Movement Stability of Tractor Unit

The article studies how movement stability of the tractor unit with a semi-mounted two-axle trailer is influenced by some kinematic parameters, in particular, by a change in the ratio between eccentricity (displacement of the platform support point of the trailer in relation to the axis of the front bogie wheels) and the wheelbase of the front bogie when the required additional load to the rear tractor wheels is selectively applied. The conclusion is made that the critical speed of a semi-mounted two-axle trailer increases with an increase in the ratio between eccentricity and the wheelbase of the front bogie. Which means that displacement of the platform support point of a trailer along the vehicle dolly wheelbase towards the tractor leads to more stable movement of the tractor unit for any ratios between the wheelbases of a dolly and a semitrailer.