DRIVE ASSEMBLY

Abstract

A drive assembly of a vehicle which can be operated by means of muscle power and/or motor power. The drive assembly includes: a drive unit, a frame interface, wherein the drive unit is disposed at least partially between a first wall and a second wall of the frame interface, wherein the drive unit comprises a through-bore, two sleeves which are inserted into the through-bore of the drive unit on both sides, and a through-bolt which is inserted through the through-bore and the two sleeves and holds the drive unit on each of the two walls. The through-bolt braces the two walls against one another.

Claims

1. A drive assembly of a vehicle which can be operated by means of muscle power and/or motor power, the drive assembly comprising: a drive unit; a frame interface, wherein the drive unit is disposed at least partially between a first wall (31) and a second wall of the frame interface, and the drive unit includes a through-bore; two sleeves which are inserted into the through-bore of the drive unit on both sides; and a through-bolt which is inserted through the through-bore and the two sleeves and holds the drive unit on each of the first and second walls, wherein the through-bolt braces the first and second walls against one another.

2. The drive assembly according to claim 1, wherein each sleeve of the two sleeves includes a shank and a flange, wherein the shank is disposed inside the through-bore, and the flange is disposed outside the through-bore.

3. The drive assembly according to claim 2, wherein each sleeve of the two sleeves includes a damping element which is disposed on a side of the flange of the sleeve facing the drive unit, and wherein the damping element is made of a vibration-damping material.

4. The drive assembly according to claim 3, wherein the damping element at least partially surrounds the shank.

5. The drive assembly according to claim 1, wherein the two sleeves are configured such that, when they are fully inserted into the through-bore and not braced, there is a predefined axial spacing between the two sleeves inside the through-bore.

6. The drive assembly according to claim 5, wherein the predefined axial spacing is configured such that, in a braced state, the axial spacing is compensated by the bracing by the through-bolt and by elastic deformation of the damping element.

7. The drive assembly according to claim 1, wherein the two sleeves touch inside the through-bore, and wherein the two sleeves are configured such that the two sleeves are clamped between the first and second walls by a screw connection via the through-bolt.

8. The drive assembly according to claim 7, wherein the two sleeves and the drive unit are configured such that the drive unit is held between the first and second walls without tension.

9. The drive assembly according to claim 7, wherein the first wall includes a predetermined bending point.

10. The drive assembly according to claim 2, wherein the shank of each sleeve of the two sleeves includes a pressing region, and a press fit is formed between the pressing region and the through-bore.

11. The drive assembly according to claim 10, wherein the pressing region is disposed adjacent to the flange of each sleeve of the two sleeves, and the shank of each sleeve of each of the two sleeves further includes a tapering region which has a smaller outer diameter than the pressing region of the sleeve.

12. The drive assembly according to claim 1, wherein the through-bore includes a centering region in a center, which has a smaller inner diameter than the rest of the through-bore, for centering the two sleeves.

13. The drive assembly according to claim 1, wherein the through-bolt is a screw, and wherein the through-bolt is screwed into an internal thread of the second wall.

14. The drive assembly according to claim 1, wherein the through-bolt is a screw, and the through-bolt is screwed into a nut disposed on the second wall.

15. The drive assembly according to claim 14, wherein the nut is disposed in a non-rotatable manner in a recess of the second wall.

16. The drive assembly according to claim 2, wherein the shank of each sleeve of the two sleeves is inserted into the through-opening of the drive unit, wherein the flange of each sleeve includes a plurality of projecting form-fit elements on a side facing a respective wall of the first and second walls, and wherein the form-fit elements are configured to press into the respective wall as a result of screwing to the respective wall.

17. The drive assembly according to claim 16, wherein each form-fit element of the form fit elements includes a pyramid or a cone, which projects from a surface of the flange of each sleeve of the two sleeves.

18. The drive assembly according to claim 17, wherein each form-fit element of the form fit elements includes a recess in the surface of the flange adjacent to the pyramid.

19. The drive assembly according to claim 1, wherein at least one sleeve of the two sleeves includes a shank and a flange, wherein the flange includes a taper at a radially outer end and on a side facing the shank, and wherein the taper is compensated by the damping element.

20. The drive assembly according to claim 19, wherein the drive unit includes at least one projecting annular rib which is disposed concentrically to one of the through-opening, wherein the projecting annular rib and the taper of the flange of the at least one sleeve are disposed on a same radius with respect to a bore axis of the through-bore.

21. The drive assembly according to claim 2, wherein: (i) the flange of at least one sleeve of the two sleeves has a thickness that corresponds substantially to a wall thickness of the shank of the at least one sleeve, or (ii) the flange of at least one sleeve of the two sleeves has a thickness that corresponds to at least 1.5 times a wall thickness of the shank the at least one sleeve.

22. A vehicle which can be operated by means of muscle power and/or motor power, the vehicle being an electric bicycle, the vehicle comprising: a drive assembly including: a drive unit, a frame interface, wherein the drive unit is disposed at least partially between a first wall (31) and a second wall of the frame interface, and the drive unit includes a through-bore, two sleeves which are inserted into the through-bore of the drive unit on both sides, and a through-bolt which is inserted through the through-bore and the two sleeves and holds the drive unit on each of the first and second walls, wherein the through-bolt braces the first and second walls against one another.

23. The vehicle according to claim 22, further comprising: a chainring which is connected to an output shaft of the drive unit, and wherein the second wall of the drive assembly is disposed on a side of the chainring.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0033] The present invention will be described in the following with reference to embodiment examples in conjunction with the figures.

[0034] In the figures, functionally equivalent components are identified with the same respective reference signs.

[0035] FIG. 1 shows a simplified schematic view of a vehicle comprising a drive assembly according to a first embodiment example of the present invention.

[0036] FIG. 2 shows a sectional view of the drive assembly of FIG. 1 fully screwed together.

[0037] FIG. 3 shows a sectional view of a drive assembly according to a second embodiment example of the present invention not screwed together.

[0038] FIG. 4 shows a sectional view of the drive assembly of FIG. 3 partially screwed together.

[0039] FIG. 5 shows a sectional view of the drive assembly of FIGS. 3 and 4 fully screwed together.

[0040] FIG. 6 shows a sectional view of a drive assembly according to a third embodiment example of the present invention fully screwed together.

[0041] FIG. 7 shows a detail of a drive assembly according to a fourth embodiment example of the present invention.

[0042] FIG. 8 shows a detail sectional view of FIG. 7.

[0043] FIG. 9 shows a detail sectional view of a drive assembly according to a fifth embodiment example of the present invention.

[0044] FIG. 10 shows a further detail sectional view of the drive assembly of FIG. 9.

[0045] FIG. 11 shows a sectional view of a drive assembly according to a sixth embodiment example of the present invention.

[0046] FIG. 12 shows a sectional view of a drive assembly according to a seventh embodiment example of the present invention.

DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS

[0047] FIG. 1 shows a simplified schematic view of a vehicle 100 which can be operated by means of muscle power and/or motor power and comprises a drive assembly 1 according to a first embodiment example of the present invention. The vehicle 100 is an electric bicycle. The drive assembly 1 is disposed in the region of a bottom bracket and comprises a drive unit 2. The drive unit 2 comprises an electric motor and a transmission, and is provided to support the rider's pedal force generated by muscle power by means of a torque generated by the electric motor. The drive unit 2 is supplied with electrical power by an electrical energy store 109.

[0048] The drive assembly 1 of the first embodiment example is shown in a sectional view in FIG. 2. The drive assembly 1 comprises a U-shaped frame interface 3, inside which the drive unit 2 is partly accommodated. The frame interface 3 is an integral part of a vehicle frame 105 of the vehicle 100 (see FIG. 1). The frame interface 3 comprises a first wall 31 and a second wall 32, between which the drive unit 2 is disposed. The first wall 31 and the second wall 32 are connected to one another via a connecting wall 33 and are thus configured as a one-piece component.

[0049] The drive unit 2 is fastened to the frame interface 3 by means of a through-bolt connection, as described in further detail below.

[0050] In detail, the drive unit 2 comprises a through-bore 20 that passes all the way through the drive unit 2 in transverse direction. The through-bore 20 is in particular configured in a housing, which is preferably made of aluminum or magnesium, of the drive unit 2. The housing of the drive unit 2 can be configured in two parts, wherein a housing seal 2c disposed between the two housing halves 2a, 2b.

[0051] Two sleeves 41, 42 are inserted into the through-bore 20. The two sleeves 41, 42 are each inserted into the through-bore 20 from a respective side, i.e. at an axial end of the through-bore 20. The sleeves 41, 42 are preferably made of aluminum or steel.

[0052] Each sleeve 41, 42 comprises a shank 43, which is substantially hollow cylindrical and is inserted into the through-bore 20, and a flange 44. The flange 44 is disposed outside the through-bore 20 and has a larger outer diameter than the shank 43.

[0053] The shank 43 comprises a pressing region 43a, which is disposed directly adjacent to the flange 44. Adjacent to the pressing region 43a, there is also a tapering region 43b on the shank 43. The pressing region 43a is configured such that a press fit, i.e. an interference fit, is configured between the pressing region 43a and the through-bore 20. The tapering region 43b has a smaller outer diameter than the pressing region 43a, so that the sleeves 41, 42 can easily be inserted into the through-bore 20.

[0054] A tapering region 20a, in which an inner diameter of the through-opening 20 is tapered, is configured in the center of the through-bore 20. A clearance fit is preferably configured between the tapering region 20a and the tapering regions 43b of the sleeves 41, 42. The tapering region 20a consequently brings about a centering of the tapering regions 43b and thus a particularly precise arrangement of the sleeves 41, 42.

[0055] The two sleeves 41, 42 are preferably configured identically for simple and cost-efficient production.

[0056] The axial lengths of the sleeves 41, 42, in particular of the respective shank 43, are designed such that the sleeves 41, 42 touch inside the through-bore 20 when they are inserted. The axial lengths of the shanks 43 are configured such that only one of the flanges 44 of the two sleeves 41, 42 can rest against the drive unit 2, in which case there is a gap 41m between the other flange 44 and the drive unit 2. For this purpose, an axial length of each shank 43 is preferably slightly more than half the axial length of the through-bore 20.

[0057] The sleeves 41, 42 are pressed into the through-bore 20 such that the flange 44 of the second sleeve 42 rests against the drive unit 2 on the side of the second wall 32 and the gap 41m is present between the flange 44 of the first sleeve 41 on the side of the first wall 31 when the two sleeves 41, 42 touch inside the through-bore 20.

[0058] The drive assembly 1 also comprises a through-bolt 5, which is inserted through the through-bore 20 and the two sleeves 41, 42. The through-bolt 5 is configured as a screw and comprises a bolt head 53 at one axial end and an external thread 54 at the other axial end, wherein the external thread 54 extends only over a portion of the through-bolt 5.

[0059] The through-bolt 5 is screwed into an internal thread 32a of the second wall 32 by means of the external thread 54. The internal thread 32a is configured directly in a through-opening of the second wall 32. The bolt head 53 is located on the side of the first wall 31, and in particular rests against an outer side of the first wall 31.

[0060] A clearance fit is preferably configured between the through-bolt 5 and an inner through-opening of the sleeves 41, 42 to enable simple insertion. In the center, the through-bolt 5 preferably comprises a tapering of its outer diameter in order to enable particularly smooth insertion. A seal, for example an O-ring seal 56, is preferably disposed between the through-bolt 5 and the sleeve 41 and 42 in the regions of the clearance fit, in order to prevent fluid ingress into the interior of the sleeves 41, 42 and into the interior of the through-bore 20.

[0061] The through-bolt 5 is screwed in such that it braces the two walls 31, 32 against one another in the axial direction of the through-bolt 5. The first wall 31 comprises a predetermined bending point 31b, which causes the first wall 31 to be bent in the direction of the second wall 32 as a result of the bracing by means of the through-bolt 5. The second wall 32 is preferably designed to in particular be rigid, so that it does not deform. Since the drive unit 2 with the sleeves 41, 42 projecting from the through-opening 20 is disposed between the two walls 31, 32, the deformation of the first wall 31 is limited by the two sleeves 41, 42. The two sleeves 41, 42 are thus braced against one another in axial direction by the through-bolt 5. The gap 41m between the flange 44 of the first sleeve 31 and the drive unit 2 ensures that this bracing does not lead to any clamping, i.e. no compressive loading, of the drive unit 2 in axial direction between the two walls 31, 32. In other words, the two sleeves 41, 42 provide a neutral installation state with no tensile or compressive loading of the drive unit 2.

[0062] The special through-bolt connection of the drive assembly 1 provides numerous advantages. For example, the use of the through-bolt 5 and the bracing of the two walls 31, 32 with said through-bolt allows a particularly robust fastening of the drive unit 2. A screw connection can in particular take place with high torque. Absorbing the compressive forces by means of the sleeves 41, 42 makes it possible to prevent impermissibly high mechanical loading of the drive unit 2 in a particularly reliable manner. A tolerance position of the drive assembly 1 can furthermore be set in a defined manner simply and cost-efficiently, for example by adapting the sleeves 41, 42. The through-bolt connection also allows a particularly simple assembly of the drive assembly 1, because the through-bolt 5 can only be inserted, and the through-bolt 5 can only be worked to screw it in, from one side, namely from the side of the first wall 31. This is particularly advantageous in the case of limited accessibility on the side of the second wall 32, for example if there is a chainring 106 (see FIG. 1) on this side.

[0063] FIG. 3 shows a sectional view of a drive assembly 1 according to a second embodiment example of the present invention. The drive assembly 1 is only partially assembled in FIG. 3 and is shown not screwed together. In FIG. 4, the drive assembly 1 of the second embodiment example is shown fully assembled and partially screwed together. In FIG. 5, the drive assembly 1 of the second embodiment example is shown fully screwed together. The second embodiment example substantially corresponds to the first embodiment example of FIG. 2, with the difference being an alternative configuration of the sleeves 41, 42.

[0064] In the second embodiment example, each sleeve 41, 42 additionally comprises a damping element 45, which is made of an elastic and vibration-damping material. The damping element 45 is in particular made of an elastomer. In detail, a respective radially outer outer side of the shank 43, the flange 44, and the side of the flange 44 that faces the drive unit 2, is covered or coated with the damping element 45. The damping element 45 is thus preferably configured as an overmolding of the sleeve 41, 42.

[0065] In the second embodiment example, the axial lengths of the shanks 43 of the sleeves 41, 42 are furthermore configured differently from those in the first embodiment example. In detail, they are configured such that, when fully inserted into the through-opening 20 (see FIG. 3), there is a predefined axial spacing 27, i.e. a gap, between the two sleeves 41, 42 inside the through-opening 20. A state is considered, in which the two sleeves 41, 42 are not braced, but the damping element 45 rests against the drive unit 2 in the region of each flange 44 of each sleeve 41, 42. The axial lengths of the two shanks 43 are in particular less than half the axial length of the through-opening 20 by a predetermined difference, wherein the predetermined difference is less than twice the thickness of one of the damping elements 45 in the region of the flange 44.

[0066] In the not braced state shown in FIG. 3, there is a predefined gap 28 between the first wall 31 and the first sleeve 41.

[0067] This special coordination of the lengths of the two sleeves 41, 42 and the through-bore 20 ensures that the respective part of the damping element 45 of each sleeve 41, 42 positioned between the flange 44 and the drive unit 2 is partially compressed or clamped between the flange 44 and the drive unit 2 by the bracing by means of the through-bolt 5 and thus elastically deformed. This is illustrated by FIGS. 4 and 5. FIG. 4 shows a state in which the through-bolt 5 is tightened to such an extent that the first wall 31 just rests against the flange 44 of the first sleeve 41. Further tightening of the through-bolt 5 results in further bracing, such that the elastic damping element 45 deforms and the axial spacing 27 between the two sleeves 41, 42 is compensated, that is until the sleeves 41, 42 touch inside the through-opening 20. This state is shown in FIG. 5. The damping elements 45 can thereby partially be pushed radially outward by the bracing.

[0068] The damping elements 45 and the corresponding design of the sleeves 41, 42 with an axial spacing 27 in the not braced state result in a slight compressive load being applied to the drive unit 2 in the braced state. This can have an advantageous effect on a tightness of the drive unit 2 itself. The elastic deformation of the damping elements 45 moreover enables a particularly reliable seal between the sleeves 41, 42 and the drive unit 2.

[0069] In addition to the advantageous accessibility and simplified assembly of the drive assembly 1, the special screw connection of the drive unit 2 to the frame interface 3 also provides the advantage of a direct transmission of force between the output shaft 108 and the frame interface 3. The output shaft 108 is connected to the chainring 106 (see FIG. 1) in a rotationally fixed manner. The output shaft 108 can be driven on the one hand by the muscle power of the rider and on the other by the motor power of the drive unit 2. The chainring 106 is always located on the side of the second wall 32. The higher mechanical forces on the chainring side can be absorbed particularly well by the direct and robust connection of the drive unit 2 to the second wall 32. This also ensures a defined position of the chainring 106 in relation to an axial direction of the output shaft 108 and relative to the frame interface 3, which provides the advantage of a reliably precisely disposed chain line.

[0070] Connecting the drive unit 2 and the frame interface 3 via the damping elements 45 moreover provides the advantage of a vibration-decoupled mounting of the drive unit 2 on the vehicle 100. In addition to preventing or reducing a transmission of acoustic vibrations, which has an advantageous effect on noise reduction during operation of the vehicle 100, a transmission of mechanical vibrations is reduced or prevented as well. A damaging effect of such vibrations on the screw connection can thus be prevented or reduced. This means that loosening or unscrewing of the screw connection can be prevented or reduced. The elasticity of the damping element 45 itself can moreover provide a certain tolerance compensation, for example with respect to a coaxiality of the bores or openings or the like.

[0071] FIG. 6 shows a sectional view of a drive assembly 1 according to a third embodiment example of the present invention. The third embodiment example substantially corresponds to the second embodiment example of FIGS. 3 to 5, with the difference that the damping element 45 is disposed only on the flange 44 of the respective sleeve 41, 42. In other words, in each case, the damping element 45 is disc-shaped and is disposed only between the side of the flange 44 facing the drive unit 2 and the drive unit 2. The third embodiment example can in particular be regarded as a combination of the first embodiment example and the second embodiment example.

[0072] FIG. 7 shows a detail of a drive assembly 1 according to a fourth embodiment example of the present invention. The fourth embodiment example substantially corresponds to the first embodiment example of FIGS. 1 to 2, with the difference being alternative sleeves 41, 42.

[0073] Only one of the two sleeves 41, 42 is shown in FIG. 7, wherein the two sleeves 41, 42 are preferably configured identically. This sleeve 41 is shown in FIG. 8 in a perspective view.

[0074] The sleeve 41 comprises a shank 43 and a flange 44. The shank 43 is inserted into the through-opening 20 of the drive unit 2. The flange 44 is provided to rest against an inner side of the respective wall 31, 32 of the frame interface 3 (see e.g. FIG. 2). On the side assigned to the wall 31, 32, the flange 44 of the sleeve 41 comprises a plurality of projecting form-fit elements 41c. The form-fit elements 41c are preferably disposed in one or more, preferably two as in FIG. 7, circles that are concentric to the through-opening of the sleeve 41.

[0075] A single form-fit element 41c of the sleeve 41 of FIG. 7 is shown in a detail sectional view in FIG. 8. Each form-fit element 41c comprises a pyramid 41d which projects from a surface 41f of the flange 44. Alternatively preferably, each form-fit element 41c can also comprise a projecting cone. The pyramid 41d is configured as a straight pyramid and has an opening angle 41k of preferably less than 60°.

[0076] The pyramids 41d have the effect that they press into the surface of the wall 31, 32, i.e. plastically deform said wall, when the sleeve 41 is screwed to the wall 31, 32. This creates a micro form fit between the sleeve 41 and the wall 31, 32 in a plane perpendicular to the screw axis, as a result of which a particularly firm connection of the drive unit 2 and the frame interface 3 to one another can be made possible. Slipping of the drive unit 2 relative to the frame interface 3 can thus reliably be prevented.

[0077] In addition to the pyramid 41d, each form-fit element 41c comprises a respective recess 41e, which is configured on an outer perimeter of the pyramid 41d and in the surface 41f of the flange 44. The recess 41e can accommodate material of the wall 31, 32 displaced by the penetration of the pyramid 41d into the wall 31, 32, for example, so that the wall 31, 32 and the flange 44 can reliably precisely rest flat on top of one another. One recess 41e can be provided for each pyramid 41d, for example, which partly or entirely surrounds the pyramid 41d. Alternatively preferably, a single recess 41e can be configured in the surface 41f of the flange 44, on the radial inner side and/or outer side of which the pyramids 41d are disposed FIG. 9 shows a detail sectional view of a drive assembly 1 according to a fifth embodiment example of the present invention. FIG. 9 shows only one of the damping sleeves, namely the sleeve 42 on the side of the second wall 32. The first sleeve 41 on the first wall 31 is preferably configured identically. The fifth embodiment example substantially corresponds to the second embodiment example of FIGS. 3 to 5, with the difference being an alternative configuration of the sleeve 42 in the region of the flange 44. The sleeve 42 at a radially outer end of the flange 44 comprises a taper 41g on the side of the flange 44 facing the shank 43. The taper 41g is configured such that a difference between the maximum thickness 41h and a minimum thickness 41i of the flange 44 corresponds to at least 50%, preferably at most 150%, of a wall thickness 43h of the shank 43 of the sleeve 42. The thicknesses along a direction parallel to a longitudinal axis of the sleeve 42 are considered.

[0078] The damping element 45 is configured such that it compensates the taper 41g of the flange 44. The damping element 45 further comprises a thickening 42g at a radially outermost Ende. There is therefore a particularly thick damping element 42 at the radially outer end of the flange 44. This has an advantageous effect on an optimal seal between the sleeve 42 and the drive unit 2.

[0079] This seal is further supported by a projecting annular rib 2g of the drive unit 2, which is provided in the fifth embodiment example as shown in FIG. 10. The projecting annular rib 2g has a trapezoidal cross-section and is disposed concentrically to the through-opening 20 of the drive unit 2. When the sleeve 42 is pressed into the through-opening 20, the projecting annular rib 2g and the taper 41g of the sleeve 42 are disposed on the same radius with respect to the opening axis 20g of the through-opening 20. As a result, the projecting annular rib 2g plunges into the soft zone of the damping element 45 in the region of the taper 41g when the sleeve 42 and the drive unit 2 are pressed against one another when fully screwed together. The elasticity of the damping element 45 thus enables optimal sealing at the drive unit 2.

[0080] FIG. 11 shows a sectional view of a drive assembly 1 according to a sixth embodiment example of the present invention. The sixth embodiment example substantially corresponds to the first embodiment example of FIGS. 1 to 2, with the difference that the drive unit 2 is indirectly screwed to the frame interface 3.

[0081] In detail, the two walls 31, 32 to which the drive unit 2 is screwed here are configured as separate components to the frame interface 3. The walls 31, 32 can be configured as retaining plates, for example. The walls 31, 32 can be connected to frame walls 31e, 32e by means of (not depicted) additional screw connections and/or weld connections. A particularly high degree of flexibility of the drive assembly 1 can thus be provided.

[0082] FIG. 12 shows a sectional view of a drive assembly 1 according to a seventh embodiment example of the present invention. The seventh embodiment example substantially corresponds to the fifth embodiment example of FIGS. 9 and 10, with the difference that alternative sleeves 41, 42 are used. In detail, the flanges 44 of the sleeves 41, 42 are thicker in the seventh embodiment example of FIG. 15 than in the fifth embodiment example. In detail, the thickness 41h of the flanges 44 in the seventh embodiment example is a multiple, preferably at least three times, a wall thickness 43h of the corresponding shank 43 of the respective sleeve 41, 42. As a result, an overall width 1h of the drive assembly 1 can be larger compared to the fifth embodiment example, in which the thickness 41h of the flange 44 is approximately equal to the wall thickness 43h of the shank 43, for example. The seventh embodiment example of FIG. 12 thus illustrates that, by modifying the sleeves 41, 42, the drive assembly 1 can be adapted to different vehicles 100 in a particularly simple and cost-efficient manner.