Disassemble
The disassembly of the bearing is for regular maintenance, and it is carried out when the bearing is replaced. After disassembly, if you continue to use it, or you need to check the state of the bearing, the disassembly should be carried out as carefully as the installation. Be careful not to damage the various parts of the bearing, especially the disassembly of the interference fit bearing, which is difficult to operate.
It is also important to design and manufacture disassembly tools as needed. When disassembling, study the disassembly method and sequence according to the drawings, and investigate the matching conditions of the bearing, so as to obtain a foolproof disassembly operation.
Removal of the outer ring To remove the outer ring with interference fit, set several screws for the outer ring extrusion screw on the circumference of the outer casing in advance, and tighten the screw evenly while disassembling. These screw holes are usually covered with blind plugs, separable bearings such as tapered roller bearings, and several notches are set on the shoulders of the housing. Use spacers to remove them with a press, or gently tap to remove.
The dismantling of the inner ring can be the easiest to pull out with a press. At this time, pay attention to let the inner ring bear its pulling force. Furthermore, the pull-out clamps shown are mostly used, and no matter which kind of clamps, they must be firmly clamped on the side of the inner ring. For this reason, it is necessary to consider the size of the shaft shoulder, or study the machining of the upper groove at the shoulder, so as to use the drawing jig.
The disassembly of the inner ring of the large bearing adopts the hydraulic method. Oil pressure is applied through the oil hole provided in the bearing to make it easy to pull out. For bearings with large widths, the hydraulic method is used in combination with the pulling jig for disassembly.
The inner ring disassembly of cylindrical roller bearings can use the induction heating method. A method of drawing by heating the part in a short time to expand the inner ring. Where a large number of these bearing inner rings need to be installed, the induction heating method is also used.
Cleaning
When removing the bearing for inspection, first make a record of the appearance by means of photography and other methods. Also, confirm the amount of remaining lubricant and sample the lubricant before cleaning the bearing.
a. The cleaning of the bearing is divided into coarse cleaning and fine cleaning, and a metal mesh frame can be placed at the bottom of the container used.
b. During rough cleaning, use a brush in the oil to remove grease or adhesions. At this time, if the bearing is rotated in oil, be careful that the rolling surface may be damaged by foreign matter or the like.
c. During fine cleaning, slowly rotate the bearing in the oil, which must be done carefully.
The commonly used cleaning agent is neutral non-water diesel oil or kerosene, and sometimes warm lye is also used as needed. Whatever cleaning agent is used, it should be filtered frequently to keep it clean.
After cleaning, apply anti-rust oil or anti-rust grease to the bearing immediately.
Inspection and judgment
In order to judge whether the removed bearing can be reused, it is necessary to focus on checking its dimensional accuracy, rotation accuracy, internal clearance, and mating surface, raceway surface, cage and sealing ring. Because large bearings cannot be rotated by hand, pay attention to checking the appearance of rolling elements, raceway surfaces, cages, rib surfaces, etc. The higher the importance of the bearing, the more careful inspection is required.
Causes of heating of rolling bearings and their elimination methods
Low bearing accuracy: Select bearings with specified accuracy grades.
The spindle is bent or the box hole is not concentric: Repair the spindle or the box.
Poor lubrication: Select the specified grade of lubricating material and clean it properly.
Low assembly quality: Improve assembly quality.
Bearing inner casing running ring: Replace the bearing and related wear parts.
Axial force is too large: Clean and adjust the clearance of the sealing ring to be between 0.2 and 0.3mm, correct the diameter of the impeller balance hole and check the static balance value.
Bearing damage: Replace the bearing.
Custody
Bearings are coated with an appropriate amount of anti-rust oil and packed with anti-rust paper when leaving the factory. As long as the packaging is not damaged, the quality of the bearings will be guaranteed. However, for long-term storage, it is advisable to store it on a shelf 30cm above the ground when the humidity is lower than 65% and the temperature is about 20°C. In addition, the storage place should avoid direct sunlight or contact with cold walls.
