WO1999064794A1

WO1999064794A1 - Chiller assembly

Info

Publication number: WO1999064794A1
Application number: PCT/US1999/007992
Authority: WO
Inventors: John D. Read; Michael L. Buckley
Original assignee: York International Corporation
Priority date: 1998-06-11
Filing date: 1999-04-13
Publication date: 1999-12-16
Also published as: AU3491699A

Abstract

A chiller assembly (5) comprises a frame (2, 4) of sheetmetal parts interconnected by mechanical tabs (64) and corresponding holes (164). The weight imparted by the fully assembled chiller unit produces a locking effect on the interconnected parts. The use of tabs (64) and holes (164) makes the mating parts self-aligning and lessens the number of discrete fasteners required, significantly reducing the time needed to assemble the chiller unit (5).

Description

Chiller Assembly Description Field of the Invention

The present invention relates to HVAC chiller assemblies, and more particularly to a structure and system for assembling chillers through the use of a frame having tabbed sheetmetal parts. Description of the Related Art

An air cooled chiller for an air conditioning system is largely a collection of heat exchanger components — including, for example, condenser coils, fans, and piping — held together in a metal frame including supporting beams and sheetmetal. Typically, the metal frame is assembled by connecting individual sheetmetal parts to the supporting beams through the use of any of a number of discrete mechanical fasteners. Thus, owing at least in part to the size of the chiller frame and the weight of the components the frame must support, the commonly followed procedure for assembling chillers entails the use of a large number of nuts, bolts, rivets, sheetmetal screws, or similar fasteners.

While the use of such fasteners generally provides the structural strength and alignment necessary for a fully assembled chiller, the use of such fasteners also produces drawbacks. For example, because of the high number of fasteners that must be installed, a significant amount of time is required to complete the assembly of the chiller. Also, additional time must be taken for appropriate quality inspections because of the possibility that an assembler may fail to install all of the fasteners required to generate a safe and sound frame. The time spent in this regard is further increased by the distinct possibility that, even where a fastener has been installed, it may not have been installed properly. Thus, for example, where nuts and bolts are used to join the frame, every nut and bolt should be checked to ensure that they have been tightened to specified torque values. Another disadvantage of present assembly techniques is the danger of fasteners loosening after assembly — for example, during transportation, installation, and operation of the chiller unit. Loosened fasteners obviously can lead to a structurally unsound frame and chiller assembly. Moreover, loose fasteners and other components of the assembly may fall and cause damage to the various chiller components, particularly the fans.

Consequently, a goal of the present invention is to provide an improved chiller assembly that overcomes these disadvantages, without compromising the structural integrity of the frame.

Summary of the Invention

An object of the present invention is to provide a simple and inexpensive structure and system for assembling a chiller.

Another object is to provide a system and method requiring reduced time for assembling a chiller.

Still another object of the invention is to provide a system and method for assembling a chiller that uses minimal discrete fasteners.

Additional objects and advantages of the invention will be set forth in part in the description that follows, and in part will be obvious from the description, or may be learned by practice of the invention. The objects and advantages of the invention will be realized and attained by means of the elements and combinations particularly pointed out in the appended claims.

To achieve the objects and in accordance with the purpose of the invention, as embodied and broadly described herein, the invention comprises a chiller assembly, comprising a plurality of interconnected parts wherein at least a portion of said parts includes a first set of components, said first set of components including tabs having opposed side ends, a distal end, and a proximal end, wherein said tabs are connected to said first set of components along the proximal ends; and at least a portion of said parts includes a second set of components having corresponding openings adapted to receive said tabs, wherein the tabs and the openings substantially provide the connection for the first set of components to the second set of components, respectively.

The improved chiller assembly of the present invention comprises a frame of sheetmetal pieces containing mechanical tabs and corresponding holes or slots. The pieces are joined by inserting the integrally formed tabs of one piece into the mating holes of another piece. The respective dimensions of the tabs and corresponding holes are such that, when joined, the parts become securely attached to one another. In the preferred embodiment, the chiller assembly includes a plurality of condenser coil subassemblies that include a plurality of tabs (or holes) that correspond to respective holes (or tabs) in the frame. Once the condenser coils are mounted onto the frame, their weight imparts a locking effect to the frame, resulting in a frame of rigid construction. In this manner, the coils assume an additional function by acting as structural members.

The chiller assembly of the present invention offers several advantages over the prior art, including, for example, the need for fewer parts and a reduction in chiller assembly time. In a conventional chiller assembly, mating parts are joined by separately and individually securing each fastener in place, an activity entailing as many operations as there are fasteners. The chiller assembly of the present invention, by contrast, uses mating pairs of tabs and holes, each formed integrally to its respective sheetmetal part or component. Thus, whereas parts in a conventional chiller may be joined by fastening, by way of example, 100 nuts and bolts, most if not all of the various chiller components of the present invention, on the other hand, which parts have tabs and/or holes instead of discrete fasteners, are joined simply by positioning the components on the frame adjacent the respective holes or tabs on the frame and allowing the component to drop into a locked position. By sliding the parts to be mated adjacent one another, the tabs of one piece engage the corresponding holes of the other piece. The holes and slots are preferably designed and sized to produce a locking feature. In the alternative, once the components are slid into place with the tabs and holes engaged, a few mechanical fasteners, such as bolts or rivets, can be installed through the engaged components, so they cannot slide out of the engaged position.

Moreover, by virtue of the dimensional congruence between the tabs, on one hand, and the corresponding holes, on the other hand, the present structure is self-aligning. Further, the danger of damage from fasteners and associated hardware parts (such as, for example, nuts, bolts, flat washers, lock washers, and sheetmetal screws) working free from their points of attachment and becoming lodged in various chiller components is greatly reduced — the tabs and holes of the present invention are integral to the sheetmetal pieces that form the frame.

The present invention also provides advantages over conventional assemblies with respect to complete or partial disassembly. Here, again due to the use of integral tabs and holes in place of discrete fasteners, mated pieces can be separated by applying a single force sufficient to decouple the tabs of one piece from the holes of the other piece. A conventional chiller frame, on the other hand, requires the removal of each fastener individually.

The invention further comprises a method for assembling a chiller unit, said chiller unit including a plurality of interconnected parts wherein at least a portion of said parts includes a first set of components having tabs, and at least a portion of said parts includes a second set of components having corresponding openings adapted to receive said tabs, the method comprising positioning a component of one set adjacent a component of the other set, so the tabs from the component of the first set are proximate to and in substantial alignment with the corresponding holes of the component of the second set; and inserting the tabs of the component of the first set in the corresponding holes of the component of the second set, thereby joining the component of the first set and the component of the second set.

It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory only and are not restrictive of the invention, as claimed.

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments of the invention and together with the description, serve to explain the principles of the invention.

Brief Description of The Drawings

Figure 1 is a perspective view of a chiller assembly with a transparent view of the front upper portion.

Figure 2 is a side view of the chiller assembly of the present invention.

Figure 3 is a partial section view taken along line 3-3 of Figure 1. Figure 4 is a partial section view taken along line 4-4 of Figure 2.

Figure 5 is an enlarged view of a preferred embodiment of the present invention showing a condenser coil subassembly engaged with a side panel.

Figure 6 is a side view of a preferred embodiment of the tab of the present invention.

Figure 7 is a plan view of the preferred embodiment of the tab shown in Figure 6.

Description of The Preferred Embodiments

Reference will now be made in detail to exemplary embodiments of the invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

As will be explained more fully below, the present invention is directed to an improved chiller assembly comprising a frame and metal parts joined by mechanical tabs and mating holes.

As shown in Figure 1 , the frame of an air-cooled chiller unit 5 has an upper section 2 supported by a lower section 4, which includes a base 30 and legs 50. In a preferred embodiment, the lower section 4 is comprised of formed sheet steel, fastened together by conventional fasteners. The base 30 includes supporting members for the refrigeration components. The support legs 50 extend from the base 30 to the bottom of the upper section 2. Additional sheet metal pieces act as bracing components to aid in providing a rigid structure. These bracing components are secured to the other members by means of conventional fasteners.

In a preferred embodiment, the upper section 2 includes condenser coils, piping, a control panel 40, and a number of fans mounted to fan decks 10. The fans operate to circulate air over the condenser coils, thus effecting the desired heat exchange for the chiller's given application. The fans, with motors, are bolted to sheet metal supports, which are in turn bolted to the underside of the fan decks 10. Each fan deck 10 has two fans and is supported by side panels 60, a center spine 75, and an outer coil 20. The space to the front and rear of the upper section 2 not covered by the fan decks 10 is covered by sheet metal panels, which prevent the entry of debris and provide protection from adverse weather elements.

The condenser coils can be arranged in various ways within the chiller unit 5. For example, in a preferred embodiment shown in Figures 1 and 2, inner condenser coils 70 are positioned at an oblique angle relative the fan deck 10 along the length of the chiller unit 5. In addition, outer condenser coils 20 can be arranged along the front face and rear face of the chiller 5. For optimizing air flow across the condenser coils 20, 70, a plurality of side panels 60, made from sheetmetal, preferably are placed at selected distances perpendicular to and between facing sets of inner 70 and outer coils 20. Such placement of the panels 60 affords more efficient chiller performance by providing defined pathways for the air, thus ensuring that a desired volume of air will be directed over and through the coils 20, 70.

The means of connecting the constituent parts of the chiller unit 5 is illustrated in Figures 3, 4, and 5, where the example of mating between side panels 60 and condenser coils 20, 70 is shown. On the side panel 60, integral tabs 64 extend from a right angle flange 62 on both sides of the side panel 60. The condenser coils 20, 70 have coil fins 170 with holes 180 for accepting condenser tubes. Preferably, the coil fins 170 are enclosed within sheetmetal coil panels 160 having right angle bends 165. These bends 165 interface with the right angle flanges 62 of the side panels and contain holes 164 sized to accept the tabs 64 of the flanges 62. Further, the coil panel bends 165 are spaced at a sufficient distance from the proximate edge of the coil fins 170 to permit insertion of a tab 64 without physical interference between the tabs 64 and fins 170.

As further described below, to mate the condenser coils 20, 70 to the side panels 60, a side panel 60 is positioned adjacent an inner coil 70, which rests on the center spine 75 and a lower spine 76, so the tabs 64 of the side panel 60 are aligned with the corresponding holes 164 of the coil 70. The center spine 75 and lower spines 76 are preferably made of sheetmetal and are configured to provide ample surfaces appropriately positioned to support the inner coils 70. The tabs 64 are then inserted through the holes 164 and the panel 60 is then lowered until the tabs 64 are fully engaged. In turn, an outer coil 20 is positioned adjacent the side panel 60, and lowered until the holes 164 of the coil 20 are fully engaged by the tabs 64 of the panel 60. By virtue of their weight, the condenser coils 20, 70 produce a locking effect once they are mated to the panel 60. As a result, the chiller frame assumes a construction of rigid structural integrity.

Figures 6 and 7 show a preferred embodiment of the tabs 64. Preferably, the tabs 64 are approximately 1 inch long and 3/4 inch wide, and are formed with an offset of approximately 0.06 inch from the sheetmetal surface. To ensure secure engagement of the mating parts, the mating pieces preferably have thicknesses of approximately 0.08 inch. As a result of this dimensional combination, the union of mating parts produces a desirable interference fit. In addition, to facilitate the passage of the tabs 64 through their corresponding holes 164, a portion of the distal end of the tab 64 can be bent at an angle α upward. Preferably, this angle α is approximately 30°. Further facilitating engagement, the tab 64 can be tapered at an angle β along both edges. Preferably, this angle β is approximately 5°.

In assembling the chiller, initially the bottom frame of the upper section 2 is assembled at floor level by fastening the components together, including the lower spines 76. Using temporary supports, which hold the inner coils 70 in a properly separated configuration at their upper ends until the center spine 75 is installed, the inner coils 70 can be set in place against the lower spines 76 using a crane and lifting fixture designed for the purpose of coil handling. The lifting fixture can comprise a beam substantially the same length as the coil 70 and can include sheetmetal pieces containing tabs, corresponding to the holes 164 of the coils 70, for holding the coils 70 during lifting and lowering, thus permitting more even distribution of the loads imparted to the coils 70 during this step. The center spine 75 is then placed between the widened opening (provided by the temporary support) at the upper end of these coils 70 and the temporary support is adjusted so the upper ends of the coils 70 come to rest against the supporting surfaces of the spine 75. The temporary fixture, which can be a set of brackets or a saw horse-like structure, is then removed, leaving the center spine 75 to provide permanent support. By virtue of the support provided by the center spine 75 and the lower spines 76, in addition to their own weight, the inner coils 70 need not be fastened to the spines 75, 76. The side panels 60 next are put into position, preferably by hand, by inserting the tabs 64, which point generally downward along the surface that interfaces with the inside coils 70, into the corresponding holes 164 of the coils 70. The tabs 64 are engaged by moving the panel 60 in a downward motion. With the side panels 60 joined to the inner coils 70, the panels 60 are further secured in place by fastening them 60, using conventional fasteners, to the leg of the center spine 75 adjacent the panel 60. Next, the outside coils 20 are lifted into position with the crane and gently lowered so the panel tabs 64, which point upward along the surface that interfaces with the outer coils 20, engage the holes 164 along the bend 165 of the coils 20. At this point, the coils 20 are allowed to drop and the outside coils 20, panels 60, and inside coils 70 become locked together, by virtue of the tabbing-hole arrangement and the weight of the coils 20, 70. A few strategically placed fasteners can be placed to assure there is no shipping damage. The fan decks 10, with motors and wiring pre-assembled, are then placed on top of the upper section 2 and fastened, completing assembly of the upper section 2.

Preferably, the entire assembly of the chiller upper section 2 occurs at floor level, where the assembly can be performed most efficiently and expeditiously. To further reduce the time to assemble the chiller unit, the lower section 4 can simultaneously be assembled, also at floor level, proximate the upper section 2. Thus, when both sections 2, 4 have been assembled, the upper section 2 can be lifted with a crane and moved but a short distance before positioning it atop the lower section 4, at which the time the two sections are joined by conventional fasteners. Finally, the few remaining electrical and piping connections needed to complete the assembly of the chiller are connected.

The above-described present invention provides important improvements in the assembly of chiller units. For example, much less time is required to assemble the unit, alignment of the mating parts is simplified, and the troubles and dangers from having a large number of discrete fasteners and associated hardware is reduced. At the same time, the structural integrity of the assembled chiller unit remains robust, owing to the firm fit between the tabs and corresponding holes and the locking effect imparted to the frame by the weight of the condenser coils.

Other embodiments of the invention will be apparent to those skilled in the art from consideration of the specification and practice of the invention disclosed herein. It is intended that the specification and examples be considered as exemplary only, with a true scope and spirit of the invention being indicated by the following claims.

Claims

1. A chiller assembly, comprising a plurality of interconnected parts wherein at least a portion of said parts includes a first set of components, said first set of components including tabs having opposed side ends, a distal end, and a proximal end, wherein said tabs are connected to said first set of components along the proximal ends; and at least a portion of said parts includes a second set of components having corresponding openings adapted to receive said tabs, wherein the tabs and the openings substantially provide the connection for the first set of components to the second set of components, respectively.

2. The chiller assembly of claim 1 , wherein the tabs and corresponding openings are sized to form an interference fit.

3. The chiller assembly of claim 1 , wherein the first set of components include substantially planar polygonal sheetmetal panels having an integrally formed right angle flange adjacent at least one end, with the tabs disposed on said flange.

4. The chiller assembly of claim 3, wherein the second set of components include condenser coil assemblies, said condenser coil assemblies including substantially planar exterior sheetmetal walls, with the openings formed on said walls and aligned for engagement with the tabs of the panels.

5. The chiller assembly of claim 4, wherein the tabs have a length of approximately 1 inch and a width of approximately 3/4 inch.

6. The chiller assembly of claim 5, wherein at least a portion of the tabs are substantially parallel to the flanges and offset from the flanges to provide a gap of approximately 1/16 inch between the tabs and the flanges.

7. The chiller assembly of claim 6, wherein a portion of the tabs proximate the distal end is formed at an angle of approximately 30┬░ from the plane of the tab.

8. The chiller assembly of claim 7, wherein the tabs are tapered approximately 5┬░ along the opposed side ends.

9. The chiller assembly of claim 8, wherein the panel flanges and the condenser coil assembly walls have a thickness of .08 inch.

10. A method for assembling a chiller unit, said chiller unit including a plurality of interconnected parts wherein at least a portion of said parts includes a first set of components having tabs, and at least a portion of said parts includes a second set of components having corresponding openings adapted to receive said tabs, the method comprising: positioning a component of one set adjacent a component of the other set, so the tabs from the component of the first set are proximate to and in substantial alignment with the corresponding holes of the component of the second set; and inserting the tabs of the component of the first set in the corresponding holes of the component of the second set, thereby joining the component of the first set and the component of the second set.

11. The method of claim 10 wherein the step of positioning a component of one set adjacent a component of the other set further comprises: supporting the component of the second set in a frame; lowering the component of the first set into a position adjacent the component of the second set, such that the tabs and corresponding holes are in alignment; and engaging the tabs and corresponding holes so that the components become joined.

12. The method of claim 11 further comprising: lowering a second component of the second set into a position adjacent the component of the first set, such that the holes and tabs are in alignment; and engaging the holes and tabs so that the components become joined.

13. The method of claim 12 wherein the components of the first set include substantially planar polygonal sheetmetal panels.

14. The method of claim 12 wherein the components of the second set include condenser coil assemblies.