Yaw drive for wind generating set

The invention discloses a yaw drive for a wind generating set, which comprises a primary counterweight planet gear, a primary internal gear, a primary planet gear, a cross slider, a secondary counterweight planet gear, a secondary internal gear, a duplex planet gear, an output-stage internal gear, an input shaft and a secondary input shaft. The input shaft is connected with a motor to form a rocker arm. One end of the cross slider is connected with the input shaft, and a primary less-differential planetary transmission output member and a secondary less-differential planetary transmission input member are arranged at the other end, connected with the secondary input shaft, of the cross slider. The yaw drive is in two stages of less-differential planetary transmission which can meet the requirement of high transmission ratio of the yaw drive. Compared with the existing five-stage planetary transmission yaw drive, the yaw drive has reduced stages of gear transmission, and a yaw large gear is driven to achieve yawing of a wind turbine through a small gear on the output-stage internal gear when the yaw drive is operated. Specifically, the yaw drive is mainly composed of a gear box body, the planet gears, the internal gears and the like to achieve yawing.