In fig. 8 and 9, the same reference numerals are given to the constituent elements common to those of the first embodiment, and redundant description is omitted.

Fig. 8 is an exploded perspective view showing the differential mechanism 3A of the present embodiment together with the slide member 5. Fig. 9 is a partial cross-sectional view showing the first to third pinion shafts 35 to 37 of the differential mechanism 3A together with cross-sections of the first support member 381 and the second support member 382.

The differential mechanism 3A of the present embodiment has first to third pinion shafts 35 to 37 in the form of shafts, and 4 pinion shafts 31 are supported by the first to third pinion shafts 35 to 37. In fig. 8, illustration of the pair of side gears 32 meshing with the 4 pinion 31 is omitted. The first to third pinion shafts 35 to 37 are input members of the differential mechanism 3A. The differential mechanism 3A includes a first support member 381 and a second support member 382 for supporting the first to third pinion shafts 35 to 37.

The first pinion shaft 35 integrally has: a pair of engaged portions 351 that engage with the engaging portions 530 of the slide member 5; a pair of pinion supports 352 inserted through the pinion 31; and a connection portion 353 connecting the pair of pinion support portions 352. The second pinion shaft 36 has an engaged portion 361 that engages with the engagement portion 530 of the slide member 5 at one end, and a contact portion 363 that contacts the connection portion 353 of the first pinion shaft 35 at the other end. The second pinion shaft 36 has a pinion support 362 that is inserted into the pinion 31 between the engaged portion 361 and the impact portion 363.

The third pinion shaft 37 has an engaged portion 371 engaged with the engaging portion 530 of the slide member 5 on one end, a collision portion 373 colliding with the coupling portion 353 of the first pinion shaft 35 on the other end, and a pinion support 372 inserted into the pinion 31 between the engaged portion 371 and the collision portion 373, similarly to the second pinion shaft 36.

The first to third pinion shafts 35 to 37 are inserted into an insertion hole 381a formed in the first support member 381 and an insertion hole 382a formed in the second support member 382. The first support member 381 is cylindrical and is disposed inside the slide member 5. The second support member 382 has a square cylindrical shape and is disposed inside the first support member 381. The 4 pinion gears 31 are disposed between the first support member 381 and the second support member 382.

The first to third pinion shafts 35 to 37 are prevented from rotating with respect to the first support member 381 by 4 pins 383. In fig. 8, 3 of the pins 383 are illustrated. The first support member 381 has 4 pin insertion holes 381b through which the 4 pins 383 are inserted, respectively, and 4 oil holes 381c through which lubricating oil flows. In the

first pinion shaft

35, 2 pin insertion holes 35a are formed between the engaged portion 361 and the pinion support 362, and in the second and

third pinion shafts

36 and 37, 1

pin insertion hole

36a and 37a are formed between the engaged

portion

361 and 371 and the

pinion support

362 and 372, respectively. The 4 pins 383 are press-fitted and fixed to the

pin insertion holes

381b, 35a, 36a, and 37 a.

The present embodiment also provides the same operation and effects as those of the first embodiment.

Next, a differential device according to a third embodiment of the present invention will be described with reference to fig. 10. The differential device of the present embodiment is configured in the same manner as the differential device 1 of the first embodiment except that the configuration of the input member of the differential mechanism is different from that of the first embodiment, and therefore, the different portions thereof will be described. In fig. 10, the same reference numerals are given to the constituent elements common to those of the first embodiment, and redundant description is omitted.

Fig. 10 is a configuration diagram showing a pinion support member 39 as an input member of the differential mechanism of the present embodiment. In the present embodiment, the pinion support member 39 supporting the pinion 31 has 4 shaft portions 391 and a coupling portion 392 coupling the 4 shaft portions 391 to each other. Each shaft portion 391 has an engaged portion 391a engaged with the engaging portion 530 of the slide member 5 and a pinion support portion 391b that supports the pinion 31. Thus, the pinion support member 39 is provided with 4 shaft portions 391 in a radial shape and is integrally formed in a cross shape as viewed in the central axis direction, the end portions of the 4 shaft portions 391 engage with the engagement portions 530 of the slide member 5, and the 4 shaft portions 391 each support the pinion 31.

Claims

1. A differential device, comprising:

a differential case that houses the differential mechanism; and

the clutch mechanism includes: a slide member disposed in the differential case so as to be relatively movable and relatively non-rotatable with respect to the differential mechanism in a center axis direction along a rotation axis of the differential case; and an actuator for applying a moving force to the sliding member in the central axis direction,

the sliding member has a first engaging portion provided at one end portion in the central axis direction and having a plurality of engaging teeth,

the differential case is formed by joining a plurality of case members, and a first case member of the plurality of case members has: a second engaging portion formed at a position opposite to the first engaging portion in the center axis direction and having a plurality of engaging teeth; and an engaging portion engaged with an input gear rotating integrally with the differential case,

the actuator is configured to be switched between a coupled state in which the first engagement portion and the second engagement portion are engaged in the circumferential direction and the slide member and the differential case are coupled so as to be relatively non-rotatable, and a non-coupled state in which the slide member and the differential case are relatively rotatable.

2. The differential apparatus according to claim 1,

the clutch mechanism is configured such that the sliding member is disposed inside the differential case and the actuator is disposed outside the differential case, the moving force of the actuator is transmitted to the sliding member via a pressing member disposed between the actuator and the sliding member,

a second housing member of the plurality of housing members has a wall portion formed with a plurality of insertion holes, the slide member being disposed between the second engagement portion and the wall portion,

the pressing member has a plurality of shaft portions inserted through the plurality of insertion holes, respectively.

3. The differential apparatus according to claim 2,

the input gear is fixed to the differential case by a plurality of bolts,

the first housing member and the second housing member each have a flange portion in which a plurality of bolt insertion holes through which the plurality of bolts are inserted are formed.

4. The differential apparatus according to claim 2 or 3,

the second case member is a bottomed cylindrical shape that houses the differential mechanism and the slide member, and an opening of the second case member is covered with the first case member.