Frame interface of an electric bicycle

Abstract

The present invention relates to a frame interface of an electric bicycle, comprising a frame element which has a first mounting area which is configured for fixed-bearing-like fixation of a drive unit to the frame element, and a mounting element which has a second mounting area, wherein the frame element has a third mounting area for attaching the mounting element to the frame element, and wherein the second mounting area of ​​the mounting element is annular and is configured for substantially backlash-free fixation to a bearing area of ​​the drive unit.

Description

State of the art

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

[0002] Electric bicycle drive units are commonly attached to a frame interface. Often, the drive unit housing is screwed to a wall of the frame interface. Achieving a robust attachment while simultaneously compensating for tolerances is particularly challenging when the drive unit is mounted on both sides. Disclosure of the invention

[0003] In contrast, the frame interface 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 mounting of the drive unit of a frame interface is enabled, which additionally allows for tolerance compensation. This is achieved according to the invention by a frame interface of an electric bicycle comprising a frame element which has a first mounting area configured for the fixed-bearing fixation of a drive unit to the frame element. Furthermore, the frame interface comprises a mounting element which has a second mounting area for attaching the drive unit. The frame element also has a third mounting area configured for the, in particular, backlash-free attachment of the mounting element to the frame element.The second mounting area of ​​the fastening element is ring-shaped and designed to fix a bearing area of ​​the drive unit with virtually no play. A completely immobile and play-free fix is ​​defined as a fixation that is virtually free of movement. This means that the drive unit can be firmly fixed to the frame element at the first mounting area, thus precisely defining the relative position of the drive unit and the frame element. In particular, the drive unit can be fixed directly at the first mounting area, for example, by means of direct mechanical contact, or alternatively, preferably, via an intervening, preferably non-deformable element, such as a spacer or the like.

[0004] Preferably, the frame element can also be fixed to the frame element essentially without play by means of the third fastening area.

[0005] In particular, the second mounting area can have a mounting surface designed for essentially backlash-free fixation to the bearing area of ​​the drive unit. Preferably, the mounting surface can be cylindrical.

[0006] The bearing area of ​​the drive unit is defined in particular as a section of the drive unit where a bearing, preferably a bottom bracket, can be arranged. In particular, the bearing area is part of a housing, the housing preferably having a bearing seat at the bearing area where the bottom bracket can be fixed immovably. Preferably, the bearing area is cylindrical on an outer surface of the drive unit.

[0007] In particular, the second mounting area can be designed to be fixed to the bearing area of ​​the drive unit by means of a material-bonded and / or force-fit connection. Preferably, the mounting area can be welded to the bearing area of ​​the drive unit.

[0008] In other words, a frame interface is provided that allows the drive unit to be attached to the frame element at the first mounting point, in particular directly, in a fixed bearing manner, and at the third mounting point indirectly via the mounting element. The mounting element at the second mounting point can also be fixed to the bearing area of ​​the drive unit with essentially no play. The mounting element is specifically designed as a component separate from the frame element. The mounting element can be fixed to the frame element by means of the second mounting point.

[0009] In the context of the present invention, a fixed-bearing-like fixing is considered to be, in particular, a substantially immovable fixing, especially one that is substantially immovable in the axial direction, of the drive unit to the frame element. With this fixed-bearing-like fixing, the drive unit is fixed to the frame element, in particular, with substantially no play. The fixing is designed to be substantially free of axial and / or radial play. The first fastening area is designed in such a way that substantially no tolerance compensation, in particular no axial tolerance compensation, occurs between the frame element and the drive unit. That is, the drive unit is fixed directly or...The drive unit is fixed directly to the frame element by means of the first mounting area, preferably allowing the drive unit and frame element to be in direct contact with each other, or, for example, immovable and / or inelastic elements, such as sealing washers, can be arranged between the drive unit and the frame element. For example, the drive unit is fixed to the frame element immovably or with virtually no play by means of a fixing element in the form of a screw, similar to a fixed bearing arrangement.

[0010] The frame interface offers the advantage of a particularly robust yet flexible mounting of the drive unit to the frame interface, achieved through a simple and cost-effective design with few components. Because the mounting element indirectly secures the bearing area to the third mounting point of the frame element, it allows for a particularly flexible geometric connection. For example, adapting the mounting element allows for easy compatibility with different drive units. Furthermore, the mounting element itself, particularly through its inherent flexibility, enables simple and cost-effective tolerance compensation between the drive unit and the frame interface.This also allows for particularly simple and time-efficient assembly, as the respective mounting areas always allow for a direct, play-free attachment. Furthermore, because the second mounting area of ​​the fastener can be fixed to the bearing area of ​​the drive unit with virtually no play, an optimal, load-bearing connection of the drive unit to the frame element can be achieved. Specifically, by fixing the bearing area, the area relevant for force transmission during the operation of an e-bike is defined and fixed. This means, for example, that a force flow from the bottom bracket, via the bearing area and the fastener, can be provided directly to the frame interface, specifically without the force flow passing through a drive unit housing.This allows, for example, a particularly simple and lightweight design of the drive unit.

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

[0012] Preferably, the fastening element is designed to be at least partially elastically compliant in order to provide tolerance compensation, particularly axial tolerance compensation, between the drive unit and the frame element through elastic deformation of the fastening element. That is, the fastening element is made of a material and / or has a geometry such that at least partial areas of the fastening element are elastically deformable to provide axial tolerance compensation between the drive unit and the frame element. In particular, the axial tolerance compensation relates to a pedal axle of the drive unit. This allows for an optimally robust, and especially radially backlash-free, fastening of the drive unit using a particularly simple and cost-effective frame interface design, whereby axial tolerances can be compensated solely by the fastening element.

[0013] Preferably, the second mounting area has a retaining opening, which is particularly circular. The retaining opening is designed for virtually play-free fixation to the bearing area of ​​the drive unit. In particular, the retaining opening has a cylindrical contact surface, which is intended for full contact with the bearing area of ​​the drive unit. This means that the mounting element and the bearing area of ​​the drive unit can be attached to each other virtually play-free because the bearing area is positioned within the retaining opening. This ensures that the bearing area is positively locked in a plane orthogonal to the pedal axis by means of the mounting element.Preferably, axial backlash-free fixation can also be achieved by a positive-locking and / or material-locking connection between the second mounting area and the bearing area of ​​the drive unit, for example by welding. This allows the mounting area to be easily attached to the bearing area of ​​the drive unit and preferably subsequently welded to provide essentially backlash-free fixation.

[0014] Preferably, the frame interface further comprises at least one fixing element, which is configured to fix the drive unit and the first mounting area of ​​the frame element to each other along a first mounting axis for a fixed-bearing-like fixation of the drive unit. In particular, the first mounting axis is essentially parallel to a pedal axle of the drive unit. Preferably, the frame interface can comprise exactly two fixing elements at the first mounting area. Preferably, the fixing element is designed as a screw. In other words, the first mounting area of ​​the frame interface and the drive unit can be screwed together by means of the fixing element. This allows the fixed-bearing-like fixation of the drive unit by means of the first mounting area on the frame element in any direction to be carried out in a particularly simple and cost-effective manner.Preferably, the first fastening axis corresponds to an axis along which the fixing element extends, that is, preferably along which the fixing element is screwed into the drive unit.

[0015] Preferably, the frame interface further comprises at least one additional fixing element, which is configured to attach the fastening element to the frame element along a second fastening axis parallel to the first fastening axis. Particularly preferably, the frame interface can comprise exactly two additional fixing elements by means of which the fastening element is fixed to the second fastening area of ​​the frame element. In particular, a screw can be provided as an additional fixing element. Thus, the fastening element and the third fastening area of ​​the frame element can be screwed together, with the screw connection being made along the second fastening axis, which is parallel to the first fastening axis. For example, the screw connection at the first fastening area and at the third fastening area can be made from opposite directions. This allows for simple assembly and robust fastening of the frame interface.

[0016] The fastening element is preferably designed as a sheet metal plate. In particular, the sheet metal plate is made of a metal, preferably steel or a steel alloy, or aluminum or an aluminum alloy. This allows for a particularly simple and cost-effective manufacturing of the frame interface. Furthermore, the elastic deformability of the fastening element can be easily and precisely achieved to compensate for tolerances in the axial direction.

[0017] In particular, the fastening element can be designed as a formed part, which can be manufactured, for example, using forming processes.

[0018] Preferably, the second mounting area is arranged in a second mounting plane. The third mounting area is arranged in a third mounting plane. The second and third mounting planes are arranged at a predetermined distance from each other. In particular, the two mounting planes are arranged at an axial distance from each other, especially along the pedal axis of the drive unit. Preferably, the second mounting plane intersects the bearing area of ​​the drive unit. In particular, the third mounting plane intersects a motor area of ​​the drive unit, within which the motor of the drive unit may preferably be arranged. That is, preferably, the third mounting plane is arranged offset from the second mounting plane along the axial direction towards the center of the drive unit.In other words, the third mounting area is axially closer to the first mounting area than the second. This allows for a particularly compact geometry of the frame interface and, preferably, of the entire drive assembly with the drive unit. In particular, this enables a small axial dimension for the drive assembly.

[0019] The fastening element preferably has at least one stiffening rib, which is preferably arranged in a bending region of the fastening element. The bending region can preferably be, for example, an L-shaped bend in the base body of the fastening element in a cross-sectional plane in which the pedal axle of the drive unit can lie. In this bend, for example, one or more stiffening ribs can be provided along a circumferential direction at one or more locations of the fastening element, which is preferably at least partially cup-shaped. For example, the stiffening rib can be formed by a locally increased radius in the bending region. This provides greater resistance to bending in the bending region of the fastening element by means of the stiffening rib.This allows for targeted local stiffening to provide specific areas of the fastener that are more easily or less deformable. Preferably, the stiffening rib is arranged axially at the level of the second fastening area.

[0020] Furthermore, the invention leads to a drive arrangement for an electric bicycle, comprising the described frame interface and a drive unit which is attached to the frame interface. The drive unit is preferably attached to the frame interface exclusively by means of the first mounting area and the second mounting area.

[0021] Preferably, the second mounting area of ​​the fastening element and the drive unit, preferably a housing of the drive unit, are fixed to each other with virtually no play. This can be achieved, for example, by means of a material-fit and / or force-fit connection, and particularly preferably by means of a welded connection. That is, the fastening element is fixed to the bearing area of ​​the drive unit with virtually no play by means of the second fastening element.

[0022] Preferably, the drive unit has a bearing area that is coaxial with a drive unit axle. In particular, the drive unit axle is defined by a crank shaft, which is preferably connectable by cranks. The drive unit is fixed axially at the level of the bearing area to the second mounting area of ​​the fastening element with virtually no play. This allows for a particularly robust mounting of the drive unit at the frame interface, ensuring that mechanical forces from the bearing can be transmitted directly into the fastening element and the frame interface via the bearing area.

[0023] The bearing area particularly preferably comprises a bearing seat for a bottom bracket. In particular, the bearing seat can be a recess formed inside the housing of the drive unit in the bearing area, in which the bottom bracket of the drive unit is held. Alternatively or additionally preferably, the bottom bracket can be arranged in another component, such as a bearing receptacle, which is immovably held in the housing in the bearing area.

[0024] The frame element preferably comprises a first wall and a second wall. The two walls are preferably arranged parallel to each other. The drive unit is arranged at least partially between the first wall and the second wall, preferably in the axial direction, particularly with respect to the pedal axis of the drive unit. The first mounting area is arranged on the first wall, and preferably the third mounting area is arranged on the second wall. The mounting element is arranged at least partially between the second wall and the drive unit. In other words, the mounting element is arranged at least partially axially between the two walls. That is, the part of the mounting element that is fixed to the frame element by means of the third mounting area can be arranged on the inside, i.e., facing the drive unit, of the second wall.This allows for a particularly compact drive arrangement, especially in the axial direction.

[0025] Furthermore, the invention leads to an electric bicycle comprising the described frame interface or the described drive arrangement. Brief description of the drawings

[0026] 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 frame interface according to a preferred embodiment of the invention, Fig. 2 a sectional view of a drive arrangement with the frame interface of the Fig. 1, Fig. 3 a side view of the drive arrangement of the Fig. 2, Fig. 4 a perspective view of the drive arrangement of the Fig. 2, Fig. 5 a detailed view of the frame interface of the preferred embodiment, and Fig. 6 a detailed sectional view of the frame interface of the preferred embodiment. Preferred embodiments of the invention

[0027] Preferably, all identical components, elements and / or units in all figures are provided with the same reference numerals.

[0028] Fig. Figure 1 shows a simplified schematic view of an electric bicycle 100 with a frame interface 1 according to a preferred embodiment of the invention. Details of the frame interface of the preferred embodiment are given in the Fig. 2, Fig. 3, Fig. 4, Fig. 5 to Fig. 6 shown.

[0029] The frame interface 1 is part of a drive assembly 10, which is located in the area of ​​a pedal axle 15 of the electric bicycle 100. The drive assembly 10 also includes a drive unit 5.

[0030] 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. The output shaft 103 extends along the pedal axle 15 of the drive unit 5.

[0031] The frame interface 1 is an integral part of a bicycle frame 105 of the electric bicycle 100. The frame interface has two walls 26, 27, which are arranged parallel to each other and essentially orthogonal to the pedal axle 15 of the output shaft 103 (compare Fig. 2).

[0032] The two walls 26, 27 are preferably formed together as a single, one-piece component, which forms a frame element 2 at the frame interface 1. The frame element 2 is preferably at least partially U-shaped in cross-section.

[0033] The drive unit 5 is in a state mounted at the frame interface 1 and is at least partially arranged between the first wall 26 and the second wall 27, i.e., it is in particular partially enclosed by the frame element 1.

[0034] The frame element 2 has a first mounting area 21 on the first wall 26. The drive unit 5 is directly and rigidly fixed to the first wall 26 of the frame element 2 by means of the first mounting area 21. For this purpose, at least two, preferably three, fixing elements 4 are provided, which fix the drive unit 5 to the first mounting area 21.

[0035] The fixing elements 4 are each designed as screws, which are screwed directly into the drive unit 5 along a first mounting axis 20, which is parallel to the pedal axle 15. By means of the fixing elements 4, the drive unit 5 is thus fixed axially and radially without play and immovably directly to the first wall 26.

[0036] This fixing by means of the first mounting area 21 takes place on an output side of the drive unit 5. In detail, an output element 107 of the drive unit 5 is arranged on the output side, to which the pedaling torque and / or motor torque can be transmitted to the further drive train of the electric bicycle 100. The output element 107 can, for example, be a chainring (compare Fig. 1) This allows for a particularly robust and precisely positioned fixing of the drive unit 5 to the frame interface 1 on the output side.

[0037] The drive unit 5 is indirectly attached to the second wall 27 of the frame element 2 by means of an additional fastening element 3, which is also part of the frame interface 1.

[0038] The fastening element 3 is designed as a sheet metal part, preferably a metal sheet. For example, the fastening element can be made of steel or aluminum or a suitable alloy.

[0039] The fastening element 3 is designed as a formed part, meaning it is shaped by forming processes such as deep drawing and / or bending. This allows for a particularly simple and cost-effective manufacturing process for the fastening element 3.

[0040] The fastening element 3 is fixed directly, essentially without play, to a third fastening area 23 of the frame element 2 on the second wall 27 at the frame interface side. Specifically, the fastening element 3 is fixed to the third fastening area 23 by means of exactly two further fixing elements 6. These further fixing elements 6 are also designed as screws. The fixing of the fastening element 3 by means of these further fixing elements 6 is achieved along second fastening axes 60 that are parallel to each other and parallel to the first fastening axes 20.

[0041] Preferably, for each additional fixing element 6, a nut 29 can be provided on the fastening element 3, into which the fixing element 6 can be screwed (compare Fig. 2 and Fig. 6) The nuts 29 can, for example, be pressed into the fastening element 3.

[0042] The fastening element 3 has a second fastening area 22, which is ring-shaped and designed for essentially backlash-free fixation to a bearing area 51 of the drive unit 5. In detail, the second fastening area 22 is designed as a circular retaining opening 22a, within which the bearing area 51 of the drive unit 5 can be fixed without backlash in the radial and axial directions.

[0043] As in the Fig. As can be seen in Figure 6, the second mounting area 22 has a circular retaining opening 22a. A radially inner side of the circular retaining opening 22a is bounded by a cylindrical surface 22b. This cylindrical surface 22b is in contact with an outer cylindrical surface of the bearing area 51 of the drive unit 5.

[0044] In particular, the bearing area 51 is a cup-shaped area of ​​a housing 55 of the drive unit 5, within which a bearing 59 of the drive unit 5 is arranged without play and without movement. Specifically, the bearing 59 is one of the bottom bracket bearings of the drive unit 5.

[0045] The radial fixation of the drive unit 5 is achieved through contact between the cylindrical surface 22b and the bearing area 51. An additional axial fixation is achieved by a material-fit connection 25 between the fastening element 3 and the bearing receptacle 51 at the second fastening area 22. This connection 59 is, in particular, a welded joint. Thus, a completely backlash-free connection is established between the drive unit 5 and the fastening element 3 at the second fastening area 22.

[0046] The fastening element 3 can further have stiffening beads 37, which are arranged at bending areas 36 of the fastening element 3 (compare Fig. 4 and Fig. 5) This allows the deformability of the fastening element 3 to be reduced at these bending areas 36, thus enabling stiffening in these areas.

[0047] The fastening element 3 is shaped such that the second fastening area 22 is arranged in a second fastening plane 32, which is arranged at a predetermined distance 35 in the axial direction from a third fastening plane 33, in which the third fastening area 23 is arranged, as shown in the Fig. 2 can be identified. The second mounting level 32 intersects the bearing area 51 and in particular the bearing 59, and the third mounting level 33 intersects the motor 5c of the drive unit 5.

[0048] In particular, the third mounting area 23 along the pedal axle 15 is axially offset from the second mounting area 22, especially in the direction of the output element 107. This allows for a particularly space-saving and compact geometry of the drive arrangement 10.

[0049] In particular, a particularly compact axial drive unit 5 can be provided. This allows, for example, the entire axial length of the drive arrangement 10 to be located in the area of ​​the pedal axle 15, which has a beneficial effect on the geometry and kinematics of the pedal actuation and can thus provide a high level of rider comfort.

[0050] The fastening element 3 to the third fastening area 23 can be achieved by means of a radially projecting area 3a of the fastening element 3 (compare Fig. 5) This projecting area 3a is arranged within the frame element 2, that is, on one side of the second wall 27 facing the first wall 26 (compare Fig. 2).

[0051] Preferably, the fastening element 3 is designed such that axial flexibility is provided by the fastening element 3 itself. In particular, the areas 3a of the fastening element 3 are preferably designed to be elastically compliant. This allows axial tolerance compensation between the drive unit 5 and the frame interface 1 to occur when the drive unit 5 is fixed to the frame interface 1 by means of the fastening element 3, through deformation of the fastening element 3 at the areas 3a. Thus, a robust fastening of the drive unit 5 to the frame interface 1 can be achieved using a particularly simple, compact, and cost-effective design, while also reliably and easily compensating for axial tolerances.

Claims

[1] Frame interface of an electric bicycle (100), comprising: - a frame element (2) which has a first fastening area (21) which is designed for fixed-bearing fixing of a drive unit (5) to the frame element (2), and - a fastening element (3) which has a second fastening area (22), - wherein the frame element (2) has a third fastening area (23) for fastening the fastening element (3) to the frame element (2), and - wherein the second fastening area (22) of the fastening element (3) is ring-shaped and is designed for essentially backlash-free fixation to a bearing area (51) of the drive unit (5). [2] Frame interface according to claim 1, wherein the fastening element (3) is designed to be at least partially elastically flexible, for the, in particular axial, compensation of tolerances between the drive unit (5) and the frame element (2) by elastic deformation of the fastening element (3). [3] Frame interface according to one of the preceding claims, wherein the second fastening area (22) has a retaining opening (22a), in particular circular, which is designed for essentially backlash-free fixation fully on the bearing area (51) of the drive unit (5). [4] Frame interface according to one of claims 2 or 3, further comprising at least one fixing element (4) which is arranged to fix the drive unit (5) and the first mounting area (21) to each other along a first mounting axis (20) for fixed bearing-like fixing of the drive unit (5), in particular wherein the first mounting axis (20) is substantially parallel to a pedal axle (15) of the drive unit (5). [5] Frame interface according to claim 4, further comprising at least one further fixing element (6) which is configured to fasten the fastening element (3) to the frame element (2) along a second fastening axis (60) parallel to the first fastening axis (20). [6] Frame interface according to one of the preceding claims, wherein the fastening element (3) is designed as a sheet metal part. [7] Frame interface according to claim 6, - wherein the second fastening area (22) is arranged in a second fastening plane (32), - wherein the third fastening area (23) is arranged in a third fastening plane (33), and - wherein the second mounting level (32) and the third mounting level (33) are arranged at a predetermined distance (35) from each other. [8] Frame interface according to claim 6 or 7, wherein the fastening element (3) has at least one stiffening bead (37) which is arranged in particular at a bending area (36) of the fastening element (3). [9] Drive arrangement of an electric bicycle (100), comprising: - a frame interface (1) according to any of the preceding claims, and - a drive unit (5) which is attached to the frame interface (1). [10] Drive arrangement according to claim 9, wherein the second fastening area (22) of the fastening element (2) and the drive unit (5), in particular a housing (55) of the drive unit (5), are fixed to each other essentially without play. [11] Drive arrangement according to claim 9 or 10, wherein the drive unit (5) has a bearing area (51) formed coaxially with a pedal axle (15), which the second fastening area (22) of the fastening element (3) surrounds in a ring shape. [12] Drive arrangement according to claim 11, wherein the bearing area (51) comprises a bearing seat of a bottom bracket (59). [13] Drive arrangement according to any one of claims 9 to 12, - wherein the frame element (2) has a first wall (26) and a second wall (27), - wherein the drive unit (5) is at least partially arranged between the first wall (26) and the second wall (27), - wherein the first fastening area (21) is arranged on the first wall (26), and - wherein the fastening element (3) is arranged at least partially between the second wall (27) and the drive unit (5). [14] Electric bicycle comprising a frame interface (1) according to any one of claims 1 to 8 or a drive arrangement (10) according to any one of claims 9 to 13.

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