ABSTRACT
The reliability of the main transmission mechanisms of the dump trucks largely depends on the load of the machine with the rock mass, as well as on the profile of the technological roads.
On modern dump trucks of the BelAZ series with a carrying capacity of up to 90 tons, a hydromechanical transmission (GMP) is used, and larger vehicles (120-450 tons) are equipped with an electromechanical transmission.
Hydromechanical transmission includes a torque converter (GT) and a gearbox (CAT). Two types of gearboxes can be installed on machines of the same series: a four-shaft gearbox with permanent toothed gear wheels in pairs and individual friction clutches; gearboxes with four-stage planetary gears, individual friction clutches and brakes.
As a result of the analysis of failures of the GMP dump trucks, the authors found that the design parameters of friction with the leading elements of gearboxes had a significant impact on their reliability and operational efficiency. Repeated gear changes during one trip of the car in the laden condition are accompanied by intense slipping of the drive disks relative to the slaves and, as a result, they have a negative effect on the thermal regime of the working fluid in the crankcase. Therefore, preference should be given to clutches with a larger diameter and fewer discs.
