US2350939A - Blower - Google Patents

Description

BLOWER Filed April 22, 1943 713, Z. nws/vnm, I

Verner E p we Patented June 6, 1944 owirso STATES PATENT OFFICE 9;

BLOWER Verner E. Sprouse, Columbus, Ind.

Application April 22, 1943, Serial No. 484,009

3 Claims.

" This invention relates to a blower which may be used in varying sizes for supercharging engines and, in general, moving air as may be required for ventilating, exhausting, air conditioning, drying, humidifying, defrosting, heating, and the like.

5 A primary object of the invention is to provide a structure having an exceedingly high efficiency and economy for air delivery in respect to the power input, permitting a smaller unit to be emplo'ye'dthan has been possible in the heretofore customary structures. A still further primary object of the invention is to provide a blower structure which may be constructed in an exceedingly simple manner at a relatively low cost of production, and at the same time be safe in use. r These and many other objects and advantages of the invention will become apparent to those versed in the art in the following description of one specific form of the invention as illustrated in the accompanying drawing, in which :"Fig. 1 is a view in side elevation of a unit embodying the invention;

Fig. 2, a view in end elevation and partial section on an enlarged scale of the intake end of the blower of the unit;

Fig. a view in side elevation from the leading of an impeller blade used in the blower;

Fig. l, 2. view in end elevation from the inner of impeller blade;

Fig. 5, a view in end elevation of the outer end of the impeller blade;

Fig. 6, a view in vertical section on the line 66 in Fig. 3; and

'7, .a view in horizontal section on the line l in Fig. 3.

. Like characters of reference indicate like parts throughout the several views in the drawing.

The blower embodying the present invention is intended to deliver a large volume of air or gases at relatively low pressures. The rotor of the blower may be made in any suitable manner, such as-by casting or building it up from stamped metal parts. In the present embodiment of the invention as herein described and illustrated, the rotor is formed from stamped metal members. In this form, a circular metal disc ll] serves as the member to which the individual vanes are attached. The invention contemplates the use of two different types of vanes for reasons as will become more apparent in the following description. Forsake of distinction, these blades will be referred to as long and short blades.

1 Along blade, generally designated by the numeral II, is formed to have an attaching foot 12 to rest against the forward face of the disc Ill and be secured thereto in any suitable manner, such as by welding or screws, scre'ws'l3 being shown in the present instance to pass through the foot l2 and screw-threadedly engage with the disc H). The shape and contour of the blade 11 is extremely important. The blower isdesigned to take air in adjacent the axial region of the rotor and discharge the air from'the peripheral ends of the several blades. The inner ends of the blades will therefore be the intake port'ionsi Each long blade II has a straight inner edge l4, that is, perpendicular to the disc H3 and parallel to the axis of rotation. I v

From this edge [4, the blade I l is cupped back wardly from the normal direction'of rotation of the blade, the cupped portion "of the blade being in general spoon-shaped. To form this cupped portion of the blade I I, the blade is curve'darovnd rearwardly over the foot l2 to form'the forwardly concave part of the blade by having the-outer edge curved back and around forwardly in relation to the foot l2. 5

The outer portion of the blade l l, removedax'- ially from the disc It, is sloped downwardlyand outwardly from the major elevation of the blade adjacent the edge portion M and has a part of the edge portion turned over and forwardly to form an extending lip l5,this lip extending in increasing circumferential lengthlin respect to the disc Ill) as it approaches the outer portion of the disc Iii; In other words, this lip l5,'when viewed from the outer side of the disc ill, is in general triangularly shaped with the base at the outer edge portion of the disc l0 and spaced-forwardly therefrom a distance to permit escape of air or gases thereunder. The extreme outer" end of the blade, measured 'axiall'yfrom the face-of the blade I l is curved from the edge l l'to merge by a smooth curve aroun'd'into the sloping outer edge portion that blends into the lip 15, as best indicated in Figs. 3 and 4. The forward or 'leading side of the blade It presents a concave sur= face having its deepest portion toward the outer end adjacent the edge I4 to continue on around and under the lip if: by a decreasingfdep'th. 'Be-' tween the outer base end of the lip 15 and'the' face of the disc H], the outwardly extending wall portion of the blade ll, designated by the 'nu{ meral I 6, curves rearwardly', as bestillustrated in Fig. 5, back of 'the'line of the edge l4, this edge 5 being the contour line of the concave part of the blade at that position. w 1 v A pluralityofblades ll are mounted around the disc to have the foot portions 12 radially disposed and the inner edges l4 spaced one from the other of the respective blades a distance to permit flow of air between those blades across the axialportion of the disc H), as indicated in Fig. 2. The number of blades H employed will vary according to the size of blower and the volume of air desired as its output. In the present instance, for the sake of simplicity, but four of the blades II are shown although this number may be increased to give a higher rate of air delivery. Between adjacent blades II is located in each instance a short blade Il. Each short blade I! up to its inner end has exactly the same contour and dimensions as the corresponding part of the blade II, the short blade ii, for example, being identical with the blade 1 l', as shown in Fig. 3, from the right-hand side to the vertical section line 5-4. In other words, in effect the short blade I! is a blade I l with the inner intake endcut off to leave an opening around its inner end between the two adjacent blades i l. The inner end of the blade I! terminates throughout its The rotor unit comprising the disc It! with the blades II and I1 mounted as above described on its face, is housed between a back plate i8 and a forward housing portion l9 which forms the scroll terminating in the delivery end duct 20. A shroud 2| is secured to the forward side of the scroll l9 witha central circular opening therethrough forming the intake of the blower. As indicated in Figs. 1 and 2, the shroud 2| is limited in extent so as to cover over only the outer peripheral portions'of the blades whereby the major parts of the blades are left uncovered across the intake opening through the shroud. The surface generated by the outer edges of the assembled blades would be essentially conical by reason of the slopes of the various blades from the intake ends to the outer peripheral portions.

In operation, the rotor would be mounted upon any suitable shaft 22 and driven by a motor 23 carried by some support, such as the base 24, affording a direct drive arrangement. The rotor would turn in a clockwise direction as viewed in Fig. 2. Air entering through the wide opening of the shroud 2| is caught in the concave portions of the several blades H and I! and through centrifugal action, carried back under the overhanging lips I5, causing a concentration or compression thereof whereby the air in escaping from the outer ends of the blades from underthe lips I5 is given an extremely high velocity, setting up an operation similar to that of a fluid traveling through a Venturi construction. Thetrapping of'the air under the-overhanging lips IE to force it through the restrictedpassageway under'the lip- |5at its outer edge may tend to set up an extreme vibration in the various long blades H with the tendency for the air to unload inwardly and thereby, reduce a volume of air taken in through the shroud. To avoid both of those undesirable features, the shorter blades I1 are employed alternately with the blades ll whereby air tending to back up may flow around the inner ends of the blade I! in particular and be picked up by the next on-coming blade H. Further, there is the essential opening provided around the inner ends of the long blades II to permit travel of the air slowly therearound as an additional aid in overcoming these indicated undesirable features. Furthermore an additional advantage is obtained by employing the shorter blades I! alternately with the blades II in that a greater number of blades may be employed in a given diameter of rotor without unduly restricting the entrance of air over the axial portion of the rotor.

" It has been found in actual test that in comparing the blower embodying the present invention with other blowers having like blade numbers and sizes, the efficiency of the blower embodying the invention greatly exceeds these other types and does so without undue or dangerous vibrations of the elements of the blower at the same R. P. M.

While I have herein shown and described my invention in the one particular form, it is obvious that structural variations may be employed without departing from the spirit of the invention and I therefore do not desire to be limited to that precise form beyond the limitations as may be imposed by the following claims.

Iclaim:

1. In a blower rotor having a blade mounting member having an intake side surface normally disposed to the rotor axis of rotation, a blade having a straight line inner edge normal to said member and parallel to said axis; a main body portion cupped back from said edge to present a spoon-shaped, concave surface in the direction for rotation of the block; a straight line foot edge normal to said inner edge to contact said mounting member; said concave surface being formed by curving of the blade rearwardly from said inner edge and said foot edge and forwardly to an outer discharge portion of the blade to have a deeper portion adjacent said inner edge; a forward lip portion extending in the direction of blade rotation and starting from a forward blade edge curving around from the forward end of said inner edge and sloping rearwardly by a widening, generally triangular planar area to terminate at a forward line spaced from said mounting member.

2. In a blower rotor having a blade mounting member having an intake side surface normally disposed to the rotor axis of rotation, a blade having a straight line inner edge normal to said member andparallel to said axis; a main body portion cupped back from said edge to present a spoon-shaped, concave surface in the direction for rotation of'the blade; a straight line foot edge normal to said inner edge to contact said mounting member; said concave surface being formed by curving of the blade rearwardly from said inner edge and said foot edge and forwardly 7 mounting member; said outer discharge portion of the blade terminating by an edge, the line of which curves backwardly from said foot line and then around forwardly, all substantially within a plane parallel to said axis, to merge into said lip widened terminal line.

3. In a blower rotor having a blade mounting member having an intake side surface normally disposed to the rotor "axis of rotation, a blade having a straight line inner edge normal to said member and parallel to said axis; a main body portion cupped back from said edge to present a spoon-shaped, concave surface in the direction for rotation of the blade; a straight line foot edge normal to said'f'finner edge to contact said mounting member; said concave surface being formed by curving of ,the blade rearwardly from said inner edge and said foot edge and forwardly to an outer discharge portion of the blade to 16 have a deeper portion adjacent said inner edge; a forward lip portion extending in the direction of blade rotation and starting from a forward blade edge curving around from the forward end of said inner edge and sloping rearwardly by a widening, generally triangular planar areaf to terminate at forward line spaced from said mounting member; and a second blade intermediate two'of said first blades, said second blade bein identical in shape andv size of said first blade from an inner end in a plane normal to a radius through said axis at a distance therefrom removed from that of said inner edge of the first, blade.

VERNER E. SPROUSE.

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