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/*728*90 created on 2018/5/16*/ var cpro_id = "u3440131"; Home>Bearing knowledge>Measuring the quality of rolling bearings on the quality of precision Measuring "the quality of rolling bearings is good for accuracy"
1. Accuracy improvement method Rolling bearing after the end of the device in the main machine; if the radial runout of the measuring spindle is measured; it can be found that the measured value of each revolution has a certain change, and the measurement is carried out successively; it can be found that after passing the certain number of revolutions; The change will be approximately repeated. The target for measuring the degree of change is the cycle rotation precision; the change of the number of revolutions required to approximately repeat the presentation represents the "quasi-period" of the cycle rotation accuracy; the magnitude of the magnitude change in the quasi-period is large. ; that is, the cycle rotation accuracy is poor. /*250*250 was created on 2017/12/25*/ var cpro_id = 'u3171089';
For example, the preload is properly applied to the main shaft; the rotational speed is gradually increased to the near-operation speed; the "run-in" effect of the bearing is implemented; the cyclic rotation accuracy of the main shaft can be improved.
2, a method to improve the accuracy of the bearing a factory trial production of fine instruments; spindle with 6202 / P2 type bearing and its accuracy is still not satisfactory; after the thickening of the journal and on which the raceway is made to replace the inner ring; The ball is finely measured; it is divided into three groups of scales; each group of steel balls is separated by a distance of nearly 120°; because it reduces the appearance of a heavy machining; it also reduces the cooperation appearance; together, the rigidity of the shaft-rolling bearing system is improved. The maximum three particles and the smallest three steel balls are nearly equidistantly distributed; the axis reversal accuracy is improved; therefore, the accuracy requirements of the instrument are satisfied.
3. Inductive verification method of device accuracy After loading the angular touch ball bearing into the spindle; the order of verification of the device accuracy is as follows (for example, a general lathe with a shaft diameter of 60?100mm):
(1) Measuring the dimensions of the shaft and the bearing housing hole; to determine the cooperation precision of the bearing; the cooperation requirements are as follows:
The inner ring and the shaft adopt the interference cooperation; the interference is 0～+4μm (0 in light load and high precision), the outer ring and the bearing housing hole adopt the gap cooperation; the clearance is 0～+6μm (but the bearing at the free end) When the angular contact ball bearing is used; the gap can be increased), the roundness of the shaft and the seat hole is less than 2μm; the parallelism of the end face of the spacer used for the rolling bearing is less than 2μm; the outer end of the shoulder end is less than 2μm. The bearing block hole shoulder jumps to the axis below 4μm, and the inner end face of the spindle front cover jumps below 4μm.
(2) The fixed-end front bearing on the shaft device completely removes the rolling bearing with a clean clearing fire oil; the grease is smooth; the organic solvent rich in 3% to 5% smooth grease is first written into the bearing for degreasing; Then use the oil gun to fill the bearing with the smooth grease (10% to 15% of the bearing space volume), heat the bearing to raise the temperature by 20 ~ 30 °C; use the hydraulic press to install the bearing into the shaft end, press the adapter sleeve The shaft is placed on the shaft with a suitable pressure to axially position the bearing, and the belt of the spring balance is wound on the outer ring of the bearing; whether the regular preload can be greatly changed by measuring the starting torque (even The bearing is correct; but because of the cooperation or deformation of the cage; the preload can also be changed).
(3) The bearing shaft assembly body is installed in the seat hole heating seat hole to raise the temperature by 20 to 30 ° C, and the bearing shaft assembly body is inserted into the seat hole by the successively gentle pressure, and the front cover is adjusted; 0. 02～0. 05μm; based on the outer end of the bearing seat; the head of the dial gauge conflicts on the outer surface of the journal; the shaft is rotated to measure its runout; the demand error is below 10μm, and the dial gauge is positioned at On the shaft; the head conflicts with the inside and outside of the seat hole; the shaft is rotated to measure the coaxiality of the front and rear seat holes of the bearing housing.
(4) Selecting the free end bearing in an orientation capable of canceling the error; supporting the bearing after the device is placed to the bearing housing; and canceling the roundness error and the coaxiality error between each other as much as possible.
4. The device with tapered bore double row short cylindrical roller bearing is equipped with NN3000K series tapered bore double row short cylindrical roller bearing; it is necessary to pay attention to the correct matching of the inner diameter of the rolling bearing and the taper of the shaft; it can be coated in the case of less production value. The color method performs touch verification; however, when the production batch size is large; it is better to use a fine cone gauge to verify.
When the rolling bearing device is mounted on the tapered shaft; the inner ring should be adjusted to the proper orientation in the axial direction; the radial clearance is close to zero.
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Measuring "the quality of rolling bearings is good for accuracy"
Source: China Bearing Network Time: 2013-12-14