# Patent

## Title
Standby generator including enclosure with intake opening in rear wall and exhaust opening in front wall

## Abstract

A standby generator includes an engine, an alternator, and an enclosure including a base and a number of walls extending from the base including a front wall, a rear wall, a left wall, and a right wall. The standby generator includes an intake opening configured to allow air to be drawn into the enclosure and an exhaust opening configured to allow heated air and exhaust gases to be expelled from the enclosure. The intake opening is provided on the rear wall and the exhaust opening is provided on the front wall.

## Background
CROSS-REFERENCE TO RELATED PATENT APPLICATIONS
This application is a continuation of U.S. application Ser. No. 14/496,867 filed on Sep. 25, 2014, which is a divisional of U.S. application Ser. No. 13/358,417, filed Jan. 25, 2012, both incorporated herein by reference in their entireties.


BACKGROUND
The present application relates generally to the field of standby generators. Standby generators have become popular as sources of limited amounts of power for short-term use. For example, standby generators are often connected to homes or businesses to provide power in situations where the normal power source (e.g., utility power grid) fails. Standby generators generally include a prime mover that provides mechanical power to a generator or alternator that includes a rotor that rotates to generate useable electricity. The electricity is delivered via a switch, breaker, or other interruptible device to the home, business, or facility for use. Such generators may be provided in an enclosure to protect internal components from tampering and the elements and to manage generator noise and exhaust.
SUMMARY
One embodiment of the invention relates to a standby generator including an engine, an alternator and an enclosure. The enclosure includes a base and a number of side walls extending from the base including a front wall, a rear wall, a left wall, and a right wall. A first intake opening configured to allow air to be drawn into the enclosure is provided on the rear wall and an exhaust opening configured to allow heated air and exhaust gases to be expelled from the enclosure is provided on the front wall.
Another embodiment of the invention relates to a standby generator including an engine, an alternator, a base, a first pair of opposing walls and a second pair of opposing walls each coupled to the base. The first pair of opposing walls includes a front wall and a rear wall. The second pair of opposing walls includes a left wall and a right wall. A first intake opening is positioned in the rear wall and is configured to draw air into the generator and an exhaust opening is positioned in the front wall and is configured to expel exhaust gases and heated air from the generator.
Alternative exemplary embodiments relate to other features and combinations of features as may be generally recited in the claims.



BRIEF DESCRIPTION OF THE DRAWINGS
The disclosure will become more fully understood from the following detailed description, taken in conjunction with the accompanying figures, in which:
FIG. 1 is a perspective view of an enclosure for a generator, in accordance with an exemplary embodiment.
FIG. 2 is a perspective view of the enclosure of FIG. 1 with the top in an open position.
FIG. 3 is a perspective view of the enclosure of FIG. 1 with the top in an open position and with a portion of the front panel and the rear panel removed.
FIG. 4 is a schematic isometric cross section view of a compressed fiberglass panel, in accordance with an exemplary embodiment.
FIG. 5 is a top view of the enclosure of FIG. 1 showing an exemplary air flow path.
FIG. 6 is a front view of the enclosure of FIG. 1.
FIG. 7 is a rear view of the enclosure of FIG. 1.
FIG. 8 is a side view of the enclosure of FIG. 1.
FIG. 9 is a perspective view of an enclosure of FIG. 1 with the outer panels removed to show interior components, in accordance with an exemplary embodiment.
FIG. 10 is a front view of a portion of a muffler exhaust duct for a generator enclosure in a flattened state, in accordance with an exemplary embodiment.
FIG. 11 is a top view of the portion of the muffler exhaust duct of FIG. 10 in a folded, assembled state.
FIG. 12 is a side view of the portion of the muffler exhaust duct of FIG. 10 in a folded, assembled state.



DETAILED DESCRIPTION
Before turning to the figures, which illustrate the exemplary embodiments in detail, it should be understood that the present application is not limited to the details or methodology set forth in the description or illustrated in the figures. It should also be understood that the terminology is for the purpose of description only and should not be regarded as limiting.
Referring to FIG. 1, a standby generator 20 is shown according to an exemplary embodiment. The generator 20 may be configured to provide power in the event of a utility power failure. According to various exemplary embodiments, the generator 20 may be a home standby generator, a portable generator, or any generator capable of providing power to a distribution panel of a building.
The standby generator 20 includes a prime mover such as an internal combustion engine 24 (e.g., a diesel engine, a rotary engine, petrol engine, etc.), and an alternator 26. Together, the engine 24 and the alternator 26 may be referred to as an engine-generator set. According to one exemplary embodiment, the engine 24 is a two-cylinder internal combustion engine with an output shaft 28 arranged such that the output shaft 28 extends substantially horizontally. The engine 24 includes an air-fuel mixing device (not shown), such as a carburetor, and an air cleaner positioned to filter particulate matter from an air stream before the air is directed to the air-fuel mixing device. Other embodiments may utilize other engines or other engine arrangements. For example, other embodiments may include a vertical shaft engine that may be coupled to a gearbox or may be directly coupled to the alternator 26. In other still embodiments, the engine 24 may be a single-cylinder engine or an engine with three or more cylinders. In other embodiments, the engine 24 may employ other fuel mixing devices such as fuel injection.
Referring to FIGS. 1 and 2, the engine 24 and the alternator 26 are contained within a housing or enclosure 22. In an exemplary embodiment, the enclosure 22 is a box-like structure with a bottom 30 (e.g., base, floor, platform, etc.) supporting the engine 24 and the alternator 26 and side walls including front 32, rear 34, left 36, and right 38 walls surrounding the engine 24 and the alternator 26. The walls 32, 34, 36, and 38 may be supported by internal frame members 40 (see FIGS. 3 and 9). A top 42 (e.g., lid, cover, roof, etc.) covers the open end of the enclosure 22. The top 42 is coupled to the rear 34 via hinges 44, allowing the top 42 to be pivoted to allow access to the interior of the enclosure 22 (e.g., to service or repair the standby generator 20). The hinges 44 are compact and occupy a minimal amount of space within the interior of the enclosure 22. A locking device 48 may be provided to retain the top 42 in a closed position, as shown in FIG. 1. According to other exemplary embodiments, the enclosure 22 may lack hinges 44 and the enclosure 22 may be opened by lifting the top 42 off of the enclosure 22.
The top 42 may include a handle 46 to facilitate the opening of the top 42. The hinges 44 may include positive lifting devices such as gas springs that generate an upward force to assist in the opening of the top 42 and prevent the unintended closing of the top 42 from the open position. Referring to FIG. 3, the top 42 is able to be opened more than 90 degrees from the horizontal position (i.e., past vertical), further reducing the unintended closing of the top 42. The hinges 44 are coupled to the top 42 at a distance away from the back edge 43 of the top 42. In an open position, the hinges 44 space the top 42 away from the rear wall 34, creating a gap 50. The rear wall 34 in the embodiment shown in FIG. 3 includes a removable panel 52. With the top 42 in an open position, the removable panel 52 can be removed upward through the gap 50 without further disassembly of the enclosure 22 (e.g., removing the top 42) to allow access to the engine 24 and the alternator 26 through an opening 54. Other portions of the enclosure 22, including all or part of the front 32, the left side 36, or the right side 38 (e.g., a front removable panel 56) may also be removed without removing the top 42. In this way, multiple sides of the engine 24 and the alternator 26 can be accessed for service or repair with a minimum of time and effort.
The panels of the enclosure 22 may be formed of a fiberglass material. Interior panels and components, such as ductwork may also be formed of a fiberglass material. Referring to FIG. 4, a portion of a fiberglass panel 80 is shown according to an exemplary embodiment. The panel 80 is formed of one or more fiberglass substrate layers 82. Additional reinforcing bond layers 84 may be included to increase the rigidity of the panel 80. One or both outer surfaces of the panel 80 may further include an outer facing layer 85 formed of a reflective material, such as a metallic foil. A thicker facing layer 85 may be provided for a panel located in the path of exhaust gasses from the engine 24. The fiberglass panel 80 is non-combustible and able to withstand elevated temperatures. According to an exemplary embodiment, air temperatures of approximately 175-200° F. may be encountered inside the enclosure 22 and air temperatures of approximately 550-700° F. may be encountered near exhaust gasses.
The panel 80 may have both compressed portions 86 and uncompressed portions 88 to facilitate the folding of a panel or the joining of multiple panels. The compressed portions 86 provide areas for secure fastening with rivets, standard threaded fasteners, curable sealants, adhesive tape, or any other suitable fastening methods. Compressed portions 86 may also be provided to increase structural rigidity and facilitate a seal between the panel 80 and a sealing member such as a gasket. In one embodiment, the compressed fiberglass panel 80 is manufactured by MAI Manufacturing of Richwood, Ohio. In such an embodiment, the compressed fiberglass substrate layer 82 may have fiber diameters in the range of 0.00023 to 0.00043 inches with a binder content in the range of approximately 10.5% to 17.5%.
Forming the panels of a compressed fiberglass material has several advantages over conventional sheet-metal panels. Conventional sheet metal panels may be coupled to an additional insulation panel (e.g., foam insulation with an aluminum or metallic polymer film layer), with the sheet metal providing structural rigidity and the insulation panel providing sound absorption and thermal insulation. A compressed fiberglass panel, on the other hand, is a single component and provides better thermal management by reflecting a greater amount of heat and better sound management by absorbing a greater amount of sound from generator exhaust and fans. Further, a compressed fiberglass panel is generally less expensive than a comparable sheet metal panel with an attached layer of insulation. Compressed fiberglass panels are able to be molded and joined in ways sheet metal cannot. Compressed fiberglass panels may be formed to lack the sharp edges common to sheet metal panels.
Referring now to FIGS. 5-7, the engine 24 and the alternator 26 produce heat as a byproduct that can raise the internal temperature of the enclosure 22. Air is therefore circulated through the enclosure 22 to cool the engine 24 and the alternator 26. Air is also drawn in to be mixed with fuel for combustion in the engine 24 (e.g., with a carburetor or fuel injection). Air intakes are provided to allow air to be drawn into the enclosure. Outlets or exhaust openings are provided to allow heated air and exhaust to be expelled from the interior of the enclosure 22. According to an exemplary embodiment, the enclosure 22 includes separate air intakes 60 and 62 for the engine 24 and the alternator 26, respectively. The enclosure 22 further includes an exhaust opening 64 through which exhaust from the engine 24 is expelled. In other embodiments, the enclosure 22 may include more than two air intakes or a single air intake or may include multiple exhaust openings.
The exhaust opening 64 is located on the front wall 32 (see FIG. 6). The exhaust opening 64 is relatively large, diffusing the exhaust flow and slowing the exhaust velocity to reduce impact on vegetation adjacent to the enclosure 22. Because standby generators are generally placed with the rear towards an adjacent structure, locating the exhaust opening 64 on the front wall 32 directs the hot exhaust away from the adjacent structure. Confining the exhaust to the front wall 32 is intended to typically allow vegetation and combustible objects to be placed in close proximity (e.g., approximately 18′′ away) to the other three sides of the enclosure 22.
The air intakes 60 and 62 are located opposite of the exhaust opening 64 on the rear wall 34 (see FIG. 6). Locating the air intakes 60 and 62 on the opposite side from the exhaust opening 64 reduces the likelihood that hot air from inside the enclosure 22 will be recirculated, and reduce the efficiency and durability of the cooling system. The engine air intake 60 and the generator air intake 62 may be provided on opposite sides of the rear wall 34.
Referring now to FIG. 8, the top 42 is pitched to advantageously direct water and debris away from the air intakes. According to an exemplary embodiment, when the top 42 is in a closed position, the upper surface 68 is inclined at pitch angle Θ toward the front 32. In contrast to a horizontal top or domed top for an enclosure, in which water or debris striking the top of the enclosure may be shed in any direction, the top 42 with a forward-pitched upper surface 68 sheds water towards the front of the enclosure, away from the air intakes 60 and 62. Reducing the amount of air and debris that is ingested into the air intakes 60 and 62 reduces the chance of component damage and is intended to prolong the life of the engine 24 and the alternator 26. Further, with a typical installation in which the rear 34 of the enclosure 22 is oriented towards an adjacent structure (e.g., a house), the forward-pitched upper surface 68 also directs water away from the structure, reducing the likelihood of water-related damage, such as basement leaks or foundation damage. Still further, the pitched upper surface 68 discourages the placement of objects on the top 42.
Referring now to FIG. 9, interior ductwork and separators may be utilized inside the enclosure 22 to route cooling air toward the engine 24 and the alternator 26 and to route exhaust gasses out of the enclosure 22. According to an exemplary embodiment, an engine intake duct 70 routes outside air from the air intake 60 (FIG. 7) to the engine 24. An generator intake duct 72 routes outside air from the air intake 62 to the alternator 26. The outside air may be utilized to cool the generator components directly, or may be utilized to cool an intermediate coolant fluid with a device such as a radiator. A muffler exhaust duct 74 (e.g., muffler box) routes exhaust gasses from the engine 24 to the exhaust opening 64. The duct members 70, 72, and 74 are configured to introduce at least one 90 degree turn to the air flow between the exterior openings and any noise-producing internal components. In this way, a direct path is not present for propagating sound waves to the exterior of the enclosure 22, reducing the volume of the sound produced by the generator 20.
The duct members 70, 72, and 74 may be formed of compressed fiberglass, similar to the fiberglass panel 80 described above. The duct members 70, 72, and 74 may be formed of a combination of formed panels, flat panels, and folded panels. Referring to FIGS. 10-12, folded panel 75 for a muffler exhaust duct 74 is shown according to one exemplary embodiment. The folded panel 75 includes uncompressed areas 76 and compressed areas 78. Compressed areas 78 may be utilized, for instance, along fold lines and in areas with openings 79 for coupling the panel 75 to other portions of the muffler exhaust duct 74 or to frame members 40.
The fiberglass material for the duct members 70, 72, and 74 provides thermal management by reflecting a greater amount of heat (e.g., from hot exhaust gasses) and sound management by absorbing sound from generator exhaust and fans. As described above, the fiberglass panels may also be shaped to create non-direct paths between sound-producing components and the exterior. The fiberglass duct members 70, 72, and 74 compartmentalize the interior of the enclosure 22 and reduce undesirable thermal transfer between ducts or compartments by blocking both conductive and radiant heat transfer. As illustrated in FIG. 10, members formed of fiberglass panels may be manufactured and shipped in flattened configurations, reducing warehouse and shipping space.
The construction and arrangements of the standby generator and related enclosure, as shown in the various exemplary embodiments, are illustrative only. Although only a few embodiments have been described in detail in this disclosure, many modifications are possible (e.g., variations in sizes, dimensions, structures, shapes and proportions of the various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.) without materially departing from the novel teachings and advantages of the subject matter described herein. Some elements shown as integrally formed may be constructed of multiple parts or elements, the position of elements may be reversed or otherwise varied, and the nature or number of discrete elements or positions may be altered or varied. The order or sequence of any process, logical algorithm, or method steps may be varied or re-sequenced according to alternative embodiments. Other substitutions, modifications, changes and omissions may also be made in the design, operating conditions and arrangement of the various exemplary embodiments without departing from the scope of the present invention.

## Claims

1. A standby generator, comprising:
an engine including an output shaft:
an alternator;
an enclosure comprising:
a base;
a plurality of walls extending from the base comprising a front wall, a rear wall, a left wall, and a right wall, wherein the output shaft of the engine extends toward the alternator and the left wall; and
a cover coupled to the rear wall;

a first intake opening configured to allow air to be drawn into the enclosure;
a second intake opening provided on the rear wall configured to allow air to be drawn into the enclosure; and
an exhaust opening configured to allow heated air and exhaust gases to be expelled from the enclosure;
wherein the first intake opening is provided on the rear wall and the exhaust opening is provided on the front wall;
wherein the first intake opening is configured to allow air to be drawn into the engine and wherein the second intake opening is configured to allow air to be drawn into the enclosure to cool the alternator;
wherein the cover comprises an upper surface pitched away from the rear wall, the first intake opening, and the second intake opening.

2. The standby generator of claim 1, wherein the first intake opening and the second intake opening are positioned on opposite sides of the rear wall.

3. The standby generator of claim 1, wherein the first intake opening is positioned proximate the right wall and the second intake opening is positioned proximate the left wall.

4. The standby generator of claim 1, wherein the exhaust opening is positioned proximate the left wall.

5. The standby generator of claim 1, wherein the first intake opening and the second intake opening draw air into the enclosure in the same direction as an expulsion of exhaust gases from the exhaust opening.

6. The standby generator of claim 1, further comprising:
an engine intake duct configured to route air entering the first intake opening to the engine;
an alternator intake duct configured to route air entering the second intake opening to the alternator; and
a muffler exhaust duct configured to route exhaust gases from the engine to the exhaust opening.

7. A standby generator, comprising:
an engine including an output shaft;
an alternator;
a base;
a first pair of opposing walls coupled to the base comprising:
a front wall; and
a rear wall;

a second pair of opposing walls coupled to the base comprising:
a left wall, wherein the output shaft of the engine extends toward the alternator and the left wall; and
a right wall;

a cover coupled to the rear wall;
a first intake opening positioned in the rear wall configured to draw air into the standby generator;
a second intake opening positioned in the rear wall configured to draw air into the standby generator; and
an exhaust opening positioned in the front wall configured to expel exhaust gases and heated air from the standby generator;
wherein the second pair of opposing walls does not include the first intake opening or the exhaust opening;
wherein the first intake opening is configured to draw air into the standby generator to cool the engine and wherein the second intake opening is configured to draw air into the standby generator to cool the alternator;
wherein the first intake opening and the second intake opening are positioned on opposite sides of the rear wall;
wherein the first intake opening and the second intake opening draw air in the same direction as an expulsion of exhaust gases from the exhaust opening;
wherein the cover comprises an upper surface pitched away from the rear wall, the first intake opening, and the second intake opening.

8. The standby generator of claim 7, further comprising:
an engine intake duct configured to route air entering the first intake opening to the engine; an alternator intake duct configured to route air entering the second intake opening to the alternator; and
a muffler exhaust duct configured to route exhaust gases from the engine to the exhaust opening.

9. The standby generator of claim 7, wherein the engine intake duct comprises a 90-degree turn to air flow between the first intake opening and the engine.

10. The standby generator of claim 7, wherein the alternator intake duct comprises a 90-degree turn to air flow between the second intake opening and the alternator.

11. The standby generator of claim 7, wherein the muffler exhaust duct comprises a 90-degree turn to air flow between the engine and the exhaust opening.