Title:
Blower
United States Patent 2350939


Abstract:
SThis 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. A primary object of the invention is to provide...



Inventors:
Sprouse, Verner E.
Application Number:
US48400943A
Publication Date:
06/06/1944
Filing Date:
04/22/1943
Assignee:
Sprouse, Verner E.
Primary Class:
Other Classes:
415/228, 416/197R, 416/243
International Classes:
F04D29/30
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Description:

SThis 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.

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 employed than 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.

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. 3. a view in side elevation from the leading siide of arn impeller blade used in the blower; Fig. 4, a view in end elevation from the inner endc of the 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 6-6 in Fig. 3; and Fig. 7, a view in horizontal section on the line 7-7 in Fig. 3.

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

SThe 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 10 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. For sake of distinction, these blades will be referred to as long and short blades.

. A long blade, generally designated by the numeral II, is formed to have an attaching foot 12 to rest against the forward face of the disc 10 and be secured thereto in any suitable manner, such as by welding or screws, screws 13 being shown in the present instance to pass through the foot 12 and screw-threadedly engage with the disc 10. The shape and contour of the blade II is extremely important. The blower is designed 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 portions. Each long blade 11 has a straight inner edge 14; that is, perpendicular to the disc 10 and parallel to the axis of rotation.

From this edge 14, the blade 11 is cupped backwardly 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, the blade is curved around rearwardly over the foot 12 to form the forwardly concave part of the blade by having the outer edge curved back and around forwardly in relation to the foot 12.

The outer portion of the blade I I, removed axially from the disc 10, is sloped downwardly and outwardly from the major elevation of the blade adjacent the edge portion 14 and has a part of the edge portion turned over and forwardly to form an extending lip 15, this lip extending in increasing circumferential length (in respect to the disc 10) as it approaches the outer portion of the disc 10. In other words, this lip 15, when viewed from the outer side of the disc 10, is in general triangularly shaped with the base at the outer edge portion of the disc 10 and spaced forwardly therefrom a distance to permit escape of air or gases thereunder. The extreme outer end of the blade, measured axially from the face of the blade I 1 is curved from the edge- 14 to merge by a smooth curve around 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 1 presents a concave surface having its deepest portion toward the outer end adjacent the edge 14 to continue on around and under the lip 15 by a decreasing depth. Between the outer base end of the lip 15 and the face of the disc 10, the outwardly extending wall portion of the blade 11, designated by the numeral 16, curves rearwardly, as best illustrated in Fig. 5, back of the line of the edge 14, this edge 16 being the contour line of the concave part of the blade at that position.

A plurality of blades I1 are mounted around the disc 10 to have the foot portions 12 radially disposed and the inner edges 14 spaced one from the other of the respective blades a distance to permit flow of air between those blades across the axial portion of the disc 10, as indicated in Fig. 2. The number of blades 1 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 17. Each short blade 17 up to its inner end has exactly the same contour and dimensions as the corresponding part of the blade 11, the short blade I7, for example, being identical with the blade I I, as shown in Fig. 3, from the right-hand side to the vertical section line 6-6. In other words, in effect the short blade I is a blade 11 with the inner intake end cut off to leave an opening around its inner end between the two adjacent blades I . The inner end of the blade l7 terminates throughout its contour in a plane normal to a rad'us passing through the axis of the disc 10 parallel with the edge of the foot 12.

As above indicated, the essential features of the blades reside in the spoon shape of the blade in general in conjunction with the downwardly sloping and overturned lip extending toward the outer discharge end of the blade, the forward concave side of the blade being in the main back of a radial line on which the foot of the blade is located.

The rotor unit comprising the disc 10 with the blades 11 and 17 mounted as above described on its face, is housed between a back plate 18 and a forward housing portion 19 which forms the scroll terminating in the delivery end duct 20.

A shroud 21 is secured to the forward side of the scroll 19 with a central circular opening therethrough forming the intake of the blower. As indicated in Figs. 1 and 2, the shroud 21 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 21 is caught in the concave portions of the several blades 1 and 17 and through centrifugal action, carried back under the overhanging lips 15, causing a concentration or compression thereof whereby the air in escaping from the outer ends of the blades from under the lips 15 is given an extremely high velocity, setting up an operation similar to that of a fluid traveling through a Venturi construction. The trapping of the air under the overhanging lips 15 to force it through the restricted passageway under the lip 15 at its outer edge may tend to set up an extreme vibration in the various long blades II 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 17 are employed alternately with the blades II whereby air tending to back up may flow around the inner ends of the blade 17 in particular and be picked up by the next on-coming blade 11. Further, there is the essential opening provided around Sthe inner ends of the long blades 11 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 0 blades 17 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.

SIt 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 Stypes 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 25 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.

I claim: 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 si 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 0 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; said outer discharge portion of the blade terminating by an edge, the line of which curves backwardly from said foot line and ta 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 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 forward line spaced from said mounting member; and a second blade intermediate two of said first blades, said second blade being identical in shape and 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.