Oil seal contribution recognized in the world’s first electronically controlled CVT “YECVT”

NOK Corporation (Headquarters: Shibadaimon, Minato-ku, Tokyo; Representative Director, Group Chief Executive Officer: Masao Tsuru; hereinafter referred to as “NOK”) is pleased to announce that it has received the 2025 Global Award for excellence in Technology and Development  for the first time at the 2025 YAMAHA Global Suppliers Conference, hosted by Yamaha Motor Co., Ltd. (Headquarters: Iwata City, Shizuoka Prefecture ; President and Representative Director: Motofumi Shitara ; hereinafter referred to as “Yamaha Motor”). This award recognizes NOK’s contribution through its oil seal to the development of “YECVT”, the world’s first electronically controlled continuously variable transmission (CVT) in the 150cc segment, for compact scooters.

“YECVT” is a CVT system that optimizes gear shifting through electronic motor control based on rider input. It is the world’s first system for compact scooters to deliver the kind of responsive acceleration and engine braking traditionally associated with manual transmission vehicles, offering riders a broader range of riding experiences tailored to their preferences. To support the realization of “YECVT”, NOK developed custom rotary and reciprocating oil seals. By dividing functions and refining specifications, NOK achieved both a compact design and stable performance while maintaining high sealing performance in a limited space. We believe this award recognizes not only the quality of our products but also our attentive support and global supply framework. 
Guided by our Purpose: Shaping possibilities with unique technology, NOK will continue working alongside customers to create new value and contribute to society.

■ Remarks from Tatsuya Masuda, Executive Officer and Chief General Manager of the Procurement Center, Yamaha Motor Co., Ltd.  

In developing this ECVT system, it was essential to make it smaller and more affordable so that it could be offered to a wider range of customers. However, achieving a simpler mechanism presented a significant technical challenge: increased shaft runout in sliding and rotary sealing areas. Thanks to NOK’s technical expertise and proposal based on its extensive know-how, we were able to jointly develop an oil seal that meets high-performance requirements and successfully bring “YECVT” to market.
We are grateful for NOK’s outstanding technology and contributions to our new model development.

■ About the 2025 YAMAHA Global Suppliers Conference Global Award for Excellence in Technology and Development

Each year, Yamaha Motor recognizes outstanding suppliers from around the world and across regional operations for their achievements in various areas such as technological development, cost innovation, environmental contribution, and quality improvement. The Technology and Development Award, which NOK received this year, is a prestigious honor presented to suppliers whose innovative technological proposals have been adopted in Yamaha Motor products and contributed to enhancing product value.
The award ceremony was held on Friday, May 23, 2025, at the Okura Act City Hotel Hamamatsu  in Hamamatsu City, Shizuoka Prefecture.