Patent ID: 9678510
Date: 2017-06-13
CPC Classifications: F16H,G05D,H02P

Claim:
1. An electromechanical actuator comprising: a housing, a drive motor disposed in or on the housing and including a rotatable drive shaft, an annular element disposed on a rotatable drive shaft of the drive motor, a rotary-to-linear motion converter driven by the drive motor and comprising a movable traveling means that is movable in a translational direction, and range limiting means disposed in the electromechanical actuator for controlling the drive motor by turning off the drive motor when the traveling means has reached a desired maximal travel position, wherein the range limiting means is formed as a contact-less electronic switching device and comprises a controller and at least one Hall-effect sensor in electronic communication with the controller, wherein the range limiting means utilizes electric impulses of the at least one Hall-effect sensor to avoid utilizing mechanical parts that are prone to wear when measuring a length of travel of the traveling means, wherein the controller is configured to count a number of drive cycles of the traveling means and measure a current of the drive motor, wherein the controller comprises a memory element configured to store the number of drive cycles of the traveling means and a momentary value of the current of the drive motor, wherein the annular element includes two magnets at diametrically-opposite circumferential positions to provide a discontinuous magnetic field that varies as the rotating drive shaft rotates, wherein the at least one Hall-effect sensor is disposed proximal to the two magnets, wherein the controller counts a number of the electric impulses outputted by the at least one Hall-effect sensor in accordance with the discontinuous magnetic field provided by the wo magnets to extrapolate the length of travel of the traveling means during a traveling movement in the translational direction, wherein the controller, during the traveling movement, turns off the drive motor after a predetermined number of the electric impulses has been counted since a start-up of the traveling means and after the number of electric impulses indicates that the traveling means has reached the desired maximal travel position in a linear direction of the traveling movement.