|
|
|
|
A New Material for
Spindle Bearings Over the years SNFA has developed and used many new bearing materials to meet the demands of the aerospace market. Until now there has been no need to transfer these materials to the machine tool sector but with modern spindle and electro-spindle designs that need is now there. To satisfy this need SNFA have decided to introduce bearings made using CHROMEX40. CHROMEX40 is a corrosion-resistant steel alloyed from nitrogen, molybdenum, chromium, vanadium, carbon and iron in such a way as to produce the fine grain structure which is so necessary to deliver the properties demanded. |
|
|
This fine, clean structure gives the material , the ability to operate safely at the higher speed and loads required by modern spindles whilst giving an enhanced fatigue life. It even performs well under poor lubrication conditions and at higher temperatures. These bearings will be supplied as standard with ceramic balls. Ceramic material balls are essential components of high speed bearings and are an ideal solution where low density, high rigidity and life are major concerns. |
|
|
The ceramic material normally used for balls is Silicon Nitride (Si3 N4) whose production process gives them high material integrity and hardness. Other important characteristics of silicon nitride are given in the Comparison Table below. The advantage of hybrid bearings with steel rings and ceramic balls can be summarised as follow: |
|
