Chamfering can not only remove burrs, but also affect the important process of bearing assembly
Chamfering refers to the machining of cutting the edges and corners of the workpiece into a certain inclined plane. Chamfering is to remove the burr caused by machining Bearing Assembly on the part, and generally chamfering is made at the end of the part for the convenience of part assembly.
Chamfering is a term in mechanical engineering. Generally, chamfering is made at the end of the part in order to remove the burr caused Bearing Assembly by machining and facilitate the assembly of the part. Chamfering can be seen everywhere in our life, on the mobile phone frame, on the toughened door, on the vase and so on.
Generally, the function of chamfering is to remove burrs and make it beautiful. However, the chamfering specially pointed out in the drawing is Bearing Assembly generally the requirements of the installation process, such as the installation guide of fag bearing, and some arc chamfering (or called arc transition) can also reduce the stress concentration and strengthen the strength of shaft parts. In addition, it can also make the assembly easy, which is generally carried out before the end of processing.
On agricultural machinery parts, especially the end faces of circular fittings and circular holes are often machined into chamfers of about 45 °. Bearing Assembly These chamfers have many functions.
We must carefully check them in the maintenance operation and make full use of them, otherwise it will bring many difficulties to the maintenance of Bearing Assembly agricultural machinery and even cause unexpected faults. For example, before the forming process of small parts such as bolts, chamfering will also be carried out to facilitate the material to enter the forming die.
1. The bearing steel must be chamfered during rough machining Bearing Assembly before heat treatment, which plays a very important role in the release of stress, redistribution of internal structure, less crack and reduction of deformation during heat treatment. Chamfering can solve the problem of stress concentration.
2. Chamfering and deburring make the product not sharp and will not cut the user
3. It plays a guiding and positioning role during assembly.
Generally, the outer chamfer of the outer ring and the inner chamfer of the inner ring of NSK bearing are rounded corners. In addition to effectively avoiding contact stress, the main thing is that the size of the chamfer directly affects whether the bearing can be correctly installed in place.
When the bearing is installed between the axle box and the shaft, its chamfer is larger than that of the bearing box and the shaft shoulder. The chamfer of the bearing must be larger than this arc to ensure that the bearing fits to the axial positioning surface.
When the bearing chamfer is smaller than the chamfer of bearing housing and shaft shoulder, it cannot be assembled in place, which is easy to cause stress concentration at the bearing chamfer and facilitate installation. Fillet can ensure good transitional loading.
Especially in the process of NTN bearing, the matching shaft and the positioning surface of the shaft hole, that is, the shaft shoulder and the retaining shoulder of the bearing seat, the assembly of this part is inclined, and other matching parts cannot be matched. Therefore, the fit of two chamfers must be fully considered in the assembly process of the bearing.
When the grindstone surface is in contact with the rough raceway surface, due to the small contact area and large stress per unit area, the “reverse cutting” effect of the bearing workpiece will be affected under a certain pressure, and some abrasive particles on the grindstone surface will fall off, resulting in new wear and debris.
At the same time, the bumps on the surface of bearing workpiece are quickly cut, and the bumps and grinding metamorphic layer are removed by cutting and reverse cutting. This stage is called the cutting stage, in which most of the remaining metal is removed.
With the continuous processing, the surface of NSK precision bearing workpiece is gradually ground. At this time, the contact area between the grindstone and the workpiece surface increases, the pressure per unit area decreases, the cutting degree decreases and the cutting capacity decreases.
At the same time, the pores on the surface of the grindstone are blocked and in a semi cutting state. This stage is called the half cutting stage of bearing finishing. In the half cutting stage, the cutting marks on the surface of the bearing workpiece become shallow and appear dark luster.