Syringe pump

thingiverse

A fully automatic pump, with which the desired fluid amount can be pumped with. The first design sketches were inspired by open-source designs available on the Internet (Wijnen, Hunt, Anzalone, & Pearce, 2014), but didn’t match our quality requirements or functionality requirements. None of the available open-source designs were offering the possibility to go back and forth with the syringe plunger. Most of the designs were experimental, didn’t have a convenient structure and allowed the user to use only one type and size of syringe. This is why it’s been decided to completely re-imagine the pump design with inspiration coming directly from the commercially available syringe pumps. The resulting design is an easy to use device with convenient features that allow the user to use multiple syringe sizes, an easy-to-use system for the replacement of the syringe, and a bi-directional pumping possibility. Each one of the five parts of the pump has been sketched on paper first, and the dimensions have been calculated according to standard sizes of commercially available screws, nuts, metallic tubes, ball bearings and couplers. Instructions The design based on the sketches has been 3D modelled using the CAD software AutoCAD (source, company). Five different designs have been created, corresponding to the five different parts of the pump. The first piece is the base plate that includes the syringe support on one side and the motor support on the other side. Each of those supports contains excavations to leave room for the different screws, guiding bars, ball bearing and z-coupler. The “plunger holder” is made out of two parts. The first one is the one attached to the guiding screw, powered by the motor. It is the one that will be pushing the syringe plunger to deliver its content. Two slots in the block allow two nuts to go down to the screw axis, and will allow that part to move forwards and backwards. The second one has two functions: holding the plunger straight and pull the plunger when the first part goes backwards. The last two parts are the “syringe holders”. Those are made to firmly hold the syringe on the syringe support in the front part of the base plate, and have been designed in two different sizes in order to adapt to every existing syringe sizes. After a first test of the syringe pump, a design improvement has been made to the second part of the plunger holder, in order for it to be stronger, and to avoid having screws preventing the plunger to run its course entirely.