Sure, it’s hard to imagine a hybrid truck, but thanks to new technologies, times are a-changin’. While hybrid setups are complex and more expensive, here is still hope in the form of hybrid trailers. Not only they are comparatively simpler and cheaper, they quickly pay back their owners on initial investment.
In fact, one group of engineers in Pittsburg, Pa. is developing an as yet unnamed device that should be ready for market around mid-2017. The system is designed to capture energy as the tractor-trailer runs downhill, then reapplies it through a drive axle when the truck is running up a hill.
The best part? Outside of an on/off switch, the entire operation runs completely autonomously. Electronic controls are able to read road conditions, terrain and speed to optimally assist the tractor during vehicle operations.
All About That Mass
The main problem with big rig efficiency lies in their mass. Why can’t all that weight be captured and put to good use, as many hybrid passenger cars do today? This new company essentially uses lithium ion batteries and regenerative breaking technology to generate, capture and reuse power.
While there are a number of different battery and motor combinations out there, falling prices are making much easier for new entrants to begin innovating. As supplies go down in price, being environmentally conscious becomes quite beneficial.
What if you could save over 21 percent in fuel savings just from using a tandem trailer? Add aerodynamic accessories, and you could see that number jump to a full quarter of a percent, no small amount no matter what the price of a gallon of gas may be at the moment.
Even better, these new hybrid trailer setups would come out of the gate designed to meet the proposed Phase 2 greenhouse-gas and fuel economy regulations unveiled by the EPA.
How Does It Work?
By the end of its design period, a hybrid trailer may come complete with axles and a suspension that would completely replace the existing setups we use today. Even better, a hybrid tandem system could be changed out in less than 30 minutes.
The suspension itself could be either mechanical or air spring, with a sliding tandem being the first one planned. A fairing will be mounted ahead of the tandem to ensure air flow remains smooth and all electronic and mechanical components are protected.
The first step is in using a drive axle with a differential for standard trailer axles. A 300-hp Remy motor-generator could then transmit energy into a battery pack set directly in between the two rails of the slider box. The whole setup would then propel the trailer through the axle differential and wheel shafts.
While early prototypes used belts and pulleys to transfer power, production models will mount the motor within the differential so that the motor can be gear-driven. Determining the gear rations would depend on usage, with one set calibrated for an operator doing local pick-up and delivery and another for highway use.
Algorithms would program an electronic control unit, itself used to process data from GPS systems and wheel sensors. These complex algorithms would then be able to determine what road speed should be maintained. If there is a wheel slip, the system can alter the energy capture to maintain control. The system could also work in tandem with onboard anti-lock braking systems or electronic stability control units.
While a hybrid-electric tandem would pack on an extra 400 or 500 pounds, some of that could be offset by changing from dual wheels to widebase tires. And better yet, excess power could be used to power a sleeper cab HVAC system. Imagine this not just as a fuel saving option, but also as an auxiliary power unit.
In the end, the overarching goal goes back to the truck itself. When you have a 80,000-pound vehicle throwing its weight around, why not capture some of that energy for future use?