Circuit breaker housing and method of assembling
10224163 ยท 2019-03-05
Inventors
- Mari Keiko Freitas (Plainville, CT, US)
- Enamul Haque (Plainville, CT, US)
- Wolfgang Meyer-Haack (Plainville, CT, US)
- Dhirendra Tiwari (Farmington, CT, US)
Cpc classification
H01H33/08
ELECTRICITY
H01H1/2058
ELECTRICITY
H01H33/53
ELECTRICITY
International classification
H01H33/53
ELECTRICITY
Abstract
A circuit breaker housing assembly is disclosed. The housing (47) includes a first housing piece (14) defining a first interior surface (52) including a first mating surface (152), and a second housing piece (60) defining a second interior surface (62) including a second mating surface (260) which is opposingly coupled to the first mating surface to define a seam (202) therebetween. An adhesive material (201) is disposed between the corresponding first and second mating surfaces along the seam. A moveable contact is disposed in the housing and is selectively moveable with respect to a corresponding stationary contact. The first and second interior surfaces (52,62) further cooperatively define a first recess (120) therebetween, and the moveable contact assembly is disposed in said first recess.
Claims
1. A circuit breaker comprising: a housing comprising: a first housing piece having a first interior surface defining a first mating surface; a second housing piece having a second interior surface defining a second mating surface, wherein said first and second interior surfaces cooperatively define a first recess therebetween, and said second mating surface is opposingly coupled to said first mating surface to define a seam therebetween; and an adhesive material disposed between said first and second mating surfaces along said seam; a moveable contact assembly selectively moveable with respect to a corresponding stationary contact, wherein said moveable contact assembly is operatively disposed in said housing, and said moveable contact assembly is further disposed in said first recess; and a blocking element disposed along at least a first portion of said seam and oriented to block an ingress of said adhesive material into said first recess.
2. The circuit breaker of claim 1, wherein said seam defines an interior portion and an exterior portion, and said blocking element is disposed between said interior portion and said first recess.
3. The circuit breaker of claim 1, wherein said blocking element is further disposed between said adhesive material and said first recess.
4. The circuit breaker of claim 1, wherein said blocking element defines a third interior surface oriented at an angle to said first and said second interior surfaces.
5. The circuit breaker of claim 1, wherein said blocking element is integrally formed with at least one of said first and second mating surfaces.
6. The circuit breaker of claim 1, wherein said blocking element is at least one of a wall, rib, lip, dam, groove, and trough.
7. The circuit breaker of claim 1, wherein said blocking element is further disposed proximal to said movable contact assembly.
8. The circuit breaker of claim 1, wherein: said housing further defines an opening therethrough; said first and second interior surfaces further cooperatively define a second recess therebetween, said second recess extending to said opening; a conductor is disposed in said second recess; and said adhesive material is disposed within a portion of said second recess between said conductor and at least one of said first and second interior surfaces to prevent venting of a gas out of the housing.
9. The circuit breaker of claim 8, wherein said blocking element disposed along at least the first portion of said seam is omitted from a second portion of said seam proximal to said second recess.
10. The circuit breaker of claim 1, wherein: a portion of said first recess is defined by respective conductive strap recesses opposingly disposed in said first and second interior surfaces; a conductive strap is disposed in said first recess; and said adhesive material is disposed within said first recess between the first and second interior surfaces and said conductive strap to prevent an egress of gasses from the first recess during an arcing event.
11. The circuit breaker of claim 1, wherein the adhesive material is selected from a group consisting of thermosetting adhesives, thermoplastic adhesives, hybrid adhesive systems, and sealants.
12. The circuit breaker of claim 1, wherein said first and second housing pieces are further coupled by at least one mechanical fastener.
13. The circuit breaker of claim 12, wherein the at least one mechanical fastener comprises at least one of a rivet, screw, or dip.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF THE INVENTION
(18) Exemplary embodiments of circuit protection systems and apparatus are described herein. These embodiments enhance the quenching and controlling of gases, heat, and pressure that are generated within a circuit breaker after an arc is generated.
(19) While various embodiments are described herein with reference to an electrical circuit breaker having one or more moveable rotary contacts, other contemplated embodiments are not so limited and may also embody other electrical devices having any number or type of moveable contacts, for example, switches or electrical switching devices such as single or multi-pole circuit switching devices, including contactors, motor starters, motor controllers, and other load controllers.
(20) As described herein, a housing 47 (
(21) Referring to
(22) Generally, in operation, an electrical current flows through the circuit breaker 10 conductive parts disposed within housing 47. With reference to
(23) The arc chute assemblies 20, 22 are positioned within the electrically insulative housing half piece 60 and adjacent the respective pairs of first fixed and first moveable contacts 123a, 122b and second fixed and second moveable contacts 123b, 122a. The first and second movable contacts 122b, 122a and moveable contact arm 32 move in order to selectively engage and disengage the respective first and second fixed contacts 122b, 123b. Each arc chute assembly 20, 22 is adapted to interrupt and extinguish the arc which forms when the circuit breaker 10 is tripped, for example in response to an electrical fault, and the first and second moveable contacts 122b, 122a are suddenly separated from the first and second fixed contacts 123a, 123b.
(24) Referring to
(25) Referring to
(26) In an embodiment, second electrically insulative housing half piece 60 is bonded to the first electrically insulative housing half piece 14 (
(27) In an embodiment, (
(28) In other embodiments, one or more mechanical fasteners 203, such as rivets or screws, may additionally be used in cooperation with the adhesive 201 material to mechanically join the first and second housing half pieces 14, 60. The one or more fasteners 203, may be disposed in corresponding aligned through-holes or apertures 215 provided in the respective first and second housing half pieces 14, 60 and arranged therethrough to provide a clamping force.
(29) Referring to
(30) In an embodiment, the rotor 37 is assembled into second electrically insulative housing half piece 60 by locating pin 114 into a centrally located aperture 158. The pin 114 locates rotor 37 within rotor recess 68 in spaced relationship from the first and second mating surfaces 152, 260, and permits operational travel of the rotor 37 within the recess 68. By disposing pin 114 into aperture 158 into the second electrically insulative housing half piece 60 during assembly of the rotor 37 into second housing half piece 60, the rotor 37 will be spaced from said seam 202, to prevent inadvertent or undesired contact by the rotor 37 with the adhesive 201 during assembly. Additionally, as discussed in further detail herein, a blocking element 102 may additionally be disposed to prevent excess adhesive 201 from contacting the movable rotor 37.
(31) Referring to
(32) Referring to
(33) A second arc chute assembly 20 comprises a plurality of plates 68 and third and fourth side members 82, 84. Third and fourth side members 82, 84 are identical to first and second side members 70, 72. Third and fourth side members 82, 84 are assembled so as to be opposedly oriented to each other. Third side member 82 has a tab 80 centrally located on an end opposite to the radiused notch 78 of the plate 68. A tab 80 is similarly located along the fourth side member 84.
(34) In an embodiment, the first arc chute assembly 22 is positioned into the first electrically insulative housing half piece 14. Similarly, the second arc chute assembly 20 is positioned into the first electrically insulative housing half piece 14.
(35) Referring now to
(36) In an embodiment, prior to joining the first and second insulative housing half pieces 14, 60, an adhesive 201 material is applied to the second mating surface 260 of the second insulative housing half piece 60. Alternatively, the adhesive 201 material could instead be applied to the first mating surface 152 of the first insulative housing half piece 14. In other embodiments, the adhesive material 201 is placed on both the first and second mating surfaces 152, 260 of the first and second insulative housing half pieces 14, 60. After the application of the adhesive 201 to the selected mating surface 152, 260, the first and second housing half pieces 14, 60 are then carefully joined, aligning the first and second mating surfaces 152, 260 with the adhesive 201 disposed therebetween. The housing assembly may then be clamped until the adhesive material has set-up or sufficiently cured. Alternatively, the housing assembly may be additionally be clamped by fasteners 203 such as rivets, screws or clips disposed in the corresponding aligned through-holes or apertures 215, 225 provided in the respective first and second housing half pieces 14, 60.
(37) It is important that the adhesive 201 be carefully applied, and be prevented from flowing or otherwise migrating into the interior recesses or cavities defined in the housing interior, such as first interior recess 120, particularly in the vicinity of the circuit breaker moving parts, such as the rotor 37 and moveable contact arm 32. As can be seen in the cross-sectional views of
(38) In various embodiments, the blocking element 102 may define one or more of a wall, rib, lip, dam, groove, and trough. While the blocking element 102 in the embodiment of
(39) In an embodiment, the line-side and load-side contact strap recesses 92, 94 are communicatively coupled in flow communication to the respective line-side and load-side contact strap openings 35, 36; and the first and second mating surfaces 152, 260 are arranged proximal to at least one of the line-side and load-side contact strap recesses 92, 94. Additionally, in an embodiment, and as depicted in of
(40) The adhesive 201 may be chosen from adhesive systems of varying compositions and chemistries and must be capable of withstanding the high temperatures and high pressures generated during arcing events. The adhesive 201 is a structural adhesive made from thermoset polymeric resins such as epoxy and polyurethane. Such structural adhesives may provide high shear and tensile strength and good environmental resistance.
(41) In various embodiments, adhesive 201 may comprise either thermosetting or thermoplastic adhesives. Thermosetting adhesives include, but are not limited to one or two component epoxy and polyurethane, epoxy hybrids, acrylic, cyanoacrylates, phenolics, polyesters, polysulfide, anaerobic and room temperature vulcanizing (RTV) silicones. Thermoplastics adhesives include, but are not limited to thermoplastics resin based polyamide, polyester, polysulfone, polyolefins, phenoxy, and elastomeric resins based butyl rubber, styrene butadiene copolymers, polychloroprene, polyisobutylene and silicone elastomers.
(42) Adhesive 201 may alternatively comprise Hybrid systems adhesives based on silane modified polymers (SMP) that are solvent-free and isocyanate-free and based on either polyether modified silanes and polyurethane modified silanes, and are not limited to silane terminated prepolymers (STP) and silane terminated urethane (STU).
(43) In yet other embodiments, the adhesive 201 may comprise various types of sealants which include but are not limited to hydrocarbon rubber-based, acrylic, polysulfides, polyethers, polyurethane, silicones and epoxy.
(44) Selection of a high strength adhesive 201 enables uniform distribution of the developed stresses during an arcing event over the overlapped region of the corresponding mating surfaces 152, 26. Additionally, the additional strength provided by the adhesive 201 enables use of less expensive molding materials to form the housing halves 14, 60. For example, a bulk molding compound may be selected (BMC), which uses along with a less expensive molding process (injection molding) as compared to using SMC and compression molding when using mechanical rivets only to join the housing halves. Moreover, by reducing or eliminating the need for mechanical fasteners, the weight and cost of the final assembly is reduced. Another advantage of the embodiments disclosed herein, by using a structural adhesive for adhesive 201 is improved stress-distribution characteristics and inherent toughness provided by such adhesives yields bonds with superior fatigue resistance and resistance to vibration due to the viscoelastic properties of such adhesives. Yet another advantage is that the adhesive 201 additionally functions as an electrical and thermal insulator in the joint or seam 202 between the housing halves 14, 60.
(45) In some embodiments, the housing halves 14, 60 are adhesively joined using an adhesive 201 without the use of mechanical fasteners 203. In other embodiments, a combination of adhesive 201 and mechanical fasteners 203 are used. Embodiments employing the combination of adhesive 201 and fasteners 203 can provide properties that are superior to either adhesive bonding or mechanical fastening alone. For example, the number of mechanical rivets 203 needed can be reduced without sacrificing strength and reliability. Additionally, when assembling a housing employing a combination of adhesive 201 and mechanical fasteners 203, the fasteners 203 may be employed to provide a holding or clamping force to fix the housing assembly while the adhesive 201 cures. In this way, expensive fixturing equipment and associated setup are avoided. Additionally, delays in the assembly process due to adhesive cure time are thereby eliminated or reduced to speed the overall assembly process.
(46) In an embodiment, the corresponding first and second mating surfaces of first and second housing halves are thoroughly cleaned prior to application of the adhesive 201 and assembly. For example, a plasma treatment of the substrates for the adhesive 201, that is the first and second mating surfaces, by not using any conventional cleaning or pretreatment process. By using plasma treatment, an improved adhesion is obtained via surface modification and increased surface energy. In an embodiment, simultaneous ultrafine cleaning to remove all organic contaminants and dirt prior to bonding is performed.
(47) While this invention has been described with reference to a preferred embodiment, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the invention. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the invention without departing from the essential scope thereof. Therefore, it is intended that the invention not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this invention, but rather that the invention will include all embodiments falling within the scope of the appended claims.
(48) The order of execution or performance of the operations in the embodiments of the invention illustrated and described herein is not essential, unless otherwise specified. That is, the operations may be performed in any order, unless otherwise specified, and embodiments of the invention may include additional or fewer operations than those disclosed herein. For example, it is contemplated that executing or performing a particular operation before, contemporaneously with, or after another operation is within the scope of aspects of the invention.
(49) When introducing elements of aspects of the invention or embodiments thereof, the articles a, an, the, and said are intended to mean that there are one or more of the elements. The terms comprising, including, and having are intended to be inclusive and mean that there may be additional elements other than the listed elements.
(50) This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art. Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal language of the claims.