Patent ID: 7179183
Filing Date: 2007-02-20
Classification: F16H

Abstract:
1. A continuously-variable-ratio-drive, comprising an input shaft; a drive pulley connectable to said input shaft; an output shaft; and a driven pulley connected to the output shaft; each of said pulleys being defined by a fixed-pulley and a movable half-pulley defining between them a groove of variable size for V belt; at least one of said pulleys ( 6 , 7 ) comprising a torque-sensitive, axial thrust compensating device including at least one slot carried by one of said half-pulleys and at least one cam follower carried by the other of said half-pulleys and engaging said slot; said slot having a first side delimiting said slot in a first tangential direction so as to be contacted by said cam follower in response to a drive torque and to generate an axial thrust on said movable half-pulley in the belt compression direction in response to said drive torque, and a second side delimiting said slot in a second tangential direction so as to be contacted by said cam follower in response to a braking torque and to generate an axial thrust on said movable half-pulley in the belt compression direction in response to said braking torque; said first and second sides of said slot converging with one another to form an axial end portion of said slot that is engaged by said cam follower when said fixed and movable half-pulleys are in a maximum-parted position, said slot having a base side defining an axial stop for said cam follower in a maximum-approach position of said fixed and movable half-pulleys, said second side having a sloping profile extending from said base side to said axial end portion, said first side having an inclined portion adjacent to said base portion with a slope opposite to said second side and converging with respect to said second side towards said end portion of said slot, and an intermediate knee portion between said inclined portion and said axial end portion.