By Zac Knoll, Application Engineer
Ball screws minimize friction torque while maintaining a high level of accuracy. Dependent on the industry and/or application, the operating conditions vary. Certain industries may have more risks of contamination, which can pose a challenge for achieving optimal ball screw performance. Adding a seal to the design helps protect the ball nut by minimizing adverse effects related to contamination. Therefore, NSK offers different sealing options to ensure reliable performance even in heavily contaminated environments. NSK seals are designed with specific features that are available in a variety of shaft sizes to meet specific application needs.
The V1 seal is a triple wiper seal designed to reduce entry of fine particles. Its design was developed especially for high-quality machine tools as well as applications requiring protection from fine particle contamination. The V1 seal is used to process highly abrasive dusts like graphite, ceramics, and other sintered materials. This seal is ideal for medium diameter ball screws (shaft diameters 32-50 mm).
Understanding the Technology behind the V1 Seal
The triple wiper design offers increased sealing protection against the smallest of particles. Each wiper is specifically profiled to the shaft surface of a ball screw in order to prevent entry of fine particle contaminants. The entry rate is less than 7% compared to standard seals. The use of a V1 seal will increase life expectancy four times as long in comparison to standard labyrinth seal designs.
When combined with a K1™ Lubrication Unit, the V1 Seal is extremely effective. The K1™ lubrication unit offers maintenance-free operation, which eliminates the need to install automatic lubrication systems that require frequent downtime related to maintenance. The K1™ lubricant consists of a porous synthetic resin that contains a large volume of lubricant that dispenses low amounts of oil upon contact with the surface of the ball screw raceway. The combination of NSK’s V1 seal and K1™ lubrication unit provides additional support to the linear drive system enabling smoother motion, lower friction torque, as well as maintenance-free operation.
The X1 seal is an innovative step forward in the design of ball screw seals. Similar to the A1 seal, the X1 seal also features pre-packed grease that retains and eliminates grease splatter caused by grease build up on the ball screw shaft. Unlike the A1 seal, the X1 goes two steps further featuring a double seal lip. It features a lip on the seal’s edge located on the outside edge of the ball screw nut. This seal lip is designed to prevent entry of fine particles such as dust. Then, inside of the nut is a grease seal lip that prevents the pre-packed grease from escaping.
Understanding the Technology Behind the X1 Seal
The X1 seal is a dynamic duo; not only does it retain grease, but it also prevents entry of contaminants. Therefore, the X1 seal is an ideal solution for machine tool applications that require medium diameter ball screws (shaft diameters 32-50 mm). Machine tools often operate in environments characterized by high levels of dust, debris and coolant.
The X1 design reduces penetration of foreign matter to less than one-thirtieth in comparison to standard seals and retains grease approximately three times better than standard seals. Low friction torque is maintained in high-speed machine tool operations as a result of the optimized lip section on the edge of the seal. A special plastic material is used to create low-contact resistance enabling the X1 seal to deliver both low torque and high sealing performance. All of these improvements are critical to achieving longer service life in machine tool applications as well as reducing the environmental impact.
V1 vs X1 Seals
Both V1 and X1 seals are commonly used in machine tool applications requiring medium diameter ball screws (shaft diameters 32-50 mm). Both seal types reduce, limit and prevent entry of contaminants into the ball screw nut. The X1 seal retains grease and prevents entry of contaminants with a double lip seal technology whereas the V1 Seal utilizes a triple wiper seal to prevent entry of fine particles.
Regardless of the industry or application, NSK can work with you to recommend the best solution. Interested in learning more about ball screw seals, contact one of our Application Engineers 1-800-255-4773 or firstname.lastname@example.org.