CHARACTERIZATION OF GEAR PUMPS FABRICATED BY LIGA

This paper presents the characterization of a positive displacement, m agnetically-coupled, self-priming gear pump and a direct drive metal g ear pump. In the magnetically coupled design (the in-line pump), the g ears are indirectly driven by a electric motor coupled to a pair of ma gnets. The pump provides a flow rate of 350 mu l/min at 5000 rpm, over 140 cm-H2O (similar to 2 psi) of head pressure and 28.8 cm-H2O vacuum on the suction side for a single stage pump. A two stage in-line pump generated 53 cm-H2O vacuum at its inelt (21 '' H2O). Very recently, w e demonstrated a direct driven gear pump using a 3 mm smoovy(TM) brush less DC motor. The direct driven pump provides a maximum flow rate of 2.5ml/min at 1200 Hz (72 krpm) and 3.6 psi dead head pressure. The dir ect drive pump provided 18 cm-H2O vacuum at its inlet due to the large clearances in the first generation device.