US20090110586A1

US20090110586A1 - Refrigerant compressor

Info

Publication number: US20090110586A1
Application number: US12/315,719
Authority: US
Inventors: Walter Brabek; Manfred Jost
Original assignee: ACC Austria GmbH
Current assignee: Secop Austria GmbH
Priority date: 2006-06-08
Filing date: 2008-12-05
Publication date: 2009-04-30
Also published as: EP2027391A1; SI2027391T1; CN101466950A; EP2027391B1; AT9233U1; WO2007141326A1; ATE547630T1

Abstract

A hermetically encapsulated refrigerant compressor which comprises a hermetically sealed compressor housing (1), in the interior of which a piston-cylinder unit which compresses a refrigerant and a suction pipe (2) and a pressure pipe (3) are provided, with refrigerant flowing via the suction pipe (2) to the piston-cylinder unit and the refrigerant compressed by the piston-cylinder unit being conveyed out of the compressor housing (1) via the pressure pipe (3), with connection openings (5) for the suction pipe (2) and the pressure pipe (3) being provided on the compressor housing (1), with the connection of the suction pipe (2) and pressure pipe (3) to the connection openings (5) occurring in a hermetically tight manner by means of a connection apparatus (9) and with the connection apparatus (9) comprising a preferably sleeve-like body element (8) and at least one spacer element (7) which spaces the body element (8) from the suction pipe (2)/pressure pipe (3). It is provided in accordance with the invention that the body element (8) is attached to an outside (13) of the compressor housing (1) outside of the connection opening (5) by enclosing the same in a hermetically sealing manner.

Description

BACKGROUND OF THE INVENTION

The present invention relates to a hermetically encapsulated refrigerant compressor which comprises a hermetically sealed compressor housing, in the interior of which a piston-cylinder unit which compresses a refrigerant and a suction pipe and a pressure pipe are provided, with refrigerant flowing via the suction pipe to the piston-cylinder unit and the refrigerant compressed by the piston-cylinder unit being conveyed out of the compressor housing via the pressure pipe, with connection openings for the suction pipe and the pressure pipe being provided on the compressor housing which enable the overflow of the refrigerant from the outside of the compressor housing into the interior of the compressor housing and vice-versa, with the connection of the suction pipe and pressure pipe to the connection opening occurring in a hermetically tight manner by means of a connection apparatus, with the connection apparatus comprising a preferably sleeve-like body element and at least one spacer element which spaces the body element from the suction pipe/pressure pipe, in accordance with the preamble of claim 1.
Such refrigerant compressors are used in the field of households and the industry where they are mostly arranged on the rear side of a refrigerator or refrigerated case. It is their task to compress and further convey refrigerant circulating in the cooling system, thus dissipating heat from the interior of the refrigerating, passing it on to the ambient environment and a refrigerating chamber or refrigerated case are thus refrigerated in the known manner.
The refrigerant compressor comprises a hermetically sealed compressor housing and an electric motor which drives a piston oscillating in a cylinder via a crankshaft to compress the refrigerant. The compressor housing consists of a cover part and a base part and connection openings, with a suction pipe, a pressure pipe and other pipes optionally being provided which lead into and out of the compressor housing to convey the refrigerant to the cylinder and therefrom further in the refrigerant loop.
In view of the large number of refrigerant compressors all over the world, any degree of improvement in the efficiency made in a refrigerant compressor leads to a considerable potential in energy savings which is becoming increasingly more important in view of the globally diminishing energy resources.
Possibilities for an improvement of the efficiency are especially the reduction of the temperature of the refrigerant at the beginning of the compression process. Any reduction of the intake temperature into the cylinder of the cylinder-piston unit therefore causes, like the reduction of the temperature during the compression process and, connected thereto, the expulsion temperature, a reduction of the required technical work for the compression process.

DESCRIPTION OF THE PRIOR ART

In known hermetically encapsulated refrigerant compressors there is a strong heating of the refrigerant on its path from the compressor (cooling space) to the intake valve of the piston-cylinder unit as a result of the design. Since a considerable quantity of heat is generated as a result of the compression process and the same is also transferred to the compressor housing, there is obviously also a subsequent heat transfer from the compressor housing to the pipe connections of the refrigerant compressor, especially to the suction pipe.
The pressure pipe indirectly also causes an additional heating of the suction pipe and thus the refrigerant which is directly before the compression cycle. Since the compressed refrigerant which is removed in the pressure pipe has temperatures of up to 100° C., there is also a strong heating of the pressure pipe which is transferred especially also in the area of the connection opening onto the compressor housing and from this to the suction pipe.
Since the drawn refrigerant is thus heated, there is an adverse effect on the efficiency of the refrigerant compressor.
In addition to a known insulation of the sections of the suction and pressure pipes which are guided in the interior space of the compressor housing, an insulation of the same in the area of the connection openings is of special relevance, i.e. at such a location where the suction pipe and pressure pipe and the compressor housing touch each other directly.
A compressor housing with a suction pipe consisting of two pipe elements that are slid into each other is known from U.S. Pat. No. 6,361,293, with the pipe element with the smaller diameter comprising an enlarged end section which is provided with an O-ring and makes contact with the inside of the other pipe element. This measure is provided to ensure mobility of the suction pipe connected to a cylinder housing. As a result of the thus obtained air gap between the outside diameter of the first pipe element and the inside diameter of the second pipe element, a certain insulating effect against the conveyed refrigerant is also obtained in the connection region of the compressor housing, but the reduction of the heat transmission thus achieved is relatively low because the wall of the compressor housing ends directly on the suction pipe.
U.S. 2004/096338 A1 discloses a compressor housing with a tubular body element which is guided through the wall of the compressor housing in order to receive a pressure pipe, with an insert or spacer element that is also tubular being arranged between the body element and the pressure pipe. The spacer element is welded together at the end side with the pressure pipe, while the body element is welded together at the end side with the spacer element.
A hermetically sealed compressor housing with a pipe connection apparatus is known from U.S. Pat. No. 6,257,846 B1, with an outer sleeve element which is guided through the wall of the compressor housing and an inner sleeve element being provided. A suction pipe is held within the inner sleeve element. The inner and outer sleeve element and the suction pipe are soldered together simultaneously.
A compressor housing is known from EP 0 430 790 A1 whose components in adjacent areas are provided with a hermetically sealing layer or a bulge in order to dampen vibrations. It also discloses a pressure pipe connection with a body element made of an elastic material. Said body element is fastened by means of an adhesive layer to the housing wall and the pressure pipe.

SUMMARY OF THE INVENTION

It is therefore the object of the present invention to reduce the efficiency losses caused by the heating of the aspirated refrigerant in the area of the connection openings of the compressor housing and to optimize the efficiency of the refrigerant compressors. A connection apparatus is to be provided for this purpose which considerably reduces the heat transmission between the compressor housing and suction pipe or pressure pipe, so that the lowest possible temperature level of the refrigerant is ensured at the beginning of the compression process, i.e. during the aspiration into the cylinder of the piston-cylinder unit.
This is achieved in accordance with the invention by a refrigerant compressor with the characterizing features of claim 1.
A refrigerant compressor comprises a hermetically sealed compressor housing in the interior of which a piston-cylinder unit works which compresses a refrigerant and a suction pipe and a pressure pipe is provided, with a refrigerant flowing in the known manner via the suction pipe to the piston-cylinder unit and the refrigerant compressed by the piston-cylinder unit being expelled from the compressor housing via the pressure pipe, with connection openings being provided on the compressor housing for the suction pipe and the pressure pipe which enable the overflow of the refrigerant from the outside of the compressor housing to the inside of the compressor housing and vice-versa, with the connection of the suction pipe or the pressure pipe to the connection opening. occurring in a hermetically sealed way through a connection apparatus. The connection apparatus comprises a preferably sleeve-like body element and at least one spacer element which keeps the body element away from the suction pipe and pressure pipe. The body element is thus not in direct contact with the suction pipe and pressure and the introduction of heat into the body element occurs only to a limited extent through the spacer element.
In accordance with the invention, the body element is attached outside of the connection opening to an outside of the compressor housing by enclosing the same in a hermetically sealing manner.
The body element can either be fastened with one face side directly to the compressor housing or by means of a contact section which is bent off at an angle of 90° for example.
Since the heat transmission from the compressor housing to the suction pipe or from the hot pressure pipe to the compressor housing and subsequently from the same to the suction pipe is reduced, a considerable reduction of the temperature of the refrigerant which is guided in the suction pipe and is directly before the compression process in the piston-cylinder unit is achieved, thus leading to an increase in the efficiency of the refrigerant compressor. By avoiding the heat transmission from the hot pressure pipe to the compressor housing, a heating of the compressor housing itself and the interior of the compressor housing (oil, the refrigerant disposed in the interior, compressor housing temperature) is reduced, leading to an improvement in the efficiency.
According to the characterizing features of claim 2 it is provided that the spacer element consists of a material that has a lower thermal conductivity than the body element in order to avoid heat transmission to a highest possible extent.
According to the characterizing features of claim 3, the body element and preferably also the spacer element is made of austenitic steel. Austenitic steel is characterized in the present field of application by its reduced thermal conductivity and a high resistance to corrosion, tenacity and resistance to high temperatures.
According to another preferred embodiment of the invention, the spacer element is made of foamed glass, plastic or a ceramic material according to the characterizing features of claim 4. The mentioned materials lead to a strong reduction of the undesirable heat transmission from the compressor housing or the body element in direct contact with the same to the suction pipe and vice-versa from the pressure pipe to the body element and the compressor housing as a result of their low heat transmission coefficient.
In addition to a direct arrangement of a separate spacer element having an insulating effect between the body element and the suction pipe or pressure pipe according to the characterizing features of claim 5, with the suction pipe or pressure pipe being enclosed by the spacer element in a hermetically sealing manner, it is also possible in an alternative embodiment to arrange the body element and the spacer element as an integral component. As such it is provided for according to the characterizing features of claim 6 that the spacer element is arranged as a section, preferably an end section of the body element, which extends under an angular inclination, preferably a right angle, relative to the axis of the suction pipe or pressure pipe in order to enclose the suction pipe or pressure pipe in a hermetically sealing manner. Since this geometry also leads to the consequence that the inside diameter of the body element (with the mere exception of its end section) is always larger than the outside diameter of the suction pipe/pressure pipe, an air cushion is formed between the suction pipe/pressure pipe which has an insulating function and strongly reduces the undesirable heat transmission between the suction pipe/pressure pipe and the compressor housing. This embodiment allows a simple and economical production of the connection apparatus.
In this embodiment it is provided according to the characterizing features of claim 7 that the section or end section of the body element encloses the suction pipe/pressure pipe at a section of its longitudinal extension which lies outside of the connection opening or outside of the cross-sectional wall surface of the compressor housing which is projected in the normal direction onto the circumferential surface of the body element. Since the contact surface of the section or the end section of the body element with the suction pipe/pressure pipe is as far away as possible from the contact surface of the body element with the compressor housing, the path of heat transport to be bridged is extended and the heat transmission between suction pipe/pressure pipe and compressor housing is given the largest possible obstruction.
In order to enclose the suction pipe/pressure pipe in a hermetically sealing manner, the end section of the body element which is arranged as a spacer element is provided with an annular opening according to the characterizing features of claim 8.
According to the characterizing features of claim 9, the body element comprises a contact section which is fastened to the one on the outside of the compressor housing. The diameter of the connection opening is preferably larger than the outer diameter of the section of the body element which is led through the connection opening. It is thus ensured that an abutting surface of the connection opening does not touch the body element, but remains spaced from the same. This measure too ensures that the insulating function of the connection apparatus in accordance with the invention is increased and the heat transmission between the suction pipe/pressure pipe and compressor housing is reduced.
Both the body element as well as the spacer element can also be arranged in several parts according to the characterizing features of claim 10 in order to enable further advantages in relation to production and heat technology.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is now explained in closer detail by reference to an embodiment, wherein:

FIG. 1 shows a basic part of a compressor housing in an oblique view;

FIG. 2 shows a basic part of a compressor housing in a top view;

FIG. 3 shows a partial sectional view of the compressor housing of FIG. 2 along lines A-A and B-B with a connection apparatus according to the state of the art;

FIG. 4 shows an enlarged view of the detail A of FIG. 3;

FIG. 5 shows an alternative embodiment of a connection apparatus according to the state of the art;

FIG. 6 shows a further alternative embodiment of a connection apparatus according to the state of the art;

FIG. 7 shows a further alternative embodiment of a connection apparatus according to the state of the art;

FIG. 8 shows a further alternative embodiment of a connection apparatus according to the state of the art;

FIG. 9 shows an embodiment of a connection apparatus according to the invention;

FIG. 10 shows a further embodiment of a connection apparatus according to the invention;

FIG. 11 shows a further embodiment of a connection apparatus according to the invention;

FIG. 12 shows a further embodiment of a connection apparatus according to the invention;

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A refrigerant compressor comprises a hermetically sealed compressor housing 1, with a suction pipe 2, a pressure pipe 3 and a service pipe 4 opening into the same via connection openings 5.
A refrigerant flows via the suction tube 2 in the known manner to a piston-cylinder unit (not shown) which is arranged within the compressor housing 1 and in which a compression of the refrigerant occurs, with the pressure pipe 3 subsequently leading the compressed and therefore strongly heated refrigerant from the piston-cylinder unit out of the compressor housing 1 to a cooling circuit (also not shown) of a cooling space. The piston-cylinder unit is driven by an electromotor via a crankshaft, so that cooling space associated with the refrigerant compressor is continually cooled by means of the circulating refrigerant.
Compressor housing 1 comprises several standing elements 6 which are used to position the same on a floor space of a refrigerating device determined for this purpose.
Although FIG. 1 merely shows a base part of a compressor housing 1 in this connection on which subsequently a cover part (not shown) will be placed, the compressor housing 1 can also be arranged in another manner, e.g. in the form of a compressor housing 1 which is divided in an oblique way or composed in another manner. It is also possible to lead the suction pipe 2, the pressure pipe 3 or service pipe 4 through the cover part into the interior of the compressor housing, with suction pipe 2 and pressure pipe 3 not needing to extend necessarily in pairs next to one another as shown in FIG. 1, but can also open in connection openings 5 of the compressor housing 1 which are arranged offset in a random way, or can lead out of the same.
Service pipe 4 is merely used for filling the compressor housing 1 with a suitable refrigerant or with an oil required for lubrication.
FIG. 2 shows a top view of the compressor housing 1 shown in FIG. 1 in an oblique view and forms the reference for the partial sectional view as shown in FIG. 1 with the sectional guides A-A and B-B as shown therein, which partial sectional view shows a conventional pipe connection to the compressor housing 1 as known from the state of the art. The suction pipe and/or the pressure pipe pass through the connection opening 5 through a connection apparatus 9 which is connected with the compressor housing 1 in a hermetically sealed manner, with the connection apparatus 9 on its part being connected with the suction pipe and pressure pipe in a hermetically sealed manner, preferably by being welded.
FIGS. 4 and 5 also show pipe connections according to the state of the art in a detailed view. The compressor housing 1 mostly consists of deep-drawing steel, whereas the suction pipe 2 and the pressure pipe 3 consist of copper, a copper/iron alloy or also of a pure iron material. According to the illustration in FIG. 4 it is common practice to fasten the suction pipe 2 and the pressure pipe 3 by means of a connection apparatus 9 to the connection openings 5 of the compressor housing 1. For this purpose, a steel disk is soldered onto suction pipe 2 and pressure pipe 3 for example and this system is welded in a further process of work to the compressor housing 1. The connection opening 5 or the area of the compressor housing 1 enclosing the same can be prepared in a manner that an interlocking contact is enabled between the mutually contacting surfaces of the compressor housing 1 and the connection apparatus 9, e.g. by mutually corresponding bezels 14 (FIG. 4) which are provided both on the connection apparatus 9 as well as the compressor housing 1.
Another kind of connection of the suction pipe 2 and pressure pipe 3 to the compressor housing 1 is shown in FIG. 5, with a Cu or Cu/Fe pipe being shown which was swaged and is brought into contact with a bezel 14 of the connection opening 5 of the compressor housing 1 by means of a protrusion of the pipe cross section which was obtained in the course of the swaging and is connected in a hermetically sealed manner with the compressor housing 1 by means of welding for example.
FIGS. 6 to 8 show other connection possibilities for the suction pipe 2/pressure pipe 3 as known from the state of the art, comprising a contact of the connection apparatus 9 with the outside 13 of the compressor housing 1 (FIG. 7), a pipe connection with contact of the connection apparatus 9 with inside 12 of the compressor housing 1 (FIG. 8) or a pipe connection without contact of the connection apparatus 9 on the compressor housing (FIG. 9)
Irrespective of how the pipe connection may have been arranged according to the previously described FIGS. 3 to 8 specifically, it is a fact in the known connection variants that a connection apparatus 9 made of a metallic material or a metal alloy provides a high heat transmission from the compressor housing 1 to the suction pipe 2 and from the pressure pipe 3 which carries a strongly heated refrigerant to the compressor housing 1 and thus again to the suction pipe 2 which is in direct contact with the compressor housing 1 or is in direct contact via the connection apparatus 9. An unhindered heat transmission at the mentioned places is undesirable for the reasons as explained above and reduces the efficiency of the refrigerant compressor because the refrigerant drawn into the cylinder of the piston-cylinder unit is heated unnecessarily in this process.
In order to considerably reduce such a heat transmission from the compressor housing 1 to the suction pipe 2 and from the pressure pipe 3 to the compressor housing 1, the connection apparatus 9 comprises a body element 8 and at least one spacer element 7 which spaces the body element 8 from the suction pipe 2 and pressure pipe 3. Body element 8 therefore is no longer in direct contact with the suction pipe 2 or pressure pipe 3, or the contact zones between these elements are kept very small.
In accordance with the invention, the body element 8 is arranged on the compressor housing 1 outside of the connection opening 5 and enclosing the same (FIG. 11) . The body element 8 is fastened with an obtuse cross-sectional surface area directly to the outside 13 of the compressor housing 1. A contact section which is bent by an angle of 90° for example can also be provided for a more stable fastening of the body element 8.
If the body element 8 is not arranged on the outside 13 but on the inside 12 (as shown in FIG. 11), a rear venting space is formed between the suction pipe 2/pressure pipe 3 and body element 8, which space communicates with the ambient air indicated by arrows 15 outside of the compressor housing 1 via the connection opening 5 of the compressor housing 1 and thus enables an additional cooling effect. The diameter of the connection opening 5 is larger for this purpose than the diameter of the suction pipe 2/pressure pipe 3.
FIG. 11 already shows an alternative embodiment of the connection apparatus 9, with body element 8 and spacer element 7 being arranged as an integral component. The spacer element 7 is arranged as an end section of the body element 8 which extends under an angular inclination, preferably at a right angle, to the axis of the suction pipe 2/pressure pipe 3 in order to enclose the suction pipe 2/pressure pipe 3 in a hermetically sealing manner, e.g. by soldering or welding.
The body element 8 is preferably arranged in a sleeve-like manner, and thus comprises a wall section (see FIG. 9) which extends substantially parallel to the axis of the suction pipe 2/pressure pipe 3 or to the axis of the connection opening 5. optionally, it is also possible to provide any other shape of the arrangement instead of a rotational-symmetrical shape of the body element 8. Instead of a sleeve-like or cylindrical shape, the body element 8 can also be arranged in a convex, concave or irregular geometrical way. The relevant aspect is always that the body element 8 does not touch the suction pipe 2/pressure pipe 3 over a length which enables an unhindered heat transmission, but is spaced from the same via a spacer element 7, even if only minimally. In a preferred embodiment according to FIG. 9, a cylindrical foamed glass body is used as a spacer element 7 which is arranged between body element 8 and the suction pipe 2/pressure pipe 3, with the foamed glass body being connected in a hermetically sealed manner with the suction pipe 2/pressure pipe 3 on the one hand and the body element 8 on the other hand.
In order to reduce heat transmission to the highest possible extent, the spacer element 7 preferably consists of a material that has a worse thermal conductivity than the body element 8. In order to fasten the body element 8 reliably on the compressor housing 1, it can be provided with a stop section 10 which rests on the outside 13 or on the inside 12 of the compressor housing 1 and is fastened there in the known manner, i.e. it is soldered or welded. The contact section 10 preferably concerns an integral part of the body element 8 which is provided with its desired dimensioning in a bending or deep drawing process. In the case of a multi-part arrangement of the body element 8, the contact section 10 can also be made as a separate element which is soldered or welded onto the sleeve-like body element 8.
In order to further reduce the heat transmission between compressor housing 1 and the suction pipe 2/pressure pipe 3, the diameter of the connection opening 5 is dimensioned larger than the outer diameter of the section of the body element 8 which is guided through the connection opening 5. It is thus ensured that an abutting surface 11 of the connection opening 5 does not contact the body element 8, but is spaced from the same. An annular gap is thus formed in this way between the body element 8 and the abutting surface 11 in which outside air can circulate and can cool the connection apparatus 9.
When choosing suitable materials for the spacer element 7, its coefficient of thermal conduction λ is of relevance; it defines the heat quantity which passes in a unit of time through a layer of the surface area and thickness unit at 1 K temperature difference and is expressed in W/(m*K). Whereas copper (temperature-dependent) has a comparatively high coefficient of thermal conduction λ of approximately 380 W/(m*K), λ in unalloyed steel is approximately 100 W/(m*K) . By adding suitable alloy elements such as chromium, nickel, manganese or molybdenum, the coefficient of thermal conduction λ of steel can be reduced to a considerable extent. Cr/Ni steel can have a coefficient of thermal conduction λ of less than 20 W/(m*K) for example.
The already mentioned material of foamed glass with a coefficient of thermal conduction λ of approximately only 0.05 W/(m*K) has proven in tests to be especially advantageous. Foamed glass has an only slightly larger λ-value than air with 0.024 W/(m*K).
Similarly, ceramic materials have proven to be very advantageous in the present field of application, especially such on the basis of metal oxides. For example, so-called special ceramic masses or technical masses such as highly sintered oxide ceramics made of aluminum, magnesium, beryllium or zirconium oxide can be used.
Preferably, solderable ceramic materials are concerned, so that perfect soldering of spacer element 7 and suction pipe 2/pressure pipe 3 on the one hand and body element 8 and even compressor housing 1 on the other hand is enabled in order to achieve the required tightness.
Ceramic materials have proven to be especially advantageous for use in insulating suction pipe 2/pressure pipe 3 at their connection point on the compressor housing 1 as a result of their fire resistance and their temperature and dimensional stability in addition to their low coefficient of thermal conduction [λ=0.5−1.5 W/(m*K)].
Plastic materials which offer temperature stability and resistance to ageing can also be used as materials for the spacer element 7, which materials are applied by suitable fastening measures such as shrinking, gluing, lasing, extrusion-coating or laminating onto the suction pipe 2/pressure pipe 3.
As a result of their low coefficient of thermal conduction, the mentioned materials lead to a strong reduction in the undesirable heat transmission from the compressor housing 1 or from the body element 8 which is in direct contact with the same onto the suction pipe 2 and vice-versa from the pressure pipe 3 to the body element 8 and the compressor housing 1.
Austenitic steel is preferred as a material for the body element 8. Austenitic steel is characterized in the present field of application by its alloy percentage (e.g. Cr/Ni or Mg-alloys) with a reduced thermal conductivity and a high resistance to corrosion, tenacity and high-temperature resistance. At the same time, this material also allows hermetically sealed connection of the body part 8 to the compressor housing by means of welding.
FIG. 10 shows an alternative embodiment of the connection apparatus 9, with the body element 8 and the spacer element 7 being arranged as an integral component. The spacer element 7 is arranged as an end section of the body element 8 which extends under an angular inclination, preferably a right angle to the axis of the suction pipe 2/pressure pipe 3 in order to enclose the suction pipe 2/pressure pipe 3 in a hermetically sealing manner, e.g. by soldering or welding.
As is shown in the illustration according to FIG. 10, the inside diameter of the sleeve-like body element 8 is always larger than the outside diameter of the suction pipe 2/pressure pipe 3, so that an air cushion (gas mixture, refrigerant) is formed between the suction pipe 2/pressure pipe 3 and the body element 8 which has an insulating function and also strongly reduces the heat transmission between suction pipe 2/pressure pipe 3 and compressor housing 1. Similarly, the end section of the body element 8 can also be a separately produced element which is attached to the face side of the sleeve-like body element 8 and encloses the suction pipe 2/pressure pipe 3. The relevant aspect is that the heat flow from the body element 8 to the suction pipe 2 and from the pressure pipe 3 to the body element 8 occurs only via the spacer element 7 due to lack of contact between body element and suction pipe 2/pressure pipe 3, with the body element 8 and the spacer element 7 being produced in an integral way or also in several parts.
Body element 8 can also be arranged in a position reversed over the one shown in FIG. 10, i.e. with an end section as a spacer element 7 which is arranged in the area of the inside 12 of the compressor housing 1, with the suction pipe/pressure pipe section being subjected in the area of the connection opening to a rear ventilation and cooling by the air enclosing the compressor housing 1.
As is further shown in FIG. 10, the end section of the body element 8 encloses the suction pipe 2/pressure pipe 3 at a section of its longitudinal extension which lies outside of the connection opening 5 or outside of a cross-sectional wall surface of the compressor housing 1 projected against the circumferential surface of the body element 8. The contact surface of the end section of the body element 8 with the suction pipe 2/pressure pipe 3 is therefore not arranged in the direct vicinity of the contact surface of the body element 8 with the compressor housing 1, but at a distance promoting the insulating function.
In order to enclose the suction pipe 2/pressure pipe 3 and to enable a hermetically sealing connection with the same, the end section of the body element 8 which is arranged as a spacer element 7 is provided with an annular opening within which the suction pipe 2/pressure pipe 3 is fastened in a sealed manner.
In order to achieve further production and thermal advantages in the respective application, it may optionally be appropriate to arrange the body element and/or the spacer element 7 in several parts. A body element 8 in several parts which consists of several elements engaging into each other has the advantage of larger flexibility in the production and surface machining and allows for a specific arrangement of the connection system depending on the respective requirements and fields of application.
FIG. 12 finally shows a special embodiment of a connection apparatus 9 which comprises a spacer element 7 which is preferably made of foamed glass, plastic or ceramic material, with the spacer element 7 being arranged in an L-shaped way and being arranged directly between the abutting area 11 of the connection opening 5 and suction pipe 2/pressure pipe 3. A leg section 16 of the spacer element 7 is enclosed by the body element 8 and pressed against the outside 13 of the compressor housing 1. The spacer element 7 need not necessarily have a hermetically sealing function in this configuration if the body element 8 is connected in a hermetically sealing manner both with the compressor housing 1 as well as the suction pipe 2/pressure pipe 3. This configuration thus offers the advantage that materials can also be used for the spacer element 7 with which a hermetically sealing connection can be produced only with difficulty to another medium, especially such materials which cannot be soldered or welded.

Claims

1. A hermetically encapsulated refrigerant compressor which comprises a hermetically sealed compressor housing (1), in the interior of which a piston-cylinder unit which compresses a refrigerant and a suction pipe (2) and a pressure pipe (3) are provided, with refrigerant flowing via the suction pipe (2) to the piston-cylinder unit and the refrigerant compressed by the piston-cylinder unit being conveyed out of the compressor housing (1) via the pressure pipe (3), with connection openings (5) for the suction pipe (2) and the pressure pipe (3) being provided on the compressor housing (1) which enable the overflow of the refrigerant from the outside of the compressor housing (1) into the interior of the compressor housing (1) and vice-versa, with the connection of the suction pipe (2) or pressure pipe (3) to the connection openings (5) occurring in a hermetically tight manner by means of a connection apparatus (9), with the connection apparatus (9) comprising a preferably sleeve-like body element (8) and at least one spacer element (7) which spaces the body element (8) from the suction pipe (2)/pressure pipe (3), wherein the body element (8) is attached to an outside (13) of the compressor housing (1) outside of the connection opening (5) by enclosing the same in a hermetically sealing manner.

2. A hermetically encapsulated refrigerant compressor according to claim 1, wherein the spacer element (7) consists of a material that has a lower thermal conductivity than the body element (8).

3. A hermetically encapsulated refrigerant compressor according to claim 1, wherein the body element (8) and preferably the spacer element (7) is made of austenitic steel.

4. A hermetically encapsulated refrigerant compressor according to claim 1, wherein the spacer element (7) is made of foamed glass, plastic or a ceramic material.

5. A hermetically encapsulated refrigerant compressor according to claim 1, wherein the spacer element (7) is arranged between body element (8) and the suction pipe (2)/pressure pipe (3) and encloses the suction pipe (2)/pressure pipe (3) in a hermetically sealing manner.

6. A hermetically encapsulated refrigerant compressor according to claim 1, wherein the spacer element (7) is a section, preferably an end section of the body element (8), which extends under an angular inclination, preferably a right angle, relative to the axis of the suction pipe (2)/pressure pipe (3) and encloses the suction pipe (2)/pressure pipe (3) in a hermetically sealing manner.

7. A hermetically encapsulated refrigerant compressor according to claim 6, wherein the section or end section of the body element (8) encloses the suction pipe (2)/pressure pipe (3) at a section of the circumference which lies outside of the connection opening (5) or outside of cross-sectional wall surface of the compressor housing (1) which is projected in the normal direction onto the circumferential surface of the body element (8).

8. A hermetically encapsulated refrigerant compressor according to claim 6, wherein the section or end section of the body element (8) which is arranged as a spacer element (7) ends in an annular opening.

9. A hermetically encapsulated refrigerant compressor according to claim 1, wherein the body element (8) has a contact section (10) and is fastened with the same to the outside (13) of the compressor housing (1), with the diameter of the connection opening (5) preferably being larger than the outer diameter of the section of the body element (8) which is guided through the connection opening (5), so that an abutting surface area (11) of the connection opening (5) is spaced from the body element (8).

10. A hermetically encapsulated refrigerant compressor according to claim 1, wherein the body element (8) and/or the spacer element (7) are arranged in several parts.