DE2216762

A self-pressurizing shaft seal for an oil filled submersible motor is characterized by an inboard spiral grooved face seal and an outboard conventional face seal disposed in series relationship along the motor shaft. During operation, the inboard spiral grooved face seal pumps oil from the motor interior into a substantially confined zone between the seals to increase the oil pressure at the outboard face seal without the necessity for structurally strengthening the entire motor housing. Also disclosed is the disposition of a shoulder on the spiral grooved seal runner face remote from the pumping interface to permit the oil pressure within the confined zone to hydraulicly increase the axial force upon the runner thereby increasing the pumping pressure of the spiral grooved seal in boot strap fashion. Other disclosed seals contain means for measuring the pressure within the confined zone to actuate remote signaling devices upon a failure of the outboard seal as well as spiral grooved face seals having valving means to alter the pumping rate of the inboard seal upon a loss of pressure in the confined zone between seals.