NSK Ltd. (NSK; Headquarters: Tokyo, Japan; President and CEO: Toshihiro Uchiyama) has won two awards from the Japanese Society of Tribologists (JAST)*1, the FY2016 Tribology Online Best Paper Award and the FY2016 Tribo-Technology Award. These awards recognize the originality of NSK's outstanding research outcomes and their potential to make a contribution to society in the future.

*1: JAST was established in 1956 for the purpose of improving technologies relating to tribology (the science and technology of interacting surfaces in relative motion and of related subjects and practices).

From left: Ueda, Shimizu, Noda,Taniguchi

1. Award-winning Paper: “X-Ray CT Imaging of Grease Behavior in Ball Bearing and Numerical Validation of Multi-Phase Flows Simulation”
As grease behavior inside rolling-element bearings cannot be observed without first dismantling the bearing, a method needed to be developed that would enable visualization of the internal state of the bearing without removing seals and shields. The novel idea of this research was to examine grease using X-rays, resulting in the first-ever successful imaging of the distribution of grease inside a bearing, which had previously been impossible. Computational fluid dynamics (CFD) analysis was also implemented in parallel with the experiment, resulting in the numerical expression of the hydrodynamic grease transition from churning to channeling, which is a phenomenon associated with excess grease lubrication. These research outcomes will enable effective grease lubrication design that will further improve bearing performance, helping to reduce bearing friction and extend operating life.


FY2016 Tribo-Technology Award
1. Award-winning Technology: “Development of Composite Alumina-Zirconia Rolling Elements”
Silicon nitride is the conventional ceramic material employed in bearings and is used in rolling elements in a variety of special-purpose bearings, including high-speed rotation machine tool bearings and for measures to counteract electrolytic corrosion in fan motors. In its raw state, silicon nitride is powdered and the sintering process makes it more costly to produce than oxide-based ceramics such as alumina and zirconia. Silicon nitride ceramics have far superior performance in rolling parts compared to conventional oxide-based ceramics. However, through this research, a high-strength composite oxide-based ceramic rolling element was developed by optimizing the mixing ratio of alumina and zirconia. Tests confirmed that the composite material had an operating life more than 100 times longer than alumina or zirconia alone. This composite oxide-based ceramic rolling element is being used in fan motor bearings to counteract electrolytic corrosion, which has become a growing issue in recent years due to the increased use of inverters. It is also expected that this material will become more widely used as an assistive technology in the development of electric vehicles.


Using our world-class technological expertise to control machine friction and minimize energy loss, NSK remains committed to making major contributions to the realization of a safe, comfortable, and eco-friendly society, and to promoting development of industry and advances in machinery.