JP2629191B2 - Power distribution device for vehicles - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a power distribution device for a vehicle, and more particularly to a power distribution device for a four-wheel drive vehicle that distributes engine power to front and rear wheels.

(Prior art)

As one form of a vehicle power distribution device, an input shaft and a first output shaft which are rotatably supported coaxially and rotatably in a casing, and which are rotatably supported in the casing and are connected to the two shafts. A second output shaft arranged in parallel, a differential device disposed between the input shaft and the first output shaft for distributing power from the input shaft to the output shafts, and a differential device disposed between the output shafts; And a coupling mechanism for transmitting one of the powers distributed by the differential device to the second output shaft, and a coupling mechanism disposed on an outer periphery of the first output shaft to limit a differential between the two output shafts. A power distribution device equipped with a viscous fluid coupling is called "Technical Service Manu
al (1981, AMC). In such a power distribution device, the power transmitted to the input shaft is distributed to both output shafts by the differential device, and is output from each output shaft to the front and rear wheels, so that the vehicle is driven by four wheels, The fluid coupling functions to restrict the differential rotation between the front and rear wheels by a predetermined amount or more.

[Problems to be solved by the invention]

By the way, in such a power distribution device, since the bevel gear type differential device is adopted as the differential device, the dimension in the axial direction becomes longer, and there is a possibility that the power distribution device may be hindered from being mounted on a vehicle. Since the viscous fluid coupling functioning as a limiting device is arranged on the outer periphery of the differential, there is a restriction on the outer diameter, and the capacity of the viscous fluid coupling cannot be increased.

Therefore, an object of the present invention is to reduce the axial length of a power distribution device having a differential device and a differential limiting device, and to increase the capacity of the differential limiting device.

[Means for solving the problem]

A power distribution device for a vehicle according to the present invention includes an input shaft and a first output shaft which are coaxially and rotatably supported in a casing, and a rotatably supported shaft in the casing. A second output shaft arranged in parallel, a planetary gear unit disposed between the input shaft and the first output shaft for distributing power from the input shaft to the two output shafts, and a planetary gear unit disposed between the two output shafts; A coupling mechanism for transmitting one of the powers distributed by the planetary gear unit to the second output shaft; and a viscous fluid coupling disposed on the first output shaft between the planetary gear unit and the coupling mechanism. A power distribution device having the following configuration requirements.

That is, the power distribution device is the power distribution device described above, in which a ring gear forming the planetary gear unit is connected to the input shaft and a sun gear is connected to the first output shaft, and an inner member forming the viscous fluid coupling is provided. An outer member coupled to the first output shaft and liquid-tightly and rotatably mounted on the outer periphery of the inner member to constitute the viscous fluid coupling is coupled to a carrier constituting the planetary gear unit and the coupling mechanism. The inner member of the viscous fluid coupling has an annular outward flange portion, and a pair of annular inward flange portions surrounding each end of the outer member from the radial inside of the outer member. As a configuration having the outer member at the inward flange portions, While surrounding each end of the outward flange portion of the inner member and assembling the inner member with a seal member interposed between the two flange portions, the outer member is provided with a radially inward portion on one inward flange portion of the outer member. It is characterized in that it is coupled to a carrier of a planetary gear unit.

[Functions and effects of the invention]

In the power distribution device having such a configuration, the power transmitted to the input shaft is distributed by the planetary gear unit, one of which is transmitted to the first output shaft, and the other is transmitted from the outer member of the viscous fluid coupling to the coupling mechanism and the second output shaft. The vehicle is thus driven by four-wheel drive.

Thus, in the power distribution device, the ring gear of the planetary gear unit is configured as the input element, and the other two-element sun gear and the carrier are each configured as the output element. The occurrence of the tight corner braking phenomenon due to the differential is prevented. Also, in the power distribution device, the viscous fluid coupling functions as a differential limiting mechanism between the two output shafts, so that the traveling performance of the vehicle on a rough road is improved, and the bevel gear type differential device is not used. Thus, the various problems described above do not occur at all.

By the way, in the vehicular power distribution device according to the present invention, the inner member of the viscous fluid coupling has an annular outward flange portion, and the outer member surrounds each end of the outward flange portion of the inner member from the radial inside. As a configuration having a pair of annular inward flanges, the outer member is assembled to the inner member with each inward flange surrounding each end of the outer flange of the inner member with a seal member interposed between the two flanges. At the same time, a configuration is adopted in which the outer member is coupled to the carrier of the planetary gear unit at a radially inward portion of one of the inward flange portions.

For this reason, the sealing portion between the inner member and the outer member of the viscous fluid coupling and the coupling portion between the outer member and the carrier are superimposed on each other in the radial direction of the first output shaft on the first output shaft. The axial length of the joint itself and the device in which the viscous fluid joint and the planetary gear unit are integrated can be significantly reduced, and the power distribution device can be reduced in size.

Further, since the viscous fluid coupling is provided on the first output shaft, restrictions on assembly due to the outer diameter are greatly relaxed, and the viscous fluid coupling is enlarged in the radial direction to increase its differential limiting capacity. Can be easily increased.

〔Example〕

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
The figures show a power distribution device according to the invention. The power distribution device is fixed to a casing of a transmission (not shown). An input shaft 12, a first output shaft 13, and a second output shaft 14 are rotatably supported in a casing 11, and the input shaft 12 And the first output shaft 13 are coaxially and relatively rotatable, and the two shafts 12, 13 and the second output shaft 14 are arranged in parallel with each other. An output shaft of the transmission is connected to one end of the input shaft 12 so as to transmit torque, and a rear wheel side propeller shaft is connected to the other end so as to transmit torque.
A front wheel side propeller shaft is connected to one end of the output shaft 14 so that torque can be transmitted. A planetary gear unit 20 is provided between the input shaft 12 and the first output shaft 13, and a viscous coupling 30 which is a viscous fluid coupling is provided on the first output shaft 13,
A connecting mechanism 40 is provided between the two output shafts 13 and 14.

Planetary gear unit 20 includes ring gear 21 and sun gear
22, a carrier 23 and a plurality of pinions 24a, 24b, and the ring gear 21 is a flange portion 12a on the inner end side of the input shaft 12.
The sun gear 22 is integrally formed on the outer periphery of the first output shaft 13. 24 each pinion
The ring gears a and 24b are rotatably supported by the carrier 23.
The pinion 24 a is meshed with the ring gear 21 while the other pinion 24 b is meshed with the sun gear 22. The carrier 23 has a cylindrical portion 23a at one end, and an outer spline 23b is formed on the outer periphery of the cylindrical portion 23a, and is rotatable with respect to the first output shaft 13.

The viscous coupling 30 includes an inner member 31, an outer member 32, an inner plate 33, an outer plate 34, and a viscous fluid such as silicone oil.
The sealing member 32 is attached to the outer periphery of the inner member 31 and seals the viscous fluid.

The inner member 31 has a configuration including an inner cylindrical portion 31b and an annular outward flange portion 31a formed at an outer periphery thereof at a predetermined interval. Further, the outer member 32 includes annular inward flange portions 32a and 32b at respective inward ends of the annular main body portion having a U-shaped cross section and opening radially inward, and coaxially outward from the inward flange portion 32b. It has a configuration provided with an extending cylindrical portion 32c.

Each inward flange portion 32a, 32b of the outer member 32 is formed in a shape surrounding each end of the outward flange portion 31a of the inner member 31 from the radial inside, and the outer member 32 is formed by the inner member at each inward flange portion 32a, 32b. Each end of the outward flange portion 31a of the inner member 31 is surrounded from the radial inside, and assembled to the outer periphery of the outward flange portion 31a of the inner member 31 with a sealing member interposed between the two flange portions 31a, 32a, 31a, 32b. It is attached.

A number of inner plates 33 and outer plates 34 are accommodated in a sealed chamber formed by the inner member 31 and the outer member 32. Each inner plate 33 is integrally rotatably mounted on the outer periphery of the inner member 31, and
Reference numeral 34 is attached to the inner periphery of the outer member 32 so as to be integrally rotatable, and is alternately located with each inner plate 33.

In the viscous coupling 30, the inner member 31
The inner spline 31c provided on the inner circumference of the inner cylindrical portion 31b
A predetermined gap is formed between the outer circumference of the first output shaft 13 and the inward flange portion 32a of the outer member 32 because the outer spline 13a is meshed with the outer spline 13a provided on the outer circumference of the output shaft 13.
The cylindrical portion 32c of the outer member 32 is rotatably supported on the outer periphery of the first output shaft 13 and extends therefrom.

On the other hand, the carrier constituting the planetary gear unit 20
The 23 cylindrical portion 23a is the inner member 3 of the viscous coupling 30
1 inner cylinder portion 31b and inward flange portion 32a of outer member 32
The outer spline 23b meshes with and connects to an inner spline 32d provided on the outward flange portion 32a.

The coupling mechanism 40 includes a drive sprocket 41, a driven sprocket 42, and a chain 43, and the drive sprocket 41 meshes with an outer spline 32e provided on the outer periphery of the cylindrical portion 32c of the outer member 32 with an inner spline 41a provided on the inner periphery thereof. I have. The driven sprocket 42 is the second output shaft 14
This driven sprocket is formed integrally with
A chain 43 is suspended between 42 and the drive sprocket 41.

In the power distribution device having such a configuration, when power from a transmission (not shown) is transmitted to the input shaft, the ring gear 21 of the planetary gear unit 20 rotates integrally with the input shaft 12 to rotate the carrier 23 and the sun gear 22. . Accordingly, the first output shaft 13 rotates with the rotation of the sun gear 22, and the input power is output to the rear wheel side. On the other hand, the outer member 32 of the viscous coupling 30 rotates with the rotation of the carrier 23, and the drive sprocket of the coupling mechanism 40
Rotate 41. As a result, the driven sprocket 42 and the second output shaft 14 integrated therewith rotate via the chain 43, and the input power is also output to the front wheels, so that the vehicle travels with four wheels.

In the power distribution device, the planetary gear unit 20 has a differential function because the planetary gear unit 20 has an input of the ring gear 21 and outputs of both the sun gear 22 and the carrier 23. Is allowed by the planetary gear unit 20, and the occurrence of the tight corner braking phenomenon is prevented.

Further, in the power distribution device, both output shafts 13, 14
Since the viscous coupling 30 is disposed therebetween, the coupling 30 functions as a differential limiting mechanism, and improves the running performance of the vehicle on a rough road or the like. Further, since such a device does not use a bevel gear type differential device, there are no problems caused by this. In particular, in the present embodiment, the inner member 31 of the viscous coupling 30
On the first output shaft 13 and the inner member 31
The outer member 32 as a configuration having a pair of annular inward flange portions 32a, 32b surrounding the respective ends of the outer flange portion 31a of the inner member 31 from the radial inside. 32, each inward flange portion 32a, 32b surrounds each end of the outward flange portion 31a of the inner member 31, and these two flange portions 31a, 3
A configuration in which the seal member is interposed between 2a and 31a, 32b and attached to the inner member 31, and the outer member 32 is coupled to the carrier 23 of the planetary gear unit 20 at a portion radially inward of one of the inward flange portions 32a of the outer member 32. Has been adopted.

For this reason, the inner member 31 of the viscous coupling 30
Seal member between the outer member 32 and the outer member 32
The coupling portion between the carrier 32 and the carrier 32 is superimposed on the first output shaft 13 in the radial direction of the output shaft, whereby the viscous coupling 30 itself and the viscous coupling 30 and the planetary gear unit 20 are connected. The axial length of the integrated device can be greatly reduced, and the power distribution device can be reduced in size.

Further, since the viscous coupling 30 is provided on the first output shaft 13, restrictions on assembly due to the outer diameter are greatly relaxed. The dynamic limiting capacity can be easily increased.

[Brief description of the drawings]

The drawings are sectional views of a power distribution device according to one embodiment of the present invention. Explanation of reference numerals 12 ... input shaft, 13, 14 ... output shaft, 20 ... planetary gear unit, 21 ... ring gear, 22 ... sun gear, 23 ...
... Carrier, 30 ... Viscous coupling, 31 ... Inner member, 32 ... Outer member, 40 ... Coupling mechanism, 41,
42 ... sprocket, 43 ... chain.

Claims (1)

(57) [Claims] An input shaft and a first output shaft coaxially and rotatably supported in a casing, and a second shaft rotatably supported in the casing and parallel to the two shafts.
An output shaft, a planetary gear unit disposed between the input shaft and the first output shaft and distributing power from the input shaft to the output shafts, and a planetary gear unit disposed between the output shafts. A coupling mechanism for transmitting one of the powers distributed to the second output shaft to the second output shaft, and a viscous fluid coupling disposed between the planetary gear unit and the coupling mechanism on the first output shaft; And a sun gear connected to the first output shaft, and an inner member forming the viscous fluid coupling is connected to the first output shaft, and a liquid-tight seal is formed on an outer periphery of the inner member. An outer member that constitutes the viscous fluid coupling and is rotatably assembled with the carrier that constitutes the planetary gear unit and the carrier. The inner member of the viscous fluid coupling is configured to have an annular outward flange portion, and the outer member surrounds each end of the outward flange portion of the inner member from a radially inner side. The outer member is assembled to the inner member in a state where each of the inner flange portions surrounds each end of the outer flange portion of the inner member and a sealing member is interposed between the two flange portions. A power distribution device for a vehicle, wherein the outer member is coupled to a carrier of the planetary gear unit at a radially inward portion of one of the inward flange portions of the outer member.