Bearing type and identification method
Bearing type
Needle bearing
Needle roller bearings are equipped with thin and long rollers (the length of the roller is 3 to 10 times the diameter and the diameter is generally not more than 5 mm), so the radial structure is compact, and the inner diameter and load capacity are the same as those of other types of bearings. The smallest diameter, especially suitable for radial mounting size limited support structure. Needle roller bearings can be selected according to different applications, the inner ringless bearing or needle roller and cage assembly, the journal surface and outer casing matched with the bearing The surface of the hole directly serves as the inner and outer rolling surface of the bearing. To ensure the load capacity and running performance, the hardness of the raceway surface of the shaft or the outer casing hole is the same as that of the ferrule bearing. The machining accuracy and surface quality should be combined with the bearing ring. The needle bearing is a bearing unit composed of a combination of a radial needle roller bearing and a thrust bearing component. The compact structure is small, the rotation precision is high, and it can withstand a certain axial load while receiving a high radial load. And the product structure is diverse, adaptable and easy to install. Combined needle roller bearings are widely used in various mechanical equipment such as machine tools, metallurgical machinery, textile machinery and printing machinery, and can make the mechanical system design very compact and dexterous.
Self-aligning ball bearing
Self-aligning ball bearings: Bearings with drum rollers mounted between the inner ring and the raceway of the two raceways are spherical outer rings. The center of curvature of the outer raceway surface is identical to the center of the bearing, so it has the same self-aligning function as the self-aligning ball bearing. When the shaft and outer casing are deflected, they can be adjusted automatically without increasing the bearing load. Spherical roller bearings can withstand radial loads and axial loads in both directions. The self-aligning ball bearing has a large radial load capacity and is suitable for heavy load and impact load. The inner ring inner diameter is a tapered bore bearing that can be mounted directly. Or use the adapter sleeve and the removal cylinder to mount on the cylindrical shaft. The cage is made of steel stamping cage and polyamide forming. Self-aligning ball bearings are suitable for bearing heavy loads and impact loads, precision instruments, low noise motors, automobiles, motorcycles, metallurgy, rolling mills, mining, petroleum, paper, cement, and pressing. Sugar and other industries and general machinery.
Deep groove ball bearing
Working principle: Deep groove ball bearings mainly bear radial load, and can also bear radial load and axial load at the same time. When it is only subjected to radial loads, the contact angle is zero. When the deep groove ball bearing has a large radial clearance, it has the performance of an angular contact bearing and can withstand a large axial load. The deep groove ball bearing has a small friction coefficient and a high limit speed.
Deep groove continuous uninterrupted raceway for SKF deep groove ball bearings. There is a very good fit between the raceway and the steel ball, which allows the bearing to withstand both radial and axial loads. These bearings are extremely versatile and extremely simple to design. They are not separable. They are suitable for high speed and ultra high speed environments. They are stable in operation and basically do not require any maintenance from a maintenance point of view. And deep groove ball bearings are also the most widely used type of bearing. Therefore, SKF also offers bearings in a variety of designs, varieties, series and sizes. SKF deep groove ball bearings are available in shaft diameters ranging from 3 to 1500 mm. They are available in three performance levels:
SKF high quality standard bearings
SKF High Load Capability Explorer Bearing [1]
SKF energy efficient (E2) bearing
SKF also produces engineered solutions for specific applications, including the following:
SKF bearings for extreme temperatures
SKF DryLube bearing
SKF solid oil bearing
SKF insulated bearing
SKF polymer bearing
SKF NoWear never wears bearings
SKF sensor bearing unit
Spherical roller bearing
The spherical roller bearing is a bearing in which a drum-shaped roller is assembled between an inner ring having two raceways and an outer ring having a spherical race.
Spherical roller bearings have two rows of rollers that are mainly subjected to a radial load and can also withstand axial loads in either direction. High radial load capacity, especially suitable for heavy or vibration loads, but not for pure axial loads. 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.
The spherical roller bearing has 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 aligning performance when the shaft is stressed. The bearing can still be used normally when bending or installing different cores. The centering property varies with the bearing size series. Generally, the allowable centering angle is 1~2.5 degrees. The bearing capacity of this type of bearing is large, except for the radial load. The outer bearing can also withstand the axial load of two-way action and has better impact resistance. Generally speaking, the adjustable rotational speed of the spherical roller bearing is low.
Double row tapered roller bearing Spherical roller bearings are divided into two types: symmetrical spherical roller and asymmetric spherical roller according to the shape of the roller. The asymmetric spherical roller bearing is an early product, mainly for the main engine. For repair service, symmetrical spherical roller bearings are rarely used in the design of the main engine. The internal structure has been comprehensively improved and the parameters have been optimized. Compared with the early production of spherical roller bearings, it can withstand greater axial loads. The bearing has a low operating temperature, so it can adapt to the requirements of higher speed. According to the inner ring with or without the rib and the cage used, it can be divided into C type and CA type. The C type bearing is characterized by the inner ring. Without ribs and steel stamping cages, CA bearings are characterized by ribs on both sides of the inner ring and solid cages for the car. In order to improve the lubrication of the bearings, the outer ring can be provided with an annular oil groove and Spherical roller bearings with three oil holes are indicated by bearing rear code/W33. Spherical roller bearings with inner ring oil holes are also available according to user's requirements. In order to facilitate loading and unloading and replacement of bearings, customers can also provide Inner hole with taper Roller bearing, the taper taper is 1:12 and the code is K. In order to meet the requirements of special users, the bearing with inner taper of 1:30 can be provided. The rear code is K30. The inner taper is tapered. The bearing can be mounted directly on the tapered journal by a lock nut, or the bearing can be mounted on the cylindrical journal by means of an adapter sleeve or a withdrawal sleeve.
The thrust bearing is divided into two parts: a tight ring and a live ring. The tight ring and the sleeve are tight, and the ring is supported on the bearing housing. The ferrule and the rolling element are usually made of rolling bearing steel with high strength and good wear resistance. The surface hardness after quenching should reach HRC60-65. The cage is made of soft steel stamping, and can also be made of copper alloy cloth bakelite or plastic.
Thrust roller bearing
The rolling element is a roller thrust bearing.
Linear Bearings
Linear bearings are divided into metal linear bearings and plastic linear bearings
Metal linear bearings are linear motion systems that are produced at low cost for use with infinite strokes in conjunction with cylindrical shafts. Since the carrier ball is in point contact with the shaft, the load used is small. The steel ball rotates with a very small frictional resistance, so that high-precision smooth motion can be obtained.
The plastic linear bearing is a self-lubricating linear motion system. The biggest difference between the metal linear bearing is that the metal linear bearing is rolling friction, and the bearing is in point contact with the cylindrical shaft, so this is suitable for low-load high-speed motion; The plastic linear bearing is sliding friction, and the bearing is in surface contact with the cylindrical shaft, so this is suitable for high-load medium-low speed movement;
Thrust cylindrical roller bearings Spherical roller bearing rolling elements are cylindrical roller thrust rolling bearings.
Thrust tapered roller bearings: Rolling elements are tapered roller thrust bearings.
Thrust needle roller bearings, rolling elements are needle roller thrust bearings.
Thrust spherical roller bearings, rolling elements are spherical self-aligning thrust rolling bearings with convex or concave rollers. The raceway of the bearing race with the convex spherical roller has a spherical shape, and the raceway of the bearing collar with the concave spherical roller has a spherical shape.
Bearing with seat
A combination of a radial bearing and a seat has a mounting plate on the support surface parallel to the bearing axis.
Joint bearing
The sliding contact surface of the thrust ball bearing is spherical, and is mainly suitable for spherical sliding bearings of oscillating motion, tilting motion and rotational motion.
Combined bearing
A bearing in which a bearing is assembled from a combination of the above two or more types of bearing structures. Such as needle roller and thrust cylindrical roller combination bearings, needle roller and thrust ball combination bearings, needle roller and angular contact ball combined bearings.
Other bearings: Rolling bearings of other structures than the above.
Sliding bearings: Sliding bearings are not divided into inner and outer rings and have no rolling elements, and are generally made of wear-resistant materials. Commonly used for low speed, heavy load and lubrication, and mechanical rotation of difficult maintenance.
Rolling mill bearing
Tapered roller bearing mill bearings are generally only used to withstand radial loads. Compared with deep groove ball bearings of the same size, they have large radial load capacity. The limit speed is close to deep groove ball bearings, but it is compatible with such bearings. The machining requirements of the shaft and the housing hole are high, and the inclination of the inner ring axis and the outer ring axis is small (2°-4°). The inclination of the two axes is beyond the limit, and the contact between the roller and the ferrule raceway will deteriorate. , seriously affect the load capacity of the bearing and reduce the service life of the bearing. Therefore, such bearings need to be installed in the main components that are subjected to the axial load, and can only be used if other types of bearings are used simultaneously to withstand the axial load.
Folded angular contact ball bearing
Generally referred to as the 36 type bearing represented by 36, 46 type bearings, the angular contact is generally 15 degrees, 25 degrees, 45 degrees and so on.
Radial insert ball bearing type
Bearing with spherical ball bearing
With vertical seat ball bearings
Spherical bearing with square seat
Diamond spherical ball bearing
Round spherical ball bearing with boss
Outer spherical ball bearing with ring seat
Spherical ball bearing with slider seat
Suspended seat spherical ball bearing
Spherical ball bearing with suspension
Adjustable diamond-shaped outer spherical ball bearing
Spherical ball bearing with stamping seat
Radial insert ball bearing with other seats
Thrust angular contact ball bearing thrust angular contact ball bearing contact angle is generally 60 ° commonly used thrust angular contact ball bearings are generally two-way thrust angular contact ball bearings, mainly used for precision machine tool spindles, generally used together with double row cylindrical roller bearings It can withstand two-way axial load and has the advantages of high precision, good rigidity, low temperature rise, high speed, convenient assembly and disassembly.
Folded deep groove ball bearings
Each ferrule of the structure deep groove ball bearing has a continuous grooved raceway having a cross-section of approximately one-third of the circumference of the equator of the ball. Deep groove ball bearings are mainly used to withstand radial loads and also withstand certain axial loads. When the radial clearance of the bearing is increased, it has the property of an angular contact ball bearing and can withstand the axial load alternating in two directions. Compared with other types of bearings of the same size, this type of bearing has a small friction coefficient, high speed limit and high precision, which is the preferred bearing type for users. Deep groove ball bearings are simple in structure and easy to use. They are the first type of imported bearings with the largest production volume and the widest application range.
Discriminate
To identify the quality of equipment bearings, we usually carry out 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 to design the outer packaging, and arrange the production facilities to produce and produce. Therefore, the packaging of the products is from the line. The color blocks should be very clear and unambiguous.
Whether the steel print clear
Each bearing product will be printed with its brand name and label on the bearing product body. Although the font size is very small, the products produced by the regular manufacturers are printed by the stamp printing technology, and the characters are pressed before the heat treatment, so the font is small, but the recess is deep and very clear. Under normal circumstances, the fonts of counterfeit products are not only blurred, because the printing technology is rough, the fonts float on the surface, and some can even be easily erased by hand or serious by hand.
Wheher has any noise
Hold the inner sleeve of the bearing with your left hand, and rotate the outer sleeve with a small amount of the right hand to make it rotate, and listen to the noise during the operation of the bearing. Due to the backward production conditions of most counterfeit products, it is completely hand-worked. In the production process, the bearing body will inevitably be mixed with impurities such as dust and sand. Therefore, when the bearing rotates, there will be noise or unsmooth operation. . This is the key to judging whether the product comes from a brand-name product of a regular manufacturer that is strict in production standards and operated by machines.
whether has turbid oil on the surface
Whether there are turbid oil marks on the surface requires special attention when purchasing imported bearings. Since the domestic anti-rust technology has a certain gap with the foreign advanced manufacturing countries, it is easy to leave a thick oil trace when the bearing body is rust-proof, and it feels sticky and sticky when touched by hands, and foreign original There is almost no trace of rust preventive oil on the imported bearings. According to industry insiders, particularly attentive people can smell a special taste on imported bearings, which is the taste of rust-proof oil.
Whether the chamfer is uniform
The so-called chamfering of the bearing, that is, the intersection of the horizontal and vertical faces, the counterfeit bearing products are handled unsatisfactorily at the corners of these corners due to the limitation of production technology, which we can easily distinguish.
Bearing packaging
The packaging inner and outer packaging bearings are cleaned and rust-proofed after being manufactured and tested, and then placed in the inner packaging to achieve waterproof, moisture-proof, dust-proof, impact-proof, and maintain bearing quality and precision. And for the convenience of use and sale purposes.
The inner packaging of the bearing is divided into three categories according to the anti-rust period:
1 Short rust-proof period Packing: The rust-proof period is 3 to 6 months. It is suitable for bearings that are shipped to the same subscriber in large quantities and put into use in a short period of time. According to the agreement between the two parties, the principle of convenient use is adopted, and simple packaging is adopted.
2 general anti-rust period packaging: anti-rust period of one year, suitable for general purpose bearings.
3 long anti-rust period packaging: anti-rust period of two years, suitable for special and precision bearings.
The inner packaging material of the bearing is polyethylene plastic tube (box), kraft paper, plain and wrinkle polyethylene composite paper, carton, polyethylene or polyethylene plastic film, nylon fastening tape or plastic fastening tape, waterproof high-strength plastic tape , linen bags, etc. All of the above materials are required to ensure that the corrosion resistance of the material is tested.
