Combine harvester threshers operator workplace vibration load study and substantiation their secondary cushioning systems design principles

The work is devoted to a research of working conditions of combine harvester threshers operators for the purpose of their workplace vibroloading. The results of the conducted experimental studies of classical configuration modern combine attendant workstation vibroloading are presented. It is demonstrated that the complete value of vibration in all space directions on the operator seat and on the cabin floor significantly exceeds permissible normative values. At the control points the most loaded frequency range located in the field of mid frequencies and also the most active directions of vibration action vibration are determined. For the analysis of the established processes reasons and the list of events for its elimination, spectral contents of the fluctuations operating on the bearing system in cabin installation sites and also on a cabin framework are measured and analyzed. The distinctions on frequency structure and also amplitude of the vibration accelerations operating under cabin support on its stretcher are revealed. It is proved that the existing system of a cabin cushioning of the studied machines is not capable to reduce effectively vibrations of leading frequencies and the directions as rubber-metal vibrator isolators, which performances do not correspond to character and features of the operating vibroloadings, are used in it. For the analysis of the vibro ditherings asymmetry reasons, operating on a cabin from its carrying system, the results of the analysis of natural frequencies and forms of fluctuations of the combine cabin stretcher are presented and the need of accounting of its properties in the course of selection of vibrator isolators is proved. Vibration protection effective systems design philosophy is offered and the directions of further researches on this subject are proved.