What is difference between variable piston pump and fix piston pump？

There are two primary types of hydraulic pumps to choose from: fixed displacement and variable displacement. Choosing the right kind of pump is essential to generating the correct amount of fluid pressure and volume while ensuring the pump and hydraulic system operate efficiently. It’s ultimately about optimizing the performance of your system while proactively controlling costs.

What Is a Fixed Displacement Pump?

A fixed displacement hydraulic pump is ideal when you need a predetermined and constant fluid volume for each pumping cycle. They are referred to as fixed displacement pumps because the volume of fluid pressure for every stroke is fixed.

Internal gear and external gear pumps are both examples of fixed displacement pumps as they generate a constant flow rate. Gear pumps are inexpensive, don’t produce much heat, operate at high speeds, generate high flow rates, and are relatively quiet during operation. Vane and piston pumps can also be fixed.

Common Applications

Fixed displacement pumps are ideally suited for equipment and machinery that require high fluid pressures. These pumps can also handle a wide range of viscosities and are ideal for industrial manufacturing environments where dirt and debris are present.

Common applications for fixed displacement pumps include:

• Material Handling
• Machine Tools
• Conveyors
• Industrial Manufacturing Machines
• Marine Applications
• Agricultural Equipment
• Lubrication Systems

What Is a Variable Displacement Pump?

The variable displacement hydraulic pump is called variable because the fluid volume per stroke can be altered or changed electronically, hydraulically, or manually during operation.

Because of its ability to adjust its flow rate for different applications, the variable displacement pump is more complex in its design. As such, it’s a more expensive pump, and its maintenance and upkeep costs are higher than a fixed displacement pump. However, the costs are offset by its energy efficiency and ability to operate different equipment.

Common Applications

You’ll often find variable displacement pumps in heavy-duty industrial, commercial, and construction equipment like cranes, excavators, and backhoes, or any application where fluid pressure must adjust for different loads.

General applications for these pumps include:

• Cranes
• Excavators
• Backhoes
• Industrial Automation Systems
• High-Performance Machine Tools
• Marine Propulsion Systems
• Mining Equipment
• Medical Devices
• Wind Turbines
• Injection Molding Machines
• Some Harvesters & Tractors