Pump with automatic prime device

Claim 2

A submerged pump and electric motor unit especially adapted for aircraft fuel tanks which comprises a housing having a mounting flange at one end thereof for attachment to the sidewall of a fuel tank and having an inlet flange on the other end thereof for attachment to an inlet pipe in the fuel tank, said housing defining a centrifugal pump volute chamber adjacent the inlet pipe mounting flange, a casing in said housing having an open end adjacent the mounting flange, and end cap attached to the housing closing the open end of the casing and providing a shaft bearing support, a motor in the casing adjacent said cap, a motor shaft having one end supported from said cap, said casing providing a piston chamber, a hydroturbine pump chamber, a bearing chamber, and a pump inlet chamber communicating with the volute chamber of the housing, said motor shaft extending through said chambers, a centrifugal impeller in said pump inlet chamber mounted on said motor shaft, thrust bearings in said bearing chamber surrounding said shaft, a hydroturbine pump rotor in said hydroturbine pump chamber, a clutch connecting said rotor with said motor shaft, a piston in said piston chamber, a spring biasing said piston for loading said clutch to couple the motor shaft with the hydroturbine rotor, passageways connecting the volute chamber with the cylinder chamber to act on said piston against the bias of said spring for declutching the hydroturbine rotor from the motor shaft, passageways connecting the pump inlet chamber with the hydroturbine pump chamber, and an outlet in said housing vented to said hydroturbine pump chamber for releasing gases and vapors from the hydroturbine pump back to the fuel tank whereby said hydroturbine pump will draw gases and vapors from the pump inlet chamber and will remain operative only when pressure in the volute chamber is insufficient to overcome the spring bias on the clutch.

Claim 3

A submerged gas-expelling centrifugal pump and motor unit adapted for aircraft fuel tank installation which comprises a housing having a first end flange for mounting the unit in a tank, a second opposite end flange for mounting an inlet pipe in the tank and a volute portion with a tangential outlet terminating in a side flange between said first and second flanges for mounting an outlet pipe, an electric motor in said housing adjacent said first end flange, a centrifugal pump impeller in said housing adjacent said second end flange and discharging into said volute portion, a liquid ring priming pump in said housing between said electric motor and said centrifugal pump impeller, a clutch selectively coupling the liquid ring pump with said motor, means venting the central portion of the area of the housing containing the centrifugal pump impeller with said liquid ring pump to draw gases and vapor from said portion into the liquid ring pump, said housing having a dischaRge passage from the liquid ring pump to an outlet for feeding the gases and vapors back to the tank in which the housing is mounted, and means actuated by pressure in the volute portion for releasing said clutch whenever liquid is being pumped by said impeller through the volute portion whereby said liquid ring pump will only be driven by said motor when the centrifugal pump loses it prime.

Claim 4

A submerged gas-expelling centrifugal pump and motor unit adapted for aircraft fuel tank installation which comprises a housing having a first end flange for mounting the unit in a tank, a second opposite end flange for mounting an inlet pipe in the tank and a volute portion with a tangential outlet terminating in a side flange between said first and second flanges for mounting an outlet pipe, an electric motor in said housing adjacent said first end flange, a centrifugal pump impeller in said housing adjacent said second end flange and discharging into said volute portion, a liquid ring priming pump in said housing between said electric motor and said centrifugal pump impeller, a clutch selectively coupling the liquid ring pump with said motor, means venting the central portion of the area of the housing containing the centrifugal pump impeller with said liquid ring pump to draw gases and vapor from said portion into the liquid ring pump, said housing having a dischaRge passage from the liquid ring pump to an outlet for feeding the gases and vapors back to the tank in which the housing is mounted, and means actuated by pressure in the volute portion for releasing said clutch whenever liquid is being pumped by said impeller through the volute portion whereby said liquid ring pump will only be driven by said motor when the centrifugal pump loses it prime.

Claim 5

The pump of claim 2 including a stack of clutch places coupling the liquid ring pump to the motor and a spring-biased piston loading said stack and actuated by centrifugal pump pressure against the spring bias for unloading said stack.

Claim 6

An electric motor-driven centrifugal pump unit which comprises a casing housing an electric motor, a centrifugal pump, and a liquid ring priming pump having an inlet and an outlet in the casing, means in the casing venting the centrifugal pump to the priming pump inlet for drawing gases and vapors from the centrifugal pump, means in the casing venting liquid from the priming pump outlet back to the priming pump inlet to prime the priming pump, an outlet in said casing for gases and vapors expelled from said priming pump, and clutch actuated by pressure from the centrifugal pump for disconnecting the priming pump from the electric motor upon development of a predetermined pressure by said centrifugal pump whereby the priming pump will be actuated only when the centrifugal pump loses its prime.

Claim 7

An electric motor-driven centrifugal pump unit which comprises a casing housing an electric motor, a centrifugal pump, and a liquid ring priming pump having an inlet and an outlet in the casing, means in the casing venting the centrifugal pump to the priming pump inlet for drawing gases and vapors from the centrifugal pump, means in the casing venting liquid from the priming pump outlet back to the priming pump inlet to prime the priming pump, an outlet in said casing for gases and vapors expelled from said priming pump, and clutch actuated by pressure from the centrifugal pump for disconnecting the priming pump from the electric motor upon development of a predetermined pressure by said centrifugal pump whereby the priming pump will be actuated only when the centrifugal pump loses its prime.

Claim 8

The pump of claim 4 including a clutch composed of a stack of alternating driving and driven discs.

Claim 9

The combination of claim 4 wherein a liquid-collecting reservoir is provided between the centrifugal pump and the priming pump for maintaining liquid in the priming pump.

Claim 10

In combination a centrifugal pump having a pumping chamber discharging into a surrounding volute, a liquid ring priming pump having an inlet vented to said pumping chamber and effective to draw gases and vapors therefrom and an outlet communicating with said inlet, a vent for releasing gases and vapors from said outlet, a drive shaft, a centrifugal impeller in said pumping chamber driven by said shaft, a priming pump rotor receiving said shaft therethrough, a stack of alternating discs coupled to said shaft and to said priming pump rotor, means loading said stack to cause the discs coupled to the shaft to drive the discs coupled to the rotor, and means sensitive to pressure in the volute chamber for unloading said stack to declutch the priming pump rotor whenever the centrifugal pump is operating under primed conditions.

Claim 11

In combination a centrifugal pump having a pumping chamber discharging into a surrounding volute, a liquid ring priming pump having an inlet vented to said pumping chamber and effective to draw gases and vapors therefrom and an outlet communicating with said inlet, a vent for releasing gases and vapors from said outlet, a drive shaft, a centrifugal impeller in said pumping chamber driven by said shaft, a priming pump rotor receiving said shaft therethrough, a stack of alternating discs coupled to said shaft and to said priming pump rotor, means loading said stack to cause the discs coupled to the shaft to drive the discs coupled to the rotor, and means sensitive to pressure in the volute chamber for unloading said stack to declutch the priming pump rotor whenever the centrifugal pump is operating under primed conditions.

Claim 12

The combination of claim 7 wherein the driving discs of the clutch are internally keyed to the shaft and wherein the driven discs of the clutch are externally keyed to the priming pump rotor.

Claim 13

The combination of claim 7 including a liquid reservoir between the centrifugal pump chamber and the priming pump for maintaining liquid in the priming pump.

Claim 14

The combination of claim 7 wherein the priming pump is a hydroturbine pump and a reservoir is provided for supplying liquid to the hydroturbine pump to maintain a liquid ring therein.

Claim 15

A gas-expelling centrifugal pump and liquid ring priming pump said pump inlet connecting for aircraft fuel tank installation which comprises a housing providing a central inlet, a surrounding volute chamber, a liquid ring pump chamber behind the inlet chamber, a clutch chamber behind the liquid ring pump chamber, and an electric motor chamber behind the clutch chamber, a centrifugal pump impeller in said pump inlet having a ring of vanes discharging centrifugally into the volute chamber, an electric motor in said motor chamber having a shaft extending through the clutch and liquid ring pump chambers into the pump inlet, means mounting the centrifugal pump impeller on said shaft in said pump inlet, ports in the central portion of said pump inlet connecting the central portion of the pump impeller inwardly from the pumping vanes thereon with the liquid ring pump chamber, a liquid ring pump impeller in said liquid riNg pump chamber receiving gases and vapors from said ports, a clutch in said clutch chamber connecting said liquid ring pump impeller with said shaft, means actuated by pressure in said volute chamber declutching said liquid ring pump impeller from said shaft, said housing having a chamber surrounding said liquid ring pump communicating with the inlet and outlet of said liquid ring pump whereby liquid discharged from the ring pump may flow to the inlet of the liquid ring pump for priming the pump, and said housing having a gas and vapor outlet communicating with said chamber surrounding the liquid ring pump chamber for releasing gases and vapors from liquid discharged by the liquid ring pump whereby gases and vapors will be drawn from the centrifugal pump inlet by said liquid ring pump to prevent the centrifugal pump impeller from becoming gas bound, the liquid ring pump will be primed liquid as needed from liquid discharged therefrom and the clutch will couple the liquid ring pump impeller whenever the centrifugal pump pressure is established.

Claim 16

A gas-expelling centrifugal pump and liquid ring priming pump said pump inlet connecting for aircraft fuel tank installation which comprises a housing providing a central inlet, a surrounding volute chamber, a liquid ring pump chamber behind the inlet chamber, a clutch chamber behind the liquid ring pump chamber, and an electric motor chamber behind the clutch chamber, a centrifugal pump impeller in said pump inlet having a ring of vanes discharging centrifugally into the volute chamber, an electric motor in said motor chamber having a shaft extending through the clutch and liquid ring pump chambers into the pump inlet, means mounting the centrifugal pump impeller on said shaft in said pump inlet, ports in the central portion of said pump inlet connecting the central portion of the pump impeller inwardly from the pumping vanes thereon with the liquid ring pump chamber, a liquid ring pump impeller in said liquid riNg pump chamber receiving gases and vapors from said ports, a clutch in said clutch chamber connecting said liquid ring pump impeller with said shaft, means actuated by pressure in said volute chamber declutching said liquid ring pump impeller from said shaft, said housing having a chamber surrounding said liquid ring pump communicating with the inlet and outlet of said liquid ring pump whereby liquid discharged from the ring pump may flow to the inlet of the liquid ring pump for priming the pump, and said housing having a gas and vapor outlet communicating with said chamber surrounding the liquid ring pump chamber for releasing gases and vapors from liquid discharged by the liquid ring pump whereby gases and vapors will be drawn from the centrifugal pump inlet by said liquid ring pump to prevent the centrifugal pump impeller from becoming gas bound, the liquid ring pump will be primed liquid as needed from liquid discharged therefrom and the clutch will couple the liquid ring pump impeller whenever the centrifugal pump pressure is established.