bearingengineer

  The application and development of high-speed machine tools require the increase of spindle speed. However, in the manufacturing process of machine tool spindle group parts, it is inevitable that the center of gravity will deviate from the center of rotation due to uneven material, asymmetric shape and machining and assembly errors, which will cause vibration and vibration force of the machine tool, noise of the machine tool and heating of the bearing. With the increase of rotating speed, the vibration caused by imbalance becomes more and more intense. Because the deformation of the spindle assembly of machine tool is very small when it rotates, in order to simplify the calculation, it is regarded as a balancing method of rigid rotor. The rotor is regarded as an absolute rigid body, and it is assumed that the rotating shaft will not be significantly deformed under the action of unbalanced centrifugal force when working. Therefore, under these conditions, many complex unbalanced s...

  Rust occurred, which not only affected the accuracy and surface roughness, but also reduced the service life, even scrapped and could not be used. Bearing rust prevention is an important work, especially the rust prevention between processes. For example, there are many processes for bearing after pickling, cleaning and grinding in heat treatment workshop. When the product is not produced by assembly line, it will be stored in the intermediate warehouse after one-time sequential processing, so the bearing rings stored between processes must be rustproof. Traditional rust-proof methods using the same rust-proof oil as rust-proof paint and their shortcomings generally adopt the following methods for rust prevention between bearing processes: 1. Immerse in the rust-proof tank Immersing the bearing ring in the aqueous solution of 5% sodium nitrite and 0.6% sodium carbonate has a good antirust effect, but it takes up a lot of space and is inconvenient to manage. 2. Dip coating concent...

  1. Standard type Several methods of installing bearing box with snap ring and fixing plate. Installing bearings with set screws will cause deformation of bearing housings and should be avoided as far as possible. 2. Flange type When installing flange type linear bearing, the matching bearing box bore surface accuracy must be accurate. 3. Adjustable integer (small opening type) When the opening on the bearing is perpendicular to the opening on the bearing box, a uniform preload in the circumferential direction can be obtained. 4. Large opening type If it is used with a suitable bearing seat, the clearance of the large opening bearing can also be adjusted, and even the preload can be lightened. 5. Precautions during installation When installing the linear bearing into the bearing seat, auxiliary work should be used to avoid directly knocking on the end face or sealing ring. The bearing should be used to guide it evenly, and the buffer plate should be used to install it with the hel...

  Rolling bearings are mass-produced mechanical parts, and the manufacturing accuracy is very strict, and the degree of technical specialization is very high. Therefore, for the vast majority of bearing varieties that are easy to buy, it should be more cost-effective to buy than repair. Only under the following circumstances can the bearing repair be considered, namely: (1) The failure forms of a large number of bearings of the same model used in large factories are mainly the wear, fatigue or fretting of rolling surfaces, especially the damaged parts are mostly cages or rolling bodies, and the rings or washers still have repair value; (2) Large and extra-large bearings are on the verge of failure, or have failed without major damage to parts, or expensive bearings must try to extend their effective service life; (3) Some bearing varieties that are really difficult to buy have to be repaired without spare parts after failure, especially imported bearings; (4) The bearing is slightl...

  It is very important to check the bearing seal regularly to keep the bearing in the best condition. The most favorable inspection time is arranged in the periodic downtime inspection period. Importance of clean bearings: It is important to keep bearings and lubrication clean. Before inspection, clean the machine surface, and then remove the parts around the bearing. The oil seal is a very fragile part, so it needs to be disassembled carefully. Do not apply excessive force, and then carefully check the oil seal and its surrounding parts. If it shows bad symptoms, it must be replaced. Bad oil seal will lead to bearing damage and equipment shutdown. Check lubricant Rub a little lubricant between your fingers. If there are pollutants, you can feel them, or apply a thin layer of lubricant on the back of your hand, and then seal the light for inspection. Change lubricant After draining the old oil from the oil-lubricated bearing, if possible, fill it with fresh oil and let the machine ...

  Determining bearing size parameters On many occasions, the inner hole size of bearings has been specifically defined by the structure of machines or devices. No matter whether the working life, static load safety factor and economy meet the requirements, the remaining dimensions and structural forms of bearings must be calculated before they are finally selected. This calculation includes comparing the actual load of the bearing with its load capacity. Static load of rolling bearing means that the bearing is static after loading (there is no relative motion between inner and outer rings) or the rotation speed is very low. In this case, the safety factor of excessive plastic deformation of raceway and roller is calculated. Most bearings are subjected to dynamic load, and the inner and outer rings move relatively. The safety factor of early fatigue damage of raceway and rolling elements is checked by dimensional calculus. Only under special circumstances, the nominal life calculati...

  Failure form of rolling bearing Abnormal heating, vibration and sudden increase of noise occur in the running process of the rolling imported bearing, which indicates that the rolling imported bearing may have been damaged, and the reasons should be checked and analyzed in time. Common failure forms are: 1. Fatigue spalling On the raceway or roller surface of the rolling inlet bearing, the surface metal of the contact surface exfoliates and gradually expands to form pits due to the alternating load. If the operation continues, an area peeling area will be formed. Due to improper installation or the inclination of the bearing seat hole and the center line of the shaft, the local area of the bearing will bear a large load and early fatigue failure will occur. 2. Cracks and fractures Material defects, improper heat treatment, excessive fit interference and improper combination design, such as stress concentration caused by grooves on the bearing surface, will form cracks and fractur...

  The fault diagnosis technology of rolling bearing mainly includes vibration diagnosis technology, ferrography diagnosis technology, temperature diagnosis technology, acoustic diagnosis technology, oil film resistance diagnosis technology and optical fiber monitoring diagnosis technology, among which vibration, iron shop and temperature diagnosis technology are the most widely used. 1. Vibration diagnosis technology When fatigue peeling, indentation or local corrosion occurs on the working surface of bearing elements, periodic pulse signals will appear in the operation of bearings. This periodic signal can be received by a sensor (speed type or acceleration type) installed on the bearing seat, and the fault of the bearing can be diagnosed by analyzing the vibration signal. Features: Vibration diagnosis technology is widely used; Online monitoring can be realized; The diagnosis is fast and the diagnosis theory is mature. Application: It is especially suitable for fault monitoring o...

In the process of grinding, the working surface of bearing is ground by high-speed rotating grinding wheel, so if the equipment is not operated and adjusted according to the work instruction, various defects will appear on the working surface of bearing, which will affect the overall quality of bearing. In precision grinding of bearings, due to the high requirements of roughness, the grinding marks on the working surface can often be observed with the naked eye, mainly as follows. The reason for the appearance of cross helix trace is mainly due to the poor flatness of the bus of the grinding wheel and the concave-convex phenomenon. During grinding, the grinding wheel is only partially in contact with the workpiece. When the workpiece or the grinding wheel moves back and forth several times, the cross helix will reappear in the workpiece and can be observed by the naked eye. The pitch of these spirals is related to the speed of the workpiece table and the rotational speed of the workpie...

Commonly used methods for adjusting the radial clearance of NSK bearings are as follows: 1. The side clearance of cylindrical and elliptical bearing shells can be adjusted by hand grinding and scraping or by repairing and scraping after turning the bearing with split pads. 2. The top clearance of cylindrical and elliptical bearing shells can be adjusted by manual grinding or by adding pads to the bearing split surface when circumstances permit. 3. In principle, it is not allowed to scrape and adjust the clearance of the fixed bearing bush with multiple oil wedges. If the clearance is inappropriate, a new bearing bush should be replaced. 4. For tilting bearing shells with multiple oil wedges, it is not allowed to repair and scrape the tiles. If the gap is not appropriate, the tiles should be replaced. For the tile with adjustable thickness, the tile amount can be adjusted by adding a stainless steel pad under the adjusting block behind the tile or thinning the thickness of the adjusting...

1.the vibration of the bearing Bearing vibration is very sensitive to bearing damage, such as peeling, indentation, corrosion, crack and wear, etc., which will be reflected in bearing vibration measurement. Therefore, the magnitude of vibration can be measured by using a special bearing vibration measuring instrument (frequency analyzer, etc.), and the specific situation of abnormality can not be inferred by frequency analysis. The measured values are different due to the service conditions of bearings or the installation position of sensors, so it is necessary to analyze and compare the measured values of each machine in advance to determine the judgment standard. 2.the temperature of the bearing Generally, the temperature of the bearing can be inferred from the temperature outside the bearing chamber, and it is more appropriate to directly measure the temperature of the bearing outer ring by using the oil hole. Usually, the temperature of the bearing rises slowly with the start of be...

When the inner diameter of the bearing is greater than 70mm, or the fit interference is large, the bearing hole is expanded by heating, which saves labor and time in installation and avoids damage caused by excessive force. At this time, what needs to be controlled is the heating temperature. Generally, it is enough to heat the bearing to 80℃, up to 100℃. If the temperature exceeds 120℃, the bearing will be tempered, which will reduce the hardness and accuracy of the ring. Commonly used heating methods are: 1 electric heating plate heating method Put the bearing on an electric heating plate with a temperature of 100℃ for a few minutes. This method is the simplest. If the bearing is turned over several times, it can be heated evenly and the efficiency is high. This method can be used for both large and small bearings. 2 electric furnace heating method The bearing is heated in a closed automatic temperature control electric furnace, which has the advantages of uniform heating, accurate t...

1. The reason of bearing temperature rise: (1). The bearing cooling water is interrupted. (2) The oil quality is deteriorated, and the oil itself is not clean or the oil is deteriorated in operation. For example, the increase of water in the oil will increase the acidity of the oil, which will reduce the lubricating effect of the oil, corrode the bearing bush and cause the bearing temperature to rise. 2. Phenomenon: (1) There is an alarm bell ringing. (2). The light plate of hydraulic machinery fault on the side plate of the machine lights up, the temperature of the instrument indicating the bearing temperature rises, and the signal relay acts. (3) The black needle of thermometer dial (expansion thermometer) coincides with or exceeds the yellow needle. (4) Send out the fault signal of bearing temperature rising. Step 3 deal with When the bearing temperature rises, first judge whether it is misoperation. If it does rise, the following measures should be taken: (1). Check whether the coo...

Causes and diagnosis methods of locomotive rolling bearing faults This paper introduces the simple diagnosis and precise diagnosis of rolling imported bearings of locomotives, and lists the detection examples. Keywords: Fault detection of rolling imported bearings of locomotives 1 Introduction Imported bearings, as the main components of locomotives, especially traction motors and axle box bearings, play an important role in safe transportation. When locomotives are running online, once the bearings fail, the whole train will be unable to run and the main transportation line will be blocked, especially when passenger trains fail, which will have a greater negative impact. At the same time, once the locomotive bearings fail, it is very difficult to repair the locomotive. Therefore, it is very difficult to prevent and reduce the occurrence of locomotive bearing failures. It is very important for the safe transportation of locomotives. The key point of this paper is whether the bearings w...

Precautions for use Compared with general mechanical parts, the precision of rolling bearing is higher, so it should be used with caution accordingly. 1) Keep the bearing and its surroundings clean. 2) when using carefully. If the bearing is severely impacted by carelessness during use, it will cause scars, indentations, fractures and other injuries to the bearing. 3) Use the right tools 4) Pay attention to the rust prevention of bearings. Avoid using in damp places, and wear gloves to avoid sweat. 5) Users should be familiar with bearings. 6) Work out the operation specifications for bearing use. A, bearing custody B, bearing and its surrounding cleaning C, the size of the installation parts and processing quality inspection D, installation work E. Inspection after installation F. Dismantling operation G, maintenance (regular inspection) H, lubricant supplement Bearing storage Bearings are coated with proper amount of antirust oil and packed with antirust paper when they leave the fac...

Bearing storage should first fully consider the size and weight of the bearing, and then consider the necessary handling space and equipment to ensure that the bearing will not collide when stored and taken. The bearing should not be placed directly on the ground. Therefore, appropriate shelves should be configured, and the bottom of the shelf should be 30cm above the ground. Under the general packaging condition,the antirust effect is 13 years depending on the storage environment.When it needs to be stored for nearly 10 years under special circumstances,it can be kept by soaking in turbine oil(as bearing lubricant). (1)Installation of bearings There are many ways to install the bearing,and the same operation should be handled after installation.After the bearing is installed,the outer ring must be coated with lubricant for bearing obliquely.{TodayHot} 1)Coating of lubricant 1 When lubricating with grease Apply lubrication to cover all roller surfaces,and restore the position of the ou...

The selection of bearing grease is directly related to the stable operation of equipment. In order to give full play to the best condition of bearings, the selection of bearing grease must be considered from the following aspects: 1. antirust performance The grease used in bearings must have antirust effect, and the antirust agent should be insoluble in water. Grease should have good adhesion and can form an oil film on the surface of steel. 2. Mechanical stability Grease will soften during machining, leading to leakage. During normal operation, grease will be thrown into the bearing from the bearing seat. If the mechanical stability of grease is not enough, the structure of grease soap will disintegrate mechanically during operation, resulting in the destruction of grease and loss of lubrication. 3. Oil seal Oil seal is a necessary barrier to protect bearings and lubricants from external pollution. During the operation of bearings, no matter sundries or moisture can penetrate into the...

For bearings, lubrication is an important issue that affects their performance. Whether the lubricant or lubrication method is suitable or not will greatly affect the life of bearings. The function of lubrication is as follows: 1) lubricate all parts of the bearing to reduce the rotary friction between the raceway surface and the steel ball, the sliding friction between the steel ball and the retainer, and the sliding friction between the retainer and the raceway guide surface. 2) Take away the heat generated by internal friction inside the bearing and other heat transmitted from the outside to prevent the bearing from heating and the deterioration of lubricant. 3) Make the rolling contact surface of the bearing often form an appropriate oil film to relieve the concentrated stress of impact load and prolong the fatigue life of the bearing; 4) Prevent the corrosion of steel balls, grooves and retainers, the intrusion of garbage, foreign objects and moisture, and prevent the bearing from...

This paper introduces the simple diagnosis and precise diagnosis of locomotive rolling bearing,and lists the detection examples. 1 Introduction Bearing,as the main component of locomotive,especially traction motor and axle box bearing,plays an important role in safe transportation.When the locomotive runs online,once the bearing fails,the whole train will be unable to run and the main transportation line will be blocked,especially when the passenger train fails,which will have a greater negative impact.At the same time,once the locomotive bearing fails,it is very difficult to repair the locomotive.Therefore,it is very difficult to prevent and reduce the occurrence of locomotive bearing failure.It is very important for the safe transportation of locomotives.The key point of this paper{TodayHot}is whether the bearings with hidden trouble can be detected before loading the bearings to ensure the qualified bearing parts get on the train. 2 bearing failure The serious damage of bearings is ...

Due to its own quality and external conditions, its bearing capacity, rotation accuracy and antifriction performance will change during use. When the performance index of the bearing is lower than the use requirements and cannot work normally, it is called bearing damage or failure. Once the bearing is damaged, its machines and equipment will stop running and its functions will be damaged. Therefore, it is necessary to investigate the causes in a short period of time and take corresponding measures. Of course, the damage of rolling bearings is much more complicated than the damage of general mechanical parts. The damage of rolling bearings is characterized by many forms and complicated reasons. Besides the internal factors of bearing design and manufacture, most of the damage of bearings is caused by improper use, such as: suitable selection of cloth (see customer's instructions), unreasonable support design, improper installation, poor lubrication, poor sealing and other external ...