Stepper motor driven proportional rotary actuator
AssigneeWoodward, Inc.
InventorsMark A. Spickard, Brian K. Lawver
Life of this patent
Estimating the term…
Abstract
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.
Claims24
A stepper motor driven actuator system comprising:
- a stepper motor;
- a cam;
- a gearbox system including a ring gear, 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;
- and
- a rotary actuator, the rotary actuator fluidly connected to the valve;
- wherein translation of the control piston of the valve directly imparts only rotary motion to the rotary actuator;
- and
- wherein the rotary actuator is configured to rotate the ring gear of the gearbox system to re-center the cam.
A stepper motor driven actuator system comprising:
- a stepper motor;
- a cam;
- a gearbox system including a ring gear, 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;
- and
- a rotary actuator, the rotary actuator fluidly connected to the valve;
- wherein translation of the control piston of the valve directly imparts rotary motion to the rotary actuator;
- and
- wherein the rotary actuator is configured to rotate the ring gear of the gearbox system to re-center the cam;
- and further comprising
- 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 the ring gear;
- wherein the re-nulling gear is in mesh relation to the 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.
Dependencies are inferred from the claim text.