Machine tool spindle to choose what kind of bearing right?

The composition of nc machine tool parts, main shaft bearing is a very important part of. For machine tool spindle choose different configuration of bearing speed, load capacity, temperature rise, stiffness and service life have different effects. There are five commonly used bearing spindle: tapered roller bearings, two-way thrust angular contact ball bearings, angular contact ball bearings, double row cylindrical roller bearings, deep groove ball bearings. Different bearing function is not very kind, be able to use the machine equipment is not sample. Then we know to analysis them one by one, and see what's the point. 1. Tapered roller bearings can withstand radial and axial load at the same time, double row tapered roller bearing can be subject to bi-directional load. For tapered roller with sliding friction between inner ring guard, its limit rotational speed is often less than the size of cylindrical roller bearing. Hollow taper roller bearing oil cooling roller, lower the temperature, so as to improve the speed of the allowed. But this kind of bearing manufacture process is complex, the requirement of the lubrication system of nc machine tools is higher also, only for there is special requirement on the horizontal axis. 2. Two-way thrust angular contact ball bearings are usually using 230000 type two-way thrust angular contact ball bearing, contact Angle 60 °, by a belt of lubricating oil hole seat ring, two axis, a baffle and two sets of steel ball and cage components. Choose the right baffle height can make the bearing has the required pre-load after assembly. The bearing can be subject to bi-directional load and have good rigidity, low temperature during normal lubrication, high speed, and easy to install, as a kind of new structure, is used for grinding machine, lathe, boring machine, milling machine, drilling machine, such as the spindle, use commonly equipping with the double row cylindrical roller bearings. 3. Angular contact ball bearing this kind of bearings can withstand radial and axial load at the same time, because under the radial load will cause internal axial force, so should to install and use, the configuration way 'back to back', 'face to face' and 'series' and 'split', etc. , and through the preloaded can improve the stiffness of the spindle. This kind of bearing contact Angle is 15 °, 25 °, 40 ° three, one of the contact Angle is 15 ° B7000CY type high precision angular contact ball bearing is designed for high speed grinder spindle bearing, the bearing in addition to the internal structure design changed, ring and selects the high quality of electroslag roller bearing steel manufacturing. Cage materials for phenolic laminated tube, tolerance, etc. 5, 4 and 2. Therefore, this kind of bearing has high rotation accuracy and limit rotational speed, friction small, low temperature rise. 4. Double row cylindrical roller bearing this kind of bearing can withstand the bigger radial load and high speed are allowed. Two columns of bearing roller with cross arranged, rotates than single bearing to improve The Times, the frequency of the wave amplitude reduced by 70%. Commonly used this kind of bearing has two forms: NN30 / W33, NN30K/W33 two series of bearing inner ring guard, outer separable; NNU49 / W33, NNU49K/W33 two series of bearing outer ring guard, inner ring can be separated, of which NN30K/W33 and NNU49K/W33 series inner ring for the taper hole ( Taper 1:12) , to match the conical journal of main shaft, the axial movement within the circle, can make the inner ring swelling, to reduce the bearing clearance and preload bearings. Cylindrical hole bearing usually adopt hot charging, using the interference fit decrease the bearing clearance, and achieve the goal of preloaded. Inner circle of separable NNU49 series bearings, inside is installed as a main shaft of raceway again after finishing, in order to obtain high precision of the spindle rotation. 5. Deep groove ball bearings as these bearings are only used to bear radial load, because the clearance is not adjustable, so often used for accuracy is not high, not to be preloaded occasions, such as ordinary drilling machine spindle. Above is the five kinds of common machine tool spindle bearing, which is suitable for depends on your needs, normal drilling spindle can choose deep groove ball bearing, the particular horizontal spindle can choose tapered roller bearings, etc. Choose suitable for machine tool spindle bearing, can let support mechanical body rotation and friction reduces. Tags: machine tool spindle