On-demand dual variable displacement positive displacement pumping system

Patent metadata

Field	Value
Publication number	US-11725647-B2
Application number	US-202117324017-A
Country	US
Kind code	B2
Filing date	May 18, 2021
Priority date	May 18, 2021
Publication date	Aug 15, 2023
Grant date	Aug 15, 2023

Abstract

A pumping system includes a first variable displacement pump having a first inlet and a first outlet. The first outlet is fluidically connected to a system outlet. A first actuator is mechanically coupled to a first displacement mechanism of the first variable displacement pump A second variable displacement pump includes a second inlet and a second outlet. The second outlet is fluidically connected to the system outlet. The pumping system also includes a second actuator mechanically coupled to a second displacement mechanism of the second variable displacement pump. An electrohydraulic servo valve is hydraulically connected to the first and second actuators. An electronic engine controller is in communication with the electrohydraulic servo valve and is configured to send electrical current to the electrohydraulic servo valve to drive the first actuator and the second actuator.

First claim

The invention claimed is:

1. A pumping system for supplying fuel to a jet turbine engine, the pumping system comprising:
a first variable displacement pump comprising a first inlet and a first outlet, wherein the first outlet is fluidically connected to a system outlet;
a first actuator mechanically coupled to a first displacement mechanism of the first variable displacement pump;
a second variable displacement pump comprising a second inlet and a second outlet, wherein the second outlet is fluidically connected to the system outlet;
a second actuator mechanically coupled to a second displacement mechanism of the second variable displacement pump;
an electrohydraulic servo valve hydraulically connected to the first and second actuators; and
an electronic engine controller in communication with the electrohydraulic servo valve and configured to send electrical current to the electrohydraulic servo valve to drive the first actuator and the second actuator,
wherein the first actuator comprises a linear variable differential transducer in communication with the electronic engine controller and configured to measure a linear displacement of the first actuator, and wherein the second actuator comprises a second linear variable differential transducer in communication with the electronic engine controller and configured to measure a linear displacement of the second actuator.

2. The pumping system of claim 1 , wherein the first actuator is a piston assembly comprising:
a housing;
a fluid chamber contained within the housing;
a piston cylinder inside the housing;
a spring chamber inside the housing opposite the fluid chamber relative to the piston cylinder;
a piston rod attached to the piston cylinder; and
a spring compressed in the spring chamber.

3. The pumping system of claim 2 , wherein the piston rod is connected to the first displacement mechanism of the first variable displacement pump.

4. The pumping system of claim 3 , wherein the second actuator is a piston assembly comprising:
a second housing;
a second fluid chamber contained within the second housing;
a second piston cylinder inside the second housing;
a second spring chamber inside the second housing opposite the second fluid chamber relative to the second piston cylinder;
a second piston rod attached to the second piston cylinder; and
a second spring compressed in the second spring chamber.

5. The pumping system of claim 4 , wherein the second piston rod is connected to the second displacement mechanism.

6. The pumping system of claim 1 , wherein the electrohydraulic servo valve comprises:
a sleeve extending axially along a center axis;
an inlet port formed on the sleeve;
a first outlet port formed on the sleeve and hydraulically connected to the first actuator;
a second outlet port formed on the sleeve and hydraulically connected to the second actuator, wherein the second outlet port is staggered with the first outlet port such that an axial position of the first outlet port overlaps an axial position of the second outlet port relative to the center axis of the sleeve; and
a spool inside the sleeve, wherein the spool comprises:
a chamber formed on the spool;
a first position range within the sleeve within which the second outlet port is closed and the first outlet port is at least partially open to the chamber and the inlet port; and
a second position range within the sleeve within which the second outlet port is at least partially open to the chamber and the inlet port, and wherein a majority of the first outlet port is open to the chamber and the inlet port.

7. The pumping system of claim 6 , wherein the electrohydraulic servo valve further comprises:
a motor connected to the spool,
wherein the motor is configured to position the spool within the first position range when a first current range is applied to the motor, and
wherein the motor is configured to position the spool within the second position range when a second current range is applied to the motor.

8. The pumping system of claim 7 , further comprising:
a first check valve downstream from the first outlet of the first variable displacement pump, wherein the first check valve prevents backflow into the first variable displacement pump;
a second check valve downstream from the second outlet of the second variable displacement pump, wherein the second check valve prevents backflow into the second variable displacement pump;
a first hydraulic pressure line comprising a first end and a second end, wherein the first end is fluidically connected to the electrohydraulic servo valve, and wherein the second end is fluidically connected between the system outlet and the first and second check valves; and
a second hydraulic pressure line fluidically connecting the electrohydraulic servo valve to a fluid supply.

9. The pumping system of claim 8 , wherein the system outlet comprises a fuel nozzle.

10. A fuel delivery system for supplying fuel to a jet turbine engine, the fuel delivery system comprising:
a fuel line connected to a fuel nozzle;
a first pump assembly comprising:
a first pump with a first outlet fluidically connected to the fuel line;
a first hydraulic actuator mechanically coupled to the first pump;
a first linear variable differential transducer attached to the first hydraulic actuator; and
a first check valve downstream from the first pump, wherein the first check valve prevents backflow into the first pumping assembly;

a second pump assembly comprising:
a second pump with a second outlet fluidically connected to the fuel line;
a second hydraulic actuator mechanically coupled to the second pump;
a second linear variable differential transducer attached to the second hydraulic actuator; and
a second check valve downstream from the second pump, wherein the second check valve prevents backflow into the second pumping assembly;

an electrohydraulic servo valve hydraulically connected to the first and second hydraulic actuators; and
an electronic engine controller in communication with the first linear variable differential transducer, the second linear variable differential transducer, and the electrohydraulic servo valve.

11. The pumping system of claim 10 , wherein the first pump is a variable displacement pump comprising a first swashplate mechanically coupled to the first hydraulic actuator, and wherein the second pump is a variable displacement pump comprising a second swashplate mechanically coupled to the second hydraulic actuator.

12. The pumping system of claim 11 , wherein the electrohydraulic servo valve further comprises:
a sleeve;
an inlet port formed on the sleeve;
a first outlet port formed on the sleeve and hydraulically connected to the first actuator;
a second outlet port formed on the sleeve and hydraulically connected to the second actuator, wherein the second outlet port is staggered with the first outlet port such that an axial position of the first outlet port overlaps an axial position of the second outlet port relative to a center axis of the sleeve; and
a spool inside the sleeve, wherein the spool comprises:
a chamber formed on the spool;
a first position range within the sleeve within which the second outlet port is closed and the first outlet port is at least partially open to the chamber and the inlet port; and
a second position range within the sleeve within which the second outlet port is at least partially open to the chamber and the inlet port, and wherein a majority of the first outlet port is open to the chamber and the inlet port.

13. The pumping system of claim 12 , wherein the electrohydraulic servo valve further c

Assignees

• Hamilton Sundstrand Corp

Inventors

• Susca Ryan
• O'Rorke Morgan
• Rutar Matej
• Haugsjaahabink Todd

Classifications

• F04B49/002 Primary

  Hydraulic systems to change the pump delivery · CPC title

• F02C7/236

  Fuel delivery systems comprising two or more pumps · CPC title

• F04B1/295 Primary

  by changing the inclination of the swash plate · CPC title

• F04B1/324

  by changing the inclination of the swash plate · CPC title

• F04B23/06

  the pumps being all of reciprocating positive-displacement type · CPC title