Bearing unit and rotary drive using the same

Abstract

A bearing unit for rotatably supporting a shaft comprises a seamless holding member with a gap allowing a shaft to run through and extend to the outside, a bearing arranged in the inside of the holding member to rotatably support the shaft so as to make it radially revolvable, an anti-shaft-release member fitted to the shaft so as to abut the bearing in order to prevent the shaft from slipping away in the thrusting direction and a space-forming member arranged in the inside of the holding member so as to secure a space around the anti-shaft-release member. A bearing unit may further comprise an lubricating oil seal member and the space-forming member may be used to form a passage way for lubricating oil to prevent lubricating oil from leaking.

1 - 8 . (canceled)  
   
   
       9 . A bearing unit having a shaft and bearing means for rotatably supporting the shaft, comprising: 
 a lubricating oil seal member arranged between the shaft and the bearing means with a gap interposed between them; and    a housing member made of synthetic resin for holding the lubricating oil seal member and the bearing means from the outer peripheries thereof.    
   
   
       10 . The bearing unit according to  claim 9 , wherein 
 a radial bearing means for bearing the radial load being applied to the shaft and a thrust bearing means for bearing the thrust load being applied to the shaft are provided as the bearing means,    and further comprising:    an anti-shaft-release member attached to said shaft, and    a space-forming member provided separately from the lubricating oil seal member in order to secure a space around said anti-shaft-release member, wherein    the radial bearing means, the lubricating oil seal member and the space-forming member are held by the housing member.    
   
   
       11 . The bearing unit according to  claim 9 , wherein the housing member is made of a polymeric material.  
   
   
       12 . The bearing unit according to  claim 10 , wherein a hydrodynamic fluid bearing is used as the radial bearing means.  
   
   
       13 . The bearing unit according to  claim 10 , wherein the thrust bearing means is realized by making an end of the shaft to show a curved profile and bringing it into contact with the second member.  
   
   
       14 . The bearing unit according to  claim 9 , wherein the part of the shaft adapted to form a gap with the lubricating oil seal member is tapered so as to have a diameter that increases toward the inside of the shaft.  
   
   
       15 . The bearing unit according to  claim 10 , wherein a hydrodynamic fluid bearing is formed as the thrust bearing means by using the anti-shaft-release member and the space-forming member.  
   
   
       16 . A rotary drive comprising a rotary body, a shaft adapted to revolve with the rotary body, bearing means for rotatably supporting the shaft and drive means for driving the rotary body to revolve, wherein 
 a lubricating oil seal member arranged so as to produce a gap between the shaft and a housing member made of synthetic resin for peripherally holding the member and the bearing means are provided.    
   
   
       17 . The rotary drive according to  claim 16 , wherein 
 radial bearing means for bearing the radial load being applied to the shaft and thrust bearing means for bearing the thrust load being applied to the shaft are provided as the bearing means,    and further comprising:    an anti-shaft-release member attached to said shaft, and    a space-forming member provided separately from the lubricating oil seal member in order to secure a space around the anti-shaft-release member, wherein    the radial bearing means, the lubricating oil seal member and the space-forming member are held by the housing member.    
   
   
       18 . The rotary drive according to  claim 16 , wherein the housing member is made of a polymeric material.  
   
   
       19 . The rotary drive according to  claim 17 , wherein a hydrodynamic fluid bearing is used as the radial bearing means.  
   
   
       20 . The rotary drive according to  claim 17 , wherein the thrust bearing means is realized by making an end of the shaft to show a curved profile and bringing it into contact with the second member.  
   
   
       21 . The rotary drive according to  claim 16 , wherein the part of the shaft adapted to form a gap with the lubricating oil seal member is tapered so as to have a diameter that increases toward the inside of the shaft.  
   
   
       22 . The rotary drive according to  claim 17 , wherein a hydrodynamic fluid bearing is formed as the thrust bearing means by using the anti-shaft-release member and the space-forming member.  
   
   
       23 - 29 . (canceled)