SKF angular contact ball bearing assembly with bearing features
SKF bearing set angular contact ball bearings are paired and multi-group angular contact ball bearings, mainly used in machine tools as well as precision instruments, high-speed centrifuges, compressors, high-frequency or large vertical motors and rolling mills.
SKF bearing assembly bearings can withstand radial and axial combined loads, which are mainly radial loads, and can also withstand pure radial loads. Depending on the application, the assembled bearings are usually divided into two types: general bearings and precision bearings. Precision bearings are representative of the type of bearings. Since precision bearings are mainly used for machine tool spindles, they are also called spindle bearings. The assembled bearing is a single-row angular contact ball bearing of the same specification and is constructed in different combinations.
What is the role of bearing lubrication?
First, the role of bearing lubrication
Lubrication has an important influence on the fatigue life of rolling bearings and friction, wear, temperature, vibration, etc. Without normal lubrication, the bearings cannot work. Analysis of the cause of bearing damage indicates that about 40% of bearing damage is associated with poor lubrication. Therefore, good lubrication of the bearings is an effective measure to reduce bearing friction and wear. In addition, the lubrication of the bearing also has various functions such as heat dissipation, rust prevention, sealing, and shock mitigation. The role of bearing lubrication can be briefly explained as follows:
a. Forming an oil film between the two rolling surfaces or sliding surfaces that contact each other to separate the two surfaces, reducing friction and wear on the contact surfaces.
b. When using oil lubrication, especially when using circulating oil lubrication, oil mist lubrication and fuel injection lubrication, the lubricating oil can take away most of the friction heat inside the bearing and effectively dissipate heat.
c. When grease lubrication is used, foreign matter such as dust can be prevented from entering the bearing and sealing.
d. Lubricants have the effect of preventing metal corrosion. e. Extend the fatigue life of the bearing.
Second, the comparison of grease lubrication and oil lubrication
The lubrication method of the bearing is roughly divided into two types: grease lubrication and oil lubrication. In order to fully utilize the function of the bearing, it is important to use a lubrication method depending on the purpose of use reduction and use. Table 4-2 shows the advantages and disadvantages of grease lubrication and oil lubrication. Third, grease lubrication Grease is a lubricant composed of base oil, thickener and additives. When selecting, you should choose a grease that is very suitable for the conditions of use of the bearing. Due to the different trademarks, there will be great differences in performance, so you must pay attention when choosing.
Commonly used greases for bearings include calcium-based greases, sodium-based greases, calcium-sodium-based greases, lithium-based greases, aluminum-based greases, and molybdenum disulfide greases.
The amount of grease filled in the bearing is preferably 1/2-1/3 of the internal space of the bearing. It should be reduced to 1/3 at high speed. Excessive grease will increase the temperature rise. 4. Selection of grease When selecting grease according to working temperature, the main indicators should be dropping point, oxidation stability and low temperature performance. The dropping point can generally be used to evaluate high temperature performance. The actual working temperature of the bearing should be lower than the dropping point of 10-20 °C. . Synthetic grease should be used at a temperature below the drop point of 20-30 °C.
When selecting the grease according to the bearing load, the grease with a small penetration should be selected for the heavy load. When working under high pressure, in addition to the small penetration, it also has higher oil film strength and extreme pressure performance.
INA bearing repair and maintenance considerations
Rolling INA bearings are precision components and should be used with great care. Even high quality INA bearings, if not used properly, will not achieve the desired results.
The precautions for the use of INA bearings are as follows.
Keep the INA bearing and its surroundings clean
Even tiny dust that is invisible to the naked eye can have an adverse effect on the INA bearing. Therefore, keep the area clean so that dust does not intrude into the INA bearing.
Use with care.
In the use of the INA bearing strong impact, it will produce scratches or indentations, causing accidents. In severe cases, it will cause cracks and breaks and must be taken care of.
Use INA bearing special tools.
Special tools must be used and cannot be replaced.
Avoid rusting the INA bearing.
When operating an INA bearing, hand sweat can cause rust. Be careful to use clean hands, try to wear gloves and pay attention to corrosive gases.
2. Installation
Whether the INA bearing is installed correctly or not directly affects the accuracy, life and performance of the bearing. Therefore, the design and assembly department should fully study the installation of INA bearings and follow the operating standards. The job standard items are usually as follows:
Cleaning INA bearings and related components
Check the size and accuracy of related parts
installation
INA bearing inspection after installation
Filling lubricant
I hope to open the INA bearing package again during installation. Generally, when the grease is lubricated, the bearing is not cleaned and the grease is directly filled. When lubricating oil, it is generally not necessary to clean. However, for instruments or high-speed INA bearings, clean the oil and remove the rust inhibitor applied to the INA bearing. The INA bearing with the rust preventive removed is easy to rust, so it cannot be placed at will.
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Analysis of Abnormal Phenomenon Caused by FAG Bearings
One: FAG bearing grease rheology:
1. When the grease is not subjected to external force, it can maintain a certain shape like a solid, that is, it will not automatically lose when it is at rest.
2. In the case of extremely high shear stress (high shear rate), the grease flows like a Newtonian fluid, and the viscosity can be kept constant without changing with the shear rate.
3. When subjected to weak external force, elastic deformation occurs; after removing the external force, it can return to its original position and shape, exhibiting the elastic properties of the solid.
4. When the applied external force is large enough, the grease deforms and flows, and thus can no longer automatically return to the original position and shape, so the starting torque of the grease on the mechanically moving part is larger than that of the liquid lubricating oil.
Two: FAG bearing grease defects:
1. Grease is semi-solid and does not flow at normal temperature, so it is difficult to add grease or change grease on friction parts. FAG bearing cleaning is not very convenient.
2. The stirring resistance is large, so the heat generation is large and the cooling effect is poor. However, it should be noted here that this has a close relationship with the lubrication method. If the lubricating oil is lubricated with a fully immersed (or semi-immersed) oil bath, the grease will consume less power than the oil. For example, the British Journal of Friction and Lubrication reported in 1973, 6th issue: With a rolling FAG bearing with a diameter of 100, the speed is 1500r/min, and it is lubricated with grease. There are many examples of energy consumption in China, such as the refractory plant of Chongqing Iron and Steel Company. The motor power of the refractory tunnel kiln induced draft fan is grease compared to the N68 lubricant. The FAG bearing temperature is 4~6 °C lower.
3. The base oil is the carrier of the additive, and the additive does not function if the base oil fails.
4. Due to the mechanical action, the lubricating base filled in the FAG bearing configuration will gradually lose its lubricating properties. Therefore, the grease needs to be continuously replenished and updated. The interval between lubricant replenishment varies depending on the formation, size, and rotational speed of the FAG bearing, and the approximate interval of replenishment of the grease is required depending on the operation time.
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SKF imported bearings with good grease or oil choice
Imported bearings have both friction and sliding friction. Sliding friction is caused by the deviation of the inlet bearing on the surface curve and the deformation of the inlet bearing under load. For example, between the body and the ring, since the ball and the ring are not absolutely rigid bodies, their contact areas always have elastic deformation, which is theoretically point contact or line contact, but in fact the working conditions under load always become surface contact. Therefore, contact points having different diameters have different linear velocities to generate sliding friction. Sliding friction is also created between the body and the retainer as well as the retainer and the inner and outer rings for a variety of different reasons. The sliding friction increases with the increase of speed and load. In order to reduce friction, wear, reduce temperature and noise, prevent the rust of the components of the imported bearings, properly select the lubricant and use reasonable lubrication to properly control the lubricant. Quantity is an important issue to improve the life of imported bearings.
1. The basis of imported bearings for oil or grease:
The advantages of using imported lubricants for imported bearings are:
1) Under certain operating specifications, the starting torque and friction loss of lubricating oil is significantly smaller than that of lubricating grease.
2) Since the lubricating oil takes away the heat in the circulation to cool, the imported bearing can reach a relatively high rotational speed.
3) It can guarantee a relatively high operating temperature.
4) When changing the grease, the relevant connecting parts must be disassembled, and when it is lubricated with oil, there is no such trouble.
5) When the inlet bearing in the reduction gearbox is lubricated with lubricating oil, it is suitable because the oil simultaneously achieves the purpose of lubricating the gear and the imported bearing at the same time.
6) In the imported bearings, the grease is gradually contaminated by the products worn by the product, the abrasives, the products penetrated from the outside through the sealing device and the products that are aging by themselves. If not replaced in time, the imported bearings are accelerated and worn, and when the liquid lubricant is applied It can be filtered to ensure its normal operation.
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The reason why SKF bearings stimulate the sound
Many users have encountered many problems in the use of SKF bearings. Many problems have arisen in the use of SKF bearings. The general mechanical enterprise staff understand the knowledge of SKF bearings, know how to maintain the bearings, and pay attention to the use of the bearing process. Everything is clear, some newcomers don't understand, just know that simply watching the machine running, today we will introduce a phenomenon that the SKF bearing in the machine will be excited, what is the reason?
1. Vibration behavior in applications
In many applications, the stiffness of an SKF bearing is the same as the stiffness of the surrounding structure. Due to this feature, it is possible to reduce the vibration in the application by properly selecting the SKF bearings (including preload and clearance) and their configuration in the application.
2. The waviness of SKF bearing components
In the case of a tight fit between the SKF bearing ring and the SKF bearing housing or the drive shaft, the SKF bearing ring may be deformed in accordance with the shape of the adjacent component. If deformation occurs, vibration may occur during operation. Therefore, it is important to machine the SKF housing and drive shaft to the required tolerances.
3. Excitation caused by the change in the number of loaded rolling elements
When a radial load is applied to a SKF bearing, the number of rolling elements carrying the load changes slightly during operation, ie this causes a shift in the load direction. The resulting vibration is unavoidable, but can be mitigated by axial preloading and applied to all rolling elements (not suitable for cylindrical roller SKF bearings).
4, local damage
Small parts of SKF bearing raceways and rolling elements may be damaged due to handling or installation errors. In operation, rolling through damaged SKF bearing components produces a specific vibration frequency. Vibration frequency analysis identifies damaged SKF bearing components.
A small way to solve the vibration of SKF bearings:
There are three ways to reduce vibration:
1. Remove critical excitation vibration from the application;
2. suppressing the critical excitation vibration between the excitation component and the resonance component;
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Talking about the Application of Magnetic Bearings on the High Speed Spindle of Machine Tools
The magnetic bearing can be used on the high-speed spindle to obtain 100,000 rpm. On the one hand, it can improve the surface processing effect, on the other hand, its service life is far greater than that of the conventional bearing. Although this technology is still in the prototype test stage, many advantages have been fully reflected. Its performance is not affected by thermal effects, no wear and tear, and can be automatically shut down in case of overload.
Conventional bearings provide radial or axial support to the main shaft, allowing relative movement between the inner and outer rings. The inner ring and the outer ring are connected by balls or rollers, and the supporting force is also transmitted between the three. Oil film bearings have no balls or rollers and are lubricated or dissipated with pressurized oil. Both of these bearings have been used for hundreds of years. Magnetic bearings support the rotating parts differently than the above two products.
A magnetic bearing is a non-contact bearing that suspends a rotating component between fixed components by electromagnetic force. This means no friction, no wear, and higher stability, and higher speeds can be achieved. The electromagnetic force is mainly related to the current and the size of the gas gap. The sensor collects the data of the gap size, and the control system adjusts the current output according to the input signal.
The magnetic bearing is mainly composed of three parts:
Bearings and sensors: Bearings provide support to the spindle and sensors are responsible for collecting position signals.
Control system: responsible for providing power and calculating the correct corrective force based on the feedback signal to drive the controller in different directions.
Software system: responsible for calculating and outputting feedback signals.
The main disadvantages of magnetic bearings are: they are bulky, require power, and complex structures and algorithms.
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Some methods for reducing the bearing temperature of horizontal hydro-generator sets
1 Power station overview
Guangdong Gezhou Cang Hydropower Plant is a run-of-river power station with a rain collection area of 39.6km2 and an installed capacity of 2800kW, one of which is 800kW and the other is 2000kW. The turbine models are: HLA218-WJ-60 and HL160-WJ-71; the generator models are: SFW800-6/1180 and SFW2000-6/1430. The two hydro-generator units are products of Chongqing Turbine Works. They are two-point structure. The thrust bearing is located on the side of the permanent magnet machine, which changes the traditional setting, that is, the thrust bearing is between the generator and the turbine. Both units were put into operation in September 1991. Until the seven months of January 1998, the bearings of the unit were in an ultra-high temperature operation, sometimes as high as 73 ° C, and forced to stop, which has caused burnt accidents many times. After numerous treatments by our technicians, engineers of the Bureau and neighboring brothers, it still has little effect. Later, after the participation of the engineer and author of the factory, Wang Shouzhong, the bearing circulation oil circuit and the cooling system were transformed, and the temperature was significantly reduced, which was a complete success.
2 existing defects
In the past maintenance process, we strictly deal with the levelness, concentricity, smoothness and sanding of the main shaft in accordance with the requirements of the factory and relevant regulations. The water quality and water pressure of the cooling water are also in line with the standard, but the temperature is not lowered. Finally, in December 1997, the engineer Wang Shouzhong came to the site to instruct and inspect, and found that there are some problems in the internal design of the main thrust bearing: 1. The cooler capacity is too small to take away a large amount of the bearing inside. The residual heat causes the temperature to rise. 2. The verticality of the main mirror plate of the thrust plate is not enough, and one of the units is mainly caused by the looseness of the thrust head. Some places are 0.5mm higher, and some places are depressed by 0.15mm, causing some places on the thrust tile surface to be overstressed, and some places are not stressed at all, so that the temperature of the force surface is frictional after a certain period of operation. The temperature gradually rises, eventually leading to a burnt tile accident. 3. The thrust bearing is not specially equipped with a cooling oil pump. The circulation of the cooling oil mainly relies on the high-speed rotation of the smooth and complete thrust ball to bring a part of the cold oil, which fails to produce the effect of temperature reduction. 4. The oil inlet holes of the upper and lower bearing bushes are too small, so that the circulation of the cold oil is greatly hindered, so it cannot reduce the temperature.
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How to repair worn fan IKO bearings
Faulty fans and IKO bearings are not unrepairable. I will introduce a repair method now. The material is very simple, just a small piece of cans of aluminum and a little bit of butter (the butter should be clean and free of impurities).
1. First clean the dust on the fan to avoid dust from entering the IKO bearing during the installation process;
2. Remove the IKO bearing seal sticker and remove the bayonet pin on the shaft;
3. Wipe the residual oil in the IKO bearing with a clean tissue or a soft cloth, and then wipe the shaft clean;
4. Add a little butter to the IKO bearing. The principle is to keep it from being too much to avoid seriously affecting the speed;
5. Cut the aluminum skin of the can to cut a disc as large as the outer diameter of the IKO bearing, and dig a small hole in the middle that can pass through the shaft and place it between the IKO bearing and the bayonet. , to reduce the distance of the IKO bearing axial movement and parallel movement. If the gap is large, it is necessary to put a few thickening on the pad to make the IKO bearing's front and rear moving distance below 0.5mm;
6. Seal the oil seal, add a little butter, and finally put the fan back into the graphics card. Try connecting the power, you will find that the sound is much smaller, and this can be used for at least 2 years. But need to be reminded, although the sound is a little smaller, but because of the limited manual accuracy, the speed will drop a little.
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Notes on regular maintenance of TIMKEN bearings
When inspecting TIMKEN bearings that have been removed during regular inspection and operation of TIMKEN bearing equipment and replacement of peripheral parts, it is necessary to judge whether the TIMKEN bearing parts can be reused and recorded in good or bad. It is also necessary to carefully investigate and record the TIMKEN bearings and appearance that have been removed. In order to clarify and investigate the remaining amount of lubricant, after sampling, the TIMKEN bearing should be cleaned well.
Next, check the raceway surface of the TIMKEN bearing, the condition of the rolling surface and the mating surface, and the wear state of the cage, etc., for damage and abnormality, especially to observe the running track of the raceway surface. To determine whether the TIMKEN bearing can be used again, it is necessary to consider the degree of damage to the TIMKEN bearing, the machine performance, importance, operating conditions, inspection cycle, etc.
If the TIMKEN bearing is found to be damaged or abnormal, please find out the cause according to the TIMKEN bearing damage phenomenon and formulate countermeasures. In addition, the inspection results, if there are the following defects, TIMKEN bearings can no longer be used, need to replace the new TIMKEN bearings.
a. Cracks and fragments appear in any of the inner and outer rings, rolling elements, and cages.
b. Any one of the inner and outer rings and the rolling elements are peeled off.
c. The raceway surface, the ribs, and the rolling elements have significant jamming.
d. The cage is worn out or the rivets are loose.
e. The raceway surface, rolling elements are rusted and flawed.
f. There are significant indentations and marks on the rolling surface and the rolling elements.
g. There is creep on the inner diameter surface of the inner ring or the outer diameter of the outer ring.
h. Superheated and discolored.
i. Grease seal TIMKEN bearing seals and dust caps are damaged.
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How to properly handle NSK imported bearings
Due to the high precision mechanical parts of the rolling bearings, they must be handled accordingly. Even if the use of high-quality NSK bearings is not properly handled, its expected benefits will not be realized.
The main precautions should be observed as follows:
Keep NSK imported bearings and surrounding areas clean
Dust and dirt, even if the eyes are invisible to the naked eye, have a detrimental effect on the bearing. To prevent dust and dirt from bearing and keep its environment clean as an entry point.
Handle with care
Handling heavy impacts can cause bearings to be scratched or damaged and can cause their failure. Too strong impact can cause damage or cracks.
Use the right tools
Always use appropriate equipment to handle NSK bearings and avoid general purpose tools.
Corrosion protection
Due to the sweat of hands and other various contaminants, it may cause corrosion, keep hands clean, and then handle NSK bearings. Wear gloves if possible. Pay attention to the corrosive gas of the rustproof bearing.
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Self-lubricating bearing applications
1. SF-2 Boundary Lubrication Bearing: Acidic polymethyl aldehyde with high wear resistance. The bearing surface has a regular arrangement. The oil storage pit must be coated with grease when it is assembled. It is especially suitable for high load and low speed. The following rotary motion, rocking motion and the part that is often under load and open and closed are not easy to form fluid lubrication. Under boundary lubrication conditions, it can be used for a long time without oiling and maintenance, and the process can be used to increase the service life of the bearing. More extension, currently applicable to metallurgical machinery, mining machinery, hydraulic machinery, auto parts, construction machinery, agricultural machinery.
2. Oil-free self-lubricating bearing: The product is made of steel plate as the base, the middle layer is sintered with spherical bronze powder, and the surface layer is rolled with a mixture of polytetrafluoroethylene [ptfe] and lead. It has the characteristics of small friction coefficient, wear resistance and corrosion resistance, oil-free self-lubrication and long service life. It can reduce cost, reduce noise and prevent sticking and slipping. It is widely used in various mechanical sliding parts such as printing machines, textile machines, hydraulic pallet trucks, tobacco machines, medical machinery, fitness equipment, micro-motors, automobiles, motorcycles, etc.
3. Metal-based inlaid solid self-lubricating bearing: It is a novel lubricated bearing that combines the characteristics of metal bearing and the characteristics of self-lubricating bearing. The metal matrix bears the load, and the specially formulated solid lubricating material acts as a lubrication. It has the characteristics of high bearing capacity, impact resistance, high temperature resistance and strong self-lubricating ability.
4, the traditional oil-bearing bearing: due to the advantages of low hum and self-lubrication, oil-bearing bearings have become the new darling of computer CPU fan bearings, the market demand is large; in addition, as people's requirements for voices are getting higher and higher, oily The use of bearings in everyday household appliances is also expanding.
Causes and prevention methods of corrosion of imported bearings
Causes and Prevention of Corrosion of Imported Bearings Corrosion of imported bearings is caused by various internal and external factors. The main ones are:
1, metal surface finish (oxygen concentration difference battery corrosion).
2. The chemical composition and structure of the metal material itself.
3. The composition of the solution and the pH value in contact with the metal surface;
4. Ambient temperature and humidity.
5. Various environmental media in contact with the metal surface.
6, other people's sweat is also the cause of bearing corrosion, its pH is 5 ~ 6. Therefore, in order to prevent rust caused by hand sweat, the installation and production personnel should wear gloves, do not touch the imported bearings by hand.
Apply anti-rust oil to prevent skf bearing from rusting
1. Immersion method: Some small imported bearings are immersed in anti-rust grease. The thickness of the oil film can be achieved by controlling the temperature or viscosity of the anti-rust grease. A method of adhering a layer of rust preventive grease to the surface.
2, brushing method: pay attention to evenly spread on the surface of the imported bearing when brushing, do not produce accumulation, but also pay attention to prevent leakage coating.
3. Spray method: Some large-scale anti-rust materials are not suitable for oiling by immersion method. Generally, the compressed air with a pressure of about 0.7Mpa is sprayed in the air cleaning place. The spray method is suitable for solvent-diluted rust preventive oil or thin layer rust preventive oil. This method must use sound fire protection and labor protection measures.
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Repair method of roller bearing
The lubricant inside the roller bearing can be roughly divided into oil and grease. Basically, most of the lubricants used in the production of SKATE are grease lubricants, and some of the products on the market are made of oil as a lubricant.
Repair method
· Preparation: Dry towel, sharp tongs, bearing cleaning night, bearing lubricant or grease.
a. Remove the C-ring and shroud: Wipe the dirt off the bearing with a dry towel, then use a pointed plier to lift the side of the C-ring and remove the C-ring and shroud.
b. Bearing cleaning fluid: soak the bearing in the bearing cleaning fluid bought on the market, and shake it at this time, the foreign matter inside the bearing will be shaken out, and some supermarkets buy ultrasonic cleaning machine is also very helpful in removing foreign matter. .
c. Drying: Remove the bearing from the cleaning solution, wipe the cleaning solution with a dry towel, and dry in a cool place.
d. Inject the lubricant according to the trend to inject grease or oil into the bearing, cover the shroud and reattach the C-ring.
e. Detection: Perform several rotations after grasping the inner ring with the fingers that have been assembled into the original state.
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Common quality defects of bearing parts after heat treatment
Common quality defects of bearing parts after heat treatment include: quenching microstructure overheating, underheating, quenching cracks, insufficient hardness, heat treatment deformation, surface decarburization, soft spots, etc.
Overheat
The microstructure after quenching can be observed from the rough mouth of the bearing part, but the microstructure must be observed to determine the degree of overheating. If coarse needle-shaped martensite appears in the quenched structure of gcr15 steel, it is quenched and superheated. The formation may be caused by excessive overheating of the quenching heating temperature or excessive heating and holding time; or it may be due to the serious banding of the original structure, forming a local martensite needle-like coarseness in the low carbon zone between the two zones. Local overheating caused. The retained austenite increases in the superheated structure, and the dimensional stability decreases. Due to the overheating of the quenched structure, the coarse crystal of the steel causes the toughness of the part to decrease, the impact resistance is lowered, and the life of the bearing is also lowered. Excessive heat can even cause quenching cracks.
2. Underheat
If the quenching temperature is low or the cooling is poor, the tortite structure exceeding the standard is formed in the microstructure, which is called the underheated structure, which lowers the hardness and sharply reduces the wear resistance, which affects the bearing life.
3. Quenching crack
The crack formed by the internal stress of the bearing part during the quenching and cooling process is called quenching crack. The causes of such cracks are: due to excessive heating temperature of quenching or too rapid cooling, the microstructure stress when the thermal stress and metal mass volume change is greater than the fracture strength of the steel; the original defects of the working surface (such as surface micro cracks or scratches) Trace) or steel internal defects (such as slag inclusions, severe non-metallic inclusions, white spots, shrinkage residuals, etc.) form stress concentration during quenching; severe surface decarburization and carbide segregation; insufficient tempering after quenching of parts Or not tempered in time; the cold punching stress caused by the previous process is too large, forging and folding, deep turning tool marks, sharp edges and corners of the oil groove. In short, the cause of quenching crack may be one or more of the above factors, and the existence of internal stress is the main reason for the formation of quenching cracks. The quenching crack is deep and slender, the fracture is straight, and the fractured surface has no oxidation color. It tends to be a longitudinal straight crack or annular crack on the bearing ring; the shape on the bearing steel ball is s-shaped, t-shaped or ring-shaped. The microstructure of the quenching crack is that there is no decarburization on both sides of the crack, and the difference is obvious with forging cracks and material cracks.
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Detailed explanation: maintenance, cleaning and overhaul of bearings
Bearing maintenance
Rolling bearings are a wide range of important mechanical basic components that are widely used in various fields of the national economy and national defense. The mechanical and working environment in which rolling bearings are used varies widely, so special attention should be paid to the maintenance of the bearings and the service life of the bearings. Bearing Installation Rolling bearings are precision parts that are of high precision and, if not properly installed, will lose their precision and performance and, in severe cases, cause bearing failure. Therefore, the site where the bearings are mounted and the installation tools must be cleaned to prevent various particulates from being carried inside the bearings. When installing and disassembling the bearing, it should not be directly hammered. Uniform pressure should be applied. When the shaft and the bearing are engaged with a large interference, the bearing should be installed immediately after heating.
Anti-rust of bearing products
The bearing is a precision mechanical part. From the factory to the long-term circulation. In order to prevent the bearing from rusting during transportation or storage under various environmental conditions, it must be rust-proofed. According to the national GB/TS597 standard. The rust prevention period of the bearing is half a year. Generally, the anti-rust period of the bearing is one year, and the anti-rust period of the bushing with higher requirements for use is two years. Bearings cannot be used during rust prevention for a variety of reasons. When the bearing rust prevention period is reached, the original rust inhibitor should be removed.
Bearing packaging
Since the bearings are precision parts and there are many circulation links, the products are easily damaged by environmental conditions such as snow, dust, temperature, corrosive substances during these circulation processes. Therefore, the bearing packaging is required to have multiple performances, such as shockproof, moisture-proof, anti-collision, anti-corrosion, and pressure resistance.
Bearing storage
No leakage of rain should be allowed in the warehouse. The bearing storage position should be protected from direct sunlight. The indoor air should be circulated, but there should be no dust. Ventilation and temperature control equipment should be installed in the warehouse. The warehouse should be kept dry, the relative temperature should be controlled below 80%, the indoor temperature should be controlled at 25 degrees, and there should be no large temperature changes during the day and night. When the temperature is too low, the rusting agent is easy to crystallize and crack, resulting in rusting of some metal exposed. The temperature is too high, the rusting agent is easily lost (evaporated) or deteriorated, and the temperature difference between day and night is likely to cause moisture to condense on the bearing surface to cause rust. For winter seasons, the bearing storage location should not be close to the heating. The ground in the warehouse should be hard and not easy to get dust on the ground. Bearings must not be stored in a warehouse with corrosive materials such as acids, alkalis, and salts, chemical raw materials, and large materials. It is not easy to invade harmful gases around the warehouse where the bearings are stored.
Bushing transport
Improper transportation of the eclipse is the most likely to cause loss to the bearing, such as fretting wear, rust, smashing, indentation, etc., the most unloading can even lead to cracks in the bearing and directly fail. Therefore, special attention should be paid to the transportation quality of the transportation link to avoid unnecessary damage to the bushing. The bearing transporter should be placed horizontally and the pressure should not be applied to the outer diameter of the bearing to prevent deformation of the bushing. When the transport tools are placed on the pallet, the distance between the boxes should be as close as possible to reduce the impact and vibration caused by the shaking during transportation.
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Vibration motor imported bearing installation skills
When the imported bearing replaces the vibration motor, the effect is different, and the same bearing as the original model must be used, and the effect in this aspect has a better meaning, so that it can be used in this respect. Reflects better results. First introduce the installation of imported bearings from the following situations.
When replacing a new bearing with a vibrating motor, the same bearing as the original model must be used.
1) Wash the bearing with kerosene, press it into the bearing seat, fill the roller of the outer ring of the bearing with Shell No. 3 lithium base grease to two-thirds full, apply evenly with the net hand, install the bearing gland, and apply the bolt The fastening bolt of the anti-loosening rubber presses the bearing gland;
2) The bearing is a cylindrical roller bearing with a detachable inner casing. The bearing should be placed on the rotating shaft and placed in place;
3) Mount the bearing housing on the casing. If there is grease grease hole, it must be aligned. Pressing the bearing block with the fastening bolts of the anti-loosening rubber;
4) The inner and outer eccentric blocks are mounted on the rotating shaft and are in place. If there is an axis key, the shaft key should be inserted into the keyway and then the outer eccentric block should be installed, and the shaft can be mounted on the rotating shaft with the retaining ring;
5) Tightly fix the eccentric block fastening bolts and turn the adjustable eccentric block to the angular position before the unloading and tighten the fastening bolts. After the above assembly is completed, the shaft should have a certain axial movement;
6) The protective cover on both ends of the upper vibration motor is fastened with screws.
The imported bearings have certain changes to the installation form of the vibration motor and other aspects of the performance, and the form considered from different angles has a certain change effect, and slowly the installation situation of all aspects has also been I understand it.
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How to properly install the thrust bearing
The thrust bearing is to be inspected after installation. When installing the thrust bearing, first check the verticality of the shaft ring and the centerline of the shaft. The test method is: fix the dial gauge on the end surface of the casing, so that the contact of the watch top rotates the bearing on the bearing shaft raceway, and then observe the dial gauge pointer. If the shaft ring and the shaft center line are not perpendicular, then the pointer Hemiplegia. The pointer of the dial gauge has a relatively long length. If the box hole is deep, you can also choose to use the extended dial gauge for inspection.
The seat ring can automatically adapt to the rolling of the rolling elements, ensuring that the rolling elements are located in the upper and lower ring raceways, indicating that the thrust bearings are installed correctly. If the thrust bearing is reversed, if this happens. The bearings are not working properly and the mating surfaces of the bearings are subject to severe wear. The difference between the shaft ring and the seat ring is not very obvious, so care should be taken in the assembly. Moreover, there should be a gap of 0.2-0.5mm between the seat ring of the thrust bearing and the bearing seat hole. This gap is used to compensate for the error caused by inaccurate machining and installation. If there is an accident, the bearing sleeve is in operation. When the center of the circle is offset, this gap can make a big difference, ensuring that it automatically adjusts to avoid contact friction and keep the bearing running normally. If there is no such gap, it will cause severe damage to the bearing. The bearing is damaged and cannot be used.
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SKF imported bearings need to pay attention to when choosing
Core Tip: Bearing types, types and sizes vary. In order to make the mechanical equipment perform as expected, it is crucial to choose the most suitable SKF bearing. Selected bearings need to be analyzed a lot
Bearing types, types and sizes vary. In order to make the mechanical equipment perform as expected, it is crucial to choose the most suitable SKF bearing.
The selection of bearings that require analysis is due in many ways, from research, evaluation procedures, to bearings with special specifications, but usually in the following order:
(1) Master the conditions of use of mechanical devices and SKF bearings
(2) Clear requirements for bearings
(3) Type of selected bearing
(4) Selected bearing configuration
(5) Selection of bearing size
(6) Selected bearing size
(7) Method of installing selected bearings
Bearings using conditions and environmental conditions
Under the premise of correct use and the conditions of the mechanical equipment and the SKF bearing area used under the environmental conditions, select the appropriate bearing. Who, to get the following data and information:
(1) Function and structure of mechanical equipment
(2) Site use of SKF bearings
(3) Bearing load (size, direction)
(4) Rotation speed
(5) Vibration, shock
(6) Bearing temperature (ambient temperature, temperature rise)
(7) Ambient atmosphere (corrosive, clean, lubricated)
Bearing types, types and sizes vary. In order to make the mechanical equipment perform as expected, it is crucial to choose the most suitable SKF bearing.
The selection of bearings that require analysis is due in many ways, from research, evaluation procedures, to bearings with special specifications, but usually in the following order:
(1) Master the conditions of use of mechanical devices and SKF bearings
(2) Clear requirements for bearings
(3) Type of selected bearing
(4) Selected bearing configuration
(5) Selection of bearing size
(6) Selected bearing size
(7) Method of installing selected bearings
Bearings using conditions and environmental conditions
Under the premise of correct use and the conditions of the mechanical equipment and the SKF bearing area used under the environmental conditions, select the appropriate bearing. Who, to get the following data and information:
(1) Function and structure of mechanical equipment
(2) Site use of SKF bearings
(3) Bearing load (size, direction)
(4) Rotation speed
(5) Vibration, shock
(6) Bearing temperature (ambient temperature, temperature rise)
(7) Ambient atmosphere (corrosive, clean, lubricated)
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Common quality defects of KOYO imported bearing parts after heat treatment
Core Tips: Common quality defects of KOYO imported bearing parts after heat treatment include: quenching microstructure overheating, underheating, quenching cracks, insufficient hardness, heat treatment variants, surface decarburization, soft spots.
Common quality defects of KOYO imported bearing parts after heat treatment include: quenching microstructure superheat, underheating, quenching crack, insufficient hardness, heat treatment variant, surface decarburization, soft point.
Overheat
Overheating of the microstructure after quenching can be observed from the rough mouth of KOYO imported bearing parts.
However, in order to correctly judge the degree of overheating, it is necessary to observe the microstructure. If coarse needle-shaped martensite appears in the quenched structure of gcr15 steel, it is quenched and superheated. The formation may be caused by excessive heating of the quenching heating temperature or the heating temperature is too long; or it may be due to the serious banding of the original structure, forming a local martensite needle-like coarse in the low carbon zone between the two zones. Cause local overheating. The retained austenite increases in the superheated structure, and the dimensional stability decreases. Due to the overheating of the quenched structure, the crystal of the steel is coarse, which leads to a decrease in the toughness of the part and a decrease in the impact resistance. The life of the KOYO bearing is also reduced. Excessive heat can even cause quenching cracks.
2. Underheat
Low quenching temperature or poor cooling will produce a tortite structure exceeding the standard in the microstructure, called underheated structure, which will reduce the hardness and sharply reduce the wear resistance, affecting the life of KOYO bearings.
3. Quenching crack
The crack formed by KOYO imported bearing parts due to internal stress during quenching and cooling is called quenching crack. The causes of such cracks are: the heating temperature is too high due to quenching or the cooling is too fast. The thermal stress and the mass of the metal change the tissue stress greater than the fracture strength of the steel; the original defects of the working surface (such as micro cracks or scratches on the surface) or internal defects of the steel (such as slag inclusions, severe non-metallic inclusions) , white spots, shrinkage holes, etc.) stress concentration during quenching; severe surface decarburization and carbide segregation; insufficient firepower or timely tempering after quenching; excessive cold stress caused by previous processes, forged folding, deep Turning tool marks, sharp edges and corners of oil hooks.
4. Heat treatment deformation
KOYO imported bearing parts have thermal stress and tissue stress during heat treatment. These internal stresses can be superimposed or partially canceled. It is complex and variable because it can follow heating temperature, heating speed, cooling method, cooling rate, The shape and size of the part change, so heat treatment deformation is inevitable. Knowing and mastering the changing laws can make the deformation of KOYO imported bearing parts (such as ellipse of the sleeve, large size increase, etc.) in a controllable range, which is conducive to the production. Of course, mechanical collisions during heat treatment can also cause deformation of the part, but this deformation can be reduced and avoided with improved operation.
Common quality defects of KOYO imported bearing parts after heat treatment include: quenching microstructure superheat, underheating, quenching crack, insufficient hardness, heat treatment variant, surface decarburization, soft point.
Overheat
Overheating of the microstructure after quenching can be observed from the rough mouth of KOYO imported bearing parts.
However, in order to correctly judge the degree of overheating, it is necessary to observe the microstructure. If coarse needle-shaped martensite appears in the quenched structure of gcr15 steel, it is quenched and superheated. The formation may be caused by excessive heating of the quenching heating temperature or the heating temperature is too long; or it may be due to the serious banding of the original structure, forming a local martensite needle-like coarse in the low carbon zone between the two zones. Cause local overheating. The retained austenite increases in the superheated structure, and the dimensional stability decreases. Due to the overheating of the quenched structure, the crystal of the steel is coarse, which leads to a decrease in the toughness of the part and a decrease in the impact resistance. The life of the KOYO bearing is also reduced. Excessive heat can even cause quenching cracks.
2. Underheat
Low quenching temperature or poor cooling will produce a tortite structure exceeding the standard in the microstructure, called underheated structure, which will reduce the hardness and sharply reduce the wear resistance, affecting the life of KOYO bearings.
3. Quenching crack
The crack formed by KOYO imported bearing parts due to internal stress during quenching and cooling is called quenching crack. The causes of such cracks are: the heating temperature is too high due to quenching or the cooling is too fast. The thermal stress and the mass of the metal change the tissue stress greater than the fracture strength of the steel; the original defects of the working surface (such as micro cracks or scratches on the surface) or internal defects of the steel (such as slag inclusions, severe non-metallic inclusions) , white spots, shrinkage holes, etc.) stress concentration during quenching; severe surface decarburization and carbide segregation; insufficient firepower or timely tempering after quenching; excessive cold stress caused by previous processes, forged folding, deep Turning tool marks, sharp edges and corners of oil hooks.
4. Heat treatment deformation
KOYO imported bearing parts have thermal stress and tissue stress during heat treatment. These internal stresses can be superimposed or partially canceled. It is complex and variable because it can follow heating temperature, heating speed, cooling method, cooling rate, The shape and size of the part change, so heat treatment deformation is inevitable. Knowing and mastering the changing laws can make the deformation of KOYO imported bearing parts (such as ellipse of the sleeve, large size increase, etc.) in a controllable range, which is conducive to the production. Of course, mechanical collisions during heat treatment can also cause deformation of the part, but this deformation can be reduced and avoided with improved operation.
For more information and purchase please visit: https://www.supplyforever.com
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