When most people think of ceramic bearings, they are usually referring to hybrid versions. Hybrid bearings sit in the middle of ceramic and steel, typically including stainless steel races or rings, and ceramic balls. The steel inner and outer rings of a hybrid bearing can be machined to very close tolerances, meaning that they are best suited for applications such as electric motors, laboratory equipment, and machine tooling.
On a grinder machine, for example, 25% higher revolutions per minute (RPM) can be achieved by adding in ceramic hybrid bearings and synthetic grease lubricant due to the reduced friction. Grinding spindles with hybrid ceramics may run 4,000 hours without problems, compared to 3,000 hours with steel bearings. Hybrid bearings can also lower temperatures by nearly 50%. In a horizontal machining center, switching from traditional bearings to the hybrid alternative has been shown to drop bearing temperature from 60° Celsius to 36° Celsius at 12,000 RPM.
Using a hybrid bearing combination allows for higher speeds than full ceramic options, as the less brittle metal rings are not as prone to sudden catastrophic failure under high speed or load. That said, a hybrid bearing’s corrosion resistance pales in comparison to a full ceramic equivalent.
Specifying the right bearings for extreme environments has always been a complex issue. But just as Zirconia clarified the origin of life, asking these three questions will help with the decision-making process.