Optimization of contact stresses in shoe brakes of mine hoisting machines

Purpose. The research aims to develop recommendations for reducing the maximum contact stresses between the brake lining and the mine hoisting machine drum. Methods. Existing methodologies for calculating shoe brakes of mine hoisting machines often use a hypothesis that assumes absolute stiffness of the brake rim and beam. The developed methodology, using a set of various mathematical and engineering methods, makes it possible to determine the pattern of contact pressure distribution depending on the ratio of the brake lining transverse stiffness to the brake beam bending stiffness. Findings. An analytical model of the brake beam, presented in the form of a circular bar of constant section, has been developed, which is based on the Winkler elastic foundation concept, providing the ability to adapt the stiffness in accordance with the complex brake lining parameters. The stress-strain analysis has identified a key dimensionless indicator – the relative lining stiffness, which has a significant impact on the contact pressure distribution. The research results are presented in the form of a comparative analysis of various design approaches used to provide a more uniform contact pressure distribution along the brake beam. Originality. The proposed analytical model is based on the Winkler elastic foundation involving variable stiffness parameters, which provides high accuracy in modeling the actual physical characteristics of the braking system. This is far superior to traditional methodologies that are based on the assumption of absolute component stiffness, thereby increasing the relevance and scientific value of the results. Practical implications. The proposed recommendations make it possible to optimize the design of braking systems, reducing maximum contact stresses, thereby improving the efficiency, reliability and durability of mine hoisting machines.