Improvement measures 1:

On the fit of dimensions

In view of the sinking wear of the shaft shoulder, and from the summary-1 shoulder sinking picture (Figure 1), it can be seen that the outer diameter of the bearing inner ring and the outer diameter of the shaft shoulder are not reasonable.

1、 The outer diameter D of bearing outer ring is far less than the outer diameter DC of shaft shoulder. The inner ring of bearing directly falls into the inner part of shaft shoulder, resulting in the sliding friction surface of end face and end face. High speed operation of bearing will inevitably cause high temperature, resulting in hot cracks at the friction part and wear metal particles entering the bearing and the fitting of bearing inner diameter and journal, resulting in more harmful damage.

2、 The protrusion A1 of the cage relative to the inner ring is 2mm, and the chamfering width a of the shaft shoulder is 5mm. In summary-1, it is known that the displacement of the cage towards the roller body is about 3mm of the shoulder end face sinking, and the protrusion A1 of the cage relative to the inner ring is 2mm, and the total axial movement is about 5mm. As a result, the cage is easily interfered by the outer diameter of shaft shoulder da.

3、 After measuring the inner diameter D1 of bearing cage is less than the outer diameter Da of shaft shoulder, the total axial movement of cage is about 5mm, and the chamfering value of shaft shoulder a is 5mm, it can be determined that once the total axial movement of cage is greater than 5mm, the cage will receive interference from the outer diameter of shaft shoulder da. The bearing is stuck and burned.

Therefore, the following adjustments are made to the dimension fit:

The outer diameter DC of the shoulder should be adjusted to be smaller than the outer diameter D of the outer ring, and the appropriate value should be that the outer diameter DC value is about 90% of the outer diameter D.

The protrusion A1 value of cage relative to inner ring is adjusted to 0-1 mm by cage process control.

The chamfering width a of the shaft shoulder should be adjusted to a large value without affecting the bearing seal assembly, or the angle between the chamfer and the roller axis should be adjusted to 15-20 °.

The value of cage inner diameter D1 should be larger in bearing design or adjusted according to the outer diameter Da of roller shoulder.

Conclusion of the first measure:

Strictly speaking, except for the three necessary dimensions (inner diameter / outer diameter / height), which are standard dimensions, the design of other dimensions belongs to the category of non-standard parts. The roller manufacturer will adjust some detail dimensions or chamfering of the roller according to the field use. Similarly, if the bearing needs to achieve a higher matching degree with the customer's field application, it is necessary to It is necessary to understand the dimensions of some key parts on site, especially those directly fitted with bearings. This is particularly important for bearing design, manufacturing and field use. DMD bearing always adheres to one-to-one customized service, and continues to build more durable rolling mill bearings!!! (to be continued...)