Rotary pump

Abstract

A rotary pump includes: a pump rotor having a flat rotor side surface facing in an axial direction; a housing body having an opening in the axial direction and a flat flange surface formed around the opening, the housing body rotatably housing the pump rotor in the opening such that the rotor side surface is flush with the flange surface; and a cover member having a flat mating surface that is fixed while being pressed against the flange surface by fastening of a bolt, and a flat sliding/guiding surface that slides and guides the rotor side surface. The cover member is formed of a crosslinked fluororesin and a metal body. The metal body is provided with the mating surface, and a recess obtained by recessing an area corresponding to the sliding/guiding surface, in the axial direction with respect to the mating surface.

1 . A rotary pump comprising:
 a pump rotor having a flat rotor side surface facing in an axial direction;   a housing body having an opening in the axial direction and a flat flange surface formed around the opening, the housing body rotatably housing the pump rotor in the opening such that the rotor side surface is flush with the flange surface; and   a cover member having a flat mating surface that is fixed while being pressed against the flange surface by fastening of a bolt, and a flat sliding/guiding surface that slides and guides the rotor side surface, wherein   the cover member is formed of a crosslinked fluororesin and a metal body,   the metal body is provided with the mating surface, and a recess obtained by recessing an area corresponding to the sliding/guiding surface, in the axial direction with respect to the mating surface, and   the crosslinked fluororesin is filled in the recess so as to form the sliding/guiding surface flush with the mating surface.   
     
     
         2 . The rotary pump according to  claim 1 , wherein
 the cover member is a plate-shaped side cover that is fixed by being sandwiched between the housing body and a cover body disposed so as to oppose the flange surface of the housing body.   
     
     
         3 . The rotary pump according to  claim 1 , wherein
 the recess has a shape obtained by recessing, in the axial direction, also an area corresponding to a part of the mating surface such that the crosslinked fluororesin filled in the recess is in contact with the flange surface in an annular area contiguous, without a break, around the opening.   
     
     
         4 - 6 . (canceled) 
     
     
         7 . The rotary pump according to  claim 2 , wherein
 the recess has a shape obtained by recessing, in the axial direction, also an area corresponding to a part of the mating surface such that the crosslinked fluororesin filled in the recess is in contact with the flange surface in an annular area contiguous, without a break, around the opening.   
     
     
         8 . The rotary pump according to  claim 2 , wherein
 the mating surface and the sliding/guiding surface are a contiguous machined surface having a surface roughness not greater than a ten-point average roughness Rz JIS  of 6.3 μm.   
     
     
         9 . The rotary pump according to  claim 3 , wherein
 the mating surface and the sliding/guiding surface are a contiguous machined surface having a surface roughness not greater than a ten-point average roughness Rz JIS  of 6.3 μm.   
     
     
         10 . The rotary pump according to  claim 7 , wherein
 the mating surface and the sliding/guiding surface are a contiguous machined surface having a surface roughness not greater than a ten-point average roughness Rz JIS  of 6.3 μm.   
     
     
         11 . The rotary pump according to  claim 2 , wherein
 the pump rotor comprises: an inner rotor having, at an outer periphery thereof, a plurality of outer teeth; and an annular outer rotor supported to be rotatable around a position eccentric from a center of the inner rotor, the outer rotor having, at an inner periphery thereof, a plurality of inner teeth meshing with the outer teeth.   
     
     
         12 . The rotary pump according to  claim 3 , wherein
 the pump rotor comprises: an inner rotor having, at an outer periphery thereof, a plurality of outer teeth; and an annular outer rotor supported to be rotatable around a position eccentric from a center of the inner rotor, the outer rotor haying, at an inner periphery thereof, a plurality of inner teeth meshing with the outer teeth.   
     
     
         13 . The rotary pump according to  claim 7 , wherein
 the pump rotor comprises: an inner rotor having, at an outer periphery thereof, a plurality of outer teeth; and an annular outer rotor supported to be rotatable around a position eccentric from a center of the inner rotor, the outer rotor having, at an inner periphery thereof, a plurality of inner teeth meshing with the outer teeth.   
     
     
         14 . The rotary pump according to  claim 8 , wherein
 the pump rotor comprises: an inner rotor having, at an outer periphery thereof, a plurality of outer teeth; and an annular outer rotor supported to be rotatable around a position eccentric from a center of the inner rotor, the outer rotor having, at an inner periphery thereof, a plurality of inner teeth meshing with the outer teeth.   
     
     
         15 . The rotary pump according to  claim 2 , wherein
 the pump rotor comprises: a rotor body having, at an outer periphery thereof, a plurality of vane-containing grooves; and a plurality of vanes contained in the respective vane-containing grooves so as to be slidable in a radial direction.   
     
     
         16 . The rotary pump according to  claim 3 , wherein
 the pump rotor comprises: a rotor body having, at an outer periphery thereof, a plurality of vane-containing grooves; and a plurality of vanes contained in the respective vane-containing grooves so as to be slidable in a radial direction.   
     
     
         17 . The rotary pump according to  claim 7 , wherein
 the pump rotor comprises: a rotor body having, at an outer periphery thereof, a plurality of vane-containing grooves; and a plurality of vanes contained in the respective vane-containing grooves so as to be slidable in a radial direction.   
     
     
         18 . The rotary pump according to  claim 8 , wherein
 the pump rotor comprises: a rotor body having, at an outer periphery thereof, a plurality of vane-containing grooves; and a plurality of vanes contained in the respective vane-containing grooves so as to be slidable in a radial direction.   
     
     
         19 . (canceled) 
     
     
         20 . The rotary pump according to  claim 1 , wherein
 the mating surface and the sliding/guiding surface are a contiguous machined surface having a surface roughness not greater than a ten-point average roughness Rz JIS  of 6.3 μm.   
     
     
         21 . The rotary pump according to  claim 1 , wherein
 the pump rotor comprises: an inner rotor having, at an outer periphery thereof, a plurality of outer teeth; and an annular outer rotor supported to be rotatable around a position eccentric from a center of the inner rotor, the outer rotor having, at an inner periphery thereof, a plurality of inner teeth meshing with the outer teeth.   
     
     
         22 . The rotary pump according to  claim 1 , wherein
 the pump rotor comprises: a rotor body having, at an outer periphery thereof, a plurality of vane-containing grooves; and a plurality of vanes contained in the respective vane-containing grooves so as to be slidable in a radial direction.