A pump with flat-ring-shaped magnets

Previously, authors developed a novel linear actuator with flat-ring-shaped magnets and applied it to a pump. In this article, the output power of the actuator and the efficiency of the pump are obtained by experiments. A pai r of flat-ring-shaped Nd-Fe-B magnets having N and S Doles on the surface a re put on the same axis and face each other. Rotating one of the ring magne ts in the direction of its circumference, an oscillating force occurs on th e other magnet. When this magnet is restricted to linear motion along the a xis, the mechanical power driving the rotating magnet is transferred to the linear motion power. A pump was made with this mechanism. The efficiency o f the pump is experimentally obtained, where water pressure difference betw een the intake and the outlet has been changed. As a result, the efficiency of the pump attains to about 45%. The efficiency of the actuator itself is very high, because the actuator has no copper and iron losses, and a negli gibly small eddy current loss. (C) 1998 American Institute of Physics. [S00 21-8979(98)19011-4].