Patent ID: 7874626

Claim:
A hydraulic modulator for a brake device comprising: a cylinder for slidably supporting a piston and changing the volume of a hydraulic chamber communicating with a brake caliper according to the sliding of said piston; and a motor for sliding said piston through power transmitting means; said power transmitting means being arranged so that said cylinder extends parallel to a rotating shaft of said motor; wherein said power transmitting means includes a push slider for pushing the piston, the push slider having a convex end part shaped as an outer portion of part of a sphere, and the piston having a concave end part shaped as an inner portion of part of a sphere, the convex end part of the push slider being in direct spherical contact with the concave end part of the piston, and a rotational motion of said motor being converted into a linear motion of the push slider on an axis parallel to said rotating shaft, wherein a radially extending guide projection is formed on one side of the push slider, the guide projection being fitted into an axially extending groove so that the push slider is movable within the hydraulic modulator only in an axial direction of the push slider, and wherein a push plate is connected to the push slider on a side opposite to where the guide projection is formed.