The 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 recommended to store them on a shelf 750cm above the ground at a temperature below 65% and a temperature of about 20 degrees Celsius. In addition, the storage place should avoid direct sunlight or contact with cold walls.

Bearing installation

1. Precautions before installation

① Bearing preparation

Since the bearings are rust-proofed and packaged, do not open the package before installation. In addition, the anti-rust oil applied to the bearings has good lubrication properties. For general-purpose bearings or bearings filled with grease, they can be used directly without cleaning. However, for instrument bearings or bearings used for high-speed rotation, the anti-rust oil should be washed off with clean cleaning oil. At this time, the bearings are prone to rust and cannot be placed for a long time.

② Inspection of shaft and housing

Clean the bearings and housing to confirm that there are no scars or burrs left by machining. There must be absolutely no abrasives (SiC, Al2O3, etc.), molding sand, chips, etc. in the housing. Secondly, check whether the size, shape and processing quality of the shaft and housing are consistent with the drawings. Before installing the bearing, apply mechanical oil to the mating surfaces of the shaft and housing that have passed the inspection.

2. Bearing installation method

The bearing installation method varies depending on the bearing type and matching conditions. Since the shaft is generally rotated, the inner ring and the outer ring can be respectively used for interference fit and clearance fit, while when the outer ring rotates, the outer ring adopts interference fit. The bearing installation methods when using interference fit can be mainly divided into the following types:

① Press-in installation

Press-in installation generally uses a press, and can also use bolts and nuts. When necessary, it can be installed with a hammer.

② Hot-fit installation

The hot-fit method of heating the bearing in oil to expand it and then installing it on the shaft can prevent the bearing from being subjected to unnecessary external forces and complete the installation work in a short time.

Heating precautions:

① Generally, the heating should not exceed 100 degrees Celsius.

② The bearing is not allowed to contact the bottom of the oil tank.

In addition, the hot-fit installation can also use the induction heating device to heat the bearing to expand it before installing it on the shaft.

3. Bearing disassembly

When regularly checking or replacing parts, it is necessary to disassemble the bearing. Usually the shaft and bearing box are almost always used, and the bearing is often used. Therefore, the structural design should take into account that when disassembling the bearing, the bearing, the shaft, the bearing box and other parts will not be damaged, and appropriate disassembly tools should be prepared. When disassembling the static fit ring, the tension can only be applied to the ring, and the ring must not be pulled through the rolling element.

Bearing maintenance

In order to give full play to the bearing and maintain its due performance for a long time, regular maintenance (regular inspection) must be carried out.

Through appropriate regular inspections, early detection of faults and prevention of accidents are very important for improving productivity and economy.

1. Cleaning

When disassembling the bearing for inspection, first use photography and other methods to record the appearance. In addition, confirm the amount of remaining lubricant and sample the lubricant before cleaning the bearing.

a. The cleaning of bearings is divided into rough cleaning and fine cleaning, and a metal grid can be placed at the bottom of the container used.

b. During rough cleaning, use a brush to remove grease or adhesive in the oil. If you turn the bearing in the oil at this time, be careful that the rolling surface may be damaged by foreign matter.

c. During fine cleaning, slowly turn the bearing in the oil and be careful. The commonly used cleaning agent is neutral diesel or kerosene without water, and sometimes warm alkali solution is used as needed. Regardless of the cleaning agent used, it must be filtered frequently to keep it clean. After cleaning, immediately apply anti-rust oil or anti-rust grease to the bearing.

2. Inspection and judgment

In order to determine whether the dismantled bearing can be reused, it is necessary to focus on checking its dimensional accuracy, rotation accuracy, internal clearance, matching surface, raceway surface, cage and seal ring. The inspection results can be judged by those who are accustomed to bearings or proficient in bearings. The judgment criteria vary according to mechanical properties, importance, inspection cycle, etc. If there is the following damage, the bearing cannot be reused and must be replaced.

①Breakage and defects of bearing parts.

②Peeling of the raceway surface.

Methods for identifying bearing faults

It is very important to identify or predict whether the bearing in operation has faults without disassembly inspection.

The main identification methods are as follows:

①Identification by sound

Identification by sound requires rich experience. It is necessary to be fully trained to be able to distinguish between bearing sounds and non-bearing sounds. For this reason, this work should be done by a dedicated person as much as possible. The sound of the bearing can be clearly heard by sticking a listening device or listening stick to the shell.

②Identification by operating temperature

This method is a comparative identification method and is limited to occasions where the operating state does not change much. For this reason, continuous temperature recording must be carried out. When a fault occurs, not only the temperature rises, but also irregular changes occur.

③Identification by the state of the lubricant

The lubricant is sampled and analyzed, and the degree of contamination is judged by whether it is mixed with foreign matter or metal powder. This method is particularly effective for bearings that cannot be observed closely or large bearings.