Electric bicycle drive unit mounting arrangement

Abstract

Electric bicycle drive unit mounting arrangement (50) for mounting an electric drive unit (20) to a drive mount (10) of a bicycle frame (12), wherein the drive receptacle (10) has two mutually parallel vertical frame legs (14, 16) each with a horizontal bore (17, 18), wherein the drive unit (20) has two parallel vertical housing flanges (44, 46) each with a horizontal bore (47, 48), wherein the two housing flanges (44, 46) are arranged parallel to the frame legs (14, 16), wherein the two housing flanges (44, 46) are floatingly mounted on the two frame legs (14, 16) by at least one horizontal retaining bolt (60) which is held in the horizontal bores (17, 18, 47, 48), and wherein an annular gap (110, 110') is formed between the retaining bolt (60) on the one hand and the frame leg horizontal bores (17, 18) and / or the housing flange horizontal bores (47, 48) in each case an elastic wire mesh sleeve (100) is arranged in each case, which radially completely fills the annular gap (110, 110').

Description

[0001] The invention relates to an electric bicycle drive unit mounting assembly for mounting an electric bicycle drive unit to the bicycle frame of the electric bicycle.

[0002] In this context, an electric bicycle is understood to mean any type of bicycle that has a supporting electric drive unit that supplements the human drive power applied by a rider to the pedal crank with a corresponding electric drive power, if desired. In particular, the present invention relates to a mounting arrangement for so-called mid-motor drive units, which both rotatably support the pedal crank shaft and have an output element, for example, at least one chainring that drives a rear wheel of the electric bicycle.

[0003] With a mid-motor drive unit, very high mechanical forces can act on the drive unit for short periods, which must be transferred to the bicycle frame via the mounting arrangement. Furthermore, the acoustic properties of electric bicycle drive units play a major role in purchasing decisions.

[0004] EP 3 960 605 A1 discloses an electric bicycle drive unit mounting arrangement in which several rubber sleeves are used to acoustically decouple the drive unit from the bicycle frame. However, rubber is subject to aging under the influence of temperature fluctuations, light, and time, which leads to a deterioration in strength and elasticity.

[0005] Against this background, the object of the invention is to provide an electric bicycle drive unit fastening arrangement with acoustic decoupling of the drive unit from the bicycle frame with improved durability.

[0006] This object is achieved according to the invention with an electric bicycle drive unit fastening arrangement having the features of claim 1.

[0007] By means of the electric bicycle drive unit fastening arrangement according to the invention, the electric drive unit is attached to a drive mount of the bicycle frame in a floating manner, i.e., it is attached while completely avoiding a rigid connection between the drive unit housing and the bicycle frame.

[0008] For this purpose, the drive mount of the bicycle frame has two frame flanges that are essentially vertically aligned and fixed to the frame. The drive unit housing has two essentially parallel vertical housing flanges that are each arranged distally or proximally, but preferably proximally, i.e. on the inside of the frame flanges when the drive unit is installed. The left housing flange is attached to the left frame flange and the right housing flange is attached to the right frame flange. The drive unit is therefore attached to the bicycle frame by two flange pairs, each flange pair consisting of a frame flange and the associated housing flange. The frame flange and / or the housing flange do not necessarily have to be formed by a web that stands in a vertical plane.In particular, the housing flange can be formed by a flange surface of the housing body that does not protrude vertically from the enclosing part of the drive housing, but is formed by this part itself. Preferably, the frame legs and the housing flanges are each located in a vertical longitudinal plane.

[0009] The two frame legs each have a horizontal bore extending in the transverse direction, and the two drive unit housing flanges each have a horizontal bore, with one frame leg horizontal bore being aligned with at least one drive unit horizontal bore. Particularly preferably, all horizontal bores are aligned with each other in the horizontal transverse direction.

[0010] The two housing flanges are mounted in a floating manner on the two frame legs by at least one horizontal retaining bolt, which is held in the horizontal bores. Particularly preferably, a single retaining bolt is provided, which is held or fixed in all four horizontal bores. Between the retaining bolt on the one hand and the frame leg horizontal bores and / or the housing flange horizontal bores, a circumferential annular gap is formed radially in each case, in which an elastic wire mesh sleeve is arranged, which fills the respective annular gap. The wire mesh sleeve is preferably designed as a hollow cylindrical sleeve and consists of a wire mesh with a spring constant that ensures that the wire mesh sleeve is radially deformed by a maximum of a few millimeters, even under high, short-term load peaks.This can be adjusted in particular by selecting the sleeve lengths of the elastic wire mesh sleeves to be correspondingly large.

[0011] The wire mesh sleeve is - based on a typical lifetime of an electric bicycle - exposed at most to slight aging, which does not have a significant effect on its mechanical properties, so that the mechanical stability of the fastening arrangement on the one hand and the acoustic decoupling of the drive unit from the bicycle frame on the other hand remain practically unchanged in the long term.

[0012] Preferably, the two wire mesh sleeves are arranged axially, i.e., in the horizontal transverse direction, between a drive-side ring step and a housing-side ring step. In this way, the wire mesh sleeve can also determine the position of the drive unit in relation to the drive mount of the bicycle frame in the horizontal transverse direction and, at the same time, provide acoustic decoupling.

[0013] Preferably, the wire mesh sleeve lies radially on the outside directly against an inner cylindrical bore wall of the relevant housing flange horizontal bore.

[0014] Preferably, two flanged bushings are pushed onto the retaining bolt, each of which directly supports the wire mesh sleeve on the outside. The flanged bushing is of constant internal cylindrical design and has a circumferential annular collar on the radial outer side at one longitudinal end, which forms the collar of the flanged bushing. The flanged bushings are pushed onto the retaining bolt in such a way that the two annular collars of the flanged bushings are arranged distally. Each annular collar forms a distal axial stop for the respective wire mesh sleeve.

[0015] The retaining bolt preferably has a bolt head and a threaded shaft at the end, with a lock nut screwed onto the threaded shaft, which is located at the axial end of the retaining bolt opposite the bolt head. The lock nut is preferably externally cylindrical and is seated with a clamp fit in the internally cylindrical horizontal bore of the respective frame leg. Particularly preferably, the two flanged bushings are axially clamped indirectly and / or directly between the lock nut and the bolt head of the retaining bolt.

[0016] The elastic wire mesh sleeve is preferably manufactured using an additive manufacturing process, such as 3D printing. For example, the wire mesh sleeve can be generated from a titanium-containing metal powder by laser sintering or laser melting. In principle, other materials are also suitable for the wire mesh sleeve, such as elastic base materials. This allows the mechanical properties of the wire mesh sleeve to be precisely defined.

[0017] In the following, an embodiment of the invention is explained in more detail with reference to the figure.

[0018] The figure shows a schematic vertical cross-section of an electric bicycle drive unit mounting arrangement according to the invention.

[0019] The figure shows an electric mid-motor drive unit 20 mounted on a bicycle frame 12 of a pedelec electric bicycle. The drive unit 20 is designed purely as a support and assists the human drive power of a rider during riding. Only a short lower section of a frame down tube and a drive mount 10, to which the drive unit 20 is attached or suspended, are shown.

[0020] The drive unit 20 has a drive housing 22 with a bearing for a pedal crank shaft 30 oriented in the horizontal transverse direction y, which has a pedal crank 36, 36' at each of its two shaft ends, to whose free longitudinal ends a pedal 35 is fastened. The pedal crank shaft 30 further carries an output element 32 located in a vertical longitudinal plane xz, which in this case is designed as a chainring. The output element 32 drives a drive chain that leads to a rear wheel pinion of a bicycle rear wheel. The pedal crank shaft 30 also forms the output shaft in this case, since the electric traction motor 24 also directly drives the pedal crank shaft 30 via a drive gear 26. In principle, however, the drive unit 20 can also be structured differently.

[0021] The traction motor 24 and the drive gear 26 are located in the drive housing 22, whereas the output element 32 is arranged outside the drive housing 22.

[0022] The drive housing 22 is essentially composed of two housing halves 22', 22'', which - viewed in the longitudinal direction x, i.e., in the direction of travel - form a left housing half 22' and a right housing half 22''. In this case, a housing half does not mean that each half must form exactly or approximately half of the drive housing 22, but can, for example, also be a housing pot on the one hand and a housing cover on the other. The drive unit 20 is fastened to the bicycle frame 12 by a fastening arrangement 50. For this purpose, the bicycle frame 12 has the drive mount 10, to which the drive unit 20 is fastened by the fastening arrangement 50.

[0023] The drive mount 10 is essentially formed by two frame legs 14, 16 of the bicycle frame 12, which are arranged in a vertical longitudinal plane xz, are spaced apart from one another in the transverse direction and arranged parallel to one another, and are formed integrally with the bicycle frame 12. The two frame legs 14, 16 and the bicycle frame 12 define a receiving frame with a U-shaped cross-section and opening downwards, into which two corresponding housing flanges 44, 46 of the drive housing 22 are inserted from below.

[0024] The two frame legs 14, 16 each have a horizontal bore 17, 18, and the two housing flanges 44, 46 each have a horizontal bore 47, 48, with all four horizontal bores 17, 18, 47, 48 being precisely aligned with each other in the horizontal transverse direction y. The horizontal bore 17 of the left frame leg 14 has an internally cylindrical design, whereas the remaining three horizontal bores 18, 47, 48 are stepped.

[0025] A retaining bolt 60 is provided, arranged in the transverse direction y, which is held in all four horizontal bores 17, 18, 47, 48. The retaining bolt 60 has a bolt head 64 and a bolt shaft 62 with a threaded shaft 66 at the end with an external thread. The retaining bolt 60, with its bolt head 64 and the adjacent section of the bolt shaft 62, is inserted into the stepped horizontal bore 18 of the right frame leg 16.

[0026] An externally cylindrical lock nut 70 with an internal thread 76 is screwed onto the threaded shaft 66. The lock nut is formed by a metal nut body 72 and is clamped into the internally cylindrical horizontal bore 17 of the left frame leg 14. Two internally cylindrical flanged bushings 80, 80' are pushed serially onto the externally cylindrical bolt shaft 62 of the retaining bolt 60, each having a radially outwardly projecting annular collar 84 at their distal longitudinal ends. The two flanged bushings 80, 80' are axially clamped on the retaining bolt 60 by the lock nut 70.

[0027] The two housing flange horizontal bores 47, 48 each have an annular step 28, which defines a radially expanded inner cylindrical bore wall 85 in the distal transverse direction y. Together with the distal end portion of the two flange bushings 80, 80', each defines a cylindrical annular gap 110, 110', which is axially delimited by the annular step 28 and the annular collar 84. An elastically prestressed wire mesh sleeve 100 is arranged in each annular gap 110, 110', which completely fills the respective annular gap 110, 110'.

[0028] The wire mesh sleeve 100 is formed by an inherently elastic wire body 102 with an axial length of 5-20 mm. The annular collar 84 of the flanged bushing 80, 80' forms the distal axial stop for the hollow cylindrical wire mesh sleeve 100 as an annular step 88. The elastic wire mesh sleeve 100 is manufactured using an additive manufacturing process, in this case, a so-called 3D printing process. The wire mesh sleeve 100 is manufactured from a titanium-containing metal powder by laser sintering or laser melting.

[0029] Both the bolt head 64 and the lock nut 70 each have a form-locking structure 63, 74 distally for a complementarily shaped assembly tool. QUOTES CONTAINED IN THE DESCRIPTION

[0000] This list of documents submitted by the applicant was generated automatically and is included solely for the convenience of the reader. This list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions. Cited patent literature

[0000] EP 3 960 605 A1

[0004]

Claims

[1] Electric bicycle drive unit mounting arrangement (50) for mounting an electric drive unit (20) to a drive mount (10) of a bicycle frame (12), wherein the drive receptacle (10) has two mutually parallel vertical frame legs (14, 16), each with a horizontal bore (17, 18), wherein the drive unit (20) has two mutually parallel vertical housing flanges (44, 46), each with a horizontal bore (47, 48), wherein the two housing flanges (44, 46) are arranged parallel to the frame legs (14, 16), wherein the two housing flanges (44, 46) are mounted in a floating manner on the two frame legs (14, 16) by at least one horizontal retaining bolt (60) which is held in the horizontal bores (17, 18, 47, 48), and wherein an annular gap (110, 110') is formed between the retaining bolt (60) on the one hand and the frame leg horizontal bores (17, 18) and / or the housing flange horizontal bores (47, 48), in each of which an elastic wire mesh sleeve (100) is arranged, which completely fills the annular gap (110, 110') radially. [2] The electric bicycle drive unit mounting assembly (50) of claim 1, wherein the two wire mesh sleeves (100) are axially disposed between a drive-side annular step (28) and a housing-side annular step (88). [3] Electric bicycle drive unit mounting assembly (50) according to any one of the preceding claims, wherein the wire mesh sleeve (100) is substantially hollow cylindrical. [4] Electric bicycle drive unit fastening arrangement (50) according to one of the preceding claims, wherein the wire mesh sleeve (100) radially outwardly bears directly against a bore wall (85) of the respective housing flange horizontal bore (47, 48). [5] Electric bicycle drive unit fastening arrangement (50) according to one of the preceding claims, wherein two flanged bushings (80, 80') are pushed onto the retaining bolt (60), on each of which the wire mesh sleeve (100) sits directly on the outside. [6] Electric bicycle drive unit mounting assembly (50) according to claim 5, wherein each flange bushing (80, 80') has a respective annular collar (84) which forms a respective annular step (88) as a distal axial stop for the wire mesh sleeve (100). [7] Electric bicycle drive unit mounting assembly (50) according to any one of the preceding claims, wherein the retaining bolt (60) has a bolt head (64) and a threaded end shaft (66), wherein a lock nut (70) is screwed onto the threaded shaft (66). [8] Electric bicycle drive unit fastening arrangement (50) according to claim 7, wherein the lock nut (70) is externally cylindrical and is seated with a clamp fit in the internally cylindrical horizontal bore (17) of the respective frame leg (14). [9] Electric bicycle drive unit mounting assembly (50) according to one of claims 5 or 6 and one of claims 7 or 8, wherein the lock nut (70) clamps the two flange bushings (80, 80') axially onto the retaining bolt (60). [10] Electric bicycle drive unit mounting assembly (50) according to any one of the preceding claims, wherein the drive unit (20) is a mid-engine, supports a pedal crank shaft (30) and has an output element (32) arranged outside the drive housing (22) of the drive unit (20). [11] The electric bicycle drive unit mounting assembly (50) according to any one of the preceding claims, wherein the elastic wire mesh sleeve (100) is manufactured by an additive manufacturing process.

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