installation and maintenance Points to Note From the perspective of use, to ensure that the bearing can work reliably, pay attention to the following points: 1. Improve the quality of lubrication, control the pressure, temperature and flow of oil, and strengthen oil filtration. 2. Use fuel and lubricating oil that meet the regulations. 3. It is unfavorable to control the temperature state of the diesel generator set, and it is unfavorable to work under the condition of supercooling and overheating. In cold weather, the diesel engine should be preheated before starting, and the crankshaft should be turned by hand to allow the oil to enter the friction surface. 4. The surface quality and geometry of bearings and journals should be strictly guaranteed. 5. The bearing clearance should be appropriate. If the generator set is too large, it will cause shock. If it is too small, the lubrication will be poor and the tiles may burn. How to ensure the reliable operation of the bearing Generally speaking, from the perspective of use, the following points should be paid attention to: 1. The bearing clearance should be appropriate, if it is too large, it will cause impact, and if it is too small, the lubrication will be poor, and the tile may be burned; 2. The surface quality and geometry of bearings and journals should be strictly guaranteed; 3. Improve lubrication quality, control oil pressure, temperature and flow, and strengthen oil filtration; 4. Use fuel and lubricating oil that meet the requirements.

Bearing action In terms of its function, it should be a support, that is, it is used to bear the shaft in a literal interpretation, but this is only a part of its function. The essence of support is to be able to bear radial loads. It can also be understood that it is used to fix the shaft. Bearing quick and easy automatic selection is included. It is to fix the shaft so that it can only rotate, and control its axial and radial movement. A motor would not work at all without bearings. Because the shaft may move in any direction, and the motor requires that the shaft can only rotate. In theory, it is impossible to achieve the function of transmission. Not only that, the bearing will also affect the transmission. In order to reduce this effect, good lubrication must be achieved on the bearings of the high-speed shaft. Some bearings have already been lubricated themselves, which are called pre-lubricated bearings. Most bearings must have lubricating oil, which is responsible for not only increasing energy consumption due to friction during high-speed operation, but also terrifyingly easily damaging the bearings. The argument to convert sliding friction into rolling friction is one-sided, because there is something called a sliding bearing. lubricating The purpose of lubricating rolling bearings is to reduce internal friction and wear of the bearing, prevent burning and sticking; prolong its service life; discharge friction heat, cooling, prevent bearing overheating, and prevent the aging of the lubricating oil; effect. Lubrication method Bearing lubrication methods are divided into grease lubrication and oil lubrication. In order to make the bearing function well, first of all, it is necessary to select a lubrication method suitable for the conditions of use and the purpose of use. If only lubrication is considered, the lubricity of oil lubrication is dominant. However, grease lubrication has the advantage of simplifying the structure around the bearing. Compare the advantages and disadvantages of grease lubrication and oil lubrication. When lubricating, pay special attention to the amount, whether it is oil lubrication or grease lubrication, if the amount is too small, the lubrication will not fully affect the bearing life, and if the amount is too large, it will cause large resistance and affect the speed.

2. Wear resistance When the bearing is working, not only rolling friction but also sliding friction occurs between the ring, the rolling element and the cage, so that the bearing parts are constantly worn. In order to increase the wear of bearing parts, maintain the accuracy and stability of the bearing, and extend the service life, the bearing steel should have good wear resistance. 3. Hardness Hardness is one of the important qualities of bearing quality, and it has indirect effects on contact fatigue strength, wear resistance, and elastic limit. The hardness of bearing steel under operating conditions should reach HRC61~65, which can enable the bearing to achieve higher contact fatigue strength and wear resistance. 4. Anti-rust performance In order to prevent bearing parts and finished products from being corroded and rusted during processing, storage and use, bearing steel is required to have good rust-proof properties. 5. Processing performance In the production process of bearing parts, many cold and hot working processes are required. In order to meet the requirements of small quantity, high efficiency and high quality, bearing steel should have good processing performance. For example, cold and hot formability, machinability, hardenability, etc. In addition to the above basic requirements, bearing steel should also meet the requirements of proper chemical composition, average external structure, less non-metallic impurities, compliance with specifications for external surface defects, and surface decarburization layers that do not exceed the specified concentration.

Linear Bearings Linear bearings are divided into metal linear bearings and plastic linear bearings. Metal Linear Bushings are low-cost production linear motion systems for use with cylindrical shafts with infinite travel. Since the bearing ball is in point contact with the shaft, the operating load is small. The steel ball rotates with minimal frictional resistance, resulting in a smooth motion with high precision. The plastic linear bearing is a linear motion system with self-lubricating characteristics. The big difference between the metal linear bearing and the metal linear bearing is that the metal linear bearing is rolling friction, and the point contact between the bearing and the cylindrical shaft, so it is suitable for low-load high-speed motion; Plastic linear bearings are sliding friction, and there is surface contact between the bearing and the cylindrical shaft, so this is suitable for high-load, low-speed motion. Bearing material Features of bearing steel: 1. Contact fatigue strength Under the action of periodic load, the contact surface of the bearing is prone to fatigue damage, that is, cracking and spalling, which is an important damage form of the bearing. Therefore, in order to improve the service life of the bearing, the bearing steel must have a high contact fatigue strength. 2. Wear resistance When the bearing is working, not only rolling friction but also sliding friction occurs between the ring, the rolling element and the cage, so that the bearing parts are constantly worn. In order to increase the wear of bearing parts, maintain the accuracy and stability of the bearing, and extend the service life, the bearing steel should have good wear resistance.

Outer spherical ball bearing The outer diameter surface of the outer ring of the outer spherical ball bearing is spherical, which can play the role of self-alignment. Spherical roller bearing Spherical roller bearings have two rows of symmetrical spherical rollers, which mainly bear radial loads, and can also bear axial loads in any direction, but cannot bear pure axial loads. The outer ring raceway of this type of bearing is spherical, so its self-aligning performance is good, and it can compensate for the coaxiality error. When the shaft is bent under force or installed non-concentrically, the bearing can still be used normally. The self-aligning performance varies with the bearing size series. , Generally, the allowable centering angle is 1~2.5 degrees. This type of bearing has a large load capacity. In addition to bearing radial load, the bearing can also bear axial load acting in both directions, and has good impact resistance. Generally, For spherical roller bearings, the allowable working speed is lower. Suitable for working under heavy or vibrating loads. flange bearing Flanged bearings have flanged flanges on the outer wheel. The characteristic is that it can simplify the structure of the main engine, reduce the size of the main engine, and make the bearing easier to locate. Pillow block bearing An assembly of a radial bearing and a seat that has a base plate for mounting screws on a support surface parallel to the bearing axis. Combined bearing A set of rolling bearings composed of the above two or more bearing structures at the same time. Such as needle roller and thrust cylindrical roller combined bearing, needle roller and thrust ball combined bearing, needle roller and angular contact ball combined bearing, etc.

Thrust Roller Bearings Including thrust cylindrical roller bearings, thrust tapered roller bearings, thrust needle roller bearings and thrust spherical roller bearings. Needle Roller Bearings Needle roller bearings are equipped with thin and long rollers (the length of the roller is 3~10 times the diameter, and the diameter is generally not more than 5mm), so the radial structure is compact, and its inner diameter and load capacity are the same as other types of bearings. The diameter Z is small, which is especially suitable for the support structure with limited radial installation size. Needle roller bearings can choose bearings without inner rings or needle roller and cage assemblies according to different applications. At this time, the journal surface and The surface of the housing hole is directly used as the inner and outer rolling surfaces of the bearing. In order to ensure the same load capacity and running performance as the bearing with ring, the hardness, machining accuracy and surface quality of the surface of the shaft or the raceway of the housing hole should be the same as that of the bearing ring. Needle roller bearing is a bearing unit composed of radial needle roller bearing and thrust bearing components. It has a compact structure, small volume, high rotation accuracy, and can bear a certain axial load while bearing a high radial load. And the product structure is diverse, adaptable and easy to install. Combined needle roller bearings are widely used in machine tools, metallurgical machinery, textile machinery and printing machinery and other mechanical equipment, and can make the mechanical system design very compact and flexible.

Angular contact ball bearings It is generally customary to call the six types of bearings represented by 36 and 46 type bearings, and the angular contact is generally 15 degrees, 25 degrees, 45 degrees, etc. Self-aligning ball bearings Self-aligning ball bearings are bearings equipped with spherical balls between the inner ring of two raceways and the outer ring of which the raceways are spherical. The center of curvature of the outer ring raceway surface is consistent with the center of the bearing, so it has the same self-aligning function as the self-aligning ball bearing. When the shaft and housing are deflected, they can be adjusted automatically without increasing the bearing burden. Spherical roller bearings can withstand radial loads and axial loads in two directions. Self-aligning ball bearings have a large radial load capacity and are suitable for heavy loads and shock loads. The inner diameter of the inner ring is a bearing with a tapered bore, which can be directly mounted. Or install it on the cylindrical shaft using an adapter sleeve and a dismantling sleeve. The cage is made of steel stamping cage and polyamide forming. Self-aligning ball bearings are suitable for heavy loads and shock loads, precision instruments, low-noise motors, automobiles, motorcycles, metallurgy, rolling mills, mining, petroleum, paper, cement, press Sugar and other industries and general machinery. Thrust ball bearing Thrust ball bearings are divided into one-way and two-way. They can only carry axial loads and must not carry any radial loads. Thrust bearing is divided into two parts: tight ring and moving ring. The tight ring is tight with the shaft sleeve, and the moving ring is supported on the bearing seat. Rings and rolling elements are usually made of rolling bearing steel with high strength and good wear resistance, and the surface hardness after quenching should reach HRC60-65. The cage is mostly made of mild steel stamping, and can also be made of copper alloy cloth bakelite or plastic. Two-way thrust angular contact ball bearings Double row tapered roller bearings The contact angle of thrust angular contact ball bearings is generally 60°. Commonly used thrust angular contact ball bearings are generally bidirectional thrust angular contact ball bearings, which are mainly used for precision machine tool spindles. It has the advantages of high precision, good rigidity, low temperature rise, high speed, and convenient assembly and disassembly.

Deep groove ball bearings Deep groove ball bearings are representative rolling bearings. Compared with other types of bearings of the same size, this type of bearing has a small friction coefficient, high limit speed, simple structure, low manufacturing cost, high precision, no need for frequent maintenance, and a wide range of sizes and forms. It is a widely used type of bearing. . It mainly bears radial load, but also can bear certain axial load. When it is only subjected to radial load, the contact angle is zero. After the deep groove ball bearing is mounted on the shaft, within the axial clearance range of the bearing, the axial displacement of the shaft or the housing can be limited in two directions, so it can be axially positioned in both directions. When the deep groove ball bearing has a large radial clearance, it has the performance of an angular contact bearing and can bear a large axial load. Under high-speed operation conditions with large axial load, deep groove ball bearings are more advantageous than thrust ball bearings. In addition, this type of bearing also has a certain self-aligning ability. When it is inclined 2' to 10' relative to the housing hole, it can still work normally, but it has a certain impact on the bearing life.

Bearing classification Plain bearing Sliding bearings have neither inner and outer rings nor rolling elements, and are generally made of wear-resistant materials. Commonly used in low speed, light load and mechanical rotating parts that are difficult to lubricate and maintain. spherical plain bearing The sliding contact surface of the spherical plain bearing is spherical, which is mainly suitable for swing motion, tilt motion and rotary motion. rolling bearing Rolling bearings are divided into radial bearings and thrust bearings according to the load direction or nominal contact angle they can bear. The radial contact bearing is a radial bearing with a nominal contact angle of 0, and the radial angular contact bearing is a radial bearing with a nominal contact angle greater than 0 to 45. Axial contact bearings are thrust bearings with a nominal contact angle of 90, and thrust angular contact bearings are thrust bearings with a nominal contact angle greater than 45 but less than 90. According to the shape of the rolling elements, it can be divided into ball bearings and roller bearings. Roller bearings are divided into cylindrical roller bearings, needle roller bearings, tapered roller bearings and spherical roller bearings according to the types of rollers. According to whether it can be self-aligning at work, it can be divided into self-aligning bearings----the raceway is spherical, which can adapt to the angular deviation and angular movement between the two raceway axis lines and non-aligning bearings (rigid bearings) ---- Bearings that can resist the angular deviation of the axis line between the raceways. According to the number of rows of rolling elements, it is divided into single-row bearings, double-row bearings and multi-row bearings. According to whether its parts (rings) can be separated, it can be divided into separable bearings and non-separable bearings. According to its structural shape (if there is no filling groove, with or without the shape of the inner and outer rings and the ferrule, the structure of the rib, and even with or without a cage, etc.), it can also be divided into various structural types. According to its outer diameter, it is divided into miniature bearings (<26mm), small bearings (28-55mm), medium and small bearings (60-115), medium and large bearings (120-190mm), large bearings (200-430mm) and special bearings. Large bearing (>440mm). According to the application field, it is divided into motor bearings, rolling mill bearings, main bearings, etc. According to the material, it is divided into ceramic bearings, plastic bearings, etc.

seal The seal of the bearing can be divided into two types: self-contained seal and external seal. The so-called bearing self-sealing is to manufacture the bearing itself into a device with sealing performance. Such as bearing with dust cover, sealing ring and so on. This kind of seal takes up little space, is easy to install and disassemble, and has a relatively low cost. The so-called bearing plus sealing performance device is a sealing device with various performances manufactured inside the installation end cover, etc. Bearing seals are divided into non-contact seals and contact seals. Among them, the non-contact seal is suitable for high-speed and high-temperature occasions, and has different structural forms such as gap type, labyrinth type and gasket type. Contact seals are suitable for medium and low-speed working conditions, and commonly used structural forms such as felt seals and leather cup seals. According to the working conditions of the bearing and the requirements of the working environment for the degree of sealing, various sealing forms are often used comprehensively in engineering design to achieve a better sealing effect. The following main factors should be considered in the selection of additional seals for bearings: Bearing lubricants and types (grease and oil); The working environment of the bearing and the size of the space occupied; Advantages of shaft support structure, allowable angle deviation; The peripheral speed of the sealing surface; the operating temperature of the bearing; manufacturing cost.