Drive unit of vehicle having freewheel assembly

Abstract

The invention relates to a drive unit of a vehicle, in particular of an electric bicycle, comprising a freewheel assembly comprising an output element, a shaft, a freewheel with a freewheel element, and a housing, the freewheel being arranged between the output element and the shaft and being designed to cause a torque transmission between the output element and the shaft in a locking configuration, torque transmission is prevented in the freewheel configuration, and wherein the freewheel has at least one bearing element by means of which the shaft and the output element are rotatably mounted relative to one another.

Description

Technical Field

[0001] The invention relates to a drive unit of a vehicle having a freewheel assembly and to the vehicle. Background Art

[0002] In vehicles, such as electric bicycles, freewheels are known that are designed to interrupt the connection between the driven shaft and the motor transmission when the driven shaft rotates faster in a forward-directed direction of rotation than the output of a motor transmission connected to the drive motor (i.e., in a direction of rotation that causes the vehicle to be driven in the forward-directed direction of travel). Typically, such freewheels are arranged in the area of ​​the pedal bearings of electric bicycles. Summary of the Invention

[0003] In contrast, the drive unit according to the present invention is characterized by an advantageously compact design that requires a particularly small amount of space while being simple to manufacture with few components. This is achieved according to the present invention by a drive unit for a vehicle, preferably an electric bicycle, having a freewheel assembly comprising a drive element, a shaft, and a freewheel. The freewheel has a plurality of freewheel elements and is arranged between the driven element and the shaft. It is configured to enable torque transmission between the driven element and the shaft in a locked configuration, while preventing torque transmission in a freewheel configuration, in particular by allowing free rotation of the driven element and the shaft relative to each other in the freewheel configuration. The freewheel has at least one bearing element, by means of which the shaft and the driven element are rotatably supported relative to each other.

[0004] Any transmission element for transmitting torque can be considered a shaft, in particular. A shaft can preferably provide both a driven function and a driving function. In particular, a shaft can be connected to another drive train of the vehicle, for example via a chain link and preferably via a chain or an alternative transmission element.

[0005] For example, a housing can be provided in addition. The housing can be, for example, a housing for holding components of the freewheel assembly and, for example, other components of the vehicle. In particular, the housing is thus a fixed component, relative to which at least the shaft is rotatably arranged.

[0006] In particular, a freewheel element is to be understood as a device which is suitable for establishing and releasing a torque transmission between a driven element and a shaft, preferably in each case in both directions of rotation.

[0007] The bearing element is preferably considered to be a device which allows a rotation of the shaft and the driven element relative to one another while simultaneously ensuring that the shaft and the driven element are held and positioned relative to one another, in particular in the radial direction, preferably also in the axial direction.

[0008] In particular, the driven element can be considered as any transmission element for transmitting torque. Preferably, the driven element can provide a driven function as well as a driving function. The driven element can preferably be a gear of a vehicle transmission, for example the last gear of a transmission of a vehicle drive.

[0009] In other words, a freewheel assembly is provided, which has a freewheel between a driven element and a shaft, in particular for transmitting a drive torque, for example, intended to drive a vehicle forward, to the shaft. The freewheel has a support element as an integral component, which at least partially contributes to supporting the shaft and the driven element relative to each other.

[0010] Preferably, the bearing element of the freewheel can be provided as the only element for supporting the shaft and the driven element relative to one another. Alternatively, further elements can preferably be provided, in particular inside and / or outside the freewheel, or in addition to the bearing element, as separate components for freewheeling, which contribute to the support.

[0011] The freewheel assembly offers the following advantages: it can provide a particularly simple and cost-effective design while simultaneously fulfilling both the freewheel and support functions. By integrating at least part of the support into the freewheel, a vehicle drive including a freewheel assembly can be provided with a particularly small number of components, resulting in a lightweight and cost-effective design. Furthermore, the reduced number of components reduces the risk of failure. The reduced installation space of the freewheel assembly also creates more space for other components of the drive, thereby enabling an optimized and particularly compact design for the entire drive. In particular, when the freewheel is in the freewheel configuration, the relative positioning of the driven element and the shaft relative to one another can be particularly precisely defined by the support element, which performs the additional support function. For example, eccentricity can thus be avoided in a simple and particularly reliable manner.

[0012] Preferred embodiments of the present invention are given below.

[0013] The support element preferably includes at least one plain bearing. Particularly preferably, the at least one plain bearing is designed in the form of a plain bearing disk, which is preferably arranged axially directly adjacent to the freewheel element. Preferably, exactly two plain bearing disks can be provided as plain bearings, which are arranged axially on both sides of the freewheel element. The freewheel with a plain bearing can be designed so that support is always provided solely by sliding friction via the plain bearing. Alternatively, the freewheel with a plain bearing can preferably be designed so that radial support is provided by the freewheel element, particularly by a small radial gap, preferably between the plain bearing and the shaft, and the plain bearing provides, in particular, only axial support. The plain bearing can provide a particularly simple, robust, and cost-effective support.

[0014] Particularly preferably, the bearing element comprises a rolling bearing, in particular a rolling bearing having at least one, preferably a plurality of rolling elements, thereby making it possible to provide a bearing having particularly low friction.

[0015] Preferably, at least one bearing element is arranged axially adjacent to the freewheel element of the freewheel. This means that the bearing element and the freewheel element are completely axially adjacent to each other, for example at least partially or completely at the same radial height. Alternatively, the freewheel element and the at least one bearing element are preferably arranged at least partially axially overlapping. This means that the bearing element and the freewheel element are at least partially at the same height in the axial direction and, in particular, radially adjacent to each other.

[0016] The freewheel is further preferably designed such that, in the freewheel configuration, the shaft is supported relative to the driven element, in particular exclusively via the at least one support element, and in the locked configuration, the shaft is supported relative to the driven element, in particular exclusively via the freewheel element. This allows a particularly robust configuration of the freewheel, in particular in the locked configuration, to be provided, in order to achieve an optimal torque transmission.

[0017] The freewheel is preferably designed such that radial support of the shaft relative to the driven element is achieved solely by the freewheel element. In this case, at least one support element is provided for, in particular, solely axial support of the shaft relative to the driven element. In this case, for a simple and cost-effective design, the support element can preferably comprise a plain bearing. This allows for a particularly simple and robust design of the freewheel, thereby simultaneously providing both the freewheel and support functions.

[0018] The freewheel is particularly preferably designed as a clamping roller freewheel. This means that the freewheel element is formed, in particular, by the clamping rollers of a clamping roller freewheel. This allows for a reliable freewheel and locking function with a simple and cost-effective function. Furthermore, the support function can be integrated into the freewheel in a simple and reliable manner, enabling precise support, in particular with regard to reliable concentricity of the driven element and the shaft.

[0019] Preferably, the freewheel has a first number of clamping rollers forming a freewheel element, wherein the freewheel additionally has a second number of support rollers forming a support element. In particular, the clamping rollers and support rollers are regularly distributed around the circumference of the freewheel in a uniform pattern. Particularly preferably, the support rollers are arranged in a pattern that is evenly distributed around the circumference. For example, two clamping rollers can be arranged diametrically opposite each other. In particular, the freewheel can include an inner ring and an outer ring, wherein the clamping rollers and support rollers are arranged between the inner and outer rings and are preferably held relative to each other by a cage. For example, the cage can also be used to control the freewheel function. This allows for a particularly simple and cost-effective design with few components.

[0020] Preferably, the second number is at least 2, preferably 4. In particular, a plurality of freewheel elements can thus be provided in order to be able to provide the freewheel function particularly reliably.

[0021] The freewheel preferably includes a clamping geometry that, in particular, can provide the freewheel function together with the clamping rollers. The clamping geometry is geometrically arranged only in the region of the clamping rollers, i.e., in particular, at a circumferential position of the freewheel corresponding to the clamping rollers. For example, the clamping geometry can be arranged on the inner and / or outer ring of the freewheel. This allows for simple and cost-effective production of the freewheel.

[0022] The freewheel particularly preferably has a bearing geometry that is arranged, in particular, only in the region of the support rollers. That is, the bearing geometry is arranged at a circumferential position of the freewheel corresponding to the support rollers. In particular, the bearing geometry is designed such that when the freewheel is in the freewheel configuration, the bearing geometry is in contact with the support rollers. The freewheel is particularly preferably designed such that, in the freewheel configuration, there is no clamping contact between the clamping rollers and the clamping geometry. That is, in the freewheel configuration, the support rollers can roll or rotate on the bearing geometry, thereby achieving a torque-free bearing.

[0023] Preferably, the freewheel assembly further comprises at least one, preferably a plurality of, additional separate bearings for supporting the shaft relative to the driven element. The at least one additional separate bearing can be separate from the freewheel and arranged spaced apart from the freewheel.

[0024] The shaft is preferably supported relative to the driven element solely by means of the freewheel. The freewheel can preferably comprise a freewheel element and a support element at at least two different axial positions on the shaft. This allows for a particularly simple and cost-effective design with few components.

[0025] Particularly preferably, the freewheel is designed as a bidirectional freewheel. That is, the freewheel configuration and the locking configuration can each be realized in both directions of rotation. Preferably, this can be achieved by means of actively controllable actuation or alternatively by friction.

[0026] Furthermore, the invention relates to a vehicle, in particular an electric bicycle, comprising the described freewheel assembly.

[0027] The vehicle preferably further comprises a drive unit, which is connected to the driven element, in particular in a torque-transmitting manner, and a crank gear, which is connected to the shaft, in particular in a torque-fixed manner. In particular, the freewheel is thus arranged between the gear of the drive unit and the shaft, which in particular forms a pedal shaft or crankshaft of the vehicle. The freewheel may also be referred to as a motor freewheel, for example. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The present invention will be described below in conjunction with the accompanying drawings according to an embodiment. In the accompanying drawings, components with the same function are respectively marked with the same reference numerals. Here, it is shown:

[0029] Figure 1 : A simplified schematic diagram of a vehicle having a freewheel assembly according to a first embodiment of the present invention;

[0030] Figure 2 : Figure 1 Detailed cross-sectional view of the freewheel assembly;

[0031] Figure 3 : Figure 1 Another detailed cross-sectional view of the freewheel assembly;

[0032] Figure 4 : A detailed cross-sectional view of a freewheel assembly according to a second embodiment of the present invention;

[0033] Figure 5 : Figure 4 Alternative view of the freewheel assembly;

[0034] Figure 6 : Figure 4 and Figure 5 Detail of the freewheel assembly. DETAILED DESCRIPTION

[0035] Figure 1 A simplified schematic diagram of a vehicle 100 is shown, which includes a freewheel assembly 1 according to a first embodiment of the present invention. The vehicle 100 is a vehicle that can be run by muscle power and / or motor power, in particular an electric bicycle.

[0036] The electric bicycle 100 comprises a drive unit 10 , which comprises a motor, in particular an electric motor. The motor can be supplied with electrical energy by means of an electrical energy storage device 109 of the electric bicycle 100 .

[0037] The drive unit 10 is arranged in the region of a pedal bearing of the electric bicycle 100. The motor torque generated by the motor can assist the pedaling force generated by the muscle force of the rider of the electric bicycle 100.

[0038] The muscle force of the rider can be applied to the shaft 3 via a crank transmission including a crank 104. The shaft 3 extends along the driven axis 15. The driven element 2 of the drive unit 10 is arranged coaxially with the shaft 3, which is in particular a gear (see Figure 2 and Figure 3 ).

[0039] The output element 2 forms the last gear of a transmission (not shown) of the drive unit 10 , via which the motor can transmit the motor torque to the output element 2 .

[0040] The shaft 3 also includes a connection area 108 (see Figure 4 In the second embodiment of the invention), the driven element 107 can be fixed in a rotationally fixed manner on this connection area, the driven element being in particular a chain plate (see Figure 1 ).

[0041] Between the driven element 2 and the shaft 3 there is a freewheel 4 which, in the first exemplary embodiment shown, is designed as a clamping roller freewheel and has a plurality of freewheel elements 41 distributed around the circumference, which are designed in particular as clamping rollers.

[0042] When the driven element 2 rotates relative to the shaft 3 in the locking direction, the freewheel 4 locks and causes a torque transmission between the driven element 2 and the shaft 3. In this case, the freewheel 4 is in a locked configuration.

[0043] When the driven element 2 rotates relative to the shaft 3 in the opposite direction of the freewheel, the freewheel 4 is released from rotation and prevents torque transmission. In this case, the freewheel 4 is in a freewheel configuration.

[0044] The freewheel 4 is designed as a bidirectional freewheel. That is, the freewheel 4 can be opened in both directions of relative rotation between the driven element 2 and the shaft 3, i.e., it allows free rotation without transmitting torque. This can be achieved by selectively controlling the actuation of the freewheel cage 44 of the freewheel 4.

[0045] The freewheel cage 44 is provided here to ensure a predetermined distance between the clamping roller 41a and the support roller 41b in the circumferential direction. In addition, for example, in certain operating states, the freewheel cage 44 can specifically cause the movement of the clamping roller 41a so that it is brought into an open freewheel configuration of the entire freewheel 4.

[0046] By means of the friction element 47 connected to the freewheel cage 44 in a rotationally fixed manner, the freewheel cage 44 can be moved in such a way as to provide a control actuation of the freewheel function, ie, a bidirectional functionality is achieved by a corresponding movement of the clamping roller 41 a .

[0047] exist Figure 3 Here, the connection of the freewheel cage 44 to the friction element 47 , which is designed in the form of a sheet metal, can be seen. Figure 3 Shown with Figure 2 A similar detailed sectional view of the freewheel assembly 1, in which the section plane is positioned differently, namely in the middle of one of the friction elements 47. The friction element 47 can extend in the radial direction through a recess in the output element 2 or in a subregion 26 of the output element 2, wherein these recesses are correspondingly dimensioned to enable a certain relative rotation between the output element 2 and the freewheel cage 44 having the friction element 47.

[0048] The friction element 47 is configured as a spring element which, by means of spring force, presses a plurality of friction surfaces 47 a distributed on the circumference radially inward against the housing friction surface 65 on the housing 6. Consequently, during a corresponding relative rotation, a friction torque is generated between the housing 6 and the freewheel cage 44 via the friction element 47, thereby causing the freewheel cage 44 to rotate relative to each other in the circumferential direction, thereby moving the clamping roller 41 a and thereby locking or releasing the freewheel 4.

[0049] When the freewheel 4 is locked, the drive unit 10 can drive the shaft 3 via the output element 2 and the freewheel 4 by means of the generated motor torque.

[0050] Furthermore, the drive unit 10 comprises a housing 6 which is configured to receive and retain the components of the drive unit 10 and the freewheel assembly 1. Furthermore, the housing 6 may be configured to be mounted on a frame of the electric bicycle 100.

[0051] The freewheel assembly 1 is further configured such that the bearings provided for supporting the shaft 3 and the driven element 2 relative to each other are integral components of the freewheel 4. For this purpose, the freewheel 4 further comprises two bearing elements 5, each of which is configured as a plain bearing. In particular, the two bearing elements 5 are each configured as a plain bearing disk, which is arranged axially adjacent to the freewheel element 41. In other words, the freewheel element 41 is arranged axially between the bearing elements 5.

[0052] In detail, the first supporting element 5 (at Figure 2 The second support element 5 (on the right side) is arranged radially between the shaft 3 and the partial area 26 of the driven element 2. Figure 2The driven element 2 is arranged radially between the shaft 3 and the freewheel sleeve 45 (center left), which in particular forms the radially outermost sleeve of the freewheel 4. In particular, the driven element 2 is arranged directly on the outer circumference of the freewheel sleeve 45.

[0053] exist Figures 1 to 3 In the first exemplary embodiment shown, the freewheel 4 is designed such that, in the freewheel configuration, radial support of the shaft 3 relative to the driven element 2 is achieved solely via the bearing element 5. The freewheel 4 is also designed such that, in the locked configuration, radial support is achieved solely via the freewheel element 41 due to corresponding dimensioning of the freewheel element 41 and the bearing element 5. In this configuration, a slight radial gap is formed in the radially inner region 55 between the bearing element 5 and the shaft 3, so that no radial contact occurs.

[0054] However, in the locked configuration, it can be provided that the bearing element 5 forms at least a part of the axial support of the output element 2 and the drive shaft 3 relative to each other, wherein the axial support can be realized directly or indirectly, for example via other components.

[0055] In another alternative (not shown) modified embodiment of the first embodiment, the freewheel 4 can be designed alternatively so that a slightly larger diameter support element 5 is provided. In this alternative modified embodiment, the support element 5 does not provide radial support neither in the locked configuration nor in the freewheel configuration, but is merely provided to form at least part of the axial support of the driven element 2 and / or the drive shaft 3.

[0056] The freewheel assembly 1 offers the advantage of a particularly simple and cost-effective design. By integrating the bearing at least partially directly into the freewheel 4 , a particularly compact design of the freewheel assembly 1 with few components can be provided.

[0057] Figure 4 A detailed cross-sectional view of a freewheel assembly 1 according to a second embodiment of the present invention is shown. Figure 5 and Figure 6 Shown in Figure 4 An alternative detailed view of the freewheel assembly of the second embodiment corresponds essentially to Figures 1 to 3 The first embodiment differs from the alternative configuration of the support. In the second embodiment, the support is achieved by configuring the support element 5 in the form of a rolling bearing.

[0058] Specifically, the bearing element 5 is designed here as part of a clamping roller freewheel, so that the freewheel 4 has a first number of clamping rollers 41a forming the freewheel element 41 and also a second number of bearing rollers 41b forming the bearing element 5. In particular, in this case, the bearing element 5 and the freewheel element 41 are arranged axially overlapping.

[0059] In the embodiment shown, a total of four support rollers 41b are provided, which are arranged evenly distributed around the circumference and are further arranged such that exactly two support rollers 41b are each arranged diametrically opposite each other (see Figure 5 ).

[0060] The clamping roller 41a and the support roller 41b can have the same geometry or alternatively different geometries. Preferably, the clamping roller 41a and the support roller 41b are each designed as a cylindrical roller.

[0061] In the area of ​​each support roller 41b, the freewheel 4 has a support geometry 43 in a freewheel sleeve 45. The support geometry 43 is formed in the form of a groove in the freewheel sleeve 45, which is bounded by a cylindrical circumference. As a result, the support rollers 41b can roll freely in both directions of relative rotation of the driven element 2 and the shaft 3, thus providing flexible support in the radial direction.

[0062] Furthermore, the freewheel 4 comprises a clamping geometry 42 per clamping roller 41a in the freewheel sleeve 45. The clamping geometry 42 is preferably arranged obliquely with respect to the tangential direction and is designed so as to, depending on the configuration of the freewheel 4, cause the clamping rollers 41a to be clamped in order to provide a locked configuration, or to release the clamping rollers 41a in order to provide a freewheel configuration.

Claims

1. A drive unit (10) of a vehicle (100), in particular an electric bicycle, having a freewheel assembly, the freewheel assembly comprising: - a driven element (2); - shaft (3); and - a freewheel (4) having a freewheel element (41); wherein the freewheel (4) is arranged between the driven element (2) and the shaft (3) and is designed to bring about a torque transmission between the driven element (2) and the shaft (3) in a locked configuration and to prevent the torque transmission in a freewheel configuration; wherein the freewheel (4) has at least one bearing element (5), by means of which the shaft (3) and the driven element (2) are rotatably supported relative to one another.

2. The drive unit according to claim 1, wherein: The support element (5) comprises at least one sliding bearing.

3. A drive unit according to any one of the preceding claims, wherein The at least one supporting element (5) comprises a rolling bearing.

4. A drive unit according to any one of the preceding claims, wherein The at least one bearing element (5) is arranged axially next to a freewheel element (41) of the freewheel (4), or the at least one bearing element (5) and the freewheel element (41) are arranged at least partially axially overlapping.

5. A drive unit according to any one of the preceding claims, wherein The freewheel (4) is designed such that the shaft (3) and the driven element (2) are supported relative to one another in a freewheel configuration by means of the at least one support element (5) and in a locked configuration by means of the freewheel element (41).

6. A drive unit according to any one of the preceding claims, wherein The freewheel (4) is designed such that radial support of the shaft (3) and the driven element (2) relative to one another is achieved exclusively via the freewheel element (41), and wherein the at least one supporting element (5) is provided for axially supporting the shaft (3) and the driven element (2) relative to one another.

7. A drive unit according to any one of the preceding claims, wherein The freewheel (4) is designed as a clamping roller freewheel.

8. The drive unit according to claim 7, wherein: The freewheel (4) has a first number of clamping rollers (41a) forming the freewheel element (41), and the freewheel (4) has a second number of supporting rollers (41b) forming the supporting element (5).

9. The drive unit according to claim 8, wherein: The second number is at least 2, preferably 4.

10. The drive unit according to any one of claims 7 to 9, wherein: The freewheel (4) is designed such that the clamping geometry (42) is geometrically arranged only in the region of the clamping roller (41a).

11. The drive unit according to any one of claims 7 to 9, wherein: The freewheel (4) geometrically comprises a bearing geometry (43) in the region of the bearing roller (41b), the bearing geometry being designed in particular such that in the freewheel configuration the bearing roller (41b) is in contact with the bearing geometry (43).

12. Drive unit according to any of the preceding claims, further comprising at least one additional separate bearing (7) for supporting the shaft (3) and the driven element (2) relative to each other.

13. The drive unit according to any one of claims 1 to 11, wherein: The shaft (3) and the driven element (2) are supported relative to one another solely by means of the freewheel (4).

14. A drive unit according to any one of the preceding claims, wherein The freewheel (4) is configured as a bidirectional freewheel.

15. A vehicle, in particular an electric bicycle, comprising a drive unit (10) according to any one of the preceding claims.

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