Patent ID: 9051981
Filing Date: 2015-06-09
Classification: F16D

Abstract:
1. A brake mechanism for stopping rotation of a shaft, the brake mechanism comprising: a solenoid including a coil and an armature, wherein the armature is attracted in a first direction toward the coil when the coil is energized by current; at least one spring biasing the armature in a second direction opposite the first direction; an opposing plate spaced from the armature in the second direction; a ball carrier rotor arranged between the armature and the opposing plate, the ball carrier rotor having a plurality of ball-receiving recesses angularly spaced about the ball carrier rotor, and the ball carrier rotor being mounted on the shaft for rotation with the shaft; a plurality of balls received in the plurality of ball-receiving recesses; wherein the armature and the opposing plate have respective braking surfaces associated therewith for applying braking force to the plurality of balls when current to the coil is shut off; wherein the plurality of ball-receiving recesses open through a circumferential edge of the ball carrier rotor, the brake mechanism comprises an outer race having a cylindrical internal surface facing the plurality of balls, and at least one of the respective braking surfaces includes a ramp surface, wherein the ramp surface is configured to urge the plurality of balls radially outward against the internal surface of the outer race as the armature moves in the second direction under the biasing of the at least one spring when current to the coil is shut off.