Design and construction of a high-speed high-performance direct-drive handpiece

Abstract

The electrical and mechanical design of a precision handpiece (or handtool) delivering 10 W at 150 000 rev/min is described. The 2-pole synchronous drive motor has a samarium-cobalt rotor magnet of axial length 7 mm and diameter 3 mm. The motor has mumetal laminations and a bar winding which is supplied at 2.5 kHz by three toroidal transformers built into the unit. An equivalent circuit and experimental data are given from a prototype constructed according to the design procedure.