Machine tool bearing is an important part of machine tool, its accuracy and stability directly affect the performance of machine tool and processing quality. The clearance of the bearing is the key factor affecting its accuracy and stability. Therefore, mastering the clearance adjustment skills and maintenance methods of machine tool bearings is of great significance for ensuring the normal operation of machine tools and improving the processing quality. This paper will introduce how to effectively maintain machine tool bearings from two aspects of clearance adjustment skills and maintenance methods.
The clearance adjustment of machine tool bearings is to adjust the internal clearance of bearings to achieve the best working state. Here are a few key steps to adjust the clearance:
Determine the diameter of the drilling hole: Before adjusting the clearance, it is necessary to calculate the diameter of the drilling hole according to the inner and outer diameter of the bearing. In general, the diameter of the drilling hole can be calculated by the formula (D-d) /2, where D is the outer diameter of the bearing and d is the inner diameter of the bearing.
Select the tap and tightening force: according to the calculated drilling diameter, select the appropriate tap for tapping. In the tapping process, it is necessary to pay attention to control the tightening force to avoid damage to the bearing. Generally speaking, the tightening force of the tapping should not exceed the yield strength of the bearing inner ring.
Measuring the clearance: After tapping is completed, the clearance of the bearing needs to be measured. The commonly used measuring methods are gauge method and dial gauge method. The feeler method is suitable for small clearance measurement, while the dial gauge method is suitable for large clearance measurement. When measuring, it is necessary to place the dial gauge or feeler between the outer ring and the inner ring of the bearing, and then rotate the bearing, read the maximum and minimum values, and take the average value of the two is the bearing clearance.
Regular maintenance of machine tool bearings can extend their service life and improve processing quality. Here are some common maintenance methods:
Daily inspection: Check the appearance of machine tool bearings every day to see if there are cracks, wear, rust and other phenomena. At the same time, it is necessary to check the lubrication status of the bearing to ensure that the grease or lubricating oil is sufficient and clean.
Common faults and preventive measures: The common faults of bearings are wear, corrosion, burn and so on. In order to prevent these failures, the following measures can be taken: keep the bearings clean and dry; Avoid overload and excessive lubrication; Regular inspection of bearing clearance and wear; Timely detect and deal with abnormal vibration and noise of bearings.
Bearing replacement method and precautions: When the bearing is seriously worn or fails, it needs to be replaced in time. The following points should be paid attention to when replacing bearings: select the appropriate bearing model and specification; Ensure the cleanliness and lubrication of the new bearing; Properly install bearings to avoid uneven force and excessive compression; After the replacement is completed, it is necessary to conduct a test check to ensure the normal operation of the bearing.
Taking the spindle bearing of a certain type of CNC machine tool as an example, abnormal vibration and noise appear in the process of the bearing. After inspection, it was found that there was a large clearance between the inner ring and the outer ring of the bearing. In order to solve this problem, we used the clearance adjustment technique to adjust the bearing. The specific steps are as follows:
The diameter of drilling hole is calculated according to the inner diameter and outer diameter of bearing, and the appropriate tap is selected for tapping.
Control the tightening force and adjust the bearing;
The dial gauge method is used to measure the adjusted bearing clearance to ensure that it is within the normal range;
Bearings are lubricated and cleaned, and then inspected for test run.
After the above treatment, the abnormal vibration and noise of the bearing disappeared, and the processing quality was also significantly improved. This example illustrates the important role of clearance adjustment techniques in solving machine tool bearing failures.
This paper introduces the clearance adjustment technique and maintenance method of machine tool bearing. Mastering these methods and skills can help us better maintain and maintain machine tool bearings, extend their service life and improve processing quality. At the same time, we also need to continue to learn and accumulate more experience in order to better solve problems in practical applications.
