Komatsu has rolled out a single hybrid excavator, but the technology could easily spread to other models.“Komatsu decided to introduce the hybrid technology in a PC200 size class machine because it is the largest excavator size class,” says Yureskes. “Expansion of the hybrid concept is a possibility, as the technology can be scaled up for larger size class machines or down for smaller size class machines.”
The HB215LC-1 is identical to a standard machine with the exception of three components that make up the hybrid system. The swing motor used on the Hybrid model is electric as opposed to hydraulic. The braking portion of the swing during the work cycle is what generates the kinetic energy that is stored in the Ultra Capacitor, the second hybrid component. The Ultra Capacitor converts the stored kinetic energy to usable energy that the third hybrid component, the generator motor, uses to assist the engine.
“The hybrid excavator provides the same performance, but can reduce fuel consumption up to 25% to 40% in certain applications when compared to a standard excavator,” says Yureskes. “An equivalent reduction in CO2 emissions is another advantage of the Hybrid.”
By utilizing a purely electric swing motor, the hybrid is able to capture the kinetic energy that is produced during the braking action during the swing phase of the work cycle. “This energy would normally be dissipated as heat when the machine swing slows down,” notes Yureskes. “The hybrid stores this energy in an Ultra Capacitor, which can be used to assist the engine during various stages of the work cycle.”
An integrated system approach
Hyundai integrates several systems to increase the efficiency of its hydraulic excavators.
“The latest generation of Hyundai –9 excavators combines several new systems that work together to give proper power to different systems based on the job at hand,” says Shane Sirmons, sales and product support manager. These systems include the Computer Aided Power Optimization (CAPO) system, the Boom and Arm Flow Regeneration System, Hydraulically Dampered Travel Controls, Attachment Flow Control Systems and Pump Flow Control System.
“The CAPO system allows the operator to set power based on the job he is doing,” says Sirmons. “It allows for three power mode settings (Power/Standard/Economy), three work mode settings (Digger/Breaker/Crusher) and user-defined settings based on the operator’s needs.”
The Pump Flow Control System reduces pump flow when controls are in the neutral position, saving power loss. “During operation, maximum flow is delivered to each actuator based on control movement, providing fast, smooth operation of each component,” explains Sirmons.
The Attachment Flow Control Systems provide adequate hydraulic flow to attachments, preventing excess flow and smooth operation. “The attachment used is selected through the LCD cluster,” adds Sirmons.