Ball ramp drive for electromechanical brake

Abstract

A ball-ramp assembly for a vehicle brake having brake pads and a rotor includes a shaft rotatable about an axis. A ball ramp has a first ramp rotatable with the shaft and a second ramp aligned with the first ramp. Bearing balls are positioned between and engage the first and second ramps for transforming rotation of the first ramp into axial movement of the second ramp. A nut has a threaded connection with the second ramp with a lead of the threads of the nut being multiple times larger than a lead of the threads on the second ramp. The ball ramp has a first condition in which rotation of the shaft rotates the ball ramp to axially move the nut relative to the ball ramp for engaging the brake pads with the rotor and a second condition thereafter in which rotation of the shaft rotates the first ramp relative to the second ramp to axially move the second ramp and nut together relative to the first ramp for applying the vehicle brake.

Dependencies are inferred from the claim text.