Cargotec introduces Kalmar hydraulic parallel hybrid drive terminal tractor; up to 20% lower fuel consumption, lower emissions
|The new Kalmar hydraulic hybrid drive terminal tractor. Click to enlarge.|
Cargotec has introduced a hydraulic hybrid drive terminal tractor offering customers improved performance, significant savings in fuel costs and even greater reductions in NOx and particulate matter emissions. Paired with the Kalmar Ottawa 4x2 off-highway terminal tractor, the hydraulic hybrid system will initially be available to customers operating in North America.
The new machine is the result of Cargotec’s partnership with Singapore Technologies Kinetics Ltd (ST Kinetics) and its subsidiary Kinetics Drive Solutions (KDS). The Kalmar hydraulic hybrid drive terminal tractor is equipped with a parallel system that simultaneously transmits power from two distinct sources: the primary diesel engine and the secondary hydraulic motor. Kalmar has also participated in the EPA-led development of a hydraulic series hybrid terminal tractor, earlier post.
The normal application of a terminal tractor involves many stops and starts where frequent idling and reverse motion is common. This inconsistent use of power makes it difficult to consistently capture regenerative energy. After carrying out extensive testing on a variety of alternatives, it was clear that ST Kinetics’ Hy-POWER hydraulic hybrid drive system combined with clean diesel engine technology offered the most benefits to the customer and environment. In this application, energy is only transferred twice as opposed to four times with an electric hybrid.—Mikko Vuojolainen, Vice President, Terminal Tractors
|Components of the hydraulic hybrid drive. Click to enlarge.|
Although fuel consumption with the hydraulic hybrid system can vary depending on driving style and the operational application, in the typical port environment, fuel savings of 20% and an even greater reduction of NOx and particulate matter emissions can be achieved., Cargotec said. Cargotec has given the new Kalmar hydraulic hybrid drive terminal tractor its Pro Future rating, adding to the company’s expanding portfolio of environmentally friendly solutions.
The pressure to reduce emissions at ports and in urban areas is strongest in the United States. We have engineered the Kalmar hydraulic hybrid drive terminal tractor to help customers meet ever-stricter regulations in this part of the world and to combat expensive exhaust after-treatment solutions. In addition to financial constraints, companies operating large fleets of equipment in confined spaces, often near urban developments, can come under significant pressure to reduce their environmental footprint.—Mikko Vuojolainen
The Hy-POWER hydraulic hybrid drive system also enjoys significantly smoother acceleration helping to reduce driver fatigue and driveline wear. The machine’s inching function allows the vehicle to advance without engine power, further saving fuel and eliminating emissions altogether.
The configuration of the hydraulic hybrid components allows them to be easily accessed, and they have been built to even outlast the normal life cycle of a terminal tractor. Scheduled maintenance intervals of the hybrid components are twice as long as the regular intervals required to properly maintain a terminal tractor. The hybrid system does not require expensive replacement parts, further helping to drive down the machine’s lifetime operating costs.
Involved in multiple hybrid terminal tractor projects, the company delivered one hybrid hydraulic drive machine to PSA Singapore Terminals together with ST Kinetics late last year. Cargotec’s drive to reduce fuel consumption and emissions using hybrid technology has been underway for some time. Starting in 2008, the company was the industry’s first to offer straddle carriers and later shuttle carriers with hybrid drive systems.
KDS has developed a range of Hydro-Mechanical IVT (HMIVT) systems that combine a hydrostatic transmission with a planetary gearset in a hybrid configuration; existing HMIVT designs span a torque range from 800 to more than 2600 N·m. The HMIVT systems provide a parallel dual power path through the transmission, permitting it to transfer power in any of three modes: purely hydraulic, combined hydraulic and mechanical, or purely mechanical.
At low output speeds, most power is transmitted hydraulically and a small amount mechanically. At high output speeds, all power is transmitted mechanically as the transmission “locks up” in an overdrive ratio allowing cruising speeds with low engine rpm. Between these two extremes, power is transmitted as a mixture of hydraulic and mechanical with the ratio continually favoring mechanical power as it progresses upward through the range. Additionally, a 2-speed planetary with a speed matching shift transition is used to expand the operating range of the transmission.