Patent ID: 6508590
Filing Date: 2003-01-21
Classification: F16C

Abstract:
An externally-pressurized gas bearing spindle comprising:a housing; a bearing sleeve mounted in said housing and having a bearing surface; a main shaft supported in said bearing sleeve; a gas supply passage extending through said bearing sleeve and through said housing; a plurality of radial nozzles formed in said bearing sleeve and communicating with said gas supply passage so as to form a radial bearing by supplying gas to a bearing clearance area between said bearing surface of said bearing sleeve and said main shaft, said bearing clearance area having a radial width in a range of 6 &mgr;m to 9 &mgr;m, said radial nozzles being arranged in a plurality of rows, each of said rows including a quantity of radial nozzles in a range of 6 to 12, said rows being spaced along an axial direction of said bearing sleeve in a ratio S/W having a range of 0.7 to 0.9, wherein S is an axial distance between nozzles, and W is a bearing width of said radial bearing, said radial nozzles being operable to supply gas so as to maintain a ratio Q/H in a range of 2 to 10, wherein Q is a flow rate of the supply gas, and H is a stiffness of the bearing.