Angular contact ball bearings are widely used in high-speed applications such as machine tool spindles, electric motors, etc.

However, as operating speeds increase, so does the challenge of managing limiting speed and temperature rise. Understanding how to balance these factors is key to maximizing bearing performance and reliability.

What Is the Limiting Speed of a Bearing?

The limiting speed refers to the maximum rotational speed at which a bearing can operate reliably without excessive heat generation, loss of lubrication, or dimensional instability. For angular contact ball bearings, the limiting speed is influenced by:

1. Contact angle

2. Bearing size and internal design

3. Lubrication method (oil-air, grease, oil mist, etc.)

4. Preload level

5. Cage material and design

Bearings with smaller contact angles and optimized internal geometry typically support higher speeds.

Why Is Temperature Rise a Critical Factor?

As speed increases, friction within the bearing also increases, leading to temperature rise. If not properly controlled, this can result in:

1. Lubricant degradation

2. Increased wear and fatigue

3. Dimensional changes

4. Premature bearing failure

In high-speed applications, controlling bearing temperature rise is as important as selecting the right bearing.

Techniques to Control Temperature Rise in Angular Contact Bearings

1. Lubrication Optimization

・Use high-speed compatible lubricants.

・Consider oil-air lubrication for ultra-high-speed spindles.

・Monitor lubricant flow and quality during operation.

2. Preload Management

・Excessive preload increases friction and heat.

・Use calculated and adjustable preload based on application demands. 3. Cage Design Selection Bearings with phenolic resin cages or ceramic balls can significantly reduce friction. Modern polyamide or machined brass cages may improve heat dissipation.

3. Bearing Arrangement

・Use tandem or back-to-back arrangements to distribute load and reduce heat concentration.

・Angular contact ball bearings are often used in matched sets for this reason.

4. Proper Housing Design

・Ensure effective heat dissipation through housing materials and structure.

・Integrate cooling systems when needed.

Example: High-Speed Spindle Bearing

In a CNC spindle application operating at 30,000 RPM, a pair of 70-mm bore angular contact ball bearings with ceramic balls and oil-air lubrication managed to maintain a temperature rise under 25°C. By optimizing preload and lubricant flow, the system achieved stable long-term operation without overheating or lubricant breakdown.

Achieving high performance with angular contact ball bearings requires a close understanding of limiting speed and temperature rise control.

From selecting the right bearing type and cage material to optimizing lubrication and preload, each factor plays a vital role in the bearing's success in high-speed environments.

If you need assistance choosing the most suitable bearing for your high-speed application, or want to learn more about temperature control solutions, feel free to contact our engineering team.