초록 ▼

A friction brake assembly for applying a braking torque to a rotating shaft such as a transmission output shaft utilizing a primary ball ramp mechanism having a control ring and activation ring with opposed variable depth grooves and rolling members disposed therebetween to load a friction brake in

A friction brake assembly for applying a braking torque to a rotating shaft such as a transmission output shaft utilizing a primary ball ramp mechanism having a control ring and activation ring with opposed variable depth grooves and rolling members disposed therebetween to load a friction brake in response to a secondary ball ramp mechanism which creates a braking torque on the control ring to activate the primary ball ramp mechanism in response to the rotation of a control lever. Rolling members disposed in opposed variable depth grooves formed in the control lever and a control plate force the control plate towards a housing extension thereby applying a friction force to a clamp ring where the clamp ring is connected to the control ring of the primary ball ramp mechanism using a flex extension to allow relative axial movement between the clamp ring and the control ring. In this manner, the friction brake assembly of the present invention can function as a vehicle parking brake.

대표청구항 ▼

[ What is claimed is:] [1.] A friction brake comprising:a housing having a cavity formed therein;a shaft rotatable relative to said housing;a brake surface extending from said housing;a primary ball ramp mechanism disposed within said cavity comprising:an activation ring disposed adjacent to said br

[ What is claimed is:] [1.] A friction brake comprising:a housing having a cavity formed therein;a shaft rotatable relative to said housing;a brake surface extending from said housing;a primary ball ramp mechanism disposed within said cavity comprising:an activation ring disposed adjacent to said brake surface where axial movement of said activation ring results in a frictional loading and unloading of said activation ring against said brake surface; a control ring disposed opposing said activation ring, said control ring and said activation ring having opposed faces provided with circumferentially extending grooves, said grooves comprised of at least three opposed pairs of grooves having portions of varying depth with a maximum depth at a center and a minimum depth at either of two ends; rolling members disposed one in each opposed pair of said grooves; said grooves in said control ring and said activation ring being arranged so that relative angular movement of said control ring relative to said activation ring in either a clockwise or counterclockwise direction from a starting position thereof, causes said rolling members to roll along each opposed pair of said grooves thereby causing axial movement of said activation ring away from said control ring to axially load said activation ring against said brake surface thereby providing a braking torque on said shaft relative to said housing;a clamp ring attached to said control ring;a secondary ball ramp mechanism activated by the movement of a control lever creating a clamping force on said clamp ring to activate said primary ball ramp mechanism, said secondary ball ramp mechanism including at least one pair of opposed grooves formed in said secondary ball ramp mechanism, said grooves having a variable depth along their length and a rolling member disposed between said opposed grooves and wherein said secondary ball ramp mechanism further comprises a control plate axially slidingly supported by said housing and acted upon by said rolling member wherein the first of said pair of opposed grooves is formed in said control lever and the second of said pair of opposed grooves is formed in said control plate.