You might have heard of them before, but do you know what exactly a ball bearing is? If the image that you conjure up in your mind is a small brightly polished metal ball, then you are about half right. A ball bearing is actually a pair of tracks with multiple balls between them. Ball bearings are designed to reduce the friction between two rotating objects as well as to help support loads. Though they do tend have lower load capabilities than other types of bearings, they can handle misalignment better, which earns them their niche in the work world. The simplest example of a ball bearing can be found in most rotating bar stools and the Lazy Susan that your Aunt Ethel has.
Ball bearings have been around for thousands of years, going back all the way to ancient Egypt. The first actual patent however was actually for a bicycle mechanic in the mid 1800's. Though they have existed for a very long time, their design has always been the same, the paired tracks sandwiching a series of metal balls of the same size that are allowed to rotate freely with the tracks. Proper lubrication is required though, and each set of bearings needs its own specific viscosity of oil or other lubricant. Their lifespan is always defined by the baseline that the bearing will rotate one million times, at the very least. Thats not to say that they will lock up at one million and one, that is just the highest standard that was found. A good portion of bearings can hold up for many times that long, as long as they are properly lubricated and not subjected to torsional force, which can destroy the bearings by tearing the tracks out of alignment. Once again, proper maintenance can prevent any and all of the most common issues found in broken or damaged bearings, and that maintenance often surrounds the lubricant used.
Now, there are two ways to keep the bearing lubricated. Grease and oil. Grease has the advantage that it is sticky enough that it will remain inside the bearing with little issue unless it the bearing grows too hot. When this occurs, the grease will melt and run out of the bearing. This can decrease the lifespan and maximum load. Oil as the other option has its own benefits and disadvantages. It can allow the bearing to achieve a higher maximum load, but requires more maintenance and care. Since oil is not sticky, it has to be contained inside the bearing. Also, the cooler the oil is kept, the longer it will perform at peak proficiency. If they oil is kept under fifty degrees Celsius, then it needs only to be changed once a year.
Properly maintained ball bearings can last for a very long time under repeated stresses that would bend and destroy other bearings in their place. Provided that the orientation of the bearing under its load is correct, they can support a great deal of weight while still maintaining their rotational ability with a minimum amount of force. Not to mention the fact that ball bearings are the least expensive of the rotating element bearings, and they are used in virtually everything.
Ball bearings have been around for thousands of years, going back all the way to ancient Egypt. The first actual patent however was actually for a bicycle mechanic in the mid 1800's. Though they have existed for a very long time, their design has always been the same, the paired tracks sandwiching a series of metal balls of the same size that are allowed to rotate freely with the tracks. Proper lubrication is required though, and each set of bearings needs its own specific viscosity of oil or other lubricant. Their lifespan is always defined by the baseline that the bearing will rotate one million times, at the very least. Thats not to say that they will lock up at one million and one, that is just the highest standard that was found. A good portion of bearings can hold up for many times that long, as long as they are properly lubricated and not subjected to torsional force, which can destroy the bearings by tearing the tracks out of alignment. Once again, proper maintenance can prevent any and all of the most common issues found in broken or damaged bearings, and that maintenance often surrounds the lubricant used.
Now, there are two ways to keep the bearing lubricated. Grease and oil. Grease has the advantage that it is sticky enough that it will remain inside the bearing with little issue unless it the bearing grows too hot. When this occurs, the grease will melt and run out of the bearing. This can decrease the lifespan and maximum load. Oil as the other option has its own benefits and disadvantages. It can allow the bearing to achieve a higher maximum load, but requires more maintenance and care. Since oil is not sticky, it has to be contained inside the bearing. Also, the cooler the oil is kept, the longer it will perform at peak proficiency. If they oil is kept under fifty degrees Celsius, then it needs only to be changed once a year.
Properly maintained ball bearings can last for a very long time under repeated stresses that would bend and destroy other bearings in their place. Provided that the orientation of the bearing under its load is correct, they can support a great deal of weight while still maintaining their rotational ability with a minimum amount of force. Not to mention the fact that ball bearings are the least expensive of the rotating element bearings, and they are used in virtually everything.
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