Elastic shaft joint and elastic bush forming method

Abstract

An elastic shaft joint is constituted of a joint member, a shaft member being fitted in a shaft of the joint member, and an elastic bush having a cylindrical inner sleeve fitted and fixed on the joint member, a cylindrical elastic member fixed on an outside surface of the inner sleeve, and a cylindrical outer sleeve fixed on an outside surface of the elastic member, for elastic torque transmission between the joint member and the shaft member, wherein the outer sleeve is fixed on the shaft member.

What is claimed is:  
     
         1 . An elastic shaft joint comprising: 
 a joint member;    a shaft member being fitted in a shaft of said joint member; and    an elastic bush having a cylindrical inner sleeve fitted and fixed on said joint member, a cylindrical elastic member fixed on an outside surface of said inner sleeve, and a cylindrical outer sleeve fixed on an outside surface of said elastic member, for elastic torque transmission between said joint member and said shaft member,    wherein said outer sleeve is fixed on said shaft member.    
     
     
         2 . An elastic shaft member comprising: 
 a joint member;    a shaft member being fitted in a shaft of said joint member;    an elastic bush having a cylindrical inner sleeve fitted and fixed on said joint member, an elastic member fixed on an outside surface of said inner sleeve, and a cylindrical outer sleeve fixed on an outside surface of said elastic member, for elastic torque transmission between said joint member and said shaft member; and    a torque transmitting member whose one end is fitted and fixed on said elastic bush and whose other end is fixed on said shaft member,    wherein said elastic member is lopsidedly distributed largely on both end sides in the axial direction between said inner sleeve and said outer sleeve.    
     
     
         3 . An elastic shaft joint comprising: 
 a joint member;    a shaft member being fitted in a shaft of said joint member;    a plurality of elastic bushes each having a cylindrical inner sleeve fitted and fixed on said joint member, an elastic member fixed on an outside surface of said inner sleeve, and a cylindrical outer sleeve fixed on an outside surface of said elastic member, for elastic torque transmission between said joint member and said shaft member; and    a torque transmitting member whose one end is fitted and fixed on said plurality of elastic bushes and whose other end is fixed on said shaft member,    wherein said plurality of elastic bushes are disposed between said joint member and said torque transmitting member on both end sides in the axial direction.    
     
     
         4 . An elastic shaft joint according to  claim 3 , 
 wherein said plurality of elastic bushes constitute plural sets each which has said elastic member with different rigidity, and said elastic members with high rigidity are disposed on both end sides in the axial direction between said joint member and said torque transmitting member.    
     
     
         5 . An elastic shaft joint according to  claim 1 , 
 wherein in said elastic bush, after said inner sleeve, said elastic member and said outer sleeve are fixed, in order to subject said elastic member to compressive deformation, the diameter of said inner sleeve is increased or the diameter of said outer sleeve is decreased.    
     
     
         6 . An elastic shaft joint according to  claim 2 ,  3  or  4 , wherein in said each elastic bush, after said inner sleeve, said elastic member and said outer sleeve are fixed, in order to subject said elastic member to compressive deformation, the diameter of said inner sleeve is increased or the diameter of said outer sleeve is decreased.  
     
     
         7 . An elastic shaft joint according to  claim 2 ,  3  or  4  wherein a cross section of said each elastic bush taken perpendicular to the axis of said elastic bush is formed noncircular so as to subject said elastic member to compressive deformation at the time of relative rotation of said inner sleeve and said outer sleeve.  
     
     
         8 . A method of forming an elastic bush having a cylindrical inner sleeve, an elastic member fixed on an outside surface of said inner sleeve and a cylindrical outer sleeve fixed on an outside surface of said elastic member, comprising: 
 increasing the diameter of said inner sleeve or decreasing the diameter of said outer sleeve so as to subject said elastic member to compressive deformation after fixing said inner sleeve, said elastic member and said outer sleeve.