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What are the precautions for assembling bearings?
The correct installation of bearings will have a direct impact on their accuracy, service life, performance, and other aspects. The general requirements are to follow standard projects, mainly including:
(1) Cleaning bearings and associated components
(2) Check component dimensions and accuracy
(3) Installation operation
(4) Various inspections after installation
(5) Supply lubricant
During this process, the following points need special attention:
1. Concentricity of inner and outer rings to avoid axial deviation
Axis deviation is a very common phenomenon, which can cause uneven oil film thickness inside the bearing, leading to oil film rupture and premature bearing failure. When installing, a whole shell structure can be used. When two bearing holes are installed in different shells, the two shells should be combined together for boring.
2. Inadequate installation, resulting in too small bearing clearance
The temperature of the shaft is usually higher than the outer ring during operation, and the thermal expansion of the shaft is greater than that of the outer shell. If the clearance is too small, it may cause jamming.
3. Types of cooperation between rotating and stationary coils
The type of fit for bearings should be determined based on the type and size of the bearing, load and direction, and load properties. Generally speaking, the fit of the rotating ring is tighter than that of the stationary ring. For working conditions with high rotational speed, heavy load, and strong vibration, or for installation on thin-walled shells or hollow shafts, a tighter fitting method should be selected. However, it should be noted that an overly tight fit may lead to a decrease or even disappearance of the internal clearance of the bearing and deformation of the inner and outer rings.
4. Excessive bearing preload
A small preload force can cause the bearing to experience vibration and noise during operation due to excessive clearance, reduced stiffness and accuracy. However, if the preload force is too large, it will increase the friction between the rolling element and the raceway, resulting in faster heating and lower transmission efficiency. Appropriate preload force can keep the position of the bearing ring relatively stable.
5. Open the bearing packaging before installation.
The bearings obtained after opening the packaging and removing the rust inhibitor are prone to rusting. The packaging of the bearings should be opened when installation is required to avoid contamination and rusting of the bearings
