What are the common faults of fatigue test electro-hydraulic servo system
Date: 2025-07-22Read: 30
Common faults in fatigue testing electro-hydraulic servo systems include Valve not working, valve out of control, slow response, vibration noise, unstable output, oil contamination, electrical interference, incorrect parameter settings, abnormal test data Wait, here are the specific faults and solutions: -
Valve not working
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reasonMotor coil breakage or desoldering; Reverse oil inlet or outlet connection; Front stage blockage, valve core stuck in the middle position; The motor coils are connected in series or parallel, and the two coils are reversed.
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SolutionCheck the coil connection, repair any broken wires or solder joints; Confirm that the oil port connection is correct; Clean the pre stage and remove blockages; Adjust the coil connection method.
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The valve has a fixed output, but it has lost control
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reason: Front stage nozzle blocked; The valve core is stuck by stolen goods or the valve body is deformed, causing the valve core to get stuck; The internal protective filter is blocked by stolen goods.
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SolutionClean or replace the pre stage nozzle; Remove dirt from the valve core or repair valve body deformation; Replace the filter element, return to the factory for cleaning and repair.
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Slow valve response, slow response
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reason: Decreased fuel supply pressure; Protect the filter from partial blockage; Some valve zero adjustment mechanisms are loose, and motor parts and components are loose; The oil is too dirty, the valve resolution deteriorates, and the hysteresis widens.
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SolutionAdjust the fuel supply pressure to the specified value; Clean or replace the protective filter; Tighten the zero adjustment mechanism and motor components; Replace the clean oil.
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The system experiences high-frequency vibrations and noise
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reasonExcessive amount of air mixed into the oil; The oil is too dirty; The system gain is set too high; Power supply noise from the amplifier side; Poor insulation between the servo valve coil, valve casing, and ground wire; We chose a servo valve with a relatively low frequency instead.
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SolutionRemove air from the oil; Replace the clean oil; Adjust the system gain to an appropriate value; Check and repair power noise issues; Improve the insulation between the servo valve coil, valve housing, and ground wire; Choose a servo valve with an appropriate frequency.
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The valve output fluctuates between positive and negative, and cannot be continuously controlled, forming a "switch" control
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reasonThe feedback mechanism inside the servo valve has failed; There is a certain positive feedback phenomenon; Oil leakage between the motor cover and valve body (such as spring tube rupture, internal oil pipe rupture, etc.).
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SolutionRepair or replace feedback mechanism; Eliminate positive feedback phenomenon; Repair the leaking area, such as replacing the spring tube or internal oil pipe.
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Oil contamination causes servo valve failure
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reasonParticle size, acidity, and other indicators in the oil exceed the specified standards, resulting in blockage or insensitive operation of the servo valve oil filter.
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SolutionRegularly clean or replace the oil filter inside the electro-hydraulic servo valve; Strengthen oil management to ensure that the oil quality meets the prescribed standards.
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Electrical interference causes abnormal operation of servo valve
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reasonPoor power filtering or introduction of external interference signals.
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SolutionCheck the power filtering condition to ensure good grounding; Eliminate external interference signal sources, such as reconnecting the ground wire to the ground wire network.
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Hardware parameter setting error
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reasonAfter the software goes offline and enters the hardware parameter setting interface, the direction of force, displacement, beam direction, or test space selection is incorrect.
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SolutionEnter the hardware parameter setting interface, re determine the direction of force, displacement, beam direction, and the selection of test space.
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Abnormal experimental data
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reasonThe clamping of the "test piece" is not firm enough; The settings for the "force sensor" and "decoder" are incorrect; The 'Force Zero' and 'Deformation Zero' keys have not been pressed.
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SolutionEnsure that the "test piece" is firmly clamped; Check and reset the 'Force Sensor' and 'Decoder'; Press the 'Force Zero' and 'Deformation Zero' buttons before the experiment begins.