Press Release

NSK Develops Low-Torque, Highly Rigid, Sealed Thin-Walled Angular Contact Ball Bearings for High-Precision Factory Automation Devices

New energy-conserving product saves space and dramatically reduces maintenance

Tokyo, Japan, June 19, 2009 - NSK Ltd. (NSK; Headquarters: Tokyo, Japan; President and CEO: Norio Otsuka) has developed new low-torque, highly rigid, sealed thin-walled angular contact ball bearings especially for use in factory automation equipment. The new bearings deliver lower torque, smaller size, lighter weight and better rigidity than conventional angular contact ball bearings. When used in electrical actuators and industrial robots, the new bearings will enhance precision and energy efficiency, as well as save space and dramatically reduce maintenance. NSK expects annual sales of 500 million yen by fiscal 2011.

Low-Torque, Highly Rigid, Sealed Thin-Walled Angular Contact Ball Bearings for High-Precision Factory Automation Devices

In a wide range of industries including medical treatment, biotechnology, optical components and automobiles, there is a growing need to improve processing accuracy, reduce transport process, and improve precision and efficiency. In the actuators and the joints of robots utilized in transport and processing applications, gear drives were the conventional choice. Today, however, DD (direct drive) motors that enable high-precision positioning are becoming increasingly common, driving demand for bearings with even lower torque and higher rigidity.

Optimizing the design of the internal specifications of the bearings, NSK has developed compact, highly rigid, energy-saving angular contact ball bearings that realize both low torque and minimal torque fluctuations.

Utilizing angular contact ball bearings in robot joints and electrical actuators featuring advanced DD motorization improves precision and energy efficiency, while also saving space and dramatically reducing maintenance.

Product features

Improves precision and conserves energy by ensuring low torque and minimal torque fluctuations
At present, transport devices, positioning tables and industrial robots mainly use cross roller bearings (rolling bearings). Addressing the problem of the high torque of cross roller bearings, NSK has succeeded in reducing starting torque by 50% and dynamic torque by up to 75% by employing balls in the rolling elements. In addition to significantly improving energy conservation, torque fluctuations are kept to a minimum to realize high positioning accuracy.
Helps save space by offering both compactness and high load capacity
NSK has optimized the number and diameter of the balls, and designed the seals to prevent bearing ring deformations after heat treating, processing and installation, in order to ensure rigidity and load capacity equal to or greater than that of cross roller bearings. As a result, the outer diameter dimensions have been reduced by up to 30%, helping to reduce the footprint of factory automation equipment.
Maintenance-freeness achieved via longer operating life
The new angular contact ball bearings are packed in grease that is highly fretting-resistant and locked in with seals. NSK developed improved plastic cages that retain grease well and are highly heat resistant. Thanks to these advancements, operating life is approximately six times longer than conventional cross roller bearings, which dramatically reduces the frequency of equipment maintenance.
ow-Torque, Highly Rigid, Sealed Thin-Walled Angular Contact
<Low-Torque, Highly Rigid, Sealed Thin-Walled Angular Contact>
Conventional cross roller bearings
<Conventional cross roller bearings>