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Automotive Transmissions: Efficiently Transferring Power from Engine to Wheels
(Released January 2008)

  by Chao-Hsu Yao  


Key Citations




Resources News Articles
Historical Newspapers

News Articles

  1. Transmission Considerations: Beyond the Manual Gearbox
    Kimberly, William
    Automotive Design & Production 02-01-2006

    As Far as the majority of European drivers are concerned, the only transmission worth considering is the manual, which accounts For Four out oF every Five gearboxes Found in new cars sold in the region. There are two key Factors in this dominance: (1) the extra cost in purchase price oF automatic transmissions; (2] the in-built prejudice against automatics. The typical European driver still believes that not having a shiFt stick dilutes control oF the car. "In Europe, iF a customer can obtain an air conditioning system or light-alloy sports wheels For the same extra cost as an automatic transmission, the majority choose the other options," said Dr-Ing Gerhard Wagner, group vice president, ZF in his plenary speech at the Innovative Automotive Transmissions conference organized by the Car Training Institute in Berlin at the beginning of December 2005. "However, it should be noted that the extra cost charged For an automatic transmission is not in any way related to their manuFacturing costs. Instead, the whole issue is governed by the pricing policy oFthe vehicle manuFacturers which still determines that some items of equipment are cost options."

    Wagner continued, "The figures quoted in sales brochures For Fuel economy, emission levels and 0-100 km/h acceleration times are the next obstacle to overcome when selling a vehicle equipped with an automatic transmission. If these figures are significantly worse than those of a vehicle with a manual transmission, European customers tend as a general rule to favor the manual transmission. As a consequence, the requirement for low fuel consumption and good performance figures form an essential component in any automatic transmission development work." . . .

    Copyright Gardner Publications, Inc. Feb 2006

  2. Industrial Management & Technology: The Amazing Infinite-Ratio 'Gearbox' This fuel-saving transmission is going into a new Saturn SUV, among other vehicles. At its heart is a very special belt like transmission
    Stuart F. Brown
    Fortune 11-13-2000

    Back in 1989 I was piloting a little Subaru mini-car called the Justy ECVT through the rowdy traffic on Manhattan's West Side Highway. Spotting an opening ahead in the adjacent lane, I nailed the throttle and began steering to the right. That's when I narrowly missed sideswiping a big Oldsmobile. Time expands a lot at such moments, and as the milliseconds marched by I felt like the captain of a huge ship who had ordered a change of speed. It was as if the first officer had briefly second-guessed my command before relaying it belowdecks to the crew members in charge of actually opening the steam valves that send power to the propellers. There was an unsettling time lag before the car finally got up and went.

    The Justy was equipped with a continuously variable transmission, or CVT, and I was experiencing what engineers at the time called the "rubber-band effect." Justy owners soon learned not to expect acceleration until a second or two after applying the throttle. It took that long for mysterious electrohydraulic hardware under the hood to adjust the transmission's gear ratios to suit the conditions of the moment. With its tiny 1.2-liter engine and slo-mo throttle response, the Justy ECVT wasn't suited to American driving conditions and in a few years faded from the scene. But the idea of a thrifty transmission with an infinite number of ratios, instead of just a few, stayed alive in engineering labs around the world. Now there's a new generation of CVTs that really work. . . .

    Copyright 2000 Time Inc.

  3. Know your transmission. (manual vs. automatic transmissions)
    Peters, Eric
    Consumers' Research Magazine 04-01-1996

    Two-thirds of the cars and trucks sold in America come with automatic transmissions, yet few consumers understand the basic workings of the mysterious "slushbox" or even know its relative strengths and weaknesses compared to a manual transmission.

    Although this may seem a matter of concern for engineers only, the more you know about how your automobile works, the better equipped you'll be to make intelligent purchasing decisions and to discuss repairs with your mechanic.

    Let's begin with the automatic transmission. It relies on a fluid coupling and torque converter to transfer engine power (torque, or rotational force) to the drive wheels.

    A torque converter consists of three major components--the impeller, stator, and turbine--working together in a single round housing that looks kind of like a doughnut. It is bolted directly to the back of the engine at the flywheel and spins at high speed whenever the engine is running. The other end of the converter fits snugly against the front of the transmission, where it accepts the input shaft that transfers engine power to the drive wheels. . . .

    COPYRIGHT 1996 Consumers' Research Inc.

News Articles taken from ProQuest's eLibrary.

Historical Newspapers

  1. FOUR MOTOR SPEEDS FORECAST IN TESTS; Saving in "Gas" and Almost Noiseless Gears Sought
    Christian Science Monitor (1908-Current file). Boston, Mass.: Jan 29, 1927

    DETROIT, Mich., Jan. 29 (Special) --That the automobile is far removed from its ultimate development was emphasized at closing sessions of the Society of Automotive Engineers here when it was pointed out by Harold Nutt of Durant Motors, Inc., that transmissions having more . . . .

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    New York Times (1857-Current file). New York, N.Y.: Jul 1, 1928

    WHAT is likely to be the automobile of the future, at least in a number of particulars, was discussed last week at Quebec at the Summer meeting of the Society of Automotive Engineers. The various speakers talked about details of development which promised motor car improvement along several lines.

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  3. Some Kind Of Turbine Drive Seen; Auto Engineer Thinks It's Probable Solution of Desire for Automatic Transmission
    The Hartford Courant (1923-present). Hartford, Conn.: Apr 21, 1940

    Detroit, Mich., April 20.--Some form of turbine drive is the probable solution for the multiplicities that confront the engineer in trying to work out the problems involved in the much-sought automatic transmission for the modern car.

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Articles and Abstracts Taken from ProQuest's Historical Newspapers.
  1. Newcomen steam engine
    Wikimedia Foundation Inc.)

  2. Watt steam engine
    (Wikimedia Foundation Inc.)

  3. How Manual Transmissions Work
    (HowStuffWorks, Inc.)

  4. Automatic transmission
    (Wikimedia Foundation, Inc.)

  5. Continuously Variable Transmission
    (Wikimedia Foundation, Inc.)

  6. Semi-Automatic Transmission
    (Wikimedia Foundation, Inc.)

  7. Epicyclic Gearing
    (Wikimedia Foundation, Inc.)