Tenneco Inc.
Shaped collet for electrical stress grading in corona ignition systems

Abstract:

A corona igniter assembly which is designed to reduce the amount of air gaps between insulating components and thus reduce electrical fields concentrated in those air gaps and the associated unwanted corona discharge. The assembly includes a high voltage center electrode surrounded by a ceramic insulator and a high voltage insulator. A dielectric compliant insulator is disposed between the ceramic insulator and the high voltage insulator. A layer of metal is applied to at least one of the insulators, for example the ceramic insulator. A compliant collet formed of a partially resistive material covers a sharp edge of the layer of metal to reduce the electric field and smooth the electric field distribution at the sharp edge of the metal layer.