Ejector fan shroud arrangement

• US 3,937,192 A
• Filed: 09/03/1974
• Issued: 02/10/1976
• Est. Priority Date: 09/03/1974
• Status: Expired due to Term

• Current Assignee: General Motors Corporation (General Motors Company)
• Original Assignee: General Motors Corporation (General Motors Company)
• Inventors: Longhouse, Richard E.
• Primary Examiner(s): Burns, Wendell E.
• Assistant Examiner(s): O'Connor, Daniel J.
• Application Number:
  US05/502,276
• Time in Patent Office: 525 Days
• Field of Search: 123/41.58, 123/41.66, 123/41.65, 123/41.48, 123/41.49, 165/51, 415/2, 415/4, 415/DIG. 1
• US Class Current: 123/41.49
• CPC Class Codes: F01P 5/06 Guiding or ducting air to, or from, ducted fans

Abstract

An engine cooling arrangement embodying a single fan and various embodiments of dual concentric shrouds associated therewith for producing an ejector action for substantially diminishing recirculation of the air flow.

Claims

1. An automotive engine cooling means for use intermediate a radiator and an engine, said cooling means comprising a fan having a plurality of fan blades and being operatively connected to and driven by said engine, and concentric inner and outer fan shrouds, each mounted so as to have a portion thereof positioned radially outwardly of said fan with said outer shroud extending a predetermined distance past said fan toward said engine, one of said shrouds having a rectangular-shaped face formed on an end thereof and secured to said radiator with the other end thereof being circular-shaped, and the other of said shrouds being cylindrically-shaped and secured to one of said fan at the outer tips of said fan blades thereof, said other shroud, and a separate fixed abutment, providing a clearance of a predetermined width intermediate said inner and outer shrouds, the air drawn through said fan and the air entrained through said clearance between said shrouds terminating in an ejector action extending from the engine end of said inner shroud to the engine end of said outer shroud, said ejector action serving to substantially diminish air-flow recirculation around the outer tips of said fan blades to the low-pressure area intermediate the fan and the radiator.

2. An automotive engine cooling means for use intermediate a radiator and an engine, said cooling means comprising a fan having a plurality of fan blades and being operatively connected to and driven by said engine, and concentric inner and outer fan shrouds, each mounted so as to have a portion thereof positioned radially outwardly of said fan with said outer shroud extending a predetermined distance past said fan toward said engine, said outer shroud having a rectangular-shaped face formed on one end thereof and secured to said radiator with the other end thereof being circular-shaped, and said inner shroud having a diffuser formed at the engine end thereof and being secured to said fan blades at the outer tips thereof, the air drawn through said fan and the air entrained through the clearance between said shrouds terminating in an ejector action extending from the engine end of said inner shroud to the engine end of said outer shroud, said ejector action serving to substantially diminish air-flow recirculation around the outer tips of said fan blades to the low-pressure area intermediate the fan and the radiator.

3. An automotive engine cooling means for use intermediate a radiator and an engine, said cooling means comprising a fan having a plurality of fan blades being operatively connected to and driven by said engine, and concentric inner and outer fan shrouds, each mounted so as to have a portion thereof positioned radially outwardly of said fan with said outer shroud extending a predetermined distance past said fan toward said engine, said outer shroud having a rectangular-shaped face formed on one end thereof and secured to said radiator with the other end thereof being circular-shaped, and said inner shroud being substantially cylindrically-shaped and having a diffuser formed at the engine end thereof and being secured to said outer shroud via equallyspaced struts connected therebetween, providing minimal clearance between said inner shroud and the outer tips of said fan blades, the air drawn through said fan and the air entrained through the clearance between said shrouds terminating in an ejector action extending from the engine end of said inner shroud to the engine end of said outer shroud, said ejector action serving to substantially diminish air-flow recirculation around the outer tips of said fan blades to the low-pressure area intermediate the fan and the radiator.

4. An automotive engine cooling means for use intermediate a radiator and an engine, said cooling means comprising a fan having a plurality of fan blades and being operatively connected to and driven by said engine, and concentric inner and outer fan shrouds, each mounted so as to have a portion thereof positioned radially outwardly of said fan with said outer shroud extending a predetermined distance past said fan toward said engine, said inner shroud having a rectangular-shaped face formed on one end thereof and secured to said radiator and having the other end thereof circular-shaped and providing minimal clearance between the inner surface thereof and the outer tips of said fan blades, and said outer shroud being cylindrically-shaped, having a toroidal inlet formed at its radiator end and being secured at its engine end to a separate fixed abutment, the air drawn through said fan and the air entrained through the clearance between said shrouds terminating in an ejector action extending from the engine end of said inner shroud to the engine end of said outer shroud, said ejector action serving to substantially diminish air-flow recirculation around the outer tips of said fan blades to the low-pressure area intermediate the fan and the radiator.

5. An automotive engine cooling means for use intermediate a pair of spaced radiators and located forward of and aligned with an engine, said cooling means comprising a fan having a plurality of fan blades and being operatively connected to and driven by said engine, and concentric inner and outer fan shrouds, each mounted so as to have a portion thereof positioned radially outwardly of said fan with said outer shroud extending a predetermined distance past said fan toward said engine, said inner shroud having a rectangular-shaped face formed on one end thereof and secured to said forwardmost radiator and having the other end thereof circular-shaped and providing minimal clearance between the inner surface thereof and the outer tips of said fan blades, and said outer shroud being cylindrical-shaped, having a toroidal-shaped inlet formed at its forward end and a progressively varying circular-to-rectangular transition section formed at its rearward end and being secured at its rectangular end to said rearwardmost radiator, the flow drawn through said fan and the flow entrained through the clearance between said shrouds terminating in an ejector action extending from the engine end of said inner shroud to said transition section of said outer shroud, said ejector action serving to convert some of the fan dynamic pressure to static pressure, thereby offsetting the losses encountered at said rearwardmost radiator.