EP0251603A2
Expired / Lapsed
EP
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Hydraulic actuator controlled by servovalve
Assignee: Group Lotus PLC
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Filing: 1987-06-22
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Granted: —
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Expires: 2007-06-22
Abstract
Abstract In an hydraulic system in which an hydraulic actuator (1) is controlled by a servovalve (10;50), a feed back signal derived from fluid flow associated with actuator movement is used to operate the servovalve, to ensure accurate control of the hydraulic actuator. The feedback signal can be an hydraulic signal derived from the pressure differential developed across a restriction (30) in the fluid flow, which can be applied to the servovalve directly, or an electrical signal for application to an electrical input to the servovalve, after modification if required, obtained from the pressure differential.
Inventors
- 👤 David Allen Williams
- 👤 Peter Godfrey Wright
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-03 20:41
CPC Classifications
F; F15; F15B; F15B11/00; F15B13/00; F15B13/16
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
37 words
An hydraulic system comprising an hydraulic actuator (1), and a servovalve (10;50) for controlling movement of the hydraulic actuator, characterized by means (30,31,32;30,32,51) responsive to actuator movement to provide a feedback signal for application to the servovalve.
Claim 2
Dependent Claim
37 words
An hydraulic system comprising an hydraulic actuator (1), and a servovalve (10;50) for controlling movement of the hydraulic actuator, characterized by means (30,31,32;30,32,51) responsive to actuator movement to provide a feedback signal for application to the servovalve.
Claim 3
Dependent Claim
25 words
An hydraulic system as claimed in claim 1 wherein the feedback signal is derived from fluid flow between the servovalve (10;50) and the actuator (1).
Claim 4
Dependent Claim
23 words
An hydraulic system as claimed in claim 2 wherein the feedback signal is derived from a pressure differential developed by the fluid flow.
Claim 5
Dependent Claim
35 words
An hydraulic system as claimed in claim 3 wherein the pressure differential is developed by fluid flow through an orifice (30) in a fluid connection (19) between the servovalve (10) and the hydraulic actuator (1).
Claim 6
Dependent Claim
31 words
An hydraulic system as claimed in claim 1, 2, 3 or 4 wherein the means (30,32,51) responsive to actuator movement provides the feedback signal in the form of an hydraulic signal.
Claim 7
Dependent Claim
25 words
An hydraulic system as claimed in claim 5 wherein the hydraulic feedback signal is applied directly to the valve member (55) of the servovalve (50).
Claim 8
Dependent Claim
28 words
An hydraulic system as claimed in claim 6 wherein the hydraulic feedback signal is applied as a pressure differential to opposed ends of the servovalve valve member (55).
Claim 9
Dependent Claim
31 words
An hydraulic system as claimed in claim 1, 2, 3 or 4 wherein the means (30,31,32) responsive to actuator movement provides the feedback signal in the form of an electric signal.
Claim 10
Dependent Claim
28 words
An hydraulic system as claimed in claim 3 or 4 wherein the pressure differential is sensed by pressure transducers (31) providing electrical outputs which constitute the feedback signal.
Claim 11
Dependent Claim
39 words
An hydraulic system as claimed in claim 8 or 9 wherein the servovalve (10) is hydraulically operated under control of a torque motor (20), the torque motor position being controlled by circuitry (25) responsive to the electric feedback signal.
References Cited (Backward Citations)
No citation records indexed.
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