How Do Hydraulics Work In a Scissor Lift

How Do Hydraulics Work In a Scissor Lift

Meta Description: Learn about hydraulic power scissor lifts, their components, operation, and safety mechanisms, and how they are used for efficient vertical movement.

This article provides a straightforward breakdown of how scissor lifts utilize hydraulic systems to raise and lower their lifting platforms. It examines the essential components and sequence of operations, from hydraulic fluid and pumps to cylinders, valves, and safety mechanisms.

Key Takeaways

• Scissor lifts use hydraulic fluid and pumps to pressurize fluid and power cylinders, enabling vertical movement.
• Cylinders attached to scissor arms and platforms raise and lower the lift through hydraulic pressure changes.
• Control valves regulate fluid flow for various job sites and industries to raise or lower the platform as needed.

Understanding the Scissor Lift Basic Components

A scissor lift uses hydraulic fluid, typically oil, to power its hydraulic cylinders, pumps, and control valves. The lift consists of scissor legs or arms that fold up and down in a crisscross pattern through pivot points at their hinged intersections.

A lifting platform is load-bearing and attached to the top of the scissor mechanism, which can raise and lower the hydraulic scissor lift work platform to desired heights through the lifting action of pneumatic or hydraulic cylinders as needed for various construction, building, and repair jobs that require handling heavy loads or reaching operating heights.

Essential Steps On How Scissor Lift Work

A scissor lift uses various components to raise and lower its lifting platform. The first essential component is the hydraulic fluid that powers the lift’s movements.

1. Hydraulic Fluid

Hydraulic fluid, typically oil, enables the scissor lift to function through hydraulic pressure. The fluid is stored in a reservoir tank and pressurized with a hydraulic pump. It then flows through control valves and hydraulic cylinders, utilizing hydraulic pressure to power the scissor lift’s up-and-down movements.

This pressurized hydraulic fluid fills the cylinders attached to the scissor arms and lifting platform. When the valves are opened, the fluid enters the cylinders, forcing the piston upwards and extending the structure of the scissor mechanism.

This folding and unfolding of the crisscrossing scissor arms and blades connected at pivot points allows the load-bearing lifting platform to reach various operating heights needed for construction, building repairs, and handling heavy loads.

2. Pump

The hydraulic pump is a critical component that pressurizes the hydraulic fluid to power the lift. Electric motors or combustion engines typically drive hydraulic pumps, which use their power source to pressurize the fluid within the hydraulic system.

When activated, the pump creates pressure, enabling the fluid to flow and exert force through the lift’s other components.

3. Cylinders

Hydraulic cylinders are located at each corner of the scissor lift, attached to both the scissor arms and the lifting platform. When filled with pressurized hydraulic fluid that enters the cylinders, the fluid pushes upwards on the piston inside each cylinder. This action extends the cylinders and raises the structure formed by the crisscrossing scissor arms and blades connected at hinged pivot points.

The lifting platform, load bearing and stable, can then be raised to the desired operating height needed for construction work, equipment operation, building repairs, and handling heavy loads at height.

4. Valves

Control valves regulate the flow of pressurized hydraulic fluid to the cylinders. They can be opened or closed using valve controls to determine the direction of fluid movement. This controls whether the lift platform moves upwards or downwards.

5. Lift in the Lowered Position

When in the lowered position, the control valves are typically closed. This prevents the hydraulic fluid from flowing out of the cylinders. Then, the weight of the lifting platform and any loads attached cause the scissor arms to fold down in their crisscross pattern at the intersections of the hinged pivot points.

This compresses the fluid inside the hydraulic cylinders until the structure is fully retracted. The stable platform can then be used at ground level for load-handling tasks.

6. Lift in the Raised Position

When the operator needs to raise the lift platform, a control is activated to open the valves. This allows the pressurized hydraulic fluid from the pump to enter the cylinders. The fluid exerts force on the piston inside each hydraulic cylinder, extending the hydraulic cylinders and unfolding the scissor arms structure.

The crisscrossing scissor arms and blades then raise the stable and load-bearing lifting platform vertically to the desired operating height for tasks.

7. Safety Mechanisms

Hydraulic scissor lifts generally incorporate safety mechanisms like check valves to prevent sudden descent of the work platform. These provide overload protection to ensure the stable platform remains safely at height, even in a hydraulic system failure. This protects anyone onboard and equipment or materials being handled at height.

8. Release of Pressure

To lower the lifting platform, the operator activates controls that open the valves, allowing the release of pressurized hydraulic fluid from the cylinders. As the pressure escapes, the weight of the stable and load-bearing platform causes the scissor arms to fold back down in their crisscross pattern through the hinged pivot points.

The lowering action compresses the fluid back into the hydraulic cylinders until the pantograph structure is fully retracted, lowering the work platform for safe ground-level access.

This controlled lowering using hydraulic pressure release enables convenient vertical movement to and from the desired operating heights needed for construction, building repairs, and load handling.

Benefits of Hydraulic Scissor Lifts

Here are some possible benefits of hydraulic scissors, including:

• Hydraulic scissor lift tables offer robust lifting capabilities, efficiently powered by hydraulic systems and electric motors, allowing smooth up and down movement for various applications.
• Standard scissor lifts, including hydraulic versions, provide sturdy lifting mechanisms with cross-braced arms and steel supporting beams, ensuring a stable platform for safely lifting heavy loads.
• The hydraulic scissor lift mechanism presents a pantograph design with connected scissor blades, operated by cylinders filled with compressed air pressure or hydraulic fluid, allowing for precise control of the lift table’s height.
• These scissor lift tables boast a high weight capacity, with the hydraulic system’s flow control valve and down valve regulating the lifting unit’s speed and ensuring controlled descent.
• Whether for construction sites or industrial settings, hydraulic scissor lifts offer a reliable lifting solution with their versatile design, remote power pack options, and ability to extend to the desired height while maintaining platform stability.