US 5,174,250 A · Dual seal pump

Abstract

Pressurizing an intermediate fluid chamber of a pump housing is useful to substantially eliminate fluid loss across the seal faces in the pump housing. The subject dual seal pump has a spring-loaded diaphragm in an intermediate fluid chamber of the pump housing separating the intermediate fluid chamber into primary and secondary compartments. A fluid chamber in the pump housing is in fluid communication with the primary compartment of the intermediate fluid chamber. A fluid connecting means, including a conduit, an annulus, a pair of passages, and a recess communicate fluid into the primary compartment of the intermediate fluid chamber. The secondary compartment of the intermediate fluid chamber contains a non-corrosive fluid which is pressurized accordingly by the spring-loaded diaphragm. The result is a higher pressure in the second compartment of the intermediate fluid chamber which substantially eliminates fluid loss across the seal. A small pressure difference between the intermediate fluid chamber and an atmospheric pressure chamber may allow a minute amount of fluid leakage across the seal. However, the buffer fluid contained in the intermediate fluid chamber has no corrosion inhibitors to score the seal face, thus, a longer seal life is obtained.

Claims29

Dependent claims

A fluid circulating pump having a housing rotatably mounting a shaft adapted for use in an internal combustion engine, comprising:

a first fluid chamber defined by the housing;
a second fluid chamber defined by the housing and being located adjacent the first fluid chamber;
means for separating the first fluid chamber into primary and secondary compartments;
a pair of seal assemblies disposed in the housing in sealing engagement with the shaft and operatively associated with the first fluid chamber with one of the seals sealingly separating the second fluid chamber from the secondary compartment of the first fluid chamber;
and
means for fluidly connecting the primary compartment of the first fluid chamber and the second fluid chamber.

3 more elements

Dependencies are inferred from the claim text.

Dual seal pump

Life of this patent

Dual seal pump

Life of this patent

Abstract

Claims29