Scroll compressor

Abstract

The invention relates to a scroll compressor (2.1) comprising at least one spiral stator blade (6) fastened to a housing-fixed base plate (4) and one spiral displacement blade (10) arranged on a movable base plate (9), said stator blade and displacement blade meshing with one another and delimiting pressure chambers (12) between them, wherein the movable base plate is rotatably mounted on an eccentric pin of a drive shaft and can be guided in an orbital movement by means of a guide device, and wherein an outlet opening (14), which is fluidically connected to a high-pressure chamber (26), and a cooling channel (22), through which a cooling liquid can flow, are formed in the housing-fixed base plate (4). In addition, the high-pressure chamber has a first section in a cover housing (28) and a second section in a cover (44) which is placed axially outside on the cover housing; the first section of the high-pressure chamber is delimited axially inside by a planar bottom wall (30) and is delimited by a cylindrical side wall (32) of the cover housing, said side wall adjoining said bottom wall axially outwardly; the second section of the high-pressure chamber is delimited axially outside by a planar cover wall (46) and is delimited by a cylindrical side wall (48) of the cover, said side wall adjoining said cover wall axially inwardly; the bottom wall of the cover housing (28) is seated on an axial outer wall (8) of the housing-fixed base plate; the bottom wall of the cover housing has a through-opening (38) aligned with the outlet opening (14) of the housing-fixed base plate; and an aftercooler (56) for compressed air that can be generated is integrated in the cover housing and in the cover.

Description

[0001] spiral compressor

[0002] The invention relates to a spiral compressor, with at least one spiral stator blade attached to a housing-fixed base plate and a spiral displacement blade arranged on a movable base plate, which axially interlock and define crescent-shaped pressure chambers between each other, wherein the movable base plate is rotatably mounted on an eccentric pin of a drive shaft and is guided in a translational orbital motion by means of a guide device when the drive shaft is rotating, and wherein at least one outlet opening connected fluidically to an axially adjacent high-pressure chamber and at least one cooling channel through which a cooling fluid flows are formed in the housing-fixed base plate.

[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 blade and one movable, spiral displacement blade, which define several crescent-shaped pressure chambers between them. While the stator blade is attached to a housing-mounted base plate, the displacement blade is arranged on a movable base plate, which is movably mounted on an eccentric journal of a drive shaft.With a rotating drive shaft, i.e., driven by a motor, the movable base plate with the displacer blade should perform a translational orbital motion to achieve high efficiency, meaning it should be deflected radially in accordance with the rotating displacement of the eccentric pin. However, the displacer blade should largely maintain its circumferential orientation, i.e., it should not pivot around its own hub axis. This allows the blades to be designed and arranged in such a way that the displacer blade approaches the stator blade 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, shift circumferentially in the direction of rotation and radially from the outside inwards, reducing their volume.The translational orbital movement of the movable base plate is ensured by a suitable guide device.

[0004] This document describes a scroll compressor in which at least one outlet opening connected to an axially adjacent high-pressure chamber and at least one cooling channel through which a cooling fluid flows are arranged in the housing-mounted base plate. A check valve may be arranged between the outlet opening in the housing-mounted base plate and the high-pressure chamber. This check valve is designed and positioned to open towards the high-pressure chamber and close in the opposite direction. The check valve prevents backflow of compressed air into the scroll compressor when 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.

[0005] The high-pressure chamber, to which at least one compressed air consumer is connected, is a calming chamber in which the pulsating compressed air flow passing through the outlet opening of the housing-mounted base plate and the pulsating air pressure present there are equalized.

[0006] US Patent 6695,598 B2 discloses a scroll compressor whose housing-mounted base plate has an outlet opening that is connected via a check valve designed as a spring-loaded valve to an axially adjacent high-pressure chamber. The high-pressure chamber is bounded by the axially 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 102019204 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 designed as a spring-loaded leaf valve. 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 cylindrical inner wall of a pot-shaped housing.

[0008] During extended operating phases and the generation of high air pressures, high temperatures inevitably arise 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 can flow in the housing-mounted base plate 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, which is arranged in the inner end wall of a housing wall adjacent to the housing-fixed base plate.

[0010] US Patent 11 454241 B2 describes 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 web lugs, and which is arranged in the outer end wall of the housing-fixed base plate.

[0011] The object of the invention is to present a spiral compressor of the aforementioned design with high mechanical stability and a further improved cooling effect.

[0012] This problem is solved by a spiral compressor with the features of claim 1. Advantageous embodiments of this spiral compressor are defined in the dependent claims. Accordingly, the invention relates to a spiral compressor with at least one spiral stator blade attached to a housing-fixed base plate and a spiral displacement blade arranged on a movable base plate, which axially interlock and define crescent-shaped pressure chambers between them, wherein the movable base plate is rotatably mounted on 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, and wherein at least one outlet opening, fluidically connected to an axially adjacent high-pressure chamber, and at least one cooling channel through which a cooling fluid can flow are formed in the housing-fixed base plate.

[0013] The problem is solved in this spiral compressor by the fact that the high-pressure chamber has a first section in a cover housing and a second section in a cover mounted axially on the outside of the cover housing, that the high-pressure chamber in its first section is bounded axially on the inside by a flat bottom wall and by a cylindrical side wall of the cover housing adjoining the bottom wall axially on the outside, that the high-pressure chamber in its second section is bounded axially on the outside by a flat cover wall and by a cylindrical side wall of the cover adjoining the cover wall axially on the inside, that the bottom wall of the cover housing rests against an axial outer wall of the housing-fixed base plate, and that the bottom wall of the cover housing has a through-opening aligned with the outlet opening of the housing-fixed base plate.and that an aftercooler for the compressed air generated by the spiral compressor is integrated into the cover housing and the cover, wherein the aftercooler has at least one cooling channel through which a cooling liquid can flow and at least one air channel through which compressed air can flow, and wherein the air channel leads from the high-pressure chamber to an outlet connection of the spiral compressor.

[0014] By arranging the high-pressure chamber in a lid housing with a flat bottom wall resting against the housing-mounted base plate, the mechanically and thermally stressed housing-mounted base plate is stabilized, and its elastic deformation is minimized. The inclusion of an aftercooler in the lid housing and the lid housing, with at least one cooling channel through which a cooling fluid flows and at least one air channel through which compressed air flows, leading from the high-pressure chamber to an outlet connection, ensures very effective cooling of the compressed air and increases the efficiency of the scroll compressor.

[0015] According to a preferred embodiment of the aftercooler, the cooling channel and the air channel of the aftercooler are each formed with a spiral path coaxially around the high-pressure chamber in the cylindrical side walls of the cover housing and the cover, with the coils of the cooling channel and the air channel arranged radially alternately next to each other. This results in increased heat transfer from the compressed air to the cooling liquid during operation of the scroll compressor, and thus improved cooling of the compressed air.

[0016] A further improvement in heat transfer from the compressed air to the cooling liquid can be achieved by designing the air duct of the aftercooler as a finely scaled, meandering flow channel by means of radially alternating, circumferentially offset transverse ribs on its radial side walls. This design of the air duct creates turbulence in the compressed air flowing through it, thus enabling more intensive cooling.

[0017] Furthermore, it can be advantageously provided that the cooling channel and the air channel of the aftercooler each have two axial sections, that the two axial sections of the cooling channel and the air channel are each designed as open spiral grooves, that the spiral grooves are formed in the end walls of the cover housing and the cover which abut each other in the assembled state, and that the two axial sections of the spiral grooves in the cover housing and in the cover are aligned with each other in such a way that they form closed channels in the axial direction of the spiral compressor.

[0018] This simplifies the demolding of the components manufactured as castings during the production of the spiral compressor and enables any necessary mechanical post-processing of the spiral channels.

[0019] Regarding the depth of their spiral grooves, the cooling channel and the air channel can be divided between the cover housing and the cover in a ratio of 1:1 to 2:1. To further improve the cooling of the compressed air, a deflection element can be arranged axially adjacent to the through-opening of the cover housing in the high-pressure chamber. The deflection element is intended to force the compressed air flowing from the through-opening into the high-pressure chamber into a vortex flow along the inner walls of the high-pressure chamber, thereby further improving the heat transfer from the compressed air to the cover housing and the cover.

[0020] In an advantageous embodiment, the deflection element is attached at one end between the cover housing and the cover. This attachment can be achieved, for example, by means of a screw connection or by the engagement of at least one positive-locking element in a corresponding recess in the cover housing or the cover.

[0021] Furthermore, to improve the cooling of the compressed air in the high-pressure chamber, several cooling fins connected to the cover housing or the cover itself can be arranged or formed. According to an advantageous embodiment, the cooling fins are designed as curved vanes and axially projecting and are integrally connected to the cover wall, thereby further improving the heat transfer from the compressed air to the cover.

[0022] The invention is explained in more detail below with reference to two exemplary embodiments illustrated in the accompanying drawing. The drawing shows

[0023] Fig. 1 shows a first embodiment of a spiral compressor according to the invention in a partial longitudinal sectional view,

[0024] Fig. 2 shows the spiral compressor according to Fig. 1 in a cross-sectional view, and

[0025] Fig. 3 shows a second embodiment of a spiral compressor according to the invention in a partial longitudinal sectional view.

[0026] The first embodiment of a spiral compressor 2.1 according to the invention, shown in the partial longitudinal section view of Fig. 1 (section plane A - A in Fig. 2) and the cross-sectional view of Fig. 2 (section plane B - B in Fig. 1), has a housing-fixed base plate 4 with at least one spiral stator blade 6 projecting axially from it, and an orbitable base plate 9, only indicated in Fig. 1, with at least one spiral displacement blade 10 projecting axially from it.

[0027] The stator blade 6 and the displacement blade 10 interlock axially and define crescent-shaped pressure chambers 12. The movable base plate 9 is rotatably mounted on an eccentric pin (not shown) of a drive shaft and, when the drive shaft rotates, is guided in a translational orbital motion by a guide device. An outlet opening 14 is formed in the housing-fixed base plate 4 and is connected via a check valve 16 to an axially adjacent high-pressure chamber 26. The check valve 16 comprises a spring-loaded leaf valve 18 and a stop element 20.

[0028] In the housing-fixed base plate 4, a cooling channel 22 through which a cooling fluid can flow is arranged, which is formed in the form of an axially open annular or spiral groove 24 mostly in the axial outer wall 8 of the housing-fixed base plate 4.

[0029] The high-pressure chamber 26 is axially divided into two parts: a cover housing 28 and a lid 44 placed on the cover housing 28. The cover housing 28 has a flat bottom wall 30, an axially outer cylindrical side wall 32 with an outer end wall 34, and an axially inner bell-shaped shell wall 36.

[0030] The bottom wall 30 of the cover housing 28 is sealed against the axial outer wall 8 of the housing-fixed base plate 4 and is connected to a central housing part (not visible in the figures) via a screw connection. In Fig. 1, two screws 40 are visible, and in the sectional view of Fig. 2, seven screws 40 of this screw connection are visible. Furthermore, the bottom wall 30 of the cover housing 28 has a through-opening 38 that is aligned with the outlet opening 14 of the housing-fixed base plate 4. The outer wall 36 of the cover housing 28 radially surrounds the housing-fixed base plate 4, the stator blade 6, and the displacer blade 10 and is sealed against the central housing part. The cooling channel 22 of the housing-fixed base plate 4 is shown here as an example with a small axial portion in the form of an open annular or spiral groove 42 in the bottom wall 30 of the cover housing 28, which is aligned with the annular or spiral groove 24 in the housing-fixed base plate 4.

[0031] The cover 44 has a flat cover wall 46 on its outer axial side and a cylindrical side wall 48 arranged on its inner axial side with an inner end wall 50. The cover 44 rests with its inner axial end wall 50 against the outer axial end wall 34 of the cover housing 28 and is connected to the cover housing 28 via a screw connection. In the sectional view of Fig. 1, five screws 52 and in the sectional view of Fig. 2, eight screws 52 of this screw connection are visible, not all of which are labeled.

[0032] The high-pressure chamber 26 is bounded by the bottom wall 30 and the cylindrical side wall 32 of the cover housing 28, as well as by the cover wall 46 and the cylindrical side wall 48 of the cover 44. The cover 44 is also provided with an outlet port 54 to which a supply line leading to compressed air consumers can be connected.

[0033] The high-pressure chamber 26 is relatively small and acts as a settling chamber, where the pulsating compressed air flow and the pulsating air pressure present at the outlet opening 14 of the housing-mounted base plate 4 during operation are equalized. The check valve 16 prevents backflow of compressed air into the spiral compressor 2.1 when the air pressure in the high-pressure chamber 26 is higher than in the pressure chamber 12 adjacent to the outlet opening 14 of the housing-mounted base plate 4. The flat bottom wall 30 of the cover housing 28, which rests against the housing-mounted base plate 4, mechanically stabilizes the mechanically and thermally stressed housing-mounted base plate 4 and minimizes its thermo-elastic deformability. Furthermore, the housing-mounted base plate 4 is cooled by the coolant flowing through the cooling channel 22, thus further reducing the risk of thermally induced deformation.

[0034] The cover housing 28 and the cover 44 also incorporate an aftercooler 56, which comprises at least one cooling channel 58 through which a cooling liquid flows and at least one air channel 60 through which compressed air flows, leading from the high-pressure chamber 26 to the outlet port 54. The cooling channel 58 and the air channel 60 of the aftercooler 56 are each arranged coaxially around the high-pressure chamber 26 in a spiral shape within the cylindrical side walls 32, 48 of the cover housing 28 and the cover 44, with the coils of the cooling channel 58 and the air channel 60 arranged radially alternately next to each other. This enables particularly good heat transfer from the compressed air to the cooling liquid and thus improved cooling of the compressed air.

[0035] As can best be seen from the sectional view of Fig. 2, the air duct 60 of the aftercooler 56 forms a finely scaled meandering flow channel by means of radially alternating, circumferentially offset transverse webs 62 on its radial side walls, whereby the flowing compressed air can be swirled and cooled particularly intensively.

[0036] In this design, the cooling channel 58 and the air channel 60 of the aftercooler 56 are each formed as aligned open spiral grooves 64, 66; 68, 70 in the adjacent end walls 34, 50 of the cover housing 28 and the cover 44, respectively. This simplifies the demolding of the components manufactured as castings and allows for any necessary mechanical post-processing of the spiral grooves 64, 66; 68, 70. As the sectional view in Fig. 1 shows, the cooling channel 58 and the air channel 60 are divided between the cover housing 28 and the cover 44 in a 1:1 ratio with respect to the depth T, T' of their spiral grooves 64, 66; 68, 70. However, it is also possible to divide the cooling channel 58 and the air channel 60 in favor of the cover housing 28 in a ratio of up to 2 : 1 .

[0037] A second embodiment of a spiral compressor 2.2 according to the invention, shown in the partial longitudinal section view of Fig. 3, differs from the first embodiment according to Figures 1 and 2 by a larger high-pressure chamber 26' and additional components within the high-pressure chamber 26', which may be provided as required for further improved cooling of the compressed air.

[0038] In the high-pressure chamber 26', a deflection element 72 is arranged axially adjacent to the through-opening 38 of the cover housing 28. This element is, by way of example, designed as a curved plate. The deflection element 72 is intended to force the compressed air flowing from the through-opening 38 into the high-pressure chamber 26' into a vortex flow along the aforementioned walls 32', 46', 48' of the high-pressure chamber 26', thereby increasing the heat transfer from the compressed air to the cover housing 28' and the cover 44'. The deflection element 72 is fastened at its end in a recess 74 between the cover housing 28' and the cover 44'. This fastening can be achieved, for example, by a screw connection or by the engagement of at least one positive-locking element of the deflection element 72 in a corresponding recess in the cover housing 28' or the cover 44' (not shown in Fig. 3).

[0039] Furthermore, several cooling fins 76 connected to the cover housing 46' are arranged in the high-pressure chamber 26'. In this example, the cooling fins 76 are designed as curved blades and are integrally connected to the cover wall 46' of the cover 44', projecting axially, thereby increasing the heat transfer from the compressed air to the cover 44'.

[0040] Reference numeral list (part of the description)

[0041] Spiral compressor, scroll compressor (first embodiment)

[0042] Spiral compressors, scroll compressors (second design)

[0043] Housing-mounted base plate

[0044] Stator blade on the housing-mounted base plate

[0045] Axial outer wall of the housing-mounted base plate

[0046] Movable, orbitable base plate

[0047] Displacement blade on the movable base plate

[0048] Printing rooms

[0049] Exit opening in the housing-mounted base plate

[0050] non-return valve

[0051] Spring leaf valve

[0052] Stop element of the check valve

[0053] Cooling channel in the housing-mounted base plate

[0054] Ring or spiral groove in the housing-mounted base plate, 26' High-pressure chamber, 28' Cover housing, 30' Bottom wall of the cover housing, 32' Side wall of the cover housing

[0055] Front wall of the lid housing

[0056] Shell wall of the lid housing

[0057] Through-hole in the lid housing

[0058] First screws

[0059] Ring or spiral groove on the axially inner end face of the cover housing, 44' Cover, 46' Cover wall of the cover, 48' Side wall of the cover

[0060] Front wall of the lid

[0061] Second screws

[0062] Output connection

[0063] Aftercooler

[0064] Cooling channel

[0065] Air duct crossbeams in the air duct

[0066] Spiral groove of the cooling channel 58 in the cover housing

[0067] Spiral groove of the cooling channel 58 in the lid

[0068] Spiral groove of the air duct 60 in the lid housing

[0069] Spiral groove of the air duct 60 in the lid

[0070] Deflection element in the high-pressure chamber

[0071] Recess in the lid housing 28'

[0072] Cooling fins in the high-pressure chamber

[0073] Depth of spiral grooves 64, 68 in the lid housing 28, 28'

[0074] Depth of spiral grooves 66, 70 in the lid 44, 44'

Claims

Patent claims 1. Spiral compressor (2.1, 2.2), comprising at least one spiral stator blade (6) attached to a housing-fixed base plate (4) and a spiral displacement blade (10) arranged on a movable base plate (9), which axially interlock and define crescent-shaped pressure chambers (12) between them, wherein the movable base plate is rotatably mounted on 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, and wherein at least one outlet opening (14) fluidically connected to an axially adjacent high-pressure chamber (26, 26') and at least one cooling channel (22) through which a cooling fluid flows are formed in the housing-fixed base plate (4), characterized in that the high-pressure chamber (26, 26') has a first section in a cover housing (28,28') and a second section in a cover (44, 44') mounted axially on the outside of the cover housing (28, 28'), that the high-pressure chamber (26, 26') in its first section is bounded axially on the inside by a flat bottom wall (30, 30') and by a cylindrical side wall (32, 32') of the cover housing axially adjoining the bottom wall (30, 30'), that the high-pressure chamber (26, 26') in its second section is bounded axially on the outside by a flat cover wall (46, 46') and by a cylindrical side wall (48, 48') of the cover (44, 44') axially adjoining the cover wall (46, 46'), that the bottom wall (30, 30') of the cover housing (28, 28') abuts an axial outer wall (8) of the housing-fixed base plate (4), that the bottom wall (30, 30') of the lid housing (28, 28') has a passage opening (38) aligned with the outlet opening (14) of the housing-fixed base plate (4),and that an aftercooler (56) for the compressed air generated by the scroll compressor (2.1, 2.2) is integrated into the cover housing (28, 28') and into the cover (44, 44'), wherein the aftercooler (56) has at least one cooling channel (58) through which a cooling liquid can flow and at least one air channel (60) through which compressed air can flow, and wherein the air channel (60) leads from the high-pressure chamber (26, 26') to an outlet port (54) of the scroll compressor (2.1, 2.2).

2. Spiral compressor (2.1 , 2.2) according to claim 1 , characterized in that the cooling channel (58) and the air channel (60) of the aftercooler (56) are each formed with a spiral course coaxially around the high pressure chamber (26, 26') in the cylindrical side walls (32, 32'; 48, 48') of the cover housing (28, 28') and the cover (44, 44'), wherein the turns of the cooling channel (58) and the air channel (60) are arranged radially alternately next to each other.

3. Spiral compressor (2.1 , 2.2) according to claim 1 or 2, characterized in that the air duct (60) of the aftercooler (56) is designed as a finely scaled meandering flow channel by means of radially alternately, circumferentially offset transverse webs (62) on its radial side walls.

4. Spiral compressor (2.1, 2.2) according to one of claims 1 to 3, characterized in that the cooling channel (58) and the air channel (60) of the aftercooler (56) each have two axial sections, that the two axial sections of the cooling channel (58) and the air channel (60) are each designed as open spiral grooves (64, 66; 68, 70), that the spiral grooves (64, 66; 68, 70) are formed in the end walls (34, 50) of the cover housing (28, 28') and the cover (44, 44') which abut each other in the assembled state, and that the two axial sections of the spiral grooves (64, 66; 68, 70) in the cover housing (28, 28') and in the cover (44, 44') are aligned with each other such that they are closed channels are formed in the axial direction of the spiral compressor (2.1 , 2.2).

5. Spiral compressor (2.1 , 2.2) according to claim 4, characterized in that the cooling channel (58) and the air channel (60) are divided between the cover housing (28, 28') and the cover (44, 44') in a ratio of 1 : 1 to 2 : 1 with respect to the depth (T, T') of their spiral grooves (64, 66; 68, 70).

6. Spiral compressor (2.2) according to one of claims 1 to 5, characterized in that a deflection element (72) is arranged axially adjacent to the passage opening (38) of the cover housing (28') in the high pressure chamber (26').

7. Spiral compressor (2.2) according to claim 6, characterized in that the deflection element (72) is attached at its end in a recess (74) between the cover housing (28') and the cover (44').

8. Spiral compressor (2.2) according to one of claims 1 to 7, characterized in that several cooling fins (76) connected to the cover housing (28') or the cover (44') are arranged or formed in the high pressure chamber (26').

9. Spiral compressor (2.2) according to claim 8, characterized in that the cooling fins (76) are designed as curved blades and are axially projecting and integrally connected to the cover wall (46') of the cover (44').

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