Ball bearing, in the study of mechanics, refers to a type of machine elements functioned to limit the relative movement between two or more components. This way, the machine will always move in the intended direction. Meanwhile, bearing also keeps the shaft to always spin and linear components to make them stay on their path.
There are some classifications of the bearing. Based on bearing references, this component is divided into two based on the friction. First, it is anti-friction bearing, a kind of bearing that cannot produce friction. Some examples are roller and ball bearing. Second, it is friction bearing which, of course, produces friction including bush and plain bearing.
Meanwhile, when it is seen from the burden held by the component, there are at least 3 types of bearing; journal, footstep or pivot, and thrust bearing. Journal bearing is designed to hold the burden which is vertical toward the horizontal shaft. Next, the footstep or pivot bearing is designed right on the vertical shaft to hold the burden parallel toward the shaft. Lastly, the thrust bearing is designed to hold the horizontal burden parallel toward the horizontal shaft.
Sure, to find the best products, you need to go to the trusted stores or market. In fact, there are bearings available in the stores that are damaged and they cannot work well. Anyway, NTN-SNR is one of the recommendations due to the wide range of options related to bearing including the materials, cages, internal clearance, lubrication, and more.
Particularly if you want to buy the ball bearings, there are several types provided. They are the deep-groom ball-bearings, single-row angular contact bearings, thrust ball bearings, and more. Each of types covers some series to meet your necessities. For example, the single-row angular contact bearings have 4 points of contacts and they are made from various materials.