US 8,523,537 B2Granted

Integral plus proportional dual pump switching system

AssigneeWoodward, Inc.

InventorMichael P. Garry

Life of this patent

Estimating the term…

Loading patent…

Abstract

A dual-pump fluid distribution system that includes a first pump having an inlet and an outlet, and configured to supply a first flow of fluid, and a second pump having an inlet and an outlet, and configured to supply a second flow of fluid. In an embodiment, a bypass flow valve with a four-way hydraulic bridge is configured to initiate the switch between single-pump mode and dual-pump mode based on fluid flow demand. The bypass flow valve is configured such that the position of the bypass flow valve member relative to the four-way hydraulic bridge operates a pump selector valve. In an embodiment, the pump selector valve has a valve member, a biasing element, and a pressure switching port, and is configured such that the position of the valve member determines whether the second flow of fluid is combined with the first flow of fluid.

Claims13

Dependent claims

A dual-pump fluid distribution system capable of switching between a single-pump mode and a dual-pump mode depending on a fluid flow demand, the dual-pump fluid distribution system comprising:

a first pump having an inlet and an outlet, the first pump configured to supply a first flow of fluid;
a second pump having an inlet and an outlet, the second pump configured to supply a second flow of fluid;
and
a bypass flow valve having a valve member, a biasing element, and a four-way hydraulic bridge, the bypass flow valve configured to initiate the switch between single-pump mode and the dual-pump mode based on the fluid flow demand;
wherein the bypass flow valve is configured such that a position of the bypass flow valve member relative to the four-way hydraulic bridge operates a pump selector valve;
and
wherein the pump selector valve has a valve member, a biasing element, and a pressure switching port, the pump selector valve configured such that a position of the pump selector valve member determines whether the second flow of fluid is combined with the first flow of fluid, and further comprising:
a variable pressure regulator that includes a first port coupled to the second pump outlet, a second port coupled to the second pump inlet, and a third port directly coupled to the pump selector valve pressure switching port, and
a actuation supply unit disposed between the second pump outlet and the pump selector valve, the actuation supply unit configured to provide a pressurized flow of fluid.

6 more elements

A method of supplying fluid using a fluid distribution system capable of alternating between a single-pump operation and a dual-pump-operation, the method comprising the steps of:

operating the fluid distribution system in a single-pump mode when a flow demand can be satisfied using a first pump;
operating the fluid distribution system in a dual-pump mode by adding a flow from a second pump to a flow of the first pump when the flow demand exceeds a capacity of the first pump to meet the flow demand;
alternating between the single-pump mode and the dual-pump mode by sensing the flow demand based on a pressure at an outlet of the first pump, wherein sensing the flow demand based on the pressure at the outlet of the first pump comprises placing a bypass flow valve between the first pump outlet and a second pump outlet and a metering valve,
wherein alternating between the single-pump mode and the dual-pump mode by sensing the flow demand based on the pressure at the outlet of the first pump further comprises providing the bypass flow valve with a four-way hydraulic bridge such that the bypass flow valve is configured to operate a pump selector valve to regulate an outlet pressure of the second pump,
wherein operating the fluid distribution system comprises operating the fluid distribution system wherein an actuation supply unit is coupled between the second pump outlet and the pump selector valve, and
wherein operating the fluid distribution system in the single-pump mode comprises positioning a pump selector valve member in the pump selector valve such that a flow path from the second pump outlet to the first pump outlet is directly blocked by the pump selector valve member, and wherein operating the fluid distribution system in the dual-pump mode comprises positioning the pump selector valve member such that the flow path from the second pump outlet to the first pump outlet is not blocked by the pump selector valve member.

3 more elements

Dependencies are inferred from the claim text.