High current liquid metal collectors

Abstract

Acyclic machines require the transfer of very high d.c. currents from stationary to rotating contacts at low (5–300 V) voltages. A development program was undertaken to study new collector concepts for high current collector applications. A new “narrow-gap” liquid metal collector was developed, analyzed and tested in the laboratory. Several test series were completed that demonstrated a collector design capable of operating at more than 30.9 MA m −2 at rotor velocities from 0 to 28 m s −1 for acyclic motor applications. A twocollector test fixture was operated for over 9000 h without any significant change in current collector characteristics. A narrow-gap collector design was also tested at speeds up to 100 m s −1 for acyclic generator applications. An analytical model of the collector concept was developed to allow predictions of collector performance for various machine designs.