Backhoes are used more often in construction projects than larger pieces of equipment because of their agility and versatility. Backhoes can navigate narrow roads and tighter worksite conditions better than their larger counterparts. However, older backhoes can produce more emissions and therefore, more pollution. Due to increasing emission standards, equipment manufacturers have been driven to design new equipment that meets environmental regulations. One backhoe manufacturer redesigned its hydraulic circuit from a traditional fixed displacement gear pump solution to one that more effectively makes use of the equipment’s engine power.
Parker provided the manufacturer with its new P1 M Series, developed specifically for the OEM mobile application market. P1 M is the next generation in the P1 family of mobile pumps. It is more compact and its patented inlet design provides higher power density, best-in-class speed ratings and longer life expectancy.
The P1 M Series allows the backhoe to operate at its finest when combined with Electronic Displacement Control (EDC). When encountering varying loads and running multiple functions simultaneously during operation, the P1 M Series with EDC helps increase the effectiveness of the engine’s power by managing pump output, based on the engine power available and where that power is needed.
By reading system parameters such as pressures and engine speed and knowing engine performance curves, the machine control can adjust the flow command to the pump, in order to match pump power input to engine power output. As engine speeds vary, engine performance varies. With traditional torque or power limiting controls, only a single torque setting can be chosen; therefore, only a specific engine operating scenario can be used as the basis for the torque setting.
In addition, traditional hydromechanical torque or power controls on mobile piston pumps are unable to exactly duplicate an actual torque or power curve throughout the entire curve range. As a result, the pump’s power control may limit the pump’s output even when the engine does not droop and has available power. With EDC, torque output can be infinitely varied, and the low hysteresis and high repeatability of the P1 M control allows the machine to most effectively manage its power.
By more effectively matching pump power to engine power, the new P1 M Series pump with EDC toes the line between stalling the engine and having available, unused power. The net result allows the machine to operate at levels previously unreachable, which increases operational efficiency, reduces fuel consumption, minimizes emissions and increases productivity.
This article contributed by Keith McDonald, product manager, Parker Hannifin Corporation Hydraulic Pump and Power Systems Division.