Several factors affect ball bearing speed limitation 

Factors affecting ball bearing speed limitation include temperature, load, vibration, radial play, retainer, lubricant, ball material and closures. It is important to remember that, for long bearing life, the actual speed should be significantly lower than the bearing’s maximum speed rating.

Learn more about high-temperature bearings. 

Temperature excesses and higher loads require slower speeds. Bearings fitted with contact seals can't achieve the same speeds because of increased friction between the seal lip and bearing inner ring. 

The choice of lubricant may also have a significant effect on the speed rating. The maximum revolutions per minute (rpm) at which a lubricant can effectively operate varies from type to type.

The adjustment factors we provide are approximate and are based on bearings with a metal crown or ribbon cage. Using a nylon or phenolic cage and a suitable lubricant can further increase the maximum speed of a bearing.

Lubrication in bearings for high-speed applications

Choosing the right lubricant is important for the speed rating of a system. It affects how fast the lubricant can work effectively. Different types of lubricants exhibit varying capabilities in handling high-speed applications. 

The composition and viscosity of the lubricant impacts its ability to withstand the mechanical forces and heat generated at higher speeds, like in a jet engine, which can rotate at speeds exceeding 30,000 rpm.

Certain lubricants excel in high-speed conditions, offering enhanced thermal stability and reduced friction. These qualities keep the system running smoothly, prevent damage and increase service life, even at high speeds. 

The lubricating-film thickness and stability are also critical factors. In high-speed applications, the right lubricant thickness keeps moving parts separate, stopping performance decline at higher speeds.

To determine which lubricant suits your application, take our choose your grease quiz. We also provide a specialised relubrication service if your bearing is not performing as intended.

Ceramic as ball material 

The choice of ball material plays a critical role in achieving higher speeds in ball bearings. Using ceramic balls is one strategy for increasing the maximum speed capabilities of ball bearings. However, it is necessary to acknowledge that this increase in speed has certain drawbacks. These drawbacks primarily revolve around the limitations in its load capacity. 

Ceramic balls, made from silicon nitride or zirconia, are good for high-speed applications because of their unique qualities. Compared to traditional steel balls, ceramic balls are lighter and exhibit lower friction.

As a result, using ceramic balls in ball bearings can lead to a notable reduction in frictional resistance, allowing for smoother and more efficient high-speed rotation, increasing speed by up to 40 per cent. 

However, ceramic balls also reduce the load capacity of a bearing as the harder ceramic balls cause an increase in stress on the bearing rings. This, in turn, reduces the load-carrying capacity of the bearing. In practical terms, while ceramic balls offer higher speeds, heavy loads may not make them the optimal choice for applications where the bearing is subjected to this. 

Check out this guide to learn more about ceramic bearings and balls.

The speeds in our technical drawings are approximate. They apply to bearings used on a horizontal shaft with a metal cage, standard tolerance grade, and radial play. The bearings should be under medium loading and have a rotating inner ring. Additionally, you should lubricate them with a suitable lubricant (refer to the table for more details). 

To learn more about tolerance grade, head to our tolerance tables for ball bearings page.

It is important to note that for vertical shaft applications, there is a need for a maximum speed reduction of around 20 per cent. Factors such as reduced cage guidance and less effective lubricant retention in vertical orientations contribute to this reduction.  

If you're looking to optimise the maximum speed of a bearing, the use of a nylon or phenolic cage can be considered. However, it's crucial to pair these alternative cage materials with a suitable lubricant for optimal performance.

The factors below provide rough estimates and rely on bearings with a metal crown or ribbon cage. 

Speed reduction table 

	Rotating Inner Ring		Rotating Outer Ring
	Open/ZZ	2RS	Open/ZZ	2RS
Petroleum Oil	Nil Reduction	40% Reduction	20% Reduction	40% Reduction
Synthetic Oil	Nil Reduction	40% Reduction	20% Reduction	40% Reduction
Silicon Oil	30% Reduction	40% Reduction	50% Reduction	50% Reduction
Standard Grease	30% Reduction	40% Reduction	50% Reduction	50% Reduction
High Speed Grease	Nil Reduction	40% Reduction	20% Reduction	40% Reduction
Silicon Grease	30% Reduction	40% Reduction	50% Reduction	50% Reduction

 

 

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