GB1577244A

GB1577244A - Axial-flow fan

Info

Publication number: GB1577244A
Application number: GB1040977A
Authority: GB
Original assignee: Torin Corp
Current assignee: Torin Corp
Priority date: 1977-03-11
Filing date: 1977-03-11
Publication date: 1980-10-22

Description

(54) AXIAL-FLOW FAN (71) We, TORIN CORPORATION, a corporation organized under the laws of the State of Connecticut, United States of America, of Kennedy Drive, Torrington, Connecticut 06790, United States of America, do hereby declare the invention, which was communicated from Erman Vincent Cavagnero, 134 Funston Avenue, Torrington, Connecticut 06790, U.S.A. (A United States Citizen) and Ashok Zaverbhai Patel, 24 Francis Street, Avon, Connecticut 06001, U.S.A., (A United States Citizen), for which we pray that a patent may be granted to us, and the method by which it is to performed, to be particularly described in and by the following statements: This invention relates to axial flow-fans and particularly to axial flow fans with relatively wide but short blades having performanc characteristics which are highly desirable for certain applications.Such fans require a substantial degree of structural strength particularly throughout the hub sections, spider arms, and at inner portions of the blades. Accordingly, it has been a conventional practice to provide a separate fan spider of a relatively heavy gauge sheet metal and to provide in addition four (4) separate sheet metal blades, the latter being attached at inner end portions to the spider and in some instances being constructed of a relatively lighter gauge sheet metal. Thus, even in cases where the same gauge sheet metal is used for spider ad blades, the separate steps of fabricating individual spiders and blades and thereafter fastening the blades to the spider at four discrete locations must be carried out.When the blades are made from a lighter gauge sheet metal than the associated spider, it is of course also necessary that two different gauges of sheet metal be provided.

It is an object of the present invention to provide an axial flow fan with relatively wide but short blades which may be constructed throughout from material such as sheet metal of the same relatively light gauge, and which has but two similar or identical parts.

According to the present invention there is provided an axial flow fan comprising two similar spider-blade members; each spiderblade member having a substantially flat central hub section, two substantially right angularly arranged pairs of narrow radially outwardly projecting spider arms, each arm being integral with the hub section at a radially inner end portion and each arm being twisted at an intermediate portion so that radially outer end portions of the arms of each pair are inclined in opposite directions relative to the hub section, two air moving blades integral at inner end portions respectively with the outer end portions of the spider arms of one of said pairs of arms, and two laterally projecting blade support members integral respectively with said outer end portions of the other pair of spider arms; in each said spider-blade member each laterial blade support member having a width at least 50% greater than each spider arm, each blade having a width at least twice the width of each spider arm, and each blade having a width at least 1/3 its length; and said two spider-blade members being arranged with their hub sections and spider arms in contiguous face-to-face relationship and with the lateral support members of the one spider-blade member in face-to-face engagement with and supporting inner end portions of the blades of the other spider-blade member, said hub sections, spider anns, support members and blades being fastened together.

By the present invention it is possible to accommodate the desired pitching of the blades at the spider arms without undesired deformation of the blades and accompanying loss of performance characteristics. Thus, each blade may have the same pitch throughout its length.

Furthermore, identical spider-blade blank members may be employed in the manufacture of axial flow fans having different blade pitch angles.

One embodiment of an axial flow fan in accordance with the present invention will now be described by way of example only, with reference to the accompanying drawings, in which: Figure 1 is a plan view of the embodiment; Figure 2 is a side view of the fan of Figure 1, and Figure 3 is a plan view of a single spiderblade blank member employed in the manufacture of the axial flow fan of Figures 1 and 2.

Referring particularly to Figures 1 and 2, it will be apparent that the axial flow fan indicated generally at 10 comprises two identical spider-blade members 12. In Figure 3, a single blank or partially formed spider-blade member 12 is illustrated and may be regarded as representative of the spider-blade members 12 shown in Figure 1. Preferably, the members 12 are formed of sheet metal but plastics and other materials fall within the scope of the invention.

Each spider blade member 12 has a substantially flat centrally located hub section 16 and the hub sections 16 of the two members 12 are illustrated in Figures 1 and 2 in contiguous overlaying and face-to-face relationship in the assembled condition of the fan 10. Formed integrally with each hub section 16 are two right angularly arranged pairs of relatively narrow radially outwardly projecting spider arms 18 and 20. As illustrated, each spider arm is integral and substantially coplanar with the hub section 16 at a radially inner end portion and, in its final formed condition, each of the spider arms 1 8 and 20 is twisted at an intermediate portion so that radially outer end portions of the arms of each pair are inclined in opposite directions relative to the hub section, Figure 2.

At the radially outer end portion of each of the spider arms 18 an air moving blade is provided. The blades 24 are formed integrally respectively with the spider arms 1 8 and project radially outwardly thereform. The blades are of relatively wide or broad configuration.

Pitching of the blades as desired is accomplished by the aforementioned twisting of the spider arms at intermediate portions and, accordingly, no deformation of the blades occurs, Figure 2.

Further, it will be apparent that the blade pitch is determined wholly by the amount or degree of twisting of the spider arms 18 and that a single spider-blade blank design can be employed in providing axial flow fans of varying degrees of blade pitch.

Referring again to Figure 3, and more particularly to the spider arms 20, it will be observed that a laterally projecting blade support member 26 is formed integrally with each arm 20. That is, each arm 20 has a laterally extending blade supporting member 26 formed integrally at its outer end portion and projecting radially outwardly and laterally with respect thereto.

Twisting of the arms 20 at intermediate portions is accomplished as with the arms 18 to pitch the members 26 for blade engagement and support.

When spider-blade members 12 are assembled in right angular relationship as in Figures 1 and 2 the support members 26 of one spider-blade member engage and support the blades 24 of the other spider-blade member as shown, the lateral support members 26 of the vertical spider-blade member 12 being disposed behind the blades 24 of the horizontal member 12 in Figure 1. Thus, on attachment of the support members to the blades, the desired degree of structural strength and integrity is provided at inner blade portions. Attachement of the spider-blade members 12 in assembled relationship is preferably accomplished by welding and, as shown, several welded areas are provided in the form of a plurality of substantially similarly spaced spot welds 28.The spot welded areas 28 preferably extend throughout the contiguous areas between lateral support members 26 and blades 24, throughout the contiguous areas of the spider arms 18 and 20, and throughout the contiguous areas of the hub sections 16.

Various dimensional relationships of parts are contemplated within the scope of the invention. It is however important to maintain dimensional relationships within selected ranges. Thus, a relatively wide or broad and short blade configuration is desired and in order to provide for the necessary pitching of the blades without undesirable blade deformation a relatively narrow spider arm configuration is essential. That is, the width of the spider arms 18 and 20 must be substantially less than that of the blades 24 and, accordingly, blade width is at least twice the width of the spider arms.

As shown, and currently preferred, blade width is approximately four times the width of the spider arms. Each lateral blade support member 26 should be at least 50% greater in width than its associated spider arm 20 and, as shown, the width of each support member 26 is approximately twice that of the spider arm 20. Still further, the lateral extension of each support member 26 across it associated blade 24 should be at least one third with width of the blade and, preferably, the said support members extend across approximately one-half the width of the associated blade as illustrated.

Finally, the blades 24 each have a width at least one third their length and as shown, the said blades are approximately equal in width and length.

The right angular relationship of the spiderblade members may also vary through a few degree and even as much as 20% for improved sound attenuation. Thus, it is only essential to the invention that such relationship be "substantially" at right angle.

With the aforementioned dimensional relationships, it is found that a judicious com promise is achieved. A relatively light gauge sheet metal any be employed throughout, a simple two-piece axial flow fan construction can be provided, and a high degree of structural integrity results particularly at the double thickness areas of the the hub sections, spider arms, and between support members and blades.

Further, the desired blade pitch can be readily provided for in a given fan design without undesirable deformation of the blades and performance loss and if desired, axial flow fans having various blade pitches can be manufactured from a stock of identical spider-blade blanks.

WHAT WE CLAIM IS: 1. An axial flow fan comprising two similar spider-blade members; each spider-blade member having a substantially flat central hub section, two substantially right angularly arranged pairs of narrow radially outwardly projecting spider arms, each arm being integral with the hub section at a radially inner end portion and each arm being twisted at an intermediate portion so that radially outer end portions of the arms of each pair are inclinded in opposite directions relative to the hub section, two air moving blades integral at inner end portions respectively with the outer end portions of the spider arms of one of said pairs of arms, and two laterally projecting blade support members integral respectively with said outer end portions of the other pair of spider arms; in each said spider-blade member each lateral blade support member having a width at least 50% greater than each spider arm, each blade having a width at least twice the width of each spider arm, and each blade having a width at least 1/3 its length; and said two spider-blade members being arranged with their hub sections and spider arms in contiguous face-to-face relationship and with the lateral spport members of one spiderblade member in face-to-face engagement with and supporting inner end portions of the blades of the other spider-blade member, said hub sections, spider arms, support members and blades being fastened together.

2. An axial flow fan as claimed in claim 1 in which the two spider-blade members are right angularly arranged.

3. An axial flow fan as claimed in claim 1 or claim 2 in which each blade has the same pitch throughout its length; the pitch of the blade being provided by the twist in the res pective spider arm.

4. An axial flow fan as claimed in any one of claims 1 to 3 in which each said lateral support member extends across at least one third (1/3) the width of its respective air moving blade.

5. An axial flow fan as claimed in claim 4 in which each said lateral support member extends across one-half (1/2) the width of its respective air moving blade.

6. An axial flow fan as claimed in any one of the preceding claims in which each air moving blade a width approximately four (4) times that of each spider arm.

7. An axial flow fan as claimed in any one of the preceding claims in which each air moving blade is approximately equal in width and length.

8. An axial flow fan as claimed in any one of the preceding claims in which each lateral support member is approximately twice as wide as each spider arm.

9. An axial flow fan as claimed in any one of the preceding claims in which the spiderblade members are fastened together by welded areas between contiguous spider arms and between contiguous support members and blades.

10. An axial flow flan as claimed in any one of the preceding claims in which the spiderblade members are fastened together by welded areas between contiguous hub sections and between contiguous support members and blades.

11. An axial flow fan as claimed in claim 9 or claim 10 in which said welded areas take the form of a plurality of substantially similarly spaced spot welds.

12. An axial flow fan as claimed in any one of the preceding claims which is constructed from a light gauge sheet metal or plastics material.

13. An axial flow fan substantially as herein described with reference to the accompanying drawings.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims

**WARNING** start of CLMS field may overlap end of DESC **. promise is achieved. A relatively light gauge sheet metal any be employed throughout, a simple two-piece axial flow fan construction can be provided, and a high degree of structural integrity results particularly at the double thickness areas of the the hub sections, spider arms, and between support members and blades. Further, the desired blade pitch can be readily provided for in a given fan design without undesirable deformation of the blades and performance loss and if desired, axial flow fans having various blade pitches can be manufactured from a stock of identical spider-blade blanks. WHAT WE CLAIM IS:

1. An axial flow fan comprising two similar spider-blade members; each spider-blade member having a substantially flat central hub section, two substantially right angularly arranged pairs of narrow radially outwardly projecting spider arms, each arm being integral with the hub section at a radially inner end portion and each arm being twisted at an intermediate portion so that radially outer end portions of the arms of each pair are inclinded in opposite directions relative to the hub section, two air moving blades integral at inner end portions respectively with the outer end portions of the spider arms of one of said pairs of arms, and two laterally projecting blade support members integral respectively with said outer end portions of the other pair of spider arms; in each said spider-blade member each lateral blade support member having a width at least 50% greater than each spider arm, each blade having a width at least twice the width of each spider arm, and each blade having a width at least 1/3 its length; and said two spider-blade members being arranged with their hub sections and spider arms in contiguous face-to-face relationship and with the lateral spport members of one spiderblade member in face-to-face engagement with and supporting inner end portions of the blades of the other spider-blade member, said hub sections, spider arms, support members and blades being fastened together.