Effect of impeller and volute design on the performance of a miniature rotary shaft pump (RSP)

The paper presents the experimental and the numerical results obtained with micro rotary shaft pumps (RSP) with overall dimensions smaller than 10 mm. The impeller is the key component of these micro pumps. It is made by boring a hole in one end of the shaft and cutting slots in the side of the shaft at the bottom of the bored hole, such that the metal between the slots define the impeller blades. Two impellers with diameters of 2.5 mm and different blade widths were coupled with volutes with different heights (0.4 and 0.6 mm) and shapes. The pumps were tested and compared over a range of operating conditions. Pump performance characteristics, including pressure increases up to 4.2 kPa, and flow rates up to 50 ml/min are presented for several different pump speeds. Furthermore, 3_D numerical simulations were performed to model the micropumps. Focuses of the simulations were to study the blade height effects, and the stator rotor interference influence on the pump characteristics.