Modern Machine Shop
Available from the company are RotoDress motor dressing spindles AES-72 and MZ-50. The company says these spindles represent a flexible solution for precisely controlled dressing. The frequency converter permits infinitely variable control of speeds up to 30,000 1/min as well as the direction of rotation of the asynchronous motors.
A further feature of the spindles is the sealing of the spindle nose by means of air which simultaneously provides for constant cooling of the motor and the bearings as external air cooling. In this way, the dressing process can be externally cooled without any water entering the spindle. Use of this process also ensures that the diamond used as a grinding medium in dressing operations can be cooled without any negative influences on the spindle, according to the company.
On the MZ-50, maintenance-free, lubricated-for-life hybrid spindle bearings with ceramic balls and shields are used to increase the life of the spindle, the company says. The fixed O-bearing is said to guarantee that the spindle nose will suffer a minimum of dilatation. Dilatation is caused by a mechanical component (centrifugal force on the balls in the spindle bearing) and a thermal component (heat dissipated from the bearings and the motor) that cause the spindle shaft to expand axially.