PRELOADED LINEAR ACTUATOR SYSTEM AND A METHOD FOR CONTROLLING A SUCH

摘要

A linear actuator system (100) for providing a linear actuator force transferred from an electric motor (50), comprises: a rod (110) with threads (111); a ring (120) with at least one circumferential groove (121) facing the threads of the rod, the ring and the rod being configured to perform a relative rotation to each other, wherein one of the ring and the rod is configured to couple to the electric motor such that the electric motor is able to drive the relative rotation. The system further comprises a plurality of balls (130) arranged between the ring and the rod to roll along the circumferential groove and the threads to move the other one of the ring and the rod in a longitudinally direction in response to the relative rotation; and a control unit (140) configured to control the electric motor to provide a constant preload force acting between the rod and the ring without moving the other one of the ring and the rod in the longitudinally direction.