Motor Grader Filter

Many devices are composed of individual components, especially in our crane industry. As one of the crane components, the reducer plays an important role that cannot be ignored. Today, we will summarize the reasons for the fracture of the gear shaft of the crane reducer. Let's take a look at the following text.
1. In terms of material selection for gear shafts, for shafts that mainly transmit power, high hardenability and superior quenched and tempered steel should be selected based on the torque transmitted and the corresponding journal size. However, metallographic analysis shows that the material of small gear shafts has a loose structure and excessive inclusions, resulting in a decrease in impact toughness. Under high variable loads, cracks rapidly propagate, leading to fracture.
2. In terms of structural design, the shoulder of the shaft has almost no transition fillet after welding repair, resulting in severe stress concentration and fatigue cracks under bending stress, which is the main cause of shaft fracture.
3. In terms of heat treatment, preheating treatment was not carried out as required before welding repair, resulting in differences in the surrounding tissue of the welding area. These differences exist in narrow areas and can generate high internal stress. Due to the effect of this internal stress, cracks immediately occur after phase transformation, leading to fracture. Secondly, after shaft welding repair, appropriate heat treatment was not taken, resulting in large residual welding stress and a decrease in shaft resistance to alternating stress. Once subjected to vibration, cracks are easily generated, leading to fracture.
4. In terms of processing technology, it has been tested that there is a large deviation in the machining of the shaft neck, which results in a loose fit between the shaft and the bearing inner ring, causing relative rotation between the shaft and the bearing inner ring, that is, running the inner ring, thereby causing the bearing inner ring to slide on the shaft and causing shaft wear, which is also another major factor leading to shaft wear and fracture.
After understanding the reasons for the fracture of the gear shaft of the crane reducer, I believe it will provide greater help for everyone in future use. What are the common faults in the use of the crane reducer? We will introduce them one after another. Welcome to inquire by phone!