Patent ID: 7793915

Claim:
A valve drive device comprising: an inflow port for fluid; an outflow port for fluid; a valve element for opening or closing the inflow port or the outflow port; a drive mechanism for driving the valve element; an abutting part which is provided in any operation member included between the drive mechanism and the valve element; a restriction part for restricting rotation of the valve element by abutting with the abutting part, which is provided in another operation member included between the drive mechanism and the valve element; a gear train which includes the operation members; and a recessed part which is formed in a vicinity of a tooth part of a gear member; wherein the valve element is rotated by the drive mechanism so that the inflow port or the outflow port is opened or closed, and one of the abutting part and the restriction part is formed of an elastic member, wherein the abutting part and the restriction part are respectively provided in a tooth part of a gear member or in a vicinity of a gear member of the gear train so as to be capable of engaging with each other, and wherein the elastic member is formed in a ring shape and is disposed in the recessed part.