The thesis is devoted to solving the problem of increasing the technical level of working machines, its preservation during a certain period of operation, as well as restoration at the stage of repair and modernization is the actual tasks of modern engineering.
Production efficiency in the mining and processing industries is associated with the level of development of transport and energy systems, whose drives include unique large-sized gears with a diameter of 8.5 meters and a module of up to 65 mm. Mining and transport vehicles operate at high loads under extreme environmental conditions, the abrasive wear and vibration nature of which leads to an accelerated loss of the functional parameters of gears, reducing the operating life of the drives. The problem of ensuring the life cycle of such machines is to determine the feasibility of manufacturing new drive parts or restoring worn out ones. To solve the problem of ensuring the operational properties of gears, taking into account their bearing capacity and contact interaction, which depend on the state of the surface layer as a whole (macrovidality, waviness, roughness, physicochemical properties), and not only on the roughness parameters, an integrated approach to studying changes the shape of teeth, wear and subsequent restoration of large gear wheels.
The selections of the repair strategy based on the metrological system for monitoring the parameters of the state of the surface layer of gear wheels, characterizing their operational properties, are investigated and implemented. The regularities of the processes of restoring the functional parameters of coarse-grained gears as the basis of the complex variational choice of the repair strategy are studied. The analysis of methods for restoring the functional characteristics of coarse-toothed gear and the features of restoring coarse-grained wheels with various methods of processing with the provision of minimal plastic deformations of the teeth of restored coarse-grained gears has been developed. The integrated use of the proposed principles makes it possible to obtain highly productive processes for the processing of cylindrical worn and reconstructed large-sized gear wheels, provided that the required quality parameters and the accuracy of the surface layer of the gear wheels are provided.
The proposed fundamentals of predicting the structure and parameters of the teeth processing systems of coarse-grained gears after restoring and modeling the parameters of the surface layer in order to reduce fatigue chipping and prevent tooth breakage of the restored large gears. The tasks of modeling the processes of optimal control of the parameters of accuracy, quality and productivity of the gear processing of large-sized gear wheels are proposed to be solved using impact methods, taking into account the specific conditions of formation of gear wheels.
Improved design and organizational optimization of the recovery systems for large-module external gears with the modeling of the internal relationships of the gear processing process for large-module transmissions during their restoration.
The tasks of modeling the processes of optimal control of the parameters of accuracy, quality and productivity of gear processing of worn and renewable large-sized gear wheels are proposed to be solved using impact methods, taking into account the specific conditions of the formation of gear wheels. The developed schemes of multi-criteria optimization of the process of restoring coarse-grained gears and the assessment of the nature of changes in the quality characteristics of gears. The method of selecting and assigning parameters for the process of reconstructing geometry and the physicomechanical properties of open cylindrical coarse-grained gears has been rooted
The modeling of the formation of the surface layer of gears with regard to internal relations, prediction of quality indicators in conjunction with the complex parameter of the state of the surface layer of hardened coarse-grained toothed colostas has been developed. An improved method for assessing the influence of vibrations on the process of forming the surface layer during the gear cutting of worn and renewable large-sized gear wheels.
The process of optimizing the restoration of large-sized precision gear rims and the repair and restoration of large-modulated hardened gears by the method of high-speed blade processing has been developed. To improve the characteristics of the surface layer of the teeth of restored and worn large-sized gear wheels, an improved method of restoring by rolling rollers. To improve the quality of restoration of coarse-grained gears, a spray hardening method has been introduced. The general principles of modeling the optimal control of the parameters of accuracy, quality and productivity of gear processing of restored and worn large-sized gears are performed.
