Selection Method precision machine tool spindle bearings

Rolling use on the machine is mainly used for the following three parts: the spindle, ball screws and general drive shaft. First, the rotation accuracy of precision rolling bearings for machine tool spindle system accuracy precision machine tool spindle bearings on the P5 and above level should be, and for machine tools, machining centers, high-speed, high-precision machine tool spindle bearings, P4 and above should be used Ultra precision bearings.
Rolling use on the machine is mainly used for the following three parts: the spindle, ball screws and general drive shaft.
First, the accuracy of precision machine tool spindle rotation system Machining centers, high-speed, high-precision machine tool spindle rolling mill bearing should be used in P4 and above-grade super-precision bearings. Machine tool spindle bearings as the basis for matching pieces, and its performance directly affects the speed of the machine, rotary precision, rigidity, resistance to cutting chatter vibration, noise, temperature and thermal deformation, thereby affecting the accuracy, surface quality of machined parts and the like. Therefore, high-performance machine must be equipped with high-performance bearings.
Precision spindle rotation system means that the machine is idling at a low speed manual or motorized rotating case, the measurement reference plane radial front spindle runout, section runout and axial movement of accuracy.Precision spindle system is mainly affected by the following factors Radial runout channel bearing rings, corresponding to the precision spindle bearings axis of the spindle system is radial runout, so that the complex part of the errors of these enantiomers on the surface being processed.
Diameter rolling element bearings inconsistencies and shape error will cause the spindle to produce a regular errors.
The axial end surface of the channel on the side of the pendulum will cause the spindle runout, axial play of the spindle for precision grinding machines, especially spindle bearing

 grinder influence was particularly notable, if tributary Mogou way using the process, will make the rejection rate improved significantly, the noise will be greatly improved.
Size and shape make errors bearing mounting face bearing raceway produce the corresponding deformation, so that the bearing inner and outer rings tilted so that the stiffness of the bearing in each direction is inconsistent, which will reduce the rotational accuracy spindle system. Gap adjustment nut, the spacer, the washer is required for grinding the end face and perpendicular to the axis of rotation of the shaft and the bearing installation accuracy corresponding, otherwise it will decrease the working accuracy of the bearing.
Second, the precision machine tool spindle lubrication and seal Earlier we mentioned the lubricant is an important part of the bearing arrangement, different lubrication, speed limit data bearing is different. In accordance with the design requirements lubricant replenish (High Speed ​​Precision Spindle grease filling amount is generally 10% to 20% of the bearing space), reasonable lubricant can reduce friction and wear shafting, extend the fatigue life of the bearing, frictional heat can be discharged simultaneously bearing system and play a role in cooling the bearing system; in addition to the grease, as well as liquid lubricating oil lubrication, oil mist lubrication and oil lubrication, etc. bearing system, oil lubrication system in which high-speed spindle abroad has been widely used, fuel oil lubrication, no pollution, and can significantly increase the DN value of the spindle system, and is able to intelligently control shaft lubricant requirements recharge.
Spindle structure design, lubrication and sealing must take different forms depending on the situation. Timely replacement of worn seals, seal lip contact with the rotating body at more than 15m / s is necessary to use non-contact sealing structure, high-speed precision machine tools they use a labyrinth, and the need to dump oil in place designed grooves, because contact Not only will seal sealing contact friction loss and overheating at, but will impact on the bearing system rotation accuracy.
Third, as a precision ball screw, efficient and sensitive transmission components, should be used in addition to high-precision screw, nut and ball, we must also pay attention to the choice of the axial stiffness, low friction torque, high operating precision bearings. Ball bearing used in the past two-way thrust angular contact ball bearings, tapered roller bearings, needle roller and thrust roller bearings, deep groove ball bearings and thrust ball bearings. Currently, ball bearing using the most is the contact angle of 60 ° single row angular contact ball bearings, and precision grade is mainly to P4 level and above.