Study on the Load Distribution in the Ball Screw (4th Report)

When ball screws are equipped in machines, there are many cases that the moment acts on the nut due to shaft weight and setting error and the both thrust and radial loads acting on the ball screw. In this paper, we dealt with the load distribution in the ball screw when the moment acts on the nut loaded by some thrust. After the various load distributions were analyzed theoretically, the results were ascertained by means of photoelastic experiments. Main results are as follows.(1) The effect of the moment on the load distribution in the ball screw is large.(2) In order to equalize the load distribution in the ball screw loaded by the moment, it is effective to set the first ball on the bottom position of the nut at the working side of radial load acting on the shaft of the ball screw in the axial loading condition of the T-T type.(3) The theoretical values of load distributions coincide fairly well with the photoelastic experimental results.