Multitronic

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Animated representation of the principle

Multitronic is the brand of the car manufacturer Audi for a continuously variable, fully automatic transmission that works with two pairs of V-pulleys based on the principle of the adjustable V-belt transmission. The wide V-belt is designed here as a link chain .

history

With the Multitronic transmission, Audi tried to introduce transmissions with stepless, continuous transmission into higher-priced cars. In mechanical engineering , such gears are already used in industrial machines . Since the 1950s there have been V-belt transmissions in road vehicles in two-wheelers at DKW and the “ Variomatic ” in small Daf cars . Improved transmissions based on licenses from Daf were found in the Ford Fiesta , Fiat Punto ("Selecta") and others. The Multitronic developed jointly by Audi and the LuK Group was first used in 1999 in the Audi A6 C5 (Type 4B) .

The maximum transferable torque has been increased over the years from 300 Nm (2002) to 400 Nm (2006), but reduced to 380 Nm in 2007.

In the Audi A6 C7 and Audi A4 B8 models , the 3.0 TDI and 2.7 TDI have a variant for 400 Nm.

The Multitronic transmission was only offered by Audi in combination with front-wheel drive.

The transmission was also used in the Seat Exeo in combination with the 2.0 TFSI engine with 147 kW (200 PS) and the 2.0 TDI with 105 kW (143 PS).

technology

The Multitronic consists of the variator with the conical V-belt pulleys and the rocker- joint plate chain , the control and two multi-plate clutches . The wide link chain runs in the variator between two conical variator discs. By changing the distance between the variator disks in opposite directions, the link chain moves inwards on one axis and outwards on the other axis to different radii. This results in a stepless change in the transmission ratio. The control processes a large number of signals and measured variables, compares them with the setpoints and changes the transmission ratio accordingly. The multi-plate clutch connects the engine and transmission and enables the vehicle to be started. The second clutch offers reverse gear.

Thanks to the continuously variable ratio and the use of an adaptive map control , the economical speed range with the highest torque is used to a large extent . In addition, the Multitronic enables better acceleration than conventional manual transmissions and, by controlling the gear ratio close to the best point, low fuel consumption. The spread of about 6: 1 is above the values ​​of most other CVT transmissions (approx. 4: 1 to 5: 1).

Trivia

The term multitronic is used in 1968 in Raumschiff Enterprise for a complex computer.

Web links

Individual evidence

  1. ↑ Georg Jacobs (Ed.): Maschinengestaltung Volume II. Verlag Mainz, Aachen 2016, ISBN 978-3-86130-749-5 , pp. 241–243.
  2. ^ Starship Enterprise - Transporter Room Wesley