Power transmission mechanism

Abstract

A power transmission mechanism has a first rotary body, a second rotary body and an elastic body. The second rotary body is located coaxially with the first rotary body. The first rotary body is operatively connected to the second rotary body through the elastic body for transmitting torque. The elastic body has a plurality of elastic members so as to stepwise change an elastic coefficient of the elastic body in accordance with the value of the torque.

What is claimed is:  
     
         1 . A power transmission mechanism comprising; 
 a first rotary body;    a second rotary body located coaxially with the first rotary body; and    an elastic body through which the first rotary body is operatively connected to the second rotary body for transmitting torque, the elastic body having a plurality of elastic members so as to stepwise change an elastic coefficient of the elastic body in accordance with the value of the torque.    
     
     
         2 . The power transmission mechanism according to  claim 1  wherein the number of the elastic members engaging with the rotary bodies increases as the value of the torque increases.  
     
     
         3 . The power transmission mechanism according to  claim 1  wherein the elastic members have at least a first elastic member and a second elastic member having different elastic coefficients from each other and start to engage with the rotary bodies in order of increasing the elastic coefficients of the elastic members as the value of the torque increases.  
     
     
         4 . The power transmission mechanism according to  claim 1  wherein the elastic members are made of plate springs.  
     
     
         5 . The power transmission mechanism according to  claim 1  wherein the first rotary body has a main body which functions as the elastic member by engaging with a part of the second rotary body.  
     
     
         6 . The power transmission mechanism according to  claim 1  wherein the first rotary body has a support portion for supporting a plurality of the elastic members.  
     
     
         7 . The power transmission mechanism according to  claim 6  wherein the second rotary body has a plurality of engaging portions, and wherein the distal ends of the elastic members supported by the support portion engage with different engaging portions, respectively.  
     
     
         8 . The power transmission mechanism according to  claim 6  wherein at least a part of each of the elastic members is layered.  
     
     
         9 . The power transmission mechanism according to  claim 1  wherein the elastic body is connected to the first rotary body and is capable of engaging with the second rotary body.  
     
     
         10 . The power transmission mechanism according to  claim 1  wherein the first rotary body is a drive rotary body and the second rotary body is a driven rotary body.  
     
     
         11 . A compressor operatively connected to an external drive source, the compressor comprising: 
 a compression mechanism having a drive shaft for compressing fluid; and    a power transmission mechanism including; 
 a pulley operatively connected to the external drive source,  
 a receiving member connected to the drive shaft, and  
 an elastic body through which the pulley is operatively connected to the receiving member for transmitting torque, the elastic body having a plurality of elastic members so as to stepwise change an elastic coefficient of the elastic body in accordance with the value of the torque.  
   
     
     
         12 . The compressor according to  claim 11  wherein a piston type compressor is applied.  
     
     
         13 . The compressor according to  claim 12  wherein the piston type compressor is a single-headed piston type compressor.  
     
     
         14 . The compressor according to  claim 11  wherein a variable displacement type compressor is applied.  
     
     
         15 . A rotary machine comprising: 
 a rotary mechanism having a rotary shaft; and    a power transmission mechanism including; 
 a first rotary body,  
 a second rotary body connected to the rotary shaft, and  
 an elastic body through which the first rotary body is operatively connected to the second rotary body for transmitting torque, the elastic body having a plurality of elastic members so as to stepwise change an elastic coefficient of the elastic body in accordance with the value of the torque.