1. Classification by rolling bearing structure type

(1) Bearings are divided into: according to the load direction or nominal contact angle they can bear:

1) Radial bearings - rolling bearings mainly used to bear radial loads, with nominal contact angles from 0 to 45. According to different nominal contact angles, they are divided into: radial contact bearings - radial bearings with a nominal contact angle of 0; centripetal angular contact bearings - radial bearings with a nominal contact angle greater than 0 to 45.

2) Thrust bearings - rolling bearings mainly used to bear axial loads, with nominal contact angles greater than 45 to 90. According to the different nominal contact angles, they are divided into: axial contact bearings - thrust bearings with a nominal contact angle of 90°; thrust angular contact bearings - thrust bearings with a nominal contact angle greater than 45 but less than 90°.

(2) Bearings are divided into: according to the type of rolling elements:

1) Ball bearing----the rolling element is ball:

2) Roller bearing----The rolling elements are rollers. According to the type of roller, roller bearings are further divided into: cylindrical roller bearings - bearings in which the rolling element is a cylindrical roller, and the ratio of the length to diameter of the cylindrical roller is less than or equal to 3; needle roller bearings - Bearings in which the rolling element is a needle roller, the ratio of the length to diameter of the needle roller is greater than 3, but the diameter is less than or equal to 5mm; tapered roller bearings - bearings in which the rolling element is a tapered roller; spherical roller bearings one by one The rolling elements are spherical roller bearings.

(3) Bearings are divided into: according to whether they can be aligned during operation:

1) Aligning bearing - a bearing whose raceway is spherical and can adapt to the angular deviation and angular movement between the axis lines of the two raceways;

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

(4) Bearings are divided into: according to the number of rows of rolling elements:

1) Single row bearing - a bearing with one 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) Bearings are divided into: according to whether their components can be separated:

1) Separable bearings - bearings with separable parts;

2) Non-separable bearings - bearings in which the rings cannot be separated freely after the bearings are finally assembled.

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

2. Classification according to the size of rolling bearings Bearings are divided into: according to their outer diameter size:

(1) Miniature bearings - bearings with a nominal outer diameter range of less than 26mm;

(2) Small bearings----bearings with nominal outer diameter ranging from 28-55mm;

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

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

(5) Large bearings----bearings with nominal outer diameter ranging from 200-430mm;

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