TRANSFER GEARBOX FOR VEHICLE WITH COMBINED PROPULSION UNIT

Abstract

The distribution of torque onto the driving axles of an all-wheel drive vehicle for special purpose is carried out by a transfer gearbox (TG). To increase the passability of the vehicle, it is necessary for a TG to have a rigid blocking drive to the leading axes. However, in this case, there is a power circulation which leads to unnecessary drive loading, so the design of the TG presupposes a differential. The paper presents a diagram and a mathematical description of the TG, which allows to automatically change the kinematic mismatch magnitude (KMM) to ensure the torque distribution depending on road conditions. This is especially important in case of torque distribution between different types of propulsion: elastic (wheel vehicles) and rigid (caterpillar vehicles). Three variants of torque distribution have been considered. A number of calculations for both non-controlled and controlled KMM have been performed to determine the coupling effect depending on the loading conditions of transmission elements. Simulation movement of a special purpose all-wheel drive vehicle for a given typed cycle was carried out in the conditions of a differentiated type of TG coupling between the elastic propulsion unit inter-axis and the controlled KMM of the elastic and rigid propulsion units. In the course of the calculation results processing, the obtained data of changing the torques onto the leading elements of a different type of propulsion units were subjected to a schematization by the maxima method. Subsequently, the schematized processes were represented as a function of the accumulated frequencies of the repeated cycle amplitudes as: a result of 100 km of run, and a distribution density function of process maxima. A comparative analysis of the structural schemes of transmissions has shown that the use of the power drive with a TG having a mechanism for regulating the magnitude of kinematic mismatch is the most expedient.