Radial Piston Pumps

Fixed Displacement and High Pressure Hydraulic Performance

Radial piston pumps are designed for continuous high-pressure operation in compact hydraulic systems. Pressures of up to 650 bar are normal, meaning, they’re ideal for applications requiring precise flow control and long-term reliability – even under extreme conditions.

While most models are fixed displacement, some advanced designs allow individual plungers to be deactivated, offering a form of variable displacement for added flexibility.

Our website shows only a selection of what we supply. For impartial advice and access to our full range of hydraulic components, contact our expert team.

radial piston pumps. For impartial advice and access to our full range of hydraulic components, contact our expert team.

Radial piston pumps use a series of plungers arranged around a central shaft. These plungers connect to a floating ring, which is moved horizontally by a control lever. This movement creates eccentricity, altering the stroke length and discharge volume. By shifting the eccentricity, the pump can reverse suction and discharge without interrupting flow.

Some designs allow plungers to be switched off individually, enabling a semi-variable displacement mode, useful for systems that require adaptable flow without sacrificing pressure.

Our award-winning team of hydraulic experts can provide world-class support and supply radial piston pumps directly from leading manufacturers, including: Bosch Rexroth, Parker, SAI, Hawe …and more. Whether you’re replacing a unit or designing a whole new system, we’ll always help you find the optimal solution.

Hydraulics Online is also proud to be the only company in the fluid power sector to hold Export Champion status – trusted by customers in over 130 countries across more than 20 industrial sectors.

When should I choose a radial piston pump instead of an axial piston pump? Radial piston pumps come into their own when extremely high pressures, stable flow at very low speeds, or long‑duration continuous duty are required. Their multi‑piston layout distributes load evenly, making them more tolerant of pressure spikes and better suited to applications where reliability under harsh conditions is non‑negotiable.

How sensitive are radial piston pumps to contamination and fluid quality? Because radial piston pumps rely on tight tolerances and precise piston movement, fluid cleanliness has a major impact on service life. They generally handle high pressures well, but contamination can cause accelerated wear or sticking plungers. Correct filtration and fluid conditioning are essential for maintaining long‑term performance.

What factors influence the efficiency and smoothness of a radial piston pump? Efficiency is shaped by piston geometry, the design of the cam or eccentric mechanism, and how well the pump is matched to the system’s operating pressure. Smoothness improves when the number of pistons increases, as this reduces flow ripple. If your system is sensitive to pulsation or vibration, we can help you select a configuration optimised for low‑ripple output.