JPS63251326A - Power transmission - Google Patents

Abstract

PURPOSE:To make it possible to dispose a viscous coupling with the use of a dead space and to aim at enhancing the efficient use of a space by disposing the viscous coupling between a first transmission shaft and a second transmission shaft. CONSTITUTION:A center differential gear train 24 and a front wheel differential gear train 32 are laid side-to-side, and a viscous coupling 46 is disposed between a first transmission shaft 30 and a second transmission shaft 31. By this arrangement, the space A defined among the clutch housing part 4 of a trans-axle casing 14, a transfer casing 22 and the oil pan of an engine, which has conventionally been a dead space can be effectively used.

Description

[Detailed description of the invention] ゛　[Industrial application field] The present invention relates to a power transmission device for a four-wheel drive vehicle.

[Prior Art] As a conventional power transmission device for a four-wheel drive vehicle, there is one described, for example, in Japanese Patent Laid-Open No. 58-63523.

As shown in FIG. 3, this conventional power transmission device includes a final reduction gear 3 that is rotationally driven by a drive gear 2 of a transmission 1, a central differential gear 4 that rotates integrally with this final reduction gear 3, and a central differential gear 4 that rotates integrally with this final reduction gear 3. A front wheel differential gear device 5 is drivingly connected to the differential device 4, and a direction change is performed by the central differential device 4 to convert the rotational direction of the driving force to a right angle and transmit it to the rear wheel differential gear device 6. It is equipped with a gear set 7. A pull-up mechanism 8 as a means for stopping the differential distribution of the driving force of the central differential gear 4 between the front wheel differential gear device 5 and the rear wheel differential gear device @6 includes: It is provided between a hollow first transmission shaft 9 for driving the front wheel differential tooth width device and a hollow second transmission shaft 10 for driving the rear wheel differential gear device.

With this configuration, when the front wheels of the vehicle become stuck due to muddy conditions, etc., the lock-up mechanism 8 can be manually operated to stop the differential distribution of the rotational force of the central differential device 4 and rotate the front and rear wheels. The rotational force is evenly distributed between the differential devices 5 and 6 of the rear wheels, and the rotational force is applied to the rear wheels to escape from the slip state.

Further, if the L1 pull-up mechanism 8 is released, differential rotation between the front and rear wheels is allowed by the gear mechanism inside the central differential device 4, and so-called tight corner braking phenomenon can be prevented.

[Problems to be Solved by the Invention] However, in this conventional power transmission device, there is a gap between the first transmission shaft for driving the front wheel differential gear device and the second transmission shaft for driving the rear wheel differential gear device. The problem is that the driver has to manually operate the lock-up mechanism provided in the vehicle, which is cumbersome to operate.

On the other hand, recently, as described in Japanese Patent Application Laid-Open No. 61-38226, a viscous coupling has been applied to a differential gear device, and it is possible to improve the above-mentioned problem by applying this. However, space is generally limited around the differential tooth width device, which may make it difficult to add additional viscous couplings.

In view of the above-mentioned conventional problems, this invention provides a power transmission device that can realize a normally open four-wheel drive, does not require manual operation to escape from a slip state, and is advantageous in terms of space. purpose.

[Means for Solving the Problem] The power transmission device of the present invention includes a final reduction gear that is disposed substantially coaxially with either the front axle or the rear axle and is rotationally driven by the output shaft of the transmission, and this final reduction gear. a central differential that rotates in conjunction with the reduction gear; and a Yu1 differential that is arranged in parallel with the central differential on substantially the same axis as the one axle and receives driving force from the central differential through a first transmission shaft. and the medium heat M! which is arranged substantially coaxially with the one axle. A second transmission shaft that transmits the driving force of l171"r, ζii'? to the other axle, either the front axle or the rear axle, and a direction conversion gear set that transmits a signal to a second differential gearing device disposed on the axle; and a direction conversion gear set disposed between the central differential device and the first differential gearing device, and a gear set on the first transmission shaft side. and a viscous coupling that limits the differential between the transmission shaft and the second transmission shaft side.

1. In the power transmission device of the present invention, the rotational force from the engine is distributed between the -C first transmission shaft and the second transmission shaft by the central differential device °v. The rotational force 1 from the first transmission shaft is transmitted to one of the front and rear axles via the first differential gear device, and the rotational force from the second transmission shaft is transmitted via the direction conversion gear set and the second differential gear device. This is transmitted to the other of the front and rear axles.

If the front or rear wheels are likely to get stuck due to muddy conditions, etc., the viscous coupling will automatically increase the distribution of rotational force to the wheel on the opposite side of the wheel that is likely to get stuck.
Find B from the slip state.

[Embodiment 1] Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

FIG. 1 is a skeleton diagram of a four-wheel drive vehicle to which an embodiment of the present invention is applied, and FIG. 2 is a detailed sectional view of the main parts thereof. As shown in FIGS. 1 and 2, reference numeral 11 is an engine placed horizontally at a curved portion of the vehicle, and is arranged such that a crankshaft 12 extends in the lateral direction of the vehicle body.

Reference numeral 13 denotes a lance pump, which includes a clutch 15 in the transaxle case 14 and the engine "11".
The transmission 16 is arranged in series with the transmission 16. This transmission 16 includes an input shaft 1 connected to a crankshaft 12 of an engine 11 via a clutch 15.
7, an output shaft 18 arranged parallel to this input shaft 17, and a transmission gear set 1 provided between these two shafts 17 and 18.
Consists of parts.

A drive gear 20 is provided at one end of the output shaft 18, and a final reduction gear 21 meshes with this drive gear 20.

The gear 21 is supported so that the shaft extending in the lateral direction of the C1 vehicle body in the transfer sheath 22 adjacent to the 1 Herance axle case 14 overlaps with the rotating shaft, [)t1
The casing 2 of the central differential 24 is located on the final reduction gear 21.
5 are fixed together.

The central differential 24 includes a differential gear set built into the gauging 25. This differential gear set includes binion gears 26 and 27 rotatably supported by a binion gear left 25a inserted into the casing 25, and these pinion gears 2.
6.27 and a pair of side gears 28.29 meshing with each other.

A hollow first transmission shaft 30 through which the front axle 23 is inserted is spline-coupled to one of the ride gears 28 . A hollow second transmission shaft 31 that is enclosed in the first transmission shaft 30 is integrally formed with the other side gear 29 . This second transmission shaft 31 may be formed separately from the side gear 29, and the boss portion 45a of the power transmission gear 45 that covers the rear
It can also be formed integrally with the Furthermore, the second transmission shaft 3
1 is formed integrally with the boss portion 45a, and this is connected to the side gear 2.
9 and the power transmission gear 45 can also be constructed separately.

Within the transfer case 22, the central differential 2/I
A front wheel differential gear device 32 is arranged as a first differential gear device apart from the front wheel differential gear device in the lateral direction of the vehicle body. The front wheel differential gear device 32 has a C-configuration including a casing 33 spline-connected to the first transmission shaft 30 and rotatably supported, and a differential gear set incorporated in the casing 33. This differential gear set includes a pair of pinion gears 35 and 36 that are supported by a rotating white t on a pinion shirt 1-34 inserted into a casing 33, and these pinion gears 3.
5.36, and a pair of glued gears 37 and 38 mesh with each other. Said side 1! The wheels 37, 38 are splined to the front axle 23, 39, respectively.

The front axles 23, 39 each have a constant velocity joint 40.
, the drive axle 41, and the left and right front axles 43. through the constant velocity joint 42. /1.4.

A power transmission gear 45 for driving the rear width shaft is spline-fitted to the end of the second transmission shaft 31 from the central differential device 24 at a boss portion 45a. The power transmission gears 45 are arranged to coaxially rotate with respect to the casing 33 of the front wheel differential gear device 32, and a viscous coupling 46 is connected to these power transmission gears 45 as shown in the rear view.
and the casing 33.

A direction conversion gear set 47 is disposed within the transfer case 22 to convert the rotation horn of the power transmission gear 45 into a direction perpendicular to the power transmission gear 45. This direction conversion gear set 4
Reference numeral 7 denotes an intermediate gear 48 that meshes with the power transmission gear 45, a first bevel gear 50 that is spline-connected to the shaft/'I9 of this intermediate south center 7'I8 and is rotationally driven, and this first bevel gear 50.
The second umbrella wheel 51 meshes with the second umbrella wheel 51, and the transmission shaft 52 extends toward the rear of the vehicle body, which is rotated by the second umbrella wheel 51.

Therefore, the rotational force from the central differential device 24 is converted from the lateral direction of the vehicle body to the longitudinal force direction of the vehicle body at right angles and is transmitted rearward.

The transmission shaft 52 of the YJ direction conversion gear set 47 is connected to the -C rear wheel final reduction gear 56 via the lL double joint 53, the propeller shirt 1 54, and the universal joint 55.

The rear wheel final reduction gear 56 includes a rear wheel differential gear device 57 as a second differential gear device. This rear wheel differential gear device 57 is a constant velocity joint) 8, left and right rear wheels @59, 60. It is connected to left and right rear wheels 62 and 63 via a constant velocity joint 61.

As detailed in FIG. 2, the viscous coupling 74
6 fills the space between the outer case 64 and the inner case 65 with silicone oil, and the j7 outer case 6
4, and attach the inner boots 67 to the inner case 65 alternately with the outer plates 66. In this embodiment, the outer case 64 is The inner case 65 is integrally formed with the power transmission gear 45, and the inner case 65 is connected to the casing 33 of the front wheel differential gear device 32.
The boss portion 33a is integrally formed with the boss portion 33a. The power transmission gear 45 and the integral outer case 64 are supported on both sides by bearings 45b.

The front wheels 43, 44 and the rear wheels 62 are connected to each other from the central differential device 24 through the first transmission shaft 30 and the second transmission shaft 31.
．． 63 can be limited.

The operation of the power transmission device having the above configuration will be explained next.

The rotational force output from the engine 11 is input to the input @17 of the transmission 16 via the clutch 15,
Here, the speed is changed by the speed change gear set 19 and output from the output shaft 18, and the final reduction gear 21 is rotationally driven via the dove gear 20.

As the final reduction gear 21 rotates, the casing 25 of the central differential 24 is rotated. The central differential device 24 is
The rotational force of this casing 25 is transferred to both side gears 28 and 29.
The rotational force from one lead gear 728 is distributed to the first
The rotational force is transmitted to the casing 33 of the front wheel differential gear device 32 via the transmission shaft 30, and the rotational force from the other two side gears is transmitted to the power transmission gear 45 for rear wheel drive via the second transmission shaft 31.

The rotational force transmitted to the casing 33 is transmitted to the pinion gears 35 and 36 of the front wheel differential gear 32 and the side gear 37.
．． 38 and is transmitted to the left and right front axles 23.39, passing through a constant velocity joint 40, a drive axle 41, and a constant velocity joint 42 to drive a front axle 43.44.

The rotational force applied from the second transmission shaft 31 to the power transmission gear 45 is within the direction conversion gear set 47. 1Ila car 4
8. The rotational direction is converted to a right angle through the intermediate shaft 49, the first bevel gear 5o, and the second bevel gear 51, and the output is output from the transmission shaft 52 toward the rear of the vehicle body.

The rotational force applied to the transmission shaft 52 is transmitted to the rear wheel final reduction gear 56 via the universal joint 53, the propeller shaft 54, and the universal joint 55.
Here, the rotational direction is again changed to a right angle, the speed is decelerated, and the rotational speed is applied to the rear wheel differential gear device 57. Rear wheel differential gear device 5
7, the applied rotational force is distributed to the left and right, and the constant velocity joint 58, rear H1 (shafts 59, 60. constant velocity joint 1 intro 1
The left and right rear wheels 62 and 63 are driven through.

In this power transmission device, the rotational force is distributed to the rear wheels by the central differential device 21! It is done by I.

The rotational force is distributed between the left and right front wheels 43.44m by the front wheel differential gear device 32, and the left and right rear wheels 62.
The rotational force is distributed between the two wheels by a rear differential gear 57.

The first transmission shaft 30 and the second transmission shaft 3 by the central differential device 24
1, the viscous coupling 46 does not provide differential limiting. However, in this viscous coupling 46, there is a difference in the distribution of rotational force between the first transmission shaft 30 and the second transmission shaft 31, and the larger the rotation difference between the front and rear wheels, the larger the differential. It has the ability to generate limiting power.

Therefore, if one of the front wheels 43, 44 is about to get stuck in mud or the like, the rotational force applied to the front wheel is transferred to the rear wheel 62, 63 by the viscous coupling 46.
This allows the driver to easily escape from the slip condition.

Also, when driving at low speeds such as when parking in a garage, there is a difference in rotation between the front and rear wheels, but since the speed is low, this difference in rotation can be absorbed by the viscous coupling 46, which is called a tight corner braking phenomenon. It is possible to prevent the occurrence of a phenomenon unique to four-wheel drive vehicles.

Further, as in the above embodiment, the central differential gear 24 is provided with a mower differential gear i1i device 32 side by side, and the first transmission shaft 30
and the second transmission shaft 31, the transfer case and the clutch housing part 14a of the transaxle case 14, which used to be a dead space in the case of a transverse engine vehicle, can be removed. The space A between 22 and the engine oil pan can be used effectively, which is advantageous in terms of space.

In addition, since the outer case of the viscous coupling 46 is integrally provided on the power transmission gear 45 coupled to the second transmission shaft 31 and supported on both sides by the bearing 45b, the power transmission gear 45 can be stably supported. First transmission shaft 31
, the centering support of the front wheel differential gear device 32 is reliable. As a result, the vibration of the rotating part is reduced, and the generation of abnormal noise can be suppressed.

Furthermore, the viscous coupling 46 is assembled and integrated with the power transmission gear 45 in advance, and this is attached to the front wheel differential gear device 32.
The work of assembling the viscous coupling 46 becomes easier by shifting the subassembly so that it is fitted onto the boss portion 33a of the casing 33.

[Effects of the Invention] According to the present invention, by providing a viscous coupling, four-wheel drive can be obtained at all times while eliminating the need for troublesome operations such as escaping from a stack by operating a conventional manual lock-up mechanism. This makes it easier to escape from a slip situation on a frozen road. In addition, by arranging a viscous coupling between the first transmission shaft and the second transmission shaft at a position between the central differential and the first differential gear that is aligned laterally, the engine oil pan The dead space created between the transaxle case and the 1-herance fairing case can be used to store and cover the viscous coupling, allowing efficient use of space.

[Brief explanation of drawings]

FIG. 1 is a mechanical diagram of the sprues 1 to 1 of an embodiment of the present invention, FIG. 2 is a cross-sectional view of the main parts of the above-mentioned embodiment, and FIG. 3 is a skeleton mechanism diagram C showing a conventional example. 11...Engine 13...Transaxle 20...Drive gear 21...Final reduction gear 23.39...Front axle 24...Central differential 30...First transmission shaft 31... ...Box 2 transmission shaft 32...Front wheel differential gear device 33...Casing 45...Power transmission gear 46...Viscous coupling 47...Direction conversion gear set 57...Rear wheel differential Hey! 17 device 59.60...rear axle

Claims (1)

[Claims] a final reduction gear that is arranged approximately coaxially with either the front axle or the rear axle and is rotationally driven by the output shaft of the transmission; a central differential that rotates in conjunction with the final reduction gear; a first differential gear device that is arranged substantially coaxially in parallel with the center differential and receives driving force from the center differential through a first transmission shaft; and a first differential gear device that is arranged substantially coaxially with the one axle and said center differential. a second transmission shaft for transmitting the driving force of the drive device to the other of the front axle or the rear axle, and a second difference between the rotational directions of the second transmission shaft and the other axle by converting the rotational direction of the second transmission shaft to a right angle. A direction changing gear set for transmitting data to a dynamic gear device, and a gear set disposed between the central differential device and the first differential gear device to limit differential movement between the first transmission shaft side and the second transmission shaft side. A power transmission device comprising a viscous coupling.