US1983606A - Fan - Google Patents

Description

Dec. 11, 1934. w A, GESE 1,983,606

FAN

Filed Feb. 12, 1931 Patented Dec. 11 1934 OFFICE Walter A. Geise, Flint, Micln, moi to Game I Motors Corporation, Detroit, Micln, a corporation of Delaware applicati n February 12, 1931, Serial No. 515,167 '1 1 onm' (01. 170-159) This invention relates to multi-blade fans of the screw or propeller type, such as those which are used to draw cooling air through the radiator of an automotivevehicle and force it over the 5 propelling engine thereof.

' It has been found that the cooling fan of an automotive vehicle is the cause of a large part of the noise which is commonly attributed to the propelling engine of the vehicle and, further- .more, that the noise caused by the fan cannot be eliminated by redesigning the blades or by any other expedient known or practised prior to the time of my invention. During the course of." experiments, which were conducted with the object of producing a fan which would operate more noiselessly than the fans then known, I discovered that a'much quieter fan was produced when theblades were so arranged that the angle betweenone blade and the next was greater or less than that between the last-mentioned blade and the following blade.

My invention may be embodied in multi-blade fans which have even or uneven numbers of blades; and in either type of fan, the angle between one blade and the following blade may be different than the angle between every other pair of adjacent blades or the angle between one blade'and the following blade may be different than the angle between another pair orother pairs of adjacent blades but equal to the angle between still another-pair or other pairs of adj acent blades. In the case of multi-blade fans which have even numbers of blades, in number at least four, the blades may be arranged in a special manner which has obvious advantages, viz. that in whichthe center lines of pairs of the blades are aligned. In this construction, the angle between one blade and the following blade will differ from the angle between'the last-mentioned blade and the next blade, but'theangles between the diametrically opposite pairs of blades of necessity, be equal.

For a better understanding of the nature and objects of my invention, reference is made to the following specification in which. are described the preferred embodiments of my invention which are illustrated in ,the accompanying drawing, in which:

Figure l is a fragmentary side elevation of the front end of an automotive vehicle on which is installed a. cooling fan in which is embodied my invention.

Figure 2 is a front elevation of the cooling which is shown in Figure 1. i

Figure 3 is a front elevation of a modified form of cooling fan.

fan

' In the drawing, referring mommy to Figures 1 and 2, the reference character 9 indicates the water cooling radiator of an automotive vehicle and the reference character 10 the propelling engine thereof. To draw .cooling 'air through the radiator and force it over the engine,

there is' provided a cooling fan 11 which is arure 2, the center lines of the blades 13 and 14 are aligned, respectively, with the center lines of the bladeslfi and 15, and, consequently, the angle between the center lines of the blades 13 and 141s equal to the angle between the center lines of the blades 15 and 16 and the anglevbetween the center lines of the blades Band 15 is I equal tothe angle between the center lines of the blades 14 and 16. But, as will'also be apparent from a glance at Figure 2, the angle between the center lines of the blades 13 and 15 and the blades 14 and 16 is considerably-greater than the angle between the center hues of the blades 13 and '14 and. the blades 15 and 16. The value of the difference between these angles which will give the most highly satisfactory results will depend upon the characteristics of the vehicle in which the fan is installed and may, be determined experimentally. In the fan which is shown in Figures 1 and 2 the angle between the center lines of the blades 13 and 14 and the blades 16 and 15 is 76 degrees, while that between the center lines of the blades 15 and 13 and the blades 14 and 16 is 104 degrees. A fan in which the blades are arranged as described in the preceding sentence has been found to be the. most satisfactory for use on the series 8-50 models of the present Buick automobiles.

In Figure 3 of the drawing, there is shown a fan which consists of a hub (not shown) to which there are secured and on which there are mounted five propeller or screw type fan blades 17, 18, 19, and 21. It will be apparent from an inspection of Figure 3 that the angle between the center line of each blade and the center line of the following blade difiers from that hetween the center lines of every other pair of ad- .lacent blades.

When a fan in which is embodied my invention is operated, 'much less noise results than when a fan of equal capacity in which all blades two types of fans and apparently results Ironr the fact that blades of my fans set up in the current of air generated by the fan vibrations.

of different frequencies which interfere with and tend to attenuate each other and thus reduce the total volume of noise created by the operation of the fan. To eliminate unbalance in my fans, when it exists, some or the blades may be made heavier, orlarger and heavier than, others or counterweights may be applied to the fan assembly.

Although I have shown and described as preferred embodiments of my invention, four-blade and five-blade fans, it will be understood that the principles underlying my invention may be incorporated in fans which have a greater number of blades as well as in two-blade and threeblade fans.

In the claim, the word blade" is used to designate a main blade as distinguished from an auxiliary vane 01 a compound blade.

vI claim:

In an automotive vehicle, the combination of a radiator, an internal combustion engine, and a rotary fan which is located between the radiator and the engineand operated by the engine to draw air through the radiator and circulate it over the engine and which consists of a plurality oi substantially coplanarly disposed blades arranged around the axis of rotation so that the angle which separates one blade from the following blade so difiers from that which separates the last-mentioned blade from the following blade that the sound waves set up by the blades have such characteristics that the noise created durlngthe operation of the fan is audible to a minimum degree.

WALTER A. GEISE.

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