The mechanical speed rating – or limiting speed – for 6000 series deep groove ball bearings typically runs between 3,000-28,000 RPM. However, there are design options that affect the maximum rotational speed of ball bearings.
These options include:
- Bearing size
- Lubrication type
- Bearing seal style
Limiting speeds are key to preserving the service life of a bearing. Exceeding speed limitations can cause damage to not only the bearing but to other components or parts of the application as well.
Axis deep groove ball bearings use mechanical limits to determine the maximum recommended RPM of a bearing. These limiting speeds can typically be found in manufacturer catalogs or product tables.
Bearing size affects the limiting speed. Generally speaking, larger bearings will have a lower limiting speed than smaller bearings. This happens for a few reasons, but most notable is the linear distance the rolling elements must travel to make a single rotation around the shaft.
The rolling elements of smaller bearings have less physical distance to travel in a revolution and so they have higher RPM limits. Larger bearings have more ground to cover and so they have lower RPM Limits.
Lubrication type also plays a role in a maximum bearing speed. Bearings that run with oil lubrication have higher limiting speeds than those that operate with grease lubrication. If a catalog does not list separate limits for grease and oil lubrication, it is possible that oil lubrication will be required to achieve the highest listed limiting speed without damage to the bearing.
Another factor that affects the speed limit of a deep groove ball bearing is the type of seal used. There are three common seal options: open, shielded, and sealed.
Open: Open-sided bearings work with either grease or oil lubrication. When making use of oil lubrication, open bearings can achieve the highest rotational speeds. In grease applications they allow for relubrication. The downside is that open seals offer the least amount of protection against contamination.
Shielded: Pre-filled with grease, shielded bearings provide some protection against the ingress of contaminants. They provide protection without lowering the limiting speed of the bearing. This is because the shields don’t make contact with the inner ring of the bearing.
Sealed – Also pre-filled with grease, sealed bearings provide the best protection against contamination. The rubber seals make contact with the inner ring of the bearing, leaving no gaps for the ingress of contaminants. However, this contact creates friction that must be accounted for. Because of seal drag, the maximum rotational speed of a sealed bearing will almost always be lower than shielded or open bearings.
Each of these factors will play an important role in selecting the correct bearing for your application. As always, make sure to review manufacturers catalogs before operation.
Looking For Specific Limiting Speeds?
Download our catalog for bearing speed ratings.Download