1. Power Components (Hydraulic Pumps)

2. Actuating Components (Hydraulic Cylinders)

3. Control Components (Hydraulic Valves)

Function: Regarded as the brain and nerve of the system, they govern and adjust oil flow direction, system pressure and flow rate.

• Directional control valves (e.g. directional spool valves): Change oil flow path to control cylinder lifting, lowering and halt.

• Pressure control valves (e.g. relief valves): Cap maximum working pressure and provide overload protection.

• Flow control valves (e.g. throttle valves): Modulate oil supply flow to adjust lifting speed.

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4. Auxiliary Components

• Oil tank: Stores hydraulic fluid and dissipates operational heat.

• Oil filter: Maintains fluid cleanliness to avoid component abrasion and blockage.

• Tubing & fittings: Connect all components and deliver pressurized oil.

• Seals: Prevent hydraulic fluid leakage.

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5. Working Medium (Hydraulic Oil)

III. Main Features

Advantages

1. High output force: Hydraulic units are compact and lightweight at equal power rating while delivering massive lifting thrust.

2. Stable operation: Low compressibility of hydraulic fluid enables smooth transmission with reliable overload protection.

3. Stepless speed regulation: Flow valves facilitate wide-range stepless adjustment of lifting speed.

4. Easy automatic control: Compatible with electrical parts to realize complex sequential motion and remote control.

Disadvantages

1. Potential fluid leakage: High precision machining and strict sealing standards are required; leakage may cause contamination and efficiency loss.

2. Temperature sensitivity: Oil viscosity varies with ambient temperature and impairs system stability.

3. Strict maintenance criteria: Regular fluid cleaning is required to avoid clogging and premature wear.

4. Higher cost: Higher upfront investment and professional maintenance cost versus purely mechanical equipment.

Typical Application Fields

• General Industry: Injection molding machines, die-casting machines, machine tools, lifting tables and workpiece clamping units on automated production lines.

• Construction Machinery: Boom & bucket lifting systems for excavators, loaders, truck cranes and bulldozers.

• Logistics & Transportation: Hydraulic lift tables, forklifts, container tippers and truck tail lifts.

• Aerospace: Aircraft door actuation, landing gear retraction and flight simulator equipment.

• Special Vehicles: Lifting mechanisms for aerial platform vehicles, fire ladder trucks and wreckers.

• Civil Use: Hydraulic jacks, vehicle lifts for auto repair, disabled access lifts and hydraulic elevators.

Maintenance & Troubleshooting Guidelines

• Keep hydraulic oil clean: Periodically replace hydraulic fluid and filter cartridges to extend service life.

• Eliminate external leakage: Regular inspection of pipelines and sealing elements.

• Bleed trapped air: Entrapped air leads to judder, creeping or abnormal noise and must be vented promptly.

Common Malfunctions

1. No lifting or insufficient thrust: Low oil level, defective pump, faulty relief valve or severe internal leakage.

2. Excessively slow lifting speed: Insufficient pump flow, undersized throttle opening or overly high oil viscosity.

3. Unexpected load dropping during standby: Internal leakage inside cylinders or valves, malfunction of pilot operated check valves (hydraulic locks).

4. Abnormal noise & vibration: Air ingestion, contaminated oil or worn pump components.