Parameters of YUKEN Piston Pumps Models A37-E-R and A70-S-R

1. Model Interpretation

1.1 Model Coding Rules (Unified for Both Models)

• A: Series code, indicating YUKEN A series variable displacement axial piston pump, featuring a robust swash plate design for high pressure and high efficiency operation.
• 37/70: Nominal displacement code, representing the maximum displacement of the pump (37 cm³/rev for A37, 70 cm³/rev for A70), which directly determines the flow capacity of the pump.
• E/S: Control type code, indicating the specific control mechanism:
  • E: Electro-hydraulic proportional control (proportional solenoid for remote flow and pressure adjustment).
  • S: Manual servo control (manual adjustment with servo feedback for precise flow control).
• R: Rotation direction code, indicating the standard clockwise rotation (viewed from the shaft end), suitable for most hydraulic system configurations.
• Additional Code Explanation: Complete model typically includes mounting type, shaft specification, and design number:
  • Mounting type: F (flange mounting), S (spline shaft).
  • Shaft specification: Standard keyed shaft or splined shaft for direct coupling to prime movers.
  • Design number: 10/11/12, indicating specific design variations (installation dimensions remain unchanged for minor design changes).

2. Technical Parameters

3. Product Features

3.1 Common Features (Applicable to Both Models)

• Swash Plate Design: Compact structure, high power density, and excellent mechanical efficiency (up to 95%), suitable for high pressure and high flow applications.
• Variable Displacement: Allows precise adjustment of flow rate from 0 to maximum displacement, improving energy efficiency and reducing system heat generation.
• High Pressure Capability: Continuous operating pressure up to 31.5 MPa, peak pressure up to 35 MPa, suitable for heavy-duty hydraulic systems.
• Low Noise Operation: Special design reduces operating noise by up to 5dB compared to conventional piston pumps, ideal for noise-sensitive environments.
• High Controllability: Equipped with advanced control mechanisms (E-type: electro-hydraulic proportional control; S-type: manual servo control) for precise flow and pressure adjustment.
• High Reliability: Adopts high-quality materials and precision manufacturing processes, ensuring long service life (≥10,000 hours) and stable operation under harsh conditions.
• Easy Maintenance: Modular design, easy to disassemble and maintain, with replaceable wear parts for cost-effective maintenance.

3.2 Model-Specific Features

• A37-E-R:
  • Medium displacement (37 cm³/rev), suitable for medium-sized hydraulic systems requiring moderate flow rates (up to 66.6 L/min at rated speed).
  • Electro-hydraulic proportional control (E-type) enables remote flow and pressure adjustment via electrical signals, improving system automation and controllability.
  • Compact size and light weight (approx. 32 kg), ideal for installation in space-limited applications.
  • Suitable for industrial machinery requiring precise flow control, such as injection molding machines, metalworking equipment, and plastic processing machinery.
• A70-S-R:
  • Large displacement (70 cm³/rev), suitable for large-sized hydraulic systems requiring high flow rates (up to 126.0 L/min at rated speed).
  • Manual servo control (S-type) provides precise flow adjustment with servo feedback, ensuring stable operation even under varying load conditions.
  • Heavy-duty structure (approx. 58 kg), strong pressure-bearing capacity, and stable operation under high flow and high pressure conditions.
  • Suitable for construction equipment, mining machinery, and other heavy-duty applications requiring high power and reliable performance.

4. Application Fields

• A37-E-R: Injection molding machines, metalworking equipment (lathes, milling machines), plastic processing machinery, woodworking machinery, and other medium-sized industrial hydraulic systems requiring electro-hydraulic proportional control and moderate flow rates.
• A70-S-R: Construction equipment (excavators, loaders), mining machinery, hydraulic presses, and other heavy-duty hydraulic systems requiring manual servo control and high flow rates for heavy loads and continuous operation.

5. Typical Model Variations

6. Installation and Operation Notes

• Before installation, check the pump model, nominal displacement, control type, and rotation direction to ensure they match the system requirements.
• Mount the pump on a rigid base using suitable mounting bolts and torque specifications (refer to YUKEN technical documentation) to prevent vibration and ensure stable operation.
• Align the pump shaft with the prime mover (motor/engine) shaft accurately (concentricity ≤ 0.1 mm) to avoid shaft bending and bearing damage.
• Use a flexible coupling to connect the pump and prime mover, absorbing vibration and reducing mechanical stress on the shaft and bearings.
• Connect the hydraulic lines correctly: pressure port (P) to the system pressure line, tank port (T) to the oil tank line, and control ports (X/Y) to the control system lines; reverse connection will cause pump failure and system damage.
• Fill the pump with hydraulic oil before starting to ensure proper lubrication of internal components and prevent dry running.
• Prime the pump by rotating the shaft manually (5-10 revolutions) to remove air from the pump and hydraulic lines before starting.
• Start the pump at low speed (≤1000 rpm) and no load, gradually increasing the speed and load to the rated values to avoid sudden pressure changes causing equipment damage.
• Maintain hydraulic oil cleanliness at NAS 7 level or higher, and install a high-precision filter (≥10 μm) in the system to prevent impurities from damaging the pump’s internal components (swash plate, piston, cylinder block).
• The operating temperature of the hydraulic oil should be controlled within -10°C to 80°C; excessive temperature will affect the service life of the seal and pump performance.
• Regularly inspect the pump for oil leakage, abnormal noise, and pressure fluctuations; if any abnormality is found, stop the system immediately for inspection and maintenance.
• When adjusting the flow or pressure, follow the YUKEN technical manual and ensure the system is in a safe state to avoid injury or equipment damage.
• When replacing parts, use only genuine YUKEN replacement parts to ensure compatibility and maintain pump performance; non-genuine parts may cause reduced efficiency, increased noise, and premature failure.
• Do not disassemble the pump without authorization; if maintenance is required, refer to the YUKEN technical manual or contact professional maintenance personnel.
• Store the pump in a dry, clean, and well-ventilated environment when not in use, protecting it from dust, moisture, and corrosion.