Bearing model meaning

1) The bearing inner diameter is indicated by the first number on the right side of the basic code. Commonly used bearings with internal diameter D = 20 ~ 480 mm, the internal diameter is generally a multiple of 5. These two digits represent the quotient of the bearing inner diameter dimension divided by 5, for example, 04 represents D = 20mm；; 12 means d = 60 mm and so on.

Bearings with internal diameters of 10mm, 12mm, 15mm and 17mm have internal diameter codes of 00, 0 1, 02 and 03 in turn. For bearings with inner diameter less than 10mm and more than 500mm, the expression method of inner diameter is otherwise specified.

2) The diameter series of the bearing (that is, the series of bearing with the same structure and inner diameter whose outer diameter and width change) is represented by the third digit from the right of the basic code. For example, radial bearing and radial thrust bearing, 0 and 1 represent ultra-light series; 2 stands for light series; 3 means medium series; 4 means heavy series. Thrust bearings are exactly the same as radial bearings except that the ultra-light series is represented by 1. ?

3) Bearing width series (that is, bearing width variation series with the same structure, inner diameter and diameter series) is represented by the fourth digit on the right side of the basic code.

When the comparison of diameter series in width series diagram 13-4 is classified as 0 series (common series), the width series code o may not be marked for most bearings, but for self-aligning roller bearings and tapered roller bearings, the width series code 0 should be marked. Diameter series code and width series code are collectively called size series code. ?

4) The bearing type code is represented by the fifth digit on the right side of the basic code (for cylindrical roller bearings and needle roller bearings, the code is a letter).

Rolling bearings are divided into radial bearings and thrust bearings according to the load direction or nominal contact angle they can bear. The radial contact bearing is a radial bearing with a nominal contact angle of 0, and the radial contact bearing is a radial bearing with a nominal contact angle greater than 0 to 45. The axial contact bearing is a thrust bearing with a nominal contact angle of 90, and the thrust angle contact bearing is a thrust bearing with a nominal contact angle greater than 45 but less than 90.

According to the shape of the rolling body, it can be divided into ball bearing and roller bearing. Roller bearings are divided into cylindrical roller bearings, needle roller bearings, tapered roller bearings and self-aligning roller bearings.

According to whether it can be self-aligning during work, it can be divided into self-aligning bearings-spherical raceway bearings and non-self-aligning bearings (rigid bearings) that can adapt to the angular deviation and angular movement between two raceway axes-bearings that can resist the angular deviation between raceway axes.

According to the number of rows of rolling elements, it can be divided into single row bearings, double row bearings and multi-row bearings.

According to whether its components (rings) can be separated, it can be divided into separable bearings and inseparable bearings.

According to its structural shape (such as whether there is a filling groove, whether there is the shape of inner ring, outer ring and ferrule, the structure of flange, and even whether there is a cage, etc.). ), can also be divided into various structural types.

According to its outer diameter, it is divided into miniature bearings (440mm).

According to the application field, it is divided into motor bearing, rolling mill bearing and main bearing.

According to materials, it is divided into ceramic bearings and plastic bearings.

Extended data:

national standard

1. National standard of vibration acceleration (commonly known as Z standard)

The standard was formulated earlier, and the quality grade of bearing was judged by measuring the vibration acceleration value when bearing rotates. From low to high, it was divided into three quality grades: Z 1, Z2 and Z3. At present, domestic bearing manufacturers are still using it, and the vibration acceleration value is used to measure the quality of bearings and simply reflect the fatigue life of bearings.

2. Vibration speed standard (commonly known as V standard)

Because the original vibration acceleration standard has not been abolished, it appeared as a standard issued by the Ministry of Machinery Industry, and was formulated with reference to European standards in combination with China's actual situation and needs. By detecting the vibration speed of bearings, the quality grade of bearings was classified (equivalent to national standards). It is divided into five quality grades: v, V 1, V2, V3 and V4.

The quality grades of various ball bearings are V, V 1, V2, V3 and V4 from low to high. The quality grades of roller bearings (cylinder and cone) are V, V 1, V2 and V3 from low to high.

It reflects the quality of the bearing by detecting the vibration B velocity of the bearing in different frequency bands (low frequency, intermediate frequency and high frequency). Generally, we can analyze whether there are geometric size problems (such as steel ring ellipse), raceway/roller quality problems and cage quality problems in bearings, which has made remarkable progress compared with vibration acceleration.

Domestic bearings are exported to Europe, and our army and aerospace industry carry out bearing quality inspection according to this standard, which provides a feasible means to detect the quality of bearings imported from Europe and distinguish counterfeit bearings.

There are two parallel standards for bearing quality inspection, but the bearing with high quality grade of "Z standard" may not have good quality and performance by "V standard" inspection, and there is no corresponding relationship between them. This point should be paid special attention to in bearing quality inspection.

According to the requirements of bearing working conditions and working environment for sealing degree, various sealing forms are often used comprehensively in engineering design to achieve better sealing effect. The following main factors should be considered when selecting the external seal of the bearing:

1 bearing lubricants and types (grease and lubricating oil);

2. The working environment of the bearing and the size of the occupied space;

3. Advantages and allowable angle deviation of the supporting structure of the shaft;

4 peripheral speed of sealing surface;

5 working temperature of bearing;

6 manufacturing cost.

From the use point of view, in order to ensure the bearing can work reliably, we should pay attention to the following points:

1. Improve lubrication quality, control oil pressure, temperature and flow, and strengthen oil filtration.

2. Use fuel and lubricating oil that meet the requirements.

3. The diesel generator set should not control the temperature state and work under the conditions of supercooling and overheating. In cold weather, the diesel engine should be warmed up before starting, and the crankshaft should be turned by hand to make the oil enter the friction surface.

4, bearing and journal surface quality and geometry should be strictly guaranteed.

5, bearing clearance should be appropriate, the generator set is too large to produce impact, too small is poor lubrication, may burn tiles.

References:

Baidu encyclopedia-bearings