JPH02208131A - Power transmission device for vehicle - Google Patents

Abstract

PURPOSE:To make it easy to carry out work such as adjustment and repair by arranging a viscous coupling around the outer periphery of the section protruding from the case storing a differential gear on one side of a driving shaft, and connecting an outer member to a differential case and an inner member to one side of driving respectively. CONSTITUTION:A viscous coupling 20a is composed of an inner shaft 22a, an outer case 23a, inner and outer plates 24a, 25a and high viscosity fluid such as silicone oil, and the outer case 23a is supported through a bearing 26a so that it may rotate against a bracket 21a assembled on an accelerator case 11. he inner shaft 22a is fitted to the outer periphery of one end of an intermediate shaft 32a for torque transmission, and the cylindrical portion of the other end of the outer case 23a is fitted to the cylindrical portion 16a of a differential case 16 for torque transmission. It is thus possible to facilitate the inspection, repair and adjustment of the viscous coupling.

Description

[Detailed description of the invention] (Industrial application field) The present invention relates to a power transmission device for a vehicle.

(Prior Art) As a type of vehicle power transmission device, there is a differential that distributes the power input to the differential case to each side gear and outputs it to each drive shaft connected to each side gear so that torque can be transmitted. There is a power transmission device for a vehicle equipped with a viscous coupling that generates viscous torque through relative rotation between an outer member and an inner member during a differential to limit the differential movement of the differential. Another example is shown in FIG. 7 of the accompanying drawings in Japanese Patent No. 134823.

(Problems to be Solved by the Invention) By the way, in this type of power transmission device, the viscous coupling 1 is built in the differential case 2a, so the differential 2 has the viscous coupling 1 built in as shown in FIG. It is necessary to change many of the constituent members of the normal differential 3 that does not have the same structure, and it also becomes larger, and along with this increase in size, the size, shape, etc. of the case 4 that houses the differential 2 must also be changed. 2a, due to the space inside the case 4 that accommodates the differential 2, increasing the capacity of the viscous coupling 1 and the differential 2, reinforcing each part, etc. are restricted, and the work of adjusting, repairing, replacing, etc. the function of the viscous coupling 1 is large. This is extremely troublesome.

Therefore, an object of the present invention is to solve each of the above problems by disposing a viscous coupling outside the differential case and the case housing the differential.

(Means for Solving the Problems) The present invention provides a power transmission device of the type described above, in which the viscous coupling is disposed on the outer periphery of a portion of one of the drive shafts that protrudes from a case that accommodates the differential; The viscous coupling is characterized in that its outer member is coupled to the differential case and its inner member is coupled to the one drive shaft in a manner capable of transmitting torque.

(Operations and Effects of the Invention) According to this configuration, when differential rotation occurs between both drive shafts, the outer member connected to the differential case is connected to one of the drive shafts, and the outer member is connected to one of the drive shafts via the same shaft. Relative rotation occurs between the inner members connected to the side gear, and in the viscous coupling, viscous torque is generated according to the differential rotation speed between both drive shafts. This viscous torque acts to limit the differential motion between both drive shafts, increases the torque of the low speed drive shaft, and improves the running performance of the vehicle.

In this power transmission device, since the viscous coupling is disposed outside the differential case and the case housing the differential, there is a means for connecting the outer member and inner member of the viscous coupling to the differential case and the drive shaft. There is no need to change other components of the differential or the case that houses the differential, and the viscous coupling can be placed anywhere in the axial direction on the outer circumference of the drive shaft. In relation to the support structure of the drive shaft, it can be placed in an advantageous position for vibration and noise countermeasures, and since there is plenty of space, the capacity can be easily increased by increasing the size of the viscous coupling. In addition, operations such as adjustment, repair, and replacement of the viscous coupling function can be easily performed. Furthermore, the viscous coupling can be easily installed even when there is no installation space in the differential or the case that accommodates the differential.

(Example) Examples of the present invention will be described below based on the drawings.
The figure shows a power transmission device according to a first embodiment of the present invention, and FIG. 2 shows the main parts of the device. The power transmission device includes a front wheel drive transaxle IOA that integrally includes a transmission 10a and a front differential 10b, and a differential limiting mechanism 2OA.
0b is housed in the axle case 11, and a viscous coupling 20a constituting the differential limiting mechanism 20A is supported by a bracket 21a assembled to the axle case 11. The axle case 11 is assembled on one side of the engine E, and the input shaft 12 of the transmission 10a is connected to the crankshaft via a clutch (not shown).

In this power transmission device, when power from the engine is input to the input shaft 12 of the transmission 10a, the input power is transmitted to the output shaft 13 via one set of each gear train, and also to the final gear 14. The signal is then outputted via the ring gear 15 to the differential case (hereinafter referred to as differential case 16) of the differential 10b. Further, the power input to the differential case 16 is transmitted to the left and right side gears 18a, 18 via a pinion shaft 17a and a pinion gear 17b.
b, and output to each drive shaft. The left drive shaft is composed of a normal side gear shaft 31, and the right drive shaft is composed of an intermittent shaft 32a and a side gear shaft 33a.

Thus, the viscous coupling 20a consists of an inner shaft 22a, an outer case 23a, both inner and outer plates 24a, 25a, and a highly viscous fluid such as silicone oil.
The inner shaft 22a forms a viscous fluid storage chamber,
In the same accommodation chamber, the inner plate 24a is fitted to the outer periphery of the inner shaft 22a so that torque can be transmitted, and the outer plate 25a is fitted to the inner periphery of the outer case 23a so that torque can be transmitted. It is located in In such a viscous coupling 20a, the inner shaft 22a is fitted to the outer periphery of one end of the intermediate shaft 32a so as to transmit torque, while the outer case 23a is rotatably supported by the bracket 21a via the bearing 26a. , and the other end cylindrical portion of the outer case 23a is fitted to the outer periphery of one end of the cylindrical portion 16a of the differential case 16 so as to be able to transmit torque, and the bracket 21a is fixedly assembled at the joint surface of the outer case 11. There is. In this state, the other end cylindrical portion of the outer case 23a faces the opening of the axle case 11, and the outer case 23a is liquid-tightly and rotatably sealed to the axle case 11. Side gear shaft 33a
is rotatably fitted to the inner circumference of the cylindrical portion at one end of the outer case 23a so that torque can be transmitted to the inner circumference of the inner shaft 22a, and a bearing 35 is attached to a bracket 34 assembled to the engine block at one end side. It is rotatably supported through.

In the power transmission device having such a configuration, when differential rotation occurs between the left and right front wheels, differential rotation occurs between the differential case 16 of the differential 10b, the intermittent shaft 32a, and the side gear shaft 33a, and the viscous coupling 20a is inner shaft 22
Relative rotation occurs between a and the inner plate 24a and the outer case 23a and the outer plate 25a,
Viscous torque is generated depending on the differential rotation speed. This viscous torque acts to limit the differential between the side gear shaft 31 and the intermediate shaft 32a, that is, between the left and right front wheels, and increases the torque of the lower speed shaft of both shafts 31, 32a, thereby increasing the speed of the vehicle. Aim to improve driving performance.

By the way, in the power transmission device, the viscous coupling 20a constituting the differential limiting mechanism 2OA is connected to the intermediate shaft 3 outside the axle case 11.
2a and the side gear shaft 33a (drive shaft), an inner shaft 22a constituting a viscous coupling 20a is connected to the drive shaft, and an outer case 23a is connected to the differential case 16 so that torque can be transmitted. Therefore, when arranging the viscous coupling 20a, the drive shaft (32
a, 33a), it is only necessary to form a spline or other connecting means to the inner shaft 22a and outer case 23a on the differential case 16, and it is also necessary to change the shape and structure of the constituent members of the differential 10b and the shape of the axle case 11. Also, viscous coupling 2
0a can be disposed at any position in the axial direction of the drive shaft (32a, 33a), and by supporting it on the joint end surface of the axle cases 1 to 1 via the bracket 21a as in this embodiment, it is possible to prevent vibration due to vibration. It is possible to suppress the generation of vibration and noise and a decrease in durability, and it is also possible to easily perform operations such as adjustment, repair, and replacement of the function of the viscous coupling 20a.

Note that in this embodiment, the viscous coupling 20a
The inner shaft 22a constituting the inner shaft 32a is connected to the intermediate shaft 32a by spline fitting.
Instead, as shown in FIG. 3, the inner shaft 22a
and the intermittent shaft 32a may be integrally formed.

FIG. 4 shows the main parts of a power transmission device according to a second embodiment of the present invention. The power transmission device according to the second embodiment has the same transaxle as the first embodiment, except that the intermediate shaft 32b constituting the right drive shaft is longer and the side gear shaft 33b is shorter. A viscous coupling 20b constituting the differential limiting mechanism 20B is arranged on the outer periphery of the opposing ends of both shafts 32b and 33b. The viscous coupling 20b includes an inner shaft 22b, an outer case 23b, and both inner and outer plates 24.
b, 25b, and the outer case 23b includes a long cylindrical connecting portion.

In such a viscous coupling 20b, the inner shaft 22b is connected to the intermediate shaft 32b and the side gear shaft 33 while the outer case 23b is rotatably supported by the bracket 21b assembled to the engine block via a pair of bearings 26b.
In this embodiment, the bracket 21b is fitted with a viscous coupling, and the connecting portion of the outer case 23b is fitted with the outer periphery of the cylindrical portion 16a of the differential case 16 so as to transmit torque. 20b and the drive shaft, and the viscous coupling 20b is disposed at the end support portion of the drive shaft, which is extremely preferable in terms of preventing vibration and noise generation.

FIG. 5 shows the main parts of a power transmission device according to a third embodiment of the present invention, and FIG. 6 shows a power transmission device according to a modification thereof. In the power transmission device according to the same embodiment, the right drive shaft is formed as one long side gear shaft 32c.
A viscous coupling 20c constituting a differential limiting mechanism 20C is disposed on the outer periphery of the intermediate portion of the shaft. The viscous coupling 20c includes an inner shaft 22C, an outer case 23c, and both inner and outer plates 24c and 25c.
A bracket 21 is fitted to the axle case 11 in a liquid-tight manner and assembled to the engine block.
It is housed in a case 27 supported by c. In the viscous coupling 20c, the outer case 2
3c is rotatably supported by the case 27 via a pair of bearings 26c. With this configuration, the power transmission device exhibits the same effects as the power transmission devices according to the first and second embodiments.

In this embodiment, as shown in FIG. 6, the shapes of the axle case llc and the case 27c are slightly changed and the case 27c is assembled to the joint end surface of the axle case 11c, thereby omitting the bracket 21c. Can be done.

In addition, in these embodiments and modifications, examples were shown in which the present invention was implemented in a power transmission device for a front wheel drive vehicle equipped with a front differential, but the present invention is also applicable to a power transmission device for a rear wheel drive vehicle equipped with a front differential. It can also be implemented in a power transmission device.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of a power transmission device according to a first embodiment of the present invention, Fig. 2 is an enlarged sectional view of the main part of the same device, and Fig. 3 is an enlarged view of the main part showing a modification of the same device. 4 is a sectional view corresponding to FIG. 2 of the power transmission device according to the second embodiment; FIG. 5 is a sectional view corresponding to FIG. 2 of the power transmission device according to the third embodiment; FIG. 6 is a sectional view corresponding to FIG. 2 showing a modification of the same device, and FIGS. 7 and 8 are partial sectional views of a conventional power transmission device. Explanation of symbols 10A...Transaxle, 10a...Transmission, 10b...Differential, 11.
...Axle case, 16...Differential case, 18a,
18b...Side gear, 20A-20C...Differential limiting mechanism, 20a-20C...Viscous coupling,
22a to 22c, inner shaft, 23a to 23c...
・Outer case, 32a, 32b...Intermediate shaft, 3a, 33b, side gear shaft.

Claims (1)

[Claims] A differential that distributes the power input to the differential case to each side gear and outputs it to each drive shaft connected to each gear so that torque can be transmitted, and a gap between the outer and inner members of the differential during differential operation. In a vehicle power transmission device including a viscous coupling that generates viscous torque through relative rotation to limit differential movement of the differential, the viscous coupling is accommodated in the differential on either one of the drive shafts. A power source for a vehicle, characterized in that the outer member of the viscous coupling is arranged on the outer periphery of a portion protruding from the case, and the outer member of the viscous coupling is connected to the differential case, and the inner member is connected to the one drive shaft so that torque can be transmitted. transmission device.