A speed reducer having a brake system in

摘要

A deceleration machine having a brake is provided to minimize a size of a motor by installing the brake in a body of the deceleration machine, without installing a brake in a servo motor. A deceleration machine includes a body fixed to a servo motor by an adaptor(30), an input gear spline(24) formed on an input gear, and brake(40) fixed to an inner end of the adaptor so that the input gear spline meshes with a brake spline. The brake is a dry brake, and an oil seal is formed on an inner end of an input flange(50) to seal a gap between a brake mounting portion and an oil chamber. An oil seal(31) is installed on one side of the adaptor.