Abstract
The ball bearing is built-in the nut of the ordinary taper collet chuck. But, the ball bearing is used for radial rotation and the thrust load when tightening the nut is absolutely no good for the ball bearing. The new mechanism of the nut is developed to sort out this problem. The TiN coated plane bearing (TiN bearing) is built-in the nut. When tightening the nut, between the nut and the upper surface of the TiN bearing is sliding and between the lower surface of the TiN bearing and the collet is not sliding, therefore the TiN bearing is pushing the collet straight down to the taper hole of the collet chuck. Thus, the run-out accuracy and the gripping torque are improved substantially.
