Title:
BALL SCREW DEVICE
Document Type and Number:
Japanese Patent JP3728917
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To realize the improvement of speed and accuracy while restraining the generation of inner clearance and preventing the lowering of inner prepressurization by forming a rolling element of the ceramics material having the given specific gravity, and reducing the quantity of thermal expansion of a ball and a nut.
SOLUTION: A peripheral surface of a screw shaft 1 is formed with a spiral ball screw groove 7, and the inner peripheral surface of a ball and a nut is formed with a ball screw groove opposed to the ball screw groove 7. multiple balls are fitted or housed in the ball screw groove 7 of the screw shaft 1 and the ball screw groove of the ball and nut so as to support the ball and nut with the screw shaft 1 through the balls. The ball is made of the ceramics material having a specific gravity at 2-4, especially the ceramics material having a coefficient of thermal expansion at 4×10-6/°C or less. Generation of inner clearance of the ball screw is thereby restrained, and high-speed feeding is enabled so as to restrain the lowering of the inner prepressurization. Thermal displacement is restrained by the cooling effect, and accuracy is improved.
Inventors:
Shinya Nakamura
Kazuo Miyaguchi
Kazuo Miyaguchi
Application Number:
JP7776498A
Publication Date:
December 21, 2005
Filing Date:
March 25, 1998
Export Citation:
Assignee:
Nippon Seiko Co., Ltd.
International Classes:
F16H25/22; F16H25/24; (IPC1-7): F16H25/22; F16H25/24
Domestic Patent References:
| JP8312744A | ||||
| JP60220256A | ||||
| JP63001956U | ||||
| JP64015567A | ||||
| JP6049964Y2 | ||||
| JP5096605U |
Attorney, Agent or Firm:
Yoshiyuki Inaba
Katsuro Tanaka
Shinji Oga
Katsuro Tanaka
Shinji Oga