Worm gear device

The present invention relates to a worm gear device. The worm gear device according to the present invention comprises: a body; a worm wheel rotatably contained in the body to transmit power; slew ring units provided on upper and lower sides, with reference to the worm wheel, to facilitate rotation of the worm wheel; a cover coupled to the body so as to surround the slew ring units; bearing units installed on one side of the body and provided on both sides of a worm shaft, which meshes with the worm wheel and is thereby driven, to support the worm shaft to be able to rotate; a planetary reducer provided on one side of a bearing unit to reduce the rate of rotation and increase the torque; a DC motor provided on one side of the planetary reducer to rotate the worm shaft; and a limit switch provided on one side of a bearing unit, which is provided on the opposite side of the planetary reducer, to control the range of rotation of the worm shaft, wherein rotation of the worm wheel is facilitated, and grease can be supplied without dissembling components.