Nidec Corporation

Masaaki Uchiyama

Isao Misu

Tatsuya Yoshida

Takeshi Ichinose

Oil which will serve as a lubricating fluid of a fluid dynamic pressure bearing is degassed in a first environment under a first pressure which is lower than atmospheric pressure. First and second members of the bearing are place in a second environment under a pressure lower than atmospheric pressure and higher than the pressure in the first environment. The degassed oil is supplied to the gap between bearing surfaces of the first and second members while the first and second members are in the second environment under pressure lower than atmospheric pressure and higher than the pressure in the first environment. Subsequently the pressure in the second environment is increased to force the oil into the gap between the bearing surfaces of the first and second members of the hydrodynamic fluid.

Method for use in the manufacturing of a fluid dynamic pressure bearing

Under a reduced-pressure environment, stopping at will liquid that flows out from a nozzle tip, or dispensing liquid with the level of energy at which it will not splatter has proven difficult. To address such difficulties, parameters including nozzle bore, and surface tension and viscosity of, and delivery pressure on, a liquid are selected so that the surface tension that acts on the liquid when flowing out from the nozzle tip will be greater than the momentum of the liquid. By dispensing liquid under such conditions, outflow of the liquid is reliably controlled, and rapid infusion work is realized.

Fluid dispensation method

Method of charging dynamic-pressure bearing device with lubricating fluid. Preparatorily, lubricating fluid is put into a vacuum chamber and the chamber is vacuum-evacuated to subject the lubricating fluid to a degassing process. An appropriate quantity of fluid is dispensed in one end of the bearing gap, with the bearing device having been placed in a reduced-pressure ambient. In carrying out the dispensation, the pressure of the ambient is adjusted so as to be higher than the pressure during the degassing process. The method in this way prevents the lubricating fluid from frothing when it is being dispensed, and makes it possible to charge dynamic-pressure bearing devices with lubricating fluid without soiling the bearing-device surfaces with splashes or other contaminants.

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Kyoto, Japan

Masaaki Uchiyama