Industrial Products and Applicationsyear , issue 2, april-may 2021

NSK Super Large Ball Screw offers class-leading load capacity

NSK has expanded its series of high load capacity ball screws. The companys new Super Large Ball Screw makes it possible to injection-mould even bigger plastic components in line with growing demand from sectors such as automotive. The Super Large Ball Screw, which features 800 mm long nuts to help increase axial load and operating life, is designed for electrically operated plastic injection moulding machines requiring a clamping force of 3000 tons or more. With the move towards more energy efficient automobiles and ever-stricter emissions regulations, there is an increased requirement to reduce vehicle weight. In turn, this creates demand for larger, single-piece plastic parts such as bumpers, door modules and instrument panels. The traditional solution for forming large plastic components has been to use hydraulic injection moulding machines with high load capacities. However, the industrys desire for clean, energy efficient systems has led to the emergence of large all-electric injection moulding machines. This trend has prompted NSK to develop a new generation of high load Super Large Ball Screw, for use in such machines. To ensure the successful production of Super Large Ball Screws, NSK has developed an innovative new method of grinding nuts up to 800 mm in length. The long nuts can accommodate a greater quantity of load balls,thus resulting in maximum axial load that is increased by a factor of 1.3, while operational life is extended by a factor of 2.8. Despite the size and load capacity of NSKs Super Large Ball Screws, there is no compromise in speed. A dedicated ball circulation design, which facilitates a tangential pick-up method using a proprietary deflector, makes it possible to achieve high speed rotation even with ball screws of 140 mm in diameter or more. Today, high load capacity ball screws have become essential components in electric injection moulding machines and servoless machines. In 1996, NSK introduced the industrys very first series of high load drive ball screws, since when the company has continued to expand the series to meet demand for higher speeds and reduced lubrication. NSKs latest Super Large Ball Screws are offered in diameters of 140, 160 and 200 mm, with leads of 25, 30 and 32 mm. NSK is looking to achieve a target of 7.8 million in annual global sales of these super large, high load capacity ball screws by 2018.