Patent ID: 7942099
Filing Date: 2011-05-17
Classification: F16C

Abstract:
1. A static bearing conveying apparatus employing static bearings and having magnetic preloading and motional error correcting functions, the apparatus comprising: a guide including a guide surface formed on a side of the guide facing a table; a plurality of static bearing pads fixed to the table so as to face the guide surface; magnetic preload units provided on the table to generate a preload; and a motional error correcting control unit including a controller to control the magnetic preload units and a power amplifier to apply electric current according to a control signal from the controller, wherein the controller calculates the motional error of the conveying apparatus based on information about locations and errors of the conveying apparatus caused by machining errors on the guide surface, the magnetic preload units convert an additional correction signal that compensates the motional error into an associated electric current, the associated current being applied to an electromagnetic coil of each of the magnetic preload units, and the magnetic preload units correct a floating gap between the static bearing pads and the guide surface by changing a magnetic force of a permanent magnet of the magnetic preload units applied to generate the preload through a change of electrical current applied to the electromagnetic coil.