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US3902318A Expired / Lapsed US ⏱️ 0.0 years remaining

Power transmission

Assignee: Vickers Inc
•
Filing: 1974-08-28
•
Granted: 1975-09-02
•
Expires: 1994-08-28
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Abstract

Abstract An integrated electro hydraulic actuator package for remotely controlling the position of an aircraft control surface has both its input power and its input command signals supplied solely by wires from remote locations. The package encloses an electric motor running wet in the hydraulic fluid and driving a reversible variable displacement pump connected directly to a differential piston and cylinder actuator and is designed to be completely manifolded. A differential piston and cylinder reservoir carries fluid to make up for any losses of fluid from the actuator to the outside of the package. An auxiliary pump supplies fluid to a servo motor circuit for control purposes, the circuit being governed by an electro-hydraulic servo valve whereby a servo motor system adjusts the displacement of the main pump. Loss of fluid from the package or mechanical failure in a pump causes loss of delivery pressure at the auxiliary pump and actuates a bypass valve to bypass the actuator allowing make-up of fluid from the reservoir. Overload protection is provided in the servo motor circuit by a pair of pressure responsive dumping valves. A linearly variable differential transformer provides a signal indicating the position of the actuator which is combined with a command signal from a remote location to govern the electrohydraulic servo valve. The position of the displacement adjuster of the main pump is also fed to the electro-hydraulic servo valve providing a signal indicative of the velocity of the actuator. A heat exchanger surrounds the electric motor and carries the fluid returning from the pump housing to the reservoir. An auxiliary electric motor driven fan cools the heat exchanger.

Inventors

  • 👤 Kenneth F Becker
  • 👤 Raymond P Lambeck
  • 👤 Nicholas F Pedersen

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-30 20:15
CPC Classifications
B; B64; B64C; B64C13/00; B64C13/24; B64C13/38; B64C13/50; B64C13/504; F; F15; F15B; F15B15/00; F15B15/18; F15B9/00; F15B9/02; F15B9/04; Y; Y10; Y10S; Y10S60/00; Y10S60/916

Claims Analysis

Total Claims: 9
Claim 1
Independent Claim 146 words
An integrated actuator package comprising a hydraulic actuator, a rotary electric prime mover, a reversible variable displacement hydraulic pump driven by the prime mover and driving the actuator, an auxiliary pump also driven by the prime mover, a servo motor connected to regulate the displacement of the first pump and supplied with fluid by the second pump, an electro hydraulic servo valve controlling the supply of fluid to the servo motor, a closed expansible chamber reservoir, means connecting the reservoir to the intake of both pumps, and a unitary housing enclosing all of the foregoing components with the prime mover running in the fluid handled by the pumps, whereby the supply of electric power to the prime mover and of an electric error signal to the servo valve will produce, solely through electric conductors, a powered amplification of a command signal originating at a remote location.
Claim 2
Dependent Claim 146 words
An integrated actuator package comprising a hydraulic actuator, a rotary electric prime mover, a reversible variable displacement hydraulic pump driven by the prime mover and driving the actuator, an auxiliary pump also driven by the prime mover, a servo motor connected to regulate the displacement of the first pump and supplied with fluid by the second pump, an electro hydraulic servo valve controlling the supply of fluid to the servo motor, a closed expansible chamber reservoir, means connecting the reservoir to the intake of both pumps, and a unitary housing enclosing all of the foregoing components with the prime mover running in the fluid handled by the pumps, whereby the supply of electric power to the prime mover and of an electric error signal to the servo valve will produce, solely through electric conductors, a powered amplification of a command signal originating at a remote location.
Claim 3
Dependent Claim 41 words
An actuator package as defined in claim 1 wherein the actuator has a differential area piston and cylinder and the reservoir is a differential area piston and cylinder biased to pressurize the reservoir by the output pressure of the second pump.
Claim 4
Dependent Claim 65 words
An actuator package as defined in claim 2 having a valve spring loaded to connect the auxiliary pump intake to the reservoir and normally closed by auxiliary pump pressure during operation of the package whereby any loss of fluid from the package reduces the auxiliary pump pressure allowing the reservoir to make up the loss through the bypass valve and restore the auxiliary pump pressure.
Claim 5
Dependent Claim 60 words
An actuator package as defined in claim 1 having a bypass valve spring loaded to connect the two ends of the actuator cylinder and normally closed by auxiliary pump pressure during operation of the package whereby any loss of fluid from the package reduces the auxiliary pump pressure allowing the valve to bypass the actuator and the load to float.
Claim 6
Dependent Claim 36 words
An actuator package as defined in claim 1 wherein the servo valve controls a pressure responsive overload limiting valve connected to dump the servomotor circuit upon attainment of a predetermined limit of pressure in the actuator.
Claim 7
Dependent Claim 37 words
An actuator package as defined in claim 1 wherein the servo valve is responsive both to the error between the command signal and the position of the actuator and to the momentary displacement of the first pump.
Claim 8
Dependent Claim 46 words
An actuator package as defined in claim 1 wherein the actuator includes a linearly variable differential transformer and the servo valve is responsive both to the error between the command signal and the position of the actuator and to the momentary displacement of the first pump.
Claim 9
Dependent Claim 38 words
An actuator package as defined in claim 1 having a heat exchanger surrounding the prime mover and receiving the fluid circulated by the second pump and an independent electric motor driven fan arranged to cool the heat exchanger.

References Cited (Backward Citations)

US2276591A Cited
US2631431A Cited
US2643555A Cited
US2942581A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1978-09-01 1979-03-03 1979-09-02 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1982-09-01 1983-03-03 1983-09-02 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1986-09-01 1987-03-03 1987-09-02 $7700.00 Window Closed / Lapsed

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