JP2002070986A - Differential device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a loss of a differential limiting force caused by an energizing means, to improve rise of the differential limiting force, and to arrange the energizing means by utilizing an existing space. SOLUTION: This device is equipped with a differential mechanism 9 having a pinion gear 25 and output side side gears 27, 29, a friction clutch 11 for restricting its differential rotation, and the energizing means 13 arranged on the inside of each gear 25, 27, 29, for applying an initial torque by pressing the friction clutch 11 in the same direction as an interlocking reaction force of the side gears 27, 29.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential device having a constant differential limiting force by an initial torque and a torque-sensitive differential limiting function.

[0002]

2. Description of the Related Art Japanese Unexamined Patent Publication No. 9-89086 discloses a differential device 201 as shown in FIG.

The differential device 201 includes a differential case 203, a bevel gear type differential mechanism 205, a pair of multi-plate clutches 207, 207, and disc springs 209, 209.

The differential mechanism 205 has a differential case 20 at both ends.
3, a pinion shaft 211, a pinion gear 213 supported on the pinion shaft 211, and a pair of output side gears 215, 217 meshing with the pinion gear 213, respectively.

[0005] Each side gear 215, 217 is mounted on the axle 21.
9, 221 are connected to the respective wheel sides.

The driving force of the engine is transmitted from a drive pinion gear 223 via a ring gear 225 to a differential case 203.
Is rotated, and the rotation of the differential case 203 is changed from the pinion shaft 211 through the pinion gear 213 to the side gear 2.
15, 217 and transmitted to each wheel side.

The multi-plate clutch 207 includes a differential case 203
And the side gears 215, 217, respectively, and are fastened by receiving the meshing thrust force of the side gears 215, 217.

Since the engagement reaction force of the side gears 215 and 217 increases in proportion to the transmission torque, when each multi-plate clutch 207 is engaged, a torque-sensitive differential limiting function can be obtained by the frictional resistance. .

The differential rotation of the differential mechanism 205 is limited by the torque-sensitive differential limiting function, and the maneuverability and stability of the vehicle are improved particularly when starting or accelerating when a large driving force is applied.

[0010] However, in a condition where the driving wheels are liable to idle, such as on a rough road, in the case of a torque-sensitive differential limiting mechanism, the torque is escaping from the idle wheels, and the differential limiting function is degraded. You may not be able to get the limiting power.

Therefore, it is necessary to apply an initial torque (a constant limiting force) by the preload means.

The disc spring 209 serving as the preload means is disposed between the multi-plate clutch 207 and the differential case 203, and connects the multi-plate clutch 207 to the side gears 215, 217.
Side to give initial torque.

For example, when one of the driving wheels tries to spin largely when starting or accelerating the vehicle, or on a rough road, the initial torque of each multi-plate clutch 207 causes
Driving force is sent to the wheels on the grip side, so that the ability to travel on rough roads is kept high, and the starting performance and acceleration performance are improved.

[0014]

However, in the differential device 201, the disc spring 2 for the initial torque is used.
09 is disposed between the differential case 203 and the multi-plate clutch 207 (outside the side gears 215 and 217 in the axial direction), so that the direction of the meshing reaction force of the side gears 215 and 217 and the direction of the pressing force of the disc spring 209 are opposite. It has become.

In such a configuration, the side gears 215,
While the bending of the disc spring 209 is progressing due to the meshing reaction force of 217, the meshing reaction force is absorbed by this bending, so that the multi-plate clutch 207 cannot be strongly pressed, and the bending of the disc spring 209 is reduced. Upon completion, the multi-plate clutch 207 is pressed against the differential case 203 for the first time, and the differential limiting force rises.

As described above, the differential device 201
Then, the side gear 215,
217 (the pressing force of the multi-plate clutch 207:
The loss occurs in the differential limiting force, and the rise of the differential limiting force is delayed.

FIG. 3 shows a left axis torque and a right axis torque on the vertical axis and the horizontal axis, respectively, and the magnitude of the driving torque (torque distribution) transmitted to the left wheel by the differential limiting force when the right wheel idles. (Characteristics: torque bias ratio).

The graph 251 shows the differential device 2
When the friction clutch is pressed from the outside of the side gear in the direction opposite to the meshing reaction force as in 01 (external push type)
The graph 151 shows the case where the friction clutch is pressed in the same direction as the meshing reaction force of the side gear and no loss is caused by the disc spring (biasing means: preload means) (inwardly-pressed type).
It shows the characteristic of. Ti is the initial torque.

The portion 253 in the graph 251 shows the characteristic until the meshing reaction force of the side gears 215 and 217 presses the multi-plate clutch 209 toward the differential case 203 as described above. Stand up with such a gradient.

As indicated by the reference numeral 253, in the case of the external push type, the rise of the differential limiting force is gradual, and the occurrence of the differential limiting function is momentarily delayed. The improvement effect is insufficient.

When the right wheel idles and its shaft torque becomes T
When the torque is reduced to R, the torque transmitted to the left wheel is TL1 in the externally-push type, and is larger than T in the inner-push type.
L2.

The difference (TL2-TL1) is the above-mentioned loss, and the effect of improving maneuverability and stability at the time of starting or accelerating is reduced accordingly.

As is well known, if the initial torque is increased to some extent, the tight corner braking phenomenon and the tight corner braking phenomenon may occur when the vehicle turns sharply at a low speed or when the vehicle repeatedly moves forward and backward while operating a large steering angle. An abnormal sound may be generated due to this.

In the external push type in which the meshing reaction force of the side gear and the pressing force of the spring press in opposite directions, the direction and strength of the meshing reaction force of the side gear fluctuate greatly during a sharp turn or garage, so that tight corners are required. Breaking phenomenon and abnormal sound are likely to occur.

The disc spring 209 includes side gears 215,
Since the expansion and contraction are repeated under the engagement reaction force of 217, the spring characteristics (initial torque) are liable to change (degrade) and the durability is liable to decrease.

Further, an urging means such as a disc spring 209 is
There is a demand to arrange in a space inside the differential device to avoid interference with peripheral members such as gears and wear.

Accordingly, an object of the present invention is to provide a differential device which prevents a loss of a differential limiting force due to an urging means for applying an initial torque and improves a rise of the differential limiting force.

[0028]

According to a first aspect of the present invention, there is provided a differential device having a plurality of pinion gears and a pair of output side gears meshed with the plurality of pinion gears, and the driving force of the engine input to the pinion gears is transmitted from each side gear to the wheel side. A differential mechanism for distributing, a friction clutch for restricting the differential rotation, and an axially inner side of both side gears and a radially inner side of the pinion gear, which press the friction clutch in the same direction as the meshing reaction force of the side gears to initialize an initial torque. And urging means for providing

The driving force of the engine is distributed from the pinion gear to each wheel via each output side gear.

At this time, the friction clutch is pressed by the meshing reaction force of the side gear, and a torque-sensitive differential limiting function can be obtained. With this differential limiting function, the differential of the differential mechanism is limited, and the maneuverability and stability of the vehicle can be improved at the time of starting or accelerating when a large driving force is applied.

The friction clutch is provided with an initial torque by an urging means. When one of the driving wheels tries to idle at the time of starting, accelerating, or on a rough road, the initial torque is applied to the wheel on the grip side by the initial torque. Since the driving force is transmitted, a decrease in the starting performance, acceleration performance, and running performance on a rough road is prevented.

In addition, the differential device according to the present invention is an internally-pushed type in which the urging means presses the friction clutch in the same direction as the meshing reaction force of each side gear, and as shown in a graph 151 in FIG. Since the differential limiting force due to the meshing reaction force instantaneously rises and there is no delay, maneuverability and stability can be sufficiently improved at the time of starting or accelerating.

Further, unlike the conventional example, since the differential limiting force is not lost by the urging means, as shown in a graph 151, when one wheel runs idle, the torque transmitted to the other wheel increases. In addition, at the time of starting or accelerating, the effect of improving maneuverability and stability is further improved.

Further, the urging means comprises side gears 215, 2
Since the clutch 17 does not receive the meshing reaction force, deterioration of the pressing characteristic of the friction clutch is prevented, the initial torque is stabilized, and the durability is greatly improved.

Further, by arranging the urging means in the axially inner side of both side gears and in the radially inner side of the pinion gear, the existing space is effectively used, so that the urging means can be used without changing the internal structure and layout. By disposing the differential device, the differential device can be inwardly pressed at a low cost, and the above-described effects of the inwardly pressed type can be enjoyed.

Further, the biasing means arranged in the above space prevents interference with peripheral members such as gears and avoids abrasion and breakage, so that a normal initial torque can be obtained for a long period of time.

Further, in the case of the inner push type, the biasing means and the differential mechanism can be wrapped (overlaid) in the axial direction (disposed in the radial direction), so that they are disposed in the axial direction. Compared with the conventional example, the differential device is made more compact in the axial direction, and the vehicle mountability can be improved.

Further, the inner push type makes it hard to be affected by the meshing reaction force of the side gears when making a sharp turn or entering a garage, so that the tight corner braking phenomenon and abnormal noise are hardly generated.

According to a second aspect of the present invention, in the differential device according to the first aspect, the biasing means includes a bracket formed integrally with the pinion shaft, and a biasing member held by the bracket. Therefore, the same operation and effect as those of the first aspect can be obtained.

Also, by holding the urging member with the bracket, the initial torque is stabilized, and the sub-assembled bracket and the urging member are easily assembled, so that the assembling workability can be improved. .

Further, since the bracket is supported on the differential case via the integrally formed pinion shaft, the holding function of the urging member and the initial torque are further stabilized.

Further, since the bracket is supported on the differential case side and, similarly to the urging member, disposed on the inner side in the axial direction of both side gears and the inner side in the radial direction of the pinion gear, the thrust block for abutting the axle is provided. A bracket can be used, and the number of parts and cost can be reduced accordingly.

In a differential device using a thrust block, the present invention can be implemented at low cost and very easily only by replacing the bracket and the urging member with the thrust block.

According to a third aspect of the present invention, there is provided the differential device according to the first or second aspect, wherein an isolating member for preventing contact between the urging member and the side gear is arranged. Accordingly, the same operation and effect as those of the first or second aspect can be obtained.

In addition, since the separating member is disposed between the urging member and the bracket, the urging member and the bracket do not slide with the side gear, wear and durability are prevented, and a normal initial torque can be obtained for a long period of time. it can.

In the structure of the second aspect using the bracket, if the separating member is assembled to the bracket to form a subassembly, the biasing member is prevented from falling off, and the assembling workability is further improved.

According to a fourth aspect of the present invention, there is provided the differential device according to the third aspect, wherein the isolation member includes a positioning portion for the urging member.
The same operation and effect as those of the above configuration can be obtained.

Further, the biasing member is stably supported by the positioning portion of the separating member, and the initial torque is further stabilized.

A fifth aspect of the present invention is the differential device according to any one of the first to fourth aspects, wherein the biasing means is a coil spring. The same operation and effect as the configuration can be obtained.

The coil spring has a small change in load (spring force) with respect to the stroke (bending amount), so that a stable initial torque can be obtained.

Since the coil spring is longer in the axial direction than a spring having another shape having the same spring force, for example, a pair of friction clutches disposed at both ends of the differential case are pressed to initialize the coil spring. And the configuration becomes easy.

The invention according to claim 6 is the differential device according to any one of claims 1 to 5, wherein the biasing means is constituted by a plurality of biasing members having different spring constants. Thus, the same operation and effect as those of the first to fifth aspects can be obtained.

In this configuration in which a plurality of biasing members having different spring constants are combined, it is easy to set the initial torque to a desired value, so that it can be widely applied to different types of vehicles.

[0054]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A differential apparatus 1 (an embodiment of the present invention) will be described with reference to FIGS.

[0055] The differential device 1 is characterized in that:
It has 3, 4, and 5 features. The left and right directions are the left and right directions in FIG. 1, and the members and the like without reference numerals are not shown.

The differential device 1 comprises a differential case 3, pressure rings 5, 5, cams 7, 7 (cam mechanism), a bevel gear type differential mechanism 9, a multi-plate clutch 11,
11 (friction clutch), biasing means 13 and the like.

The differential device 1 is disposed inside a differential carrier, and the differential carrier is provided with an oil reservoir.

The differential case 3 has left and right boss portions 15, 17 supported by a differential carrier by bearings. Further, a ring gear is fixed to the differential case 3, and a drive pinion gear meshing with the ring gear is connected to the engine through a power transmission system, and the differential case 3 is driven to rotate by the driving force of the engine.

On the inner periphery of the differential case 3, as shown in FIG.
A large number of lug grooves 19 are formed in the axial direction. Each pressure ring 5 is connected to the differential case 3 so as to be axially movable by engaging the same number of protrusions 21 as the lug grooves 19 provided on the outer periphery with the lug grooves 19.

The cams 7, 7 are formed between the distal end of the pinion shaft 23 of the differential mechanism 9 and each of the pressure rings 5, and the rotation of the differential case 3 is carried out from each of the pressure rings 5 via the cams 7, 7. Pinion shaft 23
And input to the differential mechanism 9.

At this time, the cams 7, 7 operate by receiving torque transmitted from the pressure rings 5 to the pinion shaft 23 side, and the respective pressure rings 5 are moved by the cam thrust force to the respective multi-plate clutches 11 as described below. And tighten it.

The differential mechanism 9 includes four pinion shafts 2
3, a pinion gear 25 rotatably supported on each pinion shaft 23, and output side gears 27 and 29 meshing with the respective pinion gears 25 from the left and right.

Each of the pinion shafts 23 is formed integrally with the bracket 31 as shown in FIG. 2, and is arranged radially around the bracket 31 and at regular intervals in the circumferential direction.

The side gears 27 and 29 are spline-connected to the axle via respective bosses 33 and 35, fixed by snap rings 37, and connected to the left and right wheels via the respective axles.

Each pressure ring 5 is formed with four spherical washer portions 39 at four locations. These spherical washer portions 39 support the rear surface of each pinion gear 25,
It receives the centrifugal force and the meshing reaction force.

Each multi-plate clutch 11 has an inner periphery of the differential case 3 and bosses 33, 35 (side gears 27, 29).
And the outer circumference of the. Outer plate 41
Are engaged with the lug grooves 19, and the inner plate 43 is engaged with the lug grooves 45 provided in the boss portions 33 and 35.

The pressure ring 5 is disposed between the multi-plate clutch 11 and the side gears 27 and 29.

The urging means 13 is composed of four coil springs 47 (urging members), the bracket 31 described above, and two covers 49, 49 (separating members).

As shown in FIGS. 1 and 2, the urging means 13 (bracket 31) is provided inside the side gears 27 and 29 in the axial direction and
Each of the pinion gears 25 is disposed radially inside. The cross section of the bracket 31 is substantially square, and through holes 51 are provided at four corners thereof, and a large diameter through hole 53 is provided at the center thereof.

The coil spring 47 is attached to each through hole 51.

The covers 49 are disposed between the left and right surfaces of the bracket 31 and the side gears 27 and 29, respectively, to prevent the coil spring 47 and the bracket 31 from sliding with the side gears 27 and 29. ing.

The cover 49 is provided with four convex portions 55 (positioning portions) and through holes 57. These projections 55 are engaged with the inner periphery of the coil spring 47 and hold both ends thereof. Further, the through hole 57 is provided in the bracket 31.
Are formed at positions facing the through holes 53.

Each of the coil springs 47 is bent to a predetermined length in the assembled state.
The multi-plate clutches 11, 11 are provided via covers 49, 49, side gears 27, 29, and pressure rings 5, 5.
To give an initial torque.

Due to the initial torque, a constant differential limiting force is generated in the multiple disc clutches 11, 11 irrespective of the transmission torque and the differential rotation speed.

The initial torque is set to a desired value by selecting the spring constant of the coil spring 47.

The driving force of the engine for rotating the differential case 3 is transmitted from the pressure rings 5 and 5 to the pinion shaft 23 via the cams 7 and 7, and the pinion gear 25 is rotated.
And is distributed to the side gears 27 and 29 and transmitted to the left and right wheels.

When a difference in driving resistance occurs between the wheels at the time of starting, accelerating, or traveling on a rough road, the driving force of the engine is differentially distributed to the left and right wheels by the rotation of the pinion gear 25.

While the vehicle is running, the pinion gear 25
Meshes with the side gears 27 and 29 to generate a thrust force. The pressure rings 5 arranged on the rear surfaces of the side gears 27 and 29 press the respective multi-plate clutches 11 with the differential case 3 by this meshing thrust force and fasten them.

Further, at this time, each pressure ring 5
Receives the transmission torque applied to the pinion shaft 23, the cams 7, 7 operate, and the pressure ring 5 presses and engages each multi-plate clutch 11 by the cam thrust force.

The meshing thrust force of the side gears 27, 29 and the cam thrust force of the cams 7, 7 can be obtained in both forward traveling and reverse traveling.

Since the meshing reaction force of the side gears 27, 29 and the cam thrust force of the cams 7, 7 increase in proportion to the transmission torque, when each of the multi-plate clutches 11 is engaged by these forces, the torque is reduced by the frictional resistance. A sensitive differential limiting function is obtained, and the differential of the differential mechanism 9 is limited.

At the time of starting or accelerating when a large driving force is applied to the differential device 1, the torque-sensitive differential limiting function reinforces the differential limiting force and greatly improves the maneuverability and stability of the vehicle.

The initial torque is applied to each multi-plate clutch 11 by the coil spring 47 as described above.

Accordingly, the initial torque can be obtained even under the condition that one wheel is largely idling and the torque-sensitive differential limiting function is deteriorated, such as when traveling on a rough road or when starting or accelerating. With constant differential limiting force,
Deterioration of rough road running performance, starting performance, acceleration performance, etc. is prevented, the behavior of the vehicle body is stabilized, and maneuverability is greatly improved.

A graph 151 in FIG. 3 shows a torque distribution characteristic of the differential device 1.

As described above, the differential device 1
Is an internally-pressed type in which the coil spring 47 of the urging means 13 presses the multi-plate clutches 11, 11 in the same direction as the meshing reaction force of the side gears 27, 29 and the cam thrust force of the cams 7, 7. The meshing reaction force and the cam thrust force are not absorbed by the bending of the coil spring 47, and the loss of the differential limiting force does not occur.

Therefore, unlike the conventional external push type, as shown in a graph 151, the differential limiting force of the multiple disc clutches 11, 11 rises instantaneously when receiving the meshing reaction force and the cam thrust force, and no delay occurs. .

The differential case 3 has an opening 59 formed in the axial direction, a radial opening 61 formed at a position facing the two pinion shafts 23, and a radial opening 63 formed at other positions. The boss portions 15 and 17 are provided with spiral oil grooves 65 and 67 on the inner periphery thereof.

The oil in the oil sump is filled with these openings 59, 61, 63 and the oil groove 6 with the rotation of the differential case 3.
From 5,67, it flows into the differential case 3 and the multi-plate clutch 1
1, 11; meshing portions of gears 25, 27, 29; sliding surface between pinion shaft 23 and pinion gear 25; spherical washer 39; sliding surface between convex portion 21 of pressure ring 5 and lug groove 19; The sliding surfaces of the pressure ring 5 and the cover 49 with respect to 27 and 29, the sliding surfaces of the coil spring 47 and the through hole 51, and the like are sufficiently lubricated and cooled to enhance durability.

Thus, the differential device 1 is configured.

As described above, the differential device 1
FIG. 3 shows that the coil spring 47 of the urging means 13 is an internally-pressed type in which the multiple disc clutches 11, 11 are pressed in the same direction as the meshing reaction force of the side gears 27, 29 and the cam thrust force of the cams 7, 7. As shown in the graph 151, the differential limiting force instantaneously rises, and the maneuverability and stability of the vehicle can be improved when starting or accelerating when a large driving force is applied.

Also, if one of the wheels tries to spin,
The driving force is sent to the wheels on the grip side by the initial torque applied to the multiple disc clutches 11 by the urging means 13, so that it is possible to maintain high running ability on rough roads, startability, and acceleration.

Also, unlike the conventional example, since the meshing reaction force of the side gears 27 and 29 and the loss of the cam thrust force of the cams 7 and 7 by the coil spring 47 do not occur, one of the wheels idles as shown in a graph 151. At this time, the torque transmitted to the other wheel is increased, so that the running performance, maneuverability, stability, and the like are improved correspondingly when driving on a rough road, starting, accelerating, and the like.

Further, since the coil spring 47 does not receive the meshing reaction force of the side gears 27, 29 and the cam thrust force of the cams 7, 7, deterioration of the spring characteristics and decrease in durability are prevented, and the coil spring 47 is stable for a long period of time. Initial torque can be obtained.

The urging means 13 is connected to the side gear 27,
By arranging in the space formed in the axial direction inside of 29 and the radial inside of each pinion gear 25, the existing space was effectively used, so that the differential device 1 was pushed inward without greatly changing the structure and layout. It is easy to construct into a mold and can be implemented at a lower cost.

Since the urging means 13 and the pinion gear 25 of the differential mechanism 9 are arranged in the radial direction, the disc spring 209
Compared with the conventional example in which the differential mechanism 205 is arranged in the axial direction, the differential device 1 is more compact in the axial direction, and the in-vehicle performance is improved.

Further, since the internal gear is of the inward-push type, the coil spring 47 (initial torque) of the differential device 1 can be reduced by the side gear 2 when the vehicle turns sharply or enters the garage.
It is less susceptible to the meshing reaction force of the cams 7 and 29 and the cam thrust force of the cams 7 and 7, and the tight corner braking phenomenon and abnormal noise are less likely to occur.

Further, by incorporating the coil spring 47 into the bracket 31, the coil spring 47 is stably supported, and the initial torque is also stabilized.

Further, since both ends of the coil spring 47 are engaged with the convex portions of the cover 49, the support of the coil spring 47 and the initial torque are further stabilized.

Since the bracket 31 is supported by the differential case 3 via the pinion shaft 23, the cams 7, 7 and the pressure rings 5, 5, the holding function of the coil spring 47 and the initial torque are further stabilized.

Further, by disposing the cover 49 between the coil spring 47 and the bracket 31, there is no longer sliding with the side gears 27, 29, so that wear and durability are prevented, and normal initials can be maintained for a long period of time. The torque can be obtained.

The coil spring 47 and the cover 49
Are assembled into the bracket 31 to form a sub-assembly, so that these can be easily assembled and the assembling workability can be improved.

The coil spring 47 has a small change in load (spring force) with respect to the stroke (bending amount), so that a stable initial torque can be obtained.

Further, since the coil spring 47 is long in the axial direction, the coil spring 47 is optimal for a configuration in which the multi-plate clutches 11, 11 disposed at both axial ends of the differential case 3 are pressed to apply initial torque. Becomes easier.

Further, by disposing the coil spring 47 between the side gears 27 and 29, it is possible to increase the amount of deflection while shortening the free length of the coil spring 47.
By using this, a large initial torque can be generated, and the ability to travel on rough roads, the ability to start, the ability to accelerate, and the like can be sufficiently improved.

Since the bracket 31 is supported on the differential case 3 side and is disposed axially inside the side gears 27 and 29 and radially inside the pinion gear 25, it is used as a thrust block for abutting the axle. It is possible to reduce the number of parts and the cost only by this thrust block.

Further, in a differential device using a thrust block, the differential device 1 can be configured very easily at low cost only by replacing the urging means 13 with a thrust block.

The invention according to claim 6 has a structure in which a plurality of biasing members having different spring constants are combined, so that the initial torque can be easily set to a desired value, and is widely applied to different types of vehicles. It is possible.

In the present invention, the biasing member is not limited to a coil spring. For example, other springs such as a disc spring and elastic members other than metal springs can be used.

Further, the friction clutch is not limited to the multi-plate clutch or the single-plate clutch, but may be another type of friction clutch such as a conical clutch.

The differential device of the present invention
Front differential (differential device that distributes engine driving power to left and right front wheels) and rear differential (differential device that distributes engine driving force to left and right rear wheels)
And a center differential (a differential device for distributing the driving force of the engine to the front wheels and the rear wheels).

[0112]

According to the differential device of the first aspect, since the differential limiting force is not lost due to the biasing means, the differential limiting force instantaneously rises, and the maneuverability and stability at the time of starting or accelerating are improved. Greatly improved.

Further, when one of the wheels spins, the torque transmitted to the other wheel increases, and the maneuverability and stability are further improved.

Further, since the urging means does not receive the meshing reaction force of the side gear, the fluctuation of the initial torque is prevented, and the durability is greatly improved.

Further, by arranging the biasing means in the axially inner side of both side gears and in the radially inner side of the pinion gear, the existing space is effectively used. Therefore, the structure of the differential device can be reduced without changing the structure and layout. It becomes easy to make an internal push type at a cost.

Further, since the biasing means is arranged in the radial direction of the differential mechanism, the differential device can be made more compact in the axial direction, and the vehicle mountability can be improved.

According to the differential device of the second aspect, the same effect as that of the configuration of the first aspect can be obtained.

Further, the sub-assembled bracket and the urging member are easy to assemble, and the assembling workability can be improved.

Further, the biasing member is stably held by the bracket, so that the initial torque is stabilized, and interference with the gears, abrasion and breakage are prevented, so that the initial torque applying function can be maintained normally.

Further, in a differential device using a thrust block, the bracket and the urging member can be easily implemented at a very low cost by replacing the thrust block with the bracket.

The differential device according to the third aspect can provide the same effect as the configuration according to the first or second aspect.

Further, the separation member prevents sliding of the urging member, the bracket, and the side gear, abrasion, and a decrease in durability, so that a normal initial torque can be obtained for a long period of time.

When the bracket is used, the separating member is sub-assembled to the bracket, so that the biasing member is prevented from falling off, and the assembling workability is further improved.

The differential device according to the fourth aspect can provide the same effect as the configuration according to the third aspect.

Further, the support of the urging member is stabilized by the positioning portion of the separating member, and the initial torque is further stabilized.

According to the differential device of the fifth aspect, the same effect as the configuration of the first to fourth aspects can be obtained.

Since the load of the coil spring changes little with respect to the stroke, the initial torque becomes more stable.

The coil spring that is long in the axial direction is
Ideal for a configuration that applies initial torque by pressing a pair of friction clutches arranged at both ends of the differential case,
Such a configuration is facilitated.

The differential device according to the sixth aspect can obtain the same effects as the configurations according to the first to fifth aspects.

Further, by combining a plurality of biasing members having different spring constants, it is easy to set the initial torque to a desired value, and the invention can be widely applied to different types of vehicles.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of the present invention.

FIG. 2 is a sectional view taken along line XX of FIG.

FIG. 3 is a graph comparing torque distribution characteristics of an internally-pushed differential device and an externally-pushed differential device.

FIG. 4 is a sectional view showing a conventional example.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 differential device 3 differential case 5 pressure ring 7 cam (cam mechanism) 9 bevel gear type differential mechanism 11 multi-plate clutch (friction clutch) 13 biasing means 31 bracket 47 coil spring (biasing member) 49 cover (isolating member) 55 Convex part (positioning part)

Claims (6)

[Claims] 1. A differential mechanism having a plurality of pinion gears and a pair of output side gears meshed with the pinion gears, for distributing a driving force of an engine input to the pinion gears from each side gear to the wheels, A friction clutch to be restricted, and biasing means disposed axially inside the two side gears and radially inside the pinion gear, and pressing the friction clutch in the same direction as the meshing reaction force of the side gears to apply initial torque. Differential device. 2. The differential according to claim 1, wherein the biasing means comprises a bracket formed integrally with the pinion shaft, and a biasing member held by the bracket. apparatus. 3. The differential device according to claim 1, wherein an isolation member for preventing contact between the biasing member and the side gear is arranged between the biasing member and the side gear. 4. The differential device according to claim 3, wherein the separating member includes a biasing member positioning portion. 5. The differential device according to claim 1, wherein the biasing means is a coil spring. 6. The differential device according to claim 1, wherein the biasing means includes a plurality of biasing members having different spring constants.