Rotary Displacement Pump for Pumping Flowable Viscous Materials

Abstract

A rotary displacement pump ( 2 ) according to the present invention is for pumping flowable viscous materials and comprises a liner ( 26, 36 ); a rotor ( 28 ) configured to be driven by a shaft ( 8 ); said rotor ( 28 ) including a shaft portion ( 30 ) and a radially protruding web ( 32 ) having a configuration of an undulatory disk type; a scraper gate ( 38 ) having an engagement slot of predetermined radial height and predetermined axial width, said engagement slot engaging said protruding web ( 32 ) of said rotor ( 28 ); said scraper gate ( 38 ) being supported by a scraper gate guide ( 40 ) so as to be retained in circumferential direction and to allow a reciprocating movement in a substantially axial direction; a pump housing ( 14 ) comprising a front end part ( 52 ) and a rear end part, said pump housing ( 14 ) enclosing said liner ( 26, 36 ), said rotor ( 28 ), said scraper gate ( 38 ) and said scraper gate guide ( 40 ), said shaft ( 8 ) extending through said rear end part of said pump housing ( 14 ); said liner ( 26, 36 ) including a first liner element ( 26 ) and a second liner element ( 36 ), said first and second liner elements ( 26, 36 ) abutting to each other laterally along a radially outer abutment portion so as to form a liner channel through which said radially protruding web ( 32 ) of said rotor ( 28 ) runs and to define an enclosure that encircles a portion of said radially protruding web ( 32 ) of said rotor ( 28 ); an inlet chamber and an outlet chamber being defined by said liner ( 26, 36 ), said scraper gate ( 38 ) and said scraper gate guide ( 40 ) or by said liner, said pump housing, said scraper gate and said scraper gate guide; said scraper gate ( 38 ) together with said scraper gate guide ( 40 ) forming a partition between said inlet chamber and said outlet chamber; said inlet and outlet chambers being provided with respective inlet and outlet ports ( 16, 18 ); said liner channel extending from said inlet chamber to said outlet chamber; said web ( 32 ) of said rotor ( 28 ) being rotatable through said inlet chamber, said liner channel, said outlet chamber and said slot of said scraper gate ( 38 ); wherein said scraper gate ( 38 ) and/or said liner ( 26, 36 ) consists of 85 to 95 Vol-% of a Polyethylene basis material having a high molecular weight of 0.6*10 6 g/mol to 1.4*10 6 g/mol, particularly of 0.8*10 6 g/mol to 1.2*10 6 g/mol, and more particularly of around 1.0*10 6 g/mol, and 15 to 5 Vol-% of glass particles having a spherical or oval shape distributed within said Polyethylene basis material, such that the surface of said scraper gate ( 38 ) and/or said liner ( 26, 36 ) comprising rounded surface portions formed by such glass particles constitutes a hard slide face for the flowable viscous materials to be pumped.

1 . A rotary displacement pump ( 2 ;  62 ) for pumping flowable viscous materials, said rotary displacement pump comprising:
 a liner ( 26 ,  36 ;  70 ,  80 );   a rotor ( 28 ) configured to be driven by a shaft ( 8 );   said rotor ( 28 ) including a shaft portion ( 30 ) and a radially protruding web ( 32 ) having a configuration of an undulatory disk type;   a scraper gate ( 38 ;  82 ) having an engagement slot of predetermined radial height and predetermined axial width, said engagement slot engaging said protruding web ( 32 ) of said rotor ( 28 );   said scraper gate ( 38 ;  82 ) being supported by a scraper gate guide ( 40 ;  84 ) so as to be retained in circumferential direction and to allow a reciprocating movement in a substantially axial direction;   a pump housing ( 14 ) comprising a front end part ( 52 ) and a rear end part, said pump housing ( 14 ) enclosing said liner ( 26 ,  36 ;  70 ,  80 ), said rotor ( 28 ), said scraper gate ( 38 ;  82 ) and said scraper gate guide ( 40 ;  84 ), said shaft ( 8 ) extending through said rear end part of said pump housing ( 14 );   said liner ( 26 ,  36 ;  70 ,  80 ) including a first liner element ( 26 ;  70 ) and a second liner element ( 36 ;  80 ), said first and second liner elements ( 26 ,  36 ;  70 ,  80 ) abutting to each other laterally along a radially outer abutment portion so as to form a liner channel through which said radially protruding web ( 32 ) of said rotor ( 28 ) runs and to define an enclosure that encircles a portion of said radially protruding web ( 32 ) of said rotor ( 28 );   an inlet chamber and an outlet chamber being defined by said liner ( 26 ,  36 ), said scraper gate ( 38 ) and said scraper gate guide ( 40 ) or by said liner ( 70 ,  80 ), said pump housing ( 14 ), said scraper gate ( 82 ) and said scraper gate guide ( 84 );   said scraper gate ( 38 ;  82 ) together with said scraper gate guide ( 40 ;  84 ) forming a partition between said inlet chamber and said outlet chamber;   said inlet and outlet chambers being provided with respective inlet and outlet ports ( 16 ,  18 );   said liner channel extending from said inlet chamber to said outlet chamber;   said web ( 32 ) of said rotor ( 28 ) being rotatable through said inlet chamber, said liner channel, said outlet chamber and said slot of said scraper gate ( 38 ;  82 );   characterized in that   said scraper gate ( 38 ;  82 ) and/or said liner ( 26 ,  36 ) consists of 85 to 95 Vol-% of a Polyethylene basis material of high molecular weight and 15 to 5 Vol-% of glass particles of spherical or oval shape distributed within said Polyethylene basis material, such that the surface of said scraper gate ( 38 ;  82 ) and/or said liner ( 26 ,  36 ;  70 ,  80 ) comprising rounded surface portions formed by glass particles that protrude out constitutes a hard slide face for the flowable viscous materials to be pumped.   
     
     
         2 . The rotary displacement pump ( 2 ) of  claim 1 , further comprising a ring-formed front sliding insert ( 41 ) arranged in axial direction between said shaft portion ( 30 ) of said rotor ( 28 ) and a front shaft sleeve/bearing element ( 42 ) being secured to the front end portion of said shaft ( 8 ). 
     
     
         3 . The rotary displacement pump ( 2 ) of  claim 2 , wherein the front shaft sleeve/bearing element ( 42 ) has an annular groove in its rear side facing said shaft portion ( 30 ) of said rotor ( 28 ), said ring-formed front sliding insert ( 41 ) being placed with an anchoring portion thereof in such annular groove. 
     
     
         4 . The rotary displacement pump ( 2 ) of  claim 1 , further comprising a ring-formed rear sliding insert ( 24 ) arranged in axial direction between a rear shaft sleeve sealing element ( 22 ) being secured to said shaft ( 8 ) and said shaft portion ( 30 ) of said rotor ( 28 ). 
     
     
         5 . The rotary displacement pump ( 2 ) of  claim 4 , wherein the rear shaft sleeve sealing element ( 22 ) has an annular groove in its front side facing said shaft portion ( 30 ) of said rotor ( 28 ), said ring-formed rear sliding insert ( 24 ) having a substantially rectangular cross-section or a T-shaped cross-section being placed with an anchoring portion thereof in such annular groove. 
     
     
         6 . The rotary displacement pump ( 2 ) of  claim 2 , wherein at least one of the front and rear sliding inserts ( 24 ,  41 ) has a T-shape with an anchoring portion being placed in the respective annular groove and with an abutment portion abutting against the respective shaft portion ( 30 ) of said rotor ( 28 ). 
     
     
         7 . The rotary displacement pump ( 2 ) of  claim 2 , wherein at least one element of the front sliding insert ( 24 ), the rear sliding insert ( 24 ,  41 ) and the front shaft sleeve/bearing element ( 42 ) consists of 85 to 95 Vol-% of a Polyethylene basis material of high molecular weight and 15 to 5 Vol-% of glass particles having a spherical or oval shape evenly distributed within said Polyethylene basis material, such that surface of said sliding insert ( 24 ,  41 ) comprising said Polyethylene basis material and glass particles protruding out of the same forms a rounded and hard slide face for the flowable viscous materials to be pumped. 
     
     
         8 . The rotary displacement pump ( 2 ;  62 ) of  claim 1 , wherein the diameter of said glass particles is 10-40 μm, particularly 20-30 μm, and more particularly around 24 μm. 
     
     
         9 . (canceled) 
     
     
         10 . The rotary displacement pump ( 2 ) of  claim 1 , wherein the first liner element ( 26 ) and the second liner element ( 36 ) are generally semi-circular arc-formed. 
     
     
         11 . The rotary displacement pump ( 2 ) of  claim 10 , wherein the enclosure that encircles a portion of said radially protruding web ( 32 ) of said rotor ( 28 ) is generally semi-circular arc-formed. 
     
     
         12 . The rotary displacement pump ( 62 ) of  claim 1 , wherein the first liner element ( 70 ) and the second liner element ( 80 ) are generally cup shaped and define a circumferential wall. 
     
     
         13 . The rotary displacement pump ( 62 ) of  claim 12 , wherein said scraper gate ( 82 ) and/or said scraper gate guide ( 84 ) are completely arranged within said liner ( 70 ,  80 ). 
     
     
         14 . The rotary displacement pump of  claim 13 , wherein said scraper gate guide ( 84 ) is supported by said liner ( 70 ,  80 ). 
     
     
         15 . The rotary displacement pump of  claim 12 , wherein said scraper gate guide ( 84 ) is supported by said liner ( 70 ,  80 ).