RECLINING DEVICE AND SEAT

A reclining mechanism includes: a guide bracket, an internal gear, a plurality of lock gears, a cam configured to rotate to radially move the lock gears, and a lock spring that urges the cam rotatably. The cam has a plurality of protrusions constituting a shaft part S inserted into a center hole of the guide bracket. Each of the protrusions has: a radially outer face constituting an outer circumferential surface being in contact with an inner circumferential surface defining the center hole of the guide bracket; and an engaged end. The cam is rotatably supported by the contact of the radially outer faces of the protrusions with the inner surface defining the center hole of the guide bracket and is rotatably urged by the lock spring engaging with the engaged end.