|Publication number||US3827482 A|
|Publication date||Aug 6, 1974|
|Filing date||Dec 21, 1972|
|Priority date||Dec 21, 1972|
|Publication number||US 3827482 A, US 3827482A, US-A-3827482, US3827482 A, US3827482A|
|Original Assignee||Pope R|
|Export Citation||BiBTeX, EndNote, RefMan|
|Patent Citations (8), Referenced by (12), Classifications (13)|
|External Links: USPTO, USPTO Assignment, Espacenet|
llnite States atent 1191 Pope 1 1 Aug. 6, 1974 RADIATOR FAN FOR EARTH MOVERS  Inventor: Robert R. Pope, 13100 Skiomah, 'm EXamHFerTAlbert Davis Apple Valley Calif. 92307 Ass/stunt Examiner-S. .l. Rlchter Attorney, Agent, or FirmHerbert E. Kidder  Filed: Dec. 21, 1972 21 A 1. N 317,202 1 pp 0 57 ABSTRACT  11.8. C1 165/119, 55/407, 123/41.49, A radiator fan for earth moving equipment, in which 165/134, 415/121 G, 416/236 air is blown through the radiator, said fan being de-  1nt. Cl F28f 19/00 signed to remove most of the rock and dirt from the  Field of Search 5 5/269, 306, 406, 407; air before the air is blown through the radiator, so as 123/4149; 165/119, 134; 261/92; 416/236 to prevent damage to the radiator core. The trailing edges of the fan blades are curled around on the side  References Cited facing the radiator, so that stones or dirt are caught by UNITED STATES PATENTS the curled portion and accelerated in a circular path 1 around the axis of the fan, causing the debris to be thrown radially outward by centrifugal force. The cen- 1,7033867 3/1929 Bursley e1 51. :IIIIIWIII 55 407 X "ifugally thrown Sand and dust Particles are Caught by 2,140,953 12/1938 Dugan 55/407 Shroud Surrounding the fan, and are then Picked p 2,288,917 7/1942 Norris 415/121 0 and carried forwardly through the radiator core at rel- 2,317,785 4/1943 Koftheim 55/407 atively low velocity by the turbulent air outside the 3,023,840 3/1962 Flamm 123/4l.49 X main blast of the fan,
FOREIGN PATENTS OR APPLICATIONS 10/1910 Germany 55/407 4 Claims, 4 Drawing Figures 1 RADIATOR FAN roa EARTH MOVERS BACKGROUND OF THE INVENTION The present invention pertains to radiator fans for heavy duty earth moving or construction equipment, such as diesel-engined tractors, or bull dozers, of the type wherein air is blown forwardly through the radiator core by a pusher fan.
Tractor vehicles having front end loaders or shovel attachments are usually equipped with cooling systems that include a pusher fan positioned behind the radiator core, which blows the air forwardly through the core and away from the operators compartment. The advantage of this arrangement is that sand and dirt or other foreign matter is not blown back into the operators face, and the result is better visibility and working conditions.
When a tractor, skip loader or bull dozer operates in loose dirt and rock, particles of sand and rock are caught up by the air stream of the fan and blown against the radiator core with great force. This condition is particularly aggravated when considerable amounts of sand spill from the shovel during operation, or when the caterpillar tracks of the tractor churn up loose sand and rock and throw it up into the engine compartment. The sand and rock churned up and hurled by the fan against the'radiator core produces a sand blasting effect that causes severe damage to the fins and tubes, particularly where the tubes have already been worn thin by sand blasting. This continuous sand blasting, together with the bombardment of larger rock particles, can cause a radiator core to leak after only a short period of operation. Under severe conditions, a new radiator core can be destroyed in 3 months or less. The cost of replacing radiator cores may run from $600.00 to $1000.00, plus the cost of down time. If the radiator should be punctured by a rock, and all of the cooling water lost, the cylinder head may be cracked, at a total cost of $2500.00 plus down time.
In the past, it has been attempted to overcome this difficulty by placing a screen between the fan blades and the radiator core, but this has not proved satisfactory, as a screen fine enough to intercept the smaller particles of abrasive sand interferes with the air flow through the radiator core, thereby lowering the efficiency of the cooling system to a point where the engine overheats badly.
SUMMARY OF THE INVENTION The primary object of this invention is to provide a new and improved pusher type radiator fan which has the characteristic of ejecting all of the sand and rock particles from the air stream blown through the radiator core, so that the radiator core is not subject to damaging sand blasting and bombardment by rocks. As a result, the life of the radiator core is increased by 650 percent or more under severe, dirty working conditions.
A further object of the invention is to provide a pusher type fan that separates sand and rock particles from the air stream, which is compact and takes up no more room than a conventional fan, and which does not reduce the efficiency of the cooling system.
These objects are achieved in the present invention by means of a fan blade configuration wherein the trailing edge of the blade is curled, or bent forwardly on the side facing toward the radiator core, so as to provide a catcher that catches all sand and dust particles in the air stream and accelerates them along a circular path around the rotational axis of the fan. Centrifugal force hurls the sand and dust particles radially outward, and they are caught by a shroud surrounding the fan. The sand and dust particles thus separated out of the main fan jet are caught up by the turbulent air swirling around within the shroud enclosure, and carried through the radiator core at relatively low velocity, without damage to the core. The high velocity jet of air thrown forwardly by the fan is relatively clean, with most of the sand, dust and rock particles removed therefrom, and therefore abrasive damage to the core is minimized.
Other objects and advantages of the invention will become apparent to those skilled in the art from the following detailed description of the preferred embodiment thereof, with reference to the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS:
DESCRIPTION OF THE PREFERRED EMBODIMENT In the drawings, the radiator fan of the present invention is designated in its entirety by the reference numeral 10, and comprises a plurality of blades 12 mounted on the arms 14 of a spider 16, said spider having a circular ring 18 that is mounted on a hub 20, as
shown in FIG. 2. Hub 20 has a pulley 22 on its rear end driven by a V-belt 24, and the latter is driven from the engine crankshaft in the usual manner. Fan 10 blows air forwardly through the radiator core 26, which has tanks 28 and 30 at the top and bottom thereof. Surrounding the fan 10 is a heavy gauge sheet metal shroud 32, which is open on the right-hand side (as seen in FIG. 2), facing toward the engine.
Each of the fan blades 12 comprises a rectangular piece of heavy gauge sheet metal, bent into a slightly curved configuration, as best shown in FIG. 3A, one end of which is riveted to an arm 14, which is twisted slightly, so that the blade has an angle of attack to the air stream. The direction of rotation of the fan is clockwise in FIG. 1, and the leading edge of each blade is designated by the reference numeral 36, while the trailing edge is indicated at 38.
The trailing edge 38 of each blade is curled forwardly for a substantial portion of its length (about half of its length, in the illustrated embodiment) on the side toward the radiator core, forming a somewhat conical, forwardly facing scoop, or catcher 40 which increases in width toward the outer end of the blade. The increasing width of the catcher 40 is clearly seen in FIGS. 38, 3C and 3D, which are sections through the blade, taken at increasingly greater distances out from the axis of rotation.
As the fan 10 turns at high speed, each of the blades 12, in effect, takes a thin slice of air and accelerates it forwardly through the radiator core. Because of its higher mass and inertia, dirt that is momentarily suspended in that thin slice of air is caught by the forwardly advancing catcher 40, and accelerated abruptly, in the direction of fan rotation, along a circular path around the axis of rotation. Centrifugal force due to the high rotational speed of the fan causes the dirt and stones caught by the catcher 40 to be thrown radially outward, where it is stopped by the surrounding shroud 32. The sand and dust particles thus separated out from the main stream of the fan blast, are caught up by the turbulent air swirling around within the shroud enclosure and carried through the radiator core at relatively low velocity, without damage to the core.
The catcher 40 is rolled into the trailing edge of the blade and tapers from nothing to a maximum curl at the outer end of the blade. This causes the groove of the catcher to be inclined forwardly in the direction of rotation at an angle of 8 to 10, which has the effect of slowing down the discharge of dirt particles. The forward inclination of the groove tends to deflect the dirt inwardly toward the center of rotation, but this tendency is overpowered by centrifugal force, and the result is that the dirt is thrown radially outward, but with somewhat less force than would be the case if the groove were not so inclined. The area swept by the catchers 40 is the area that is responsible for most of the sand blasting effect, and the center portion of the fan produces little or no sand blasting in conventional Y fans.
The air blown forwardly through the radiator core by the fan 10 is relatively free of sand, dirt and rocks, and radiator cores supplied with air by fans embodying the invention have shown virtually no sign of abrasion or damage after long periods of use under extremely dirty conditions. In one experimental test, a bull dozer operating on the Mojave Desert under extremely hot and dusty conditions without side panels or screen shielding the engine, had sand blasted through two successive radiator cores in a 6-month period, using a conventional fan. After repairing the second core and turning it around, the fan was replaced with another fan embodying the invention. The bull dozer was then operated for 6 months in the same hot, dusty conditions, followed by 6 months more of only slightly less severe working conditions. There were no heating problems encountered. After 2,200 hours of working under conditions that had previously destroyed radiator cores at the rate of one every 300 to 400 hours, the radiator equipped with the fan of the present invention was still in good condition, and showed little evidence of abrasion, or damage. The radiator appeared to be capable of working for another 6 months or a year before being replaced. One big advantage of the present invention is that the ejector fan requires no protective side panels or screens, and the elimination of these panels makes the engine more readily accessible for routine maintenance.
Four other blade embodiments, illustrated in FIG. 4, show other catcher configurations. In FIG. 4A, the blade 12a has a cylindrically curled catcher 40a extending the full length of the blade. FIG. 4B shows a blade 11211 with cylindrically curled catcher 40]) extending from a point intermediate the ends of the blade, to the outer end thereof. FIG. 4C shows a blade 112C, in which the conically tapered catcher 40c extends the full length of the trailing edge. FIG. 4D shows a blade 12d in which the flat blank from which the blade is made initially has the trailing edge profile shown in broken lines 38d, so that when the catcher 40d is rolled into the blade, the final blade profile is rectangular, and the bottom of the catcher groove is parallel to the leading and trailing edges of the blade, instead of inclined forwardly, as in FIG. 1. All of these blade configurations will eject sand and rocks from the air stream, and the invention may be used with any of these blade forms, instead of the form shown in FIG. 1, although the latter is the preferred form.
While I have shown and described in considerable detail what I believe to be the preferred embodiment of my invention, itwill be understood by those skilled in the art that the invention is not limited to such details, but may take various other forms within the scope of the following claims.
1. In the combination of a radiator core of an internal combustion engine and a pusher-type fan having a hub and angularly spaced blades thereon for blowing a stream of air through the radiator core;
the improvement to minimize damage to the radiator core by solid particles entrained in the airstream comprising:
at least one of said blades having a surface adjacent the trailing edge thereof projecting in the direction of the flow of the airstream and facing in the direction of rotation of the blade to catch solid particles in its path of rotation to accelerate them in the direction of rotation of the blade and thus cause the particles to be thrown radially outward from the blade by centrifugal force.
2. An improvement as set forth in claim 1 in which said surface is the surface of a bent portion of the trailing edge of the blade.
3. An improvement as set forth in claim 2 in which said bent portion is arcuate in transverse, cross-section with its concave side facing in the direction of rotation of the blade.
4. An improvement as set forth in claim 1 which includes means surrounding the fan to intercept particles thrown off centrifugally by the fan.
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|U.S. Classification||165/119, 415/121.2, 165/134.1, 416/236.00R, 123/41.49, 55/407|
|International Classification||F04D29/00, F04D29/70, F04D29/38|
|Cooperative Classification||F04D29/701, F04D29/384|
|European Classification||F04D29/38C, F04D29/70C|