Scientific paper ID 1901 : 2019/2

The present paper deals with some questions, and their answers, which very often are arising, when performing a modernization process of crane travelling mechanisms. There are reviewed the important requitements, which have to be observed by selection of new electrical motors of crane travelling mechanisms according to modern European standards. There are reviewed a couple of basic theoretical principles, including calculation ot necessary static power, dynamic power and total power, as well as recommendations of crane manufacturers, concerning check calculations of necessary power for selected electrical motors. There are presented the basic technical parameters and criteria, which have to be used by evaluation of selected new electrical equipment of crane travelling mechanisms, according to modern ments, including: check criteria for necessary rated torque of electrical motor, check criteria for necessary average starting torque of electrical motor, as well as check criteria for necessary brake torque, which is performed according to two criteria: criteria for smooth stopping and criteria for necessary brake holding torque. Check criteria for necessary rated torque of electrical motor s also calculations of: real rated torque at the shaft of selected new electrical motor, necessary static torque at the shaft of electrical motor during starting of travelling mechanism, necessary static torque at the shaft of electrical motor during stopping of travelling mechanism, as well as necessary total torque (static dynamic) at the shaft of electrical motor during starting of travelling mechanism. Finally, a conclusion is given, which summaries the most important questions of the present paper.