Core Part Information

• Part Number: 0445020122

• Description: High-Pressure Fuel Pump (Fuel Supply Pump)

• Engine Application: Specifically designed for Cummins QSB Series diesel engines, most commonly the:

• QSB5.9 (5.9-liter displacement)

• QSB6.7 (6.7-liter displacement)

• System: This is a critical component of the High-Pressure Common Rail (HPCR) fuel system.

Typical Equipment Applications

This pump is found in a wide range of machinery and vehicles powered by Cummins QSB engines, including:

• Construction Equipment: Excavators, wheel loaders, bulldozers, forklifts.

• Power Generation: Diesel generator sets.

• Agricultural Machinery: Large tractors, combines.

• Industrial & Marine: Some marine propulsion and industrial power units.

• Commercial Vehicles: Certain medium-duty trucks and buses.

Function & Importance

1. Primary Role: As the heart of the HPCR system, this pump takes low-pressure fuel from the tank and pressurizes it to extremely high levels (typically 1600 - 2000+ bar or 23,000 - 29,000+ PSI). It then supplies this high-pressure fuel to the common rail (accumulator).

2. Critical Impact: It is essential for maintaining precise fuel pressure to the electronic injectors, directly affecting:

• Engine power and torque

• Fuel efficiency

• Emission controls (meeting Tier 3/Tier 4 standards)

• Cold start performance and overall smooth operation.

 Structural Characteristics and Technical Advantages of the High-Pressure Fuel Pump (0445020122)

Structural Characteristics:

A. Compact Modular Design:

• Integrated Design: Combines low-pressure transfer pump, high-pressure pumping elements, pressure regulation valve, and fuel metering unit into a single compact housing

• Radial Piston Arrangement: Typically features 3 or 4 radially arranged plunger/piston assemblies driven by an eccentric cam

• Gear-Driven Operation: Directly driven by the engine gear train at camshaft speed (1:2 crankshaft ratio)

B. Key Components:

1. Inlet Metering Valve (IMV): Electronically controlled proportional valve regulating fuel entering the high-pressure section

2. Pressure Relief Valve: Spring-loaded safety mechanism preventing excessive pressure buildup

3. Plunger and Barrel Assemblies: Precision-machined hardened steel components with micron-level clearances

4. Tappet and Roller Assemblies: Convert cam motion to plunger movement with minimal friction

5. Integrated Fuel Temperature Sensor: Monitors fuel temperature for density compensation

C. Material Construction:

• High-Grade Alloy Steel: For plungers, barrels, and cam surfaces

• Advanced Surface Treatments: Diamond-like carbon (DLC) coatings, nitriding, or chromium plating for wear resistance

• Precision Bearings: High-load capacity bearings supporting the camshaft

Technical Advantages:

A. Performance Excellence:

• Exceptional Pressure Generation: Capable of producing 1,600-2,000+ bar (23,000-29,000+ psi) rail pressure

• High Volumetric Efficiency: Typically 85-92% across operating range

• Precise Flow Control: IMV provides accurate metering with response times < 10ms

• Wide Operating Range: Functions efficiently from idle (600 rpm) to maximum engine speed (2,800+ rpm)

B. Durability & Reliability:

• Extended Service Life: Designed for 8,000-12,000+ hours in heavy-duty applications

• Contamination Tolerance: Robust filtration requirements (typically 4-10 micron) but designed to withstand some contamination

• Thermal Stability: Maintains performance across -40°C to +140°C fuel temperatures

C. System Integration Advantages:

1. Simplified Plumbing: Reduces external high-pressure lines compared to earlier systems

2. Built-In Diagnostics: Supports comprehensive fault detection through the ECM

3. Adaptive Control: Self-learning capability for wear compensation over service life

4. Reduced NVH: Optimized cam profiles and balanced design minimize noise and vibration

D. Emission Compliance:

• Enables ultra-fine fuel atomization (droplets < 5 microns)

• Supports multiple injection events per cycle (pilot, main, post)

• Facilitates precise injection timing critical for meeting Tier 3/4, EPA 2010+ standards

Main Technical Parameters of Cummins HPCR Pump (0445020122)