GB2325967A

GB2325967A - Apparatus for operating a selector shaft of a gearbox

Info

Publication number: GB2325967A
Application number: GB9811826A
Authority: GB
Inventors: Andreas Deimel; Reinhard Berger; Andreas Rogg; Gunter Hirt
Original assignee: LuK Getriebe Systeme GmbH
Current assignee: LuK Getriebe Systeme GmbH
Priority date: 1997-06-04
Filing date: 1998-06-03
Publication date: 1998-12-09
Anticipated expiration: 2018-06-03
Also published as: DE19823767A1; ITMI981239A1; BR9801753A; GB2325967B; FR2764358A1; BR9801753C1; GB9811826D0; FR2764358B1

Abstract

Apparatus for operating a selector shaft 2 of a shift gear which can swivel about an axis and is displaceable along the axis. The apparatus has a displacement mechanism 20 which is connected to the selector shaft 2 through a structural connecting assembly 24,28,44 which can displace the selector shaft 2 in an axial direction. A swivel mechanism 18 is connected to the selector shaft through a structural connecting assembly 22,26,38,32 and can rotate the selector shaft. The structural connecting assembly 22,26,38,32 engages with articulated movement on a swivel lever or crank 12 rigidly connected to the selector shaft 2. The displacement and swivel movement are uncoupled from each other, and the structural connecting assemblies each contain an articulated rod 44,38 whose one end is connected for articulated movement to the associated actuator 20,18 and whose other end is connected for articulated movement to the selector shaft 2.

Description

APPARATUS FOR OPERATING A SELECTOR SHAFT OF A GEARBOX The invention relates to apparatus for operating a selector shaft of a change-speed gearbox able to swivel about an axis and displaceable along the axis, containing a displacement actor which is connected to the selector shaft through a structural connecting assembly to displace the selector shaft, and a swivel actor which is connected to the selector shaft through a structural connecting assembly to swivel the selector shaft, which structural connecting assembly engages for articulated movement on a swivel lever connected rigidly to the selector shaft wherein the displacement and swivel movement are uncoupled from each other at least substantially.

The automation of shift gears has become increasingly important in recent times. On the one hand automated shift transmissions of this kind are more cost effective than conventional automatic gears which operate with for example planetary sets or are formed as contact belt gearboxes with continuously variable transmission. On the other hand automated shift gears operate with a better degree of efficiency than conventional automatic gearboxes so that the improvement in comfort is not at the expense of increased fuel consumption. In order to operate shift gears there is normally a selector shaft which is mounted for swivel movement and is displaceable along its bearing axis. A conventional selector shaft of this kind is shown in Figure 6. This selector shaft 2 engages with an integral shift finger 4 into recesses of shift forks 4 formed as an overall U-shaped structure each displaceable to and fro in known way linearly along shift gates 8 in order to change gears. The selector shaft 2 is axially displaceable in the direction of the double arrow W to select a shift gate. In order to displace a relevant shift fork 6 and change gear the selector shaft 2 can turn or swivel in the direction of the double arrow S Likewise designs are known wherein the selector shaft ic turned for selecting the shift gate and is displaceablf axially or longitudinally to change gear.

When automating a shift gear operating apparatus of thie kind one actor is provided for swivelling the selector shaft 2 and one actor is provided for displacing thf selector shaft 2 and each are connected to the selector shaft through an associated structural connect inc assembly. With an operating device known from US 4 85d 360 the two actors have linearly displaceable operatinc members. The operating member for displacing the selector shaft is connected to the selector shaft through structural part which is connected to the selector shaft rigidly relative to its axial direction but allows relative rotation of the selector shaft. The operatinc member for swivelling the selector shaft engages in C swivel lever rigidly connected to the selector shaft s that during activation it produces a swivel movement o! the selector shaft but during axial displacement of thf selector shaft a corresponding relative movement is possible between the operating member and swivel lever.

A feature of these and other operating devices fo selector shafts is that the coupling between the selector shaft and operating member which is rigid relative to onf direction but loose relative to a direction at right angles thereto only allows a restricted precision of thf operation. Otherwise high frictions occur which requirE strong actors and can also lead to tensions inside thf structural connecting assemblies.

The object of the invention is to provide apparatus fo2 operating a selector shaft of a shift gear which caI swivel about one axis and is displaceable along the axis whereby the apparatus is simple in construction, functions with precision and experiences little loss of power.

This is achieved in that at least one of the structural connecting assemblies contains an articulated rod whose one end is connected for articulated movement to the associated actor and whose other end is connected for articulated movement to the selector shaft.

According to a further inventive idea this is also achieved in that the connecting structural assemblies each contain an articulated rod whose one end is connected for articulated movement to the associated actor and whose other end is connected for articulated movement to the selector shaft. It is thereby expedient in one embodiment if the articulated rod contained in the connecting structural assembly for displacing the selector shaft acts parallel to the axis of the selector shaft.

Further designs of the invention are apparent from the features of the sub-claims.

The apparatus according to the invention where the structural connecting assembly for shifting, the structural connecting assembly for selecting or the two structural connecting assemblies contain an articulated rod provided with two articulated joints which produces the coupling between the actor and selector shaft, is designed overall as a three-dimensional articulated drive with at least four articulated joints. No frictionassociated linear displacements are thereby required between the various structural parts of the structural connecting assembly or structural parts of the structural connecting assembly and selector shaft. Problems which occur for example during displacement of wedged teeth under moment load, even if groups of rolling bodies are used to reduce friction are thus completely avoided. The apparatus according to the invention can be manufactured more cost-effectively and operates extremely reliably and with low power losses.

Sub-claims 3 to 6 are based on advantageous further developments of the apparatus according to the invention whereby particularly with the features of claim 5 a practically complete uncoupling is obtained between the shift and selecting operation of the selector shaft.

Claim 7 is based on a further development of the apparatus according to the invention which is characterised in that through the elastically pliable articulated rod no excessive forces can occur inside the structural connecting assembly and the operating devices of the shift gear cannot be overstressed if an end position of stop is reached. Furthermore an elastically pliable design of the articulated rod of this kind is advantageous in certain cases where a force is to be measured because this force can be determined directly through measuring the elastic deformation of the articulated rod.

Claims 8 to 10 are based on advantageous embodiments of the elastically pliable articulated rod.

The invention can be used advantageously everywhere where conventional shift gears which are operable by a selector shaft which can swivel about an axis and is displaceable along the axis are to be operated by means of actors, whether the shift gears are fully automated or whether the gears are shifted at the behest of the driver but this does not happen direct from a shift lever but by means of actors. Actors of this kind can be electric motors, hydraulic motors or other types of motorized drive devices.

The invention will now be explained in further detail below with reference to the accompanying drawings in which: Figure 1 is a perspective view of the principle of the apparatus according to the invention; Figure 2 shows a further development of the apparatus according to Figure 1; Figure 3 is a diagrammatic partial illustration of a pretensioned elasticity within a connecting rod linkage; Figure 4 shows a side sectional view of an elasticity in a connecting rod linkage; Figure 5 shows a sectional view through the arrangement according to Figure 4 in the sectional plane V-V of Figure 4; and Figure 6 shows a selector shaft according to the prior art.

According to Figure 1 the selector shaft 2 which is axially displaceable and swivel guided in the gearbox housing 10 projects out of a gearbox housing 10. A swivel lever 12 is rigidly attached to the selector shaft 2 and has at one end a bearing pin 14. A further bearing pin 16 is fixed through connecting means as close as possible to the centre axis of the selector shaft or directly on the selector shaft 2.

In order to operate the selector shaft 2 two actors are provided which are formed as electric motors 18 and 20 and are fixed directly on the gearbox housing 10. Each of the electric motors 18 and 20 has an output shaft 22 and 24 which forms the worm of a reducing worm gear whose worm wheel is marked 16 and 28 respectively. The worm wheels 26 and 28 are likewise mounted like the electric motors directly on the gearbox housing 10.

One eccentric lever 30, 32 each is connected rotationally secured to each worm wheel 26, 28 and has at the end a bearing pin 34 and 36 respectively. The bearing pins 14 and 34 are connected by an articulated rod 38 which is provided at the ends with ball heads 40 and 42 which are fitted onto the bearing pins 34 and 14. The bearing pins 16 and 36 are connected similarly by an articulated rod 44 which is provided at the ends with ball heads 46, 48 which are pushed onto the bearing pins 16 and 36. The method of functioning of the apparatus described is immediately comprehensible. During operation of one of the electric motors 18 or 20 the associated worm wheel 26 or 28 is turned so that the relevant articulated rod 38 or 44 is moved and the selector shaft 2 is turned in the direction of shifting or is displaced in the direction of selecting.

As can be seen the articulated rod 38 is advantageously aligned tangentially to a circumferential direction of the axis of the selector shaft 2 whilst the articulated rod 44 extends axially parallel to the selector shaft 2. Through expedient lengths of the articulated rods 38, 44 the angular position of the articulated rod 38 during displacement of the selector shaft 2 in the selecting direction is only changed by some few degrees , for example 5 to 30 degrees and the angular position of the articulated rod 44 during a shifting swivel movement of the selector shaft 2 is likewise only changed by some few degrees. Thus the shift position of the selector shaft 2 during its displacement in the selecting direction remains substantially unchanged and vice versa. It is obvious that the mutual influence of the selecting position when changing the shift position and vice versa can also be taken into account in the software in a control device which controls the electric motors 18 and 20. The entire assembly can according to the structural requirements be integrated in the gearbox housing 10 or fitted afterwards in simple manner on the gearbox housing 10 so that a costeffective refitting is possible on conventional shift gears. Furthermore it is possible to mount both rod linkages inclined to the axis and to produce the purely rotational movements of the shaft through suitable superimposed positioning of the drives. Similarly with a further embodiment the longitudinal movement of the shaft can be reached through a suitable superimposition of the two drives. The suitable superimposition of the two drives can be taken into account through control in the control software in the control device.

The apparatus operates with a high functioning reliability and with reduced friction and is substantially insensitive to dirt and contamination.

The embodiment according to Figure 2 is basically similar in construction to that of Figure 1. Reference numerals are only given to those structural parts which differ from those in Figure 1. As can be seen the articulated rod 50 corresponding to the articulated rod 38 of Figure 1 is provided with an elasticity 52 which is pretensioned where applicable and which will be explained in further detail with reference to Figures 3 to 5.

An oblong hole 56 is formed in a retaining component part 54 consisting of two superposed punched-out sheet metal parts. A coil spring 58 is housed where applicable under pretension in the oblong hole. Outside of the oblong hole 56 the retaining component part has two oblong stop holes 59 through each of which a stop pin 60 projects which is formed in one piece with a further punched out metal part 61 which is located underneath the retaining component part 54 and has an oblong hole 62 (Figure 4) corresponding to the oblong hole 56. A further punched out metal part 64 (not shown in Figure 3) is mounted above the retaining component 54 and is formed with a further oblong hole 66 corresponding to the oblong hole 56 whereby the coil spring 58 likewise projects into the further oblong hole 66. The component part 64 is fixedly connected to the component part 61 or is formed in one piece with same.

The retaining component part 54 is provided at the end with an articulated bearing which undertakes the function of the ball head 40 or 42 (Figure 1). The component parts 61 and 64 likewise together support an articulated bearing which undertakes the function of the second ball head.

The function of the arrangement described is as follows: Figure 4 shows the rest position in which the coil spring 58 is supported on the end side on the edges of all the oblong holes 56, 62 and 66 whereby all structural parts are aligned relative to each other so that the stop pins 60 are located centrally in the stop holes 59. If a pulling force is exerted on the articulated rod 50 through the ball heads 40 and 42 (Figure 1) then the structural part 54 is displaced according to Figure 4 to the right relative to the structural parts 61 and 64 whereby the pretensioned spring 58 (the pretension determines the force necessary for the start of the relative movement) is compressed and the displacement is restricted by the stop pin 60 stopping against the wall of the stop holes 59.

Similarly the coil spring 58 is compressed if a compressive force acts on the articulated rod 50 whereby the reduction in length of the articulated rod 50 is in turn restricted by the stop pin 60 stopping against the walls of the stop holes 59.

Overall an articulated rod 50 is provided in the manner described which can be deformed within a certain extent as soon as the longitudinal forces acting on same exceed a predetermined value.

The patent claims filed with the application are proposed wordings without prejudice for obtaining wider patent protection. The applicant retains the right to claim further features disclosed up until now only in the description and/or drawings.

References used in the sub-claims refer to further designs of the subject of the main claim through the features of each relevant sub-claim; they are not to be regarded as dispensing with obtaining an independent subject protection for the features of the sub-claims referred to.

The subjects of these sub-claims however also form independent inventions which have a design independent of the subjects of the preceding claims.

The invention is also not restricted to the embodiments of the description. Rather numerous amendments and modifications are possible within the scope of the invention, particularly those variations, elements and combinations and/or materials which are inventive for example through combination or modification of individual features or elements or process steps contained in the drawings and described in connection with the general description and embodiments and claims and which through combinable features lead to a new subject or to new process steps or sequence of process steps insofar as these refer to manufacturing, test and work processes.

Claims

1. Apparatus for operating a selector shaft of a shift gearbox which is capable of swivelling about an axis and is displaceable along the axis, the apparatus comprising a displacement actor which is connected to the selector shaft through a structural connecting assembly to displace the selector shaft, and a swivel actor which is connected to the selector shaft through a structural connecting assembly to swivel the selector shaft, which structural connecting assembly engages for articulated movement on a swivel lever connected rigidly to the selector shaft wherein the displacement and swivel movement are uncoupled from each other at least substantially, characterised in that at least one of the structural connecting assemblies contains an articulated rod whose one end is connected for articulated movement to the associated actor and whose other end is connected for articulated movement to the selector shaft.

2. Apparatus for operating a selector shaft of a shift gear capable of swivelling about an axis and displaceable along the axis, containing a displacement actor which is connected to the selector shaft through a structural connecting assembly to displace the selector shaft, and a swivel actor which is connected to the selector shaft through a structural connecting assembly to swivel the selector shaft, which structural connecting assembly engages for articulated movement on a swivel lever connected rigidly to the selector shaft wherein the displacement and swivel movement are uncoupled from each other at least substantially, characterised in that the structural connecting assemblies each contain an articulated rod whose one end is connected for articulated movement to the associated actor and whose other end is connected for articulated movement to the selector shaft.

3. Apparatus according to claim 1 or 2 characterised in that the displacement actor and the swivel actor each contain an electric motor which through a reduction gearing drives a component part which is connected for articulated movement to the associated articulated rod.

4. Apparatus according to claim 3 characterised in that the component part driven by the actor and connected for articulated movement to the articulated rod is rigidly connected to the worm wheel of a worm gear.

5. Apparatus according to one of claims 1 to 4 characterised in that the articulated joints of the articulated rods are ball joints.

6. Apparatus according to one of claims 1 to 5 characterised in that the lengths of the articulated rods are measured so that a displacement or swivel movement of the selector shaft only leads to small angular changes in the position of the articulated rod associated with the swivel actor or displacement actor respectively.

7. Apparatus according to one of claims 1 to 6 characterised in that at least one of the articulated rods is formed elastically pliable in respect of both its longitudinal directions when overcoming a predetermined force.

8. Apparatus according to claim 7 characterised in that the elastically pliable articulated rod contains a push/pull rod linkage.

9. Apparatus according to claim 8 characterised in that the push/pull rod linkage contains a retaining component with an oblong hole in which a coil spring is housed with pretension whereby the coil spring additionally projects into an oblong hole which is formed aligned with thf oblong hole in the retaining component in a structural part which belongs to the articulated rod and is displaceable relative to the retaining component part.

10. Apparatus according to claim 9 characterised in that the displacement of the structural part belonging to thf articulated rod relative to the retaining component iE restricted by at least one stop pin which engages in < suitably oversized stop hole of the structural part belonging to the articulated rod.

11. Apparatus for operating a selector shaft of a shift gearbox substantially as herein described with reference to any one embodiment shown in the accompanying drawings.