What are the common active bearings
There are five types of bearings commonly used in machine tool spindles: deep groove ball bearings, angular contact ball bearings, two-way thrust angular contact ball bearings, double row cylindrical roller bearings, tapered roller bearings, deep groove ball bearings. These bearings are generally only used to accept diameters. Because of the non-adjustable clearance, it is often used in places where the accuracy requirements are not high and preload is not required, such as ordinary drilling machine spindles.
Angular contact ball bearings can accept radial and axial loads at the same time. Because they will cause internal axial forces when receiving radial loads, they should be used as devices. The configuration methods include "back-to-back", "face-to-face", and "face-to-face". "Tandem" and "multiple", etc., and pre-tightened can improve the rigidity of the spindle. The contact angles of this type of bearing are 15°, 25°, and 40°.
Among them, the B7000CY high-precision angular contact ball bearing with a contact angle of 15° is a special bearing specially designed for the spindle of a high-speed grinder. In addition to the internal structural design changes, the rings and rolling elements are made of high-quality electroslag bearing steel . The material of the holding frame is phenolic laminated cloth tube, with tolerance grades of 5, 4 and 2. Therefore, this type of bearing has high rotation accuracy and limited speed, low friction and low temperature rise.
Two-way thrust angular contact ball bearings usually use 230,000-type two-way thrust angular contact ball bearings with a contact angle of 60°. They consist of a seat ring with a smooth oil hole, two shaft washers, a spacer ring, and two sets of steel balls and cage components. constitute. Choosing a suitable spacer ring height can make the bearing have the required preload after assembly. This type of bearing can accept bidirectional axial load, has good rigidity, low temperature rise when normal and smooth, and high speed.
It is also easy to assemble and disassemble. As a new structure, it is currently mostly used on spindles such as grinders, lathes, boring machines, milling machines, drilling machines, etc. It is often used in combination with double row cylindrical roller bearings. Double row cylindrical roller bearings are acceptable Larger radial load and higher speed are allowed. The two rows of rollers in the bearing are arranged in an interleaved manner, and the shaking frequency during rotation can be doubled compared to a single row bearing.