Variomatic
Vario Matic is the name of the Dutch car manufacturer DAF for a continuously stellbares fully automatic transmission, a design of the CVT transmission (English: Continuously variable transmission ) as a belt transmission.
Nowadays, this type of transmission in mopeds and scooters is popular and is also referred to them as VARIOmatic.
Between conical pulleys pairs a V-belt runs. By simultaneous change of the distance of the pulleys according to the speed (due to the centrifugal weights, depending on the walking speed and to the outside by the belt force to the outside) to an infinitely variable gear ratio change resulted. Additional control moment was the vacuum from the intake tract depending on the accelerator pedal position. The vacuum has been implemented on two very large, spring-loaded boxes into a force, the changed the pulleys accordingly.
One advantage resulted from the twistability: As seen in the picture, the V-belt allowed some distortion during compression; could thus be dispensed with universal joints in the drive.
In the DAF models 600-55 for not using a differential gear. Each rear wheel is individually powered by a V-belt; the different wheel speeds on bends made up for the slip of the belt. On slippery road surfaces a single wheel could not spin (like a part limited slip differential ), which is especially rally driver knew appreciate. The DAF was forwards and backwards at the same speed, thanks to its technology. That was some " spectacle race " called AVRO Achteruitrijden (German AVRO - reversing ) for the Dutch television station AVRO sufficiently proved with dilapidated DAF models. However, these attempts ended with the most inevitable rollovers after steering maneuvers. The caster of the steering axle, the wheels automatically brings in the ' Geradeaus' direction when moving forward, is perverted when reversing in the opposite and leads to full lock the wheels with corresponding consequences for the driving stability, especially at higher speeds.
In the DAF models 46, 66, 77 and the derived therefrom Volvo models a De Dion axle was installed, plus a synchro shuttle gearbox with reverse shift pattern ( " lever forwards = backwards" ), a differential gear and propeller shafts. The limited slip differential effect fell off it. With the weaker engine in DAF 46 was therefore a pulley group accounts for what inertial mass, friction and costs saved.
In still young car racing Rallycross were of the DAF sports department in Eindhoven ( under the direction of Rob Koch and later by Fred Hagendoorn ) even two DAF 555 Coupé 4WD used at the beginning of the 1970s as the official CAMEL- DAF racing team. The third 5 in the model designation stood for the group 5 according to FIA regulations. The vehicles possessed a sports VARIOmatic - wheel drive, each with a belt for the propeller shafts to the front and rear axle and self-locking differentials, the BMW 2002. Sporting VARIOmatic used had originally been developed for the Formula 3. The well -equipped 200 -hp Ford BDA engine vehicles were among the two brothers and forwarders Jan de Rooy (later also become famous as DAF Trucker at the Dakar Rally ) in Europe and Harry de Rooy for some time almost unbeatable, even though they were mostly drive off 5 seconds after the vehicles with two-wheel drive (4WD penalty ).
Currently Riemenvariomatik gearbox can be used, for example in motor scooters, quads, ATVs, snowmobiles and drilling machines.
Similarly CVT transmission work with slats instead of chain belts. The force is not transmitted via V-belts, but on steel member bands ( see picture) or chains. These transmissions have been developed and offered by different manufacturers, however, could not yet prevail on a larger scale. At Audi, this form of transmission is offered, for example under the name Multitronic.
The A- and B -Class from Mercedes -Benz Daimler Group are equipped with a CVT automatic transmission with virtual gears ( Autotronic ), which can be switched by hand also optional.
- Vehicle transmission