Reclining device and seat

A reclining device, comprising:

• a guide bracket that is a plate member having a center hole in a circular shape, the guide bracket being configured to be fixedly attached to one of a frame of a seat cushion and a frame of a seatback;
• an internal gear configured to be fixedly attached to the other of the frame of the seat cushion and the frame of the seatback in such a manner as to be rotatable relative to the guide bracket;
• a plurality of lock gears each having an external tooth configured to mesh with an internal tooth of the internal gear, each arranged in such a manner as to be movable along the guide bracket in a radial direction of the guide bracket, and each being shiftable between a meshing position where the external tooth and the internal tooth mesh and a release position where the meshing is released;
• a cam that is rotatable relative to the guide bracket, and configured to radially move each of the lock gears between the meshing position and the release position;
• and
• at least one lock spring that urges the cam rotatably in such a direction as to shift the lock gear from the release position to the meshing position, wherein
• the guide bracket has a plurality of guide parts located away from each other in a circumferential direction around the center hole to respectively radially guide the lock gears,
• the cam has a shaft part located in the center hole of the guide bracket,
• the shaft part has an outer circumferential surface being in contact with an inner circumferential surface defining the center hole and an engaged section for engagement with the lock spring, and
• the cam is rotatably supported relative to the guide bracket by the contact of the outer circumferential surface of the shaft part with the inner circumferential surface defining the center hole, and is rotatably urged by the lock spring by the engagement of the lock spring with the engaged section.