Electric Direct Current Starter Motors for Gas Turbine Engines

The broad range of design and operating requirements for gas turbine engine starters is addressed. Requirements more demanding than those for conventional combustion engine starters, such as longer cranking time resulting in the need for higher temperature capability, and starter-to-engine compatibility are of particular significance. The compounding effects of environment and limited space and weight allowance, along with discussion of the high reliability required for aerospace and transportation applications, are included. Starter design features such as electromagnetic design for improved commutation, high quality brushes and commutators, and rugged high temperature insulation systems are described. Twenty years' experience in the design and manufacture of starters for gas turbines and the resulting field service experience is referred to for discussion of design features. Two particular recent applications used as examples are: The starter for the gas turbine driven Ml Tank and the Boeing 767 Jumbo-Jet Auxiliary Power Unit Starter.