Fuel pump systems for turbomachines

Patent metadata

Field	Value
Publication number	US-11236682-B2
Application number	US-201815902898-A
Country	US
Kind code	B2
Filing date	Feb 22, 2018
Priority date	Feb 22, 2018
Publication date	Feb 1, 2022
Grant date	Feb 1, 2022

Abstract

A fuel pump system for a turbomachine engine can include a boost pump driven by an electric motor and configured to be in fluid communication with a fuel tank, a primary pump configured to be driven by a shaft connected to the turbomachine engine, wherein the primary pump is in fluid communication with the boost pump downstream of the boost pump by a boost branch, a bypass flow branch that connects the boost branch to a downstream branch that is downstream of the primary pump, the downstream branch is in fluid communication with one or more metering valves and/or one or more fuel nozzles, and a bypass valve disposed in the bypass flow branch and/or the downstream branch and configured to selectively directly fluidly communicate the boost branch and the downstream branch.

First claim

What is claimed is:

1. A fuel pump system for a turbomachine engine, comprising:
a boost pump driven by an electric motor and configured to be in fluid communication with a fuel tank;
a primary pump configured to be driven by an input shaft connected to the turbomachine engine, wherein the primary pump is in fluid communication with the boost pump downstream of the boost pump by a boost branch;
a bypass flow branch that connects the boost branch to a downstream branch that is downstream of the primary pump, wherein the downstream branch is in fluid communication with one or more metering valves and/or one or more fuel nozzles; and
a bypass valve disposed in the bypass flow branch and/or the downstream branch and configured to selectively directly fluidly communicate the boost branch and the downstream branch, wherein the bypass valve includes a three-way valve, wherein when the bypass valve is in a bypass position, the bypass valve prevents flow from the primary pump to the downstream branch, allows fluid communication between an output of the primary pump and the boost branch, such that flow from the bypass branch flows to the downstream branch, wherein the electric motor is controlled by a controller, wherein the controller is operatively connected to a speed sensor that senses the speed of the input shaft, and the controller controls the electric motor at least in part as a function of the input shaft speed.

2. The system of claim 1 , wherein the bypass valve includes a check valve.

3. The system of claim 2 , wherein the check valve is configured to open with a predetermined pressure from the boost pump to cause fluid communication between the boost branch and the downstream branch.

4. The system of claim 1 , wherein the primary pump is a gear pump and the boost pump is a centrifugal pump.

5. The system of claim 1 , wherein the controller is a full authority digital engine control (FADEC).

6. The system of claim 5 , wherein at least one of the FADEC and the electric motor is cooled by fuel flowing through the system.

7. The system of claim 6 , wherein the FADEC is in cooling flow communication with the bypass branch, wherein the electric motor is in cooling flow communication with both the FADEC and the boost pump to create loop through the boost pump.

8. The system of claim 1 , wherein the controller is configured to control the bypass valve between a normal flow position where flow is prevented from flowing through the bypass branch to the downstream branch, and the bypass position where flow is allowed to flow through the bypass branch to the downstream branch.

9. The system of claim 8 , wherein the controller is configured to control the electric motor as a function of bypass valve position such that the controller increases electric motor speed when the bypass valve is in the bypass position.

10. The system of claim 1 , wherein the input shaft is a gear box shaft connected to a gear box, wherein the gear box is connected to a shaft of the turbomachine engine.

11. A fuel system for a turbomachine engine, comprising:
a mechanically driven primary pump configured to be driven by an input shaft connected to the turbomachine engine;
a boost pump driven by an electric motor configured to supply pressurized fuel to the primary pump via a boost branch;
a bypass valve that includes a three-way valve disposed in a downstream branch downstream of the primary pump and the boost pump, and
a flow system configured to allow the boost pump to also directly provide pressurized fuel to one or more fuel metering valves and/or one or more fuel nozzles through a bypass branch to the downstream branch, such that when the bypass valve is in a bypass position, flow from the primary pump does not flow to the downstream branch, and the bypass valve allows communication between an output of the primary pump and the boost branch, wherein the electric motor is controlled by a controller, wherein the controller is operatively connected to a speed sensor that senses the speed of the input shaft, and the controller controls the electric motor at least in part as a function of the input shaft speed.

12. The system of claim 11 , wherein the primary pump is a gear pump and the boost pump is a centrifugal pump.

13. The system of claim 11 , wherein the controller is a full authority digital engine control (FADEC).

14. The system of claim 13 , wherein at least one of the FADEC and the electric motor is cooled by fuel flowing through the system.

15. A method of providing fuel to a turbomachine engine, comprising:
pumping fuel with a primary pump mechanically driven by an input shaft of the turbomachine engine;
pumping fuel with a boost pump driven by an electric motor;
supplying pressurized fuel from the boost pump to the primary pump via a boost branch;
moving a bypass valve to a bypass position, wherein the bypass valve is or includes a three-way valve disposed in a downstream branch downstream of the primary pump and the boost pump;
supplying pressurized fuel from the boost pump directly to one or more fuel metering valves and/or one or more fuel nozzles through a bypass branch from the boost branch to the downstream branch such that when the bypass valve is in a bypass position, flow from the primary pump does not flow to the downstream branch, and the bypass valve allows communication between an output of the primary pump and the boost branch; and
controlling the electric motor with a controller at least in part as a function of a speed of the input shaft, wherein the controller is operatively connected to a speed sensor that senses the speed of the input shaft.

Assignees

• Hamilton Sundstrand Corp

Inventors

• Veilleux Jr Leo J
• Ribarov Lubomir A

Classifications

• F02C9/26 Primary

  Control of fuel supply (F02C9/48 takes precedence; fuel valves F02C7/232) · CPC title

• F04D25/06

  the pump being electrically driven (F04D25/08 takes precedence) · CPC title

• F04D27/009

  by bleeding, by passing or recycling fluid · CPC title

• F05D2220/323

  for aircraft propulsion, e.g. jet engines · CPC title

• F02M39/02

  Arrangements of fuel-injection apparatus to facilitate the driving of pumps; Arrangements of fuel-injection pumps; Pump drives · CPC title