P planetary gearboxes Modular design can be combined according to customer requirements. Involute planetary gear was used to transmission, rational use of internal and external gear, power split, box with cast iron, greatly increased the cabinet's rigidity and shock resistance, carburizing quenching gears are used to obtain high wear resistant hard surface, all the gears are grinded after heat treatment. The noise is reduced, the efficiency is improved and the service life is long. Therefore, the characteristics were light weight, small size, large ratio range, high efficiency, smooth operation, low noise, high adaptability. Reducers are widely used in metallurgy, mining, lifting and transportation, electricity, energy, building materials, light industry, transportation and etc.