Patent Application
20160084326
The present disclosure relates to a one-way wedge clutch with a displaceable weight element to eliminate lockup in free-wheel mode, in particular, a multi-piece weight element arranged to radially contract a wedge plate while the clutch is in free-wheel mode.
A wedge one-way clutch including an inner race with a plurality of ramps and a wedge plate with a plurality of ramps engaged with the plurality of ramps for the inner race is known. In a free-wheel mode, the inner race and the wedge plate rotate together. If the inner race is the driven component of the clutch and the rotational speed of the inner race is high enough in the free-wheel mode, the rotation of the inner race and wedge plate produces a centrifugal force acting to expand the wedge plate radially outward. If the radially outward expansion is large enough, the outer circumference of the wedge plate can frictionally engage an outer race for the clutch, initiating an undesirable lock-up of the clutch (non-rotatable connection of the inner and outer race).
According to aspects illustrated herein, there is provided a one-way clutch, including: a wedge plate including a first radially innermost circumference with a first plurality of ramps; an inner race including a first radially outermost circumference with a second plurality of ramps and arranged to receive torque and transmit the torque to the wedge plate in a lock-mode for the one-way clutch; and a weighting element engaged with the wedge plate. The weighting element is arranged to displace, in response to rotation of the inner race, to radially contract the wedge plate.
According to aspects illustrated herein, there is provided a one-way clutch, including: a wedge plate including a first radially innermost circumference with a first plurality of ramps and first and second pluralities of slots; an inner race including a first radially outermost circumference with a second plurality of ramps engaged with the first plurality of ramps and arranged to receive torque and transmit the torque to the wedge plate; a weighting element including first and second components and first and second pluralities of pins. The first and second pluralities of pins are fixed to the first and second components, respectively and disposed in the first and second pluralities of slots, respectively. For rotation of the inner race: the first and second components are arranged to displace away from each other; and to radially contract the wedge plate, the first component is arranged to displace to slide the first plurality of pins in the first plurality of slots and the second component is arranged to displace to slide the second plurality of pins in the second plurality of slots.
According to aspects illustrated herein, there is provided a one-way clutch, including: an outer race including a first radially inner circumference; and a wedge plate disposed radially inward of the outer races and including: a second radially innermost circumference with a first plurality of ramps; a first radially outermost circumference; first and second ends connecting the second radially innermost circumference and the first radially outermost circumference; and first and second pluralities of slots. The clutch includes: an inner race including a second radially outer circumference with a second plurality of ramps and arranged to receive torque and transmit the torque to the wedge plate; and a weighting element including a first component including a first plurality of pins fixed to the first component and disposed in the first plurality of slots and a second component including a second plurality of pins fixed to the second component and disposed in the second plurality of slots. For a free-wheel mode for the one-way clutch: the inner race is arranged to rotate in a circumferential direction; the first and second components are arranged to displace away from each other; the first and second pluralities of pins are arranged to slide in the first and second pluralities of slots, respectively, to urge the first and second ends toward each other to radially contract the wedge plate; and the inner race is rotatable with respect to the outer race.
Various embodiments are disclosed, by way of example only, with reference to the accompanying schematic drawings in which corresponding reference symbols indicate corresponding parts, in which:
At the outset, it should be appreciated that like drawing numbers on different drawing views identify identical, or functionally similar, structural elements of the disclosure. It is to be understood that the disclosure as claimed is not limited to the disclosed aspects.
Furthermore, it is understood that this disclosure is not limited to the particular methodology, materials and modifications described and as such may, of course, vary. It is also understood that the terminology used herein is for the purpose of describing particular aspects only, and is not intended to limit the scope of the present disclosure.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood to one of ordinary skill in the art to which this disclosure belongs. It should be understood that any methods, devices or materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure.
To clarify the spatial terminology, objects 12, 13, and 14 are used. An axial surface, such as surface 15 of object 12, is formed by a plane co-planar with axis 11. Axis 11 passes through planar surface 15; however any planar surface co-planar with axis 11 is an axial surface. A radial surface, such as surface 16 of object 13, is formed by a plane orthogonal to axis 11 and co-planar with a radius, for example, radius 17. Radius 17 passes through planar surface 16; however any planar surface co-planar with radius 17 is a radial surface. Surface 18 of object 14 forms a circumferential, or cylindrical, surface. For example, circumference 19 is passes through surface 18. As a further example, axial movement is parallel to axis 11, radial movement is orthogonal to axis 11, and circumferential movement is parallel to circumference 19. Rotational movement is with respect to axis 11. The adverbs “axially,” “radially,” and “circumferentially” refer to orientations parallel to axis 11, radius 17, and circumference 19, respectively. For example, an axially disposed surface or edge extends in direction AD, a radially disposed surface or edge extends in direction R, and a circumferentially disposed surface or edge extends in direction CD.
In an example embodiment, weighting element 114 includes components 114A and 114B arranged to displace in opposite directions D1 and D2, respectively, in response to rotation of inner race 102 in circumferential direction CD2 (free-wheel mode). That is, components 114A and 114B displace away from each other. Components 114A and 114B include radially outermost circumferences 116 and 118, respectively. Clutch 100 includes resilient element 120 engaged with circumferences 116 and 118 and urging components 114A and 114B in directions D2 and D1, respectively, that is, toward each other.
In an example embodiment, at least a portion of weighting element 114 is aligned with wedge plate 108 so that line L1 parallel to axis of rotation AR for clutch 100 passes through weighting element 114 and wedge plate 108 as shown in
Circumference 115 extends further direction RD, orthogonal to axis of rotation AR, than circumferences 116 and 118.
In an example embodiment, wedge plate 108 includes slots 126 and weighting element 114 includes pins 128 fixed to the weighting element. Each pin 128 is disposed in a respective slot 126. In response to rotation of inner race 102 in direction CD2, pins 128 are arranged to displace in slots 126 to radially contract wedge plate 108. In an example embodiment, wedge plate 108 includes ends 130A and 130B separated from each other in circumferential direction CD2. At least respective portions of ends 130A and 130B are aligned with each other so that line L3 in direction CD2 passes through ends 130A and 130B and space 132, separating ends 130A and 130B.
Pins 128 are arranged to displace in slots 126 to urge ends 130A and 130B toward each other. Specifically, pins 128 are arranged to displace in slots 126 to urge end 130A in direction CD2 and to urge end 130B in circumferential direction CD1, opposite direction CD2. As ends 130A and 130B are drawn toward each other, at least a portion of circumference 115 is drawn closer to axis AR.
Each slot 126 includes a respective longitudinal axis LA. Extent 134 of each slot 126, parallel to longitudinal axis LA, is greater than extent 136 of slot 126 orthogonal to longitudinal axis LA. Each longitudinal axis LA is at acute angle AA with respect to line R orthogonal to axis of rotation AR for clutch 100.
In an example embodiment, slots 126 includes slots 126A-D. Each respective axis LA passes through respective ends 138A and 138B of each slot. Ends 138A are closer to axis AR than are ends 138B. Ends 138A for slots 126A and 126B are closer together in direction CD1 than are ends 138B for slots 126A and 126B. In like manner, ends 138A for slots 126C and 126D are closer together in direction CD1 than are ends 138B for slots 126C and 126D. In an example embodiment, slots 126 are symmetrically placed in wedge plate 108. For example, line L4 passes through axis of rotation AR and slots 126A and 126D.
In an example embodiment, pins 128A and 128B are fixed to component 114A and disposed in slots 126A and 126B. Pins 128C and 128D are fixed to component 114B and disposed in slots 126C and 126D. Each slot 126 includes a respective edge 140, for example, parallel to axis LA. In response to rotation of inner race 102 in direction CD2, pins 128A and 128B are arranged to contact edges 140A and 140B, respectively, and pins 128C and 128D are arranged to contact edges 140C and 140D, respectively. Radially outward displacement of components 114A and 114B and contact between pins 128 and edges 140 causes the circumferential displacement of wedge plate 108, for example, of ends 130A and 130B, and concurrent radial contraction of wedge plate 108.
Clutch 100 includes outer race 142 located radially outward of wedge plate 108 and including radially innermost circumference 144. For a free-wheel mode for one-way clutch 100, in which inner race 102 is rotatable with respect to outer race 142, inner race 102 rotates in circumferential direction CD2 with respect to outer race 142 and ramps 112 are arranged to slide down ramps 106. As is known in the art, as ramps 112 slide down ramps 106, wedge plate 108, in particular at least a portion of radially outermost circumference 115, constricts radially inward to prevent frictional engagement of radially outermost circumference 115 and radially innermost circumference 144 with sufficient force to trigger the lock-up mode of clutch 100. As noted above, in free-wheel mode, displacement of element 114 causes radial contraction of wedge plate 108.
For the lock-up mode for one-way clutch 100, in which wedge plate 108 is non-rotatably connected to inner race 102 and outer race 142, inner race 102 rotates in circumferential direction CD1 with respect to outer race 142 and ramps 112 are arranged to slide up ramps 106. As is known in the art, as ramps 112 slide up ramps 106, wedge plate 108, in particular radially outermost circumference 115, expands radially outward to frictionally engage radially outermost circumference 115 and radially innermost circumference 144 with sufficient force to trigger the lock-up mode of clutch 100. Note that the configuration of element 114 and slots 126 is such that the displacement of element 114 does not interfere with implementation of the lock-up mode. During lock-up mode, element 120 urges elements 114A and 114B into contact with each other to prevent rattling of elements 114A and 114B.
It should be understood that increasing a speed of rotation of inner race 102 in direction CD2 causes further displacement of component 114A and 114B in directions D1 and D2, respectively. It also should be understood that decreasing a speed of rotation of inner race 102 causes displacement of component 114A and 114B in directions D2 and D1, respectively, enabling ends 130A and 130B to displace away from each other.
Advantageously, weighting element 114 prevents the undesirable lock-up during free-wheel mode described above. As noted above, the lock-up is caused by centrifugal force displacing a radially outermost circumference, such as radially outermost circumference 115, radially outward far enough to frictionally engage an outer race with sufficient force to trigger a lock-up. For example, cause ramps on a wedge plate to slide up ramps on an inner race. Using the configuration shown in the figures as an example, as inner race 102 and wedge plate 108 rotate, the centrifugal force noted above causes components 114A and 114B to displace away from each other in directions D1 and D2, respectively.
Because slots 126 are angled, in particular because slots 126A and 126B and slots 126C and 126D, respectively, taper toward each other in a radially inward direction, as pins 128 contact edges and displace in directions D1 and D2, respectively, ends 130A and 130B are forced together to accommodate the motion of pins 128 along edges 140. Pushing ends 130A and 130B toward each other radially contracts wedge plate 108, in particular, at least a portion of radially outermost circumference 115 is drawn closer to axis AR, preventing the undesirable engagement of wedge plate 108 and outer race 142.
Wedge plate 108 is flexible in circumferential directions CD1 and CD2, while components 114A and 114B are displaceable only in directions D1 and D2. Therefore, the flexibility of wedge plate 108 and the displacement of ends 130A and 130B are able to accommodate the displacement of components 114A and 114B in directions D1 and D2, respectively.
In an example embodiment (not shown), wedge plate 108 is circumferentially continuous. In this case, circumferential and radial contraction and expansion of wedge plate 108 is enable by radial slots, such as slots 146.
It should be understood that clutch 100 is not limited to the configuration shown in the figures. For example, the circumferential orientation of ramps 106 and 112 can be reversed.
It will be appreciated that various of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Various presently unforeseen or unanticipated alternatives, modifications, variations, or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Patent Application No. 62/052,840, filed Sep. 19, 2014, which application is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 62052840 | Sep 2014 | US |
