HERMETICALLY ENCLOSED COMPRESSOR WITH MECHANICAL AND ELECTRICAL CONNECTION MEANS

Abstract: For an electrically operated, hermetically enclosed compressor (2) particularly for use in domestic refrigerators there is provided a novel system for the electric connect­ ion of the compressor (2) to the electric circuit of the refrigerator by means of a single support and fixation system (13) on the compressor which may be used for alternatively connecting two different components, one such component being a conventional support adapted to receive onle the power supply cables for the compressor, the other compon­ ent comprising a complete terminal strip (23) to which all the circuits of the refrigerator are connected and which is designed for the automatized mounting thereon of an electric connector.

Description: The present invention relates to a hermetically enclosed compressor according to DE-B-26 04 764. According to the actual state of the art, the design of the electric connection of such compressors is fundamentally dictated by the design of the electric circuit of the refrigerator as a whole. The innumerable possibilities of designing an electric circuit for a domestic refrigerator manufactured on an industrial scale may be basically reduced to just two alternative arrangements: the first of these arrangements is directed to the provision at any suitable location within the refrigerator of a suitable terminal strip or box so as to be accessible from the exterior, usually from the rear of the refrigerator. Combined in this terminal box or strip are the terminals of all the electric component circuits of the refrigerator, the terminal box or strip being internally provided with means for interconnecting the various component circuits so as to result in a unitary circuit. The terminal box or strip is finally connected to an external power supply cable to thereby complete the wiring of the refrigerator. This solution is represented by DE-A-31 42 773 with respect to the connections between relays, the starter and the thermal protection device. The second arrangement, applicable as an alternative to the first one proceeds from the recognition that the compressor is usually provided with certain electric components associated and connected thereto in a permanent manner and required for ensuring proper operation of the compressor, typically a starter and a thermal protection device. As this assembly already constitutes an elementary electric circuit, it is found convenient to connect the compressor itself directly to the external power supply. The power is then supplied to the remaining circuit components of the refrigerator via a suitable connection arrangement including a terminal box or strip to which the circuit components other than the compressor are connected and which serves the same purpose as described before, to thereby complete the wiring of the refrigerator. This second solution is represented by DE-A-33 20 391. A box includes the starter and the thermal protection device. From a purely electrical viewpoint the two solutions are substantially equivalent. From the viewpoint, however, of assembly of the connections in the production line there are relevant differences. In the first case, in which the various components are electrically connected to the terminal box or strip, there is the advantage of good accessibility, since the terminal box or strip can be disposed at the optimum location; on the other hand this solution requires the additional electric connection of the compressor to the terminal box or strip, obviously resulting in economical disadvantages as regards material requirements and assembly operations. In contrast thereto, in the second case explained above there is a concentration of the various circuits at a single location, namely, on the compressor, with evident advantages with regard to material requirements, but indubitably with greater difficulties in finishing and inspection of the wiring, because the connections are established manually after the compressor has been installed, these operations being sometimes rendered difficult by limited accessibility on all sides of the already installed compressor in its housing. In addition to all that has been said above, it is to be kept in mind that up to now all of the connections in the wiring of the refrigerator are established by wholly conventional manual operations, with the inevitable possibility of human errors and at relatively high cost. The present invention is therefore directed to the obtention of the following advantages: In a hermetically enclosed compressor similarly conceived for connection via a separate terminal strip or an integrated terminal strip, to permit the alternative employ of two integrated structures each having the same mechanical and electrical mounting base to be attached to the compressor, and an integral module including the starter, the thermal protection device and a protection cover, but having different systems for the electric connection to the remaining circuit components of the refrigerator. According to the invention, these objects are attained in a domestic refrigerator comprising a compressor having the features defined in claim 1. The cable connection members comprise at least one integrated structure including a mounting base and a terminal strip, or alternatively an integrated structure including a mounting base and a cable clamping insert, said integrated structures being adapted to be mechanically mounted in an interlocking fit on a metallic base formed by punching and bending a sheet metal blank and permanently secured to the compressor adjacent the hermetically sealed connection terminal thereof. It normally also happens that one and the same compressor model is used by different refrigerator makers in different refrigerator models having different wiring systems, so that it is not always possible to employ an integral structure incorporating a terminal strip for different refrigerator models having different electric circuits. The characteristics and advantages of the invention will become evident from the following description, given by way of example with reference to the accompanying drawings, wherein: Fig. 1 is a diagrammatic perspective rear view of a domestic refrigerator of conventional type; fig. 2 is an elevational view of a compressor according to the invention, including a starter, a thermal protection device and a terminal strip; fig. 3 is an elevational view of a compressor according to the invention, including a cable clamping insert; fig. 4 shows an exploded perspective view of the components of the integrated structure. With reference to Fig. 1, a domestic refrigerator presents, when viewed from the rear, a lower cavity 1 housing a compressor 2 with its external components 3 and the delivery and return pipes 4 and 5, respectively, of the refrigerant circuit. Also diagrammatically shown are a condenser 6 and a capillary 7. In the "external terminal strip" version shown in fig. 1, the refrigerator further includes a terminal strip or box 8, an external power supply cable 9, a connection 10 leading from terminal strip 8 to compressor 2, and a number of connections 11, 12 leading from terminal strip 8 to other electrical components of the refrigerator. With reference to Fig. 2, there is shown a metallic mounting base 13, suitably welded to the outer casing 14 of the compressor adjacent the power supply terminals (not shown) thereof so that the latter extend through an opening 15 formed in mounting base 13. Also shown in Fig. 4 are the horizontally positioned starter 20 and the thermal protection device 21 housed respectively in suitable cavities of the dismountable support 26. Support 26 is provided with a plurality of preferably internal contacts 31, the employ of which will be specified in the following. A first element 22 acting as a connector-terminal unit is composed of external electrical terminals 23 arranged and disposed for being connected to corresponding external conductors, of internal electric connections 32 between said terminals 23, of at least one external contact 321, and of a tongue 27 and detent 28 mechanism for releasably mounting and positioning said element 22 in cooperation with a corresponding guide 29 and recess 30, respectively, provided on an angularly extending leg portion of mounting plate 13. The mechanical configuration is selected so that, when element 22 is mounted on mounting plate 13, contact 321 is positively coupled to one of contacts 31. With reference to figs. 3 and 4, a second dismountable element 24 is composed of a tongue and detent mechanism fully identical to the above described elements 27 and 28, and of one or several cable holder inserts for individually retaining the power supply and grounding conductors leading to the compressor, and to be manually connected in the conventional manner to contacts 31 and/or to contacts projecting from the rear part of one of the relays, e.g. relay 21. The employ of the device is now evident: depending on the type of the circuitry of the refrigerator, the electric connections are established on element 22 or alternatively on element 24. Any of these elements can be readily and interchangeably mounted on the compressor thanks to the complementary construction of the respective mounting structures 27, 28 and 29, 30, respectively. In the first case the electric connection is automatically established either between contacts 321 and 31, or through a suitable connection between one of terminals 23 and one of the contacts projecting from the rear part of one of the relays, e.g. relay 21. In the second case the electric connection is established by manually connecting in the conventional manner the incoming cables to the above named contacts. The electric connection between the two components 20 and 21, the support 26 and the compressor may be established in any suitable manner and shall therefore not be described. From a comparison of Fig. 2 to Fig. 3 it is evident that the employ of one and the same dismountable support 26 in the two different arrangements on the one hand permits one and the same compressor to be employed with any of the two different wiring arrangements described above, and on the other hand results in optimum cost-effectiveness, inasmuch as the employ of cable holder 24 is just an alternative to the employ of element 22, so that the electric subassembly composed of compressor 2, the two relays 20 and 21, and support 26 can be readily and directly connected to the wiring of any refrigerator. Independently of the type of the connections between the above named electric components, it is finally to be noted that a further simplification in the mounting of these components is obtainable by the provision of a single protective cover 25 dimensioned so as to be able to accommodate any of the two connection arrangements described above and thus to be indifferently employed in any of the two cases.

Claims: Hermetically enclosed compressor (2) with a mounting base (13) secured to the compressor for carrying the electrical connections, characterized by a support member (26) which is dismountably attached to the compressor (2) and formed as a single module adapted to hold a starter (20) and a thermal protection device (21); and two different cable connection members, one being a terminal strip (22) and the other being a cable clamping insert (24), the mounting base (13), the terminal strip (22) and the cable clamping insert (24) being formed such that the terminal strip (22) and the cable clamping insert (24) are selectively mountable on the mounting base (13). Compressor according to claim 1, characterized in that there is provided a housing (25) to cover the support member (26) and the cable connection member (22 or 24).

Inventors: MORET, DORINO
Applicants: ZANUSSI ELETTROMECCANICA S.P.A.
Application year: 1988
Main classification: F25B31
IPC codes: H01H1, H01H61, F25B31