Spiral compressor for refrigerant-oil mixtures with oil recirculation

Abstract

Spiral compressor (1) for refrigerant-oil mixtures with oil return, comprising a housing element (2) and a fixed spiral (3), wherein the housing element (2) is connected to the fixed spiral (3) by means of a seal (4) such that an outlet chamber (6) is formed between the housing element (2) and the fixed spiral (3), wherein for oil separation and oil return an oil separator chamber (9) with a refrigerant high-pressure outlet (10) and an oil collection area (13) as well as an oil return channel (12) to a suction pressure chamber (15) are arranged after the outlet chamber (6), characterized in that in the geodetically lower area of ​​the outlet chamber (6) an outlet chamber drain (11) for oil into the oil return channel (12) of the oil separator chamber (9) is formed and that the outlet chamber drain (11) is directly connected to the oil return channel (12) of the oil separator chamber (9).

Description

[0001] The invention relates to a spiral compressor for compression refrigeration systems in which refrigerant-oil mixtures are compressed. After compression, the refrigerant oil is separated and, in a short circuit, supplied to the areas of the mechanically acting compressor elements requiring lubrication for efficient lubrication of the compressor.

[0002] Refrigerant compressors of this type have an outlet chamber downstream of the compressor chamber, into which the refrigerant-oil mixture is introduced at high pressure. The outlet chamber has only one outlet for the compressed mixture containing the refrigerant-oil, which leads directly to the oil separator. In the oil separator, the oil is separated and, via an oil return channel, is routed through at least one pressure reducing element to the suction side in front of the compressor unit. The outlet chamber itself does not have any special design elements that function as an oil separator, as a specially designed oil separator is located downstream. Accordingly, there is no oil return path or similar feature. The outlet chamber is preferably designed as a cavity with the largest possible volume, since a large volume dampens the discharge pressure pulsation and thus improves NVH (Noise, Vibration, Harshness) performance.

[0003] A known problem with state-of-the-art scroll compressors is that the discharge chamber in the rear casing, downstream of the compressor unit, is not designed as an oil separator. This is because a large-volume chamber is typically placed at this location to dampen discharge pressure pulsations. Due to the large volume of this chamber compared to the outlet of the fixed scroll, the flow velocity is significantly reduced. Particularly at low mass flow rates, this reduction in flow velocity in the discharge chamber unintentionally acts as an oil separator due to the different inertias of oil and refrigerant. Consequently, the oil separated in the discharge chamber is no longer available to the compressor at low mass flow rates.Only during operation with high mass flows, for example at high speeds, can this oil be transported back from the outlet chamber and made available to the compressor.

[0004] From the prior art, JPA 2019-056322 discloses a refrigerant compressor with two oil separators arranged in series and two separate oil return channels to overcome the aforementioned disadvantage of scroll compressors. Design elements for oil separation are integrated directly into the discharge chamber to create an upstream additional oil separator. Furthermore, the oil separated in the first upstream oil separator is routed directly to the compressor unit via a dedicated oil return channel with its own nozzle element. This oil return channel is in addition to the conventional oil return channel, which is fed by the oil separated in the oil separator according to the prior art. The oil return channels lead to separately positioned inlets into the intake chamber and the compressor chamber of the scroll compressor.

[0005] The object of the invention is to improve the oil return in the compressor in order to ensure stable and reliable lubrication of the compressor in operating conditions with lower mass flow.

[0006] The problem is solved by an object having the features according to claim 1. Further developments are specified in the dependent claims.

[0007] The object of the invention is achieved in particular by a scroll compressor for refrigerant-oil mixtures with oil recirculation, which, in addition to other conventional components of a scroll compressor, comprises a housing element and a fixed spiral attached thereto. The housing element is connected to the fixed spiral in such a way that an outlet chamber for the compressed refrigerant-oil mixture is formed between the housing element and the fixed spiral downstream of the compressor chamber, or that the outlet chamber is bounded by the housing element and the fixed spiral. A seal is arranged between the housing element and the fixed spiral to seal the outlet chamber. An oil separator chamber is provided for oil separation and oil recirculation downstream of the outlet chamber; this separator chamber, in turn, has a high-pressure refrigerant outlet and an oil collection area.In the lower part of the oil collection area, an oil return channel leads to the suction pressure chamber of the scroll compressor. The pressure difference is equalized via a nozzle element or similar device. The scroll compressor is characterized by the fact that an outlet chamber drain for oil into the oil return channel of the oil separator chamber is formed in the geodetically lower part of the outlet chamber. During operating conditions with low mass flow rates, the oil separated in the outlet chamber flows directly and via the shortest route into the oil return channel and subsequently into the suction pressure chamber to lubricate the moving parts of the scroll compressor.

[0008] Preferably, an outlet chamber valve is integrated into the outlet chamber of the scroll compressor and is arranged and designed such that a compressor outlet located in the fixed spiral is controllable towards the outlet chamber. The outlet chamber valve thus regulates the refrigerant-oil mass flow that enters the outlet chamber from the compressor outlet.

[0009] A particularly advantageous feature is the design of an outlet chamber channel in the geodetically upper region of the outlet chamber, connecting the refrigerant-oil mixture to the oil separation chamber. Thus, after the compression process and flowing through the outlet chamber, the refrigerant-oil mixture enters the oil separation chamber via the outlet chamber channel, where targeted oil separation from the mixture then takes place.

[0010] Advantageously, both the oil separation chamber and the oil return channel are integrated into the housing element, so that no additional components are required.

[0011] An advantageous embodiment of the invention consists in the oil return channel being formed at least partially through the fixed spiral towards the suction pressure chamber. In such an embodiment, the transition of the oil return channel from the housing element to the fixed spiral is fluid-tight by means of a seal.

[0012] The outlet chamber drain is particularly preferred as a channel also formed in the housing element.

[0013] The inventive concept is further developed by designing the channel as a bore in the housing element. From a manufacturing perspective, this is a very simple and cost-effective method for creating the channel.

[0014] Another advantageous embodiment of the channel consists of designing it as a stepped bore in the housing element, with a nozzle-like constriction formed before the connection to the oil return channel. This nozzle-like constriction allows for particularly precise regulation of the fluid flow passing through the channel into the oil return channel.

[0015] A separate nozzle element is particularly advantageously arranged in the channel, and this element is preferably designed to be replaceable. This allows, for example, the nozzle element to be adapted to different rheological properties of the refrigerant oil when changing it.

[0016] As an alternative to the design of a channel according to the aforementioned descriptions, the outlet chamber drain is designed as a groove in the sealing surface of the housing element.

[0017] Alternatively, the outlet chamber drain is designed as a groove in the sealing surface of the fixed spiral.

[0018] Alternatively, the outlet chamber drain is designed as a seal with a cutout, so that the outlet chamber drain is formed by a recess in the seal.

[0019] Another advantageous alternative for the design of the outlet chamber drain is that it is designed as a channel in the sealing surface of the housing element.

[0020] The aforementioned design is further improved by forming the channel in the sealing surface of the housing element as a labyrinth or meander.

[0021] The outlet chamber drain preferably has a circular flow cross-section with a diameter of 1.2 mm at its narrowest point when designed as a bore or circular channel. If the diameter of the outlet chamber drain is too large, a significant increase in back pressure occurs, which is necessary to press the orbiting spiral against it.

[0022] This corresponds to a flow cross-section of approximately 1.131 mm². 2 of the outlet chamber flow at the narrowest point, for example the nozzle opening.

[0023] The concept of the invention consists of creating not a second oil return channel, but a second access point to the existing oil return channel in order to discharge the quantities of oil that are unintentionally separated from the outlet chamber depending on the operating point. This second access point is located downstream of the standard oil separator, but upstream of the nozzle element of the oil return channel, and is therefore at approximately the same pressure level as the oil separated in the oil separation chamber, in order to return the quantity of oil unintentionally separated in the outlet chamber, depending on the mass flow rate, to the compressor.The shape and cross-section of the further outlet, the discharge chamber outlet, must be designed so that, on the one hand, the oil can be drained from the discharge chamber, and on the other hand, at operating points with no or only a small amount of separated oil, the efficiency of the compressor must not be reduced and the possibly existing back pressure system for pressing the movable spiral must not be changed.

[0024] Accordingly, the outlet from this chamber should be located near the bottom. In particular, the access to the standard oil return channel must be positioned so that, at operating points with little separated oil in the chamber, no refrigerant is mixed into the oil return, as this leads, among other things, to a reduction in the viscosity of the oil-refrigerant mixture and thus to an increase in back pressure.

[0025] The refrigerant-oil mixture reaches the outlet chamber in the rear housing after the compressor outlet of the fixed coil. After the outlet chamber, the refrigerant-oil mixture enters the oil separator. From there, the oil-poor portion of the refrigerant-oil mixture leaves the compressor via the high-pressure refrigerant outlet. The separated oil is transported to the suction side via the oil return channel.

[0026] The invention solves the problem in a particularly simple and easily implemented manner with minimal design effort. The unintentionally separated oil is removed from the outlet chamber via the second outlet, the outlet chamber drain, to the oil return channel. This improved oil management leads, among other things, to a reduction in the amount of oil required for the air conditioning system and thus to improved system performance. This concept also results in improved pulsation characteristics under low-flow operating conditions. A particularly advantageous aspect is that there are no negative effects on efficiency or on any back pressure that may be present when pressing the orbiting spiral of the electric compressor.

[0027] A particular advantage of the invention is that, due to the reduced amount of unintentionally separated oil, the pulsation characteristics are improved under operating conditions with low mass flows or flow rates.

[0028] To integrate the mass flow unintentionally separated in the outlet chamber into the lubrication circuit, the separated oil is returned to the compressor via an additional inlet to the existing oil return line. The shape and cross-section of this connection are advantageously designed so that the unintentionally collected oil from the outlet chamber drains into the designated oil return path without altering the efficiency and backpressure characteristics.

[0029] Further details, features, and advantages of embodiments of the invention will become apparent from the following description of exemplary embodiments with reference to the accompanying drawings. These show: Fig. 1A: Spiral compressor in partial view, longitudinal section Fig. 1B: Housing element and fixed spiral detail longitudinal section Fig. 2A: Housing element axial view Fig. 2B: Housing element section AA Fig. 2C: Nozzle element detail B integrated design Fig. 2D: Nozzle element detail B formed separately Fig. 2E: Nozzle element detail B designed as a stepped bore Fig. 2F: Housing element with seal cross-section Fig. 3A: Fixed spiral and housing element, axial view Fig. 3B: Housing element section BB Fig. 3C: Housing element detail C Fig. 3D: Housing element section DD gap sector Fig. 3E: Housing element section DD gap length Fig. 3F: Housing element detail C Fig. 3G: Housing element seal gap sector Fig. 4A: Housing element detail C Channel in seal Fig. 4B: Housing element section FF Fig. 4C: Housing element with seal, perspective view Fig. 4D: Seal with gap Fig. 4E: Seal with groove Fig. 4F: Seal with groove enlargement Fig. 5A: Housing element cross-section with channel Fig. 5B: Housing element section GG Fig. 5C: Housing element cross-section with meandering channel.

[0030] In Fig. Figure 1 shows a scroll compressor 1, partially and in longitudinal section. The scroll compressor 1 is shown with the components housing element 2 and fixed scroll 3, which are connected to each other. Between the housing element 2 and the fixed scroll 3, sections of the overlapping surfaces are sealed fluid-tight by a gasket 4. A compressor outlet 5 is formed as a passage in the fixed scroll 3, through which the compressed refrigerant-oil mixture flows at high pressure into the outlet chamber 6 formed between the fixed scroll 3 and the housing element 2. The outlet chamber 6, as a cavity, is formed within the housing element 2 and is bounded on one side by the rear side of the fixed scroll 3. The outlet chamber 6 has an outlet channel 8 in its upper region, which opens into the oil separator chamber 9.The oil separator chamber 9 has a refrigerant high-pressure outlet 10 in its upper section and an oil collection chamber 13 in its lower section, optionally with an integrated particle filter. This filter is positioned such that the channel from the outlet chamber 6 is still upstream of the filter, meaning that the oil must pass through the filter before entering the oil return channel 12. The oil return channel 12 extends from the oil collection chamber 13 to the fixed spiral 3, where it passes through the spiral and finally terminates in the suction pressure chamber 15 or the back pressure chamber 14 with corresponding throttling elements. In the embodiment described above, the scroll compressor 1 conforms to the state of the art. The mass flow of the refrigerant-oil mixture in the scroll compressor 1 is guided as follows.The refrigerant-oil mixture is conveyed from the mechanically driven compressor unit of the scroll compressor 1, via the compressor outlet 5 (also referred to as the main outlet) in the fixed spiral 3, into the high-pressure area of ​​the rear housing, the outlet chamber 6. Due to the increasing cross-sectional area flowing through the compressor outlet 5 into the outlet chamber 6, any oil entering the outlet chamber 6 along with the refrigerant-oil mixture is separated from the refrigerant and not carried further. This occurs, for example, depending on the operating conditions at lower speeds of the scroll compressor 1. The separation of a portion of the oil from the refrigerant-oil mixture at this point is not intended, and the oil undesirably separated in the outlet chamber 6 is only reabsorbed and carried away by the refrigerant mass flow under operating conditions with higher volume flows.However, the amount of oil currently circulating depends on the operating conditions of the scroll compressor 1. The refrigerant-oil mixture leaves the outlet chamber 6 and flows into the oil separator chamber 9, which is designed as a cyclone separator. In the oil separator chamber 9, the refrigerant and oil are separated due to their density differences. The refrigerant then exits the scroll compressor 1 via the high-pressure refrigerant outlet 10. The oil separated in the oil separator chamber 9 collects in the oil collection area 13 and is transported via the oil return channel 12 into the suction pressure chamber 15 and the back pressure chamber 14. Depending on the design of the scroll compressor 1, the back pressure for pressing the orbiting scroll in the back pressure chamber 14 is also set via the oil return channel 12, as shown in [reference missing]. Fig. 1 indicated.

[0031] The present invention is characterized by the fact that a second outlet to the oil return channel 12 is provided in the housing element 2. This is shown in the exemplary embodiment according to Fig. Figure 1A is highlighted. This second outlet is designed as an outlet chamber drain 11 and connects the outlet chamber 6, and in particular the geodetically lower region of the outlet chamber 6, with the oil return channel 12. As previously described, the refrigerant-oil mixture is conveyed from the compressor unit via the compressor outlet 5 of the fixed spiral 3 into the high-pressure region of the housing element 2, the outlet chamber 6. Due to the increase in the cross-sectional area through which the mixture flows, a portion of the oil in the refrigerant-oil mixture is not carried further, depending on the operating conditions. This undesirable side effect occurs at lower speeds of the spiral compressor 1. Accordingly, the amount of oil in the outlet chamber 6 depends on the operating conditions.The oil return is achieved by directing the mass flow of the refrigerant-oil mixture from the outlet chamber 6 to the oil separator chamber 9, where the refrigerant and oil are separated. The refrigerant, now free of oil and containing a small amount of oil, exits the scroll compressor 1 via the high-pressure refrigerant outlet 10. The oil, selectively separated from the oil separator chamber 9, is collected in the oil collection area 13 formed in the housing and transported to the suction side of the scroll compressor 1 via the oil return channel 12. Depending on the compressor design, this channel also serves to adjust the back pressure for pressing the orbiting spiral. Crucially important for improving the oil circulation is the additional inflow to the oil return from the outlet chamber 6 through the outlet chamber drain 11, as provided according to the invention.A small volume flow, mainly containing oil, exits the outlet chamber 6 at the bottom of the outlet chamber 6 through the outlet chamber drain 11. This oil volume flow contains only a small amount of dissolved refrigerant and is added to the oil volume flow in the oil return channel 12. This occurs depending on the operating conditions and is shown schematically with arrows in the lower part of the housing element 2.

[0032] In Fig. Figure 1B shows a highly schematic representation of the housing element 2 and the fixed spiral 3 it contains as essential components of the spiral compressor 1. The channels for receiving and guiding the refrigerant-oil mixture are shown enlarged. The compressor outlet 5 in the fixed spiral 3 opens into the outlet chamber 6, the walls of which are formed on one side by the housing element 2 and on the other side by the fixed spiral 3. A seal 4 is arranged between the fixed spiral 3 and the housing element 2 to seal the outlet chamber 6. The outlet chamber 6 transitions in its upper region into an outlet chamber channel 8, which opens into the oil separator chamber 9. This chamber has the refrigerant high-pressure outlet 10 in its upper region and the oil collection area 13 in its lower region. The oil return channel 12 begins in the oil collection area 13, into which the outlet chamber drain 11 from the outlet chamber 6 opens. Thus, oil that has already been unintentionally separated in the outlet chamber 6 under certain operating conditions can flow directly into the oil return channel 12 via the outlet chamber drain 11 and remain in the oil circuit under all operating conditions. This is particularly true even when only small flow rates are being delivered at relatively low engine speeds. The oil return channel 12 initially runs within the housing element 2 to the fixed spiral 3 and continues within it, with a seal 4 positioned accordingly in this area to seal the transition from the housing element 2 to the fixed spiral 3. In the illustrated embodiment, the outlet chamber valve 7 is arranged in the outlet chamber 6, which regulates the mass flow of the refrigerant-oil mixture from the compressor outlet 5.

[0033] In the Fig. 2A, B, Fig. C, Fig. D, E and F shows a housing element 2 in which an outlet chamber drain is designed as a channel 17. Fig. Figure 2A shows the housing element 2 in cross-section in axial view with a marked section AA, which is in Fig. 2B is shown. Detail B from Fig. 2B is in Fig. Figure 2C is shown enlarged. According to this embodiment of the invention, a nozzle geometry of the channel 17 is incorporated into the material of the housing element 2. A different hatching pattern is used to visualize the nozzle element, which itself is part of the base material. The variable nozzle thickness t corresponds to the flow length of the nozzle. The nozzle position can be arranged along the bore axis in the region of the bore depth h of the channel 17. The nozzle diameter d N and the bore diameter d B are still schematically in Fig. Designated 2C. The arrangement of the nozzle as well as the diameters of channel 17 and the nozzle are variable depending on the refrigerant used, the oil and the operating conditions. It should be emphasized that a variable cross-section along the nozzle thickness t can also be designed. In Fig. 2D is a separate nozzle element 19 according to detail B based on Fig. 2B is shown. The separate nozzle element 19 has a diameter d N The nozzle can be designed to be reversibly interchangeable, and its external geometry and shape can differ from the one shown. Advantageously, a variable nozzle cross-section can be formed along the nozzle length IN, where IN can vary depending on the nozzle geometry and available material thickness. The nozzle length IN extends over the entire thin nozzle diameter d. N of the nozzle element 19. A variable bore diameter for the nozzle inlet dB and the nozzle outlet d TB are in Fig. 2D also shown. The position t N The position of the nozzle element 19 along the bore depth h is variable. The nozzle element 19 can be fixed in the bore using various fastening methods, such as positive locking, material locking, or force locking. Depending on the design of the positive locking, material locking, or force locking connection, the position of the nozzle element 19 above the height h, the bore depth, can be predetermined. In Fig. 2E is a directly manufactured bore designed as channel 17. The bore diameters d B and the nozzle outlet d TB The drilling depth t can vary accordingly. B and t TB can be adjusted depending on the available space. A variable ratio between t TB and t B and d TBThese are possible so that, for example, the flow resistance or the mass flow rate can be adjusted. A general requirement is that d B larger than d TB and preferably d B much larger than d TB are designed. Channel 17 is therefore initially designed as a stepped bore with a bore diameter d B over the length of the drilling depth t B and subsequently with the diameter of the nozzle outlet d TB over the length t TB designed. The bore, designated as channel 17, can alternatively also be drilled without cross-sectional narrowing, using the diameter of the nozzle outlet d. tb be executed. Over the entire length tB and t tb Then there is a constant bore diameter d B before. Fig. Figure 2F shows a position range for the aforementioned configuration. The housing element 2 and a section of the sealing surface 20 from the sealing area 24 between the fixed spiral 3 and the housing 2 are shown. All versions or variants can be positioned on the marked sealing surface 20. A fully filled area is also shown, within which the individual channels 17 are located. If necessary, material accumulations can be added if the available material thickness is insufficient. This additional material accumulation must allow a connection to the high-pressure channel. All versions of the in the Fig. 2A to Fig. The variants shown in 2E can be executed perpendicular, parallel or inclined relative to the plane shown in sketch 2F.

[0034] The Fig. Figures 3A to G show embodiments of the invention in which the sealing surface in the housing element 2 or in the fixed spiral 3 is interrupted, partially removed, for example by cutting or milling. The seals 4 shown in the figures are, for example, designed as O-rings, molded rubber seals, and coated or uncoated metal seals. The Fig. 3A to Fig. 3D shows grooves in the sealing surface of the outer housing, of housing element 2. In Fig. Figure 3A shows the fixed spiral 3 and the housing element 2 in axial view. Fig. 3B shows the longitudinal section BB through the relevant region of the spiral compressor 1. In Fig. Detail C in 3C is now shown enlarged, and the groove depth t G as well as the seal 4 and the cutting line DD shown. Fig. Finally, 3D shows section DD, where housing element 2 is cut away and oil return channel 12 is shown. The groove 22 has a tangential groove length L. R , which is represented as a sector. The groove 22 in the housing element 2 connects the outlet chamber 6 and the oil return channel 12. The seal 4 does not extend across the width of the groove 22. The value of the groove depth t G and the tangential slot length I R or L R is variable, the aim being to prevent large particles from passing through the resulting cross-section of the groove 22. The groove depth t G and the tangential slot length I R or L Rdefine the required flow limitation characteristic. The position of the groove 22 can be freely selected within the entire sealing area 24 relative to the fixed spiral 3, as long as a connection to the oil return channel 12 is possible. The groove 22 can be produced by milling, as a pre-cast or forged feature, or by another method. The presentation is supplemented in Fig. 3E, which in another embodiment shows section DD. This embodiment is characterized in that a slot is provided in the housing sealing wall of the housing element 2 towards the fixed spiral 3. The groove depth t, not shown, G The groove 22 is variable and large compared to the design according to Fig. 3D. The variable tangential groove length I R is small compared to the design according to Fig. 3D. Both dimensions define the required flow limitation characteristic. The position of the slotted groove 22 can be freely selected within the entire sealing area 24 towards the fixed spiral 3, as long as a connection to the oil return channel 12 is maintained. The slot can be produced by milling, as a pre-cast or forged feature, or by another method. In Fig. Figure 3F shows detail C with the outlet chamber 6, the housing element 2, the fixed spiral 3, the seals 4, and the groove 22, wherein in this embodiment the groove 22 is incorporated into or formed within the fixed spiral 3. Section EE, which runs through the seal 4, is also shown. The line defining the outlet chamber 6 is at the same level as the sealing surface of the housing element 2. The groove depth t G and the tangential slot length IR or L R are variable. Both values ​​are selected to achieve the required flow-limiting characteristic. The position of the groove 22 can be freely chosen along the sealing line between housing element 2 and fixed spiral 3, as long as a connection to the oil return channel 12 can be achieved. The groove 22 can be produced by milling, as a pre-cast or forged feature, or by another method. The shape of the groove 22 can differ from the illustration shown without departing from the path of the inventive concept. Fig. 3G shows the section EE in the seal 4, where the groove length I R in the top view is formed in the fixed spiral 3. The Fig. 4A and Fig. Figure 4B shows a further embodiment with an adapted seal 4. In Fig. Figure 4A shows detail C with the fixed spiral 3, the housing element 2, and the outlet chamber 6 and oil return channel 12 formed between them. The crucial feature is the trimmed seal 4, which is trimmed between the outlet chamber 6 and the oil return channel 12 in such a way that oil from the outlet chamber 6 can enter the oil return channel 12 and the seal 4 does not act at the trimmed point but allows a targeted and controlled passage of oil through or around the seal 4. The section line FF is in Fig. Figure 4B shows a detailed, enlarged view. The cutout 23 in the seal 4 is depicted, with the cutout having a sealing depth tc. The variable sealing depth tc can also be achieved by modifying the tool. A variable cut length along the sealing element ensures that no large particles can pass through the resulting cross-section. Both values ​​are selected to achieve the required flow-limiting characteristic. The position is freely chosen along the entire sealing line between the housing and the fixed spiral, as long as a connection to the oil return channel 12 is maintained. In Fig. 4C shows the housing element 2 with the oil return channel 12 in perspective. The Fig. 4D and Fig. Figure 4E each shows a seal 4, which is partially permeable to oil. The seal 4 can be designed as a sealing ring, a molded rubber part, or a coated or uncoated metal corrugated seal. The depth and length of the permeable section of the seal are adjusted based on functional tests to achieve the required characteristics. The permeable section of the seal 4 can move freely along the sealing line as long as a connection to the oil return channel 12 and / or the outlet channel is possible. Fig. Figure 4D shows a fully slotted seal 4 with a cutout 23. The cutout 23 is designed as a slot across the entire seal 4. In Fig. 4E is an embodiment of the seal 4 shown, where the cutout 23 does not extend over the entire height of the sealing element, in contrast to Fig. 4D. An enlargement of the area of ​​the seal 4 with the cutout 23 is shown in Fig. 4F is shown. The seal 4 is only cut off over a partial height of the sealing element. In the Fig. 5A, Fig. 5B and Fig. 5C channels 17 are formed on the sealing area 24 of the housing element 2 for the removal of oil from the outlet chamber 6. In Fig. Figure 5A shows the housing element 2 in which the outlet chamber 6 is arranged. The channel 17 connects the outlet chamber 6 to the oil return channel 12. The channel 17 has a channel width bc. In Fig. 5B is the GG cut from Fig. 5A is shown, where in this illustration the channel depth tc is shown, which corresponds to the sealing cut depth in the corresponding preceding embodiment. A variable channel contour and / or channel width bc and channel depth tc are selected to adjust the flow characteristics. The length of channel 17 is adapted to the high-pressure chamber geometry. Channel 17 is manufactured, for example, during casting, forging, or machining processes of the housing element 2. Channel 17 is also designed as a laminar flow restrictor, for example, with a flat spiral shape or by means of a 3D spiral shape. In Fig. In Figure 5C, the channel 17 is shown as a meandering connection between the outlet chamber 6 and the oil return channel 12 in the housing element 2. This configuration of the channel 17 is also referred to as a labyrinth, which also implies a meandering shape for the channel 17. For the configurations of the channel 17 in the housing element 2 or as a labyrinth, an alternative embodiment is that the channel 17 can also be provided by a separate part, for example, a seal or spiral nozzle. The material required for creating the labyrinth channel, as shown in Figure 5C, is shown in Figure 5C. Fig. The labyrinth shown in Figure 5C must be provided within housing element 2. The labyrinth can be produced using prefabricated molds, forged molds, or by machining. All properties, in particular the ability to function as a laminar flow restrictor, also apply to this design. Reference symbol list 1 spiral compressor 2 Housing element 3 Fixed Spiral 4 Seal 5 Compressor outlet 6 Outlet chamber 7 Exhaust chamber valve 8 Outlet chamber channel 9 Oil separator chamber 10 Refrigerant high-pressure outlet 11 Outlet chamber drain 12 Oil return channel 13 Oil collection area 14 Counterpressure chamber 15 Suction pressure chamber 16 Compressor chamber Channel 17 18 Nozzle-like constriction 19 Nozzle element 20 sealing surface 22 Nut 23 Excerpt 24 Sealing area t nozzle thickness h Drilling depth d B Bore diameter d N Nozzle diameter IN nozzle length d TB Nozzle discharge t TB tB drilling depth t G Groove depth t N Nozzle element position tB length I R , L R Groove length tc sealing depth, channel depth b C Channel width

Claims

[1] Scroll compressor (1) for refrigerant-oil mixtures with oil return, comprising a housing element (2) and a fixed spiral (3), wherein the housing element (2) is connected to the fixed spiral (3) by means of a seal (4) such that an outlet chamber (6) is formed between the housing element (2) and the fixed spiral (3), wherein for oil separation and oil return after the outlet chamber (6) an oil separation chamber (9) with a refrigerant high-pressure outlet (10) and an oil collection area (13) as well as an oil return channel (12) to a suction pressure chamber (15) are arranged, characterized by that in the geodetically lower region of the outlet chamber (6) an outlet chamber outlet (11) for oil into the oil return channel (12) of the oil separation chamber (9) is formed. [2] Scroll compressor (1) according to claim 1, characterized bythat an outlet chamber valve (7) is arranged and designed in the outlet chamber (6) in such a way that a compressor outlet (5) arranged in the fixed spiral (3) can be controlled thereby. [3] Scroll compressor (1) according to claim 1 or 2, characterized by that in the geodetically upper region of the outlet chamber (6) an outlet chamber channel (8) is formed for connection to the oil separation chamber (9) for the refrigerant-oil mixture. [4] Scroll compressor (1) according to one of claims 1 to 3, characterized by that the oil separation chamber (9) and the oil return channel (12) are integrated into the housing element (2). [5] Scroll compressor (1) according to one of claims 1 to 4, characterized by that the oil return channel (12) is formed at least partially through the fixed spiral (3) towards the suction pressure chamber (15). [6] Scroll compressor (1) according to one of claims 1 to 5, characterized bythat the outlet chamber drain (11) is designed as a channel (17) in the housing element (2). [7] Scroll compressor (1) according to claim 6, characterized by that the channel (17) is designed as a bore in the housing element (2). [8] Scroll compressor (1) according to claim 6 or 7, characterized by that the channel (17) is designed as a stepped bore in the housing element (2), wherein a nozzle-like constriction (18) is formed before the connection to the oil return channel (12). [9] Scroll compressor (1) according to one of claims 6 to 8, characterized by that a separate nozzle element (19) is arranged in the channel (17). [10] Scroll compressor (1) according to one of claims 1 to 5, characterized by that the outlet chamber drain (11) is designed as a groove (22) in the sealing surface of the housing element (2). [11] Scroll compressor (1) according to one of claims 1 to 5, characterized bythat the outlet chamber drain (11) is designed as a groove (22) in the sealing surface of the fixed spiral (3). [12] Scroll compressor (1) according to one of claims 1 to 5, characterized by that the outlet chamber drain (11) is designed as a seal (4) with a cutout (23). [13] Scroll compressor (1) according to one of claims 1 to 5, characterized by that the outlet chamber drain (11) is designed as a channel (17) in the sealing surface of the housing element (2). [14] Scroll compressor (1) according to claim 13, characterized by that the channel (17) in the sealing surface of the housing element (2) is designed as a labyrinth or meander-shaped. [15] Scroll compressor (1) according to one of claims 1 to 14, characterized by that the outlet chamber drain (11) has a circular flow cross-section with a diameter of 1.2 mm at the narrowest point. [16] Scroll compressor (1) according to one of claims 1 to 14, characterized bythat the outlet chamber outlet (11) has a flow cross-section of 1.131 mm at its narrowest point 2 has.

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