Extend the maintenance and maintenance of TIMKEN angular contact ball bearings

In order for TIMKEN bearings to be fully utilized and to maintain their proper performance for a long time, regular maintenance (regular inspection) must be performed.

Through proper periodic inspections, early detection of failures and prevention of accidents are important to improve productivity and economy.

1, cleaning

When the angular contact ball bearing is removed for inspection, the appearance record is first recorded by photography. Also, verify the amount of lubricant remaining and sample the lubricant before cleaning the bearings.

a. The cleaning of the bearing is carried out by rough washing and fine washing, and a metal mesh frame can be placed on the bottom of the used container.

b. When rough washing, remove the grease or adhesive with a brush or the like in the oil. At this time, if the TIMKEN bearing is rotated in the oil, be careful that the rolling surface will be damaged by foreign matter or the like.

c. When washing finely, slowly rotate the bearing in the oil and carry out it carefully.

The cleaning agent generally used is a neutral non-aqueous diesel oil or kerosene, and a warm alkali liquid or the like is sometimes used as needed. Regardless of which cleaning agent is used, it is often filtered and kept clean.

Immediately after cleaning, apply anti-rust oil or anti-rust grease to TIMKEN bearings.

2, inspection and judgment

In order to judge whether the removed angular contact ball bearings can be reused, it is important to check the dimensional accuracy, rotation accuracy, internal clearance, mating surfaces, raceway surfaces, cages and seals.

Regarding the inspection result, it can be judged by a person who is using a conventional bearing or a proficient bearing.

The criteria for judgment vary depending on mechanical properties and importance, inspection period, and the like. Bearings must not be reused if they are damaged and must be replaced.

1) Breakage and defects of bearing components.

2) Peeling of the rolling surface of the raceway surface.

After the bearings have been installed, alignment may result in additional loads, friction and vibration of the angular contact ball bearings if not carefully aligned. These can accelerate fatigue and reduce bearing life and can damage the life of other machine parts. In addition, increased vibration and friction can greatly increase energy consumption and risk of premature failure.
Precautions for preventing premature failure of TIMKEN deep groove ball bearings
Enlarge font Decrease font Publish date:2012-06-01 Views:106
TIMKEN bearing contact fatigue failure is the failure of the working surface of the bearing due to the alternating stress, and deep spalling is the intrinsic cause of contact fatigue failure.

We know that contact fatigue spalling occurs on the working surface of deep groove ball bearings, often accompanied by fatigue cracks, first generated from the maximum alternating shear stress below the contact surface, and then extended to the surface to form different spalling shapes, such as dots. Peeling or pitting, peeling off into small pieces called shallow peeling. Due to the gradual enlargement of the exfoliation surface, it tends to expand deeper and form deep exfoliation.

Wear failure refers to the failure of the relative sliding friction between the surfaces resulting in the continuous wear of the metal on the working surface.

Continued wear and tear will cause gradual damage to the bearing components and ultimately lead to loss of bearing dimensional accuracy and other related problems. Wear may affect the shape change. The increase of the clearance and the change of the surface of the working surface may affect the lubricant or cause the pollution to a certain extent, resulting in complete loss of the lubrication function, thus causing the bearing to lose the rotation precision or even the normal operation. Wear failure is one of the common failure modes of various types of bearings. It is usually classified into the most common abrasive wear and adhesive wear according to the form of wear.

The main cause of TIMKEN bearing fracture failure is the defect of TIMKEN bearing itself and the overload during use.

When the applied load exceeds the material strength limit and the part is broken, it is called overload fracture. The main reason for the overload is the sudden failure of the host or improper installation. Defects such as microcracks, shrinkage cavities, air bubbles, large foreign objects, overheated tissue and localized burns of the bearing parts also cause breakage at the defects during impact overload or severe vibration, called defect fracture. It should be pointed out that in the manufacturing process, in the process of re-inspection of raw materials, quality control of forging and heat treatment, and process control, the above defects can be correctly analyzed by instruments, and control must be strengthened in the future. However, in general, most of the deep groove ball bearing fracture failures are overload failure.

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Skeleton oil seal specification

       Structure and sealing principle of skeleton oil seal

       The skeleton oil seal is relatively simple and generally consists of three parts: an oil seal, a reinforcing skeleton and a self-tightening coil spring. The sealing body is further divided into a bottom portion, a waist portion, a cutting edge and a sealing lip according to different parts. Generally, the skeleton oil seal in the free state has a smaller inner diameter than the shaft diameter, that is, has a certain "interference". Therefore, after the oil is encapsulated in the oil seal seat and the shaft, the pressure of the oil seal edge and the contraction force of the self-tightening coil spring exert a certain radial tightening force on the shaft, and after a period of operation, the pressure will rapidly decrease or even disappear. Therefore, the spring can compensate the oil seal self-tightening force at any time.

       Sealing principle: This oil film has fluid lubrication properties due to the oil film controlled by the oil seal edge between the oil seal and the shaft. Under the action of the surface tension of the liquid, the stiffness of the oil film just forms a crescent surface at the contact end of the oil film and the air, preventing the leakage of the working medium, thereby achieving the sealing of the rotating shaft. The sealing ability of the oil seal depends on the thickness of the oil film on the sealing surface. If the thickness is too large, the oil seal leaks; if the thickness is too small, dry friction may occur, causing oil seal and shaft wear; if there is no oil film between the seal lip and the shaft, it is easy to cause heat and wear. .

       Therefore, when installing, it is necessary to apply some oil on the sealing ring, and at the same time ensure that the skeleton oil seal is perpendicular to the axis of the shaft. If it is not vertical, the sealing lip of the oil seal will drain the lubricating oil from the shaft, which will also lead to excessive sealing lips. abrasion. During operation, the lubricant in the casing slightly exudes a little to achieve a state in which an oil film is formed at the sealing surface.https://www.supplyforever.com/

What is the oil seal

       Oil seal is a mechanical component used to seal oil (oil is the most common liquid substance in the transmission system, also refers to the general liquid substance). It isolates the parts of the transmission parts that need to be lubricated from the output parts, so as not to let the lubrication Oil leaks. Seals for static and dynamic seals (generally reciprocating) are called seals. The representative form of the oil seal is the TC oil seal, which is a double-lip oil seal with a self-tightening spring completely covered by rubber. Generally speaking, the oil seal often refers to this tc skeleton oil seal.

       What material is the oil seal?

       The oil seal is made of rubber. The oil seal is mainly used in the joint parts of two lubricating parts to prevent oil leakage, such as crankshaft oil seal, semi-shaft oil seal, transmission shell oil seal and the like.

       What is the skeleton oil seal?

       The skeleton oil seal is a typical representative of the oil seal. Generally speaking, the oil seal refers to the skeleton oil seal. The function of the oil seal is generally to isolate the parts of the transmission parts that need to be lubricated from the output parts, so as not to let the lubricating oil leak. The skeleton acts like a reinforcing bar inside the concrete member, which acts to strengthen and maintain the shape and tension of the oil seal.

       According to the structure, the single lip skeleton oil seal and the double lip skeleton oil seal can be divided. The secondary lip of the double-headed skeleton oil seal acts as a dustproof to prevent dust and impurities from entering the inside of the machine. According to the skeleton type, it can be divided into an inner skeleton oil seal, an exposed skeleton oil seal and an assembled oil seal. According to working conditions, it can be divided into rotating skeleton oil seal and reciprocating skeleton oil seal. Used in gasoline engine crankshafts, diesel engine crankshafts, gearboxes, differentials, shock absorbers, engines, axles, etc.

       What is the general material of the skeleton oil seal?

       The general material of the skeleton oil seal is divided into: nitrile rubber (NBR), fluororubber (VITON), silica gel (SIL), nylon (PA), which are the most common materials, of course, PTFE Teflon oil seals, and Skeleton oil seals and more.

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Method for distinguishing the quality of INA stainless steel bearings

The proper selection of materials is still a factor that must be considered in the INA bearing failure analysis. The main task of bearing failure analysis is to find out the main factors causing the failure of stainless steel bearings based on a large amount of background materials, analysis data and failure modes, so as to propose improvement measures in a targeted manner, prolong the service life of bearings and avoid sudden occurrence of bearings. Early failure of sex. The installation condition is one of the primary factors in the use factor. The bearing is often changed due to improper installation, and the force state between the parts of the whole bearing changes, and the bearing runs in an abnormal state and fails early. According to the technical requirements of bearing installation, use, maintenance and maintenance, monitor and check the load, speed, working temperature, vibration, noise and lubrication conditions of the bearing in operation, find out the cause and immediately adjust the cause, make adjustment Back to normal.
1. Whether the outer packaging is clear: Under normal circumstances, the factory brand has its own special designer to design the outer packaging, and arrange the production facilities to produce and produce, so the packaging is very clear from line to color. unambiguous.
2. Whether the steel printing is clear: the brand name and label will be printed on the INA bearing body. The font is very small, but most of the products produced by the factory use the stamping technology, and the type is pressed before the heat treatment, so the font is small, but the recess is deep and very clear. The fonts of counterfeit products are not only blurred, but because of the rough printing technology, the fonts float on the surface, and some can even be easily erased by hand.
3. Is there any noise: hold the stainless steel bearing inner sleeve in the left hand, and turn the outer sleeve with your right hand to make it rotate to hear if it has noise. Due to the backward production conditions of most counterfeit products, it is completely hand-worked. In the production process, it is inevitable to incorporate impurities such as sand and sand into the INA bearing body, so it will make noise when rotating. This is the biggest difference between a factory brand that strictly enforces production standards and operates with machines.
4. Is there any turbid oil on the surface: this should be paid special attention when purchasing stainless steel bearings. Since the current domestic anti-rust technology is not particularly good at home, it is easy to leave a thick oil trace when the INA bearing body is rust-proofed, and it is sticky on the hand, and the foreign original bearing can hardly be seen. To the traces of anti-rust oil, it is a very careful expert who said that the bearing smells like a smell, it must be under the anti-rust oil, just can't see it.
5. Whether the chamfer is uniform: the so-called chamfer of the bearing, that is, the intersection of the horizontal surface and the vertical surface. The counterfeit bearing is unsatisfactory in the processing of these corners due to the limitation of production technology.

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Rolling bearings generally consist of four basic components

Core Tip: Rolling bearings generally consist of the following four basic components: inner ring, outer ring, cage and rolling element counter-center or centripetal thrust bearing (inner or outer ring can be collectively referred to as ferrule), shaft ring, seat ring
Rolling bearings generally consist of the following four basic components: inner ring, outer ring, cage and rolling elements - counter-center or centripetal thrust bearings (inner or outer ring can be collectively referred to as ferrules), shaft rings, races, Cage and rolling elements - for thrust or thrust radial bearings (shaft rings or races can be collectively referred to as washers). The rolling element is the basic structural feature of the rolling bearing. In order to save space, or to load more rolling elements, a few types of rolling bearings can be used without outer ring or inner ring, without inner or outer ring, or without cage. However, all rolling bearings must have rolling elements. Usually the inner ring or the shaft ring is mounted on the shaft, the outer ring or the seat ring is mounted in the bearing housing bore, and the rolling elements are assembled between the inner and outer rings or between the shaft and the race. The external load is transmitted to the outer ring or the race by the inner ring or the shaft ring through the rolling element, or is transmitted to the inner ring or the shaft ring by the outer ring or the seat ring, and the two sides are relatively rotated by the rolling elements. The cage is used to separate the rolling bodies to avoid mutual contact of the rolling bodies, since the relative speed at which the rolling bodies are in direct contact is approximately one time the rolling speed of the single rolling body, which can result in abrasion of the rolling bodies. The advantages and disadvantages of rolling bearings are mostly related to the existence of rolling elements. For example, rolling friction is used to form rolling friction. The static and dynamic friction coefficients are low, the transmission efficiency is high, the axial dimension is small, and on the other hand, the high secondary contact ("point") is also formed. Contact or "wire" contact) makes the quality of the rolling bearing less rigid, vibration, noise, etc. than some types of plain bearings, and the radial size is also large.

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Standard method and lubrication maintenance for installing NSK rolling bearings

Since the rolling bearings are rust-proofed and packaged, do not open the package until installation.

In addition, the anti-rust oil coated on the bearing has good lubricity. For general-purpose NSK bearings or grease-filled bearings, it can be used without cleaning. However, for instrument bearings or bearings for high-speed rotation, the cleaning oil should be washed with a clean cleaning oil. The bearing is prone to rust and cannot be placed for a long time.

Clean the bearing and the casing to confirm the burrs left by scratches or machining. There must be no abrasive (SiC, Al2O3, etc.) sand or chips in the outer casing.

Secondly, check whether the size, shape and processing quality of the shaft and the casing are in accordance with the drawings.

The method of installing the rolling bearing depends on the fit, condition and structure of the NSK bearing. Generally, since the shaft is mostly rotated, the inner ring needs an interference fit. Cylindrical bore bearings, press with multiple presses, or use hot charging methods. For taper holes, mount directly on the taper shaft or with a sleeve.

When installed in the outer casing, the general clearance fits a lot, and the outer ring has an interference amount, which is usually pressed by a press or a cold shrink fit method after cooling. When dry ice is used as the coolant and the shrinkage is installed, the moisture in the air will condense on the surface of the bearing. Therefore, appropriate rust prevention measures are required.

Mounting bearing: Whether the rolling bearing is installed accurately, affecting accuracy, life and function. Therefore, the bearing installation plan and the disassembly part are enriched. I hope I can install it according to my homework. The names of the homework scales are as follows:

(1) Clearing and bearing related components;

(2) Check the size and packing components related to the case;

(3) installation;

(4) Checking after bearing installation;

(5) A smoothing agent supplied.

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Judging the fault maintenance method of SKF self-aligning ball bearing in use

SKF bearings exhibit a strong regularity during their use and are very repeatable. Normal high-quality bearings (SKF bearings) have relatively small vibration and noise at the beginning of use, but the spectrum is somewhat scattered and the amplitude is small, which may be due to some defects in the manufacturing process, such as surface burrs.

After a period of motion, the vibration and noise are maintained at a certain level, and the spectrum is very single, only one or two times the frequency. There are very few spectrums above the power frequency, and the state of the self-aligning ball bearings is very stable and enters a stable working period.

After continuing to run, the vibration and noise of SKF bearings begin to increase, and sometimes abnormal sounds appear, but the change of vibration increases slowly. At this time, the bearing kurtness value suddenly reaches a certain value. We believe that SKF bearings are initially faulty at this time.

At this time, it is required to closely monitor the SKF bearing and pay close attention to its changes. After that, the bearing kurtosis value begins to drop rapidly and approaches the normal value, while the vibration and noise begin to increase significantly, and the increase rate begins to accelerate. When the vibration exceeds the vibration standard (such as ISO2372 standard), the bearing kurtosis value also begins. Rapid increase, when both exceed the vibration standard, and the kurtosis value also exceeds the normal value (the available kurtosis is relative to the standard), we believe that the self-aligning ball bearing has entered the late fault production, and it is necessary to repair the equipment in time and replace the SKF bearing.

SKF bearings exhibit late failure characteristics to serious failures (generally bearing damage such as axles, burns, sand cracks, raceways, bead wear, etc.) are not more than one week. The larger the equipment capacity, the faster the speed. The shorter the interval. Therefore, in the actual fault diagnosis of self-aligning ball bearings, once the late fault characteristics are found, the bearing should be judged decisively and the maintenance should be arranged as soon as possible.

The use factors mainly refer to whether the installation adjustment, use and maintenance, maintenance and repair, etc. meet the technical requirements. According to the technical requirements of SKF bearing installation, use, maintenance and maintenance, monitor and check the load, speed, working temperature, vibration, noise and lubrication conditions of the SKF bearing in operation, find the cause and immediately adjust the cause. Make it back to normal.

First of all, when the spindle bearing in the spindle is in operation, it is necessary to fully ensure the lubrication, and the lubricant is periodically added according to the actual use condition, and the oil cannot be cut off for a long time. Therefore, for the user company, a better and more suitable spindle lubricant should be used. The new special spindle oil can significantly improve the lubrication performance, extend the oil change interval, extend the service life of the spindle and the self-aligning ball bearing, and also has better anti-rust and anti-corrosion properties.

Secondly, the bearing with reinforced nylon material cage should be used at a temperature lower than 120 °C.

In addition, care should be taken when cleaning and cleaning the spindle to prevent damage and scratching the surface of the roller. To remove the residue of the SKF bearing part as much as possible, it is better to rinse and suck the inside of the ingot to clean the residual oil. Care should be taken to avoid the use of the dumping type to cause the accumulation of cleaning waste to remain in the bearing parts, resulting in problems such as noise and wear failure of the self-aligning ball bearings.

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