Bearing model and its meaning Bearing model components
Bearing model and its meaning Bearing model components
The bearing model generally has a pre-code, a basic code and a post-code. In general, the bearing model is only indicated by the basic model. The basic model generally consists of three parts, type code, size code and inner diameter code. The post code is to use letters and numbers to indicate the structure, tolerance and special requirements of materials of the bearing. The prefix code is used to indicate the sub-components of the bearing, which are represented by letters.
General bearing (rolling bearing) code method
Divided into: pre-code, basic code and post-code.
1. Basic code
(type code, size code, inner diameter code [2 digits])
The basic code is used to indicate the inner diameter, diameter series, width series and type of the bearing, generally up to five digits, firstly described as follows:
1) The inner diameter of the bearing is represented by the first digit from the right of the basic code. The inner diameter of bearings with commonly used inner diameter d=20~480mm is generally a multiple of 5. These two digits represent the quotient of the bearing inner diameter size divided by 5, such as 04 means d=20mm; 12 means d=60mm and so on. For bearings with inner diameters of 10mm, 12mm, 15mm and 17mm, the inner diameter codes are 00, 01, 02 and 03 in turn. For bearings with an inner diameter less than 10mm and greater than 500mm, there are other regulations on the expression method of inner diameter, please refer to GB/T272-93.
2) The diameter series of the bearing (that is, the series of changes in the outer diameter and width of bearings with the same structure and the same inner diameter) is represented by the third digit from the right of the basic code. For example, for radial bearings and radial thrust bearings, 0 and 1 represent extra light series; 2 represent light series; 3 represent medium series; 4 represent heavy series. The size comparison between each series is shown in the figure below. Thrust bearings are the same as radial bearings except that 1 is used to indicate the extra light series.
3) The width series of bearings (that is, the change series of bearing widths with the same structure, inner diameter and diameter series) are represented by the fourth digit from the right of the basic code. When the comparison of the diameter series in Figure 13-4 of the width series is 0 series (normal series), the width series code O may not be marked in the code for most bearings, but for spherical roller bearings and tapered roller bearings, the width series Code 0 shall be marked.
The diameter series code and the width series code are collectively referred to as the dimension series code.
4) The bearing type code is represented by the fifth digit from the right of the basic code (for cylindrical roller bearings and needle roller bearings, the codes are letters).
The post code of the bearing is to use letters and numbers to indicate the structure, tolerance and special requirements of the material of the bearing, etc. There are a lot of postcodes, here are a few commonly used codenames.
1) The internal structure code indicates different internal structures of the same type of bearing, and is represented by letters followed by the basic code. For example: Angular contact ball bearings with contact angles of 15°, 25° and 40° respectively use C, AC and B to indicate the difference in internal structure.
2) The tolerance grades of bearings are divided into 2 grades, 4 grades, 5 grades, 6 grades, 6X grades and 0 grades, a total of 6 grades, from high to low, and their codes are /PZ, /P4, /PS, /P6, /P6X, and /PO. Among the tolerance classes, class 6X is only applicable to tapered roller bearings; class 0 is ordinary class, which is not marked in the wheel bearing code. .
3) The commonly used radial clearance series of bearings are divided into 1 group, 2 groups, 0 groups, 3 groups, 4 groups and 5 groups, a total of 6 groups, and the radial clearances are in order from small to large. The o group clearance is a commonly used clearance group, which is not marked in the bearing code, and the rest of the clearance groups are represented by /CI, /CZ, /C3, /C4, /CS in the bearing code.
3. Front code
The prefix code of the bearing is used to indicate the sub-components of the bearing, which are represented by letters. For example, L represents the separable ring of the separable bearing; K represents the rolling body and cage assembly of the bearing, etc.
There are many types of rolling bearings used in practice, and the corresponding bearing codes are also relatively complicated. The codes introduced above are the most basic and commonly used parts of the bearing codes. If you are familiar with this part of the codes, you can identify and check the commonly used bearings. Please refer to GBT272-93 for the detailed code method of rolling bearings.
The development history of China's bearing code
Before 1990, China has been using the former Soviet Union's rolling bearing code method that is completely expressed in numbers, which is very different from the internationally accepted bearing code method expressed in English letters and numbers.
The basic code of the old standard bearing is composed of seven Arabic numerals. The code can be preceded by a pre-code, followed by a supplementary code.
The seven-digit number counts from the right as the first digit, and the first and second two digits indicate the inner diameter of the bearing, for example: 00 is 10MM, 01 is 12MM, 02 is 15MM, 03 is 17MM, 04 is an integer multiple of 5, and 09 indicates the inner diameter is 45mm. The large inner diameter that cannot be expressed by two digits is directly marked with numbers after /. For miniature bearings with an inner diameter less than 10MM, the first digit directly indicates the inner diameter.
The third digit indicates the diameter series.
The fourth digit indicates the bearing type.
The fifth and sixth digits indicate the structural characteristics of the bearing.
Since the reform and opening up, China's bearing exports have increased rapidly. However, due to the different bearing codes, the export of Chinese bearings has been seriously hindered. therefore. In 1990, China decided to revise the original code name method for rolling bearings, adopting the internationally accepted code code method for rolling bearings represented by English letters and numbers, and formulated a national standard: GB/T 272-1993 "Rolling Bearing Code Name Method", and The decision was implemented on July 1, 1994. The impact of the change in the code number method of rolling bearings is even wider. The Ministry of Commerce organized the compilation of "Rolling Bearing Application Handbook" in 1994, which was published by Machinery Industry Press in 1996.
Explanation of bearing model:
B20 Reduced width tolerance
C2 Axial internal clearance is smaller than normal grade
C2H Axial internal clearance in the upper half of the C2 range
C2L Axial internal clearance in the lower half of the C2 range
C3 Axial internal clearance greater than normal
C4 axial internal clearance is greater than C3
CNL Axial internal clearance in the lower half of the normal range
FA machined steel cage, outer ring centered
MA Machined brass cage, outer ring centered
N2 There are two positioning grooves on the side of the large outer ring, separated by 180 degrees
PHAS Injection molded polyetheretherketone (PEEK) window cage, outer ring piloted, lubrication grooves on the pilot surface
P6 Dimensional accuracy and running accuracy are improved, and conform to ISO tolerance level 6 (higher than ordinary level)
P63 P6 + C3
P64 P6 + C4
S1 is dimensionally stabilized for bearing rings at temperatures up to 200°C
3E+05 C2H + CNL
In the process of selling SKF bearings, I encountered a lot of inquiries from customers, such as whether the bearings sold are originally from Sweden. In fact, the Swedish SKF bearing has now evolved into a brand.
There are 11 processing factories in Sweden that produce SKF bearings. In addition to the 11 factories in Sweden, there are 61 factories all over the world that are distributed in different countries. SKF can produce bearings of the same high quality, such as Argentina. , Austria, Brazil, China, France, Germany, India, Indonesia, Italy, Japan, Korea, Malaysia, Mexico, the Netherlands, South Africa, Spain, Sweden, the United Kingdom or the United States.
According to the allocation of resources, different types of SKF bearings are produced, so as to realize the optimization and specialization of resource allocation. The vast majority are still produced in the SKF bearing factory in Sweden. More than 80% of the steel used in SKF bearings is provided by SKF steel mills to ensure the high quality of raw materials. All important equipment is designed and assembled by SKF, so as to make the production equipment reach the highest level!
Therefore, when you buy and choose SKF bearings, it is not necessarily produced in Sweden. Don't think that the place of origin is not in Sweden, which will cause quality doubts.
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