Improvement of materials of cylinders of actuators with active piston

摘要

The actuator has an outer cylinder (5) made of a positive or zero thermal expansion coefficient material and an inner sliding cylinder (7) made of an anisotropy material presenting a zero or negative thermal expansion material along an axis and zero or positive thermal expansion in another axis. An active piston (2) comprises sections made of a piezo-electric material and elongated inside the cylinder (7) to axially move the piston by dry friction inside the cylinder.