From electric motors to inline skate wheels, there are many different uses for ball bearings. If you find yourself in a position where you need to purchase this product, you will undoubtedly take a look on the Internet only to find hundreds and hundreds of options at your disposal.
This can be a little bit confusing and daunting for someone that has never purchased a bearing before. One of the first things you need to do is make sure you buy the right type of bearing. A lot of people end up purchasing a needle bearing or roller bearing by accident instead of a ball bearing. Keeping that in mind, we will assess the differences between the three.
What constitutes a ball bearing?
Ball bearing [bearingboys.co.uk]
So, let’s begin by taking a look at ball bearings themselves, which are the most common type of bearing, and are used in everything from hard drives to inline skates. They are typically found in applications where the load is relatively small, and they can handle both thrust and radial loads.
With this type of bearing, the load is transmitted from the outer race to the ball and then from the ball to the inner race. The reason why a ball bearing is able to spin extremely smoothly is because it is sphere in shape, which means it only contacts the outer and inner race at a small point. You need to be mindful of overloading a ball bearing however, as you can ruin the bearing, as it will lose its shape.
Roller bearings and Needle bearing characteristics
Roller bearing [bearingboys.co.uk]
Roller bearings differ from ball bearings dramatically, as they are a cylinder rather than a sphere. Because of this, they are used in different applications, typically those where it is necessary to hold heavy radial loads.
They are often found in the likes of conveyor belt rollers. When using roller bearings, the load is spread out over a large area because the cylinder shape means that the contact between the outer and inner race is a line rather than a point, this allows the roller bearing to hold much heavier loads than a ball bearing. However, it is vital to bear in mind the fact that this type of bearing has not been designed to handle a lot of thrust loading, rather it is for radial loading.
What about needle bearings? A needle bearing is a variation of a roller bearing. The only difference is that the cylinders used have an extremely small diameter, which ensures the bearing can be fit into tight places.
Needle bearing [engineerlive.com]
Hopefully, you now have a better understanding of the difference between roller bearings, needle bearings and ball bearings. There are many other types of bearings to choose from as well, including tapered roller bearings, roller thrust bearings and ball thrust bearings.
Tapered roller bearings are designed to support both large thrust loads and large radial loads. You will often find that they are used in car hubs, where they are carefully placed so they can handle thrust in both directions. In this instance, they will be used in pairs and mounted facing operate directions. If you are looking for something that is simply designed for great thrust loads, roller thrust bearings are a good option, which can often be found in gear sets. Finally, you will find that ball thrust bearings are a popular choice in barstools, as they are commonly used for low-speed applications, since they cannot handle a great deal of radial load.
All in all, there are plenty of different bearings for you to choose from and the importance of selecting the right bearing for your application is something that simply cannot be ignored.
Source: Bearing Boys