Excavator Supporting Wheel Assembly

The supporting wheel of excavator carries its own mass and operation load, and the property of the supporting wheel is an important standard to measure its quality. This paper analyzes the property of the supporting wheel, damage and causes. The main shaft is made of 50Mn high-quality carbon structural steel with C content of 0.48%~0.56%, Si content of 0.17%~0.37%, Mn content of 0.7%~1.0%, S content of less than 0.035%, P content of less than 0.035%, Cr content of less than 0.25%, Ni content of less than 0.30%. The Cu content is less than 0.25%.   Among them, Mn is an important element in alloy steel, which can improve the forging and plasticity of steel, and ensure that the material has enough toughness and wear resistance. After heat treatment, 50Mn steel has higher strength and hardness, excellent hardenability, deeper hardening layer, finer pearlite structure, and better mechanical properties.   The main shaft design standard requires that the depth of the hardened layer T is 2~7mm, and the quenching hardness is 50~62HRC. In order to improve the wear resistance of the support wheel body, the wheel body material is 40Mn2 alloy structural steel. The content of C is 0.37% to 0.44%, Si is 0.17% to 0.37%, Mn is 1.4% to 1.8%, P is less than 0.030%, and S is less than 0.030%.   The wheel body is formed by forging. After forming, the blank of the wheel body is tempered and the hardness reaches 26~32HRC to keep the inside of the wheel body with high strength, plasticity, toughness and comprehensive mechanical properties.   The surface of the wheel body is quenched to improve the hardness and wear resistance of the track surface of the support wheel. The hardening hardness is 50~58HRC, and the depth of the hardening layer is 6~12mm, so that the hardness of the track surface is basically close to the hardness of the chain rail section (48~58HRC).   Seal O-ring groove size and surface roughness should meet the design requirements, the matching surface should be chamfered, and clean burrs and sharp edges.