Walvoil, an Italian manufacturer of fluid power and e-motion systems, is launching a solution that enables use of “pressure control functions paired with flow-sharing directional control valves of Walvoil’s DPX and EPX series,” according to a press release.
Walvoil debuts the solution at the bauma trade show, Oct. 24-30, in Munich, Germany. The show caters to companies in construction and mining machinery.
The system manages and conditions the load sensing signal of the circuit to reduce consumption and optimize control. The modern mobile machinery market demands a constant increase in productivity and performance, together with lower operating costs, greater efficiency, and reduced emissions.
Research in the field points out that up to 40% of the energy supplied to a hydraulic system is dissipated by the limited efficiency of the components and pressure drops due to the metering and control of the movements. The problem is even more evident on electrified applications, where energy efficiency is synonymous with prolonged range and reduced battery capacity.
Walvoil aims for increased efficiency of the hydraulic system and its components, with a possibility of reducing consumption by more than 20%.
Walvoil pursues this goal in two ways: by reducing consumption and energy dissipation with its adaptive load sensing (ALS) systems; and by recovering energy that would otherwise be wasted through EPX meter out compensation technology.
ALS is a synergistic set of components for the efficiency of mobile operating machines. The joint control of the hydraulic directional control valve and the pump makes it possible to cut down pressure drops due to the pressure margins of the metering system. At the same time, a series of logics are available to improve machine control, productivity, and driving comfort.
Walvoil offers different ALS solutions to provide extreme versatility and adapt to the performance and system requirements of the machine. In fact, the ALS system can be used as an integral part of the hydraulic directional control valve or fitted to the variable displacement pump.
This solution enables use of pressure control functions paired with flow sharing directional control valves of the DPX and EPX series. The system manages and conditions the load sensing signal of the circuit in order to reduce consumption and optimize control.
Since the ALS system can be fitted directly to the directional control valve, it yields benefits when combined with fixed displacement pumps.
When using variable displacement pumps, the ALS system further expands its energy-saving and controllability capabilities by managing the electronic control of the pump itself.
The system is managed by an electronic control unit and specially developed software in the PHC STUDIO environment.
The special feature of this configuration is the combination of a normal electro-proportional open center directional control valve with the electronically controlled variable displacement pump equipped with ALS logic. The variable displacement pump supplies the flow demand settled by the operator logic (dedicated software), accordingly with single or multiple operations.
In this configuration the flow-on-demand logic ensures better load metering and greater vehicle stability combined with a tangible reduction in fuel consumption.
The main benefits of the ALS system are:
The ALS is also available standard with some basic functions. These include the precision function, which reduces the pressure margin value, improving accuracy and sensitivity of operation; and the boost function, which temporarily increases the pressure margin value for higher speeds and productivity without needing to install larger pumps.
EPX Series directional control valves are a new range of electro-proportional valves designed to enable the management and recovery of hydraulic energy in mobile machines. It achieves recovery in two ways:
The example diagrams below show the circuit difference between a load sensing (precompensated) system, a flow sharing (postcompensated) system, and EPX technology.
With the energy recovered through an EPX Series directional control valve, it is possible to charge a battery set through a hydraulic motor connected to an alternator + inverter; make it available in the hydraulic system for reuse by machine functions; and store it in hydraulic accumulators.
These two highly flexible technologies can be combined to yield their respective benefits. A variety of configurations and strong electronic integration allows solutions to be adapted to a wide variety of circuit configurations. Different levels of complexity and performance can be achieved thanks to the modularity of the PHC STUDIO software.
Studies and the application of ALS to various types of vehicles demonstrate energy savings of up to 5%. Far broader is the potential for energy recovery of the EPX system, which is capable of lowering consumption and returning a share of energy, with overall energy savings of up to 20%, depending on the application.
For more information, visit www.walvoil.com.