1. Classifying by structure:
Classifying by loading direction or contact angle (nominal contact angle):
● Radial bearing--The rolling bearing whose loading direction is radial direction and contact angle is from 0° to 45°.
● Radial contact bearing--The radial bearing whose contact angle is 0°.
● Angular contact radial bearing--The radial bearing whose contact angle is greater than 0° and less than or equal to 45°.
● Thrust bearing--The rolling bearing whose loading direction is axial direction and contact angle is greater than 45° and less than or equal to 90°
Classifying by nominal contact angle:
● Axial contact bearing--The thrust bearing whose contact angle is 90°.
● Angular contact thrust bearing--The thrust bearing whose contact angle is greater than 45° and less than 90°.
2. Classifying by types of rolling element:
● Ball bearing--The rolling element is ball.
● Roller bearing--The rolling element is roller.
Classifying by types of roller:
cylindrical roller bearing--the bearing whose roller is cylindrical roller and the ratio of the length to the diameter of the roller is less than or equal to 3; needle bearing--the bearing whose roller is needle roller and the ratio of the length to the diameter of the roller is greater than or equal to 3 and the diameter of the roller is less than or equal to 5mm; tapered roller bearing--the bearing whose roller is tapered roller; self-aligning roller bearing--the bearing whose roller is spherical roller.
3. Classifying by self-aligning or not:
● Self-aligning bearing--The bearing whose raceway is spherical and can adopt to angular deviation of the two-axis between the axis line and angular motion.
● Non-self-aligning bearing (rigid bearing)--The bearing that can prevent angular deviation of raceway axis line.
Classifying by column number of roller:
a. Single row bearing--The bearing that has roller of one column.
b. Double row bearing--The bearing that has roller of two columns.
c. Multi-row bearing--The bearing that has roller of many columns.
4. Classifying by whether the bearing separate:
● Separable bearing--The bearing that has separable parts.
● Non-separable bearing--The bearing that can't be separable after forming a complete set.
Classifying by structure and shape (for example, having slot-filling or not, having the inner and outer ring or not, the structure of ferrule and flange, having retainer or not):
Classifying by size:
Classifying by size of external diameter:
1) Miniature bearing--The bearing whose external diameter is less than 26mm.
2) Small bearing--The bearing whose external diameter is between 28mm and 55mm.
3) Midsize bearing--The bearing whose external diameter is between 60mm and 115mm.
4) Medium and large bearing--The bearing whose external diameter is between 120mm and 190mm.
5) Large bearing--The bearing whose external diameter is between 200mm and 430mm.
6) Super large bearing--The bearing whose external diameter is between 440mm and 2000mm.
7) Super huge bearing--The bearing whose external diameter is greater than 2000mm.
5. Discriminating the bearing
We usually identify the bearing quality from the following ways:
1) Whether the external packing is clear?
For the double row tapered roller bearing, regular manufacturer has their professional designer to design the external packing and produces the external packing through professional factory. So, the external packing should be clear from the line to the color patch.
2) Whether the steel prints is clear:
Each bearing has brand word, label and so on, though these are very small. Regular manufacturer press the word before heat treatment by the technology of steel stamping. So the word is concaved deeply and clear. But the bogus products is not. Its word is blurry and on surface.
3) Whether there is abnormal noise:
Left hand holding the inner set of the bearing and right hand stirring the outer set repeatedly to make it rotating, then listen to whether there is abnormal noise. For bogus products, there is abnormal noise or the phenomenon of running unsmoothly. Because of the backward production conditions and manual operation, there are sand and dust in the bearing. This point is the key to judge whether the production process of the bearing is under strict-standard and whether the bearing is from regular manufacturer.
4) Whether the chamfering is symmetrical:
The chamfering of bearing is intersection of the cross and the vertical. Because of the limitation of production technology, the bogus products have unsatisfying parts of corner. So we can distinguish the salable product from this point.
5) Bearing packaging
The packaging includes inner packing and external packing. We put the bearing to inner packing after washing and rust prevention for being waterproof, moisture proof, dustproof, striking resistant, keeping the bearing's quality and precision, easy to use and sale.
Classifying the bearing inner packaging by rustproof period:
a. Short rustproof period packaging: The rustproof period is 3 to 6 months. This packaging is suit for offering large number bearings to same subscriber and being put into use in the short term. By the agreement between the two sides, we use simple packaging under the principle of using easily.
b. General rustproof period packaging: The rustproof period is 1 year. This packaging is suit for the bearing in usual use.
c. Long rustproof period packaging: The rustproof period is 2 years. This packaging is suit for dedicated and precise bearing.
The materials of bearing packaging include polyethylene plastic cylinder(box), brown paper, plain and wrinkle polyethylene laminated paper, paper box, polyethylene plastic film, nylon fastening line or plastic fastening tape, waterproof high strength plastic band, sack and so on. These materials are all up to the standard of decay resistance.