Scroll machine

Abstract

The invention relates to a scroll machine for transporting a fluid, in particular a refrigerant of a vehicle air-conditioning system, comprising: a stationary first scroll and an orbiting second scroll, which enclose a transport chamber; a high pressure chamber disposed on a back side of the first substrate; a valve opening formed in the first base plate of the first scroll, through which the conveyed fluid leaks into the high pressure chamber during as-specified operation; the limiting stopper is used for the valve plate. The envelope of the contact surface of the stopper, which is in contact with the valve plate in the open state, approximates the outer contour of the region of the valve plate, which is in contact with the contact surface. A recess is formed in the contact surface in order to provide a contact surface of the valve plate on the stopper, which contact surface is reduced compared to the area surrounded by the envelope, and / or wherein a recess is formed on the rear surface of the first substrate, which recess is partially covered by the valve plate in the closed state of the valve plate.

Description

TECHNICAL FIELD

[0001] The invention belongs to the field of volumetric machines according to the screw principle and relates to a scroll machine, in particular in the form of a scroll compressor, which is preferably an electric refrigerant drive, in particular as a refrigerant expeller for refrigerants for vehicle air conditioning systems. BACKGROUND

[0002] In motor vehicles, air conditioning systems are usually installed which air-condition the interior of the vehicle by means of a system which forms a refrigerant circuit. Such a system has, in principle, a circuit in which the refrigerant is guided. The refrigerant, for example R-744 (carbon dioxide, CO2) or R-134a (1,1,1,2-tetrafluoroethane), is heated at an evaporator and compressed by means of a (refrigerant) compressor or expeller, wherein the refrigerant then releases the heat absorbed again via a heat exchanger before being redirected to the evaporator via a throttling element.

[0003] As refrigerant compressors, so-called scroll machines are usually used in order to compress the refrigerant. The structure and the mode of operation of such a scroll machine as a compressor for refrigerants for motor vehicle air conditioning systems are described, for example, in DE 10 2012 104 045 A1. The main components of such a scroll machine are two scroll parts ("scrolls") which can move relative to one another. In the system, there is also usually oil in the form of droplets or as mist, which is at least partially separated from the (usually gaseous after compression) refrigerant after compression. The refrigerant, perhaps with a residue of oil, is then introduced into the air conditioning circuit, while the separated oil can mostly be guided past the moving parts within the scroll machine in order to lubricate them.

[0004] The scroll parts are generally embodied as a stationary, fixed scroll ("fixed scroll", "expulsion scroll") and a movable, orbiting scroll ("mating scroll", "rotary scroll"). The two scrolls are basically built similarly and each have a base plate ("base", "scroll plate") and a helical ("spiral") wall ("helical wall", "scroll wall") which extends from the base plate in the axial direction. In the assembled state, the helical walls of the two scrolls are intermeshingly nested and form a plurality of transport chambers between the sectionwise touching scroll walls.

[0005] In order to drive the movable scroll, an electric motor is typically provided, the motor shaft of which (on the A side, i.e. the driven side) is coupled in a drive-technological manner to the movable scroll part by means of an eccentric shaft journal (which is also referred to as "shaft pin").

[0006] In this and the following, the orbiting movement is understood in particular as an eccentric circular movement path, wherein the movable scroll does not rotate about its own axis. The two scrolls have the smallest possible axial spacing from one another in operation, wherein in each orbiting movement a substantially sickle-shaped (compression or transport) cavity is formed between the spiral walls, which cavity, during the movement of the two scrolls relative to one another (at least in the compression process), migrates from the outside along the spiral wall in the direction of the central axis of the respective scroll and is reduced there (and thus compresses the medium guided therein).

[0007] For the purpose of guiding the transported medium (fluid), outlet openings (also referred to as outlet openings or valve openings) are mostly introduced in the base plate of the scroll screw in order to discharge the fluid (e.g. refrigerant) compressed between the screws into the high-pressure region of the scroll machine. In most cases, a check valve in the form of a so-called reed valve (flutter valve, reed valve) is used here in order to avoid backflow of the compressed fluid. However, the outlet openings in any case result in so-called dead volumes, which are also known from other extrusion machine principles. For example, in reciprocating piston compressors, the dead volume limits the compression ratio to be achieved, since the compressed fluid has already accumulated in the dead volume and then expands again. Due to the so-called reverse expansion, the suction of further fluid is also disadvantageously limited.

[0008] Due to the screw geometry and the necessity of the outlet openings, a so-called backflow effect (also referred to as Back flow in the English literature) occurs in scroll machines. This effect occurs as soon as the pressure ratio set by the fluid cycle (e.g. refrigerant cycle) is greater than the geometrically predetermined pressure ratio of the scroll screw itself. The intrinsic pressure ratio of a scroll machine is predetermined by its screw geometry. The intrinsic pressure ratio is usually defined via the ratio of the stroke volume (suction chamber) to the innermost cavity volume at the discharge point. Depending on the scroll properties, it cannot be precisely defined as, for example, in reciprocating piston compressors (stroke volume / dead volume).

[0009] The backflow phenomenon occurs in particular when the scroll spiral has just expelled the compressed refrigerant from the innermost (scroll) chamber into the high-pressure chamber. At this operating point, the compression ratio is often greater than the compression ratio in the interior of the scroll spiral. If the scroll spiral continues to move, the so-called backflow gap between the outlet opening and the extrusion chamber located behind the innermost chamber (in addition to the innermost chamber, which is also referred to as "discharge chamber", there are always two symmetrical extrusion chambers) is opened. As a result, compressed fluid flows back from the high-pressure chamber via the opened valve, via the outlet opening into the discharge chamber. The pressure in the outlet opening thus drops and the valve is closed. The pressure in the outlet opening now drops abruptly, since no compressed fluid can flow in again via the valve. At the same time, the fluid also expands out of the region between the scroll spirals of the innermost chamber. The counter-expanding gases from the innermost chamber and the outlet opening generate an oscillating pressure wave in the discharge chamber located behind.

[0010] In addition, noise also occurs as a result of the movement of the valve. The reed valve is combined with a "stopper", which is also referred to as a stop or a limiter, which limits the (valve) stroke of the valve flap. Here, noise can occur as a result of the valve flap striking the stopper and / or the back of the (scroll) base plate, but also as a result of the oil present in the high-pressure chamber, which can cause the valve flap to stick (oil sticking) to the base plate and / or the stopper. As a result of this sticking, a "click noise" occurs when the valve flap is released, which can also resemble a "clatter" when striking the respective face. SUMMARY

[0011] It is the task of the present application to specify an improved scroll machine.

[0012] According to the application, this task is solved by a scroll machine having the features of claim 1. Advantageous and partly inventive embodiments and refinements of the application are listed in the dependent claims and the following description.

[0013] The scroll machine according to the application is set up and designed for conveying a fluid, in particular a refrigerant of a motor vehicle air conditioning system. To this end, the scroll machine has a stationary first scroll (for short: "F-scroll") having a first base plate and a first spiral wall projecting from the first base plate and forming a first spiral channel, and a second scroll (for short: "O-scroll") which is orbitable and has a second base plate and a second spiral wall projecting from the second base plate, which second spiral wall is embedded in the first spiral channel of the F-scroll and forms a number of conveying chambers (also referred to as: extrusion chambers, compression chambers) with the first spiral wall. Furthermore, the scroll machine has a high-pressure chamber arranged on the back side of the first base plate, i.e. in particular on the back side of the F-scroll, and a valve opening (also referred to as: valve bore) constructed in the central region of the first base plate, through which valve opening the fluid conveyed by means of the conveying chambers leaks into the high-pressure chamber in the prescribed operation of the scroll machine. Furthermore, the scroll machine has a valve flap and a stopper for the valve flap, which together with the valve bore form a non-return valve (in particular a so-called reed valve or reed). Here, the envelope of the abutment face of the stopper (on which the valve flap abuts in the open state) approximates the outer contour of the at least one region of the valve flap which abuts against the abutment face. Furthermore, at least one recess is machined in the abutment face in order to provide a contact area of the valve flap on the stopper which is reduced compared to the area enclosed by the envelope. Additionally or alternatively, at least one recess is constructed on the back of the first base plate, which recess is at least partially (preferably only partially) covered by the valve flap in the closed state of the valve flap.

[0014] The envelope here forms an elliptical contour and thus has a contour which is always curved in one direction. That is to say, the center point or anchor point of the associated bending radius is always located on the same side of the contour. Here and in the following, "approximates the outer contour of the at least one region of the valve flap which abuts against the abutment face" is in particular understood to mean that the envelope at least substantially imitates the shape of the valve flap (or the region of the valve flap mentioned). For example, the area covered by the envelope can be slightly reduced compared to the region of the valve flap mentioned. In the case where the region of the valve flap mentioned is configured as a circle, the envelope may, for example, form a slightly smaller circle, for example reduced by less than 1 mm, preferably less than 0.5 mm. Even in the case where the region of the valve flap and the envelope of the abutment face are other, in particular elliptical, geometrical shapes, the envelope preferably recedes ("falls back") by less than 1.0 mm, preferably less than 0.5 mm, than the outer contour of the valve flap.

[0015] Due to the abutment surface having at least one recess, the valve disc abuts on the stopper only with a reduced area (compared to the area described by the envelope), in particular not over the entire area. In this way, in particular, adhesion or sticking ("oil sticking") caused by the liquid, i.e. the valve disc adhering to the stopper due to the intermediate fluid (liquid refrigerant and / or oil) when the valve disc is released, can be reduced or even avoided. Even when opening the check valve, the noise caused by the valve disc striking against the stopper is reduced. The same applies to the back of the first base plate. If this back has the above-mentioned recess, in this way too the striking noise and / or the release noise caused by the gas trapped inside can be reduced. In addition to or alternatively to this noise reduction, the "reaction speed" of the valve disc can advantageously be increased, since the delay of the valve disc when it is released from the stopper or the base plate when closing and / or opening due to oil sticking can be reduced.

[0016] According to one preferred embodiment, the recess is configured as an internal opening in the stopper. This means that the recess is completely bordered by the material of the stopper. In this case, the stopper thus provides the valve disc with a ring-shaped closed contact surface. This embodiment is mechanically advantageous, in particular with respect to high rotational speeds of 300 revolutions per minute to 9000 revolutions per minute, in particular 300 revolutions per minute to 3000 revolutions per minute, which often occur in operation.

[0017] For example, in this case, the recess is formed by a hole, in particular a cylindrical hole.

[0018] Alternatively, the recess has a non-circular, in particular a contour which follows the shape of the valve disc. For example, the contour is roughly drop-shaped or roughly imitates a tennis racket or a table tennis bat.

[0019] According to one suitable embodiment, in addition to or alternatively to the above-mentioned (internal) opening, the recess is configured as a recess in the abutment surface. Optionally, for this purpose, the wall thickness of the stopper is reduced. However, suitably, the recess forms a kind of pressure rib. This enables a particularly high mechanical stability of the stopper. In particular, the above-mentioned internal opening is arranged in this pressure rib or recess. This combination enables the recess (pressure rib) to "vent" when the valve disc strikes against it.

[0020] According to a further suitable embodiment, the recess is configured as a groove on the back of the first base plate. As described above, the groove is partially exposed below the valve disc when the valve disc is arranged in the closed position. In this way, the recess can vent when the valve disc strikes against the first base plate, and the "popping" or "popping noise" caused by the gas trapped inside is prevented or at least reduced, and / or the reaction speed of the valve disc during opening is increased.

[0021] According to an advantageous embodiment, the valve opening (valve bore) is funnel-shaped widened in the first base plate in the direction away from the side diffuser. That is to say, the cross-sectional area of the valve opening increases in the direction of the high-pressure chamber. Optionally, the valve opening is only open in the funnel shape (i.e. in particular continuously) in the end region, for example in the last third of the length of the valve opening. The contour of the valve disc, in particular the area of the valve disc that covers the valve opening (which is also referred to as the "valve head"), is suitably matched to the contour (in particular the diameter or cross-sectional area) of the valve opening on the side away from it, preferably completely covering the valve bore. In other words, the diameter of the valve head or, in the case of a non-circular geometry, at least the area of the valve head, increases in accordance with the widening of the valve opening, so that the valve opening, which is safely widened, is completely covered (closed off) on the side away from it by the valve head in the closed state. As mentioned above, the funnel-shaped widening of the valve opening thus results in a larger flow cross-section in the valve opening and thus in a reduced flow velocity.

[0022] In the case of a funnel-shaped widening of the valve opening, the valve opening preferably has a half-cone angle of between 0 and 30 degrees, in particular between 5 and 25 degrees, preferably between 5 and 15 degrees. Here, the half-cone angle is preferably understood in the longitudinal section of the valve opening as the angle between the valve axis and the section of the side wall of the valve opening that is inclined relative to the valve axis (or, in the case of a non-circular cross-section and / or a funnel-shaped widening that is not rotationally symmetrical, the region with the greatest inclination), (see funnel).

[0023] It is preferable for the edge of the valve opening on the side away from the outer face of the first base plate (arranged in the high-pressure chamber) to be rounded or chamfered. Thereby, an abrupt transition of the wall of the valve opening relative to the outer face of the base plate is avoided, but rather a "soft", more fluid-dynamically advantageous transition is achieved. The rounding radius is for example in the range of 0.5 mm to 2 mm.

[0024] Due to the increase in the flow cross-section caused by the funnel-shaped widening of the valve opening, it is advantageously possible to design the (opening) stroke of the valve disc to be shorter, which in turn leads to a shortening of the time for the valve opening and closing by the valve disc (due to the reduced movement range). This in turn facilitates a high rotational speed of the O-volute. Furthermore, the differential pressure can also act via the valve on an increased (in particular valve disc) area (at least compared to a cylindrical valve opening), so that with the same differential pressure, the valve disc is subjected to a greater force and thus enables a faster "reaction" of the valve disc.

[0025] According to an expedient refinement, the (opening) stroke of the valve disc is reduced in comparison to embodiments with a cylindrical valve opening (valve bore). In particular, due to the single-sided articulation of the valve disc to the first base plate and thus the inclined posture of the valve disc relative to the base plate in the open position, the stroke (stroke value) is approximated in particular by an "average" stroke, which is preferably measured in the area center of gravity of the cross-sectional area of the exit side of the valve opening between the valve disc and the base plate (in particular its outer face) arranged in the open position. Preferably, the stroke is chosen such that the ratio of the cross-sectional area of the exit side of the valve opening (i.e. the area of the valve bore to the opening to the high-pressure chamber) to the lateral surface area of the cylinder described by the diameter (or area) of the valve head and the stroke is in the range between 1 and 5, preferably between 1.3 and 2.7. In contrast, in the case of a cylindrical (i.e. non-diffuser-like widened) valve opening, such a ratio is usually below 1.5, mostly below 1. Here, the lateral surface area describes the area through which the fluid flows upon exiting the valve opening into the high-pressure chamber. Thus, the lateral surface area also determines the volume flow into the high-pressure chamber.

[0026] The conjunction "and / or" is understood here and in the following, inter alia, as follows: The features associated by means of this conjunction can not only be present together, but also alternatively to one another. BRIEF DESCRIPTION OF DRAWINGS

[0027] Embodiments of the application are explained in detail below with reference to the drawings. Therein:

[0028] Figure 1 A scroll machine according to the prior art is shown schematically in perspective view;

[0029] Figure 2 A longitudinal section of a scroll machine according to the prior art is shown schematically in a sectional, partially cut view;

[0030] Figure 3 A portion of a compression module of a scroll machine according to an embodiment of the application is shown schematically in perspective, exploded view;

[0031] Figures 4 to 6 Embodiments of a stopper of a check valve of a scroll machine are shown schematically in individual views, respectively;

[0032] Figures 7 to 9 Embodiments of the stopper are shown schematically in sectional views according to Figure 4 , respectively; and

[0033] Figure 10 A stationary scroll and a check valve are shown schematically in a further sectional, partially cut view.

[0034] In all figures, parts corresponding to one another are provided with the same reference signs. Detailed Implementation

[0035] Figure 1 A scroll machine according to the prior art is shown. This scroll machine is installed here as a scroll compressor 2 (specifically a refrigerant compressor) in a refrigerant circulation loop (not shown in detail) of an air conditioning system in a motor vehicle. The scroll compressor 2 is electrically operated and has an electric drive module 4 and a compression module 6 coupled to the drive module. A mechanical interface 8 is provided between the drive module 4 and the compression module 6, by means of which the compression module 6 is driven to connect to the drive module 4. The compression module 6 is connected to the drive module 4 here by means of flange connections 10 distributed circumferentially, specifically by bolts.

[0036] The drive module 4 has a driver housing 12, which has an internal space 14 (see...). Figure 2 The compression module 6 has a compressor housing or "scroll housing 16", which has a "scroll space 18". An electric motor 20 (partially shown) is arranged in the internal space 14 as a drive. Figure 1 The housing portion of the drive housing 12, indicated in the lower center, surrounds an electronics space (not shown), in which motor electronics (not shown) that drive and control the electric motor 20 during operation are arranged.

[0037] The scroll compressor 2 has a refrigerant inlet 24 (or also referred to as an interface) and a refrigerant outlet 26 for connecting the refrigerant circulation loop. The inlet 24 is formed in the region of the drive housing 12 facing the electronics space. The outlet 26 is formed on the "bottom 28" of the scroll housing 16. In the connected state, the inlet 24 forms the low-pressure side or suction side (suction gas side) of the scroll compressor 2, and the outlet 26 forms the high-pressure side or pump side (pumping side) of the scroll compressor.

[0038] like Figure 2 As can be seen, a bearing end cap 30 on the "driven side" (facing the "A" side of the downstream element to be driven) is arranged in the area of ​​mechanical interface 8. This bearing end cap forms an intermediate wall between drive module 4 and compression module 6, which is also referred to as the "center plate".

[0039] like Figure 2It can be seen that the compression module 6 of the scroll compressor 2 has a stationary first scroll member (scroll portion, hereinafter referred to as fixed scroll, for short: "F-scroll 32") arranged in the scroll member housing 16 and a movable second scroll member (scroll portion, hereinafter referred to as orbiting scroll, for short: "O-scroll 34"). The O-scroll 34 is coupled to a (drive or motor) shaft 38 of the electric motor 20 by means of a radius compensation system (hereinafter referred to as "Swing Link 36") which is guided into the bearing end cap 30. The radius compensation system (or Swing Link) 36 has an eccentric (or also referred to as bearing journal 40) which is connected to the shaft 38 by means of a joint pin or shaft journal (here: "pivot pin 42"; see Figure 2 ). The Swing Link 36 also has a counterweight 44 which is connected eccentrically to the bearing journal 40.

[0040] The bearing journal 40 is also supported in a rolling bearing or ball bearing 48 which is held in the O-scroll 34. A further rolling bearing or ball bearing 50 is arranged in the bearing end cap 30 for supporting the shaft 38. The O-scroll 34 is driven orbitally in the operation of the scroll compressor 2 by means of the shaft 38 and the pivot pin 42 which is introduced eccentrically into the shaft 38. The F-scroll 32, on the other hand, is rigid, i.e. fastened against relative rotation in the scroll member housing 16.

[0041] Both scroll members 32, 34 have an associated helical or spiral spiral wall 52, 54 (scroll wall, scroll spiral) which projects axially from a respective base plate 56, 58. The F-scroll 32 additionally also has a circumferentially surrounding boundary wall 60. The two scroll members 32 and 34 are in the assembled state interleaved in their spiral walls 52, 54. Between the scroll members 32, 34, this means between their spiral walls 52, 54 and the base plates 56, 58, a (transport or) compression chamber 62 is thus formed, the volume of which changes when the electric motor 20 is operated, in particular by the compression chamber 62 moving inwards along the spiral walls 50, 52.

[0042] Due to the change in volume and in particular the reduction of the compression chamber 62, the fluid, in particular gas, located therein is continuously pressed in the prescribed compression operation of the scroll compressor 2. The dimensions of the F-scroll 32 and the O-scroll 34 here predetermine an inherent pressure ratio between the outermost and innermost compression chambers 62, wherein there are always two symmetrical compression chambers 62 which merge centrally into a discharge chamber 64 (see Figure 2From the discharge chamber 64, a valve opening ("valve hole" 66) leads into a high-pressure chamber 68 arranged on the back of the base plate 56 of the F-scroll 32. The valve hole 66 forms, together with a valve flap 70 and a stopper 72, a non-return valve or "reed valve" 74. The reed valve 74 enables a predetermined system pressure or opening pressure from the coolant circulation circuit side, at which the valve flap 70 is opened. This occurs when the pressure value of the scroll pressure in the discharge chamber 64 exceeds the pressure value of the system pressure in the high-pressure chamber 68 as a result of the continuously decreasing volume of the discharge chamber.

[0043] Figure 3 The reed valve 74 is shown in detail. In particular, in order also to enable a system pressure value that is lower than the intrinsic pressure value of the scroll compressor 2, additional holes 76, here specifically two, are introduced into the base plate 56, which connect the compression chamber 62, which lies upstream of the discharge chamber 64, with the high-pressure chamber 68. These two additional holes 76 are also each equipped with a valve flap 78 and a stopper 80. In the present embodiment, these additional valve flaps 78 form a common, integral component with the valve flap 70. Specifically, the respective valve flaps 70 or 78 each form a finger of a spring steel sheet. Similarly, the stopper 72 and the additional stopper 80 form an integral component. This component, and thus each individual stopper 72 and 80, is formed from a steel sheet, the edges of which are rounded in order to avoid any stress loads on the valve flaps 70, 78 when they strike against the respective stopper 72, 80. The respective stopper 72, 80 is bent over on the free end side, so that it projects as a beak over the respective valve hole 66 and additional hole 76. The stoppers 72 and 80 form a stop for the respective valve flap 70 or 78 in its open position, so that the valve flaps open only to the inclined position predetermined by the stopper 72 or 80.

[0044] In the prescribed operation, with consideration only of the discharge chamber 64, the valve flap 70 is opened when the pressure value in the discharge chamber 64 exceeds the pressure value in the high-pressure chamber 68. At this point, the valve flap 70 is bent into the high-pressure chamber 68 and comes into abutment with the stopper 72. The valve flap 70 has here a roughly racket shape, i.e. a relatively narrow stem region, which is clamped by the stopper 72 against the base plate 56 in the prescribed installed state. Coupled to the stem region on the free end side is an enlarged region, which is also referred to as valve head 82. The valve head 82 is here configured approximately circular and has a diameter that matches the diameter of the valve hole 66, in particular the diameter of the exit side, so that the valve head 82 in the closed state closes off (covers) the valve hole 66 on the exit side. In other words, the diameter of the valve head 82 is greater than the diameter of the exit side of the valve hole 66, or more precisely, the cross-sectional area of the valve head 82 exceeds the cross-sectional area of the valve hole 66, in the case of a non-circular geometry of the valve head 82 and / or the valve hole 66.

[0045] The head region 84 of the stopper 72 matches the valve head 82 in area and shape, so that their areas and shapes fit together, or the valve head 82 slightly (for example by an excess of less than 1 mm) exceeds the head region 84.

[0046] In the embodiment shown in Figure 3 The head region 84 of the stopper 72 is provided with a drop-like or tennis racket-like cutout 86. An envelope 88, which here corresponds to the remaining, ring-closed edge of the stopper 72, i.e. of its head region 84, here is elliptical.

[0047] The cutout 86 causes the valve plate 70 to be able to rest on the stopper 72 only over a smaller area than without the cutout. As a result, the oil film deposited on the stopper 72 during operation of the scroll compressor 2 hardly exerts an adhesive effect on the valve plate 70, which is resting on the stopper 72 with its valve head 82, i.e. a so-called "oil stick". As a result, it is possible to prevent or reduce the rattling or crackling noise that occurs when the valve head 82 is detached from the stopper 72. However, it is also possible to reduce the noise that occurs when the valve head 82 hits on the head region 84 of the stopper 72.

[0048] In order to also reduce the noise that occurs when the valve head 82 hits or detaches from the back of the base plate 56, two pockets 90 (or recesses, slots) are machined in the base plate 56, which are only partially obscured by the valve plate 70 in its closed state.

[0049] In order to reduce the outflow speed of the extruded fluid from the valve hole 66, the valve hole has a varying cross section, specifically a diffuser-like widening towards the high-pressure chamber 68 (outlet side) (see Figure 3 and Figure 10In other words, the cross-sectional area Aa of the valve orifice 66 at the exit portion into the high-pressure chamber 68 is larger than the area on the entry side. To continue blocking the valve orifice 66, the valve head 82 is also enlarged, matching the area Aa of the valve orifice 66 at the exit portion into the high-pressure chamber 68. Specifically, the area Avk of the valve head 82 is larger than the area Aa on the exit side of the valve orifice 66. This advantageously reduces the opening stroke h of the valve plate 70. The opening stroke h is approximately defined here as the distance between the valve plate 10 in the open position (abutting against the limiter 72) and the first substrate 56, measured at the center of the area Aa (in the rotationally symmetric embodiment of the valve orifice 66). The reduction in the opening stroke h, in turn, leads to a decrease in the speed of the valve plate 70 during opening and closing, because the available acceleration stroke is reduced. Here, the opening stroke h is reduced such that the ratio of the area Aa of the valve orifice 66 to the circumferential area that can be calculated from the area Avk of the valve head 82 and the opening stroke h is between 1.3 and 2.7, or optionally between 1.5 and 2.5.

[0050] exist Figures 4 to 7 Different embodiments of limiters 72 and 80 are shown here. Figure 4 Corresponding to according to Figure 3 An example of this embodiment. Here, the empty portion 86 is roughly shaped like a tennis racket.

[0051] exist Figure 5 In the middle, the empty portion 86 is formed by a circular hole. Therefore, Figure 4 and Figure 5 An internal opening is shown, which is surrounded by the material of the retainer 72 on the edge side.

[0052] On the contrary, according to Figure 6 In one embodiment, the edge-side clearance (“notch” 92, or also referred to as: gap) is machined into the limiter 72. The dotted curve here represents the aforementioned envelope 88. According to... Figure 6 In one embodiment, the envelope is also elliptical.

[0053] exist Figure 7 The text shows the data based on... Figure 4 The longitudinal section VII-VII passes through the limiter 72. It can be seen from this that the limiter is roughly located at the last third (in...) Figure 7 (Left side) Bend up. This bend forms the boundary of the (opening) stroke of the valve plate 70 as described above. The tennis racket-shaped clearance 86, specifically the "grip area" of a tennis racket, extends from the area of ​​the valve head 82 and extends to the surface area of ​​the limiter 72. The clearance 86 is formed by punching and subsequently deburring and rounding the punched edges.

[0054] Figure 8Different embodiments are shown in the figures. Here, the recess 86 is configured as a depression, in particular as a bulge of the material of the stopper 72, which faces downward (in Figure 8 the direction of the valve hole 66, i.e. away from the valve hole 66. Thus, the recess 86 forms a pressure rib. Thereby, the stopper 72 can be made particularly mechanically stable. Due to the depression, an oil adhesion layer cannot easily be configured.

[0055] Figure 9 Further embodiments are shown in the figures. The further embodiments show, for the recess 86, a combination of a pressure rib according to Figure 8 the prior art with an additional opening (hole 94) within the pressure rib. Thereby, it is possible to vent the depression through the hole 94, thereby avoiding or at least significantly reducing a potential "popping noise" due to a gas volume trapped inside when the valve plate 70 hits.

[0056] The subject matter of the present application is not limited to the above-described embodiments. Rather, further embodiments of the present application can be deduced by the person skilled in the art from the above description. In particular, individual features of the present application described in connection with the different embodiments and design variants thereof can also be combined with one another in other ways.

[0057] List of reference signs

[0058] 2 scroll compressor

[0059] 4 drive module

[0060] 6 compression module

[0061] 8 interface

[0062] 10 flange connection

[0063] 12 drive housing

[0064] 14 inner space

[0065] 16 scroll housing

[0066] 18 scroll space

[0067] 20 electric motor

[0068] 24 inlet

[0069] 26 outlet

[0070] 28 bottom

[0071] 30 bearing end cap

[0072] 32 F-scroll

[0073] 34 O-scroll

[0074] 36 swing lever

[0075] 38 shaft

[0076] 40 bearing journal

[0077] 42 shaft pin

[0078] 44 counterweight

[0079] 48 ball bearing

[0080] 50 ball bearing

[0081] 52 spiral wall

[0082] 54 spiral wall

[0083] 56 base plate

[0084] 58 base plate

[0085] 60 boundary wall

[0086] 62 compression chamber

[0087] 64 discharge chamber

[0088] 66 valve bore

[0089] 68 high-pressure chamber

[0090] 70 valve disc

[0091] 72 stopper

[0092] 74 reed valve

[0093] 76 additional bore

[0094] 78 valve disc

[0095] 80 stopper

[0096] 82 valve head

[0097] 84 head region

[0098] 86 cutout

[0099] 88 envelope

[0100] 90 pocket

[0101] 92 notch

[0102] 94 bore

[0103] Aa area

[0104] Ae area

[0105] Avk area

[0106] h stroke

Claims

1. Scroll machine (2) for conveying a fluid, in particular a refrigerant of a vehicle air conditioning system, having - a first scroll element (32) which is stationary, having a first base plate (56) and a first spiral wall (52) which projects from the first base plate (56) and which forms a first spiral channel, and - a second scroll element (34) which is orbitable, having a second base plate (58) and a second spiral wall (54) which projects from the second base plate (58) and which is embedded in the first spiral channel of the first scroll element (32) and forms a number of conveying chambers (62) with the first spiral wall (52), - a high-pressure chamber (68) which is arranged on the back side of the first base plate (56), - a valve opening (66) which is configured in a central region of the first base plate (56), through which, in a prescribed mode of operation, the conveyed fluid escapes into the high-pressure chamber (68), - a valve flap (70) and a stopper (72) for the valve flap (70), which together with the valve opening (66) form a non-return valve (74), - an envelope of a contact surface of the stopper (72) which abuts against the valve flap (70) in an open state of the valve flap, which envelope is approximately congruent with an outer contour of at least one region of the valve flap (70) which abuts against the contact surface, and wherein at least one recess (86) is machined into the contact surface in order to provide a reduced contact surface of the valve flap (70) on the stopper (72) compared to an area enclosed by the envelope (88), and / or - wherein at least one recess (90) is configured on the back side of the first base plate (56), which recess is at least partially covered by the valve flap (70) in a closed state of the valve flap.

2. Scroll machine (2) according to claim 1, wherein the recess (86) is configured as an internal opening in the stopper (72).

3. Scroll machine (2) according to claim 2, wherein the recess (86) is configured as a hole.

4. Scroll machine (2) according to claim 2, wherein the recess (86) has a non-circular contour which follows the shape of the valve flap (70).

5. Scroll machine (2) according to any one of claims 1 to 4, wherein the recess (86) is configured as a recess in the contact surface.

6. Scroll machine (2) according to any one of claims 1 to 5, wherein the recess (86) is configured as a laterally open slit (92) in the contact surface. wherein 7. Scroll machine (2) according to any one of claims 1 to 5, wherein the recess (90) is configured as a groove in the back side of the first base plate (56).

8. Scroll machine (2) according to any one of claims 1 to 7, ​ ​ wherein, ​ ​ wherein ​ ​ wherein ​ ​ wherein ​ ​ wherein ​ ​ wherein ​ ​ wherein The valve opening (66) is widened in the exit direction and wherein the diameter or area (Avk) of the region of the valve flap (70) which covers the valve opening (66) in the closed state is adjusted accordingly.

9. The machine (2) according to claim 8, wherein The edge of the valve opening (66) towards the outside of the first base plate (56) is rounded or chamfered.

10. The machine (2) according to claim 8 or 9, wherein, The opening stroke (h) of the valve flap (70) is reduced such that the ratio of the cross-sectional area (Aa) of the exit side of the valve opening (66) to the lateral area of the cylinder described by the diameter or area (Avk) of the region of the valve flap (70) which covers the valve opening (66) in the closed state and the opening stroke (h) is between 1 and 5, preferably between 1.3 and 2.7.

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