Pyörännavat

Pyörännavat, or wheel hubs, are the central component of a wheel assembly. They are responsible for connecting the wheel to the axle of a vehicle and allowing it to rotate freely. A typical wheel hub consists of a bearing, a spindle or axle shaft, and a mounting surface for the wheel itself.

The bearing within the hub is crucial for smooth rotation. It reduces friction between the rotating wheel and the stationary axle. There are several types of bearings used in wheel hubs, including ball bearings and roller bearings. These bearings are often sealed to protect them from dirt, water, and other contaminants, which helps to extend their lifespan.

The hub is also where the wheel is attached. This is typically done using lug bolts or studs, which pass through the wheel and thread into the hub. The number and pattern of these mounting points vary depending on the vehicle's make and model.

In some modern vehicles, the wheel hub assembly may integrate other components, such as the brake rotor and sometimes even the wheel speed sensor for anti-lock braking systems (ABS) and electronic stability control (ESC). This integration can simplify assembly and reduce the number of individual parts. Proper maintenance of wheel hubs, including checking for play and listening for unusual noises, is important for vehicle safety and performance.