Balancer

Abstract

A weight 4 which is held by a weight holder 3 in a balancer has a pressing face 4 b ′ which is pressed against a guide face 12 a provided along the circumferential direction of rotation of the weight holder 3 by centrifugal force generated by rotation of a rotary body. When the rotary body rotates, the weight 4 which is pressed against the guide face 12 a via the pressing face 4 b ′ changes its position relative to the rotary body in the circumferential direction of rotation, whereby the weight 4 is disposed in a position in which it suppresses whirling motion of the rotary body. The guide face 12 a and pressing face 4 b ′ are inclined relative to the axial direction of rotation so as to tend to outward side in the diametrical direction of rotation as tending to one side in the axial direction of rotation. The weight 4 is pressed against a receiving portion 7 a ′ by component of the centrifugal force, in which the component acts along the guide face 12 a and pressing face 4 b′.

1 . A balancer comprising: 
 a weight holder which is integrated with a rotary body; and    a weight which is held by the weight holder; wherein: 
 the weight holder has a guide face provided along the circumferential direction of rotation;  
 the weight has a pressing face which is pressed against the guide face by centrifugal force generated by rotation of the rotary body; and  
 when the rotary body rotates, the weight which is pressed against the guide face via the pressing face changes its position relative to the weight holder in the circumferential direction of rotation, and thereby the weight is disposed in a position in which it suppresses whirling motion of the rotary body,  
   said balancer being characterized in that: 
 the guide face and pressing face are inclined relative to the axial direction of rotation so as to tend to outward side in the diametrical direction of rotation as tending to one side in the axial direction of rotation;  
 a receiving portion which is positioned at the one side relative to the weight in the axial direction of rotation is provided on the weight holder; and  
 the weight is pressed against the receiving portion by component of the centrifugal force, in which the component acts along the guide face and the pressing face.  
   
   
   
       2 . The balancer according to  claim 1 , wherein a fluid material storage chamber is provided in the weight, and 
 fluid material is stored in the fluid material storage chamber so as to be flowable.    
   
   
       3 . A balancer comprising: 
 a weight holder which is integrated with a rotary body; and    a weight which is held by the weight holder, wherein: 
 the weight holder has a guide face provided along the circumferential direction of rotation;  
 the weight has a pressing face which is pressed against the guide face by centrifugal force generated by rotation of the rotary body; and  
 when the rotary body rotates, the weight which is pressed against the guide face via the pressing face changes its position relative to the weight holder in the circumferential direction of rotation, and thereby the weight is disposed in a position in which it suppresses whirling motion of the rotary body,  
   said balancer being characterized in that: 
 a fluid material storage chamber is provided in the weight; and  
 fluid material is stored in the fluid material storage chamber so as to be flowable.  
   
   
   
       4 . The balancer according to  claim 2  or  claim 3 , wherein the fluid material is at least one of a large number of microspheres, liquid, and powder.  
   
   
       5 . The balancer according to  claim 1 , wherein an auxiliary weight storage chamber is provided in the weight, and 
 an auxiliary weight is stored in the auxiliary weight storage chamber so as to be capable of changing its position in the circumferential direction of rotation of said rotary body.    
   
   
       6 . A balancer comprising: 
 a weight holder which is integrated with a rotary body; and    a weight which is held by the weight holder, wherein: 
 the weight holder has a guide face provided along the circumferential direction of rotation;  
 the weight has a pressing face which is pressed against the guide face by centrifugal force generated by rotation of the rotary body; and  
 when the rotary body rotates, the weight which is pressed against the guide face via the pressing face changes its position relative to the weight holder in the circumferential direction of rotation, and thereby the weight is disposed in a position in which it suppresses whirling motion of the rotary body,  
   said balancer being characterized in that:    an auxiliary weight storage chamber is provided in the weight, and 
 an auxiliary weight is stored in the auxiliary weight storage chamber so as to be capable of changing its position in the circumferential direction of rotation of said rotary body.  
   
   
   
       7 . The balancer according to  claim 5  or  claim 6 , wherein: 
 the auxiliary weight storage chamber has an auxiliary guide face provided along the circumferential direction of rotation;    the auxiliary weight has an auxiliary pressing face which is pressed against the auxiliary guide face by centrifugal force generated by rotation of the rotary body;    the auxiliary guide face and auxiliary pressing face are inclined relative to the axial direction of rotation so as to tend to outward side in the diametrical direction of rotation as tending to one side in the axial direction of rotation;    an auxiliary receiving portion which is positioned at the one side relative to the auxiliary weight in the axial direction of rotation is provided on the auxiliary weight storage chamber; and    the auxiliary weight is pressed against the auxiliary receiving portion by component of the centrifugal force, in which the component acts along the auxiliary guide face and the auxiliary pressing face.    
   
   
       8 . The balancer according to  claim 7 , wherein the auxiliary guide face has one end and another end in the circumferential direction of rotation, and the distance from the auxiliary guide face to the rotational center of the rotary body gradually decreases in the circumferential direction of rotation from the two ends of the auxiliary guide face toward the central point between the two ends thereof.  
   
   
       9 . The balancer according to any one of claims  1 ,  3 ,  5  or  6 , wherein the guide face has one end and another end in the circumferential direction of rotation, and the distance from the guide face to the rotational center of the rotary body gradually decreases in the circumferential direction of rotation from the two ends of the guide face toward the central point between the two ends thereof.