Planetary gear transmission principles, is from a powered turret external torque by clutch passes to the planet, as well as leading public planet as the planet orbits the round conveyor standard. Internal gear stationary, with internal gear public in Planetary gears with orbits in the opposite direction of rotation. Common rotation of the planetary gear drive instead of meshing of the Sun wheel. Sun wheel drive output shaft, so as to achieve speed and torque output, output shaft turning the input shaft turning the opposite. In the case do not take into account the inertia of rotating members, when to the additional and more suitable for angular velocity of planetary gear train, make them into bodies, the relative angle between each gear in the gear train speed and force does not change between the teeth, friction coefficient does not change. Therefore, can approximate the idea that planetary gear system and the transformation of their friction loss power in institutions are equal, and planetary gear train friction losses and meshing power is proportional to the value.