Reciprocating combination mechanism

The utility model discloses a reciprocating type combination mechanism which comprises a motor, a worm gear, a worm, a transmission shaft, a guide through key, an ellipsoidal screw and an axial limiting body assembly, the transmission shaft penetrates through the worm and the ellipsoidal screw, and one end of the transmission shaft is connected with the motor; the guide through key is arranged onthe transmission shaft and penetrates through the ellipsoidal screw and the worm; the worm is fixedly connected with one end of the ellipsoidal screw; the worm wheel is matched with the worm to realize the rotation of the worm wheel; the ellipsoidal screw is in key connection with the transmission shaft, a first spiral groove and a second spiral groove are formed in the surface of the ellipsoidalscrew, and the first spiral groove and the second spiral groove are spirally arranged from one end of the ellipsoidal screw to the other end of the ellipsoidal screw. The first spiral groove and the second spiral groove are pa