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The assembly of slide bearings

Slide bearing is a kind of sliding friction bearing, which is characterized by stable operation, reliable and low noise, and can withstand heavy loads and large impact loads. According to the different structural forms, it can be divided into integral type, split type and tile type.


(1) Assembly of integral slide bearing


Integral slide bearings are commonly known as bushings, and they are also the simplest form of slide bearings. They are mainly assembled by pressing and hammering. In special occasions, hot mounting is used. Most bushings are made of copper or cast iron. You should be careful, and you can use a wooden hammer or hammer to assemble the block. When the interference size tolerance is large, use a press to press in. Whether it is knocked or pressed, it must be prevented from tilting. After assembly, the oil groove and oil hole should be in the required position.


Bearings deformed after assembly should be trimmed. Smaller sizes can be cut by reaming, and larger ones can be scraped. At the same time, pay attention to control the matching clearance with the shaft within the tolerance range. In order to prevent the shaft sleeve from rotating when it is working, the contact surface of the shaft sleeve and the box body is equipped with positioning pins or seam screws. Because the hardness of the box body and the shaft sleeve are different when drilling, it is easy to deflect the drill bit to the side of the soft material. The solution: one is to punch the hard material with a sample before drilling, and the other is to use a short drill to increase the drilling. The rigidity of the drill bit when making a hole.


(2) Assembly of split bearings


Split bearings, also called split bearings, have the characteristics of simple structure and convenient adjustment and disassembly. Two bushes are set on the bushes, and a gasket is used at the joint to adjust a reasonable gap.


①Assembly of bearing bush and bearing body

The upper and lower bearing shells must be in good contact with the inner hole of the bearing body. If it does not meet the requirements, take the inner hole of the thick-walled bearing shell as the reference, and scratch the back of the bearing shell. At the same time, the steps of the two ends of the bearing shell should be close to the two ends of the bearing body. Thin-walled bushes only need to make the middle parting surface of the bearing bush higher than the middle parting surface of the bearing body by about 0.1mm, without scraping.


② The bearing bush is installed in the bearing body, no displacement is allowed in the radial or axial direction. The steps at both ends of the bearing bush are usually used to stop the positioning or locate the positioning pin.


③Scraping of bearing bush

Split bearing shells generally use matching shaft grinding points. Generally, the bearing shells are scraped off first, and then the bearing shells are scraped. In order to improve efficiency, the bearing shells and covers need not be installed when the bearing shells are scraped. The contact points of the current bearing shells are basically When the requirements are met, the upper bearing bush and the upper cover are pressed tightly, and the contact point of the lower bearing bush is further corrected when the upper bearing bush is scraped. The tightness of the shaft can be adjusted by changing the thickness of the gasket with the increase of the number of scraping. When the bearing cover is tightened, the shaft can easily rotate without obvious gap, and the scraping is completed when the contact point meets the requirements.


④Measurement of bearing clearance

The size of the bearing gap can be adjusted by the gasket at the center dividing surface, or it can be obtained by directly scraping the bearing bush. The lead pressure method is usually used to measure the bearing gap. Take a few pieces of lead wire with a diameter larger than the bearing gap and place them on the journal and the center dividing surface. Then tighten the nut to compress the center dividing surface. Then unscrew the nut and remove the bearing cap. Take out the flattened lead wire and measure the thickness with a micrometer for each section. The bearing clearance can be known according to the average thickness of the lead wire. Generally, the clearance of the bearing should be 1.5‰-2.5‰ (mm) of the shaft diameter. The smaller the clearance value is when the diameter is larger. If the shaft diameter is 60mm, the bearing clearance should be between 0.09-0.15mm.