Bearing size is an important aspect of roller bearings and several factors determine the size of a roller bearing. These factors include the diameter of the shaft it will be mounted on, the bore diameter of the bearing, the outside diameter, and the width of the bearing.
The bore diameter is the inner diameter of the roller bearing and is typically measured in millimetres (mm). The width of the bearing is the distance between the outer races of the bearing and is also measured in millimetres.
To determine the proper size of a roller bearing where the shaft is the rotating element and the outer ring has a transition fit, the diameter of the shaft it will be mounted on must be known. The diameter of the shaft must be larger than the bore diameter of the bearing, as the bearing must fit snugly over the shaft. A tight fit is needed to prevent the bearing from rotating on the shaft, which could cause damage to the bearing and reduce its lifespan.
On the other hand, if the outer ring is rotating, then the housing must have a smaller diameter than the outer ring, and the shaft will have a transition fit.
In addition to the bore diameter and width, the load capacity of the bearing must also be considered when selecting the right size. The load capacity of a roller bearing is determined by the type of bearing, its size, and its material. For example, larger bearings can typically manage higher loads than smaller bearings.
It's also important to consider operating conditions, such as speed and temperature, as these can affect the size and load capacity of the bearing. In high-speed applications, for example, bearings with a low friction coefficient and high load capacity may be needed.
To ensure the proper functioning and longevity of a roller bearing, it is crucial to select the proper size based on the specific application requirements. It is also essential to select the correct lubrication for the conditions.
