METHOD OF DETECTING FAILURE OF A SERVO-VALVE, AND A SERVO-VALVE APPLYING THE METHOD

• US 20130087223A1
• Filed: 10/09/2012
• Published: 04/11/2013
• Est. Priority Date: 10/10/2011
• Status: Active Grant

• Current Assignee: Safran Aerosystems Hydraulics
• Original Assignee: In-Lhc
• Inventors: OZZELLO, Guylain
• Granted Patent: US 9,897,116 B2
• Time in Patent Office: Days
• US Class Current: 137/551
• CPC Class Codes: F15B 13/0436 the pilot valves being of the steerable jet type
• CPC Class Codes: F15B 19/005 Fault detection or monitoring
• CPC Class Codes: H02K 11/20 for measuring, monitoring, testing, protecting or switching rectifiers H02K11/04; power electronics H02K11/33
• CPC Class Codes: H02K 26/00 Machines adapted to function as torque motors, i.e. to exert a torque when stalled
• CPC Class Codes: Y10T 137/0318 Processes
• CPC Class Codes: Y10T 137/0396 Involving pressure control
• CPC Class Codes: Y10T 137/2278 Pressure modulating relays or followers
• CPC Class Codes: Y10T 137/8158 With indicator, register, recorder, alarm or inspection means
• CPC Class Codes: Y10T 137/8242 Electrical
• CPC Class Codes: Y10T 137/8275 Indicator element rigidly carried by the movable element whose position is indicated
• CPC Class Codes: Y10T 137/86598 Opposed orifices; interposed modulator

Abstract

A method of detecting failure of a two-stage servo-valve in which the power-controlling movable member is connected to the rotor of a torque motor of a pilot stage by mechanical feedback. A malfunction signal is generated in response to detecting that the rotor of the torque motor has engaged a stop. The invention also provides a servo-valve including means for implementing such a method.

Claims

1. A method of detecting a failure of a servo-valve having a power stage with a movable member for distributing power and a pilot stage that includes a motor having a stationary portion and a movable portion that occupies a position that is controlled in order to move the movable member for distributing power in controlled manner, said movable member for distributing power being connected to the movable portion of the motor by a feedback member, the method including detecting the movable portion of the motor engaging a stop, and generating a malfunction signal in response to such detection.

2. A method according to claim 1, wherein the rotor engaging a stop is detected by a sensor operationally connected to the movable portion of the motor in such a manner as to change state when the movable portion of the motor engages a stop, with the change in state generating a malfunction signal.

3. A servo-valve comprising a power stage with a movable member for distributing power and a pilot stage that includes a motor having a stationary portion and a movable portion that occupies a position that is controlled in order to move the movable member for distributing power in controlled manner, said movable member for distributing power being connected to the movable portion of the motor by a feedback member, wherein the servo-valve is fitted with means for detecting the movable portion of the motor engaging a stop.

4. A servo-valve according to claim 3, including a sensor operationally connected to the movable portion of the motor in such a manner as to change state when the movable portion of the motor engages a stop, the change of state generating a malfunction signal.