CHARACTERISTICS OF BALL SCREWS UNDER SLIGHT OSCILLATING MOTION .3. EXPERIMENTAL CONSIDERATION OF MINIMUM OSCILLATING ANGLE NECESSARY TO PREVENT FRETTING ABRASION

The friction tests of grease plated ball screws were performed with va rious oscillating angles. In the tests, the tested angles of the ball screws were chosen on the basis of an angle that was obtained theoreti cally as the minimum oscillating angle necessary to prevent fretting a brasion. As a result, for tested angles smaller than the minimum oscil lating angle, the axial loads (friction torques of the ball screws) in creased along with increasing number of oscillations, whereas for test ed angles larger than the minimum oscillating angle, the axial loads d id not change until a certain value of the number of oscillations was reached. Therefore, It was proved that the theory of minimum oscillati ng angle can be applied to oscillatory ball screws.