Drive unit and assembly method for an electric bicycle having a stator support section.

Abstract

The present invention relates in particular to a drive unit (A) for an electric bicycle, and includes an electric motor drive unit having a stator (2) and a rotor (3). The rotor (3) is rotatable about a rotor axis (R), and the unit comprises a housing (G1) provided with a support portion (1) for the stator (2). The support portion (1) has a wall (11) that surrounds the rotor axis (R) in the circumferential direction, defining a means for receiving the stator (2). An edge portion (12) surrounding the rotor axis (R) in the circumferential direction is formed on the wall (11), the edge portion (12) protrudes in the axial direction with respect to the rotor axis (R), is surrounded by an enclosing portion (412) of a component (40) attached to the housing (G1), and is supported by a part (4120) of the enclosing portion (412) in a direction toward the radially outward direction with respect to the rotor axis (R).

Description

Technical Field

[0001] The proposed solution particularly relates to the drive unit of an electric bicycle.

Background Art

[0002] Drive units for electric bicycles equipped with at least one electric motor drive unit are widely known. At least one electric motor drive unit is used to supply a driving torque by external operation to the output member of the drive unit. The output member is connected, for example, via a transmission medium such as a belt or chain, to a power transmission member connected to the rear wheel of the electric bicycle. The driving torque by external operation is usually applied in addition to the driving torque by muscle operation applied to the pedal shaft via the pedal.

[0003] On the other hand, the output member and the power transmission member are usually provided on a pedal shaft assembly consisting of a pedal shaft equipped with a freewheel. Thereby, since the rotation axis of the pedal shaft can be made the same as the rotation axes of the output member and the power transmission member, miniaturization of the drive unit becomes possible.

[0004] The electric motor drive unit of the drive unit is usually provided with at least one electric motor having a stator and a rotor. The stator is housed in the housing part of the drive unit, rotationally fixed and supported. The housing part forms a support part, for this purpose, in the form of, for example, a bearing pot, and at the time of assembling the drive unit, the stator (together with the rotor already assembled if necessary) is arranged therein. The arrangement and fixation of the stator with excellent positional accuracy in the housing-side support part are particularly important regarding the adverse torque generated during the operation of the electric motor drive unit. If the stator is not arranged at the center regarding the rotor axis of the rotating rotor, if the stator is excessively deformed, or if the center position of the stator cannot be maintained during the operation of the drive unit, adverse torque is generated due to the axial misalignment (eccentricity) and / or ovalization of the stator.

Summary of the Invention

Problems to be Solved by the Invention

[0005] Given this background, an improved drive unit and assembly method are needed in this regard. These would allow the stator to be more easily and / or more stably fixed to the housing with higher positional accuracy, and / or simplify the assembly of the drive unit.

[0006] According to one embodiment of the proposed solution, a drive unit for an electric bicycle is provided. This drive unit comprises an electric motor drive section including a stator and a rotor, and a housing section having a support section for the stator inside. The support section has a wall surrounding the axis of the rotor. This wall defines the receiving section for the stator in the support section. The wall also has an edge (discontinuous or continuous) that extends circumferentially along the rotor axis, and this edge protrudes axially with respect to the rotor axis and is surrounded by an enclosure of a component attached to the housing section. Thus, the edge is supported by a portion of the enclosure in a direction radially outward with respect to the rotor axis.

[0007] Therefore, the enclosure on the wall that protrudes axially (opposite to the mounting direction in which the stator is attached to the support) is enclosed by an enclosure of an additional component attached to the housing, thereby supporting the edge radially outward. Thus, the support is reinforced, particularly at the edge, by the additional component attached to the housing. The structural rigidity of the insertion opening of the support is improved by the component attached to the housing. This insertion opening is defined by the edge and formed for positioning the stator in the support. This is particularly effective in preventing ellipsification of the stator during and after assembly to the support due to forces generated during the operation of the drive unit and externally applied forces.

[0008] By providing a circumferential surrounding enclosure, that is, an enclosure formed in a completely annular shape along the rotor axis, and a configuration that surrounds the edge in relation to it, even a component with an additional enclosure attached to the support can be easily centered with respect to the rotor axis. By connecting the surrounding enclosure and the edge, the component can be automatically centered when attached to the housing.

[0009] In one embodiment, the edge is formed by an axially projecting edge on a wall that extends annularly around the rotor axis. Thus, the edge is provided with, for example, an annular, axially projecting collar or flange, which is surrounded from the outside by a surrounding portion when the drive unit is assembled as intended.

[0010] The enclosed portion is formed, for example, on the bottom surface of a component attached to the support, facing the stator, and protrudes axially toward the wall. The lower surface of the component attached to the support may partially or completely cover the axial end face of the stator, and thus may also partially or completely cover the insertion opening of the support of the stator, which is surrounded by the edge.

[0011] To completely enclose the edge in the circumferential direction, for example, the enclosure of a component attached to a support can extend in an annular shape surrounding the rotor axis.

[0012] For example, the enclosure and the edge are fitted together by a transition fit or an oversize fit. Therefore, the components attached to the support are connected to the edge by force-fitting during assembly into the housing.

[0013] The component attached to the support is, for example, part of the drive unit's transmission mechanism assembly, and its transmission member is connected to the rotor of the electric motor drive unit. For example, the rotor may have a motor shaft to which a pinion is formed or connected in a rotationally fixed state. This pinion meshes with the gears of the transmission mechanism assembly to transmit the drive torque generated by the electric motor drive unit toward the power transmission member of the drive unit. The rear wheel of the electric bicycle is connected to the corresponding power transmission member via a transmission medium such as a belt or chain. The component including the enclosure becomes part of the corresponding transmission mechanism assembly provided for torque transmission and reinforces the support of the already positioned stator when assembling at least some of the drive unit's gears into the housing.

[0014] The at least one transmission member may be rotatably supported on a component of a transmission mechanism assembly mounted on a support. This includes the component mounted on the support being configured as a transmission mechanism carrier of the transmission mechanism assembly, on which multiple (at least two) interconnected transmission members are rotatably supported. The corresponding interconnected transmission members of the transmission mechanism assembly may be, for example, gears that mesh with each other.

[0015] For further functional integration into the component including the enclosure (either as a transmission mechanism carrier or in addition to it), the component may have a support portion on which at least one electronic component of the drive unit is positioned. Thus, the component may be configured and provided to support, and in particular to fix, at least one electronic component of the drive unit. In this embodiment as well, the purpose is not solely to reinforce the support portion at the edge. For example, the component may be configured and provided for the positioning of at least one electronic component of the control electronics circuit of the drive unit, in particular at least one printed circuit board. For example, when the drive unit is in a predetermined assembled state, the printed circuit board is fixed to the support portion.

[0016] Essentially, the stator can be specified to be press-fitted into the support. This may involve press-fitting the stator into the support using thermal support, for example, by heating the housing before and / or during insertion of the stator into the support.

[0017] Another aspect of the proposed solution, which can be readily combined with the first aspect described above, relates to a drive unit in which at least one first recess is formed in the wall of the receiving portion, and at least one second recess is provided on the outer surface of the stator at a position opposite to the first recess. A form-fit element for fixing the stator to the support portion engages with the first recess and the second recess. The form-fit element includes a transmission portion for transmitting an axially acting biasing force with respect to the rotor axis to the stator.

[0018] According to this aspect of the proposed solution, a shape-fitting member is provided, which is formed from a separate component and then assembled after the stator is inserted into the receiving portion of the support. This shape-fitting member not only fixes the stator to the support by shape-fitting but also functions to transmit axially acting biasing forces to the stator. Thus, this shape-fitting member makes it possible to provide an (additional) mating connection (e.g., a tongue and groove connection) between the stator and the support. However, this shape-fitting member functions primarily to transmit axial biasing forces to the stator. The stator is fixed in the support by at least one shape-fitting member so as not to rotate around the rotor axis (in addition, if necessary, to press-fit connections between the outer surface of the stator and the wall). Furthermore, axially acting biasing forces (i.e., parallel to the rotor axis) are transmitted to the stator through the transmission portion of the shape-fitting member. This ensures the axial position of the stator in the support.

[0019] For example, the shape-fitting member can be fitted through shape-fitting portions provided in the first recess of the wall and the second recess of the stator. The overlapping portion can also be configured to be particularly elastically displaceable with respect to this shape-fitting portion. For example, when the stator is already installed and the shape-fitting member is not yet attached to the support, the transmission portion is in a first relative position with respect to the shape-fitting portion. When the shape-fitting member is attached to the wall and stator as intended, the transmission portion can be displaced from this first relative position to a second relative position with respect to the shape-fitting portion by the action of an axial biasing force. For example, the transmission portion can be displaced by attaching additional parts to the housing portion. In this embodiment, the parts attached to the housing portion apply a load to the transmission portion during assembly. As a result, the transmission portion is displaced relative to the shape-fitting portion fitted into the first and second recesses by the biasing force applied by the additional parts attached.

[0020] For example, when the shape fitting member is mounted in the first and second recesses as intended, the transmission portion can be formed to protrude radially inward from the shape fitting member, based on the positional relationship between the rotor axis and the shape fitting portion. For example, in this configuration, the cross-section of the shape fitting member becomes L-shaped, with the first leg of the L-shape defined by the fitting portion and the second leg of the L-shape defined by the transmission portion.

[0021] The mating portion can generally be formed in an elongated shape, and in particular, it can be formed in a pin or rod shape. The first and second recesses are each elongated and have grooves in the longitudinal direction, and in particular, their longitudinal axes can be substantially or precisely parallel to the rotor axis.

[0022] In one embodiment, the shape-fitting member further includes a head portion for receiving assembly forces for insertion into the first and second recesses during the assembly of the drive unit, and this assembly force displaces the shape-fitting portion of the shape-fitting member along the first and second recesses to reach a final position. The head portion provided on the shape-fitting member is configured to receive assembly forces, thereby displacing the shape-fitting portion along the first and second recesses to a final position for this purpose, specifically, being pushed in. The head portion can be provided on the shape-fitting member spatially separated from the transmission portion, and specifically, can be formed thereon. In this way, the assembly force and the axial biasing force after assembly can act on the shape-fitting member at different positions provided for this purpose. Thus, the shape-fitting member has different parts, one part on which the assembly force acts and the other part on which the axial biasing force acts.

[0023] Basically, multiple first and second recesses are provided on the wall of the support and the outer circumferential surface of the stator, and a shaped fitting member is fitted into each recess. Therefore, multiple shaped fitting members for fixing the stator to the support can be provided at multiple locations around the stator or the support, and each of these members is equipped with a transmission part that transmits an axial biasing force to the stator.

[0024] The axial biasing force applied to the transmission portion of the shape-fitting member is applied, for example, by a component of a drive unit attached to the support portion. This component may be, for example, part of the drive unit's transmission mechanism assembly, and in particular may be the transmission mechanism carrier described above. The component that applies the axial biasing force to the transmission portion may be, referring to the first aspect of the proposed solution described above, a component that forms the enclosure for reinforcing the edge of the support portion.

[0025] One of the proposed solutions is an electric bicycle equipped with an embodiment of the proposed drive unit.

[0026] Furthermore, a method for assembling the stator into the housing of the drive unit of an electric bicycle is also part of the proposed solution.

[0027] This particularly includes the following assembly methods. · An edge (intermittent or continuous) extending circumferentially around the rotor axis is formed on the wall of the support portion, and this edge projects axially with respect to the rotor axis. · After the stator and rotor of the drive unit are arranged in the support portion, the components of the drive unit are attached to the housing portion, and the surrounding portion of the housing portion surrounds the edge of the support portion, and the edge is supported in the radially outer direction with respect to the rotor axis by a part of the surrounding portion.

[0028] For example, the component attached to the support portion is arranged at the central position with respect to the rotor axis by connecting its surrounding portion to the edge of the support portion. By reinforcing the edge of the support portion with an additional component having a surrounding portion, when the component is attached to the housing portion, due to the support portion, the component is automatically arranged at the central position with respect to the rotor axis.

[0029] The component attached to the support portion can be, for example, a part of the transmission mechanism assembly of the drive unit. The transmission member is connected to the rotor of the electric motor drive unit. As described above, this can be the transmission mechanism carrier of the transmission mechanism assembly, and at least one transmission member of the transmission mechanism assembly is rotatably supported thereon. In particular, at least one transmission member may be rotatably attached to the transmission mechanism carrier in advance, and for this reason, the transmission mechanism assembly may be pre-assembled before the transmission mechanism carrier having a surrounding portion is attached to the support portion.

[0030] In an alternative or additional assembly method provided, at least one first recess is formed in the wall of the support. This recess faces a second recess provided on the outer circumferential surface of the stator of the drive unit when the stator is inserted as intended into the support. In one of the subsequent assembly steps, a shape-fitting member is inserted into the first recess and the opposing second recess to secure the stator to the support. The shape-fitting member has a transmission section for transmitting an axial biasing force of the rotor of the drive unit relative to the rotor axis to the stator.

[0031] For example, the shape fitting member can be inserted into the first and second recesses until it contacts a portion of the stator with the shoulder portion of the transmission unit. The shape fitting member is inserted into the first and second recesses along the mounting direction (the direction in which the stator is inserted into the housing) until it reaches its final position. In this final position, the transmission unit contacts the edge of the stator, for example, in the outer peripheral region of the stator, and can transmit an axial biasing force to the stator through this edge.

[0032] When the shape-fitting portion of the shape-fitting member is inserted as intended into the first recess of the wall and the second recess of the stator, the transmission portion receives an axial biasing force and fixes the stator axially (and additionally as necessary) within the receiving portion. In this case, the transmission portion that transmits the axial biasing force to the stator can be displaced particularly elastically relative to the shape-fitting portion that fits into the first and second recesses by components of the drive unit that will be attached to the housing portion thereafter.

[0033] As mentioned above, the component that displaces the transmission unit and applies an axial biasing force to the transmission unit when attached to the housing may be the component that forms the enclosure that reinforces the edge of the support unit. In particular, the component that applies the axial biasing force may be formed by a part of the drive unit's transmission mechanism assembly, specifically by the transmission mechanism carrier of the transmission mechanism assembly.

[0034] In the proposed assembly method, the stator is typically press-fitted into the receiving portion of the support. Specifically, this press-fitting is performed by heating at least a portion of the housing.

[0035] The proposed assembly method embodiment is particularly suitable for the assembly of the stator and housing in the proposed drive unit embodiment. Accordingly, the advantages and features of the proposed drive unit embodiment (according to the first and / or second embodiment) described above and below also apply to the proposed assembly method embodiment, and vice versa. [Brief explanation of the drawing]

[0036] The attached drawings illustrate examples of possible embodiments of the proposed solution. [Figure 1A] This is a perspective view showing one embodiment of the proposed drive unit, and is a diagram showing the unit from different vertical side views. [Figure 1B] This is a perspective view showing one embodiment of the proposed drive unit, and is a diagram showing the unit from different vertical side views. [Figure 2A] Figures 1A and 1B show the first housing portion of the drive unit housing as viewed from the outside. [Figure 2B] This figure shows the inside of the first housing section (Figure 2A). [Figure 3] This figure shows the first housing section to which the stator of the electric motor drive section of the drive unit is assembled. [Figure 4] This diagram shows the stage in the assembly process where the rotor is assembled to the first housing section, which already has the stator installed. [Figure 5] This diagram shows the first housing section in which the stator and rotor are assembled. [Figure 6] This diagram shows the stage in which the gear assembly and bearing shield are assembled into the first housing section, which already has the stator and rotor installed. [Figure 7]This figure shows a first housing portion to which a gear assembly is fixed, and a bearing shield fixed to the gear assembly. [Figure 8] This figure shows the bottom view of the transmission mechanism carrier of the gear assembly. [Figure 9] This is a cross-sectional view of the first housing section, to which the rotor and stator are mounted and the gear assembly and bearing shield are fixed. [Figure 10] This is an enlarged excerpt of Figure 9, and in particular, it shows a reinforcing structure in which the edge of the support portion that protrudes in the axial direction is surrounded by the surrounding portion of the bearing shield. [Figure 11] This figure shows a partially illustrated embodiment in which a shaped fitting member is inserted into recesses in the wall of the support and the outer surface of the stator, thereby transmitting the axial biasing force applied by the transmission mechanism carrier to the stator.

[0037] Figures 1A and 1B are perspective views of the drive unit A of an electric bicycle, viewed from two different sides. The drive unit A includes a housing G that houses electronic and mechanical components. The housing G consists of a first housing section G1 and a second housing section G2 that are interconnected, each forming half of the housing.

[0038] The ends of the pedal shaft T protrude from both sides of the housing G. After attaching the pedals to these ends and mounting the drive unit A to the electric bicycle as prescribed, the electric bicycle can be driven by applying driving torque to the pedal shaft T with muscle force. In particular, the torque generated by muscle force can be transmitted to the rear wheel of the electric bicycle via a power transmission member K on the pedal shaft T or a transmission medium such as a belt or chain. For example, a belt wheel or chainring connected to the transmission member K in a rotationally fixed state can be used. The torque generated by external operation is transmitted to the power transmission member K via a transmission mechanism also housed in the housing G by an electric motor drive unit housed in the housing G.

[0039] On one side formed by the first housing portion G1, a plug connector portion ST emerges from inside the housing G. The plug connector portion ST has one or more plug connectors for connecting the drive unit A to a power supply and / or a higher-level control electronic circuit of the electric bicycle.

[0040] Figures 2A and 2B show the first housing portion G1 in the proposed embodiment of the drive unit A from different viewpoints. The first housing portion G1 is formed as a housing half and, together with the second housing portion G2, defines the housing space for housing the electronic and mechanical components of the drive unit A. For connection to the second housing portion G2, i.e., the second housing half in this embodiment, the first housing portion G1 includes a plurality of fixed positions B1, B2, and B3 (at least two, three in this embodiment) distributed on its outer circumference. Furthermore, a housing opening OT for the pedal shaft T of the drive unit A and a support opening OR for the rotor shaft 30 of the electric motor drive portion of the drive unit A are formed in the first housing portion G1. The rotor shaft 30 is a part of the rotor 3 that can rotate around a rotor axis R that coincides with the axis of the rotor shaft 30 relative to the stator 2 of the electric motor drive portion, and applies a drive torque generated by external operation (see Figures 3 to 7 in particular).

[0041] As is particularly clear from the view of the inside of the first housing G1 shown in Figure 2B, the first housing G1 forms a (motor) support section 1 equipped with a support pod. The support section 1 is specifically intended for arranging the stator 2 of the electric motor drive unit.

[0042] The pot-shaped support portion 1, or the support portion provided by forming a support pot within the first housing portion G1, has an arc-shaped wall 11 that extends so as to completely surround the bearing opening OR of the rotor shaft 30 (and thus the rotor axis R of the rotor 3 as defined by the rotor shaft 30) in the circumferential direction. The wall 11 extends perpendicularly to the bottom portion 10 of the support portion 1 and, in this embodiment, is exemplaryly formed by a rib structure that spreads out in a flower-like manner from the bearing opening OR.

[0043] In Figure 3, the stator 2 is already inserted into the first housing G1 and fixed in place during the assembly of the drive unit A. Subsequently, the rotor 3 is mounted to the housing G1 along a mounting direction parallel to the rotor axis R and inserted into the stator 2. The base 20 of the stator 2 supports the coil 23 of the stator 2, and the entire structure is placed within the pot-shaped receptacle of the support part 1.

[0044] After the stator 2 is attached to the first housing G, in the next assembly step shown in Figure 4, the rotor 3, which consists of multiple parts, is inserted into the stator 2 and thereby inserted into the first housing G1. The rotor 3 consists of a rotor unit equipped with magnets covered with a sheet and a rotor shaft 30. The (motor) pinion 31 is formed or fixed to the rotor shaft 30 in a rotationally fixed state, thereby transmitting the drive torque generated by the electric motor drive units 2 and 3 via the pinion 31.

[0045] When the drive unit A is installed in a predetermined state, the drive torque generated by external operation is transmitted from the pinion 31 to the transmission mechanism connected to the power transmission member K. In this embodiment, at least a part of this transmission mechanism is provided by a pre-assembled transmission mechanism assembly 4. As shown in Figure 5, after the stator 2 and rotor 3 are positioned in a predetermined support part 1, the transmission mechanism assembly 4 is assembled to the first housing part G1.

[0046] In this embodiment, multiple gears that mesh with each other are rotatably mounted on the transmission mechanism carrier 40 of the transmission mechanism assembly 4. These gears are specifically intended to mesh with the pinion 31 when the transmission mechanism assembly 4 is mounted to the first housing G1 as predetermined. The corresponding gears of the transmission mechanism can be pre-mounted on the transmission mechanism carrier 40.

[0047] After the transmission mechanism assembly 4 is pre-assembled, it is attached to the first housing G1 according to the procedure shown in Figure 6 and fixed inside the first housing G1 with fastening members such as screws and bolts. Subsequently, the bearing shield 5 is positioned and fixed into the first housing G1, which has been inserted into the transmission mechanism assembly 4 as described above (see Figure 7).

[0048] After attaching mechanical and electronic components to the first housing section G1, the second housing section G2 is attached to the first housing section G1 and fixed in place. This seals the housing space of the housing G that contains the transmission mechanism assembly 4 and the motor drive units 2 and 3.

[0049] Figures 8, 9, and 10 show, in particular, the connection between the transmission mechanism carrier 40 and the first housing G1 in the support section 1.

[0050] Figure 8 is a perspective view of the transmission mechanism carrier 40 as seen from the bottom surface 400, where the bottom surface 400 faces the stator 2 housed in the support part 1 and is attached to the first housing part G1. The transmission mechanism carrier 40 has multiple fixing positions 401 on its outer circumference and is fixed to the first housing part G1, for example, using screws or bolts.

[0051] The transmission mechanism carrier 40 has a surrounding portion 412 at its bottom surface 400 that extends circumferentially and protrudes axially. The surrounding portion 412 is annular and is formed as a reinforcing and centering ring 412. This ensures that the transmission mechanism carrier 40 is centered with respect to the rotor axis R when attached to the first housing portion G1. The support portion 1 at the insertion opening, which opens toward the gear assembly 4 and from which the stator 2 and rotor 3 are inserted, is also reinforced by the reinforcing and centering ring 412. As shown in Figures 6 and 7, when the transmission mechanism carrier 40 is attached to the first housing portion G1 in a predetermined state and positioned to cover the insertion opening and thereby cover the end face of the stator 2, the transmission mechanism carrier 40 with the reinforcing and centering ring 412 surrounds the annular edge 12 of the support portion 1, and the annular edge 12 protrudes axially opposite to the assembly direction of the support portion 1 (upward during assembly).

[0052] The reinforcing and centering ring 412 of the transmission mechanism carrier 40 is fitted onto the edge 12 of the support portion 1, which is a continuous annular projection along the entire circumference of the wall 11. As a result, at least a portion of the reinforcing and centering ring 412 (the support portion) supports the edge 12 in a direction that points radially outward with respect to the rotor axis R, and the support portion 1 is reinforced in the area of ​​the opening that is open upward, i.e., the insertion opening through which the transmission mechanism carrier 40 is attached to the first housing portion G1. At this time, the insertion of the reinforcing and centering ring 412 onto the edge 12 ensures that the transmission mechanism carrier 40 is reliably centered relative to the stator 2 and rotor 3. This allows the pinion opening 403 formed in the transmission mechanism carrier 40 to be fitted over and inserted onto the end of the rotor shaft 30 that protrudes from the rotor 3 on which the pinion 31 is provided. In this way, the transmission mechanism carrier 40 is aligned with the stator 2 and rotor 3 such that when the transmission mechanism assembly 4 is attached to the first housing G1, the gears of the transmission mechanism assembly 4, which are rotatably supported on the transmission mechanism carrier 40 in a predetermined state, mesh with the pinion 31.

[0053] As shown in the cross-sectional view of Figure 9 and the enlarged sub-view of Figure 10, after the transmission mechanism assembly 4 is attached to the first housing G1, the transmission mechanism carrier 40 and the support 1 are firmly connected in a force-fitting state by transition fit or oversize fit at the positions of the reinforcing / centering ring 412 and the edge 12. This creates a fixed connection between the transmission mechanism carrier 40 and the wall 11 of the support 1. The upper end of the wall 11 is open toward the transmission mechanism assembly 4 and is reinforced by the reinforcing / centering ring 412. The resulting increased structural rigidity prevents ellipsification of the stator 2 in particular. Thus, the transmission mechanism carrier 40 of the transmission mechanism assembly 4 serves not only as a pre-assembly of the transmission members (in this case, in the form of meshing gears) rotatably supported thereon, but also as a further reinforcement of the support 1.

[0054] Furthermore, in this embodiment, the transmission mechanism carrier 40 also forms a support portion 407 for at least one electronic component of the drive unit A. At least one component of the control electronic circuit of the drive unit A is positioned and fixed to the support portion 407 on the support surface facing away from the stator 2. For example, this could be at least one printed circuit board connected to the plug connector portion ST (either directly or via at least one electronic component, such as another printed circuit board and / or one or more wires).

[0055] Based on the enlarged cross-sectional view of Figure 11, one embodiment of the proposed solution is shown. In this embodiment, the stator 2 is fixed radially and axially within the pot-shaped receiving portion of the support portion 1 by at least one additional shape-fitting member 2. The shape-fitting member 6, together with an elongated pin-shaped or rod-shaped shape-fitting portion 60, is inserted into a first recess 116 of the wall portion 11 and a second recess 216 of the stator 2. The first recess is formed as a longitudinal groove 116 on the inside of the wall 11, and the second recess, opposite the first recess 116, is formed as a longitudinal groove 206 on the outer circumferential surface of the base 20 of the stator 2. In this embodiment, the shape-fitting portion 60 extending parallel to the rotor axis R is fitted into the two longitudinal grooves 116 and 206 along the mounting direction parallel to the rotor axis R after the stator 2 is inserted into the support portion 1. The stator 2 is (additionally) fixed so as not to rotate relative to the wall 11 around the rotor axis R by the shape fitting portion 60 of the shape fitting member 6, which engages with both the longitudinal grooves 116 and 206.

[0056] To insert the elongated shaped fitting portion 60 into both vertical grooves 116 and 206, the shaped fitting member 6 has a head portion 61 at one end. Through the head portion 61, it is possible to apply an assembly force M in the direction of the bottom portion 10 of the support portion 1, i.e., in the axial direction, thereby pushing the shaped fitting portion 60 downward along the vertical grooves 116 and 206 to reach its final position. Since the axial length of the vertical groove 116 on the wall side is longer than the length of the shaped fitting portion 60, the shaped fitting member 6 abuts against the shoulder portion 620 that protrudes radially inward from the transmission portion 62 at the end of the stator 2. When inserted to the maximum extent into the vertical grooves 116 and 206 as intended, a gap g remains between the axial end face of the shaped fitting portion 60 facing away from the head portion 61 and the end face of the vertical groove 116 located on the wall side in the assembly direction. Therefore, when the shaped fitting member 6 is inserted to its maximum extent into the vertical grooves 116 and 206 in a predetermined state, the transmission portion 62 having the shoulder portion 620 comes into contact with the edge of the stator 2.

[0057] The transmission section 62 protrudes radially inward from the head section 61 of the shaped fitting member 6 and has a region from which an axial load can be applied from the bottom surface 400 of the transmission mechanism carrier 40. When the transmission mechanism carrier 40 is attached to the first housing section G1, a biasing force V acting axially toward the stator 2 is applied to the shaped fitting member 6, which has an L-shaped cross-section, at the transmission section 62. Due to the action of this biasing force V, the transmission section 62, which is elastically displaceable relative to the shaped fitting section 60, is displaced toward the end side of the stator 2. Therefore, the transmission section 62 is axially loaded by the transmission mechanism carrier 40 attached to and fixed to the first housing section G1, and the biasing force V acts on the transmission section 62. This biasing force V is transmitted to the stator 2 via the transmission section 62 and its shoulder section 620. The stator 2 is then further fixed in the axial direction.

[0058] Unlike the modified example shown in Figure 11, the transmission mechanism carrier 2 that applies the axial biasing force V does not need to be configured as a reinforcing / centering ring 412 provided to reinforce the support portion 1 at its edge 12. The edge 12 protrudes axially and is formed in an annular shape as a bottom or collar. The additional functional integration into the transmission mechanism carrier 40 can significantly simplify the assembly process of the drive unit A. [Explanation of symbols]

[0059] 1 Support part 10 bottom 11 Side wall 116 vertical grooves 12 Edge 2 staters 20 Base 206 Longitudinal groove 23 coils 3 rotors 30 rotor shaft 31 (Motor) Pinion 4. Transmission mechanism assembly 40 Transmission mechanism carrier 400 base 401 Fixed position 403 Pinion opening 407 Support part 412 Reinforcement / Centering Ring (Enclosed Part) 4120 Support part 5 Bearing Shield 6 Shaped fitting members 60 Shape of fitting part 61 Head section 62 Transmission section 620 heel A Drive Unit B1-B3 Fixed position G Housing G1, G2 Housing Half (Housing Section) g gap K Power transmission member M Assembly force OR rotor shaft bearing opening OT Pedal Axle Housing Opening R rotor axis ST Plug Connector Section T pedal axle (assembly) V biasing force

Claims

1. An electric motor drive unit having a stator (2) and a rotor (3) that can rotate around a rotor axis (R), A housing portion (G1) having a support portion (1) for the stator (2) inside, wherein the support portion (1) has a wall (11) surrounding the rotor axis (R) in the circumferential direction, and the wall (11) defines the receiving portion for the stator (2), An electric bicycle drive unit comprising: an edge portion (12) formed on the wall (11) that extends in the circumferential direction of the rotor axis (R), which protrudes in the axial direction with respect to the rotor axis (R), is surrounded by an enclosing portion (412) of a component (40) attached to the housing portion (G1), and is supported by a portion (4120) of the enclosing portion (412) in a direction toward the radially outward direction with respect to the rotor axis (R).

2. The drive unit according to claim 1, characterized in that the edge portion (12) is formed having an edge that protrudes axially onto the wall (11), and the edge extends so as to surround the rotor axis (R) in an annular manner.

3. The drive unit according to claim 1 or 2, characterized in that the enclosing portion (412) protrudes axially in the direction of the wall (11) on the bottom surface (400) of the component (40) attached to the support portion (1) that faces the stator (2).

4. The drive unit according to claim 3, characterized in that the enclosing portion (412) of the component (40) attached to the support portion (1) extends to enclose the rotor axis (R) in an annular manner.

5. The drive unit according to any one of claims 1 to 4, characterized in that the enclosed portion (412) and the edge portion (12) are connected to each other by an intermediate fit or a tight fit.

6. A drive unit according to any one of claims 1 to 5, characterized in that the component (40) attached to the support portion (1) is positioned at a central position with respect to the rotor axis (R) via the surrounding portion (412) of the component (40) connected to the edge portion (12).

7. The drive unit according to any one of claims 1 to 6, characterized in that the part (40) attached to the support part (1) is part of the transmission mechanism assembly (4) of the drive unit (A), and the transmission member of the transmission mechanism assembly (4) is connected to the rotor (3) of the electric motor drive unit (2, 3).

8. The drive unit according to claim 7, characterized in that at least one transmission member of the transmission mechanism assembly (4) assembled to the support portion (1) is rotatably supported in the component (40) of the transmission mechanism assembly (4).

9. The drive unit according to claim 7, characterized in that the component attached to the support portion (1) is a transmission mechanism carrier (40) of the transmission mechanism assembly (4), and a plurality of interacting transmission members of the transmission mechanism assembly (4) are rotatably supported on the transmission mechanism carrier (40).

10. The drive unit according to any one of claims 1 to 9, characterized in that the component (40) attached to the support portion (1) has a support portion (407) on which at least one electronic component of the drive unit (A) is arranged.

11. A drive unit according to any one of claims 1 to 10, characterized in that the stator (2) is press-fitted into the support portion (1).

12. An electric motor drive unit having a stator (2) and a rotor (3) that can rotate around a rotor axis (R), A drive unit for an electric bicycle comprising: a housing portion (G1) having a support portion (1) for the stator (2) inside, wherein the support portion (1) has a wall (11) surrounding the rotor axis (R) in the circumferential direction, and the wall (11) defines the receiving portion for the stator (2); At least one first recess (116) is formed in the wall of the receiving portion, and at least one second recess (206) is provided on the outer circumferential surface of the stator (2) at a position opposite to the first recess (116), A drive unit for an electric bicycle, as described in any one of claims 1 to 11, characterized in that a shaped fitting member (6) for fixing the stator (2) to the support portion (1) engages with the first recess (116) and the second recess (206), and the shaped fitting member has a transmission portion (62) that transmits an axial biasing force (V) acting with respect to the rotor axis (R) to the stator (2).

13. The drive unit according to claim 12, characterized in that the shaped fitting member (6) is fitted to the first recess (116) of the wall (11) and the second recess (206) of the stator (2) via a shaped fitting portion (60), and the transmission portion (62) is formed to be particularly elastically displaceable with respect to the shaped fitting portion (60).

14. The drive unit according to claim 13, characterized in that the transmission portion (62) is formed on the shape fitting member (6) and protrudes radially inward with respect to the rotor axis (R) and the shape fitting portion (60).

15. The drive unit according to claim 14, characterized in that the shape fitting member (6) is formed in an L-shape in cross-sectional view, including the shape fitting portion (60) and the transmission portion (62) of the shape fitting member (6).

16. The drive unit according to any one of claims 12 to 15, wherein the shaped fitting member (6) further comprises a head portion (61), and is configured to receive an assembly force (M) via the head portion (61) for insertion into the first recess and the second recess (116, 206) during assembly of the drive unit (A), and the shaped fitting portion (60) of the shaped fitting member (6) is displaced along the first recess and the second recess (116, 206) by the action of the assembly force to reach a final position.

17. The drive unit according to claim 16, characterized in that the head portion (61) is provided on the shape fitting member (6) at a spatial distance from the transmission portion (62).

18. A drive unit according to any one of claims 12 to 17, characterized in that a plurality of first recesses (116) are provided in the wall (11) of the support portion (1), a plurality of second recesses are provided on the outer circumferential surface of the stator (2) that are opposite to the first recesses (116), and a plurality of shape fitting members (6) that engage with each pair of first recesses and second recesses (116, 206) are provided.

19. A drive unit according to any one of claims 12 to 18, characterized in that the axial biasing force (V) acting on the transmission portion (62) of the shape fitting member (6) is applied by a component (40) of the drive unit (A) attached to the support portion (1).

20. The drive unit according to claim 19, characterized in that the part (40) attached to the support part (1) is part of the transmission mechanism assembly (4) of the drive unit (A), and the transmission member of the transmission mechanism assembly (4) is connected to the rotor (3) of the electric motor drive unit (2, 3).

21. A drive unit according to claim 1, characterized in that the axial biasing force (V) is applied to the transmission unit (62) by the component (40) that forms the enclosed portion (412), further as a drive unit according to claim 19 or claim 20.

22. An electric bicycle characterized by comprising a drive unit as described in any one of claims 1 to 21.

23. A method for assembling a stator (2) to the housing (G1) of a drive unit (A) of an electric bicycle, The housing portion (G1) is provided with a support portion (1) for the stator (2) and a rotor (3) that is rotatable relative to the stator (2) around the rotor axis (R). The support portion (1) has a wall (11) that surrounds the rotor axis (R) in the circumferential direction, and the wall (11) defines the receiving portion for the stator (2). The wall (11) has an edge (12) that extends in the circumferential direction of the rotor axis (R), and the edge (12) protrudes in the axial direction with respect to the rotor axis (R). A method characterized in that, after the stator (2) and the rotor (3) are positioned on the support portion (1), a component (40) of the drive unit (A) is attached to the housing portion (G1), the component (40) surrounds the edge portion (12) of the support portion (1) with a surrounding portion (412), and the edge portion (12) is supported by a portion (4120) of the surrounding portion (412) in a direction radially outward with respect to the rotor axis (R).

24. The method according to claim 23, characterized in that the component (40) attached to the support portion (1) is positioned at a central position with respect to the rotor axis (R) by the surrounding portion (412) of the component (40) connected to the edge portion (12) of the support portion (1).

25. The method according to claim 23 or 24, characterized in that the part (40) attached to the support part (1) is part of the transmission mechanism assembly (4) of the drive unit (A), and the transmission member of the transmission mechanism assembly (4) is connected to the rotor (3) of the electric motor drive unit.

26. The method according to claim 25, characterized in that the component attached to the support portion (1) is a transmission mechanism carrier (40) of the transmission mechanism assembly (4), and at least one transmission member of the transmission mechanism assembly (4) is rotatably supported on the transmission mechanism carrier (40), and the transmission mechanism carrier (40) is assembled to the support portion (1) via the enclosure portion (412) of the transmission mechanism carrier (40).

27. The method according to claim 26, characterized in that the transmission mechanism assembly (4), which has a plurality of transmission members that interact to transmit the drive torque generated by the electric motor drive (2, 3), is pre-assembled to the transmission mechanism carrier (40), the transmission mechanism carrier (40) has the enclosure portion (412) formed on its bottom surface (400), and the pre-assembled transmission mechanism assembly (4) is fixed to the housing portion (G1) via the enclosure portion (412).

28. A method for assembling a stator (2) to the housing (G1) of a drive unit (A) of an electric bicycle, The housing portion (G1) is provided with a support portion (1) for the stator (2) and a rotor (3) that is rotatable relative to the stator (2) around the rotor axis (R). The support portion (1) has a wall (11) that surrounds the rotor axis (R) in the circumferential direction, and the wall (11) defines the receiving portion for the stator (2). At least one first recess (116) is formed in the wall (11), and a second recess (206) is provided on the outer circumferential surface of the stator (2), and after the stator (2) is inserted into the receiving portion, the second recess (206) is positioned opposite to the first recess (116). A method, particularly according to any one of claims 23 to 27, characterized in that the shaped fitting member (6) is inserted into the first recess (116) and the second recess (206) in order to fix the stator (2) to the support (1), and the shaped fitting member has a transmission part (62) that transmits an axial biasing force (V) acting in the axial direction with respect to the rotor axis (R) to the stator (2).

29. The method according to claim 28, characterized in that the shaped fitting member (6) is inserted into the first recess and the second recess (116, 206) until it contacts the shoulder portion (620) of the transmission portion (620), which is part of the stator (2).

30. The method according to claims 28 and 29, characterized in that the shaped fitting member (6) having a shaped fitting portion (60) is inserted into the first recess (116) of the wall (11) and the second recess (206) of the stator (2), and the transmission portion (62) that transmits the axial biasing force (V) to the stator (2) is displaced relative to the shaped fitting portion (60) by a component (40) of the drive unit (A) which is attached after the housing portion (G1).

31. The method of claim 23, further characterized in that the component (40) that moves the transmission portion (62) and applies the axial biasing force (V) to the transmission portion (62) when attached to the housing portion (G1) is the component (40) that forms the surrounding portion (412), the method according to any one of claims 27 to 30.

32. The method according to any one of claims 23 to 31, characterized in that the stator (2) is press-fitted into the receiving portion of the support portion (1).

33. The method according to claim 32, characterized in that at least a portion of the housing portion (G1) is heated for press-fit connection to the support portion (1), thereby press-fitting the stator (2) into the receiving portion of the support portion (1).

Images