Patent attributes
An actuator for a valve serving to transfer turning power from a motor to an output shaft through an inner gearing planet gear speed reducing mechanism that is imposed in a casing and adapted to effect speed reduction of the turning power, and utilize rotation of the output shaft to open and close a valve by rotation. The gear speed reduction mechanism includes an eccentric body rotated in consequence of transfer of the turning power from the motor, an outer gear disposed so as to generate a vibrating rotation through the eccentric body, an inner gear meshed in an inscribing manner with the outer gear, a rotation transferring mechanism for extracting rotation from the vibrating rotation of the outer gear and transferring the extracted rotation to the output shaft, and an output shaft connected through the rotation transferring mechanism. The gear speed reducing mechanism is furnished with an angular positioning part that is a stopper part or an engaging region for controlling the rotation of the output shaft in a prescribed angle.
