制造和工程的经济学继续推动机床制造商和重新设计公司提高生产速度，精度和可靠性或他们的机器。 更高的切割速度和更高的机器精度要求更高的主轴转速，因此主轴轴承正是机器精度的核心。 这些轴承比许多其他组件更能决定主轴转速的上限。
为了使机床主轴达到更高的切削速度，同时保持高度的运行精度，必须使用超精密轴承。 这些是角接触球轴承类型中最常见的。 从与机床公司和主轴制造商的合作中，NSK开发了一系列角接触轴承产品组合，涵盖了最广泛的工作速度范围内的机床主轴应用。
整个系列被认为是一家制造商提供的最全面的产品，并且由NSK欧洲技术中心（ETC）的研发设施作为后盾，这是欧洲最先进的单位之一。 ETC利用新型润滑脂和AIR MIST润滑技术对角接触轴承进行深入测试。 这些测试的目的是确定润滑剂的物理性能与轴承性能有何关系。
现代机床（如加工中心）对刀具更换的频繁要求意味着优化生产时间不仅需要更高的最大主轴转速，而且更重要的是加速和减速更快。 但是，在快速加速或减速期间，主轴轴承会承受严酷的热负荷条件。 这些是由于电机产生的热量，房屋冷却和其他因素导致的周围环境剧烈变化引起的。 NSK针对这些问题的解决方案是ROBUST系列轴承，专为超高速主轴设计。
The ROBUST series of ultra high speed bearings employs a larger number of smaller diameter balls as their rolling elements, enabling them to operate at rotational speeds some 20 percent higher than conventional designs. The ROBUST range retains the same external dimensions as conventional angular contact bearing designs and as a result is directly interchangeable. However, the lower mass of its smaller rolling elements results in lower ball centrifugal force, and hence lower friction and heat generation. Ball centrifugal force is reduced at high speeds and internal stresses are lower, enabling speeds of 3 x 106 dmN to be achieved with air/oil lubrication.
Such high levels of performance owe much to the substantially improved rolling contact conditions within the bearings. These ensure reduced heat generation and considerably lower bearing operating temperatures than can be achieved with the standard design of angular contact ball bearings. Of course, reduced friction and cooler running add up to increased bearing reliability, a benefit further enhanced by the provision of a single shoulder which allows better lubricant distribution within the bearing.
Within the ROBUST range there are a number of options available to customers who may need to improve further on the standard configuration. These bearings can have ceramic (silicon nitride) balls rather than the standard steel option with rings manufactured from SHX, a new steel developed by NSK. SHX is a result of special proprietary materials and heat treatment technology, which offers ultra high speed performance and extended fatigue life, making it highly suited for use in machine tool spindles, which must run at ultra high speeds with a minimum supply of lubricant. Its heat resistance is nearly equal to M50 steel, a material which is used widely in bearings for jet engines, while its wear resistance, resistance to seizure and durability are all setting new industry standards.
Development of materials for use in ultra high speed bearings has also included the use of alternatives for the cage construction. With the base specification using a Phenolic cage, those requiring a higher specification would be advised to choose the Polyamide design. For ultimate performance, requiring speeds in excess of 2.5 x106 dmN, the PEEK cage is available which has excellent temperature characteristics.
Bearing design for such high speed applications must also focus on proper lubrication in order to deliver high levels of performance and durability. Some applications require oil jet lubrication and this requires the machine tool design to accommodate such a system, as well as suitable quantities of high grade oil together with adequate filtration capability.
另一种替代方法是油气润滑，这是一种通过使用压缩空气将油雾化成雾状的方法。 这种方法需要较简单的机床设计，并且大大减少了所需的油量。 另外，轴承设计也简化了，因为不需要将油端口结合到轴承环中。
The ROBUST range is also available with conventional grease lubrication or as a sealed version, which makes for easy handling and also improves grease life time. For a higher specification, the Spinshot™II, an exclusive oil air lubrication system developed by NSK, can be requested.
While investment continues year on year in research and development, NSK has also invested in the state of the art production facility in Newark, UK, where the super precision bearings are manufactured as well as streamlining the warehouse and dispatch areas allowing more efficient service to customers. NSK has a stock holding of £17 million in the UK warehouse, guaranteeing the best possible delivery times for the majority of the vast product range.
For more details on the super precision bearings or to discuss the specification of bearings for ultra high speed applications, contact:
NSK UK Ltd：营销传播专家Mary Fletcher，