Bearing unit and motor and electric apparatus having bearing unit

Abstract

A bearing unit, including: a shaft; a first radial bearing configured to support the shaft in a circumferential direction; a second radial bearing disposed in a spaced relationship from the first radial bearing in an axial direction of the shaft configured to support the shaft in the circumferential direction; a thrust bearing configured to support one end of the shaft in a thrust direction; a spacer disposed between the first and second radial bearings; a housing in which the first and second radial bearings and the thrust bearing are disposed and which has an enclosed structure except a shaft insertion hole in which the shaft is fitted; and viscous fluid filled in the housing.

1 . A bearing unit, comprising: 
 a shaft;    a first radial bearing configured to support said shaft in a circumferential direction;    a second radial bearing disposed in a spaced relationship from said first radial bearing in an axial direction of said shaft configured to support said shaft in the circumferential direction;    a thrust bearing configured to support one end of said shaft in a thrust direction;    a spacer disposed between said first and second radial bearings;    a housing in which said first and second radial bearings and said thrust bearing are disposed and which has an enclosed structure except a shaft insertion hole in which said shaft is fitted; and    viscous fluid filled in said housing.    
   
   
       2 . The bearing unit according to  claim 1 , wherein: 
 said spacer is formed such that, when the volume of said viscous fluid filled in said housing is expanded or contracted by a temperature variation, the variation of the liquid level of said viscous fluid remains within a range within which said shaft insertion hole of said housing is formed.    
   
   
       3 . The bearing unit according to  claim 1 , wherein: 
 said spacer has a flow path for said viscous fluid formed therein.    
   
   
       4 . A motor, comprising: 
 a stator;    a rotor; and    a bearing unit configured to support    said rotator for rotation with respect to said stator;    said bearing unit including: 
 a shaft;  
 a first radial bearing configured to support said shaft in a circumferential direction;  
 a second radial bearing disposed in a spaced relationship from said first radial bearing in an axial direction of said shaft configured to support said shaft in the circumferential direction;  
 a thrust bearing configured to support one end of said shaft in a thrust direction;  
 a spacer disposed between said first and second radial bearings;  
 a housing in which said first and second radial bearings and said thrust bearing are disposed and which has an enclosed structure except a shaft insertion hole in which said shaft is fitted; and  
 viscous fluid filled in said housing.  
   
   
   
       5 . An electronic apparatus, comprising: 
 a motor including a stator;    a rotor; and    a bearing unit configured to support said rotator for rotation with respect to said stator;    said bearing unit including: 
 a shaft;  
 a first radial bearing configured to support said shaft in a circumferential direction;  
 a second radial bearing disposed in a spaced relationship from said first radial bearing in an axial direction of said shaft configured to support said shaft in the circumferential direction;  
 a thrust bearing configured to support one end of said shaft in a thrust direction;  
 a spacer disposed between said first and second radial bearings;  
 a housing in which said first and second radial bearings and said thrust bearing are disposed and which has an enclosed structure except a shaft insertion hole in which said shaft is fitted; and  
 viscous fluid filled in said housing.