When NGCL drum-shaped gear coupling with brake wheel works, the relative angular displacement of two axes occurs, and the tooth surface of inner and outer teeth slides relative to each other periodically, which inevitably results in tooth surface wear and power consumption. Therefore, the gear coupling must work in a good and sealed state. Tooth couplings are small in radial dimension and large in load carrying capacity. They are often used in shafting transmission under low speed and heavy load conditions. Tooth couplings with high accuracy and dynamic balance can be used in high speed transmission, such as shafting transmission of gas turbine. Because the angular compensation of drum gear coupling is larger than that of straight gear coupling, drum gear coupling is widely used at home and abroad. Straight tooth coupling belongs to the eliminated product, so the selector should not choose it as far as possible.