This series of motors are fully enclosed independent three-phase asynchronous motors with strong refrigeration and variable frequency speed regulation. By choosing variable frequency motors with different reference pole numbers, stepless speed regulation within the range of 100 to 3550 revolutions per minute can be achieved, with a wide speed regulation range. It is applicable to the fields of fans, pumps, conveyor line automation equipment and machine tools (such as CNC machine tools, machining centers) in industries like metallurgy, chemical engineering, textile, pharmaceuticals and printing.