Ball Bearing Thermal Speed Rating

Physical heat generation plays an important role in bearing life and operation. Maintaining a steady temperature will be vital as the EV market grows in the future.

Hello folks, I hope all is well in bearing land. I had a chance to meet up with some old bearing pals over the weekend. We all worked in the same small bearing office at one time and had really developed a special relationship that is hard to find in a mega-complex corporate world headquarters. A few of us have left over the years, but we still all work together occasionally as customer/supplier. Even though we all work in different tiers of the business, we are all feeling the heat of the electrification revolution.

The expectations are high and workloads are substantial. We all understand that there is a backside to this mountain—one where there are not 10,000 engine part numbers, transmissions with four planetaries and clutches, no transfer case, independent axles, exhaust system, etc. With this potential massive part reduction, I have already seen two large, tapered bearing plants in the United States close with no replacement. Additionally, consolidation moves throughout the industry. The companies that supply traditional powertrain components are trying to pivot or prepare for the eventual diminishment—if not demise—of the 120-year-old model of building cars and trucks. This isn’t going to happen overnight, but most real predictions see classic powertrain models at about 30 percent of today’s numbers by 2030.

Today, we are not just talking about heat as a metaphor for workload, we are talking about physical heat generation in our bearings. We are going to talk about ISO 15312:2018 which discusses the thermal speed rating. Unlike the limiting speed we discussed last time, where we’re concerned about the strength of the cage for high-speed dynamic, thermal speed ratings are focused on the ability to cool the bearing to maintain a steady temperature.