Research on calculation methods of motor power for driving system of rack and pinion shiplift

LIAO Le-kang， FANG Yang， LIN Xin-zhi
（Changjiang Institute of Survey Planning Design ＆ Research， Wuhan 430010， China）

Abstract： The driving system in the rack and pinion climbing type shiplift is consists of four driving mechanisms and a synchronous axis system，of which the motor power must satisfy the normal working principle of the shiplift，so that the shiplift can continue to operate if the motor faults occurred in any one of the driving mechanisms. There hasn't been method among the open literatures and the test data for motor power calculation. The reverse path method，the power balance method and the total efficiency method for the motor power calculation were put forward and corresponding formulas were derived according to the mechanical transmission theory. The three methods were respectively applied in the driving power calculation of the Three Gorges shiplift and the Xiangjiaba shiplift. The results of the three methods for each shiplift are rather close. Through synthetically comparison in applicability，simplicity and accuracy of calculation，it is recommended that the power balance method can be preferentially applied when the layout of driving system has been determined，and the total efficiency method can be applied in the primary stage of the design.
Key words： rack and pinion climbing type ship-lift； driving system；motor power； reverse path method； power balance method； total efficiency method