Operability assessment of drive shafts of john deere tractors in operational parameters

Operational observations of agricultural machinery are criteria-based assessment of reliability of their technical systems, in particular, of drive shafts of the John Deere 7830 tractors. 35 tractors, which are operated in the conditions of ordinary operation in the agrarian enterprises of the Belgorod region, Russia, were monitored. At the heart of experiment planning the observations of duration of the operating time and cross-section of loading of tractor engines according to the on-board computer with control of radial play in the joints of the drive shaft of the gearbox are put. The purpose – establishment of regularity of the size of radial play in cardan joints depending on the level of loading and duration of the operating time of the shaft in transmission of tractors at agricultural work. The technique of operational observations contained fixing of the following data: 1) control of the operating time of the tractor in physical hours according to onboard computer system; 2) measurement of radial play in the joints of the drive shaft by means of the developed device; 3) removal of the cross-section of loading of the engine on power at the measured torque and rotary speed of the crankshaft of the engine. As a result of statistical processing of the experimental data it is established: 1) average operating time of drive shafts of the observed tractors has made 4277 hours (share from selection is about 60 %); 2) loading of the drive shafts on the engine of the tractor averages 48.2 kW (share from selection is about 50 %); 3) average radial play in the joints of the studied drive shaft makes 0.350 mm (share from selection is about 50 %). For the purpose of studying of interconnection and influence of the experimental data on the basis of the multiple regression analysis the two-factor mathematical model of dependence of radial play in the function on loading and operating time is received.