Product Description:
Spherical roller bearings are bearings with drum rollers assembled between an inner ring with two raceways and an outer ring with spherical raceways.
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Name
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Spherical Roller Bearings
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Function
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paper making machinery, reduction gears
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Instuction
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Roller bearings
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Type
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symmetrical spherical roller asymmetrical spherical roller
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Basic Definition
Spherical roller bearings are bearings with drum-shaped rollers assembled between an inner ring with two raceways and an outer ring with spherical raceways.
Basic Introduction
Spherical roller bearings have two rows of rollers, mainly to withstand radial loads, but also can withstand either direction of the axial load. There is a high radial load capacity, especially suitable for heavy load or vibration load work, but can not withstand pure axial load. This type of bearing outer ring raceway is spherical, so its good performance of centring, can compensate for coaxiality error.
There are two symmetrical spherical roller, the outer ring has a common spherical raceway, the inner ring has two with the bearing axis tilt an angle of the raceway, has good centring performance, when the shaft force bending or installation of different bearings can still be used normally, centring with the bearing size series different, the general allowable centring angle of 1 ~ 2.5 degrees, the type of bearings load capacity, in addition to withstand radial loads Bearing can also withstand two-way action of the axial load, has a good impact resistance, generally speaking, spherical roller bearings are allowed to work at a lower speed.
Spherical roller bearings according to the roller cross-section shape is divided into symmetric spherical roller and asymmetric spherical roller two different structures, asymmetric spherical roller bearings belong to the early products, at present is mainly for the host maintenance services, the new design of the host is seldom used symmetric spherical roller bearings, the internal structure of the internal structure of the comprehensive improvement of the design and optimisation of the parameters, and the early production of the spherical roller bearings compared to the axial load, this kind of bearing running temperature is lower, and the bearing can bear more axial load. This kind of bearing's running temperature is lower, so it can adapt to the requirement of higher speed, according to the inner ring with or without the edge and the use of different cage can be divided into two kinds of C-type and CA-type, C-type bearings are characterised by the inner ring without the edge and the use of steel plate stamping cage, CA-type Trane bearings are characterised by the inner ring on both sides of both sides of the edge and the use of the car-made solid cage in order to improve the lubrication of the bearings, the outer ring can be supplied to the user with a ring-shaped oil groove and three oil grooves. Spherical roller bearings with ring-shaped oil groove and three oil holes in the outer ring, to bearings after the code / W33, according to user requirements can also supply with inner ring oil holes in the spherical roller bearings, in order to facilitate the customer loading and unloading and replacement of bearings, but also with a taper in the bore of the spherical roller bearings bearings, taper hole taper for 1:12 after the code for the K that, in order to adapt to the requirements of the special users can also be supplied with a taper of 1:30 bearings, bore taper for 1:30 bearings, to adapt to the special user requirements, can also be supplied with a taper of 1:30 bearings. 1:30 bearings can also be supplied to meet special customer requirements, the rear code is K30 bearings with taper in the bore can be mounted on tapered journals directly with locknuts, or on cylindrical journals with the aid of tightening sleeves or back-off bushings. In order to ensure that the bearings in high-speed operation to prevent the centrifugal effect in the raceway and roller between the harmful slip, the bearing should bear a certain minimum radial load size can be estimated according to the following formula:
Fr = 0.02C
In the formula
Fr - minimum radial load N
C - the basic dynamic load rating of the bearing N
Equivalent dynamic load
P=Fr+Y1Fa When Fa/Fr e
P=0.67Fr+Y2Fa when Fa/Fr e
where
P-equivalent dynamic load N
Y1 Y2-Axial dynamic load coefficient
Equivalent static load
P0=Fr+Y0Fa
In the formula
P0-equivalent static load N
Y0-Axial static load coefficient
Basic type
Spherical roller bearings
Spherical roller bearings are divided into: cylindrical bore, tapered bore.
Tapered bore taper were 1:12 rear code for K spherical roller bearings (153000 or 113000 type) and 1:30 rear code for K30 spherical roller bearings. When these bearings are matched with tapered shafts, the radial clearance of the bearings can be adjusted by moving the inner ring in the axial direction.
Folding spherical roller bearings rear code:
The rear code for K, K30 tapered hole self-aligning roller bearings, installed in the matching tight sleeve, then become the rear code for K + H type and K30 + H type bearings. These bearings can be mounted on bare shafts without shoulders and are suitable for applications requiring frequent mounting and dismounting of bearings. In order to improve the lubrication performance of the bearings, the outer ring of the bearings have ring-shaped oil grooves and drilled with three evenly distributed oil holes, and their rear code is W33.
Specific classification and type control.
1、Spherical roller bearings (20000 CC type)
2、Spherical roller bearings with tapered holes (20000 CCK type)
3、Aligning roller bearings (20000 CC/W33 type)
4、Spherical roller bearings with tapered bore (20000 CCK/W33 type)
5、Spherical roller bearings with holes mounted on the tightening sleeve (20000 CCK+H0000 type)
6、Spherical roller bearings with holes mounted on the tightening sleeve (20000 CCK/W33+H0000 type)
Different types of spherical roller bearings
Example: NTN LH series self-aligning roller bearings
The application of self-aligning bearings is gradually increasing, especially for long life bearings in high temperature environments. For different application environments, NTN engineers developed the STJ2 type of steel, which can extend the service life in a wide range of temperatures, from room temperature to 250°C. This steel is used in the LH series of self-aligning roller bearings. This steel is the standard material for self-aligning roller bearings of the LH series. The characteristics of these bearings are as follows (compared with SUJ2) Long life bearings over a wide temperature range, 3.5 times the life of ordinary materials at room temperature and 30 times the life of ordinary materials at high temperatures (250°C), prevention of surface damage, 7 times the anti-spalling ability, 1.4 times the anti-scratch ability, 2.5 times the anti-friction ability, dimensional stability at high temperatures, almost no dimensional change at 250°C, enhanced resistance to breakage fatigue, and high dimensional stability at high temperatures. Strengthen the strength of rupture fatigue, increase the life of rupture fatigue by 2 times under high temperature and tight fit. Increase the strength of anti-breakage fatigue by 2 times, simplify parts storage and management procedures, a single standard bearing type can be used from room temperature to 250℃, self-aligning roller bearings will be gradually converted to the "LH series".
Application
Mainly applicable cages: Pressed steel plate cages (suffix E), glass fibre reinforced polyamide 66 cages (suffix TVPB), machined brass solid cages (suffix M), pressed steel plate cages for vibration applications (suffix JPA).
Main applications: paper making machinery, speed reducing devices, railway vehicle axles, rolling mill gearbox bearing housings, rolling mill rollers, crushers, vibrating screens, printing machinery, woodworking machinery, various types of industrial speed reducers, vertical housed spherical bearings.
Installation method
Spherical roller bearings in the two raceways of the inner ring and raceway for the spherical surface of the outer ring, assembled with a drum-shaped roller bearings. The curvature centre of the outer ring raceway surface is the same as the bearing centre, so it has the same self-aligning function as the self-aligning ball bearing. In the case of shaft and shell deflection, it can automatically adjust the load and axial load in two directions. Radial load capacity is large, suitable for heavy load, shock load situation. Bearings with tapered bore inner ring can be mounted directly. Or mounted on the cylindrical shaft using a retaining sleeve or dismantling cylinder. The cage uses steel plate stamping cage, polyamide forming cage and copper alloy turning cage.
In the case of self-aligning bearings, the use of an intermediate mounting ring prevents the outer ring from tilting and rotating when the bearing with shaft is mounted in the bore of the housing. It should be remembered that some sizes of self-aligning ball bearings have balls that protrude from the side of the bearing, so the centre mounting ring should be recessed to prevent damage to the balls. A large number of bearings are generally mounted by mechanical or hydraulic press-in.
For separable bearings, the inner and outer rings can be mounted separately, which simplifies the mounting process, especially when both the inner and outer rings require an interference fit. When mounting the shaft with the inner ring in place into a bearing box containing the outer ring, care must be taken to check that the inner and outer rings are correctly centred in order to avoid scoring the bearing raceways and rolling elements. In the case of cylindrical and needle roller bearings with inner rings without flanged retaining edges or with flanged edges on one side, it is recommended to use a mounting sleeve. The outer diameter of the sleeve should be equal to the raceway diameter of the inner ring F and the machining tolerance standard should be d10. Drawn cup needle roller bearings are preferably mounted using an arbor.
Identifying Bearings
Identify the quality of equipment bearings, we usually from the following aspects
Whether the outer packaging is clear Double row tapered roller bearings In general, the brands produced by regular manufacturers have their own special designers for the design of the outer packaging, and to arrange the production conditions to pass the production of the factory to produce the production, therefore, the product packaging from the lines to the colour block should be very clear, unambiguous.
Whether the steel printing word is clear
Each bearing product will be printed on the bearing product body with its brand words, labelling and so on. Although the font is very small, but the products produced by regular manufacturers have adopted the steel printing technology printing, and in the heat treatment before the pressure of the word, so its font is small, but the concave deep, very clear. Usually, the fonts of counterfeit products are not only blurred, but also float on the surface due to the rough printing technique, and some of them can even be easily wiped off by hand or have serious manual traces.
Whether there are noises
Hold the inner sleeve of the bearing with your left hand, and then turn the outer sleeve with your right hand to make it rotate in small increments, and listen to whether there is any noise during the running process of the bearing. Due to the backward production conditions of most counterfeit products, completely handmade workshop operation, in the production process, the bearing body will inevitably be mixed with dust, sand and other impurities, so in the bearing rotation will be miscellaneous noise or running phenomenon is not smooth. This point is to determine whether the product is from the production standard is strict, and with the machine operation of the regular manufacturers of brand-name products the key.
Whether the surface has cloudy oil stains
Whether the surface of the cloudy oil stains that we need to buy imported bearings should pay special attention to. Because of the domestic rust technology and foreign advanced manufacturing countries still have a certain gap, so the bearing body rust treatment is easy to leave thick traces of oil, hand contact with the feeling of sticky and thick, and foreign original imported bearings on the almost invisible traces of any rust oil. According to industry insiders, especially careful people can smell a special smell on the imported bearings, which is the taste of anti-rust oil.
Chamfering is uniform
The so-called chamfering of bearings, that is, the intersection of horizontal and vertical surfaces, counterfeit bearings due to the limitations of production technology, these edges and corners of the parts of the treatment is not satisfactory, which we can easily identify.
Bearing packaging
Packaging is divided into inner packaging and outer packaging bearings in the finished manufacturing and qualified by the inspection, that is, cleaning and rust treatment, and then put into the inner packaging, in order to achieve waterproof, moisture-proof, dust-proof, shock-proof, maintenance of the quality and accuracy of the bearing and the purpose of easy to use and sell.
Bearing packaging is divided into three categories according to the rust prevention period:
① short rust prevention period packaging: rust prevention period of 3 to 6 months, applicable to large quantities shipped to the same subscriber, short-term will be put into use of the bearing. By mutual agreement, in order to facilitate the principle of use, the use of simple packaging.
② General rust-proof period packaging: rust-proof period of one year, applicable to general-purpose bearings.
③Long anti-corrosion packaging: anti-corrosion period of two years, applicable to special-purpose and precision bearings.
Bearing packaging materials within the polyethylene plastic tube (box), kraft paper, plain and wrinkled polyethylene composite paper, cardboard boxes, polyethylene or polyethylene plastic film, nylon fastening tape or plastic compilation of fastening tapes, waterproof high-strength plastic belts, burlap bags and so on. All of the above materials are required to ensure that the material passes the corrosion resistance test.
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