Loading modes control for testing tracked tractor transmission

Abstract

BACKGROUND: Confirmation of the operability of agricultural tractor transmission units is obtained by machinery manufacturers on the basis of bench tests. The development of technical solutions for test rigs for transmissions and load control systems with an approximation to operational modes is a relevant technical task.
 AIMS: Development of technical solutions of test rigs for testing transmissions of tracked tractors and load management systems based on the analysis of operational loading of transmissions.
 METHODS: An analysis of the operational loading of the transmissions of the DT and VT series tracked agricultural tractors was performed, based on the results of which the technical solutions for loading devices of test rigs were developed that allow reproducing loading modes with parameters statistically equivalent to the operational loading modes on the tested transmissions.
 RESULTS: A technical solution is proposed for a test rig with a hydro-closed power circuit, in which a hydraulic loader with a rotating spool, by lifting and relieving the pressure of the working fluid in the pressure lines, forms a load on the parts of the tested transmission in accordance with the operational loading mode obtained as a result of preliminary analysis. A technical solution for a test rig with eccentric loaders is also proposed, in which a constant level of load on the tested transmission is created by hydraulic loaders acting on the track chains, and variable loads are formed by eccentric mechanisms and disturbances from the track chains rewinding.
 CONCLUSIONS: The practical value of the study lies in the possibility of using the proposed technical solutions of test rigs to conduct tests of tracked tractor transmissions with an increase in the degree of reliability of their results due to the approximation of the transmission loading conditions on the test rigs to the operational ones.