Agricultural machinery has a strong timeliness, especially the combine harvester that operates in an off-site place. It runs for thousands of miles, and sometimes it can't be repaired in time due to the damage of a disk bearing, which is difficult to buy locally, resulting in huge economic losses. Therefore, learning some substitute knowledge of rolling bearings has important practical significance.

1.Substitution principle of rolling bearings

The substitution of rolling bearings should follow the following principles.

(1)Do not change the size of the matching hole on the housing and the bearing sleeve.

(2)Do not change the size of the Journal on the shaft that fits with the inner sleeve of the bearing.

(3)The allowable static load and limit speed of the substitute bearing are similar to those of the original bearing.

2. Mutual substitution of radial ball bearings

Common single row radial ball bearings include 100 type (extra light series), 200 type (light wide series), 300 type (medium wide series) and 400 type (heavy wide series). As the series of bearings with the same inner diameter increases, the static load parameters also increase. We can use this feature to replace each other.

For example, the 305 bearing on the agricultural tricycle has an inner diameter of 25mm, an outer diameter of 62mm, a width of 17mm, a static load of 1160, and a limit speed of 1400. If 206 bearing is used instead, its outer diameter is 62mm, the inner diameter and width are 30mm and 16mm respectively, and the static load and limit speed are 1020 and 1300 respectively, which is similar to 305 bearing. So as long as the inner diameter of 206 bearing is 2 A 5mm thick sleeve can be replaced by a 1mm thick washer at the journal. Similarly, the outer diameter of 205 bearing can be inserted and 2mm thick washer can be added instead. However, the bearing with the same outer diameter as the original bearing and larger inner diameter than the original bearing should be selected as far as possible during replacement, because this not only ensures the strength of the substitute bearing, but also facilitates processing and installation.

Pay attention to the concentricity of the inner and outer diameters during the processing of the insert to ensure the installation accuracy. Centripetal ball bearings also have protective dust covers on one side (60000 type) and dust covers on both sides (80000 type, 50000 type, 160000 type, 180000 type). Some of their outer diameters have stop grooves and some have sealed dust covers. However, the inner diameter, outer diameter and width are exactly the same as those of ordinary (0000) bearings. In case of damage during operation, the ordinary type can be directly used instead, and the prototype bearing can be replaced after the operation. For example, if the bearings 180204 and 160209 used on Xinjiang-2 combine are damaged during operation, the bearings 204 and 209 can be directly used instead, and the prototype bearing can be replaced at the end of maintenance.

On Xinjiang-2 combine harvester, there is also a single row centripetal ball (roller) bearing with outer spherical surface, such as 960069 (with jackscrew on the inner sleeve of the bearing) and 390506 and 390507 (with eccentric sleeve). This kind of bearing can automatically adjust the center when the deflection of the shaft is large. If this kind of bearing is damaged during operation, it can also be temporarily replaced by 206, 507 and 506 ordinary bearings and a certain thickness of sleeve can be added to the shaft under the condition of good working environment (such as flat land, dry wheat, and small feeding).

3.Substitution of single row tapered roller bearings

The most commonly used single row tapered roller bearings are 7200 (light narrow Series), 7300 (medium narrow Series), 7500 (light wide series) and 7600 (medium wide series). The structural dimensions of this kind of bearings are characterized by 7200 and 7500 series, 7300 and 7600 series. The outer diameter of bearings with the same inner diameter is also the same, but the width is different. For example, the inner diameter and outer diameter of 7207 bearing and 7507 bearing on Xinjiang-2 combine harvester are exactly the same, but the width difference is 6mm, and the static load difference between them is not big, and the limit speed is the same, so as long as the washer thickness is increased or decreased, they can be used instead of each other.

4.Substitution of single row radial short cylindrical roller bearings

This kind of bearing is commonly used in 2200 type (outer ring without retaining edge), 3200 type (inner ring without retaining edge), 4200 type (inner ring with single retaining edge), etc. Its series and size structure characteristics are the same as those of single row tapered roller bearings, that is, the inner diameter and outer diameter dimensions of 2200 and 2500, 2300 and 2600 are exactly the same, but the width is different, so the substitution method is also the same. For example, the 32612 bearing in the tieniu-55 tractor can be replaced by the 32312 bearing, which only needs a washer. At the same time, 32515 bearing insert can also be used instead.

5. Mutual substitution of various bearings

In the code of rolling bearings, although the structure and type of bearings with the same last three digits are different, the inner diameter and width dimensions are exactly the same, so the following substitutions can be made. Generally speaking, try not to replace other types of bearings with single row radial ball bearings, so the bearing has low bearing capacity and short service life after replacement.

1. Single row centripetal short round roller bearings can bear large radial loads. When other suitable substitutes cannot be found, single row centripetal ball bearings can also be used temporarily. For example, the 2206 bearing of tieniu-55 tractor can be replaced by 206 bearing.

2. Single row centripetal thrust ball bearings can bear certain unidirectional axial force in addition to radial load. 36000 type (contact angle) is commonly used β=  12 °) and 46000 (contact angle β=  26 °), and those with large contact angle bear large axial force. They can be substituted for each other. For example, the 36203 bearing in the tieniu-55 tractor can be replaced by the 46203 bearing. 203 bearing can also be used instead when necessary.

3. Single row tapered roller bearings 36000 and 46000 bearings can bear axial force, so they can also be substituted for each other.

4. Double row radial spherical ball bearings (types 1000 and 111000) and double row radial spherical roller bearings (types 3000 and 113000) can be self-aligning, so they can also be used instead of each other. When there is still no substitute, the 1000 and 3000 bearings can also be replaced by single row radial ball bearings and single row radial roller bearings respectively.

More about WSW Tapered Roller Bearing：

The raceways of the inner and outer rings are tapered sections and the rollers are tapered, so the tapered surface of the raceway and the roller axis (if projected) will intersect at a common point on the bearing spindle. This geometry keeps the motion of the cone coaxial, and there is no sliding between the raceway and the outer diameter of the roller.

This conical geometry produces a linear contact surface that allows greater loads to be carried than spherical (ball) bearings with point contact. The geometry means that the tangent speed of each roller surface is the same as the raceway along the whole length of the contact surface, and there will be no differential scrubbing.

The rollers are stabilized and restrained by the flange on the inner ring, and their big ends slide against the flange, which can prevent the rollers from popping out due to the "pumpkin seed effect" of their conical shape. The larger the half angle of these cones, the greater the axial force that the bearing can bear.

WSW tapered roller bearing adopts outer ring and inner ring assembly. The outer ring is composed of an outer ring, and the cone assembly is composed of an inner ring, a roller and a cage. This bearing structure can withstand combined loads and provide low friction during operation. Rigid bearing applications can be achieved by adjusting a single row tapered roller bearing to a second tapered roller bearing and applying preload.