| Due to its special structure, planetary roller screw has better bearing capacity and longer life than the ball screw with the same specifications, and it’s an ideal substitutes of ball screw in high-speed and heavy-load condition. But the planetary roller screw was known in China for a short time, and domestic theory research in planetary roller screw still can’t keep pace with the international, which hindered the application and development of planetary roller screw. In order to solve this problem, the paper explored the causes of friction and influence factors of transmission efficiency from the perspective of motion and stress characteristics of the planetary roller screw, besides verified the theoretical analysis by the test.Firstly, based on the structure characteristics of specific planetary roller screw, the paper established the simplified motion model of planetary roller screw was, then analyzed the relationship between rotational and translational components from the view of kinematics. According to the loading characteristics of contact surface, analyzed contact deformation on the contact surface by Hertz contact theory. Secondly, according to the moving feature of the planetary roller screw, discussed the formation mechanism and influencing factors of the friction. Then established mathematical model of transmission efficiency of the planetary roller screw, and analyzed the structure affecting the transmission efficiency.In order to verify the correctness of the kinematics model and the transmission efficiency model, this paper designed the test rig of planetary roller screw transmission precision and efficiency, researched the home-made planetary roller screw by the test of transmission accuracy and transmission efficiency, investigated the influence of processing technology on the transmission accuracy, Finally summarized the influence law of structure parameters, such as processing craft, contact angle and helix angle,on transmission efficiency.
|
PDF Full Text Request