EFFECT OF A TORSEN DIFFERENTIAL MECHANISM ON CAR TYRE WEAR

摘要

4WD systems include various constructions aimed at optimal distribution of torque between drive axles. In these systems, it is necessary to apply mechanisms separating the power provided from the engine to drive wheels. Many systems operate on the basis of wet multi-disc clutch or/and dog clutch control with the use of mechatronic devices. However, in view of their reliability and construction simplicity, the most valuable 4WD systems under field conditions are mechanical solutions. Torsen is an inter-axle differential mechanism, where the emerging internal friction moment of this mechanism causes that all kinematic discrepancies between transmission shafts of the front and rear axle of a vehicle produce a change in the distribution of torque, helping to level the rotational speeds of transmission shafts of the front and rear axles. As a result of the phenomenon described, the drive wheels of both axles of the vehicle move with different peripheral speeds, which causes energy losses and wear of tyres on both vehicle axles. This paper presents an analysis of the results obtained in tests on a vehicle with the Torsen system and describes phenomena occurring in the examined system as a result of emerging kinematic discrepancies, which may be caused by such factors as vertical force acting on the wheels of individual drive axles and tyre pressure.