Patent ID: 8998586
Filing Date: 2015-04-07
Classification: F04D

Abstract:
1. A self-priming pump assembly, comprising: a motor having a motor housing; a main pump having a main pump impeller; a drive shaft having a rotation axis, the drive shaft extending between the motor and the main pump impeller, the drive shaft directly driving the main pump impeller from the motor; a vacuum pump, separate from the main pump, having a vacuum pump impeller rotatably disposed in a vacuum pump housing along a rotation axis, the vacuum pump impeller situated between the main pump and the motor, and the vacuum pump impeller being coupled to the drive shaft and rotating about the rotation axis of the drive shaft; a first bearing supporting the drive shaft between the motor and the vacuum pump impeller; a second bearing supporting the drive shaft between the vacuum pump impeller and the main pump impeller; a first seal physically engaging and providing a seal about the drive shaft, the first seal positioned adjacent a first side of the vacuum pump impeller; a first seal chamber holding a liquid bath to lubricate the first seal; a second seal physically engaging and providing a seal about the drive shaft, the second seal positioned adjacent a second side of the vacuum pump impeller opposite the first side; a second seal chamber holding a liquid bath to lubricate the second seal; a third seal physically engaging and providing a seal about the drive shaft, the third seal positioned between the main pump impeller and the vacuum pump; and a third seal chamber holding a liquid bath to lubricate the third seal.