Marine engine housing cooling apparatus

Apparatus for use in cooling a marine engine, wherein the apparatus is driven by the engine, said apparatus comprising:

• a rotatable impeller having a hub means to which a plurality of radially outwardly extending vanes are attached, a first end of said impeller being operatively connected to the marine engine by said hub means whereby said impeller rotates when the engine is operating, said impeller having a generally cylindrical shape and being capable of moving water when rotated;
• an impeller housing generally surrounding said impeller, said housing having a generally cylindrical side wall and an outer end wall;
• liner means for providing a wear resistant surface adapted to be contacted by said impeller, said liner means having a cylindrical side wall substantially coextensive with said side wall of said housing and having a closed end adjacent said outer end wall of said housing, the inside of said liner means defining a portion of a main chamber in which said impeller is located;
• inlet means communicating said main chamber a supply of water when said marine engine is placed in water for operation and adapted to admit water into said main chamber;
• outlet means communicating with aid main chamber and adapted to expel water from said main chamber;
• rotation of said impeller applying a suction force for moving water into said main chamber from said inlet means and out of said main chamber through said outlet means;
• said impeller housing and said liner means defining a second chamber located between a portion of said liner means and said outer end wall, said housing including a space communicating said second chamber with said main chamber whereby water is admitted into sad second chamber when said impeller is rotated;
• said housing including at least a first flow directing rib located on the inside surface of the outer end wall of said housing for directing flow of water through said second chamber in a manner whereby water flow is directed across a substantial portion of the surface area of said outer end wall so that heat transfer is increased relative to that achieved in the event water flowed directly from said space to purge conduit means;
• and,
• said purge conduit means being attached to said housing and being adapted to expel water from said second chamber;
• rotation of said ,impeller causing water to flow through said second chamber to said purge conduit means for cooling said impeller housing outer end wall.