Hydrodynamic bearing device and inspection method of amount of working fluid

Abstract

A hydrodynamic bearing device in a hydrodynamic bearing device in which a sleeve ( 2 ) is covered with a cover ( 5 ), which is capable of easily confirming that a working fluid is favorably filled between the cover and the sleeve, and easily confirming that an adhesive ( 21 ) which bonds the cover and the sleeve is favorably filled, and an inspection method of an amount of the working fluid are provided. By using the cover having translucency, the filled state of the working fluid is visually recognized through the cover, and is confirmed with an image recognition apparatus.

1 . An inspection method of an amount of a working fluid of a hydrodynamic bearing device for inspecting an amount of said working fluid into a hydrodynamic bearing device in which a shaft is inserted into a bearing hole of a sleeve in a relatively rotatable posture via a gap, dynamic pressure grooves are formed on at least one of surfaces of said shaft and said sleeve opposed to each other, a working fluid is filled into the gap, and the shaft is supported relatively rotatably with respect to the sleeve, the method comprising: covering at least one end surface of the sleeve with a cover with a space therebetween and forming a fluid storage space part which supplies the working fluid to the gap between the cover and the sleeve; and detecting an amount of the working fluid based on an area defined by a gas-to-liquid boundary line of the working fluid and air in said fluid storage space part. 
   
   
       2 . The inspection method of an amount of a working fluid of a hydrodynamic bearing device according to  claim 1 , wherein the cover is formed into a shape in which a depth in an axial direction of the fluid storage space part gradually changes in a circumferential direction. 
   
   
       3 . The inspection method of an amount of a working fluid of a hydrodynamic bearing device according to  claim 1 , wherein the amount of the working fluid is detected based on a position of the gas-to-liquid boundary line of the working fluid and air, which increases and decreases in the circumferential direction, in the fluid storage space part. 
   
   
       4 . The inspection method of an amount of a working fluid of a hydrodynamic bearing device according to  claim 1 , wherein at least a part of the cover has translucency. 
   
   
       5 . The inspection method of an amount of a working fluid of a hydrodynamic bearing device according to  claim 1 , wherein the working fluid is colored. 
   
   
       6 . The inspection method of an amount of a working fluid of a hydrodynamic bearing device according to  claim 1 , wherein the cover is fixed to the sleeve by an adhesive, and the adhesive of a color which is different from that of the working fluid and visually recognizable is used. 
   
   
       7 - 22 . (canceled)