Installation of rolling bearings

Update:04-11-2021
Summary:

Whether the bearing is installed well or not will affec […]

Whether the bearing is installed well or not will 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.
1. Cleaning 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.
2. Check the size and finishing of related parts
3. 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 surface of the tightly fitted ring, and the pressure cannot be transmitted through the rolling elements. The bearing installation generally adopts the following methods:
a. Press-fit the inner ring of the bearing to make a tight fit with the shaft. When the outer ring and the bearing seat hole are loosely fitted, the bearing can be press-fitted on the shaft with a press, and then the shaft and the bearing are installed in the bearing seat hole. , During press-fitting, pad an assembly sleeve made of soft metal material (copper or mild steel) on the end face of the bearing inner ring. The inner diameter of the assembly sleeve should be slightly larger than the journal diameter, and the outer diameter should be larger than the bearing inner ring. The side is slightly smaller to avoid pressing on the cage. 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 in a tight fit 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 fit The installation method that uses thermal expansion to transform the tight fit into a loose fit by heating the bearing or bearing seat. 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 separable bearing ring into the oil tank and heat it evenly at 80-100℃, and then take it out of the oil and install it on the shaft as soon as possible. To prevent the inner ring end face 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 tempering effect and reduce the hardness of the ferrule.
c. Installation of tapered bore bearings. Tapered bore bearings can be directly installed on the tapered journal, or on the tapered surface of the adapter sleeve and withdrawal sleeve. The tightness of the fit can be reduced by the reduction in the radial clearance of the bearing. Therefore, the radial clearance of the bearing should be measured before installation, and the clearance should be measured frequently during the installation process to achieve the required clearance reduction. The installation is generally done with a lock nut, or it can be installed by heating. .
d. Thrust bearing installation The fit of the thrust bearing and the shaft is generally a transition fit, and the fit between the seat ring and the bearing housing hole is generally a clearance fit, so this kind of bearing is easier to install, and the center axis spring of the two-way thrust bearing should be on the shaft. The upper is fixed to prevent rotation relative to the shaft. Generally speaking, the installation method of the bearing is that the shaft rotates. Therefore, the fit between the inner ring and the shaft is an over-win fit, and the fit between the outer ring of the bearing and the bearing chamber is a clearance fit.

0
Views: 70