Research on the technology of fixed stroke lead screw transmission mechanism with self positioning function

The traditional screw drive has the difficulty of precise position and complex program control, which increases the difficulty of technical personnel's development. Aiming at this pain point, this paper proposes a fixed stroke lead screw transmission mechanism with self positioning function. After the technical improvement, the lead screw no longer needs the travel switch and the corresponding switch state judgment circuit, which simplifies the circuit composition of the whole system. It simplifies the mechanical structure layout of the whole system, and does not need to reserve the installation position and wiring position of the travel switch, especially for the limited space environment. For the screw transmission structure which needs to be used in the sealed environment, the stroke distance in the closed cavity reserved due to the installation of the travel switch can be saved, and the length of the instrument can be shortened. In addition, it is no longer necessary to judge the status of the travel switch and issue control commands in the program. It only needs to reserve enough motor rotation time according to the motor speed, which simplifies the program structure. The starting and ending positions and travel distance of the whole travel are accurate and reliable, which can avoid the over travel, blocking and impact caused by the damage of the travel switch, and ensure the safety of the instrument, equipment and operators.