PSI continues to reach milestones in its effort to offer customers an alternative to traditional gas-powered engines. Our engineering team recently successfully demonstrated PSI’s new Lithium-Ion Power Unit – which features an electric motor powered by a Lithium-Ion battery – in a woodchipper.

PSI’s New Energy and engineering teams began work on the unit in 2022, with a concept unit displayed in fall 2023 during the Tree Care Industry (TCI) Expo. The unit generated a great deal of interest from industrial equipment OEMs, particularly within the woodchipping industry. After the concept unit returned to PSI, Aleks Koledov of the engineering team along with Weichai engineers worked with the testing team in Burr Ridge to dyno test the machine. Testing included verifying that the motor produced the power and torque expected as well as understanding the current draw from the batteries under a simulated chipper load profile.

While the dyno testing was under way, the PSI engineering team put together designs and drawings for more than 60 new parts so the design could be eventually be reproduced and built on PSI assembly lines.

Expert Engineering

Aleks Koledov integrated the controller with a 4.3-inch color display to control the motor and display electrical parameters from all electrical components including the motor, battery management system, control unit and on-board battery charger. Additionally, he incorporated woodchipper feed roller control logic safeties to the woodchipper

application and integrated thermocouple modules to the existing telematics system for temperature data logging. Koledov worked with the Weichai team to go through a sequence of operation for individual electrical components and verified the electrical power unit operates as designed. Once engineers were confident that the unit was ready to operate the chipper, the drive belts and other mechanical features had to be attached.

Connecting parts including a primary drive shaft were ordered, but the supplier was more than a month late with delivery. With a demonstration scheduled in a short time frame, engineering team members Nick Nokovic, Steven Gnoffo and Kevin Kendzierski determined they could modify the original shaft by cutting and welding to produce a workable drive shaft for the demo. Completing the rework project took several days of careful machining work in the machine shop, since any mistake would ruin the only existing prototype part.

Once the shaft was completed, the next step was to install the original belt guard. Design Engineering Technician Jimmy Schmidt worked with Gnoffo to modify the existing belt guard by welding in a section and adding additional attachment points to secure it on the machine.

Koledov and the Weichai Team then started the machine and tested it in an unloaded condition. After some slight adjustments the machine was ready for an initial test at 1465. Kendzierski brought in logs and tree trimmings, and the team also loaded wood debris found near the 1465 facility.

Demo Runs

After the successful initial test, Jason Lundin arranged for a demo at Streamwood Park District. Streamwood kept two of their crews at their facility to perform the demo, and the woodchipper worked well. The Park District as well as both the PSI and Weichai Teams were pleased with the results.

The next day, Dave Goodwin arranged for a demo at Steve Piper and Sons Tree Service. The PSI Team put on their personal protective equipment and demonstrated the

woodchipper on a hot Thursday afternoon in 95 degree heat. The demonstration was again successful and impressed another potential customer. Both the PSI and Weichai Teams have worked diligently to make the project a success. Wood chipping is a severe duty cycle application, and the machine withstood the vibrations and very large logs.

The power unit has many other high volume potential applications beyond chippers and is a new concept for industrial machines that is in the process of being Patented by PSI. Additional prototype units are planned to be assembled in late July and August. The PSI team working on the project includes Aleks Koledov, Curtis Boyd, Dave Goodwin, Robert Shailes, Jason Lundin, Jimmy Schmidt, Kevin Kendzierski, Nick Nokovic, Carly Bartholomew, Tien Cao, John Sager, Sebastian Newman, James Abrahamson and Steven Gnoffo, supported by the Weichai Team consisting of Billy Lin, Hamming Tao, Ping Xia and Qiang Fu.

Hats off to a job well done by all involved!