The remote-controlled intelligent water meter has been popularized. The ball valve used in the intelligent water meter is mainly driven by DC motor. Its working principle is as follows: The DC motor starts after receiving the instruction of the controller, the reducer slows down the speed of the motor, increases the torque to drive the ball valve to rotate, so as to achieve the function of opening and closing. Constar has developed a solution of micro coreless motor (or cored motor) with planetary gearbox (or spur gearbox). With small volume and high torque, the product can meet the requirements that intelligent water meter ball valve is used in narrow space.