March 9, 2020
Briefly discuss the measurement of main bearing size
The main measurement data and measurement methods of bearing are as follows:
1. Bearing inner diameter:
Before the measurement, the SKF bearing shall be installed and combined according to the requirements. The bearing cover bolts shall be tightened according to the requirements. The inner diameter gauge shall be used to measure the base size after the outer micrometer measure.
The difference between the inner diameter of the bearing and the outer diameter of the corresponding journal is the mating gap.
2. Bearing thickness:
The external micrometer fixed probe is changed from a plane to a sphere, which can be used to measure the bearing thickness.
Generally, the bearing thickness should be controlled within the range of 0.005~0.010 mm, otherwise the inner diameter of SKF bearing will be out of tolerance.
Bearing in the vicinity of the opening has a trace of thinning, measurement should be paid attention to.
3. Coaxiality of main bearing inner hole:
The coaxiality error of the main bearing inner hole is mainly caused by the coaxiality error of the bearing hole, while the coaxiality error of the bearing hole is caused by the deformation of the cylinder block.
When the radial circular runout of the spindle neck is within the specified tolerance, check the runout marks of the spindle neck and bearing. If the positions of the runout marks of each main bearing are obviously inconsistent, it indicates that the error of coaxiality is large. Methods such as scraping, boring and replacing the bearing or cylinder block can be adopted to solve the problem.
4. Tightness of bearing and bearing hole:
The fit compactness is guaranteed by the free spring opening of the bearing and the height of the remaining surface.
Under the method of measuring the residual surface height, the bearing shall be assembled according to the regulations, the cross-bearing cover bolt shall be tightened to the specified torque, and one of the bolts shall be loosened. The clearance of the bearing cover joint shall be measured with a feeler, and the value shall be within the range of 0.05~0.15 mm.