CENTRIFUGAL PUMP Russian patent published in 1998 - IPC

FIELD: mechanical engineering; pumps. SUBSTANCE: impeller 1 with hub 3 is rigidly installed on shaft 4. Edges of impeller 1 at side of drive are arranged with small clearance "a" relative to rear wall 5 of pump housing. Wall 5 forms labyrinth clearance 6 with impeller 1. Labyrinth clearance 6 connects pumping chamber 2 with hub chamber 7. Coaxial impeller rigidly connected with impeller 1 is arranged in chamber 7. Coaxial impeller serves to increase rotary motion of liquid in chamber 7 and to eject liquid. Chamber 7 has peripheral hole 12 to let liquid out. Air accumulating in zone of shaft 4 comes out through clearance 10 formed by wall 20 of hub body and shaft 4. Hole 12 is located in wall 20 of hub body and is made in form of pressure nozzle. It ends in chamber 11 adjoining chamber 7 and connected with the latter with clearance 10 and is directed towards diffuser pipe 13 forming jet pump 12, 13 through which liquid, coming out of chamber 7, flows. EFFECT: improved separation of gas and liquid in pump. 3 cl, 2 dwg