Patent Publication Number: US-2017356442-A1

Title: Reciprocating Compressor and Process for Mounting Hermetically Sealed Housing of Reciprocating Compressor

Description:
FIELD OF THE INVENTION 
     The invention in question refers to a reciprocating compressor and, more particularly, a reciprocating compressor comprising a hermetically sealed housing having an electrical or electronic circuit protective plate attached to a part of its outer face. In general terms, the invention in question stands out for presenting a protective plate composed of at least two plate segments, which can be fixed to each other after mounting and closing the hermetically sealed housing of the reciprocating compressor. 
     The invention in question also refers to the process of mounting the hermetically sealed housing of the reciprocating compressor, including the specific steps of conformation of the protective plate of the electric or electronic circuit composed by at least two plate segments. 
     BACKGROUND OF THE INVENTION 
     As it is of knowledge of a person skilled in the art, the current state of the art comprises a plurality of reciprocating compressor models and, in particular, a plurality of reciprocating compressor models useful for being applied in refrigeration systems. 
     According to the scope of the present invention, it is particularly highlighted the reciprocating compressors, whose mechanisms and functional systems are closed inside a hermetically sealed housing and, in a simultaneous manner, whose mechanisms and functional systems are electrically powered and/or controlled by electrical or electronic circuits arranged outside such hermetically sealed housing. It is important to highlight that reciprocating compressors of this kind are broadly known by a person skilled in the art, as well as being broadly described in specialized technical literature. 
     Conventionally, and due to various issues, it is noted that, according to the current state of the art, certain electrical or electronic circuits (frequency inverter circuits, engine start circuits, electrical protection circuits, among others) are arranged outside the hermetically sealed housing of the reciprocating compressors, wherein for said purpose, it is common to be used, posteriorly, at least one protective plate, and, frontally, at least one protective cover, both capable of isolating and/or protecting said circuits from the environment to which the hermetically sealed reciprocating compressor is exposed. 
     Preliminary, it remains to emphasize that protective covers, as well as their constructive details, are not part of the scope of the invention in question. 
     As regards the protective plates, it is common to observe that, according to the current state of the art, a protective plate is usually welded to the outer face of the hermetically sealed housing of the reciprocating compressor and, in particular, welded near to the region where the hermetically sealed compressor terminal is disposed.  FIG. 1  illustrates, in a schematic form, a typical embodiment in accordance to the current state of the art. 
     However, due to technical issues of the manufacturing process, the conventional protective plates are welded to the hermetically sealed housings of the reciprocating compressors, while the said housings are still open (usually, the hermetically sealed housing of a reciprocating compressor is composed of a base and a lid, which are fixed to each other by welding), that is, it is common that a protective plate is welded to the base of the hermetically sealed housing before the welding between the base and the lid of the said hermetically sealed housing. This fact occurs, mainly, due to the type of welding process used. 
     In this sense, and as illustrated in  FIG. 1 , it is noted that, according to the current state of the art, the dimensions of a protective plate and/or the dimensions of the electric or electronic circuit (especially the height) are analogous or inferior to the dimensions of the base of the hermetically sealed housing of the reciprocating compressor. This makes it possible for the protective plate to cause no problem or limitation for the welding between the base and the lid of the said hermetically sealed housing. 
     This means, on the other hand, that it is extremely undesirable that the protective plate and/or the electric or electronic circuit comprises dimensions (especially the height) greater than the dimensions of the base of the hermetically sealed housing of the reciprocating compressor. In this sense, it is noted that the dimensions (especially the height) of the protective plate can represent great limitations to the miniaturization of reciprocating compressors, after all, it becomes extremely complicated (and, sometimes, even impossible) to close the hermetically sealed housing of a reciprocating compressor, whose the protective plate has larger dimensions than the dimensions of the base of the hermetically sealed housing. 
     Considering this whole context, the patent documents JP 2013024067 and KR 200963414 are highlighted. 
     The JP 2013024067 document describes and illustrates a compressor whose protective plate has regions perpendicularly folded in relation to the general orientation of the hermetically sealed housing base of the compressor. As a result, a free space is reached between the upper end of the protective plate and the upper end of the hermetically sealed housing, which will allow the common welding between the base and the lid of the hermetically sealed housing of the reciprocating compressor. Although the achievement described and illustrated in the JP 2013024067 document does not harm the welding between the base and the lid of the hermetically sealed housing, further enabling the controlled miniaturization of the reciprocating compressor, on the other hand, it is verified that such achievement limits the dimensions of the electric or electronic circuit to be fixed on the protective plate, thereby precluding the use of frequency circuit inverters (and enabling only the use of engine starting circuits, for example). 
     The KR 200963414 document describes and illustrates a compressor whose protective plate is mounted near to the base of the hermetically sealed housing by means of welded mounting guides, which are individually fixed to the base of the hermetically sealed housing. The said protective plate can be subsequently linked to its mounting guides, either with the opened hermetically sealed housing (unbounded base and lid) or with the hermetically sealed housing (base and lid welded). Although the achievement described and illustrated in the KR 200963414 document does not harm the welding between the base and the lid of the hermetically sealed housing, further enabling the controlled miniaturization of the reciprocating compressor, on the other hand, it is verified that the welding process of the mounting guides requires an extremely precise and sophisticated control, after all, if only one of the said mounting guides stays out of position, the protective plate will not be properly mounted near to the base of the hermetically sealed housing of the reciprocating compressor. 
     It is then based on this scenario that arises the present invention. 
     OBJECTIVES OF THE INVENTION 
     Based on the context previously presented, it is the central objective of the invention in question to disclose a reciprocating compressor comprising a hermetically sealed housing whose the electrical or electronic circuit protective plate does not represent, regardless of the dimensions of the hermetically sealed housing, limitations to the closing process of the said hermetically sealed housing, that is, limitations to the welding of the housing lid at the housing base. In this sense, it is also one of the objectives of the invention that the dimensions of the electric or electronic circuit are not guided and/or stagnated by the dimensions of the hermetically sealed housing of the reciprocating compressor. 
     It is also one of the objectives of the invention in question to disclose a process of mounting hermetically sealed housing of the reciprocating compressor whose closing steps of the housing are not influenced or influence the steps of conformation of the protective plate of the electric or electronic circuit, being the reciprocal being totally true. 
     BRIEF DESCRIPTION OF THE INVENTION 
     The aforementioned objectives are fully achieved by means of the reciprocating compressor now disclosed, which, in general terms, comprises a compression mechanism and a compression mechanism-driven system, a hermetically sealed housing conformed by a lid and a base which is liable to be fixed to each other and at least one protective plate for at least one electrical or electronic circuit. 
     According to the invention in question, the said protective plate is conformed by at least one first plate segment and at least one second plate segment, wherein the said first plate segment is definitively fixed to a part of the outer face of the base of the hermetically sealed housing by fixing means and wherein the said second plate segment being fixed to the said first plate segment by fixing means. 
     Preferably, the fixing means used for fixation between the first plate segment and the outer face of the hermetically sealed housing base comprises loose points made between the first plate segment and parts of the outer face of the hermetically sealed housing base. The fixing means between the second plate segment and the first plate segment comprise definitive or selective fixing means. 
     Also preferably, it is further foreseen at least one mounting guide between the first plate segment and the second plate segment of the said protective plate. 
     Regarding the process of mounting the hermetically sealed housing of the reciprocating compressor includes, minimally, a first step of fixing the first plate segment on the base of the compressor housing, a second step of fixing the lid on the base so as to conform the hermetically sealed housing and a third and final step of fixing the second plate segment on the first plate segment. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The present invention will now be described in detail on the basis of the following listed figures, which: 
         FIGS. 1A, 1B and 1C  illustrate in perspective, respectively, the reciprocating compressor with only one segment of the protective plate fixed to its housing, the reciprocating compressor having only one segment of the protective plate fixed to its housing and the other segment of the protection plate in explosion, and the reciprocating compressor with the protective plate properly mounted; and 
         FIGS. 2A, 2B and 2C  illustrate in a planned lateral view, respectively, the reciprocating compressor with only one segment of the protective plate fixed to its housing, the reciprocating compressor with only one segment of the protective plate fixed to its housing and the other segment of the protective plate in explosion, and the reciprocating compressor with the protective plate properly mounted. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     As explained above, it is the main objective of the invention in question to unbind the existing dimensional limitations between the hermetically sealed housing of a reciprocating compressor and the protective plate of an electrical or electronic circuit used for controlling or command electronic systems of the reciprocating compressor. 
     For example, the illustrated electric or electronic circuit (not illustrated) comprises a frequency inverter circuit through which it is possible to control the rotation speed of the electric engine (not illustrated) that triggers the compression mechanism (not illustrated) of the reciprocating compressor. However, it is important to highlight that the scope of the invention in question is not limited solely to the frequency inverter circuit, and it can cover all and any electrical or electronic circuit used to lead, control, monitor or trigger the compression mechanism (not illustrated, but essentially composed by the assembly formed by the cylinder-block, piston and head) or the triggering system of compression mechanism (not illustrated, but essentially composed of an electric engine). 
     As illustrated in the figures, it is noted that in accordance with the preferential embodiment of the invention in question, the reciprocating compressor now treated comprises a hermetically sealed housing  1  conformed by a lid  11  and a base  12 , both capable of fixing each other by the usual and known means (welding, for example). Although it is not illustrated, it is of general knowledge that both the compression mechanism and the triggering system of the compression mechanism (as well as other components and systems) are enclosed inside the hermetically sealed housing. 
     Also, according to the invention in question, the reciprocating compressor further comprises a protective plate  2  and a protective cover (not illustrated) for an electrical or electronic circuit (not illustrated). 
     More particularly, the protective plate  2  is conformed by at least one first plate segment  21  and a second plate segment  22 . Evidently, the other plate segments could exist and still be part of the protective plate  2  according to the invention in question. 
     Preferably, but not being limitative, the plate segments  21  and  22 , in addition to any possible other segments, they are made of metallic blade, by already known industrial processes. 
     In any case, it is noted that the first plate segment  21  is fixed, in a definitively manner, to a part of the outer face of the base  12  of the hermetically sealed housing  1  by traditional fixing means (not particularly illustrated) and the second plate segment  22  is fixed to the said first plate segment  21  by fixing means  3 . 
     The traditional fixing means (not particularly illustrated), which are responsible for the definitive fixation between the first plate segment  21  and the part of the outer face of the base  12  of the hermetically sealed housing  1  (part that is near to the hermetic end  4 ), comprise conventional means, such as, for example, welding points. 
     As to the fixing means  3 , responsible for fixation between plate segments  21  and  22 , they are more versatile, which may or may not be definitive or selective (that is, removable, detachable, and similar concepts), such as, for example, union by screwing, union by welding, union by rivet, union by fitting, union by glue, among others. 
     Additionally, they are also foreseen—in an optional manner —mounting guides  5  between the first plate segment  21  and the second plate segment  22 . Preferably, these mounting guides comprise similar rails or equivalent structures. 
     The invention in question solves the problem of the miniaturization of the reciprocating compressors, after all, the fact that the protective plate  2  is composed of plate segments  21  and  22  allows to increase the size of the protective plate  2  without being observed problems or limitations relating to the closure of hermetically sealed housing  1 . In particular, the invention in question allows frequency inverter circuits to be coupled in reciprocating compressors extremely smaller. 
     To do so, it is necessary that the mounting and fixing of the components (especially the mounting and fixing of the hermetically sealed housing  1  formed by lid  11  and base  12  and the protective plate  2  formed by the first plate segment  21  and the second plate segment  22  comprise the following order: 
     (A) fixing the first plate segment  21  on the base  12 ; 
     (B) fixing the lid  11  on the base  12  so as to conform the hermetically sealed housing  1 ; and 
     (C) fixing the second plate segment  22  on the first plate segment  21 . 
     Finally, it is also important to emphasize that the above description has as the sole objective describing in exemplary manner the particular embodiment of the invention in question. Therefore, it becomes clear that modifications, variations and constructive combinations of the elements that exert the same function substantially in the same manner to achieve the same results, remain within the scope of protection delimited by the attached claims.