I. Product Overview
TheMoog G761-3512Bis a high-performance two-stage electro-hydraulic servo valve manufactured by Moog Inc., part of theG761/-761 Series. This series employs amechanical feedback pilot-stage design, offering high response speed, precision, and reliability for industrial applications requiring precise flow and pressure control.
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II. Key Features
1. Structure & Operating Principle
• Pilot Stage:
• Symmetrical nozzle-flapper torque motor with variable orifices between the flapper and nozzles. Controls pressure to drive the second-stage spool.
• Output Stage:
• Four-way sliding spool design. Spool displacement is proportional to input signals, enabling precise flow or pressure modulation.
• Feedback Mechanism:
• Hardened alloy feedback rod provides mechanical feedback of spool position to the torque motor, ensuring closed-loop stability.
2. Performance Parameters
• Rated Flow:
• 0.5 to 75 L/min (0.125 to 20 gpm), depending on model and pressure drop.
• Rated Pressure:
• 310 bar (4,500 psi) or 350 bar (5,000 psi), suitable for high-pressure systems.
• Signal Range:
• 8 to 200 mA, supporting wide input signal compatibility.
• Response Speed:
• Short step response time with excellent dynamic performance for high-frequency applications.
3. Environmental Adaptability
• Explosion-Proof Options:
• Intrinsically safe models (e.g., G761K) available, meeting certifications for hazardous environments (mining, chemical plants).
• Contamination Resistance:
• Built-in filter with a nominal clearance of 200 μm extends service life and reduces maintenance costs.
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III. Applications
1. Industrial Automation
• Injection Molding Machines:
• Controls mold opening/closing speed and pressure for high-precision part production.
• Metallurgical Equipment:
• Rolling mill screw-down systems and continuous casting machine screw-down systems for precise position control under heavy loads.
2. Aerospace
• Flight Simulators:
• Drives motion platforms to simulate flight attitudes, requiring high response and low latency.
• Engine Testing:
• Regulates fuel or hydraulic system flow/pressure during testing for accuracy.
3. Energy & Marine
• Wind Turbines:
• Pitch control systems adjust blade angles to optimize wind energy capture.
• Ship Steering Gear:
• Provides precise steering control against water resistance.
4. Construction Machinery
• Excavator Slewing Drives:
• Replaces high-speed motor + reducer combinations, simplifying transmission systems.
• Crane Hoisting Mechanisms:
• Stabilizes heavy-lift operations to avoid shock loads.
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IV. Technical Advantages
1. High Efficiency & Energy Savings
• Pilot-stage flow utilization exceeds90%, reducing energy consumption, especially in multi-valve parallel systems.
2. High Reliability
• Mechanical feedback design minimizes electronic component failure risks, maintaining positional accuracy even under contamination or fluid force interference.
3. Integration & Intelligence
• Optional built-in fieldbus interfaces (e.g., CANopen, EtherCAT) support parameter configuration, valve activation, and performance monitoring.
4. Standardization & Compatibility
• Installation specifications comply withISO 10372-04-04-0-92, facilitating integration with other equipment.
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V. Selection & Usage Guidelines
1. Model Selection
• Choose based on system pressure, flow requirements, and installation space (e.g., G761-3003B, G761-3512B).
2. Installation Specifications
• Ensure external control port sizes meet standards (some models require additional adapters).
3. Maintenance & Care
• Regularly check hydraulic fluid cleanliness to prevent contaminants from entering the valve.
• Follow manufacturer-recommended replacement intervals for seals and filters.
