Installation of motor bearings

Update:17-09-2021
Summary:

Whether the motor bearing is installed or not will directly affect the accuracy, life and performance of the bearing. Therefore, please fully study the installation of the bearing, that is, please install the bearing in accordance with the operating standards including the following items.
●Clean the bearings and related parts, (for grease-lubricated bearings and oil seals or dust caps on both sides, the seal ring bearing does not need to be cleaned before installation.)
●Check the size and finishing of related parts
●Installation method
The installation of the bearing should be determined according to the bearing structure, size and the matching nature of the bearing components. The pressure should be directly applied to the end face of the tightly fitted ring, and no pressure can be transmitted through the rolling elements. The bearing installation generally adopts the following methods:
a. Press fit
When the inner ring of the bearing and the shaft are tightly fitted, and the outer ring and the bearing seat hole are loosely fitted, the bearing can be press-fitted on the shaft by a press, and then the shaft and the bearing are installed in the bearing seat hole. On the end face of the inner ring of the bearing, an assembly sleeve made of soft metal material (copper or mild steel) is cushioned.
The outer ring of the bearing is tightly fitted with the bearing seat hole. When the inner ring and the shaft are loosely fitted, the bearing can be pressed into the bearing seat hole first. At this time, the outer diameter of the assembly sleeve should be slightly smaller than the diameter of the seat hole.
If the bearing ring is tightly fitted with the shaft and the seat hole, the inner ring and outer ring should be installed into the shaft and the seat hole at the same time. The structure of the assembly sleeve should be able to tighten the end faces of the inner ring and the outer ring at the same time.
b. Heating coordination
By heating the bearing or the bearing seat, thermal expansion is used to transform the tight fit into a loose fit installation method. It is a common and labor-saving installation method. This method is suitable for the installation of bearings with large interference. Put the bearing or the ring of the separable bearing into the oil tank and heat it evenly at 80-100°C, then remove it from the oil and install it on the shaft as soon as possible. To prevent the end face of the inner ring and the shaft shoulder from not fitting tightly after cooling, the bearing can be axially tightened after cooling. When the outer ring of the bearing is tightly fitted with the light metal bearing seat, the hot-fitting method of heating the bearing seat can be used to avoid scratches on the mating surface.
When heating the bearing with an oil tank, there should be a grid at a certain distance from the bottom of the box, or the bearing should be hung with a hook. The bearing cannot be placed on the bottom of the box to prevent sinking impurities from entering the bearing or uneven heating. There must be a thermometer in the oil tank. Strictly control the oil temperature not to exceed 100°C to prevent the occurrence of tempering effects and reduce the hardness of the ferrule.