Description
Woodward 8528-104
Technical Specifications
- Actuation Type: Single-acting or double-acting electro-hydraulic.
- Control Signal Input: 4-20 mA or 0-10V DC from electronic governor.
- Position Feedback: Integrated LVDT or potentiometer for closed-loop control.
- Hydraulic Pressure: Operates on standard engine lube oil or dedicated hydraulic supply.
- Force Output: High-force output capable of overcoming fuel rack friction and spring loads.
Functional Features
- Fail-Safe Spring Return: Internal spring automatically drives the fuel rack to the shut-off position upon loss of hydraulic pressure or electrical power.
- High Resolution: Minimal hysteresis and deadband for precise fuel metering.
- Integrated Positioner: Built-in electro-hydraulic servo valve for fast, accurate response.
- Damping Adjustment: External adjustable damping to prevent hunting and oscillation.
Application Scenarios
Used extensively in medium and large diesel engines, dual-fuel engines, and industrial gas turbines requiring precise fuel control.
Performance Parameters
- Response Time: Fast dynamic response for excellent transient load acceptance.
- Linearity: High positional linearity across the entire operating stroke.
- Pressure Rating: Rated for continuous operation at standard engine oil pressures.
Material Composition
Precision-machined steel body with hardened internal components. Seals are made of high-performance elastomers compatible with petroleum-based hydraulic fluids.
Structural Characteristics
- Mounting: Flange or bracket-mounted design for direct attachment to the engine fuel pump.
- Connections: Standard SAE or NPT hydraulic ports and multi-pin electrical connector.
- Adjustments: External screws for zero and span calibration of the position feedback.
Working Principle
The governor sends a current signal to the actuator’s internal torque motor, which shifts the servo valve spool. This allows pressurized oil to enter the actuator piston chamber, moving the piston against the spring force. The integrated LVDT continuously monitors the piston position and provides feedback to maintain the exact commanded position.
Installation Requirements
- Ensure hydraulic supply oil is clean and meets Woodward filtration specifications.
- Mechanically link the actuator to the fuel rack with zero binding or side load.
- Connect the position feedback wiring using shielded cable.
Usage Precautions
- Always verify the fail-safe spring is functioning correctly before placing the engine in automatic mode.
- Do not exceed the maximum hydraulic pressure rating to prevent seal damage.
- Periodically check for external oil leaks and verify linkage tightness.
