IMPROVEMENT IN THE HEAD AND SILENCER OF A REFRIGERATION COMPRESSOR

Abstract: Electric compressor comprising a compression cylinder and the respective head, a valve plate arranged between the head and the body of said cylinder and provided with a gas inlet opening, a silencer arranged at the inlet side of said opening and comprising an elongated portion with an aperture adapted to fit in with said opening. The head is provided externally with a concave recess which is laterally open towards the inner cavity of the compressor, said elongated portion of the silencer being firmly housed in said recess so that the aperture engages the opening in the valve plate in an air-tight, sealed manner. In said recess there is provided a hollow space between said elongated portion and the outer wall, said hollow space being adapted to accommodate an elastic element for locking the silencer in place.

Description: IMPROVEMENT IN THE HEAD AND SILENCER OF A REFRIGERATION COMPRESSOR DESCRIPTION The present invention lefeis to a particular foim of both the head and the suction conduit of the silencei thiough which the refrigeiant gas flows mside a sealed casing that encloses an electric motoi , as particularly used m refrigerating appai atuses foi home and sirmlai applications To the purpose of moie effectively exemplifying the piesent invention, said silencei is assumed to operate m close association with the compressor and to be made of plastics moulded by the injection moulding oi any othei appropriate plastic moulding piocess, without this of course limiting the scope of the same invention to just such a kind of coupling and material The gas pressure oscillations mside positive displacement compressors, in particular those used in domestic refrigeration equipment, are critically important owmg to the extent to which they affect both the efficiency of and the level of sound power radiated by the compressors themselves In these compressors, it is the lefngeiant gas that comes from the suction tube that enters mside the sealed casing of the compiessoi The body of the compressoi has a suction tube provided mside the casing which is connected to the suction valve thiough a numbei of channels and cavities that enable the suction gas to be conveyed into the cyl ndei The basic mechanisms governing the gas motion dynamics and, more genei lly, the state of the art aie descnbed m the Italian patent application no PN00014 filed by the same Applicant, to which reference should therefore be made foi obvious leasons of conciseness and of which the present invention shall be intended as constituting an improvement To the pmpose of 1 educing the noise emissions fiom the suction conduit, the pi actice is commonly known of mounting a silencer element at the inlet at which the gas enters the head of the compiessoi , said silencei practically constituting in this mannei the teimmal portion of the gas suction conduit In view of using the sound-deadening effect theieof to the greatest possible extent, such a silencei is usually applied directly on to the inflow mouth of the valve plate, with such a constmction as to be able to get ovei the thickness of the head It theiefoie is quite obvious that the head must be given an appropriately deep recess to accomodate at least a part of the silencei , le the one that is applied on to the inflow mouth of the valve plate Owing to constructive leasons, such a connection is earned out aftei the valve plate has been assembled on the compressor body, but before assembling the head Such a method, however, calls foi a numbei of manual assembly operations to be peifoimed, so that the automatic piocess used to assemble the whole compressor must necessarily be interrupted and, as a result, a much longer time is requned foi manufacturing the compressoi owing to both said interruption of an automated piocess and the time requned foi assembling the silencei manually This piacticaUy turns out to constitute a di wback that considerably affect the overall production efficiency It therefore would be desirable, and it actually is a mam purpose of the piesent invention, to piovide a compiessoi head and silencing appaiatus with such a form and size as to enable the whole assembly of the compressor to be carried out without assembling the silencer, and the silencer to be then assembled only upon completion of the actual manufacturing process, le after also the compressor head has been assembled It is a furthei purpose of the piesent invention to provide such a head and such silencei so that they enable techniques and materials to be used which are simple, cost-effective and leadily available in the art These aims are leached m a compressor as it is described below by way of meie non-hmihng example with leference to the accompanying diawings, m which - Figure 1 is a plan top view of the compressor body without valve plate, - Figuie 2 is a top view of the valve plate of a compressor accoidmg to the present invention, - Figure 3 is a top view of a head of a compressoi according to the present invention, - Figure 4 is a top view of a silencei of a compressor according to the present invention, - Figure 5 is a top view of the assembly of the four component parts illustrated in the above listed Figures, shown here in their final assembly condition, - Figuie 6 is a ci oss-sectional view of an improved variant of a compressor according to the present invention, - Figuie 7 is a perspective view oof a head of a compiessoi according to the present invention - Figures 8 to 10 are respective views along the section plane A - A of the positions taken by a component pail of the present invention at subsequent moments dm mg the assembly thei eof on the compi essor head The basic idea behind the present invention is as described below As m the afoie cited patent specification, the gas entering the compressoi , and coming fiom the refrigerating circuit, is immediately "intercepted" by the silencer and conveyed towaids the head without it being allowed to diffuse Accoidmg to the present invention, howevei , both the silencer and the compressor body are so shaped and sized as to make it possible for the same silencei to be assembled after the compressor body itself has been fully assembled In this connection, and with lefeience to the above listed Figures, it can be noticed that the compressor body comprises a cylinder body 1 , a valve plate 2, a head 3 of the compiessoi , and a silencei 4 As compared with pπoi-art solutions, both the cylmdei body 1 and the cylrndei plate 2 may be left substantially unaltered, whereas the present invention mtioduces definite modifications relating to the head 3 of the compressor and the silencer 4 With reference to the compressor head 3, it can be noticed that it is provided with a projecting border 5 along its outer surface, said projecting border bemg formed with a side 6 that is substantially orthogonal to the surface of the plate and said side 6 extending with a second side 7 that is substantially transversal with lespect to said side 6 and substantially fiontal, at a certain distance therefrom, with respect to the suction opening 20 provided m the plate 2 Furthermore, said head is so shaped as to leave uncoveied a portion 8 of the plate situated theiebelow , which is substantially opposing said second side 7 and, theiefoie, substantially encn cling said suction opening 20 Said contiguous sides 6 and 7 are geometrically associated with each other so as to subtend a lecess 9 that is defined by at least said side 7 and the opposing surface of said portion 8 of the plate situated therebelow It is therefoie quite apparent that the suction opening 20 is m this way able to let into the avove cited and defined recess 9 The silencei 10 is in turn provided with an elongated portion 11 , on a side of which theie is piovided an opening 12 through which the gas is ejected towards the suction opening 20 provided m the valve plate The mutual shapes and dimensions of the described component parts will be such, and easily identifiable by those skilled in the art in their many variants as far as both the geometry and the dimensions are concerned, as to enable said elongated portion 11 of the silencer to be piogressively inserted into said recess, aftei the head has been assembled, until the opening 12 provided to allow the gas contained in the silencer to escape establishes a perfect and tight fit with the corresponding opening 20 provided in the valve plate For the silencer to be kept in position, the dimensions of the described component parts are selected in such a manner that a hollow space 23 is obtained between the outer surface 1 of said elongated portion, which is situated m front of the respective opening 20, and the inner surface 22 of said border 7, said hollow space is used to accomodate an elastic element 24 which, by acting elastically against said two mutually opposing surfaces 21 and 22, firmly holds the silencer m the desired position by blocking said elongated portion 11 In an advantageous mannei , in ordei to make it possible for said elastic element to be more easily and readily inserted, preferably without any use of particulai tools 01 opeiations, the same element is obtained in the form of an appiopi lately bent high-elasticity metal leaf, as lllustiated m Figuie 6 In a prefened mannei , in ordei to ensuie that it takes a coirect position, said elastic leaf is provided on its outei edge 24 with an appropriate fold 25 Such a fold serves also the purpose of definitively fastening the leaf mside the hollow space To this furthei puipose, said fold shall be such as to easily adapt to the projecting edge 26 of said side 7 of the projecting border 5 An advantageous variant of the above described embodiment of the present invention consists m piovidmg said head and the silencer with such a recess 31 and such a protmsion 30, lespectively, that they are able to mutually engage, thereby consolidating the final assembly of said component parts and ensmmg an exact, conect positioning theieof It will be appieciated that the above description and illustrations have been given, with refeience to the accompanying drawings, to the meie purpose of exemplifying the piesent invention, and that a numbei of variants can be implemented and modifications can be made thereto without departing from the scope of the piesent invention

Claims: CLAIMS 1 Electi lc compressoi , m particular foi household refrigerating apparatuses, comprising a cylrndei body (1), a lespective head (3), a valve plate (2) arranged between said head and the body of said cylinder and provided with a gas suction opening (20), a silencer (4) arianged between the inner recess of the compressor casing and said head of the cylrndei , said silencer being formed by a central gas-suction body and an elongated portion (11) extending from said body and provided with a respective opening (12) foi the ejection of the gas contained m the silencei , said opening (12) being adapted to fittingly engage said suction opening (20) m said valve plate, characterized m that - said head is piovided externally with a hollow seat or recess (9) that is laterally accessible towards the innei volume of said compressor, - said elongated portion (11) of the silencer is adapted to be accomodated in a firm and stable manner m said recess (9) m such a position as to enable said respective opening (12) to fittingly and tightly engagesaid opening (20) of said valve plate so as to communicatmgly connect the interior of said silencer with the mtenoi of said cylinder body, and - said head is shaped in a manner that it leaves uncovered a portion (8) of the plate situated therebelow encu cling said suction opening 2 Electric compressoi according to claim 1 , characterized in that said recess (9) is delimited, on its side opposing said plate, by a wall (7) whose inner surface (22) oriented towards said plate is parallel to the latter 3 Electi lc compressoi according to claim 1 or 2 characterized m that between said innei suiface (22) and the outei surface (21) of said elongated portion, m a position which is opposite to the lespective opemng (20), there is piovided a hollow space (23) that is accessible fiom the interior of said compiessoi casing 4 Electi lc compiessoi accoidmg to claim 3, characterized m that in said hollow space there is arranged an elastic element (24) which is adapted to act between said two surfaces (21 , 22) 5 Electi lc compiessoi accoidmg to claim 4, characterized in that said said elastic element (24) is foimed by means of a substantially plane metal leaf that is bent mwaidly so that the two so obtained flanks theieof are capable of acting against said surfaces (21 , 22), respectively 6 Electric compressor according to claim 4 or 5, characterized in that said elastic element is piovided with means (26) that aie capable of engaging the outer edge of the wall (25) of said lecess m a stable mannei 7 Electric compiessor accoidmg to any of the preceding claims, characterized m that a protrusion (30) is provided mside said elongated portion (11), an outwaidly open recess (31) is piovided m said valve plate (2), and said protiusion and said lecess are capable of mutually engaging in the position of final assembly of said silencer

Inventors: RIGO MASSIMO, RIGO, MASSIMO
Applicants: RIGO MASSIMO, ZANUSSI ELETTROMECC, RIGO, MASSIMO, ZANUSSI ELETTROMECCANICA S.P.A.
Application year: 1997
Main classification: F04B39
IPC codes: F04B39