Roller pump

Abstract

To prevent damage to a tube in a roller pump which pumps a fluid contained in the tube by squeezing it against an inner wall surface of a housing with a roller, so that the tube can be used continuously for a long time. A depression which a part of the tube enters when squeezed with the roller is formed on at least one of a roller surface of the roller and the inner wall surface of the housing. This alleviates a load on the tube, thereby preventing damage to the tube. Alternatively, the roller may include a plurality of disc rollers that are separately rotatable. This reduces differences in frictional force acting upon the tube when squeezed by the roller, thereby preventing damage to the tube. According to these constructions, the tube can be used continuously for a long time.

1 . A roller pump that pumps a fluid contained in a tube by squeezing the tube against a wall surface of a housing with a roller, characterized in that 
 a depression which a part of the tube enters when squeezed with the roller is formed on at least one of a roller surface of the roller and the wall surface of the housing.    
   
   
       2 . The roller pump of  claim 1 , 
 wherein the depression is continuously formed around a circumference of the roller surface of the roller.    
   
   
       3 . The roller pump of  claim 2 , 
 wherein the depression is formed as a ring.    
   
   
       4 . The roller pump of  claim 2 , 
 wherein the depression is formed in the middle of the roller surface in a direction of a rotation axis of the roller.    
   
   
       5 . The roller pump of  claim 2 , 
 wherein a projection is formed on the wall surface of the housing in an area corresponding to the depression on the roller surface of the roller.    
   
   
       6 . The roller pump of  claim 5 , 
 wherein the projection is continuously formed along the tube.    
   
   
       7 . The roller pump of  claim 1 , 
 wherein a width of the depression in a direction of a rotation axis of the roller is no smaller than a wall thickness of the tube and no larger than three times the wall thickness of the tube.    
   
   
       8 . The roller pump of  claim 1 ,  
     wherein a depth of the depression is no smaller than a wall thickness of the tube.  
   
   
       9 . The roller pump of  claim 1 , 
 wherein the wall surface of the housing is a curved inner wall surface of the housing, and    a rotor which moves the roller along the inner wall surface of the housing is provided in the housing, with the roller being rotatably attached to the rotor.    
   
   
       10 . A roller pump that pumps a fluid contained in a tube by squeezing the tube against a wall surface of a housing with a roller, characterized in that 
 the roller includes a plurality of disc rollers which are separately rotatable.    
   
   
       11 . The roller pump of  claim 10 , 
 wherein at least three disc rollers of the plurality of disc rollers contact the tube when the tube is squeezed with the roller.    
   
   
       12 . The roller pump of  claim 10 , 
 wherein a gap which a part of the tube enters when squeezed with the roller is provided between adjacent disc rollers of the plurality of disc rollers.    
   
   
       13 . The roller pump of  claim 12 , 
 wherein a width of the gap is no smaller than a wall thickness of the tube and no larger than three times the wall thickness of the tube.    
   
   
       14 . The roller pump of  claim 10 , 
 wherein the wall surface of the housing is a curved inner wall surface of the housing, and    a rotor which moves the roller along the inner wall surface of the housing is provided in the housing, with the roller being rotatably attached to the rotor.    
   
   
       15 . A blood circuit in which a blood circulation tube is set in the roller pump of  claim 1 .  
   
   
       16 . An infusion circuit in which an infusion circulation tube is set in the roller pump of  claim 1 .  
   
   
       17 . A dialysis circuit comprising: 
 a dialyzer which performs dialysis by having blood and dialysate pass through a dialyzing membrane;    at least one of a blood circulation tube and an infusion circulation tube; and    the roller pump of  claim 1  in which the tube is set and which pumps a fluid contained in the tube to the dialyzer.    
   
   
       18 . A blood circuit in which a blood circulation tube is set in the roller pump of  claim 10 .  
   
   
       19 . An infusion circuit in which an infusion circulation tube is set in the roller pump of  claim 10 .  
   
   
       20 . A dialysis circuit comprising: 
 a dialyzer which performs dialysis by having blood and dialysate pass through a dialyzing membrane;    at least one of a blood circulation tube and an infusion circulation tube; and    the roller pump of  claim 10  in which the tube is set and which pumps a fluid contained in the tube to the dialyzer.