Scroll compressor

Abstract

The invention relates to a scroll compressor (6). This comprises a scroll (24) with a base plate (24b) and with a spiral wall (24a) extending upwards in the scroll direction (H) from its compressor chamber side (40), wherein the base plate (24b) has a recess (36) extending through in the scroll direction (H), in which a nozzle (38) separate from the base plate (24b) is received. The invention further relates to a refrigerant drive with such a scroll compressor (6).

Description

[0001] The invention lies in the field of positive displacement machines based on the spiral principle and relates to a scroll compressor and a refrigerant compressor for refrigerants of a vehicle air conditioning system.

[0002] Some vehicles are equipped with an air conditioning system that uses a refrigerant circuit to cool the vehicle interior. These systems essentially consist of a closed loop containing a refrigerant. The refrigerant, for example R-134a (1,1,1,2-tetrafluoroethane) or R-744 (carbon dioxide), is heated at an evaporator and compressed by a refrigerant compressor. The refrigerant then releases the absorbed heat via a heat exchanger before being returned to the evaporator through an expansion valve.

[0003] To compress a refrigerant-oil mixture, a scroll compressor is used, for example. The compressed gas-oil mixture is then separated, with the separated gas being introduced into the air conditioning circuit, while the separated oil can optionally be used within the scroll compressor (ideally an electrically driven refrigerant compressor) to lubricate moving parts.

[0004] The scroll compressor comprises a stationary scroll (stator scroll, fixed scroll, F-scroll) and a movable, orbiting scroll (rotor scroll, displacement scroll, O-scroll). Each scroll has a base plate and a spiral wall extending perpendicular to the base plate, which is referred to as the spiral wall. When assembled, the spiral walls of the two scrolls overlap, forming compressor chambers between the sections of the scroll walls that touch each other.

[0005] As the moving scroll orbits, the aspirated gas-oil mixture passes through an inlet from a low-pressure chamber to a first, radially outer compressor chamber (suction chamber), and from there through further compressor chambers (compression chamber) to the radially innermost compressor chamber (discharge chamber, exhaust chamber), and from there through a central outlet opening into a discharge or high-pressure chamber. The chamber volume in the compressor chambers decreases from radially outer to radially inner, and the pressure of the increasingly compressed medium increases. Thus, during operation of the scroll compressor, the pressure in the compressor chambers rises from radially outer to radially inner.

[0006] During operation of the scroll compressor, the pressure generated in the compressor chambers and the resulting axial force cause the moving and stationary scrolls to be forced apart axially, potentially creating a gap and thus leakage between the chambers. To prevent this as much as possible, the orbiting scroll is pressed against the stationary scroll, possibly in addition to an oil film between the friction surfaces of the two scrolls. The corresponding axial force (counterforce) is generated by providing a back pressure chamber (receiving or pressure chamber) with the appropriate pressure on the back of the orbiting scroll's base plate. For this purpose, one of the compressor chambers is fluidically connected to the back pressure chamber via a fluid connection.

[0007] From DE 10 2020 210 452 A1, a scroll compressor is known in which the back pressure chamber is connected to the radially innermost compressor chamber by means of a fluid connection. The fluid connection is designed as a bore in the base plate.

[0008] German patent DE 10 2017 105 175 B3 describes a positive displacement machine based on the spiral principle. This machine comprises an orbiting displacer spiral that engages with a counter-spiral, forming compression chambers between the displacer spiral and the counter-spiral. The displacer spiral has at least two passages that establish a fluid connection, at least temporarily, between the counter-pressure chamber and at least one of the compression chambers. These passages are designed as through-holes.

[0009] The diameter of the respective fluid connections is chosen to be as small as possible in order to reduce mass flow loss and thus improve the efficiency of the scroll compressor. For example, the diameter of the respective fluid connection is chosen to be less than 1 mm.

[0010] When creating these fluid connections by machining in the scroll, there is a risk that, due to manufacturing tolerances, the bore diameter may deviate significantly from a specified target diameter, which in turn results in a reduction of the scroll compressor's compression performance. With such a large deviation in bore diameter, the scroll is therefore typically not used and is considered scrap.

[0011] The invention is based on the objective of providing a particularly suitable scroll compressor. In particular, it aims to avoid, as simply and / or cost-effectively as possible, deviations in the diameter of a fluid connection from a nominal diameter, which are considered defective. Furthermore, a refrigerant drive system incorporating such a scroll compressor is to be provided.

[0012] This problem is solved according to the invention with respect to the scroll compressor by the features of claim 1. With respect to the refrigerant drive, the problem is solved according to the invention by means of the features of claim 15.

[0013] Advantageous further developments and configurations are the subject of the dependent claims. The statements relating to the refrigerant drive also apply to the scroll compressor and vice versa.

[0014] The scroll compressor is specifically designed for electric refrigerant drive in a motor vehicle air conditioning system.

[0015] The scroll compressor has a scroll, i.e. a scrolling part, which in turn has a base plate, also called a base plate, and a spiral wall that rises from its compressor chamber side in the scroll direction.

[0016] The base plate has a recess extending through the scrolling direction. This recess is a perforated opening in the base plate, specifically designed as a through-hole. A fluid can therefore flow through this recess in and / or against the scrolling direction. A nozzle, separate from the base plate, is housed within the recess, specifically fixed and / or held there. The nozzle, in turn, includes a fluid passage, allowing a fluid to flow through the nozzle, specifically through its fluid passage, in and / or against the scrolling direction.

[0017] In summary, the nozzle is a separate component from the scroll; it is not simply formed by machining, for example by drilling, the base plate. Specifically, the nozzle is a push-fit component. This allows a fluid, particularly a refrigerant-oil mixture, to flow through the nozzle located in the receptacle and its fluid passage from the compressor chamber side of the base plate to a space at the rear of the base plate. In short, the receptacle and the nozzle within it create a fluid connection between the space at the rear of the base plate and the space at the compressor chamber side of the base plate.

[0018] The nozzle is advantageously arranged in the housing in a fluid-tight manner. This prevents the fluid, especially the refrigerant-oil mixture, from flowing past the nozzle, i.e., from flowing through the housing in the area between the side wall of the nozzle and the side of the base plate that defines the housing. The fluid therefore flows only through the nozzle and its fluid passage.

[0019] Furthermore – and especially if CO2 is used as the refrigerant – the fluid passage has a diameter of less than 0.7 mm, for example less than 0.5 mm, and in particular less than 0.3 mm. Suitablely, the diameter is greater than 0.03 mm, for example greater than 0.05 mm, and in particular greater than 0.1 mm. Additionally or alternatively, the clear area of ​​the fluid passage is less than 1.5 mm². 2 and / or more than 0.003 mm 2 if the fluid passage is not circular.

[0020] For example, when compressing CO2, the pressure in the suction chamber can reach up to 150 bar high pressure, with a suction pressure of 20 bar. With such a comparatively small diameter of the fluid passage, the mass flow through the nozzle is correspondingly reduced, and the efficiency of the scroll compressor is thus advantageously improved.

[0021] For example, the base plate of the scroll includes at least one further recess in which another separate nozzle is inserted in a similar manner. For instance, the diameters of the fluid passages of the two nozzles are different.

[0022] If a scroll has two (or more) fluid connections, their diameters are typically matched. If, as in the previously mentioned prior art, the fluid connection is formed by drilling into the base plate, a quality control error would result in the entire scroll being marked as defective. Using a separate nozzle, on the other hand, has the advantage that it can be tested relatively easily before installation. If the nozzle is faulty, a different one simply needs to be used. Therefore, only tested and approved nozzles are used for installation in the scroll, thus reducing the cost of errors. Furthermore, automating the process of creating the fluid passage is also simpler than drilling directly into the scroll, as the spiral wall often obstructs the drilling process.

[0023] If the scroll has more than one (single) inlet, each with its own nozzle, matching the diameters of the fluid passages of these nozzles is comparatively difficult due to tolerances in the machining process. Because the nozzles are separate from the scroll (and therefore interchangeable), if the diameters do not meet the specified ratio or the specified diameters, only one or both nozzles need to be replaced; the scroll can still be used effectively.

[0024] In summary, compared to the previously mentioned state of the art, where the nozzle is formed by a bore in the base plate, only the separate nozzle can be replaced or a different nozzle used in a comparatively simple manner if its fluid passage diameter does not meet a specified value. The scroll itself, however, can continue to be used. Thus, the costs associated with errors are significantly reduced.

[0025] The scroll is, for example, the so-called orbitally driven scroll (orbiting scroll, O-scroll) of the scroll compressor. For instance, a compressor chamber formed between this orbitally driven scroll and another scroll (F-scroll) that is fixed relative to a (compressor) housing of the scroll compressor is fluidically connected or connectable to a back pressure chamber of the scroll compressor, which is located, in particular, on the rear of the base plate of the O-scroll.

[0026] Alternatively, the scroll with its housing and nozzle is stationary relative to a scroll compressor housing. For example, the compressor chamber formed between this housing and the orbitally driven scroll is fluidically connected or connectable to a high-pressure chamber of the scroll compressor, particularly one located on the rear of the base plate of the stationary scroll.

[0027] For example, the other scroll of the scroll compressor has a receptacle with a nozzle incorporated in it, in a similar manner.

[0028] In summary, the F-Scroll and / or the O-Scroll each have a continuous recess in the respective scroll vertical direction with a nozzle embedded within it.

[0029] The compressor chamber side of the base plate is therefore the (base) side of the base plate on which the spiral wall is located. Thus, the compressor chamber side is the side of the base plate that borders the compressor chambers. Similarly, the rear or underside of the base plate refers to the (base) side of the base plate facing away from the compressor chamber side, i.e., the side of the base plate oriented parallel to the compressor chamber side.

[0030] According to a first variant of the scroll compressor, the nozzle is a hollow cylinder. The nozzle thus has a cylindrical, in particular circular cylindrical, base body with a coaxial cylindrical, in particular circular cylindrical, recess that extends through the nozzle in the axial direction. This recess forms the fluid passage.

[0031] Such a nozzle is relatively easy to manufacture using a machining process, for example by turning, whereby the fluid passage is introduced into the base body produced by turning, for example by drilling.

[0032] For example, in this first variant, the clear width of the receptacle and / or the outer diameter (outer diameter of the base body) of the nozzle is between 1 mm and 7 mm, particularly between 3.0 mm and 5.0 mm, for example, 4.5 mm. With such a large nozzle or receptacle design, handling the nozzle, especially its insertion, is comparatively easy. This significantly increases process reliability.

[0033] According to a second variant, the nozzle is cup-shaped. In other words, the nozzle, forming a cup shape, comprises a pot base and a side wall oriented perpendicular to the pot base. When the nozzle is mounted in the housing, it is arranged such that the pot base is oriented perpendicular to the scroll vertical direction and / or that the side wall extends from the inner side of the pot base, facing away from the compressor chamber side of the base plate, in the opposite direction to the vertical direction.

[0034] The side wall is advantageously designed in a hollow cylindrical shape. The wall thickness of the side wall and / or the base of the pot is, in particular, between 0.1 mm and 0.3 mm, especially 0.2 mm.

[0035] In this second variant, the outer diameter of the side wall and / or the clear width of the opening is expediently between 1.0 mm and 3.0 mm, in particular 1.5 mm or 2.0 mm. Alternatively, analogous to the first variant, the outer diameter of the side wall and / or the clear width of the opening is expediently a value between 1 mm and 7 mm, in particular between 3.0 mm and 5.0 mm, for example 4.5 mm.

[0036] The nozzle cup base has a fluid passage, i.e., a nozzle opening. This is advantageously designed as a through-hole. In other words, the fluid passage is designed as a continuous recess in the cup base, particularly in the scrolling direction.

[0037] For example, the cup-shaped nozzle is manufactured by deep drawing. The fluid passage is created in the base of the cup, for example, by punching or using a laser. In particular, when creating the fluid passage using a laser, the tolerance of its diameter is comparatively low compared to machining by drilling. Furthermore, especially compared to machining the fluid passage, repeatability is comparatively high, and tool wear is avoided.

[0038] According to an advantageous embodiment, the distance of the nozzle, in particular its base surface facing the compressor chamber (first variant) or its cup bottom (second variant), to the compressor chamber side in the scroll direction is less than 2 mm, and in particular less than 1 mm. The distance is therefore between 0.0 mm and 2 mm, and in particular between 0.0 mm and 1 mm. In this way, the space between the cup bottom and the plane defined by the compressor chamber side is comparatively small. An undesirable and / or undefined influence of this so-called dead volume on the pressure in the space behind the base plate, especially in the back pressure chamber, is thus advantageously avoided.In particular, pressure equalization between this dead volume and the space area at the rear of the base plate is avoided if the spiral wall of the further scroll partially or completely separates the dead volume from the compressor chamber into which the intake leads.

[0039] Preferably, the nozzle does not extend vertically beyond the base plate on the compressor chamber side. In other words, the nozzle does not protrude into the compressor chamber.

[0040] Ideally, the bottom of the pot should be flush with the compressor chamber side of the base plate.

[0041] According to an advantageous embodiment, the material from which the nozzle is formed and the material from which the scroll is formed have the same coefficient of thermal expansion. This advantageously prevents the nozzle from loosening or even detaching from its housing due to differing thermal expansion. It is also advantageous, or alternatively, for the nozzle to be made of the same material as the scroll.

[0042] Additionally or alternatively, the nozzle and / or the scroll are made of a metal or alloy, suitablely either steel or aluminum. For example, both the scroll and the nozzle are made of steel. Alternatively, both the scroll and the nozzle are made of aluminum. This prevents or at least reduces the risk of nozzle deformation during operation of the scroll compressor due to the pressure and / or temperature acting upon it, and thus also prevents or reduces the risk of the nozzle becoming unintentionally detached from its housing.

[0043] According to a suitable embodiment, the nozzle is held in the receptacle by friction, preferably by means of an interference fit. Thus, the nozzle is seated in the receptacle. The nozzle is therefore press-fitted to the receptacle and / or held in the receptacle by friction.

[0044] Alternatively, the nozzle is held in the holder by means of a threaded connection. For example, the nozzle may have a thread on its outer circumference, in particular an external thread, and / or the holder may have a corresponding mating thread.

[0045] According to a preferred embodiment, the base plate forms a stop for the nozzle, in particular for its cup base, in the scrolling direction. The nozzle is thus positioned in a defined position within the receptacle by means of this stop. Furthermore, the stop defines an end position when inserting the nozzle into the receptacle.

[0046] For example, the receptacle for forming the stop has an undercut. The undercut is, for instance, an extension of the receptacle in a direction perpendicular to the scrolling direction. In other words, the diameter of the receptacle is increased in the area of ​​the undercut. In particular, the side of the base plate that limits the undercut in the scrolling direction forms the stop surface for the nozzle. Specifically, the side wall of the nozzle is completely located within the undercut. During assembly, the nozzle is deformed, at least slightly, preferably elastically, to fit into the receptacle and thereby bring the side wall into the area formed by the undercut.

[0047] Alternatively or additionally to forming the stop using the undercut, the base plate has a projecting shoulder extending into the recess to form the stop. Advantageously, the shoulder is positioned at the end of the recess in the scroll direction, i.e., at the compressor chamber-side end.

[0048] If a drill head with a drill head angle of less than 180° is used when manufacturing the nozzle holder, the contact side of the contact shoulder facing the nozzle is inclined relative to the scroll direction. In particular, the holder tapers conically. However, if the base of the cylindrical nozzle (first variant) or the bottom of the cup-shaped nozzle (second variant) is oriented perpendicular to the scroll direction, a dead volume is formed between the nozzle and the contact shoulder. To avoid this, according to a practical design, the contact side of the contact shoulder facing the nozzle is flat and / or oriented perpendicular to the scroll direction.

[0049] In particular, in the second variant of the scroll compressor, the nozzle is held in the receptacle by means of a snap connection in addition to or as an alternative to the press fit and / or in addition to or as an alternative to the stop, according to a suitable design.

[0050] For example, the side wall of the nozzle has a snap-fit ​​tab to form the snap connection. This tab projects laterally from the side wall, i.e., outwards from the nozzle, in other words, away from the nozzle's central axis. This tab is conveniently spring-loaded for assembly. The receptacle also includes an undercut or a snap lug for the snap tab. In the assembled state, the snap tab engages in the undercut or engages behind the snap lug.

[0051] Alternatively or additionally, the base plate has a projection extending into the recess. The side wall has a recess, particularly a groove-shaped one, projecting inwards towards the nozzle. Advantageously, the shape of the projection corresponds to the shape of the recess so that the projection can be received within it. In the assembled state, the projection engages in the recess. Advantageously, the side wall is at least slightly elastically deformable so that the nozzle can be slid over the projection, and any deformation of the side wall that may occur when the nozzle is slid over the projection returns to its original state. In summary, the recess forms a snap-fit ​​groove into which the projection of the base plate is received.

[0052] According to an advantageous embodiment of the second variant of the scroll compressor, the side wall of the nozzle has a stop at its free end, i.e., at the end facing away from the base of the housing, extending outwards in a direction perpendicular to the upward direction of the scroll, i.e., perpendicular to the central axis of the nozzle. This stop is also referred to as the scroll stop. This stop serves, firstly, as a stop for mounting the nozzle in the housing, particularly if the base plate does not have a stop for the nozzle. Furthermore, this stop serves as a sealing surface for measuring the flow rate of a fluid through the fluid passage when the nozzle is not yet mounted in the scroll, i.e., for checking the nozzle.

[0053] Due to tolerances in the nozzle's outer diameter, particularly its sidewall, and the diameter of the housing, there is a risk that the nozzle will plastically deform, i.e., bulge, during insertion into the housing. According to an advantageous embodiment of the second variant of the scroll compressor, the base of the housing and / or the scroll stop has a recess, particularly groove-like or rib-like, extending expediently in the opposite direction of the scroll's vertical axis H, to increase the flexibility of the sidewall inwards towards the nozzle's central axis. This recess, or these recesses, creates a resilient contour in the nozzle, thereby preventing or at least reducing bulging during installation.

[0054] Additionally or alternatively, to prevent or reduce nozzle bulging, the nozzle is designed such that the side wall tapers towards the bottom of the pot. In other words, the diameter of the side wall decreases in the vertical scroll direction, i.e., towards the bottom of the pot. This reduces the contact area of ​​the side wall with the holder and also reduces the stiffness of the nozzle in the area where the side wall connects to the bottom of the pot.

[0055] According to an advantageous embodiment of the first and, in particular, the second variant of the scroll compressor, the base plate of the scroll has a bent section at its rear side, facing away from the compressor chamber. For example, the bent section is formed by the base plate having a recess, arranged concentrically, for the recess, wherein the section of the base plate located between the recess and the recess forms the bent section. Alternatively, for example, the bent section is formed by means of a projection extending in the opposite direction to the vertical direction, which is expediently arranged on the underside at the edge of the recess.

[0056] In some cases, the bent section, when assembled with the nozzle in the holder, is bent towards the nozzle and presses against its side wall and / or even bends the side wall inwards. During assembly, for example, the scroll stop is pressed into the recess or against the side of the bent section facing away from the holder (which, in the pre-assembled state, should extend parallel to the central axis of the nozzle), causing it to bend towards the nozzle.

[0057] Another aspect of the invention relates to a refrigerant drive comprising a scroll compressor in one of the variants shown above. Advantageously, the refrigerant drive further comprises a motor, in particular an electric motor, for driving the orbitally driven scroll.

[0058] Exemplary embodiments of the invention are explained in more detail below with reference to a drawing. The drawing shows: Fig. 1 schematically in a longitudinal section a refrigerant drive with a scroll compressor having a stationary and an orbitally driven scroll, wherein the base plate of the orbitally driven scroll has a receptacle with a nozzle received therein, and wherein a compressor chamber of the scroll compressor and a back pressure chamber are fluidically connected or connectable by means of the nozzle, Fig. 2a to c an embodiment of the orbitally driven scroll, wherein its base plate has two receptacles designed as through-bores, in each of which a nozzle separate from the scroll is received, in a top view of the compressor chamber side, in a top view of the rear or in a sectional view with a section plane through the receptacles, Fig. 3a, Fig. 3b schematically one of the nozzles of the Fig. 2a to 2c in perspective view looking at the bottom of their pot or at the scroll stop, Fig. 4a, Fig. 4b in perspective view an alternative design of the nozzle, wherein its side wall has a recess projecting inwards towards the nozzle, Fig. 4c schematically and in part according to the Fig. 4a and Fig. 4b designed nozzle which is held in the receptacle by means of a snap connection, Fig. 5 schematically an alternative embodiment of the nozzle and the scroll, wherein the nozzle is held in the receptacle by means of a press fit, Fig. 6 schematically and in part the nozzle arranged in the recording according to an alternative embodiment, wherein the recording has an undercut in which the nozzle is seated, Fig. 7 schematically and in part the nozzle arranged in the image according to an alternative embodiment, wherein the nozzle has a snap-fit Fig. 8 schematically in a sectional view an alternative design of the nozzle, wherein the nozzle tapers at its compressor chamber-side end, Fig. 9 schematically in a sectional view an alternative design of the nozzle, wherein its scroll stop has a recess, Fig. 10 schematically in a sectional view an alternative design of the nozzle, wherein both its scroll stop and the pot base each have a recess, Fig. 11 schematically and in part the scroll in an alternative embodiment in a sectional view, wherein the nozzle is inserted into the receptacle, and wherein its scroll stop is pressed into a recess, so that a bending section arranged on the back of the scroll bends towards the nozzle, Fig. 12. Schematically and in part, the scroll in an alternative embodiment in a sectional view, wherein the nozzle is a hollow cylinder, and Fig. 13 schematically and in part the scroll in an alternative embodiment in a sectional view, wherein the nozzle is a hollow cylinder, wherein the diameter of its coaxial recess has a diameter extension.

[0059] Corresponding parts and sizes are always marked with the same reference symbols in all figures.

[0060] The in Fig. The refrigerant drive 2 shown in Figure 1 is preferably designed and configured as a refrigerant compressor for a refrigerant circuit (not shown) of a motor vehicle air conditioning system. The electric refrigerant compressor 2 has an electric (electromotive) drive 4 and a scroll compressor 6 coupled to it. The scroll compressor 6 is hereinafter also referred to simply as compressor 6.

[0061] The drive 4 has a drive housing 8, which defines a motor compartment in which an electric motor 10 is housed.

[0062] The drive housing 8 has a suction inlet or port (not shown) at approximately the level of the electric motor 10 for connection to the refrigerant circuit of the air conditioning system. A fluid, in particular the refrigerant, flows into the drive housing 8 through the inlet. From there, the fluid can flow through a bearing shield 12 to the compressor 6. The refrigerant is then compressed by the compressor 6 and exits into the refrigerant circuit of the air conditioning system at a bottom-side refrigerant outlet 14 of the compressor 6.

[0063] The outlet 14 is formed on the bottom of a pot-shaped (compressor) housing 16 of the compressor 6. When the refrigerant drive 2 is operating, the inlet forms the low-pressure or suction side and the outlet 14 the high-pressure or pump side.

[0064] The electric motor 12, which is particularly brushless, comprises a rotor 20 which is coupled to a motor shaft 18 in a rotationally fixed manner and which is arranged to rotate within a stator 22.

[0065] The compressor 6 has a movable scroll 24 arranged in the compressor housing 16. This scroll is coupled to the motor shaft 18 of the electric motor 10. During operation of the compressor 6, the movable scroll 24 is driven in an orbiting motion by the electric motor 10 and is therefore also referred to as an O-scroll, an orbiting-driven scroll, or an orbiting-driven scroll.

[0066] The scroll compressor 6 also has a rigid, i.e., fixedly mounted scroll (scroll part) 26 within the compressor housing 16. The two scrolls (scroll parts) 24, 26 interlock with their helical or spiral spiral walls (scroll walls, scroll spirals) 24a, 26a, which project axially from a respective base plate 24b, 26b. The spiral walls 24b, 26b are only indicated by reference numerals in the figures for illustrative purposes.

[0067] In the assembled state of the compressor 6, the spiral wall 24a of the movable scroll 24 engages in the free spaces or gaps of the spiral wall 26a of the stationary scroll 26. Between the scrolls 24, 26, that is, between their spiral walls 24a, 26a and their base plates 24b, 26b, compressor chambers 28 are formed, the volume of which changes during compressor operation.

[0068] The scrolls 24, 26 are connected to the motor compartment of the drive housing 8 via a suction or low-pressure chamber 30 of the compressor housing 16. During operation, the fluid is conveyed from the low-pressure chamber 30 to a high-pressure chamber 32 of the compressor housing 16.

[0069] In the following, “axial” or an “axial direction A” is understood in particular to mean a direction parallel (coaxial) to the axis of rotation of the electric motor 10.

[0070] Between the bearing shield 12 (centerplate) and the movable scroll 34 there is a backpressure chamber 34. This is fluidically connected to at least one of the compressor chambers 28.

[0071] For this purpose, the base plate 24b of the orbiting scroll 24 includes a through-bore extending in the axial direction A. This forms a receptacle 36 in which a nozzle 38 is received. This is shown in the Fig. 1 only schematically indicated. In the Fig. Figures 2 to 11 show variants of the scroll 24 and / or the nozzle 38.

[0072] According to an alternative compressor configuration (not shown further), the stationary scroll 26 additionally or alternatively has a continuous recess in the axial direction A, in which a nozzle 38 is received. This nozzle 38, received in the recess, forms a fluid connection between the corresponding compressor chamber 28 and the high-pressure chamber 32. In particular, this creates an additional pre- or auxiliary outlet (pre-outlet) to a main outlet 40. Such an auxiliary outlet serves, in particular, to prevent over-compression of the refrigerant during operation of the compressor 6. The explanations regarding the Fig. Sections 2 to 11 apply analogously to the stationary scroll 26. In particular, the stationary scroll includes at least one receptacle 36 with a nozzle 38 included therein.

[0073] In the Fig. 2a to 2c is one of the scrolls, here the orbiting scroll 24 is shown as an example. From its base plate 24b, the spiral wall 24a rises vertically in the vertical direction H. The vertical direction H is therefore parallel to the axial direction A.

[0074] The side of the base plate 24b from which the spiral wall 24a rises is also referred to as the compressor chamber side 40. The side facing away from the compressor chamber 28 or compressor chamber side 40 is referred to as the rear side 42 or the underside. The scroll 24 here includes, by way of example, two receptacles 36, which are designed as through-bores extending in the vertical direction H, with each receptacle 36 accommodating the respective nozzle 38, which is designed as a separate component relative to the base plate 42a. The nozzles 38, which are located in the Fig. 3a and Fig. The nozzles 38, shown enlarged in Figure 3b, are pot-shaped. To form the pot shape, the nozzles 38 comprise a pot base 38a and a side wall 38b extending from the pot base 38a and oriented perpendicular to it. The side wall 38b is essentially hollow and cylindrical.

[0075] A fluid passage 54, designed as a through-hole, is provided in the base of the pot 38a. This passage has a diameter of less than 0.5 mm. In particular, the diameter is less than 0.3 mm. This applies analogously to the nozzles of the Fig. 3 to 11. If the scroll has more than one inlet 36 and more than one such nozzle 38, the diameters are expediently different from each other.

[0076] For example, the nozzle 38 is manufactured by deep drawing. The fluid passage 54 is introduced into the pot base 38a, for example, using a laser or by punching.

[0077] Preferably, the nozzle 38 and / or the scroll 24 are made of a metal or an alloy, particularly suitable steel. Preferably, the nozzle 38 and the scroll 24 are made of the same material. This applies analogously to the nozzles of the Fig. 3 to 11.

[0078] The side wall 38b of the nozzle 38 comprises, at its free end, i.e., at its end facing away from the pot base 38a, a scroll stop 44 for the back 42 of the scroll 24, which extends outwards perpendicularly to a central axis M of the side wall 38b, thus perpendicular to the scroll vertical direction H, in other words, projects outwards from the nozzle.

[0079] Additionally, the base plate 24b of the scroll 24 forms a stop for the nozzle 38 with respect to the scroll vertical direction H. For this purpose, the base plate 24b has a support shoulder 46 projecting into the receptacle 36, which is arranged at the end of the receptacle 36 in the scroll vertical direction H, i.e., at the compressor chamber-side end. The support shoulder 46 partially covers the nozzle 38, in particular its cup base 38a, with respect to the scroll vertical direction H.

[0080] Here, the nozzle 38 is held in the receptacle 36, in particular solely, by means of an interference fit. The nozzle 38 was pressed into the receptacle 36.

[0081] Alternatively, according to an alternative not shown, the nozzle 38 is held in the holder by means of a threaded connection.

[0082] In the Fig. Figure 6 schematically shows an alternative embodiment of the scroll 24 and the nozzle 38. Here, the stop for the nozzle 38 with respect to the scroll's vertical direction H is formed by an undercut 48. The undercut is an extension of the receptacle 36 in a direction perpendicular to the scroll's vertical direction H, whereby the nozzle 28 can abut the side wall 48a of the undercut 48, which is oriented vertically H and is perpendicular to it.

[0083] The side wall 38b of the nozzle 38 is completely arranged within the undercut 48. Advantageously, the nozzle 38 is additionally held in the receptacle 36 by means of an interference fit.

[0084] In the Fig. 4a and Fig. Figure 4b shows an alternative embodiment of the nozzle 38. According to this embodiment, the side wall 38b of the nozzle 38 has a groove 50 that engages inwards towards the nozzle. In other words, the side wall of the nozzle has a recess projecting inwards. Put another way, the side wall 38b, particularly in its central section along the central axis M, has a section with a reduced diameter.

[0085] In the Fig. 4c is the nozzle of the Fig. 4a and Fig. Figure 4b schematically shows the assembled state in the receptacle 36 of the scroll 24 in a sectional view through the nozzle 38. The base plate 24b of the scroll 24 has a projection 52 extending into the receptacle 36 and shaped to correspond to the groove 50 of the nozzle 38. During assembly, the nozzle is pushed over the projection with slight elastic deformation and then snaps into place, with the projection 52 being received in the groove 50. In summary, a snap connection is formed by means of the (snap) groove 50 of the nozzle 38 and the projection 52 of the scroll 24 to hold the nozzle 38 in the receptacle. This snap connection is in addition to or alternative to the press fit of the nozzle 38 in the receptacle 36.

[0086] In the Fig. Figure 7 shows a further embodiment of the nozzle 38 and the scroll 24. Here, the nozzle comprises one or more projecting snap tabs 56 on the outside of its side wall 38b, which, in the assembled state, engage in an undercut 48 or an undercut 58, i.e., in an extension of the receptacle 36 in a direction perpendicular to the scroll's vertical direction H. In summary, the nozzle 38 is positively locked in the receptacle 36 by means of the snap connection thus formed. Advantageously, the nozzle 38 is additionally held in the receptacle 36 by means of an interference fit.

[0087] In the Fig. Figure 5 schematically and partially illustrates an alternative embodiment of the nozzle 38 and the scroll in a sectional view through the nozzle 38. In this embodiment, the nozzle 38 is held in the receptacle 36, specifically solely by means of an interference fit. Neither the nozzle 38 nor the receptacle 36 includes a stop. Alternatively, according to an alternative embodiment not shown, the nozzle 38 is held in the receptacle 36 by means of a threaded connection.

[0088] In the Fig. Figures 8 to 10 show alternative configurations of the nozzle 38. These are used, for example, in the Fig. The scroll 24 shown is used, the base plate 24b of which has a mounting shoulder 46. Alternatively, this nozzle is used for a scroll 34, the mount of which does not have such a mounting shoulder 46.

[0089] The one in Fig. The nozzle 38 shown in section 8 tapers in the upward scroll direction H, i.e., towards the bottom of the pot 38a. In other words, the diameter of the side wall 38b decreases in the upward scroll direction H, i.e., towards the bottom of the pot 38a. Consequently, the contact area of ​​the side wall against the receptacle 36 is reduced. The compressor chamber-side end of the nozzle 38 therefore tapers conically.

[0090] To increase the flexibility of the side wall 38b of the nozzle 38 towards the nozzle inwards, the scroll stop of the nozzles points according to the Fig. 8 to 11 a bead-like and circumferential depression 60. The nozzle 38 according to the Fig. In addition, part 10 has a groove-like depression 60 in its pot base that projects inwards towards the nozzle.

[0091] In the Fig. Figure 11 schematically shows the base plate 24b of the scroll 24 according to an alternative embodiment. Here, the base plate 24b has a bent section 62 on its rear side 42 at the receptacle 36. The bent section 62 is formed by the base plate 62 having a recess 64 arranged, in particular concentrically, with the receptacle 36, wherein the section of the base plate located between the receptacle 36 and the recess 64 forms the bent section 62.

[0092] During assembly, the nozzle 38 is inserted into the receptacle 36. At the same time, the scroll stop 44, especially the folded-over one, is pressed into the recess 64. This is shown in the Fig. Figure 11 is represented by an arrow R. As a result of the pressing action, a force F acts on the bent section 62 towards the nozzle 38, i.e., in the direction of the receptacle 36, causing the bent section 62 to bend, at least slightly, into the receptacle 36. For example, the pressing force and the associated deformation of the bent section 62 are selected such that the bent section 62 presses against the side wall 38b of the nozzle 38 and, advantageously, such that the side wall 38b is also deformed inwards towards the nozzle, particularly plastically, by the bending section 62. In this way, a comparatively reliable hold of the nozzle 38 in the receptacle 36 is achieved.

[0093] If the base plate does not have a mounting shoulder 46 arranged at its end in the vertical direction H in the recess 36, see below. Fig. 4c to 7, a distance d from the bottom of the pot 38a to the compressor chamber side 40 with respect to the scroll vertical direction H, in other words, the distance between the bottom of the pot and the plane defined by the compressor chamber side 40, is less than 2 mm, in particular less than 1 mm. Preferably, the bottom of the pot is flush with this plane. In this way, the formation of a dead volume is avoided.

[0094] In the Fig. Figure 12 shows a partial and schematic section view of an alternative scroll compressor with a section plane through the nozzle 38 shown in the recording 36.

[0095] The nozzle 38 is, according to the Fig. 12 is designed as a hollow cylinder. This therefore comprises a circular cylindrical base body with a coaxial and axially continuous recess.

[0096] The diameter of the coaxial recess forming the fluid passage 54 is less than 0.7 mm, in particular less than 0.5 mm. For example, it is 0.3 mm or 0.5 mm. The outer diameter of the nozzle 38 is between 1 mm and 7 mm, in particular between 3.0 mm and 5.0 mm, for example 4.5 mm. The nozzle 38 is therefore solid. For example, it is manufactured by turning, with the fluid passage being created by drilling.

[0097] This comparatively large and / or massive design of the nozzle 38 makes handling during assembly advantageously simpler.

[0098] For example, the nozzle 38 is held in the receptacle 36 by a press fit.

[0099] As further in the Fig. As can be seen in Figure 12, the base plate 24b, forming the stop, includes the contact shoulder 46 projecting into the receptacle 36 at its end in the scroll direction H. The side of the contact shoulder 46 facing the nozzle 38, i.e., the side of the contact shoulder against which the nozzle 38 rests, is flat and oriented perpendicular to the scroll direction H. Consequently, the formation of a dead space between the nozzle 38 and the contact shoulder 46 is avoided.

[0100] In the Fig. Figure 13 shows a partial and schematic sectional view of an alternative nozzle 38 with a section plane through the nozzle 38 recorded in the image 36.

[0101] For example, in analogy to the Fig. 2a to 2c the nozzle 38 of the Fig. 12 into a first recording 36 of the base plate and the nozzle 38 of the Fig. 13 into a second receptacle 36 of this base plate, in particular inserted.

[0102] The nozzle of the Fig. For example, 13 also has an outer diameter between 1 mm and 7 mm, in particular between 3.0 mm and 5.0 mm, for example 4.5 mm.

[0103] The diameter of the fluid passage 54 is that of the nozzle 38. Fig. 13, shown here in a step-like manner, is enlarged. The diameter at the end facing away from the system shoulder 46 is larger than at the end of the nozzle 38 facing the system shoulder 46, in particular the compressor chamber side. For example, the diameter of the fluid passage 54 at the end facing away from the system shoulder 46 is 1.0 mm and at the end facing the system shoulder 46 is 0.3 mm.

[0104] The invention is not limited to the embodiments described above. Rather, other variants of the invention can also be derived by a person skilled in the art within the scope of the claims, without departing from the subject matter of the invention. In particular, all individual features described in connection with the embodiments and / or in the claims can also be combined with one another in other ways without departing from the subject matter of the invention. Reference symbol list 2 Refrigerant drive 4 Drive 6 scroll compactors 8 drive housings 10 Electric motor 12 Storage sign 14 Outlet 16 compressor housings 18 Motor shaft 20 Rotor 22 Stator 24 orbiting driven scroll 24a Spiral wall of the orbiting driven scroll 24b Base plate of the orbiting driven scroll 26 fixed scroll 26a Spiral wall of the fixed scroll 26b Base plate of the fixed scroll 28 Compressor chamber 30 Low-pressure chamber 32 High-pressure chamber 34 Counterpressure chamber 36 recording 38 nozzle 38a Pot base 38b Side wall of the nozzle 40 Compressor chamber side 42 Back 44 scroll stops 46 Attachment shoulder 48 Undercut 48a Side wall 50 Nut 52 continuation 54 Fluid passage 56 snap tabs 58 Undercut 60 In-depth study 62 Bending section 64 recess A Axial direction d distance F force H Scroll up direction M Central axis of the nozzle R insertion direction QUOTES INCLUDED IN THE DESCRIPTION

[0000] This list of documents cited by the applicant was automatically generated and is included solely for the reader's convenience. The list is not part of the German patent or utility model application. The DPMA accepts no liability for any errors or omissions. Cited patent literature

[0000] DE 10 2020 210 452 A1

[0007] DE 10 2017 105 175 B3

[0008]

Claims

[1] Scroll compressor (6), in particular for an electric refrigerant drive for an air conditioning system of a motor vehicle, comprising - a scroll (24) with a base plate (24b) and with a spiral wall (24a) rising from its compressor chamber side (40) in scroll vertical direction (H), - wherein the base plate (24b) has a continuous recess (36) in the scroll vertical direction (H), in which a nozzle (38) separate from the base plate (24b) with a fluid passage (54) is received, and - wherein the fluid passage (54) has a diameter less than 0.7 mm, for example less than 0.5 mm, in particular less than 0.3 mm, and / or has a clear area less than 1.5 mm 2 is. [2] Scroll compressor (6) according to claim 1, characterized by , that the nozzle (38) is a hollow cylinder, wherein the fluid passage (54) is formed by means of its coaxial cylindrical recess. [3] Scroll compressor (6) according to claim 1, characterized by , that the nozzle (38) forms a pot shape, has a pot bottom (38a) which has the fluid passage (54), and a side wall (38b) oriented perpendicular to the pot bottom (38a). [4] Scroll compressor (6) according to any one of claims 1 to 3, characterized by , that the distance (d) of the nozzle (38) to the compressor chamber side (40) in scroll vertical direction (H) is less than 2 mm, in particular less than 1 mm. [5] Scroll compressor (6) according to any one of claims 1 to 4, characterized by , that the nozzle (38) has an outer diameter between 1 mm and 7 mm, in particular between 3.0 mm and 5.0 mm. [6] Scroll compressor (6) according to any one of claims 1 to 5, characterized by , - that the material from which the nozzle (38) is formed and the material from which the scroll (24) is formed have the same coefficient of thermal expansion, and / or - that the nozzle (38) is made of the same material as the scroll (24), in particular of a metal or an alloy, suitablely of steel or of aluminium. [7] Scroll compressor (6) according to any one of claims 1 to 6, characterized by that the nozzle (38) is held in the receptacle (36) by means of a frictional connection, in particular by means of a press fit or by means of a threaded connection. [8] Scroll compressor (6) according to any one of claims 1 to 7, characterized by , - that the base plate (24b) forms a stop for the nozzle (38) in the scrolling vertical direction (H), and / or - wherein the receptacle (36) has an undercut (48) to form the stop, and / or - wherein the base plate (24b) has a support shoulder (46) projecting into the receptacle (36) to form the stop, in particular at the end in the scroll direction (H). [9] Scroll compressor (6) according to claim 8, characterized by , that the side of the system shoulder (46) facing the nozzle (38) is flat and / or perpendicular to the scroll vertical direction (H). [10] Scroll compressor (6) according to any one of claims 3 to 9, characterized by , - that the nozzle (38) is held in the receptacle (36) by means of a snap connection, and / or - wherein, to form the snap connection, the side wall (24a) of the nozzle (38) has a projecting snap tab (56) which engages in an undercut (58) of the receptacle (36), and / or - wherein, to form the snap connection, a projection (52) of the base plate (24b) extending into the receptacle (36) engages in a groove (50) of the side wall (38b) of the nozzle (38). [11] Scroll compressor (6) according to any one of claims 3 to 10, characterized by, that the side wall (38b) of the nozzle (38) has at its free end a scroll stop (44) extending outwards in a direction perpendicular to the scroll vertical direction (H) towards the nozzle. [12] Scroll compressor (6) according to any one of claims 3 to 11, characterized by , that to increase the flexibility of the side wall (38b) of the nozzle (38) towards the nozzle inwards, the pot base (38a) and / or the scroll stop (44) has a recess (60). [13] Scroll compressor (6) according to any one of claims 3 to 12, characterized by , that the side wall (38b) tapers towards the bottom of the pot (38a). [14] Scroll compressor (6) according to any one of claims 1 to 13, characterized by , that the base plate (24b) of the scroll (24) has a bending section (62) on its rear side (42) facing away from the compressor chamber side (40) at the receptacle (36), which is bent towards the nozzle (38) and presses against the side wall (24a) of the nozzle (38). [15] Refrigerant drive (2) with a scroll compressor according to any one of claims 1 to 14.

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