Patent ID: 6632075
Filing Date: 2003-10-14
Classification: F04D

Abstract:
A sealing and cooling device for a submersible machine, such as a pump or a mixer, said submersible machine comprising a driving unit such as an electric motor (1), a hydraulic unit (2) with a pump impeller or a propeller connected to the motor via a driving shaft (3) and an intermediate seal unit (4), the latter comprising two mechanical face seals, separated by a room containing a liquid which acts as a barrier medium for the two seals as well as a cooling medium for the motor, a circulation pump (10) for said medium being integrated in the seal unit (4), characterized in thatthe barrier/cooling medium during its circulation obtains a mainly turbulent flow and passes at least two narrow gaps, a first gap (6) surrounding the stator (5) of the motor, where heat is absorbed, and a second gap (7) which on one of its sides is limited by a wall (9) that is cooled by the working medium of the machine, said second gap (7) being mainly radially directed and having a radially inward increasing width for compensation of the inward decreasing space, thereby securing an essentially constant cross section and a constant flow speed through the gap.