Patent ID: 7942247
Filing Date: 2011-05-17
Classification: B60T,F16D

Abstract:
1. A vehicle disk brake in which a brake piston, having a rear surface facing a hydraulic chamber, is slidably fitted in a hollow bore formed in a caliper body, a nut which relatively nonrotatably abuts against the brake piston from behind is housed in the hydraulic chamber, a rear portion of a screw shaft which fluid-tightly protrudes from the hydraulic chamber, said screw shaft and said nut cooperating to define a screw mechanism which is entirely disposed within said caliper body, and an electric motor, having a motor housing mounted to the caliper body, is operatively connected to a rear portion of the screw shaft via a reduction mechanism interposed therebetween, wherein a bulkhead through which the rear portion of the screw shaft rotatably and fluid-tightly passes, and a housing recess which holds the bulkhead between itself and the hydraulic chamber are provided in the caliper body, wherein the motor housing is comprised by connecting together a bottomed cylindrical yoke which rotatably supports, at a closed end thereof, one end of an output shaft provided with an armature having a commutator, wherein said yoke coaxially surrounds the armature, a brush holder which holds a brush that comes into slide contact with the commutator, and a lid plate which holds the brush holder between itself and an opening end of the yoke, wherein a case is disposed in the housing recess, said case including the lid plate as a component, and into which case the other end of the output shaft fluid-tightly protrudes, the motor housing being mounted to the caliper body via an annular seal member that surrounds an opening end of the housing recess, wherein the reduction mechanism comprises an output rotating member and reduces rotational power input from the other end of the output shaft and outputs the reduced rotational power, wherein said reduction mechanism is sealed in the case, while part of the output rotating member fluid-tightly protrudes from the case so as to be coaxially and operatively connected to the rear portion of the screw shaft, wherein grease is charged into the case; wherein said grease contacts said reduction mechanism, and wherein said case is configured and arranged to retain said grease therein.