BALL RAMP MECHANISM, LINEAR MOTION ACTUATOR, AND ELECTRIC DISC BRAKE DEVICE

摘要

A ball ramp mechanism is configured such that a driving-side rotor and a driven-side rotor are located on the same axis in opposing relationship with each other; three opposed pairs of arc-shaped ramp grooves are provided on the respective opposing faces of the two rotors at uniform intervals in the circumferential direction, with the depth thereof being changed gradually in the circumferential direction and the direction of the change being made opposite therebetween; a ball is incorporated between each set of the opposing paired ramp grooves; the balls are retained by the cage; and flexibility is imparted to pillar sections defined between pockets of the cage so as to make the pillar sections elastically deformable; dimensional variations due to manufacturing tolerances of the ramp grooves are absorbed via elastic deformation of the pillar sections so that each of the plurality of balls is enabled to contact the ramp grooves uniformly.

主权项

1. A ball ramp mechanism comprising:
a driving-side rotor and a driven-side rotor which are provided on a common axis in opposing relationship with each other, wherein a plurality of opposed pairs of circumferentially equidistantly spaced apart first and second arc-shaped ramp grooves are provided on opposing faces of the rotors, with depths of the ramp grooves being gradually changed in the circumferential direction and the direction of the change being made opposite between the first and second ramp grooves; balls each incorporated between each of the opposed pairs of ramp grooves; and a cage having pockets for accommodating the balls and retaining the balls, wherein the ball ramp mechanism is configured such that when the driving-side rotor and the driven-side rotor rotate relative to each other, the balls are moved along the respective ramp grooves such that the driving-side rotor and the driven-side rotor are relatively moved in an axial direction relative to each other, and wherein pillar sections are defined between respective adjacent pairs of the pockets of the cage and flexibility is imparted to the pillar sections so as to make the pillar sections elastically deformable.