As one of the commercial applications of DC motor, the huge demand for power tools attracts many motor manufacturers. Compared with other DC motor slightly higher-end brushless motor, also hope to conquer this industry, to share profits. According to the characteristics of brushless motor products, hand-held charging drill is expected to become the first fortress to be conquered.

The hand-held charging drill is mainly composed of DC motor, gear, power switch, battery pack, drill chuck, casing, etc. It is mainly used for screw, wood screw, self-tapping screw and so on. It can also be used for various metal and wood drilling. It is powered by batteries, usually DC7.2V-18V. Like other electric tools, high speed and high torque is also a problem that must be solved when brushless motor is used in hand-held charging drill. Taking the parameters of a 18V hand-held electric drill as an example (Fig. 1), at its efficiency point, the load speed is 15000 rpm, the load torque is 136 mNm, the output power is 360 W, and the outer diameter of the motor is not more than 40 mm.

According to this data, we can find that the key to solve the problem of high torque and high power of brushless motor is to control the current. Under a certain voltage, excessive heating of the current will cause the motor driver components to be burned out. If the use of external drive, you can solve this problem very well, but this brushless motor built-in drive has lost its advantages.

However, technology has always been improved in the continuous application, step by step to overcome the problem is also the most effective method in the application of brushless motor. We hope that our engineers will eventually be able to find a solution, that is, to retain the brushless motor built-in drive features, but also to enable the hand-held drill to obtain better performance, to achieve a perfect fit!