Wearing ring and pump having the same

Abstract

In a pair of wearing rings, the inner-cylinder wearing ring ( 5 a , 5 b ) or the outer-cylinder wearing ring (4 a , 4 b ) is formed of a carbon fiber reinforced plastic and constituted so that the coefficient of thermal expansion in the radial direction is −1×10 −6 /° C. to 30×10 −6 /° C. This makes it possible to maintain a clearance between the case wearing ring and the impeller wearing ring within a small fixed range even when the temperature rises due to rotation and when a high-temperature fluid is used. A pump provided with the wearing ring is excellent in stability and has a good efficiency.

1 . An inner-cylinder wearing ring or an outer-cylinder wearing ring each of which is used in a pair of wearing rings of the combination of inner-cylinder side and outer-cylinder side; wherein, the inner-cylinder wearing ring or the outer-cylinder wearing ring is formed of a carbon fiber reinforced plastic and has a coefficient of thermal expansion in the radial direction of −1×10 −6 /° C. to 30×10 −6 /° C.  
     
     
         2 . An inner-cylinder wearing ring or an outer-cylinder wearing ring according to  claim 1 , in which its coefficient of thermal expansion in the radial direction is 3×10 −6 /° C. to 20×10 −6 /° C.  
     
     
         3 . An inner-cylinder wearing ring or an outer-cylinder wearing ring according to  claim 1 , in which the above-described carbon fiber reinforced plastic contains carbon fibers oriented in the axial direction and carbon fibers oriented in the circumferential direction of the wearing ring and in which the ratio of (weight of axial carbon fibers): (weight of circumferential carbon fibers) is (1:10) to (100:10).  
     
     
         4 . An inner-cylinder wearing ring or an outer-cylinder wearing ring according to  claim 3 , in which the ratio of (weight of axial carbon fibers): (weight of circumferential carbon fibers) is (15:85) to (85:15).  
     
     
         5 . An inner-cylinder wearing ring or an outer-cylinder wearing ring according to  claim 1 , in which the carbon fibers in the carbon fiber reinforced plastic which constitutes an outermost layer of the inner-cylinder wearing ring or the outer-cylinder wearing ring are a fabric.  
     
     
         6 . An inner-cylinder wearing ring or an outer-cylinder wearing ring according to  claim 1 , in which a matrix resin contained in the carbon fiber reinforced plastic is a thermosetting resin.  
     
     
         7 . An inner-cylinder wearing ring or an outer-cylinder wearing ring according to  claim 1 , which is used in a pair of wearing rings in which a metal wearing ring is used as an opposed wearing ring.  
     
     
         8 . An inner-cylinder wearing ring or an outer-cylinder wearing ring according to  claim 1 , in which the carbon fiber reinforced plastic is fabricated of continuous carbon filaments whose tensile modulus is in the range of 49 Gpa to 950 GPa.  
     
     
         9 . An inner-cylinder wearing ring or an outer-cylinder wearing ring according to  claim 1 , which is used in a pump provided with an impeller having an impeller wearing ring and a pump casing having a case wearing ring.  
     
     
         10 . An inner-cylinder wearing ring according to  claim 1 .  
     
     
         11 . An inner-cylinder wearing ring according to  claim 1 , which is used in a pair of wearing rings in which a metal wearing ring is used as an opposed wearing ring.  
     
     
         12 . A pump having the inner-cylinder wearing ring or the outer-cylinder wearing ring according to  claim 9 .  
     
     
         13 . A pump having the inner-cylinder wearing ring according to  claim 9.