The variable piston pump is a key component of the hydraulic system and plays a vital role in regulating the output flow. These pumps are designed to vary the amount of fluid delivered per revolution of the pump shaft, allowing for flexible flow control based on system requirements.
The mechanism behind variable displacement piston pumps is their ability to vary the displacement of the piston within the pump chamber. Here's how it works:
Piston stroke adjustment: The piston of the variable piston pump can move in and out of the pump chamber. By adjusting the stroke length of these pistons, the volume of fluid displaced during each cycle can be varied. This adjustment is usually achieved by hydraulic, mechanical or electronic means.
Swashplate Angle: Another method used with variable piston pumps is to manipulate the swashplate angle. The swash plate is the inclined surface on which the piston reciprocates. By tilting the swash plate, the effective stroke length of the piston can be modified, thereby changing the pump's output flow.
Control mechanism: The variable piston pump uses a control mechanism to adjust the displacement of the piston or the angle of the swash plate. These mechanisms may include hydraulic feedback systems, electronic controls, or manual adjustments. By monitoring parameters such as pressure, flow, or system demand, these controllers adjust the pump's output to meet the requirements of the hydraulic system.
Feedback Loops: Many modern variable displacement piston pumps utilize feedback loops to maintain precise control of output flow. Sensors measure variables such as pressure, temperature and flow within hydraulic systems. This data is then fed back to the pump's control mechanism so that real-time adjustments can be made to optimize performance and efficiency.
Variable Displacement Designs: Variable displacement piston pumps are available in a variety of designs, including axial, radial and oblique axis configurations. Each design offers unique advantages in compactness, efficiency and flow. Regardless of design, the basic principles of regulating output flow remain consistent across different types of variable displacement pumps.
Variable displacement piston pumps provide a versatile solution for regulating the output flow of hydraulic systems. Through mechanisms such as piston stroke adjustment, swash plate angle manipulation and complex control systems, these pumps can precisely tailor fluid delivery to meet the dynamic demands of industrial applications. Their ability to adapt to changing operating conditions makes them an indispensable component in hydraulic machinery in various fields.
Poocca hydraulic manufacturer sells hydraulic pumps of brands such as Rexroth Parker Danfoss Vickers, among which our most popular is the A10VSO series of Rexroth piston pumps. It has high working efficiency and good performance, and is the choice of more users.
LA...– pressure, flow and power controllers
Using DR (G) equipped pressure control, DRS (DFR1) and other flow control equipment,
In order to maintain a constant transmission torque under changing operating pressures, the swing angle and the corresponding axial piston pump flow rate need to be changed so that the outflow flow rate and pressure remain unchanged. Flow control may be below the power control curve. When ordering, please state clearly the power characteristics to be set at the factory, e.g. 20 kW at 1500 rpm.
A10VSO Piston pump curve performance:
Modern variable displacement piston pumps, such as the Rexroth A10VSO series, go beyond basic flow control. They incorporate advanced technologies that enable:
Precise proportional flow control based on load sensing feedback.
Power limit curves to protect the prime mover or motor.
Compensator control, which automatically adjusts displacement to maintain pressure or flow based on preset values.
Load sensing operation, where the pump adjusts output flow based on load demand, maintaining system stability and fuel efficiency.
These advanced features make variable displacement piston pumps ideal for closed-loop and open-loop systems that require a high degree of automation and precision.
Types of Control Options Available
At Poocca, we offer a variety of variable piston pump control options to suit your system needs:
Control Type Description Application
DR Pressure Only Control Maintains constant system pressure
DFR / DFR1 Pressure + Flow Control Load sensing systems; adjusts flow based on load
LR / LA Pressure Limiting Control with remote control option for systems requiring remote pressure regulation
DH / EP Electro-hydraulic Control for integration with PLCs and digital controllers
Power Control (DP) to maintain constant input power at varying pressure/flow, ideal for systems driven by prime movers with limited power
These control modules are available with factory presets or custom designs. When ordering, we recommend specifying the desired pressure range, flow, speed, and power settings to ensure optimal settings and avoid delays in field adjustments.
Common Use Cases and Industry Applications
Poocca's variable piston pumps are widely used in:
Excavators and Loaders: Enables precise boom and bucket movements with energy-efficient flow demand regulation.
Hydraulic Presses: Ensures smooth pressurization and depressurization with pressure holding function.
Injection molding machines: Match injection, holding and cooling phases with flow and pressure regulation.
Marine equipment: Compact axial piston design enables high output in a narrow cabin.
Agricultural machinery: Reduce engine load under light load conditions and increase flow on demand.
Our customers benefit from fuel savings, smoother system response and lower maintenance costs, especially in demanding 24/7 production environments.
Matching the right pump to your needs
There are several key factors to consider when selecting the right variable displacement piston pump:
System pressure and flow requirements (e.g., 280 bar @ 80 L/min)
Drive motor power limitations (e.g., 20 kW @ 1500 rpm)
Required control type (pressure, flow, load sensing, electronic)
Installation space limitations (compact bent axis vs in-line design)
Fluid type and viscosity range
Ambient temperature and cooling system capacity
Poocca's technical team can assist you with model selection, custom configurations and compatibility checks. We offer a range of products compatible with Rexroth such as A10VSO, A4VG, A11VLO, A7VO, as well as other brands such as Parker PVP, Danfoss PVG and Vickers PVH.
Why Choose Poocca Hydraulic Manufacturer?
✅ One-stop solution – supply standard and custom piston pumps
✅ Full stock – A10VSO series models are fully stocked: A10VSO18, A10VSO28, A10VSO45, A10VSO71, A10VSO100, A10VSO140
✅ Strict quality control – each unit is flow, pressure and leak tested before shipment
✅ Flexible support – technical documentation, graphs, spare parts and remote video assistance are available
✅ Fast delivery time – most popular models can be shipped within 3-5 business days
Our products have been sold to more than 50 countries, and we provide stable supply and reliable quality support to dealers, original equipment manufacturers (OEMs) and machine shops.
Variable piston pumps play a vital role in modern hydraulic systems, providing precise control, energy saving and system protection.
Whether you need to control flow in a high-speed automation system or maintain torque under variable load conditions, a properly configured piston pump like the Rexroth A10VSO series can significantly improve performance.
If you are looking to purchase, replace or upgrade a hydraulic piston pump, Poocca Hydraulic Manufacturing is a supplier you can trust. Let us help you find the right model and the right control solution to ensure your hydraulic system operates reliably.
