A3H180-FR09-55A4K-10 YUKEN Variable Piston Pump

Product Overview

The YUKEN A3H180-FR09-55A4K-10 is a high-pressure variable displacement axial piston pump from the A3H Series, configured with FR09 constant-power/torque control. YUKEN’s official documentation identifies the A3H180-FR09-***K-10 configuration as a high-pressure variable piston pump and specifies a 180.7 cm³/rev geometric displacement.

For the A3H180 FR09 configuration, the official published data confirm:

• 180.7 cm³/rev displacement
• 125 cm³/rev minimum adjustable displacement
• 35 MPa / 350 bar maximum working pressure
• 1800 rpm maximum speed
• 600 rpm minimum speed
• Constant Power (Torque) control
• Approx. 74.2 kg flange-mounted mass
• Approx. 102.2 kg foot-mounted mass.

The public YUKEN documents reviewed do not provide a character-by-character explanation of the 55A4K configuration suffix. It is therefore retained as the complete identification code without assigning unsupported shaft, port or material functions.

For aftermarket replacement, the engineering objective is in-place interchangeability, including mounting geometry, drive interface, port arrangement and FR09 control characteristics, followed by 100% simulated working-condition testing.

Technical Specifications

• Brand: YUKEN
• Complete Model: A3H180-FR09-55A4K-10
• Series: A3H Series
• Pump Type: High-pressure variable displacement axial piston pump
• Control Type: Constant Power (Torque) Control
• Geometric Displacement: 180.7 cm³/rev
• Minimum Adjustable Displacement: 125 cm³/rev
• Maximum Working Pressure: 35 MPa / 350 bar
• Maximum Speed: 1800 rpm
• Minimum Speed: 600 rpm
• Flange-Mounted Reference Mass: approximately 74.2 kg
• Foot-Mounted Reference Mass: approximately 102.2 kg
• Structure: Swashplate axial piston design
• Hydraulic Interfaces Identified in Official Drawing: Suction port, discharge port, case drain port, filling port
• Pressure Adjustment: Provided
• Flow Adjustment: Provided
• Input Power Adjustment: Provided and factory-set.

Pressure Rating Note

The official FR09 documentation reviewed states 35 MPa maximum working pressure, rather than publishing a separate rated and peak value for this exact configuration.

A separate YUKEN A3H R01KK control version is documented at 28 MPa rated / 35 MPa intermittent, but those values must not be transferred to the FR09 model.

Fluid Requirements

For the A3H family, YUKEN-related published specifications for petroleum-based hydraulic oil recommend:

• Anti-wear or R&O hydraulic oil;
• ISO VG 32 or 46;
• Viscosity: 20–400 mm²/s;
• Temperature: 0–60 °C.

Key Technical Advantages

1. Constant-Power / Constant-Torque Regulation

The FR09 control architecture manages pump displacement according to load so that the required output flow and pressure can be delivered without allowing the input power requirement to rise without control.

YUKEN explicitly classifies the FR09 version as Constant Power (Torque) Control Type.

2. Large 180.7 cm³/rev Displacement

With 180.7 cm³/rev displacement and an 1800 rpm maximum speed, the geometric flow capacity is approximately:

180.7 × 1800 / 1000 ≈ 325.3 L/min

This is a theoretical geometric value before volumetric and mechanical losses, not a guaranteed delivered flow.

3. 350 Bar High-Pressure Capability

The FR09 A3H configuration is published with a maximum working pressure of 35 MPa / 350 bar, making it suitable for demanding high-pressure and high-flow hydraulic circuits.

4. Precision Swashplate Variable Mechanism

The A3H uses a swashplate variable-displacement architecture.

Critical manufacturing and inspection points include:

• Cylinder-block geometry;
• Piston fit;
• Piston slipper contact;
• Valve-plate flatness;
• Swashplate surface condition;
• Variable-control mechanism;
• Bearing alignment.

These interfaces directly affect volumetric efficiency, pressure stability and service life.

5. High Volumetric Efficiency

YUKEN’s A3H product information highlights high volumetric efficiency even at 35 MPa / 5080 psi.

For a large 180.7 cm³/rev pump, leakage control at high pressure has a direct impact on actual flow, thermal loading and hydraulic efficiency.

6. Low-Noise, High-Efficiency Design

YUKEN describes its piston pumps as swashplate piston pumps developed for low noise and high efficiency.

In large-displacement units, acoustic performance depends on fluid pulsation, rotating-group balance, suction stability, bearing condition and precision of the valve-plate/cylinder-block interface.

7. High-Flow Power Management

At large displacement, the hydraulic input power can become substantial as pressure increases. FR09 control helps manage the relationship between displacement, pressure, flow and input power, making the configuration suitable for systems where a large amount of hydraulic flow must be supplied without continuously operating at maximum displacement.

8. Verified Engineering Rather Than Unsupported Material Claims

YUKEN’s public documents reviewed here do not disclose complete material grades for every internal component of A3H180-FR09-55A4K-10.

Therefore, no unsupported claims are made regarding:

• Alloy grade;
• Surface treatment thickness;
• Valve-plate material;
• Hardness value;
• Bearing manufacturer.

For replacement manufacturing, these characteristics should be demonstrated through material inspection, dimensional inspection, hardness testing and full bench testing.

Application Areas

Typical applications for A3H180-FR09 include:

• Heavy construction machinery
• Large excavators
• Hydraulic presses
• Material-handling equipment
• Industrial hydraulic power units
• Metallurgical machinery
• Marine hydraulic systems
• High-flow actuator systems
• Heavy-duty machine tools
• Mobile hydraulic equipment

Final compatibility should be checked against:

• Mounting dimensions;
• Drive shaft;
• Suction/discharge ports;
• Rotation direction;
• Control configuration;
• Input-power setting;
• Case drain arrangement;
• Suction conditions.

Displacement and pressure matching alone do not guarantee interchangeability.

Expert Maintenance Tips

1. Do Not Adjust the Input-Power Screw Without Test Data

The official YUKEN drawing identifies the input power setting screw as a factory-adjusted item and specifically warns against turning it.

Before changing any factory setting, verify pressure, flow, speed, inlet conditions and actual input power.

2. Check the Suction Circuit Before Opening the Pump

At large displacement and high speed, inadequate inlet conditions can cause cavitation and unstable flow.

Inspect:

• Suction-line diameter;
• Filter restriction;
• Reservoir level;
• Air ingress;
• Hose collapse;
• Oil viscosity.

3. Keep the Case-Drain Path Unrestricted

The official FR09 drawing identifies a dedicated case-drain port.

A restricted drain path can increase internal housing pressure and contribute to seal leakage, heating and abnormal variable-control behavior.

4. Diagnose Pressure, Flow and Power Together

For an FR09 pump, monitor:

• Inlet pressure;
• Outlet pressure;
• Flow;
• Drive speed;
• Input power;
• Housing temperature;
• Case-drain flow.

A single pressure reading is not enough to identify a constant-power control problem.

5. Inspect the Rotating Group During Overhaul

Critical components include:

• Cylinder block;
• Valve plate;
• Pistons;
• Piston shoes;
• Swashplate;
• Retainer;
• Bearings.

Valve-plate or cylinder-block wear can significantly increase internal leakage under high-pressure operation.

6. Use the Correct Hydraulic Fluid

For the A3H family, use compatible petroleum-based hydraulic oil, with ISO VG 32 or 46 commonly specified and viscosity maintained within the published operating range.

7. Perform 100% Simulated Working-Condition Testing

A replacement A3H180-FR09-55A4K-10 should be tested under controlled conditions covering:

• Start-up;
• Suction performance;
• 600 rpm low-speed operation;
• Normal operating speed;
• Flow adjustment;
• 350 bar pressure verification;
• Constant-power response;
• Input-power stability;
• Case leakage;
• Temperature rise;
• Noise;
• Vibration;
• Thermal endurance.

The quality target should be:

Interchangeability + Constant-Power Control Compatibility + 100% Simulated Working-Condition Testing

Engineering Verification Statement

The recommended primary product identity for SEO is:

A3H180-FR09-55A4K-10 — YUKEN High-Pressure Variable Displacement Piston Pump

The strongest verified specifications are:

• 180.7 cm³/rev
• 35 MPa / 350 bar maximum working pressure
• 1800 rpm maximum speed
• 600 rpm minimum speed
• 125 cm³/rev minimum adjustable displacement
• FR09 Constant Power (Torque) Control
• Approx. 74.2 kg flange-mounted mass.

The public official documentation confirms the A3H180-FR09-***K-10 configuration family, while the exact 55A4K suffix should be retained as the complete identification code unless the original YUKEN nameplate or order confirmation is available for a character-level decoding. This keeps the product page technically defensible and prevents unsupported SEO parameter stuffing.