Ball Bearings are of special requirement in machines that involve friction free running for their smooth performance and ultimate output. Made usually from stainless steel, chrome steel, plastic and ceramic, the balls in these bearings are integral for proper functioning of any bearing ball variety. Of special importance are these ball bearings in the dental and medical sector, where sterilization and avoiding corrosion (for maintaining hygiene) is of utmost importance. These can be divided into many different types as per their applications namely deep groove, angular contact, thrust, self-aligning and four-point contact ball bearing. However, this is not the scope of this article.
In the article, I would be throwing light on the ball accuracy in these bearings. In addition, this is very important. Moreover, you should take note of the fact that in order to get the optimal benefit from these ball bearings is to get balls in them that are perfectly round and smooth. Well, the whole process is quite laborious with getting a perfectly shiny ball from a piece of metal wire.
The first and foremost step involves putting in a metal wire of the desired metal and size of the ball inside a heading machine. This machine has a metal cavity that slams shut on the wire thus forcing it to become the shape of a ball for your ball bearings. However, the process leaves a ring of metal (called flash) around the ball, which is removed in the next step by rolling the ball between two very heavy hardened steel plates called rill plates. This is followed by other operations where the ball travels through a groove, and then tagged along by heat-treated, grinding operation, lapping operation and finally the inspection process.
It is to be mentioned here that all kind of balls for ball bearings should abide by certain rules and regulations set down by the Anti-Friction Bearing Manufacturers Association (AFBMA) grading. For example: a grade three ball has to be spherical within 3 millionths of an inch and the diameter must be accurate within 30 millionths of an inch and so on. It is to be mentioned here that getting smooth and round balls are of extreme importance as they are used in important industry sectors.
Wayne Mah from Vancouver, Canada in his picture on the balls in bearing balls has rightly captioned it thus, 'these little critters are ubiquitous but often work behind the scenes and therefore receive little credit.' However, you know how important they are now!