backtop


Print 58 comment(s) - last by Skywalker123.. on Jun 11 at 4:08 AM

Special fluid would only allow the driver to choose the correct gear

Walk into a room full of automotive enthusiasts and ask about manual transmissions and you'll likely get mixed responses. Sports car purists think a row-your-own, manual gearbox is the only way to go. However, many feel that the new semi-automatic gearboxes where shifts are made by clicking paddles behind the steering wheel are superior. Based solely on how quickly gear changes can be made, fans of the semi-automatic gearbox have a point.
 
Efficiency and speed aside, many sports car fans won't buy a car without a manual transmission. While BMW sells more cars with automatic or SMG gearboxes, a patent has surfaced that shows the traditional manual transmission still has a place with the BMW brand. The patent shows that BMW is considering a future with manual transmissions that have more than the normal six forward gears common today.
 
Many automatic transmissions are capable of better fuel efficiency than a manual transmission simply due to the fact that some have more forward gears with high seventh or even eight ratios to cut fuel consumption.
 
BMW's patent describes the problem was simply adding more gears to the current six speed manual transmission. The patent reads, "an 8 speed manual transmission would need four shift gates for the 8 gears alone." The problem with adding more gates is that it becomes difficult for the driver to shift gears and the potential for accidentally shifting into a lower gear and damaging the engine by over-rev grows.
 
BMW's solution of adding more gates and the growing complexity for drivers is both insane, and incredibly smart. BMW wants to design a manual transmission that will only allow the driver to shift into the correct gear. Anyone that's accidentally grabbed second on a 4 to 3 shift at speed will appreciate that innovation.
 
BMWs innovation creates shift gates that are surrounded by a magnetorheologic or electrorheologic fluid. That is a complicated way of saying that the fluid would prevent any improper shift when a voltage is applied to change viscosity of the fluid, therefore physically blocking any gear but the correct gear for downshift. The technology could be used on manual transmissions with a clutch pedal or without.
 
BMW sees an interesting potential by creating a shift-by-wire transmission where you can shift gears with a lever without having use a clutch pedal. This would be sort of a combination of an automated SMG and a traditional manual transmission. There is no indication of when this technology might come to market at this time, but it sounds like a very good idea.
 
Porsche already has a seven-speed manual transmission available in the 2012 911.

Source: E90 Post



Comments     Threshold


This article is over a month old, voting and posting comments is disabled

RE: Shifter design
By djc208 on 6/7/2012 12:16:46 PM , Rating: 3
They're not developing any magical fluid. This is the same type of fluid Delphi developed for shock absorbers that is used in GM and some Ferrari vehicles. It changes viscosity based on an electrical input.

So I'm guessing there would be some sort of cavities inside the shift mechanism with this fluid inside it. The computer would charge certain pockets of it to make it thicker so that if you tried to pull the shifter into that gear the fluid in that shift rail would be "harder" and make it more difficult to select that gear.

Many modern manuals have mechanical interlocks to prevent selecting first or reverse above certain speeds. Sounds like this would just work over more gears. Like anything electronic though the question would be how "restrictive" the system is. Sevent to second would probably be bad, but maybe I do want to go to 4th or 3rd. Being told no by the manual would be just as annoying as driving the auto.


RE: Shifter design
By lelias2k on 6/7/2012 5:03:53 PM , Rating: 2
Exactly. Can I hear you say Corvette Magnetic Ride Control? :)

Also, why do people like to bash new technologies without even giving it a chance?

Guess what, you might be as good as a race car driver (I highly doubt), but 95% of the people out there are not.

On that note, I can't wait for freaking self-driven cars.


"If they're going to pirate somebody, we want it to be us rather than somebody else." -- Microsoft Business Group President Jeff Raikes














botimage
Copyright 2014 DailyTech LLC. - RSS Feed | Advertise | About Us | Ethics | FAQ | Terms, Conditions & Privacy Information | Kristopher Kubicki