“BELAZ” JSC — management company of holding “BELAZHOLDING” (Zhodino, Republic of Belarus):

Reginya V. V., Head of the Bureau of Hydromechanical Transmissions (Department of the Chief Design Engineer of Scientific and Engineering Center), e-mail: kbst@belaz.minsk.by

The automatic control system of hydromechanical transmissions was introduced on the basis of the selector of automated transmissions on the following mine dump trucks:
- the dump truck BelAZ – 7555B with 55 t of payload capacity;
- the dump truck BelAZ – 7555E with 60 t of payload capacity;
- the dump truck BelAZ – 75450 with 45 t of payload capacity.
Selector executes the following functions:
- control of electromagnets of hydromechanical transmission in automatic and command mode;
- automatic control of electromagnets of block system of torque converter and a delay brake;
- control of electromagnet of hydrodistributor, installed in the control line of loading brake;
- formation of engine control signals;
- protection from irregular operations of driver, during the controlling of hydromechanical transmission;
- failure definition in hydromechanical transmission with the possibility of failure codes reading;
- information exchange with electronic devices of other manufacturers on the CAN-interface (report J1939).
The plant manufactured the test models of mine dump trucks BelAZ-7555E and BelAZ-75450 with the modernised hydromechanical transmission and mechatronic automatic control system. Mehatronic control system represents the set of electronic, electric and hydraulic components, operating under the control of the high-efficiency digital controller. This controller realizes the problem solving of information handling and control of hydromechanical transmission in real-time mode, as well as the proportional valves for the control of hydraulic fluid flow to frictional clutches. Proportional electrohydraulic valves of switching the frictional clutches on, are the devices, which realize the transformation of electric signals, received from the electronic control package in the fluid flow, with the pressure, proportional to the value of control signals. During the maintenance operation of the “BELAZ” JSC dump truck, it is possible to connect the laptop with service program to the CAN tire. This program makes it possible to electronic block to record the new version of the control program of hydromechanical transmission, and to change the values of parameters of the control algorithm. This program also allows to consider the fault codes as the defined operating period of dump truck, and to realize the scanning of signals of transmitters, connected to the controller.