Gearbox for reducing DC motor rotation speed and increasing torque. Includes worm gearboxes, planetary gear reducers, and parallel shaft gear reducers, used in conveyor systems, positioning mechanisms, rotary tables, and drive units of automation equipment in manufacturing devices. Selected based on specifications such as reduction ratio, allowable torque, backlash, and mounting method, combined with DC motors to achieve precise speed control and torque transmission. Differs from AC motor gearboxes and servo motor gearboxes in applicable motor type.