US2678104A - Resiliently mounted rotary fan - Google Patents

Description

May 11, 1954 R. c. DAvls 2,678,104

RESILIENTLY MOUNTED ROTARY FAN Filed March l5, 1951 mlm Q Q xdlllll-m! IN V EN TOR. E c. Mmm a 0/41//5 [g2/awww#- H/J Amm/1m Patented May 11, 1954 RESILIENTLY MOUNTED ROTARY FAN Raymond C. Davis, Dayton, Ohio, assignor to.

General Motors Corporation, Detroit, Mich., a

corporation of Delaware Application March 15, 1951, Serial No. 215,813

(Cl. 17o-173) 1 Claim.

This invention relates to the construction of rotary fans, especially electrically driven high speed fans such as are commonly used for circulating air in homes and oilices.

An object of the invention is to provide an improved fan rotor structure which will absorb vibrations and substantially prevent transmission of noise vibrations between the driving shaft and the fan impeller. Thus the usual noise vibrations in the electric motor are not transmitted to the fan impeller which otherwise would act as a sort of sounding board for the motor vibrations.

Another object is to provide an improved means for resiliently securing together in metal-isolated spaced parallel relation two metal plates by a series of very economically made attachment members of resilient rubber or rubber-like material which may be assembled upon the plates simply by forcing the attachment members laterally into place within registering apertures in said two metal plates.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawings wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. 1 is an end view of an electric fan rotor made according to this invention, the outer portions of the impeller blades being broken away.

Fig. 2 is a section taken on line 2 2 of Fig. 1.

Fig. 3 is a side elevation of one of the resilient connecting blocks.

Fig. 4 is an end view of Fig. 3.

Reference numeral I designated an electric '1 motor having a drive shaft I I. The fan rotor has a hub I2 rigidly fixed to shaft II. A sheet metal hub plate I3 is rigidly fixed to hub I2 by any suitable means, preferably by welding. The fan impeller unit I5 comprises a plurality of fan blades I6 riveted to a central annular plate I'I.

Now according to this invention the inner marginal portion of plate II is resiliently attached to the overlapping outer marginal portion of hub plate I3 thru a series of relatively small resilient connecting blocks 2li of rubber or other material having rubber-like physical characteristics. These blocks are made with a uniform cross section along the length thereof and hence can be very economically made by first making long i ting off short lengths of said strip to form the r individual blocks 2D.

Figs. 3 and 4 of the drawings are detail views of one such block 20, representing a short length out oif from a relatively long strip. Each block 20 has two straight grooves 2| on opposite sides thereof adapted to snugly receive two parallel marginal portions of a correspondingly shaped hole 22 in one of the connected platesll for instance plate I3. and also two straight grooves 23 similarly arranged to receive two parallel marginal portions of hole 2d in plate I'I. Since all four grooves 2l and 23 are straight and extend in the direction of extrusion of the long strip from which each block 20 is out olf these grooves are readily formed by the extrusion die. Thus the fully formed blocks 2|] can be made in a very economical manner.

The holes 22 and 24 (in plates I3 and I1 respectively) each has two parallel straight edges. The outer end of each resilient rubber block 20 can be readily forced into its hole by bending the straight flexible end fianges 25 thereof outwardly until the end of block 20 can be forced thru the hole. Obviously the straightness of grooves 2I and 23 and the adjacent flanges 25 greatly facilitates such bending, and the straightness of the parallel edges of holes 22 and 24 greatly facilitates the forcible insertion of blocks 20 into said holes.

The blocks 20 are symmetrically arranged around the axis of the drive shaft I I. The drawings illustrate only three blocks 2n spaced angularly degrees apart, but obviously two or any desired number of blocks 20 may be used to effect the desired resilient connection between plates I3 and I1. .Blocks 20 are preferably arranged with their plate-gripping grooves 2I and 23 extending approximately in the direction of rotation of the fan rotor, as shown in Fig. l, but they may be arranged in other angular positions if so desired. In operation the blocks 2l] resiliently carry the torque and prevent transmission of sound and other vibrations from the electric motor to the fan impeller unit I5. Thus unit I5 is prevented from acting as a sounding board for the motor vibrations of all kinds, and therefore the noise will be greatly reduced.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

A driving mechanism for preventing transmis--Y sion of sound vibration between a driving member and a driven member having fan blades attached thereto comprising in combination; a rotatable metal driving plate, a driven metal plate having the blades of a fan connected thereto and adapted to be driven by said driving plate and parallelly spaced to and lconcentrically located with respect thereto, each of said plates having a series of spaced registering apertures disposed symmetrically around a common axis of rotation, and a pluralitylof resilient blocks ,insaid apertures, said 'blocks ihavinga generally :larger across section than said apertures and `having two spaced groove portions substantially of the same cross section as said apertures and of a size to be forced laterally into said reg'is'terngapmttures of each plate for seating said plates therein and maintaining said plates inca spaced :parallel re- H5 -Zii'l'fl 4 lation, said blocks forming the sole connection therebetween whereby said driving plate transmits its rotation to said blade carrying driven plate only through said blocks and thereby substantially preventing the transmission of sound vibrations therebetween.

References Cited in the ile of this patent STEESP'LENI- 10 Number Name Date :2,041,507 Zeder May 19, 1936 2,154,385 Reisng Apr. 11, 1939 2399;011) @011221,11 Oct. 13, 1942 `2A42J154 Beam June 8, 1948 gnndchild Dec, 12, 1950

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