WO2015143108A1

WO2015143108A1 - Reduced weight rigid hvac fan construction

Info

Publication number: WO2015143108A1
Application number: PCT/US2015/021388
Authority: WO
Inventors: Jeffrey William ROBINSON; Daniel Richard SCHULZ
Original assignee: Twin City Fan Companies, Ltd.
Priority date: 2014-03-20
Filing date: 2015-03-19
Publication date: 2015-09-24
Also published as: US20150267713A1; MX2016012212A

Abstract

A fan assembly and associated methods are shown. Examples shown include components such as box section rails, truss structures, formed features and thinner gauge material that used in prior configurations. These and other features shown provide a lighter and/or stiffer fan assembly.

Description

REDUCED WEIGHT RIGID HVAC FAN CONSTRUCTION

Claim Of Priority

This application claims the benefit of priority to U.S. Patent Application Serial No. 14/220,540, filed on March 20, 2014, which is hereby incorporated by reference herein in its entirety.

Technical Field

Embodiments described herein generally relate to fan assemblies.

Specific examples may include industrial fan assemblies, such as plenum fans.

Background

Fan assemblies, such as plenum fans are commonly used in a number of industrial and consumer applications. The fan structure provides positioning of the motor and impeller assembly with respect to an inlet plate and/or inlet funnel, whilst also supporting the whole fan, rigidly or sprung, with respect to a customer's equipment.

Current designs of plenum fan construction consist of heavy gauge steel channels/beams that in turn support a separate heavy gauge steel motor mounting pedestal and inlet plate. Improved fan assemblies are desired that use less metal, are lighter weight, and exhibit improved performance, such as higher stiffness and/or higher stiffness to weight ratio.

Brief Description of the Drawings

FIG. 1 is a fan assembly in accordance with some embodiments of the invention.

FIG. 2A is chart illustrating some example material specifications in accordance with the prior art.

FIG. 2B is chart illustrating some example material specifications in accordance with some embodiments of the invention. FIG. 3 is chart illustrating some additional material specifications in accordance with some embodiments of the invention.

FIG. 4 is a flow diagram of an example method in accordance with some embodiments of the invention.

Description of Embodiments

The following description and the drawings sufficiently illustrate specific embodiments to enable those skilled in the art to practice them. Other embodiments may incorporate structural, logical, electrical, process, and other changes. Portions and features of some embodiments may be included in, or substituted for, those of other embodiments. Embodiments set forth in the claims encompass all available equivalents of those claims.

Figure 1 shows a fan assembly 100 according to an example of the invention. The fan assembly 100 includes a motor 110 and an impeller 112. Examples of motors 110 include electric motors such as DC or AC motors, however other motors such as hydraulic motors, etc, are within the scope of the invention. Although Figure 1 shows a centrifugal impeller, having a number of blades 114, the invention is not limited to centrifugal impellers. Examples of the invention may also be used with axial impellers, and/or mixed flow impellers. Although a plenum fan assembly 100 is shown as an example, configurations of the present invention may also be used with other types of fans.

The fan assembly 100 includes a support frame 120 to hold the motor 110, which in turn holds the impeller 112. In the example shown, the support frame 120 further includes an inlet plate 130 that couples to an inlet funnel 134.

Examples of the fan assembly 100 include features that allow the fan assembly 100 to be significantly lighter and stiffer than prior fan assemblies. Lighter fan assemblies are desirable for a number of reasons. A lighter fan assembly is cheaper to ship. A lighter fan assembly requires less structural support at installation, for example on a rooftop or other ceiling structure. A lighter fan assembly may also use less material, such as sheet metal, and as a result, will be less expensive to manufacture. A stiffer fan assembly may be quieter than a less stiff fan assembly. In one example, a stiffer assembly allows the use of less material, and thus a lighter assembly. Using configurations described in the present disclosure, a fan assembly is shown that may be stiffer than prior configurations. Using configurations described in the present disclosure, a fan assembly is shown that may be lighter than prior configurations. Using configurations described in the present disclosure, a fan assembly may be both lighter and stiffer than prior

configurations.

The example fan assembly 100 of Figure 1 shows a plurality of box section rails. A first pair of box section rails 122 are shown running parallel to an axis of rotation of the motor 110. In one example, the box section rails 122 are formed from box section stock material, such as extruded stock. In one example the box section rails 122 are formed by joining more than one formed component, such as two "L" shaped sections together to form the box section. In the example of Figure 1, an L shaped section 123 is shown joined with a second L shaped section to form each box section rail 122. Although two L shaped components are used as an example, other shapes of sub-components are possible when forming box section rails.

In one example, substantially all components of the support frame 120 are formed from sheet metal. In one example, the sheet metal includes steel. In one example, the sheet metal includes aluminum. Other metals, or alloys are also possible within the scope of the invention. One advantage of forming box section rails from L shaped sections is that the sub-components are more easily formed from sheet metal. In many instances, sheet metal is less expensive that other types of stock material. As noted above, in examples of the present invention, cost and weight are further reduced by using thinner gauge sheet metal that in prior configurations.

A second pair of box section rails 124 are further shown coupled between the first pair of box section rails 122. In the example shown in Figure 1, the first and second pair of box section rails 122, 124 form a ladder base unit, although the invention is not so limited. Other configurations of box section rail base units may include out of plane sections, and/or angles between box section rails that are different than 90 degrees. An advantage of using box section rail components includes increased stiffness that allows reduced weight (higher stiffness to weight ratio). The ladder configuration shown in Figure 1 is particularly effective at providing a high stiffness to weight ratio. The support frame 120 of the Figure 1 example further shows a motor mount 126. The motor mount is shown coupled to the second pair of box section rails 124. In one example, at least one internal member 128 is included with the motor mount 126 to form a plurality of triangular units within the motor mount 126. In one example, the resulting motor mount 126 forms a truss to further increase stiffness of the support frame 120, and provide a higher stiffness to weight ratio.

In one example a number of formed features are also included in at least a portion of the support frame 120. One or more formed features may add stiffness to individual components, and further increase stiffness of the support frame 120 and/or provide a higher stiffness to weight ratio. In one example, the inlet plate 130 includes formed features 132. In one example, the motor mount 126 includes formed features 127. In one example, at least one internal member 128 includes formed features 129.

The formed features are shown as stamped or otherwise formed from within a planar surface of a component of the support frame 120. In one example, such a configuration provides stiffness within larger planar portions of a thinner gauge sheet, providing an increased stiffness to weight ratio. Although selected components such as the inlet plate 130, motor mount 126, and internal member 128 are shown in Figure 1 with formed features, other examples of the invention may utilize formed features in fewer or greater numbers of individual components.

Figure 1 further shows a number of fastening locations 102. In one example, fasteners such as rivets, swage locks, screws, bolts, etc. are used to join components of the support frame 120. In one example, the components are joined using other methods, such as adhesives, or welding. In one example, spot welding is used at fastening locations 102. Using components and support frame configurations as described, a stiffer and/or lighter fan assembly 100 is possible. Although individual components may be too flexible on their own, when assembled as described and shown in the figures, the support frame 120 becomes stiff, even though a material, such as sheet metal, used to form the support frame 120 is thinner than in prior designs. In one example the assembly functions as a monocoque structure, where only in the assembled state does the frame exhibit the stiffness and strength necessary for operation. As noted above, this provides an increased stiffness to weight ratio. Figure 2A shows some prior material lists for assembly of three fan assembly examples. The fan size column at the left of the chart shows a fan diameter in millimeters. The materials specifications in the chart are shown for steel sheet metal, with the numbers indicating gauge thickness.

Figure 2B shows a material list for assembly of thee fan assemblies with the same fan diameters from Figure 2A, but using component designs as described in embodiments of the invention. As can be seen, the gauge thickness is significantly reduced using component designs as described in embodiments of the invention. In one example, due to reduction in gauge thickness, the mass of the support frame is equal to or less than half of the mass used in prior designs. In one example, a stiffness of the support frame is equal to or greater than a stiffness from prior designs, while the mass is equal to or less than half of the mass used in prior designs.

Figure 3 shows a material list for a selection of example fan assemblies formed according to examples described in the present disclosure. Using methods and configurations shown, the fan assemblies are lighter and/or stiffer than prior designs.

The chart in Figure 3, illustrates sheet metal gauge thickness for example fan assembly configurations formed from galvanized mild steel sheet. The fan sizes indicated in column 1 show fan diameters given in millimeters. In the fan industry, fan assemblies are often categorized into Air Movement and Control Association (AMCA) international standard classifications. Factors that affect a fan assembly's AMCA class include motor power, and fan size.

In the chart of Figure 3, class I (CL1) indicates a fan assembly operating range between a low value of approximately 3,400 cubic feet per minute at a static pressure of approximately 2.5 inches water gauge (W.G.) and a high value of approximately 2,415 cubic feet per minute at a static pressure of

approximately 5.0 inches water gauge (W.G.). Class II (CL2) indicates a fan assembly operating range between a low value of approximately 3,400 cubic feet per minute at a static pressure of approximately 2.5 inches water gauge (W.G.) and a high value of approximately 2,415 cubic feet per minute at a static pressure of approximately 5.0 inches water gauge (W.G.). Class III (CL3) indicates a fan assembly operating range between a low value of approximately 5,500 cubic feet per minute at a static pressure of approximately 6.6 inches water gauge (W.G.) and a high value of approximately 4,000 cubic feet per minute at a static pressure of approximately 13.5 inches water gauge (W.G.).

Figure 4 shows a flow chart of one example method of forming a fan assembly. In operation 402, a number of box section rails are formed. In operation 404, the number of box section rails are coupled together to form a base unit. In operation 406, an inlet plate is coupled to the base unit. In operation 408, a motor mount is coupled to the base unit, and in operation 410 a motor is coupled to the motor mount. In operation 412, an impeller is coupled to a shaft of the motor.

As discussed above, any of a number of coupling techniques or fasteners may be used to couple components together to form a support frame of the fan assembly. In addition to any suitable fastener, welding and/or adhesives may be used. As discussed above, in one example, box section rails are formed by joining multiple components, such as L shaped sections, together. In one example method, formed features are further added to selected components of the fan assembly. In one example, the formed features are stamped. As discussed above, other forming techniques, such as drawing, bending, forging, etc. are also within the scope of the invention.

To better illustrate the method and apparatuses disclosed herein, a non- limiting list of embodiments is provided here:

Example 1 includes a fan assembly. The fan assembly includes a motor, an impeller coupled to a shaft of the motor, a support frame coupled to the motor, wherein the support frame includes a number of sheet metal components, and a number of formed features within a planar surface of at least one of the number of sheet metal components.

Example 2 includes the fan assembly of example 1 , wherein the number of sheet metal components include steel sheet metal.

Example 3 includes the fan assembly of any one of examples 1-2, wherein the number of sheet metal components include aluminum sheet metal.

Example 4 includes the fan assembly of any one of examples 1-3, further including an inlet funnel coupled to an inlet plate, wherein the inlet plate includes a number of formed features within a planar surface.

Example 5 includes the fan assembly of any one of examples 1-4, wherein the number of sheet metal components are joined together using a fastener chosen from a group consisting of rivets, swage locks, bolts, screws, and adhesives.

Example 6 includes the fan assembly of any one of examples 1-5, wherein the number of sheet metal components are joined together using welding.

Example 7 includes the fan assembly of any one of examples 1-6, wherein the impeller includes an axial impeller.

Example 8 includes the fan assembly of any one of examples 1-7, wherein the impeller includes a centrifugal impeller.

Example 9 includes a fan assembly that includes a motor, an impeller coupled to a shaft of the motor and a support frame coupled to the motor, wherein the support frame includes a plurality of box section rails coupled together to form a base unit, an inlet plate coupled to the base unit, and a motor mount coupled to the base unit.

Example 10 includes the fan assembly of example 9, wherein the motor mount includes a plurality of diagonal cross members to form a truss.

Example 11 includes the fan assembly of any one of examples 9-10, wherein the plurality of box section rails includes a first pair of box section rails parallel to a rotation axis of the motor, and at least two second box section rails coupled between the first pair of box section rails to form a ladder base unit.

Example 12 includes the fan assembly of any one of examples 9-11, wherein the support frame includes a number of formed features within a planar surface of at least a portion of the support frame.

Example 13 includes the fan assembly of any one of examples 9-12, wherein the number of formed features are formed within a portion of the motor mount.

Example 14 includes the fan assembly of any one of examples 9-13, wherein the number of formed features are formed within a portion of the inlet plate.

Example 15 includes the fan assembly of any one of examples 9-14, wherein the support frame is formed from steel sheet metal having a gauge thickness equal to or less than 14.

Example 16 includes the fan assembly of any one of examples 9-15, wherein the support frame is formed from steel sheet metal having a gauge thickness equal to or less than 14 for a centrifugal impeller diameter of approximately 365mm.

Example 17 includes the fan assembly of any one of examples 9-15, wherein the support frame is formed from steel sheet metal having a gauge thickness equal to or less than 16 for a centrifugal impeller diameter of approximately 270mm.

Example 18 includes the fan assembly of any one of examples 9-15, wherein the support frame is formed from steel sheet metal having a gauge thickness equal to or less than 18 for a centrifugal impeller diameter of approximately 122mm.

Example 19 includes a method of forming a fan assembly. The method includes forming a number of box section rails, coupling together the number of box section rails to form a base unit, coupling an inlet plate to the base unit, coupling a motor mount to the base unit, coupling a motor to the motor mount, and coupling an impeller to a shaft of the motor.

Example 20 includes the method of example 19, wherein forming the number of box section rails includes bending a flat sheet of metal to form the number of box section rails.

Example 21 includes the method of any one of examples 19-20, wherein forming the number of box section rails includes joining two L shaped sections of sheet metal together to form the number of box section rails.

Example 22 includes the method of any one of examples 19-21, further including stamping a number of features within a planar surface of at one sheet metal component of the fan assembly.

Example 23 includes the method of any one of examples 19-22, wherein stamping a number of features includes stamping a number of features into a portion of the inlet plate.

Example 24 includes the method of any one of examples 19-23, wherein stamping a number of features includes stamping a number of features into a portion of the motor mount.

Example 25 includes a fan assembly, including a motor, and an impeller coupled to a shaft of the motor, a support frame coupled to the motor, wherein the support frame includes a number of sheet metal components with no component thicker than 14 gauge steel. The fan assembly is designed to operate in a range between a low value of approximately 5,500 cubic feet per minute at a static pressure of approximately 6.6 inches water gauge (W.G.) and a high value of approximately 4,000 cubic feet per minute at a static pressure of

approximately 13.5 inches water gauge (W.G.).

Example 26 includes a fan assembly, including a motor, and an impeller coupled to a shaft of the motor, a support frame coupled to the motor, wherein the support frame includes a number of sheet metal components with no component thicker than 14 gauge steel. The fan assembly is designed to operate in a range between a low value of approximately 4,400 cubic feet per minute at a static pressure of approximately 4.3 inches water gauge (W.G.) and a high value of approximately 3,150 cubic feet per minute at a static pressure of

approximately 8.5 inches water gauge (W.G.).

Example 27 includes a fan assembly, including a motor, and an impeller coupled to a shaft of the motor, a support frame coupled to the motor, wherein the support frame includes a number of sheet metal components with no component thicker than 14 gauge steel. The fan assembly is designed to operate in a range between a low value of approximately 3,400 cubic feet per minute at a static pressure of approximately 2.5 inches water gauge (W.G.) and a high value of approximately 2,415 cubic feet per minute at a static pressure of

approximately 5.0 inches water gauge (W.G.).

The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as "examples." Such examples can include elements in addition to those shown or described.

However, the present inventors also contemplate examples in which only those elements shown or described are provided. Moreover, the present inventors also contemplate examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

In this document, the terms "a" or "an" are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of "at least one" or "one or more." In this document, the term "or" is used to refer to a nonexclusive or, such that "A or B" includes "A but not B," "B but not A," and "A and B," unless otherwise indicated. In this document, the terms "including" and "in which" are used as the plain-English equivalents of the respective terms "comprising" and "wherein." Also, in the following claims, the terms "including" and "comprising" are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms "first," "second," and "third," etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to comply with 37 C.F.R. § 1.72(b), to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. A fan assembly, comprising:

a motor;

an impeller coupled to a shaft of the motor;

a support frame coupled to the motor, wherein the support frame includes;

a number of sheet metal components; and

a number of formed features within a planar surface of at least one of the number of sheet metal components.

2. The fan assembly of claim 1, wherein the number of sheet metal components include steel sheet metal.

3. The fan assembly of claim 1, wherein the number of sheet metal components include aluminum sheet metal.

4. The fan assembly of claim 1, further including an inlet funnel coupled to an inlet plate, wherein the inlet plate includes a number of formed features within a planar surface.

5. The fan assembly of claim 1, wherein the number of sheet metal components are joined together using a fastener chosen from a group consisting of rivets, swage locks, bolts, screws, and adhesives.

6. The fan assembly of claim 1 , wherein the number of sheet metal components are joined together using welding.

7. The fan assembly of claim 1, wherein the impeller is an axial impeller.

8. The fan assembly of claim 1, wherein the impeller is a centrifugal impeller.

9. A fan assembly, comprising:

a motor;

an impeller coupled to a shaft of the motor;

a support frame coupled to the motor, wherein the support frame includes;

a plurality of box section rails coupled together to form a base unit;

an inlet plate coupled to the base unit; and

a motor mount coupled to the base unit.

10. The fan assembly of claim 9, wherein the motor mount includes a plurality of diagonal cross members to form a truss.

11. The fan assembly of claim 9, wherein the plurality of box section rails includes a first pair of box section rails parallel to a rotation axis of the motor, and at least two second box section rails coupled between the first pair of box section rails to form a ladder base unit.

12. The fan assembly of claim 9, wherein the support frame includes a number of formed features within a planar surface of at least a portion of the support frame.

13. The fan assembly of claim 12, wherein the number of formed features are formed within a portion of the motor mount.

14. The fan assembly of claim 12, wherein the number of formed features are formed within a portion of the inlet plate.

15. The fan assembly of claim 9, wherein the support frame is formed from steel sheet metal having a gauge thickness equal to or less than 14.

16. The fan assembly of claim 9, wherein the support frame is formed from steel sheet metal having a gauge thickness equal to or less than 14 for a centrifugal impeller diameter of approximately 365mm.

17. The fan assembly of claim 9, wherein the support frame is formed from steel sheet metal having a gauge thickness equal to or less than 16 for a centrifugal impeller diameter of approximately 270mm.

18. The fan assembly of claim 9, wherein the support frame is formed from steel sheet metal having a gauge thickness equal to or less than 18 for a centrifugal impeller diameter of approximately 122mm.

19. A method of forming a fan assembly, comprising:

forming a number of box section rails;

coupling together the number of box section rails to form a base unit; coupling an inlet plate to the base unit;

coupling a motor mount to the base unit;

coupling a motor to the motor mount; and

coupling an impeller to a shaft of the motor.

20. The method of claim 19, wherein forming the number of box section rails includes bending a flat sheet of metal to form the number of box section rails.

21. The method of claim 19, wherein forming the number of box section rails includes joining two L shaped sections of sheet metal together to form the number of box section rails.

22. The method of claim 19, further including stamping a number of features within a planar surface of at one sheet metal component of the fan assembly.

23. The method of claim 22, wherein stamping a number of features includes stamping a number of features into a portion of the inlet plate.

24. The method of claim 23, wherein stamping a number of features includes stamping a number of features into a portion of the motor mount.

25. A fan assembly, comprising: a motor;

an impeller coupled to a shaft of the motor;

a support frame coupled to the motor, wherein the support frame includes a number of sheet metal components with no component thicker than 14 gauge steel; and

wherein the fan assembly is designed to operate in a range between a low value of approximately 5,500 cubic feet per minute at a static pressure of approximately 6.6 inches water gauge (W.G.) and a high value of approximately 4,000 cubic feet per minute at a static pressure of approximately 13.5 inches water gauge (W.G.).

26. A fan assembly, comprising:

a motor;

an impeller coupled to a shaft of the motor;

wherein the fan assembly is designed to operate in a range between a low value of approximately 4,400 cubic feet per minute at a static pressure of approximately 4.3 inches water gauge (W.G.) and a high value of approximately 3,150 cubic feet per minute at a static pressure of approximately 8.5 inches water gauge (W.G.).

27. A fan assembly, comprising:

a motor;

an impeller coupled to a shaft of the motor;

wherein the fan assembly is designed to operate in a range between a low value of approximately 3,400 cubic feet per minute at a static pressure of approximately 2.5 inches water gauge (W.G.) and a high value of approximately 2,415 cubic feet per minute at a static pressure of approximately 5.0 inches water gauge (W.G.).