GB2368105A

GB2368105A - Device for operating a selector shaft of a shift transmission

Info

Publication number: GB2368105A
Application number: GB0201870A
Authority: GB
Inventors: Andreas Rogg; Norbert Esly
Original assignee: LuK Getriebe Systeme GmbH
Current assignee: LuK Getriebe Systeme GmbH
Priority date: 1997-05-30
Filing date: 1998-05-27
Publication date: 2002-04-24
Anticipated expiration: 2018-05-27
Also published as: GB0201870D0; GB2368105B

Abstract

The device comprising a rotatable and displaceable shift/select member 2 having engagement means for a first actuator, which actuates rotational movement of the member 2, and a second actuator, which actuates displacement movement of the member 2. Each actuator has a rotary drive, and the axis of rotation AA and BB of the rotary drives are substantially at right angles to one another. Pinions 20 and 22 mesh with teeth 40 and 44 formed on the shift/select member 2 to produce a keyed engagement in a circumferential direction and to allow relative displacement of the teeth parallel to the pinion axis of rotation AA and BB.

Description

Device for operating a selector shaft of a shift transmission The invention relates to a device for operating a selector shaft of a shift transmission which can be swivelled about an axis and is displaceable along the axis, containing a swivel actuator for swivelling the selector shaft and a displacement actuator for displacing the selector shaft.

Automating shift transmissions has grown in importance in recent times. On the one hand such automated shift transmissions are more cost-effective than conventional automatic gearboxes which normally operate with planetary sets or are formed as belt contact gearboxes with continuously variable transmission. On the other hand automated shift transmissions work with a better degree of efficiency than conventional automatic gearboxes so that the improvement in comfort need not be paid for by increased fuel consumption.

A selector shaft as shown in Figure 6 is normally used for operating conventional shift transmissions. The shift/select member 2 is displaceable on a gearbox housing (not shown) along the axis A and is guided for swivel movement about the axis and has a shift finger 4 which engages in mouths of selector forks 6. Each of the selector forks 6 is attached to a shift rod 10 guided in the gearbox housing by means of linear guides 8 whereby a further fork (not shown) is fixed to each other end to operate a synchroniser sleeve for synchronising the relevant gear. During linear displacement in the direction of the double arrow W the shift/select member 2 executes a rolling movement whereby it is determined in which of the selector forks 6 the shift finger 4 engages, i. e. which of the selector forks is then moved during swivel movement of the shift/select member 2 in the

direction of the double arrow S and thus which gears are shifted. Selection is likewise possible through rotary movement of the shaft and shifting is possible through linear movement of the shaft.

When automating a shift transmission-operating device of this kind one actuator is provided each for swivelling and for displacing the selector shaft and the actuators are connected to the selector shaft through an associated structural connecting assembly. With an operating device known from US 4 856 360 the two actuators have linearly displaceable operating members. The operating member for displacing the selector shaft is connected to the selector shaft by a component part which is rigidly connected to the selector shaft regarding its axial direction but which allows relative rotation of the selector shaft. The operating member for swivelling the selector shaft engages in a swivel lever connected rigidly to the selector shaft so that during its activation it produces a swivel movement of the selector shaft but with an axial displacement of the selector shaft a corresponding relative movement is possible between the operating member and shift lever.

The object of the present invention is to provide a device of the kind already mentioned which with a simple construction allows precision operation of the selector shaft where the swivel and displacement movements of the selector shaft take place independently of each other.

According to the invention, there is provided a device for operating an automatic gearbox with a shift and select function, the device comprising a rotatable and displaceable shift/select member which forms a shift finger and engagement means both for a first actuator which actuates rotational movement of the member and for a

second actuator which actuates displacement movement of the member, wherein the shift/select member is mounted on a housing of the gearbox and the actuators each have a rotary drive for providing drive about one axis of rotation, and the axes of rotation of the rotary drives are substantially at right angles to one another, wherein a drive component is formed as a pinion with teeth which run parallel to its axis of rotation and which mesh with teeth formed on the shift/select member to produce a keyed engagement in a circumferential direction and to allow relative displacement of the teeth parallel to the pinion axis of rotation.

Further advantageous developments of the device according to the invention are set forth in the sub-claims.

The invention will now be explained in detail by way of example with reference to the following drawings in which: Figures 1 & 2 show perspective views of different operating devices; Figures 3 to 5 show perspective views of different operating devices according to the invention; and Figure 6 is a perspective view for illustrating the interaction of the selector shaft with selector forks in the case of a conventional manual transmission.

According to Figure 1 a central shift/select member 2 which has a shift finger 4 is formed in a thickened area integral with forks 12 and 14. The arms 12a and 12b of the forks form between them a circumferential groove 12c which is concentric with the axis of the shift/select

member 2. The groove need not necessarily be formed concentric. It can also be formed straight and stand perpendicular on the axis of the selector shaft. Similarly the arms 14a and 14b of the fork 14 form a groove 14c running parallel to the axis of the shift/select member 2.

The central guide axis can either be formed fixed on the housing whereby the selector shaft is then formed longitudinally movable relative to this guide axis or is mounted on the guide axis, or the guide axis is mounted longitudinally movable and rotatable in the gearbox housing or in a built-on housing wherein the selector shaft is connected fixed to the guide axis or is formed in one piece therewith.

Next to each fork 12 and 14 a component part 16,18 is mounted to swivel about an axis fixed on the gearbox housing and engages with a projection 16a, 18a into the groove 12c, 14c.

On the side remote from the projection each component part 16,18 has teething 16a, 18a which mesh with further teething 20a, 20b which are formed on the drive shaft 20, 22 of an electric motor 24,26.

Each of the grooves 12c, 14c is matched with the associated projection 16a, 18a so that the projection directly adjoins the inner walls of the arms but is movable in the longitudinal direction of the groove. The projections are ball-shaped so that swivelling is possible and a freedom of play is substantially obtained.

The function of the device described is as follows:

If for example the electric motor 24 serving as the actuator is controlled by a control device (not shown), the component part 16 is swivelled whereby through keyed engagement in the vertical direction between the projection 16a and the fork 12 the shift/select member 2 is moved up or down accordingly direct. The projection 18b can thereby be moved in the longitudinal direction of the groove 14c relative to same so that the displacement movement of the shift/select member 2 in the direction of selecting a shift gate is not blocked by the component part 18.

If on the other side the electric motor 26 forming a further actuator is operated then the component part 18 is swivelled so that through the keyed engagement between the projection 18a and the fork 14 the shift/select member 2 is swivelled without this swivel movement being hindered by the component part 16. The shift/select member 2 executes a shift movement or causes a shift process.

With a simple construction of the device a reliable operation of the shift/select member 2 is achieved whereby the selection process is carried completely independently of the shift process.

It is obvious that numerous modifications of the device described are possible; for example a reduction gear can be provided between each of the electric motors 24 and 26 and the associated drive shaft 20,22 to allow the use of smaller electric motors. It is further obvious that depending on the design of the gearbox the displacement movement of the shift/select member 2 can be connected with a shift process and the swivel movement can be connected with a selection process.

The embodiment according to Figure 2 differs from that in Figure 1 mainly in that as indicated by the double arrows in the same direction the component parts 16 and 18 are fixed direct rigidly to a shaft mounted fixed relative to the gearbox housing and driven in rotation by an associated actuator, so that the teeth of Figure 1 are omitted. Otherwise the method of operation of the device of Figure 2 corresponds to that of Figure 1.

The embodiment according to Figure 3 differs from that in Figure 1 mainly in that the component parts 28, 30 mounted fixed on the gearbox housing are formed overall U-shaped or fork-shaped whereby the bearing axis is located each time in the base of the component parts and the arms 26a and 28b or 30a and 30b which form between same the grooves 28a and 30c respectively each receive a projection 30,32 which is formed integral with the shift/select member 2.

In this embodiment the shaft 2 is mounted movable relative to the housing. The movement takes place along the axis A-A. The shaft 100 is connected integral or rotationally secured with the shaft 2 whereby the shaft 2 has the shift finger 4. The shaft 100 can likewise have the shift finger 4. The shaft 2 engages by the journal 4 in the gearbox and operates shift elements inside the gearbox.

The shaft 100 can be mounted outside of the gearbox whereby the shaft 100 can be mounted inside its own housing.

With the embodiment of Figure 3a the shaft 102 is mounted fixed relative to the housing and the hollow shaft 101 is movable and rotatable relative to the shaft 102. The hollow shaft 101 is mounted and guided on the shaft 102.

The shaft 102 and the shaft 101 are mounted so that the journal 4 engages in the gearbox and switches shift elements inside the gearbox.

The outsides of the bases of the component parts 28, 30 are each provided with teeth 28a, 30a which mesh with corresponding teeth 20a, 22a of the drive shafts 20,22.

Each of the projections 30,32 is, similar to the embodiment according to Figure 1, matched with the groove 28c, 30c so that a direct keyed engagement is provided in the operating direction but relative movement is provided perpendicular thereto. It is obvious that the bearing axis of the component part 30 is parallel to the axis of the shift/select member 2 whilst the bearing axis of the component part 28 is perpendicular to the axis of the shift/select member 2. The function of the arrangement according to Figure 3 corresponds moreover to that of Figure 1.

The embodiment according to Figure 4 differs from that of Figure 3 in the same way as the embodiment according to Figure 2 differs from that in Figure 1. The component parts 28,30 are not provided with teeth but are connected rigidly direct to each one of the shafts driven by one of the actuators and are thereby mounted at the same time fixed relative to the gearbox housing. The function of the device according to Figure 4 corresponds moreover to that of Figure 3.

With the arrangement according to Figure 5 the shift/select member 2 has an attachment 36 which has teething 40 whose teeth extend circumferentially concentric with the axis of the shift/select member 2. The teething 40 meshes with teething of a rotary-driven drive shaft 20 which is mounted fixed on the gearbox housing and which has teething 44 which is overall coaxial with the axis of the shift/select member 2, with the teeth however running axially parallel. The teething 44 meshes with corresponding teething of a rotary-driven drive shaft 22.

The function of the device according to Figure 5 is as follows : Rotation of the drive shaft 22 leads to a corresponding swivel movement of the shift/select member 2 wherein this swivel movement is not hindered through the engagement between the teeth 40 and teeth of the drive shaft 20 since both sets of teeth can be displaced relative to each other in the direction of their individual cogs.

If the drive shaft 20 is turned then the shift/select member 2 is displaced axially whereby this displacement is not hindered by the engagement between the teeth 44 and the teeth of the drive shaft 22 since both can be displaced relative to each other without the toothed engagement being lost. The embodiment of the device according to Figure 5 is particularly simple since it requires a minimum of component parts.

The embodiments described can be modified in many respects and can be combined together. By way of example the teeth in the embodiments according to Figure 1 or Figure 3 can also be designed as non-circular teething which compensate different lever transmission ratios according to the angular position of the component parts 16 and 18 or 28 and 30.

The invention is also not restricted to the embodiments of the description. Numerous amendments and modifications are possible within the scope of the claims, particularly those variations, elements and combinations and/or materials which are combinations or modifications of individual features or elements or process steps contained in the drawings and described in connection with the general description and embodiments and claims.

Claims

1. Device for operating an automatic gearbox with a shift and select function, the device comprising a rotatable and displaceable shift/select member which forms a shift finger and engagement means both for a first actuator which actuates rotational movement of the member and for a second actuator which actuates displacement movement of the member, wherein the shift/select member is mounted on a housing of the gearbox and the actuators each have a rotary drive for providing drive about one axis of rotation, and the axes of rotation of the rotary drives are substantially at right angles to one another, wherein a drive component is formed as a pinion with teeth which run parallel to its axis of rotation and which mesh with teeth formed on the shift/select member to produce a keyed engagement in a circumferential direction and to allow relative displacement of the teeth parallel to the pinion axis of rotation.

2. Device as claimed in Claim 1, wherein the shift/select member has engagement means which engage with engagement means of drive components which are driven in rotation by respective ones of the actuators.

3. Device as claimed in Claim 1 or Claim 2, wherein the drive component is mounted directly on a shaft driven by the actuator.

4. Device as claimed in any preceding claim, wherein a drive component ends in a projection which engages in a fork formed on the shift/select member such that a keyed engagement is provided by the projection bearing against inner faces of the arms of the fork, and wherein the projection is movable along a channel formed between the fork arms.

5. Device as claimed in any preceding claim, wherein both actuators have a drive component to actuate the shift/select member, and the actuator drive components operate independently on the shift/select member.

6. Device as claimed in any preceding claim, wherein the drive component for rotating the shift/select member is journalled on a bearing which is parallel to the axis of rotation of the shift/select member.

7. Device as claimed in Claim 6, wherein the rotary movement of the selector shaft takes place about a guide spindle.

8. Device as claimed in Claim 6 or Claim 7, wherein the axial movement of the selector shaft takes place along a guide spindle.

9. Device for operating an automatic gearbox substantially as herein described with reference to and as shown in Figure 5 of the accompanying drawings.