JPH11247970A - Differential gear device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To uniformly distribute the bearing pressure of a differential limiting multi-disc clutch while maintaining the lubricity and the interchangeability of differential gear casings. SOLUTION: A differential gear device is composed of a differential mechanism 5 for distributing the rotation of a differential gear casing 3 among wheels through the intermediary of output members 25, 27, a multi-disc clutches 7 located between the differential casing 3 and the output member 25, a pressing means 9 for pressing the multi-disc clutch 7 against a pressure receiving part 55 of the differential casing 3 so as to exert a differential limiting force, an oil opening 13 formed in the pressure receiving part 55, and a spacer 11 located between the pressure receiving part 55 and the multi-disc clutch 7. In this arrangement, the opening 13 is communicated with the multi-disc clutch 7 side, radially outside of the spacer 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a differential device.

[0002]

2. Description of the Related Art Japanese Unexamined Utility Model Publication No. 5-8093 discloses a differential device 201 as shown in FIG.

The differential device 201 is a differential mechanism 209 that distributes the rotation of the engine for rotating the differential case 203 from the side gears 205 and 207 to the wheels.
A multi-plate clutch 211 for limiting the differential between the differential case 203 and the side gear 205;
Springs 213 and 215 for preloading the oil, an opening 217 for oil provided in the differential case 203, and the like.

[0004] The multi-plate clutch 211 includes disc springs 213 and 2.
A fixed differential limiting force is generated by the 15 preloads, and the differential limiting force improves the running performance and the escape performance of the vehicle on a rough road or the like.

A plurality of openings 217 are formed circumferentially in a pressure receiving portion 219 of a differential case 203 which receives preloads of disc springs 213 and 215 via a multi-plate clutch 211, and oil is supplied from these openings 217 to the differential case. 203
To lubricate the multi-plate clutch 211 and the differential mechanism 209.

[0006]

However, since the opening 217 is provided in the pressure receiving portion 219 of the differential case 203 as described above, when the preload of the disc springs 213 and 215 is received on the opening 217, The clutch plate of the multi-plate clutch 211 bends.

For example, if the number of outer and inner clutch plates is 12 in total, the influence of this bending extends to about half, that is, about six, and the surface pressure of the clutch plate is reduced at each part in the circumferential direction by this bending. As a result, the differential limiting function becomes unstable, and the effect of improving the traveling performance of the vehicle as described above decreases.

In addition, the surface of the clutch plate where the surface pressure is large is rough, and the sufficient durability of the multi-plate clutch 211 cannot be obtained.

However, if the opening 217 is abolished, the lubricity is reduced, so that it is necessary to redesign the differential case, which lowers the compatibility of the differential case and increases the cost.

[0010] Further, since the sliding area with the clutch plate is reduced by the opening 217, the load on the pressure receiving portion 219 is correspondingly increased, and the durability of the differential case 203 is reduced.

Therefore, the present invention makes the surface pressure of the differential limiting multi-plate clutch uniform while keeping the internal lubrication and the compatibility of the differential case high, and prevents the running performance from being improved and the durability from being reduced. The purpose is to provide a differential device.

[0012]

According to a first aspect of the present invention, there is provided a differential device, comprising: a differential case rotatably driven by a driving force of an engine; a differential mechanism for distributing rotation of the differential case to wheels via a pair of output members; A multi-plate clutch for limiting the differential disposed between the differential case and the output member; pressing means for pressing the multi-plate clutch toward the pressure-receiving portion of the differential case to apply a differential limiting force; and forming the pressure-receiving portion. In the differential device provided with the opening for the oil, a spacer that is prevented from rotating on the differential case side between the pressure receiving portion and the multi-plate clutch, and the opening is
At least one of the radially outer side and the inner side of the spacer communicates with the multi-plate clutch side.

As described above, in the differential device of the present invention, the spacer is disposed between the pressure receiving portion of the differential case and the multi-plate clutch, and the spacer supports the multi-plate clutch including the opening over the entire surface. Unlike the conventional example, bending of the clutch plate when pressed on the opening is prevented, and the surface pressure becomes uniform over the entire surface of the clutch plate.

Since the surface pressures of the clutch plates are equalized, the differential limiting function of the multi-plate clutch is stabilized, and the traveling performance of the vehicle is improved.

In addition, the clutch plate has a rough surface, galling,
Seizure and noise are prevented, and the durability of the multi-plate clutch is greatly improved.

Further, at least one of the radially outer side and the inner side of the spacer has an opening communicating with the multi-plate clutch side, and a necessary amount of oil flows in and out. Lubricated.

As described above, sufficient lubricity can be obtained with the existing differential case, and interchangeability of the differential case can be maintained. Therefore, it is not necessary to make a new differential case in order to enhance lubrication, and it is possible to avoid an increase in cost associated therewith. Can be

Also, since the spacer is prevented from rotating toward the differential case, the differential case is released from sliding with the multi-plate clutch, and the durability is greatly improved.

According to a second aspect of the present invention, in the differential device according to the first aspect, the thickness of the spacer is set to a value at which a portion corresponding to the opening of the differential case does not deform when receiving the pressing force of the pressing means. In this case, the same effects as those of the first aspect are obtained.

In addition, the thickness of the spacer is selected so as not to be deformed even when pressed by the opening of the differential case.
Excessive thickness of the spacer is avoided, thus minimizing the space for placing the spacer.

[0021] This can maintain the compatibility of the differential case as described above and minimize the reduction in the number of clutch plates arranged in a limited space. Is kept.

According to a third aspect of the present invention, there is provided the differential device according to the second aspect, wherein a surface pressure (kg / cm ² ) generated in the multi-plate clutch by receiving a pressing force and a thickness (m) of the spacer.
m) at 14 kg / cm ² and 1.6 mm point and 23 k
The characteristic is set on a straight line graph connecting g / cm ² and a point of 4.0 mm, and an effect equivalent to the configuration of the second aspect is obtained. In addition to this, the thickness selection can be standardized.

The invention according to claim 4 is the invention according to claims 1 to 3.
The differential device according to any one of claims 1 to 3, wherein the pressing means is a spring for preloading the multi-plate clutch, and the same effects as those of the first to third aspects are obtained.

In addition, in this configuration using a spring as the pressing means, an appropriate differential limiting force is always applied to the multi-plate clutch by the preload of the spring, and the traveling performance of the vehicle is increased by the differential limiting force. improves.

Further, if a disc spring is used as the spring, the space for the pressing means can be reduced, and the number of clutch plates can be increased accordingly, and the differential limiting force can be strengthened.

The invention of claim 5 is the invention of claims 1 to 3
The differential device according to any one of claims 1 to 3, wherein the pressing means is a pressure actuator that presses the multi-plate clutch via a piston, and an effect equivalent to the configuration of any one of claims 1 to 3. Get.

In addition, the differential limiting force of the multi-plate clutch is applied to a pressure actuator (for example, a hydraulic actuator).
Therefore, the required differential limiting force can be obtained in accordance with the driving conditions, and the driving performance of the vehicle is greatly improved.

In this configuration, if the thickness of the spacer is determined according to the maximum pressing force of the pressure actuator, the surface pressure of the clutch plate becomes uniform as described above, and the durability of the multi-plate clutch is greatly improved. Therefore, the function of adjusting the differential limiting force can be normally maintained for a long time.

[0029]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described with reference to FIGS. FIG. 1 shows a differential device 1 according to this embodiment. The differential device 1 has the features of claims 1, 2, 3, and 4. Note that 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 includes a differential case 3, a bevel gear type differential mechanism 5, a multi-plate clutch 7, a disc spring 9 (pressing means), a spacer 11, openings 13, 15, and the like.

The differential case 3 is rotatably supported inside the differential carrier, and the differential carrier is provided with an oil reservoir.

The differential case 3 is constituted by fixing a casing body 17 and a cover 19 with bolts 20. A ring gear is fixed to the differential case 3, and this ring gear meshes with an output gear on the engine side.

Thus, the differential case 3 is driven to rotate by the driving force of the engine.

The bevel gear type differential mechanism 5 includes a pinion shaft 21, a pinion gear 23, side gears 25 and 27.
(A pair of output members).

The end of the pinion shaft 21 is engaged with and fixed to a through hole 29 of the differential case 3, and the pinion gear 23 is rotatably supported on the pinion shaft 21. Side gears 25 and 27 are pinion gears 2 from left and right.
3 and is connected to the wheel side via an axle splined to the respective bosses 31 and 33.

A clutch hub 35 is welded to the outer periphery of the boss portion 31 of the left side gear 25. The side gear 25 is connected to the support portion 3 of the differential case 3 via the clutch hub 35.
7 is supported. The right side gear 27 is provided in the boss 3
3 and is supported by a support portion 39 of the differential case 3.

The side gears 25 and 27 are pinion gears 23.
It is supported from the outside by meshing with. A thrust washer 41 is disposed between the clutch hub 35 of the side gear 25 and the differential case 3 and between the boss 33 of the side gear 27 and the differential case 3, and receives a meshing reaction force. These thrust washers 4
1 is provided with an oil hole 43 for supplying oil to the sliding surface.

A spherical washer 45 is arranged between the differential case 3 and the pinion gear 23, and receives a centrifugal force and a meshing reaction force of the pinion gear 23.

The driving force of the engine for rotating the differential case 3 is distributed from the pinion shaft 21 to the side gears 25 and 27 via the pinion gear 23 and transmitted to the respective wheels via the axle. When a difference in driving resistance occurs between the wheels on a bad road or the like, the driving force of the engine is differentially distributed to each wheel by the rotation of the pinion gear 23.

The multi-plate clutch 7 is arranged between the differential case 3 and the clutch hub 35 (side gear 25). The multi-plate clutch 7 is composed of five outer plates 47 and four inner plates 49 which are alternately arranged. Each outer plate 47 has a shaft formed on the inner periphery of the differential case 3 (cover 19). Each inner plate 49 is movably engaged with the axial groove 53 formed on the outer periphery of the clutch hub 35.

The three disc springs 9 are used in an overlapping manner, and these are arranged between the differential case 3 (casing body 17) and the multi-plate clutch 7 in a bent state. These disc springs 9 connect the multi-plate clutch 7 to the wall 55 of the differential case 3.
(Pressure receiving part) to give a constant friction torque,
The differential of the differential mechanism 5 is limited by this friction torque,
With this differential limiting force, the running performance and the escape performance of the vehicle on a rough road and the like are improved.

The spacer 11 is provided on the wall 55 of the differential case 3.
And the multi-plate clutch 7 and the casing body 1
It is stopped at 7. The spacer 11 is in contact with the leftmost outer plate 47 of the multi-plate clutch 7, so that the spacer 11 does not slide on either the casing body 17 or the outer plate 47.

The inner diameter of the spacer 11 is equal to the inner diameter of the outer plate 47, and the spacer 11 receives the preload of the disc spring 9 via the entire surface of the outer plate 47. The spacer is made of carbon steel.

The openings 13 and 15 are, as shown in FIG.
5 are provided at equal intervals in the circumferential direction. The opening 13 is rectangular and the opening 15 is circular. The opening 13 communicates with the multiple disc clutch 7 side radially outside the spacer 11, and the opening 15 communicates with the multiple disc clutch 7 side radially inside the spacer 11.

When the differential case 3 is stationary, the lower half is immersed in the oil reservoir of the differential carrier, and oil flows in from the openings 13 and 15 below the oil level. or,
When the differential case 3 rotates, the oil repelled from the oil reservoir flows in from the openings 13 and 15. The inflowing oil lubricates the meshing portion and sliding portion of each gear of the multi-plate clutch 7 and the differential mechanism 5.

As described above, the spacer 11 disposed between the wall portion 55 of the differential case 3 and the multi-plate clutch 7 also has the disc spring 9 on the openings 13 and 15 of the wall portion 55 via the multi-plate clutch 7. Under preload.

The graph 57 in FIG. 3 shows the surface pressure (kg / c) generated on each of the plates 47 and 49 under the preload of the disc spring 9.
m ² ) and a graph for selecting the minimum value of the thickness (mm) at which the spacer 11 is not deformed even when receiving the surface pressure on the openings 13 and 15.

The graph 57 shows that the surface pressure is 14 kg / cm ²
Is a graph connecting a point having a thickness of 1.6 mm, a point having a surface pressure of 23 kg / cm ² and a point having a thickness of 4.0 mm, and is set based on the material and hardness of the spacer 11.

As described above, the spacer 11 can
7, the minimum thickness is selected.
No deformation on 5

Thus, the differential device 1 is configured.

As described above, in the differential device 1, the spacer 11 disposed on the wall 55 side of the differential case 3
However, since the multi-plate clutch 7 is supported on the entire surface including the openings 13 and 15, the plates 47 and 49 are prevented from bending due to the preload of the disc spring 9, unlike the conventional example. The surface pressure becomes uniform over the entire surface.

As described above, since the surface pressures are equalized on the entire surfaces of the plates 47 and 49, the differential limiting function by the multiple disc clutch 7 is stabilized, and the running performance and the escape performance of the vehicle are improved.

Further, since the surface pressure becomes uniform, the plate 4
Roughness, galling, seizure, noise and the like of the surfaces 7 and 49 are prevented, and the durability of the multi-plate clutch 7 is greatly improved.

The opening 13 communicates with the side of the multi-plate clutch 7 radially outside the spacer 11, and the opening 15
The inner side in the radial direction communicates with the side of the multi-plate clutch 7 so that a required amount of oil can flow in and out, so that the multi-plate clutch 7 and the differential mechanism 5 are sufficiently lubricated even if the spacer 11 is disposed.

As described above, sufficient lubricity can be obtained with the existing differential case 3 and compatibility of the differential case 3 can be maintained. Therefore, it is not necessary to newly create a differential case in order to enhance lubricity, and the cost increases accordingly. Can also be avoided.

Since the spacer 11 is prevented from rotating toward the differential case 3, the differential case 3 is released from sliding with the multi-plate clutch 7, and the durability is greatly improved.

According to a graph 57 set based on the material and hardness of the spacer 11, the opening 13 of the spacer 11,
Since the minimum value of the thickness at which the portion corresponding to 15 is not deformed is selected, it is possible to avoid making the spacer 11 excessively thick, and to minimize the space for disposing the spacer 11.

This makes it possible to maintain the compatibility of the differential case 3 high as described above and to minimize the reduction in the number of plates 47 and 49 arranged in a limited space. Differential limiting force is maintained.

Further, in this configuration using the disc spring 9 as the pressing means, the space for the pressing means can be small, so that the number of plates 47 and 49 can be increased and the differential limiting force can be strengthened.

Further, since the rectangular opening 13 can be lengthened in the radial direction, it is easy to communicate with the multi-plate clutch 7 outside or inside the spacer 11 in the radial direction. Further, the circular opening 15 is advantageous in strength because stress concentration hardly occurs in the differential case 3.

In the differential device of the present invention, a pressure actuator (for example, a hydraulic actuator) may be used as the pressing means.

In this configuration, since the differential limiting force of the multi-plate clutch can be controlled by the pressure actuator, a necessary differential limiting force can be obtained according to running conditions, and the traveling performance of the vehicle is greatly improved.

In this configuration, if the thickness of the spacer is determined according to the maximum pressing force of the pressure actuator, the surface pressure of the clutch plate becomes uniform, and the durability of the multi-plate clutch is greatly improved. The regulating function of the limiting force is kept normal for a long time.

The differential mechanism is not limited to a bevel gear type differential mechanism. For example, a side gear is connected via a planetary gear type differential mechanism or a pinion gear slidably supported in a housing hole of a differential case. A differential mechanism using a worm gear or a differential mechanism using a worm gear may be used.

The differential device according to the present invention includes a front differential for distributing the driving force of the engine to the left and right front wheels, a rear differential for distributing the driving force of the engine to the left and right rear wheels, and a front differential for distributing the driving force of the engine to the front and rear wheels. It can be used for any of the center differentials distributed to the wheels.

[0066]

According to the differential device of the first aspect, since the spacer supports the entire multi-plate clutch over the opening of the differential case, the surface pressure becomes uniform over the entire clutch plate, and the differential limiting function of the multi-plate clutch is achieved. It is stable, and the running performance of the vehicle is improved.

Also, the surface roughness, galling, etc. of the clutch plate
Seizure and noise are prevented, and the durability of the multi-plate clutch is greatly improved.

Even if the spacers are arranged, the required amount of oil flows in and out from the opening communicating with the multi-plate clutch, so that the inside of the differential case is sufficiently lubricated.

Further, since the compatibility of the differential case is maintained in this way, it is not necessary to re-create the differential case in order to enhance the lubricating property, and it is possible to avoid an increase in cost associated therewith.

Further, since the spacer is prevented from rotating around the differential case, the differential case is released from sliding with the multi-plate clutch, and the durability is greatly improved.

According to the second aspect of the invention, the same effects as those of the first aspect are obtained, and the spacer is prevented from being excessively thick and the space for disposing the spacer is minimized. In addition to being kept high as described above, the reduction in the number of clutch plates is minimized, and the necessary differential limiting force is maintained.

According to the third aspect of the present invention, the same effect as that of the second aspect is obtained, and according to this disclosure, the minimum thickness of the spacer which does not deform according to the surface pressure of the multiple disc clutch is selected. Can be.

The invention of claim 4 is the first to third aspects of the present invention.
In addition to the same effect as the configuration described above, an appropriate differential limiting force is always obtained by the preload of the spring used as the pressing means, and the traveling performance of the vehicle is improved.

If a disc spring is used, the space for disposing the pressing means can be reduced, the number of clutch plates can be increased accordingly, and the differential limiting force can be strengthened.

The invention according to claim 5 is the invention according to claims 1 to 3
The same effect as the configuration described above can be obtained, and the differential limiting force of the multi-plate clutch can be controlled by the pressure actuator according to the traveling conditions, so that the traveling performance of the vehicle can be greatly improved.

Further, by arranging the spacers, the durability of the multi-plate clutch is greatly improved as described above, so that the function of adjusting the differential limiting force can be normally maintained for a long time.

[Brief description of the drawings]

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

FIG. 2 is a view taken in the direction of arrow A in FIG. 1;

FIG. 3 is a graph for selecting a minimum thickness of a spacer with respect to a surface pressure of a multi-plate clutch in the embodiment of FIG. 1;

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

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 differential device 3 differential case 5 bevel gear type differential mechanism (differential mechanism) 7 multi-plate clutch 9 disc spring (pressing means) 11 spacer 13, 15 oil opening provided in differential case 25 side gear (output member) 55 differential case Wall part (pressure receiving part)

Claims (5)

[Claims] 1. A differential case that is rotationally driven by a driving force of an engine, a differential mechanism that distributes rotation of the differential case to wheels via a pair of output members, and a differential disposed between the differential case and the output member. A multi-plate clutch for motion restriction,
In a differential apparatus provided with a pressing means for pressing the multi-plate clutch toward a pressure-receiving portion side of a differential case to apply a differential limiting force, and an oil opening formed in the pressure-receiving portion, the pressure-receiving portion and the multi-plate clutch With a spacer that is prevented from rotating on the differential case side between the above and the opening,
A differential device characterized in that at least one of the radially outer side and the inner side of the spacer communicates with the multi-plate clutch side. 2. The invention according to claim 1, wherein the thickness of the spacer is set to such a value that a portion corresponding to the opening of the differential case is not deformed when receiving the pressing force of the pressing means. Differential device. 3. The invention according to claim 2, wherein the surface pressure (kg / cm ² ) and the thickness (mm) of the spacer generated in the multi-plate clutch under the pressing force are 14 kg / cm ² . 6m
A differential device characterized by being set on a straight line graph connecting point m and points 23 kg / cm ² and 4.0 mm. 4. The differential device according to claim 1, wherein the pressing means is a spring for preloading the multi-plate clutch. 5. The differential device according to claim 1, wherein the pressing means is a pressure actuator that presses a multi-plate clutch via a piston. .