Fixed displacement axial piston pumps

Axial piston fixed displacement pumps are versatile and can be used in various areas:

• Agricultural machinery: Tractors, combine harvesters, harvesting machines
• Construction and mining equipment: Excavators, loaders, mining vehicles
• Forestry equipment: Harvesters, forwarders, logging machines
• Industrial plants: Production machines, presses
• Hydraulic transmissions: Drive systems for various machines
• Fan drives: Cooling systems, ventilation systems
• Vibration systems: Compaction machines, vibrators
• Special vehicles: Municipal vehicles, special purpose machines

Due to their constant displacement, they are particularly suitable for applications with permanently uniform oil demand, e.g., for actuating hydraulic cylinders.

These compact pumps offer several key advantages:

• High power density: Maximum performance in compact design
• Uniform flow rate: Constant and predictable delivery volume
• High operational reliability: Reliable operation even under difficult conditions
• Long service life: Robust construction and high-quality materials
• Constant displacement: Stable and predictable delivery volume
• Versatility: Ideal for mobile and stationary applications

Particularly suitable for reliable operation of hydraulic cylinders in various applications.

The Sunfab SCP-ISO series includes axial piston pumps with constant displacement from 12–130 cm³/rev and a maximum operating pressure of 40 MPa. Special features include:

• Double tapered roller bearings: Designed for high shaft loads
• External drainage: Optimal oil return
• Direction of rotation: Optional left- or right-hand rotation
• High speeds: With uniform flow rate
• Low noise level: For quieter operation
• Durable sealing systems: E.g., double shaft seals
• High-quality materials: Controlled manufacturing for maximum quality

The SCP-ISO pumps are an ideal solution for systems where constant pressure and flow is required to supply cylinders or other hydraulic actuators.

Depending on the application and drain oil temperature, the following seal variants are available:

• N (Nitrile): Standard seal for temperatures up to max. 75°C
• H (Nitrile, high-pressure version): Reinforced seal for higher pressures, max. 75°C
• V (Viton, high-temperature resistant): For high temperatures up to max. 90°C – provided the housing pressure corresponds to the external pressure at the seal

The choice of seal depends on the specific operating conditions of your application.

For trouble-free operation, the following points should be observed:

Installation and commissioning:

• Pre-filling: The pump must be filled with hydraulic oil before start-up
• Break-in operation: Operate for at least 10–15 minutes at low load (e.g., 1000 rpm at 500 PSI)
• Oil quality: Use HLP or HM hydraulic oils with filtration of at least ISO 18/16/13 and maintain the recommended viscosity range.

Line installation:

• Drain connection: Must be routed above the pump
• Return to tank: The return line must end at least 200 mm below the minimum oil level in the tank

Safety and operation:

• Temperature: Pressure lines and pump housing can become hot – observe safety distances
• Viscosity: The hydraulic fluid must be within the recommended viscosity range

For optimal performance and service life, the following hydraulic fluids are suitable:

• Mineral oils: Standard hydraulic oils according to DIN 51524 (HLP)
• Viscosity range: According to M+S documentation and diagrams
• Temperature ranges: Depending on the selected seal design
• Special fluids: Possible after consultation (e.g., biodegradable oils)

The exact viscosity diagrams can be found in the M+S documentation for optimal design.

The M+S Hydraulic axial piston pumps with constant displacement differ in several points:

Fixed displacement axial piston pumps (M+S/Sunfab):

• Fixed delivery volume: Uniform flow rate at constant speed
• Simpler construction: Fewer moving parts, higher reliability
• Cost efficiency: Lower acquisition and maintenance costs
• Compact design: Space-saving installation

Variable displacement axial piston pumps:

• Adjustable delivery volume for demand-based adaptation
• More complex control technology required
• Higher energy efficiency with fluctuating loads

Regular maintenance measures are important for maximum service life:

Regular inspections:

• Oil level and quality: Regular monitoring
• Drain oil return: Check for proper function
• Operating temperatures: Monitor temperature values
• Noise development: Detect unusual noises early

Preventive maintenance:

• Filter changes: According to manufacturer specifications
• Oil changes: According to operating hours and oil condition
• Seal inspection: Regular inspection of shaft seals

The selection of the right displacement (12–130 cm³/rev) depends on several factors:

• Required flow rate: Q = V × n (displacement × speed)
• Available drive speed: Motor or gearbox speed
• System pressure: Must be within the pump's operating range
• Application type: Continuous or intermittent operation
• Space availability: Larger displacement means larger size
• Efficiency: Optimal operating point for best efficiency

We are happy to support you in calculating and selecting the optimal pump for your application.