Rotary EMA

An electromechanical actuator (EMA) assembly comprising:

• an electric motor;
• a drive shaft in engagement with the motor to be rotated about a shaft axis by operation of the motor;
• an output ring around the drive shaft, the output ring caused to rotate with rotation of the drive shaft, the output ring configured to be connected, in use, to a load to be driven by the EMA;
• a gear assembly between the drive shaft and the output ring to transmit rotation of the drive shaft to rotation of the output ring at a gear ratio, wherein the gear assembly comprises a sun gear in engagement with the drive shaft, an outer gear in engagement with the outer ring, and planetary gears rotating between and transmitting rotation between the sun gear and the outer gear;
• a planet carrier plate mounted to the planetary gears to rotate with the planetary gears, the planet carrier having an inner surface adjacent the planetary gears and an opposite outer surface, the outer surface having a cammed profile with respect to the axial direction, the cam profile rotating about the axis as the planetary gears and, therefore, the output ring rotate;
• and
• an interface plate adjacent the outer surface, the cammed profile being such as to engage the interface plate or not engage the interface plate, depending on the rotational position of the planet carrier plate.