MULTISTAGE PUMP Russian patent published in 1997 - IPC

FIELD: oil producing industry. SUBSTANCE: pump working wheel has shape of trapezium in longitudinal section, side of which, pointed to output, is located at acute angle relative to axis of rotation and gets with clearance into guide vane assembly provided with conical cavity accommodating output holes of screw channels over conical surface of cavity. Shaft is hollow. Shaft space communicates through radial channels with working channels of pump stages and with input and output channels. End portion of shaft with axial support is provided with outer conical surface, and it forms together with housing, a diffuser at pump output. EFFECT: enlarged operating capabilities. 4 cl, 5 dwg