TRANSAXLE INCLUDING BI-DIRECTIONAL OVERRUNNING CLUTCH

摘要

A transaxle includes a transaxle casing, a bi-directional overrunning clutch in the transaxle casing, a friction mechanism, and a clutch-off biasing mechanism. The bi-directional overrunning clutch includes coaxial input and output members journalled by the transaxle casing, and includes a cage disposed between the input member and the output member. Rollers carried by the cage are rotatable to follow rotation of the output member. The cage is rotatable relative to the input member according to the rotation of the rollers following the output member until the rollers contact the input member to engage the bi-directional overrunning clutch. The friction mechanism applies a friction resistance to the cage to rotate the cage relative to the input member. The clutch-off biasing mechanism biases the cage to the initial position. The friction mechanism and the clutch-off biasing mechanism are distributed in the transaxle casing at first and second end portions of the cage.

主权项

1. A transaxle comprising:
a transaxle casing; a bi-directional overrunning clutch disposed in the transaxle casing, the bi-directional overrunning clutch comprising:
an input member journalled by the transaxle casing,an output member journalled by the transaxle casing and coaxially surrounded by the input member,wherein the input member and the output member have an annular space between an inner circumferential surface of the input member and an outer circumferential surface of the output member, andwherein the inner circumferential surface of the input member comprises a plurality of wedge portions aligned in the circumferential direction of the input member, and includes a plurality of radially expanded portions which are diametrically larger than the wedge portions,a cylindrical cage disposed coaxially to the input member and the output member in the annular space, the cage having first and second end portions opposite each other in the axial direction of the output member, anda plurality of rollers carried by the cage and contacting the outer circumferential surface of the output member rotatably following rotation of the output member,wherein the bi-directional overrunning clutch is structured so as to automatically shift between its disengagement state where the rollers are disposed at the respective radially expanded portions of the input member and are separated from the respective wedge portions, and its engagement state where the rollers contact the respective wedge portions, the shift of the bi-directional overrunning clutch depending on change of rotary speed difference between the input member and the output member; a friction mechanism structured to apply a frictional force to the cage so as to enable the cage to rotate relative to the input member according to the rotation of the rollers following the output member; and a clutch-off biasing mechanism structured to bias the cage in a direction to disengage the bi-directional overrunning clutch, wherein the friction mechanism and the clutch-off biasing mechanism are distributively disposed in the transaxle casing so that the friction mechanism is disposed at the first end portion of the cage, and the clutch-off biasing mechanism is disposed at the second end portion of the cage.