Bearing bush and composite motion device using this bearing bush

Abstract

A bearing bush enabling the excellent advancing and retarding motions of a shaft member by eliminating a clearance between the bearing bush and the shaft member to exclude rattling therebetween, capable of reducing a load on dimensional control for both the bearing bush and the shaft member, and manufacturable at low cost and a compound movement device using the bearing bush. The bearing bush (4) pivotally supporting the reciprocating motion of the shaft member (1) in the axial direction comprises an accepting hole through which the shaft member (1) is inserted. Grooves (40) are repeatedly formed, at specified intervals, in the inner peripheral surface of the bearing bush which faces the accepting hole. The inner diameter of the accepting hole is formed equal to or smaller than the outer diameter of the shaft member (1) to press-fit the bearing bush to the outer peripheral surface of the shaft member (1) by so-called a shrink fitted state.

Description

technical field [0001] The present invention relates to a bearing bush that supports the axial forward and backward movement of a shaft member such as a spline shaft. A bearing bush that supports the forward and backward movement of the spline shaft in a compound kinematic device in which the shaft rotates. Background technique [0002] As the spindle of the automatic feeding device of the workpiece or the automatic changing device of the tool in the NC machine tool, it must be able to move forward and backward freely in the axial direction, and can perform rotational movement with high precision, as a support for the movement of the spindle in the axial direction, and relative to the The part that transmits the rotational torque of the main shaft uses a combination of a spline shaft and a spline nut. [0003] In particular, when a spline nut is assembled to a ball spline on a spline shaft with a plurality of balls interposed, and the balls are pressurized, rotational torqu...

AI Technical Summary

Problems solved by technology

[0011] However, in order to completely eliminate the gap between the bearing bush and the shaft member without increasing the sliding resistance, it is still necessary to strictly control the dimensions of the inner diameter of the bearing bush and the outer diameter of the shaft member, and there is a problem that it takes man-hours for production.

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