A hub in a car is needed to fit wheels and brake discs or drums. Therefore, the hub must be strong, because it takes all the loads during driving and braking, and also withstands the weight of the car.
A car is a rather complex system. And one of the most important components is the chassis. The load that is transferred from the wheel to the axle of the car is very large, so the buffer assembly between the wheel disk and the axle shaft must have a safety margin. And this buffer unit is the hub. It has a simple design, but is robust and functional.
Hub and bearings
It is rather difficult to identify the most important unit in the design, because everything, even the smallest details, is important. So, at the base of the hub is a cylindrical metal blank. It is hollow inside, grooves of a certain diameter for bearings are made in it from both edges. The bearings are pressed into the hub without any backlash, even the smallest.
The hub with bearings pressed into it is located on the car's axle shaft. But how not to talk about bearings, because they take on the greatest load. Types of bearings used in wheel hubs:
- tapered roller;
- cylindrical ball.
All of them are good in their own way, but the reliability of the former is much higher. It's all about the design of the bearing itself. Cylindrical ball bearings consist of two clips, between which there are metal balls. The contact area of these balls is very small, so they may not experience a very large load. But this does not prevent the use of such bearings in the rear wheel hubs, because the bulk of the car is concentrated on the front axle.
Conical roller bearings are capable of withstanding heavy loads. The outer cage is cylindrical on the outside, and has the shape of a truncated cone on the inside. On this inner surface, movable cylindrical rollers slide. The contact area of these rollers with the cages is several times higher than that of ball bearings. Hence the higher reliability of this type of bearing.
Brakes and Wheel Mounts
But the hub is not only made up of bearings. The main task of the assembly is to secure the wheel. But then I also remember the brake system, because without it, driving a car is dangerous. The wheel hub is combined into one unit:
- with a flange;
- with a brake disc.
All this is a single structure, first a flange is attached to the hub, which is in the form of a cylinder. Also in the flange there are threaded holes, with the help of which the rim is attached. And two more holes with a slightly smaller thread. They are designed to be fixed to the brake disc flange using tapered head bolts.
