Danfoss Variable Displacement Piston Pumps for Road Roller Construction Machinery

As a core component in the hydraulic system of road rollers, Danfoss variable displacement piston pumps play a decisive role in ensuring the efficient and stable operation of rolling equipment. Designed specifically for the harsh working conditions of construction machinery, these pumps are engineered to convert mechanical energy into hydraulic energy with high precision, providing reliable power support for the walking, vibration and steering functions of road rollers.

Core Product Series and Models

Danfoss offers a complete range of variable displacement piston pump series tailored for road roller applications, with the 90 Series and MPV Series being the most widely used:

• 90 Series: Including models such as 90R55, 90R75, 90R100 and 90R130, this series is a classic choice for road rollers and pavers. It features a maximum working pressure of up to 430 bar (6250 psi) and peak pressure of 500 bar (7250 psi), capable of adapting to the high-pressure demands of heavy-duty rolling operations. The 90 Series pumps are available with multiple mounting flange options (e.g., SAE C) and input shaft configurations, ensuring easy integration with different road roller power systems <superscript>1<superscript>7.
• MPV Series: Covering models like MPV 046 and MPV 46, this series is favored for its compact structure and reliable performance. With a 1-year warranty, it provides stable hydraulic output for medium-sized road rollers. The series adopts a gear pump auxiliary structure, which effectively improves the suction capacity and operating stability of the pump <superscript>1.
• D1P Series: As a high-power open-circuit axial piston pump, the D1P series (e.g., D1P065) offers displacements up to 260 cm³/rev and maximum working pressure of 350 bar (5,076 psi). Equipped with multiple control options including TPSN power control and load sensing control, it is suitable for large-tonnage road rollers requiring precise flow regulation <superscript>4<superscript>11.

Working Principle

Danfoss variable displacement piston pumps operate based on the swashplate mechanism, which is composed of key components such as cylinder block, pistons, swashplate and control mechanism. The cylinder block contains multiple circumferentially arranged pistons that reciprocate under the drive of the swashplate’s rotation. The displacement of the pump is adjusted by changing the tilt angle of the swashplate: when the swashplate tilt angle increases, the piston stroke lengthens, increasing the output flow; when the angle decreases, the stroke shortens, reducing the flow. When the swashplate is perpendicular to the rotation axis, the output flow is zero <superscript>2<superscript>5.

This variable displacement design allows the pump to adjust the output flow according to the actual working needs of the road roller (e.g., different rolling speeds and vibration intensities), avoiding energy waste caused by fixed flow output and significantly improving the energy efficiency of the hydraulic system <superscript>9.

Key Features and Advantages

• High Efficiency and Energy Saving: The digital control technology adopted in some models (e.g., Digital Displacement® pumps) enables individual activation of each piston, realizing precise electronic adjustment of displacement. This design achieves unmatched full-load and partial-load efficiency, and can save up to 30% of energy compared to traditional pumps. For road roller operations, it effectively reduces fuel consumption and operating costs <superscript>3.
• Precise Control Performance: Equipped with multiple control options such as pressure compensation control, load sensing control and electronic displacement control (EDC), the pumps can quickly respond to the road roller’s operating commands. The load sensing control maintains a constant pressure margin by adjusting the swashplate angle, ensuring stable performance even with fluctuating system demands <superscript>4<superscript>9.
• Strong Durability: Made of high-strength metal materials, the cylinder block and pistons can withstand the impact of high-pressure hydraulic fluid. The roller cradle bearing and spherical valve plate design reduce wear and extend the service life. The 90 Series and H1T Series have a field failure rate of less than 0.07% in the past decade, showing excellent reliability in harsh construction environments <superscript>6<superscript>11.
• Compact Structure and Easy Installation: The pumps adopt a compact design with multiple port configurations (same-sided or opposed system ports), which saves installation space and improves application versatility. Models like the 70160 series use a die-cast aluminum housing, reducing the overall weight while ensuring structural strength<superscript>6<superscript>10.
• Comprehensive Safety Protection: Equipped with destroke solenoid valves, the pumps can quickly reduce displacement to zero in case of emergencies (e.g., operator absence or emergency stop), ensuring the safety of the equipment and operators. The built-in bypass valve facilitates cross-porting and towing operations, enhancing the maintenance convenience of the road roller <superscript>7<superscript>10.

Application Value in Road Rollers

Road rollers require stable and adjustable hydraulic power to adapt to different working conditions such as asphalt pavement compaction, cement concrete base compaction and soil compaction. Danfoss variable displacement piston pumps provide targeted solutions:

1. Walking System: The pump adjusts the output flow according to the road roller’s speed demand, ensuring smooth start-up, acceleration and deceleration. The precise flow control enables the road roller to maintain a constant speed during compaction, improving compaction uniformity.
2. Vibration System: By adjusting the displacement in real time, the pump controls the vibration frequency and amplitude of the roller drum, adapting to different material compaction requirements. The high-pressure output capacity ensures sufficient vibration force, improving compaction efficiency.
3. Steering System: The fast response speed of the pump ensures flexible and accurate steering of the road roller, enhancing operational efficiency in narrow construction areas.

Technical Support and Documentation

Danfoss provides comprehensive technical documentation for variable displacement piston pumps, including data sheets, technical information manuals, service guides and software manuals. These documents are available in English and cover product specifications, installation requirements, maintenance procedures and troubleshooting methods. Global after-sales service networks ensure timely technical support and spare parts supply for road roller manufacturers and users <superscript>3<superscript>6<superscript>10.

In summary, Danfoss variable displacement piston pumps integrate efficiency, reliability and precision, making them the preferred hydraulic components for road roller construction machinery. With continuous technological innovation (such as Digital Displacement® technology), they continue to help the construction industry achieve energy conservation, emission reduction and efficiency improvement goals.