Clamp body freewheel unit, drive device for electric bicycle, and electric bicycle equipped with the same

Abstract

The proposed solution relates to a clamp body freewheel unit (3) and a drive device (A) for motor-assisted driving of an electric bicycle (1) having the clamp body freewheel unit (3). The proposed clamp body freewheel unit (3) comprises a plurality of clamp bodies (5), a cage (35), and a plurality of rolling elements (6). The transmission of force between the inner shaft and the outer shaft, which can be connected via the clamping body freewheel unit (3), is permitted by the clamping bodies (5) only in one of two opposite rotation directions; The clamp bodies (5) of the clamp body freewheel unit (3) are held together at predetermined intervals in the circumferential direction (U) by a retainer (35), When the inner shaft and the outer shaft are connected via the clamp body freewheel unit (3), they are mounted so as to be rotatable relative to each other by a plurality of rolling elements (6). At least some of the rolling elements (6) and the clamping elements (5) are held together in a single cage (35).

Description

[Technical Field]

[0001] The proposed solution relates to a clamp body freewheel unit having a plurality of clamp bodies, a cage in which the clamp bodies are held at predetermined intervals from one another in the circumferential direction, and a plurality of rolling bodies for rotatably supporting two shafts connected to one another via the clamp body freewheel unit. [Background technology]

[0002] Clamping body freewheel units are widely known. In this case, multiple clamping bodies are used to transmit force in only one of two opposing rotational directions between internal and external components, particularly an internal or external shaft, that can be connected to each other by the clamping body freewheel units. In this way, force transmission can occur during rotation in one rotational direction, while relative rotation of the components is possible in the opposite rotational direction via the clamping body freewheel units. In this case, the clamping bodies are held in a cage of the clamping body freewheel units at a specified distance from each other in one circumferential direction around the rotation axis defined by the clamping body freewheel units, and can be tilted about a tilt axis extending perpendicular to the circumferential direction, so that depending on the rotational direction, torque is transmitted via the clamping bodies in a non-positive locking manner.

[0003] In addition to the clamping bodies of the clamping body freewheel unit, it is also known to provide rolling elements on which components intended to be coupled to each other are rotatably supported relative to each other in order to accurately support the components rotatably under relatively large torque. For example, the rolling elements are arranged in front of the components intended to be coupled to each other, between the inner ring of the clamping body freewheel unit and the outer ring of the clamping body freewheel unit, or directly on the components. For example, the inner ring can be connected to the inner shaft, and the outer ring can be connected to the outer shaft. When rolling elements are incorporated into the clamping body freewheel unit, a separate cage is usually provided for holding the rotatable rolling elements at a defined distance from each other. Alternatively, recesses are provided in the cage for the rolling elements, especially if the rolling elements are needle-shaped. Summary of the Invention [Problem to be solved by the invention]

[0004] In particular, improvements in clamp body freewheeling are required in relation to the use of clamp body freewheeling on electric bicycles, in this case with regard to the tolerances that must be provided between two parts that are intended to be connected to each other, such as the inner and outer shafts, and the stringent structural space conditions. [Means for solving the problem]

[0005] Against this background, a clamping body freewheel unit as described in claim 1 is proposed, in which at least a portion of the rolling bodies of the clamping body freewheel unit and the clamping body of the clamping body freewheel unit are held together in one retainer.

[0006] The proposed solution is based on the basic concept of providing a common cage for both the clamping body and the additional rolling elements. As a result, the receiving members for different types of cages, one for the clamping body and the other for the rolling elements, are formed in one common cage. The proposed clamping body freewheel unit consequently includes, in addition to the clamping body, a plurality of rolling elements suitable for rotatably supporting the inner and outer shafts relative to one another when the inner and outer shafts are coupled to one another via the clamping body freewheel unit. In this case, the additional rolling elements are rotatably held in the clamping body cage.

[0007] The integration of rolling elements and clamping bodies into a common cage allows for further miniaturization of the clamping body freewheel unit. In fact, the cost of the clamping body can be significantly reduced, as a larger tolerance range is permitted and additional safety devices in the tolerance setting no longer need to be provided. Assembly can also be simplified. Furthermore, it has been found that the proposed clamping body freewheel unit results in increased robustness with respect to maximum torque and reduced drag torque during freewheeling.

[0008] In this case, the proposed clamping body freewheel unit can have an inner ring and / or an outer ring, to which the clamping bodies and rolling bodies are respectively externally or internally adjacent, in order to connect the inner and outer shafts. However, this is not absolutely necessary. In particular, the clamping body freewheel unit can be configured without an inner ring and / or without an outer ring, so that the shafts are in direct contact with the clamping bodies and / or rolling bodies.

[0009] In particular, one variant of the proposed clamping body freewheel unit may be configured and provided for use in an electric drive for an electric bicycle (and thus an e-bike or pedelec). For example, when a first outer or inner shaft is rotated in a first rotational direction (motor-driven) via the clamping body freewheel unit, force can be transmitted to another second inner or outer shaft to drive the other second shaft. At the same time, the other second drive shaft can also be rotated in the first rotational direction via the clamping body freewheel unit, thereby overtaking the first drive shaft. Furthermore, the second drive shaft can also be rotated via the clamping body freewheel unit without rotating the first drive shaft. In this way, the clamping body freewheel unit may be configured and provided to decouple at least one drive motor of an electric drive for an electric bicycle from the output shaft, so that torque applied by the electric bicycle rider at the output shaft is not transmitted to the drive motor and the force flow is blocked in the direction of the drive motor by the clamping body freewheel unit. In this way, the electric drive unit of the electric bicycle can be decoupled from the pedal drive of the electric bicycle, which is operated by muscle power, via the clamp body freewheel unit, so that the rider of the electric bicycle can drive the electric bicycle in a manner that is operated by muscle power without reaction resistance as a result of at least one drive motor and / or gear mechanism of the electric drive unit when the electric drive unit is inactive (i.e., without motor assistance).

[0010] In one variant, the rolling elements of the clamping body freewheel unit are arranged in a first circumferential bearing row that runs parallel to a second bearing row of the clamping body freewheel unit having multiple clamping bodies held in one and the same cage, the first and second bearing rows thus being arranged axially offset from one another with respect to the axis of rotation defined by the clamping body freewheel unit.

[0011] In one variant, the rolling elements are arranged together with the clamping elements in a circumferentially extending bearing row of the clamping element freewheel unit, so that the rolling elements and the clamping elements follow each other in the circumferential direction in this bearing row. Such a variant particularly includes the fact that in this case, in addition to this (mixed) bearing row of rolling elements and clamping elements, an additional bearing row can also be provided in the clamping element freewheel unit, and this additional bearing row can include a mixture of rolling elements and clamping elements, only rolling elements, or only clamping elements.

[0012] In one variant, in a bearing row with a plurality of rolling elements and a plurality of clamping elements, at least two clamping elements circumferentially follow one another directly before at least one rolling element circumferentially follows one of the at least two clamping elements. In a variant based on this, there are typically more clamping elements than rolling elements in the bearing row, so that a greater torque can be transmitted due to the force transmission through the clamping elements.

[0013] In one variant, the clamping body freewheel unit comprises at least two bearing rows, each with a plurality of clamping bodies, arranged side by side along the rotation axis defined by the clamping body freewheel unit. For example, the clamping body freewheel unit may comprise three bearing rows arranged next to each other along the rotation axis. In this example, two bearing rows may each have a plurality of clamping bodies (either only clamping bodies or a mixture with a plurality of rolling bodies), while one bearing row may have only a plurality of rolling bodies. A corresponding variant of a three-row clamping body freewheel unit results in at least one bearing row with exclusively rolling elements, which are rotatably held in the same cage as the clamping bodies in one or all of the other bearing rows.

[0014] In one variant of the three-row clamping body freewheel unit, the cage forms a web extending radially outward relative to the axis of rotation between one of the bearing rows with clamping bodies and the bearing row with exclusively rolling elements, and the different bearing rows are separated from one another in the clamping body freewheel unit not only functionally but also structurally by this radially outward extending web.

[0015] In the case of two bearing rows each having a clamping body, it is in principle possible to provide a clamping body that is not connected across the bearing rows.

[0016] In an alternative variant, the clamping bodies of two adjacent bearing rows are connected to one another, in particular constructed integrally with one another, thereby forming a single clamping body row. For example, the clamping bodies of a clamping body row have a common base radially inward and are locally separated from one another by slots extending radially outward about the rotation axis. The circumferential slots result in a clamping body row formed by two bearing rows, in which a row of clamping bodies arranged circumferentially one behind the other is provided, each capable of transmitting forces to the internal shaft via the common base.

[0017] As a result, the proposed solutions include in particular variations of clamping body freewheel units in which the cage is provided with at least one row of clamping bodies (clamping body row) that follow each other in the circumferential direction in addition to the row containing only rolling elements (rolling body row).Furthermore, variations are also included in which the cage forms two bearing rows, each with rolling elements and clamping bodies, by arranging two rolling elements positioned axially one behind the other in the gaps between the clamping bodies that follow each other in the circumferential direction of the clamping body row.

[0018] For additional functional integration, in one variant at least one seal is provided in the cage, which seal is for example injection molded into the cage.

[0019] For example, the seal is provided on the axial front side of the cage with respect to the axis of rotation defined by the clamping body freewheel unit. The seal integrated into the front side of the cage, in particular injection molded thereon, allows sealing against the environment in which the clamping body freewheel unit is mounted, for example in the drive of an electric bicycle.

[0020] For example, a seal provided on the cage, in particular injection molded thereon, forms at least one sealing lip.

[0021] In one variant, at least some of the rolling elements are in the form of cylindrical rollers.

[0022] The proposed solution further relates to a drive for an electric bicycle having at least one of the proposed clamp body freewheel units, which is consequently configured and provided for, for example, an electric drive of an electric bicycle and which has at least one variant of the proposed clamp body freewheel unit for providing a clamp body freewheeling movement.

[0023] In one variant, the drive device comprises at least one drive motor and a gear mechanism for transmitting a drive torque generated by the at least one drive motor to an output shaft (via the gear mechanism). The output shaft may be, for example, a bottom bracket shaft of an electric bicycle. The at least one drive motor and the gear mechanism and / or the gear mechanism and the output shaft can then be decoupled from each other via the clamping body freewheel unit. In this way, as a result, the force flow in the direction of the drive motor is blocked via the clamping body freewheel unit, so that the electric drive device, in particular its at least one drive motor, does not have to be "dragged" during driving actuated by muscle power.

[0024] The proposed solution further comprises an electric bicycle having at least one proposed clamping body freewheel unit and / or one proposed drive device.

[0025] The attached figures show possible variants of the proposed solution by way of example. [Brief explanation of the drawings]

[0026] [Figure 1] 1 is a perspective view of a first variant of the proposed clamping body freewheel unit having three bearing rows, the clamping bodies and rolling bodies of which are held in a single common cage of the clamping body freewheel unit. [Figure 2] FIG. 1 is a perspective view of another variant of the proposed clamping body freewheel unit having two mixed bearing rows arranged axially next to each other and each having a clamping body and rolling elements in a common cage. [Figure 3] 1 is a schematic diagram of a variant of an electric bicycle in which a variant of the proposed solution is used. DETAILED DESCRIPTION OF THE INVENTION

[0027] Fig. 1 is a perspective view showing a first modified example of the proposed clamp body freewheel unit 3. The clamp body freewheel unit 3 of Fig. 1 has three rows, i.e., three bearing rows 3a, 3b, and 3c, which are adjacent to each other along the rotation axis D defined by the clamp body freewheel unit 3 and the axial direction X extending parallel thereto.

[0028] The first two bearing rows 3a, 3b, which extend from the first axial front side 30 to the axial direction X, each comprise only a clamping body 5. The clamping bodies 5 are held next to each other at a predetermined distance in the circumferential direction U about the rotation axis D and are supported tiltably about an inclined axis parallel to the rotation axis D. Depending on the rotational direction and, depending on the inclined position, of the inner and outer shafts connected to each other via the clamping body freewheel unit 3, the clamping body 5 can transmit torque between the inner and outer shafts and enable their relative rotation. For connection with the inner shaft, the clamping body freewheel unit 3 has a central bearing opening O into which the inner shaft can engage, in particular be pressed against. The outer shaft can then be connected radially outward to the clamping body freewheel unit 3, for example, by inserting the clamping body freewheel unit 3 into the hollow end of the outer shaft, or vice versa, by fitting a (hollow) shaft, at least one of whose ends is hollow, onto the clamping body freewheel unit 3 and, in particular, pressing against it.

[0029] The two bearing rows 3a and 3b with clamping bodies 5 of the clamping body freewheel unit 3 of FIG. 1 are supplemented by a third bearing row 3c with only rolling elements in the form of cylindrical rollers 6. By means of the cylindrical rollers 6, the inner and outer shafts can (additionally) be rotatably supported relative to one another when they are connected to one another via the clamping body freewheel unit 3. In this example, the cylindrical rollers 6 are held in a cage receiving element 356 at a defined distance from one another in the circumferential direction U. The cage receiving element 356 is formed by the same cage 35 that also forms the cage receiving elements 355 for the clamping bodies 5 of the other two bearing rows 3a, 3b. The cage 35 of the clamping body freewheel unit 3 of FIG. 1 therefore integrates the cage receiving elements 355, 356 for both the clamping bodies 5 and the cylindrical rollers 6.

[0030] In order to spatially separate the cylindrical rollers 6 of the bearing row 3c from the adjacent bearing row 3b with its clamping bodies 5, the cage 35 forms an annular extending, radially outwardly projecting web 350.

[0031] In principle, the clamping bodies 5 of the first two bearing rows 3a, 3b can be completely separate from one another. In the illustrated variant of Fig. 1, on the other hand, the clamping bodies 5 of the first two adjacent bearing rows 3a and 3b are integral with one another. From a structural point of view, the clamping body freewheel unit 3 of Fig. 1 consequently has a single rolling body row 3c and a single clamping body row 3a, 3b arranged axially adjacent thereto.

[0032] Thus, the clamping bodies 5 have a common base 50 on their radially inner side and are locally separated from one another by slots on their radially outer side extending about the rotation axis D.

[0033] An annular spring 7 for biasing the outer shaft is disposed in this circumferentially extending slot, and is therefore located between the two bearing rows 3a, 3b. As a result of the circumferentially extending slot, two bearing rows 3a, 3b are ultimately formed, each of which is part of a single row of clamping bodies 5 arranged circumferentially behind the clamping body rows 3a, 3b. In this way, the axial spacing defined by the slot is preset between portions of the radially outer cover surfaces of the clamping bodies 5, each of which is adjacent to the outer shaft. At the same time, the clamping bodies 5 of both bearing rows 3a, 3b transmit force to the inner shaft via a common base 50.

[0034] The three bearing rows 3a, 3b, 3c are arranged between two axial front sides 30, 31 of a cage 35. An annular seal 4 with a sealing lip is injection molded onto one of these front sides 30, 31 (front side 31 shown on the left in FIG. 1). In this way, axial and / or radial sealing can also be provided when mounting the clamping body freewheel unit 3.

[0035] In an additional variant of Fig. 2, the clamp body freewheel unit 3 provides a mixture of bearing rows 3a, 3b within a single clamp body row. Here, an annular spring 7 is also provided between the bearing rows 3a and 3b. Furthermore, the clamp body 5 and the cylinder roller 6 are held in a common cage 35 of the clamp body freewheel unit 3. The seal 4 is also injection molded into the front side 31 of this cage 35.

[0036] Unlike the clamp body freewheel unit of FIG. 1, the clamp body freewheel unit 3 of FIG. 2 is configured with two mixed bearing rows 3a, 3b, in which both the clamp bodies 5 and the cylinder rollers 6 are arranged in the circumferential direction U around the rotation axis D. As a result, in each bearing row 3a, 3b, in addition to the clamp rollers 5, the cylinder rollers 6 are also arranged in a cage 35. As a result, for each bearing row 3a, 3b, the cage 35 forms not only a cage receiving element 355 for the clamp bodies 5 but also a cage receiving element 356 for the cylinder rollers 6. In the variant of FIG. 2, exactly one cylinder roller 6 repeatedly follows a plurality of (in this case, three) clamp bodies 5 in each bearing row 3a, 3b.

[0037] In both the variant of Figure 1 and the variant of Figure 2, it may be provided that the clamping body 5 bridges the two bearing rows 3a, 3b internally, while externally they are separated by a gap into which the annular spring 7 is inserted.

[0038] The clamping body freewheel unit 3 of Figures 1 and 2 is provided for use, for example, in an electric drive A of an electric bicycle 1 according to Figure 3. This electric drive A allows electric support of the electric bicycle 1 in a manner controlled by a drive-side electronic control unit SE and an operating unit 2, for example arranged on the handlebars of the electric bicycle. In this example, a front wheel 11 and a rear wheel 12 are rotatably supported on a frame 10 of the electric bicycle 1 (in the front region by a fork articulated thereto). The rear wheel 12 can be driven by the electric drive A via a force transmission member, for example in the form of a chain or belt 13.

[0039] The drive torque is transmitted by at least one electric motor of the drive device A (typically in conjunction with a gear mechanism of the drive device A) to an output shaft connected to a chain or belt 13. In particular, the output shaft, which may be the bottom bracket shaft of the electric bicycle 1 in this example, forms the inner or outer shaft of the clamp body freewheel unit 3 and is connected to the drive shaft of the electric drive device A via the clamp body freewheel unit 3. In this example, the clamp body freewheel unit 3 prevents the electric drive device A, when not in operation, from acting against the torque generated on the output shaft as a result of muscle activation, while still allowing the torque generated by the motor to be transmitted to the rear wheel 12. In this case, a robust and compact construction type for integrating the freewheeling movement of the corresponding clamp bodies is possible by arranging the cylinder rollers 6 axially next to the clamp bodies 5 (as in the variant of FIG. 1) or between the clamp bodies 5 in a common cage 35 (as in the variant of FIG. 2). [Explanation of symbols]

[0040] 1. Electric bicycle 10 frames 11 Front wheel 12 rear wheels 13 Chain / belt (force transmission member) 2 Operation unit 3 Clamp body freewheel unit 30, 31 Front 35 Retainer 350 Web 355 Cage receiving member 356 Cage support member 3a, 3b, 3c bearing row 4 Seals 5 Clamp body 50 base 6 Cylinder roller (rolling element) 7 Annular spring A Drive Unit D rotation axis O Bearing opening SE Electronic Control Unit U Zhou direction X-axis direction

Claims

1. A clamp body freewheel unit having a plurality of clamp bodies (5), a cage (35), and a plurality of rolling bodies (6), a force transmission between an inner shaft and an outer shaft, which can be connected to each other via the clamping body freewheel unit (3), is possible by the clamping bodies (5) in only one of two opposing rotational directions, The clamp bodies (5) of the clamp body freewheel unit (3) are held at predetermined intervals relative to each other in the circumferential direction (U) by the retainer (35), The inner shaft and the outer shaft are supported by the plurality of rolling elements (6) so as to be rotatable relative to each other when they are connected to each other via the clamp body freewheel unit (3), The plurality of rolling elements (6) and at least a portion of the plurality of clamping elements (5) are held together in the single cage (35); the rolling elements (6) are arranged in a first bearing row (3c) of the clamp body freewheel unit (3), the first bearing row (3c) extending in the circumferential direction (U) and parallel to a second bearing row (3a, 3b) of the clamp body freewheel unit (3) having a plurality of clamp bodies (5); and The clamp body freewheel unit (3) comprises three bearing rows for the inner shaft and the outer shaft, the three bearing rows being arranged adjacent to each other in the order of a first bearing row (3c), a second bearing row (3b), and a second bearing row (3a) in the axial direction of a rotation axis (D) defined by the clamp body freewheel unit (3); The two second bearing rows (3a, 3b) each have a plurality of clamping bodies (5), and the first bearing row (3c) has only a plurality of rolling elements (6); a web (350) extending radially outward with respect to the rotation axis (D) is formed on the cage (35) between one of the two second bearing rows (3a, 3b) having a plurality of clamp bodies (5) and the first bearing row (3c) having only the plurality of rolling elements (6).

2. 2. The clamp body freewheel unit according to claim 1, wherein the clamp bodies (5) of the two second bearing rows (3a, 3b) adjacent in the axial direction of the rotation axis (D) are integrally constructed, have a common base (50) on the radially inner side, and are locally separated on the outer diameter side by a long groove-shaped slot that opens radially outward and extends along the circumferential direction (U).

3. A clamp body freewheel unit as described in claim 1 or 2, characterized in that the second bearing row (3a, 3b) of the clamp body freewheel unit (3) is formed by a clamp body row consisting of a plurality of clamp bodies (5) arranged consecutively with each other in the circumferential direction (U).

4. 4. A clamping body freewheel unit according to claim 1, wherein at least one seal (4) is provided on the cage (35).

5. The clamp body freewheel unit according to claim 4, characterized in that the seal (4) is provided on one axial end side (31) of the retainer (35) with respect to the rotation axis (D) defined by the clamp body freewheel unit (3).

6. 6. A clamping body freewheel unit according to any one of claims 1 to 5, characterized in that at least some of the rolling elements are in the form of cylindrical rollers (6).

7. A drive device for an electric bicycle (1) having at least one clamp body freewheel unit (3) described in any one of claims 1 to 6.

8. 8. The drive device (A) according to claim 7, characterized in that the drive device (A) comprises at least one drive motor and a gear mechanism for transmitting a drive torque generated by the at least one drive motor to an output shaft, and the at least one drive motor and the gear mechanism and / or the gear mechanism and the output shaft can be decoupled from each other via the clamp body freewheel unit (3).

9. An electric bicycle having at least one clamp body freewheel unit described in any one of claims 1 to 6, and / or having a drive device (A) described in claim 7 or 8.

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