Fan shroud exit structure

Claim 9

A heat transfer system for an internal combustion engine comprising: a heat exchanger including a front and a rear section; a shroud having a forward section arranged to enclose said rear section of said heat exchanger, and a rearwardly extending unitary contoured exit section including a cylindrical throat, radial expanding section and a radial flat portion; a fan assembly including a plurality of fan blades having leading and trailing edges, said leading edges positioned adjacent said heat exchanger wherein the following relationship within plus or minus 12 percent of AW exists: RF AW/3, CF AW/3, and R 2AW/3 where RF is the length of the radial flat portion, CF is the length of the cylindrical throat, R is the radius of the radial expanding section and AW is the projected axial width of the fan means whereby fan generated noise and horsepower requirements of said engine are reduced.

Claim 10

A heat transfer system for an internal combustion engine comprising: a heat exchanger including a front and a rear section; a shroud having a forward section arranged to enclose said rear section of said heat exchanger, and a rearwardly extending unitary contoured exit section including a cylindrical throat, radial expanding section and a radial flat portion; a fan assembly including a plurality of fan blades having leading and trailing edges, said leading edges positioned adjacent said heat exchanger wherein the following relationship within plus or minus 12 percent of AW exists: RF AW/3, CF AW/3, and R 2AW/3 where RF is the length of the radial flat portion, CF is the length of the cylindrical throat, R is the radius of the radial expanding section and AW is the projected axial width of the fan means whereby fan generated noise and horsepower requirements of said engine are reduced.

Claim 11

The heat transfer system of claim 5 wherein the trailing edge of said fan forms a plane parallel, plus or minus 12 percent, with said radial flat portion, whereby the fan induced stream of air is converged and directed out parallel to the radial flat portion.

Claim 12

A heat transfer system for an internal combustion engine comprising: a heat exchanger having a front and a rear section; a shroud having a forward section arranged to enclose said rear section, and a rearwardly extending unitary contoured exit section including means defining a cylindrical throat, means defining a radial expanding section and a radial flat portion; a fan assembly including a plurality of fan blades each having a leading and a trailing edge, said leading edge being positioned adjacent said heat exchanger, wherein the following relationship exists: RF AW/3, CF AW/3, and R 2 AW/3 where RF is the length of the radial flat portion, CF is the length of the cylindrical throat, R is the radius of the radial expanding section and AW is the projected axial width of the fan whereby fan generated noise and horsepower requirements are reduced.

Claim 13

A heat transfer system for an internal combustion engine comprising: a heat exchanger having a front and a rear section; a shroud having a forward section arranged to enclose said rear section, and a rearwardly extending unitary contoured exit section including means defining a cylindrical throat, means defining a radial expanding section and a radial flat portion; a fan assembly including a plurality of fan blades each having a leading and a trailing edge, said leading edge being positioned adjacent said heat exchanger, wherein the following relationship exists: RF AW/3, CF AW/3, and R 2 AW/3 where RF is the length of the radial flat portion, CF is the length of the cylindrical throat, R is the radius of the radial expanding section and AW is the projected axial width of the fan whereby fan generated noise and horsepower requirements are reduced.

Claim 14

A cooling system for an internal combustion engine comprising: a radiator including means defining a tube and means defining a rearward area; a shroud having a forward section arranged to include said rearward area of said radiator, and means defining a rearwardly extending unitary contoured exit section including a cylindrical throat, a radial expanding section and a radial flat portion; a fan assembly including a plurality of fan blades each having leading and trailing edges, said leading edges being positioned adjacent said radiator, wherein the following relationship plus or minus 12 percent exists: RF AW/3, CF AW/3 and R 2 AW/3 where RF is the length of the radial flat portion, CF is the length of the cylindrical throat, R is the radius of the radial expanding section and AW is the projected axial width of the fan whereby the fan induced stream of air is converged and directed out generally parallel to the radial flat portion.

Claim 15

A cooling system for an internal combustion engine comprising: a radiator including means defining a tube and means defining a rearward area; a shroud having a forward section arranged to include said rearward area of said radiator, and means defining a rearwardly extending unitary contoured exit section including a cylindrical throat, a radial expanding section and a radial flat portion; a fan assembly including a plurality of fan blades each having leading and trailing edges, said leading edges being positioned adjacent said radiator, wherein the following relationship plus or minus 12 percent exists: RF AW/3, CF AW/3 and R 2 AW/3 where RF is the length of the radial flat portion, CF is the length of the cylindrical throat, R is the radius of the radial expanding section and AW is the projected axial width of the fan whereby the fan induced stream of air is converged and directed out generally parallel to the radial flat portion.

Claim 16

The cooling system of claim 8 wherein: said radiator includes means defining a rearwardly extending perforated area; said shroud enclosinG said perforated area, and said trailing edges of said fan blades are coextensive plus or minus 12 percent with said radial flat portion wherein the following relationship exists: RF AW/3, CF AW/3, and R 2AW/3 where CF is the length of the cylindrical throat, R is the radius of the radial expanding section and AW is the projected axial width of the fan.

Claim 17

A vehicle having an operator station, an internal combustion engine, a radiator for cooling fluid from said engine an axial flow fan axially facing said radiator and including a plurality of angular blades drawing air rearwardly through said radiator, and a shroud rearwardly extending from said radiator wherein the improvement comprises: a unitary shroud exit section closely surrounding said fan and extending in the same direction as said shroud including a tubular portion forming the leading edge thereof, an arcuate portion extending generally rearwardly and outwardly from said tubular portion and terminating in a flat flange portion forming the trailing edge of said shroud and lying in a plane perpendicular to said tubular portion, said fan disposed within at least a portion of said shroud exit section wherein the following relationship plus or minus 12 percent exists: RF AW/3, CF AW/3 and R 2 AW/3 where RF is the length of the flat flange portion, CF is the length of the tubular portion, R is the radius of the arcuate portion and AW is the projected axial width of the fan whereby fan generated noise and horsepower requirement of said engine are reduced.

Claim 18

A vehicle having an operator station, an internal combustion engine, a radiator for cooling fluid from said engine an axial flow fan axially facing said radiator and including a plurality of angular blades drawing air rearwardly through said radiator, and a shroud rearwardly extending from said radiator wherein the improvement comprises: a unitary shroud exit section closely surrounding said fan and extending in the same direction as said shroud including a tubular portion forming the leading edge thereof, an arcuate portion extending generally rearwardly and outwardly from said tubular portion and terminating in a flat flange portion forming the trailing edge of said shroud and lying in a plane perpendicular to said tubular portion, said fan disposed within at least a portion of said shroud exit section wherein the following relationship plus or minus 12 percent exists: RF AW/3, CF AW/3 and R 2 AW/3 where RF is the length of the flat flange portion, CF is the length of the tubular portion, R is the radius of the arcuate portion and AW is the projected axial width of the fan whereby fan generated noise and horsepower requirement of said engine are reduced.

Claim 19

The shroud exit section of claim 10 wherein said fan has a front plane which intersects said tubular portion and a rear plane which intersects, plus or minus 12 percent, said flat flange portion whereby a stream of air is converged and directed outwardly parallel to said flat flange portion to prevent the passage of dust and particle laden air against said engine, and engine heat against said operator station.

Claim 20

The shroud exit section of claim 11 wherein said tubular portion is secured to said shroud around the entire circumference thereof forming a junction section; and said front plane struck out by said fan intersects said junction section.

Claim 21

A vehicle having an operator station and an internal combustion engine, a radiator for cooling fluid from said engine, an axial flow fan axially facing said radiator and including a plurality of angular blades drawing air rearwardly through said radiator, and a shroud rearwardly extending from said radiator wherein the improvement comprises: a unitary fan shroud exit portion secured to said shroud and extending rearwardly thereof including; a cylindrical throat defining a leading edge, a radially expanding portion, and a radial flat portion defining a trailing edge; said fan being enclosed therein, said blade means defining a front plane coextensive with said leading edge wherein the following relationship exists: RF AW/3, CF AW/3, and R 2 AW/3 where RF is the radial flat portion, CF is the cylindrical throat, R is the radius of the radial expanding section and AW is the projected axial width of the fan whereby fan generated noise and horsepower requirements of said internal combustion engine are reduced.

Claim 22

A vehicle having an operator station and an internal combustion engine, a radiator for cooling fluid from said engine, an axial flow fan axially facing said radiator and including a plurality of angular blades drawing air rearwardly through said radiator, and a shroud rearwardly extending from said radiator wherein the improvement comprises: a unitary fan shroud exit portion secured to said shroud and extending rearwardly thereof including; a cylindrical throat defining a leading edge, a radially expanding portion, and a radial flat portion defining a trailing edge; said fan being enclosed therein, said blade means defining a front plane coextensive with said leading edge wherein the following relationship exists: RF AW/3, CF AW/3, and R 2 AW/3 where RF is the radial flat portion, CF is the cylindrical throat, R is the radius of the radial expanding section and AW is the projected axial width of the fan whereby fan generated noise and horsepower requirements of said internal combustion engine are reduced.

Claim 23

The improvement of claim 13 wherein: said fan shroud exit portion is secured to said shroud around its entire circumference; and said blade means defines a rear plane, said plane being coextensive with said radial flat means plus or minus 12 percent.