Ordinary motors cannot operate for long at pressures lower than 10-4 Torr. Empire Magnetics vacuum rated motors are constructed to allow extended operation at pressures as low as 10-7 Torr without a sacrifice in motor performance.
Some vacuum applications cannot tolerate contamination by motor outgassing products. To accommodate a range of motor cleanness requirements, Empire Magnetics provides three grades of vacuum rated stepping motors in the full range of environmental motor sizes.
Frame size selection:
Motors are typically made in groups or families, the families are identified by the outer diameter or size of the square, these references are called frame sizes. In the American system, a 23 frame is a nominal 2.3 inches in diameter. For motors less than one inch in diameter, the reference is typically known as a size. Herein is a list of the frame sizes offered by Empire Magnetics Inc. and some of the characteristics of the group that will allow you to select from them.
