Calculation Features of the Bench Dynamic Parameters during Testing of the Motor-Wheel Reducer of BELAZ Mining Dump Trucks

Abstract

When conducting accelerated tests of transmissions and reducers of mobile machines, it is required to study the dynamic properties of the bench together with the test object installed on it. This is necessary to identify possible resonances in the oscillatory system and to select appropriate test modes, which exclude the occurrence of unacceptable levels of loads that violate the correspondence between the type and nature of damage in operation and during testing. The paper proposes a methodical approach to the calculational determination of the dynamic parameters (natural frequencies and natural modes of torsional vibrations) of the bench with a mechanically open loop during accelerated life tests of the two-row planetary motor-wheel reducers of BELAZ mining dump trucks, based on the study of the developed multi-mass dynamic model with lumped parameters. The calculation features consist in taking into account the existence of symmetry plane of the bench mechanical system with two reducers installed on it, as well as the presence of symmetrical branches in the planetary rows, formed by the masses of satellites rotating around their axes and elastic constraints connecting them with the sun and crown gears. The approach proposed makes it possible to significantly simplify calculations and to reduce the computation time.

Keywords

• mining dump truck
• motor-wheel reducer
• accelerated life tests
• test bench
• planetary gear train
• dynamic model
• natural frequencies
• natural modes
• resonant mode