drive unit of an electric bicycle

Abstract

The present invention relates to a drive unit of an electric bicycle, comprising a bearing receptacle which is designed to hold a bearing, wherein the bearing receptacle is designed to be attached directly to a frame interface of the electric bicycle by means of at least one fixing element.

Description

State of the art

[0001] The present invention relates to a drive unit of an electric bicycle, a drive arrangement of an electric bicycle, and an electric bicycle.

[0002] Electric bicycle drive units are known to be attached to a frame interface of the e-bike. Often, the housing of the drive unit is screwed to a wall of the frame interface. Disclosure of the invention

[0003] In contrast, the drive unit according to the invention with the features of claim 1 is characterized by the fact that, with a simple, cost-effective and lightweight construction, a particularly easy-to-manufacture and robust attachment of the drive unit to a frame interface is possible. This is achieved according to the invention by a drive unit of an electric bicycle comprising a bearing receptacle which is designed to hold a bearing, such as a bottom bracket, of the drive unit. The bearing receptacle is designed for attachment directly to a frame interface of the electric bicycle by means of at least one fixing element such that the at least one fixing element can be fixed in a recess of the bearing receptacle.

[0004] A bearing housing can be considered, in particular, a component that is designed to hold the bearing in a defined position within the drive unit.

[0005] For example, the bearing mount can be designed to hold the bearing relative to a housing of the drive unit. Preferably, the bearing mount can be rigidly attached directly to the housing of the drive unit.

[0006] The bearing housing is designed to be attached directly to the frame interface of the e-bike by means of at least one fixing element, such that the at least one fixing element can be fixed in the recess of the bearing housing. Direct attachment is defined in particular as an attachment in which the fixing element, especially on its own without any additional components, secures the frame interface and the bearing housing relative to each other. Specifically, the fixing element can be directly attached to both the bearing housing and the frame interface. For example, a section of the drive unit housing can also be positioned between the bearing housing and the frame interface.

[0007] Preferably, the bearing receptacle is designed such that the fixing element can be fixed directly to the bearing receptacle by means of a force-fit and / or form-fit and / or material-fit connection.

[0008] In particular, the drive unit, at least in the area of ​​the bearing mount, i.e. on the side of the bearing mount, is designed to be attached exclusively via the bearing mount at the frame interface.

[0009] In other words, a drive unit is provided which can be attached to a frame interface of the e-bike by means of a bearing mount that can be directly attached to the frame interface using at least one fixing element. This means that the drive unit is not attached to the frame interface via a housing or other components, but directly via the bearing mount. This is made possible by a recess in the bearing mount, which interacts with the at least one fixing element to secure the drive unit to the frame interface. In one embodiment of the invention, the fixing element is designed as a fastening screw and the recess in the bearing mount as a threaded bore. To attach the drive unit to the frame interface, the fastening screw is screwed into the threaded bore of the bearing mount.

[0010] The drive unit offers the advantage that a particularly robust mounting of the drive unit to a frame interface can be achieved with just a few simple components. This results in the particular benefit that the power flow of a rider's pedaling force can be transferred from the crank axle, through the bearing, into the bearing bridge, and then directly to the frame interface of the e-bike. This allows for a very rigid connection of the bearing and crank axle to the bicycle frame. Furthermore, this design eliminates the need for the drive unit housing to be in the power flow, meaning it does not have to transmit any holding force. Consequently, the housing can be designed to be lighter and more cost-effective.

[0011] The dependent claims contain preferred further developments of the invention.

[0012] Preferably, the drive unit comprises a housing. The bearing receptacle is arranged within the housing. Preferably, the housing includes a through-opening for each fixing element, through which the fixing element can protrude. In particular, at least a portion of the housing can be arranged between the frame interface and the bearing receptacle when the drive unit is attached to the frame interface. This allows for effective protection of components inside the drive unit while maintaining a robust and simple design.

[0013] Preferably, the bearing receptacle has a recess for each fixing element. The fixing element can be secured in the bearing receptacle by means of this recess. That is, the fixing element can be positioned at least partially within the recess to secure the bearing receptacle and the fixing element to each other. This allows for a particularly simple and robust design.

[0014] Preferably, each recess has a thread. In particular, the fixing element can thus be screwed into the thread of the bearing housing recess. This allows the bearing housing to be screwed directly to the frame interface using the at least one fixing element. This enables a particularly robust fastening of the drive unit to the frame interface with simple and time-efficient assembly.

[0015] Preferably, the bearing receptacle is plate-shaped and extends in a plane orthogonal to the drive unit's crank axle. In particular, the bearing, which can be held in the receptacle, allows for the rotatable mounting of a crank axle relative to the receptacle, which can extend along the crank axle. Specifically, the bearing receptacle is designed such that it can be fastened by means of at least one fixing element along a fixing axis that is arranged parallel to the crank axle. This allows for a particularly robust fastening of the bearing receptacle, and thus also of the bottom bracket, relative to the frame interface, while maintaining a simple and space-saving drive unit geometry.

[0016] The drive unit preferably further comprises a driven element, which is preferably rotatably connected to an output shaft of the drive unit. For example, the driven element can comprise a chainring by means of which a bicycle chain of the e-bike can be driven. The bearing is located on a side of the drive unit facing the driven element. In other words, the drive unit is mounted on the side of the driven element. This allows for a particularly direct transfer of the forces occurring on the side of the driven element into the bearing and into the frame interface. Thus, a particularly robust design and mounting of the drive unit can be provided with only a few components.

[0017] Preferably, the drive unit comprises at least two, and more preferably three, fixing elements, each of which allows the bearing mount to be attached directly to the frame interface. In particular, all fixing elements are essentially identical. Preferably, each fixing element is designed as a bolt, preferably with a thread. This means that the drive unit can preferably be screwed to the frame interface by means of at least two fixing elements. Particularly preferably, the respective fixing axes of all fixing elements are arranged parallel to each other. This allows for time-efficient and simple assembly of the drive unit, enabling a particularly robust fastening.

[0018] The drive unit preferably further comprises a bearing force sensor arranged on the bearing housing. In particular, the bearing force sensor is configured to detect a bearing force acting on the bearing. For example, the bearing force sensor can comprise a strain gauge and / or a piezoelectric element. For example, the bearing housing can comprise one or more sections designed as bending beams that deform, in particular, due to bearing forces. In particular, the bearing force sensor can be configured to detect these deformations and determine the bearing force based on them. Preferably, the bearing force sensor has at least one sensor element arranged on a radially outer side of the bearing housing.By directly attaching the bearing mount to the frame interface using at least one fixing element, particularly precise and reliable measurement of the bearing forces is possible. In particular, the direct mechanical support of the bearing mount at the frame interface reduces or prevents the influence of other forces and / or deformations on certain areas of the drive unit.

[0019] Furthermore, the invention leads to a drive arrangement comprising the described drive unit and a frame interface. The drive unit is attached to the frame interface by means of at least one fixing element directly securing the bearing mount of the drive unit to the frame interface. Preferably, the drive unit is secured by means of at least two, preferably three, fixing elements.

[0020] Preferably, the frame interface has at least one first wall. The drive unit is attached to this first wall by means of a fixing element. In particular, the first wall can be considered an integral part of the e-bike frame. Specifically, the drive unit is fixed by means of the at least one fixing element such that the bearing mount is directly screwed to the first wall. For example, the first wall can include a through-hole for each fixing element, through which the fixing element projects and is screwed into the recess with the thread of the bearing mount. This enables a particularly simple, cost-effective, and robust attachment of the drive unit to the frame interface.

[0021] Preferably, the bearing housing and the first wall are arranged essentially parallel to each other. In particular, the at least one fixing element is arranged essentially orthogonally to the bearing housing and the first wall. Most preferably, the bearing housing and the first wall are exactly parallel to each other. This allows for a robust and simple construction with few components, as well as particularly simple and time-efficient assembly of the drive assembly.

[0022] The frame interface preferably has a second wall, with the drive unit being at least partially arranged between the first and second walls of the frame interface. The second wall is preferably an integral part of the e-bike frame. In particular, the first and second walls of the frame interface can be formed together as a single, integral component. The drive unit is preferably screwed to the first wall in such a way that it rests directly against the first wall. Tolerance compensation, i.e., for example, bridging a gap, can be achieved on the side of the second wall, for example, by means of a tolerance compensation element such as a spacer.

[0023] Preferably, the drive assembly further comprises a fastening element by means of which the drive unit is attached to the second wall. That is, in addition to being attached to the first wall via the bearing mount, the drive unit is also attached to the second wall by means of the fastening element. Preferably, the fastening element can be attached to a housing of the drive unit. This allows for a particularly reliable and robust mounting of the drive unit at the frame interface on both sides.

[0024] Furthermore, the invention relates to an electric bicycle comprising the described drive unit or the described drive arrangement. Brief description of the drawings

[0025] An embodiment of the invention is described in detail below with reference to the accompanying drawings. The drawing shows: Fig. 1 a simplified schematic view of an electric bicycle with a drive unit according to a preferred embodiment of the invention, Fig. 2 a perspective detail view of the drive unit of the Fig. 1, Fig. 3 a sectional view of a detail of the drive unit of the Fig. 1, Fig. 4 a perspective detail view of the drive unit of the Fig. 1, and Fig. 5 another perspective detail view of the drive unit of the Fig. 1. Preferred embodiments of the invention

[0026] Preferably, all identical components, elements and / or units in all figures are provided with the same reference numerals.

[0027] Fig. Figure 1 shows a simplified schematic view of an electric bicycle 100 with a drive unit 5 according to a preferred embodiment of the invention. Details of the drive unit 5 of the preferred embodiment are shown in the Fig. 2, Fig. 3, Fig. 4 to Fig. 5 shown.

[0028] The drive unit 5 is arranged in the area of ​​a pedal axle 15 of the electric bicycle 100. The drive unit 5 is part of a drive arrangement 10, which, in addition to the drive unit 5, includes a frame interface 1 of the electric bicycle 100 and several fixing elements 4.

[0029] The drive unit 5 comprises a motor and a gearbox. Motor torque generated by the motor can be transmitted via the gearbox to an output shaft 103, which can be connected to cranks 104 in a rotationally fixed manner, to provide motor assistance to the rider's pedaling force. The motor is preferably an electric motor, which can be supplied with electrical energy by means of an electrical energy storage device 109 of the electric bicycle 100.

[0030] The frame interface 1 is an integral part of a bicycle frame 105 of the electric bicycle 100. The frame interface 1 has two walls 26, 27, which are arranged in particular parallel to each other and essentially orthogonal to the pedal axle 15 of the output shaft 103 (cf. Fig. 2).

[0031] The two walls 26, 27 are preferably formed together as a single, one-piece component by means of a connecting wall, which is essentially U-shaped in cross-section. The drive unit 5, when mounted at the frame interface 1, is at least partially arranged between the first wall 26 and the second wall 27, i.e., it is partially enclosed by the frame interface 1.

[0032] Alternatively, preferably, the frame interface 1 can also comprise only a single wall, namely the first wall 26.

[0033] Furthermore, the drive unit 5 includes a bearing receptacle 51, which is designed to hold a bearing 50, which can in particular be a bottom bracket of the electric bicycle 100.

[0034] The drive unit 5 is attached to the frame interface 1 of the electric bicycle 100 by means of the bearing mount 51 being directly fixed to the first wall 26 of the frame interface 1 by means of the fixing elements 4, as described in detail below.

[0035] In the illustrated embodiment, the drive arrangement 10 comprises three fixing elements 4. The fixing elements 4 are identical and each is designed as a screw.

[0036] The bearing receptacle 51 is essentially designed as a flat plate extending in a plane orthogonal to the pedal axle 15. The bearing receptacle 51 has a circular recess 50a for mounting the bearing 50 (see figure). Fig. 4 and Fig. 5).

[0037] In addition, the bearing receptacle 51 can preferably be designed to accommodate a further bearing 60, which is preferably provided for supporting an intermediate shaft of the gearbox of the drive unit 5 (see figure). Fig. 4 and Fig. 5).

[0038] The drive unit 5 can also include a bearing force sensor 8, which is arranged on the bearing receptacle 51 and is configured to determine the bearing forces of the bearing 50. For example, the bearing force sensor 8 can include strain gauges by means of which deformations of the bearing receptacle 5 can be detected.

[0039] The strain gauges of the bearing force sensor 8 can particularly preferably be arranged on specifically designed bending areas of the bearing receptacle 5, which have a smaller cross-section compared to the rest of the bearing receptacle 5. Based on the detected deformations of these bending areas, the bearing force sensor 5 can determine, in particular, the bearing forces occurring in the bearing 50 and, based on this, and preferably additionally based on a known motor torque, determine an instantaneous pedaling torque of the rider.

[0040] Based on the determined pedaling torque, the motor torque can be generated to support the rider's pedaling force, in particular by controlled activation of the motor of the drive unit 5.

[0041] The bearing receptacle 51 includes a recess 54 for each fixing element 4, each recess being designed as a blind hole. Each recess 54 includes a thread 54a into which the corresponding fixing element 4 is screwed.

[0042] Furthermore, the drive unit 5 comprises a housing 20 within which all components of the drive unit 5, as well as the bearing receptacle 51, are arranged. The housing 20 includes a housing opening 20a for each fixing element 4, through which the fixing element 4 can protrude.

[0043] The fastening of the drive unit 5 is described in detail in Fig. 3 shown.

[0044] Each fixing element 4 is screwed into one of the threads 54a of the bearing receptacle 51 from outside the frame interface 1 through a wall opening 26a of the first wall 26 and through the housing opening 20a.

[0045] The bearing receptacle 51 rests flat against an inner wall of the housing 20. For example, as shown in the Fig. As can be seen in Figure 3, a collar 52 is provided which engages in the housing opening 20a of the housing 20. Alternatively, preferably, a bearing receptacle 51 without a collar 52 may also be provided.

[0046] The housing 20 is thus located, in its screwed-together state, between the first wall 26 and the bearing receptacle 51.

[0047] The screw connection is made in such a way that the first wall 26 and the housing 20 and the bearing receptacle 51 are directly adjacent to each other and are firmly fixed together.

[0048] For example, each fixing element 4 can have a screw head 4a which rests against the outside of the first wall 26.

[0049] The fixing elements 4 can therefore be easily tightened by means of a predetermined torque in order to enable the attachment of the drive unit 5 to the frame interface 1 completely without play.

[0050] For particularly reliable attachment to the frame interface 1, the drive unit 5 can also be additionally fastened to the second wall 27 by means of a fastening element 31. The fastening element 31 can also include a screw and, if necessary, a tolerance compensation element. Any gap that may exist between the drive unit 5 and the second wall 27 can be compensated for by means of the tolerance compensation element.

[0051] The drive unit 5 further comprises a driven element 107, which can be designed in particular as a chainring. A power output from the drive unit 5 can be provided at the driven element 107. That is, for example, a sum of motor torque and pedal torque can be provided at the driven element 107 and transmitted, for example, via a bicycle chain to the rear wheel of the electric bicycle 100.

[0052] The output element 107 is preferably connected to the output shaft 103 in a rotationally fixed manner by means of an output interface 107a (see Fig. 2).

[0053] The bearing receptacle 51 is arranged on the side of the drive unit 5 facing the output element 107.

[0054] The direct screw connection of the bearing mount 51 to the frame interface 1 for fastening the drive unit 5 to the frame interface 1 offers the advantage that a particularly robust and reliable fastening can be achieved by means of a simple and cost-effective design with few components.

[0055] In particular, the relevant torque-transmitting components of the drive unit 5 are connected to the bicycle frame 105 in a very rigid manner. In detail, because the bearing receptacle 51 is directly and mechanically connected to the frame interface 1 by means of the fixing elements 4, forces and moments can be transmitted particularly directly from the output shaft 103 via the bearing 50 and the bearing receptacle 51 into the bicycle frame 105.

[0056] In addition, a very rigid connection of the output shaft 103 to the bearing force sensor 8 can be achieved, which allows for a particularly precise measurement of the bearing forces and thus also of the driver torque.

[0057] Furthermore, the special direct screw connection of the bearing mount 51 to the frame interface 1 allows the housing 20 of the drive unit 5 to be not directly in the force flow. This allows the housing 20 to be designed, for example, to be lighter and more cost-effective.

Claims

[1] Drive unit of an electric bicycle (100), comprising: - a bearing receptacle (51) which is designed to hold a bearing (50), - wherein the bearing receptacle (51) is designed for attachment directly to a frame interface (1) of the electric bicycle (100) by means of at least one fixing element (4) such that the at least one fixing element (4) can be fixed in a recess (54) of the bearing receptacle (51). [2] Drive unit according to claim 1, wherein the drive unit (1) comprises a housing (20), and wherein the bearing receptacle (51) is arranged inside the housing (20). [3] Drive unit according to one of the preceding claims, wherein the bearing receptacle (51) has a recess (54) for each fixing element (4) by means of which the fixing element (4) can be fixed to the bearing receptacle (51). [4] Drive unit according to one of the preceding claims, wherein the recess (54) has a thread (54a). [5] Drive unit according to one of the preceding claims, wherein the bearing receptacle (51) is plate-shaped and extends in a plane orthogonal to a pedal axle (15) of the drive unit (5). [6] Drive unit according to one of the preceding claims, further comprising an output element (107) which is in particular rotatably connectable to an output shaft (103) of the drive unit (5), wherein the bearing receptacle (51) is arranged on a side of the drive unit (5) facing the output element (107). [7] Drive unit according to one of the preceding claims, comprising at least two, preferably three, fixing elements (4) by means of which the bearing receptacle (51) can be attached directly to the frame interface (1). [8] Drive unit according to one of the preceding claims, further comprising a bearing force sensor (8) which is arranged on the bearing receptacle (51). [9] Drive arrangement of an electric bicycle (100), comprising: - a drive unit (5) according to one of the preceding claims, and - a frame interface (1), - wherein the drive unit (5) is attached to the frame interface (1) by means of at least one fixing element (4) being attached directly to the frame interface (1). [10] Drive arrangement according to claim 9, - wherein the frame interface (1) has at least one first wall (26), - wherein the drive unit (5) is attached directly to the first wall (26) by means of the fixing element (4). [11] Drive arrangement according to claim 10, wherein the bearing receptacle (51) and the first wall (26) are arranged substantially parallel to each other. [12] Drive arrangement according to one of claims 10 or 11, - wherein the frame interface (1) further comprises a second wall (27), and - wherein the drive unit (5) is arranged at least partially between the first wall (26) and the second wall (27). [13] Drive arrangement according to one of claims 9 to 12, further comprising a fastening element (31) by means of which the drive unit (5) is attached to the second wall (27). [14] Electric bicycle comprising a drive unit (5) according to any one of claims 1 to 8 or a drive arrangement (10) according to any one of claims 9 to 13.

Images