Because conventional spindles on machining centers are typically
designed with a fixed bearing preload (no springs), there isn’t any
compensation for the thermal expansion that occurs from heat
generation. Higher temperatures cause the bearing raceways to expand
and tighten. This causes the bearing system to increase its preload
beyond the original setting, which leads to increased axial and radial
loading on the bearing system. In addition to compromising the lifespan
of the spindle bearing system, this thermal expansion affects accuracy.
A spindle chiller is a worthwhile investment that extends spindle life, protects accuracy, increases the machine’s capacity, and reduces maintenance costs. Refer to the chart below for basic guidelines.