Requirements Imposed to Operational Parameters of Antiskid Devices
The aim of the paper is to clarify the possibility of a wheelset to be damaged while steering into skid under specific parameters of the anti-skid device. First of all it is necessary to clarify the composition of the antiskid device operational delay versus the moment when its operation becomes necessary. Initially there were obtained formulae of time interval required to reduce braking effort to the level ensuring the decrease in the wheelset slippage velocity. The aspect of slippage velocity values giving start to the wheel steel flow shear is discussed separately. Based upon the obtained formulae assessment of the antiskid device actuation time has been performed. Also the time has been assessed in which it is possible to fix the initiation of a wheelset steering into skid while using pulse transducer, generating voltage pulse after the wheelset revolution through the given angle. The investigation has been conducted to define the value of wheel - rail adhesion coefficient at which minimum time is left to actuate the antiskid device. The optimum exists so far as the wheel can’t be damaged at the coefficient’s small values and is steering into skid rather slowly at its large values. Also under discussion is the accuracy of applied models. It is concluded that with the made assumption on the adhesion coefficient variation in the course of the wheelset steering into skid there is no sense in enhancing the accuracy of the adopted models. The work resulted in defining main design principles of the antiskid devices and in answer to the question if it is possible for antiskid device with certain parameters to prevent the wheels of the certain vehicle from damage.