Ensuring reliability of hydraulic systems of road construction machines

BACKGROUND: Modern construction and agricultural machines have a hydraulic system that controls the working equipment. The reliability and long service life of the hydraulic system determines the reliability of the entire machine as a whole. Main of reasons for the failure of hydraulic systems are contamination of the working fluid with wear products of the internal surfaces of hydraulic machines, external contaminants, and changes in the properties of the working fluid. The filters currently used cannot always clean the working fluid during machine operation. The degree of cleaning of the working fluid depends not only on the fineness of filtration, but also on the features of the circulation of the working fluid circulation. Currently, insufficient attention is paid to the design of hydraulic systems, in particular to the mutual arrangement of individual elements of hydraulic systems. AIM: Increasing the reliability of the hydraulic drive of construction and agricultural machines by assessing and preventing the possibility of forming incomplete circulation of the working fluid. MATERIALS AND METHODS: The study object is a hydraulic system in which a hydraulic cylinder is installed. To evaluate the circulation of the working fluid in the hydraulic lines of the hydraulic system during the operation of the hydraulic cylinder operation, a hydraulic cylinder with a piston diameter of 100 mm, high-pressure hoses with an internal diameter of 8 mm and a length of 0.7 m to 8 m were used. A filter was provided in the hydraulic system for cleaning the working fluid, which was installed on the drain line. The assessment was made using the calculation method. RESULTS: It was found that the quality of cleaning the working fluid of hydraulic systems when using hydraulic cylinders in them is affected by the ratio of the volumes in the piston and rod cavities to the volumes in the hydraulic lines that link these cavities with the distributor. It is proposed to use the distance coefficient to check the possibility of complete cleaning of the working fluid. Several technical solutions are proposed to eliminate the formation of zones in which complete circulation of the working fluid does not occur. CONCLUSION: The reliability of hydraulic systems of construction and agricultural machines can be increased by improving the circulation of the working fluid. To do this, when designing hydraulic systems, it is necessary to take into account in advance the features of the circulation of the working fluid from hydraulic motors to distributors.