JP2692869B2 - Power transmission device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Object of the Invention] (Field of Industrial Application) [0001] The present invention relates to a power transmission device used in a vehicle or the like.

(Prior Art) Japanese Patent Laid-Open No. 60-172764 discloses, for example, a front engine / front drive (FF) -based 4WD vehicle,
A viscous clutch (a viscous coupling) and an interrupting device are arranged on a propeller shaft of a rear wheel drive system.

(Problems to be Solved by the Invention) As described above, when the power transmission is intermittently performed on the propeller shaft having a relatively long rotation speed and a high rotation speed, the inertia moment becomes large, and vibration easily occurs. For this reason, when it is arranged on the propeller shaft, its support portion must be specially provided.

Therefore, an object of the present invention is to provide a power transmission device in which vibration is unlikely to occur, a load on a propeller shaft is not increased, and a support portion need not be specially provided.

[Configuration of the invention]

(Means for Solving the Problems) In order to solve the above problems, a power transmission device of the present invention is a device for switching a torque of an engine, a propeller shaft,
A power transmission device for transmitting to a rear wheel or a front wheel via a differential device and left and right axles, wherein a viscous coupling for transmitting the torque via a viscous fluid and the differential device are integrally assembled. The differential device includes an interrupting device that connects and disconnects an output side of the viscous coupling and a differential case of the differential device, and the differential case differentially distributes engine torque to rear wheels or front wheels via the left and right axles. It accommodates the differential mechanism.

(Operation) When the disconnecting device is connected, the output side of the viscous coupling and the differential case of the differential device are connected, the input torque is transmitted to the differential device via the viscous coupling, and the differential mechanism of the differential device loads the load. Side differentially distributed. At this time, if the rotation difference between the input side and the output side of the viscous coupling becomes large due to the input to the viscous coupling and the load of the differential device, this rotation difference is greatly limited and a large torque is transmitted to the differential device. or,
When the rotation difference becomes smaller, this rotation difference is allowed and the transmission torque becomes smaller. When the disconnecting device is brought into the continuous release state, power transmission between the viscous coupling and the differential device is cut off.

Further, since the viscous coupling and the differential device are integrally arranged, it is advantageous in terms of support and the like.

(Embodiment) A first embodiment will be described with reference to FIGS. 1 and 2.

FIG. 2 shows the differential device portion of the power transmission device of this embodiment as a rear wheel differential device (rear differential).
The drive configuration of the FF-based 4WD vehicle used as is shown below. or,
The upper half of FIG. 1 shows the locked state of the disconnecting device, and the lower half shows the free state. In the following description, the left and right directions mean the left and right vehicle width directions and the left and right directions in these drawings.

First, the power transmission of this vehicle will be described with reference to FIG.
The driving force of the engine 1 is changed by the transmission 3 and transmitted to the differential case of the front wheel side differential device (front differential) 7 housed in the transfer 5 and directly to the left and right front wheels 13 and 15 via the front axles 9 and 11. Differentially distributed. On the other hand, the driving force of the engine 1 is transmitted through the differential case through a 2-4 switching mechanism which is housed in the transfer 5 and intermittently transmits power to the rear wheels and a direction changing gear set (neither is shown). Example power transmission device
It is transmitted to 19. The rear differential of the power transmission device 19 differentially distributes the transmitted driving force to the left and right rear wheels 25, 27 via the rear axles 21, 23.

 Next, the configuration of this embodiment will be described with reference to FIG.

The outer case 29 is composed of a case body 31 and a cover 33 thereof, and is rotatably supported by a diff carrier that houses the rear diff via bearings (none of which is shown). The case body 31 is provided with a flange portion 35,
The flange portion 35 is provided with a bolt hole 37 for meshing with the drive pinion gear connected to the propeller shaft 17 side and bolting a ring gear that constitutes the final reduction gear set together with the drive pinion gear. In this way, the outer case 29 is rotationally driven by the driving force from the engine 1.

Inside the outer case 29, a shaft support 39 is formed on the cover 33, and a hub member 41 is rotatably supported on the shaft support 39. A working chamber 43 is formed between the hub member 41 and the case body 31, and is filled with a viscous fluid such as silicon oil. Inside this working chamber 43,
The case body 31 is provided with splines 45, and the hub member 41 is provided with splines 47. A plurality of outer plates 49 are engaged with the spline 45, and a plurality of inner plates 51 are engaged with the spline 47 in the rotational direction. These plates 49, 51 are alternately arranged, and a spacer 53 is arranged between each of the atter plates 49 to properly maintain a gap between them. A ring 55 is arranged on the right end side of the working chamber 43, and a spline 57 provided on the outer periphery of the ring 55 is engaged with the spline 45. This ring 55
X as a rubber seal with an X-shaped cross section between the hub member 41 and
An O-ring 61 is arranged between the ring 59 and the case main body 31, and an X ring is formed on the shaft support 39 between the cover 33 and the hub member 41.
A ring 63 is arranged to keep the working chamber 43 liquid-tight. In this way, the viscous coupling 65 is configured.

Inside the outer case 29, the differential case 67 is arranged on the right side of the viscous coupling 65, and the bush 69
It is rotatably supported by the case body 31 via. Four axial grooves 71 are provided on the inner circumference of the differential case 67, and the pinion shafts arranged in a cross shape are formed in the grooves 71.
The respective ends of 73 are engaged with each other in the rotational direction. Therefore, the differential case 67 can rotate together with the pinion shaft 73, and can relatively move in the axial direction with respect to the case body 31 and the pinion shaft 73. Four pinion gears 75 are rotatably supported on the pinion shaft 73,
Side gears 77 and 7 are provided on the left and right sides of the pinion gear 75, respectively.
9 is arranged coaxially and meshes with the pinion gear 75.
A washer 81 is arranged between the differential case 67 and the pinion gear 75, a washer 83 is arranged between the hub member 41 and the left side gear 77, and a washer 85 is arranged between the case body 31 and the right side gear 79. Has been done. In this way, the rear differential 87 is constructed. The left side gear 77 is a transmission shaft that is connected to the left rear axle 21 through a joint, and the right side gear 79 is a transmission shaft that is connected to the right rear axle 23 through a joint (these are joints, transmission shafts). Are not shown in the figure).

A spline 89 is provided on the outer circumference of the right end of the hub member 41, and a spline 91 engageable with the spline 89 is provided on the inner circumference of the left end of the differential case 67. Also, differential case
A retainer 93 is integrally provided on the right end side of 67, and the washer is
A retainer 95 is provided on the 81 side. The case body 31 is provided with a plurality of windows 97 arranged in a cylinder or the like. or,
A small diameter portion is formed on the outer periphery of the right end portion of the case body 31, and a slide ring 99 is mounted on the small diameter portion so as to be movable in the axial direction. A plurality of arms 101 are integrally provided on the slide ring 99, and these arms 101 penetrate the window 97 and contact the retainer 93 via a needle bearing 103. Return spring 10 between retainer 93 and retainer 95
5 is attached and biases the differential case 67 to the right. or,
A two-pronged fork 107 is slidably engaged with the outer circumference of the slide ring 99. Fork 107 to the left of ring 99
A convex portion 19 that abuts against is provided. Therefore, the fork
If 107 is moved to the left against the urging force of the return spring 105, the differential case 67 moves to the left as the slide ring 99 moves. The step portion 111 formed between the small diameter portion and the large diameter portion of the case main body 31 acts as a stopper at this time, and the differential case 67 and the ring 55 that have moved to the left side.
It prevents that and touch. In this way, the interrupting device 113 is configured.

The differential case 67 reciprocates between the left connecting position and the right releasing position by the biasing force of the return spring 105 of the interrupting device 113 and the operation of the fork 107. When the differential case 67 moves to the connecting position, the splines 89 and 91 are engaged with each other to be connected to the hub member 41. When the differential case 67 moves to the release position, the connection with the hub member 41 is released.

Such an operation of the interrupting device 113 is performed manually from the driver's seat, or steering angle, acceleration force, braking force, 2-4
It is configured so that it can be automatically operated according to the operation of the switching mechanism.

 Next, the function of this embodiment will be described.

When the connecting / disconnecting device 113 is connected as shown in the upper half of FIG. 1, the driving force from the engine 1 is applied to the viscous coupling.
It is transmitted to the rear differential 87 via 65. At this time, front wheel 1
Outer case of viscous coupling 65 due to rotation speed difference between rear wheels 25 and 27 due to slippage on 3,15 side
When a large rotation difference occurs between 29 and the hub member 41, the differential rotation is greatly limited and a large driving force is transmitted to the rear wheels 25, 27 due to the characteristics of the viscous coupling 65. Further, when the rotation difference is small, a large amount of differential rotation is allowed and the transmission torque becomes small.

When the connecting / disconnecting device 113 is released as shown in the lower half of FIG. 1, power transmission between the viscous coupling 65 and the rear differential 87 is cut off, and the rear wheels 25 and 27 are in a free rotation state.

 Next, a function according to the performance of the vehicle shown in FIG. 2 will be described.

First, when the connecting / disconnecting device 113 is connected, the vehicle has a drive configuration equivalent to a full-time 4WD vehicle as described below. That is, the transmission torque of the viscous coupling 65 is small in a normal running state in which the rotation difference between the front wheels 13 and 15 side and the rear wheels 25 and 27 side is small, and therefore the vehicle is substantially FF-based two-wheel drive (2W).
D) Drive with a driving force distribution condition similar to that of a car. However, if the rotation speed difference between the rear wheels 25 and 27 becomes large due to slipping of the front wheels 13 and 15, large driving force is distributed to the rear wheels 25 and 27 as described above, and the vehicle becomes smooth. Drive to.

In addition, since the difference in rotation between the front and rear wheels is small during a sharp turn at low speed such as when entering a garage, this difference in rotation is the viscous coupling.
The propeller shaft 17 is not twisted by being absorbed by 65, and therefore the tight corner braking phenomenon is prevented.

The front wheels 13 and 15 are driven directly, and the rear wheels 25 and 27
Since the side is configured to be driven via the viscous coupling 65, when the rotation difference between the front and rear wheels is large, as described above, the vehicle safety, driving stability, running performance, etc. Is improved.

When the connection / disconnection device 113 is released, the vehicle is in a completely 2WD traveling state, and the performance equivalent to that of an FF vehicle is obtained.

When the 2-4 switching mechanism of the transfer 5 is switched to the 2WD side in this 2WD traveling state, the rotation of the direction changing gear set and the propeller shaft 17 in the drive system on the rear wheels 25, 27 side is stopped. Therefore, it is possible to prevent wear of each part, noise, vibration, deterioration of fuel consumption, etc. due to the wasteful rotation, and to obtain the same effect as the freehub clutch.

In this way, this power transmission device 19 is a propeller shaft.
Since the eccentricity is not arranged on the propeller shaft 17, the eccentricity can suppress an increase in the moment of inertia of the propeller shaft 17 as in the conventional example, and vibration can be prevented. Further, the propeller shaft 17 is not divided, and it is not necessary to provide a supporting portion for the device in the middle of the propeller shaft 17.

Further, since the viscous coupling 65 and the rear differential 87 are axially arranged so that the hub member 41 has a smaller diameter than the differential case 67, the power transmission device 19 is miniaturized in the radial direction. Therefore, when it is used in the power transmission system of a vehicle as in this embodiment, the minimum ground clearance can be increased, which is advantageous. Further, since the diameter of the viscous coupling 65 becomes small and the relative rotational speed between the input and output members becomes small, it is easy to improve the durability including the X rings 59 and 63.

Next, a second embodiment will be described with reference to FIG. The power transmission device 115 of this embodiment is provided at the same position as that of the first embodiment in the vehicle of FIG. Also, in FIG. 3, the upper half shows the connected state of the device 115, and the lower half shows the released state. Hereinafter, the differences from the first embodiment will be described by quoting the same members with the same numbers. The left and right directions are the left and right directions in FIG.

A rear differential 117 is arranged on the right side of the viscous coupling 65, and a hub member 4 is provided on the inner periphery of the left end portion of the differential case 119.
A spline 121 capable of engaging with one spline 89 is provided. Further, a convex portion 123 is provided on the right end portion of the outer periphery thereof, and a stopper ring 125 is engaged and fixed on the left end side. A bush 127 is slidably engaged between the convex portion 123 and the stopper ring 125. The differential case 119 is rotatably engaged with the case body 129 that constitutes the outer case 128 together with the cover 33 via the bush 127. Similar to the first embodiment, the tip portion of the pinion shaft 73 is engaged with the groove 71 provided in the inner circumference of the differential case 119 in the rotational direction. Therefore, the differential case 119 can rotate together with the pinion shaft 73 and can move in the axial direction with respect to the pinion shaft 73 and the case body 129.

The case body 129 is provided with a plurality of windows 131 in a circumferentially equidistant manner, and the bush 127 is provided with an outer peripheral groove 133. The tip of the bifurcated fork 135 is engaged with the sleeve 137, which penetrates the window 131 and pushes the bush 127.
Of the outer peripheral groove 133. In this way, the interrupting device 139 is configured.

By operating the interrupting device 139, the fork 135 is moved to the left (connecting position) as shown in the upper half of FIG.
When the hub member 41 and the differential case 119 are connected by the engagement of 21, the driving force from the engine 1 is transmitted to the rear differential 117 via the viscous coupling 65. Also, fork 1
When 35 is moved to the right (release position) as shown in the lower half of FIG. 3, the connection between the hub member 41 and the differential case 119 is released, and the torque transmission from the viscous coupling 65 to the rear differential 117 is blocked. To be done.

In the case of this intermittent operation 139, the fork 135 is moved left and right. The interrupting device 139 is configured to be manually or automatically operable as in the first embodiment.

 The other functions and effects are similar to those of the first embodiment.

Note that, in the present invention, contrary to the above embodiments, the torque of the engine 1 may be input from the hub member side of the viscous coupling.

In the above, an example in which the power transmission device is arranged on the rear wheel side of a 4WD vehicle has been described, but the power transmission device of this arrangement can also be arranged on the front wheel side of the 4WD vehicle. In this case, the rear wheels are on the direct drive side, and the front wheels are driven via the viscous coupling. The viscous coupling can also be arranged on the outer peripheral side of the differential device.

〔The invention's effect〕

As described above, in the power transmission device of the present invention, it is not necessary to divide the propeller shaft and dispose it. Therefore, there is little vibration, and there is no need to provide a separate support.

[Brief description of the drawings]

FIG. 1 is a sectional view of the first embodiment, FIG. 2 is a schematic diagram showing power transmission of a vehicle using the first or second embodiment, and FIG. 3 is a sectional view of the second embodiment. 65 …… Viscous coupling, 67,119 …… Diff case,
87,117 …… Differential device, 113,139 …… Intermittent device

Claims (1)

(57) [Claims] 1. A power transmission device for transmitting the torque of an engine to a rear wheel or a front wheel through a switching device, a propeller shaft, a differential device and left and right axles, the viscous transmitting the torque via a viscous fluid. Assembling the coupling and the differential device together,
An output device of the viscous coupling and a differential device of the differential device are provided with an interrupting device for interrupting the connection, and the differential case differentially distributes the engine torque to the rear wheels or front wheels via the left and right axles. A power transmission device including a differential mechanism for storing the power.