Devices, disc brakes and thrust generation stabilizer

Means to provide an improved disc brake and the ball ramp mechanism thrust one pair of ramp members durability occurs. The ball ramp mechanism (3a) of the main thrust generating apparatus (1a) includes: a pair of rotary ramp member (4a) and the rectilinear ramp member (5a), having a plurality of circumferentially radial section is inclined and inclined grooves formed in an arc (6a, 7a); ball member (10), which is mounted between the ramp member (4a, 5a) inclined grooves (6a, 7a), from the rotating ramp member (4a) radial cross-sectional radius of curvature (Ra to linear ramp member (5a) transmitting a force, since the inner member with the ball (10) is inclined grooves (6a, 7a) abutting the track area has an inclined groove (6a, 7a) of , Rb, Rc) different parts, it is possible to increase the rotational ramp member (4a) and the rectilinear ramp member (5a) durability.