Bearing installation skills1

Bearing installation

The quality of bearing installation will affect the accuracy, life and performance of the bearing. Therefore, please fully study the bearing installation, that is, please install the bearing according to the operating standards including the following items. 1. Clean the bearings and related parts. There is no need to clean the grease-lubricated bearings and bearings with oil seals or dust caps and sealing rings on both sides 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 face of the tightly fitted ring, and the pressure should not be transmitted through the rolling elements. The bearing installation generally adopts the following methods: A. Press-fit When the inner ring of the bearing is tightly fitted with the shaft, and the outer ring and the bearing seat hole are loosely fitted, the bearing can be pressed on the shaft by a press first, and then the shaft together with the bearing is installed into the bearing seat hole . When press-fitting, place a copper or mild steel assembly sleeve made of soft metal material on the end face of the inner ring of the bearing (as shown in Figure 2-4). The inner diameter of the assembly sleeve should be slightly larger than the journal diameter, and the outer diameter should be slightly smaller than the bearing inner ring rib to avoid pressing on the cage. When the outer ring of the bearing is tightly fitted with the bearing seat hole, and 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 (see Figure 2). -5 shown).

If the bearing ring is tightly fitted with the shaft and seat hole, the inner ring and outer ring should be pressed into the shaft and seat hole at the same time during installation, and the structure of the assembly sleeve should be able to press the bearing inner ring and outer ring at the same time. the end face of the ring (as shown in Figure 2-6). B. Heating fit By heating the bearing or bearing seat, the tight fit is transformed into a loose fit by thermal expansion. 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 ferrule of the separable bearing into the oil tank and heat it evenly at 80~100℃ before hot-loading, and then take it out of the oil and install it on the shaft as soon as possible. After the bearing has cooled, it can be axially tightened. When the outer ring of the bearing is tightly fitted with the light metal bearing, the hot-fitting method of heating the bearing seat can be used to prevent the mating surface from being scratched. When heating the bearing with the oil tank, apply a mesh grid at a certain distance from the bottom of the box (as shown in Figure 2-7), or hang the bearing with a hook, and the bearing cannot be placed on the bottom of the box to prevent the sedimentary impurities from entering the bearing or uneven For heating, there must be a thermometer in the oil tank, and the oil temperature must not exceed 100 ℃ strictly to prevent the back effect and reduce the hardness of the ferrule. C. Installation of tapered bore bearings Tapered bore bearings can be installed directly on the tapered journal, or on the tapered surfaces of the adapter sleeve and the withdrawal sleeve, and the tightness of the fit can be reduced by the radial clearance of the bearing. to measure. Therefore, the bearing radial clearance should be measured before installation, and the clearance should be measured frequently during installation to achieve the required clearance reduction. During installation, the lock nut is generally used for installation, and the method of heating installation can also be used. D. The installation of thrust bearing is generally a transition fit between the shaft washer of the thrust bearing and the shaft, and the fit between the seat washer and the bearing seat hole is generally a clearance fit, so this kind of bearing is easier to install, and the center shaft washer of the two-way thrust bearing should be in Fixed on the shaft to prevent rotation relative to the shaft.