Identifying and Understanding Sundstrand Hydrostatic Pump Models

[MikePhua]

Sundstrand, now known as Sauer-Danfoss and later as Danfoss Power Solutions, has a long-standing history in the development and manufacturing of hydraulic components. Their hydrostatic pumps, particularly the Series 15, Series 20, and Series 42, have been integral in various applications, from mobile machinery to industrial systems. Understanding how to identify and interpret the model numbers of these pumps is crucial for maintenance, repair, and replacement purposes.
Decoding the Model Number
Sundstrand's model numbers are systematically structured to convey specific information about the pump's specifications. For instance, a typical model number might look like:
CPB-055-R-2-AY-BA
Breaking this down:

• CPB: Indicates the series and type of pump. "CPB" often denotes a gear pump in the Series 15 or Series 20 range.
  
• 055: Represents the displacement in cubic centimeters per revolution (cc/rev). In this case, 55 cc/rev.
  
• R: Denotes the rotation direction. "R" typically stands for clockwise rotation when viewed from the shaft end.
  
• 2: Indicates the number of sections in the pump. A "2" suggests a two-section pump.
  
• AY: Refers to the mounting style and shaft configuration. "AY" could indicate a specific flange and shaft type.
  
• BA: Represents additional options or features, such as pressure settings or special modifications.
  

Understanding this nomenclature allows technicians and engineers to accurately identify the pump's specifications, ensuring compatibility with the system and aiding in troubleshooting.
Key Specifications to Consider
When assessing a Sundstrand hydrostatic pump, several specifications are paramount:

• Displacement: Determines the flow rate and power output. It's essential to match the pump's displacement with the system's requirements.
  
• Rotation: Ensures the pump's rotation direction aligns with the system's design to prevent operational issues.
  
• Mounting Style: Affects how the pump interfaces with the system. Common types include SAE flanges and square flanges.
  
• Shaft Configuration: Impacts how the pump connects to the drive source. Options include splined shafts, keyed shafts, and tapered shafts.
  
• Pressure Ratings: Defines the maximum operating pressure the pump can handle. Exceeding this can lead to pump failure.
  
• Seals and Bearings: Critical for maintaining system integrity and preventing leaks.
  

Common Applications
Sundstrand hydrostatic pumps are utilized in various industries:

• Construction Equipment: Powers functions in backhoes, excavators, and loaders.
  
• Agricultural Machinery: Drives systems in tractors, harvesters, and sprayers.
  
• Material Handling: Used in forklifts and conveyor systems.
  
• Industrial Equipment: Powers presses, injection molding machines, and other machinery.
  

Maintenance and Troubleshooting
Regular maintenance is vital to prolong the life of Sundstrand hydrostatic pumps:

• Check for Leaks: Inspect seals and connections regularly.
  
• Monitor Pressure: Ensure the system operates within the pump's rated pressure.
  
• Maintain Fluid Quality: Use the recommended hydraulic fluid and replace it at intervals specified by the manufacturer.
  
• Inspect Bearings and Shafts: Look for signs of wear or damage.
  

Troubleshooting common issues:

• Noise: Could indicate cavitation, air in the system, or worn bearings.
  
• Overheating: May result from excessive load, inadequate cooling, or high fluid viscosity.
  
• Erratic Operation: Often caused by contamination, worn components, or incorrect settings.
  

Conclusion
Understanding the model number and specifications of Sundstrand hydrostatic pumps is essential for effective maintenance and operation. By familiarizing oneself with the nomenclature and key specifications, technicians can ensure proper pump selection, installation, and troubleshooting, leading to enhanced system performance and longevity.