NSK Ltd recently announced that it has expanded its series of high-load drive ball screws used by electric injection molding machines. NSK will start selling this series in January 2015 and expects global sales of 1 billion yen in 2016.

The features of the expanded lineup include:

Expansion of the HTF-SRE Series for Injection axis

• Wider variety of lead options: NSK expanded the shaft diameter options for its HTF-SRE Series. Up until now, there were only larger sizes available, from 140 to 200 mm, but now the range is 50 to 200 mm, covering small and medium sizes as well. Now it is possible to select the lead option that best matches the specification of an injection molding machine for higher acceleration performance.
• Compact nut outer diameter: Same compact nut outer diameter dimensions as the HTF-SRC Series, which is widely used for injection axes. This makes it compatible with the same mounting dimensions as conventional injection axis.

 Expansion of the HTF-SRD Series for Clamping axis

• Realization of top feed speeds of 2 to 3 m/s: With the addition of larger lead sizes for high-load drive applications, this series achieves top speeds of around 2 to 3 m/sec, double the feed speed of conventional ball screws. This improved feed speed for clamping axis results in short cycle times for improved productivity.
• Low noise: Thanks to the smooth ball circulation method, this series reduces noise to about half that of the conventional tube types, which makes for quieter machine operation.

NSK Ltd, based in Tokyo, recently announced that it has developed a new technology in the form of high-performance ball screws for machine tools. The company will release innovative products with this new technology in the spring of 2015.

NSK has researched the trends of machine tool fairs for many years and developed various types of ball screws for machine tools, based on this ongoing research. In the recent years, stricter demands have appeared in the machine tool market. There is increased demand for eliminating any cooling device, which is designed to reduce the temperature rise of the ball screw itself during high-speed operations. In addition, there is another demand to minimize ball screw motion errors to achieve higher integrity on the machined surface.

In response to these needs for higher performance, NSK has created, through its new, high-performance technology, ball screws for machine tools that have been optimized in terms of design and manufacturing technology to create a better balance in preload, stiffness, heat generation and temperature rise. These new ball screws lead to higher positioning accuracy on machine tools by reducing heat generation and motion errors.

NSK’s high-performance ball screws for machine tools provide new solutions for a wide variety of machine tools such as NC lathes, machining centers and grinding machines.

Its features include:

• Reduces temperature rise by 20% based on a ball screw design that reduces heat generation and maintains the stiffness consistency of the ball screws. NSK has optimized torque, while maintaining the stiffness of the ball screw. This contributes to about a 20% reduction in the amount of heat generated.
• Improves the positioning accuracy on machine tools. NSK has reduced the amount of motion errors due to ball screw nut location differences. This leads to higher surface integrity on the workpiece, which is finished with machine tools.