NSK Corporation, a leader in the motion and control industry, is pleased to announce that it has successfully developed the world’s thinnest microactuator pivot ball bearing assembly. At just 1.83 mm in height, it is a full 25% thinner than its predecessor and is designed for use as the support mechanism of the head that reads and writes information on discs in the ultra-thin 2.5 mm HDD. Thinner than a flash memory-type media CF card, the ultra-thin 2.5 mm HDD possesses a larger storage capacity. Reducing the thickness of the assembly was not the only requirement. It also needed to offer improved impact resistance and reduced friction. NSK met the challenges head on. A critical component of their success lay in the design and manufacture of the bearing cage itself. By molding the cage from resin reinforced with nano-scale fibers, it was possible to create a cage wall that was a mere 0.1 mm thick. With the cage wall reduced to such an incredibly thin layer without sacrificing its structural integrity, engineers were able to maximize the steel ball size in the bearing, which improved impact resistance by 25%. Furthermore, the advanced cage design and materials, in conjunction with advances in process and assembly technology, also translated into lower torque and reduced friction when compared to a conventional steel cage.
