Transformer core and coil support

Information

  • Patent Grant
  • 6424246
  • Patent Number
    6,424,246
  • Date Filed
    Thursday, December 2, 1999
    25 years ago
  • Date Issued
    Tuesday, July 23, 2002
    22 years ago
Abstract
A transformer includes a tank having a side wall, a core defining a core window, and a pair of coils, each of which surrounds a portion of the core and includes a portion passing through the core window. The transformer further includes a core and coil support member that extends through the core window to support the core and coils. The core and coil support member includes an upper flange and a lower flange, each flange having a channel formed along an outer surface of the flange that conforms in shape to an inner surface of the core. The core and coil support member includes a web that extends between and connects the upper and lower flanges, the web including first and second ends that extend out from the flanges. The transformer includes a support bracket that attaches to the side wall of the tank, and centers and supports the core and coil support member. The support bracket includes three sides that define a channel through which an end of the core and coil member extends. The support bracket also includes a shelf formed from a lower end of a side panel, the shelf being substantially perpendicular to the first direction to support the weight of the core and coil support member when inserted into the channel. The support bracket also includes a tab formed from an upper end of a side panel. The tab is bent inwardly after the core and coil support member is inserted into the channel to provide a lock position to the core and coil support member in the first direction.
Description




TECHNICAL FIELD




This application relates to supporting structure for the core and coil assembly of a transformer.




BACKGROUND




Single phase transformers typically include a pair of windings that are magnetically coupled through a permeable core, or a single coil coupled with two cores. The core and coil assembly is positioned in a tank that is filled with a dielectric fluid. The fluid serves the dual purpose of cooling the assembly and electrically insulating the coils from one another and from the grounded core and tank wall. The insulating fluid also impregnates the Kraft paper utilized as solid insulation within the windings and core and coil assembly. A structure for supporting a core and coil assembly is described in U.S. Pat. No. 4,837,543, which is incorporated by reference.




SUMMARY




In accordance with one general aspect of the invention, a transformer includes a tank having a side wall, a core defining a core window, a pair of coils, and a core and coil support member that extends through the core window to support the core and coils. Each coil surrounds a portion of the core and includes a portion passing through the core window.




The core and coil support member includes an upper flange and a lower flange, each flange having a channel formed along an outer surface of the flange that conforms in shape to an inner surface of the core. The core and coil support member also includes a web extending between and connecting the upper and lower flanges. Substantially beyond the flanges, first and second ends are formed from extensions of the web. A support bracket that attaches to the side wall of the tank and supports the core and coil support member, includes three sides that define a channel through which an end of the core and coil member extends.




Embodiments may include one or more of the following features. For example, the core may include first and second vertical portions, the second vertical portion being substantially similar in shape and size to the first vertical portion. The core may include first and second horizontal portions each extending between ends of the first vertical portion and the second vertical portion. The vertical and horizontal portions define the core window.




The core and coil support member may be molded using a reinforced high temperature engineering polymer.




The upper flange may extend perpendicularly from an upper side of the web. Likewise, the lower flange may extend perpendicularly from a lower side of the web. The flanges may be convex in shape. An upper horizontal portion of the core may rest on the upper flange. The coils may rest on the lower flange, and will generally fit between the upper and lower flanges. The coils may also act as a mechanical strut to support the weight of the core on the upper flange.




The channel may include a lowered step. A width of the channel may be substantially equal to a width of a portion of the core facing the core window. The channel may be convex. The channel may serve to lock the core into a stationary position. Moreover, the channel may serve to center the core onto the core and coil support member.




The web may separate and insulate the coils from each other. Furthermore, the web may include a first vertical face that extends perpendicularly from the first end, and a second vertical face that extends perpendicularly from the second end. The vertical face may define an end groove in which the support bracket is secured during assembly and shipping of the transformer. The vertical faces may increase strength of the core and coil support member.




The tank may include dielectric fluid. The web may include a thermal duct design along a side of the web that faces the supported coil. The thermal duct design includes grooves that provide a flow path for the dielectric fluid between the supported coil and the web.




The upper and lower flanges may include a snap-fit connector that permits assembly of brackets for components to the core and coil support member.




In accordance with another general aspect of the invention, a transformer includes a tank having a side wall, a core defining a core window, and a pair of coils. Each of the coils surrounds a portion of the core and includes a portion passing through the core window. The transformer also includes a core and coil support member that extends through the core window to support the core and coils, and a first support bracket that attaches to the side wall of the tank, and supports the core and coil support member. The first support bracket includes two parallel side panels, and a rear panel that connects the parallel side panels to define a channel in a first direction through which the core and coil support member is inserted and positioned. The first support bracket also includes a shelf formed from a lower end of a side panel. The shelf is substantially perpendicular to the first direction. A locking feature is formed from an upper end of a side panel. The locking feature provides a retaining force to the core and coil support member in the first direction.




Embodiments may include one or more of the following features. For example, the first support bracket may include a shelf slot that is formed into a lower end of the side panel across the channel from the side panel that forms the shelf. The shelf slot is made large enough to accommodate and support the perpendicular shelf.




The locking feature may include side apertures through which self-tapping screws are inserted to secure the core and coil support member within the channel of the first support bracket. The locking feature also may include a tab that is bent inwardly after the core and coil support member is inserted into the channel to secure the core and coil support member within the channel of the first support bracket.




The shelf may support at least a portion of the weight of the core and coil support member when inserted into the channel. Alternatively or in addition, the tank or tank bottom may support at least a portion of the weight of the core and coil support member when inserted into the channel.




The core and coil support member may include a first end and a second end that extends from the first end in a direction perpendicular to the first direction. The rear panel may include a spring lever that applies a force to the core and coil support member in the perpendicular direction.




The transformer may further include a second support bracket identical in size and shape to the first support bracket, and attached to an opposite side wall of the tank. The first end of the core and coil support member may be inserted and positioned in the channel of the first support bracket. The second end of the core and coil support member is inserted and positioned in the channel of the second support bracket. The rear spring levers of the support brackets may automatically center the core and coil support member in the perpendicular direction.




The first support bracket may include a projection bent from on a top portion of a parallel side panel in a direction away from the channel. The angle may be based on a size of the coils relative to a size of the tank. Alternatively, the angle may be based on a length of the top portion of the parallel side panel. The projection may also facilitate guidance of the core and coil support member through the channel. Additionally, one or more components may be secured to the projection. The bend angle of the projection may be based on the components secured to the projection.




The core and coil support member serves a number of additional functions. For example, the core and coil support member can be used to anchor and support high voltage leads extending from the coils. The core and coil support member also prevents the corners of the core from cutting a core tube that is inserted into the coil windows. The core tube provides insulation between the core and the coil. The support member also eliminates the need for coil blocks, which had been used to position and clamp the core and coils between upper and lower steel core clamps. This, in turn, eliminates problems associated with the coil blocks compressing the paper at the ends of the coil, which could lead to reduced coil end margins and a higher probability of electrical shorts.




Since the core is in tension in the transformer, that is, there is no compressive stress on the core steel, no-load core losses are reduced. Moreover, elimination of top and bottom steel core clamps and associated metal brackets of prior designs reduces stray losses.




On smaller transformer designs, the core and coil support member can suspend the entire weight of the core and coils. On larger transformer designs, a strut member may be added to each side of the core and coil support member to help support the weight of the core. It is also possible to support the weight of the core by using, for example, a cradle member on the tank bottom.




Tolerances and clearances between the tank wall and the coils can be reduced because the core and coil support member centers the core and coil better in the tank than prior core clamp assemblies. Thus, some transformer designs will accommodate a smaller tank size.




Manufacturing costs are reduced because of the improved manufacturing efficiency. In particular, the core steel is easier to stack because the core and coil support member minimizes the relative movement of the coils with respect to one another. The extra time required to attach the existing steel clamps and insulation pieces is also eliminated. Additionally, the core and coils are easier to install in the tank, and hardware is eliminated by using snap fit connectors. Furthermore, for some implementations, part count proliferation may be reduced from approximately 25 parts to five parts.




The core and coil support member may be clamped in a stacking fixture to keep the coils from shifting during stacking. Furthermore, because the core and coil support member replaces many parts that were previously made of metal, an additional reduction in cost is realized. Finally, because core and coil assembly heights may be reduced in the transformer design, the tank size and amount of dielectric fluid may be reduced, thus further reducing the cost of the transformer.




The design also improves cooling of the coils because there is less obstruction to convective fluid flow around and through the coils. Cooling ducts added to the core and coil support member web further increase cooling efficiency to the coil within the core window. Because the core and coil support member can be made of a high temperature engineering polymer, the core and coil support member can be operated at higher temperatures than current Kraft-based materials without compromising the electrical and mechanical integrity of the design. The engineering polymers also exhibit better long-term aging characteristics than previously used cellulose-based materials. The high temperature engineering polymer provides the structural rigidity necessary to support the core and coils and has high dielectric strength.











DESCRIPTION OF THE DRAWINGS





FIG. 1

is a side view of a transformer tank using broken lines to show a core and coil assembly and other elements contained in the tank.





FIG. 2

is a perspective view of a core and coil assembly and support brackets of the transformer of FIG.


1


.





FIG. 3

is a perspective exploded view showing components of the core and coil assembly and support brackets of FIG.


2


.





FIG. 4

is a perspective view of a support member of the core and coil assembly of FIG.


2


.





FIGS. 5 and 6

are, respectively, side and top views of the support member of FIG.


4


.





FIG. 7

is a perspective view of the bracket that supports and attaches the support member to the tank.





FIG. 8

is a front view of the support bracket of FIG.


7


.





FIGS. 9 and 10

are side views of the support bracket of FIG.


7


.











DETAILED DESCRIPTION




Referring to

FIG. 1

, a transformer


100


includes a cylindrical tank


105


having a bottom


110


and a side wall


115


. The tank


105


contains a core and coil assembly


120


that is supported within the tank


105


by a set of support brackets


125


. The brackets


125


are welded to the side wall


115


by, for example, spot welding or projection welding. The brackets


125


may be fabricated of any suitable durable material that may be formed and punched, such as, for example, sheet metal. Because the core and coil assembly


120


reaches extreme temperatures during operation, the tank


105


is filled with a dielectric fluid that cools the core and coil assembly


120


.




Referring also to

FIGS. 2 and 3

the core and coil assembly


120


includes a core


200


that includes vertical portions


205


and


210


, and horizontal portions


215


and


220


extending between the vertical portions to define a core window


225


. The core is made of a material that has a high magnetic permeability, such as iron, and is typically laminated with sheets of iron.




The core and coil assembly


120


also includes first and second coils


230


and


235


that surround, respectively, the first and second vertical portions


205


and


210


of the core


200


. The coils


230


and


235


surround the portions


205


and


210


of the magnetic core


200


to magnetically couple the coils.




For assembly, the bottom portion


220


of the laminated core may be split in half, and the top portion


215


may be flexed, so as to pass one of the vertical portions and half of the bottom portion


220


through a core tube


236


that has been inserted into each coil to protect and separate the coil from direct contact with the core. Once the coils are in place, the bottom laminations are interleaved to form the core and complete the magnetic circuit.




Each of the coils


230


,


235


is made from, respectively, conductive wires


237


,


239


. Connection to the wires is made through high voltage electrical connectors.




The core and coil assembly


120


also includes a support member


240


, which may be in the shape of an I-beam. The I-beam


240


carries the weight of the core and coils and holds them in place within the tank and relative to each other. The I-beam


240


is made of a structural insulating material, such as a reinforced high temperature engineering polymer. The I-beam


240


includes a horizontal upper flange


245


, a horizontal lower flange


250


, and a vertical web


255


extending between and connecting the flanges


245


and


250


.




Referring also to

FIGS. 4-6

, a lowered step or channel


400


may be formed along outside surfaces of the upper and lower flanges


245


and


250


. The channel


400


has a width substantially equal to an inside (that is, facing the core window) width of the core


200


and is shaped to mate with the inside faces of the horizontal portions


215


,


220


. For example, if the inside face of the horizontal portion


215


or


220


is concave, which is typically the case due to the core forming process, then the channel


400


has a convex shape. Likewise, the upper and lower flanges


245


,


250


may have a convex shape. Such a flange design might be easier to manufacture if the channel is to be made convex. Moreover, a convex flange design would exhibit additional rigidity and strength relative to a flat flange design.




The channel


400


performs several functions that add to the sophistication of the I-beam design. First, the channel


400


increases strength to the flange


245


and


250


by providing an additional structure. Second, because the core


200


rests within the channel when assembled with the I-beam


240


, the channel


400


serves to lock the core


200


in place. And third, during assembly, the channel


400


provides a mechanism for quickly centering the core


200


relative to the I-beam.




Referring again to

FIGS. 2 and 3

, during assembly, once the coils


230


and


235


are positioned on the I-beam


240


, the core is inserted through the coils such that the I-beam vertical web


255


and the inner windings of the first and second coils


230


and


235


extend through the core window


225


. The inside surfaces of the horizontal portions


215


and


220


rest within the respective channels


400


to lock the core into a snug position. Furthermore, since the coils are nested between the I-beam flanges


245


,


250


, the coils are also locked into position.




More particularly, the upper horizontal portion


215


of the core


200


rests on the channel


400


of the upper flange


245


of the I-beam


240


. The coils


230


,


235


fit between the upper flange


245


and the lower flange


250


. Thus, the I-beam


240


supports the coils independently of the core. Alternatively stated, the weight of the coils is transferred directly to the lower flange of the I-beam, and is not transferred to the I-beam through the core. Moreover, although the coils extend through the core window, the web


255


separates and insulates the coils from each other.




Referring again to

FIGS. 4-6

, the vertical web


255


of the I-beam


240


extends beyond the flanges


245


,


250


to form first and second ends


405


and


410


. A vertical face


415


may be formed in the ends


405


,


410


to extend perpendicularly outward from the web


255


. The face


415


and an end


405


or


410


define a vertical groove


420


that may be used during assembly and shipping to secure the I-beam


240


to the bracket


125


. Moreover, the faces


415


and grooves


420


along the ends add rigidity and strength to the I-beam


240


.




The I-beam


240


may include a thermal duct design


425


along both faces of the vertical web


255


. The thermal duct design


425


includes grooves formed in the face, with the grooves being arranged in a pattern for providing a flow path for dielectric fluid between the I-beam and the adjacent coil side. For example, the pattern shown in

FIG. 4

is designed to allow fluid to flow in an upward direction with significant access to the majority of the coil surface. The duct design pattern is typically asymmetrical from one side of the web


255


to the other. In this way, uniform wall thickness is maintained throughout the web


255


to increase I-beam molding efficiency.




The I-beam


240


also includes snap-fit connectors or dimples


430


on both the upper and lower flanges


245


,


250


. The snap-fit connectors


430


permit assembly of brackets for components and lead guides to the I-beam. The snap-fit connectors


430


may be used to attach a strut member on heavier transformer units to help support the core and coil assembly


120


. Because their modulus of elasticity lies in a preferable range, plastics are ideally suited for the snap-fit connector


430


. The snap-fit connectors


430


permit a reduction in assembly and mounting time by eliminating need for separate mounting hardware. The connectors


430


may be formed in the shape and size appropriate for the attachments to be connected to the I-beam.




Referring to

FIGS. 7-9

, the support bracket


125


includes side panels


700


,


705


, a shelf


710


, and a rear panel


715


that together form an I-beam channel


720


through which the end


405


or


410


extends. When the I-beam is in position, the end


405


,


410


rests atop the shelf


710


of its respective support bracket


125


. The shelf


710


is formed directly from a lower part of one of the side panels (side panel


705


in

FIGS. 7-9

) by forming a 90° bend in the lower part of the side panel. A tab


725


formed on the end of the shelf extends through and rests atop a shelf slot


730


that is formed or punched on the other side panel (side panel


700


in FIGS.


7


-


9


). Using this design, no additional welding or fastening operation is required to attach a shelf member because the shelf is integral to a side panel of the bracket


125


. The lower part of the other side panel may be used to rest the bracket


125


on the bottom


110


of the tank.




The support bracket


125


also includes side panel slots or holes


735


that are used to weld the bracket to the tank wall by facilitating positioning of the bracket in the transformer tank. A set of rear panel holes


740


are formed in the bracket


125


to facilitate manufacturing of the bracket


125


, and therefore, are not integral to the assembled transformer structure. The rear panel holes


740


are used to locate the bracket in each station of a progressive die.




The support bracket


125


includes a spring lever


745


along the rear panel


715


. The spring lever


745


is punched from the rear panel


715


and then bent into an appropriate biasing shape. The spring lever


745


applies a force to the I-beam in the horizontal direction and therefore acts as a self-centering mechanism for the I-beam. Furthermore, the spring lever


745


accounts for different manufacturing tolerances in the fabrication of the I-beam, bracket, and assembly. For example, if the tank diameter is slightly smaller than its usual diameter, then the I-beam can still be mounted within the brackets because enough tension is provided by the spring lever


745


to properly center the I-beam. Likewise, a larger tank diameter can also be accommodated because the spring levers will still center the core and coil assembly.




One or more locking features such as side tabs


750


may be formed or punched into the side panels


700


,


705


. The side tabs


750


are flush with the side panels


700


,


705


during insertion of the I-beam


240


into the brackets


125


to permit the I-beam ends


405


,


410


to freely move through the I-beam bracket channels


720


. After the I-beam is inserted within the brackets


125


, the side tab


750


may be bent inward through an appropriate angle to secure the I-beam in the vertical direction. The side tabs


750


may be positioned in the vertical direction along the side panel


700


,


705


depending on the vertical height of the I-beam. For example, if a typical I-beam has a height of eight inches, then the bottom of the tab to be bent is approximately eight inches from the top of the shelf


710


. The distance between the shelf


710


and the bent tab is large enough to fit the I-beam yet small enough to prevent the I-beam from moving in the vertical direction. One of the tabs in the bracket


125


of

FIG. 2

is bent inward to show its use with the I-beam. Any number of tabs


750


may be formed into the side panel of the bracket depending on the size of the I-beam to be secured by the tabs.




Referring also to

FIG. 10

, the locking features may be slots or holes


1000


through which self-tapping screws are inserted to mount and secure the I-beam between the brackets. The self-tapping screws clamp the I-beam into position much like the tabs


750


to prevent movement of the I-beam in the vertical direction during shipping and installation. Because self-tapping screws would be used, additional parts, such as nuts, bolts, or clamps, are eliminated from the design. Any number of slots or holes


1000


may be designed into the side of the bracket depending on the size of the I-beam that is supported by the bracket.




In addition to holding the core and coil assembly


120


in place, the support bracket


125


serves as a guide for lowering the core and coil assembly


120


into the tank


105


. To this end, projections or wings


755


may be formed on the tops of the side panels


700


,


705


. The wings


755


serve to facilitate guidance of the I-beam down through the channel


720


during assembly by providing a point of reference relative to the side panels


700


,


705


which may be difficult to visualize within the tank


105


. The wings


755


are bent outward from the channel


720


by any suitable angle, for example 75°. Additionally, the wings


755


provide surfaces on which additional components can be mounted. To facilitate mounting components, holes


760


may be punched or extruded into the wings


755


. Alternatively, or additionally, components may be secured to the wings


755


by any other suitable technique, such as, for example, by snapping to the wing


755


. If the wing


755


is used to mount components, then the bend angle of the wing may depend on the type of component mounted onto the wing. Moreover, the bend angle and length of projection of the wing


755


may be chosen to maintain sufficient electrical clearance between the high voltage terminals of the coils and the tank wall


115


.




In previous transformer structures, sheet metal core clamps with complicated brackets that bolted to the tank wall with L-brackets were used. One such prior transformer structure included 25 separate parts. With the transformer design of

FIG. 1

, manufacturing and assembly costs are reduced because there are fewer parts and assembly of the parts is much simpler.




Because of the new I-beam and bracket design, the transformer can be used for different applications with various sized coils. For example, the support bracket


125


is adaptable to differently sized I-beams. Also, the spring levers


745


provide for I-beams of a single width to fit in multiple tank diameters. The side tabs provide for I-beams of various heights. Moreover, the width of the rear panel


715


may be universal for all I-beams. The I-beam flange width may be adjusted depending on the size of the core and the design of the transformer. The projection from the top of the bracket also facilitates greater flexibility in the number of components that can be added to the transformer design.




The I-beam


240


transfers a portion of the weight of the core and coils from the bottom


110


of the tank to the side walls


115


of the tank, thus keeping a portion of the weight of the core and coils, which often range from between around 150 to 250 lbs., off the bottom of the tank. Also, the I-beam


240


acts as an insulator between the coils and also from the coil to core ground.




Other embodiments are within the scope of the following claims.




For example, the locking features may be any features that lock the I-beam into place, such as levers, self-locking screws, rivets, or spot welding.




The weight of the core and coil assembly may be partially or wholly supported by the shelf. Alternatively or in addition, the tank bottom may partially or wholly support the core and coil assembly.



Claims
  • 1. A transformer comprising:a tank having a side wall; a core defining a core window; a pair of coils, each of which surrounds a portion of the core and includes a portion passing through the core window; a core and coil support member that extends through the core window to support the core and coils, the core and coil support member including: an upper flange and a lower flange, each flange having a channel formed along an outer surface of the flange that conforms in shape to an inner surface of the core; a web extending between and connecting the upper and lower flanges; and first and second ends formed from extensions of the web beyond the flanges; and a support bracket that attaches to the side wall of the tank and supports the core and coil support member, the support bracket including three sides that define a channel through which the first end of the core and coil member extends.
  • 2. The transformer of claim 1, wherein the core includes:a first vertical portion; a second vertical portion similar in shape and size to the first vertical portion; a first horizontal portion that extends between an end of the first vertical portion and an end of the second vertical portion; and a second horizontal portion that extends between another end of the first vertical portion and another end of the second vertical portion, wherein the vertical and horizontal portions define the core window.
  • 3. The transformer of claim 1, wherein the core and coil support member comprises a reinforced polymer.
  • 4. The transformer of claim 1, wherein:the upper flange extends perpendicularly from an upper side of the web; and the lower flange extends perpendicularly from a lower side of the web.
  • 5. The transformer of claim 1, wherein the upper and lower flanges are convex.
  • 6. The transformer of claim 1, wherein an upper horizontal portion of the core rests on the upper flange.
  • 7. The transformer of claim 1, wherein the coils fit between the lower flange and the upper flange.
  • 8. The transformer of claim 1, wherein the channel of the upper flange is separated from the channel of the lower flange by a distance that is less than a distance between the upper and lower flanges.
  • 9. The transformer of claim 1, wherein a width of the channel of each of the upper and lower flanges is substantially equal to a width of the inner surface of the core.
  • 10. The transformer of claim 1, wherein the channel of each of the upper and lower flanges is convex.
  • 11. The transformer of claim 1, wherein the channel of each of the upper and lower flanges serves to lock the core into a stationary position.
  • 12. The transformer of claim 1, wherein the channel of each of the upper and lower flanges serves to center the core onto the core and coil support member.
  • 13. The transformer of claim 1, wherein the web separates and insulates the coils from each other.
  • 14. The transformer of claim 1, wherein the web includes:a first vertical face that extends from the first end such that the first vertical face is perpendicular to the web; and a second vertical face that extends from the second end such that the second vertical face is perpendicular to the web.
  • 15. The transformer of claim 14, wherein the vertical faces increase strength of the core and coil support member.
  • 16. The transformer of claim 1, wherein the tank includes dielectric fluid.
  • 17. The transformer of claim 16, wherein the web includes a thermal duct design along a side of the web that faces the supported coil, the thermal duct design including grooves that provide a flow path for the dielectric fluid between the supported coil and the web.
  • 18. The transformer of claim 1, wherein the upper and lower flanges comprise a snap-fit connector that permits assembly of brackets for components to the core and coil support member.
  • 19. The transformer of claim 1, wherein the core and coil support member comprises an insulating material.
  • 20. A transformer comprising:a tank having a side wall; a core defining a core window; a pair of coils, each of which surrounds a portion of the core and includes a portion passing through the core window; a core and coil support member that extends through the core window to support the core and coils; and a first support bracket that attaches to the side wall of the tank, and supports the core and coil support member, the first support bracket including: two parallel side panels; a rear panel that connects the parallel side panels to define a channel in a first direction through which the core and coil support member is inserted and positioned; a shelf formed from a lower end of a side panel, the shelf being substantially perpendicular to the first direction; and a locking feature formed from in a side panel, the locking feature providing a retaining force to the core and coil support member in the first direction.
  • 21. The transformer of claim 20, wherein the first support bracket includes a shelf slot that is formed into a lower end of the side panel across the channel from the side panel that forms the shelf, the shelf slot being large enough to accommodate and support the perpendicular shelf.
  • 22. The transformer of claim 20, wherein the locking feature includes side apertures through which self-tapping screws are inserted to secure the core and coil support member within the channel of the first support bracket.
  • 23. The transformer of claim 20, wherein the locking feature includes a tab that is bent inwardly after the core and coil support member is inserted into the channel to secure the core and coil support member within the channel of the first support bracket.
  • 24. The transformer of claim 20, wherein the shelf supports at least a portion of the weight of the core and coil support member when inserted into the channel.
  • 25. The transformer of claim 20, wherein the core and coil support member includes a first end and a second end that extends from the first end in a direction perpendicular to the first direction.
  • 26. The transformer of claim 25, wherein the rear panel includes a spring lever that applies a force to the core and coil support member in the perpendicular direction.
  • 27. The transformer of claim 26, further comprising a second support bracket identical in size and shape to the first support bracket, and attached to an opposite side wall of the tank.
  • 28. The transformer of claim 27, wherein:the first end of the core and coil support member is inserted and positioned in the channel of the first support bracket; and the second end of the core and coil support member is inserted and positioned in the channel of the second support bracket.
  • 29. The transformer of claim 28, wherein the spring levers of the support brackets automatically center the core and coil support member in the perpendicular direction.
  • 30. The transformer of claim 20, wherein the first support bracket includes a projection bent from a top portion of a parallel side panel in a direction away from the channel.
  • 31. The transformer of claim 30, wherein the angle is based on a size of the coils relative to a size of the tank.
  • 32. The transformer of claim 30, wherein the angle is based on a length of the top portion of the parallel side panel.
  • 33. The transformer of claim 30, wherein the projection facilitates guidance of the core and coil support member through the channel.
  • 34. The transformer of claim 30, wherein one or more components are secured to the projection.
  • 35. The transformer of claim 34, wherein the angle is based on the components secured to the projection.
US Referenced Citations (6)
Number Name Date Kind
4833436 Martin et al. May 1989 A
4837543 Humen et al. Jun 1989 A
4890086 Hill Dec 1989 A
5194841 Galloway et al. Mar 1993 A
5319341 Bisbee et al. Jun 1994 A
5684446 Adkins et al. Nov 1997 A