Volvo’s new EC300E hydraulic hybrid excavator will make its debut on the North American market at ConExpo-Con/Agg 2020 in Las Vegas. Its performance is based on straightforward technology that stores hydraulic energy from machine motions in an accumulator, and then reuses it to supplement subsequent actions.
The hydraulic hybrid assist system is 100% Volvo-engineered, said Ray Gallant, vice president of sales support at Volvo Construction Equipment. “We take the energy generated by the boom down motion and capture that hydraulically, and use that to assist the boom up motion, which is where you need the most power to operate.”
It’s unlike competitive hybrid systems that capture the swing energy of an excavator’s superstructure to generate electricity and store it in batteries or capacitors. It also differs from Caterpillar’s hybrid excavator, which hydraulically stores swing-motion energy. Volvo’s novel hydraulic hybrid uses the accumulator to supplement lift and break-out forces without having to rely completely on the main pumps, he said.
This well-designed and uncomplicated circuit takes load off the engine and, in the process, delivers up to 15% lower fuel consumption than a conventional machine. When used in high production ‘dig and dump’ applications — especially those within a 90° swing — the fuel saving payback is approximately two years, and all with no loss of performance. “So it’s a very economical system when you consider a machine will last 10 to 12 years or more,” said Gallant.
And as an added benefit the machine generates 12% less CO2 emissions. “When you consider that Tier 4 emission regulations took carbon dioxide output down significantly over the last few years, to get another 12% on top of that is pretty impressive,” he continued.
The robust system consists of just a few add-on components. It has no electronics, other than for monitoring functions, which leads to simple maintenance, said Gallant. Previously, when the boom lowers, high-pressure oil is metered to slow movements and then routed to tank. Now, it is instead used to charge 5.2 gallon (20 liter) hydraulic accumulators mounted just behind the boom. Then, the high-pressure fluid is routed to drive hydraulic-assist motors that help power the hydraulic pump on the upswing.
“It’s all controlled automatically. The operator only feels the system is working because the engine is not lugging out during the lift,” said Gallant.
The hydraulic hybrid assist offers the same levels of controllability and performance as a standard 30-ton EC300E, including the ability to work in ECO Mode and Hybrid Mode simultaneously. As with any Volvo excavator, the boom and frame have a lifetime warranty, even with the hydraulic assist. And it is covered by the Active Care condition-monitoring system. At this time, the hybrid system is not available for aftermarket installation.
“In addition to use on the EC300E, it will be coming to other models in the line as we go forward. Within the next year it will be introduced on three mid-range models, and over the next two to three years on other models as the applications warrant,” he said.
Volvo Construction Equipment