Patent attributes
A rotary actuator is used in a shift-by-wire system for a vehicle. The actuator includes a motor, an output shaft, a speed reducer, and a case. The motor includes a motor shaft. The output shaft is disposed in parallel with the motor shaft. The case houses the motor and the speed reducer. The case includes an upper case that houses the motor and a lower case that houses the speed reducer. The speed reducer includes a first reducer that includes a ring gear embedded in a resin portion of the lower case and a parallel-shaft type second reducer that includes a drive gear on the motor shaft and a driven gear on the output shaft. The ring gear includes an annular gear portion and a cover that protrudes radially inward from one end of the annular gear portion.