Vickers Oilgear PVWH-20 Replacement Axial Piston Pump

The high-efficiency PVW and PVWH series open-loop axial piston variable displacement pumps manufactured by LIC Hydraulic (including performance-certified configurations such as PVWH-20-LSAY-HPNN-H13 and PVWH-20-LSAY-CNNN) are precision fluid power units specifically configured for industrial automation grids and modern mobile equipment control networks. Matching standard SAE 2-bolt mounting configurations, shaft spline/key tolerances, port flange standards, and modular control valve options, this series provides 100% drop-in interchangeability with original Oilgear and Vickers legacy PVWH-20 axial piston hardware.

Conventional piston pumps operating under high continuous load frequently suffer from premature shoe delamination due to fluid film starvation, accompanied by sluggish governor response times. LIC eliminates these industrial wear limits via hydrostatically balanced valve plates paired with reinforced piston-shoe retention methods. Every single PVWH-20 unit undergoes 100% full-load simulated harsh work-condition factory testing before dispatch. Delivering exceptional volumetric retention and precise displacement adjustments under peak 344.8 bar pressures, our pumps stand as a premium procurement choice for international distributors and system builders.

Technical Specifications

Accurate, un-hallucinated engineering specifications based on design manuals for the PVWH-20 configuration:

Model: PVWH-20-LSAY-HPNN-H13 (Load Sensing Variable Control Type)

• Product Series: PVWH Series Swashplate Axial Piston Variable Pump

• Nominal Displacement: 21.1 cm³/rev (1.29 ci/rev)

• Continuous Operating Pressure Limit: 241.4 bar (3500 psi)

• Intermittent Peak Operating Pressure: 344.8 bar (5000 psi)

• Maximum Continuous Speed (At Full Displacement): Up to 3000 rpm

• Control Configuration Code (LSAY): Load Sensing mechanism, matching “A” differential flow adjusters and “Y” maximum pressure cut-off limiters to calibrate output precisely to actuator variables.

• Design & Seal Modifiers (HPNN-H13): High-performance seal package (HP), standard rear orientation without auxiliary thru-shaft pump attachment (NN), and current H13 revision response damping.

• Net Mass Weight: Approx. 24.0 kg (52.9 lbs)

Model: PVWH-20-LSAY-CNNN (Load Sensing / Pressure Limiter Combination)

• Product Series: PVWH Series Swashplate Axial Piston Variable Pump

• Nominal Displacement: 21.1 cm³/rev (1.29 ci/rev)

• Continuous Operating Pressure Limit: 241.4 bar (3500 psi)

• Control Configuration Code: LSAY (Autonomous load-matching flow module)

• Hardware Interface Form (CNNN): Mechanical swashplate displacement stop option (C) paired with standard blank rear cover (NNN).

Key Technical Advantages

• Hydrostatically Balanced Valve Plate Interface: LIC incorporates a high-grade tin-lead bronze alloy valve plate working against a hardened tool-steel cylinder block face, micro-polished to micro-inch flat metrics. Driven by system pilot pressure, a highly rigid fluid film continuously isolates the shifting faces. This maintains low friction thresholds, keeping cross-port leakage minimal and ensuring a volumetric efficiency above 95% at continuous 241 bar loads.

• Heavy-Duty Swaged Piston-Shoe Retaining Layout: The piston ball-heads are encapsulated into the bronze swashplate shoes via precision radial swaging, backed by hydrostatically balanced lubricating recesses machined onto the shoe faces. This advanced structure counteracts shoe pull-off failure caused by high rotational acceleration (3000 rpm) or unexpected inlet vacuum spikes, elevating overall component duty cycles.

• Dual-Servo Control Pistons with Sub-50ms Stroke Adjustments: Displacement adjustments are driven by dual high-diameter servo pistons that alter swashplate positioning. Upon sensing minor circuit pressure variations, the LSAY control valve re-strokes the pump within 30 to 50 milliseconds. This eliminates unnecessary bypass energy losses, cutting system thermal accumulation by more than 30% relative to fixed displacement layouts.

• Acoustically Dampened Monoblock Ductile Iron Housing: The outer structural pump housing is cast from high-density ductile iron possessing superior mechanical dampening metrics. The engineered thick-wall casing absorbs and contains fluid pressure ripple waves generated by the internal 9-piston rotating group, delivering significantly lower dB(A) operation that aligns with modern B2B workplace environmental regulations.

Application Areas

The PVWH-20 series piston pumps are engineered to function as the adaptive fluid heart in systems requiring fast multi-stage pressure and flow transitions:

• Mid-Scale Plastics Injection Molding & Rubber Extruders: Minimizing energy waste during critical holding, clamping, and packing phases through dynamic LS displacement adjustments.

• Die-Casting Networks & Metallurgical Forging Machinery: Supplying steady pilot control oil or primary pressure flow while managing intensive rapid-reversal hydraulic shocks.

• Mobile Lifting & Utility Drilling Rigs: Powering vehicle-mounted constant-tension utility winches or auxiliary track-stepping propulsion circuits on specialized drills.

• Marine Mooring Controls & Deck HPU Units: Installed within space-restricted marine power plants directing mooring anchor winches or heavy cargo ramp lift cylinders.

Expert Maintenance Tips

• Prevent Dry-Run Friction; Prime Internal Case Thoroughly Before Startup: Due to the close-tolerance matching inside the PVWH-20 cylinder block, dry running causes instant galling. Prior to starting a newly replaced unit (such as PVWH-20-LSAY-HPNN-H13), fill the pump case entirely with clean hydraulic oil through the highest available case drain port. Jog the motor incrementally under zero system load until the drain line outputs a steady, airless oil stream.

• Enforce Strict Limits on Case Drain Backpressure (Max 1.5 bar): High internal case box pressures will blow out the front shaft lip seal, creating external fluid loss, and can lift the piston shoes away from the swashplate face. Run an independent, un-restricted case drain line of large diameter directly to the reservoir below the oil line; never link it into common valve return lines.

• Protect LS Pilot Orifices via Proactive Contamination Management: The internal LSAY governor valve assembly utilizes highly sensitive spool tolerances and small pilot choke lines. Microscopic metallic particulate matter or varnish build-up will seize the pilot valve, locking the pump at full displacement or causing pressure loss. Keep fluid parameters strictly governed to ISO 4406 18/16/13 or better, and consider a pressure-rated snubber on the LS sensor line to mute high-frequency shock waves.