Product Overview
The A3H56-FR01KK-10 is a YUKEN A3H series high-pressure variable displacement axial piston pump, employing a swashplate-type axial piston design with a nominal geometric displacement of 56.3 cm³/rev, a maximum working pressure of 35 MPa (350 bar), and a rated working pressure of 28 MPa (280 bar). The series covers seven sizes from A3H16 to A3H180, spanning displacements of 16.3–180.7 cm³/rev, representing YUKEN’s high-performance variable piston pump platform for industrial hydraulic systems.
The full order code A3H56-FR01KK-10 decodes as follows: A3H indicates the high-pressure variable piston pump series; 56 is the nominal size (geometric displacement 56.3 cm³/rev); F specifies flange mounting type; R specifies clockwise rotation (standard direction, viewed from shaft end); 01 specifies pressure compensator control — the pump automatically reduces displacement to maintain constant pressure when system pressure reaches the set value; K (pressure adjustment range) specifies 5–35 MPa adjustable; K (shaft extension) specifies keyed shaft; 10 is the design number.
Manufactured to exact YUKEN A3H56 platform specifications, this pump delivers true drop-in interchangeability. Every unit undergoes 100% simulated operating condition testing before shipment.
Technical Specifications
The following specifications are based on YUKEN A3H series official product catalog (JC-10001-12) and authorized distributor technical data:
Model: A3H56-FR01KK-10
Manufacturer: YUKEN
Series: A3H series
Design: Swashplate-type axial piston variable displacement pump, open circuit
Nominal Size: 56
Geometric Displacement: 56.3 cm³/rev (3.44 in³/rev)
Minimum Adjustment Flow: 35.0 cm³/rev (2.14 in³/rev)
Rated Working Pressure: 28 MPa (280 bar / 4066 PSI)
Maximum Working Pressure: 35 MPa (350 bar / 5082 PSI)
Maximum Speed: 2500 rpm (at 0 kPa suction port pressure)
Minimum Speed: 600 rpm
Pressure Adjustment Range: 5–35 MPa (K-type range)
Rotation Direction: Clockwise (R, viewed from shaft end)
Control Type: 01 — Pressure compensator control
Mounting Type: Flange mounting (F)
Shaft Specification: Keyed shaft (K)
Design Number: 10
Mass (Flange Mounting, with 01 Control): Approx. 25.7 kg (56.7 lb)
Mass (Foot Mounting, with 01 Control): Approx. 33.2 kg
Volumetric Efficiency: ≥95% (at 35 MPa, 1800 r/min)
Overall Efficiency: ≥90% (at 35 MPa, 1800 r/min)
Operating Fluid: Petroleum-based hydraulic oil (ISO VG 32 or 46)
Viscosity Range: 20–400 cSt (at 60°C)
Fluid Cleanliness Requirement: NAS Grade 10 or better
System Type: Open-circuit hydraulic system
Key Technical Advantages
1. Efficient Variable Control via Pressure Compensator
The A3H56-FR01KK-10 employs 01 pressure compensator control. When system pressure reaches the set value, the swashplate automatically returns toward center, reducing displacement from maximum 56.3 cm³/rev to minimum 35.0 cm³/rev, delivering only the flow required to maintain system pressure. This control method significantly reduces power loss and oil temperature rise in injection molding holding phases and die-casting clamping cycles. The pressure adjustment range is 5–35 MPa, with a pressure adjustment of approximately 5.5 MPa per turn of the adjustment screw, allowing flexible on-site setting for specific operating conditions.
2. High Volumetric and Overall Efficiency
The A3H series features precision-ground piston/cylinder assemblies and an optimized valve plate design, achieving volumetric efficiency above 95% and overall efficiency exceeding 90% at 35 MPa and 1800 r/min. This efficiency level leads its class among comparable high-pressure variable piston pumps, directly reducing system energy losses and operating costs.
3. Compact Size and High Power Density
The A3H series is renowned for its high output power-to-mass ratio, with a compact pump body design. The A3H56 flange-mounting version weighs approximately 25.7 kg, offering a small installation envelope and high power density within its displacement class. The compact structure facilitates integration into space-constrained industrial hydraulic power units and machine tool hydraulic systems.
4. Low Noise Operation and High Reliability
The A3H series utilizes an optimized swashplate curve and port timing design to maintain low noise levels across the full pressure range. Validated through long-term market service, the series offers high reliability and low failure rates, with extensive application experience and a strong reputation in injection molding machines, die-casting machines, machine tools, and other industrial equipment.
5. 100% Simulated Operating Condition Testing
Every pump undergoes a comprehensive factory test protocol: continuous operation at 28 MPa rated pressure to verify volumetric and overall efficiency, 35 MPa peak pressure cycling to validate housing and seal integrity, and full-speed-range verification (600–2500 rpm) of pressure compensator response and flow output linearity. Test documentation is supplied with each unit.
Application Areas
Injection Molding and Blow Molding Machines: Hydraulic power systems for plastic injection molding machines — pressure compensator control suits holding-phase duty
Die-Casting Machines: High-pressure clamping and injection hydraulic systems — A3H56 suits 200–300T die-casting machines
Hydraulic Presses: Hydraulic power units for various hydraulic press applications
Machine Tool Hydraulic Systems: CNC machine tools, machining center hydraulic power units — pressure compensator control suits clamping and holding duty
Metallurgical Equipment: Hydraulic power systems for steel processing equipment
Marine Hydraulic Systems: Marine deck machinery and steering gear hydraulic power units
Expert Maintenance Tips
1. Installation Position and Filling Port Orientation
The filling port must face upward during pump installation. If air cannot escape through the filling port, cavitation and noise will result, potentially damaging the valve plate and piston/cylinder assembly. After installation, fill with clean hydraulic fluid through the filling port until oil overflows. The A3H56 case oil filling capacity is 900 cm³.
2. Shaft Alignment Requirements
Use a flexible coupling whenever possible to avoid stress from bending or thrust. Maximum permissible misalignment is less than 0.1 mm TIR, and maximum permissible misangularity is less than 0.2°. Poor alignment will cause premature bearing failure and shaft seal leakage.
3. Suction Pressure and Piping Requirements
Permissible suction pressure at the pump suction port ranges from -16.7 to +50 kPa. When speed exceeds 1800 r/min, suction pressure should be maintained between 0 and +50 kPa. Suction piping should use pipe of the same diameter as the specified pipe flange, with the pump suction port height within one meter above the reservoir oil level. The A3H56 case drain port fitting size is 3/4″, with a minimum pipe ID of 16 mm. The pipe end must be submerged in oil and must not be combined with other return lines.
4. Fluid Cleanliness and Filtration Requirements
Maintain oil contamination within NAS Grade 10. The suction port must be equipped with at least a 100 μm (150 mesh) reservoir-type filter, and the return line must have a line-type filter of under 10 μm. Replace the return filter after the first 200 hours, then inspect or replace every 500 hours.
5. Pressure and Flow Adjustment Procedure
Pumps are shipped with pressure set to minimum and flow set to maximum. Readjust according to operating conditions before use. The pressure adjustment screw increases pressure when turned clockwise — A3H56 adjustment is approximately 5.5 MPa per turn. The flow adjustment screw decreases flow when turned clockwise — adjustment is approximately 4.2 cm³/rev per turn. Always lock the fixing nut after adjustment.
