Press Release

NSK Develops Low-Friction Reduction Gear for Electric Power Steering

Application of Newly Developed Low-Friction Grease

Low-Friction Reduction Gear for Electric Power Steering

NSK Ltd. (NSK; Headquarters: Tokyo, Japan; President and CEO: Norio Otsuka) today announced that it has developed a low-friction reduction gear for electric power steering (EPS) system that helps achieve a greater sense of unity between car and driver and that reduces steering wheel operation fatigue. This product makes for smooth steering corrections during straight driving as well as improved comfort when the steering wheel returns from large steering efforts such as turns in intersections.

NSK is planning to introduce this product in 2017.

Development Background

In recent years, there has been an urgent need to improve the fuel efficiency of cars and reduce emissions in order to lessen the impact on the environment. EPS saves power as its motor rest when the vehicle is traveling straight. This results in an improvement in fuel efficiency compared to hydraulic power steering (HPS). In addition, EPS provides for intricate electronic control of its motor in response to a variety of inputs such as travelling speed and road conditions, providing for a safer and more comfortable steering feeling. For these reasons, the application of EPS is expanding.

Smooth vehicle movement as the driver begins to turn the steering wheel and smooth steering wheel return are critical to achieving a comfortable steering feeling. EPS friction is one of the key elements in creating that kind of smoothness, especially the friction of the assist reduction drive. NSK developed a low-friction grease to reduce the friction force of the reduction gear, thereby reducing the steering effort for the driver and improving the steering feeling.

Product Features

NSK leveraged its tribology technology to optimize the formation of optimized oil film for improved lubrication and developed a new grease that incorporates additive technology that prevents the increase in viscous drag.

As a result, oil film is formed in a reliable manner between the face of the gear teeth in the reduction gear for a 17% reduction of friction in the reduction gear.

Product Benefits

  • Smoother steering wheel movement results in improved comfort and safety.
  • EPS use results in improved fuel efficiency

NSK is committed to the application of state-of-the-art technology for improved safety, comfort, and environmental performance. Going forward, NSK plans to continue to grow the global sales of its EPS business by improving its products and expanding local procurement and local production.

Market Needs
EPS Features
Benefits of Low-Friction Grease for EPS Reduction Gear