The invention provides a pre-injection type
infusion pump which can precisely control the flux and flowing speed of an infusion apparatus. The
infusion pump consists of a pump body, a pre-
injection device and a driving mechanism; a driving pump wheel, a driven pump wheel, a ring-shaped belt (chain), a
pressure injection roller, a supporting roller and a supporting track are arranged at one side of a mounting bracket of the pump body of an infusion
pipe; and the oppositeness of the infusion
pipe is provided with a pad plate and a pad plate
elastomer. A locking
pipe piece, a pre-injection mechanism shell, a pre-injection sliding block and a pre-injection
cam are arranged above the driven pump wheel at one side of the mounting bracket of the pump body; the output end of a driving motor is provided with a reducing mechanism, the output end of which is provided with a transmission shaft which is provided with the pre-injection
cam and a driving
bevel gear; a driven
bevel gear is coaxially connected with the driving gear; the driven gear is coaxially connected with the driving pump wheel which drives the ring-shaped belt (chain) to motion, thus driving the
pressure injection roller to realize the pumping out function of the liquid; furthermore, the pre-
injection device can compensate the elastic
recovery quantity of the infusion pipe after rolling by coordinating with the pump body, thus ensuring constant output flux of the
infusion pump. The pre-injection typed infusion pump has no special requirements on disposable infusion apparatus.