A37-F-R-04-H-K A56-F-R-04-H-K Yuken A Series Piston Pump

Product Overview

The A37-F-R-04-H-K-A-32366 and A56-F-R-04-H-K-32393 are precision-engineered interchangeable variable-displacement piston pumps fully compatible with the Yuken A Series. Designed in swashplate configuration for open-circuit systems, these units feature proportional electro-hydraulic load-sensing control (type 04) for precise pressure and flow regulation. They deliver 100% form-fit-function interchangeability with original Yuken models. Every pump undergoes rigorous 100% simulated operating-condition testing to guarantee volumetric efficiency, response performance and reliability under continuous rated conditions.

Technical Specifications 

• Models: A37-F-R-04-H-K-A-32366, A56-F-R-04-H-K-32393 (Yuken A Series)
• Geometric displacement: A37 – 36.9 cm³/rev; A56 – 56.2 cm³/rev (series range A16 to A145: 15.8–145 cm³/rev)
• Rated pressure: 16 MPa (approx. 160 bar)
• Intermittent pressure: 21 MPa (approx. 210 bar)
• Speed range: 600–1800 rpm
• Control type: 04 (proportional electro-hydraulic load-sensing)
• Pressure adjustment range (H): approx. 2–20.6 MPa
• Direction of rotation: Clockwise (R, viewed from shaft end)
• Mounting: Flange (F)
• Shaft: Keyed (K)
• Housing material: High-strength cast iron
• Approximate weight: A37 – 23–28 kg; A56 – 31–35 kg (depending on port configuration)
• Circuit type: Open circuit

Key Technical Advantages

1. Precision swashplate variable-displacement design delivers high volumetric efficiency and stable flow output with rapid response.
2. Proportional electro-hydraulic load-sensing control (type 04) automatically adjusts displacement and pressure according to system load, significantly reducing energy consumption.
3. Low-noise operation and long service life achieved through optimized flow paths, heavy-duty bearings and wear-resistant materials.
4. Robust cast-iron housing provides excellent rigidity and vibration resistance, supported by precision sealing for continuous industrial duty.
5. Full dimensional and functional interchangeability with original Yuken A Series units, including mounting, shaft, ports and control characteristics, allows true drop-in replacement without system modifications.

Application Areas

Suitable for open-circuit industrial hydraulic systems including injection molding machines, die-casting machines, hydraulic presses, machine tools, material-handling equipment, metallurgical machinery and any application requiring precise pressure and flow control.

Expert Maintenance Tips

Ensure precise shaft alignment and adequate suction-line conditions during installation to prevent cavitation. Confirm case drain is correctly routed to the reservoir before start-up. Use specified mineral-based hydraulic oil and maintain recommended cleanliness levels with regular filter changes. Set pressure and flow values according to the system’s maximum working pressure and requirements. Periodically inspect the port plate, pistons and control valve; replace serviceable wear components as needed to restore performance. Avoid prolonged over-pressure or overspeed operation.