NSK Develops ROBUSTDYNA™ Ultra-High Speed High Load Capacity Angular Contact Ball Bearings

NSK Ltd. has developed ROBUSTDYNA, a new series of bearings that enables highly versatile machining by delivering excellent performance across both roughing and finishing machining operations. NSK will exhibit this series for the first time at JIMTOF 2020 Online (The 30th Japan International Machine Tool Fair), which will be held from November 16-27, 2020.

Development Background

In recent years, machine tools such as machining centers have been required to meet the demands for heavy cutting in response to increasing utilization of difficult-to-cut materials such as titanium, ceramics, and composite materials, as well as for long-term, stable operation under low-maintenance or maintenance-free conditions. In order to meet these demands, machine tools have been faced with the challenge of increasing load capacity to achieve both heavy cutting and high-speed operation performance.

Features

1. High load capacity

By optimizing the bearing's internal design, such as the use of larger diameter balls, the load capacity has been increased by 15% and fatigue life (dynamic load rating) has been extended by up to three times compared to conventional products*1. This makes heavy cutting possible and can achieve reductions in machining time.

*1 “Conventional products” refers to NSK's current Robust Series (SHX steel type).

2. High impact resistance

The internal design has been optimized to increase impact resistance (static load rating) by 30% compared to conventional products, reducing the risk of bearing damage in the event of a collision (impact). This contributes to the long-term, stable operation of the spindle (avoiding unplanned downtime).

3. Ultra-high speed performance

The use of NSK's proprietary SHX steel, which has excellent heat and wear resistance, has enabled NSK to achieve the same ultra-high speed performance of 3 million dmN*2 as conventional products. In addition to heavy cutting, this enables the spindle to perform at the ultra-high speeds required for finishing.

*2 dmN: The mean value of bearing pitch diameter (dm) in millimeters multiplied by rotational speed (N).

Benefits

This product contributes to reducing machining time and enables highly versatile machining by achieving excellent performance across both roughing and finishing. High impact resistance is ideal for heavy cutting and also contributes to long-term stable operation and improved productivity (avoiding unplanned downtime).

Applications

The ROBUSTDYNA is ideal for machine tools performing heavy cutting and highly versatile machining operations, such as machining centers producing aircraft and automotive parts. Moving forward, NSK will continue to expand the ROBUSTDYNA Series lineup.