Electrical actuator

An electric actuator, comprising:

• a motor part configured to drive upon receiving supply of power;
• and
• a motion conversion mechanism part configured to convert a rotary motion of the motor part into a linear motion to output the linear motion,
• wherein the motion conversion mechanism part comprises:
• a screw shaft arranged coaxially with a rotation center of a rotor of the motor part;
• a nut member rotatably fitted to an outer periphery of the screw shaft;
• and
• a planetary gear speed reducer configured to reduce a speed of rotation of the rotor and output the rotation,
• wherein the screw shaft is configured to advance toward one side in an axial direction or retreat toward another side in the axial direction in accordance with a rotation direction of the nut member, and
• wherein the nut member is arranged on an inner periphery of the rotor, and is coupled to an output member of the planetary gear speed reducer so as to be capable of transmitting torque.