Machine tool spindle bearings are the spindle bearings of precision machine tools and similar equipment, mainly used for shaft support of CNC milling machines, lathes, grinders and other equipment, and play a key role in ensuring machining accuracy. The core products include precision angular contact ball bearings, double row cylindrical roller bearings, and bearings for ball screw support, with precision covering UP/SP/P4/P5 levels. Among them, the precision of semiconductor spindle bearings can reach P2 level, with a service life of ≥ 5000 hours . Typical structural forms include double row cylindrical roller bearings, bi-directional thrust angular contact ball bearings, and tapered roller bearings. The 60 degree contact angle design can be assembled with preloaded bearing materials made of high nitrogen bearing steel. After strengthening heat treatment, the rolling fatigue life can reach three times that of ordinary bearing steel, and the inner diameter covers the range of 15-600mm . The configuration scheme selects rolling bearings, liquid hybrid bearings, or gas bearings based on speed and load requirements. The front support commonly uses a combination of double row short cylindrical rollers and angular contact ball bearings, while the rear support uses angular contact ball bearings . Lubrication technology involves high-temperature resistant lithium based grease or oil gas two-phase flow lubrication, with a fitting tolerance requirement of outer ring tolerance
