SCREW GEROTOR HYDRAULIC MACHINE Russian patent published in 2010 - IPC E21B4/02 

FIELD: oil and gas industry.

SUBSTANCE: screw gerotor hydraulic machine includes stator with internal spiral teeth and rotor with external spiral teeth, the number of which is less by a unit than the number of stator teeth. Rotor axis is offset relative to stator axis by the eccentricity value equal to the half of radial height of the teeth; profiles of external teeth of rotor and internal teeth of stator in the end section are mutually enveloped. Travels of spiral teeth of rotor and stator are proportional to their numbers of teeth. Stator includes hollow housing, tubular cover with internal and external spiral teeth, which is located inside hollow housing; at that, internal spiral teeth of tubular cover are attached to lining from elastomer, which is equal as to thickness. External surface of tubular cover of stator with external spiral teeth and internal surface of hollow housing of stator have irregularities with depth or height of at least 0.1 mm; at that, irregularities are enveloped with an alloy filling in the space between internal surface of hollow housing of stator and external surface of tubular cover of stator with external spiral teeth. Alloy has fusion point which is 0.05-0.95 of fusion point of the material of stator hollow housing, e.g. alloy on the basis of stannum, zinc, aluminium or copper. Service life and reliability of screw gerotor hydraulic machine when in operation is improved. Manufacturing procedure is simplified.

EFFECT: increasing operating torque and efficiency of screw gerotor hydraulic machine.

8 cl, 13 dwg