Valve opening/closing timing control device

A valve opening/closing timing control device, comprising:

• a driving-side rotating body that rotates in synchronization with a crankshaft of an internal combustion engine around a rotational axis;
• a driven-side rotating body disposed inside of the driving-side rotating body on the same axis as the rotational axis, the driven-side rotating body rotating as a single body together with a valve opening/closing camshaft of the internal combustion engine;
• and
• a phase adjustment mechanism that sets a relative rotation phase between the driving-side rotating body and the driven-side rotating body using a driving force of an electric actuator;
• wherein the phase adjustment mechanism is provided with an output gear provided in the driven-side rotating body on the same axis as the rotational axis, an input gear that rotates on an eccentric axis having an attitude parallel to the rotational axis, has fewer teeth than the output gear, and is disposed on the same axis as the eccentric axis, the input gear configured to couple to the driving-side rotating body through an Oldham coupling, and a cylindrically-shaped eccentric member that supports the input gear inside of the input gear so as to allow the input gear to rotate around the eccentric axis, the phase adjustment mechanism thereby changing a position where the output gear and the input gear engage with each other by causing the eccentric axis to revolve with rotation of the eccentric member due to driving force of the electric actuator, and
• the valve opening/closing timing control device is provided with a first bearing disposed between an inner periphery of the driven-side rotating body and an outer periphery of the eccentric member, a second bearing disposed between the outer periphery of the eccentric member and the inner periphery of the input gear on a side of the first bearing away from the camshaft in a direction along the rotational axis, and a front plate fixed to the driving-side rotating body on a side of the second bearing away from the camshaft in the direction along the rotational axis, the Oldham coupling being disposed on the side away from the camshaft of both the first bearing and the second bearing in the direction along the rotational axis.