Drive motor and swivel actuator using same

A swivel actuator comprising:

• a lower housing with a hollow cylindrical portion protruding upward in the center thereof, which serves as a support shaft of the rotor;
• an upper housing stacked and assembled on an upper portion of the lower housing and having a through hole formed in a central portion thereof in which the hollow cylindrical portion protrudes upward through the through hole;
• a drive motor which is arranged on a bottom surface of the lower housing and has a rotor worm gear integrally formed on an outer periphery of a cylindrical extension portion of the rotor support extending to an upper portion of the through hole;
• first and second gear trains, each being arranged at intervals of 180 degrees at the outer periphery of the rotor worm gear protruding to the upper housing and being coupled thereto, having, in the middle of first and second power transmission shafts, first and second worm wheels gear-coupled to the rotor worm gear, and having first to fourth worm gears formed at both sides of each of the first and second power transmission shafts;
• first to fourth pinion gear units in which third to sixth worm wheels gear-coupled to the first to fourth worm gears are formed at the lower end portions of first to fourth support shafts, respectively, and first to fourth pinion gears are formed on the upper end portions of the first to fourth support shafts, respectively;
• a rotary table gear-coupled to a ring gear having the first to fourth pinion gears integrally formed on the inner side of the side surface portion thereof, so as to rotate;
• first and second bearings arranged between the cup-shaped lower end portion of the rotor support and a lower end portion of the hollow cylindrical portion to rotatably support the rotor, and stacked in series;
• and
• a third bearing rotatably supporting the rotary table on an outer periphery of an upper end portion of the hollow cylindrical portion.