MCY14-1B SCY14-1B YCY14-1B CY14-1B Axial Piston Pump 31.5MPa

Product Overview

The MCY14-1B, SCY14-1B, and YCY14-1B belong to the CY14-1B Series of rotating cylinder block, swashplate-type axial piston pumps/motors — one of the most widely applied fixed and variable displacement piston pump platforms in Chinese hydraulic industry. The series is characterized by its hydraulic hydrostatic balance oil film design between the slipper and the variable head, and between the port plate and the cylinder block. This design enables both critical friction pairs to operate under pure liquid friction conditions, eliminating the need for heavy-duty thrust bearings and delivering combined advantages of simple construction, compact size, light weight, high efficiency, long service life, and strong self-priming capability.

The three models correspond to three control types: the MCY14-1B is a fixed displacement pump with the simplest and most reliable construction; the SCY14-1B is a manual variable pump with infinitely adjustable displacement via handwheel; and the YCY14-1B is a pressure-compensated variable pump that automatically adjusts swashplate angle based on system pressure, reducing displacement to near-zero during holding conditions for significant energy and heat reduction. The full series covers displacements from 1.25 ml/r to 400 ml/r, with a uniform rated pressure of 31.5 MPa and peak pressure of 40 MPa.

Manufactured to original CY14-1B Series technical specifications with full drop-in interchangeability. Every pump undergoes 100% simulated load testing at the factory, covering pressure hold, flow accuracy, and variable mechanism dynamics for seamless replacement in forging machinery, metallurgical equipment, marine hydraulics, and other demanding applications.

Technical Specifications 

• Series: CY14-1B Series

• Design: Rotating cylinder block, swashplate-type axial piston pump/motor, open circuit

• Displacement Range: 1.25 / 2.5 / 5 / 10 / 13 / 16 / 25 / 32 / 40 / 63 / 80 / 100 / 125 / 160 / 250 / 400 ml/r

• Rated Pressure: 31.5 MPa (uniform across the series)

• Peak Pressure: 40 MPa

• Nominal Speed: 1,500 r/min (1.25–160 ml/r); 1,000 r/min (250–400 ml/r)

• Maximum Speed: 3,000 r/min (small displacement configurations)

• Volumetric Efficiency: ≥92%

• Overall Efficiency: ≥85%

• Control Types: Fixed displacement (MCY14-1B) / Manual variable (SCY14-1B) / Pressure compensated variable (YCY14-1B)

• Recommended Oil Viscosity: 10–100 cSt, optimum 16–48 cSt

• Oil Temperature Range: 15–65°C

• Oil Cleanliness Requirement: NAS 1638 Class 9 or better

• Inlet Pressure: ≤0.1 MPa (absolute), flooded suction recommended

• Mounting: Flange mounting, standard cylindrical key shaft end

• Reference Weight: Approx. 6.9–7.2 kg (1.25/2.5 ml/r); approx. 16.4–26 kg (10–16 ml/r); approx. 28.4–41 kg (25–40 ml/r); approx. 56–74 kg (63–80 ml/r); approx. 80–110 kg (100–125 ml/r); approx. 138–168 kg (160 ml/r); approx. 200–232 kg (250/400 ml/r)

Model Code Interpretation:

• MCY14-1B (e.g., 10MCY14-1B): M for fixed displacement, CY for axial piston pump, 14 as series code, 1B as design number. 10 as displacement code (10 ml/r). Fixed swashplate angle, non-adjustable displacement.

• SCY14-1B (e.g., 13SCY14-1B): S for manual variable, remaining designations same as above. Displacement infinitely adjustable via handwheel and screw mechanism. Clockwise rotation decreases flow, counterclockwise increases flow.

• YCY14-1B (e.g., 13YCY14-1B): Y for pressure compensated variable. Flow-pressure characteristic curve set via spring sleeve and limit screw for constant horsepower or constant pressure output control.

Data based on CY14-1B Series industry technical documentation.

Key Technical Advantages

1. Hydrostatic Balance Oil Film Design — Pure Liquid Friction Operation

The defining engineering feature of the CY14-1B Series is its hydraulic hydrostatic balance oil film design between the slipper and variable head, and between the port plate and cylinder block. This design establishes a stable oil film thickness between the mating surfaces, enabling both critical friction pairs to operate under pure liquid friction conditions without heavy-duty thrust bearings. This fundamentally reduces mechanical wear and power loss, forming the technical foundation for the series’ long life, high efficiency, and low-noise operation. The hydrostatic support between slipper and variable head simultaneously bears the axial hydraulic force of the piston assembly, maintaining stable operation at 31.5 MPa rated pressure.

2. Rotating Cylinder Block Design — Strong Self-Priming, Flexible Installation

The CY14-1B Series employs a rotating cylinder block with stationary swashplate layout. The drive shaft drives the cylinder block via spline connection, with seven pistons uniformly distributed around the rotation axis. Compared to rotating swashplate designs, the rotating cylinder block configuration offers stronger self-priming capability, with flooded suction recommended (oil level above pump inlet) and maximum suction height not exceeding 500 mm. This design also simplifies internal oil passage routing, reduces leak points, and improves overall reliability. The pump can serve as a hydraulic motor by simply replacing the swashplate with the motor version.

3. Three Control Types — Full Coverage from Fixed to Constant Horsepower

The CY14-1B Series offers three standard control types for different system requirements. The MCY14-1B fixed pump has the simplest construction, suitable for stable flow demand and low load variation applications such as machine tool feed and clamping circuits. The SCY14-1B manual variable pump provides infinitely adjustable displacement via handwheel, suitable for non-frequent variable adjustment applications without remote operation requirements. The YCY14-1B pressure-compensated variable pump automatically adjusts swashplate angle based on system pressure, reducing displacement to near-zero during holding conditions, fundamentally eliminating relief losses and reducing energy consumption by over 30% in holding applications. The flow-pressure characteristic curve is set via spring sleeve and limit screw, with automatic operation along the preset curve after setup.

4. Wide Displacement Coverage and High Power Density

The CY14-1B Series spans 16 displacement sizes from 1.25 ml/r to 400 ml/r, covering the full range of flow requirements from micro hydraulic systems to large forging equipment. All models share the same design architecture and mounting interface standards, facilitating pump selection and replacement within the series without changing piping layout or control system design. Small displacement configurations (1.25–2.5 ml/r) weigh only approximately 7 kg, achieving high-pressure output in a compact envelope with excellent power density. Maximum theoretical torque ranges from 17.5 Nm (2.5 ml/r) to 1,905.2 Nm (400 ml/r), meeting all drive requirements from small machine tools to large presses.

Application Areas

• Forging Machinery: Hydraulic press main drive, forging manipulator hydraulic systems, punch press hydraulic power units — YCY14-1B pressure-compensated variable pump automatically destokes during press holding, eliminating relief heat

• Machine Tool Hydraulics: Grinding, milling, planing, and broaching machine hydraulic power units — MCY14-1B fixed pump provides stable flow output for machining precision

• Metallurgical Machinery: Rolling mill hydraulic screwdown systems, continuous casting equipment hydraulic drive, metallurgical furnace hydraulic stations — 31.5 MPa high-pressure output for heavy-duty conditions

• Marine Hydraulic Systems: Steering gear hydraulic drive, deck machinery hydraulic power, ship crane hydraulic systems — strong self-priming capability for shipboard conditions

• Mining Machinery: Mining hydraulic supports, hoist hydraulic drive, crusher hydraulic systems — high-reliability design for harsh working environments

• Plastic Machinery: Injection molding machine clamp and injection circuits — YCY14-1B automatic displacement reduction during holding, reducing energy consumption

• Construction Machinery: Mini excavator auxiliary circuits, loader hydraulic systems — SCY14-1B manual variable adapts to multi-condition flow requirements

Expert Maintenance Tips

Pre-Installation Alignment Requirements: Before installing CY14-1B Series pumps, the pump shaft and prime mover shaft must be precisely aligned with concentricity error less than 0.1 mm. A flexible coupling is recommended. The pump mounting bracket must have sufficient rigidity to withstand pump weight and reaction forces during operation. Radial loads on the pump shaft are strictly prohibited. Rotation direction viewed from shaft end is typically clockwise — verify against the pump nameplate before wiring.

Pre-Start Filling and Bleeding: Before initial start or after extended shutdown, the pump case must be filled with clean hydraulic oil. Start in unloaded or low-pressure condition and run for at least 10 minutes to allow complete system bleeding and stable oil film establishment. Suction piping should be short and large-diameter for unobstructed flow, with self-priming height not exceeding 500 mm. Flooded suction (oil level above pump inlet) is strongly recommended to improve suction conditions and extend pump service life.

SCY14-1B Manual Variable Pump Adjustment: System pressure should be reduced below 5 MPa before adjusting the variable mechanism. Turn the handwheel clockwise to decrease flow, counterclockwise to increase flow. Read approximate percentage values from the graduated dial. After reaching the required flow, tighten the locking nut to secure the adjustment screw and prevent displacement drift from vibration during operation. This variable method is suitable only for non-frequent adjustment applications without remote operation requirements.

YCY14-1B Pressure Compensated Pump Calibration: To adjust the flow-pressure characteristic, first turn the limit screw to the upper position, then adjust the spring sleeve so that the pressure at which flow begins to change matches the target value. Then turn the limit screw to the position where flow ceases to change. The intermediate flow-pressure relationship is pre-designed by the pump itself and requires no additional adjustment. Once the start and end points are correctly set, the pump automatically follows the preset characteristic curve. The pressure regulating spring must be correctly selected according to system pressure requirements and must not be arbitrarily adjusted or replaced.

Oil Maintenance Schedule: Replace hydraulic oil and filter after the first 500 hours of operation. Thereafter, replace every 2,000 hours or 12 months, whichever comes first. A 100–180 μm coarse filter must be installed at the suction port, with a high-precision filter in the system return line. Recommended VG 32–68 anti-wear hydraulic oil with cleanliness maintained at NAS 1638 Class 9 or better. A safety valve (relief valve) must be installed in the system. Operation beyond 31.5 MPa rated pressure and maximum speed is strictly prohibited.

Long-Term Storage Protection: For pumps stored over 3 months, drain case oil, fill with rust-preventive oil, and plug all ports. Before recommissioning, flush with flushing oil for 30 minutes and confirm flushing oil cleanliness meets specification before connecting to the system. Always refill the case with clean hydraulic oil before restart and run unloaded for at least 10 minutes for complete bleeding.