BORE-HOLE PUMP AND METHOD FOR ITS PROTECTION

摘要

A motor pump set having two coaxial shafts is provided with a fluid circuit for protecting the rotary packing-gland against any ingress of solid particles such as sand. Pumped fluid is withdrawn from an intermediate space of the pump and returned upstream via a duct within the pump shaft in order to lubricate the bearings as it passes. The fraction of the fluid stream which is discharged from the last bearing flows in the vicinity of the packing-gland and is driven through radial discharge ducts under the action of centrifugal force.