Transmission assembly with plug-in connection and / or damping element for a drive unit of an electric bicycle

Abstract

The proposed solution relates in particular to a drive unit (A) for an electric bicycle (F), comprising a housing (G), at least one drive motor (R, S), a bottom bracket shaft assembly (T) rotatably mounted in the housing (G), and a transmission assembly (1) for transmitting a drive torque generated by the at least one drive motor (R, S) to an output element (AT) of the drive unit (A). In order to rotatably support transmission elements (32, 42) of the transmission assembly (1), said transmission elements interacting with one another, two transmission structural components (10, 2) are provided which are fixed to one another and which are received in the housing (G) together with the drive motor (R, S) and the bottom bracket shaft assembly (T). The two transmission structural components (10, 2) are plugged together in a form-fitting manner at at least two connection points (101B, 102B) and are oriented relative to one another. Alternatively or additionally, at least one of the transmission structural components (10, 2) rests against a section (GA) of the housing (G) via a damping element (6).

Description

[0001] Gearbox assembly with plug connection and / or damping element for a drive unit of an electric bicycle

[0002] Description

[0003] The proposed solution specifically concerns a drive unit for an electric bicycle.

[0004] Drive units for electric bicycles have at least one drive motor, typically in the form of at least one electric motor, which is housed in a casing of the drive unit. The casing also contains a transmission assembly through which a drive torque generated by the at least one drive motor can be transmitted to an output element of a bottom bracket assembly. Such an output element is, for example, a component that is arranged coaxially to a shaft axis of a bottom bracket assembly and that is rotationally fixed to a pulley or chainring in order to transmit a drive torque generated at the drive unit to a rear wheel of the electric bicycle via a belt or chain.

[0005] For the rotatable mounting of interacting gear elements within the gearbox assembly, two gear structure components, fixed to one another and also housed within the casing, are provided. A gear structure component can be, for example, part of the gearbox assembly itself, or it can be a component provided separately from the gearbox assembly. In any case, the gear structure components serve to rotatably mount interacting gear elements, enabling the transmission of the motor's drive torque towards the output element.

[0006] To ensure sufficient structural rigidity during operation of the drive unit and to guarantee the intended alignment of the gear elements relative to each other, it is already known in practice to provide corresponding gear structure components within a housing of the drive unit, to fix these components to one another, and in turn to fix at least one of the gear structure components to a housing part of the housing. Nevertheless, there is still a need for improvements to such drive units.

[0007] The proposed solution provides a remedy here.

[0008] A drive unit for an electric bicycle is proposed in which two transmission structure components are positively connected to each other at at least two connection points and aligned relative to each other, and / or in which at least one of the transmission structure components rests against a section of the housing via a damping element.

[0009] Overall, the proposed solution allows for a comparatively high stiffness of the gearbox structure within the housing of the drive unit, with corresponding advantages in terms of wear and noise generation from the gearbox assembly during operation of the drive unit.

[0010] According to the first aspect of the proposed solution, the two gearbox components are fixed to each other and aligned relative to each other by a positive locking mechanism at two connection points where the gearbox components can be plugged together. During assembly of the drive unit, the two gearbox components can thus be plugged together, so that they are fixed to each other in a predetermined orientation via plug connections before being further secured by at least two separate fixing elements, such as screws or bolts. In principle, one of the gearbox components could be, for example, a gearbox carrier fixed to a housing part, while the other gearbox component could be a bearing shield fixed to the gearbox carrier.

[0011] In one embodiment, at least two connection points are equipped with a positive locking mechanism for securing the two transmission structure components to one another and aligning them relative to each other. This positive locking element engages in a recess on at least one of the transmission structure components. At each connection point, one of the plug connections is thus realized via this positive locking element. In principle, at least one of the two positive locking elements can be formed on a section of a transmission structure component or be formed by a separate component. If a positive locking element is formed by a separate component, this component can be pre-assembled onto one of the transmission structure components before the other transmission structure component is attached to it.

[0012] For example, a separate component is designed as a pin or socket. A pin or socket can have one section that engages a first recess in the first gear structure component and another section that engages a second recess in the second gear structure component when the two components are joined. By providing a socket at a connection point, it is also possible to extend a section of a fixing element through the socket, thereby securing the two gear structure components together. Thus, during assembly, a socket at a connection point allows the two gear structure components to be fixed in a defined orientation relative to each other.Subsequently, a fixing element with a section protruding through the bushing is mounted at the same connection point, via which the two gearbox structure components are fixed to each other.

[0013] In one embodiment, the two gear structure components are plugged together along a connecting axis and then fixed to each other and aligned relative to each other at least two connection points in a plane perpendicular to the connecting axis by means of two positive locking elements. In the plane perpendicular to the connecting axis, the plugged-together gear structure components are already in a predefined orientation relative to each other, so that only the fixation of the gear structure components along the connecting axis needs to be ensured by two additional fixing elements.

[0014] Independently of the above, it may additionally be provided that the two gear structure components are fixed to one another by (separate) fixing elements, each of which has a coefficient of linear expansion that is (essentially or exactly) identical to a coefficient of linear expansion of the second gear structure component. In particular, it may be provided that, for fixing the two gear structure components to one another, only fixing elements are used, each of which has a coefficient of linear expansion that is (essentially or exactly) identical to a coefficient of linear expansion of the two gear structure components.If one or more axes of rotation of the gearbox assembly run parallel to the connecting axis along which the two gearbox components are joined and along which fixing elements for securing the gearbox components are also mounted, an axial preload can thus be specifically focused on the fixing elements that have an identical coefficient of thermal expansion. Radial or tangential forces with respect to the one or more axes of rotation in a plane perpendicular to the connecting axis are absorbed via the plug connections provided at the connection points between the gearbox components.

[0015] The above variants can, in principle, be combined with the second aspect of the proposed solution, although independently of it, according to which at least one of the transmission structure components rests against a section of the housing via at least one damping element.

[0016] Via at least one damping element, one of the transmission components inside the housing rests against a section of the housing. This effectively suppresses any relative movement of the transmission assembly, and thus of the transmission components, relative to the housing, thereby preventing any disruptive noise that might occur during operation of the drive unit. The transmission component is thus coupled to the housing via at least one damping element. Such a damping coupling is particularly advantageous when direct fixing of the housing to the transmission component is not possible or cannot be achieved due to design or assembly constraints. For example, bolting a housing part to the transmission component may not be possible or may be undesirable given the need for external access to such a connection.However, at least one damping element enables a tolerance-compensating coupling between the housing and this one gearbox structural component.

[0017] The at least one damping element typically consists, at least partially, of an elastic material. In particular, an elastic section of the at least one damping element can be pressed between the housing section and the transmission structure component. An elastic section of the damping element is thus held and clamped without play in a space between the housing and the transmission structure component. In one embodiment, for cost-effectiveness, the at least one damping element is designed with an O-ring. Here, the O-ring can, for example, be attached to a section of one of the transmission structure components.

[0018] In one embodiment, a cross-sectional view of the drive unit shows a section of a gear structure component, a section of at least one damping element, and the section of the housing against which the gear structure component rests via the at least one damping element. These sections follow one another along a spatial direction that extends radially to an axis of rotation about which at least one of the gear elements of the gear assembly is rotatable. The at least one damping element thus provides a damping coupling between the gear structure component and the housing in a radial direction relative to the axis of rotation of the gear assembly. For example, the damping element can be arranged on a section of the gear structure component that projects axially with respect to the axis of rotation.

[0019] The gearbox assembly can, in principle, form a pre-assembled unit that is fixed to at least one housing part. This includes, in particular, a pre-assembled unit consisting of two gearbox structural components fixed to one another. The two gearbox structural components and the interacting gearbox elements are thus pre-assembled and are to be mounted in a pre-assembled state to a (first) housing part, on which, for example, the drive motor of the drive unit is already provided. In one possible embodiment, the section of the housing against which a gearbox structural component rests via the at least one damping element is formed by another (second) housing part, which is fixed to the (first) housing part that supports the drive motor and the gearbox assembly during the assembly of the drive unit, for example, in the manner of a housing cover.

[0020] In principle, the at least two gear elements rotatably mounted on one of the gear structure components and interacting with each other can be different types of gear elements, for example, friction wheels or belt pulleys. In one embodiment, the interacting gear elements are gears. For example, a stepped gear (of a first gear stage) can be rotatably mounted on one of the gear structure components, meshing with a pinion on a rotor shaft of a rotor assembly of the electric motor drive. This stepped gear is then rotationally fixed to a stepped pinion as the first gear element (of a second gear stage) of the gear assembly. A second gear element, fixed to the first gear structure component via a bearing element, can be an intermediate gear that meshes with the stepped pinion.The intermediate gear can in turn mesh with an output gear of the bottom bracket shaft assembly to transmit a motor-generated drive torque to an output element which, when the drive unit is attached to an electric bicycle, transmits a drive force to a rear wheel of the electric bicycle via a belt or chain.

[0021] In one embodiment, the stepped gear and the stepped pinion of the gear assembly are connected to a bearing shaft in a rotationally fixed manner, which is rotatably mounted via a (first) bearing received on one of the gear structure components.

[0022] For further functional integration at the gearbox assembly, one embodiment may provide that one of the gearbox structural components includes a bearing section to which at least a part of an electronic assembly of the drive unit is attached. This single gearbox structural component can thus, for example, form a bearing section for fixing the electronic assembly within the housing of the drive unit, separate from the areas where the rotatable gearbox elements are mounted on the gearbox structural component. Such a bearing section can, for example, serve to fix at least a part of at least one circuit board of the electronic assembly of the drive unit. Consequently, in the drive unit's intended assembled state, at least a part of a circuit board is fixed to the bearing section.Such a circuit board could, for example, contain parts of a control electronics system for controlling the electric motor drive.

[0023] The proposed solution also includes an electric bicycle with a variant of the proposed drive unit.

[0024] Part of the proposed solution is also a method for assembling a drive unit for an electric bicycle. The fully assembled drive unit comprises a housing, at least one drive motor, a bottom bracket assembly rotatably mounted in the housing, and a gearbox assembly for transmitting a drive torque generated by the at least one drive motor to an output element of the bottom bracket assembly. The housing is designed to accommodate the at least one drive motor and the gearbox assembly. For the rotatable mounting of interacting gearbox elements of the gearbox assembly, two gearbox structural components, which are fixed to one another and must also be accommodated in the housing, are provided.Within the framework of the proposed assembly method, it is provided that a) the transmission structure components are positively connected to each other at at least two connection points and aligned relative to each other before the two transmission structure components are fixed to each other (for example, via at least two additional fixing elements at the connection points or spaced apart therefrom), and / or b) during the assembly of the drive unit, at least one damping element is arranged on one of the transmission structure components or on a section of the housing, wherein one transmission structure component rests against the section of the housing via the at least one damping element in the fully assembled drive unit.

[0025] One embodiment of a proposed assembly method is therefore particularly suitable for assembling one embodiment of a proposed drive unit.

[0026] For example, one embodiment of a proposed assembly method may provide that the two gear structure components are plugged together along a connecting axis, so that the two gear structure components are fixed to each other and aligned relative to each other in a plane perpendicular to the connecting axis by means of two positive locking elements, before the two gear structure components are fixed to each other along the connecting axis by means of at least two separate fixing elements, such as screws or bolts.

[0027] Alternatively or additionally, it may be provided that the at least one damping element comprises at least one elastic section which, in one embodiment of the proposed assembly method, is pressed in between the section of the housing and one of the gear structure components when the housing is closed and the two gear structure components are as intended inside the housing.

[0028] The accompanying figures illustrate possible implementation variations of the proposed solution. These show:

[0029] Figure 1 shows an outside view of a first housing part of a housing of an embodiment of a proposed drive unit;

[0030] Figure 2 shows the interior of the first housing part of Figure 1 with a stator and a rotor of a drive motor already included therein;

[0031] Figure 3 shows the first housing part with a gear assembly mounted on it, to which a second gear structure component in the form of a bearing shield is fixed;

[0032] Figure 4 shows the gearbox assembly of Figure 3 with the bearing shield in a partial exploded view;

[0033] Figure 5 shows an excerpt of a cross-sectional view of the fully assembled

[0034] Drive unit;

[0035] Figure 6 schematically shows an electric bicycle with the drive unit;

[0036] Figure 7 shows the assembled drive unit in perspective view.

[0037] View of the outside of the second housing part of the case.

[0038] Figure 6 illustrates an electric bicycle F with a drive system comprising an electric motor drive unit A. The electric bicycle F has a frame 110, which here exemplarily includes a top tube, a down tube, and a seat tube, and to which the drive unit A is attached at the intersection of the seat tube and the down tube. The drive unit A includes control electronics SE and a sensor device 115. At least one electric motor of the drive unit A can be controlled via the control electronics SE, in particular to specify the level of externally generated assistance for propelling the electric bicycle F. The sensor device 115 is designed to detect the rotational speed of the drive shaft of a bottom bracket assembly T of the drive unit A. For this purpose, the sensor device 115 can include a speed sensor by which the rotational speed of the drive shaft can be measured.A driving force for propelling the electric bicycle F can be applied to the drive shaft by a rider using muscle power via a pair of cranks and pedals connected to it. Optionally, the sensor device 115 can also be designed to detect a torque applied to the drive shaft by muscle power and may, for example, be equipped with a torque sensor and / or a position sensor.

[0039] A drive element of the drive unit A, for example a drive element mounted coaxially to the drive shaft, is connected to a rear wheel 112 of the electric bicycle F via a belt or chain 113 as a power transmission link in order to drive the electric bicycle F. This rear wheel 112 is equipped, for example, with a wheel sensor 114 for determining the speed of the electric bicycle F. Of course, the wheel sensor 114 could instead be located on a front wheel 111 of the electric bicycle F.

[0040] The drive system of the electric bicycle F further comprises a control unit 117. In Figure 6, for example, the control unit 117 is attached in the area of ​​the handlebars of the electric bicycle F and connected to the control electronics SE of the drive unit A, typically via one or more cables. User input can be detected via the control unit 117 and used to control the drive unit A. For example, the control unit 117 includes at least one display to inform a user of the electric bicycle F about

[0041] - the current operating status of drive unit A, for example with regard to a set support level,

[0042] - a state of charge of an energy storage device 116 that supplies the drive unit A with electrical energy, which contains, for example, at least one (rechargeable) battery, and / or

[0043] - to inform a set gear that specifies the gear ratio with which a drive torque initiated at the drive shaft by muscle power is transmitted to the output element of the drive unit A.

[0044] Figure 7 shows a perspective view of an embodiment of the drive unit A, looking at the outside of a housing G of the drive unit A. The housing G is designed with two housing parts G1 and G2 fixed to one another. Housing parts G1 and G2 each form one of two housing halves of the housing G. Each housing half G1, G2 has a housing opening OT1 or OT2 through which an end of the bottom bracket axle of the bottom bracket axle assembly T, to be connected to pedals, protrudes from the inside of the housing G to the outside.

[0045] On the outer side of the second housing half G2, as shown in Figure 7, the end of the bottom bracket shaft assembly T is extended outwards, providing access to an output element AT. This output element, rotatably mounted coaxially with respect to the axis of rotation of the bottom bracket shaft, can be connected, for example, to a pulley or chainring in a rotationally fixed manner to drive the power transmission element 113.

[0046] Figures 1, 2, and 3 show, in different views, the other, first housing half G1 of the housing G for a variant embodiment of a proposed drive unit A. The first housing half G1, together with the second housing half G2, defines an internal housing space for the electronic and mechanical components of the drive unit A. For connection to the second housing half G2, the first housing half G1 has several (at least two) – in this case, three – mounting points B1, B2, and B3 distributed around its outer circumference. In addition to the housing opening OT1 for the bottom bracket axle assembly T of the drive unit A, the first housing half G1 also features a bearing opening OR for a rotor shaft RW of an electric motor drive for the drive unit A.The housing opening OT1 on the first housing half G1 is designed coaxially to the housing opening OT2 on the second housing half G2, so that the ends of the drive shaft of the bottom bracket shaft assembly T protrude on both sides of the housing G in order to be able to attach pedals to it.

[0047] As can be seen particularly from the inside of the first housing half G1 in Figure 2, the first housing half G1 forms a motor bearing point with a bearing cup for the arrangement of a stator S of the electric motor drive. In Figure 2, this stator S is already inserted into the first housing half G1 during the assembly of the drive unit A. A rotor assembly R is inserted into the stator S. The rotor assembly R comprises a rotor unit with lamination-covered magnets and a rotor shaft RW. A (motor) pinion is formed on the rotor shaft RW or fixed in a rotationally fixed manner, so that a drive torque generated by the electric motor drive R, S can be transmitted via the pinion.

[0048] After the rotor assembly R is inserted into the first housing half G1, the rotor shaft RW with the pinion projects axially as shown in Figure 3, allowing the pinion to engage a stepped gear 31 of a gear assembly 1 (see Figure 4). In the illustrated embodiment, a gear assembly 1 with a two-stage gearbox is pre-assembled on a gear carrier 10 and then pre-mounted and fixed to the first housing half G1. Subsequently, a bearing shield 2 is attached to the gear carrier 10 of the gear assembly 1. This basic procedure is illustrated in the exploded view of Figure 4. Figure 3 shows the first housing half G1 after completion of the corresponding assembly steps, with the gear assembly 1 and the bearing shield 2 fixed to the gear carrier 10 of the gear assembly 1.

[0049] In the assembled state of the drive unit A, an electrically generated drive torque can be transmitted via an intermediate gear 42 of the transmission assembly 1 (see Figure 4) to an output gear and from there to the output element AT of the bottom bracket shaft assembly T. The output element AT, to which, for example, a belt pulley or a chainring can be attached, can then drive the power transmission element 113 of Figure 6 to transmit torque to the rear wheel 112 of the electric bicycle F.

[0050] The intermediate gear 42 meshes with a stepped pinion 32 of the gear assembly 1, which is rotationally fixed to the stepped gear 31, which is driven by the pinion of the rotor shaft RW. A first bearing, e.g., in the form of a rolling bearing, is provided for the rotatable mounting of the stepped gear 31 and the stepped pinion 32 on the gear carrier 10. The outer ring of this bearing is fixed in a bearing seat 10D of the gear carrier 10. A bearing shaft, which rotatably couples the stepped gear 31 and the stepped pinion 32 to each other, is rotatably mounted via an inner ring of this first bearing. At a shaft end spaced apart from the bearing seat 10D, a further, second bearing 33, also for example in the form of a rolling bearing, is provided, so that the bearing shaft and thus the stepped gear 31 and the stepped pinion 32 are rotatably mounted on the gear carrier 10 about a first rotation or gear axis D of the gear assembly 1 defined by the bearing shaft (see Figure 5).This first axis of rotation or transmission runs parallel to a second axis of rotation or transmission of the transmission assembly 1, about which the intermediate gear 42 is rotatably mounted on the transmission carrier 10 and which is defined by a bearing pin 41. The bearing pin 41, on which the intermediate gear 42 is rotatably mounted, is positively engaged with one end provided by the transmission carrier 10 in a bearing opening of the bearing shield 2 and, when the drive unit A is fully assembled, projects into a receptacle of the second housing part G2 (see cross-sectional view of Figure 5).

[0051] Figure 4 shows a partial exploded view of the gearbox assembly 1 with the bearing shield 2. As can be seen in particular from this, the gearbox support 10 forming the bearing seat 10D has several fastening points 10C, via which the gearbox support 10 and thus the pre-assembled gearbox assembly 1 can be fixed inside the first housing half G1, for example by means of screws or bolts.

[0052] For further functional integration, a bearing section 10A is provided on the gear carrier 10 of the gear assembly 1. At least part of an electronics assembly for the control electronics SE of the drive unit A is mounted on this bearing section. The bearing section 10A, which is intended for fixing the electronics assembly in the housing G of the drive unit A, is located away from those areas, such as the bearing seat 10D, where the rotatable gear elements, such as the stepped gear 31, the stepped pinion 32, and the intermediate gear 42, are mounted on the gear carrier 10. The bearing section 10A serves, for example, to fix at least part of at least one printed circuit board of the electronics assembly of the drive unit A.

[0053] The bearing shield 2 is fixed to the gearbox carrier 10 at connection points in the form of screw bosses 101 B and 102 B, each of which has an internal thread. With the bearing shield 2 properly attached to the gearbox carrier 10, fixing elements – here in the form of screws 7 – can be passed through laterally projecting connecting sections 21 and 22 of the bearing shield 2 and screwed into the respective corresponding screw boss 101 B or 102 B.

[0054] To ensure a predetermined alignment of the bearing shield 2 relative to the gearbox carrier 10 before it is fixed to the gearbox carrier 10 using several screws 7, to simplify assembly, and, if necessary, to apply an axial preload, primarily relative to the axes of rotation of the gearbox elements of the gearbox assembly 1, via the fixing with the screws 7, the bearing shield 2 can be plugged onto the gearbox carrier 10. Using corresponding plug connections, the bearing shield 2 can therefore be positively locked and correctly aligned on the gearbox carrier 10 during assembly, even without screws. For the plug connections, positive locking elements in the form of centering bushings 51B and 52B are arranged on the screw bosses 101B and 102B.The centering bushings 51B and 52B are each inserted into a recess on the corresponding screw boss 101B or 102B of the gearbox carrier 10, so that one end of each gearbox bushing 51B, 52B protrudes axially from a screw boss 101B, 102B and can thus engage in a recess on a connecting section 21, 22 of the bearing shield 2. The screw 7 provided for fixing can also be guided through the respective centering bushing 51B or 52B and screwed into the screw boss 101B or 102B.

[0055] In the sectional view of Figure 5, for example, it can be seen how the centering bushing 52B is received in a recess 1020B at the open end of the screw dome 102B and engages in a recess 220 of the connecting section 22 of the position plate 2.

[0056] The bearing shield 2 is attached to the gearbox carrier 10 along a connecting axis that runs parallel to a z-direction with respect to a Cartesian coordinate system. The bearing shield 2 is inserted into the gearbox carrier 10 along the -z-direction. The screws 7 are then also installed along this direction. The bearing shield 2 is then fixed and aligned in an xy-plane on the gearbox carrier 10 by means of the centering bushings 51B and 52B before the screws 7 are installed. Through the additional centering bushings 51B and 52B, in combination with the screws 7 provided for fixing, the two gearbox structural components, namely the gearbox carrier 10 and the bearing shield 2, form a comparatively rigid gearbox structure within the housing 2.

[0057] In one possible embodiment, the screws 7 have a coefficient of linear expansion that is (essentially or exactly) identical to the coefficients of linear expansion of the gear carrier 10 and the bearing shield 2. The screws 7 thus primarily provide the axial preload along the connecting axis running parallel to the z-direction.

[0058] In the illustrated embodiment, a damping element in the form of an O-ring is further provided that, when the drive unit A is fully assembled, a shoulder 20 of the bearing shield 2 projects axially towards the second housing half G2 with respect to the axis of rotation D. During assembly, the O-ring 6 is secured to the shoulder 20 before the housing G is closed by attaching the second housing half G2 to the first housing half G1. With the housing G closed, the shoulder 20 lies within the second housing half G2 with a cylindrical surface partially opposite a housing section GA in a radial direction with respect to the axis of rotation D. A narrow gap remains between the outer cylindrical surface of the shoulder 20 and an inner surface of the housing section GA.

[0059] A section of the elastic O-ring 6 is pressed into this gap when the second housing half G2 is attached to the first housing half G1. In this way, the shoulder 20 rests against the housing section GA via the pressed-in O-ring. The O-ring 6 thus provides a damping connection between the shoulder 20 and, consequently, the bearing shield 2 to the housing G. Without the bearing shield 2 being fixed to the second housing half G2 via a separate fixing element, a connection between the bearing shield 2 and the second housing half G2 is ensured. This also contributes to a reduction in gearbox noise during the operation of the drive unit A and to a reduction in wear on the mechanically interacting gearbox elements of the gearbox assembly 1.

[0060] Reference symbol list

[0061] 1 Gearbox assembly

[0062] 10 Gearbox carrier (1st gearbox structural component)

[0063] 101B, 102B Screw dome (connection point)

[0064] 1020B recess

[0065] 10A Storage section

[0066] 10C Mounting point

[0067] 10D bearing seat

[0068] 110 (bicycle) frames

[0069] 111 front wheel

[0070] 112 rear wheel

[0071] 113 Belts / Chains

[0072] 114 Wheel sensor

[0073] 115 Sensor device

[0074] 116 Energy storage

[0075] 117 Control unit

[0076] 2 Bearing shield (2nd gearbox structure component)

[0077] Paragraph 20

[0078] 21, 22 connecting section

[0079] 220 recess

[0080] 31 stepped gear

[0081] 32-speed sprocket

[0082] 33 (rolling) bearings

[0083] 41 bearing bolts

[0084] 42 Intermediate gear

[0085] 51 B, 52B Centering bushing (positive locking element)

[0086] 6 O-rings (damping element)

[0087] 7 Screw (fixing element)

[0088] A drive unit

[0089] AT output element

[0090] B1 - B3 junction

[0091] D axis of rotation

[0092] G Housing

[0093] G1, G2 Housing half (housing part)

[0094] GA Housing Section

[0095] OR Bearing opening for rotor shaft OT1, OT2 Housing opening for bottom bracket shaft

[0096] R Rotor assembly

[0097] RW rotor shaft

[0098] S Stator

[0099] SE Control Electronics

[0100] TT retlagerwellenbaugruppe

Claims

Claims 1. Drive unit for an electric bicycle (F), comprising a housing (G), at least one drive motor (R, S), a bottom bracket shaft assembly (T) rotatably mounted in the housing (G), and a gear assembly (1) for transmitting a drive torque generated by the at least one drive motor (R, S) to an output element (AT) on a bottom bracket shaft assembly (T), wherein the at least one drive motor (R, S) and the gear assembly (1) are housed in the housing (G), and two gear structure components (10, 2) fixed to one another are provided for a rotatable mounting of interacting gear elements (32, 42) of the gear assembly (1), which are also housed in the housing (G), characterized in that the two gear structure components (10, 2) are positively connected to one another at at least two connection points (101B, 102B) and aligned relative to each other, and / or at least one of the gear structure components (10,2) is in contact with at least one damping element (6) on a section (GA) of the housing (G).

2. Drive unit according to claim 1, characterized in that at the at least two connection points (101 B, 102 B) for fixing the two Gear structure components (10, 2) are connected to each other and for the alignment of the two gear structure components (10, 2) relative to each other a positive locking connection is provided via a positive locking element (51 B, 52B) which engages in a recess (1020B, 220) on at least one of the gear structure components (10, 2).

3. Drive unit according to claim 2, characterized in that at least one of the two positive locking elements (51 B, 52B) is formed on a section of a transmission structure component (10, 2) or is formed by a separate component.

4. Drive unit according to claim 3, characterized in that the separate component is designed as a pin or socket (51 B, 52B).

5. Drive unit according to claim 4, characterized in that, in at least one positive locking element formed by the bushing (51 B, 52B), a section of a fixing element (7) projects through the bushing (51 B, 52B) with which the two gear structure components (10, 2) are fixed to one another.

6. Drive unit according to one of claims 2 to 5, characterized in that the two gear structure components (10, 2) are plugged together along a connecting axis (z-axis) and are fixed to each other and aligned relative to each other in a plane (xy-plane) perpendicular to the connecting axis (z-axis) via the two positive locking elements (51 B, 52B).

7. Drive unit according to one of the preceding claims, characterized in that the two gear structure components (10, 2) are fixed to one another by fixing elements (7) which each have a coefficient of linear expansion that is identical to a coefficient of linear expansion of the two gear structure components (10, 2).

8. Drive unit according to one of the preceding claims, characterized in that the at least one damping element (6) comprises at least one elastic section which is pressed in between the section (GA) of the housing (G) and the one transmission structure component (2).

9. Drive unit according to one of the preceding claims, characterized in that the at least one damping element comprises an O-ring (6).

10. Drive unit according to one of the preceding claims, characterized in that in a cross-sectional view a section of one gear structure component (2), a section of the at least one damping element (6) and the section (GA) of the housing (G) on which one gear structure component (2) abuts via the at least one damping element (6) follow one another along a spatial direction which extends radially to an axis of rotation (D) about which at least one gear element (32, 42) is rotatable.

11. Drive unit according to claim 10, characterized in that the at least one damping element (6) is arranged on a section (20) of one gear structure component (2) which projects axially with respect to the axis of rotation (D).

12. Drive unit according to claim 9 and claim 11, characterized in that the O-ring (6) is attached to an axially projecting section of one of the transmission structure components (2).

13. Drive unit according to one of the preceding claims, characterized in that the gear assembly (1) forms a pre-assemblable unit which is fixed to at least one housing part (G1) of the housing (G).

14. Electric bicycle with a drive unit according to one of the preceding claims.

15. Method for assembling a drive unit for an electric bicycle (F), wherein the fully assembled drive unit (A) comprises a housing (G), at least one drive motor (R, S), a bottom bracket shaft assembly (T) rotatably mounted in the housing (G), and a gear assembly (1) for transmitting a drive torque generated by the at least one drive motor (R, S) to an output element (AT) of the bottom bracket shaft assembly (T), wherein the at least one drive motor (R, S) and the gear assembly (1) are to be accommodated in the housing (G), and two gear structure components (10, 2) to be fixed to one another are provided for a rotatable mounting of cooperating gear elements (32, 42) of the gear assembly (1), which are also to be accommodated in the housing (G), characterized in that the two gear structure components (10, 2) are connected at at least two connection points (101 B,102B) are positively fitted together and aligned relative to each other before the two gear structure components (10, 2) are fixed to each other, and / or during the assembly of the drive unit (A) at least one damping element (6) is arranged on one of the gear structure components (10, 2) or on a section (GA) of the housing (G), via which, in the fully assembled drive unit (A), one gear structure component (2) bears against the section (GA) of the housing (G).

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