US 3819294 A
A propeller type fan adapted to be self locating on a fan motor shaft including means to protect the motor and shaft from deleterious atmospheric conditions and circulate air through the motor and around the exterior thereof for improved motor cooling.
Claims available in
Description (OCR text may contain errors)
United States Patent [191 Honnold et al.
[ June 25, 1974 1 FAN CONSTRUCTION  Inventors: Fred V. Honnold, North Syracuse;
William C. Martin, Jr., Syracuse,
both of NY.
 Assignee: Carrier Corporation, Syracuse, NY.
 Filed: May 25, 1972 21 Appl. No.: 256,699
 US. Cl 416/93, 416/241, 416/245  Int. Cl. F04d 29/32  Field of Search 416/93, 241, 170, 245; 417/353, 354
 References Cited UNITED STATES PATENTS 2,262,695 11/1941 Moeller 416/93 2,620,970 12/1952 Palmer et a1.
2,698,128 12/1954 Ault et al 2,801,793 8/1957 Kline 416/93 3,303,995 2/1967 Boeckel 417/353 3,378,192 4/1968 Friese 417/353 3,385,516 5/1968 Omohundro 416/93 FOREIGN PATENTS OR APPLICATIONS 449,067 6/1948 Canada... 417/353 609,740 11/1960 Canada. 416/93 1,384,004 11/1964 France 416/93 594,563 6/1959 ltaly 416/93 973,853 6/1960 Germany 417/354 Primary EraminerEverette A. Powell, Jr. Attorney, Agent, or FirmJ. Raymond Curtin; D. Peter Hochberg  ABSTRACT A propeller type fan adapted to be 'self locating on a fan motor shaft including means to protect the motor and shaft from deleterious atmospheric conditions and circulate air through the motor and around the exterior thereof for improved motor cooling.
1 Claim, 3 Drawing Figures FAN CONSTRUCTION BACKGROUND OF THE INVENTION A number of problems are ordinarily encountered in the use of propeller type fans in outdoor locations where the fan may be subjected to rain, snow or corrosive gases present in the atmosphere in many industrial or highly populated areas.
To protect the motor and the motor shaft, rain shields are ordinarily employed between the fan blades and the motor and waterproof compounds are employed on the end of the motor shaft to seal the space between the'motor shaft and the fan hub to prevent entry of water and subsequent corrosion between the hub and the shaft.
Ordinarily, the fan must be carefully positioned on the motor shaft relative to the fan orifice plate and se cured in the proper position to obtain optimum air flow. Further, to provide adequate motor cooling, the rain shield employed therewith must be spaced from the motor a sufficient distance to preventinterference with the cooling air flow through the motor.
SUMMARY OF THE INVENTION This invention relates to a fan construction adapted for mounting on the shaft of a fan motor for providing rotary motion to the fan, the fan including a hub having BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a top view of the fan forming the subject of the present invention,
FIG. 2 is a view partially in section taken along line 22 of FIG. 1 illustrating the fan mounted on a fan motor, and
FIG. 3 is a partial bottom plan view of the fan illustrating the central portion of the fan of FIGS. 1 and 2.
DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to the drawings, there is illustrated a fan 1, including an integrally formed hub section 3 having a bore 5 formed therein. The hub section 3 is in turn integrally connected to a cylindrical motor protection cap section 7, the cap having an imperforate top section and cylindrical sidewalls arranged about the motor shaft and the top portion of the motor housing to protect the shaft and the motor from rain, snow, etc. The cap section 7 is provided with a plurality of internal vanes 9 adapted to strengthen the motor protection cap and to act as an internal fan to draw air through the motor windings and discharge the air through the clearance between the sidewalls ll of the cap and the motor for improved motor cooling. Due to the improved air circulation, the cylindrical sidewalls of the cap may enclose the motor to a greater extent than has heretofore been possible and the sidewalls may be located in closer proximity to the motor housing, thereby minimizing the outside diameter of the cap to increase the area of the air flow passage between the outside surface '2 of the cap and the fan orifice. Suitable radially projecting fan blades 13 are integrally formed on the cap 7.
It can be seen by reference to the drawings that bore 5 does not extend completely through hub 3, but terminates at the inner surface of cap 7. The bore 5 is formed with a flat surface 15 therein adapted for mating engagement with a flat surface formed on the motor shaft. A design in the form of a protuberance having a configuration similar to the cross-section of the bore 5 may be formed on the top of cap 7 as an aid in aligning the flat surface within bore 5 with the flat surface on the motor shaft. Accurate alignment is assured for the flat on the protuberance is in alignment or registry with the flat on the inner surface of the bore 5.
By forming the fan of a suitable plastic material such as talc-filled polypropylene, sufficient resilience is obtained to enable the hub to be pressed onto the motor shaft, engagement of the motor shaft end with the end of bore 5 accurately locating the fan relative to the motor. By designing the fan blades to provide air flow in a direction from the motor toward the fan, that is, in an upward direction as viewed in FIG. 2, the air pressure generated on the fan blades will force the fan toward the motor to obviate the necessity for fastening means to secure the fan on the motor shaft.
The disclosed fan is adapted to be molded in one piece, thereby obviating numerous assembly operations and the various problems encountered with assembled fans such as loose blades, imbalance due tolerances required in the numerous elements of assembled fans, etc. Further, the fan provides complete protection for the motor shaft to prevent corrosion thereof, is self locating on the motor shaft, does not require additional elements such as set screws, etc. to secure the fan on the motor shaft and provides an integral motor protection cap which encircles the motor in close proximity thereto while-providing improved air flow through the motor to prevent overheating thereof.
While we have described the preferred embodiment of our invention, it is to be understood that the invention is not limited thereto, but may be otherwise embodied within the scope of the following claims.
1. In combination, an outdoor fan motor having a vertically upstanding rotatable fan shaft, and a plastic fan mounted on said fan shaft for rotation therewith, said fan comprising:
a hub having a closed end internal bore defined by surfaces in mating engagement with said fan shaft;
an imperforate cap for protecting said fan motor against deleterious atmospheric materials, said cap including:
a circular top wall integral with said hub and extending over and across said fan motor;
cylindrical sidewalls integral with said top wall and extending downwardly from said top wall around and spaced from a substantial part of said fan motor;
a plurality of fan blades extending outwardly from said sidewalls and a plurality of interior vanes extending between and integral with said hub and said sidewalls for drawing air through the fan motor and for discharging the air through the space between the motor and the sidewalls when the fan is rotated.