Study on Measurement of Ball Motion in Ball Screw

Abstract

In order to make clear the high speed operating limit or the seizure resistance limit of the ball screw, it is necessary to grasp the actual ball motion in the ball screw, and the development of measuring method of the ball motion has been expected. In the present paper, using a magnetized ball and hall elements arranged on the nut and the return tube, the authors tried to measure the ball motion in the ball screw (ZFT4020) rotating at the shaft speed in the range of 120∿950rpm. The results were compared with the analytical results calculated based on the kinematic geometry of ball screw mechanisms. When the magnetic circuit attached to the measuring system, it became possible to observe the changes in the hall voltage, and the measured values such as the rotational speed of ball revolution and ball rotation almost agreed with the analytical values.