WrightSpeed Links With AxleTech To Make Heavy Duty Electric Truck Drivetrains

WrightSpeed manufacturers an innovative heavy duty electric truck propulsion system. The key to its range extended vehicle (REV) powertrain is a small multi-fuel turbine range extender engine that company head Ian Wright claims is 30% more efficient than any other turbine on the market. It provides 80 kW of power to keep the onboard batteries charged and eliminate range anxiety. The turbine can run on diesel, CNG, LNG, methane, biodiesel, kerosene, propane, heating oil, or any other combustible fuel, Wright says.

Regenerative braking is an essential part of the WrightSpeed electric truck program, which is specifically designed for heavy duty trash trucks and city buses that spend their entire day starting and stopping hundreds of times. It takes a lot of energy to get a 50,000 lb vehicle moving. Some of that energy can be recaptured when the vehicle slows to a stop again.

AxleTech International also specializes in powertrain components for heavy duty vehicles. It will now build the custom made axle housings for the high power regenerative braking systems  that WrightSpeed uses for heavy duty range extended electric vehicles. “All electric vehicles offer some degree of regenerative braking, but WrightSpeed has exceptionally high power braking to virtually eliminate brake wear even in the demanding frequent-stop vehicle drive cycle,” says Arlan Purdy, product manager at Wrightspeed. “To accomplish regenerative braking, force must travel back through the drive axle, back through Wrightspeed’s proprietary gearbox, and into the electric motors.”

AxleTech will become a WrigthSpeed strategic partner to design and build additional gearbox components, Purdy says. “Together AxleTech and Wrightspeed are providing spectacular technology to the market, and our partnership plays to our respective strengths,” said Jason Giles, business development manager at AxleTech.

WrightSpeed CEO Ian Wright was one of the original founders of Tesla Motors. He split with Elon Musk about how to bring electric vehicles to market. Wright believed the focus should be on heavy duty vehicles, which are responsible for a  significant proportion of the carbon emissions attributable to the transportation sector. Today, the company has hired people from Tesla, Ford, and Cummins to help it expand into more electric truck and bus markets worldwide.

Source: Trucks.com

Ford says its regenerative brakes have saved 100 million gallons of gas

Ford is taking the time to trumpet technology that's let drivers go further by stopping gradually. Specifically, the Blue Oval says the various versions of its regenerative braking systems have generated enough energy to offset the use of 100 million gallons of fuel, Wards Auto writes.

Ford's first production car with regenerative braking was the 2004 Escape Hybrid, but regen brakes have been used on various Fords for decades. Trial versions of the feature, which captures kinetic energy generated from slowing down and saves it in the vehicle's battery, dates back to the 1990s with Ford's limited production Ranger and Ecostar (pictured) electric vehicles.

Ford's spent the past couple of decades cutting weight off of those systems while boosting their efficiency. The automaker now says that it can recapture as much as 95 percent of the braking process' kinetic energy, though stresses that a driver who brakes slow and steady will let the system store a lot more energy than one that tends to slam on that left pedal.

News Source: Wards Auto

Video: 2014 Cadillac ELR Shifts The Use Of Paddle Shifters

One interesting innovation in the automotive world is the adaption of steering wheel-mounted paddle shifters to control the transmission, usually on performance cars. The 2014 Cadillac ELR plug-in hybrid will also have paddle shifters, but they’ll serve a different purpose; generating electricity for the Regen on Demand feature, a fancy name for the ELR’s regenerative braking.

For those not in the know, electric and hybrid vehicles can “recover” a small amount of electricity from braking, utilizing the electric motor rather than the brakes to slow the car down. Most of the time this feature is automatic and controllable by selecting different modes, depending on how much “resistance” you want when slowing down.

But the Cadillac ELR’s Regen on Demand feature will give drivers a greater degree of control, pulling back on the paddle shifters in the same way you might downshift a manual transmission car. The paddle shifters won’t bring the ELR to a complete stop, but the Range on Demand feature also won’t engage until you want it to.

With 207 horsepower and 295 ft-lbs of torque, the Cadillac ELR promises to deliver a more engaging driving experience than your typical hybrid car, and the paddle shifters are a neat idea that this writer hopes other automakers copy. All hail the paddle shifter!

Source: Cadillac

A detailed look at regeneration

By George S. Bower

The Route

 
 

Some may have read a previous article I wrote describing the modeling of my daily route between my home in Tonto Basin, Ariz. and Payson, Ariz. described earlier. This route involves climbing and descending a fairly steep, 5.6-percent grade. When I modeled the route I assumed 80 percent regeneration efficiency.
 

 

Calculated regeneration efficiency from the data is 83.8 percent, somewhat better than was modeled.

Volt captures enough energy during descent to drive another four miles on battery alone with ICE shut down

 
 

 

The route profile with significant milestones is shown in figure 1. The descent was 1,700 ft in altitude in 5.6 miles for a 5.6% grade. Total energy recovered from the descent was 0.96 kwh. This captured energy was then used by Volt to travel another 4 miles with the ICE off.

Volt shifts to single motor and then to 2 motor

 

This was the interesting part, and came as somewhat of a surprise to me. The shifts are presented in figure 2. (The descent was in Drive not Low gear shift position). There’s a lot of excruciating details in the frames presented here. As a general overview, one can see the steady state condition prior to the descent in Frame 1 (extended range mode, power split engaged). In frame 2 we begin transition to single motor. In frame 4, 0.9 seconds later, we are in single motor and have begun regeneration. Volt then completes the shift to 2 motor in frame 11, 10.5 seconds later and continues in 2 motor mode for the remainder of the 6 mile, 6 minute descent.

Important to note:

1) Despite taking a seemingly long 10.5 seconds to get into 2 motor, regen is initiated quickly in only 0.9 seconds.

2) All shifts (clutch closings) occur at zero slip resulting in NO CLUTCH WEAR.

Detailed discussion of the shift

 
 

Frame 1 shows the PG set configuration just prior to the descent. Volt is in extended range mode with power split engaged and MGA is charging the battery to rebuild its 0.5-kwh buffer.
Transition to single motor begins in frame 2. Clutch 3 opens releasing the ICE from the PG set. Interesting that the ICE holds constant speed AT NO LOAD as other shifting occurs within the PG set.
After opening C3 and releasing MGA from the ICE, MGB speed is driven up which forces MGA speed down. The purpose here is to get MGA/ ring gear speed to 0 rpm so we can close clutch 1 and ground the ring gear (at which point we will be in single motor).

In frame 4 after 0.9 seconds, we get our first regen. At this point we have driven MGA/ring gear to 0 rpm and closed C1.
 

 

In frame 5, C2 opens freeing MGA from the ring gear so it can speed up and grab the ICE which is still running at 1,850 rpm, no load. This speed increase is shown in frames 6 and 7.

In frame 7 MGA has synced w/ the ICE at 1,855 rpm and locked on by closing C3. By frame 8, MGA/ICE have spooled down to 0 rpm and the ICE SHUTS DOWN. Note that while all of this is happening we are regenerating at 27 A.

In frame 9, MGA latches onto the PG set (again at 0 slip) by closing C2. C1 opens to release the ring gear from ground so MGA/ ring gear are free to speed up to the final 2 motor configuration.
Transition to 2 motor is complete in frame 11. In this configuration we are at 1,220 rpm and 2,730 rpm on MGA and MGB in 2 motor versus 5,286 rpm for pure single motor shown in frame 8.
Volt chooses 2 motor for the remainder of the descent.

In summary, Volt shifted to single motor and began regen in only 0.9 seconds, then completed transition to 2 motor in 10.4 seconds where it remained for the remaining 6 minute regen.

The 64 million dollar question

 
 

You might ask:

Why doesn’t the Volt just shift right to 2 motor? Why bother shifting to single motor first if the final configuration is 2 motor?

I don’t know … It just does.

As forum moderator and Volt Guru Walter (saghost) says: “The Volt is full of surprises.”

I would concur on that statement.

So I will leave it up to all of you Volt enthusiasts: Why does the Volt operate in this way?

Source: GM-Volt.com