Original Autos - Dynaflow

Buick''s entry into automatic transmissions actually began in the early 1920''s, when they began studying the principles of hydraulics and turbines.  This study led to the infinite variableconcept, which asserted that a transmission could operate with a large number of ratios and speeds in an uninterrupted sequence, rather than a definite number of fixed gear changes, as would be seen later in GMs Hydramatic.  The transmission Buick developed was called the IV or Roller. Testing in the early 30''s showed it to be an excellent unit, although not ready for production cars, due to parts failure after about 5,000 miles on the test tracks.  The project was put in limbo while a new semi-automatic was developed; a self-shiftingunit that was offered in 1938 Buick Specials.  It used regular gear shifting in First and Reverse, but automatic in Second and Third.  This unit was trouble-prone and was dropped for the 1939 model year.  The first real use of the Dynaflow torque converter driver was during WWII on the Hellcat tanks built by Buick for the war effort.

Work on the Dynaflow continued after the war, and by 1948 it was offered as an option on the Roadmasters.  It provided a smooth low-to-high range without the gear changes felt in GMs Hydramatic of the same period.  Dynaflow buyers complained of unusual noises and a feel of slipping while getting up to optimum driving speed, dubbing it the Dynaslush. Even with its early faults, more and more Buick owners opted for the Dynaflow, and by 1954, 85% of Buicks had them.

By definition, Dynaflow is a hydraulic torque converter in conjunction with an epicyclic 2-speed gear mounted behind it. The five basic components are the heart of Dynaflow Drive. They are contained in a sealed drum, completely filled with oil. The Pump is connected to the flywheel of the engine and turns with it. The Turbine fits inside the Pump, facing it. The Turbine is connected with the drive shaft, which turns the rear wheels.  As you speed up, the Pumps turning action throws a solid, cylindrical sheet of oil against the blades of the Turbine, causing it to revolve and move the wheels. In this manner, the unit acts like a fluid coupling (the motor can turn while the car is standing still, and oil, rather than a clutch, starts it moving). More than just a fluid coupling, however, Dynaflow is a torque converter; it multiplies the turning effort of the engine. 

The Stators and Secondary Pump fit in between the Pump and the Turbine, and they redirect the oil as it flows from the Turbine back to the Pump. Oil flows from the Pump to the Turbine around the outside, then returns through the openings at the center of the Stators. The Stators are free to spin in one direction around the shaft on which they are mounted, through a free-wheeling arrangement, but they can not turn the opposite way. This means that during initial acceleration, when the engine and the Pump are turning faster than the Turbine and drive shaft, the Stators are locked in place, redirecting the returning oil into such channels as will multiply the thrust of it, giving the effect of first gear. As the car picks up speed, then each Stator in turn ceases to re-angle the flow of oil, floatingidly on the shaft because less conversion of the engines turning effect (torque) is needed. The need now is for a more direct transfer of power at a higher speed. 

Upon reaching the free-wheeling stage of the Stators when cruising speed has been achieved and the driver eases off the throttle, the Pump and Turbine are turning at nearly the same speed--approximately one revolution of the drive shaft for each revolution of the engine. When more power is needed, for passing, or for maintaining speed on a hill, all that is required is to press harder on the throttle. As the engine speeds up to a point where the Pump is turning faster than the Turbine, the Stators lock up again, redirecting the flow of oil to convert its speed into extra torque. All this means that you now have an infinite number of gear ratios and you don''t have to select them, since the proper degree of torque multiplication is always in operation automatically. This self-adjustment is controlled by the difference in speeds between the Pump and the Turbine, and by the resulting difference in oil velocity upon the Stators. The epicyclic gear provides Reverse.

In 1953, Buick improved the original Dynaflow design with their new Twin Turbine. This incorporated two turbines but only one Stator, resulting in better performance and a feel of more direct power getting to the rear wheels. In 1955, variable-pitch Stators were developed, giving improved flexibility. The final major change to the Dynaflow was in 1957, with the Triple Turbine, or Flight Pitch. It was similar in theory to the Twin Turbine, but provided a new Grange, which gave a safe descent of grades by restraining the engines RPMs. Another difference was that the while the Twin Turbine could be push-started, the Flight Pitch could not. The most important feature of the new transmission was its 5-element torque converter, in combination with two planetary gear sets, consisting of an engine driver Pump, three Turbines and the Stator. The shift quadrant on the first series and on the Twin Turbine is PNDLR and the Triple Turbine shift quadrant is PRNDG, G being Grade Range.

 

source: http://www.southernwheels.com/Feb-08.htm

Archive

  • 2009-11-03

    Volvo I-Shift

    A transmission with intelligence....

  • 2009-10-29

    Honda i-shift

    Honda's i-SHIFT System offers Civic buyers the opportunity to rest the left foot

  • 2009-10-18

    WEBSHOP - Oil filter VW 6 speed

    We can offer oil filters for latest type of VW 6 speed transmissions

  • 2009-10-07

    WEBSHOP - Oil Pump 5L40E

    KAPS reconditioned oil pump for the 5L40E automatic transmission!

  • 2009-10-06

    Aston Martin DBS Touchtronic

    The ultimate Aston Martin is only a year old, but it's already getting some updates including a new automatic transmission.

  • 2009-09-23

    ZF Powerline Automatic

    Nissan is preparing to launch an all-new line of light commercial vehicles for the North American market in 2010 with ZFs powerline.

  • 2009-09-21

    WEBSHOP - Multitronic 01J kit (Audi)

    Spare parts kit for the Multitronic 01J (Audi) automatic transmission.

  • 2009-09-08

    Peugeot ECG

    The Peugeot Electronic Controlled Gearbox (ECG) in the 207 and 308 models.

  • 2009-08-27

    WEBSHOP - Piston kit 5L40E

    Yes we sell spare parts! Piston Kits available for Automatic Transmission 5L40E.

  • 2009-06-17

    Antonov TX6 Automatic

    In the Antonov TX6, the torque converter has been replaced with a pair of wet clutches - one for forward gears and one for reverse

  • 2009-06-10

    Zeroshift 8 Speed FWD Transmission

  • 2009-06-10

    Porsche Doppelkupplung (PDK)

    PDK is essentially two half gearboxes in one and thus requires two clutches – designed as a double wet clutch transmission

  • 2009-06-03

    MC Shift Technology

    This electro-actuated gearbox can change gears in as little as 100 milliseconds – faster than any driver could achieve with a conventional manual transmission!

  • 2009-05-27

    Modern Gearbox Technology

    Confused by the slew of abbreviations like DSG, SMG, CVT, and the like? You aren't alone.

  • 2009-05-20

    BMW DCG - Double Clutch Gearbox

    Wave goodbye to BMW's SMG sequential manual gearbox and say hello to its new DCG double clutch gearbox.

  • 2009-05-19

    BMW SMG Gearbox

    Looking back to 2002 with BMW’s SMG – Sequential Manual Gearbox

  • 2009-05-10

    Original Autos - Hydra Matic

    We take a look at the birth of the Automatic Transmission.

  • 2009-05-10

    Original Autos - Dynaflow

    We take a look at a second original Automatic Transmission.

  • 2009-04-30

    Automatic vs Manual Transmission

    We compare the major points in the debate between Manual and Automatic Transmissions. What is better for you?

  • 2009-04-30

    JaguarDrive Selector

    What is the JaguarDrive Selector?

  • 2009-04-22

    Ford Dual Clutch Powershift

    PowerShift will deliver the fuel efficiency of a manual gearbox with the convenience and ease of a premium automatic transmission

  • 2009-04-22

    Ford 6F-55 Select Shift 6 Speed

    A six-speed SelectShift automatic transmission that's specifically designed for the higher torque demands of the all-new twin-turbocharged, direct injection engine.

  • 2009-04-16

    Understanding the Valve Body 1/2

    The Valve Body of an automatic transmission contains a complex series of passages controlled by valves to direct fluid flows. We will look how this functions. Part 1 of 2

  • 2009-04-16

    Understanding the Valve Body 2/2

    The Valve Body of an automatic transmission contains a complex series of passages controlled by valves to direct fluid flows. We will look how this functions. Part 2 of 2

  • 2009-04-08

    Understanding the Lock Up Clutch

    This article will look at the operation and fluid flows controlling the lock up clutch machanism.

  • 2009-04-08

    Stall Torque Converters

    What are the pros and cons of a stall torque converter? What is their best application?

  • 2009-04-02

    Understanding Torque Converters

    In this article we look at the role of a Torque Converter in an Automatic Transmission and discuss its components.

  • 2009-04-02

    Understanding Converter Fluid Flows

    Previously, we looked at the parts that make up the torque converter and had a brief introduction on the workings of each component. We will focus this article of the fluid flow within the torque converter itself.

  • 2009-03-26

    Understanding Holding Devices for Planetary Gear Sets

    In this article, we will look at the three common types of holding devices for planetary gear sets. Each having their own distinct advantages.

  • 2009-03-25

    Understanding Planetary Gears

    This article will look at the design of planetary gear sets in an automatic transmission.

  • 2009-03-18

    Hyundai’s 6-speed Transaxle Automatic Transmission

    Designed for cleaner emission regulations and better fuel economy, by as much as 12.2%!

  • 2009-03-18

    Understanding Automatic Transmissions

    Over the coming weeks, we will look at various components of the automatic transmission. This article discusses the basics of the auto transmission.

  • 2009-03-10

    Product Info - Shell Donax Oil

    Shell Donax TX is a premium performance, semi-synthetic heavy-duty universal power shift and automatic transmission fluid

  • 2009-03-10

    Product Info - Petro-Canada Oils

    Introducing the next generation of Automatic Transmission Fluids

  • 2009-02-16

    ZF Develops Automatic 8-Speed Transmission

    Consumption savings of six percent thanks to the new transmission concept with improved efficiency

  • 2009-02-11

    VW 7 Speed DSG

    DSG – the intelligent automatic gearbox from Volkswagen World’s first 7-speed DSG for high-volume production

KAPS Automatic s.r.o. Prerovska 561, 752 01 Kojetin, Czech Republic
+420 581 764 086
kaps@kaps.cz
  • Pioneering innovations

    Carl F. W. Borgward quickly and automatically shifted gear

    More
  • World record with GTR

    Congratulations to Mike Newton and Litchfield’s achieving the world record of the “Fastest Blind Man” in the world at 200.9mph.

    More
  • Proffesional ATF products on offer!

    Professional ATF products now on sale at our eshop www.kaps-parts.com. View more..

    More
  • Two Mass Flywheel DSG

    Two Mass Flywheel for DSG transmission for the best price on the market!! If you hear unnatural sound, its time to exchange your Two Mass Flywheel now. Use: engines 1.9 TDI (77kW) code BLS vehicles VW, Audi, Skoda, Seat. With the Two Mass Flywheel you can keep the engine running at a very low speed idle on modern engines.

    More
  • Oils and Fluids

    You can now order Oils and Fluids through our eshop. Please check www.kaps-parts.com.

    More