GEAR UNIT FOR A TWO-WHEELED VEHICLE

Abstract

A shift system for shifting a gear unit has at least one movably disposed selector shaft and at least one switch element. The selected position of the switch element is changed by movement of the selector shaft relative to the switch element. A drive shaft is rotatable about a centre axis. In a first selected position of the switch element, it can be connected to co-rotate at least in one direction of rotation to a component of the gear unit. In a second selected position of the switch element, it can be disconnectable from the component of the gear unit in each direction of rotation. At least a part of the switch element co-rotates with a rotation of the drive shaft about the centre axis, so that relative movement of the switch element with respect to the selector shaft is generated. A gear unit has such a switch system.

Claims

1-14. (canceled)

15. A shift system for shifting a gear unit, comprising: at least one movably arranged selector shaft; and at least one switch element; wherein a selected position of the switch element is variable relative to the switch element by a movement of the selector shaft; and wherein a drive shaft rotatable about a center axis is configured as part of the shift system such that the drive shaft is rotationally fixedly connected to a component of the gear unit in at least one direction of rotation in a first selected position of the switch element, and is disconnectable from the component of the gear unit in any direction of rotation in a second selected position of the switch element; and whereas the switch element is configured in conjunction with the drive shaft such that at least a portion of the switch element co-rotates about the center axis with a rotation of the drive shaft; and the relative movement of the switch element relative to the selector shaft is induced by the part of the switch element rotating with the drive shaft, so that the movement of the switch element between the first and the second selected position is effected by a force branched off from the drive movement of the drive shaft.

16. The shift system in accordance with claim 15, wherein at least the part of the switch element rotating with the drive shaft has at least one pickup that is movable into contact with the selector shaft, with the pickup being axially and/or radially displaceable with respect to the center axis by the movement of the selector shaft to move the switch element into the second selected position.

17. The shift system in accordance with claim 16, wherein the selector shaft has at least one ramp and/or interacts with at least one ramp, with the pickup being axially and/or radially displaceable with respect to the center axis by movement of the pickup circulating about the center axis in contact with the ramp, with a displacement of the ramp being induced by the movement of the selector shaft.

18. The shift system in accordance with claim 16, wherein a direction of movement in which the selector shaft moves the ramp in contact with the pickup and a direction of actuation of the pickup of the selector shaft extend perpendicular to one another.

19. The shift system in accordance with claim 16, wherein the selector shaft is designed such that the pickup of the switch element is movable between the first selected position and the second selected position by the selection movement of the selector shaft independently of the rotational movement of the drive shaft, in particular by at least one ramp formed axially slantingly at the selector shaft or at a component connected to the selector shaft.

20. The shift system in accordance with claim 15, wherein the switch element is designed as a dog clutch, as a shift pawl, or as a shift pawl system.

21. The shift system in accordance with claim 17, wherein a switch procedure of the switch element into the second selected position can be carried out by contact of the ramp with the pickup and/or a tension spring is configured that urges the switch element into the first selected position.

22. The shift system in accordance with claim 15, wherein the selector shaft has a first section having a smaller diameter and a selected section having a larger diameter, whereas the shift system is configured such that a change between the switched positions of the switch element taking place by a change of contact of the switch element and in particular of the pickup via the ramp between the first section and the second section.

23. The shift system in accordance with claim 16, wherein a first selector shaft and a second selector shaft are connected to one another axially movably and rotationally rigidly.

24. The shift system in accordance with claim 23, wherein: a passage shaft is provided that extends along the center axis and on which the first and second selector shafts are received, with the first selector shaft having a first guide link in which a first guide element arranged at the passage shaft is guided and/or the second selector shaft has a second guide link in which a second guide element arranged at the passage shaft is guided so that axial positions of the first and/or second selector shafts are independent of one another along the center axis.

25. The shift system in accordance with claim 15, wherein a rotational activator is configured and is operatively connected to the selector shaft, with the rotational activator being actuable by an operator to initiate a rotational movement in the selector shaft, with the at least one selector shaft being operatively connected rotationally fixedly and axially displaceably to the rotational activator.

26. A gear unit having at least one shift system in accordance with claim 15, wherein the gear unit comprises: at least one planetary gear; and wherein a component of the planetary gear to which the drive shaft is rotationally fixedly connectable in at least one direction of rotation of the gear unit by means of the switch element is designed as an annulus gear, as a planetary carrier, and/or as a sun gear of the at least one planetary gear.

27. The gear unit in accordance with claim 26, wherein two or more planetary gears nested with one another and/or in one another are configured, with the annulus gear, the planetary carrier, and/or the sun gear being shiftable by the first and/or at least one second planetary gear by the shift system.

28. The gear unit in accordance with claim 26, wherein two interleaved planetary gears are arranged to each other, wherein a first freewheel is provided that forms an operative connection between an annulus gear of the second, outwardly disposed planetary gear and a fixedly stationary part of the gear unit; and/or a second freewheel is provided that forms an operative connection between the planetary carrier of the first, inwardly disposed planetary gear and the fixedly stationary part; and/or a third freewheel is provided that forms an operative connection between the sun gear of the first, inwardly disposed planetary gear and the drive shaft.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Further measures improving the invention will be shown in more detail below together with the description of a preferred embodiment of the invention with reference to the Figures. There are shown:

[0039] FIG. 1 is an equivalent circuit diagram of a gear with the shift system in accordance with the invention;

[0040] FIG. 2 is a perspective view of the gear;

[0041] FIG. 3 is a section through the gear with the shift system in accordance with the invention;

[0042] FIG. 4 is a perspective view of the switch unit with two selector shafts in connection with a rotational activator, but without the drive shaft;

[0043] FIG. 5 is a perspective view of the switch unit with a selector shaft in connection with the rotational activator in accordance with FIG. 4, with a drive shaft furthermore being shown so that a further selector shaft is hidden;

[0044] FIG. 6 is a perspective view of a first selector shaft;

[0045] FIG. 7 is a perspective view of a switch element designed as a shift pawl;

[0046] FIG. 8 is a further perspective view of the switch unit with the arrangement of a plurality of shift pawls in connection with the drive shaft in a sectional representation; and

[0047] FIG. 8a is a perspective view of the sun gear of the inner planetary gear.

DETAILED DESCRIPTION OF THE INVENTION

[0048] FIG. 1 shows an equivalent circuit diagram of a gear unit 1 in an upper half-section, with the shift system 14 in accordance with the invention being shown. A passage shaft 11 that can be attached in a resting manner at the frame of a two-wheeled vehicle, for example and that can also not rotate to this extent, extends through the gear unit 1 as a carrying element. The passage shaft 11 extends along a center axis 10 that simultaneously forms the axis of rotation of the two planet gears 12 and 13. The planetary gear 12 forms an inner planetary gear and the planetary gear 13 forms an outer planetary gear, the two in particular being formed lying in one another.

[0049] A drive shaft 18 that can be driven by a rider or by a motor of the two-wheeled vehicle and that forms a part of the shift system 14 extends about the passage shaft 11. The drive shaft 18 receives the switch element 15 and 16, with the switch element 15 cooperating with an annulus gear 28 of the planetary gear 13 and the switch element 16 cooperating with a planet carrier 29 of the inner planetary gear 12. The switch element 17 cooperates with a sun gear 30 of the inner planetary gear 12 and is received at a fixedly stationary part 48 of the gear unit 1 and thus provides an operative connection of the inner sun gear 30 to the fixedly stationary part 48 and to this extent also to the passage shaft 11. The switch element 17 is thus also part of the switch element 14.

[0050] The annulus gear 28 of the outer planetary gear 13 is divided into two parts with respect to the direction of extent of the center axis 10 so that a first part gear 28a is produced shown on the left and a second part gear 28b is produced shown on the right. An axial gap is thereby produced between the part gears 28a and 28b through which the output of the gear unit 1 is guided, with the output being formed, in a manner not shown in any more detail, by the casing of the gear unit 1 that is rotationally rigidly coupled to the outer planetary carrier 33 of the second planetary gear 13. The output can, for example, form a casing of the gear unit, not shown in any more detail, that is connected to the planetary carrier 33 by the gap between the part gears 28a and 28b.

[0051] The outer planet gears 34 engage in both part gears 28a, 28b of the annulus gear 28 so that the part gears 28a, 28b are rotationally rigidly connected to one another by means of the outer planet gears 34.

[0052] The first planetary gear 12 is arranged at the inner side and the second planetary gear 13 is arranged at the outer side, with both planetary gears 12, 13 being arranged lying in one another and the annulus gear of the first, inwardly disposed planetary gear 12 being of uniform construction with the sun gear of the second, outwardly disposed planetary gear 13 and thus forming the annulus sun gear 31.

[0053] The fixedly stationary part 48 at which the switch element 17 is received and that cooperates with the sun gear 30 can also be formed as part of the passage shaft 11, with the fixedly stationary part 48 advantageously forming a single component or a component group to which the freewheels 35 and 36 are also connected, while the freewheel 37 is configured between the inner sun gear 30 and the drive shaft 18. The freewheel 35 forms an operative connection of the fixedly stationary part 48 to the part gear 28b, while the freewheel 36 forms an operative connection of the fixedly stationary part 48 to the planetary gear 29.

[0054] FIG. 2 shows a perspective view of the gear unit 1 having a drive, shown by a chain 24 that is guided over a chain pinion 43 and the chain pinion 43 is directly operatively connected to the drive shaft 18. The passage shaft 11 that can be fastened to the frame of a two-wheeled vehicle, in particular of a bicycle, by the hub screws 41 extends through the gear unit 1 so that the passage shaft 11 is rotationally rigidly and restingly arranged. In this respect, a fastening arm 40 that is likewise attached to the frame of the two-wheeled vehicle is located at the passage shaft 11 in a rigid arrangement to stabilize torques occurring in the gear unit 1.

[0055] The control of the gear unit 1 takes place via Bowden cables 39 that cooperate with a rotational activator 31 that is likewise rigidly connected to the passage shaft 11 and that is shown as a functional unit. The output of the gear unit 1 takes place via the casing 32 that has means 38 for receiving wheel spokes.

[0056] FIG. 3 shows an upper half-section of the gear unit 1 and the passage shaft 11 that extends in the center axis 10 and is rigidly arrangeable at the frame of the two-wheeled vehicle is in turn shown as a main component.

[0057] The drive shaft 18 that is designed as hollow and on which the chain pinion 43 for the rotary drive of the drive shaft 18 is received extends sectionally about the passage shaft 11. The roller element bearings 44 of the drive shaft 18 are received in a supporting manner on the passage shaft 11. At the inner side, the drive shaft 18 has, toward the outer circumference of the passage shaft 11, a radial gap in which the selector shafts 19 and 20 partially extend from a side disposed opposite the arrangement of the chain pinion 43. The switch element 15 and 16 are received in or at the drive shaft 18 so that the switch element 15 and 16 also rotate to this extent about the selector shafts 19 and 20 with the rotation of the drive shaft 18 about the passage shaft 11. The switch element 17 is received at the fixedly stationary part 48. The switch element 15 is shown in rotated form in the section for the purposes of the view and is actually located at an offset position on the circumference about the center axis 10, with all the switch element 15, 16, 17 each being present pairwise at oppositely disposed positions.

[0058] The first, inner planetary gear 12 and the outer, secondary planetary gear 13 with their individual components can be shifted by the switch element 15, 16, and 17. The planetary gears 12 and 13 are received within the casing 32 of the gear unit 1, with the casing 32 serving as the output of the gear unit 1 while the drive shaft 18 serves as the drive.

[0059] The switch unit 14 has a rotational activator 21 that is operatively connected to the selector shafts 19 and 20 and that can be activated by an operator to introduce a step-wise, staged rotational movement in discrete angular increments into the selector shaft 19, 20. The stepwise rotational movement in the selector shafts 19, 20 takes place here relative to the resting passage shaft 11 and is converted as described below into an axial movement along the center axis 10.

[0060] The selector shaft 19, 20 is in two parts and has a first selector shaft 19 and a second selector shaft 20, with the first and second selector shafts 19, 20 being configured rotationally rigidly but axially movably with respect to one another.

[0061] A first component of the planetary gear 12, 13 forms the annulus gear 28 of the outer, second planetary gear 13, with the annulus gear 28 being divided into a first part gear 28a and into a second part gear 28b. The first switch element 15 or a pair of first switch element 15 here interacts with the annulus gear 28, represented by the first part gear 28a, to connect it rotationally rigidly to the drive shaft 18 on engagement of the switch element 15. A further component of the planetary gear 12, 13 is represented by the planetary carrier 29 that is part of the inner, first planetary gear 12, with the second switch element 16 or a pair of second switch element 16 cooperating with the planetary gear 29 to rotationally rigidly connect it to the drive shaft 18 on engagement.

[0062] Finally, a further shiftable component of the planetary gears 12, 13 is represented by means of the sun gear 30 of the first, inner planetary gear 12, with the third switch element 17 cooperating with the sun gear 30 to rotationally rigidly connect it to a fixedly stationary part 48 of the gear unit 1 on engagement. The switch element 17 is to this extent not received at the drive shaft 18, but rather at a fixedly stationary part 48 that can also be formed in multiple members.

[0063] The casing 32 of the gear unit 1 is supported at the fixedly stationary part 48 and furthermore rotatably supported via the drive shaft 18 by means of roller element bearings 44, with the casing 32 serving as the drive element. For this purpose, the casing 32 is connected to the outer planetary carrier 33 of the second, outer planetary gear 13. The connection takes place by the axial gap between the part gears 28a and 28b of the annulus gear 28 so that one or more webs of the outer planetary carrier 33, distributed over the circumference, are connected at least indirectly, in particular via elastic coupling elements, in an arrangement between the circumferential positions of the outer planet gears 34.

[0064] The first shown freewheel 35 forms an operative connection between the annulus gear 28 of the second, outwardly disposed planetary gear 13 and the fixedly stationary part 48. The second shown freewheel 36 forms an operative connection between the planetary carrier 29 of the first, inwardly disposed planetary gear 12 and the fixedly stationary part 48, with a third freewheel 37 being provided that forms an operative connection between the sun gear 30 and the drive shaft 18.

[0065] If the gear unit 1 is switched to the neutral NO, all the switch element 15, 16, and 17 are retracted and are not in engagement with the components of the planetary gear 12, 13 in this position.

[0066] For a first speed N1, only the switch element 15 is extended and brought into engagement with the annulus gear 28, while the further switch element 16, 17 are not in engagement.

[0067] For the second speed N2, only the switch element 16 is extended and brought into engagement with the planetary carrier 29, while the switch element 15 and 17 remain retracted.

[0068] For the third speed N3, the switch element 15 and the switch element 17 are brought into engagement with the annulus gear 28 or with the sun gear 30.

[0069] For the fourth speed N4, the switch element 15 remains retracted, while the switch element 16 and 1 are moved into engagement with the planetary carrier 29 and/or the sun gear 30.

[0070] For the fifth speed N5, the switch element 15 and the switch element 16 are extended, while the switch element 17 remains retracted.

[0071] For the sixth speed N6, finally, all three switch element 15, 16, and 17 are extended and moved into engagement with the respective components of the planetary gears 12, 13.

[0072] FIG. 4 represents a perspective view of the switch unit 14 with the selector shafts 19 and 20 in an arrangement on the passage shaft 11, with the rotational activator 21 furthermore being shown with the Bowden cables 39.

[0073] The selector shaft 19 has a guide link 22 in which a guide element 24 is guided. The guide element 24 is rigidly arranged at the passage shaft 11 and migrates through it transversely to the center axis 10. The guide link 22 has a zig-zag contour so that a direction changing axial movement is introduced along the center axis 10 into the selector shaft 19 on a rotation of the selector shaft 19 by means of the rotational activator 21.

[0074] The selector shaft 20 is admittedly received rotationally rigidly, but axially movably with respect to the selector shaft 19 so that the rotational movement can likewise by introduced into the selector shaft 20 via the selector shaft 19 by means of the rotational activator 21. A guide link 23, in which a guide element 25 is likewise guided that is rigidly attached to the passage shaft 11, is also introduced in the selector shaft 20. The guide link 23 likewise has a zig-zag contour so that the selector shafts 19 and 20 can execute a mutually independent axial movement by the two guide links 22 and 23 depending on the rotational position of the selector shafts 19 and 20 that is set stepwise by the rotational activator 21. The selector shaft 19 can here cooperate with the switch element 16 and 17, while the selector shaft 20 can cooperate with the switch element 15.

[0075] FIG. 5 shows a further perspective view of the main components of the shift system 14, with the drive shaft 18 now being shown that is driven by the chain 42 in conjunction with the chain pinion 43. In this respect, the selector shaft 20 is arranged inwardly disposed in the drive shaft 18 and is covered by it so that only the selector shaft 19 is visible.

[0076] The switch element 15 and 16 that are each preloaded by tension springs 49 such that the switch element 15, 16 are extended and can engage into the component of the planetary gears 12, 13 are received in the drive shaft 18. The same applies to the switch element 17 that is likewise shown preloaded by a tension spring 49 and can cooperate with the shown selector shaft 19; however, the switch element 17 is not received at the drive shaft 18, but rather at the fixedly stationary part 48, not shown.

[0077] There are furthermore shown the guide link 22 in the selector shaft 19 with the guide element 24 at the passage shaft 11 and the selector shaft 19 can also be adjusted by the Bowden cables 39 in the axial position by means of the rotational activator 21 in the retracted position due to the action of the guide link 22.

[0078] FIG. 6 shows the selector shaft 20, that can be displaced along the center axis 10, in an individual representation in that it is rotatably arranged at the passage shaft 11 and in that the guide element 25 extends in the guide link 23 that Is of zig-zag form. A rotation of the selector shaft 20 about the center axis 10 consequently effects a to-and-fro displacement of the selector shaft 20 on the passage shaft 11 along the center axis 10.

[0079] The outer contour of the selector shaft 20 has a first section A1 and a second section A2, with the diameter of the first section A1 being smaller than the diameter of the second section A2. The sections A1, A2, shown by way of example, in the outer contour of the shown selector shaft 20 are likewise present in the further selector shaft 19 so that the respectively associated sections A1 and A2 of the switch element 15, 16, and optionally 17, on the selector shafts 19, 20 can cooperate. The following description of the action of the sections A1 and A2 here applies to all the sections that are associated with the respective switch element and are to this extent generally described in the following for the example of sections A1 and A2 of the selector shaft 20.

[0080] If a pickup 27, see FIG. 7, of the switch element 15, 16, 17 runs off on the first section A1, the switch element 15, 16, 17 is extended and engaged in a component of the planetary gears 12, 13, which is effected by the respective tension springs 49. If the selector shaft 20 and, in the same manner also the selector shaft 19, in a manner not shown, is axially displaced in that it is rotated about the passage shaft 11 by means of the rotational activator 21, the resulting axial displacement causes a change of the contact of the pickup 27 of the switch element 15, 16, 17 against the preload force of the tension springs 49 from the first section A1 to the second section A2.

[0081] The change can take place due to the circumferential movement of the pickup 27 along the ramp 26 so that the pickup 27 can migrate upward in a certain manner from the smaller diameter to the larger. Since the selector shaft 20 only defines the contour and the switch element 15, 16 revolve due to the rotation of the drive shaft 18 about the selector shaft 19 20, a disengagement of the engagement of the switch element 15, 16, and thus a release of the force flow from the component of the planetary gear 12, 13, also takes place without problem under load since the disengagement does not have to be initiated by means of rotational activator 21, and thus via the Bowden cables 39; the disengagement rather takes place by the drive force to drive the drive shaft 18 itself, that is therefore via the drive power. The contact of the switch element 15, 16, and also 17, with the respective associated sections A1 and A2 is held by the tension spring 49 here that is shown for each of the switch element 15, 16, 17 in FIG. 5.

[0082] The ramp 28 is formed as a ramp at the radial peripheral side and can release the pickup of the switch element from the contact with the section A1 of a smaller diameter and move into contact with the section A2 of a larger diameter when the switch element circles the selector shaft 20 so-to-say with the rotation of the drive shaft. If the drive shaft is stationary and if the pickup or the switch element adopts a fixed peripheral position, a change can nevertheless take place between the contact with the section A1 and the contact with the section A2 since the selector shaft 20 has an axial-radial ramp 26 that is formed beside and at the front side of the actual ramp 26 at the selector shaft 20. A gear change can consequently also take place while stationary. The axial-radial ramp 26 is here at least sectionally formed as a cone.

[0083] Looking at FIG. 7, a simple pivoting of the switch element 15, 16, 17 about the pivot axis 45 is sufficient to move the switch element 15, 16, 17 between the selected positions, with the blocking section 46 on the front side of the switch element 15, 16, 17 in particular being convexly contoured such that a simple disengagement from the latched position of the switch element 15, 16, 17 from the component of the planetary gear 12, 13 can take place simply and with minimal force.

[0084] FIG. 8 shows a sectioned view of the switch unit 14 with the drive shaft 18 with the adjoining rotational activator 21 in operative connection with the selector shaft 19. The switch element 16 are shown in a two-fold oppositely disposed arrangement, with the switch element 16 being received in the drive shaft 18 and running off over the first section A1 of the selector shaft 19. The switch element 15, not shown by the sectional view, is received in the drive shaft 18 in the same way and the switch element 17 in conjunction with the tension spring 49 is not in an arrangement in or at the drive shaft 18.

[0085] FIG. 8a finally shows a sun gear 30 of the first inner planetary gear 12 having inwardly disposed pinion pockets 47 in which the blocking sections 46 of the switch element 17 can engage.

[0086] The invention is not restricted in its design to the preferred embodiment specified above. A number of variants is rather conceivable that also makes use of the solution shown with generally differently designed embodiments. All the features and/or advantages, including any construction details or spatial arrangements, originating from the claims, the description, or the drawings can be essential to the invention both per se and in the most varied combinations.

REFERENCE NUMERAL LIST

[0087] 1 gear unit [0088] 10 center axis [0089] 11 passage shaft [0090] 12 planetary gear [0091] 13 planetary gear [0092] 14 shift system [0093] 15 switch element [0094] 16 switch element [0095] 17 switch element [0096] 18 drive shaft [0097] 19 selector shaft [0098] 20 selector shaft [0099] 21 rotational activator [0100] 22 guide link [0101] 23 guide link [0102] 24 guide element [0103] 25 guide element [0104] 26 ramp [0105] 26 ramp [0106] 27 pickup [0107] 28 annulus gear [0108] 28a first part gear [0109] 28b second part gear [0110] 29 planetary carrier [0111] 30 sun gear [0112] 31 annulus sun gear [0113] 32 casing [0114] 33 outer planetary carrier [0115] 34 outer planet gear [0116] 35 first freewheel [0117] 36 second freewheel [0118] 37 third freewheel [0119] 38 means for receiving wheel spokes [0120] 39 Bowden cable [0121] 40 fastening arm [0122] 41 hub screw [0123] 42 chain [0124] 43 chain pinion [0125] 44 roller element bearing [0126] 45 pivot axis [0127] 46 blocking section [0128] 47 pinion pocket [0129] 48 fixedly stationary part [0130] 49 tension spring [0131] A1 first section [0132] A2 second section