Thermostatically controlled electric compressor sump heater having self-contained thermostat

摘要

An electric heater for heating oil contained in the sump well of a compressor includes a thermally conductive shell having first and second opposed inner surfaces. A ceramic core having a D-shaped cross-section throughout is positioned in the shell and is provided with longitudinal channels which are disposed substantially the same distance from the outer curved surface of core. An electric resistance heating element is disposed in the channels and is energizable by a source of power for developing heat under the control of a thermostat disposed in the shell. A resilient pad of ceramic fiberglass material having low thermal conductivity is disposed between the flat surface of the core and the thermostat and urges the curved surface of the core and the thermostat into contact with the opposed inner surfaces of the shell while substantially blocking heat transfer therethrough from the heating element to the thermostat.