Bicycle frame, housing for mounting on the frame, and bicycle with such a frame and housing

Abstract

Frame (10) for a bicycle (100) comprising: • a receiving area that is at least partially cylindrical and is designed to at least partially receive and span a cylindrical housing (20) to a maximum of half its length, wherein the receiving area has at least two circumferentially spaced contact surfaces (11) that are designed to come into contact with the housing (20), and • a retaining bracket (30) with at least one contact surface (31) that is at least partially separable and connectable to the frame (10) and is designed to fix the housing (20) to the frame (10).

Description

The invention relates to a frame for a bicycle having a receiving region which is configured to at least partially receive a housing. The invention further relates to a housing for mounting on the frame, comprising a drive unit having a pedal crankshaft and a drive machine which is configured to generate an auxiliary drive power for assisting the user. The invention also relates to a bicycle having such a frame and such a housing.Bicycles are generally known which can be driven purely by muscle power of a user or cyclist. Furthermore, bicycles are known which, in addition to the drive power of the cyclist, can be driven by a drive machine designed as an electric machine. Such bicycles are also known as electric bicycles, pedelecs or e-bikes. A driving power of the user is generally supported by the electric machine in accordance with a driver's request and a torque fed in by the user. The electric machine can be arranged as a central motor in the region of the pedal crankshaft or as a wheel drive directly on the respective drive wheel. Central motors for e-bikes are usually screwed directly to the frame. To connect the center motor to the frame, several screws are used. This type of connection has increased assembly effort and requires comparatively much installation space.For example, DE 10 2023 204 911 A1 discloses a drive unit for an e-bike operated with muscle and / or motor, comprising a housing comprising a first housing half and a further housing half, wherein a stator of a motor is fastened in the first housing half. The drive unit further comprises a pedal shaft assembly, at least one first printed circuit board, a rotor shaft assembly having a rotor and a rotor shaft, at least one further housing component and at least one gear mechanism which is configured to transmit a torque generated by the motor to the pedal shaft assembly. All the assemblies are arranged in such a way that they can be inserted from a main assembly direction.The object of the present invention is to provide an alternative frame for a bicycle and a matching housing for a drive unit designed as a central motor. In particular, the assembly effort for fastening the housing to the frame is to be reduced. Furthermore, installation space is to be saved. The object is achieved by the features of independent claim 1. advantageous embodiments are the subject matter of the dependent claims, the following description and the figures.According to a first aspect, a frame for a bicycle is provided, comprising an at least partially cylindrically formed receiving region which is configured to at least partially receive a cylindrically formed housing and to span at most half of it, wherein the receiving region has at least two contact surfaces spaced apart from one another in the circumferential direction, which contact surfaces are configured to come to rest on the housing, and a retaining bracket having at least one contact surface which is at least partially detachably connectable to the frame and is configured to fix the housing to the frame. In particular, the cylindrical receiving region on the frame is configured to conform at least partially or completely to a lateral surface of the cylindrical housing. The housing is thus clamped between the receiving region on the frame and the retaining bracket and is thereby firmly connected to the frame.Because the receiving region has at least two contact surfaces spaced apart from one another in the circumferential direction, and the contact surfaces are thus interrupted, not only is the manufacturing outlay reduced, but also the acoustics are improved, in particular the noise generation is reduced. The contact between frame and housing is thus not fully comprehensive, but only in certain regions, as a result of which the manufacturing outlay is reduced on account of the increased tolerance requirements of a cylindrical clamping on the frame. The aforementioned tolerance-critical regions are present primarily on the frame and not on the retaining bracket, since the frame has a higher rigidity. Tolerance insensitivity can be ensured in the holding bracket by a certain flexibility of the component itself and thus there is full-area contact with the housing. By delimiting the contact surfaces on the frame, the acoustic transmission path into the frame is better controlled, in particular optimized. As a result, fewer oscillations are introduced into the frame, so that the entire acoustics of the bicycle are improved and, in particular, low-frequency perceptible mechanical oscillations are at least partially decoupled.For example, the receiving region is configured to span the housing by at least 90°, preferably by at least 120°. According to one embodiment, at least four contact surfaces are formed on the receiving region, wherein in each case two contact surfaces are spaced apart in the circumferential direction and in each case two contact surfaces are spaced apart axially from one another.For example, the retaining bracket is configured to span the housing by at least 90°, preferably by at least 120° and at most by 180°. The at least one contact surface extends in the circumferential direction preferably over the entire retaining bracket. For example, the holding bracket is designed in the form of a half shell and is configured to span the housing at most half-way. The housing is configured in particular to accommodate a drive unit, which is designed as a central engine and has a pedal crankshaft and an electric machine.According to one embodiment, either the receiving region on the frame or the retaining bracket has at least one shaped element which is designed as an elevation or depression and is designed to cooperate with a shaped element on the housing which is designed as a depression or elevation. For example, a shaped element designed as an elevation is formed on the frame between two contact surfaces spaced apart from one another in the circumferential direction, wherein this elevation interacts with a depression on the housing designed correspondingly thereto in order to create, on the one hand, the mounting, in particular the positioning and centering of the housing on the frame, and, on the other hand, an additional positively locking connection for supporting the torque. In particular, the shaped element has a lens-shaped geometry. Without these shaped elements, the drive torque is supported only by a frictional connection because of the cylindrical shape of the housing. Therefore, the shape elements improve the connection by additional torque support. Furthermore, without these shaped elements, no centering elements are provided for the axial and rotational alignment of the housing on the frame due to the cylindrical shape of the housing. Therefore, the mold members facilitate assembly and enable uniform operating conditions.According to one embodiment, the retaining bracket is designed in the form of a shell and is provided as underrun protection in order to protect the housing and thus also the drive unit from stone hammer. In the event of stone impact and damage, it is not necessary to replace the entire housing, but only the shell-shaped retaining bracket. In particular, the retaining bracket completely covers the housing on an underside, so that only the axial end sides of the housing are visible. According to one embodiment, the retaining bracket has a plurality of cooling ribs. For example, the retaining bracket is formed from a thermally conductive material, in particular a metal alloy. For example, the retaining bracket is formed from an aluminum alloy. Preferably, the frame is formed from an aluminum alloy. Alternatively, the frame is formed from at least one carbon fiber-reinforced plastic. The design of the holding bracket from thermally conductive material with cooling ribs is advantageous in particular in the case of a frame made of at least one carbon fiber-reinforced plastic in order to enable sufficient heat dissipation from the housing. The cooling capacity can be increased by a plurality of cooling ribs.According to one embodiment, at least one channel for cooling the housing is formed on the frame between the at least two contact surfaces spaced apart from one another in the circumferential direction. If the frame is formed from at least one carbon fiber-reinforced plastic, thermal insulation of the housing takes place in the region of the frame, since carbon fiber-reinforced plastics dissipate heat less easily than metals. The at least one channel is then preferably used for aeration and heat dissipation via convection, whereby the engine cooling and thus the performance of the engine arranged in the housing is improved. If the frame is formed from a metal, in particular from an aluminum alloy, the at least one channel is used, for example, to accommodate a thermally conductive element, for example an adhesive pad, in order to achieve a high cooling capacity by the thermal connection of the housing to the frame. If neither air flow nor thermal bonding is desired, the at least one channel can be sealed by sealing compound or sealing elements before water enters.According to one embodiment, the retaining bracket can be connected to the frame via at least two screw elements. For example, four screw elements are provided in order to connect the holding bracket to the frame. In particular, the respective screw element is guided through a respective bore on the retaining bracket and screwed into a respective threaded bore on the frame. Preferably, the clamping force of the holding bracket is adjusted by tightening the screw elements.According to one embodiment, the retaining bracket can be connected to the frame via at least two clamping elements. For example, four clamping elements are provided in order to connect the holding bracket to the frame. In particular, the respective clamping element is formed on the retaining bracket and is suspended on a respective undercut structure formed on the frame. Alternatively, the respective clamping element is formed on the frame and is suspended on a respective undercut structure formed on the retaining bracket.According to one embodiment, the retaining bracket is pivotably connected to the frame via at least one hinge. The holding bracket is therefore connected to the frame such that it cannot be separated, but can be pivoted, at least on one side. On the other side of the holding bracket, the holding bracket can be connected to the frame either via at least two screw elements or via at least two clamping elements.According to a second aspect, a cylindrically formed housing for mounting on a frame according to the first aspect is provided. According to a third aspect, there is provided a bicycle including a frame according to the first aspect and a housing according to the second aspect. The above definitions and statements regarding technical effects, advantages and advantageous embodiments of the frame according to the invention also apply analogously to the housing according to the invention and the bicycle according to the invention.The housing comprises a drive unit having a pedal crank shaft which protrudes at least partially from the housing and is configured to receive a drive power of a user, and a drive machine which is arranged in the housing and is configured to generate an auxiliary drive power for assisting the user. The drive machine is in particular designed as an electric machine and draws electrical energy from an energy store preferably arranged on the frame in order to generate the auxiliary drive power. Optionally, the drive unit further comprises a gear mechanism which is operatively connected to the drive machine in a drive-effective manner.A bicycle is understood in the present case to be an electric bicycle, pedelec or e-bike. A driving power of the user is supported by the engine in accordance with a set traveling mode and a torque input from the user. The drive machine is arranged as an electric central motor in the region of the crank shaft and is operatively connected to a drive wheel of the bicycle via a traction drive of the bicycle. In particular, the term bicycle is also to be understood as meaning load wheels having a plurality of wheels, in particular having three or four wheels.Advantageous embodiments of the invention, which is explained below, are illustrated in the drawings, wherein identical or similar elements are provided with the same reference numerals. The following are shown: FIG. 1 is a greatly simplified schematic illustration of a bicycle, FIG. 2 is a schematic side view of a detail of a frame of the bicycle according to FIG. 1 , FIG. 3 shows a schematic exploded illustration of a detail of the frame with a drive unit arranged in a housing, FIG. 4 shows a highly schematic side illustration of a detail of the frame with a housing fixed therein according to a second embodiment, and FIG. 5 shows a highly schematic side illustration of a detail of the frame with a housing fixed therein according to a third embodiment.In FIG. 1, a bicycle 100 is shown in a greatly simplified manner. The bicycle 100 has a frame 10 on which a front wheel 101, a rear wheel 102 designed as a drive wheel, a saddle 104 and a handlebar 103 are arranged. The handlebar 103 includes a handlebar and handlebar handles. During travel, i.e. during a driving operation of the bicycle 100, a user, not shown in detail, sits on the saddle 104, for example, and is supported on the handlebar grips. In the present case, the bicycle 100 is designed as an e-bike and has a drive machine 23 designed as an electric machine, which is integrated in a drive unit of the bicycle 100. This drive unit is configured to drive the bicycle 100 at least with a muscle power of a user. For this purpose, the user introduces a torque and a rotational speed, in particular a drive power, into the drive train of the bicycle 100 via respective pedals 105 which are connected via respective cranks to a crankshaft 22 of the drive unit. The drive power is transmitted to the drive wheel via a traction drive 106 of the bicycle 100.The drive machine 23 is arranged in the present case as a central motor in the region of the crank shaft 22 and can introduce an auxiliary drive power into the drive train of the bicycle 100 in accordance with the user in order to assist the user during driving. To generate the auxiliary drive power, the drive machine 23 draws electrical energy from an energy store, not shown in detail, which can be arranged on the frame 10. The auxiliary driving power is dependent on the pedaling force of the user and divided into various adjustable levels, whereby the user can select the assist level. The pedaling force can be detected via means provided for this purpose, for example sensors on the pedal crankshaft 22. As the user applies more force to the pedals 105, the prime mover 23 increases assistance in proportion to the force or torque that the user applies to the powertrain.A portion of the frame 10 of the bicycle 100 is shown in FIG. 2. The frame 10 comprises an at least partially cylindrically formed receiving region which is configured to partially receive a cylindrically formed housing 20, which is only shown in the present case in FIG. 3, and to span it at most half, wherein the receiving region has two contact surfaces 11 spaced apart from one another in the circumferential direction, which are configured to come to rest against the housing 20. Between the two contact surfaces 11 spaced apart from one another in the circumferential direction, channels 13 are formed for cooling the housing on the frame 10. For example, cooling air is conducted through the ducts 13 in order to dissipate the heat which arises during operation of the drive engine by convection.Furthermore, the frame 10 comprises a holding bracket 30 with a contact surface 31. The holding bracket 30 has a plurality of cooling ribs 32 for improved heat dissipation. The holding bracket 30 is connected to the frame 10 in a separable manner via a plurality of screw means 31 and is configured to fix the housing to the frame 10. The screw means 31 are screwed firmly into the frame 10 until the necessary clamping force for the housing between the frame 10 and the holding bracket 30 is reached. In other words, a frictional connection is formed on the contact surfaces 11 between the housing and the frame 10, as well as on the contact surface 31 between the housing and the retaining bracket 30.Furthermore, the receiving region on the frame 10 has a shaped element 12 designed as an elevation, which is designed to cooperate with a shaped element designed as a depression on the housing. The depression on the housing is formed corresponding to the elevation on the frame 10 and is configured to receive the elevation on the frame during assembly in order, on the one hand, to preset the positioning of the housing in the frame 10 and, on the other hand, to form a rotationally fixed positive connection between the housing and the frame 10.FIG. 3 shows an exploded view of a detail of the frame 10 with the housing 20 and the retaining bracket 30. The housing 20 has a lateral surface with circumferential contact surfaces. To simplify the construction and assembly of the housing 20 on the frame 10, two shaped elements 21 formed as depressions are provided in the lateral surface of the housing 20, wherein the invisible depression is configured to receive the shaped element 12 formed as an elevation on the frame 10, and wherein the visible depression on the housing 20 is configured to receive a shaped element formed as an elevation on the retaining bracket 30. In the present case, however, no shaped element is formed on the retaining bracket 30, so that no elevation penetrates into the visible depression on the housing 20.The pedal crank shaft 22 of the drive unit protrudes at least partially out of the housing 20 and is configured to absorb a drive power of the user, wherein in the present case the pedal cranks and pedals connected thereto are not shown. The drive machine is arranged in the housing 20 and in the present case is completely covered by the housing 20. Furthermore, a connection 15 for receiving a connecting cable 14 guided through the frame 10 is formed on the housing 20. FIG. 3 shows the shell-shaped formation of the retaining bracket 30 provided as underride guard and the number of screw elements 33 provided for separable connection to the frame 10. In the present case, each screw element 33 is guided through a respective bore on the retaining bracket 30 and screwed into a respective threaded bore on the frame 10, this being indicated by the four dashed lines. By tightening the screw elements 33, the clamping force of the holding bracket 30 is adjusted.The at least partially cylindrically designed interface between frame 10 and housing 20, in particular the half-shell-shaped design on frame 10, and the at least partially cylindrically designed interface between holding bracket 30 and housing 20, in particular the half-shell-shaped design of the holding bracket, provide that housing 20 with the drive unit located therein is clamped in a planar manner. The advantages of the cylindrical interfaces enable rapid assembly and disassembly by simple shaping, good accessibility and a small number of screw elements, a high connection rigidity to the frame 10, which is necessary in particular for a good driving feel and an efficient force transmission, a good heat dissipation and a low installation space requirement.FIGS. 4 and 5 show two alternative connection possibilities between frame 10 and retaining bracket 30, which are configured for clamping the housing 20 arranged spatially therebetween.According to FIG. 4, the holding bracket 30 is pivotably connected to the frame 10 via a hinge 35, wherein the holding bracket 30 can furthermore be connected to the frame 10 via two clamping elements 34, of which only one is shown in the present case. Alternatively, the two clamping elements 34 can be replaced by two screw elements 33, as in FIG. 3.According to FIG. 5, the holding bracket 30 can be connected to the frame 10 via two clamping elements 34. Alternatively, two further clamping elements 34 can be used for connecting the holding bracket 30 and the frame 10.Reference numerals denote reference numerals10 Frame 11 Contact surface 12 Shaped element 13 Channel 14 Connecting cable 15 Connection 20 Housing 21 Shaped element 22 Pedal crankshaft 23 Drive machine 30 Retaining bracket 31 Contact surface 32 Cooling rib 33 Screw element 34 Clamping element 35 Hinge 100 Bicycle 101 Front wheel 102 Rear wheel 103 Bicycle handlebar 104 Seat 105 Pedals 106 Traction driveReferences included in the specificationThis list of documents cited by the applicant has been produced in an automated manner and is only included for the better information of the reader. The list is not part of the German patent application or utility model application. The DPMA does not take any adhesion for any faults or omissions.Patent Literature citedDE 10 2023 204 911 A1

[0003]

Claims

Frame (10) for a bicycle (100) comprising • an at least partially cylindrically formed receiving region which is configured to receive a cylindrically formed housing (20) at least partially and to span it around at most half of it, wherein the receiving region has at least two contact surfaces (11) spaced apart from one another in the circumferential direction, which contact surfaces are configured to come to rest against the housing (20), and • a retaining bracket (30) having at least one contact surface (31) which can be connected at least partially in a separable manner to the frame (10) and is configured to fix the housing (20) to the frame (10).Frame (10) according to claim 1, wherein either the receiving region on the frame (10) or the retaining bracket (30) has at least one shaped element (12) which is designed as an elevation or depression and is designed to cooperate with a shaped element (21) on the housing (20) which is designed as a depression or elevation.Frame (10) according to one of the preceding claims, wherein the retaining bracket (30) is designed in the form of a shell and is provided as underrun protection.Frame (10) according to one of the preceding claims, wherein the retaining bracket (30) has a plurality of cooling ribs (32).Frame (10) according to one of the preceding claims, wherein the retaining bracket (30) can be connected to the frame (10) via at least two screw elements (33).Frame (10) according to one of the preceding claims, wherein the retaining bracket (30) can be connected to the frame (10) via at least two clamping elements (34).Frame (10) according to Claim 5 or 6, wherein the retaining bracket (30) is pivotably connected to the frame (10) via at least one hinge (35).Frame (10) according to one of the preceding claims, wherein at least one channel (13) for cooling the housing (20) is formed on the frame (10) between the at least two contact surfaces (11) spaced apart from one another in the circumferential direction.Cylindrically formed housing (20) for mounting on a frame (10) according to one of the preceding claims, comprising a drive unit with a pedal crank shaft (22), which protrudes at least partially from the housing (20) and is configured to receive a drive power of a user, and a drive machine (23), which is arranged in the housing (20) and is configured to generate an auxiliary drive power for supporting the user.A bicycle (100) comprising a frame (10) according to any one of claims 1 to 8 and a housing (20) according to claim 9.

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