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Machine spindle common rolling bearings and characteristics

Update:24-12-2021
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1. Deep groove ball bearing This type of bearing is gen […]

1. Deep groove ball bearing This type of bearing is generally only used to withstand radial loads, which is often used for accuracy requirements, no preload, such as ordinary drilling machine spindles, etc.

 

2. Corner contact ball bearings This type of bearing can be spaced and axial load simultaneously. Since the internal axial force will cause internal axial force when the radial load is to be installed, the configuration method has a "back pair", "face-to-face" , "Series" and "multi-link", etc., and improve the stiffness of the spindle by pretensioning. The contact angles of such bearings have three types of 15 °, 25 °, 40 °, wherein the B7000 Cy-type high-precision angular contact ball bearing for the contact angle is 15 ° is specifically a special bearing for high-speed grinding spindle design, the axis to remove internal structural design. In addition, the ferrule and the rolling body are manufactured with high quality electric slag bearing steel. The cage material is a phenolic laminating tube, a tolerance grade having 5, 4 and 2. Therefore, such bearings have high rotation accuracy and limit speed, small friction, low temperature rise.

 

3. Bidirectional thrust angular contact ball bearings typically use a 230000-type two-way thrust angular contact ball bearing, a contact angle of 60 °, from a race with a lubricating oil, two axles, one spacer and two sets of steel balls and hold Sheet assembly composition. Selecting a suitable spacer height can make the bearing with the desired preload. Such bearing can withstand the bidirectional axial load, with good rigidity, low temperature rise, high speed, and easy to remove, as a new structure, currently used in grinding machines, lathes, boring machines, milling machines, drilling machines, etc. On, in use, common and double-column cylindrical roller bearing groups.

 

 

4. Double column cylindrical roller bearings Such bearing can withstand larger radial loads and allow high speeds. The two rows in the bearing are arranged in cross-intersection, and the fluctuation frequency is doubled when the rotation is doubled, and the amplitude is reduced by 70%. These bearings are commonly used: NN30 / W33, NN30K / W33 two series bearing internal ring belt bearing, outer ring can be separated; NNU49 / W33, NNU49K / W33 two series of bearing outer ring belt bearing, within The loop can be separated, wherein the NN30K / W33 and the NNU49k / W33 series inner ring is a tapered hole (taper 1:12), together with the tapered journal of the main shaft, and the inner ring of the axial movement can be reduced. Small bearing gaps or even pre-tight bearings. Cylindrical hole bearings typically use hot loading, using an interference fit to reduce bearing swaps, or to achieve pretensionable purposes. The NNU49 series bearings that can be separated in the inner ring generally load the spindle after the spindle is installed in the inner circle to obtain a high spindle rotation accuracy.

 

5. The tapered roller bearing can be spaced in the radial and axial load simultaneously, and the double row tapered roller bearing can withstand the bidirectional axial load. Sliding friction between the large end of the conical roller and the inner ring baffles, the limit speed is often lower than the same size cylindrical roller bearing. The hollow tapered roller bearing can be cooled by oil, which reduces temperature rise, thereby improving the allowable speed. However, this bearing manufacturing process is complex, and the requirements for the machine lubrication system are also high, generally only on the horizontal spindle with special requirements.

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