Development of Creep Resistance Features for Ball Bearing
JTEKT Corporation (hereinafter JTEKT) has developed a “Creep Resistance Features for Ball Bearing” primarily used in the transmissions of hybrid vehicles (HV/PHV) and electric vehicles (EV/FCV), as well as CVTs (continuously variable transmissions) of engine cars. This product suppresses housing wear that occurs inside transmission housing due to bearing creep, thus helping to increase the reliability and comfort of next-generation vehicles.
What is bearing creep?
Bearing creep is a phenomenon whereby the inner or outer ring rotates in relation to the housing or axis during operation.
This phenomenon causes various damages, such as wear, discoloration, and scuffing.
Type of creep and reason for occurrence
When creep occurs, the bearing and the housing rub together, causing mutual wear, and triggering both wear, causing axis core displacement or tilt. Consequently, poor gear engagement can lead to problems such as decrease transmission function and abnormal noise.
In the past, to avoid creep-related problems, various countermeasures were implemented, such as using a thicker outer ring or solid lubrication film, however both these measures involved issues such as size, weight, and cost, therefore there was a need to develop an optimal product.
Against such a backdrop, JTEKT developed the New Structure Anti-Creep Ball Bearing in 2016.https://www.jtekt.co.jp/news/160530.html
This product contributed to suppressing housing wear caused by strain creep by making a circumferential groove in the center of the outer ring’s outer diameter. With the new model, however, in addition to this circumferential groove, we’ve added a special film around the entire outer ring and succeeded at developing a bearing able to also suppress housing wear caused by corotation creep.
The new bearing has equivalent housing wear suppression ability as the conventional bearings suppressing creep through a thicker outer ring, solid lubricant film, etc. while being both lightweight and low cost. As such, the new model can be applied to not only automobile, but also various industrial machines for which creep-related wear is problematic.