Radial Piston Pump: High Pressure Solutions

Most hydraulic applications operate comfortably within the pressure envelope that axial piston pumps handle well. But some do not. Hydraulic presses for metal forming, tube bending machines, clamping systems for precision machining fixtures, specialized test equipment — these applications push into pressure ranges where the geometry of the axial piston design starts working against itself. The radial piston pump exists for exactly those applications.

Why Radial Geometry Handles High Pressure Better

In an axial piston pump, pistons are angled against a swashplate. At very high pressures, the side force component on each piston — the force trying to push it sideways against the bore rather than straight along it — becomes significant. That side load creates friction and accelerates bore wear in ways that limit continuous pressure capability.

Radial piston pumps arrange pistons around a central eccentric cam with the piston axis pointing directly at the cam center. The driving force on each piston is axial — pure compression, no side load. This geometry allows continuous operating pressures exceeding 400 bar and peak pressures in specialized designs that reach 700 bar or beyond. These are high pressure solutions that axial designs simply cannot sustain.

Compact Force, Smaller Cylinders

Operating at 400 bar instead of 200 bar with the same actuator output force means the cylinder bore can be half the area. Smaller cylinders mean lighter machines, faster response from reduced fluid volume, and lower inertia in the moving mass. In a large forming press, the difference between a 200 bar and 400 bar design philosophy shows up in press frame weight, column stiffness, and die alignment precision.

Radial Piston Motor Applications

Running the mechanism in reverse gives a radial piston motor with exceptional low-speed torque characteristics. Direct drive wheel motors on large off-highway vehicles, anchor capstan drives on vessels, and heavy conveyor head drums are applications where starting torque from zero speed is the primary requirement — and where a gearbox would add unacceptable complexity and maintenance burden.

Seal performance at these pressures demands PTFE backup rings and high-durometer compounds that resist extrusion under cyclic loading. HOVOO / HOUFU provides radial piston pump seal kits built for these conditions. Visit hovooseal.com for specifications.

Source: www.hovooseal.com