High Quality ED Series Electro Hydraulic Thrusters

 

 

 

2. Working Principle

The ED Series operates on a closed-loop electro-hydraulic conversion principle, integrating an electric motor, hydraulic pump, reservoir, and cylinder into a compact unit. Its working cycle includes three key states:

2.1 1. Thrust Output (Brake Release/Clutch Engagement)

When the machinery (e.g., a crane hoist) is activated, the control system supplies 380V AC (or 220V AC) power to the thruster's electric motor.

The motor drives a gear pump (or vane pump) to draw hydraulic oil from the integrated reservoir. The pump pressurizes the oil (typically 8–16 MPa, depending on the model).

Pressurized oil flows into a single-acting hydraulic cylinder, pushing the piston and output rod outward. This linear thrust (500–12,500 N) acts on the brake's lever linkage, overcoming spring tension to release the brake (or engage the clutch).

2.2 2. Thrust Retention (Sustained Operation)

Once the output rod reaches the maximum stroke (50–200 mm), a pressure relief valve in the pump opens, diverting excess oil back to the reservoir. This maintains stable pressure in the cylinder, keeping the brake released (or clutch engaged) without overloading the motor.

The motor continues to run at low load, ensuring immediate pressure adjustment if oil leakage occurs (e.g., due to seal wear).

2.3 3. Thrust Cessation (Brake Engagement/Emergency)

When the machinery stops or an emergency occurs, the control system cuts power to the motor. The pump stops, and hydraulic pressure drops.

A built-in check valve prevents oil from flowing back immediately, but residual pressure dissipates as the brake's return springs push the lever linkage. This retracts the thruster's output rod via oil backflow to the reservoir, allowing the brake to engage (or clutch to disengage) and stop the machinery.

3. Core Structure & Key Components

The ED Series features a compact, integrated design with four critical subsystems, optimized for durability and easy maintenance:

3.1 1. Electric Motor (Power Input)

A three-phase AC induction motor (standard: 380V AC, 50Hz; optional: 220V AC, 60Hz) with power ratings from 0.37–7.5 kW. It uses Class F insulation (heat resistance up to 155°C) to withstand continuous operation in high-temperature environments (e.g., steel mills).

The motor is flange-mounted directly to the pump, eliminating transmission losses and reducing overall unit size.

3.2 2. Hydraulic Power Pack (Energy Conversion)

Gear/Vane Pump: A compact, low-noise pump (noise level ≤ 75 dB) that converts motor rotation into hydraulic pressure. Gear pumps are used for low-to-medium pressure models (≤ 12 MPa), while vane pumps suit high-pressure models (12–16 MPa).

Integrated Reservoir: A cast-iron or aluminum reservoir (capacity: 0.5–5 L) that stores hydraulic oil (ISO VG 46 mineral oil). It includes an oil level gauge and air breather to maintain oil quality and prevent contamination.

Pressure Relief Valve: A safety valve that limits maximum system pressure (8–16 MPa), protecting the pump, cylinder, and seals from overpressure damage.

3.3 3. Hydraulic Cylinder (Force Output)

A single-acting cylinder with a chrome-plated output rod (diameter: 20–60 mm) for corrosion resistance and smooth movement. The cylinder's bore (40–125 mm) determines thrust output, while the stroke (50–200 mm) matches the brake's lever travel requirement.

Nitrile rubber (NBR) or fluoropolymer (FKM) seals prevent oil leakage, ensuring reliable performance in temperatures from -20°C to 80°C (FKM for high-temperature models up to 120°C).

3.4 4. Cooling & Protection Components (Durability)

Natural Cooling Fins: Fins on the reservoir and motor housing dissipate heat generated during operation, preventing oil overheating (critical for continuous-duty applications like conveyors).

Environmental Housing: A sheet-steel cover (IP54 protection) shields internal components from dust, moisture, and mechanical impact-suitable for indoor (factories) and covered outdoor (ports) use.

Oil Filter: A 10μm suction filter in the reservoir removes contaminants from the oil, extending the pump and seal service life.

4. Key Features & Advantages

The ED Series is distinguished by its integration, reliability, and compatibility with industrial braking systems, with core benefits:

4.1 1. Compact Integrated Design

Combining motor, pump, reservoir, and cylinder into one unit eliminates the need for external hydraulic hoses and valves. This reduces installation space by 40% compared to split systems and simplifies wiring/pipework.

4.2 2. Stable Thrust & Precise Stroke

The closed-loop hydraulic system maintains consistent thrust (±5% of rated value) and stroke accuracy (±1 mm), ensuring smooth brake release/clutch engagement-avoiding load sway in cranes or mechanical shock in conveyors.

4.3 3. Fast Response & Energy Efficiency

Thrust build-up time (from startup to maximum stroke) is ≤ 0.8 seconds, enabling quick brake release for machinery with short cycle times (e.g., port winches).

The pressure relief valve reduces motor load after reaching maximum stroke, cutting power consumption by 30–50% compared to constant-load systems.

4.4 4. Durable & Low-Maintenance

Class F insulated motors and high-quality seals (NBR/FKM) ensure a service life of ≥ 10,000 working hours under normal operation.

The integrated reservoir and filter simplify oil changes (required every 6–12 months), and replaceable seals/pump parts reduce maintenance costs.

4.5 5. Wide Compatibility

Standardized mounting flanges and output rod dimensions match most industrial brakes (e.g., YWZ4, YWZ5 drum brakes) and clutches. This makes the ED Series a universal replacement for legacy thrusters in retrofitting projects.

5. Typical Applications

The ED Series is primarily used as a power unit for braking and clutch systems in heavy-industry machinery:

Cranes & Hoists: Overhead cranes, gantry cranes, and mining hoists-actuating YWZ-series drum brakes to control hoisting and travel mechanisms.

Conveyors: Belt conveyors (mining, cement plants) and chain conveyors (steel mills)-releasing brakes for material transport and engaging them for emergency stops.

Winches & Windlasses: Port winches, shipyard windlasses, and offshore drilling winches-providing thrust to release load-holding brakes during lifting.

Metallurgical Equipment: Rolling mills, steel coil handlers, and blast furnace hoists-actuating brakes to ensure precise positioning of heavy metal components.

 

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