Mechanism for changing the rear axle clearance of a universal-tiller tractor

Abstract

The article is described the design of the mechanism for changing the clearance of the rear axle of a universal-tiller tractor from a low-clearance to a high-clearance position and vice versa. The most loaded place in the design of the mechanism for changing the clearance of the rear axle, which is the clip, is determined. The dynamic analysis of the load on the cage for three cases of loading in two sections passing through the bearing supports is carried out. At the same time, the main recommendations are aimed at ensuring a sufficient margin of safety in dangerous sections of the cage. In particular, one of the ways to ensure a sufficient margin of safety in dangerous sections of the cage is to use a material for its production - 45L steel. In Central Asia, all mechanized work on inter-row processing of cotton crops is carried out by a three-wheeled tractor adapted to the natural and production conditions of the region. Studies have established a negative technogenic impact of the front wheel of a three-wheeled tractor on the soil, which is eliminated by the use of a four-wheeled tractor. However, its use is constrained by the inadequacy of the agrotechnical passage. To solve this problem, LLC “DTCAM” is developing a four-wheeled tractor equipped with mechanisms for changing clearance, which provides sufficient agricultural cultivation for inter-row processing of cotton crops. Identification of dangerous places in the design of the mechanism for changing the clearance of the rear axle and dynamic analysis of the loads at this place, preventing breakdowns, increases the reliability of this tractor. It has been revealed that one of such dangerous places is a cage connected to the DCT cover, which accepts the main load transmitted from the tractor to the wheels and back. Dynamic analysis of the cage loads for various cases of loading in two sections passing through the bearing supports showed that the most loaded section is the section of the bearing support located on the DCT side. There is an insufficient margin of safety in this section when the tractor moves along irregularities. To ensure reliable operation, it is recommended to introduce the hardening of the cage area from the DCT side, where the bearing of the mechanism for changing the clearance of the rear axle is at least 35 HRCe, or use material - steel 45L.