The BTD series is developed in four sizes identified by progressive number (from 2 to 5) corresponding to identical quantity of flanges designed for defined coupling with gearboxes.

• 根据与齿轮箱联结（耦合）而设计的法兰的数量（从2到5，以整数递增），来分别确定开发的BTD系列电机的四种规格。