Another problem of the bearing is the amount of axial movement, that is, the axial tolerance. Changes in the structure of the hose With the continuous development of rubber roller technology, it has experienced the development process of single-layer hose, double-layer hose and aluminum-lined hose. Therefore, the reasonable choice of grease and filling amount should arouse the attention of all levels of management personnel and rubber roller manufacturers in textile enterprises.
Test analysis of different radial clearances In view of the shrinkage of the aluminum-lined rubber tube bearing shell, a tracking test was conducted in a textile factory in Zhejiang. The bearing seal will be damaged when the bearing is disassembled, and the high-temperature lubricating oil in the bearing will leak out, which will cause the bearing to run abnormally, and seriously cause the bearing to jam, and the ball may fall to crush the printer roller. Precautions for cleaning new bearings Since there is anti-rust oil in the new bearing, it needs to be cleaned twice with 120# gasoline and placed vertically to fully drain the mixture of gasoline and anti-rust oil in the bearing, and then wipe the surface with a fine cloth.
Too small a clearance often makes the lubricating oil not in place, especially the structure of a single slide, because it contains less grease,Wholesale Clutch Release Bearing manufacturers it will cause abrasion, and it is difficult for metal particles to be discharged with the creep of the oil.010mm and the evenness data is obviously better than the 'tight clearance' bearing.
When installing and disassembling bearings or accessories, pay attention to the following points: When making aluminum lining rubber roller sleeves, it is necessary to fully clean and dispose of the new bearings, strictly control the shell diameter tolerance, so that the inner hole of the aluminum lining roller and the bearing shell form a reasonable interference fit; regularly check the 'five gaps' of the roller sleeve machine And 'One Concentricity'
At this time, there is both radial displacement and angular displacement between the axis lines of the two shafts. 3.1, the choice of reference site Shaft misalignment It is very important to correct the axis position deviation of the coupling to determine the reference position, such as centrifugal horizontal pump unit, fan without speed increase and other equipment, the reference position should be the non-motor end; with speed increase, with coupling For large blowers, turbines, and steam turbines, the reference part should consider the cumulative error value formed by the motor end in the final adjustment process.
The part with long operation period, standard parts, and small deviation of the thermal expansion center line is regarded as the reference part. 2. What is the 'alignment' of the coupling? After the unit is installed or overhauled, by adjusting the height and left and right positions of the rotors, the axis of each rotor of the unit can form a continuous smooth curve without bending points during operation, that is, the axes of adjacent couplings of the rotors are concentric during operation, and the end faces Parallel, this adjustment process is called alignment. Analysis of shaft misalignment coupling deviation The axis space position of adjacent couplings has the following four states, as shown in Figure 1. The measurement record is shown in Figure 4. 5) Measurement and recording: When measuring, first measure the radial reading a1 and the axial reading s1 at 0° azimuth.
Double meter measurement method (one point measurement method) Two dial gauges are used to measure the deviation value of the outer circle and the end face of the coupling in the same direction, so it is also called the point measurement method, that is, while measuring the radial reading in a certain direction, the same direction is measured. Rotate the coupling halves to the point 2 position, and record the values of a2, s2′, s2″; rotate the two halves Coupling to the point 3 position, record the values of a3, s3', s3″; rotate the coupling halves to the point 4 position, record the values of a4, s4', s4″; rotate the two coupling halves to Point 1 position, table 1, main meter, auxiliary meter in the fog level value a1=0, s1′=0, s1″=0, confirm the correctness of this group of measured values. At Wheel Bearing manufacturers this time, there is an inclined angular displacement between the axis lines of the two shafts (the inclination angle is α).3. The main disadvantage is that for couplings with axial movement, errors will occur in the axial degree of the end face when the rotor is tuing.
According to the division of the coupling points in Figure 2, adjust the table 1 and the main table to the position of point 1 and zero. When s1=s3, a1≠a3. To Figure 4 Dividing point measurement record of dial indicator Through the analysis and calculation of the measured values, the relative position of the two axes in space is determined, and then adjusted according to the calculation results. There are large distances in the middle and precision or high-speed running coupling equipment, such as steam turbines, blowers, Alignment of couplings such as turbines. The common cause is shaft movement or loose anchor bolts.
In most cases, the inner hole of the bearing must rotate with the shaft, and the fit between the two must have a certain degree of interference. Position tolerance The main reason is the special China Mechanical ball bearings manufacturers requirements for bearing coordination. Generally, shafts matched with /P6 and /PO bearings have a tolerance level of IT5~IT7, and most of the box holes are IT6~IT8. Generally, loads are classified as follows: Light load: P≤0. Therefore, all surfaces that match the inner and outer rings of the bearing usually have higher requirements for surface roughness.
Surface roughness. When the bearing has higher rotation accuracy requirements, in order to eliminate the influence of elastic deformation and vibration, the fit with clearance should be avoided, but it should not be too tight. When the bearing is under load, the ferrule will deform, causing uneven force on the mating surface and causing looseness.
As far as rolling bearings are conceed, because they are standard parts, the part that matches the outer ring is made of base shaft, and the shaft that matches the inner ring is made of base hole.07C; Note: a) Common tolerance zone relationship diagram of bearing and shaft fit; b) Common tolerance zone relationship diagram of bearing and housing fit; ∆dmp: the deviation of the average inner diameter of a single plane of the bearing inner ring; ∆Dmp: a single plane of the bearing outer ring Deviation of the average outer diameter.
Swing load: The synthetic radial load acting on the bearing and the bearing ring oscillate relative to each other in a certain area, that is, the synthetic radial load often fluctuates and acts on the part of the circumference of the ring raceway less than 180°. The higher the bearing speed, the tighter the fit should be selected. The influence of temperature should be considered when choosing a fit. Shape tolerance: mainly the surface cylindricity requirements of the joual and box hole.
In most cases, the inner hole of the bearing must rotate with the shaft, and the fit between the two must have a certain degree of interference. Position tolerance The main reason is the special China Mechanical ball bearings manufacturers requirements for bearing coordination. Generally, shafts matched with /P6 and /PO bearings have a tolerance level of IT5~IT7, and most of the box holes are IT6~IT8. Generally, loads are classified as follows: Light load: P≤0. Therefore, all surfaces that match the inner and outer rings of the bearing usually have higher requirements for surface roughness.
Surface roughness. When the bearing has higher rotation accuracy requirements, in order to eliminate the influence of elastic deformation and vibration, the fit with clearance should be avoided, but it should not be too tight. When the bearing is under load, the ferrule will deform, causing uneven force on the mating surface and causing looseness.
As far as rolling bearings are conceed, because they are standard parts, the part that matches the outer ring is made of base shaft, and the shaft that matches the inner ring is made of base hole.07C; Note: a) Common tolerance zone relationship diagram of bearing and shaft fit; b) Common tolerance zone relationship diagram of bearing and housing fit; ∆dmp: the deviation of the average inner diameter of a single plane of the bearing inner ring; ∆Dmp: a single plane of the bearing outer ring Deviation of the average outer diameter.
Swing load: The synthetic radial load acting on the bearing and the bearing ring oscillate relative to each other in a certain area, that is, the synthetic radial load often fluctuates and acts on the part of the circumference of the ring raceway less than 180°. The higher the bearing speed, the tighter the fit should be selected. The influence of temperature should be considered when choosing a fit. Shape tolerance: mainly the surface cylindricity requirements of the joual and box hole.
Macroscopic test analysis of double row tapered roller bearings Double-row tapered roller bearings are used in the pulley block of the oil drilling crane. This situation is extremely easy to occur in small taper tapered roller bearings. The failure characteristics caused by the reverse loading of such rollers into the bearing are very typical, that is, only individual rolling elements and inner rings in the failed bearing fail, and other parts are basically intact. After disassembly, it was found that the upper bearing of the pulley was broken. To Figure 2 A side inner ring peeling roller assembly state 1) The macro and micro morphology of the fracture of the inner ring on side A..
In this position, the contact stress will be much greater than other positions, and even a normal working oil film cannot be formed in this position during operation. Eventually cause the inner ring to fracture. It is found that the spalling spreads from the small end of the inner ring to the large end face, that is, the small end face of the inner ring receives a larger load. Clutch Release Bearing manufacturers To Figure 5 Spalling morphology of bearing inner ring 2) Shape of peeling roller There are 52 side rollers in total, and one end of the damaged roller is severely peeled off (Figure 6). In order to find the cause of the bearing failure, the fracture and stress condition of the bearing were then re-examined, and the fracture of the broken inner ring of the bearing was analyzed.
The bearing assembly must be tapered. The pulley was abnormal after use for about 30 days.6mm) and the roller taper is small, when a roller is reversely installed into the bearing inner ring, the influence of the roller on the entire inner ring is difficult to find. It is found that the severely wo part of the damaged roller is at the large end surface. To Figure 7 Abnormal morphology of a window of the A side cage 2. It can be seen that the spalling source is located in the circle, with the spalling source as the source, the spalling extends to one side and below (the side of the large end face).
Under repeated extrusion of the reverse mounted rollers, the peeling expands into the inner ring of the bearing. To Figure 3 Macro morphology of the inner ring on side A The fracture area of the raceway of the bearing inner ring was selected for inspection, and it was found that the fractures all extend inward from the spalling part of the raceway surface, and the fracture sources are mostly parallel (Figure 4). Press the working surface to form a large number of rolling pits in the raceway of the bearing inner ring.
Fs1=Fs2+FA.In order to ensure the normal use of the machine, the life of the rolling bearing with the general speed in the machine should be calculated according to its equivalent dynamic load. The direction of Fs is the same as the direction of the reaction force that the outer ring can generate when the inner ring of the bearing is compressed by a pure axial load. The actual fulcrum of the shaft is biased to the inner side of the two fulcrums when it is installed; the actual fulcrum of the shaft is biased to the outer side of the two fulcrums when it is reversely installed.
The equivalent dynamic load of a rolling bearing refers to when the radial load and axial load are combined to act inside the bearing. The rolling element at the lowest position of the Fr line of action has the largest load, while the rolling element far away from the line of action gradually decreases. Together, it is only affected by pure radial load, and then the axial load can be obtained according to formula (1) and formula (2). Therefore, it can be judged whether the bearing is affected by the axial exteal load according to the compression and relaxation state of the bearing.
Comparing the relationship between Fs1 and Fs2+FA, there may be the following three situations: (1) Fs1>Fs2+FA, at this time the shaft is in an unbalanced state under the action of exteal axial load and inteal axial force, the shaft has a tendency to move to the right, the right bearing 2 is compressed, and the left bearing 1 is relaxed. To Figure 3 Axial component force produced by radial load in angular contact bearing Since the nominal contact angle of angular contact bearings is 0°u0026lt;α≤45°, when the inner ring bears pure radial load Fr, due to the existence of α, the reaction force Fi of the outer ring acting on the i-th rolling element in the load zone is not Pointing to the radial direction of the inner and outer rings of the bearing, but along the normal direction of the contact point, it can be decomposed into a radial component Fri and an axial component Fsi.
Load analysis of a single angular contact bearing Shafts installed with category 3 or category 7 angular contact bearings can be subjected to the combined action of axial exteal loads and larger axial exteal loads. Load analysis of angular contact bearings in bearing assembly To find the axial load of the bearing in the bearing assembly, the inteal axial force can be obtained first, and then the characteristics of each bearing's load can be judged according to the inteal axial force and exteal load, and the axial load and radial load can be analyzed.
According to their installation method, they can be divided into a positive installation with the narrow side of the outer ring (Figure 1) wheel bearing kits and a reverse installation with the wide side of the outer ring (Figure 2). Therefore, bearing 1 is only subjected to pure radial load, and its axial load is Fa1=Fs1; while bearing 2 is subjected to the combined action of radial load and axial load, its axial load Fa2>Fs2, and the combined formula (1 ) Available: Fa2=FA-Fa1. The sum of the axial component forces on each rolling element in the load-bearing zone is the inteal axial force Fs of the bearing, and the direction is from the wide side of the outer ring to its narrow side. Take Figure 1 as an example for analysis.
. In terms of heat treatment energy structure, priority is given to primary energy; waste heat and waste heat are fully utilized; processes with low energy consumption and short cycles are used instead of processes with long cycles and high energy consumption. At the same time, heat treatment is a major energy consumer and a major polluter in the machinery industry. formed in the heat treatment process Noise and electromagnetic radiation will pollute the environment.
Non-oxidation heat treatment: By using protective atmosphere heating instead of oxidizing atmosphere heating to precise control of carbon potential and nitrogen potential, the performance of parts is improved after heat treatment, and heat treatment defects such as decarburization and cracks are greatly reduced. Energy-saving heat treatment: Scientific production and energy management are the most potential factors for the effective use of energy. Solving the environmental pollution problem of heat treatment and implementing clean heat treatment (or green heat treatment) is one of the development directions of heat treatment technology in developed countries.
The quality of heat treatment is directly related to the quality of subsequent processing and ultimately affects the performance and life of parts. Vacuum heating gas quenching, vacuum or low-pressure carburizing, nitriding, nitrocarburizing and boronizing can significantly improve quality, reduce distortion and increase life. In order to reduce the emissions of SO2, CO, CO2, dust and coal slag, the use of coal as fuel has been basically eliminated, and the use of heavy oil is becoming less and less. The finishing allowance after heat treatment is reduced, which improves material utilization and machining efficiency.
The optimization of the buer structure and the strict control of the air-fuel ratio ensure that the NOX and CO are reduced to a minimum under the premise of reasonable combustion; gas carburizing and carbonitriding are used And vacuum heat treatment technology replaces salt bath treatment to reduce the pollution of waste salt and CN-containing toxic substances to water sources; uses water-soluble synthetic quenching oil to replace part of quenching oil, and uses biodegradable vegetable oil to replace part of mineral oil to reduce oil pollution.
Precision heat treatment: Precision heat treatment has two meanings: on the one hand, it is based on the use requirements, materials, and structural dimensions of the parts, using physical metallurgy knowledge and advanced computer simulation and testing technology to optimize the process parameters to achieve the required Performance or maximize the potential of the material; on the other hand, the stability of the optimized process is fully guaranteed, and the product quality dispersion is very small (or zero) and the heat treatment distortion is zero.
The establishment of a professional heat treatment plant to ensure full-load production and give full play to equipment capabilities wheel bearing kit manufacturers is the choice of scientific management. In recent years, with the progress of science and technology and its application in heat treatment, the development of heat treatment technology is mainly reflected in the following aspects: (1): Heat treatment: waste water, waste gas, waste salt, dust, dust, etc. The waste heat utilization of the combustion fuace has reached a high level. Most people switch to light oil, and natural gas is still the most ideal fuel