Решающим требованием для привода одноковшевых экскаваторов является создание оптимальной формы механической характеристики. В настоящее время для экскаваторов с емкостью ковша 3—5 ж3 нашла применение система трехобмоточный генератор-двигатель ТГ-Д. Генератор, имеющий три обмотки возбуждения, создает падающую «экскаваторную» характеристику. Управление приводом осуществляется изменением тока задающей обмотки 1. Отрицательная одноступенчатая связь по току — обмотка 3 — определяет падающую форму механической характеристики при перегрузках. Положительная связь по напряжению — обмотка 2 — обеспечивает высокий коэффициент заполнения (0,7—0,8).
When designing, the excavator drive is calculated for maximum loads without taking into account the possible conditions of machine use and the forces that arise. As a result, the drive power often does not match the bucket capacity, which leads to incomplete use of the machine. The purpose of the author's research was to study the static lifting force during digging under various excavator operating conditions. When designing excavators, it is necessary to construct diagrams for all possible operating modes, on the basis of which a choice can be made of the optimal drive modes, its power and regulation. The proposed calculation method is simple and clear. It is of particular importance for the design of high-power excavators intended for specific conditions with previously known geological data.
Currently, the excavator drive of the generator-motor system with continuous electric machine regulation has become widespread. Our analysis of currently existing systems (drives of excavators SE-3, EGL-15, ESh-75/10) made it possible to propose a classification for electric drives of single-bucket excavators with continuous electric machine regulation. The classification is based on two features: the regulation principle and the excitation system in which the control links are located. The proposed classification made it possible to identify the advantages and disadvantages of individual systems, showed the prospects for their development and the expected properties of individual electric drive systems. The final choice of the optimal excavator drive system can only be made with strict consideration of the geological and mining conditions of the deposit, the development systems used, typical load schedules, technical conditions of regulation and economic indicators.
