GB750856A - Improvements in rotary pumps - Google Patents

Abstract

750,856. Rotary pumps. CREAMERY PACKAGE, MFG. CO. March 26, 1954 [May 29, 1953], No. 8917/54. Class 110(2) A single or multi-stage rotary pump having one or more rotors has shaft sealing means to prevent the ingress of deleterious substances and the fluid being pumped is utilized for lubricating and sealing. A pump of the gear wheel or Rootes-blower type is described in which the intermeshing gear wheels 14, 15 have their peripheries enclosed in a plastic material preferably rubber or latex material and are splined on to shafts 18, 24, the shaft 18 driving the shaft 24 through gears 22, 23 enclosed in a compartment 13 which contains a lubricant and has a drain plug 28a and an air vent 27. Formed on each face of the gear wheels 14, 15 from the plastic material covering is a rim 34b which contacts the surface 35 or 36 of the pump casing and encloses a cavity 43. Grooves 38, 40 formed in the surfaces 35, 36, respectively, place the cavity 43 in communication with the discharge side of the pump. On the shafts 18, 24 are mounted V-shaped crosssection sealing rings 45 contained in annular recesses 44 in the surface 36. The fluid under discharge pressure in cavities 43 acts on the rings 45 causing them to spread out and form a more efficient seal. In a modification ribs may be formed on the surfaces 35, 36 enclosing the cavities 43 similar to but in place of the rims 34b.