The working principle of manual hydraulic forklifts is based on hydraulic transmission, which achieves the conversion and transmission of mechanical energy through manual operation, thereby completing the lifting, handling, and landing of goods. The core principles and processes can be summarized as follows:

1、 Fundamentals of Hydraulic Transmission

Manual hydraulic forklifts use oil as the working medium, transmit motion through changes in sealing volume, and transmit power through internal pressure of the oil. This process is similar to a syringe sucking and pushing liquid: when the piston is pushed, the liquid inside the cylinder is squeezed out, achieving the transmission of motion and power.

2、 Core components and working principle

Power section: Hydraulic pump (manual plunger pump/gear pump)

Operation method: The operator presses the handle up and down to drive the plunger of the oil pump through the lever system.

Energy Conversion:

Pressing the handle: The plunger descends, and the oil is sucked into the plunger chamber from the oil tank through the suction valve.

Lifting handle: The plunger moves upward, the oil suction valve closes, and the oil in the plunger chamber is pressed into the cylinder through the oil outlet valve under pressure.

Function: Convert the mechanical energy of human hands into the pressure energy of hydraulic oil (hydraulic energy).

Execution section: Hydraulic cylinder and fork

Hydraulic cylinder operation: After high-pressure oil enters the cylinder, it pushes the piston upwards. The piston is connected to the chain through the piston rod, and the chain drives the fork to rise, achieving the lifting of goods.

Forklift descent: Open the descent valve (manually controlled valve), and the oil in the cylinder flows back to the tank through the descent valve under the gravity of the cargo. The piston moves downwards under the combined action of cargo gravity and oil reflux, causing the fork to descend accordingly.

Function: Convert hydraulic energy into mechanical energy to drive the fork to complete the lifting action.

Control section: Hydraulic valve (pressure/flow/direction control valve)

Pressure control valve: regulates system pressure to prevent overload damage to components.

Flow control valve: controls the flow of oil and adjusts the lifting speed of the fork.

Directional control valve: determines the direction of oil flow, controls the fork to rise, fall, or remain stationary.

Function: Ensure the safe and precise implementation of hydraulic system functions.

Auxiliary parts: pipelines, fuel tanks, filters, etc

Pipeline: Transport hydraulic oil to various components, similar to human blood vessels.

Oil tank: stores hydraulic oil and provides oil reserve for the system.

Filter: Filter impurities in the oil to ensure cleanliness and prevent component wear.

Function: Support the normal operation of hydraulic systems and extend their service life.

3、 Workflow Example

Cargo lifting

The operator presses the handle → the hydraulic pump generates high-pressure oil → the oil enters the cylinder → pushes the piston up → the chain drives the fork to lift the cargo.

cargo handling

By relying on human power to push the forklift handle, walking is achieved by rolling it on the ground through casters (load-bearing wheels+steering wheels).

Cargo landing

Open the descent valve → the oil flows back to the tank → the piston descends → the fork descends with the chain to its initial position.

4、 Characteristics and advantages

Simple structure: No need for engine or motor drive, only manual operation, low cost.

Flexible operation: suitable for handling narrow spaces or light and small goods, such as warehouses, workshops, logistics centers, etc.

Safe and reliable: The hydraulic system provides stable support to avoid the risk of cargo slipping; Safety devices such as overflow valves prevent overload.

Convenient maintenance: With few components and low failure rate, daily maintenance only requires checking the oil, cleaning the filter screen, lubricating the wheel axle, etc.

The main equipment produced by Hebei Makita: stage electric hoist, electric chian hoist, wire rope electric hoist，Hand chain hoist, lever hoist, pneumatic hoist and other lifting equipment