Abstract: A connection unit connected to a rotation body by fitting to transmit a rotation force includes a rotation shaft, having a width across flat portion; and a core member, having fitting portions fitted to the rotation body in a direction perpendicular to the width across flat portion and an annular portion that the width across flat portion are slidably fitted, and held on the rotation shaft to be capable of moving relatively in two dimensions along the width across flat portion while rotating integrally with the rotation shaft. Accordingly, generation of vibration or noise can be prevented, and easiness of assembly work, cost reduction, miniaturization and the like can be achieved.

Abstract: A phase changing unit of the present invention changes the relative rotational phase of a first rotating body and a second rotating body, and includes: a rotating member to which an external drive shaft is connected and to which a rotational driving force is applied; and a relative rotation mechanism that generates a relative rotation between a first rotating body and a second rotating body by the rotation of the rotating member. The rotating member includes: an action part that is made of metal and acts on the relative rotation mechanism; a connection part which is made of resin and to which the drive shaft is connected; and a fragile part that is made of resin and functions to cut the transmission of a rotational force between the drive shaft and the rotating member when an excessive load has occurred.

Abstract: A connection unit connected to a rotation body by fitting to transmit a rotation force includes a rotation shaft, having a width across flat portion; and a core member, having fitting portions fitted to the rotation body in a direction perpendicular to the width across flat portion and an annular portion that the width across flat portion are slidably fitted, and held on the rotation shaft to be capable of moving relatively in two dimensions along the width across flat portion while rotating integrally with the rotation shaft. Accordingly, generation of vibration or noise can be prevented, and easiness of assembly work, cost reduction, miniaturization and the like can be achieved.