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Taking the electric motors out of the drivetrain delivers two benefits. When moving heavy loads at a steady clip, the electric motors are inefficient because they actually represent a drag on the engine. Taking the electric motors completely offline in such scenarios makes the car's overall operation more efficient. The more significant benefit, says Grewe, comes in packaging the transmission. By swapping out the motors under high-power operation, the alliance partners get by with smaller motors. The result is a hybrid transmission that is no bigger than a conventional transmission. "We took clutches out and we put electric motors in, and with that we were able to get it to package in a similar volume," says Grewe. That should simplify the design and assembly changes required to offer hybrid as an option on existing vehicles.
Rich Schaum, former chief engineer at Chrysler and the incoming president of the Warrendale, PA-based Society of Automotive Engineers, says GM has a "very robust" patent position for the two-mode transmission and that is allowing the alliance partners to go their own way with a better technology. "The architecture of the dual-mode technology being pursued by GM, DaimlerChrysler, and BMW is superior to what's currently on the streets from other manufacturers," says Schaum.
Of course, warns Schaum, one should not assume that Toyota will stand still. Toyota hybrid engineer Hermance won't commit on whether Toyota would consider a two-mode system. For one thing, says Hermance, it's not clear whether drivers actually cruise enough to deliver a significant benefit. "The question becomes, what fraction of the total drive is in that steady-state regime? Until we see actual cycle test data for their system, it's hard to evaluate what kind of an improvement they may or may not have made," says Hermance.
Nevertheless, Hermance calls the two-mode concept a "good idea" in principle, especially in full-size trucks--a market segment where Toyota has yet to apply its hybrid technology.
GM will debut the two-mode late next year in the full-size Chevy Tahoe SUV, and DaimlerChrysler will follow in early 2008 with a hybrid version of the equally beefy Dodge Durango. Both manufacturers claim the two-mode system and more-efficient engines will make their SUVs as much as 25 percent less fuel-thirsty than their nonhybrid counterparts--performance that could be worth big bucks if it can reverse the recent sharp decline in high-profit margin SUVs brought on by high prices at the pumps.
Micro-Projectors for your laptop Anyone?
The number of possibly applications for a cheap (lower than $50) small size (wallet or cell phone size) projector technology are impressive, like projectors for cell phones, PDAs, in store advertising devices, laptops, not to mention creating a new type of portable TV. Of course, the premise here is that nothing more than a three color laser pen and a small set of optics and driver electronics will be needed to create a (MLD) projector.
However, the development time for high volume production will be length (3+ years). Regardless, I see the development and commercializing of these Micro-Laser-Displays (MLDs) as another promising result of the research in the MEMs Field.
Brian Glassman
Innovation Management
Commercialization of technology
Guest (Paul712)
Re: Micro-Projectors for your laptop Anyone?
http://www.technologyreview.com/read_article.aspx?id=17395&ch=nanotech
I'm guessing someone likes to view multiple articles at once; unless he knows something we don't about these new hybrids.
I am waiting to play with a SMART. I am a tall 6ft4 American and classic small cars don't work for me. My problem is headroom.
The SMART as I understand it has the space and headroom of an S Class for the two seats that it does have.
That is what I need, then I can lose the rest of the car.
I would also like to see NEV's taken up to 45mph so they can become second cars and pickups running on eletric only. I would buy one today, but they can't touch the 45mph roads to go grocery shopping.
Manufacturing in the United States is in trouble. That's bad news not just for the country's economy but for the future of innovation.
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anonymole
4 Comments
Run in dual mode
I would hope this tranny can run in dual op mode so as to use the electric motor (AC induction?) to act as a generator to recharge the batteries. Or they'll need to add additional infrastructure in order to use the ICE engine to charge the (probably very limited KW loaded) batteries. Add a plug-in option to these vehicles? Why ever would we do that?
Reply
marvkausch
1 Comment
Re: Run in dual mode
This GM patent, as described on www.hybridcenter.org appears not as good a concept as the Toyota mechanical transmission, and you point out that locking out the motor/generator locks out just that: the big generator. How could this be an advantage?
This looks like GM wants to patent at least something in the hybrid area, for better or worse. Their now destroyed EV1 cars had far superior engineering, even back in 1995.
Their latest effort to "show us their superiority", the new fuel cell car, has this major problem: just where do you fuel up? This looks an awful like, "See, we can develop new technology, but we're sorry you can't fuel it up. So would you please go back to buying SUVs and Hummers?"
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zifos
11 Comments
Re: Run in dual mode
They lock out the "big generators" when cruising down the highway (we have many long highways in the US). Hybrid cars run the "generators" during regenerative BREAKING. For (hopefully) obvious reason using regenerative breaking while driving down the freeway is a bad idea. Try driving your car down the freeway at 60mph with your foot pressed firmly on the breaks. The motors engage while slowing down and recharge the battery when you want to decrease the kinetic energy of your vehicle not when you want to maintain it (they are converting kinetic energy into electrical energy).
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timcen
1 Comment
Re: Run in dual mode
My Prius runs the generator and charges the battery while driving down the highway, with no ill effects. Basically the generator runs under light loads over 37 mph when the electric motor is not being used, i.e. accelerating. Regenerative braking is only built into the hybrids to recover energy that would normally be dissipated through heat. (Very nice benefit of brake pad life being extended. A lot.) The regenerative braking alone will not keep the batteries charged. If the car did not run the generator to keep the charge at 50-80% the life of the battery would be cut short. Unless there is a big change in batteries, deep cycle capability and faster charge rates, or capacitors, the vehicles will have to continue to run their generators, while cruising, to charge the batteries.
Reading this article leads me to believe GM is looking more towards developing a transmission that they can use with their existing engine and vehicle inventory, and are not interested in actual change.
“By swapping out the motors under high-power operation, the alliance partners get by with smaller motors”
This seems to be more for performance boosting than anything else. Instead of using a big electric motor with a small gas motor, they will be using small electric motors with large gas motors.
Does anyone else find this a bit backwards?
Reply
zifos
11 Comments
Re: Run in dual mode
I think you missed the point of the new system GM designed. They don't use the electric motors while cruising, only the ICE, so therefore they don't need to continuously charge the batteries. The toyota hybrid uses both the electric motors all the time so yes, it has to charge the batteries while cruising. The idea is to use the motors when they are most efficient (low rpm, high torque) and use the ICE when it is most efficient (cruising).
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