A device for conveying a liquid, in particular a cutting liquid from a machining operation containing production residues. The device includes a vertical pump having a pump housing (14), a pump impeller (13), a drive shaft (19) surrounded by a housing (18), an electric motor, and a shaft connection between the electric motor and the pump impeller (13). The pump housing (14) has an inlet opening (15) and a liquid delivery opening (16). When the pump is started, a negative pressure is generated in the housing (18) surrounding the drive shaft (19). The zone of negative pressure extends into the pump housing (14) through a gap (22) between the shaft (19) and the housing (18) and thus assures that fluid will be drawn into the pump even when the liquid level is extremely low.

 
Web www.patentalert.com

> Apparatus for preventing vacuum state in scroll compressor

~ 00320