Method and apparatus for cooling and replenishing aircraft hydraulic actuators

Claim 2

A hydraulic control system for an aircraft, comprising: a plurality of actuator assemblies within said aircraft, each actuator assembly including a hydraulic actuator, a high pressure pump means for providing hydraulic fluid under high pressure to said actuator, and a motor means for driving said pump, each of said actuator assemblies being located generally adjacent an aircraft control effector to be controlled by said actuator assembly; an electrical power cable coupled to each of said actuator assemblies; a low-pressure pumping means for forcibly circulating low-pressure hydraulic fluid from said pump to said actuator assemblies under low pressure; and a fluid transmission means extending in series between each of said actuator assemblies and said pumping means for providing a series flow of said low-pressure hydraulic fluid to each of said actuator assemblies from one actuator assembly to another actuator assembly.

Claim 3

The system of claim 1 wherein said actuator assembly also includes an electronic controller located within said actuator assembly.

Claim 4

The system of claim 2, further including: a signal transmission circuit coupled to said electonic controller of each of said actuators; and a central controller coupled to said signal transmission circuit for transmitting control signals to said actuator assemblies for controlling their operation.

Claim 5

The system according to claim 1, further including a temperature-sensing means within said low-pressure hydraulic fluid for sensing the temperature of said low-pressure fluid.

Claim 6

The system according to claim 1, further including a fluid-tight housing enclosing said motor, and said pump, said fluid transmission means being coupled to an inlet and an outlet of said housing, said housing being filled with said low-pressure hydraulic fluid which surrounds said actuator assembly to maintain the temperature of said actuator assembly within a selected range.

Claim 7

The system according to claim 5, further including a fluid compensator coupled to the outlet of said housing for controlling the fluid flow out of said housing.

Claim 8

The system accoding to claim 1 wherein said plurality of actuator assemblies includes only a portion of the actuator assemblies used on said aircraft.

Claim 9

The system according to claim 1, further including a filter means in said fluid transmission means for filtering said low-pressure hydraulic fluid.

Claim 12

The method according to claim 9, further including the step of: mixing said hydraulic fluid under low pressure with the hydraulic fluid in said actuator, said hydraulic fluid under low pressure being the same type that is within each of said actuators.

Claim 13

The method according to claim 9, further including: sensing the temperature of said hydraulic fluid within each of said actuator assemblies; and varying the circulating flow volume of said hydraulic fluid under low pressure to said actuator assemblies to maintain the temperature of said actuator assemblies within a selected temperature range.

Claim 14

A hydraulic control system for aircraft, comprising: a plurality of actuator assemblies within said aircraft, each actuator assembly including a hydraulic actuator, a high-pressure pump means for providing hydraulic fluid under pressure to said actuator, and a motor means for driving said pump, each of said actuator assemblies being located generally adjacent an aircraft control effector to be controlled by said actuator assembly; a fluid-tight housing enclosing at least a portion of said actuator assembly, said fluid-tight having an inlet and an outlet, said housing being filled with low pressure hydraulic fluid which surrounds said portion of said actuator assemble to maintain the temperature of said actuator assembly within a selected range; a fluid compensator coupled to the outlet of said housing for controlling the fluid flow out of said housing; an electrical power cable coupled to each of said actuator assemblies; a low-pressure pumping means for forcibly circulating low-pressure hydraulic fluid from said pressure pumping means to said actuator assembly portions within said under low pressure; and a fluid transmission means coupled from said low pressure pumping means to said inlet of said housing and from said outlet of said housing to a return line for providing said low pressure hydraulic fluid to each of said housings and the portion of said actuator assembly within said housings.

Claim 15

A hydraulic control system for aircraft, comprising: a plurality of actuator assemblies within said aircraft, each actuator assembly including a hydraulic actuator, a high-pressure pump means for providing hydraulic fluid under pressure to said actuator, and a motor means for driving said pump, each of said actuator assemblies being located generally adjacent an aircraft control effector to be controlled by said actuator assembly; a fluid-tight housing enclosing at least a portion of said actuator assembly, said fluid-tight having an inlet and an outlet, said housing being filled with low pressure hydraulic fluid which surrounds said portion of said actuator assemble to maintain the temperature of said actuator assembly within a selected range; a fluid compensator coupled to the outlet of said housing for controlling the fluid flow out of said housing; an electrical power cable coupled to each of said actuator assemblies; a low-pressure pumping means for forcibly circulating low-pressure hydraulic fluid from said pressure pumping means to said actuator assembly portions within said under low pressure; and a fluid transmission means coupled from said low pressure pumping means to said inlet of said housing and from said outlet of said housing to a return line for providing said low pressure hydraulic fluid to each of said housings and the portion of said actuator assembly within said housings.

Claim 16

The system according to claim 12, wherein said transmission means extends from said pump to said actuator assemblies in parallel to create an individually controllable fluid flow from said pump to each of said actuator assemblies.

Claim 17

The system according to claim 12, further including a central reservoir means coupled to said fluid transmission means tubing for providing reservoir fluid to each of said actuator assemblies, and wherein said high-pressure pump includes an inlet coupled to said low-pressure fluid for receiving said low-pressure fluid to replenish the supply of said high-pressure hydraulic fluid.

Claim 18

The system of claim 14 wherein said low-pressure hydraulic fluid is mixed with said high-pressure fluid to maintain the temperature of said high-pressure hydraulic fluid within a selected range.

Claim 19

A hydraulic control system for an aircraft, comprising: a plurality of actuator assemblies within said aircraft, each actuator assembly including a hydraulic actuator, a high-pressure pump means for providing hydraulic fluid under pressure to said actuator, and a motor means for driving said pump, each of said actuator assemblies being located generally adjacent an aircraft control effector to be controlled by said actuator assembly; an electrical power cable coupled to each of said actuator assemblies; a low-pressure pumping means for forcibly circulating low-pressure hydraulic fluid from said pump to said actuator assemblies under low pressure; a temperature sensor means within said actuator assembly for sensing the temperature of said high-pressure hydraulic fluid within said actuator assembly; a fluid transmission means extending between each of said actuator assemblies and said pumping means for providing low-pressure hydraulic fluid to each of said actuator assemblies; and a flow control means coupled between each of said actuator assemblies; and said pumping means for varying the flow volume of said pressure hydraulic fluid to each respective actuator assembly based on said temperature to maintain said temperature within a selected range.

Claim 20

A hydraulic control system for an aircraft, comprising: a plurality of actuator assemblies within said aircraft, each actuator assembly including a hydraulic actuator, a high-pressure pump means for providing hydraulic fluid under pressure to said actuator, and a motor means for driving said pump, each of said actuator assemblies being located generally adjacent an aircraft control effector to be controlled by said actuator assembly; an electrical power cable coupled to each of said actuator assemblies; a low-pressure pumping means for forcibly circulating low-pressure hydraulic fluid from said pump to said actuator assemblies under low pressure; a temperature sensor means within said actuator assembly for sensing the temperature of said high-pressure hydraulic fluid within said actuator assembly; a fluid transmission means extending between each of said actuator assemblies and said pumping means for providing low-pressure hydraulic fluid to each of said actuator assemblies; and a flow control means coupled between each of said actuator assemblies; and said pumping means for varying the flow volume of said pressure hydraulic fluid to each respective actuator assembly based on said temperature to maintain said temperature within a selected range.

Claim 21

The system of claim 16 further including a tremperature-control means for controlling the temperature of said low-pressure hydraulic fluid, said low-pressure hydraulic fluid being in thermal contact with said actuator assembly and said electronic controller to maintain their temperature within a selected range.

Claim 22

The system of claim 17 wherein said temperature-control means includes said fluid transmission means extending between said low-pressure pump means and said actuator assembly for cooling the low-pressure hydraulic fluid using ambient air within the aircraft, as said low-pressure hydraulic fluid is circulated from said actuator assemblies to said low-pressure pump means.

Claim 23

The system of claim 17 wherein said temperature-control means includes a heat exchanger for cooling said low-pressure fluid to a selected temperature.

Claim 24

The system of claim 17 wherein said temperature-control means includes a heater for heating said low-pressure fluid to a selected temperature.