Collet Closer

A machine tool user in the US was experiencing premature bearing failures in the machine‘s spindle collet closer. Downtime, bearing replacement and maintenance costs were amounting to 171,560€ per annum.

Why are machining operations so frequently halted?

Weekly bearing replacement was required on the spindles, leading to lost production.

NSK investigated the spindle collet closer application.

High thrust loads and elevated temperatures were causing the standard double-row angular contact ball bearings to only last for 100 hours, instead of the expected 15,000 hours.

Extended and more reliable machining operations moving forwards

NSK proposed a redesign of the collet closer using a pair of its NSKHPS Precision Angular Contact Ball Bearings with P4Y precision class. This arrangement has provided greater capability for supporting the high thrust loads and resulted in cooler running temperatures and longer bearing life, leading to annual savings of 164,960€ thanks to the elimination of downtime and maintenance costs.