80% Of Bearings Are Damaged Early, Which May be Caused By Incorrect Bearing Installation

80% of bearings fail prematurely because they are not properly installed. The correct installation of bearings can not only increase the service life of bearings, reduce costs, but also greatly improve production efficiency. Therefore, it is urgent to learn the correct bearing installation knowledge.How to install it correctly? We share a valuable bearing installation article for you. As long as you spend a few minutes, you will have a certain understanding of bearing installation and extend the service life of the bearing.Bearings are used to support the parts, but also used to support the rotation of the parts on the shaft, the types of bearings according to the friction properties: sliding bearings and rolling bearings; According to the direction of load: centripetal bearing, push bearing, centripetal thrust bearing, etc.1. Assembly of sliding bearingsSliding bearing is a kind of sliding friction bearing, characterized by stable work, reliable noise, can bear heavy load and large impact load, according to the different structural forms can be divided into integral type, split type and tile type.(1) Assembly of integral sliding bearingsIntegral sliding bearing, commonly known as bushings, is also the simplest form of sliding bearing, mainly using the method of pressing and hammering to assemble, special occasions using hot assembly, most bushings are made of copper or cast iron, assembly should be careful, available wooden hammer or hammer pad wood block strike method assembly, interference size tolerance is large with press into. No matter tapping or pressing must prevent tilt, after assembly, oil tank and oil hole should be in the required position.The bearings deformed after assembly should be trimmed with inner holes. The smaller ones can be reamed, and the larger ones can be scraped. At the same time, pay attention to control the matching gap with the shaft within the tolerance range. In order to prevent the shaft sleeve from rotating when working, the contact surface of the shaft sleeve and the box body is equipped with positioning pin or riding screw. Because the box body and the shaft sleeve material hardness is not the same when drilling, it is easy to make the bit biased towards the soft material side, the solution: one is to drill with the sample before punching hard material side punching, the second is to use a short drill, in order to increase the rigidity of the drill bit when drilling.2 Assembly of split bearingSplit bearing, also known as split bearing, has the characteristics of simple structure, convenient adjustment and disassembly. Two bearing bushes are inlaid on the bearing bush, and gasket is used to adjust the reasonable gap at the joint.① Assembly of bearing bush and bearing bodyThe contact between the upper and lower bearing bush and the bearing body hole must be good. If it does not meet the requirements, the bearing body hole of the thick wall bearing bush is used as the benchmark, and the back of the bearing bush should be scraped. At the same time, the two ends of the bearing bush should be close to the two ends of the bearing body. Thin-wall tile as long as the middle part of the bearing bush is about 0.1mm higher than the middle part of the bearing body, it is not required to be repaired and scraped.② The bearing bush is installed in the bearing body, no matter radial or axial displacement is allowed, usually with the steps at both ends of the bearing bush to stop positioning or positioning pin positioning.③ Bearing bush with scrapingThe open bearing bush is generally used to match the shaft research point, generally is the first to scratch the bearing bush, and then scratch the bearing bush, in order to improve the efficiency of scraping the bearing bush can not be installed on the bearing bush and cover, the contact point of the current bearing bush basically meets the requirements, and then the upper bearing bush and the upper cover pressure, and in the scraping on the bearing bush, further modify the contact point of the bearing bush. The tightness of the shaft can be adjusted with the increase of scraping times by changing the thickness of the gasket. When the bearing cover is tightened, the shaft can easily rotate without obvious clearance, and the contact point meets the requirements that the scraping is completed.(4) Measurement of bearing clearanceThe size of the bearing clearance can be adjusted by the gasket at the middle section, or by directly repairing and scraping the bearing bush. Lead pressure method is usually used to measure the bearing clearance, take several sections of lead wire with diameter greater than the bearing clearance, put it on the journal and the middle part surface, and then tighten the nut to make the middle part surface compressed, and then unscrew the nut, remove the bearing cover, carefully take out the compressed lead wire, each section to make the micrometer measure the thickness, according to the average thickness of the lead wire can know the bearing clearance. The clearance of general bearing should be 1.5‰-2.5‰ (mm) of the shaft diameter, and the smaller clearance value is taken when the diameter is large. If the shaft diameter is 60mm, the bearing clearance should be between 0.09-0.15mm.2. Assembly of rolling bearingsRolling bearings have the advantages of low friction, small axial size, easy replacement and simple maintenance.(1) Technical requirements for assembly(1) The end face of the rolling bearing marked with the code name should be installed in the visible direction, so that the replacement can be checked.② The arc radius at the step of the shaft journal or shell hole should be less than the corresponding arc radius on the bearing.③ After the bearing is assembled on the shaft and the shell hole, there should be no deviation.(4) In the two coaxial bearings, there must be a shaft movement with the thermal expansion of the shaft.⑤ When assembling rolling bearings, it is necessary to strictly prevent dirt from entering the bearing.⑥ After the assembly of bearings, must be flexible operation, low noise, working temperature generally should not exceed 65℃.(2) Assembly methodWhen assembling bearings, the most basic requirement is to make the added axial force directly act on the end face of the bearing ring (installed on the shaft, so that the added axial force directly act on the inner ring, installed on the hole so that the added force directly act on the outer ring). Try not to affect the rolling body. The assembly methods are hammer method, press assembly method, hot assembly method, freezing assembly method and so on.① Hammer methodHammer the copper rod and some soft materials with a hammer, pay attention to do not make copper and other foreign bodies into the bearing raceway, do not directly use a hammer or punching cylinder directly hit the inner and outer ring of the bearing, so as not to affect the bearing matching accuracy or cause bearing damage.Screw press or hydraulic press assembly methodFor bearings with large interference tolerance, they can be assembled by screw press or hydraulic press. Before pressing, the shaft and bearing should be flat and coated with a little lubricating oil. The pressing speed should not be too fast. After the bearing is in place, the pressure should be removed quickly to prevent damage to the bearing or shaft.③ Hot loading methodThe hot loading method is to heat the bearing in the oil to 80℃-100℃, so that the inner hole of the bearing is inflated and then fitted to the shaft, which can prevent the shaft and the bearing from damage. For the bearing with dust cover and seal ring, the interior has been filled with grease is not suitable for hot assembly.(3) The clearance of tapered roller bearing is adjusted after assembly. The main method is gasket adjustment, screw adjustment, nut adjustment, etc.(4) When assembling thrust ball bearings, the tight ring and loose ring should be distinguished first. The inner diameter of the tight ring is slightly smaller. The tight ring after assembly and the shaft are relatively static at work, and it is always leaning on the step or hole end face of the shaft, otherwise the bearing will lose its rolling effect and accelerate wear.3. Instructions for rolling bearingsWhen installing bearings, the force should be uniform and can not be directly hammered. For example, if the interference is large, the bearing should be heated in the air heating furnace or oil furnace with automatic temperature control, and the heating temperature shall be strictly controlled below 120°.Bearings equipped with nylon cage can work continuously and stably at -40°-120° for a long time, and should not work more than 4 hours at 150°, and the transient temperature peak can reach 180°.The warehouse where bearings are stored should be clean, dry and not stored in the same warehouse as chemical products, relative humidity should not exceed 65%, and bearings are not allowed to be stored on the ground.(1) Installation and use of deep groove ball bearingsWhen installing bearings, the force should be uniform and can not be directly hammered. For example, if the interference is large, the bearing should be heated in the air heating furnace or oil furnace with automatic temperature control, and the heating temperature shall be strictly controlled below 120°.Bearings equipped with nylon cage can work continuously and stably at -40°-120° for a long time, and should not work more than 4 hours at 150°, and the transient temperature peak should not exceed 180°.The warehouse where bearings are stored should be clean, dry and not stored in the same warehouse as chemical products, relative humidity should not exceed 65%, and bearings are not allowed to be stored on the ground.Stock bearings should be re-cleaned every other year for rust-proof packaging.(2) Installation and use of angular contact ball bearingsWhen installing bearings, the force should be uniform and can not be directly hammered. For example, if the interference is large, the bearing should be heated in the air heating furnace or oil furnace with automatic temperature control, and the heating temperature shall be strictly controlled below 100°.Bearings equipped with nylon cage can work continuously and stably at -40°-120° for a long time, and should not work more than 4 hours at 150°, and the transient temperature peak can reach 180°.The warehouse where bearings are stored should be clean, dry and not stored in the same warehouse as chemical products, relative humidity should not exceed 65%, and bearings are not allowed to be stored on the ground.(3) Installation and use of self-aligning roller bearingsThe user should choose the appropriate fit and the strong clearance of the bearing according to the use requirements. Please check the bearing code after unpacking.Before bearing installation, if it is necessary to add grease in the bearing, the grease must be clean and appropriate.When installing, it is appropriate not to hammer the end face and roller of the inner and outer ring directly, so as not to crack the inner ring or the middle and small edge. Usually the user should put the bearing into the mineral oil heating to 90°-100° immediately install the spindle. By all means avoid using local spray burning method for bearings, and users should also use special sleeve installation when it is difficult to "hot load".In the use of bearings, there should be good sealing and dustproof device and lubrication, can not break the oil.The bearing warehouse should be clean and dry, without environmental pollution, bearing stacked without landing, packaging without damage. Bearings stored for more than 1 year must be cleaned and oiled again.(4) Installation and use of thrust self-aligning roller bearingsWhen installing bearings, the bearing oil seal should be washed and then coated with clean, high-quality lubricating oil.When installing bearings, the force should be uniform and can not be hammered. If the interference is large, the bearing should be heated to 90°-100° in mineral oil and installed immediately.The warehouse where the bearings are stored shall be clean, clean, and the relative humidity shall not exceed 65%.The stock bearing should be cleaned and oiled once every other year, and the oil seal packaging should be kept well.When using bearings, there should be a good sealing dustproof device, and the work should be checked frequently.(5) Cylindrical roller bearing installation and useThe bearing is a separation type, users can adjust the clearance according to their needs when installing.Before use, the bearings should be cleaned with gasoline or kerosene and keep well lubricated.When the bearing is installed, the bearing should be pressed into the parts, and it is strictly prohibited to knock.The bearing storage place should be clean and ventilated to avoid moisture. The bearing that needs long-term storage should be rust-proof regularly.(6) Installation and use of thrust ball bearingsWhen installing the bearing, the bearing seal should be removed, washed and then coated with clean quality lubricating oil.When installing bearings, the force should be uniform and can not be hammered. If the interference is large, the bearing should be heated to 90°-100° in mineral oil and installed immediately.The warehouse where the bearings are stored shall be clean, clean, and the relative humidity shall not exceed 65%.The stock bearing should be cleaned and oiled once every other year, and the oil seal packaging should be kept well.When using bearings, there should be a good sealing dustproof device, and the work should be checked frequently.