JPH0361123A - Final drive device for four-wheel drive car - Google Patents

Abstract

PURPOSE: To secure traveling stability by coupling operating members of a switching device, where each clitch operates, together with each other in regard to each switching state, in a device which transmits a rotation at the side of a propeller shaft, to both symmetrical rear wheels via two fluid friction clutches. CONSTITUTION: A final drive unit 8 wherein motive power of a driving motor is inputted via a propeller shaft 7, has a viscous coupling 21 equipped with a ring gear 18 in which a drive pinion 17 on the propeller shaft 7 is engaged, and two driven shafts 31 and 32 are rotatably supported in the housing 20. In addition, two coupling hubs 22 and 23 being relatively rotatable are fitted in this housing 20, and thereby two inner plates 25 and 26 being situated in an alternate manner with an outer plate 24 connected to the housing 20, are installed in these respective hubs 22 and 23. In this case, a recess 49 is formed in both ends 47 and 48 to be fitted in these hubs 22 and 23 of the driven shafts 31 and 32, and a spherical supporting ring 51 connected to an operating pin 50 in the axial direction is set up in this recess 49.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is a final drive device for a four-wheel drive vehicle, in which the wheels on the front axle are constantly driven via a front axle differential, and the wheels on the rear axle are constantly driven via a front axle differential. drive the wheels, or connect the cardan shaft and the rear wheels intermediately by the propeller shaft and connect and disconnect the two wheels.
The two liquid friction clutches are arranged in one common housing and have two coupling hubs rotatable relative to each other, these coupling hubs being connected to the final The present invention relates to a type of drive device which is torque-connected to a rear wheel as an output section of a drive device, and can be disconnected from both output sections from the respective rear wheels by means of a switching device.

[Conventional technology]

It is known to use final drives of this type in place of differentials. For example EP0216749
According to the example described in C2, the torque distributed to each axle is transmitted to the respective associated wheel via two histogram couplings. Such an arrangement has the advantage that the customary differential gearing with bevel gears can be saved. By allowing the coupling hubs to rotate relative to each other, it is possible to compensate for differential movements between the inner and outer wheels during cornering.

A further development of this torque splitting torque splitter is shown in EP 0 330 776 A1, in which a torque cut-off device is arranged in the differential gear. The role of this torque cutoff device is to cut off the torque from the other axle to the axle being driven via the torque splitter during brake operation or ABS control, thereby avoiding mutual influence between the axles during braking. . However, this torque isolating device has the disadvantage that both wheels of the associated axle are sometimes in a torque connection with each other. In particular, if an axle driven via a torque splitter is subjected to significant loads for a short period of time and has to transmit large torques, both viscous couplings forming the final drive may exhibit a so-called hump phenomenon. , so that the viscous coupling becomes similar to a fully locked differential.

DE 3317247 C2 specification also contains 1
Two torque splitters are listed.

In the case of this torque splitter, a device that can be disconnected or disconnected is provided on both output parts leading to each wheel of the final drive device, and via these devices, the wheel or final The connection with the drive device is cut off.

This example of a torque splitter presents the disadvantage of dangerous driving conditions when a technical defect causes one device to have a different switching state than the other. Such a situation occurs, for example, when an operating member fails, and as a result, a yawing moment is generated around the rear axle, impairing driving stability.

[Problem to be solved by the invention]

An object of the present invention is to prevent unstable running conditions from occurring due to torque connection between wheels belonging to the rear axle and the final drive device in the final drive device of the type mentioned at the beginning. be.

[Means to solve the problem]

The present invention has solved these problems as follows. That is, the operating members for the switching device are connected to each other for each switching state, and the base position of the operating member when not receiving operating force corresponds to the switching state in which both rear wheels are disconnected from the propeller shaft. .

With this configuration of the final drive device, a one-sided moment that negatively affects the running stability of the vehicle is not generated on one of the wheels, and even in the event of a failure in the operating member, The final drive device is in the cut-off switching state, and the torque connection of both associated wheels is cut off.

In one advantageous embodiment, both coupling hubs or one
It can be connected to the rear wheel via a common mechanical switching device, in particular a coupling key, which is actuated by a pneumatic, hydraulic or magnetic actuating element.

According to this embodiment, the synchronous disconnection of both wheels is effected simply via pneumatic, hydraulic or magnetic actuating elements.

In a further embodiment, both coupling hubs are controlled via two separate switching devices with electromagnetic actuating elements, the actuating elements belonging to these switching devices being arranged in series.

This embodiment ensures that both switching devices do not react in the event of a cable break or a blowout of the fuse in the circuit.

In a further embodiment, both switching devices are controlled via two separate switching devices with hydraulic or pneumatic actuating elements, and the pressure chambers of the actuating elements belonging to each switching device are controlled via one common switching device. It is supplied with pressure medium via a pressure channel.

This embodiment also makes it possible to simultaneously load each pressure chamber with a pressure medium and to cut it off in common.

〔Example〕

The invention will now be described in detail according to two illustrated embodiments.

FIG. 1 shows a four-wheel drive motor vehicle 1, in which a prime mover 2 is connected to front wheels 6 via a transmission 3, a front axle differential 4, and a front wheel half shaft 5. Further, a drive system is branched from the front axle differential device 4 to the rear axle via the propeller shaft 7.

The propeller shaft 7 is used to drive the final drive device 8. The final drive device 8 has a joint 9. The drive shaft 14.15 is connected to the rear wheel 13 via the wheel joint 11.degree. 12.

The final drive device 8, as shown in FIGS. 2 and 3, includes one final drive housing 16, in which a drive pinion 17 or propeller shaft 7 is supported, and the drive pinion 17 is mounted on a ring. It is meshed with gear 18. ring gear 1
8 is a viscous coupling 21 with a fixing screw 19
The coupling housing 20 is relatively immovably connected to the coupling housing 20 . Two coupling hubs 22, 23 are rotatably supported in the coupling housing 20, in which case a set of outer plates 1 and 24 are arranged in parallel with each other in the coupling housing 20. Two sets of inner plates 25, 26 are arranged on each of the coupling hubs 22, 23, and the outer plates 1 to 24 are alternately overlapped with the inner plates 25, 26.

The coupling hubs 22, 23 are sealed to the coupling housing 20 by sealing elements 27,28. The coupling housing 20 itself is a roller bearing 2
Final drive housing 16 through 9.30
supported within.

Two driven shafts 31, 32 are rotatably supported in this coupling housing 20, and these driven shafts 31, 32 each have one joint l-
Drive shirts 1 to 14 of the rear wheel 13 via 9 and 10.
15. Joins I-9 and 10 are outer joint bodies 33 and 34 and inner joint bodies 35, respectively.
, 36, and the inner joint body 35.36
A ball cage 37.38 holding a join ball 39.40 is arranged within the ball cage 37.38. The drive shafts 14.15 of the rear wheels 13 each mesh via splines 41.42 with corresponding splines 43.44 of the inner joint bodies 35, 36. Drive shaft 14
．． Boots 45.46 on 15 seal joints 9.10 which are left open on one side.

In FIG. 2, the connected state of the rear wheel 13 is shown in the upper half, and the disconnected state is shown in the lower half. The ends 47, 48 of the driven shaft 31, 32 or the coupling hub 22,
23 and has a recess 49 in which a spherical support ring 51 axially connected to a coupling key or operating pin 50 is arranged.

A radial through hole 52 is formed in the driven shirt 1-31.32 in the area of the cavity 049, in which a locking body 53 is held. The actuating pin 50 is guided in one of the driven shafts, in the illustrated case the driven shaft 31, and is axially connected at its outer end to the diaphragm 54. The diaphragm 54 and the sealing member 76 seal off the pressure chamber 55, which is loaded via the filling pipe 77, from the outside. A spring 56 is arranged on the actuating pin 50 , which loads the actuating pin 50 via its spherical support ring 51 into the release position for the locking body 53 . This allows the locking body 53 to be displaced radially inwards in the loaded position of this spring.

An axial groove 57 is formed in the through hole 52 of the driven shaft 3L32, and within this groove 57, the coupling hub 2223 is moved to the driven shaft 31 by the action of the locking body 53 or the spherical support ring 5I. .32
and is held for torque connection.

In the embodiment of FIG. 3, the final drive device 8 has two
The driven shaft 31.32, whose ends 47.48 fit into the coupling hubs 22, 23, is connected to the joints l-9, 10 of the drive shaft 14.15 via two electromagnetic operating elements. Or shut it off. In this case, the two actuating elements are preferably arranged in series with one another, which ensures a synchronous cutting and joining of the drive shirt 1-14.15. The lower half of FIG. 3 shows the connected state of the rear wheel 13, and the second part shows the disconnected state. The driven shirt 1-31.32 is provided at its second end 58, 59 with a driven disc 60.61 having teeth 62.63 and a radially stepped bearing portion 64.65; Adjustment disk 66.6 is on 64.65
7 is mounted and arranged for axial movement via a number of circumferential bearing pins 68,69. The adjustment discs 66, 67, by means of their teeth 70.71, engage in the connected state the teeth 62,63 of the driven disc 60,61 to transmit the drive torque to the drive shaft 14,15.

In this case, the ring magnet 72.73, which is fixedly connected to the final drive housing I6, is energized and draws the adjusting disk 66.67 axially towards the viscous coupling 21, which by tooth 62
．． 63 and the tooth 70.71 is ensured. The rear wheel 13 is returned to the cut-off state by the disc springs 74 and 75 when the voltage is cut off. The countersunk 74.75 is fastened on the one hand to the adjustment disk 66.67 and on the other hand to the outer joint body 33.34. The bearing pins 68, 69 are anchored in this outer joint body 33, 34.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram showing a drive system of an automobile, FIG. 2 is a longitudinal sectional view of a first embodiment of the invention, and FIG. 3 is a longitudinal sectional view of a second embodiment of the invention. 2... Prime mover, 3... Transmission, 4... Front shaft differential, 5... Half shaft, 6... Front wheel, 7
...Propeller shaft, 3 8...Final drive device, 9.10...Joint, 1112...Wheel joint, 13...Rear wheel, 14.15...Drive shaft, 16...・Final drive housing, 17
...Drive pinion, 18...Ring gear, 19...Fixing screw, 20
...Coupling housing, 21...Viscous coupling, 22.23...Coupling hub, 24...Outer plate, 25.26...Inner plate, 27.28...Seal member, 29.30...Roller bearing, 31.32...Driven shaft, 33.34...Outer joint body, 35.36...Inner joint body, 37.38...Ball cage, 39.40 ...Joint ball, 41,'42...Spline, 3.44...Spline, 5,46...Boots, 49...Housing, 0...
Operation pin, 51... Support ring, 2... Through hole, 53... Locking body, 4... Diaphragm, 55
... Pressure chamber, 6 ... Spring, 57 ... Miso, 0.61 ... Driven disk, 2.63, 70.71 ... Teeth, 4.65 ... Supporting part, 6. 67... Adjustment disc, 8.69... Support pin, 2.73... Ring magnet, 4.75... Belleville spring.

Claims (1)

[Claims] 1. A final drive device for a four-wheel drive vehicle, comprising:
The wheels (6) on the front axle are constantly driven via the front axle differential (4), and the wheels (13) on the rear axle are driven by a propeller shaft (7) that connects the cardan axle and the rear wheels (13). This is done through two liquid friction clutches that are intermediately connected between them and can be disconnected or connected, the two liquid friction clutches are arranged in one common housing, and two coupling hubs (22 , 23),
These coupling hubs are torque-connected to the rear wheels (13) as outputs of the final drive device, and both outputs can be disconnected from their respective rear wheels (13) by a switching device. , the operation members (50, 72, 73) for the switching device are connected to each other for each switching state, and the base position of the operation members (50, 72, 73) when not receiving the operation force is the same as the propeller shaft (7). ), which corresponds to a switching state in which both rear wheels (13) are cut off. 2. Both coupling hubs (22, 23) can be connected to the rear wheel (13) via one common mechanical switching device, which switching device can be a pneumatic, hydraulic or magnetic actuating member. The final drive device of claim 1, wherein the final drive device is operable by (50). 3. Both coupling hubs (22, 23) are controlled via two separate switching devices with electromagnetic operating members (72, 73), the operating members (72, 73) belonging to these switching devices The final drive device according to claim 1, wherein the final drive devices are arranged in series. 4. Both coupling hubs (22, 23) are controlled via two separate switching devices with hydraulic or pneumatic actuating elements, the pressure chambers belonging to the switching devices of the actuating elements being one
2. The final drive device according to claim 1, wherein the final drive device is loaded with a pressure medium via two common pressure channels.