US 5,378,121 A · Pump with fluid bearing

Abstract

A pump including a submersible motor sealed within a motor chamber, an impeller rotatably mounted in an impeller chamber, and motor and impeller shafts coupled to one another to interconnect the motor and impeller. The impeller pumps fluid from the impeller chamber into the motor chamber where the fluid flows around the motor to cool the motor and muffle the motor noise before being discharged from the pump. The impeller shaft is rotatably mounted in a bearing fixed to the impeller housing and having grooves facing the shaft and providing fluid communication between the impeller and motor chambers. Fluid flows into the grooves from the impeller or motor chamber depending on the pressure gradient across the bearing, which varies according to downstream pump conditions (e.g., pressure). As the impeller shaft continues to rotate, fluid from the grooves forms a thin lubricating film in the clearance space provided between the impeller shaft and bearing. With this construction, the need for conventional impeller shaft seals is eliminated.

Claims18

Dependent claims

A pump comprising:

a tubular shell that defines a motor chamber;
a motor disposed in said motor chamber and spaced from said shell such that a channel is formed therebetween, said motor having an output shaft;
an impeller housing coupled to said shell, said impeller housing having a cavity and a passageway formed therein, said passageway having an inlet in fluid communication with said cavity and an outlet in fluid communication with said channel;
an impeller disposed in said cavity;
an impeller shaft having a first portion coupled to said impeller and a second portion coupled to said output shaft;
and
a bearing coupled to said impeller housing, said bearing having an inner circumferential surface defining an opening through which said impeller shaft extends, said surface having a groove formed therein that extends between and fluidly couples said cavity and motor chamber.

4 more elements

A pump comprising:

an impeller housing having a cavity and a passageway formed therein, said passageway having an inlet port in fluid communication with said cavity and an outlet port;
an impeller positioned in said cavity;
a motor having an output shaft extending from one end thereof and a tubular outer casing;
an impeller shaft having first and second portions, said first portion being coupled to said impeller and said second portion being coupled to said output shaft of the motor;
a bracket having first and second end portions, said first bracket end portion being coupled to said impeller housing and said second bracket end portion being coupled to said motor casing, said bracket having an opening formed therethrough between said first and second bracket end portions;
a tubular motor cover having a first end portion extending from said impeller housing and a second end portion, said motor cover being spaced radially outward from said bracket and motor casing such that a first channel is formed between said motor cover and said bracket and casing, said first channel being in fluid communication with said passageway outlet port and bracket opening;
and
a bearing disposed in said impeller housing, said bearing rotatably supporting said impeller shaft and having a groove that forms a second channel with said impeller shaft, said second channel having an inlet in fluid communication with said first channel through said bracket opening and an outlet in fluid communication with the impeller housing cavity.

5 more elements

Dependencies are inferred from the claim text.

Pump with fluid bearing

Life of this patent

Pump with fluid bearing

Life of this patent

Abstract

Claims18