US3649130A - Blower - Google Patents

Abstract

A transverse current blower having a casing, the internal surface thereof, together with a fan wheel asymmetrically arranged therein define a passage that includes an air intake and air discharge portions and a portion of minimum width therebetween. Both the intake and exhaust portions are in spiral form increasing in width from the portion of minimum width.

Description

United States Patent Moller 51 Mar. 14, 1972 [54] BLOWER 3,310,228 3/1967 Laing ..4l5/54 3,397,463 8 1967 L ..4l5 54 [721 Invenm" Heinrich Ke'kheim' 3,415,443 1241968 Gilliam" 415454 many [73] Assignees Braun Aktiengesellschatt, Frankfurt am FOREIGN PATENTS 0R APPLICATIONS Main, Germany 237,782 1/1965 Austria AIS/I54 [22] Filed: 1970 Primary ExaminerC. J. Husar [21] Appl. No.: 1,649 Attorney-Emest F. Marmorek o [57] ABSTRACT [30] Foreign Appllcation Priority Data A transverse current blower havlng a casing, the internal sur- Jan. 14, Luxembourg face thereof together a fan whee] a ranged therein define a passage that includes an air intake and [52] U.S.Cl ..4l5/54,4l5/219 air discharge portions and a portion of minimum width Int-Cl "F046 5/00 therebetween. Both the intake and exhaust portions are in [58] Field of Search ...4l5/54, 219 spiral form increasing in width from the portion of minimum width.

[56] References Cited 8Cla|ms,3Drawing Figures UNITED STATES PATENTS 7. r 1,920,952 8/1933 Anderson .....415/5 4 BLOWER BACKGROUND OF THE INVENTION The invention relates to a blower, and more particularly to a blower of the transverse current fan type in which the fan wheel is asymmetrically arranged in a casing.

In fans heretofore known, in order to facilitate efficient functioning thereof, it is necessary to create as localized an air swirl as possible at a given location. The foregoing ensures that the emerging air medium will not mix within the fan with the entering air medium. This is accomplished by a baffle plate, separating wall or the like, which are arranged between the inlet and outlet portions of the air media, known as air intake and air discharge portions respectively.

SUMMARY It is accordingly among the principal objects of the invention to provide an efficient, inexpensive and reliable fan.

It is another object of the invention to prevent the emerging air medium from mixing within the fan with the entering medium, without the aid of a separating wall.

Further objects and advantages of the invention will be set forth in part in the following specification and in part will be obvious therefrom without being specifically referred to, the same being realized and attained as pointed out in the claims hereof.

In accordance with the present invention it is possible to discharge the air swirl from the fan in a different and simpler manner than heretofore used.

Broadly speaking the foregoing is achieved by arranging the fan wheel asymmetrically within a fan wheel casing so that a portion of minimum'width exists between the fan wheel and that portion of the internal casing which faces the periphery of the fan wheel. This area is arranged on the air intake'side of the casing so that a narrow passageway at this point of minimum width is widened in approximately spiral form in the direction of both the air intake and air discharge portions.

In accordance with the present invention a stabilization of the air swirl is achieved without the use of additional means, such as a separating wall or a baffle plate.

The air swirl only changes its position when a high counter pressure exists on the outlet side. The effectiveness of the fan is thereby not offset, on the contrary, the arrangement which is carried out in accordance with the present invention has the character of a high pressure blower, the output of which mainly depends on how far the casing wall which conducts the inflowing air, extends beyond the narrow passageway which is the one located at the portion of minimum width between the external fan wheel portion and the internal casing surface. It is especially effective if the so-called looping angle 7 amounts to at least 45 at this location. However, a looping angle of 30 will also exert a stabilizing effect on the air swirl in the fan wheel.

Due to the fact that additional stabilization media can be abolished, the present invention will provide a common and non-divided opening for the air intake and air discharge portions of the fan.

As far as the separation of inflowing and outflowing media outside the fan is concerned, it is advantageous if the casing wall at the air outlet side projects to a greater distance then that of the air intake side, away from the fan wheel. The

reason being that in the case of the fan which is designed in accordance with the present invention, the casing wall without an additional separating wall, exerts a suction effect with respect to the outflowing medium and thereby the direction of flow, in the sense of a separation of in and outflowing air media.

For the width of the narrow passageway between the fan wheel and the internal casing surface it is recommended that it form the minimum width which can be technically produced. Such an arrangement distinguishes itself especially through its low noise level.

The present invention provides that the width of the narrow passageway can be changed, for'example, through a shifting of the fan wheel in order to influence the characteristics of the fan, depending on the duties it is to perfonn.

With the above and other objects of the invention in view, the invention consists in the novel'cons'truction, arrangement and combination of various devices, elements and parts, as set forth in the claims hereof, certain embodiments of the same being illustrated in the accompanying drawings'anddescribed in the specification.

In the accompanying drawings,

FIG. 1 is a cross sectional view of a transverse current blower in accordance with an embodiment ofthe invention;

FIG. 2 is a cross sectional view similar to FIG. 1 but embodying a modification; and

FIG. 3 is a side elevational view of a table blower incorporating the invention.

In carrying the invention into effect in the embodiments which have been selected for illustration in the'accompanying drawings and for description in this specification, the casing I, of the transverse current blower consists of a semicylindrical wall 10, two side walls ll, 12 and of an open outlet duct 13 which borders on the semicylindrical wall 10 and the side walls 11 and 12. I

A fan wheel 2 is asymmetrically arranged within this casing 11, namely parallel to the semicylindrical wall 10, said fan wheel 2 being arranged in a pivotable manner and displaying blades 20. Due to the asymmetrical arrangement, a narrow passageway 3 is formed between fan wheel 2 and the semicylindrical wall 10. At this spot, the difference between the internal surface of the semicylindrical wall 10 and the fan wheel 2 is a minimum width, namely, in the case of the exemplified embodiment, the passageway 3 is as small as technically producible. The narrow passageway 3 is located on the intake side, thus lying near the inlet opening opposite to arrow 42. Adjacent the narrow passageway 3, the casing wall seg= ment 131 of the outlet duct 13, extends tangentially in the direction of the inlet opening and guides the inflowing air. The center point of resulting spiral-like interior section of the casing 1 lies in the center of the fan wheel 2. The wall segment 131 extends from the narrow passageway 3 as far as the inlet opening 40 at a looping angle 7 of approximately 50 and thereby assures the stabilization of the air swirl, which is created within the fan wheel 2, due to the presence of the nar row passageway 3. The passageway 3 prevents the air medium which had been rerouted by 180 within the casing and guides the flow out in the direction of the arrow 41, from mixing itself, with the medium which flows in the direction of the arrow 42. The fan is still effective if the looping angle amounts to only 30.

The casing wall segment 132 on the air outlet side projects tangentially from the other end of the semicylindrical wall 10 and exceeds in length the casing wall segment 131 at the inlet side. The longer design of one of the wall segments, namely wall segment 132, promotes the separation of inflowing and outflowing air, especially at the exterior of the fan. The rerouting of the flowing air medium by approximately 180 is not the only one to be used; the fan also retains its effectiveness when the fan wheel 21 is surrounded by a casing 14 at an approximate angle of (FIG. 2). The center of the fan wheel 21 is asymmetrically arranged in the casing 14. Between the casing wall 141 and the periphery of the fan wheel 21 a narrow passageway 31 is left. The casing segment 142 on the outlet side projects above the casing segment 143 on the inlet side.

In the exemplified embodiment of a table fan, the fan wheel 22 is asymmetrically arranged in the casing 15 and, by a shaft or axle 6, is driven in counterclockwise direction (FIG. 1) by a motor 5 (FIG. 3). The device is pivotably arranged on a stand 7, displaying a base 7 I. The motor 5 can be switched on and off at a switch 8.

The casing which is open on one side, displaying'an inlet opening 43 and an outlet opening 44, can be covered, for ex ample, by a screen, in order to protect the fan wheel 22 from damage. The flow conditions on the inside and outside of the fan are not influenced by the presence of such a screen.

I wish it to be understood thatl do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

Having thus described the invention, what I claim as new and desire to be secured by Letters Patent, is as follows:

1. In a transverse current blower having a casing and a fan wheel eccentrically arranged in said casing, said casing being formed of a curved wall section extending within the range of an arc of 180, an intake channel wall section projecting tan gentially from one end of the curved wall section, a discharge channel wall section projecting tangentially from the other end of the curved wall section, and two opposed side walls defined by the contour of said curved wall section and said intake and discharge channel wall sections and by a continuous straight edge connecting the ends of said intake and discharge channel wall sections;

a fan wheel having its center of rotation eccentrically arranged within said casing between said side walls defining a narrow passage between an inner portion of said curved wall section near to said intake channel wall section.

2. In a transverse current blower as claimed in claim 1, wherein the length of said intake channel wall section is defined substantially by intersecting arm of an angle ranging at least from 30 and measured at the center of said fan wheel from a connection line of said center with said narrow passage.

3. In a transverse current blower, as claimed in claim 8 in combination,

the periphery of said fan wheel defining with the internal casing surface a passage including an air intake portion, an air discharge portion, and a portion of minimum width therebetween,

said minimum width portions being disposed at the air intake side of said casing,

both said intake and exhaust portions being in spiral form increasing in width from said portion of minimum width.

4. In a transverse current blower, as claimed in claim I, the wide ends of said air intake and air discharge portions defining a single opening free from subdivision.

5. In a transverse current blower, as claimed in claim 1, the width of said minimum width portion constituting substan tially the slightest attainable distance between said casing surface and the periphery of said fan wheel.

6. In a transverse current blower, as claimed in claim 1, wherein said casing at said air discharge portion extends to a greater distance than said air intake portion away from said fan wheel.

7. In a transverse current blower, as claimed in claim I, wherein said curved wall section of said casing surrounds said fan wheel through an arc of an angle of at least 8. In a transverse current blower, as claimed in claim 1 wherein said casing is approximately semicylindrical in shape.

Claims (8)

1. In a transverse current blower having a casing and a fan wheel eccentrically arranged in said casing, said casing being formed of a curved wall section extending within the range of an arc of 180*, an intake channel wall section projecting tangentially from one end of the curved wall section, a discharge channel wall section projecting tangentially from the other end of the curved wall section, and two opposed side walls defined by the contour of said curved wall section and said intake and discharge channel wall sections and by a continuous straight edge connecting the ends of said intake and discharge channel wall sections; a fan wheel having its center of rotation eccentrically arranged within said casing between said side walls defining a narrow passage between an inner portion of said curved wall section near to said intake channel wall section.

2. In a transverse current blower as claimed in claim 1, wherein the length of said intake channel wall section is defined substantially by intersecting arm of an angle ranging at least from 30* and measured at the center of said fan wheel from a connection line of said center with said narrow passage.

3. In a transverse current blower, as claimed in claim 8 in combination, the periphery of said fan wheel defining with the internal casing surface a passage including an air intake portion, an air discharge portion, and a portion of minimum width therebetween, said minimum width portions being disposed at the air intake side of said casing, both said intake and exhaust portions being in spiral form increasing in width from said portion of minimum width.

4. In a transverse current blower, as claimed in claim 1, the wide ends of said air intake and air discharge portions defining a single opening free from subdivision.

5. In a transverse current blower, as claimed in claim 1, the width of said minimum width portion constituting substantially the slightest attainable distance between said casing surface and the periphery of said fan wheel.

6. In a transverse current blower, as claimed in claim 1, wherein said casing at said air discharge portion extends to a greater distance than said air intake portion away from said fan wheel.

7. In a transverse current blower, as claimed in claim 1, wherein said curved wall section of said casing surrounds said fan wheel through an arc of an angle of at least 130*.

8. In a transverse current blower, as claimed in claim 1 wherein said casing is approximately semicylindrical in shape.

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