Title:
MAIN ROTARY SHAFT UNIT
Document Type and Number:
Japanese Patent JPS55126117
Kind Code:
A
Abstract:
PURPOSE:To make high accuracy linear motion of a main rotary shaft even though load is applied to the rotary shaft with centers of the shaft and a linear guide set geometrically cocentric with each other and a shaft housing and the guide portion of the guide held by a static pressure gas bearing. CONSTITUTION:When gas flows to a bearing clearance from an external pressure source through a gas supply hole 4, an orifice shutter 5 and a pocket 6, a casing 20 and a linear guide 22 constitute a static pressure gas bearing so that lateral linear motion is made freely. In this case, the axis 23 of a main rotary shaft 23 and that 24 of a linear guide 24 are geometrically coincided but shift from each other by several microns due to the weight of the shaft. The distance of this shift is very small and negligible although resistance is applied as moment to the guide 22 by the load applied to the shaft 31. Thereby, the resistance working on the guide becomes small so that high-accuracy linear motion can be obtained.
Inventors:
KASHIWA KIYOTAKA
ISHIDA YOSHIHIRO
BETSUI HAJIME
KIKUCHI YOSHIMICHI
AKAOSUGI MASAMI
ISHIDA YOSHIHIRO
BETSUI HAJIME
KIKUCHI YOSHIMICHI
AKAOSUGI MASAMI
Application Number:
JP3387479A
Publication Date:
September 29, 1980
Filing Date:
March 22, 1979
Export Citation:
Assignee:
HITACHI LTD
International Classes:
F16C32/06; (IPC1-7): F16C32/06