ROTARY PUMP Russian patent published in 2003 - IPC

FIELD: mechanical engineering; rotary machines. SUBSTANCE: invention relates to pumps and compressors. Pump has housing with inlet and outlet holes, driving and driven rotors mounted on shafts inside housing, shafts being coupled by synchronizing gears and provided with identical teeth with curvilinear side surfaces made to elongated epicycloids and with external cylindrical surface with radius R. Each surface of rotors arranged between surfaces of elongated epicycloids is made in form of convex cylindrical surface with radius r=0.414 R. Distance between axes of rotor shafts is equal to sum of said radii, edges in places of mating of outer cylindrical surface with surfaces of elongated epicycloids are rounded off to radius r₁ = 0,4-1,2 mm, length of all cylindrical surfaces being smaller than one fourth of generatrices of their circumferences by value of edge rounding off. Two crescent-shaped recesses are made either in one of housing walls or in both walls, perpendicular to rotor shafts at inner side. Recesses are arranged symmetrically relative to axis passing through centers of shafts, being pointed by their concave parts towards each other. EFFECT: provision of reliable operation at no cavitation. 6 cl, 5 dwg