Scroll compressor having an integrated heat exchanger

Abstract

The invention relates to an oil-free scroll compressor (2.1) for generating compressed air, comprising at least one stator scroll (6) that is fastened to a housing-mounted base plate (4), and an impeller scroll (10) that is arranged on a movable base plate (8), wherein the stator scroll (6) and the impeller scroll (10) axially inter-engagingly define pressure chambers (12), wherein the housing-mounted base plate (4) includes at least one cooling channel (22, 22') through which a cooling fluid can flow, wherein at least one outlet port (14) for letting compressed air flow therethrough is formed in the housing-mounted base plate (4), the outlet port (14) in the housing-mounted base plate (3) being fluidically connected to an adjacent high-pressure chamber (30, 86). In this scroll compressor, according to the invention, a side wall (38) and / or a bottom wall (34) of a lidded housing (32) that surrounds the high-pressure chamber (30), or a side wall (84) of a high-pressure chamber housing (83) connected to the housing-mounted base plate (4), is designed as a heat exchanger (56, 88) for the generated compressed air, said heat exchanger being coolable by means of a cooling fluid.

Description

[0001] SPIRAL COMPRESSOR WITH AN INTEGRATED HEAT EXCHANGER

[0002] The invention relates to an oil-free spiral compressor for generating compressed air, comprising at least one stator spiral attached to a housing-fixed base plate and a displacement spiral arranged on a movable base plate, wherein the stator spiral and the displacement spiral axially interlock and define pressure chambers, wherein the housing-fixed base plate has at least one cooling channel through which a cooling fluid can flow, wherein at least one outlet opening for the flow of compressed air is formed in the housing-fixed base plate, and wherein the outlet opening of the housing-fixed base plate is fluidically connected to an adjacent high-pressure chamber.

[0003] Spiral compressors, also known as scroll compressors, are primarily used in stationary and mobile refrigeration units, heat pumps, and internal combustion engines to increase boost pressure. Due to their relatively quiet, smooth, and oil-free operation, spiral compressors are also increasingly used in compressed air generation systems for electrically or hybrid-powered commercial vehicles. A spiral compressor has at least one housing-mounted spiral stator spiral and one movable spiral displacement spiral, which define several pressure chambers. While the stator spiral is attached to a housing-mounted base plate, the displacement spiral is connected to an orbital base plate, which can be rotatably driven by an eccentric pin on a drive shaft.

[0004] With a rotating drive shaft, i.e., driven by a motor, the movable base plate, together with the displacer spiral, performs a translational orbital motion to achieve high efficiency. It is deflected radially in accordance with the rotating displacement of the drive shaft's eccentric pin, but largely maintains its circumferential orientation, so that it does not pivot about its own hub axis. The two blades are designed and arranged such that the displacer spiral approaches the stator spiral to within a few tenths of a millimeter in some places, thus providing a relatively good seal for the pressure chambers, which, with a rotating drive shaft, are displaced circumferentially in the direction of rotation and radially from the outside inwards, reducing their volume.The translational orbital movement of the orbitable base plate is ensured by a guide device on the housing of the spiral compressor.

[0005] This document describes a scroll compressor with a housing-mounted base plate featuring at least one outlet opening, which is fluidically connected to an axially adjacent high-pressure chamber. The high-pressure chamber, to which at least one compressed gas consumer is connected, acts as a settling chamber. This chamber equalizes the pulsating compressed gas flow and pressure present at the outlet opening of the housing-mounted base plate. An optional check valve prevents backflow of compressed air from the high-pressure chamber into the pressure chambers of the scroll compressor if the air pressure in the high-pressure chamber is higher than in the pressure chamber adjacent to the outlet opening of the housing-mounted base plate.

[0006] From US Patent 6,695,598 B2, a scroll compressor is known whose housing-mounted base plate has an outlet opening which is connected via a check valve having a spring leaf body to an axially adjacent high-pressure chamber. The high-pressure chamber is bounded by the outer end wall of the housing-mounted base plate as well as by the bottom wall and the cylindrical side wall of a pot-shaped housing.

[0007] German patent DE 10 2019 204 866 A1 describes a scroll compressor for a vehicle air conditioning system, the housing-mounted base plate of which has an outlet opening that is connected in a similar manner to an axially adjacent high-pressure chamber via a check valve having a spring leaf body. In this scroll compressor, the high-pressure chamber is bounded by the outer end wall of the housing-mounted base plate, as well as by the bottom wall and a hollow cylindrical inner wall of a pot-shaped housing.

[0008] During extended operating phases and the generation of high gas pressures, comparatively high temperatures inevitably occur in a compressor, reducing its efficiency and potentially causing thermomechanical damage. This is particularly true when a scroll compressor forms the high-pressure stage of a two-stage compressor for compressed air generation, where the pressure in the pressure chamber adjacent to the outlet opening of the housing-mounted base plate exceeds 10 x 10 5 Pa can occur in conjunction with a correspondingly high temperature. It is therefore advantageous to arrange at least one cooling channel through which a coolant flows in the housing-mounted base plate and / or a separate heat exchanger for cooling purposes.

[0009] From US 7 942 655 B2, a spiral compressor is known in which a cooling channel for cooling the housing-fixed base plate is designed as an open annular groove and is formed in the axially inner end wall of a housing wall abutting the housing-fixed base plate.

[0010] US 11,454,241 B2 describes and illustrates a spiral compressor in which a cooling channel for cooling the housing-fixed base plate is formed by straight diagonally or tangentially arranged grooves, which are separated from each other by webs and serially connected to each other at their ends by connecting lugs, wherein this meandering cooling channel is formed in the axially outer end face of the housing-fixed base plate.

[0011] Against this background, the invention is based on the objective of presenting a spiral compressor of the aforementioned design with a particularly effective and cost-effective cooling device.

[0012] This problem is solved by a spiral compressor with the features of claim 1. Advantageous further developments are defined in the dependent claims.

[0013] Accordingly, the invention relates to an oil-free spiral compressor for generating compressed air, comprising at least one stator spiral attached to a housing-fixed base plate and a displacement spiral arranged on a movable base plate, wherein the stator spiral and the displacement spiral axially interlock and define pressure chambers, wherein the housing-fixed base plate has at least one cooling channel through which a cooling fluid flows, wherein at least one outlet opening for the flow of compressed air is formed in the housing-fixed base plate, and wherein the outlet opening of the housing-fixed base plate is fluidically connected to an adjacent high-pressure chamber.In this spiral compressor, according to the invention, a side wall and / or a bottom wall of a cover housing surrounding the high-pressure chamber or a side wall of a high-pressure chamber housing connected to the housing-fixed base plate is designed as a heat exchanger for the generated compressed air, which can be cooled by means of a cooling liquid.

[0014] The invention is based on a known, oil-free spiral compressor comprising at least one stator spiral arranged on a housing-fixed base plate and a displacement spiral arranged on a movable base plate, which axially interlock and define pressure chambers between them. The movable base plate can be driven by an eccentric pin of a drive shaft and, when the drive shaft is rotating, is guided in a translational orbital motion by means of a guide device. The housing-fixed base plate has at least one cooling channel through which a cooling fluid flows. At least one outlet opening for compressed air flow is formed in the housing-fixed base plate, which is fluidically connected to an adjacent high-pressure chamber.

[0015] To avoid the separate design and arrangement of a heat exchanger for the compressed air produced, as is common in conventional compressed air generation systems, the invention provides for the integration of this heat exchanger directly into the scroll compressor. In other words, the problem is solved constructively by providing a high-pressure chamber in either the cover housing or the high-pressure chamber housing of the scroll compressor, both connected to the housing-mounted base plate, and by designing a section of the cover housing or the high-pressure chamber housing as a heat exchanger for the compressed air generated by the scroll compressor. For this purpose, a wall of the cover housing or the high-pressure chamber housing is actively cooled and thus functions as a heat exchanger.This eliminates the need for the manufacture and separate arrangement of a heat exchanger in a compressed air generation system, offering the aforementioned advantages.

[0016] According to one embodiment of this spiral compressor, the cooling channel in the housing-fixed base plate can be spirally shaped and have at least one inlet opening and at least one outlet opening, and this cooling channel is integrally surrounded by the material of the housing-fixed base plate, i.e., except for its openings.

[0017] A cool, liquid coolant can be introduced into the inlet opening of this cooling channel and discharged, heated, through the outlet opening. The cooling channel can be manufactured relatively easily using a 3D metal printing process during the production of the housing-mounted base plate and the stator spiral mounted on it.

[0018] Alternatively, with regard to the cooling channel in the housing-fixed base plate, it can be provided that the cooling channel in the axially outer end face of the housing-fixed base plate is designed as an axially open spiral groove, and that a groove cover spanning the cooling channel and sealing it axially outwards is arranged on the axially outer end face of the housing-fixed base plate.

[0019] Alternatively, it can be provided that the cooling channel on the axially outer end face of the housing-fixed base plate is formed by several axially open and end-parallel or serially connected annular grooves, and that a groove cover spanning this cooling channel and sealing axially outwards is arranged on the axially outer end face of the housing-fixed base plate.

[0020] The grooves in the axially outer end face of the housing-mounted base plate can also be designed as annular grooves that extend only over a portion of a circle, i.e., they are closed at the ends in the circumferential direction. In this embodiment, the coolant is fed into or discharged from one or the other end of each circular groove.

[0021] Both the axially open helical groove and the at least one axially open annular groove can be manufactured together with the main body of the housing-mounted base plate and the stator spiral arranged thereon using a 3D metal printing process or a die-casting process. The aforementioned grooves can also be produced by a milling operation on the axially outer end face of the housing-mounted base plate.

[0022] Furthermore, with regard to the design of the at least one cooling channel in the housing-fixed base plate, it can be provided that the cooling channel in the axially outer end face of the housing-fixed base plate is formed as an axially open spiral groove or as axially open and end-to-end parallel or serially connected annular grooves, that a groove cover spanning this cooling channel and sealing axially outwards is arranged on the axially outer end face of the housing-fixed base plate, and that the axially outer end face of the housing-fixed base plate and the groove cover are covered by a bottom wall of a cover housing in a sealed axial direction.

[0023] The sealing of the cooling channel can be achieved, for example, by means of sealing rings, which are arranged between the axially outer end face of the housing-fixed base plate and the grooved cover and / or between the axially outer end face of the housing-fixed base plate and the axially inward-facing end face of the cover housing.

[0024] According to another embodiment, the spiral compressor having the features of the invention can be further characterized in that the cooling channel in the axially outer end face of the housing-fixed base plate is formed by an axially open spiral groove or by axially open annular grooves connected parallel or serially at their ends, that a recess spanning the cooling channel is formed in the axially outer end face of the housing-fixed base plate, in which a groove cover sealing the cooling channel in the axial direction is arranged, and that the axially outer end face of the housing-fixed base plate and the groove cover are covered by a bottom wall of a cover housing in a sealed manner in the axial direction.

[0025] By creating and utilizing the recess spanning at least one cooling channel, the grooved cover can be relatively easily positioned and attached to the axially outer end face of the housing-mounted base plate. Furthermore, the axially inner end face of a bottom wall of the cover housing does not need to perform the sealing function for the at least one cooling channel. The grooved cover is, for example, welded, soldered, bonded, or otherwise liquid-tightly connected to the housing-mounted base plate.

[0026] With regard to the constructive design of the heat exchanger mentioned above, a first embodiment provides that the bottom wall of the cover housing has a flow-connected through-opening with the outlet opening of the housing-fixed base plate, that the high-pressure chamber is bounded by the bottom wall and the side wall of the cover housing as well as by a cover sealed against the axial end face of this side wall, and that the heat exchanger is formed by a cooling channel in the side wall of the cover housing.

[0027] Accordingly, the cover housing, which is attached to and connected with the housing-mounted base plate, serves not only to cover and seal the at least one cooling channel located in or on the housing-mounted base plate, but also features a high-pressure chamber for calming the generated compressed air and a heat exchanger with which the compressed air generated and heated in the spiral compressor can be cooled. A clever design feature is that a side wall of the cover housing, radially delimiting the high-pressure chamber, has at least one cooling channel by means of which this side wall can be cooled and thus acts as a heat exchanger for cooling the generated compressed air.

[0028] In a further embodiment, the cooling channel of the heat exchanger can be designed as an annular groove open in the axially outer end face of the side wall of the cover housing, and this annular groove is sealed by means of a gasket arranged between the axial end face of the side wall and the cover of the housing. This gasket is, for example, an annular flat gasket. The annular groove in the side wall naturally has an inlet opening and an outlet opening for the flow of a cooling fluid.

[0029] The depth of the annular groove in the side wall corresponds, for example, to the height of the side wall of the cover housing, which radially surrounds the high-pressure chamber. This advantageously provides the radial inner surface of the side wall with a comparatively large cooling surface for cooling compressed air.

[0030] According to another embodiment, the cooling channel of the heat exchanger is designed as a helically or spirally wound channel in the side wall of the cover housing, having at least two turns. The cooling channel, except for its openings, is entirely within the material of the side wall of the cover housing. The number of turns can be greater; however, if the height of the side wall is limited, the diameter of the cooling channel must then be reduced. The cooling channel of the heat exchanger can also be formed by two annular channel sections, which are arranged axially and / or radially apart from each other, entirely within the material of the side wall of the cover housing, and connected to each other at their ends in parallel or in series. In this variant as well, the inlet and outlet openings for the entry and exit of coolant are, of course, open.

[0031] To prevent compressed air from flowing back from the high-pressure chamber into the pressure chambers of the spiral compressor, the spiral compressor with the features of the invention can also be provided with a flow-technical connection between the outlet opening of the housing-fixed base plate and the high-pressure chamber via a check valve, wherein the check valve is arranged to open in the direction of the high-pressure chamber and to close in the opposite direction.

[0032] Finally, it is possible to design a spiral compressor according to the invention without the described cover housing, which nevertheless has a high-pressure chamber and a heat exchanger. To achieve this structurally, a further embodiment of the spiral compressor, which has the features of the invention, provides that a pot-shaped high-pressure chamber housing is attached to or formed on the axially outer end face of the housing-fixed base plate, that the open end of the high-pressure chamber housing is in flow communication with the outlet opening in the housing-fixed base plate, that the high-pressure chamber housing has an outlet connection for attaching a compressed air line, and that a cooling channel is integrated into the side wall of the high-pressure chamber housing, whereby this side wall functions as a heat exchanger for cooling the compressed air generated by the spiral compressor.

[0033] The invention is explained in more detail below with reference to several examples illustrated in the accompanying drawing. The drawing shows seven figures, each in partial longitudinal section, depicting different embodiments of a spiral compressor incorporating the features of the invention.

[0034] A first embodiment of a spiral compressor 2.1, partially depicted in Fig. 1, with the features of the invention, comprises a housing-fixed base plate 4 with at least one axially projecting spiral stator spiral 6 formed or attached to it, and a movable base plate 8 with at least one axially projecting spiral displacer spiral 10 formed or attached to it. The stator spiral 6 and the displacer spiral 10 interlock axially and define pressure chambers 12 between them. The housing-fixed base plate 4 has a central outlet opening 14 through which the compressed air generated in the pressure chambers 12 can flow towards compressed air consumers. The movable base plate 8 can be driven in a known manner by an eccentric pin of a drive shaft and, when the drive shaft is rotating, is guided in a translational orbital motion by means of a housing-side guide device.

[0035] Both the housing-fixed base plate 4 and the orbitable base plate 8 each have at least one cooling channel 22, 22'; 24 through which a coolant flows. Each of the two cooling channels 22, 22'; 24 is connected to an external heat exchanger (not shown). The housing-fixed base plate 4 is connected to a housing part 26 via a screw connection. Two screws 28 of this fastening device are visible in the sectional view of Fig. 1.

[0036] The housing-mounted base plate 4 is connected to a cover housing 32, which, in the direction of the orbitable base plate 8, has a largely pot-shaped geometry with a flat bottom wall 34, an axially oriented hollow cylindrical outer wall 36, and a hollow cylindrical side wall 38 arranged axially outwards, i.e., furthest from the displacer blades. The bottom wall 34 of the cover housing 32 rests with its axially inner end face 37 against the axially outer end face 9 of the housing-mounted base plate 4 and is connected to it via a screw connection. In the sectional view of Fig. 1, four screws 42 of this screw connection are visible. In addition, the bottom wall 34 of the cover housing 32 has a through-opening 40 for the generated compressed air, which is in flow communication with the outlet opening 14 of the housing-mounted base plate 4 and is aligned with it.

[0037] The hollow cylindrical outer wall 36 of the cover housing 32 radially surrounds the housing-fixed base plate 4, the stator spiral 6, and the displacer spiral 12. Furthermore, the outer wall 36 of the cover housing 32 is sealed to the housing part 26 by means of a sealing ring 46 inserted into an annular groove 44 of the housing part 26. In the embodiments according to Figures 1 to 6, a high-pressure chamber 30 is formed on the cover housing 32, which is bounded by the bottom wall 34, the cylindrical side wall 38 of the cover housing 32, and a cover 48 mounted axially on the outside of the side wall 38. The cover 48 is connected to the side wall 38 of the cover housing 32 via a screw connection and sealed by means of a flat gasket 54 arranged between the axially outer end face of the side wall 38 and the cover 48. In the sectional view of Fig. 1, four screws 52 of this screw connection can be seen.In addition, the lid 42 is provided with an outlet connection 50, to which a supply line leading to compressed air consumers can be connected.

[0038] The high-pressure chamber 30 is comparatively large and acts as a calming chamber for compressed air or compressed pressurized gas, in which the pulsating pressurized gas flow and the pulsating gas pressure present in the outlet opening 14 of the housing-fixed base plate 4 are homogenized.

[0039] The bottom wall 34 of the cover housing 32, which is axially inwardly flat against the housing-fixed base plate 4 and screwed to it, stabilizes the housing-fixed base plate 4, which is subject to high mechanical and thermal stress during operation, and minimizes its elastic deformation.

[0040] The cooling channel 22 in the housing-mounted base plate 4 can be formed by a spirally wound, axially outwardly open spiral groove 62, which is formed in the axially outer end face 9 of the housing-mounted base plate 4. This cooling channel 22, or rather the spiral groove 62, is covered axially outwardly by the bottom wall 34 of the cover housing 32. To improve the sealing, in this embodiment two circular grooves 64, 64a are formed in the housing-mounted base plate 4, into each of which a circular seal 66, 66a is inserted.

[0041] Alternatively, the cooling channel 22' in the housing-fixed base plate 4 can also be formed by several axially outwardly open annular grooves 68, which are formed coaxially to each other in the axially outer end face 9 of the housing-fixed base plate 4, connected to each other at their ends in parallel or series, and covered axially outwardly by the bottom wall 34 of the cover housing 32. This cooling channel 22', also visible in Fig. 1, is radially sealed on both sides by means of seals 66, 66a inserted in grooves 64, 64a of the housing-fixed base plate 4.

[0042] The axially outwardly open annular grooves 68 can also be completely circular and axially covered by the bottom wall 34 of the cover housing 32. The supply and discharge of coolant then takes place separately for each of these annular grooves 68 by means of suitable lines (not shown).

[0043] According to the invention, a heat exchanger 56 is integrally formed on the spiral compressor 2.1 or on its cover housing 32, in which the generated compressed air can be cooled before it is directed to an external aftercooler or compressed air consumers. As shown in Figures 1 to 5, this integrated heat exchanger 56 is formed by the side wall 38 of the cover housing 32 that radially delimits the high-pressure chamber 30. For this purpose, a cooling channel 58 is formed in the side wall 38, which is fluidically connected to an external aftercooler, and through which a liquid coolant can be circulated. This allows the radial inner surface of the side wall 38, and thus the compressed air in the high-pressure chamber 30, to be cooled.

[0044] In the embodiments shown in Figures 1 and 2, the cooling channel 58 of the heat exchanger 56 is designed as an annular groove 60 open in the axially outer end face of the side wall 38 of the cover housing 32, which is sealed by means of the aforementioned cover 48 and a flat gasket 54.

[0045] In the spiral compressor 2.2 shown in Fig. 2, which is designed very similarly to the spiral compressor 2.1 according to Fig. 1, it can be seen that in the heat exchanger 56 the depth T of the annular groove 60 corresponds to the height H of the side wall 38 of the cover housing 32. This gives the annular groove 60 a comparatively large surface area for absorbing and dissipating heat.

[0046] Furthermore, in the spiral compressor 2.2 according to Fig. 2, a check valve 16 is arranged in the housing-mounted base plate 4, which is formed by a spring leaf element 18, a stop element 20 and a valve seat (not further specified). The check valve 16 prevents backflow of compressed air into the pressure chamber 12 of the spiral compressor 2.2 when the air pressure in the high-pressure chamber 30 is higher than in the pressure chamber 12 adjacent to the outlet opening 14 of the housing-mounted base plate 4.

[0047] In the third embodiment of a scroll compressor 2.3 according to the invention, shown in Fig. 3, the cooling channel 22, 22', which is formed by an axially outwardly open spiral groove 62 in the axial end face 9 of the housing-mounted base plate 4, is not sealed against coolant leakage by seals 66, 66a. Instead, the cooling channel 22, 22' is sealed by means of a flat, annular groove cover 78, which is fastened in a recess 76 in the axially outer end face 9 of the housing-mounted base plate 4. The groove cover 78 is welded, soldered, bonded, or otherwise liquid-tightly connected to the housing-mounted base plate 4, so that coolant cannot escape from the cooling channel 22, 22'.

[0048] In the two spiral compressors 2.4 and 2.5 according to Figs. 4 and 5, which also exhibit the features of the invention, the housing-mounted base plate 4 each has a spiral cooling channel 90 or several annular cooling channels, which are formed entirely in the material of the housing-mounted base plate 4 and therefore have a tubular geometry with at least one inlet opening and at least one outlet opening for a cooling fluid. The cooling channel 90 is located relatively close to the axially outer end face 9 of the housing-mounted base plate 4 and thus, by definition, in the region of the axially outer end face 9 of the housing-mounted base plate 4.This arrangement of at least one tubular cooling channel 90 not only effectively cools the housing-mounted base plate 4 together with the stator spiral 6 arranged there, but also indirectly cools the check valve 16, the cover housing 32 and the compressed air located in the high-pressure chamber 30, if present.

[0049] The spiral compressor 2.5 shown in Fig. 5 according to the invention is designed as an embodiment in which its orbitable base plate 8 has no cooling channels 24.

[0050] The spiral compressors 2.3, 2.4 and 2.5 according to Figures 3 to 5 differ from the spiral compressors 2.1 and 2.2 shown in Figures 1 and 2 with regard to the heat exchanger 56 in that the cooling channel 58' of the heat exchanger 56 is designed as a helically wound channel 70 with at least two turns 72a, 72b, which is formed completely within the side wall 38 of the cover housing 32 pointing away from the housing-fixed base plate 4.

[0051] In the case of the spiral compressors 2.3, 2.4 and 2.5 according to Figures 3 to 5, it can alternatively be provided that the cooling channel 58" of the heat exchanger 56 is formed by two annular channel sections 74a, 74b, which are axially spaced apart from each other, are completely formed within the side wall 38 of the cover housing 32 and are connected to each other at their ends in parallel or in series.

[0052] In the spiral compressor 2.6 shown in Fig. 6, the heat exchanger 56* has a helically wound cooling channel 58*. To accommodate its radially inwardly narrowing turn in the side wall 38* of the cover housing 32*, this side wall is made comparatively thick.

[0053] Finally, Fig. 7 shows a spiral compressor 2.7 incorporating the features of the invention, in which, as in the spiral compressor 2.3 according to Fig. 3, the axially outwardly open, at least one spiral groove 62 or annular groove 68 in the housing-fixed base plate 4 for forming the cooling channel 22, 22' is covered liquid-tight by an annular groove cover 78. The groove cover 78 is also inserted in a recess 79 in the end face 9 of the housing-fixed base plate 4 and is connected to it in a liquid-tight and captive manner.

[0054] Instead of the cover housing 32 present in spiral compressors 2.1 to 2.5, the spiral compressor 2.6, as shown in Fig. 6, has the open end of a cup-shaped high-pressure chamber housing 83 attached to the axial outer end face 9 of the housing-mounted base plate 4. A weld is evident for this connection. The axially inwardly open side of the high-pressure chamber housing 83, facing the base plate 4, together with the outlet opening 14 of the housing-mounted base plate 4, forms a high-pressure chamber 86 for calming the generated compressed air in a very simple manner. This high-pressure chamber housing 83 also has an outlet connection 87 for connecting a compressed air line leading to compressed air consumers.

[0055] In order to also use this high-pressure chamber housing 83 as a heat exchanger 88 for the compressed air generated in the spiral compressor 2.6, a helical cooling channel 85 is formed in the hollow cylindrical side wall 84 of the high-pressure chamber housing 83, through which a liquid coolant can be circulated. This cooling channel 85 can also be connected to an external aftercooler.

[0056] If the volume provided by the high-pressure chamber housing 83 and / or the cooling surface of the side wall 84 is too small for certain applications, the high-pressure chamber housing 83 can be extended in the axial direction if necessary. Furthermore, the high-pressure chamber housing 83 can be manufactured in one piece together with the cover housing 32.

[0057] Reference numeral list (part of the description)

[0058] Spiral compressor, (first embodiment)

[0059] Spiral compressor (second embodiment)

[0060] Spiral compressor (third embodiment)

[0061] Spiral compressor, (fourth embodiment)

[0062] Spiral compressor, (fifth embodiment)

[0063] Spiral compressor, (sixth embodiment)

[0064] Spiral compressor, (seventh embodiment)

[0065] Housing-mounted base plate

[0066] Stator spiral

[0067] Movable (orbitable) base plate

[0068] Axial outer end face of the housing-mounted base plate

[0069] Displacement bucket

[0070] Printing rooms

[0071] Exit opening in the housing-mounted base plate

[0072] non-return valve

[0073] leaf spring body

[0074] Stop body, 22' cooling channel

[0075] Cooling channel in the orbitable base plate

[0076] Housing part

[0077] screws

[0078] High-pressure chamber in the lid housing 32

[0079] Lid housing * Lid housing with spirally wound cooling channel 58*

[0080] bottom wall of the lid housing 32

[0081] Shell wall of the lid housing 32

[0082] Axial inner end face of the bottom wall 34 of the lid housing 32

[0083] Side wall of the lid housing 32

[0084] Passage opening in the bottom wall 34 of the cover housing 32

[0085] screws

[0086] Ring groove

[0087] seal

[0088] Lid 50 Output connection on the lid

[0089] 52 screws

[0090] 54 Gasket, flat gasket

[0091] 56 Heat exchangers, formed in the side wall 68 of the cover housing 32

[0092] 56* Heat exchanger with spiral cooling channel 58*

[0093] 58 Cooling channel, first embodiment

[0094] 58' Cooling channel, second embodiment

[0095] 58" cooling channel, third embodiment

[0096] 58* Spiral cooling channel of the heat exchanger 56*

[0097] 60 Ring groove

[0098] 62 spiral groove

[0099] 64, 64a grooves

[0100] 66, 66a Seals

[0101] 68 Ring groove

[0102] 70 helically wound cooling channels

[0103] 72a, 72b turns

[0104] 74a, 74b Canal sections

[0105] 76 Recess in the housing-mounted base plate

[0106] 78 Grooved lids

[0107] 83 High-pressure chamber housing

[0108] 84 Side wall of the high-pressure chamber housing 83

[0109] 85 Cooling channel in the high-pressure chamber housing 83

[0110] 86 High-pressure chamber in the high-pressure chamber housing 83

[0111] 87 Outlet connection on the high-pressure chamber housing 83

[0112] 88 Heat exchangers, formed on the high-pressure chamber housing 83

[0113] H Height of the side wall 38

[0114] T Depth of the ring groove 60

Claims

Patent claims 1. Oil-free spiral compressor (2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7) for generating compressed air, comprising at least one stator spiral (6) attached to a housing-fixed base plate (4) and a displacement spiral (10) arranged on a movable base plate (8), wherein the stator spiral (6) and the displacement spiral (10) axially interlock and define pressure chambers (12), wherein the housing-fixed base plate (4) has at least one cooling channel (22, 22') through which a cooling fluid can flow, wherein at least one outlet opening (14) for the flow of compressed air is formed in the housing-fixed base plate (4), and wherein the outlet opening (14) of the housing-fixed base plate (4) is fluidically connected to an adjacent high-pressure chamber (30, 86), thereby characterized that a side wall (38, 38*) and / or a bottom wall (34) of a lid housing (32) enclosing the high-pressure chamber (30)32*) or a side wall (84) of a high-pressure chamber housing (83) connected to the housing-fixed base plate (4) is designed as a heat exchanger (56, 56*, 88) for the generated compressed air, which can be cooled by means of a cooling liquid.

2. Spiral compressor (2.4, 2.5) according to claim 1 , characterized in that the cooling channel (90) in the housing-fixed base plate (4) is spirally shaped and has at least one inlet opening and at least one outlet opening, and that this cooling channel (90) is integrally surrounded by the material of the housing-fixed base plate (4).

3. Spiral compressor (2.3, 2.6, 2.7) according to claim 1, characterized in that the cooling channel (22, 22') is formed in the axially outer end face (9) of the housing-fixed base plate (4) as an axially open spiral groove (62) or by axially open and end-parallel or serially connected annular grooves (68), and that a groove cover (78) spanning the cooling channel (22, 22') and sealing it axially outwards is arranged on the axially outer end face (9) of the housing-fixed base plate (4).

4. Spiral compressor (2.3, 2.6) according to claim 3, characterized in that the cooling channel (22, 22') is formed in the axially outer end face (9) of the housing-fixed base plate (4) as an axially open spiral groove (62) or by axially open and end-parallel or serially connected annular grooves (68), that a spanning cooling channel (22, 22') is provided on the axially outer end face (9) of the housing-fixed base plate (4), and a grooved cover (78) is arranged to seal axially outwards, and the axially outer end face (9) of the housing-fixed base plate (4) and the grooved cover (78) are sealed in the axial direction by a bottom wall (34) of a cover housing (32).

5. Spiral compressor (2.3, 2.6) according to claim 3 or 4, characterized in that the cooling channel (22, 22') in the axially outer end face (9) of the housing-fixed base plate (4) is formed by an axially open spiral groove (62) or by axially open and end-parallel or serially connected annular grooves (68), that a recess (76) spanning the cooling channel (22, 22') is formed on the axially outer end face (9) of the housing-fixed base plate (4), in which a groove cover (78) sealing the cooling channel (22, 22') in the axial direction is arranged, and that the axially outer end face (9) of the housing-fixed base plate (4) and the groove cover (78) are covered by a bottom wall (34) of a cover housing (32, 32*) in a sealed manner in the axial direction.

6. Spiral compressor (2.3, 2.6) according to one of claims 3 to 5, characterized in that the groove cover (78) is welded, soldered, glued or otherwise liquid-tight connected to the housing-fixed base plate (4).

7. Spiral compressor (2.1 , 2.2, 2.3, 2.4, 2.5, 2.6) according to one of the preceding claims, characterized in that the bottom wall (34) of the cover housing (32, 32*) has a flow-connected passage opening (40) with the outlet opening (14) of the housing-fixed base plate (4), that the high-pressure chamber (30) is bounded by the bottom wall (34) and the side wall (38, 38*) of the cover housing (32, 32*) and by a cover (48) sealed onto the axial end face of this side wall (38, 38*), and that the heat exchanger (56) is formed by a cooling channel (58, 58' , 58“, 58*) in the side wall (38, 38*) of the cover housing (32, 32*).

8. Spiral compressor (2.1 , 2.2) according to claim 7, characterized in that the cooling channel (58) of the heat exchanger (56) is designed as an annular groove (60) open in the axially outer end face of the side wall (38) of the cover housing (32), and that this annular groove (60) is sealed by means of a seal (54) arranged between the axial end face of the side wall (38) and the cover (48) of the cover housing (32).

9. Spiral compressor (2.1 , 2.2) according to claim 8, characterized in that the depth (T) of the annular groove (60) corresponds to the height (H) of the side wall (38) of the cover housing (32).

10. Spiral compressor (2.3, 2.4, 2.5, 2.6) according to one of claims 1 to 7, characterized in that the cooling channel (58', 58*) of the heat exchanger (56, 56*) is designed as a helically or spirally wound channel (70) with at least two turns (72a, 72b), which is formed completely within the side wall (38, 38*) of the cover housing (32, 32*).

11. Spiral compressor (2.3, 2.4, 2.5) according to one of claims 1 to 9, characterized in that the cooling channel (58") of the heat exchanger (56) is formed by two annular channel sections (74a, 74b), and that these channel sections (74a, 74b) are axially and / or radially spaced apart from each other, are formed completely within the side wall (38) of the cover housing (32), and are connected to each other at their ends in parallel or in series.

12. Spiral compressor (2.7) according to one of claims 1 to 11, characterized in that a pot-shaped high-pressure chamber housing (83) is attached or formed on the axially outer end face (9) of the housing-fixed base plate (4), that the open end of the high-pressure chamber housing (83) is in flow communication with the outlet opening (14) in the housing-fixed base plate (4), that the high-pressure chamber housing (83) has an outlet connection (87) for attaching a compressed air line, and that a cooling channel (85) is formed in the side wall (84) of the high-pressure chamber housing (83), whereby this side wall (84) has the function of a heat exchanger (88) for cooling the compressed air generated by the spiral compressor (2.7).

13. Spiral compressor (2.2) according to one of the preceding claims, characterized in that the outlet opening (14) of the housing-fixed base plate (4) is fluidically connected to the high-pressure chamber (30) via a check valve (16), wherein the check valve (16) is arranged to open in the direction towards the high-pressure chamber (30) and to close in the opposite direction.

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