GB2210341A

GB2210341A - Vehicle transmission

Info

Publication number: GB2210341A
Application number: GB8822740A
Authority: GB
Inventors: Klaus Schubert; Hans Jurgin Drewitz; Hubert Thudt
Original assignee: MAN Nutzfahrzeuge AG
Current assignee: MAN Truck and Bus SE
Priority date: 1987-10-01
Filing date: 1988-09-28
Publication date: 1989-06-07
Anticipated expiration: 2008-09-28
Also published as: DE3733153A1; GB8822740D0; IT1227120B; IT8822130A0; FR2623449B1; DE3733153C2; GB2210341B; FR2623449A1

Description

22 1034 A Method of selectively connecting and disconnecting the Torque

supplied to the Shaft of driven Vehicle Wheels.

The invention relates to an arrangement for selectively connecting and disconnecting a supply of torque and more particularly but not exclusively to such an arrangement for the supply of torque to the shaft of driven motor vehicle wheels using a floating axle connection which is arranged in the axle member and is able to connected bv means of a clutch whose con-. trol means are arranged externally of the axle member.

Various arrancements have been proposed for connecting and disconnecting the supply of torque to motor vehicle wheels. Known devices normally comprise hub connecting means as for example connections usina doc, clutches. Such known designs may be arranged on the outside of the axle or intearated within the wheel; hub and have encapsulated control means which are pneuniati-call-,.-, mechanicalIv or h,?draulicall, ,.- operated. The operating means integrated on or in the vehicle wheel with dog clutch teeth, return springs and a pneumatic space defined in some way provides for a selectively discohnectable link between the drive shaft and the associated motor vehicle wheel. Such a known design does however suffer from various disadvantages. For instance, owina to the arrangement of the operating means on the outside of the wheel the axle is extended so as no longer to comply with standards. In, the case of an arrangement integrated in the hub of the wheel there is cui elaborate arrangement of the operating and clutch members fitting into each other. Furthermore it is necessar-v to have a multiplicity of seals for the rotating parts. A further disadvantage is to be seen in the creation of access for the compressed air supply required for the stationary axle parts, the result in some cases beina long, thin hole7s which interfere with rational manufacture. Furthermore there are hardly any ways of leading the compressed air ducts through the plane of the planet wheels in the case of an operating means on the outside of the axis. Another point is that in practice it is hardly possible to have a compressed air duct in the rotating floating axle.

A device of connecting and disconnecting the torque to the shaft of a motor vehicle wheel has been proposed in which at one end of the axle, the floating axle of the drive axle is divided and able to be coupled to-ether by means of a clutch (see European patent 003A324). In the case of such device fitted to a vehicle with a two wheel drive mode the so-called back-ward drive mav be prevented, which has to occur as a matter of course if a clutch is located in the transmission housing interrupting the flow of torque, there beinc. a lockilia device to the rear thereof to -Dut the auxiliary differential shaft, and thus differential housing, out of operation. This known device has substantial disadvantages inasmuch as the differential housing has to rotate as well, this J:- leading to increased losses through splashing and a reduction in efficiency. Furthermore it is not possible to design the means used in this system to provide a differential lock.

One object of the present invention is to improve the overall mechanical efficiencv of a multi-axle vehicle drive power train by ad hoc inactivation of the drive connection leadin. to the associated wheels of the drive axle which is to be respectively disconnected or connected without modifying the design of the wheel hub.

In order to achieve this object in accordance with a first aspect the invention provides an arrangement for selectivel.". connecting and interrupting the flow of torque to the shaft of driven motor vehicle wheels bv means of a floating axle connection arranged in the axle member, such axle connection being able to be connected and disconnected bv a clutch whose operating control C5 means are arranged without the axle member, wherein:

- the floating axle connection comprises two floating axles of which each is torque-transmittingly connected with the differential bevel aears and at the other end is radially supported in a differential housing, - double universal joint shafts leading to the drive wheels are provided whose ends adjacent.to the differential are rotatably supported in inner holes in the ends of the floating shafts, and - the floating axle ends and the end parts of the double universal joint shafts are able to be engaged with each other by way of clutches arranaed in a zone in the.axle member.

In accordance with a further'aspect in the invention the floating axle connection comprises two floating axl.es, of which each is torque-transmittingly connected at one end with the bevel gears of the differential and at the other end is radially supported in a differential housing, and double universal joint shafts are provided leading to the drive wheels whose ends nearer the differential are turninclx. mounted in holes in the ends of the floatina shafts and the floatina axle ends and the end parts of the double universal joint shafts are able to be brought into ericacement with each other b,,- wav of clutches arranced in -iven zones in the axle member.. The invention provides the advantageous effect of a reduction of the idling times in respect of the drive train when in the inactivated state, this in itself leadin. to an increase in working life. Furthermore there is an improvement in the overall efficiency, owing to not having the fraction of loss due to bearina friction and gear engagement and also to oil splashing. A further benefit is due to an decrease in fuel consumption otherwise due to power needed for accelerating rotating parts of the drive train when the vehicle is frequently stopped and started. The device makes it possible to inactivate the entire drive train from the output of the transmission inclusive of the axle differential bevel drive and the floatina axle fraction as far as the point of disconnection provided with the respective operating elements, this meaning that by, pneumatic or hydraulic operation of two dog clutches the floating ax-Les 111av be selectively disconnected from or connected with the floating shafts. Owing to the arrangement of clutches and points of disconnection in the zone with the difPerential there is no need to interfere with the joint part of the driven front axles, which.would present a critical design problem.

In accordance with a preferred feature of the invention the floating axle connection is provided on the one side with a dual position clutch and on the other side it provided with a triple position clutch, the former clutch making it possible for the floating axle and the double universal joint shaft to be selectively put in and out of engagement, while by means of the latter clutch, which is in the form of a double shift lever clutch, the floating axle and the double universal joint shaft may be selectively engaged and disengaged with each other. This leads to a further substantial advantage of the invention, namely that' a differential lock may be operated.

In accordance with a further feature of the invention the control means for the clutches are arranged externally of the axle member. The provides simple access to the critical expendable or wearing parts of- the coupling without extensive disassembly of the C5 drive axle being required.

Further advanta-es of the invention are to be crathered from the claims, the description and the accompanying drawing.

The drawing shows one working example of the invention.

The single figure of the drawing shows the drive axle of a motor vehicle in partial section. There is an axle member 23 and a planetarydifferential transmissioii in which floating axles 3 and 25 are arranged, which at the positions at which they emerge from the differential housina 24 have shaft sDlines for the mounting of a dog clutch 1 or an axially shifting double clutch sleeve 2. To prevent axial shift of the inner floating axle 3 on the left the dog clutch 1 is secured by: a wire ring 21. To prevent axial shift of the inner floating axles towards the inner side of the axle there are thrust washers 26 bearing on the differential housing 24. On the outer side of the axle the axial shift is prevented by the' washers 27 and the locking rings 28 0 located in relation to the differential bevel wheels 30. The inner floating axles are radially borne in the differential bevel wheels 30 and in the plain bearing means in the differential housing 24.

The ends of the double universal joint shafts 4 and 29 on the inner side of the axle are centered and bearinged with suitable pins in the inner holes 31, having suitable needle bearings 32, at the end of the floating shafts 3 and 25. The corresponding splined shaft teeth on the ends of the double universal joint shafts 4 and 29 have the axially sliding clutch sleeve 5 mounted thereon. On the right hand side of the axle member 23 there is a sinale shift lever compressed air operated clutch 11 which is integnated in the axle housing for operation of the dog clutch. This clutch 11 consists of a disengaging spring 35, a shift lever 36, an operating rod 37, a setting screw 38, an operating piston 39, an"operatina cylinder 40 and a cover Al.

On the left hand side of the axle member 23 there is a double shift lever compressed air operated clutch 10 for the operation of the double tooth clutch 5, on the axle housing opposite to the drive flange. This clutch 10 consists of n operating cylinder 6. a co-,,,er 20, an operating piston 7, a guide rod 9. operating shift levers 14 and 17, a spacer bushing 15, a disengaging spring 17, sealing rings 8 and 19, adjustment washers n iz m 0 12 and 13 and a threaded bushing 18. For operation of the differential lock the differential housing 24 is equipped with a does clutch secured bv the wire rina 21. Manner of o-Deration: In the disengaged state of the floating axles the flow oil C:- 0 m torque to the respective wheel is interrupted. On the right side IC of the axle the operating unit is free of pressure, the disengaging spring forces the shift lever against the abutment to 0 C5 0 0 the richt and the clutch sleeve 5 of the double universal joint shaft 29 is separated from the dog clutch 1 of the inner floating shaft 25. On the left side of the axle the clutch 10 is also not 35 under pressure, the disengaging spring 15 forces the two shift tz CD 0 levers 14 and 17 respectively against the cylinder cover 20 as far as thev will go. The double clutch sleeve 2 is in this state in c) 6 engagement with the dog clutch 1 of the differential housing 24 on the one hand and on the other hand is separated from the clutch sleeve 5 of the double universal joint shaft 4.

In the engaged condition of the floating axles the flow of 5 torque to the respective wheel is completed.

On the right side of the axle the clutch 11 is under pressure; against the thrust of the disengaging spring 35 the shift lever 36 is thrust to the left through the stroke 'W' as far as abutment of the operating piston against the wall of the housing. The clutch sleeve 5 of the double universal joint shaft 29 is in engagement with the inner floating axle 25.

On the left side of the axle the clutch 10 is acted on by 0 CS a thrust towards the right; aaainst the thrust of the disengaging spring 15 the right hand shift lever is forced against the abutment 15 of the left hand shift lever 14. The double clutch sleeve 2 then uncouples from the dog clutch 1 of the differential lock and couples with the clutch sleeve 5 of the double universal joint shaft 4. The inner floating axle 3 is now connected with the double universal joint shaft A kypassing the differential lock.

In t he coupled up condition with the differential lock there is no change on the right hand side of the axle. On the left hand side of the axle the clutch 10 on the right hand side is not pressurized and the double clutch sleeve 2 is engaged with the dog clutch 1 of the differential housing 24. Owing to pressure C> ty -l acting on the left side of the clutch 10 the left hand shift lever 14 is moved acainst the thrust of the disengaging spring 15 through the stroke "B" against the abutment of the right hand shift lever 17. The clutch sleeve 5 of the double universal joint shaft 4 then couples with the double clutch sleeve 3 which is already engaged with the dog clutch 1 of the differential. housing 0 24. Thus the inner floatina axle 3, the differential housina 23 and the outer double universal joint shaft 4 are connected with each other and the differential lock mas. take effect.

Clutch engagement and disengagement may take place when the vehicle is more or less stationary or is moving at walking speed. The provision for adjusting the clutch strokes 'W' and "B" 7 is on the right hand operating unit by way of the set screw 38 and on the left hand clutch by way of the washers 12 and 13. The left hand clutch 10 may be completely preassembled including the shift. levers 14 and 17, on the a suitable flange surface of the axle member 23 and then screwed together. Furthermore the clutch 11 on the 'right hand side may be completely preassembled into the axle member 23.

In the case of axles without connection and disconnection of torque flow the flange surfaces are covered with dummy covers.

8

Claims

1 An arrangement for selectively connecting and interrupting the flow of torque to the shaft of driven motor vehicle wheels by means of a floating axle connection arranged in -the axle member, such axle connection being able to be connected and disconnected te; a clutch whose operating control means are arranged without the axle member, characterized in that: - the floating axle connection comprises two floating axles of which each is torque- transmittingly connected with the differential bevel gears and at the other end is radially; supported in a differential housing, - double universal joint shafts leading to the drive wheels are provided whose ends adjacent to the differential are rotatably supported in inner holes in the ends of the floatina shafts, and - the floating axle ends and the end parts of the double universal joint shafts are able to be engaged with each other by way of clutches arranaed in a zone in the axle member.

0

2 An arranaement as claimed in clairii 1 characterized in that the floating axle connection on the one side has associated with it a dual position clutch and on the other side a triple position clutch, the former such clutch making possible selective engagement of the floating axle and the double universal joint shaft, while the latter clutch is in the form of a double shift lever clutch makes possible selective engagement of the floating c axle and the double universal joint shaft and furthermore the floatina axle and the differential housina.

3 An arrangement as claimed in claim 1 or claim 2, characterized in that the control weans of the clutches are arranged outside the axle member.

4 An arrangement as claimed in any one of' the claims 1 to 0 - 3 characterized in that the control means of the one clutch comprise a shift lever, on operating rod, a disengaging spring, a 0 set screw, a piston, an operating cylinder and a cover, the free 0 - 9 end of the shift lever fitting into the shift groove of the clutch sleeve which is able to slide longitudinally on the end part of the one universal joint shaft.

An arrangement asclaimed in any one of the claims 1 to 3, characterized in that the control means of the other clutch with two shift levers comprise shift levers, an operating cylinder, a cover, an operating piston, a guide rod, a spacer bushing, a disengaging spring, a threaded bushing, sealing rings and setting washers, the free shift lever ends of the shift lever running in the shift grooves of the double clutch sleeve sliding longitudinally on the end part of the othdr universal joint shaft and of the longitudinally sliding double clutch sleeve.

6 An arrangement as claimed in any one of the claims 1 to 5, characterized in that the clutch sleeves are arranged in the 0 end parts of the double universal joint shafts so as to be radially located but able to slide longitudinally.

0 -

7 An arran-ement as claimed an,,- one of the claiins 1 to 6. characterized in that the double clutch-sleeve is arranged on the outer end of a floating axle so that it is radially located but able to slide longitudinally and the clutch sleeve has clutch teeth on either side which are able to be selecti-,...el%- engaged with clutch teeth of the clutch sleeve or with the clutch teeth of the do. clutch arranged in torque-transmitting relation to the clutch teeth of the differential housing while being axially fixed.

8 An arrangement as claimed in any one of the claims 1 to 6, characterized in that one of the dog clutches is arranged on the outer end of the floating axle so as to be in torque transmitting relation thereto while being axially fixed.

9 An arrangement as claimed in any one of the claims 1 to 8, characterized in that the control means for the clutches are able to be operated by compressed air or oil.

An arrangement as claimed in claim 1 substantially as described-above with reference to, and as illustrated in the accompanying drawing.

A Published 1988 at The Patent Office. State House. 66 71 High Hoiborn. Londor. WC1R 4TP. Ftrther copies may be obtained from The Patent Office. Sales Branch. St Mary Cray. Orpigton, Ker,-.lR5 3RD- Primed by Multiplex techniques ltd. St. MaiT Cray. Kent. Con 1'67.