초록

Longer shaft seal life in centrifugal pumps is realized by returning liquid from the pressure side of the pump to the seal area via a passage formed in a rib of the housing wall, and without porting the impeller, so that pump efficiency is kept high and its self-priming ability is retained.

대표청구항 ▼

In a centrifugal pump comprising a housing having a wall defining an axial inlet, a peripheral outlet for liquid to be pumped, and a cavity therebetween, a straight rib extending to said wall outside of said housing and parallel to said axial inlet, an impeller rotably mounted within the housing cav

In a centrifugal pump comprising a housing having a wall defining an axial inlet, a peripheral outlet for liquid to be pumped, and a cavity therebetween, a straight rib extending to said wall outside of said housing and parallel to said axial inlet, an impeller rotably mounted within the housing cavity on a motor-driven shaft for pumping liquid between said inlet and said outlet, said shaft extending through the housing wall, and frictional seal means between said housing wall and said shaft, said seal means tending prematurely to fail from the presence of excess heat during pump operation, said imperller defining with said housing a low pressure chamber adjacent said seal means and a high pressure chamber adjacent said outlet, the improvement comprising a passage formed entriely within said housing rib, said passage communicating said high pressure chamber from a point outward beyond the periphery of said impeller along a straight line path with said low pressure chamber, whereby liquid from said high pressure chamber is directed into said low pressure chamber directly onto said seal means along a continuation of said straight line path beyond said passage to remove excess heat from said seal means and reduce premature seal means failures thereby.