GEAR SHIFTING UNIT

Abstract

A gear shifting system has a gear shift sleeve that is axially guided with driving toothing on a driving toothing of a transmission shaft, providing at least three shift positions with a rotationally fixed connection of the transmission shaft to a respective transmission component. A respective tooth flank of at least one tooth of one driving toothing has peripheral projections configured axially along the respective tooth between respective adjacent regions where teeth of the other driving toothing move axially in the shift positions of the gear shift sleeve. A gap width of a respective gap between the teeth of the other driving toothing is greater than or equal to a sum formed by a tooth width of the at least one tooth of the one driving toothing and an effective width of the projections.

Claims

1. A gear shifting system (1), for use with a transmission shaft (8) having shaft driving toothing (5) the gear shifting system comprising: a gear shift sleeve (2) configured to be guided with a sleeve driving toothing (4) in an axially displaceable manner on the shaft driving toothing (5) of the transmission shaft (8) and can thereby be positioned on the transmission shaft (8) in at least three shift positions in which the gear shift sleeve (2) produces a respective rotationally fixed connection of the transmission shaft (8) to a respective transmission component (16; 17; 18); wherein at least one tooth (19) of the shaft driving toothing (5) is respectively equipped on at least one respective tooth flank (31, 32) and has projections (27 to 30) which each project in a peripheral direction relative to the at least one respective tooth flank (31, 32) and which are configured axially along the respective tooth (19) between respectively adjacent regions (20, 21, 22) in which teeth (23, 24) of the sleeve driving toothing (4) are moved axially in the shift positions of the gear shift sleeve (2); and wherein a gap width (34) of a respective gap (33) between the teeth (23, 24) of the sleeve driving toothing (4) is greater than or equal to a sum formed by a tooth width (35) of the at least one tooth (19) of the shaft driving toothing (5) which engages in the respective gap (33) and an effective width of the projections (27 to 30) in a peripheral direction of the at least one tooth (19).

2. The gear shifting system (1) according to claim 1, wherein the at least one tooth (19) of the shaft driving toothing (5) is equipped on two respective tooth flanks (31, 32) and has projections (27 to 30) which are configured axially along the at least one tooth (19) between the respectively adjacent regions (20, 21, 22) and such that the projections project in both peripheral directions.

3. The gear shifting system (1) according to claim 1, wherein the projections (27 to 30) respectively merge continuously into the regions (20, 21, 22) of the respective tooth flank (31, 32).

4. The gear shifting system (1) according to claim 3, wherein the respective transition is linear.

5. The gear shifting system (1) according claim 1, wherein in at least one tooth (23, 24) of the sleeve driving toothing (4), a respective tooth flank (39; 40) of the at least one tooth (23, 24) of the sleeve driving toothing (4) which faces the respectively opposite projections (27, 29; 28, 30) merges directly into axial end faces (42, 43; 44, 45) of the at least one tooth (23, 24).

6. The gear shifting system (1) according to claim 1, wherein the shaft driving toothing (5) is configured on a side of the transmission shaft (8) and the sleeve driving toothing (4) is configured on a side of the gear shift sleeve (2).

7. The gear shifting system (1) according to claim 1, wherein the gear shift sleeve (2) is equipped on an inner and/or outer periphery with at least one shift toothing (9, 12) on which a respective meshing engagement with a respective associated toothing (46; 47; 48) of a respective transmission component (16; 17; 18) can be produced in the respective shift position.

8. The gear shifting system (1) according to claim 1, wherein each of the respective transmission components (16, 17, 18) is present as a respective further transmission shaft.

9. The gear shifting system (1) according to claim 1, wherein a gap width (34) is selected to be greater than the sum of the tooth width (35) of the at least one tooth (19) of the shaft driving toothing (5) and the effective width of the projections (27 to 30).

10. A motor vehicle transmission, comprising at least one gear shifting system (1) according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Advantageous embodiments of the invention, which are discussed below, are shown in the drawings. The figures show:

[0030] FIG. 1: a sectional view of a gear shifting system according to a preferred embodiment and in a first shift state;

[0031] FIG. 2: a tangential section through driving toothings of the gear shifting system in the first shift state of FIG. 1;

[0032] FIG. 3: a sectional view of the gear shifting system according to the invention in a second shift state;

[0033] FIG. 4: a tangential section through the driving toothings of the gear shifting system in the second shift state of FIG. 2;

[0034] FIG. 5: a sectional view of the gear shifting system according to the invention in a third shift state;

[0035] FIG. 6: a tangential section through the driving toothings of the gear shifting system in the third shift state of FIG. 5;

[0036] FIG. 7: a sectional view of the gear shifting system according to the invention in a fourth shift state;

[0037] FIG. 8: a tangential section through the driving toothings of the gear shifting system in the fourth shift state of FIG. 7;

[0038] FIG. 9: a sectional view of the gear shifting system according to the invention in a fifth shift state; and

[0039] FIG. 10: a tangential section through the driving toothings of the gear shifting system in the fifth shift state of FIG. 9.

DETAILED DESCRIPTION

[0040] FIG. 1 shows a sectional view of a gear shifting system 1, which is provided in a transmission. This transmission is preferably a motor vehicle transmission, which is in particular designed as an automatic transmission. The gear shifting system 1 is configured according to a preferred embodiment of the invention.

[0041] The gear shifting system 1 in this case comprises a gear shift sleeve 2, which is configured in a sleeve-like manner as a hollow cylindrical body and is equipped on an inner diameter 3 with a driving toothing 4. The gear shift sleeve 2 is guided on this driving toothing 4 in an axially displaceable manner on a driving toothing 5 configured on an outer diameter 6 of a coupling body 7. The coupling body 7 is fastened to a transmission shaft 8 in a rotationally fixed and axially immovable manner. In the present case, the two driving toothings 4 and 5 are both designed in the manner of driving toothings.

[0042] As can further be seen in FIG. 1, the gear shift sleeve 2 is equipped on the inner diameter 3 with a shift toothing 9, which is axially spaced apart from the driving toothing 4 and is designed here as a claw toothing. This shift toothing 9 is configured in the region of an axial end 10 of the gear shift sleeve 2. On an axial end 11 opposite to the end 10, the gear shift sleeve 2 is moreover equipped with a further shift toothing 12, whereby this shift toothing 12 is provided on an outer diameter 13 of the gear shift sleeve 2 and is configured as a claw toothing. Also in the region of the axial end 11 and axially adjacent to the shift toothing 12, the gear shift sleeve 2 is additionally equipped on an outer diameter 14 with a peripheral groove 15, which serves to engage an actuating element, such as a shift fork, via which the axial displacement of the gear shift sleeve 2 relative to the transmission shaft 8 can be initiated.

[0043] The gear shift sleeve 2 can be moved axially on the transmission shaft 8 into different shift positions in order to connect the transmission shaft 8 in each of the shift positions in a form-locking, rotationally fixed manner to a respective transmission component 16 or 17 or 18. These transmission components 16 to 18 in this case are further transmission shafts of the transmission. Therefore, three different rotationally fixed connections of the transmission shaft 8 can be realized via the gear shifting system according to the invention.

[0044] As a special feature, the driving toothings 4 and 5 of the gear shifting system 1 are designed in such a way that an unintentional departure from a currently selected shift position is prevented for the gear shift sleeve 2. This design of the driving toothing 4 and 5 will now be described in more detail with reference to the illustration in FIG. 2, which shows a tangential section through the driving toothing 4 and 5.

[0045] In FIG. 2, a tooth 19 of the driving toothing 5 can be seen, whereby all of the teeth of the driving toothing 5 can be configured in this way or only one tooth or individual teeth of the driving toothing 5 are designed in this way. In the latter case, the corresponding teeth are in particular distributed evenly over the periphery of the driving toothing 5.

[0046] The tooth 19 has an axial extension on the coupling body 7 which corresponds to the axial displacement range of the gear shift sleeve 2 on the transmission shaft 8. There are three regions 20, 21 and 22 along the tooth 19, in which the gear shift sleeve 2 is respectively axially positioned in a respective one of its shift positions with teeth 23 and 24 of its driving toothing 4. Projections 27 to 30 are provided on the tooth 19 in intermediate regions 25 and 26 axially between these regions 20, 21 and 22. The projections 27 and 29 are provided on a tooth flank 31 of the tooth 19 and the projections 28 and 30 are provided on a tooth flank 32 of the tooth 19. Whereas the projections 27 and 28 are provided axially at the same height in the intermediate region 25 and thus between the regions 20 and 21 and extend in peripheral direction opposite to one another, the projections 29 and 30 are located in the intermediate region 26 and thus between the regions 21 and 22. In this case, the projection 29 projects in peripheral direction in one direction relative to the tooth flank 31, whereas the projection 30 is configured such that to projects in peripheral direction in the opposite direction relative to the tooth flank 32. The transitions of the individual projection 27 or 28 or 29 or 30 into the respectively axially adjacent regions 20 and 21 or 21 and 22 of the tooth 19 are all configured to be continuous, whereby this is implemented here in the form of a linear transition.

[0047] A gap 33 between the teeth 23 and 24 of the driving toothing 4 of the gear shift sleeve 2 is designed with a gap width 34 which is greater than the sum of a tooth width 35 of the tooth 19 and the effective width of the projections 27 to 30, which is composed of the width 36 of the projections 27 and 29 and the width 37 of the projections 28 and 30 in peripheral direction. As can also be seen in FIG. 2, the tooth flanks 38 and 39 or 40 and 41 of the teeth 23 and 24, in the intermediate gap 33 of which the tooth 19 equipped with the projections 27 to 30 engages, merge directly and with an edge into axial end faces 42 and 43 or 44 and 45 of the respective tooth 23 or 24.

[0048] When the gear shift sleeve 2 is positioned with its driving toothing 4 in one of the regions 20 to 22, and thus in one of its shift positions in which the gear shift sleeve 2 respectively produces a rotationally fixed connection of the transmission shaft 8 with one of the transmission components 16 to 18, one of the teeth 23 or 24 rests with its tooth flank 39 or 40 against the tooth flank 31 or 32 of the tooth 19 of the driving toothing 5 under load. An axial displacement of the gear shift sleeve 2 relative to the transmission shaft 8 under load and thus a departure from the respective selected shift position is form-lockingly prevented by the interaction of one of the end faces 42 or 43 or 44 or 45 of the tooth 23 or 24 with the projection 27 or 29 or 28 or 30 which is axially adjacent in this direction.

[0049] FIGS. 1 and 2 show a shift state of the gear shifting system 1, in which the gear shift sleeve 2 is axially positioned in a first shift position in which the gear shift sleeve 2 connects the transmission shaft 8 in a rotationally fixed manner to the transmission component 16 via a meshing engagement of the shift toothing 12 with a toothing 46 of the transmission component 16. Under load, departure from this shift position is prevented for the driving toothings 4 and 5 by the interaction of the projection 27 of the tooth 19 with the end face 43 of the tooth 23.

[0050] The gear shift sleeve 2 can be displaced axially from the shift position shown in FIG. 1 into a neutral position shown in FIGS. 3 and 4 only when there is substantially no load on the meshing engagements of the driving toothings 4 and 5 and the gear shift sleeve 2 can then be rotated in peripheral direction relative to the coupling body 7. As can be seen in particular in FIG. 4, this axial displacement when there is substantially no load is made possible by the sufficiently large gap width 34 of the gap 33 between the teeth 23 and 24.

[0051] From the neutral position shown in FIGS. 3 and 4, the gear shift sleeve 2 can then not only be displaced into the shift position shown in FIG. 1, but also into a second shift position shown in FIGS. 5 and 6. In this second shift position, the gear shift sleeve 2 then engages with its shift toothing 9 in a toothing 47 of the transmission component 17, as a result of which the transmission component 17 and the transmission shaft 8 are connected to one another in a rotationally fixed manner via the gear shift sleeve 2. As can be seen in FIG. 6, respectively in interaction with the respective axially adjacent projection 27 and 29 of the tooth 19, the two end faces 42 and 43 of the tooth 23 form-lockingly prevent an axial displacement of the gear shift sleeve 2 in both axial directions under load, because the tooth 23 rests with its tooth flank 39 against the tooth flank 31 of the tooth 19 under load.

[0052] The gear shift sleeve 2 can be displaced from the second shift position shown in FIGS. 5 and 6 into either the neutral position of FIGS. 3 and 4 ora neutral position shown in FIGS. 7 and 8 only when there is substantially no load. Here, too, the reason is that, in the at least almost load-free state, the gear shift sleeve 2 can be rotated with its driving toothing 4 relative to the driving toothing 5 so far in peripheral direction that the teeth 23 and 24 no longer rest with their tooth flanks 39 and 40 against the respective facing tooth flank 31 and 32 of the tooth 19. The teeth 23 and 24 can therefore move axially past the projections 29 and 30.

[0053] The gear shift sleeve 2 can also be displaced axially from the neutral position shown in FIGS. 7 and 8 into a third shift position, which can be seen in FIGS. 9 and 10. In this third shift position, the gear shift sleeve 2 engages with its shift toothing 9 in a toothing 48 of the transmission component 18, as a result of which the gear shift sleeve 2 connects the transmission shaft 8 and the transmission component 18 to one another in a rotationally fixed manner. As can be seen in FIG. 10, a departure from this third shift position is again prevented under load because the tooth 23 rests with its tooth flank 39 against the tooth flank 31 of the tooth 19 under load, which form-lockingly prevents an axial displacement as a result of the interaction of the end face 42 with the projection 29. A return movement into the neutral position shown in FIGS. 7 and 8 can be undertaken only when there is substantially no load.

[0054] The use of the embodiments of a gear shifting system according to the invention enables the realization of at least three different shift positions, whereby an unintentional departure from a respectively selected shift position under load is prevented in a reliable manner.

LIST OF REFERENCE NUMERALS

[0055] 1 Gear shifting system

[0056] 2 Gear shift sleeve

[0057] 3 Inner diameter

[0058] 4 Driving toothing

[0059] 5 Driving toothing

[0060] 6 Outer diameter

[0061] 7 Coupling body

[0062] 8 Transmission shaft

[0063] 9 Shift toothing

[0064] 10 End

[0065] 11 End

[0066] 12 Shift toothing

[0067] 13 Outer diameter

[0068] 14 Outer diameter

[0069] 15 Groove

[0070] 16 Transmission component

[0071] 17 Transmission component

[0072] 18 Transmission component

[0073] 19 Tooth

[0074] 20 Region

[0075] 21 Region

[0076] 22 Region

[0077] 23 Tooth

[0078] 24 Tooth

[0079] 25 Intermediate region

[0080] 26 Intermediate region

[0081] 27 Projection

[0082] 28 Projection

[0083] 29 Projection

[0084] 30 Projection

[0085] 31 Tooth flank

[0086] 32 Tooth flank

[0087] 33 Gap

[0088] 34 Gap width

[0089] 35 Tooth width

[0090] 36 Width

[0091] 37 Width

[0092] 38 Tooth flank

[0093] 39 Tooth flank

[0094] 40 Tooth flank

[0095] 41 Tooth flank

[0096] 42 End face

[0097] 43 End face

[0098] 44 End face

[0099] 45 End face

[0100] 46 Toothing

[0101] 47 Toothing

[0102] 48 Toothing