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| | China Spherical Roller Bearing (27th Mar 23 at 7:56am UTC) | | China Spherical Roller Bearing Spherical roller bearings have double row rollers, the outer ring has a shared spherical raceway, and the inner ring has two raceways that are inclined at an angle relative to the bearing axis. This ingenious structure enables it to have self-aligning performance, so it is not easily affected by the angle between the shaft and the bearing box seat on the error or the shaft bending, and is suitable for the occasions where the installation error or the shaft deflection causes the angle error. In addition to radial loads, the bearings can also withstand axial loads acting in both directions.
Spherical roller bearings have two types of inner holes: cylindrical and conical, and the taper of the conical taper hole is 1:30 and 1:12. This conical inner hole bearing is equipped with an adapter sleeve or a withdrawal sleeve. The tapered inner hole self-aligning ball bearing can be easily and quickly assembled on the optical shaft or the stepped machine shaft.
The models of spherical roller bearings are: spherical roller bearing (type 20000CC); spherical roller bearing with tapered hole (type 20000CCK); spherical roller bearing (type 20000CC/W33); spherical roller bearing with tapered hole (Type 20000CCK/W33); Spherical roller bearing mounted on the adapter sleeve (Type 20000CCK+H); Spherical roller bearing mounted on the adapter sleeve (Type 20000CCK/W33+H) There are 6 types in total.
Specific introduction
Spherical roller bearings have two rows of rollers, which mainly bear radial loads, as well as axial loads in either direction. It has high radial load capacity, especially suitable for working under heavy load or vibration load, but cannot bear pure axial load. The outer ring raceway of this type of bearing is spherical, so its self-aligning performance is good, and it can compensate for the coaxiality error.
There are two rows of symmetrical spherical rollers, the outer ring has a common spherical raceway, and the inner ring has two raceways inclined at an angle to the bearing axis, which has good self-aligning performance. The bearing can still be used normally, and the centering performance varies with the bearing size series. Generally, the allowable centering angle is 1~2.5 degrees. The load capacity of this type of bearing is large, and the bearing can withstand radial load in addition to radial load The axial load acting in both directions has good impact resistance. Generally speaking, the allowable working speed of spherical roller bearings is low.
Spherical roller bearings are divided into two different structures: symmetrical spherical rollers and asymmetric spherical rollers according to the cross-sectional shape of the rollers. Asymmetric spherical roller bearings are early products, mainly for main engine maintenance services, newly designed main engine Symmetrical spherical roller bearings are rarely used at this time. The internal structure has been comprehensively improved and designed and parameters are optimized. Compared with the early production spherical roller bearings, it can withstand greater axial load. The operating temperature of this bearing is The bearing is relatively low, so it can meet the requirements of higher speed. According to whether the inner ring has ribs and the cage used, it can be divided into C type and CA type. The characteristics of C type bearings are that the inner ring has no ribs and adopts steel plates. Stamping cage, CA type Trien bearing is characterized by ribs on both sides of the inner ring and the use of car-made solid cage. In order to improve the lubrication of the bearing, the spherical roller bearing with an annular oil groove and three oil holes in the outer ring can be provided to the user, which is represented by the bearing rear code /W33. Spherical roller bearings with inner ring oil holes can also be supplied according to the user's requirements. In order to facilitate customer loading, unloading and replacement of bearings, spherical roller bearings with tapered inner holes can also be provided. The taper taper is 1:12 , It is represented by the post code K. In order to meet the requirements of special users, bearings with an inner hole taper of 1:30 can also be provided, and the post code is K30. Bearings with a tapered inner hole can be directly mounted on the tapered journal with a lock nut, or mounted on a cylindrical journal with the help of an adapter sleeve or a withdrawal sleeve. In order to ensure that the bearing prevents harmful slippage between the raceway and the roller due to centrifugal action when the bearing is running at high speed, the bearing should bear a certain minimum radial load, which can be estimated as follows:
Fr =0.02C
where:
Fr -- minimum radial load N
C鈥攖he basic dynamic load rating N of the bearing
Equivalent Dynamic Load
P=Fr+Y1Fa when Fa/F e
P=0.67Fr+Y2Fa when Fa/F e
where:
P鈥攅quivalent dynamic load N
Y1 Y2鈥攁xial dynamic load factor
Equivalent static load
P0=Fr+Y0Fa
where:
P0鈥攅quivalent static load N
Y0鈥擜xial static load factor
Structural classification
structure type
Spherical roller bearings are divided into: cylindrical bore, conical bore. The taper of the tapered inner hole is 1:12 for the rear-mounted spherical roller bearing (type 153000 or 113000) with the rear code K30 and the 1:30 rear-mounted spherical roller bearing with the code name K30. When this type of bearing is matched with a conical shaft, the radial clearance of the bearing can be adjusted by moving the inner ring in the axial direction.
Postcode
Install the tapered hole spherical roller bearings with the rear code K and K30 on the matching adapter sleeve, and then become the rear code K+H type and K30+H type bearings. This kind of bearing can be installed on the optical shaft without shoulder, and is suitable for occasions where the bearing needs to be installed and removed frequently. In order to improve the lubricating performance of the bearing, there is an annular oil groove on the outer ring of the bearing and three evenly distributed oil holes are drilled, and the rear code is W33.
Use and installation
Mainly applicable cage: stamped steel plate reinforced cage (suffix E, very few in China). Stamped steel plate cage (suffix CC), glass fiber reinforced polyamide 66 cage (suffix TVPB), machined brass two-piece cage (suffix MB). Machined brass integral cage (suffix CA), stamped steel cage for vibration applications (suffix JPA). Brass cage (suffix EMA) for vibration applications. For the same structure, the code on the bearing may be different.
Main uses: papermaking machinery, reduction gear, railway vehicle axles, rolling mill gearbox bearing housings, rolling mill rolls, crushers, vibrating screens, printing machinery, woodworking machinery, various industrial reducers, vertical self-aligning bearings with seats .聽
Install
Spherical roller bearings are equipped with drum-shaped roller bearings between the inner ring with two raceways and the outer ring with spherical raceways. The center of curvature of the outer ring raceway surface is consistent with the center of the bearing, so it has the same self-aligning function as the self-aligning ball bearing. When the shaft and housing are deflected, the load can be automatically adjusted and the axial load in two directions. Large radial load capacity, suitable for heavy loads
Shock load conditions. The inner diameter of the inner ring is a bearing with a tapered bore, which can be directly mounted. Or install it on the cylindrical shaft using an adapter sleeve and a dismantling sleeve. The cages use steel stamping cages, polyamide forming cages and copper alloy turning cages.
For self-aligning bearings, the use of an intermediate mounting ring prevents tilting and rotation of the outer ring when installing the bearing with a shaft into the housing shaft hole. It should be remembered that some sizes of self-aligning ball bearings have balls that protrude out of the sides of the bearing, so the middle mounting ring should be recessed to prevent damage to the balls. A large number of bearings are generally installed mechanically or hydraulically.聽
For separable bearings, the inner ring and outer ring can be installed separately, which simplifies the installation process, especially when the inner and outer rings need an interference fit. When installing the shaft with the inner ring in place into the bearing housing including the outer ring, you must pay attention to check whether the inner and outer rings are correctly aligned to avoid scratching the bearing raceway and rolling parts. Mounting sleeves are recommended for cylindrical and needle roller bearings with inner rings without flange rib or inner ring with flange on one side. The outer diameter of the sleeve should be equal to the inner ring raceway diameter F, and the machining tolerance standard should be d10. Drawn cup needle roller bearings are best mounted with mandrels.
Clearance
For the installation axial clearance of the spherical roller bearing, the adjustment nut on the journal, the adjustment washer and the thread in the bearing seat hole can be used, or the preload spring can be used to adjust. The size of the axial clearance is related to the arrangement of the bearing during installation, the distance between the bearings, and the material of the shaft and the bearing seat, which can be determined according to the working conditions. For spherical roller bearings with high load and high speed, when adjusting the clearance, the influence of temperature rise on the axial clearance must be considered, and the clearance reduction caused by temperature rise must be estimated, that is, the axial clearance The gap should be appropriately adjusted to be larger. For bearings with low speed and vibration, they should be installed without clearance, or installed with preload. The purpose is to make the rollers and raceways of spherical roller bearings have good contact, distribute the load evenly, and prevent the rollers and raceways from being damaged by vibration and impact. After adjustment, check the axial clearance with a dial gauge. The method is to fix the dial indicator on the fuselage or bearing seat first, so that the dial indicator contact can withstand the smooth surface of the shaft, and push the shaft left and right along the axial direction. The maximum swing of the dial is the axial clearance value.
Pay attention to the problem
The preloading force of the spherical roller bearing is carried out at room temperature, but in the working state, the drive shaft caused by the micro-stretching temperature of the system will change the bearing preloading force. Therefore, the set preloading force should be considered. to this factor.
It requires the ability of size, speed, and other conditions to set the reasonable use of spherical roller bearing preload to ensure the life of the transmission. If the preload is too large, the power consumption may even lead to overheating. If the preload is too small, under the action of the body load, the shaft rolling, and the gap between the outer rings, there will be beating, running, and the transmission accuracy will increase to reduce noise, affect the gear meshing, and severely damage the teeth and bearings.
According to different spherical roller bearing assemblies, such as: directly by the axial compression of the inner bearing inner ring, the bearing preload nut is rotated, and the inner and outer rings are rotated to eliminate the gap and achieve the purpose of bearing preload. Achieving common use: first, well over the preloaded bearing, last of the nut, then back 1/4 turn. Assembly method, the advantages of this method are less investment, simple, practical, and consistent with the premise of good quality tapered roller bearings, it can be used.
1.Electric heating plate heating method Put the bearing on the electric heating plate with a temperature of 100 鈩?for a few minutes. This method is the most simple. If it is turned several times, the bearing can be heated evenly, and the efficiency is also high. This method can be used.
2. Electric furnace heating method Put the bearing in a closed automatic temperature-controlled electric furnace for heating, the heating is uniform, the temperature control is accurate, the heating is fast, and it is suitable for heating many bearings in a batch.
3. Induction heating method The use of induction heaters can quickly, reliably and cleanly heat the spherical roller bearing to the required temperature, which is especially suitable for occasions where the inner ring is tightly fitted, because only the inner ring is heated, and the outer ring is heated. The ring is less heated, which makes it easier to install on the shaft and into the seat hole.
4. The light bulb heating method uses a 50W light bulb to heat the spherical roller bearing, which can ensure that the heating temperature is about 100 掳 C. The smaller bearing can be placed directly on the bulb, and the larger bearing can be placed in the cone of the bulb. The cover can prevent the heat loss of the bulb, and make the heating uniform. The conical cover can be adjusted up and down, and can be adapted to heat bearings of different sizes within a certain range. If far-infrared light bulbs are used, pay attention to the direction of the light bulbs, so as to avoid infrared rays being harmful to people. This kind of light bulb can be used for energy-saving light bulb heating method, which is suitable for a small number and is not often needed; where the bearing needs to be heated, the light bulb can also be used for lighting at ordinary times, and no other equipment is required.
5. Oil tank heating method This is a widely used traditional heating method. A metal mesh is installed at a distance of 50~70mm from the bottom of the oil tank, and the bearing is placed on the mesh. The large bearing should be lifted by hooks and should not be placed directly at the bottom of the tank to prevent contact with the tank. The bearing parts at the bottom are locally heated too high, or the dirt deposited at the bottom of the tank enters the bearing oil tank. The points to note in the heating method are as follows. Non-corrosive mineral oil with good thermal stability should be used, preferably transformer oil. Both oil and container should be used. The capacity of the oil tank to keep clean should be determined by the size and oil volume of the heated spherical roller bearing. If the container is too small, during continuous operation, the oil temperature will drop quickly once the bearing is put in, and the effect will not be good.China Spherical Roller Bearing
website:http://www.bearingssuppliers.com/spherical-roller-bearing/ | |
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