How best to choose the type of spindle bearing

Wafangdian bearing the author on June 21, explain for you: how to choose the type of spindle bearings used in machine tool spindle bearing accuracy should be ISOP5 or above ( P5 or P4 is the accuracy level of the ISO, usually from low to high as ( P0, P6、P5 P4, P2) For nc machine tools and machining center such as high speed, high precision machine tool spindle bearing, to choose ISOP4 or more accuracy. Spindle bearings including angular contact ball bearings, tapered roller bearing, spherical roller bearings and cylindrical roller bearings and other types. 1, how to choose the type of spindle bearings: precision angular contact ball bearings of precision Angle contact ball bearing is widely used, angular contact ball bearing roller is the ball, because it is a point contact ( Different from roller bearing line contact) , so can provide higher rotating speed, less calorific power and higher accuracy. In some of the ultra high speed spindle applications, will also adopt ceramic ball ( Generally for si3N4 or Al203) Hybrid bearings. Metal processing reporters that compared with the traditional full hardening of steel ball, ceramic ball material itself gives the characteristics of ceramic ball bearings with high rigidity, high speed, high temperature resistant, long service life characteristics, to meet the needs of high-end clients of machine tool bearing products. 2, how to choose the type of spindle bearings: precision cylindrical roller bearing in the application of machine tool spindle, double row precision cylindrical roller bearing can be used to, usually with precision angular contact ball bearing and thrust bearing composite applications. This kind of bearing can withstand the bigger radial load and high speed are allowed. Metal processing online two columns of roller bearing with cross arranged, rotates sharply higher than single row bearing, the frequency of the wave amplitude reduced 60% 70%. Such bearings usually has two forms: NN30, NN30K two series of bearing inner ring belt guard, outer separable; NNU49, NNU49K two series of bearing outer ring guard, inner ring can be separated, which NN30K and NNU49K series inner ring for the taper hole ( Taper 1:12) , cooperate with the conical shaft neck of the main shaft, the axial movement within the circle, can make the inner ring swell, so bearing clearance can be reduced or even preloaded bearing ( Negative clearance status) 。 Cylindrical hole bearing usually adopt hot charging, using the interference fit decrease the bearing clearance, or preloaded bearing. Inner circle of separable NNU49 series bearings, general inside is installed on the spindle to race again after finish machining, in order to improve the spindle rotation accuracy. 3, how to choose the type of spindle bearings: precision taper roller bearing in some overloaded and has certain requirements for speed of machine tool applications, such as forging snagging, pipeline car silk machine, heavy duty lathe and milling machine, etc. , choose precision taper roller bearing is a kind of ideal solution. As a result of the tapered roller bearing roller is the design of the line contact, so it can offer high rigidity and bearing for the spindle; In addition, tapered roller bearing is a kind of pure rolling bearing is designed, it can reduce the bearing running torque and fever, to ensure that the spindle rotation speed and precision. Because of the tapered roller bearing can regulate the axial preloading during the installation process ( Clearance) , this can let the customer in the bearing throughout the life of the better optimization of bearing clearance adjustment. Bearing comfortable and durable, )