Picture it: Holland, 1959. You are a successful truck company and you want to break into the passenger car market. The vehicle needs to be inexpensive and able to carry four people and their luggage around in comfort. No worries. But what about the mechanicals? Buick Dynaflow fan Huub van Doorne proposed the following. Two cylinder air-cooled boxer engine? Check. Pressurized Lubrication System? Check. Rear-wheel drive? Check. Independent rear suspension? Check. Continuously variable transmission? Check. Each rear wheel driven by a rubber belt? What in the fuck?!? Welcome to the wonderfully whacked out world of DAF. Mind blowing mechanical coolness after the jump.
This is the Variomatic transmission system of the DAF 33, including the rear wheels and the independent suspension system. Each rear wheel had its own homokinetic belt drive, this way the transmission also functioned as a self-locking differential.
This transmission system was developed by Johan van der Brugghen and quite special as you can see. You can also clearly see the two pairs of conical metal wheels (called "pulleys") in between which the rubber belt is wedged. In the position shown on the picture the transmission would have been in (almost) lowest gear: a small gear diameter at the driveshaft side and a large gear diameter at the belt driven rear wheel side. In highest gear it would be the other way around: the conical wheels at the driveshaft side would move together, forcing the rubber band to the outside to create a larger gear diameter. At the same time the conical wheels in the transmission at the rear wheel side would move further apart, letting the belt in to create a smaller gear diameter.
So the whole system was friction operated and that was also its main drawback: it made a high whining noise when changing gear ratios and the belts wore out and stretched after some time, causing them to snap or slip out of the transmission. It was very important to change the belts in time, otherwise the driver could end up at the side of the road quite unexpectedly.
We want. We want so bad! And stay tuned - you ain't seen a thing, yet.