Clamping element freewheel

Patent metadata

Field	Value
Publication number	US-9322441-B2
Application number	US-201113068415-A
Country	US
Kind code	B2
Filing date	May 10, 2011
Priority date	Nov 10, 2008
Publication date	Apr 26, 2016
Grant date	Apr 26, 2016

Abstract

A clamping element freewheel including an inner ring and an outer ring that can be rotated relative to the inner ring in at least one rotational direction. A cage for clamping elements is between the inner ring and the outer ring, with a plurality of clamping elements. The clamping elements are pivotable between a clamping position, in which they prevent relative rotation between the inner and outer rings, and a release position, in which they enable relative rotation between the inner and outer rings. A clamping element preload is provided to preload the clamping element radially inwardly and in the clamping position direction. The clamping element preloading is provided by springs that are configured separately for each clamping element.

First claim

What is claimed is:

1. A clamping element freewheel comprising:
an inner ring having an axis of rotation;
an outer ring coaxial with and rotatable relative to the inner ring in a first direction of rotation, and an annular gap between an outer cylindrical surface of the inner ring and an inner cylindrical surface of the outer ring;
a cage positioned between the outer cylindrical surface of the inner ring and the inner cylindrical surface of the outer ring for receiving and supporting in circumferentially spaced relationship a plurality of circumferentially distributed clamping elements that are carried between the inner ring and the outer ring and are in contact with the outer cylindrical surface of the inner ring, wherein the cage is in contact with the outer cylindrical surface of the inner ring and is rotatable on the outer cylindrical surface of the inner ring and includes a plurality of circumferentially spaced openings for receiving respective circumferentially spaced clamping elements, wherein the circumferentially spaced openings are provided between respective circumferentially spaced and radially extending cage components;
wherein the clamping elements are freely carried within respective circumferentially spaced openings between adjacent cage components and are pivotable between a clamping position in which the clamping elements contact both the inner ring and the outer ring to prevent relative rotation between the inner ring and the outer ring in a second direction of rotation, and a release position in which the clamping elements and the cage are spaced from the inner cylindrical surface of the outer ring and are in contact with the outer cylindrical surface of the inner ring to allow relative rotation between the inner ring and the outer ring in the first direction of rotation; wherein each of the clamping elements has a respective center of gravity that is disposed radially outward of circumferentially spaced clamping element support surfaces of respective adjacent cage components, wherein the clamping element support surfaces are provided for guiding respective outer surfaces of respective ones of the clamping elements for allowing pivotal movement of the clamping elements within respective circumferentially spaced openings between the adjacent cage components and about respective clamping element axes of rotation that are parallel to the axis of rotation of the freewheel inner and outer rings; and
wherein respective clamping element springs are carried by the cage components and act against respective ones of the clamping elements to preload the clamping elements in a radially inward direction of the freewheel to maintain contact of the respective clamping elements with the outer cylindrical surface of the inner ring and in a direction toward the clamping position.

2. The clamping element freewheel according to claim 1 , wherein the outer cylindrical surface of the inner ring and the inner cylindrical surface of the outer ring each have a circular cross-section in a sectional view perpendicular to the axial direction of the freewheel.

3. The clamping element freewheel according to claim 1 , wherein the outer ring is supported relative to the inner ring by a bearing.

4. The clamping element freewheel according to claim 3 , wherein the bearing is affixed to the inner ring.

5. The clamping element freewheel according to claim 3 , wherein the bearing includes a pair of radially-extending straight bearing rings that face respective radial sides of the cage and that include respective support surfaces to engage and rotatably support the outer ring relative to the inner ring.

6. The clamping element freewheel according to claim 1 , including a cage spring that acts against the cage to preload the cage in an axial direction of the freewheel and against a bearing ring non-rotatably carried on the outer cylindrical surface of the inner ring.

7. The clamping element freewheel according to claim 6 , wherein the cage spring is a disc spring.

8. The clamping element freewheel according to claim 1 , wherein the clamping element springs are configured as arm springs carried by the cage and having respective arms that extend axially relative to the freewheel axis of rotation and that engage respective radially outer surfaces of the clamping elements adjacent to and spaced from the inner surface of the outer ring.

9. The clamping element freewheel according to claim 1 , wherein the clamping element springs apply a radial force component on respective clamping elements to provide on the respective clamping elements a preload force that is greater than a maximum centrifugal force acting on the respective clamping elements during rotation of the inner ring of the freewheel.

10. The clamping element freewheel according to claim 1 , wherein a stop is provided on respective ones of the cage components for respective clamping elements, wherein the stop defines an end of a pivotal movement path of the clamping element when the clamping element pivots about an axis of rotation that is parallel to the freewheel axis of rotation out of the clamping position in which the clamping elements engage both the inner cylindrical surface of the outer ring and the outer cylindrical surface of the inner ring to cause the inner and outer rings to rotate together, into the release position in which the clamping elements are pivoted to a position to disengage from the inner surface of the outer ring, at which position the inner and outer rings are rotatable relative to each other.

11. The clamping element freewheel according to claim 1 , wherein the clamping elements are supported in the cage with a clearance therebetween so that the clamping elements and the cage do not slide relative to each other with high frictional contact during a movement of the clamping elements between the clamping position and the release position.

12. The clamping element freewheel according to claim 1 , wherein the outer ring includes a connecting rod eye that is offset from the axis of rotation of the inner and outer rings for receiving a connecting rod that is rotatable relative to an axis of the connecting rod eye of the outer ring.

13. The clamping element freewheel according to claim 12 , wherein the outer ring includes a pass-through opening adjacent to and spaced from the connecting rod eye and extending axially relative to the connecting rod eye of the outer ring.

14. A crank—CVT including a clamping element freewheel according to claim 1 .

15. The clamping element freewheel according to claim 1 , wherein the plurality of circumferentially spaced cage openings are each defined by a pair of opposed, concave support surfaces on adjacent cage components for guiding outer surfaces of respective clamping elements for pivotal movement within the respective cage openings.

16. The clamping element freewheel according to claim 15 , wherein one of the concave support surfaces that define respective cage openings includes a stop for engaging and limiting pivotal movement of a respective clamping element within a respective cage opening.

17. The clamping element freewheel according to claim 15 , wherein the clamping elements include a pair of oppositely-facing lugs adjacent a radially inner surface of the clamping elements and that face respective concave support surfaces of cage openings, and wherein when the clamping elements pivot between the clamping position and the release position, outer surfaces of the lugs describe respective arcs that have a curvature that corresponds with that of adjacent concave support surfaces of the cage openings.

Assignees

• Friedmann Oswald
• Schaeffler Technologies Ag

Inventors

• Friedmann Oswald

Classifications

• F16D41/073 Primary

  each member comprising at least two elements at different radii · CPC title

• F16H29/04

  in which the transmission ratio is changed by adjustment of a crank, an eccentric, a wobble-plate, or a cam, on one of the shafts · CPC title