Fatigue and fracture performance of sealing ring of hydraulic lifting system of dump truck under different working conditions

Mining dump truck is an important mining equipment. Hydraulic lifting system is important for the working efficiency and safety performance of mining dump truck. Seal ring is the key component in hydraulic lifting system, good sealing performance can better support the work of mining dump truck. ANSYS software was used to establish a finite-element analysis model of the bud-shaped seal, analyse the stress distribution of the seal under the actual working conditions without oil pressure and with oil pressure, and explore the influence of the working parameters such as the fit gap, friction coefficient and oil pressure on the sealing performance of the seal. The results show that the maximum Von-Mises stress and maximum shear stress of the seal increase linearly with the increase of the fit gap, and the maximum contact pressure decreases; when the fit gap is about 0.3 mm, the sealing performance is optimal. Increasing the friction coefficient, the seal contact pressure decreases, resulting in increased wear of the seal; when the friction coefficient is small, it is conducive to improving the sealing performance and reducing the risk of seal breakage. With the increase of oil pressure, the maximum contact pressure of the seal ring basically increases linearly, which is conducive to improving the sealing performance; the maximum Von-Mises stress and the maximum shear stress increase firstly and then remain stable. The orthogonal test method was used to optimise the combination of the structural parameters of the seal, and the optimal combination scheme was obtained; while ensuring the sealing performance, the risk of seal breakage was reduced and the reliability of the seal was improved. The results of the study can provide theoretical guidance for the design and optimisation of the combined bud-shaped seal.