CLAMPING BODY FREEWHEELING UNIT AND DRIVE DEVICE FOR AN ELECTRIC BICYCLE HAVING A CLAMPING BODY FREEWHEEL UNIT

Abstract

A clamping body freewheel unit and a drive device for motor-assisted driving of an electric bicycle having a clamping body freewheel unit. The clamping body freewheel unit includes a plurality of clamping bodies by which force transmission between an inner shaft and an outer shaft, coupled together via the clamping body freewheel unit, is allowed only in one of two opposite directions of rotation, a cage by which the plurality of clamping bodies of the clamping body freewheel unit are kept together at a defined spacing in a circumferential direction, and a plurality of rolling elements by which the inner and outer shafts are mounted rotatable relative to one another when the inner and outer shafts are coupled together via the clamping body freewheel unit, wherein at least some of the plurality of rolling elements and the clamping bodies are held jointly on the cage.

Claims

1. A clamping body freewheel unit having: a plurality of clamping bodies, by which a force transmission between an internal shaft and an external shaft which can be coupled to each other via the clamping body freewheel unit, is enabled in only one of two mutually opposing rotation directions, a cage, by which the plurality of clamping bodies of the clamping body freewheel unit are retained at a defined spacing relative to each other in a circumferential direction and a plurality of rolling bodies, by which the internal shaft and external shaft are supported so as to be rotatable relative to each other if the internal shaft and external shaft are coupled to each other via the clamping body freewheel unit, wherein at least some of the plurality of rolling bodies and the clamping bodies are retained together in the cage.

2. The clamping body freewheel unit of claim 1, wherein a plurality of rolling bodies are arranged in a first bearing row of the clamping body freewheel unit, which row extends in the circumferential direction and extends parallel with a second bearing row of the clamping body freewheel unit with a plurality of clamping bodies.

3. The clamping body freewheel unit of claim 1, wherein a plurality of rolling bodies are arranged together with a plurality of clamping bodies in a bearing row which extends in the circumferential direction of the clamping body freewheel unit.

4. The clamping body freewheel unit of claim 3, wherein at least two clamping bodies follow each other in the circumferential direction in the bearing row with a plurality of rolling bodies and a plurality of clamping bodies before at least one rolling body follows one of the at least two clamping bodies in the circumferential direction.

5. The clamping body freewheel unit of claim 1, wherein the clamping body freewheel unit comprises at least two bearing rows which each have a plurality of clamping bodies and which extend parallel with each other.

6. The clamping body freewheel unit of claim 1, wherein the clamping body freewheel unit comprises at least two bearing rows which each have a plurality of clamping bodies and which are located beside each other along a rotation axis which is defined by the clamping body freewheel unit for the internal shaft and external shaft.

7. The clamping body freewheel unit of claim 1, wherein the clamping body freewheel unit comprises three bearing rows which are located beside each other along a rotation axis which is defined by the clamping body freewheel unit for the internal shaft and external shaft.

8. The clamping body freewheel unit of claim 7, wherein, of the three bearing rows, two bearing rows each have a plurality of clamping bodies and one bearing row has exclusively a plurality of rolling bodies.

9. The clamping body freewheel unit of claim 8, wherein, between one of the bearing rows with a plurality of clamping bodies and the bearing row having exclusively a plurality of rolling bodies, a web which extends radially outwardly with respect to the rotation axis is formed on the cage.

10. The clamping body freewheel unit of claim 8, wherein the clamping bodies of two adjacent bearing rows are connected to each other, particularly constructed integrally with each other, and are separated from each other locally by a slot which extends about the rotation axis at a radially external side.

11. The clamping body freewheel unit as claimed in claim 1, wherein one or more bearing rows of the clamping body freewheel unit are formed by a clamping body row which has clamping bodies which follow each other in a circumferential direction and which are each slotted at a radially external side.

12. The clamping body freewheel unit as claimed in claim 1, wherein at least one seal is provided on the cage, in particular injection-molded thereon.

13. The clamping body freewheel unit of claim 12, wherein the seal is provided at an axial front side of the cage with respect to a rotation axis defined by the clamping body freewheel unit.

14. The clamping body freewheel unit as claimed in claim 1, wherein at least some of the rolling bodies are in the form of cylinder rollers.

15. A drive apparatus for an electric bicycle having the at least one clamping body freewheel unit as claimed in claim 1.

16. The drive apparatus of claim 5, wherein the drive apparatus comprises at least one drive motor and gear mechanism in order to transmit a drive torque which is produced 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 uncoupled from each other via the clamping body freewheel unit.

17. An electric bicycle having the at least one clamping body freewheel unit as claimed in claim 1 and having a drive apparatus for the electric bicycle.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0027] In the drawings:

[0028] FIG. 1 shows a perspective view of a first variant of a proposed clamping body freewheel unit having three bearing rows, the clamping bodies and rolling bodies of which are retained in a single common cage of the clamping body freewheel unit;

[0029] FIG. 2 shows a perspective view of another variant of the proposed clamping body freewheel unit having two mixed bearing rows which are located axially beside each other and which each have clamping bodies and rolling bodies in a common cage;

[0030] FIG. 3 schematically shows a variant of an electric bicycle, in which variants of the proposed solution are used.

DETAILED DESCRIPTION OF DRAWINGS:

[0031] FIG. 1 shows a perspective view of a first variant of a proposed clamping body freewheel unit 3. The clamping body freewheel unit 3 of FIG. 1 has three rows, that is to say, it is constructed with three bearing rows 3a, 3b and 3c. These three bearing rows 3a, 3b and 3c are present beside each other along a rotation axis D which is defined by the clamping body freewheel unit 3 and an axis direction X which extends parallel therewith.

[0032] The first two bearing rows 3a and 3b which follow each other from a first axial front side 30 in the axis direction X each have exclusively clamping bodies 5. These clamping bodies 5 are retained beside each other in a circumferential direction U about the rotation axis D with defined spacing relative to each other and supported so as to be able to tilt about a tilting axis which is parallel with the rotation axis D. In this manner, depending on the rotation direction of an internal shaft and an external shaft which are coupled to each other via the clamping body freewheel unit 3 and a tilting position which depends thereon, the clamping bodies 5 can transmit a torque between the internal shaft and the external shaft or allow a rotation of the internal shaft and the external shaft relative to each other. For connection to an internal shaft, the clamping body freewheel unit 3 has a central bearing opening O, in which the internal shaft can engage, in particular can be pressed. An external shaft can in turn be connected to the clamping body freewheel unit 3 radially externally by, for example, the clamping body freewheel unit 3 being inserted in a hollow end portion of the external shaft or, vice versa, the (hollow) shaft which is hollow at least at one end thereof being fitted onto the clamping body freewheel unit 3, in particular pressed on.

[0033] The two bearing rows 3a and 3b of the clamping body freewheel unit 3 of FIG. 1 which have the clamping bodies 5 are supplemented by a third bearing row 3c which has exclusively rolling bodies in the form of cylinder rollers 6. Via the cylinder rollers 6, the internal and external shafts can (additionally) be rotatably supported relative to each other if the internal and external shafts are coupled to each other via the clamping body freewheel unit 3. The cylinder rollers 6 are in this instance retained with a defined spacing relative to each other in the circumferential direction U in cage receiving members 356 which are formed by one and the same cage 35 which also forms cage receiving members 355 for the clamping bodies 5 of the other two bearing rows 3a and 3b. The cage 35 of the clamping body freewheel unit 3 of FIG. 1 consequently integrates cage receiving members 355 and 356 both for the clamping bodies 5 and for the cylinder rollers 6.

[0034] In order to spatially separate the cylinder rollers 6 of the bearing row 3c from an adjacent bearing row 3b with clamping bodies 5, the cage 35 forms a radially outwardly projecting web 350 which extends annularly.

[0035] In principle, the clamping bodies 5 of the first two bearing rows 3a and 3b can be configured completely separately from each other. In the variant of FIG. 1 illustrated, the clamping bodies 5 of the first two adjacent bearing rows 3a and 3b are integrally constructed with each other in contrast. In structural terms, 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 which is located axially adjacent thereto.

[0036] Thus, the clamping bodies 5 have a common base 50 at a radially inwardly located side and are separated from each other locally by a slot which extends about the rotation axis D at a radially externally located side. An annular spring 7 for abutment against the external shaft is arranged in this slot which extends circumferentially and therefore between the two bearing rows 3a, 3b. As a result of the slot which extends over the circumference, the two bearing rows 3a, 3b which are ultimately part of precisely one row of clamping bodies 5, which are located one behind the other in a circumferential direction, of a clamping body row 3a, 3b are formed. In this manner, an axial spacing which is defined by the slot is predetermined between portions of a radially external covering face of the clamping bodies 5, which portions each adjoin an external shaft. At the same time, the clamping bodies 5 of both bearing rows 3a, 3b transmit forces to the internal shaft via the common base 50.

[0037] The three bearing rows 3a, 3b and 3c are located between two axial front sides 30 and 31 of the cage 35. At one of these front sides 30, 31—in FIG. 1, the front side 31 shown on the left—an annular seal 4 with a sealing lip is injection-molded on. In this manner, an axial and/or radial seal can also be provided when the clamping body freewheel unit 3 is fitted.

[0038] In the additional variant of FIG. 2, a clamping body freewheel unit 3 provides for a mixture of bearing rows 3a and 3b within a single clamping body row. An annular spring 7 is also provided here between the bearing rows 3a and 3b. Furthermore, the clamping bodies 5 and the cylinder rollers 6 are retained in a common cage 35 of the clamping body freewheel unit 3. A seal 4 is also injection-molded on this cage 35 at a front side 31.

[0039] Unlike the clamping body freewheel unit of FIG. 1, the clamping body freewheel unit 3 of FIG. 2 is constructed with two rows and with a mixture of bearing rows 3a and 3b, wherein both clamping bodies 5 and cylinder rollers 6 are provided in the circumferential direction U about the rotation axis D. In each bearing row 3a, 3b, consequently, cylinder rollers 6 are arranged in the cage 35 in addition to the clamping rollers 5. Consequently, the cage 35 forms for each bearing row 3a and 3b not only cage receiving members 355 for clamping bodies 5 but also cage receiving members 356 for cylinder rollers 6. In the variant of FIG. 2, precisely one cylinder roller 6 repeatedly follows a plurality of clamping bodies 5 (in this case, three) in each bearing row 3a, 3b in this case.

[0040] Both in the variant of FIG. 1 and in the variant of FIG. 2, there may be provision for the clamping bodies 5 to bridge two bearing rows 3a and 3b internally while externally they are separated by a gap, in which the annular spring 7 is inserted.

[0041] The clamping body freewheel units 3 of FIGS. 1 and 2 are, for example, provided for use in an electromotive drive apparatus A of an electric bicycle 1 according to FIG. 3. This electromotive drive apparatus A allows—in a manner controlled by a drive-side electronic control unit SE and an operating unit 2 which is arranged, for example, on a handlebar of the electric bicycle—electromotive support of the electric bicycle 1. In this instance, 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 on a fork which is articulated thereto), wherein the rear wheel 12 can be driven via a force transmission member, for example, in the form of a chain or a belt 13 via the electromotive drive apparatus A.

[0042] A drive torque is transmitted towards an output shaft which is connected to the chain or the belt 13 via at least one electric motor of the drive apparatus A—typically in conjunction with a gear mechanism of the drive apparatus A. The output shaft, which may be in particular the bottom bracket shaft of the electric bicycle 1, forms in this instance an internal or an external shaft in a clamping body freewheel unit 3 which is coupled to a driving shaft of the electromotive drive apparatus A via the clamping body freewheel unit 3. In this instance, the clamping body freewheel unit 3 enables the electromotive drive apparatus A not to act counter, in the event of inactivity, a torque which is generated at the output shaft as a result of actuation by muscle power, but at the same time a torque which is generated by motor to be able to be transmitted to the rear wheel 12. In this case, a robust and compact construction type for the integration of a corresponding clamping body freewheel action is enabled via the arrangement of the cylinder rollers 6 axially beside the clamping bodies 5 (as in the variant of FIG. 1) or between the clamping bodies 5 (as in the variant of FIG. 2) in a common cage 35.