JPH0429646A - Differential gear - Google Patents

Abstract

PURPOSE:To automatically large adjust a differential limit in the case of large input torque to differential case by pressing a clutch plate set in a rotary shaft direction and friction-holding the second plate set by the clutch plate set. CONSTITUTION:Component force in a rotary shaft direction, generated by a contact pressure of a pinion gear 14, acts on a side gear 12, and it is slid in a pressing direction relating to a clutch plate 30 against energizing force of a belleville spring 34. Accordingly, in the side gear 12, the higher is increased a rotational speed of a differential case 11, the larger the pressing force is increased against the energizing force of the belleville spring 34. Then, an inner plate 31 is connected to a hub 26 by strength in accordance with strength of holding force of the clutch plate 30 by pressing the clutch plate 30 to a pressing part 40 of the side gear 12. That is, differential limiting of right/left drive shafts 8, 9 is performed by a viscous coupling through transmission of torque in proportion to a rotational speed difference by shear resistance of viscous fluid between the differential case 11 and the hub 26.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a differential device in which differential movement is automatically limited by a viscous coupling that transmits torque through viscous fluid.

[Prior Art] Generally, a differential device used in a power transmission system between left and right drive shafts of a vehicle, for example, includes a differential case that is rotatably supported and driven within a housing, and a differential case that is coaxially supported within the differential case. It includes two side gears that are rotatably housed, and a pinion gear that is rotatably disposed on a pinion shaft perpendicular to the rotational axis of the differential case and meshes with the side gears, and a pinion gear that meshes with the side gears. The left and right drive shafts are connected to each other. A viscous coupling used as a differential limiting device of the differential device is housed in the differential case having an extended structure as a cambling housing.

The viscous compression ring is arranged to be rotatable together with an outer plate set that is slidable in the direction of the rotational axis of the coupling housing and rotatably arranged together with the coupling housing, and one of the drive shafts. It includes an inner plate set that is slidable in the direction of the rotational axis of the transmission member and rotatably arranged on the transmission member, and a working chamber that is filled with a viscous fluid, and the outer plate set and the inner The plates of the plate set are alternately arranged within the working chamber, and the plates of at least one plate set are spaced apart from each other.

Therefore, when the left and right drive shafts are rotating at the same speed, such as when driving straight, the driving force transmitted from the drive shaft to the differential soyral case is transferred to the left and right side gears via the pinion gear. It is transmitted evenly and drives the left and right drive shafts equally.

Next, for example, when one drive wheel idles and a difference in rotational speed begins to increase between the rotation of the differential case due to the driving force from the drive shaft and the drive shaft on which the transmission member is arranged, shearing of the silicone oil occurs. Due to the resistance, torque is transmitted between the outer plate set engaged with the differential case and the inner plate set engaged with the transmission member, and the differential case and the drive shaft on which the transmission member is arranged are rotated at the same rotation speed. There is a differential limit to try to rotate it. In other words, it is possible to prevent the drive torque from being transmitted from the idling drive shaft to the other drive shaft and escaping from the idling drive shaft.

Therefore, the straight-line performance and escape performance on rough roads are improved, and the driving performance is improved.

[Problem to be solved by the invention]

By the way, in a differential device using such a viscous compression ring as a differential limiting device,
As shown in the graph 46 in FIG. 3, the torque transmission characteristic of the viscous coupling is such that the transmission torque changes approximately in proportion to the rotational speed difference (ΔN) due to the relative movement between the outer plate group and the inner plate group. The viscous force is applied so that sufficient differential limiting torque can be obtained in the rotational speed difference range.

Setting the puller will also increase the differential limiting torque in the low rotational speed difference range, causing interference in the braking force such as one wheel locking during braking affecting the other wheel locking, resulting in an anti-lock braking system. (AB
This may cause problems such as S) not functioning properly.

In other words, with ABS, the rotation of each wheel is detected, the vehicle speed is estimated from there, and if any wheel rotates slower than this, it is determined that the brake line is locked and the brake line pressure is controlled. If the limited torque is large, when one wheel locks, the other wheel will also try to lock at the same time, making it impossible to accurately determine whether the wheels are locked. Therefore, if the viscous force and bling are set so that the 4J differential limiting torque is small in the low rotational speed difference range, sufficient differential torque will not be obtained in the high rotational speed difference range, and it will not be possible to drive on rough roads. Sexuality decreases.

Therefore, an object of the present invention is to solve the above-mentioned problems, and to provide a small and lightweight differential device that has a simple structure and has a differential limiting torque adjustment function.

[Means for Solving the Problem] The above object of the present invention is to provide a differential case that is rotatably supported and driven within a housing, and a differential case that is rotatably housed on a coaxial line within the differential case and that is rotatably supported and driven within a housing. two side gears that engage with each drive shaft in the rotational direction; and a pinion gear that is rotatably disposed on a pinion shaft perpendicular to the rotational axis of the differential case and meshes with both of the side gears. A differential gear means, first and second transmission members arranged to be relatively rotatable, a working chamber filled with a viscous fluid, and a first plate assembly rotationally engaged with the first transmission member. and a second plate set sandwiched between the first plate set and a flange plate set arranged alternately in the working chamber and rotationally engaged with a second transmission member. A differential device comprising a limiting means, wherein a side gear disposed close to the differential limiting means is biased in advance in a direction opposite to a direction in which the flange plate assembly is pressed by a biasing member, and the side gear is biased against the pinion. When the contact pressure with the gear increases, the flange plate assembly moves in the pressing direction against the biasing force of the biasing member, presses the clutch plate assembly in the direction of the rotation axis, and turns the second plate assembly into a flanch plate assembly. This is achieved by a differential device characterized in that it is configured to be frictionally clamped.

[Effect]

When the input torque to the differential case is small and the contact pressure of the pinion gear to the side gear is small, the side gear located close to the differential limiting means is moved by the biasing member in a direction opposite to the direction in which it presses against the clutch plate assembly. Since the second set of plates is biased, the second set of plates is rotatable relative to the second transmission member and
Almost no rotational torque is transmitted between the transmission member and the second transmission member, and the differential limiting means does not act.

Further, when the input torque to the differential case is large and the contact pressure of the pinion gear with respect to the side gear becomes large, a component force in the direction of the rotation axis generated by the contact pressure of the pinion gear acts on the side gear,
The side gear is driven in a direction in which the clutch plate set is pressed. Then, the second plate set held by the flange plate Mi4 engages with the second transmission member in the rotational direction, and the first transmission member and the second
The differential limiting means acts by transmitting torque proportional to the rotational speed difference due to the shear resistance of the viscous fluid between the differential limiting means and the biasing member. By appropriately adjusting the biasing force, the differential limiting characteristic of the differential device can be changed.

[Embodiment]

Hereinafter, one embodiment of the present invention will be described in detail based on the attached FIGS. 1 to 4.

First, one implementation of the present invention is shown in FIG. 4! The configuration of the power system of a front wheel drive vehicle using IJ9 will be explained. This power system is
It is composed of an engine 5, a transmission 6, a differential device 7 of this embodiment, left and right drive shafts 8, 9, left and right front wheels 2, 1, etc., and the left and right rear wheels 4, 3 are driven.

Next, the configuration of the differential device 7 will be explained with reference to FIG. The differential device 7 has a housing (
a differential case 11 which is rotatably supported and driven by rotating shafts 17 at both ends in a
Two side gears 12.13 are rotatably housed coaxially within the differential case 11, and the side gears are rotatably disposed on a pinion shaft 19 perpendicular to the rotational axis of the differential case 11. 1213, and a pinion gear 14 meshing with the gear 1213, and the side gears 12.13 are rotatably coupled with the left and right drive shafts 8.9, respectively.

A viscous compression ring used as a differential limiting device of the differential device 7 is configured in the differential case 11 with an extended structure as a pull housing 15 .

The coupling housing 15 (first transmission member) and the hub 26 (second transmission member) constituting the viscous compression ring are arranged so as to be relatively rotatable, and the hub 26 is spline-fitted to the drive shaft 9 and A differential case 11 that rotates together with the side gear 12 and includes a coupling housing 15 is driven by the transmission 6 via a ring gear (not shown).

Cambling housing 15, hub 26 and side gear 1
2, a working chamber 25 is formed, and this working chamber 25 is filled with highly viscous silicone oil (viscous fluid). An X ring 3 is provided between the cambling housing 15, the hub 26, and the side gear 12, respectively.
7 (a seal having an X-shaped cross section) is disposed, and an O-ring 38 is disposed between the hub 26 and the side gear 12 to keep the working chamber 25 liquid-tight.

As shown in an enlarged view in FIG. 2, outer plates 32 and inner plates 31 are alternately arranged within this working chamber 25. The outer plate 32 (first plate) is spline connected to the inner periphery of the compling housing 15 so as to be movable in the axial direction, and the inner plate 31 (second play date is loosely fitted to the outer periphery of the hub 26). .Clutch plates 30 are arranged alternately with the inner plates 31 on the inner edge side of the inner plate 31, and the clutch plates 30 are spline-connected to the outer periphery of the hub 26 so as to be movable in the axial direction.

In addition, these inner plate 31 and clutch plate 30 are connected to a pressure receiving ring 36 installed between the hub 26 and the differential case 11 and the side gear 12.
It is sandwiched between the pressing part 40 and the position is regulated in the axial direction. Then, the pressing portion 40 of the side gear 12 is moved toward the pressure receiving ring 36 side, and the inner plate 31
When the clutch plate 30 is pressed in the axial direction, the inner plate 31 is clamped by the clutch plate 30 and becomes rotatable together with the clutch plate 26. Note that the side gear 12 is biased in advance in a direction opposite to the above-mentioned pressing direction by a disc spring 34 inserted into an axially opposing portion of the side gear 12 and the hub 26.

Next, the operation of the differential device 7 will be explained.

When the left and right drive shafts 8.9 rotate at the same rotation speed, such as when traveling straight, the driving force transmitted from the transmission 6 to the differential case 11 is transferred to the left and right side gears 12 via the pinion gear 14. 13, and drive the left and right drive shafts 89 equally.

Next, for example, when the drive shaft 9 idles and the side gears 12 and 13 rotate differentially, the drive shaft 9 rotates faster than the differential case 11, so there is a gap between the hub 26 and the coupling housing 15. There will be a difference in rotation speed.

Here, when the input torque to the differential case 11 is small and the contact pressure of the pinion gear 14 with respect to the side gear 12 is small, the side gear 1
2 is biased by the biasing force of the disc spring 34 in a direction opposite to the direction in which the clutch plate 30 is pressed. Therefore,
Clutch plate 30 for inner plate 31
Since the clamping force does not act on the inner plate 31 and the clutch plate 30, slippage occurs between the inner plate 31 and the clutch plate 30, and rotational torque is not transmitted. Therefore, the transmitted torque is a slight torque from the inner plate 31 to the clutch plate 30 due to the shear resistance of the silicone oil. Thus, the coupling housing 15 and the hub 26 are substantially separated and torque transmission is cut off. Therefore, differential restriction between the left and right drive shafts 8 and 9 by the viscous coupling is not performed.

Further, when the input torque to the differential case 11 is large and the contact pressure of the pinion gear 14 to the side gear 12 becomes large, the side gear 12 receives a component force in the direction of the rotating shaft due to the contact pressure of the pinion gear 14. As a result, the side gear 12 is slid in the direction of pressing against the clutch plate 30 against the biasing force of the disc spring 34. Therefore, the higher the rotational speed of the differential case 11, the more the side gear 12 becomes
The pressing force that resists the urging force of No. 4 increases. Therefore, the clutch plate 30 is pressed by the pressing part 40 of the side gear 12, and the inner plate 31 is pressed against the clutch plate 30.
It is connected to the hub 26 with a strength corresponding to the strength of the clamping force.

That is, torque is transmitted between the differential case 11 and the hub 26 in proportion to the rotational speed difference due to the shear resistance of the viscous fluid, and the viscous coupling limits the differential movement between the left and right drive shafts 8 and 9. .

The torque transmission characteristics of the viscous coupling at this time are the third
The result will be as shown in graph 46 in the figure. In addition, the rotation speed difference in Figure 3 (
ΔN) is the rotation speed difference between the differential case 11 and the hub 26.

When the input torque to the differential case 11 becomes smaller, the contact pressure of the pinion gear 14 against the side gear 12 becomes smaller, and the pressing force of the side gear 12 against the biasing force of the disc spring 34 also becomes smaller. Therefore, side gear 12 is plate-shaped. , 34 in the opposite direction to the pressing direction of the clutch plate 30, and the inner plate 31 is released from the clamping force of the clutch plate 30, so that the differential case 11 and the hub 26 are substantially separated. Torque transmission is cut off, and differential restriction between the left and right drive shafts 8.9 is also released.

The torque transmission characteristic of the viscous coupling at this time is the third
It will look like graph 47 in the figure.

In this way, in the differential device 7 of the present invention,
Torque transmission characteristics of viscous coupling and disc spring 34
By appropriately setting the biasing force, the differential limiting torque can be substantially cut off in a region where the input torque to the differential case 11 is small, and the differential limiting torque can be automatically adjusted to a large value in a region where the input torque is large.

Next, the function of the differential device 7 will be explained based on the power performance of the vehicle shown in FIG.

The rotation of the engine 5 is shifted by a transmission 6 and outputted from a differential device 7 to left and right front wheels 2.1.

When the input torque to the differential case 11 is small and the rotation difference between the left and right front wheels is small, such as when turning at low speed, the differential limiting torque by the viscous coupling is cut off, so the differential The dynamic function works and enables smooth turning.

When one of the front wheels spins on a rough road, and the driving force escapes from the spinning wheel, a difference in rotation occurs between the left and right front wheels. Then, the clutch plate 30 is pressed by the pressing portion 40 of the side gear 12 in accordance with the input torque to the differential case 11, and the inner plate 31 is pressed against the hub 26 with a strength corresponding to the strength of the clamping force of the clutch plate 30.
At the same time, torque is transmitted between the differential case 11 and the hub 26 in proportion to the rotational speed difference due to the shear resistance of the viscous fluid, and the differential movement of the left and right drive shafts 8.9 by the viscous coupling is performed. Restrictions are in place.

Therefore, the driving force can be transmitted to the wheels that are not idling, and high running performance can be achieved.

Further, when the driving force from the engine 5 is small and the input torque to the differential case 11 is small, such as when braking the vehicle, the side gear 12 is moved in the opposite direction to the pressing direction of the clutch plate 30 by the biasing force of the disc spring 34. , the inner plate 31 is energized by the clutch plate 3
Since the clamping force of 0 is released, the differential case II and the hub 26 are substantially separated, the torque transmission is cut off, and the differential restriction between the left and right drive shafts 8 and 9 is also released. Therefore, even if one wheel becomes longer due to braking and a rotation speed difference occurs between it and the other wheel, the differential restriction on the left and right drive shafts 89 is released, so there is no interference between the left and right wheels. The normal functioning of ABS is protected.

Note that the biasing member that biases the side gear 12 in the opposite direction to the pressing direction of the clutch plate 30 is not limited to the disc spring 34 in the embodiment B described above, but other biasing members such as a uniform washer may be used. .

Further, the clutch plate 30 has an outer plate 32.
and the differential case 11,
It may be provided on both sides.

Furthermore, the configuration of the differential limiting means is not limited to the type that detects the rotational speed difference between the differential case 11 and the drive shaft 9 in the above embodiment, but is also limited to the type that detects the rotation speed difference between the differential case 11 and the drive shaft 9 as shown in FIG. Of course, it is possible to adopt a type of configuration that detects the difference in rotational speed.

FIG. 5 is a partial cross-sectional view of a differential device 50 according to another embodiment of the present invention.

The differential device 50 has rotating shafts 17 at both ends rotatably supported within a housing (not shown).
A differential case 51 is driven, two side gears 52 and 53 are coaxially rotatably housed within the differential case 51, and are rotatable on a pinion shaft 55 perpendicular to the rotation axis of the differential case 51. The pinion gear 54 is disposed at the side gear 52, 53 and meshes with the side gear 52, 53, and the side gear 53 is rotatably coupled with the drive shaft 8. The viscous coupling used as a differential limiting device of the differential range cell device 50 is disposed inside the differential case 51, and includes a flange 62 of which the side gear 52 forms a part, a cover 59, and the other end. A housing 58 having a flange 60 and a hub 61 form a working chamber filled with high viscosity silicone oil (viscous fluid), and the housing 58 constitutes the viscous coupling.
(first transmission member) and hub 61 (second transmission member) are arranged to be relatively rotatable.

Further, the hub 61 is spline-fitted to the drive shaft 8 passing through the side gear 52 and rotates together with the side gear 53.
The housing 58 is spline-fitted to the drive shaft 9. Further, the side gear 52 and the flange 62 are both rotatable together, are spline-connected to the cover 59 so as to be movable in the axial direction, and are rotatably disposed relative to the hub 61. And these housings 5B
A knob 66 is disposed between the hub 61 and the hub 61 to keep the working chamber liquid-tight.

In the working chamber, outer plates 65 and inner plates 64 are alternately arranged. The outer plate 65 (first plate) is spline connected to the inner periphery of the housing 58 so as to be movable in the axial direction, and the inner plate 64 (second plate) is loosely fitted to the outer periphery of the hub 61. A clutch plate 63 is disposed on the inner edge side of the inner plate 64.
4 and are arranged alternately, and this clutch plate 63
is spline connected to the outer periphery of the hub 61 so as to be movable in the axial direction.

Further, the inner plate 64 and the clutch plate 63 are sandwiched between a pressure receiving ring 67 attached to the hub 61 and a pressing portion of the side gear 52, and their positions are regulated in the axial direction. Then, when the pressing part of the side gear 12 is moved toward the pressure receiving ring 67 and presses the inner plate 64 and the clutch plate 63 in the axial direction, the inner plate 64 is held between the clutch plates 63 and integrated with the hub 61. Can be rotated.

Note that the side gear 52 is biased in advance in a direction opposite to the above-mentioned pressing direction by a disc spring 70 inserted into a portion where the side gear 52 and the hub 61 face each other in the axial direction.

Next, the operation of the differential device 50 will be explained.

When the left and right drive shafts 8.9 rotate at the same rotation speed, such as when traveling straight, the driving force transmitted from the transmission 6 to the differential case 51 is transferred to the pinion gear 5.
4, the side gear 53 equally drives the drive shaft 8, and the side gear 52 equally drives the drive shaft 9 via the housing 5B.

Next, for example, when the drive shaft 9 idles and the side gears 52 and 53 rotate differentially, the drive shaft 9 rotates faster than the drive shaft 8, resulting in a rotation speed difference between the hub 61 and the housing 58. .

Here, when the input torque to the differential case 51 is small and the contact pressure of the pinion gear 54 with respect to the side gear 52 is small, the side gear 5
2 is biased by the biasing force of the disc spring 70 in a direction opposite to the direction in which the clutch plate 63 is pressed. Therefore,
Clutch plate 63 for inner plate 64
Since the clamping force does not act on the inner plate 64 and the clutch plate 63, slippage occurs between the inner plate 64 and the clutch plate 63, and rotational torque is not transmitted. Only the torque is transmitted, and the housing 58 and the hub 61 are substantially separated and torque transmission is cut off.

Therefore, the left and right drive shafts 8 using the viscous coupling
, 9 differential limitation is not performed.

Further, when the input torque to the differential case 51 is large and the contact pressure of the pinion gear 54 with respect to the side gear 52 becomes large, a component force in the direction of the rotation axis generated by the contact pressure of the pinion gear 54 acts on the side gear 52. , the side gear 52 is slid in the direction of pressing against the clutch plate 63 against the biasing force of the disc spring 70. Therefore, the greater the input torque to the differential case 51, the greater the pressing force of the side gear 52 against the biasing force of the disc spring 70. Therefore, the clutch plate 63 is pressed by the pressing portion of the side gear 52, and the inner plate 64 is connected to the hub 61 with a strength corresponding to the strength of the clamping force of the clutch plate 63.

That is, between the housing 58 and the hub 61, torque is transmitted in proportion to the difference in rotational speed due to the shear resistance of the viscous fluid, and the left and right drive shafts 8.9 are transmitted by the viscous coupling.
Differential limiting is performed.

When the human torque applied to the differential case 51 decreases, the contact pressure of the pinion gear 54 against the side gear 52 decreases, and the pressing force of the side gear 52 against the biasing force of the disc spring 70 also decreases. Therefore, the side gear 52 is urged in the opposite direction to the pressing direction of the clutch plate 63 by the urging force of the disc spring 70.
Since the inner plate 64 is released from the clamping force of the clutch plate 63, the inner plate 64 is substantially connected to the housing 58 and the hub 6.
1 is disconnected, torque transmission is cut off, and differential restriction between the left and right drive shafts 8.9 is also released.

Therefore, similarly to the embodiment described above, even if one wheel locks due to braking and a rotational speed difference occurs between it and the other wheel, the differential restriction between the left and right drive shafts 8.9 is released. There is no interference between the left and right wheels, the normal function of the ABS is protected, and the ability to travel on rough roads is not impaired.

[Effects of the Invention] According to the differential device of the present invention, the first and second transmission members arranged to be relatively rotatable, the working chamber filled with viscous fluid, and the first transmission member in the rotational direction. a first plate set that is engaged; and a second set of clutch plates that are sandwiched between the first set of plates and the set of clutch plates that are arranged alternately in the working chamber and that are rotationally engaged with the second transmission member; A side gear disposed close to the differential limiting means having a plate set is biased in advance by a biasing member in a direction opposite to the pressing force against the clutch plate set, and the side gear has a contact pressure with the pinion gear. When the second plate group increases, it moves in the pressing direction of the flange plate set against the biasing force of the biasing member, and presses the clutch plate set in the direction of the rotation axis, so that the second plate set is frictionally clamped by the clutch plate set. Therefore, when the input torque to the differential case is small, differential restriction is not performed, and when the input torque to the differential case is large, the differential restriction can be automatically adjusted to a large value.

In other words, even if one wheel locks due to braking and a rotation speed difference occurs between it and the other wheel, the differential restriction between the left and right drive shafts is released, so there is no interference between the left and right wheels, and ABS The normal functions of the vehicle are protected, and the vehicle's ability to travel on rough roads is not impaired.

Therefore, it is possible to provide a differential device that has a differential limiting characteristic adjustment function, has a simple structure, and is small and lightweight.

[Brief explanation of the drawing]

FIG. 1 is a longitudinal sectional view of a differential device according to an embodiment of the present invention, FIG. 2 is a partially enlarged view of the differential device shown in FIG. 1, and FIG. 3 is a torque limiter of a differential limiting device according to the present invention. A graph showing the transmission characteristics, FIG. 4 is a skeleton mechanism diagram showing the power system of a vehicle using the differential device shown in FIG. 1, and FIG. FIG. (Symbols in the diagram) 1.2...Front wheel 3,4...Rear wheel 5...
Engine 6... Transmission 7...
・Differential device 8.9... Drive shaft 11... Differential case 12... Side gear 13... Side gear 1
4... Pinion gear I5... Compling housing 17... Rotating shaft 19... Pinion shaft 25...
・Working chamber 26...Hub 30...Clutch plate 31...Inner plate (second plate) 32.
... Outer plate (first plate) 34 ... Disc spring 36 ... Pressure receiving ring 37 ... ... Differential case 52 ... Side gear 53 ... Side gear 5
4... Pinion gear 55... Binion shirt 58... Housing 59... Cover 60.
... Flange 61 ... Hub 62 ... Flange 63 ... Thalasso chip play 64 ... Inner plate 65 ... Outer play 66 ...
Seal 67...Pressure ring 70...Countersunk spring. Tototo

Claims (1)

[Claims] a differential case that is rotatably supported and driven within a housing; two side gears that are coaxially rotatably housed within the differential case and engage each drive shaft in the rotational direction; differential gear means comprising a pinion gear rotatably disposed on a pinion shaft perpendicular to the axis of rotation and meshing with the side gears; and first and second transmissions disposed relatively rotatably. a working chamber in which a viscous fluid is sealed; a first plate set rotationally engaged with a first transmission member; 2
a differential limiting means comprising a transmission member and a second plate set sandwiched by a clutch plate set engaged in the rotational direction, the differential limiting means being provided close to the differential limiting means; The side gear is biased in advance by the biasing member in a direction opposite to the direction in which the clutch plate set is pressed, and when the contact pressure with the pinion gear increases, the side gear resists the biasing force of the biasing member and pushes the clutch plate. What is claimed is: 1. A differential device, characterized in that the differential device is configured to move in a pressing direction of the clutch plate set, press the clutch plate set in the rotation axis direction, and frictionally sandwich the second plate set with the clutch plate set.