Title:
BALL SCREW AND MACHINE TOOL USING BALL SCREW
Document Type and Number:
Japanese Patent JP2019178712
Kind Code:
A
Abstract:
To reduce thermal displacement in an axial direction of a ball screw for driving used in a feed shaft in a linear direction of a machine tool with a simple constitution.SOLUTION: A ball screw 150 includes a fastening tool 70 constituted by inserting a shaft 60 composed of a carbon fiber-reinforced plastic material having thermal expansion coefficient smaller than that of a metallic material, into a hollow portion 50 of a screw shaft 12 composed of the metallic material having a prescribed thermal expansion coefficient, and having a diameter reduction portion 70a of which a diameter is reduced into the taper shape toward a central portion side of the ball screw, and a uniform diameter portion 70b disposed at a central portion side of the ball screw with respect to the diameter reduction portion 70a and including an inner peripheral face to which an end portion 12a of the screw shaft 12 can be fitted. At an end portion 150L of the ball screw 150, the end portion 12a of the screw shaft 12 is fitted to the uniform diameter portion 70b, and an end portion 60a of the shaft 60 projected from the end portion of the screw shaft 12 is fitted to the diameter reduction portion 70a of the fastening tool 70, and fixed by a bolt 801 (802).SELECTED DRAWING: Figure 4
Inventors:
GOTO SHUNSUKE
ASAKURA KAZUHIRO
ASAKURA KAZUHIRO
Application Number:
JP2018067294A
Publication Date:
October 17, 2019
Filing Date:
March 30, 2018
Export Citation:
Assignee:
MITSUI SEIKI KOGYO KK
International Classes:
F16H25/24; B23Q5/40; F16H25/22
Attorney, Agent or Firm:
Kiyoshi Kurihara