NSK is introducing a high-performance bearing for servomotors that reduces the
emission of particles such as grease and oil. This breakthrough development will
contribute to the stable operation of vital industry machines such as robots.
To identify a potential way of overcoming the issue of particle emissions from bearings,
NSK undertook research into the mechanism behind this long-standing industry problem.
Alongside the implementation of a higher-precision evaluation and test machine with a
configuration and environment similar to an actual servomotor, the company was able to
design an entirely new bearing structure featuring advanced design elements.
Using its extensive experience in tribology (controlling friction and wear via lubricants and
material surfaces), NSK succeeded in developing a bearing with new grease and seal
technology that offers twice the low-particle-emission performance of conventional
products. The grease also provides double the conventional lifespan, while the rubber seal
delivers lower torque.
With many countries enduring a shrinking labour pool, the market for industrial robots
continues to grow. However, robot uses require high levels of reliability if they are to
transition from manual to automated operations. Robot reliability is beholden to its major
components. A typical articulated arm robot, for example, might feature up to six
servomotors to facilitate robot positioning and speed in its various axes. Each servomotor
houses two bearings: a load-side bearing supporting the shaft where it exits the
servomotor; and a counter load-side bearing located between the brake disc and encoder
disc.
In high-temperature environments such as servomotors, bearings tend to scatter tiny
particles of grease and oil as they rotate. These emissions stick to the discs and cause
issues such as encoder read errors and brake slippage. The need for bearings with low-
particle-emission performance is clear in applications of this type, which is why NSK set
about developing anti-scatter grease and seals that provide a high level of hermeticity.
The new NSK grease restrains evaporation in high-temperature environments such as
servomotors and uses superior thermally resistant components to ensure low particle
emissions and better resistance to seizing. NSK’s new rubber seal features a redesigned lip
shape that again supports low particle emissions, while also facilitating 10% lower torque.
Aside from servomotors, NSK’s new bearing is also suitable for other products that require
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low-particle-emission performance, contributing to stable operation in a wide range of
industrial machinery.
Press picture
NSK’s new bearing for servomotors offers twice the low-particle-emission performance of
conventional products
About NSK Europe
NSK Europe Ltd. is the European organisation of the Tokyo-based bearing manufacturer NSK, which was
founded in Japan in 1916 and today employs nearly 25,600 people in its worldwide operations. The products
and solutions provided by the industrial and automotive supplier can be found wherever things move. In addition
to nearly all types of rolling bearings, the company’s portfolio includes housed bearings, linear technology,
wheel bearing units, transmission and engine bearings. The company is oriented to perfection in all of its
business activities. Its aim is quality leadership in its industry, which it strives for through a continuous process
of improvement, excellent product development, optimised production processes and customer-oriented service
processes. In fiscal year 2023, the more than 3,200 employees of NSK Europe Ltd. generated sales of over €
662 million.
