Transmission structure of medical injection pump

A transmission structure of a medical injection pump comprises a frame, a slider, a screw rod, a pair of guide rods and a push rod. The frame comprises a bottom plate and a pair of side plates. The side plates are fixedly arranged at two ends of the bottom plate and are perpendicular to the bottom plate. The slider is arranged on the bottom plate of the frame and is perpendicular to the bottom plate. A nut used for being spirally connected with the screw lead is arranged on the upper portion of the slider. A spring seat, a spring mounted on the spring seat and a shifting plate movably connected with the spring are arranged below the nut respectively. Two ends of the screw rod are rotationally connected to the inner side walls of the side plates of the frame respectively. The guide rods are parallelly and fixedly arranged on the inner side walls of the side plates of the frame respectively and between the bottom plate of the frame and the screw rod. The connecting end of the push rod is connected with the slider rotationally. The free end of the push rod penetrates one of the side plates and extends outwardly. A plurality of shifting plate grooves are formed in the outer surface of the push rod at intervals and are meshed with the shifting plate. The transmission structure has the advantage of novelty in design.