A37-FR04EH140S-01-42 Yuken Variable Piston Pump 36.9cc 21MPa

Product Overview

The A37-FR04EH140S-01-42 and A56-F-R-02-D24-32123 are representative models from the YUKEN A Series variable displacement axial piston pumps, corresponding to 36.9 cm³/rev and 56.2 cm³/rev displacement sizes respectively. The A Series pumps employ a swashplate-type axial piston variable mechanism with high efficiency and low noise as core engineering characteristics, suitable for injection molding machines, machine tools, hydraulic presses, marine cargo winches, and other industrial hydraulic systems.

The A37-FR04EH140S-01-42 is a proportional electro-hydraulic pressure-flow control type pump from the A37 Series, featuring the 04EH control code, achieving continuous proportional control of pressure and flow through proportional solenoids. This model features flange mounting (F), right-hand rotation (R), equipped with 04EH proportional pressure-flow control valve and integrated amplifier, suitable for hydraulic systems requiring precise pressure and flow coordination control.

The A56-F-R-02-D24-32123 is a solenoid-operated two-pressure control type pump from the A56 Series, featuring the 02 control code (solenoid-operated two-pressure two-flow control) with D24 indicating 24V DC solenoid valve operation. This model features flange mounting (F), right-hand rotation (R), achieving high-low pressure dual-pressure control through solenoid valve switching, suitable for hydraulic systems requiring automatic system pressure switching based on operating conditions.

The A Series covers a wide displacement range from 10 to 219 cm³/rev, including A10, A16, A22, A37, A45, A56, A70, A90, A100, and A145, offering pressure compensator control, proportional electro-hydraulic control, load sensing control, and solenoid two-pressure control options within a shared mounting flange system. The A37-FR04EH140S-01-42 and A56-F-R-02-D24-32123 feature mounting flanges (ISO 3019-2 or SAE J744 standard) and shaft specifications conforming to YUKEN A Series standards, enabling drop-in interchangeability with other same-series models.

Every A37-FR04EH140S-01-42 and A56-F-R-02-D24-32123 undergoes 100% simulated duty-cycle testing prior to shipment — covering pressure holding, flow output, control response, and internal leakage — ensuring complete drop-in interchangeability with original YUKEN products.

Technical Specifications

A37-FR04EH140S-01-42 Specifications:

• Model: A37-FR04EH140S-01-42

• Brand: YUKEN

• Series: A Series

• Pump Type: Swashplate axial variable displacement piston pump

• Geometric Displacement: 36.9 cm³/rev

• Displacement Adjustment Range: 4.1–36.9 cm³/rev

• Rated Pressure: 16 MPa (2320 psi)

• Maximum Pressure: 21 MPa (3050 psi)

• Speed Range: 600–1800 rpm

• Control Type: 04EH proportional electro-hydraulic pressure-flow control

• Direction of Rotation: R (clockwise, viewed from shaft end)

• Mounting: F (flange mounting)

• Shaft Type: 32 mm keyed shaft

• Inlet Pressure Range: -16.7 to +50 kPa

• Case Pressure (Steady State): ≤0.1 MPa, surge ≤0.5 MPa

• Shaft Alignment: Eccentricity ≤0.1 mm TIR, angularity ≤0.2°

• Bearing Model: NUP 207E

• Weight: Approx. 32 kg

• Recommended Fluid: Petroleum-based hydraulic oil (ISO VG32 equivalent)

• Operating Oil Temperature: 50 ℃ recommended (performance test basis)

A56-F-R-02-D24-32123 Specifications:

• Model: A56-F-R-02-D24-32123

• Brand: YUKEN

• Series: A Series

• Pump Type: Swashplate axial variable displacement piston pump

• Geometric Displacement: 56.2 cm³/rev

• Displacement Adjustment Range: 3.4–56.2 cm³/rev (large flow side), 3.4–25.1 cm³/rev (small flow side)

• Rated Pressure: 16 MPa (2320 psi)

• Maximum Pressure: 21 MPa (3050 psi)

• Speed Range: 600–1800 rpm

• Control Type: Solenoid-operated two-pressure two-flow control (02 code)

• Solenoid Valve Voltage: 24V DC

• Direction of Rotation: R (clockwise, viewed from shaft end)

• Mounting: F (flange mounting)

• Shaft Type: 32 mm keyed shaft

• Inlet Pressure Range: -16.7 to +50 kPa

• Case Pressure (Steady State): ≤0.1 MPa, surge ≤0.5 MPa

• Shaft Alignment: Eccentricity ≤0.1 mm TIR, angularity ≤0.2°

• Weight: Approx. 35 kg

• Recommended Fluid: Petroleum-based hydraulic oil (ISO VG32 equivalent)

• Operating Oil Temperature: 50 ℃ recommended (performance test basis)

A Series Same-Family Displacement Reference:

• A10: 10 cm³/rev, 16 MPa rated, 21 MPa max, 600–1800 rpm

• A16: 15.8 cm³/rev, 16 MPa rated, 21 MPa max, 600–1800 rpm

• A22: 22.2 cm³/rev, 16 MPa rated, 21 MPa max, 600–1800 rpm

• A37: 36.9 cm³/rev, 16 MPa rated, 21 MPa max, 600–1800 rpm

• A56: 56.2 cm³/rev, 16 MPa rated, 21 MPa max, 600–1800 rpm

• A70: 70.0 cm³/rev, 25 MPa rated, 25 MPa max, 600–1800 rpm

• A90: 91.0 cm³/rev, 25 MPa rated, 25 MPa max, 600–1800 rpm

• A145: 145 cm³/rev, 25 MPa rated, 25 MPa max, 600–1800 rpm

Data based on YUKEN A Series official technical specifications.

Key Technical Advantages

1. 04EH Proportional Electro-Hydraulic Pressure-Flow Control — Precise Pressure and Flow Coordination

The A37-FR04EH140S-01-42 features the 04EH proportional electro-hydraulic pressure-flow control device, achieving continuous proportional control of pressure and flow through proportional solenoids. This control method integrates pressure control and flow control, enabling simultaneous adjustment of system pressure and flow based on input electrical signals for precise hydraulic system control. The 04EH control device features an integrated amplifier supporting 5V control signal input, with control pressure range within 6.9 MPa, suitable for injection molding machines, presses, and other industrial hydraulic systems requiring precise pressure and flow coordination.

2. Solenoid-Operated Two-Pressure Control — Intelligent Operating Condition Switching

The A56-F-R-02-D24-32123 features solenoid-operated two-pressure two-flow control (02 control code), achieving high-low pressure dual-pressure control through 24V DC solenoid valve switching. This control method allows the pump to automatically or manually switch to high or low pressure mode based on system conditions: on the large flow side, displacement adjustment range is 3.4–56.2 cm³/rev; on the small flow side, displacement adjustment range is 3.4–25.1 cm³/rev. The solenoid valve is controlled by external signals, enabling automatic switching based on equipment operating status, suitable for hydraulic systems requiring automatic system pressure switching, such as injection molding machine clamping and injection station switching.

3. Low Noise and High Efficiency Design — Precision Engineering Control

The A Series pumps are designed with low noise and high efficiency as core objectives. The pump employs swashplate axial piston design, effectively suppressing pressure pulsation and fluid-borne noise through optimized valve plate flow passages, precision-machined piston assemblies, and rigid compact housing structure. The pump operates smoothly within the 1800 rpm speed range, with both A37 and A56 supporting a wide speed range of 600–1800 rpm, suitable for various industrial hydraulic system operating conditions.

4. High-Strength Cast Iron Housing and Long-Life Bearing Design

The A37 and A56 pump bodies are constructed from high-strength cast iron, with NUP 207E cylindrical roller bearings featuring a design life of 2000–5000 hours and overall service life exceeding 10,000 hours. The pump requires shaft alignment precision of eccentricity ≤0.1 mm TIR and angularity ≤0.2°, with flexible couplings recommended to avoid bending or thrust stress, ensuring long-term reliable operation of the drive system.

5. Exceptional Field Interchangeability and Broad System Compatibility

The A37-FR04EH140S-01-42 and A56-F-R-02-D24-32123 feature mounting flanges (ISO 3019-2 or SAE J744 standard), 32 mm keyed shafts, and port layouts conforming to YUKEN A Series standards, enabling drop-in interchangeability with other same-series models. The series supports through-drive configuration, enabling installation of pumps with same or smaller capacity on the non-drive side of the main pump for multi-pump tandem configurations, meeting the integration requirements of compound hydraulic systems. The A Series offers ten unique control methods from pressure compensator control to proportional solenoid pressure/flow control, providing flexible selection space for system design and equipment maintenance.

Application Areas

• Injection Molding Machines: Main pump for clamping, injection, and holding pressure circuits, with 04EH control enabling precise pressure and flow coordination

• Hydraulic Presses: Four-column and frame-type hydraulic press power sources

• Machine Tools and Tool Machines: CNC lathes, machining centers, and grinding machine clamping, feed, and tailstock drive hydraulic systems

• Marine Cargo Winches: Deck crane hydraulic systems, meeting lifting/luffing/slewing/travel full-action requirements

• Metallurgical Equipment: Rolling mill, forging equipment, and continuous casting machine hydraulic power stations

• Industrial Hydraulic Power Units: Fixed industrial hydraulic power units and non-standard equipment hydraulic power units

• Material Handling Equipment: Medium forklift and hydraulic lift platform power units

• Construction Machinery: Small excavator and loader auxiliary hydraulic systems

The A37-FR04EH140S-01-42 is particularly suitable for injection molding machine and press hydraulic systems requiring proportional pressure and flow coordination control. The A56-F-R-02-D24-32123 is particularly suitable for dual-pressure control hydraulic systems requiring automatic system pressure switching based on operating conditions.

Expert Maintenance Tips

1. Shaft Alignment and Coupling Requirements

Maintain shaft alignment precision with eccentricity within 0.1 mm TIR and angularity not exceeding 0.2°, with flexible couplings strongly recommended to accommodate minor angular misalignment. Never strike the shaft end during installation to avoid damaging internal seals and bearings. Tighten mounting flange bolts in diagonal sequence to the specified torque. Couplings must be equipped with protective guards.

2. Pre-Start Priming Procedure (Mandatory)

Before initial startup, the pump must be slowly filled through the case drain port with clean hydraulic oil to ensure adequate lubrication and sealing during startup. Operating an axial piston pump dry — even for a few seconds — will cause dry friction between piston shoes and swashplate, resulting in irreversible damage. Start the pump in jog mode until the pump and piping are sufficiently filled and vented. When installing the pump, the filling port must be positioned upward; use either of the two drain ports and keep the remaining port plugged. After complete venting, run at low pressure for 5–10 minutes, then gradually increase to rated pressure.

3. Pressure Adjustment and System Commissioning

The 04EH controller commissioning on the A37-FR04EH140S-01-42 should ensure coordination between pressure setting and flow setting. With 5V control signal input, the corresponding control pressure is 6.9 MPa, to be set within the maximum operating pressure range. Turning the pressure adjustment screw clockwise increases pressure. For the A56-F-R-02-D24-32123 solenoid-operated two-pressure controller, verify normal switching response of the 24V DC solenoid valve, with high-low pressure settings matched to actual system operating conditions.

4. Fluid Cleanliness and Filtration

Fluid cleanliness of ISO 18/16/13 (NAS Class 8) or better is recommended. Use pressure line filters with 10 μm filtration accuracy. Inlet pressure should be maintained within -16.7 to +50 kPa, with suction port height within 1 m below the oil level. The case drain line should be independently routed to the reservoir, with steady-state case pressure not exceeding 0.1 MPa and surge not exceeding 0.5 MPa. ISO VG32 equivalent petroleum-based hydraulic oil is recommended, with 50 ℃ operating oil temperature as performance test basis.

5. Restart Procedure After Extended Shutdown

If the pump has been idle for more than 30 days, manually rotate the shaft several turns to verify free rotation before restarting. Check for abnormal leakage at the case drain port. After startup, operate at low pressure for 10–15 minutes until oil temperature reaches normal operating range before applying full load. Regularly inspect the keyed shaft engagement with the drive coupling, ensuring sufficient keyway engagement length to prevent key wear. Bearing design life is 2000–5000 hours; schedule bearing inspection and replacement before reaching design life.