ANALYSIS OF OPERATING CONDITIONSFOR WHEELED NON-SUSPENDED VEHICLES BASED ON EXPERIMENTAL RESEARCH
Wheeled unsuspended machines include many slow-moving machines whose transport speed does not exceed 30-40 km/h. A distinctive feature of these machines is that the wheels and axles of these machines are rigidly attached to the frame, with no elastic and damping devices responsible for the smooth running of the vehicle. Examples of unsuspended wheeled machines are tractors, combines, as well as other agricultural, construction and special machines, the operation of which is carried out mainly on roads with uneven pavement. This article is devoted to the analysis of the operating conditions of wheeled non-suspended vehicles based on experimental studies obtained by NATI and other research organizations. Typical operating conditions for suspensionless machines are fields and dirt roads, which are very diverse and can be in different conditions depending on the intensity of operation, repair work and other factors. It was found that most (55%) of the total operating time per year, wheeled tractors carry out transport work, and a smaller (45%) they operate in the fields. The speed of movement of wheeled tractors during most operations in the fields is 5-10 km / h, for harvesting hay and silage crops - 10-15 km / h, for transport operations - 20-25 km / h. An analysis of the heights and lengths of irregularities in fields, dirt and gravel roads showed that their values vary in narrow ranges. It was found that the spectrum of the microprofile changes significantly with increasing speed. This makes it difficult to accurately determine the ranges of the most probable disturbance frequencies.