Stepper motor driven proportional rotary actuator
A stepper motor driven actuator system is provided. The system includes a stepper motor, a cam, and a gearbox system. The gearbox system operatively connects the stepper motor to the cam. The cam rotates in response to stepping of the stepper motor. The system also includes a valve having a control piston located therein. The control piston is configured to translate in response to rotation of the cam. The system further includes a rotary actuator. The rotary actuator is fluidly connected to the valve, and the rotary actuator is configured to rotate the cam in response to translation of the control piston.
1. A stepper motor driven actuator system comprising:
a stepper motor;
a cam;
a gearbox system, the gearbox system operatively connecting the stepper motor to the cam such that the cam rotates in response to stepping of the stepper motor;
a valve having a control piston located therein, the control piston configured to translate in response to rotation of the cam;
a rotary actuator, the rotary actuator fluidly connected to the valve, the rotary actuator configured to rotate the cam in response to translation of the control piston;
a driveshaft of the stepper motor;
a planet frame having an output shaft operatively connected to the cam; and
a re-nulling gear configured to rotate in response to rotation of the rotary actuator;
wherein the gearbox system includes a sun gear, a plurality of planetary gears, and a planetary ring gear;
wherein the re-nulling gear is in mesh relation to the planetary ring gear;
wherein the driveshaft of the stepper motor is integral with the sun gear; and
wherein the planet frame causes rotation of the cam in response to stepping of the stepper motor and in response to rotation of the rotary actuator.