電動サーボ式射出成形機用ボールねじの寿命に関する研究

抄録

In this paper, the life tests of the ball screw for electric injection molding machines are carried out. The ball screw for the injection drive is operated under the special condition such as a heavy load (max. 283kN) and the small stroke factor (ball screw stroke / actual nut length). Based on the experimental results, the ball screw life and the calculation method of the basic dynamic load rating are discussed. The main results are as follows: (1) Instead of the new calculation method of the basic dynamic load rating which has been used in a ball screw manufacture's catalog for these ten years, the old method based on the Lundberg and Palmgren's theory can be applied for the short-stroke ball screw life. (2) The heavy load ball screw of which the middle return-tube is located the other side, has a better contact force distribution compared with that of the normal ball screw. And this modified force distribution realized the longer life.