Power swivel device of seat for vehicle

A power swivel device for a vehicle seat comprising:

• a fixed plate fixed to a seat rail of an interior floor of a vehicle;
• a rotating plate rotatably installed on the fixed plate and mounted to a seat;
• a motor installed on a side of the fixed plate;
• and
• a brake unit installed between the fixed plate and the rotating plate, delivering rotational force of the motor to the rotating plate when the motor is operated, and constraining a flow in a rotational direction of the rotating plate when the motor is stopped and
• wherein the brake unit comprises:
• a drum housing and a housing cover coupled to each other to form a part installation space therein;
• a brake plate installed between the drum housing and the housing cover, having a plurality of wedge bosses formed on an outer circumferential surface and having a wedge surface forming a low inclination toward the wedge boss and a high inclination on an opposite side thereof on both sides of the wedge boss;
• a wedge roller provided between the wedge surface and an inner circumferential surface of the drum housing to constrain rotation of the brake plate by being sandwiched between the wedge surface and the inner circumferential surface of the drum housing when the brake plate rotates;
• and
• an elastic member installed inside of a wedge groove formed on a side surface of the wedge boss to push the wedge roller upward from the wedge surface, and wherein a driving plate is provided between the brake plate and the housing cover, and
• operating pieces are disposed respectively between the wedge bosses on an outer circumferential surface of the driving plate, and
• coupling pieces protruding outward through an inner diameter section of the housing cover are formed on an inner circumferential surface of the driving plate, and
• the coupling pieces are inserted into and welded to an inner diameter section of a driving gear located outside the housing cover.