Aerostatic bearing and linear motion guiding device using said aerostatic bearing

Abstract

Provided is an aerostatic bearing and linear motion guiding device using said aerostatic bearing. An aerostatic bearing (1) which is equipped with a bearing base (2) preferably constituted of a thermoplastic synthetic resin such as a polyacetal resin (POM), a polyamide resin (PA), or a polyphenylene sulfide resin (PPS), a filler-reinforced thermoplastic synthetic resin obtained by incorporating glass fibers, a glass powder, carbon fibers, or an inorganic filler into any of these thermoplastic synthetic resins in an amount of 30-50 mass%, or aluminum or an aluminum alloy and with a synthetic-resin bearing object (5) preferably constituted of a thermoplastic synthetic resin such as a polyacetal resin, a polyamide resin, or a polyphenylene sulfide resin, the bearing object (5) having been fastened and united to the bearing base (2) by fastening members (4) through an annular sealing member (3).

Description

technical field [0001] The invention relates to a static pressure gas bearing and a linear guide device using the static pressure gas bearing. Background technique [0002] In precision machine tools, semiconductor exposure equipment, etc., it is required to position workpieces such as processing tools and substrates with high precision. For this purpose, a linear motion guide device equipped with a hydrostatic gas bearing that hardly rubs against the positioning device of the mounting table of the workpiece is used. In such a linear motion guide device, a lubricating film of compressed air is provided between a movable table serving as a mounting table for a workpiece and a guide rail serving as a guide member so that the movable table moves in a non-contact manner with respect to the guide rail. [0003] As the throttling form of the air blowing hole of the static pressure gas bearing used in the linear motion guide device, there are porous throttling, surface throttling,...

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Problems solved by technology

[0013] Although the above-mentioned conventional static pressure gas bearings can realize ultra-low friction, ultra-high precision, and ultra-high-speed operation, they have the following problems: high-strength metals and ceramics are mainly used as bearing materials, and the bearing surfaces formed by the above-mentioned bearing materials need to be repaired. High-precision grinding and finishing, etc., therefore, there must be a problem of high cost

[0017] However, since the air blowing port in the static pressure gas bearing described in Patent Document 4 is formed by injection molding using a mold, it is formed in a relatively large self-contained orifice or small hole shape with a diameter of about 0.2 to 0.4 mm. , there is a possibility that the amount of air blown out from the air outlet is too much to cause self-excited vibration, and it still needs improvement in practical use

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