What Are Our Concerns About Bearings（50）

Q1: What type of bearing is 6205 and bearing classification standard?

A:General bearings (rolling bearings) code method:  

Divided into: pre-code, basic code and post-code.  

1.  Basic code (type code, size series code, inner diameter code) Basic code is used to indicate the bearing inner diameter, diameter series, width series and type, generally five digits, first described as follows:  

• 1) Bearing inner diameter is represented by basic code number one from the right and H digit.  For the common inner diameter d=20 ~ 480mm bearing inner diameter is generally a multiple of 5, these two numbers represent the bearing inner diameter size divided by 5 quotient, such as 04 represents D = 20mm;  12 means d = 60mm and so on.  For bearings with inner diameters of 10mm, 12mm, 15mm and 17mm, the inner diameters are 00, 01, 02 and 03 respectively.  For bearings with inner diameter less than 10mm and greater than 500mm, the inner diameter expression method is otherwise stipulated, which can be referred to GB/T272-93.  
• 2) The diameter series of bearings (that is, the bearing with the same structure and the same inner diameter changes in the outer diameter and width series) are represented by the third digit from the right of the basic code.  For example, for centripetal bearings and centripetal thrust bearings, 0 and 1 represent extra-light series;  2 indicates light series;  3 indicates the medium series.  4 indicates the repeated series.  The size pairs between the series are shown in the figure below.  In addition to 1, the thrust bearing is the same as the centripetal bearing.  
• 3) The width series of bearings (that is, the change series of bearing width with the same structure, inner diameter and diameter series) is represented by the fourth digit from the right of the basic code.  When the width series as shown in Figure 13-4 is listed as series 0 (normal series), the width series code O can not be marked in the code 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 collectively referred to as size series code.  
• 4) Bearing type codes are represented by the fifth digit from the right of the basic code (for cylindrical roller bearings and needle roller bearings and other types of codes are letters).  

2.  Post code bearing post code is to use letters and numbers to express the bearing structure, tolerance and material special requirements, etc.  Postcode is a lot of content, here are a few commonly used code.  

• 1) The internal structure code refers to the different internal structure of the same type of bearing, which is represented by letters followed by the basic code.  For example, angular contact ball bearings with contact angles of 15°, 25° and 40° are denoted by C, AC and B respectively.  
• 2) The tolerance grade of bearings is divided into class 2, class 4, class 5, class 6, class 6X and class 0, a total of 6 grades, successively from high to low, and its codes are/PZ, / P4 ‘/ PS, / P6, / P6X and/PO respectively.  In the tolerance class, class 6X is only applicable to tapered roller bearings;  Grade 0 is general grade and is not marked in the wheel bearing code.  
• 3) The commonly used radial clearance series of bearings are divided into 6 groups, namely group 1, group 2, group 0, group 3, group 4 and group 5. The radial clearance is successively from small to large.  O group clearance is a commonly used clearance group, which is not marked in the bearing code, and the other clearance groups are respectively represented by/CI, / CZ, / C3, / C4 and/CS in the bearing code.  

3.  The prefix code of a bearing is used to indicate the partial parts of the bearing, represented by letters.  For example, L represents the separable ring of the separable bearing;  K represents the rolling body and cage components of bearings, etc.  

• There are many types of rolling bearings in practical application, and the corresponding bearing codes are also more complex.  The code introduced above is the basic and common part of the bearing code. If you are familiar with this part of the code, you can identify and check the common bearings.  Detailed code method for rolling bearings can be referred to GBT272-93.  

Q2: What type of bearing is 6004D?

A:Single row deep groove ball bearings  

6004: Basic model, open  

Inside diameter: 20 mm  

Outer diameter: 42 mm  

Thickness: 12 mm  

D: One side with contact rubber sealing ring (NSK often used)  

Q3: What are the parameters of 6234 bearings?

A:Bearing type: deep groove ball bearing  

New model: 6234  

Old model: 234  

Inner diameter (mm) : 170  

Outer diameter (mm) : 310  

Width (mm) : 52  

Rated dynamic load Cr(KN) : 245  

Rated static load Cor(KN) : 260  

Grease lubrication speed (R /min) : 1700  

Oil lubrication speed (R /min) : 2200

Q4: How is the bearing type specified?

A:Bearing model is a series of numbers and letters combined, standard GB/T272-93 provisions, each bearing has the corresponding number to replace, symbol of rolling bearing structure, size, type, accuracy, etc  

Q5: What are the sizes of 1510 bearing block national label and Z2524Y bearing block national label?  

A:New code: Z2524Y inner diameter: 120mm outer diameter: 215mm thickness: 185mm product classification: bearing seat product description: ZY2500 type split bearing seat.

New code: 2210 Old code: 1510 Inner diameter: 50mm Outer diameter: 90mm thickness: 23mm Cage material  

Q6: What are the models of deep groove ball bearings with diameters less than 26?

A:The outer diameter of the following deep groove ball bearings is not greater than 26mm  

Inner diameter 3mm: 623,  

Inner diameter 4mm: 618/4,619/4,604,624,634,  

Inside diameter 5mm: 618/5, 619/5, 625,635  

Inner diameter: 618/6,619/6,626  

Inside diameter 7mm: 618/7, 619/7, 607,627  

Inner diameter 8mm: 618/8, 619/8, 608, 628  

Inner diameter 9mm: 618/9, 619/9, 609, 629  

Inner diameter: 61800, 61900, 6000  

Inside diameter 12mm: 61801, 61901  

Inside diameter 15mm: 61802  

Inner diameter 17mm: 61803  

Q7: How to distinguish the type and quality of deep groove ball bearings?

A:Features: high speed, high precision, low noise and vibration, mainly bearing radial load, also can bear a certain axial load, simple manufacturing and low cost.  

Standard models begin with “6”, such as “6204”, “61802”, among which the last two numbers represent the bearing inner diameter.  

Bearing quality can be seen from the tolerance grades “P0, P2, P4, P5, P6x, SP, UP”.  

Q8: What are the dimensional tolerances of deep groove ball bearings?  What are the upper and lower limits of size?  

A:1 millimeter (mm) =1000 microns (μm)  

Bearings have different tolerance standards for different sizes and accuracy grades.