EMO Hall 7, Booth B 16
NSK has developed a new sealing concept for ball screws especially for the machine tool industry. The aim of the development of the X1 seal was to outperform the performance and function of the labyrinth seals used so far in two decisive ways. First, the new development should have an improved sealing effect, second, this improved function should be accompanied by low friction.
On the one hand, the seal on the ball screw must seal inwards to prevent the lubricant from escaping. On the other hand, it must prevent particles from getting into the contact surface of balls, spindle and nut from the outside. For each of these two tasks, a separate seal has been developed: an outer scraper, which frees the spindle of particles, and a second, which retains the grease. Thanks to the computer-aided optimization of the sealing lip shape, the friction could be significantly reduced. Due to the effective direction of the two seals selected - derived from the arrangement in angular contact ball bearings - the name "X1 seal".
In practice, the goals set in the specifications were more than exceeded. A tenfold higher wiping effect had been performed. Measured were only 3% dirt entry compared to the labyrinth seal. At the same time, only one third of the usual amount of grease exits. Also, one wanted to allow only a marginal increase in friction. The tests showed that the X1 seal increases the preload friction by only 1%. The sealing concept thus also contributes to the smooth running properties and energy efficiency of a precision drive. The new X1 seal is offered as an option for the latest generation NSK ball screws for WZM.