Although they are not mainstream throughout most of America, electric automobiles have become a reality. Most construction equipment, on the other hand, still relies on gas or diesel engines for power. Mecalac, Annecy-le-Vieux, France, will bring these two technologies together when it introduces its all-electric mini excavator next year. Actually, all-electric refers to eliminating the machine’s internal combustion engine; hydraulics will still be essential for accomplishing work functions. An unconfirmed report explains that the machine has two electric variable-speed motors: one to drive the wheels and the other to power hydraulic system’s main pump. This configuration conserves energy by closely matching power delivered to the hydraulics required by the load.
Mecalac’s e12 mini excavator, which will debut next year, is a modified version the company’s 12MTX that replaces the internal-combustion engine with a battery pack and electric motor to drive the machine’s hydraulic pump.
Mecalac specializes in construction equipment for urban job sites, where compact size and quiet operation are paramount. Their new e12 wheeled excavator delivers the range, performance, and compact size required to support modern urban construction sites. The e12 will essentially be an electric-powered version of their existing 12MTX mini excavator. Designers placed a lithium iron phosphate (LiFePO4) battery pack in where the internal-combustion engine had been. Electrical power then runs a variable-speed electric motor that transmits mechanical power to a geared drivetrain supplied by Dana Corp., Maumee, Ohio. The mechanical drive consists of Spicer 112 axles and a Spicer 367 shift-on-the-fly transmission.
Power for a Full Work Shift
With an eight-hour working range, the LiFePO4 battery pack in the Mecalac e12 has a service life three times longer than conventional batteries. The battery pack can be charged in about seven hours and delivers 146 kW-hr of power.
Patrick Brehmer, head of design and product management at Mecalac, explains, “Any electric engine must rise to three major challenges: range, performance, andcompactness. The Mecalac e12 is the first 100%-electric excavator that does not compromise on any of those three criteria. The key to our machine’s range and performance is in its very architecture. The power source—which is separate from the upper structure—means we can install a record capacity of 146kW-hr, which results in an unrivaledrange of 8 hr.”
“As the European construction market embraces the trend toward zero-emission standards for small to mid-sized vehicles, our customers are demanding great strides in efficiency while also requiring reliable performance,” offers Jean-Baptiste Rousseau, technologies manager at Mecalac. “Dana was able to adapt the 12MTX drivetrain to add electric drive capabilities within our existing vehicle architecture. With their technical expertise and open collaboration, we developed an optimal solution and accelerated the delivery of this vehicle to market.”
“As a Tier-One supplier, we understand that the success of electrification in the off-highway industry is driven by performance. These technologies must support a smooth transition to fully integrated electric-drive technologies optimized within a single package, providing both electrified and conventional powertrain options,” said Aziz Aghili, president of Dana Off-Highway Drive and Motion Technologies. “Dana’s support for new energy vehicles has been considerable, and growing every year, as the importance of engineering for hybridization and electrification is further elevated throughout the industry.”
Click here to watch a video describing Mecalac’s e12 excavator.