JPH04351353A - Electronically controlled differential motion limiting device - Google Patents

Abstract

PURPOSE:To prevent mixing of a lubricant and a working liquid and shorten the axial direction dimension of the body of device by installing a sealing member which partitions inside of the housing together with a clutch engaging means in such a location as overlapping with a pressure bearing in the radial direction. CONSTITUTION:A plurality of side gears 8, 8' meshing with a pinion mate gear 11 and coupled with drive shafts 9, 9' are installed oppositely in a differential case 3 supported by a housing 1 rotatably, and thus the body of device is formed. A plurality of hydraulic pistons 22, 22' are provided to press friction clutches 13, 13' through pressure bearings 26, 26' in the direction of their engaging, wherein the clutches 13. 13' are installed between the side gears 8, 8' and the differential case 3, and the inside of the housing is partitioned by these pistons 22, 22' and oil seals 27, 27'. These oil seals 27, 27' are located in positions overlapping with the pressure rings 26, 26' in the radial direction.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electronically controlled differential limiting device.

0002

2. Description of the Related Art A conventional electronically controlled differential limiting device is known, for example, as described in Japanese Unexamined Patent Publication No. 61-59044.

This device includes a differential case that is rotatably supported by a housing, two side gears that are arranged facing each other in the differential case, mesh with a pinion mate gear, and are connected to an output shaft; This configuration includes a clutch disposed between the clutch and the differential case, and a hydraulic piston that presses the clutch in a direction to engage the clutch via a pressure bearing.

[0004] The pressure bearing has a hydraulic piston provided on the housing side in order to improve control accuracy, ensure seal reliability, and simplify the control hydraulic pressure supply structure, and a clutch side that rotates with respect to the housing. This is designed to transmit the pressing force while absorbing the rotational difference between the two.

[0005]

By the way, a lubricant such as differential oil is generally used in the housing for lubrication. In particular, in electronically controlled differential limiting devices, additives such as friction modifiers are added to lubricate the clutch, and performance may deteriorate due to mixing of different types of oil.

On the other hand, when a device operated by hydraulic pressure such as a hydraulic piston is used as a means for engaging the clutch as in the above-mentioned conventional technology, the liquid for operating this is a fluid that is responsive to temperature changes. Low viscosity oil is used to prevent deterioration.

Therefore, although not disclosed in the above publication, it is necessary to provide a member that seals the lubricant in the housing and the liquid that operates the clutch engagement means.

[0008] Therefore, a seal member is thus set between the inside of the housing and the hydraulic piston (clutch fastening means), and a seal member is similarly set between the hydraulic piston (clutch fastening means) and the clutch inside the housing. When the pressure bearings are arranged side by side in the axial direction, a problem arises in that the axial dimension of the device increases.

The present invention was made in view of the above-mentioned problem, and an object of the present invention is to provide an electronically controlled differential limiting device that can reduce the axial dimension.

0010

[Means for Solving the Problems] In the present invention, the above-mentioned object is achieved by arranging a seal member and a pressure bearing radially overlapping each other.

That is, the electronically controlled differential limiting device of the present invention includes a differential case rotatably supported by a housing, and the differential case is disposed facing each other in the differential case, is engaged with a pinion mate gear, and is connected to an output shaft. Two coupled side gears, a clutch disposed between the side gear and a differential case, a hydraulically actuated clutch engagement means that presses the clutch in a direction to engage it via a pressure bearing, and the clutch engagement means. and a seal member defining the inside of a housing, the seal member being disposed at a position radially overlapping with a pressure bearing.

0012

[Operation] The sealing member seals the inside of the housing filled with lubricant and the hydraulically actuated clutch engagement means, preventing the lubricant and hydraulic fluid from mixing, and preventing the mixing of the two from occurring. performance deterioration can be prevented.

Furthermore, by arranging the sealing member radially overlapping the pressure bearing, the axial dimension of the device can be shortened.

[0014]

[Embodiments] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In describing this embodiment, an electronically controlled differential limiting device for an automobile will be taken as an example.

FIG. 1 is an overall sectional view showing an embodiment of the apparatus, and numeral 1 in the figure indicates a housing. This housing 1 is supported on the vehicle body side by stud bolts (not shown), and includes a front housing 1a and a rear housing 1b.
and piston housings 1c, 1c', and the inside thereof is filled with differential gear oil for lubrication, and a friction modifier is further added to this differential gear oil to improve lubricity.

Reference numeral 3 denotes a differential case, in which tapered roller bearings 4,
The differential case 3 includes a left differential case 3a and a right differential case 3a'. The differential case 3 is provided with a ring gear 7 that meshes with a pinion gear 6 provided on the propeller shaft 5, and the rotational driving force from the propeller shaft 5 is transmitted to the differential case 3.

Reference numerals 8 and 8' denote side gears, which are disposed facing each other inside the differential case 3. The side gears 8 and 8' have a left drive shaft (output shaft) 9 and a right drive shaft. (output shaft) 9' is provided by spline connection.

10 is a pinion mate shaft,
The pinion mate shaft 10 is disposed between the side gears 8 and 8', and a pinion mate gear 11 that meshes with the side gears 8 and 8' is supported on the pinion mate shaft 10.

Reference numerals 13 and 13' denote friction clutches, which are disposed between the side gears 8 and 8' and the differential case 3.
3' is a multi-plate clutch structure, and as shown in FIG. 2, which is an enlarged sectional view of section A in FIG.
A plurality of friction plates 13a, 13 fixed to
a' and hubs 21, 21 connected to both drive shafts 9, 9'
A plurality of friction disks 13b, 1 fixed to '
3b'.

Hydraulic pistons 22 and 22' serve as clutch engagement means, and are fitted into cylinders 1d and 1d' formed in the piston housing 1c so as to be able to reciprocate in the axial direction. The control hydraulic pressure supplied from a hydraulic control device (not shown) is introduced into the pressure chambers 1g, 1g' through the hydraulic pressure introduction circumferential grooves 1e, 1e' and the hydraulic pressure introduction holes 1f, 1f'. The hydraulic pistons 22, 22' are equipped with pins 3 to improve control accuracy, ensure seal reliability, and simplify the control hydraulic pressure supply structure.
0,30' prevents rotation and piston housing 1c
, 1c'. Further, the hydraulic control device is disclosed in the above-mentioned publication as the prior art, so a description thereof will be omitted. Furthermore, as the oil for transmitting the control hydraulic pressure, a low-viscosity oil used in power steering and the like is used to ensure control responsiveness.

Between the hydraulic pistons 22, 22' and the friction clutches 13, 13', pressure plates (pressure members) 24, 24', pressure rings (pressure members) 25, 25', and pressure bearings 26,
26' is interposed.

[0022] The pressure plates 24, 24' are
The friction clutches 13 and 13' are disposed in contact with the outer surfaces thereof, and are coupled to the outer peripheries of both drive shafts 9 and 9' so as to be slidable in the axial direction. In addition, the pressure plates 24, 24'
rotates together with both drive shafts 9, 9'.

The pressure rings 25, 25' are connected to the outer peripheries of the drive shafts 9, 9' in contact with the outsides of the pressure plates 24, 24' so as to be slidable in the axial direction.

As shown in FIG. 3, which is an enlarged cross-sectional view of section B in FIG. A thrust bearing is used in which the pressure rings 25 and 25 are arranged in parallel in the axial direction.
25' and the hydraulic pistons 22, 22'.

[0025]This pressure bearing 26,
An oil seal 27 for sealing between the cylinders 1d, 1d' and the inside of the housing 1 is located at a position radially overlapping with 26' and between the pressure rings 25, 25' and the piston housings 1c, 1c'. , 27' are provided.

Further, pressure bearings 26, 26 are provided between the hubs 21, 21' and the pressure plates 24, 24' to prevent slippage between the rolling elements and the raceway.
Spring (elastic member) 28, 28' that gives preload to '
is provided.

Reference numerals 29 and 29' denote a left side transmission blocking member and a right side transmission blocking member, which are provided inside the differential case 3 and are symmetrical to the side gears 8 and 8'.
and the pinion mate gear 11, and as shown in FIG. It is arranged. Moreover, both the blocking members 29, 29' have abutting surfaces 29a, 2 at the central end.
9a' are brought into contact with each other, and the opposite end is connected to a stepped portion 3c formed on the inner wall of the differential case 3.
3d so that sliding in the axial direction is restricted.

Next, the operation of the embodiment will be explained.

When driving straight on a highway or when one wheel enters mud, etc., control hydraulic pressure at a predetermined pressure is introduced from the hydraulic control device into the pressure chambers 1g and 1g', and the hydraulic piston 22
It moves toward the center of the differential case 3 and presses the friction clutches 13, 13' to engage them.

Therefore, the driving force of the differential case 3 is transmitted to both drive shafts 9, 9 via the friction clutches 13, 13'.
', the differential is limited, and even if the road surface conditions change or a wheel on one side lifts while driving straight, a sudden drop in driving force is suppressed, and the It is possible to drive in a stable straight line without shaking, and when there is a difference in rotation between the left and right wheels due to getting into mud or driving on a road with a low coefficient of road friction, it is possible to drive more quickly than the low-speed wheel. It transmits a large amount of torque, improving the ability to escape from mud and drive on roads with a low coefficient of friction.

[0031] Furthermore, when the clutch is engaged as described above,
The hydraulic pistons 22, 22' connect the friction clutch 1 via pressure bearings 26, 26', pressure rings 25, 25', and pressure plates 24, 24'.
3, 13' is pressed, but the pressing reaction force F1, F1
is input in the direction in which the left and right transmission blocking members 29, 29' are brought into contact with each other. and,
Both members 29, 29' are in contact with each other at abutting surfaces 29a, 29a', and the magnitude of this input is equal, so this input is balanced and input to the side gears 8, 8' is prevented. Ru.

[0032] Therefore, the clutch reaction force does not affect the differential of the differential device and the differential limiting device, and high control accuracy can be obtained.

Next, for the side gears 8, 8', the reaction force F2 due to meshing with the pinion mate gear 11,
F2 is generated towards the outside. Then, when the side gears 8, 8' come into contact with both the transmission blocking members 29, 29', the meshing reaction forces F2, F2 are applied to both the transmission blocking members 29, 29.
' is input in a direction that pushes and expands the space between the left and right members. The outer ends of both the left and right members 29, 29' are stepped portions 3c, 3d formed on the inner wall of the differential case 3.
Since this input is in contact with the stepped portions 3c and 3d,
is input to the differential case 3, and input to the friction clutches 13, 13' is blocked.

Therefore, the meshing reaction force from the side gears 8, 8' with the pinion mate gear 11 is applied to the friction clutches 13, 1.
High control accuracy can be obtained without affecting the operation of 3'.

Incidentally, the inside of the housing 1 is filled with differential gear oil to lubricate the friction clutches 13, 13', and the hydraulic pistons 22, 22' are operated using a low-temperature oil such as power steering oil, which is different from the differential gear oil. A viscous oil is used, and when the two are mixed,
In particular, the lubricating performance of differential gear oil decreases due to the addition of additives. Therefore, in this embodiment, the oil seals 27, 27' are used to prevent the two from mixing, thereby preventing deterioration of lubrication performance due to oil mixing.

In this embodiment, since the oil seals 27, 27' are arranged radially overlapping the pressure bearings 26, 26', it is possible to space them apart in the axial direction. In comparison, the axial dimension of the device has been reduced.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and design changes may be made without departing from the gist of the present invention. Included in the present invention.

For example, in the embodiment, an example was shown in which one clutch and one clutch engagement means were provided on each side. Although this configuration has the advantage of increasing the control accuracy of the engagement force, it is also possible to provide only one clutch and clutch engagement means. Further, the clutch fastening means is not limited to the hydraulic piston structure as in the embodiment, but may be a means having another structure.

[0039]

[Effects of the Invention] As explained above, in the electronically controlled differential limiting device of the present invention, the clutch engagement means and the seal member defining the inside of the housing are arranged at a position radially overlapping with the pressure bearing. This means that the axial dimension of the device can be reduced.

[Brief explanation of drawings]

FIG. 1 is an overall sectional view showing an electronically controlled differential limiting device according to an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of section A in FIG. 1;

FIG. 3 is an enlarged sectional view of section B in FIG. 1;

[Explanation of symbols]

1 Housing 3 Differential case 8,8’ side gear 9 Left drive shaft (output shaft) 9’　Right side drive shaft (output shaft) 11 Pinion gear mate 13,13' Friction clutch

Claims (1)

[Claims] 1. A differential case rotatably supported by a housing; two side gears disposed facing each other in the differential case, meshing with a pinion mate gear and coupled to an output shaft; and the side gears and the differential. A clutch disposed between the case and the clutch, a hydraulically actuated clutch engagement means that presses the clutch in a direction to engage the clutch via a pressure bearing, and a seal member defining the clutch engagement means and the inside of the housing. An electronically controlled differential limiting device comprising: an electronically controlled differential limiting device, characterized in that the sealing member is disposed at a position overlapping a pressure bearing in a radial direction.