Connection device for connecting a drive unit to a bicycle frame

Abstract

Connecting device (1) for connecting a drive unit (2) to a receiving interface (3) of a bicycle frame (4), characterized by a first sleeve unit (5) with a metallic first section (5a) at the first end of which a metallic first collar (5b) is formed, which extends in a plane perpendicular to a first longitudinal axis (A) of the first section (5a), a second sleeve unit (8) with a metallic second section (8a), wherein the first (5a) and the second section (8a) extend along a common mounting axis (B) in an assembled state, the connecting device further comprising a spreading element (9) and a first clamping element (10).

Description

[0001] The present invention relates to a connecting device for attaching a drive unit to a bicycle frame. The invention further relates to a system comprising the drive unit and the connecting device. The invention is explained in connection with a bicycle and can be used in particular for a bicycle with an electric motor.

[0002] Drive units in the bottom bracket area of ​​a bicycle frame are typically fixed to a mounting interface on the frame using connecting devices. These usually involve two to three holes per side of the mounting interface, through which a screw is inserted and then secured from the other side with a nut, sleeve, or lock screw.

[0003] Often, the drive unit is axially screwed to only one side or wall surface of the mounting interface, while a tolerance compensation mechanism is provided on the other side to compensate for stresses, over-constraints, and misalignments. This creates conflicting requirements, such as sufficiently rigid connection of the drive unit, structure-borne noise damping, tolerance compensation, adjustability of the connection to prevent creaking and cracking, maintainability and replaceability, simple and cost-effective design, and low weight.

[0004] The object of the invention is to provide an improved connection device for connecting a drive unit to a bicycle frame. This object is achieved by the items with the features of the independent claims. Preferred embodiments are described in the dependent claims.

[0005] According to a first aspect, the present invention relates to a connecting device for connecting a drive unit to a receiving interface of a bicycle frame. The connecting device comprises a first sleeve unit dimensioned to form an interference fit or transition fit with a locating bore extending through the drive unit. The first sleeve unit has a metallic first section, at the first end of which a metallic first collar is formed, extending in a plane perpendicular to a first longitudinal axis (A) of the first section. The connecting device further comprises a second sleeve unit dimensioned to form a transition or clearance fit with the locating bore. The second sleeve unit has a metallic second section.The connecting device is designed such that the first section and the second section extend along a common assembly axis (B) when assembled. Furthermore, the connecting device comprises an expanding element and a first clamping element, which are jointly designed such that the outer diameter of the expanding element increases when it is forced by the first clamping element along the assembly axis towards the second sleeve unit. The first clamping element can be at least partially inserted into the second sleeve unit.

[0006] The connecting device can be used to compensate for stresses, over-constraints, and misalignments. The first sleeve unit can be fixed both axially along the mounting axis (B) and radially. The second sleeve unit, however, is fixed only radially by the expanding element. In this way, inaccuracies in the manufacturing of the bicycle frame and the drive unit can be at least partially compensated for, and stresses, over-constraints, and misalignments can be reduced or avoided. This solves the underlying problem.

[0007] According to a second aspect, the present invention relates to a system comprising a connecting device of the first aspect, the drive unit with the fitting bore which can at least partially receive the first sleeve unit and the second sleeve unit, and the bicycle frame with the receiving interface for the drive unit, wherein the receiving interface has two through holes, in particular aligned through holes, each for the first clamping element or the second clamping element. The bicycle frame can be a component to which further frame parts can be attached, so that the bicycle frame mentioned here can also be part of the entire bicycle frame. The bicycle frame and its receiving interface can be made of carbon fibers, aluminum, or steel, in particular of carbon fiber composite material, aluminum, or another commercially available material. The through holes can have the same inner diameter.This can save on manufacturing costs.

[0008] The following is an explanation of further training courses that can be advantageously combined with each other unless otherwise indicated.

[0009] In one embodiment, the first clamping element can be designed as a screw or a countersunk screw. The second section can have an internal thread for the first and / or a second clamping element. The first section can be slotted along its entire axial length. The first section can be designed without an internal thread.

[0010] According to one embodiment, the expanding element can be integrally formed as a conical section at the second end of the second section. The conical section can be designed to partially accommodate the first clamping element. The conical section can have one, two, or more longitudinal slots, which can facilitate expansion. When the first clamping element is moved along the mounting axis B into the first sleeve unit and toward the second sleeve unit, the conical section can be expanded, thereby increasing its outer diameter. The conical section can be elastically deformed, in particular, to abut a circumferential surface of one of the through-holes by the first clamping element. The integrally formed conical section cannot be lost, and the parts list is shorter.

[0011] In another embodiment, the expanding element can be designed as an elastic ring with an internal cone, independent of the second sleeve unit. The elastic ring can be slotted. It can be made of stainless steel, coated, anodized, or hard-anodized aluminum, or plastic. The internal cone can have an angle of approximately 90°. The outer diameter of the ring can increase when it is forced by the first clamping element along the mounting axis B toward the second sleeve unit. The elastic ring can be deformed, particularly elastically, by the first clamping element to conform to a circumferential surface of one of the through holes.

[0012] In one embodiment, a second collar can be formed at the second end of the second section, extending in a plane perpendicular to a second longitudinal axis (C) of the second section. This second collar can distribute a force acting on the receiving interface along the mounting axis over a larger area. The second collar can provide a bearing surface for the elastic ring.

[0013] Another embodiment includes a second clamping element and a slotted conical ring, which can be pressed by the clamping element along the mounting axis (B) towards the first collar to mechanically connect to the receiving interface. The conical ring can have a completely continuous axial slot. The conical ring can have a circumferential contact shoulder for bearing against the receiving interface. The contact shoulder can help to center the conical ring in one of the through holes. The contact shoulder can distribute a force along the mounting axis (B) that can act on the receiving interface over a larger area.

[0014] Another embodiment may include the second clamping element and a metallic underhead washer for mechanical connection to the receiving interface and for reducing mechanical stress or local load in the receiving interface. The underhead washer can be pressed by the clamping element along the mounting axis (B) towards the first collar. The underhead washer may have a conical section that can serve to center the underhead washer in one of the through holes.

[0015] According to one embodiment, the second clamping element can have an internal thread for engaging with an external thread of the first clamping element. The internal thread can be located in a blind hole of the second clamping element.

[0016] One embodiment can have a coating on at least one surface of the first or second sleeve unit for structure-borne noise decoupling. When the first or second sleeve unit is mounted, the coating can prevent metal from contacting the material of the bicycle frame. The coating can be made of a plastic or an elastomer. This makes the coating more flexible than the otherwise metallic sleeve units and allows it to compensate for tolerances to a limited extent. The coating can be applied to an outer circumferential surface of the first section, an annular surface of the first collar, an outer circumferential surface of the second section, and / or an annular surface of the second collar.

[0017] A first embodiment comprises the conical section, the underhead washer, and the second clamping element with an external thread for engaging the underhead washer. The first clamping element also has an external thread and can be a countersunk screw. The inner surface of the metallic second section has a corresponding internal thread for receiving the two external threads of the two clamping elements. The conical section of the second sleeve unit is slotted, but the second section is not. The outer circumferential surfaces of the metallic first and second sections and the conical section have the coating for structure-borne noise decoupling, as does the surface or annular area of ​​the first collar facing away from the receiving interface. When the first clamping element is screwed into the second section, the screw head can expand the conical section, thereby increasing its outer diameter.When the first clamping element is screwed into the second section, the head of the clamping element spreads the molded conical section. In this process, an outer circumference of the conical section can be pressed against an inner circumferential surface of one of the through holes.

[0018] A second embodiment has a conical ring instead of the underhead disc, but otherwise corresponds to the first embodiment.

[0019] The second embodiment can be assembled as follows if the inserted first sleeve unit forms an interference fit or transition fit with the fitting bore of the drive unit: • Pulling the second sleeve unit out of the fitting bore of the housing, • Insert the drive unit into the receiving interface so that the first collar rests around a first through-hole of the receiving interface, • Positioning the slotted cone ring in the first through hole, • Partially inserting the second clamping element into the first section of the first sleeve unit, • Insert the second sleeve unit through the second through-hole opposite the first through-hole into the fitting bore of the housing, • Screwing the second clamping element into the internal thread of the second sleeve unit, • Tightening the second clamping element with a target torque, • Greasing the first clamping element and the conical section, especially against corrosion and seizing, • Inserting the first clamping element through the second through-hole and screwing the first clamping element into the internal thread of the second sleeve unit, • Tightening the first clamping element with a target torque.

[0020] The drive unit can be disassembled in reverse order. If unwanted noises occur, the first clamping element can be readjusted.

[0021] A third embodiment differs from the first embodiment in that the first clamping element can engage in an internal thread of the second clamping element. Thus, the second section does not require an internal thread.

[0022] A fourth embodiment comprises the underhead washer, the elastic ring, the second collar, and the second clamping element with an external thread for actuating the underhead washer. The second collar also provides a contact surface for the elastic ring. The inner cone of the elastic ring is adapted to a countersunk head of the first clamping element.

[0023] In a fifth embodiment, the lower head washer is omitted, and a countersunk head of the second clamping element is provided to engage with a cone that surrounds one of the through-holes of the receiving interface. Both annular surfaces of the first and second collars have a coating for structure-borne noise decoupling. Otherwise, the fifth and fourth embodiments are identical.

[0024] A sixth embodiment differs from the fourth embodiment by the conical ring instead of the underhead disc.

[0025] The sixth embodiment can be assembled as follows if the inserted first sleeve unit forms an interference fit with the locating bore of the drive unit: • Pulling the second sleeve unit out of the fitting bore of the housing, • Insert the drive unit into the receiving interface so that the first collar rests around a first through-hole of the receiving interface, • Positioning the slotted cone ring in the first through hole, • Partially inserting the second clamping element into the first section of the first sleeve unit, • Insert the second sleeve unit through a second through-hole opposite the first through-hole into the fitting bore of the housing, • Screwing the second clamping element into the internal thread of the second sleeve unit, • Tightening the second clamping element with a target torque, • Positioning the elastic ring around the second through-hole, • Greasing the first clamping element and the inner cone of the elastic ring, especially against corrosion and seizing, • Inserting the first clamping element through the second through-hole and screwing the first clamping element into the internal thread of the second sleeve unit, • Tightening the first clamping element with a target torque.

[0026] The drive unit can be disassembled in reverse order. If unwanted noises occur, the first clamping element can be readjusted.

[0027] A seventh embodiment, compared to the fourth embodiment, has a second clamping element with an internal thread into which the first clamping element can engage. Thus, the second section does not require an internal thread. Fig. 1 is a first embodiment with a lower head washer and a second sleeve unit with a conical section and internal thread. Fig. 2 is a second embodiment with a conical ring instead of a bottom washer and a second sleeve unit with a conical section and internal thread. Fig. 3 is a third embodiment with a lower head washer, a second sleeve unit with a conical section, the second clamping element of which has an internal thread. Fig. 4 is a fourth embodiment with a bottom-head disc and elastic ring instead of a conical section. Fig. 5 is a fifth embodiment without a bottom-head disc but with an elastic ring. Fig. 6 is a sixth embodiment with a conical ring instead of a bottom-head disc and with an elastic ring. Fig. 7 is a seventh embodiment with a lower head washer, with an elastic ring, the second clamping element of which has an internal thread. Fig. Figure 8 schematically shows a bicycle with a frame, a drive unit and several connecting devices.

[0028] The first sleeve unit 5 of the Fig. 1-7 has no internal thread. The second sleeve unit 8 and its second section 8c of the Fig. 1, Fig. 2, Fig. 4, Fig. 5 and Fig. 6 has an internal thread for the first screw 10 and the second screw 11.

[0029] Fig. 1 is a first embodiment of the connecting device 1 with underhead washer 13 and second sleeve unit 8 with slotted conical section 8b and internal thread.

[0030] The connecting device comprises a first sleeve unit 5, dimensioned to form an interference fit or transition fit with a locating bore 6 extending through the drive unit 2 or its housing 2a, and having a metallic first section 5a at the first end of which a metallic first collar 5b is formed, extending in a plane perpendicular to a first longitudinal axis A of the first section 5a. The connecting device comprises a second sleeve unit 8, dimensioned to form a transition or clearance fit with the locating bore 6, and having a metallic second section 8a. The connecting device 1 is configured such that the first 5a and the second section 8a extend along a common assembly axis B in an assembled state.Furthermore, the connecting device comprises an expanding element 9 and a first clamping element 10 designed as a screw, which together are designed such that the outer diameter of the expanding element 9 increases when it is forced by the first clamping element 10 along the assembly axis B in the direction of the second sleeve unit 8. Here, the expanding element 9 is formed by the conical section 8c.

[0031] The first section 5a is formed from aluminum or steel sheet, preferably with a sheet thickness of 1 to 2 mm, onto whose outer circumferential surface a plastic or elastomer layer 5c is sprayed or vulcanized. This layer serves for structure-borne noise decoupling and can compensate for tolerances. The first section 5a can be slotted or unslotted along its entire axial length. The second section 8a is formed from aluminum or steel sheet, preferably with a sheet thickness of 1.5 to 3 mm. This layer, also plastic or elastomer, is sprayed or vulcanized onto its outer circumferential surface. This layer serves for structure-borne noise decoupling and can compensate for tolerances. The second section 8a is unslotted. The outer diameter of the first section 8a is larger than the inner diameter of the fitting bore 6. The second section 8a has an internal thread.

[0032] When the first screw 10 is screwed in, the conical section 8b of the second sleeve unit 8 is expanded radially outwards via the slotted elasticity by means of the conical screw head, thereby establishing a backlash-free contact with the cylindrical through-hole in the receiving interface 3 via the outer plastic or elastomer layer diameter. This radial expansion aims to compensate for the bore and position tolerances of the through-holes among themselves and relative to the drive unit 2, and simultaneously to create axial compensation despite differences in width between the receiving interface walls and the drive unit 2.

[0033] From the other side, the second screw 11 also engages directly in the internal thread of the second sleeve unit 8, thus clamping the drive unit axially and, if the second screw 11 is preferably a countersunk screw, also radially against the receiving interface wall. At the Fig. On the right-hand mounting interface wall, an underhead washer 13 is shown by way of example in the area of ​​the countersunk screw 11, in order to reduce the local stress on the carbon mounting interface wall, particularly in applications with carbon frames. While screwing in the second screw 11, the tightening torque on the second sleeve unit 8 is counteracted by means of a slotted screwdriver or special tool in the preferably 2 to 4 axial slots.

[0034] Between the two sleeve units 5, 8 there is an axial gap of preferably at least 1 mm in the area of ​​the fitting bore 6 of the main housing 2a, so that the preload forces of the second screw 11 are transferred via the internal thread and the shoulder of the second sleeve unit 8 and via the housing 2 to the shoulder of the first sleeve unit 5 and to the Fig. 1 right mounting interface wall goes and not directly over the two sleeve units.

[0035] When the pedals are loaded, the radial force is transmitted from the crank arm via the drive unit 2 and via the second countersunk screw 11 into the receiving interface and simultaneously via the first play-free cylindrical circumferential surface of the Fig. 1 left through hole into the in Fig. 1. Left mounting interface wall. Thus, the radial load transfer from the drive unit 2 to the mounting interface 3 occurs on both sides with similar radial stiffness.

[0036] The drive unit is connected to the recording interface as follows: • Pulling the second sleeve unit 8 out of the fitting bore 6 of the housing, • Inserting the drive unit 2 into the receiving interface 3, so that the first collar 5c rests around a first through hole of the receiving interface 3, • Positioning the lower head disc 13 in the Fig. 1 right through hole, • Partial insertion of the second clamping element 11 into the first section 5a of the first sleeve unit 5, • Insert the second sleeve unit 8 through the second through hole opposite the first through hole into the fitting bore 6 of the housing, • Screw the second clamping element 11 into the internal thread of the second sleeve unit 8, • Tightening the second clamping element 11 with a target torque, • Greasing of the first clamping element 10 and the conical section 8b, in particular against corrosion and seizing, • Insertion of the first clamping element 10 by the in Fig. 1 left through hole and screwing the first clamping element 10 into the internal thread of the second section 8a of the second sleeve unit 8, • Tightening the first clamping element 10 with a target torque.

[0037] The drive unit 2 can be disassembled in reverse order of the steps.

[0038] Fig. 2 is a second embodiment with a slotted conical ring 12 instead of a bottom washer and a second sleeve unit 8 with a conical section 8b and internal thread. The conical ring 12 is inserted into the Fig. 2 right through holes are inserted. Here, the second clamping element 11 pushes the conical ring 12 towards the first sleeve unit 5 and simultaneously radially outwards. Otherwise, the explanations regarding Fig. 1 to.

[0039] The conical ring 12 with shoulder 12a is preferably made of stainless steel, coated aluminum (anodized, hard-anodized, or similar), or high-strength plastic. The conical ring 12 has an inner cone angle of preferably approximately 90° to allow the use of a simple countersunk screw 11 on the right side.

[0040] This design of a separate conical ring 12 with shoulder 12a allows it to expand radially when the screw is tightened, and consequently in the Fig. Form or conform the 2 right through-holes under preload without play. The shoulder 12a on the cone ring 12, together with a radially enlarged first collar 5b on the first sleeve unit 5, fixes the drive unit 2 against axial movement at the in Fig. 2 right recording interface wall.

[0041] Preferably, the left and right through-holes have the same diameter. They can be produced in a single operation using the same drill or tool. This simplifies manufacturing and increases the coaxiality accuracy of the two through-holes in the receiving interface 3 relative to each other.

[0042] Fig. 3 is a third embodiment with a lower head washer 13, a second sleeve unit 8 with a conical section 8a, the second clamping element 11 of which has an internal thread for a thread of the first clamping element 10. The second sleeve unit 8 does not require an internal thread. Otherwise, the explanations regarding Fig. 1. This means that the second countersunk screw 11 can only be screwed in simultaneously with the first screw 10. The advantage is a reduced manufacturing effort for the second sleeve unit 8.

[0043] Fig. 4 is a fourth embodiment with underhead disc 13 and elastic ring 9 instead of conical section.

[0044] The connecting device comprises a first sleeve unit 5, dimensioned to form an interference or transition fit with a locating bore 6 extending through the drive unit 2, with a metallic first section 5a, at the first end of which a metallic first collar 5b is formed, extending in a plane perpendicular to a first longitudinal axis A of the first section 5a. The connecting device comprises a second sleeve unit 8, dimensioned to form a transition or clearance fit with the locating bore 6, with a metallic second section 8a. The connecting device 1 is configured such that the first 5a and the second section 8a extend along a common assembly axis B in an assembled state.Furthermore, the connecting device comprises an expanding element 9 designed as an elastic ring and a first clamping element 10 designed as a screw, which together are designed such that the outer diameter of the expanding element 9 increases when it is forced by the first clamping element 10 along the assembly axis B in the direction of the second sleeve unit 8. The second sleeve unit 8 has a second collar 8d. Both collars 5b, 8b and the outer circumferential surfaces of both sections 5a, 8a have the coating 5, 8b for structure-borne noise decoupling, which in this case comprises plastic.

[0045] The elastic ring 9 is preferably made of stainless steel, coated aluminum (anodized, hard-anodized, or similar), or plastic. Only the second sleeve unit 8 has an internal thread. The elastic ring 9 has an inner cone angle of preferably approximately 90° to allow the use of a simple countersunk screw 10. This design allows the elastic ring 9 to conform even better to the surface. Fig. 4. Spread the left through hole radially and consequently shape or conform it to the cylindrical through hole under preload without play.

[0046] Fig. 5 is a fifth embodiment without a lower head washer but with an elastic ring 9. Both ring surfaces of the first collar 5b and the second collar 8d have a plastic or elastomer overmolding, which leads to even better structure-borne noise decoupling. Furthermore, a plastic overmolding allows better radial sliding of the elastic ring 9 on the second collar 8d of the second sleeve unit 8 when expanded by screwing in the first countersunk screw 10. The remaining explanations regarding Fig. The number 4 also applies here.

[0047] Fig. 6 is a sixth embodiment with a conical ring instead of a bottom washer and with an elastic ring. Both through-holes of the receiving interface 3 have the same diameter and can be produced in one manufacturing step with the same drill. This also counteracts any axial misalignment of the through-holes.

[0048] The right-hand conical ring 12 with shoulder 12a in the figure is preferably made of stainless steel, coated aluminum (anodized, hard-anodized, or similar), or high-strength plastic. The right-hand conical ring 12 with shoulder 12a in the figure has an inner cone angle of preferably approximately 90° to allow the use of a simple countersunk screw 11 on the right side. This design of a separate conical ring 12 allows it to expand radially when the screw 11 is tightened, thus forming a tight, play-free fit under preload in the right-hand cylindrical through-hole. The shoulder 12a on the conical ring 12, together with the radially enlarged collar 5b of the first sleeve unit 5, secures the drive unit 2 against axial movement relative to the right-hand through-hole. Further explanations regarding Fig. The number 4 also applies here.

[0049] Fig. 7 is a seventh embodiment with a lower head washer 13 and an elastic ring 9, the second clamping element 11 of which has an internal thread for engaging with the first clamping element 10. The second section does not require an internal thread, which can save manufacturing costs. Furthermore, the explanations regarding Fig. 4 to.

[0050] Fig. Figure 8 schematically shows a bicycle 20 with a frame 4, a drive unit and several connecting devices. Reference sign 1 Connecting device 2 Drive unit 2a Housing 3 Recording interface 4 bicycle frames 5 first sleeve unit 5a first section 5b first collar or shoulder 5c coating for structure-borne noise decoupling 6 fitting holes 8 second sleeve unit 8a second section 8b conical section 8c coating for structure-borne noise decoupling 8d second collar or shoulder 9 Spreading element, elastic ring 10 first clamping element 11 second clamping element 11a Internal thread 12 Cone ring 12a Shoulder 13 Underhead disc A first longitudinal axis B Mounting axis C second longitudinal axis 20 bicycles

Claims

Connecting device (1) for connecting a drive unit (2) to a receiving interface (3) of a bicycle frame (4), comprising a first sleeve unit (5) dimensioned to form an interference fit or transition fit with a fitting bore (6) extending through the drive unit (2), with a metallic first section (5a) having a metallic first collar (5b) formed at the first end of the first section (5a) extending in a plane perpendicular to a first longitudinal axis (A) of the first section (5a), a second sleeve unit (8) dimensioned to form a transition or clearance fit with the fitting bore (6), with a metallic second section (8a), wherein the connecting device is configured such that the first section (5a) and the second section (8a) extend along a common assembly axis (B) in an assembled state, the connecting device further comprising a spreading element (9) and a first clamping element (10),which are jointly designed such that the outer diameter of the spreading element (9) increases when it is forced by the first clamping element (10) along the assembly axis (B) in the direction of the second sleeve unit (8). Connecting device according to claim 1, characterized in that the spreading element (9) is formed as a conical section (8b) on one end of the second section (8a), wherein the conical section (8b) is designed to partially accommodate the first clamping element (10). Connecting device according to claim 1, characterized in that the spreading element (9) is designed as an elastic ring with an inner cone independent of the second sleeve unit (8), wherein an outer diameter of the ring (9) can increase when the ring is forced by the first clamping element (10) along the assembly axis (B) in the direction of the second sleeve unit (8). Connecting device according to one of the preceding claims, in particular according to claim 3, characterized in that a second collar (8d) is formed on the second end of the second section (8a), which extends in a plane perpendicular to a second longitudinal axis (C) of the second section (8a). Connecting device according to one of the preceding claims, characterized by a second clamping element (11) and a slotted conical ring (12) which can be pressed by the clamping element (11) along the mounting axis (B) in the direction of the first collar (5b) for mechanical connection with the receiving interface (3), wherein the conical ring (12) has a circumferential contact shoulder (12a) for bearing against the receiving interface (3). Connecting device according to one of claims 1 to 4, characterized by the second clamping element (11) and a metallic underhead washer (13) for mechanical connection to the receiving interface (3) and for reducing a mechanical stress in the receiving interface (3), wherein the underhead washer (13) can be forced by the clamping element (11) along the mounting axis (B) in the direction of the first collar (5b). Connecting device according to one of claims 5 and 6, characterized in that the second clamping element (11) has an internal thread (11a) for engaging with an external thread of the first clamping element (10). Connecting device according to one of the preceding claims, characterized by a coating (5c, 8c) for structure-borne sound decoupling on a surface of at least the first sleeve unit (5) or the second sleeve unit (8). System comprising a connecting device (1) according to one of the preceding claims, the drive unit (2) with the fitting bore (6) which can at least partially accommodate the first sleeve unit (5) and the second sleeve unit (8), and a bicycle frame (4) with the receiving interface (3) for the drive unit (2), wherein the receiving interface (3) has two through holes, each for the first clamping element (10) or the second clamping element (11).

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