Patent ID: 8408795
Filing Date: 2013-04-02
Classification: F16C

Abstract:
1. A ball-spline with rotary mechanism, comprising; an elongated spline shaft circular in transverse section having raceway grooves extending lengthwise of the spline shaft on a circular surface of the shaft at locations angularly opposite to each other, a slider fitting over or conforming to the spline shaft to move up and down along the spline shaft in a sliding manner by virtue of rolling elements of balls, holders lying on lengthwise opposite ends of the slider, and rolling-contact bearings installed to keep the holders for rotation relative to a machine bed; wherein the slider is composed of a carriage of a cylindrical shell having raceway grooves on an inside circular surface thereof in opposition to the raceway grooves on the spline shaft to define load-carrying races between the raceway grooves on the spline shaft and the raceway grooves on the carriage and further having return passages extending in parallel with the load-carrying races, end caps attached to lengthwise opposite ends of the carriage, the end caps having turnaround passages to connect the load-carrying races with the return passages, and the balls recirculating through a looped circuit made up of the load-carrying races, return passages and the turnaround passages; wherein the carriage has a pair of first slots extending lengthwise of the carriage on the inside circular surface at circularly opposite locations in symmetry with each other and the end caps have paired second slots extending lengthwise of the end caps on inside circular surfaces thereof to communicate with the first slots; and wherein the holders each have a flanged portion adjacent to the end of the slider, a pair of projections extending integrally from an end surface of the flanged portion to fit into the first slots in the carriage across the second slots in one of the end caps, and a bearing mounting of a cylinder formed integral with the flanged portion to extend from another end surface opposite to the end surface of the flanged portion to fit snugly into an inner ring of one of the rolling-contact bearings.