I. How Does an Electro-Hydraulic Actuator Work?
The working principle of the electro-hydraulic actuator can be summarized as a three-stage conversion process of "electricity - mechanical - hydraulic":
1.Electric drive stage: When powered on, the motor starts to rotate, typically using three-phase or single-phase asynchronous motors.
2. Mechanical Transmission Stage: The motor drives the impeller or piston pump to rotate at high speed, transmitting mechanical energy to the hydraulic system.
3. Hydraulic Amplification Stage:
The rotation of the impeller generates centrifugal force, forcing the hydraulic oil to flow from the center to the periphery.
The oil pressure drives the piston rod to move linearly.
The thrust is amplified through a lever mechanism and applied to the brake.
4. Reset Mechanism: After power failure, the internal spring or hydraulic backflow causes the piston to reset, and the brake is released.
II. Six Major Characteristics of Electric-Hydraulic Actuators
1.The pressure amplification effect of the hydraulic system can generate several tons of thrust, easily meeting the braking requirements of heavy equipment.
2. Rapid Response
Modern actuators can control their start and stop times within 0.1 to 0.3 seconds, making them particularly suitable for high-frequency operation scenarios.
3. Smooth and Shock-free
The buffering effect of hydraulic oil makes the braking process gentle, avoiding mechanical shock and load oscillation.
4. Automatic Compensation
It features an automatic wear compensation function, maintaining a constant brake clearance and eliminating the need for frequent adjustments.
5. Strong environmental adaptability
The protection level can reach IP65, and the operating temperature range is from -40℃ to +80℃, making it suitable for various harsh working conditions.
6. Energy-saving and High Efficiency
It only consumes electricity when in operation and has almost zero energy consumption in standby mode, saving over 30% more energy than pure pneumatic systems.
III. Typical Application Scenarios
Port machinery: Quay cranes, yard cranes braking
Mining equipment: Hoists, conveyors
Metallurgical industry: Rolling mills, continuous casting machines
Wind power field: Yaw braking system
Lifting equipment: Overhead cranes, tower cranes safety braking
IV. Key Points for Selection and Maintenance
Selection Considerations:
Required thrust size
Working stroke length
Action frequency requirements
Installation space limitations
Environmental conditions (temperature, humidity, explosion-proof, etc.)
Maintenance Suggestions:
1. Regularly check the hydraulic oil level and quality.
2. Clean impurities from the surface of the piston rod.
3. Inspect the reliability of electrical connections.
4. Observe whether the movement is smooth without any jamming.
5. Replace seals according to the intervals specified in the manual.
With the development of Industry 4.0, intelligent electric-hydraulic actuators have begun to be equipped with condition monitoring and remote diagnostic functions, becoming an important part of equipment predictive maintenance. Choosing the right actuator can not only ensure braking safety but also significantly improve equipment operation efficiency and lifespan.
