Crank interface of a crank mechanism of a two-wheeled vehicle

Abstract

The invention relates to a crank interface (1) of a crank mechanism (10) of a two-wheeled vehicle (100), for connecting and / or for transmitting force between a crankshaft (11) and a crank arm (12), comprising: a cylindrical region (2) which has a cylindrical outer surface (20), a tapered region (3) which has a tapering outer surface (30), and a toothed region (4) which has a multiplicity of protruding teeth (40).

Description

[0001] Description

[0002] title

[0003] Crank interface of a crank drive of a two-wheeler

[0004] State of the art

[0005] The present invention relates to a crank interface of a crank drive of a two-wheeler, a crankshaft, a crank arm, a crank drive, and a two-wheeler.

[0006] Crank interfaces for two-wheelers are well known; they enable a mechanical connection and power transmission between a crankshaft and a crank arm of the two-wheeler. Toothing is usually provided for power transmission between the crank arm and the crankshaft. An example of such a crank interface is the so-called I SIS interface (short for: International Spline Interface Standard). In this interface, the toothing area is inclined at a predetermined angle to the axial direction. Screws and axial stops are usually provided to fix the crank arms to the crankshaft. In order to maintain a high positional accuracy of crank arms and crankshafts relative to one another, very high tolerances are required for manufacturing and assembly with known crank interfaces. Known crank interfaces are therefore often very complex and cost-intensive to manufacture.

[0007] Disclosure of the invention

[0008] In contrast, the crank interface according to the invention is characterized by a design that is simple and cost-effective to manufacture and allows particularly high positioning accuracy of the crankshaft and crank arm relative to one another. In addition, optimal power transmission and particularly high mechanical strength of the connection can be provided. This is achieved according to the invention by a crank interface of a crank drive of a two-wheeler, which is designed to connect a crankshaft and a crank arm. Additionally or alternatively, the crank interface is designed to transmit power between the crankshaft and the crank arm. The crank interface comprises a cylinder region having a cylindrical outer surface. In particular, the cylindrical outer surface can be regarded as the lateral surface of the cylinder region. In addition, the crank interface comprises a tapered region having a tapered outer surface.The tapered outer surface can preferably be considered the lateral surface of the tapered region. In particular, a tapered outer surface is considered to be a surface whose diameter decreases in the radial direction. Furthermore, the crank interface comprises a toothed region having a plurality of protruding teeth. For example, the protruding teeth can be designed in a variety of ways, preferably in the form of radially outwardly protruding teeth, in particular to provide a positive engagement in the circumferential direction of the toothed region.

[0009] Preferably, the cylinder region, the tapered region, and the toothed region are arranged directly adjacent to one another along a longitudinal axis.

[0010] In other words, a crank interface is provided that enables a mechanical coupling of a crankshaft and a crank arm of a crank mechanism. The crank interface comprises three separate areas. In particular, the three areas are spatially and functionally separate from each other.

[0011] The crank interface can preferably be provided on either a shaft or a hub. Particularly in the case of a shaft, the outer surfaces form correspondingly radially outer surfaces of the respective regions. Particularly in the case of a hub, the outer surfaces form radially inner surfaces of the respective regions. The cylinder region is provided in particular to be able to provide high mechanical stability. In particular, a press connection can be provided between the cylinder region and a corresponding cylinder region of the opposing component in order to achieve good mechanical support between the two components. The cylinder region can transmit high bending forces. In addition, the cylindrical outer surface of the cylinder region allows for particularly simple and cost-effective production.

[0012] The tapered region is preferably provided to provide relative axial positioning of the components to be connected via the crank interface. This can be achieved by means of the tapered outer surface. This allows, in particular, not only simple and cost-effective production but also a mechanically particularly robust element for axial positioning of the two components to be connected.

[0013] Furthermore, the toothed area is preferably provided to enable torque transmission between the components to be connected via the crank interface. This preferably occurs through radial engagement with teeth of a corresponding toothed area of ​​the respective opposing component. This allows for optimal power transmission.

[0014] The crank interface offers the advantage of being simple and cost-effective to manufacture, allowing the crankshaft and crank arm to be connected with high strength and high positioning accuracy. This is achieved in particular by the fact that the three separate areas of the crank interface can be manufactured independently of one another and with little effort. The special spatial and functional separation of the areas, as well as their special design, enables a strong and precise connection even with higher manufacturing tolerances. This means that the crank interface can be manufactured using particularly simple and cost-effective manufacturing processes. In particular, the three areas of the crank interface can fulfill all the required functions and properties of the connection and power transmission.This means that no additional elements such as grooves and / or retaining rings or shims or the like are required to provide a precisely positioned, reliable and robust connection between the crank arm and crankshaft. In particular, the three separate areas of the crank interface, thanks to their special design, inherently provide a precise relative arrangement of the components to be connected, so that lower requirements for component tolerances are necessary during production. This enables particularly simple, time-efficient and cost-effective production of the components. In addition, the special design of the three separate areas of the crank interface enables the use of simple and cost-effective methods for quality assurance, since, for example, deviations from target geometries can be easily determined.

[0015] The subclaims contain preferred developments of the invention.

[0016] Preferably, the tapered region is arranged axially between the cylinder region and the toothed region. In particular, the cylinder region, tapered region, and toothed region directly adjoin one another axially. This allows for an advantageous design and manufacturability of the crank interface. For example, the tapered region can form a geometric transition region between the cylinder region and the toothed region.

[0017] Particularly preferably, the tapered region forms a stepless transition between the cylindrical outer surface of the cylinder region and an outer circumference of the teeth of the toothing region. The outer circumference of the teeth is considered to be, in particular, a maximum outer diameter of the toothing region in the region of the teeth if the crank interface is part of a shaft. Furthermore, the outer circumference of the teeth is considered to be, in particular, a minimum inner diameter of the toothing region in the region of the teeth if the crank interface is part of a hub. In addition to particularly simple and cost-effective production, this offers the advantage of enabling an optimal transition between the toothing region and the cylinder region, thereby providing a mechanically particularly robust construction.

[0018] Preferably, the outer surface of the tapered region is tapered. This means that a peripheral surface of the tapered region is conical. This allows for particularly simple manufacturing and a high degree of robustness of the tapered region, while also enabling a defined axial positioning of the components to be connected in a simple manner using the conical outer surface.

[0019] Preferably, the cylindrical outer surface of the cylinder region has a diameter of at least 20 mm, preferably a maximum of 25 mm, particularly preferably 21.6 mm. Particularly preferably, the cylindrical outer surface of the cylinder region has an axial length of at least 2 mm, preferably a maximum of 10 mm, particularly preferably 5 mm.

[0020] Preferably, the tapered outer surface of the tapered region has an axial length of at least 2 mm, preferably a maximum of 5 mm, particularly preferably 3.68 mm. A cone angle between the, in particular conically tapered, outer surface of the tapered region is particularly preferably at least 0.1°, preferably 8°, particularly preferably e 0 . The cone angle is considered to be an angle between the outer surface and the longitudinal axis.

[0021] Particularly preferably, the toothed area has a total of at least 4, preferably a maximum of 38, particularly preferably 14, protruding teeth. This allows for particularly good load transmission. The toothed area preferably has an axial length of at least 5 mm, preferably a maximum of 15 mm, particularly preferably 9.43 mm.

[0022] Furthermore, the invention leads to a crank interface of a crank drive of a two-wheeler, wherein the crank interface is configured for the connection of and / or for the transmission of power between a crankshaft and a crank arm. The crank interface comprises a first cylinder region having a cylindrical first outer surface. In particular, the cylindrical first outer surface can be regarded as the lateral surface of the first cylinder region. In addition, the crank interface comprises a second cylinder region having a cylindrical second outer surface. The cylindrical second outer surface can in particular be regarded as the lateral surface of the second cylinder region. Furthermore, the crank interface comprises a toothing region having a plurality of protruding teeth.For example, the protruding teeth can be designed in a variety of ways, preferably in the form of radially outwardly projecting teeth, in particular to be able to provide a positive engagement in the circumferential direction of the toothing area.

[0023] Preferably, the second cylinder region and the toothed region are arranged directly adjacent to one another along a longitudinal axis.

[0024] Particularly preferably, the second cylinder region is arranged in the axial direction between the first cylinder region and the toothing region.

[0025] In other words, a crank interface is provided that enables a mechanical coupling of a crankshaft and a crank arm of a crank mechanism. The crank interface comprises three separate areas. In particular, the three areas are spatially and functionally separate from each other.

[0026] Preferably, the crank interface can be provided on either a shaft or a hub. Particularly in the case of a shaft, the outer surfaces form correspondingly radially outer lateral surfaces of the respective regions. Particularly in the case of a hub, the outer surfaces form radially inner lateral surfaces of the respective regions.

[0027] The first cylinder region is provided in particular to be able to provide high mechanical stability. In particular, a press connection can be provided between the first cylinder region and a corresponding cylinder region of the opposite component in order to achieve good mechanical support between the two components. The first cylinder region can transmit high bending forces. In addition, the cylindrical outer surface of the first cylinder region allows for particularly simple and cost-effective manufacturing. The second cylinder region is preferably provided to provide an axial distance between the first cylinder region and the toothed region. The cylindrical outer surface of the second cylinder region allows for particularly simple and cost-effective manufacturing. In particular, in this case, a certain relative axial displaceability of the crank arm and crankshaft to one another can be enabled.This can be advantageous for an optimally positioned arrangement of the crank arm.

[0028] Furthermore, the toothed area is preferably provided to enable torque transmission between the components to be connected via the crank interface. This preferably occurs through radial engagement with teeth of a corresponding toothed area of ​​the respective opposing component. This allows for optimal power transmission.

[0029] The crank interface offers the advantage of being simple and cost-effective to manufacture, allowing the connection of the crankshaft and crank arm with high strength and high positioning accuracy. This is achieved in particular by the fact that the three separate areas of the crank interface can be manufactured independently of one another and with minimal effort. The special spatial and functional separation of the areas, as well as their special design, enables a strong and precise connection even with higher manufacturing tolerances. This allows the crank interface to be manufactured using particularly simple and cost-effective manufacturing processes.

[0030] In particular, the three areas of the crank interface can fulfill all the required functions and properties of the connection and power transmission. This means that no additional elements, such as grooves and / or retaining rings or shims, or the like, are required to provide a precisely positioned, reliable, and robust connection between the crank arm and crankshaft. In particular, the three separate areas of the crank interface, due to their special design, inherently provide a precise relative arrangement of the components to be connected, thus reducing the requirements for component tolerances during production. This enables particularly simple, time-efficient, and cost-effective production of the components.In addition, the special design of the three separate areas of the crank interface enables the use of simple and cost-effective methods for quality assurance, as deviations from target geometries, for example, can be easily determined.

[0031] Preferably, the cylindrical second outer surface of the second cylinder region and an outer circumference of the teeth of the toothed region have the same outer diameter. This means that the outer circumference of the teeth and the cylindrical second outer surface are aligned with each other in the axial direction. This allows for particularly simple and cost-effective production, since, for example, the second cylinder region and the toothed region can be manufactured together in a single step, especially before the teeth are produced.

[0032] Preferably, the crank interface further comprises a transition region arranged between the first cylinder region and the second cylinder region. The transition region forms a predetermined axial distance between the first cylinder region and the second cylinder region. The transition region can easily enable a stress-free construction and arrangement in the assembled state. Furthermore, manufacturing can be simplified.

[0033] Preferably, the first cylindrical outer surface of the first cylinder region has a diameter of at least 15 mm, preferably a maximum of 25 mm, particularly preferably 21.6 mm. Particularly preferably, the first cylindrical outer surface of the first cylinder region has an axial length of at least 2 mm, preferably a maximum of 10 mm, particularly preferably 5 mm.

[0034] Preferably, the second cylindrical outer surface of the second cylinder region has a diameter of at least 15 mm, preferably a maximum of 25 mm, particularly preferably 21 mm. Particularly preferably, the second cylindrical outer surface of the second cylinder region has an axial length of at least 2 mm, preferably a maximum of 10 mm, particularly preferably 5 mm. Particularly preferably, the toothed region has a total of at least 4, preferably a maximum of 38, particularly preferably 14, protruding teeth. This allows for particularly good load transmission. Preferably, the toothed region has an axial length of at least 5 mm, preferably 15 mm, particularly preferably 9.43 mm.

[0035] Particularly preferably, the protruding teeth of the toothing region form a straight shaft toothing. A straight shaft toothing is considered, in particular, to be a toothing with teeth running parallel to the axis of the crank interface. The teeth can be designed in a variety of ways. For example, the teeth can have a parallelogram-shaped cross-section. Alternatively, the teeth can be designed in the form of a spline shaft toothing, i.e., for example, with mutually parallel tooth flanks. Straight shaft toothing allows for particularly simple manufacturing.

[0036] The invention further relates to a crankshaft of a crank mechanism of a two-wheeler, comprising at least one crank interface as described above. In particular, the crank interface is arranged at an axial end of the crankshaft. Preferably, the toothed area of ​​the crank interface directly adjoins an end face of the crankshaft. Such a crankshaft can be manufactured simply and cost-effectively and further exhibits the advantages of the crank interface described above.

[0037] The invention further relates to a crankshaft of a crank mechanism of a two-wheeler, comprising a crank interface at each axial end of the crankshaft, each crank interface having a cylinder region, a tapered region, and a toothed region. This means that identical crank interfaces are provided at both axial ends of the crankshaft. This allows for particularly simple and cost-effective production.

[0038] Furthermore, the invention leads to a crankshaft of a crank mechanism of a

[0039] Two-wheeler, comprising at a first axial end of the crankshaft a first crank interface which has a cylinder region, a tapered region, and a toothed region, and at a second axial end of the crankshaft a second crank interface which has a first cylinder region, a second cylinder region, and a toothed region. This means that different crank interfaces are provided at the two axial ends of the crankshaft. In particular, this makes it possible for a crank arm to be arranged on the first side in a precisely defined axial position on the crankshaft by means of the tapered region. On the opposite second side, a further crank arm can be arranged so as to be axially movable over a certain range by means of the second cylinder region.For example, the axial fixation of the second crank arm can be achieved using additional elements of a crank mechanism, such as a bearing. This allows for a flexible arrangement with a simple and few components.

[0040] The invention further relates to a crank arm of a crank drive of a two-wheeler, which comprises a crank interface as described above. Particularly preferably, the crank arm comprises a crank interface comprising a cylindrical region, a tapered region, and a toothed region. The crank interface of the crank arm is preferably designed as a hub, in particular so that the crank arm can be attached to a crankshaft with a corresponding crank interface. The crank arm is characterized by a particularly simple and cost-effective construction, which essentially has the described advantages of the crank interface.

[0041] Furthermore, the invention leads to a crank drive comprising a described crankshaft and, preferably, exactly two crank arms, which are designed as described in the previous paragraph. In particular, the two crank arms are connected to the crankshaft by means of respective crank interfaces and corresponding crank interfaces at both axial ends of the crankshaft. Preferably, the crank arms and crankshaft are connected or coupled to one another exclusively at the corresponding crank interfaces. This means that, apart from the crank interfaces, no further areas or components contribute to the mechanical connection. Such a crank drive is characterized by the advantages described above, wherein, in particular, few components and thus a particularly simple and lightweight construction can be provided.

[0042] The crank mechanism preferably comprises one fastening element per crank arm. Each crank arm is fastened to the crankshaft by means of the respective fastening element. In particular, each fastening element clamps the respective crank arm axially toward a center of the crankshaft. Preferably, each fastening element is designed as a screw and is preferably screwed into an end face of the crankshaft. This allows the crank arms to be fastened to the crankshaft in a particularly simple and cost-effective manner.

[0043] Particularly preferably, a first axial stop of the first crank arm is formed on a first side, in particular at a first axial end, of the crankshaft by means of the respective tapered regions on the crankshaft and on the first crank arm. This means that the first crank arm is axially positioned on the crankshaft by being clamped against the tapered region of the crankshaft by means of the fastening element. This allows for a particularly strong and precisely positioned connection.

[0044] Preferably, the crank drive further comprises a chainring mount configured for securing a chainring. The chainring mount is arranged on the first side, in particular on the first axial end, of the crankshaft. This allows for an optimally positioned arrangement, and thus precise positioning of a chain line.

[0045] Particularly preferably, the crank mechanism further comprises at least one bearing, preferably a ball bearing, for supporting the crankshaft. The bearing is arranged on a second side, in particular on a second end face, of the crankshaft. The bearing forms a second axial stop for the crank arm on the second side. This means that the axial positioning of the second crank arm is achieved by clamping it against the bearing by means of the corresponding fastening element.

[0046] In particular, the crank interfaces between the crank arm and crankshaft on the second side are designed in such a way that they do not form an axial stop. This allows for a particularly advantageous arrangement of the crank mechanism components.

[0047] Preferably, a press connection, preferably by means of a transition fit, is formed between the respective cylinder region of each crank arm and the corresponding cylinder region of each side of the crankshaft. This allows high mechanical forces to be transmitted between the crank arm and crankshaft via the respective cylinder regions, thereby providing a particularly robust arrangement.

[0048] Furthermore, the invention leads to a two-wheeler, preferably a bicycle, in particular an electric bicycle, comprising a crankshaft as described above, and / or, preferably precisely, two crank arms as described above, and / or a crank drive as described above. The two-wheeler can thus be provided with a particularly simple, lightweight, and cost-effective crank assembly.

[0049] Short description of the drawings

[0050] The invention is described below using exemplary embodiments in conjunction with the figures. In the figures, functionally identical components are identified by the same reference numerals. Here:

[0051] Figure 1 is a simplified schematic view of a two-wheeler with a crank interface according to a first embodiment of the invention,

[0052] Figure 2 shows a detailed view of the crank interface according to the first embodiment of the invention,

[0053] Figure 3 is a sectional view of a crank mechanism with the crank interface according to the first embodiment of the invention,

[0054] Figure 4 shows a detailed view of a crank interface according to a second embodiment of the invention, Figure 5 shows a sectional view of a crank drive with the crank interface according to the second embodiment of the invention,

[0055] Figure 6 shows a further sectional view of a crank mechanism with the crank interface according to the first embodiment of the invention, and

[0056] Figure 7 is a sectional view of a crank mechanism with a combination of the crank interface according to the first embodiment and the second embodiment.

[0057] Preferred embodiments of the invention

[0058] Figure 1 shows a simplified schematic view of a two-wheeler 100, which comprises a crank drive 10 with a crank interface 1 according to a first exemplary embodiment of the invention. The crank interface 1 is shown in detail in Figure 2. The two-wheeler 100 is an electric bicycle. The two-wheeler 100 comprises a drive unit 102, which is arranged in the region of a bottom bracket and which preferably comprises an electric motor and a transmission. The drive unit 102 is provided to provide motor assistance, by means of a torque generated by the electric motor, to the pedaling force of the rider generated by muscular power. The electric motor of the drive unit 102 is supplied with electrical energy by an electrical energy storage device 109 of the two-wheeler 100.

[0059] The two-wheeler 100 comprises a crank drive 10, by means of which the rider's muscle power can be transmitted to a chainring 108, via which a corresponding torque can be transmitted to a rear wheel of the two-wheeler 100 by means of a chain drive in order to drive the two-wheeler 100.

[0060] The crank mechanism 10 comprises two crank arms 12, to each of which, in particular, a pedal can be attached, and a crankshaft 11 to which the two crank arms 12 are attached. The crankshaft 11 is arranged to rotate about a crank axis 15. The crank arms 12 are attached by means of the crank interface 1 according to the invention, which is described in more detail below.

[0061] Figure 2 shows a detailed view of the crankshaft 11 of the two-wheeler 100 of Figure 1 with the crank interface 1 according to the first exemplary embodiment of the invention. The crank interface 1 is arranged on a first side 11a, in particular at a first axial end, of the crankshaft 11. In particular, the crank interface 1 is formed as a part of the crankshaft 11.

[0062] The crankshaft 11 comprises a chainring mount 110 on the first side 11a, preferably axially adjacent to the crank interface 1, which is schematically indicated in a highly simplified manner in Figure 2. The chainring mount 110 is configured for securing the chainring 108.

[0063] The crank interface 1 comprises a toothing region 4, which is designed as a straight shaft toothing and has a total of 14 protruding teeth 40 distributed around the circumference of the crankshaft 11. The toothing region 4 directly borders a first end face 16 on the first side 11a of the crankshaft 11. Furthermore, the crank interface 1 comprises a tapered region 3, which directly borders the toothing region 4 in the axial direction of the crank axis 15. In addition, the crank interface 1 comprises a cylindrical region 2, which has a cylindrical outer surface 20. The cylindrical region 2 is arranged directly bordering the tapered region 3 in the axial direction of the crank axis 15.

[0064] An outer circumference 45 of the teeth 40 of the toothing region 4 defines a maximum outer diameter 46 of the toothing region 4. The outer diameter 46 of the toothing region 4 is smaller than an outer diameter 26 of the cylindrical outer surface 20 of the cylinder region 2.

[0065] The tapered region 3 has a conically tapered outer surface 30, which forms a continuous transition between the cylindrical outer surface 20 of the cylinder region 2 and the outer circumference 45 of the teeth 40 of the toothed region 4. The crank interface 1 on the crankshaft 11 is provided to enable a defined arrangement of a crank arm 12 on the crankshaft 11 and a power transmission between the crank arm 12 and the crankshaft 11. Such a crank arm 12, which can be fastened to the crankshaft 11 with the crank interface 1, is shown in a detailed sectional view in Figure 3 in the state fastened to the crankshaft 11. Figure 3 thus shows a detailed sectional view of the crank drive 10 of the two-wheeler 100 of Figure 1.

[0066] The crank arm 12 has a through-opening 12c, within which a crank interface 1 is also formed, which corresponds to the shaft-side crank interface 1. This means that the crank arm 12 is designed as a hub in the region of its corresponding crank interface 1. The crank arm-side crank interface 1 also comprises a cylinder region 2 with a cylindrical outer surface 20, a tapered region 3, and a toothed region 4.

[0067] The toothed area 4 of the shaft-side crank interface 1 and the toothed area 4 of the crank arm-side crank interface 1 are designed such that the teeth 40 engage positively in the circumferential direction to enable torque transmission between the crankshaft 11 and the crank arm 12. Thus, an outer diameter 46' of the teeth 40 of the toothed area 4 of the crank arm 12, which forms a minimum inner diameter of the through-opening 12c of the crank arm 12, is preferably smaller than the outer diameter 46 of the teeth 40 of the toothed area 4 of the crankshaft 11.

[0068] The cylinder regions 2 of the crankshaft 11 and the crank arm 12 are designed such that a transition fit is formed between them. In detail, an outer diameter 26, 26' of the cylinder regions 2 of the crankshaft 11 and the crank arm 12 is thus identical. This allows stable mechanical support to be provided between the two connected components in order to enable high mechanical stability of the crank mechanism 10. In particular, this allows high bending forces to be transmitted. Furthermore, the respective tapered regions 3 of the crankshaft 11 and the crank arm 12 are designed such that they form a first axial stop 35 of the crank arm 12 on the crankshaft 11.In other words, by appropriately designing the tapered regions 3, the crank arm 12 can be pushed onto the crankshaft 11 in the axial direction along the direction indicated by arrow A in Figure 3 until the two tapered regions 3 touch each other. This allows for a stable and precise relative positioning of the crank arm 12 on the crankshaft 11 relative to each other in a simple manner.

[0069] The crank arm 12 is fixed to the crankshaft 11 by means of a fastening element 9, which is designed as a screw that can be screwed into an internal thread 90 of the crankshaft 11. This screw connection is shown in Figure 7 and will be described in more detail later.

[0070] Figure 4 shows a detailed view of a crank interface 1 according to a second exemplary embodiment of the invention. The crank interface 1 of the second exemplary embodiment is formed on the crankshaft 11 in Figure 4. This can preferably be the crankshaft 11 of Figures 2 and 3, with the crank interface 1 of the second exemplary embodiment being arranged on an opposite second side 11b, in particular at a second axial end, of the crankshaft 11.

[0071] The crank interface 1 of the second embodiment comprises a first cylinder region 6 which has a cylindrical first outer surface 60.

[0072] Preferably, the first cylinder region 6 with the cylindrical first outer surface 60 is identical to the cylinder region 2 with the cylindrical outer surface 20 of the crank interface 1 of the first exemplary embodiment (see Figures 2 and 3). Furthermore, the crank interface 1 of the second exemplary embodiment comprises a toothing region 4 which has a plurality of protruding teeth 40. Preferably, the toothing region 4 is identical to the toothing region 4 of the crank interface of the first exemplary embodiment (see Figures 2 and 3). The toothing region 4 directly borders on a second end face 17 of the crankshaft 11. A second cylinder region 7 of the crank interface 1 is located between the toothing region 4 and the first cylinder region 6. The second cylinder region 7 has a cylindrical second outer surface 70.An outer diameter 76 of the cylindrical second outer surface 70 corresponds to the outer diameter 46 of the toothing area 4.

[0073] An axial gap 67 is located between the first cylinder region 6 and the second cylinder region 7 along the direction of the crank axis 15. The axial gap 67 preferably has an axial length of 10% to 30% of the axial length of the first cylinder region 6. The axial gap 67 is formed by a transition region 8 between the two cylinder regions 6, 7. For example, the transition region 8 can have a conical taper or, for example, a circular arc-shaped transition.

[0074] Figure 5 shows a sectional view of a crank mechanism 10 with the crank interface 1 according to the second exemplary embodiment of the invention. The crank mechanism 10 additionally comprises a second crank arm 12 which is connected to the crankshaft 11. The connection is made on the shaft side by means of the crank interface 1 according to the second exemplary embodiment of the invention (cf. Figure 4) and on the crank arm side by means of a crank interface 1 according to the first exemplary embodiment of the invention (cf. Figure 3). This means that the crank arm 12 of the crank mechanism 10 in Figure 5 is identical to the crank arm 12 of the crank mechanism 10 in Figure 3. This enables a particularly simple and cost-effective provision of the crank mechanism 10, in particular since the crank arms 12 can be easily replaced.

[0075] When fastening the crank arm 12 by means of the crank interface 1 according to the second exemplary embodiment of the invention, an axial stop, i.e. an axial positioning, of the crank arm 12 does not occur directly on the crankshaft 11. Instead, a second axial stop 125 is implemented by means of a bearing 120. In detail, the bearing 120 is provided for supporting the crankshaft 11, for example in a vehicle frame of the two-wheeler 100 and / or in the drive unit 102. The bearing 120 is arranged axially immovably on the crankshaft 11. Between the bearing 120 and the crank arm 12, as shown in Figure 5, a sealing element 122 and a spacer element 121 can be arranged. For example, a tolerance position of the crank drive 10 can be precisely adjusted by means of the spacer element 121.

[0076] The second axial stop 125 for the crank arm 12 is thus formed on the bearing 120 via the sealing element 122 and the spacer element 121. The second cylinder region 7 thus enables the crank arm 12 to be displaced in the axial direction on the crankshaft 11 at least until the second stop 125 is reached. This allows for a particularly advantageous mechanical design of the entire crank mechanism 10 with a predetermined mechanical load on the bearing 120. In addition, a particularly precise and precisely defined relative arrangement of the components can be achieved in a simple manner. The second cylinder region 7 can also be manufactured in a particularly simple manner.

[0077] Figure 6 shows a further sectional view of a crank mechanism 10 with the crank interface 1 according to the first exemplary embodiment of the invention. This shows the second side 11b of the crankshaft 11 with the crank arm 12 fastened thereto. Figure 6 shows an alternative variant of the crankshaft 11, in which a crank interface 1 according to the first exemplary embodiment of the invention is formed at each of the two axial ends 11a, 11b. This means that the two sides 11a, 11b of the crankshaft 11 are identical, which enables particularly simple and cost-effective manufacturing.

[0078] The crank mechanism 10 of Figure 6 is designed such that the second axial stop 125 of the second crank arm 12 is present on the bearing 120 via the sealing element 122 and the spacer element 121. For example, in this case, the respective tapered regions 3 on the crankshaft 11 and the crank arm 12 can additionally touch when the crank arm 12 rests against the second stop 125. For example, a statically overdetermined state can thus exist. The crank mechanism 10 can preferably be designed such that elastic deformation, for example of the crank arm 12, particularly if it is made of aluminum or an aluminum alloy, compensates or equalizes. Figure 7 shows a sectional view of a crank mechanism 10 with a combination of a crank interface 1 according to the first exemplary embodiment (cf. Figures 1 to 3) on the first side 11a of the crankshaft 11, and a crank interface 1 according to the second exemplary embodiment (cf.Figures 4 and 5) on the second side 11a of the crankshaft 11. The two crank arms 12 are each fixed to the crankshaft 12 by means of a fastening element 9 designed as a screw. The fastening element 9 is screwed into an internal thread 90 of the crankshaft 11, whereby the corresponding crank arm 12 is clamped along the axial direction indicated by the arrow A or B in the direction of the center of the crankshaft 11 against the respective axial stop 35 or 125.

[0079] Each fastening element 9 can preferably be designed in two parts and comprise a first head element 93 and a second head element 91. The first head element 93 is formed integrally with a shaft of the fastening element 9, which is screwed into the internal thread 90. The second head element 91 can be designed as a separate component, wherein an additional thread 95 can be provided between the second head element 91 and the crank arm 12. A contact surface 94 that widens, for example conically, towards the center of the crankshaft 11 is preferably formed between the first head element 93 and the second head element 91. By screwing the second head element 91 separately into the thread 95 of the crank arm 12, additional bracing can be achieved between the fastening element 9 and the crank arm 12, so that a particularly stable connection of the elements of the crank drive 10 is achieved.

Claims

Claims 1. Crank interface of a crank drive (10) of a two-wheeler (100), for connecting and / or transmitting power between a crankshaft (11) and a crank arm (12), comprising: - a cylinder region (2) having a cylindrical outer surface (20), - a tapered region (3) having a tapered outer surface (30), and - a toothing region (4) having a plurality of protruding teeth (40).

2. Crank interface according to claim 1, wherein the tapered region (3) is arranged in the axial direction between the cylinder region (2) and the toothed region (4).

3. Crank interface according to claim 2, wherein the tapered region (3) forms a stepless transition between the cylindrical outer surface (20) of the cylinder region (2) and an outer circumference (45) of the teeth (40) of the toothed region (4).

4. Crank interface according to one of the preceding claims, wherein the outer surface (30) of the tapered region (3) is conically tapered.

5. Crank interface of a crank drive (10) of a two-wheeler (100), for connecting and / or transmitting power between a crankshaft (11) and a crank arm (12), comprising: - a first cylinder region (6) having a cylindrical first outer surface (60), - a second cylinder region (7) having a cylindrical second outer surface (70), and - a toothed region (4) having a plurality of protruding teeth (40). Crank interface according to claim 5, wherein the second outer surface (70) and an outer periphery (45) of the teeth (40) of the toothed region (4) have the same outer diameter (46). Crank interface according to claim 5 or 6, further comprising a transition region (8) arranged between the first cylinder region (6) and the second cylinder region (7), such that the transition region (8) forms a predetermined axial distance (67) between the first cylinder region (6) and the second cylinder region (7). Crank interface according to one of the preceding claims, wherein the protruding teeth (40) of the toothed region (4) form a straight shaft toothing. Crankshaft of a crank drive (10) of a two-wheeler (100), comprising at least one crank interface (1) according to one of the preceding claims.Crankshaft of a crank mechanism (10) of a two-wheeler (100), comprising a crank interface (1) according to one of claims 1 to 4 at each axial end of the crankshaft (11). Crankshaft of a crank mechanism (10) of a two-wheeler (100), comprising:. - a crank interface (1) according to one of claims 1 to 4 at a first axial end (11a) of the crankshaft (11), and - a crank interface (1) according to one of claims 5 to 7 at a second axial end (11b) of the crankshaft (11). A crank arm of a crank drive (10) of a two-wheeler (100), comprising a crank interface according to one of claims 1 to 8, in particular according to one of claims 1 to 4. Crank drive of a two-wheeler (100), comprising a crankshaft (11) according to one of claims 9 to 11, and two crank arms (12) according to claim 12. Crank drive according to claim 13, further comprising one fastening element (9) per crank arm (12), wherein each crank arm (12) is fastened to the crankshaft (11) by means of the respective fastening element (9). Crank drive according to claim 14, wherein on a first side (11a) of the crankshaft (11), a first axial stop (35) of the crank arm (12) is formed by means of the respective tapered regions (3) on the crankshaft (11) and crank arm (12). Crank drive according to claim 15, further comprising a chainring holder (110) which is designed to fasten a chainring, wherein the chainring holder (110) is arranged on the first side (11a) of the crankshaft (11).Crank drive according to one of claims 13 to 16, further comprising at least one bearing (120) for supporting the crankshaft (11), wherein a second axial stop (125) of the crank arm (12) is formed on a second side (11b) of the crankshaft (11) by means of the bearing (120). Crank drive according to one of claims 13 to 17, wherein a press connection, in particular by means of a transition fit, is formed between the respective cylinder region (2, 6) of each crank arm (12) and the cylinder region (2, 6) of each side (11a) of the crankshaft (11). Two-wheeler, in particular electric bicycle, comprising:. - a crankshaft (11) according to one of claims 9 to 11, and / or - two crank arms (12) according to claim 12, and / or - a crank mechanism (10) according to one of claims 14 to 18.

Images