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NSK´s new ultra-smooth motion technology, developed for the company´s popular general-purpose NH/NS series linear guides, is the first design of its type. Thanks to the use of elastic rolling elements, the patented technology achieves a highly consistent dynamic friction profile that is suitable for high-precision inspection and measurement equipment. The low friction and smooth motion characteristics of linear guides make them a valuable addition to all kinds of systems that require high-performance motion control. For this reason, NH/NS linear guides find use in a wide range of applications, including semiconductor and LCD manufacturing equipment, automotive manufacturing equipment, conveyor robots, inspection and measurement equipment, and machine tools.
An illustration showing the mechanism behind NSK´s ultra-smooth motion technology. On the left, the slide, rail, ball circulation path and elastic rolling elements are highlighted. On the right you can see the optimised ball recirculation path and added elastic rolling elements
Today, the equipment used in these applications is subject to ever-higher levels of sophistication. In particular, the latest inspection and measurement equipment demands even smoother and more accurate motion, placing high expectations on linear guides.
With these thoughts in mind, NSK set about developing its ultra-smooth motion technology by optimising the shape of the ball circulation path and using elastic rolling elements to suppress irregular ´micro-stutters´ (brief stuttering or jerking during motion caused by localised friction fluctuations). These elements reduce the effect of balls colliding with each other in the curved sections of the ball circulation path, which serves to prevent any increase in friction and, in turn, deliver ultra-smooth motion.
As well as inspection and measurement equipment, NSK linear guides with ultra-smooth motion technology benefit applications requiring vertical operation and other mounting positions where operating characteristics tend to deteriorate. Importantly, these innovative linear guides are dimensionally interchangeable with NSK´s standard NH/NS series, facilitating the replacement of units currently in use without any design changes.
These graphs show how the fluctuations in conventional smoothness (left) compare with the smooth motion of NSK´s ultra-smooth option
NSK´s new ultra-smooth technology is available for NH 15, 20 and 25 series linear guides, as well as NS 15, 20, 25 and 30 models. In total, NSK can supply 28 variations, including different slider lengths and types. The units are compatible with a wide variety of options, such as the NSK K1-L lubrication unit, stainless steel configurations and special surface treatments.
