Axis and pin components are usually machined and used as supporting parts for bearings. In the bearing industry, some people also refer to them as rolling needles or rollers. Generally, many people believe that this should be done by the manufacturer of bearings. In fact, this is not the case. Precision component processing companies like ours can also do it, not only can they do it, but they can also do it very well, Today, we will introduce the design concept and related knowledge of the accumulated parts of the shaft and pin.
Axis pin components typically exhibit delayed fracture under stress. There have been galvanized parts such as car springs, washers, screws, and leaf springs that have broken one after another within a few hours of assembly, with a fracture rate of 40% to 50%. A special product cadmium plated parts have experienced batch cracks and fractures during use, and a national research project has been organized to develop strict hydrogen removal processes. In addition, some hydrogen embrittlement does not manifest as delayed fracture phenomenon, for example, electroplating hanging tools (steel wire, copper wire) often experience brittle fracture after multiple electroplating and acid washing, resulting in severe hydrogen permeation; The core rod used for precision forging of hunting guns, after multiple chrome plating, fell to the ground and broke; Some quenched parts (with high internal stress) produce cracks during pickling. These parts have severe hydrogen leakage, which causes cracks without the need for external stress, and it is no longer possible to restore the original toughness by removing the shaft pin.
In the anti reduction design of the shaft pin, the friction type connection of the shaft pin bolt is the ultimate state where the external shear force reaches the maximum possible friction force provided by the bolt tightening force between the contact surfaces of the plate, which ensures that the internal and external shear force of the connection does not exceed the maximum friction force during the entire use period. The plate will not experience relative slip deformation (the original gap between the screw and the hole wall is always maintained), and the connected plate will be subjected to elastic overall force. In the shear design, the allowable external shear force in the high-strength axial pin bearing connection exceeds the maximum friction force. At this time, the relative slip deformation occurs between the connected plates until the bolt rod contacts the hole wall. After that, the connection is transmitted by the bolt rod shearing, the hole wall bearing and the friction force between the plate contact surfaces. Finally, the shear failure of the rod or the hole wall bearing is taken as the ultimate shear state of the connection.