Bearing is used to support the components, is also used to support the axis of rotation parts, bearing types according to friction properties: sliding bearings and rolling bearings; according to the load bearing direction: centripetal bearing, propelled bearing, centripetal thrust bearing, and so on.
1, the assembly of sliding bearing
Sliding bearing is a kind of sliding friction bearing, which is characterized by stable work, low reliability, heavy load and large impact load. According to the different structure forms, it can be divided into integral, split and tile type.
(1) assembly of integral sliding bearing
The integral sliding bearing, commonly known as the shaft sleeve, is also the simplest form of the sliding bearing. It is mainly assembled with the method of pressing and hammering. The special occasion is made of hot loading. Most of the bushes are made of copper or cast iron. The assembly should be carefully assembled with wood hammer or hammer pad. The press is pressed into the press at a large time. No matter how to enter or press in, it is necessary to avoid tilting. After assembling, the oil groove and oil hole should be in the required position.
After the deformation of the bearing, the inner hole should be trimmed. The smaller size can be trimmed by reamers, and the larger ones will be scraped. At the same time, we should pay attention to control the clearance between the shaft and the shaft in the tolerance range. In order to prevent the shaft sleeve working, the positioning pin or riding screw is installed on the contact surface of the shaft sleeve and the box box. As the hardness of the box and sleeve material is different, it is easy to make the drill bit to the side of the soft material. The solution is that the sample is punched with the hard material before drilling, and the two is to use a short drill to increase the steel character of the drill bit.
(2) assembly of split bearing
The split bearing is also called the open bearing. It has the characteristics of simple structure and easy to adjust and disassemble. Two axle bushes are inlaid on the axle bush, and the reasonable gap is adjusted with the gasket at the joint.
Assembly of bearing and bearing
The contact between the upper and lower two bushes and the bore of the bearing must be good. If it is not in accordance with the requirement of the bearing body hole of the thick wall bearing, the back of the axle bush should be scraped and studied, and the two ends of the bearing should be close to the ends of the bearing body. As long as the thin wall tile makes the middle surface of the bearing bush higher than 0.1mm of the middle part of the bearing body, it is not necessary to scrape it.
2. The bearing bush is installed in the bearing body, no displacement is allowed in radial or axial direction. The step on the two ends of the bearing bush is usually used to stop the positioning or positioning pin positioning.
The shaving of the bearing bush
In general, the axle bush is usually used to match the shaft bearing with the shaft bearing. In general, the axle bush is scraped first and then the axle bush is scraped. In order to improve the efficiency, the bearing tile and cover can not be installed when the axle bush is scraped down. At present, when the contact point of the Bush is basically conformed to the requirement, the upper bush and the upper cover are pressed tight, and further correction is made when the Bush is scraped and studied. The contact point of the lower axle bush. The degree of tightness of the shaft can be adjusted with the increase of scraping times by changing the thickness of the gaskets. When the bearing cap is fastened, the shaft can be easily rotated without obvious clearances, and the contact points meet the requirement that the scraper is completed.
Measurement of bearing clearance
The size of the bearing clearance can be adjusted by the shim of the middle face, or by direct shaving and shaving. The bearing clearance is usually measured by the method of pressure lead, taking a few sections of lead wire larger than the bearing gap, placing it on the shaft neck and the middle section, then tightening the nut to compress the middle surface, then screwing down the nut, taking the bearing cover and taking out the compressed lead wire carefully, and taking a section to measure the thickness of the micrometer, according to the average thickness of the lead wire. Know the bearing clearance. The general bearing clearance should be 1.5 -2.5 (mm) of the shaft diameter and smaller gap value when larger diameter. If the shaft diameter is 60mm, the bearing clearance should be between 0.09-0.15mm.
2. The assembly of rolling bearing
Rolling bearing has the advantages of small friction, small axial size, convenient replacement and simple maintenance.
(1) technical requirements for assembly
(1) the end face of the rolling bearing marked code should be installed in the visible direction so that it can be checked in replacement.
2. The radius of the arc at the steps of the axle neck or shell should be smaller than the arc radius corresponding to the bearing.
3. Bearing should not be skewed after assembling on axle and shell hole.
(4) in coaxial two bearings, there must be a shaft movement when the shaft expands with heat.
When assembling rolling bearings, we must strictly prevent dirt from entering the bearings.
After assembling, the bearing must be flexible in operation, low in noise, and the working temperature should not exceed 65 degrees.
(2) assembly method
When assembling the bearing, the basic requirement is to make the axial force added directly on the end face of the bearing ring. (when installed on the shaft, the axial force of the added is directly on the inner ring, and the added force should be directly acted on the outer ring when the hole is installed on the hole). Try not to affect the rolling body. The methods of assembly include hammering, press assembling, hot charging and freezing assembling.
(1) hammering
With the hammer on the purple copper rod and some soft material after the hammer, we should pay attention to not make the copper and other foreign objects fall into the bearing raceway, do not directly use the hammer or the punching cylinder to strike the inner and outer ring of the bearing directly, so as to avoid the bearing coordination precision or cause the bearing damage.
The assembly method of screw press or hydraulic press
For larger bearings with larger interference tolerance, screw presses or hydraulic presses can be used. In front of the press, the shaft and the bearing should be leveled, and a little oil is applied to the bearing. The pressure should not be too fast. The pressure should be removed quickly after the bearing is in place to prevent the bearing or shaft from being damaged.
Thermal loading method
The hot charging method is to heat the bearing in oil to 80 -100 C.
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