What is this for a truck? (5 photos)

Between the wheels of some trucks you can see a rather strange metal device that resembles either a small wheel, or a drum, or even some kind of gear.

What is it for and what functions does it perform?





As you might have guessed, the mysterious device is called a "bear". But that's just the nickname it was given to the people in the driver's environment. The strange thing is correctly called a "Robson drive". The Medvedka is used mainly on those main tractors and trucks that do not use a wheel arrangement with rear and middle (if any) drive axles, but use a wheel arrangement with only a middle drive axle. Such a "strange" at first glance technical solution is used by truck manufacturers to reduce their cost.



The problem is that vehicles with only a middle drive axle significantly lose their cross-country ability. First of all, the difference is noticeable off-road. However, the truck may also have problems on a "civilized" road, for example, in winter with a high level of snow. And here our hero of today - the Robson drive - comes to the aid of cheap trucks. One of these is installed on each side of the vehicle. All that the special wheel does is transfer torque from wheel to wheel. Thus, the mole significantly improves the driving performance of the car.





It would be a mistake to think that the Robson drive was created specifically for budget trucks. In fact, it was originally used for military purposes. It was made to improve the cross-country ability of army trucks and all-terrain vehicles. For a long time, the mole was used only in the army, as well as in the field of rescue, scientific and exploration-geological work.



This device has never really gained widespread use among civilian trucks for the simple reason that they don't need it. The lion's share of commercial trucks today are still equipped with differential and axle locks, which essentially perform the same functions.