Bearing products are very simple, I will teach you to understand bearings through classification

Classified by rolling bearing structure type

1. Bearings are divided into: according to the direction of the load they can withstand or the nominal contact Angle:

(1) Radial bearings - mainly used to bear radial loads of rolling bearings, its nominal contact Angle from 0° to 45°. According to the nominal contact Angle is different, it is divided into:

Radial contact bearings - radial bearings with a nominal contact Angle of 0°;

Radial angular contact bearings - Radial bearings with nominal contact angles greater than 0° to 45°.

(2) Thrust bearings - mainly used to bear axial loads of rolling bearings, its nominal contact Angle greater than 45° to 90°. According to the nominal contact Angle is different, it is divided into:

Axial contact bearing - thrust bearing with nominal contact Angle of 90°;

Thrust angular contact bearings - Thrust bearings with nominal contact angles greater than 45° but less than 90°.

2. Bearings according to the type of rolling body, divided into:

(1) Ball bearing - the rolling body is the ball;

(2) Roller bearing - the rolling body is a roller. Roller bearings according to the type of roller, is divided into:

Cylindrical roller bearing - The roller is the bearing of a cylindrical roller, the ratio of the length to the diameter of the cylindrical roller is less than or equal to 3;

Needle roller bearing - The rolling body is a needle roller bearing, the ratio of the length of the needle to the diameter is greater than 3, but the diameter is less than or equal to 5mm;

Tapered roller bearing - the rolling body is the bearing of the tapered roller;

Aligning roller bearing - The roller is the bearing of a spherical roller.

3. According to whether the bearing can be aligning when working, it is divided into:

(1) aligning bearings - raceways are spherical, which can adapt to the angular deviation and angular motion between the axis lines of the two raceways;

(2) Non-aligning bearings (rigid bearings) - bearings that can resist the angular deviation of the axis line between the raceways.

4. Bearings according to the number of columns of rolling elements, divided into:

(1) Single row bearing - bearing with a row of rolling elements;

(2) Double row bearings - bearings with two rows of rolling elements;

(3) Multi-row bearings - bearings with more than two rows of rolling elements, such as three-row and four-row bearings.

5. Bearing in accordance with its parts can be separated, divided into:

(1) Separable bearings - bearings with separable parts;

(2) non-separable bearing - bearing in the final matching, the ring can not be freely separated bearings.          

Classification by rolling bearing size

Bearings according to their outer diameter size, divided into:

(1) miniature bearings - bearings with nominal outer diameter size range below 26mm;

(2) Small bearing - nominal outer diameter size range of 28 ~ 55mm bearings;

(3) Small and medium-sized bearings - bearings with nominal outer diameter ranging from 60 to 115mm;

(4) Medium and large bearings - bearings with nominal outer diameter ranging from 120 to 190mm;

(5) Large bearing - nominal outer diameter size range of 200 ~ 430mm bearings;

(6) Extra-large bearings - bearings with nominal outer diameter size range of more than 440mm.

 

classification by use

Classification by use can be divided into two categories: 1. Universal bearing 2. Special bearing

Special bearings include:

General bearing: it is divided according to the above one and two classification methods.

Special bearing: It is divided according to the occasion used. Usually divided into:

(1) Rolling mill bearing:

The rolling mill can be divided into two rolls, four rolls, six rolls and up to 20 rolls. Roll bearings refer to the bearings mounted on the journal at both ends of the work roll and the support roll. Roll bearings have to withstand a lot of radial rolling force, and the radial space for installing roll bearings is limited, so rolls use multi-row roller bearings to withstand large radial forces, and sometimes angular contact ball bearings or thrust bearings are used to withstand axial forces. It mainly uses four row tapered roller bearings, four row cylindrical roller bearings and self-aligning roller bearings.

(2) washing machine bearings

In the support structure of household washing machines, the support bearing mainly bears radial load, and the spindle speed is generally low. In addition to the bearing performance requirements of a certain bearing capacity, smooth operation and long life, there is also an important condition that the vibration and noise of the bearing should be low. Therefore, in the supporting structure of the washing machine, the supporting bearings are mostly selected deep groove ball bearings.

(3) Machine tool bearings

Machine tool bearing is the main part of machine tool, and its working performance directly affects the quality and production efficiency of the workpiece. Generally use deep groove ball bearings, angular contact ball bearings, tapered hole double row cylindrical roller bearings, tapered roller bearings, thrust ball bearings and thrust roller bearings and two-way thrust angular contact ball bearings.

(4) motor bearings

The motor is widely used in various mechanical equipment, and the quality of the motor is related to the running smoothness of the bearings used to a certain extent. It requires low bearing noise, economy and simple supporting structure, usually choose deep groove ball bearings.

(5) automobile bearings

Automobile bearings include: wheel hub bearing assembly, clutch release bearing, universal joint cross bearing, water pump bearing, tension wheel bearing assembly.

There are also: railway bearings, aeroengine bearings, instruments, instrument bearings, agricultural machinery bearings, robot bearings and so on.

Classified by usage characteristics

1. High temperature bearing

Bearings with operating temperatures higher than 120 ° C are high-temperature bearings. High temperature bearings are mainly used in aviation jet engines, atomic reactor, X-ray tubes, semiconductor component manufacturing equipment and various melting and plating equipment.

2. Low temperature bearing

Bearings with an operating temperature below -60℃ are low-temperature bearings. Typical applications are all kinds of liquid gas pump, such as liquefied natural gas pump, liquid nitrogen (hydrogen, oxygen) pump, butane pump, rocket missile liquid pump, spacecraft and so on. Common low-temperature bearing structures are single-row deep groove ball bearings and cylindrical roller bearings.

3. Corrosion-resistant bearings

Bearings that work in corrosive media. Mostly made of stainless steel, generally in oxidizing media, such as sea water, fresh water, water vapor and wet environment working bearings, or in a certain concentration of acid or alkaline media working bearings, can be made of stainless steel (9Cr18, 9Cr18Mo) bearing rings and rolling body. Use 0Cr19Ni9 or 1Cr18Ni9 austenitic stainless steel as a cage; If working in corrosive media with high ambient temperature, bearing rings and rolling body materials are mostly high temperature stainless steel bearing steel (Cr14Mo4); For larger corrosion resistant bearings, semi-martensitic and martensitic stainless steels such as 1Cr13, 2Cr13 or 3Cr13 are mostly used, which are made after surface nitriding treatment, and solid cages such as stainless steel or beryllium bronze are used in the cages.

4. Anti-sulfur bearing

Bearings that work in natural gas containing hydrogen sulfide (HS) are prone to hydrogen embrittlement and electrochemical corrosion if ordinary bearing steel bearings are used, so bearings made of 00Cr40Ni55A13 alloy materials need to be used. The material is a nickel-chromium alloy; The hardness after heat treatment is 51 ~ 55HRC, which is lower than that of ordinary bearing steel, so its carrying capacity is low. In addition, if there are scratches and scratches on the surface of the bearing parts, it will greatly reduce its sulfuric acid resistance, and special attention should be paid to it when used.

5. Anti-magnetic bearing

Anti-magnetic bearings are made of non-magnetic materials with very low permeability. The most commonly used anti-magnetic bearing material is beryllium bronze (QBe2). It has good mechanical, physical and chemical properties. After quenching and tempering, it has high strength, hardness, elasticity and wear resistance, and excellent corrosion resistance in the atmosphere, fresh water and sea water.

6. Vacuum bearing

Bearings that work under the condition of ambient vacuum higher than 1.33Pa are vacuum bearings, which are mainly used in space technology and various vacuum devices such as X-ray tubes, radar multi-control tubes and high-power agility variable-frequency magnetrons.

Deep groove ball bearings and angular contact ball bearings are used for vacuum bearings. The rings and rolling elements are made of bearing steel (GCr15) or stainless steel (9Cr18, 9Cr18Mo). In recent years, high pressure and high vacuum bearings have also been manufactured with a new bearing alloy G60.

7. Self-lubricating bearings

Self-lubricating bearing is a special bearing that uses the transfer lubrication method with the cage as the lubrication source to maintain the normal operation of the bearing. The self-lubricating bearing structure is mostly single row angular contact ball bearing and centripetal short cylindrical roller bearing.

8. Ceramic bearings

Ceramic bearings can be used in high-speed, high temperature, low temperature, strong corrosion, strong magnetic field, vacuum, high pressure and other harsh working conditions. The main characteristics of ceramic bearings are: high bearing capacity, good heat resistance, high limit speed, small friction temperature rise, small friction loss, high durability, good corrosion resistance, good insulation, low magnetic permeability and good self-lubrication.

9. High-speed bearings

Generally, rolling bearings with Dm·n values exceeding 1.0×106mm·r/min are called high-speed bearings. Here, Dm is the average diameter of the rolling element and n is the rotational speed of the inner ring. At present, in practical applications, the Dm·n value of high-speed bearings has reached 3.0×106mm·r/min, and at the beginning of this century, the Dm·n value of high-speed bearings can reach 3.5×106mm·r/min.

The types of bearings suitable for high speed rotation and the Dm·n values that can be achieved under different lubrication methods are listed 2-1.

combination bearing

1. Combination bearing of needle roller and thrust ball

(1) Needle roller and thrust ball combination bearing with outer cover

(2) Needle roller and thrust ball combination bearing with inner ring

(3) Needle roller with inner ring and thrust ball combination bearing with outer cover

2. Combination bearing with needle roller and angular contact ball

3. Combination bearing of needle roller and thrust cylindrical roller

(1) Combination bearings of needle roller and thrust cylindrical roller

(2) Combination bearings with inner ring needle roller and thrust cylindrical roller

(3) Thrust cylindrical roller combination bearing with inner ring needle roller and outer cover

4. Combination bearing of needle roller and bi-directional thrust cylindrical roller

5. Combination bearing with flanged needle roller and bi-directional thrust cylindrical roller

Classification of spherical ball bearings with seat

Although the outer spherical ball bearing with seat is also a rolling bearing, it has a variety of structural forms, so it has its own unique classification method.

1. Classification method of bearing with seat

1) According to the processing method of the bearing seat, it is divided into two kinds: bearing with casting seat and bearing with stamping seat.

2) According to the shape of the bearing seat, it is divided into the following 9 types:

1 Bearing with vertical seat

2 Bearing with square seat

3 Bearing with diamond seat

4 Bearing with circular seat

5 Bearing with slider seat

6 Bearing with ring seat

7 Bearing with suspension seat

8 Bearing with suspension seat

9 Bearing with triangular seat

3) Bearing with seat is divided into 3 types according to the bearing structure type in the seat:

1 Outer spherical ball bearing with seat top wire

2 Outer spherical ball bearings with seat eccentric sleeve

3 Outer spherical ball bearings with seat tight sleeve