Common five kinds of machine tool spindle bearings Features

1. Deep groove ball bearings

This class bearings generally only used to bear radial load, due to clearance is not adjustable, so commonly used in less precision, without pretension occasions, such as the common drilling spindles.

2. angular contact ball bearings

These bearings can support radial and axial loads, since the radial load will cause internal axial force, and hence, to install and use, and its configuration has "back to back", "face to face", "series" and " multi-joint ", and by tightening can increase the stiffness of the spindle. These double row ball slewing bearing have a contact angle of 15 °, 25 °, 40 ° three, including a contact angle of 15 ° B7000CY-precision angular contact ball bearings are designed for dedicated high-speed grinder spindle bearing designs, in addition to the internal structure of the bearing design changes, rings and rolling elements are made ​​of high-quality bearing steel slag. Cage material is phenolic cloth laminated tube, tolerance levels have 5,4 and 2. Therefore, these bearings have high rotational accuracy and speed limits, low friction, low temperature rise.

3. angular contact thrust ball bearings

Usually used 230,000 two-way thrust angular contact ball bearings, the contact angle of 60 °, by a seat belt lubrication holes, two shaft washer, a spacer and two ball and cage components. Select the appropriate height of the spacer can be assembled deck crane bearing having a desired pre-load.

Such bearings can withstand axial load, with good rigidity, the normal low temperature lubrication, high speed, and easy assembly and disassembly, as a new structure, currently used for grinding machines, lathes, boring, milling, drilling and other spindle on, often with the use of double row cylindrical roller bearings group with.

4. Double-row cylindrical roller bearings

These bearings can withstand greater radial load and allows a higher speed. Bearing in two rows of rollers arranged in a cross pattern, rotation fluctuation frequency than single row bearings double the amplitude decreased 70%. Such bearings are commonly used in two forms: NN30 / W33, NN30K / W33 two series bearing inner ring with ribs, outer separable; NNU49 / W33, NNU49K / W33 two series bearing outer ring with ribs, internal Circle separable, which NN30K / W33 and NNU49K / W33 series inner ring of tapered bore (taper 1:12), and a tapered shaft journal mate, axial movement of the inner ring, the inner ring can swell to reduce even small bearing clearance bearing preload. Cylindrical bore bearings usually thermal loading, using an interference fit reduced bearing clearance, or to achieve the purpose of pretension. Separable NNU49 series on the inner bearing inner ring mounted on the spindle generally made ​​after finishing the race in order to obtain high spindle rotation accuracy.

5. Tapered Roller Bearings

Both radial and axial loads, double row tapered roller bearings can withstand axial load. Tapered Roller sliding friction due to the large end and the inner wall between the child, the speed limit is often lower than the same-size cylindrical roller bearings. Hollow tapered roller bearings available oil cooling roller, so that temperature decreases, thereby increasing the allowable speed. But this thin wall bearings

 complex manufacturing process, machine tool lubrication system requirements are higher, generally used only for the special requirements of the horizontal spindle.