April 24, 2003

"Super High Speed AT Spindle" Attaches to Machining Center Spindle

Milling of precision dies and molds used in the production of small parts for cell phones or video game devices requires high speed cutting with a small cutting tool (end mill) less than one millimeter in diameter. However, the maximum rotational speed of a spindle in a conventional high speed machining center using such a small cutting tool is typically 40,000 to 50,000 r/min. With these speed limitations, improvements in machining time are limited and endmill service life is shortened.

Attachment-type (AT) spindles are smaller than the typical machining center spindles used for milling such small, high-precision parts. However the maximum speed of AT spindles is usually limited to below 60,000 r/min. What is needed is a high-speed spindle for milling at speeds in excess of 100,000 r/min.

To meet this market demand, NTN Corporation has developed an attachment-type "Super High-Speed AT Spindle" for high speed machining. The 150,000 r/min maximum speed of the NTN spindle is unique in the machine tool field.

ATTACHMENT-TYPE (AT) SPINDLE FEATURES

1. The Attachment-type (AT) spindles install on the machining center spindle and don't require custom machine tool equipment.
2. Use aero-static bearings to deliver super-high speeds up to 150,000 r/min with high rotational accuracy.
3. Long life, low vibration, and quiet operation are provided by the NTN aero-static bearings.
4. Use a "shrink-fit chuck" for chucking stiffness and accuracy during high speed rotation.

APPLICATIONS

High-precision machining of dies, molds or other metal parts at super high speeds.