The new NFRG ball rail system by Rexroth is designed with materials and engineering making it particularly well-suited for use in humid to wet production environments. The profiled rail and the ball runner block are both made entirely of corrosion resistant steel according to DIN EN 10088 and of certified plastics according to EU Directive 2002/72/EC and US Regulation FDA21CFR. The NFRG ball rail systems are offered in five sizes and can withstand a relative humidity above 70 percent and temperatures above 30 °C over an indefinite period.
The certified plastic parts in the new ball rail system are even resistant to weak acids, lyes, organic solvents, oils and alcohols. They are strong and possess good sliding properties. Contrary to systems made from coated noncorrosion resistant steels, NRFG ball rail systems are not affected by surface damage and any corrosion resulting therefrom. This increases their service life significantly. The ball rail systems are corrosion resistance class 2 and hygiene class 3 compliant.
The profiled rail can be mounted from the top, using the clip-on stainless steel cover strip to create a smooth surface. Alternatively, the user can cover the mounting holes with white caps, or mount the profiled rail from underneath. The fully integrated sealing results in longer lubrication intervals, which means less maintenance. The ball runner blocks are not pre-lubricated so that users can fill in the proper lubricant recommended for their specific applications. Lube ports with metal threads are provided on all sides to give engineers a greater degree of freedom when space is tight.
NRFG ball rail systems are perfect in dry working zones such as primary packaging, even in environments where there is a combination of high humidity and high temperatures. Combined with screens or other protective barriers, they are also suitable for splash areas and wet working zones in food processing, where liquid, moist or sticky foods stick to machine parts, or which are wet-cleaned and disinfected. Using FDA-certified plastics throughout eliminates the risk of unacceptable contamination during processing.
The ball runner blocks, which come in a flange version or a narrow version,are available in accuracy class H and in three preload classes. The O configuration of the balls ensures that the system has the required rigidity and equally high load capacities in all four main loading directions. Users can mount parts onto the runner blocks from the top or from underneath.
Additional mounting holes in the middle of the runner blocks allow to increase both, surface and lateral rigidity. The entry zone geometry and a high number of balls reduce fluctuations in spring action in the runner block. Optimal ball rail and recirculation design results in smoother, quieter operation. For long axes, Rexroth offers multi-part ball rail systems with clearly marked part lengths for safe and easy installation.