Brake device

A brake device, comprising:

• an outer race having a cylindrical inner peripheral surface;
• at least two brake cams arranged inside the outer race in a circumferential direction, each of the brake cams having two brake surfaces and a cam-side contact portion, the brake surfaces being provided at both ends in the circumferential direction of a radially outer side of respective one of the brake cams and configured to be contactable with the inner peripheral surface of the outer race, the cam-side contact portion being provided at a radially inner side of the respective one of the brake cams, the brake cams being configured to engage with an input-side rotary member and receive a rotation moment from the input-side rotary member;
• and
• an output-side rotary member arranged at radially inner sides of the brake cams, the output-side rotary member including output-side contact portions contactable with the cam-side contact portion, the output-side rotary member being configured to rotate together with the brake cams,
• wherein a rotation moment received by the brake cams is transmitted to the output-side rotary member to cause the output-side rotary member to rotate, while a rotation moment of the output-side rotary member, as effected in at least one direction, received from the output-side rotary member by the brake cams causes both of the brake surfaces at the both ends to be pressed concurrently on the inner peripheral surface of the outer race, and thus fails to cause the input-side rotary member to rotate, and
• wherein regions of the cam-side contact portions of the respective brake cams, which are contactable with the output-side contact portions, are on a both-end reference plane connecting outer ends of the two brake surfaces of a corresponding brake cam, or on an axis-of-rotation side that is one side of the both-end reference plane on which an axis of rotation of the output-side rotary member is located.