Collet chuck tightening nut

Abstract

To provide a fastening nut for a collet chuck which can reduce the diameter of a collet by pressing a retainer against a holder body with no misalignment when fastening with a nut body and reliably prevent a ball from protruding under a centrifugal force.SOLUTION: The fastening nut comprises a nut body which keeps a nut side ball groove consisting of a ball contact surface and a ball non-contact surface formed on the inner peripheral surface, a retainer which keeps a retainer side ball groove consisting of a ball contact surface and a ball non-contact surface formed on the outer peripheral surface and is assembled on the inner peripheral surface of the nut body, and a plurality of balls arranged between the nut side ball groove and the retainer side ball groove. The nut side ball grooves and the retainer side ball grooves are formed wider than the ball diameter. A ball insertion hole communicating with the nut side ball groove is formed in the nut body to make the central axis of the ball insertion hole penetrate the nut side ball non-contact surface.SELECTED DRAWING: Figure 2

Claims

1. A nut body having a ball groove on the inner circumference formed on the nut side, A retainer is formed on its outer circumferential surface, and is assembled to the inner circumferential surface of the nut body. The system comprises a plurality of balls arranged between the nut-side ball groove and the retainer-side ball groove, The nut-side ball groove is formed to be wider than the diameter of the ball, and has a curved nut-side ball contact surface at the tip end and a nut-side ball non-contact surface at the base end. The retainer-side ball groove is formed to be wider than the diameter of the ball, and has a retainer-side ball non-contact surface at the tip end and a retainer-side ball contact surface consisting of a curved surface at the base end. The ball contacts the nut-side ball contact surface and also contacts the retainer-side ball contact surface. The nut body has a ball insertion hole that communicates with the nut-side ball groove, The tightening nut for a collet chuck is characterized in that the central axis of the ball insertion hole passes through the non-contact surface of the nut-side ball and is inclined with respect to the radial direction of the nut body.

2. In the collet chuck tightening nut according to claim 1, A collet chuck tightening nut characterized in that the nut-side ball non-contact surface and the retainer-side ball non-contact surface are curved surfaces.

3. In the collet chuck tightening nut according to claim 1, A tightening nut for a collet chuck, characterized in that the retainer is provided with a retainer retraction prevention means in the direction of the base end of the retainer.

4. In the collet chuck tightening nut according to claim 3, The retainer retraction prevention means is characterized by being a snap ring, and is a tightening nut for a collet chuck.

5. In the collet chuck tightening nut according to claim 4, A collet chuck tightening nut characterized in that the nut body has a retraction groove formed therein for holding the snap ring in a reduced diameter state.

6. In the collet chuck tightening nut according to claim 1, A collet chuck tightening nut characterized by having a pre-pressure means in the base end direction of the retainer.

7. In the collet chuck tightening nut according to claim 6, The aforementioned pressurizing means is made of an elastic material, characterized in the tightening nut for a collet chuck.

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