Fuel pump systems

Patent metadata

Field	Value
Publication number	US-11828233-B2
Application number	US-202117535902-A
Country	US
Kind code	B2
Filing date	Nov 26, 2021
Priority date	Nov 26, 2021
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

A fuel pump system can include a motor and a pump connected to the motor. The pump can be configured to receive an inlet flow from an inlet line, to pressurize the inlet flow, and to output a pressurized flow to an output line for an engine. The system can include a bypass line disposed between the outlet line and the inlet line, and a bypass valve disposed on the bypass line and configured to allow pressurized flow to flow to the inlet line in an open state, and to prevent pressurized flow from flowing to the inlet line in a closed state. The bypass valve can be configured to allow pressurized flow to flow to the inlet line to circulate flow and to maintain a constant pressure on the output line.

First claim

What is claimed is:

1. A fuel pump system, comprising:
a motor;
a pump connected to the motor and configured to receive an inlet flow from an inlet line, to pressurize the inlet flow, and to output a pressurized flow to an output line for an engine;
a bypass line disposed between the outlet line and the inlet line;
a bypass valve disposed on the bypass line and configured to allow pressurized flow to flow to the inlet line in an open state, and to prevent pressurized flow from flowing to the inlet line in a closed state, wherein the bypass valve is configured to allow pressurized flow to flow to the inlet line to circulate flow, wherein the bypass valve is configured to maintain a constant pressure on the output line, wherein the constant pressure is above a maximum required pressure in a maximum flow condition, wherein the motor is a constant speed motor configured to turn the pump at a constant speed at a constant horsepower; and
a control module configured to operate the motor at a constant speed to turn the pump at a constant speed to produce the constant pressure,
wherein the bypass valve is a pressure regulating valve (PRV), wherein the PRV is configured to open as a function of pressure differential between the output line and the inlet line.

2. The fuel pump system of claim 1 , wherein the PRV is mechanical and driven by the pressure differential between the output line and the inlet line.

3. The fuel pump system of claim 2 , wherein the pump is an inducer pump comprising an axial impeller.

4. An aircraft, comprising:
an engine; and
a fuel pump system, comprising:
a motor;
a pump connected to the motor and configured to receive an inlet flow from an inlet line, to pressurize the inlet flow, and to output a pressurized flow to an output line connected to the engine;
a bypass line disposed between the outlet line and the inlet line;
a bypass valve disposed on the bypass line and configured to allow pressurized flow to flow to the inlet line in an open state, and to prevent pressurized flow from flowing to the inlet line in a closed state, wherein the bypass valve is configured to allow pressurized flow to flow to the inlet line to circulate flow and to maintain a constant pressure on the output line, wherein the constant pressure is above a maximum required pressure in a maximum flow condition, wherein the motor is a constant speed motor configured to turn the pump at a constant speed at a constant horsepower; and
a control module configured to operate the motor at a constant speed to turn the pump at a constant speed to produce the constant pressure,

wherein the bypass valve is a pressure regulating valve (PRV), wherein the PRV is configured to open as a function of pressure differential between the output line and the inlet line.

5. The aircraft of claim 4 , wherein the PRV is mechanical and driven by the pressure differential between the output line and the inlet line.

6. The aircraft of claim 5 , wherein the pump is an inducer pump comprising an axial impeller.

7. A method, comprising:
driving an inducer pump to pump fuel on an output line connected to an aircraft engine, wherein driving is done at a constant speed; and
bypassing flow from the output line to an input line to maintain a constant pressure on the output line, wherein the constant pressure is above a maximum required pressure in a maximum flow condition, wherein a motor driving the inducer pump is a constant speed motor configured to turn the inducer pump at a constant speed at a constant horsepower; and
controlling, with a control module, the motor at a constant speed to turn the inducer pump at a constant speed to produce the constant pressure,
wherein bypassing flow includes using a mechanical pressure regulating valve which opens as a function of pressure on the output line relative to the input line, wherein driving the inducer pump includes using a motor that is too small to supply sufficient pressure at idle or low speed engine conditions without bypassing flow from the output line to the input line.

8. The method of claim 7 , wherein the constant pressure is at or above a takeoff flow pressure required by the engine at a takeoff power setting.

Assignees

• Hamilton Sundstrand Corp

Inventors

• Stoicescu Adrian L
• Goy Edward W
• Harder Benjamin T

Classifications

• F02C7/236 Primary

  Fuel delivery systems comprising two or more pumps · CPC title

• F02C7/232

  Fuel valves {(control of fuel supply by means of fuel metering valves F02C9/263)}; Draining valves or systems (valves in general F16K) · CPC title

• F02C9/263

  by means of fuel metering valves · CPC title

• F02C9/30

  characterised by variable fuel pump output · CPC title

• F02C9/32

  characterised by throttling of fuel (F02C9/38 takes precedence) · CPC title