WO2024251998A1

WO2024251998A1 - Discharge connector fixation

Info

Publication number: WO2024251998A1
Application number: PCT/EP2024/065820
Authority: WO
Inventors: Michaela Kohl; Water BRABEK; Gunther ZIPP
Original assignee: Nidec Global Appliance Austria GmbH
Current assignee: Secop Austria GmbH
Priority date: 2023-06-07
Filing date: 2024-06-07
Publication date: 2024-12-12
Anticipated expiration: 2025-12-07

Abstract

The invention relates to a refrigerant compressor with a compressor housing (3) in which a refrigerant-compressing compression unit is arranged, wherein the compression unit is connected to a pressure path for guiding refrigerant through the compressor housing (3), and the pressure path comprises a first pressure tube (5) and a second pressure tube (2) which are fluidly connected to each other via a connecting element (4), wherein the connecting element (4) is arranged on a first end section (5a) of the first pressure tube (5) and has a sleeve-shaped connecting section (4a) which is arranged in a second end section (2a) of the second pressure tube (2), characterized in that the connecting section (4a) is connected to the second pressure tube (2) via a snap connection.

Description

“DISCHARGE CONNECTOR FIXATION” [0001] The invention relates to a refrigerant compressor with a hermetically sealed compressor housing, in which a refrigerant compressing unit is arranged. The compressing unit is connected to a pressure line for guiding the refrigerant through the compressor housing, and the pressure line comprises a first pressure pipe and a second pressure pipe, which are flow-connected via a connecting element. The connecting element is arranged on a first end section of the first pressure pipe and has a sleeve-shaped connecting section, which is arranged in a second end section of the second pressure pipe. [0002] Such refrigerant compressors are particularly used in cooling devices like commercial refrigerators to compress refrigerant. For this purpose, the compressing unit preferably has a piston-cylinder unit. The compressed refrigerant is then conducted out of the compressor housing through the pressure line and is typically supplied to a condenser for heat dissipation. It is important that this connection is tight and easy to manufacture. However, low noise emission from the refrigerant compressor to the surrounding environment is also preferred. [0003] In EP 2207962 A1, a refrigerant compressor is disclosed, whose pressure pipe has a narrowed end section that secures the connecting element in axial position by engaging behind it. The metal pressure pipe is bent inward at the end section during manufacturing after the connecting element has been inserted. This can lead to damage to the first pressure pipe, which is made of plastic, or to the connecting element, reducing the tightness and lifespan of the refrigerant compressor. [0004] The object of the invention is to provide a refrigerant compressor that is as easy to assemble as possible and has the longest possible lifespan. [0005] This object is achieved according to the invention by connecting the connecting section to the second pressure pipe via a snap connection. [0006] The snap connection achieves an especially simple yet firm and stable connection. Additionally, the snap connection reduces sound transmission between the pressure pipes, as it can feature elastic elements and can have play in the axial direction. Assembly then requires no further steps, as the connection is automatically established when the pressure pipes are brought together. [0007] The snap connection is designed to snap into place when the second pressure pipe and the connecting element are brought together, creating a form-fitting connection that prevents these elements from being pulled apart. This snap connection can have axial play when moved towards each other. [0008] Preferably, it is provided that the connecting section has at least one snap element that engages in at least one radial shoulder of the second end section. The snap element and the radial shoulder can together form a snap connection. This snap element is at least partially movable in the radial direction, allowing it to elastically bend during assembly and snap into the radial shoulder after passing it. Thus, it rests against this radial shoulder when pulled apart and prevents separation. [0009] It can also be provided that the second end section has at least one snap element that engages in at least one radial shoulder of the connecting section. [00010] The shoulder is a surface that stands at an angle to the axis of the pressure pipes, thus extending radially. Preferably, it is the surface of a flange-like expansion facing away from the second end section. [00011] Preferably, it can be provided that the second pressure pipe in the area of the second end section, preferably on its outer side, has at least one, preferably radially outward-facing shoulder, and that the connecting element has at least one securing section arranged outside [00012] The shoulder engages and interlocks with the gripping element. This gripping element can represent the snap element. [00013] It can also be provided that the second end section has the radial shoulder on its inner side, i.e., the side facing the first pressure pipe. For this purpose, the second end section can have an inner recess in cross-section, which forms the shoulder. [00014] By "engaging behind," it is meant that the gripping element is farther away in the axial direction from the end of the second pressure pipe than the shoulder. This refers to the end where the second end section is located. [00015] By "interlocking," it is meant that a form- fitting and optionally a force-fitting connection is made between the gripping element and the shoulder, which prevents the axial separation of the second pressure pipe and the connecting element. [00016] The external engaging behind and interlocking of the shoulder ensures that during assembly, while inserting the connecting element into the second pressure pipe in the axial direction, the gripping element moves over the shoulder and snaps into it after passing, securing it. The gripping element and the shoulder thus form a form-fitting connection and prevent the connecting element from moving out of the second pressure pipe. [00017] Preferably, the gripping element is designed as a locking element. This can form a locking connection that prevents relative movement. [00018] Preferably, the first end section, the connecting element, and the second end section are arranged coaxially. [00019] The shoulder can have an undercut on the side facing away from the end of the second pressure pipe, into which the snap element engages. This provides a good means for a secure connection. [00020] Preferably, the shoulder has a guide surface inclined in the axial direction on the side facing the end of the second pressure pipe, to guide the snap element around the shoulder. [00021] Preferably, the shoulder is integrally connected with the second pressure pipe. More preferably, the shoulder is formed from a jacket of the second pressure pipe. [00022] Preferably, the snap element is arranged resiliently on the connecting element. This achieves a snap connection that can connect the connecting element to the second pressure pipe with minimal effort in a single step. [00023] The compressor housing is preferably hermetically sealed. [00024] Preferably, the first pressure pipe is made of plastic and/or the second pressure pipe is made of metal. This combination is particularly advantageous as it reduces noise transmission from the compressor. It can also be provided that both pressure pipes are made of plastic or metal, or that the first pressure pipe is made of metal and/or the second pressure pipe is made of plastic. [00025] Preferably, the first pressure pipe connects the compression unit with the second pressure pipe. The first pressure pipe is preferably arranged mostly within the compressor housing, with its first end section potentially protruding from the compressor housing. [00026] It can be provided that the first pressure pipe and/or the second pressure pipe extend through the housing opening. For example, the end sections can extend through the housing opening. [00027] It may be provided that the first end section is arranged in the connecting section. Preferably, the first end section of the first pressure pipe is sealingly sheathed by the connecting element. It is also advantageous if the second end section of the second pressure pipe sealingly sheaths the connecting section. Preferably, the connecting element is connected to the first pressure pipe by bonding and/or overmolding. It may also be provided that the connecting element is integral with the first pressure pipe, for example by welding. [00028] Preferably, a flow cross-section of the connecting element adjoining the first pressure pipe is larger or equal to a flow cross-section of the first pressure pipe. This prevents the connecting element from obstructing the flow of coolant. It is advantageous if the end portion of the second end section of the second pressure pipe extends at least partially radially outward or inward and at least partially forms the shoulder. The end portion is the area of the second pressure pipe that has the end face. [00029] This can be easily machined to bend radially outward or inward. This can also directly achieve that the shoulder has an undercut in longitudinal section, for example, by a hook shape. This can also be advantageous regardless of the manufacturing method because it achieves a particularly strong, form-fitting connection with the snap element. If the end extends radially outward, the snap element is arranged outside the second pressure pipe in the assembled state; if it extends radially inward, the snap element is arranged inside the second pressure pipe in the assembled state. [00030] Furthermore, it may be provided that the fixing portion has an elasticity modulus that is lower than the elasticity modulus of the shoulder and that the fixing portion preferably has an elasticity modulus of maximum 20,000 N/mm², particularly preferably maximum 15,000 N/mm². Preferably, the connecting element is made of plastic or rubber. This allows for a stable second pressure pipe to be achieved while still easily establishing a connection with the connecting element by the latter elastically bending. [00031] It is preferably provided that the fixing portion has an elasticity modulus that is lower than the elasticity modulus of the second pressure pipe. This is particularly advantageous when the shoulder and the remaining second pressure pipe are substantially made of the same material. It is particularly advantageous if the shoulder has a first radial distance and the gripping element has a second radial distance, and the first radial distance is greater than the second radial distance. This allows the gripping element to encircle the shoulder from the outside. [00032] Preferably, the connecting element has a maximum cross-section that is larger than the cross-section of the housing opening. The maximum cross-section is the cross-section of the connecting element with the largest circumference. For example, in the case of a radially symmetrical embodiment, the connecting element may have a maximum diameter that is larger than the diameter of the housing opening. This limits the movement of the pressure path through the housing opening. It may be provided that at least two snap elements are provided and that these snap elements are evenly arranged around the circumference of the fixing section. If two snap elements are provided, it may be provided, for example, that the snap elements are arranged opposite each other in cross-section. [00033] In a preferred embodiment, it is provided that the snap element extends around the entire circumference of the fixing section and/or that the shoulder extends around the entire circumference of the second pressure pipe. Particularly advantageous is the combination of both features, as it achieves a particularly stable connection. It is particularly advantageous if it is provided that the pressure path is guided through a housing opening through the compressor housing and that preferably the connecting element is arranged at the level of the housing opening. [00034] By guiding through the housing opening, a hermetic seal of the compressor housing can be easily achieved by sealing the housing opening. The arrangement of the connecting element at the level of the housing opening is particularly advantageous because the first pressure pipe can be arranged essentially inside and the second pressure pipe can be arranged essentially outside the distributor housing. This facilitates assembly, especially if the second pressure pipe is less elastic than the first pressure pipe and therefore difficult to position in the tight distributor housing. At the same time, however, the first pressure pipe is protected by the housing. By "at the level of the housing opening" it is meant that the connecting element extends along the pressure path at the level of the housing opening. [00035] Preferably, the connecting element extends through the housing opening. It is particularly advantageous if the second pressure pipe has a pressure pipe sleeve arranged on the compressor housing in the area of the housing opening, and that an inner tube of the second pressure pipe is guided through the pressure pipe sleeve. Such a pressure pipe sleeve can support the guidance of the pressure path, especially the inner tube of the second pressure pipe, and improve the connection to the compressor housing. It may be provided that the pressure pipe sleeve is hermetically and/or integrally connected to the inner tube and/or the first pressure pipe, and/or that the pressure pipe sleeve is hermetically and/or integrally connected to the compressor housing. It is particularly advantageous if the inner tube outside the compressor housing has at least one additional shoulder pointing radially outward, which limits the movement of the inner tube into the compressor housing and is preferably welded to the pressure pipe sleeve. Preferably, the shoulder abuts against the pressure pipe sleeve and/or the compressor housing in the axial direction. This ensures that the movement of the second pressure pipe in the axial direction into the compressor housing is prevented. Because the additional shoulder limits the movement of the second pressure pipe in the axial direction into the compressor housing. It may also be provided that the additional shoulder prevents or limits the movement of the second pressure pipe in the axial direction out of the compressor housing. This can be achieved, for example, by connecting the additional shoulder to the pressure pipe sleeve and/or the compressor housing, for example by welding. It is advantageous if the connecting section is connected to the inner tube via a snap connection. It may also be provided that the connecting section is connected to the pressure pipe sleeve via a snap connection. Furthermore, it may be provided that the connecting element has at least one sealing element that establishes a tight connection between the connecting element and the second pressure pipe, and that the sealing element is preferably an O-ring, which is placed in a groove in the second pressure pipe located in a groove of the connecting element facing radially outward. This ensures a good seal between the connecting element and the second pressure pipe. Subsequently, the invention will be described with reference to non-limiting embodiments according to the invention in the figures. They show: [00036] Fig. 1 is a plan view of a first embodiment of a refrigerant compressor according to the invention; [00037] Fig. 2 is a detail of a longitudinal section along line A-A of Fig. 1; [00038] Fig. 3 is a detail of a longitudinal section of a second embodiment according to the invention; [00039] Fig. 4 is a detail of a longitudinal section of a third embodiment according to the invention. [00040] In Fig. 1, a first embodiment according to the invention is shown, with the upper part of the compressor housing 3 not being shown for a better view. It is clearly visible that in the compressor housing 3, a compression unit 10 is arranged, which compresses refrigerant and directs it into a first pressure pipe 5. The first pressure pipe 5 is part of a pressure path and guides the refrigerant towards the compressor housing 3, where it exits the compressor housing 3 through a connecting element 4 into a second pressure pipe 2 and through a housing opening 7. The second pressure pipe 2 directs the refrigerant to a condenser, not shown. [00041] In Fig. 2, the area of connection between the pressure pipes 5, 2 is better visible. The first end section 5a of the first pressure pipe 5, which is the end of the first pressure pipe 5 facing the second pressure pipe 2, is arranged in a sleeve-shaped connecting section 4a. For this purpose, the connecting section 4a has a recess with an inner diameter i matched to the outer diameter of the first pressure pipe 5, into which the first pressure pipe 5 is inserted. The connecting section 4a has, upstream of the first end section 5a, a termination piece with a reduced inner diameter, defining a flow cross-section v adjoining the first pressure pipe 5, which is as large as a flow cross- section of the first pressure pipe 5. In the area of the termination piece, a groove 4c is provided on the outer circumference of the connecting section 4a, in which a sealing element 4d in the form of an O-ring is arranged. [00042] The connecting section 4a is arranged in a second end section 2a of the second pressure pipe 2 and seals with it via the sealing element 4d. [00043] The connecting section 4a is positioned at the level of the housing opening 7 and is inserted into the housing opening 7. The end sections 5a, 2a of the first and second pressure pipes 5, 2 also pass through the housing opening 7. [00044] At the end of the second end section 2a, the jacket of the second pressure pipe 2 is bent outward axially, creating a shoulder 6 that faces radially outward. The shoulder 6 is bent towards the compressor housing 3 at its radially outer end, forming an undercut and a beveled guiding surface on the side facing the first pressure pipe 5. This allows for a particularly secure fixing of the connecting element 4. [00045] The gripping element 8 is designed as a snap element 11. It has locking hooks that engage into the shoulder. This is advantageous in other embodiments as well. [00046] The connecting element 4 has a fixing section 4b, which has a gripping element 8 extending around the entire circumference. The gripping element 8 extends axially outside the shoulder 6 around the shoulder 6, engages behind it, and snaps into it. Thus, a form-fitting connection is established, in which axial movement of the connecting element 4 away from the second pressure pipe 2 is no longer possible. [00047] On the outer side of the housing opening 7, a pressure pipe sleeve 1 of the second pressure pipe 2 is connected to the compressor housing 3, which extends axially away from the housing opening 7 and in which an inner tube 2b of the second pressure pipe 2 and a portion of the connecting element 4 and the first pressure pipe 5 are arranged. The inner tube 2b has another shoulder 9 directly outside the pressure pipe sleeve 1 in the axial direction, which abuts against the pressure pipe sleeve 1 and is welded to it. It limits the movement of the inner tube 2b into the pressure pipe sleeve 1. [00048] The shoulder 6 has a first radial distance a, which in this case represents the circumference of the shoulder 6. It is smaller than a second radial distance b of the gripping element 8, which surrounds the shoulder 6 from the outside. [00049] Fig. 3 shows a second embodiment according to the invention, which is very similar to the first one. Therefore, only the most essential differences will be discussed here, equivalent components have the same reference numerals. [00050] The second embodiment has a shoulder 6 that is not on the outer side but on the inner side of the second pressure pipe 2 - in this embodiment, on the inside of the inner tube 2b. The snap element 11, again designed as a gripping element 8, faces radially outward and thus engages into the shoulder 6. The inner tube 2b has an enlarged cross- section at the second end section 2a to make room for the gripping elements 8. [00051] In the illustrated embodiment, no pressure pipe sleeve is provided. However, this embodiment is also possible with a pressure pipe sleeve. [00052] Fig. 4 shows a third embodiment according to the invention, which is very similar to the first and second ones. Therefore, only the most essential differences will be discussed here, equivalent components have the same reference numerals. [00053] Like the second one, the third embodiment has the shoulder 6 on the inner side of the second pressure pipe 2. However, it is not arranged on the inner tube 2b but on the pressure pipe sleeve 1. For this purpose, the pressure pipe sleeve 1 is guided through the housing opening 7 and protrudes into the compressor housing 3. The pressure pipe sleeve 1 has a recess 12 through which the shoulder 6 is formed. At the second end section 2a, the pressure pipe sleeve 1 also protrudes beyond the inner tube 2b, providing space for the gripping elements 8.

Claims

CLAIMS 1. Refrigerant compressor comprising a compressor housing (3) in which a refrigerant compressing compression unit is arranged, wherein the compression unit is connected to a pressure path for guiding refrigerant through the compressor housing (3), and the pressure path comprises a first pressure pipe (5) and a second pressure pipe (2) that are flow-connected to each other via a connecting element (4), wherein the connecting element (4) is arranged on a first end section (5a) of the first pressure pipe (5) and has a sleeve-shaped connecting section (4a) arranged in a second end section (2a) of the second pressure pipe (2), characterized in that the connecting section (4a) is connected to the second pressure pipe (2) via a snap connection. 2. Refrigerant compressor, according to claim 1, characterized in that the connecting section (4a) comprises at least one snap element (11) which engages in at least one radial shoulder (6) of the second end section (2a). 3. Refrigerant compressor, according to claim 1 or 2, characterized in that the second pressure pipe (2), in the area of the second end section (2a), preferably on its outer side, has at least one, preferably radially outward-facing shoulder (6), and that the connecting element (4) has at least one fixing section (4b) arranged outside the second pressure pipe (2) and comprising at least one gripping element (8) which engages behind and into the shoulder (6). 4. Refrigerant compressor, according to any one of claims 2 or 3, characterized in that the shoulder (6) has an undercut on its side facing away from the end of the second pressure pipe (2), in which the snap element (11) engages. 5. Refrigerant compressor, according to any one of claims 2 to 4, characterized in that the end portion of the second end section (2a) of the second pressure pipe (2) extends at least partially radially outward or inward and forms at least partially the shoulder (6). 6. Refrigerant compressor, according to any one of claims 1 to 5, characterized in that the fixing section (4b) has a modulus of elasticity that is lower than the modulus of elasticity of the shoulder (6), and that the fixing section (4b) preferably has a modulus of elasticity of maximum 20,000 N/mm², particularly preferably maximum 15,000 N/mm². 7. Refrigerant compressor, according to any one of claims 2 to 6, characterized in that the shoulder (6) has a first radial distance (a) and the snap element (11) has a second radial distance (b), and the first radial distance (a) is greater than the second radial distance (b). 8. Refrigerant compressor, according to any one of claims 2 to 7, characterized in that at least two snap elements (11) are provided and that these snap elements (11) are arranged uniformly around the circumference of the fixing section (4b). 9. Refrigerant compressor, according to any one of claims 2 to 7, characterized in that the snap element (11) extends around the entire circumference of the fixing section (4b) and/or that the shoulder (6) extends around the entire circumference of the second pressure pipe (2). 10. Refrigerant compressor, according to any one of claims 1 to 9, characterized in that the pressure path is guided through a housing opening (7) in the compressor housing (3), and that preferably the connecting element (4) is arranged at the level of the housing opening (7). 11. Refrigerant compressor, according to claim 10, characterized in that the second pressure pipe (2) has a pressure pipe sleeve (1) which is arranged on the compressor housing (3) in the area of the housing opening (7), and that an inner tube (2b) of the second pressure pipe (2) is guided through the pressure pipe sleeve (1). 12. Refrigerant compressor, according to claim 11, characterized in that the inner tube (2b) outside the compressor housing (3) has at least one further shoulder (9) pointing radially outward, which limits the movement of the inner tube (2b) into the compressor housing (3) and is preferably welded to the pressure pipe sleeve (1). 13. Refrigerant compressor, according to claim 11 or 12, characterized in that the connecting section (4a) is connected to the inner tube (2b) via a snap connection. 14. Refrigerant compressor, according to any one of claims 11 to 13, characterized in that the connecting section (4a) is connected to the pressure pipe sleeve (1) via a snap connection. 15. Refrigerant compressor, according to any one of claims 1 to 12, characterized in that the connecting element (4) comprises at least one sealing element (4d) that establishes a tight connection between the connecting element (4) and the second pressure pipe (2), and that the sealing element (4d) is preferably an O-ring arranged in a groove (4c) of the connecting element (4) facing towards the second pressure pipe (2).