JP2002005262A - Differential device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a ball type differential device which can obtain a differential limiting force in a simple configuration according to an input torque. SOLUTION: In accordance with a torque inputted from an input shaft 17, a cam surface 34 pressing a ball 32 in the rotating center direction is formed on a holding plate 19. By the configuration in which the contact phase of the ball 32 in an output plate 30 is formed on a taper surface 30d extensively opening toward the outside diameter in the output plate, slippage between ball holding plate 19 and output plate 30 occurring in accordance with increase of the input torque to the differential device presses the ball 32 in the direction toward the rotational center by a cam phase 34, so that tapered surfaces 30d on the both sides are pressed and opened. The outward movement by both output plates 30 leads to increase of frictional force to a differential case 14, whereby an urging force is increased according to the output torque outputted from the side of the differential case. Ultimately respective shaft-type fitting parts and the differential case 14 in the output plate 30 are connected with a jaw clutch 29 so that the differential limiting force responsive to the input torque can be acquired.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a differential gear,
In particular, the present invention relates to a differential device that can obtain a differential limiting force according to a torque input from a differential case.

[0002]

2. Description of the Related Art Conventionally, differentials for driving wheels of automobiles are known as differentials. As a differential for driving wheels of an automobile, a differential mechanism is generally configured by combining four bevel gears,
In order to reduce costs, etc., the differential mechanism
There has been proposed a ball type differential device comprising a ball and an output plate arranged to be in pressure contact with the ball. One example is disclosed in JP-A-10-169758.

The differential mechanism of this differential device will be described with reference to FIG. 13. In FIG. 13, reference numeral 01 denotes a ball holding plate.
The ball holding plate 01 is attached to a ring gear (not shown) by a bolt inserted into a bolt hole 02. This ball holding plate 01
, Four accommodation rooms 03 are provided at equal intervals. The accommodation room 03 penetrates the ball holding plate 01 in the axial direction, so that the ball 04 can rotate in each accommodation room 03, and each of the opposing surfaces of a pair of left and right output plates 05. Is housed so as to be able to abut. Each output plate 05 is provided with an output shaft 06, and further provided with a disc spring (not shown) which functions to press both output plates 05 toward the respective balls 04. Have been.

In the above arrangement, when an input shaft (not shown) is rotated in response to the driving torque of the engine, the rotation rotates the ball holding plate 01 via the ring gear. When the ball holding plate 01 rotates, the ball 04 in the storage chamber 03 also rotates. Here, since the accommodation room 03 in which the ball 04 is accommodated is located at a position radially away from the center of rotation, the ball 04 is positioned above the center of rotation when the ball holding plate 01 rotates. Will orbit. Arrow A in FIG. 13 indicates ball holding plate 0.
1 shows the rotation direction.

[0005] On both sides of the ball 04, a pair of output planes is provided.
When the ball 04 revolves, the output plates 05 on both sides of the ball 04 receive a frictional force in the same direction when the ball 04 revolves. Plate 05 is rotated in the same direction. Each output plate 0
5 has an output shaft 06 attached to each.
Both drive wheels of the car rotate at the same rotational speed, and the car goes straight.

When the car is going to bend while the vehicle is running, a difference occurs in the external load torque applied to the drive wheels due to the rotation difference between the inner wheel and the outer wheel, and the two output shafts 06 are opposite to each other due to the torque difference. You will be twisted towards. Here, since the ball 04 is rotatably accommodated in the accommodation room 03 and can rotate, each ball 0
4 rotate in the direction indicated by the arrow B. Each ball 0
When the wheels 4 rotate in the directions indicated by the arrows B, a frictional force W is applied to the two output plates 05 in opposite directions, so that the two output plates 05 are rotated in opposite directions.

As described above, when the curve is going to bend, the ball 04 rotates while revolving, and the rotation of one of the output shafts 06 is added to the revolving rotation, and the other output shaft 06 is rotated. , The rotation is subtracted from the revolving rotation, so that a rotation difference occurs between the two output shafts 06. In this way, since both output shafts 06 are differential, the vehicle can smoothly travel the curve with a difference in rotation between the inner and outer wheels.

[0008]

By the way, in the above-mentioned conventional differential, the ball 04 pushes a disc spring as urging means between a pair of output plates 05 arranged on both sides thereof. It is clamped with friction based on pressure. Therefore, the slip load of the ball 04, that is, the engagement torque of the differential gear is determined by the pressing force at the time of the initial setting of the urging means. Therefore, in this differential device, the engagement torque is constant irrespective of the torque input to the device, and as a result, the biasing force of the biasing means increases according to the torque input to the device. There is an inconvenience that the characteristic, that is, the differential limiting force according to the input torque cannot be obtained.

As a result, this differential device cannot exhibit a non-slip function, that is, a function of automatically stopping the differential function as needed. Therefore, there is a problem that it is difficult to escape when one of the drive wheels slips on a muddy road or the like or when one of the drive wheels similarly slips on a snowy road.

An object of the present invention is to provide a ball type differential as described above which can obtain a differential limiting force in accordance with an input torque with a simple structure.

[0011]

SUMMARY OF THE INVENTION In order to solve the above-mentioned conventional problems, the invention according to claim 1 is the same as a differential case that rotates by receiving a torque input from an input shaft via a ring gear. A pair of output shafts disposed on an axis and rotatably supported by the differential case; and a differential mechanism disposed in the differential case, wherein the differential mechanism is provided with the differential case. A pair of opposing surfaces provided in the housing and disposed opposite to each other, and a back surface on the back side of each of the opposing surfaces to a disk portion disposed to face the differential case and the respective disk portions. A pair of output presses, each of which has a cylindrical shaft-type fitting portion which is formed to project at a right angle and is slidably supported in each of left and right receiving portions of the differential case in the direction of the rotation axis of the differential case. And the data so as to be interposed between the opposed surfaces of the output plates. A ball holding plate attached to a case, and a plurality of balls held by the ball holding plate so as to be able to abut on the respective opposing surfaces of the two output plates. And a preload spring for pressing the two output plates in directions approaching each other, wherein the differential mechanism causes the bobbin to increase as the torque input from the input shaft increases. The input plate is provided with an input torque responsive characteristic in which an urging force for pressing the output plate against the differential case via a steering wheel increases, and a differential lock is performed when the torque input from the input shaft exceeds a predetermined value. It is characterized by comprising.

According to the first aspect of the present invention, the differential mechanism presses the output plate to the differential case via a ball in accordance with the torque input from the input shaft. It has an input torque response characteristic in which the urging force is increased, so that a differential limiting force can be obtained according to the input torque, and when the input torque exceeds a predetermined value, the outer end of each shaft-type fitting portion and Since the differential case is connected, a differential lock state is established, and a so-called non-slip function is achieved.

Next, a second aspect of the present invention is to provide a differential case which is rotated by receiving a torque inputted from an input shaft via a ring gear, and which is arranged on the same axis so as to be rotatable by the differential case. A differential mechanism provided in the differential case, the differential mechanism being provided in the differential case and arranged to face each other; A pair of opposing surfaces and a disk portion arranged to face the back surface of the back surface of each of the opposing surfaces to face the differential case, and right and left sides of the differential case formed so as to protrude at right angles to the respective disk portions. A pair of output plates each having a cylindrical shaft-type fitting portion slidably supported by a receiving portion in the direction of the rotation axis of the differential case, and the opposed surfaces of the two output plates. A ball holding plate attached to the differential case so as to be interposed therebetween; A plurality of balls held by the ball holding plate so as to be able to abut on the respective opposing surfaces of the output plate, and for pressing the two output plates in a direction approaching each other. In a differential device formed by a preload spring, a cam surface for pressing the ball toward the rotation center of the differential device as the torque input from the input shaft increases increases. And the ball contact surface of the output plate is formed on a taper surface that expands in the outer diameter direction of the output plate, and is formed outside of each of the shaft-type fitting portions. A connecting member capable of connecting an end portion and the differential case is provided.

According to a second aspect of the present invention, there is provided the above-described structure, and as the input torque to the differential device increases, the ball-type motor is driven.
A displacement occurs between the ball holding plate and the output plate, and the displacement causes the ball to be pushed out by the cam surface in the direction of the center of rotation. This movement of the ball causes the taper surfaces on both sides to move. Is pushed open. As a result, the two output plates slide outwardly, and the sliding force of the two output plates outwardly increases the frictional force of each output plate against the differential case. As a result, it is possible to obtain an input torque responsive characteristic in which the urging force increases as the input torque input from the differential case increases. If the input torque exceeds a predetermined value,
Each of the shaft-type fitting portions is moved outwardly, and the outer end portion of the shaft-type fitting portion and the differential case are connected by a connecting member, so that the differential mechanism is in a differential lock state, so-called non-slip function. Will be played.

According to a third aspect of the present invention, in the second aspect of the present invention, the coupling member has one tooth formed at the outer end of each shaft-type fitting portion and one tooth formed at the one tooth. It is characterized in that it is constituted by a dog clutch comprising the other teeth formed on the differential case so as to be meshable. Therefore, according to the third aspect of the present invention, the effect that the outer end portion of each shaft-type fitting portion and the differential case can be securely connected with a simple structure can be obtained.

[0016] Further, the invention according to claim 4 is the invention according to claim 1.
The invention according to claim 3 is characterized in that a friction plate is interposed between the rear surface of the disk portion of each output plate and the differential case. Therefore, according to the present invention, the frictional force between the differential plate and the output plate can be increased, and as a result, the contact area between the output plate and the differential plate can be reduced. As a result, the size of the differential device can be reduced.

In each of the above-mentioned inventions, a ball type in which a differential mechanism is constituted by a plurality of balls and an output plate arranged so as to be pressed against the balls. Since this is a differential device, it is possible to reduce the manufacturing cost as compared with a differential device in which a bevel gear is combined.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A description will now be given of a differential device according to an embodiment of the present invention shown in FIGS. FIG. 1 is a front view showing an assembled state of an embodiment of the differential according to the present invention, FIG. 2 is a side view showing an assembled state of the differential, and FIG. FIG. 4 is a view showing the essential portion of the differential device when the dog clutch is connected, and FIG. 5 is a sectional view taken along the line BB in FIG. 2 showing the dog clutch not connected. 6, FIG. 6 shows a state in which the dog clutch is connected, FIG. 7 is an assembled view of main parts of the differential, FIG. 8 is an exploded sectional view of main parts of the differential, and FIG. FIG. 10 is a perspective view of the case in the direction of arrow D in FIG. 7, FIG. 11 is a perspective view of the output plate in the direction of arrow E in FIG. 7, and FIG. 3 is a perspective view in the direction of arrow F in FIG.

The main body housing 11 provided in the differential device 10 comprises a pair of left and right bowl-shaped members 11a and 11b and a bolt 11c for connecting each flange portion of both bowl-shaped members 11a and 11b. The main body housing 11 has a pair of bearing holes 12, 12 on the left and right sides in FIG.
Are arranged on a coaxial line, and rotating cases 14 are formed by bearings 13 mounted on the bearing holes 12.
Are rotatably supported. Also, body housing 1
1, the input bearing portion 15 is formed by a bearing hole 36, and the input shaft 17 can be rotated in a direction orthogonal to the rotation axis of the rotating case 14 by the bearing 16 attached thereto. It is supported by.

A bevel gear 18 is attached to the tip of the input shaft 17, and a drive shaft from an engine (not shown) is connected to the input shaft 17 on the side opposite to the bevel gear 18. Rotating case 1
Reference numeral 4 denotes a casting cap 14A, and a casting case 14 which is to be hollow-connected to the inward opening of the cap 14A.
B, a reinforcing rib 14 protrudes from the outer surface of the case 14B, and an inner space 24 is formed inside the rotating case 14.

Between the case 14B and the cap 14A,
A donut-shaped ball holding plate 19 is provided. Protrusions 14f and 14h are formed on the cap 14A and the case 14B in a direction opposite to the ball holding plate 19, and the protrusions 14f and 14h are formed on the inner surfaces of the bearings 13 and 13, respectively. And the rotating case 14 is rotatably supported by the main body housing 11.

A flange 21 is formed on the case 14B, and a bevel gear-shaped ring gear 22 is attached to the flange 21 with bolts 23.
And are engaged. The meshing between the bevel gear 18 and the ring gear 22 has a function of not only changing the rotation direction by 90 ° but also reducing the speed by the difference in the number of teeth.

The inner space 24 of the rotating case 14 has a bore.
The inner space 24 is divided into two chambers by a metal holding plate 19 and formed into two internal spaces.
f, 14h. In addition, insertion hole 2
Flat receiving portions 26, 26 parallel to the ball holding plate 19 are formed at the edges of the inner space 24 on the side of the inner space 24, and two disc springs 27, 27 are formed on the receiving portions. It is arranged.

A pair of left and right output shafts 28 are arranged on the rotating case 14 on the same axis as the rotating shaft with the ball holding plate 19 as the center. Each output shaft 28 extends to the inside of the internal space 24 through the bearing hole 12 of the main body housing 11 and the insertion hole 25 of the rotating case 14, and the outer end of each output shaft 28 is selected through a selection. The output plates 30 are connected to each other, and the axle 35 is connected to the other end.

Each of the output plates 30 is urged in a direction approaching each other, that is, toward the inside by disc springs 27, 27 via friction plates 31, 31 disposed outside thereof. Have been. And cap 14
A, the case 14B, the friction plates 31, 31, and the ball holding plate 19 are composed of a male screw 14e formed on the outer periphery of the cap 14A and a female screw 14g formed on the inner peripheral surface of the case 14B. Are integrated.

As shown in FIGS. 5 and 6, the ball holding plate 19 is formed of a donut-shaped thick plate having a planar shape, and has a ball 32 on its inner peripheral surface. A ball holding portion 33 for storing and holding the ball is formed. Twelve ball holding parts 33 are formed on the inner peripheral surface of the ball holding plate 19, and they are evenly spaced at the same distance from the center of rotation of the rotating case 14 in the radial direction. Placed and the ball
And is formed so as to penetrate through the holding plate 19 in the axial direction. Protrusions 19a are provided at 90 ° intervals on the outer periphery of the ball holding plate 19, while the projections 19a are formed on the inner periphery of the case 14B.
The recesses 14d are formed at 0 ° intervals, and each projection 19a is formed.
Are respectively fitted into the recesses 14d, and the ball holding
The door 19 is mounted on the case 14B.

As shown in FIG. 9, the balls 32 are held in such a manner that they protrude from the openings 33a on both sides of the ball holding portion 33 to both sides of the ball holding plate 19, respectively. Part 3
3 and is rotatably held between the ball holding portion 33 and a taper surface 30d of an output plate 30 described later. Further, between the adjacent ball holding portions 33, as shown in FIGS. 5 and 6, a cam surface 34 having a shape protruding toward the center of rotation is formed.

The output plate 30 comprises a donut-shaped disk portion 30a and a cylindrical shaft-type fitting portion 30b mounted in a central hole of the disk portion 30a so as to be orthogonal to the hole. Have been. A set of output presses is arranged such that the side surfaces (hereinafter, referred to as “opposing surfaces”) 30c of the respective disk portions 30a to which the shaft-type fitting portions 30b are not attached face each other.
The guide 30 slides the outer peripheral surface of each shaft type fitting portion 30b in the direction of the rotation axis of the differential case 14 by the respective receiving portions 20, 20 formed on the cap 14A and the case 14B. It is movably supported. Further, each of the output shafts 28 is attached to the inner diameter portion of each shaft-type fitting portion 30b. Further, each receiving portion 2 formed at an inner position of each protruding portion 14f, 14h of the cap 14A and the case 14B.
The outer edges of 0, 20 are shown in FIGS.
As shown in FIG. 5, one tooth 29a constituting the dog clutch 29 is formed.

Further, the outer end face of each shaft type fitting portion 30b has
The dog clutch 29 meshes with the one tooth 29a.
7, 8 and 11
Each is formed as shown in FIG. As shown in FIG. 9, a tapered surface 30d extending in the radial direction is formed at the radially outer edge of each of the opposed surfaces 30c, and a pair of tapered surfaces 30d facing each other form a V-shape. The ball receiving portion 30e is formed. Further, friction plates 31, 31 are pressed against the side surface opposite to the facing surface of the disk portion 30a, that is, the rear surface 30f, by the spring force of the disc springs 27, 27, respectively.

Each of the friction plates 31 is formed of a disk having a donut shape in plan view, and each of the central circular holes 31a has a shaft-shaped fitting portion of each of the output plates 30. 30b is fitted and supported on the outer peripheral surface. Further, the protrusions 31b are provided at 90 ° intervals on the outer periphery thereof.
Is provided. And this projection 31b is the case 14
B are fitted into the recesses 14d formed at 90 ° intervals on the inner peripheral surface of B, and the friction plates 31
14B.

Each of the disc springs 27 is formed in a donut shape in plan view, and each of the center circular holes 27a is fitted to the outer peripheral surface of the shaft type fitting portion 30b of the output plate 30, and A disc spring 27 is mounted on the case 14B. In this embodiment, each output plate 30
Are pressed by the two disc springs 27 via the friction plates 31 in directions approaching each other. The provision of the friction plate 31 allows the differential plate 14 and the output plate 30 to be connected to each other.
As a result, the contact area between the output plate 30 and the differential case 14 can be reduced, and the size of the differential device 10 can be reduced. it can.

The operation of the differential 10 will be described. While the vehicle is traveling straight, the operating mechanism operates in the same manner as the conventional differential. That is, when the input shaft 17 is rotated by receiving a driving torque of an engine (not shown), the rotation rotates the ball holding plate 19 via the ring gear 22. When the ball holding plate 19 rotates, the ball 32 in the ball holding section 33 also rotates. Here, since the ball holding portion 33 in which the ball 32 is housed is located radially away from the center of rotation of the case 14, the ball 32 is a ball holding plate. 19
When it rotates, it revolves around its center of rotation.
The revolving direction of the ball 32 is the same as the arrow A in FIG.

On both sides of the ball 32, a pair of output plates is provided.
When the ball 32 revolves, the output plates 30 on both sides are in contact with each other.
Receives the frictional force in the same direction, and both output shafts 28 are rotated in the same direction. In this way, both drive wheels of the vehicle rotate at the same rotational speed and the vehicle goes straight.

When the vehicle tries to bend the curve, the difference in rotation between the inner and outer wheels causes a difference in the external load torque applied to the drive wheels, and the two output shafts 28 are screwed in opposite directions due to the difference in torque. And each ball 3
2 rotates in the same direction as that of the conventional example. Ball 3
When the wheel 2 rotates, it is pressed against both sides of the ball 32 and the output plate 30 is subjected to frictional forces in opposite directions.
Both output shafts 28 are rotated in opposite directions.

As described above, when the vehicle tries to turn the curve, the ball 32 rotates while revolving, and the rotation of one of the output shafts 28 is added to the revolving rotation, and the other output shaft 28 is rotated. The rotation of the shaft 28 is subtracted from the revolving rotation, and a rotation difference is generated between the two output shafts 28, so that the vehicle can smoothly travel on the curve due to the rotation difference between the inner and outer wheels. .

During the above operation, each ball 32 receives a load in the axial direction by the cam surface 34 of the ball holding plate 19, and the load forms a ball receiving portion 30e. Taper surfaces 30d, 30d.
Acts outwardly. Between the back of both output plates 30 and cap 14A and case 14B,
Since the friction plates 31 and 31 are provided, respectively, the rotation of the cap 14A and the case 14B, that is, the rotation of the differential case 14, causes the pressing force to the outside of each output plate 30 and the friction plate to rotate. The differential force is transmitted to the output plate 30 by the frictional force of the plates 31, 31.

FIGS. 5 and 9 show a state where the input torque is 0 or small, that is, an initial state. In this initial state, the pre-spring force of the disc spring 27 acts on the taper surfaces 30d and 30d forming the ball receiving portion 30e, and the ball 32 holds the ball by the pre-spring force. Play
In a state where it is pressed against the cam surface 34 of the door 19. In this state, as the input torque to the differential 10, that is, the driving force to the output shaft 28 increases, the ball 32 and the tape
Slip occurs between the bearing surfaces 30d and 30d, and a displacement occurs between the ball holding plate 19 and the output plate 30. This shift increases as the input torque to the differential device 10 increases.

When the above-mentioned displacement occurs, the ball 32 is pushed by the cam surface 34 and is pushed out from the center of rotation, that is, upward in FIG. By this movement of the ball 32, the taper surfaces 30d, 30d on both sides are pushed open, whereby
Both output plates 30, 30 move outward.

The outward movement of both output plates 30, 30 increases the frictional force of each output plate 30 on cap 14A and case 14B. Also, since the frictional force and the amount of outward movement of both output plates 30, 30 are substantially proportional to each other, in this differential device 10, according to the input torque input from the differential case 14 side. As a result, an input torque response characteristic in which the urging force is increased can be obtained.

When the input torque input from the differential case 14 further increases, the ball 32 is further pushed deeply between the taper surfaces 30d by the cam surface 34, whereby the output plate 30 further increases. It is slid outward. When the input torque further increases and exceeds a predetermined value, each tooth 29b at the outer end of each shaft type fitting portion 30b of each output plate 30 and each tooth 29a on the differential case 14 side are brought into mesh with each other. . In this state, each output shaft 28 rotates integrally with the differential case 14, the differential mechanism does not perform the differential function, and the differential 10 operates as a so-called non-slip differential. In the case of this embodiment, each shaft type fitting portion 3
As a means for connecting the outer end portion of Ob and the differential case 14 side,
Since the dog clutch is used, the outer end of each shaft-type fitting portion and the differential case can be securely connected with a simple configuration.

As described above, the differential device 10 according to the present embodiment can obtain a differential limiting force corresponding to the input torque with a simple configuration. As a result, during driving of a car, on a muddy ground, etc. It is possible to obtain a differential device that solves the problem that it is difficult to escape when one of the drive wheels slips, or when one of the drive wheels similarly slips on a snowy road, at a low manufacturing cost. . Naho, disc spring 2 if necessary
7 may be provided on only one output plate 30 so that only one output plate 30 is pushed open by the position of the ball 32.

[Brief description of the drawings]

FIG. 1 is a front view showing an assembled state of an embodiment of a differential gear according to the present invention.

FIG. 2 is a side view showing an assembled state of the differential device.

FIG. 3 is a sectional view taken along the line AA of FIG. 1, showing the main body housing and the dog clutch when the dog clutch is not connected.

FIG. 4 is a diagram showing a main part of the differential device when a dog clutch is connected.

FIG. 5 is a cross-sectional view taken along the line BB of FIG. 2, showing a state in which the dog clutch is not connected.

FIG. 6 is a view similar to FIG. 5, showing a state in which a dog clutch is connected.

FIG. 7 is an assembly diagram of a main part of the differential device.

FIG. 8 is an exploded side sectional view of a main part of the differential device.

FIG. 9 is an enlarged view of a part viewed from an arrow C in FIG. 3;

FIG. 10 is a perspective view of the case as viewed in the direction of arrow D in FIG. 7;

FIG. 11 is a perspective view of the output plate in the direction of arrow E in FIG. 7;

FIG. 12 is a perspective view of the cap in the direction of arrow F in FIG. 7;

FIG. 13 is an exploded perspective view of a differential mechanism in a conventional differential.

[Explanation of symbols]

10: Differential device, 11: Main body housing, 12: Bearing hole, 13: Bearing, 14A: Cap, 14B: Case, 16: Bearing, 17: Input shaft, 18: Bevel gear, 19: Ball holding Plate, 20: Receiving part, 21:
Flange, 22: Ring gear, 23: Bolt, 24: Internal space, 25: Insertion hole, 26: Receiver, 27: Disc spring, 2
8: output shaft, 29: dog clutch, 29a, 29b:
Dog clutch teeth, 30: output plate, 30a: disk portion, 30b: cylindrical shaft-type fitting portion, 30c: facing surface,
30d: tapered surface, 30e: ball receiving portion, 30f: back surface, 31: friction plate, 32: ball, 3
3: ball holding portion, 34: cam surface, 35: axle, 36:
Bearing hole.

Claims (4)

[Claims] 1. A differential case that rotates by receiving a torque input from an input shaft via a ring gear, and a pair of output shafts that are arranged on the same axis and rotatably supported by the differential case. , A differential mechanism disposed in the differential case, the differential mechanism being provided in the differential case and being disposed so as to face each other, and a pair of opposing surfaces, A disk portion disposed on the back side of the surface so as to face the differential case and projecting at right angles to the respective disk portions are formed by right and left receiving portions of the differential case, respectively.
A pair of output plates having a cylindrical shaft-type fitting portion slidably supported in the direction of the rotation axis of the motor, and a pair of output plates interposed between the opposed surfaces of the output plates. A ball holding plate attached to the differential case; and a plurality of balls held by the ball holding plate so as to be able to contact the respective opposing surfaces of the output plates. And both output planes
And a preload spring for pressing the springs in directions approaching each other, wherein the differential mechanism causes the output through the ball as the torque input from the input shaft increases. It is configured to have an input torque response characteristic in which the urging force for pressing the plate against the differential case increases, and to perform differential locking when the torque input from the input shaft exceeds a predetermined value. A differential device characterized by the above-mentioned. 2. A differential case that rotates by receiving a torque input from an input shaft via a ring gear, and a pair of output shafts disposed on the same axis and rotatably supported by the differential case. A differential mechanism disposed in the differential case, wherein the differential mechanism is provided on the differential case and is provided with a pair of opposing surfaces disposed so as to oppose each other. A disk portion disposed on the back side of the surface so as to face the differential case and projecting at right angles to the respective disk portions are formed by right and left receiving portions of the differential case, respectively.
A pair of output plates having a cylindrical shaft-type fitting portion slidably supported in the direction of the rotation axis of the motor, and a pair of output plates interposed between the opposed surfaces of the output plates. A ball holding plate attached to the differential case; and a plurality of balls held by the ball holding plate so as to be able to contact the respective opposing surfaces of the output plates. And both output planes
And a preload spring for pressing the bearings toward each other in a direction toward the center of rotation of the differential as the torque input from the input shaft increases. The cam surface that moves is the ball holding plate.
And the ball contact surface of the output plate is formed on a taper surface that expands in the outer diameter direction of the output plate, and is formed outside of each of the shaft-type fitting portions. A differential device comprising a coupling member capable of coupling an end portion and the differential case. 3. The coupling member has one tooth formed at an outer end of each of the shaft-type fitting portions, and the other tooth formed at the differential case so as to mesh with each of the one teeth. 3. The differential according to claim 2, wherein the differential is constituted by a dog clutch including teeth. 4. The friction plate according to claim 1, wherein a friction plate is interposed between the rear surface of the disk portion of each of the output plates and the differential case. Or the differential device according to the above description.