LINEAR ACTUATOR

Original (Chinese)

A linear actuator () comprising a stroke axis (), an actuator rod () extending along the stroke axis. The actuator rod comprises: an actuator rod outer surface (), and a first screw thread () on a portion of the actuator rod outer surface; a sleeve () positioned around, and coaxial with, the actuator rod. The sleeve comprises: a sleeve inner surface (), a sleeve outer surface (), a second screw thread () on a portion of the sleeve inner surface, the second screw thread configured to engage with the first screw thread, and a third screw thread () on a portion of the sleeve outer surface. A screw nut () is provided configured to engage with the third screw thread. At least one motor () configured to drive the screw nut. In use, the at least one motor applies a torque to the sleeve via the screw nut. When the applied torque is below a threshold value, the sleeve is restricted from rotating about the stroke axis, such that rotation of the screw nut causes linear displacement of the sleeve and actuator rod together along the stroke axis. When the applied torque equals or exceeds the threshold value, the sleeve is able to rotate about the stroke axis, such that rotation of the screw nut causes rotation of the sleeve, and such that rotation of the sleeve causes linear displacement of the actuator rod.