Danfoss Targets Excavators with New Digital-Hydraulics System

A building-materials supplier is comparing the performance of three Volvo excavators fitted with Danfoss’ Dextreme Swap system to standard machines.

Danfoss Power Solutions claims to increase the productivity of excavators while reducing their fuel consumption by up to 15% by swapping out the machine’s main hydraulic pump for a Digital Displacement pump, custom software and controller. The system ─ appropriately called Dextreme Swap ─ has been fitted to three 20-ton diesel-powered Volvo EC200 excavators in Ashcourt Group’s fleet for field trials, in collaboration with U.K. Volvo dealership SMT.

Dextreme Swap realizes a significant reduction in losses from ancillaries by allowing for aggressive engine down-speeding without stalling the engine. (Danfoss)
At the core of all the Dextreme systems is Danfoss’ Digital Displacement pump, which replaces the machine’s main hydraulic pump. (Danfoss)

“Our Dextreme Swap system is configured for installation directly into excavators without modification to the existing main control valve,” Leif Bruhn, head of Digital Displacement, Danfoss Power Solutions, told SAE Media. “We offer a simple first step for OEMs to experience and validate the benefits Dextreme systems can bring from a control and integration standpoint.” Danfoss is highlighting the Dextreme system at CONEXPO/IFPE 2023 (International Fluid Power Exposition) in Las Vegas.

Ashcourt, a building-materials supplier based in England, is running two of the excavators at its Partridge Hall Quarry in East Yorkshire, and the third machine at a nearby material washing facility. Forecast to complete 2,000 operating hours during the yearlong field trials that began in February, the modified excavators include data logging equipment so operating data can be compared with Ashcourt’s existing fleet of standard Volvo EC200 machines.

“Our goal is to see how the Danfoss Dextreme-equipped machines perform in terms of productivity and fuel use in a tough quarrying and material moving environment,” said Ashcourt Group plant director John Hood. “So far, the feedback from our operators has been uniformly positive. The fuel savings I can’t speak to yet, but my team is telling me the new machines are very responsive and strong, with the EC200 performing more like an EC250.”

Up to 50% fuel savings

A study by Danfoss Power Solutions revealed that excavators account for 50% of all carbon-dioxide emissions generated by construction machinery. Around 90% of those emissions come from excavators of 10 tons or more, according to Danfoss, which is why the company is specifically targeting that market with its Dextreme system.

“Today’s excavator systems are only 30% efficient, with around 70% of the engine’s energy wasted as heat in the hydraulic system,” Bruhn said. “We’ve designed the Dextreme system to radically reduce hydraulic system losses, leading to increased productivity and lower fuel consumption.”

Dextreme Flex and Max systems can benefit electrified machines by reducing control valve losses and allowing for energy recovery and reuse, according to Leif Bruhn, head of Digital Displacement, Danfoss Power Solutions. (Danfoss)

Dextreme Swap is the simplest configuration in a “solution pathway” that consists of three technology-integration levels ─ Swap, Flex and Max. Danfoss expects the Max version to deliver fuel savings of up to 50% in excavators of all sizes. Each system provides an incremental step in benefits, Bruhn explained to SAE Media.

“At the core of all the Dextreme systems is our Digital Displacement pump. In the Dextreme Swap system, we achieve significant savings by reducing the engine speed, dramatically cutting its parasitic losses without sacrificing productivity. Due to the fast control response of our pump, we can run the engine at maximum load without risk of stalling,” Bruhn said.

“In the Dextreme Flex system, dynamic allocation of pump displacement to services prevents high-loss situations from occurring in the main control valve through throttling,” he added. “The Dextreme Max system takes this even further by recovering energy from some of the excavator’s motions, such as slew deceleration or boom down. Controlling hydraulic loads directly from the Digital Displacement pump also cuts throttling losses in the main control valve.”

Electrified systems benefit, too

Dextreme can be integrated into diesel, hybrid and fully-electric excavators and will work with any machine control system. “These systems allow OEMs to take action now and start the journey of making significant energy and CO2 savings, which is why we are mainly focusing on applying Dextreme to diesel-powered excavators,” Bruhn said. “Energy savings are highest on diesel-powered machines as they inherently have higher-loss ancillaries driven by the engine.”

The benefits are slightly different for electrified systems as they don’t benefit from reducing the engine speed and associated ancillaries, Bruhn added. “Our studies have shown that we can make significant improvements in making the battery smaller or improving the runtime of electrified machines ─ both of which significantly improve the impact of these machines.”

“On electric machines, the prime mover is inherently much more efficient. However, we would still show significant efficiency and control improvements with our Dextreme Flex and Max systems as more of those systems’ benefits are in reducing control-valve losses and allowing for energy recovery and reuse,” he said.

Danfoss is in the demonstration phase with several customers globally and have an ongoing multi-machine field trial in the U.K. (Danfoss)

According to Danfoss calculations, an excavator utilizing the Dextreme system will have a lower total cost of ownership than a standard diesel machine. “We tend to focus on the impact on the fuel efficiency the end user gets where we can reduce hourly fuel consumption of something like 13 L/hr down to around 11 L/hr with Swap and all the way to 6.5 L/hr when we offer the Dextreme Max system,” Bruhn said. “With global fuel costs where they are, this directly impacts the running costs that operators face.”

For owners more interested in reducing cycle times than fuel consumption, Dextreme Swap reportedly can deliver up to 25% higher productivity. Its integral digital pump controller provides extensive data, offering fleet operators real-time performance monitoring and diagnostics.

Danfoss is in the demonstration phase with several customers globally and have an ongoing multi-machine field trial in the U.K. Dextreme systems will be available globally through the Danfoss Power Solutions network.