DE102024111797A1 - Scroll compressor for compressing high-pressure refrigerant - Google Patents

Abstract

The invention relates to a scroll compressor for compressing high-pressure refrigerant, in particular for use in the automotive sector, comprising a drive chamber (10) in which a drive (11) is arranged, and a compression chamber (20) separated from the drive chamber (10) by a housing partition (15), in which an orbiting displacer spiral (21) is arranged, which engages in a counter spiral (22) such that at least one variable compression chamber (30) for compressing the high-pressure refrigerant is formed between the displacer spiral (21) and the counter spiral (22), wherein an axial gap is formed between the displacer spiral (21) and the counter spiral (22), which is sealed by a tip seal (23, 24). The invention is characterized in that a pressure chamber (40) is formed between the displacement spiral (21) and the housing partition (15), which is fluidly connectable or fluidly connected to the compression chamber (30), at least temporarily. Furthermore, the invention relates to a vehicle air conditioning system with such a scroll compressor.

Description

The invention relates to a scroll compressor for compressing high-pressure refrigerant according to the preamble of claim 1. The invention further relates to a vehicle air conditioning system with such a scroll compressor. A scroll compressor of the type mentioned above is, for example, made of EP 3 309 399 A1 known.

EP 3 309 399 A1 This describes a scroll compressor suitable for compressing a high-pressure refrigerant, specifically carbon dioxide or R744. The scroll compressor has a drive chamber containing a drive unit and a compression chamber separated from the drive chamber by a partition wall. An orbiting displacer spiral engages with a stationary counter-spiral within the compression chamber. This creates variable compression chambers between the displacer spiral and the counter-spiral, with the high-pressure refrigerant introduced into these chambers being compressed by the movement of the orbiting displacer spiral. An axial gap is formed between the displacer spiral and the counter-spiral. To prevent refrigerant from flowing over the displacer spiral or the counter-spiral and thus exiting the compression chamber, a tip seal is provided to close the gap between the displacer spiral and the counter-spiral.

The compression of carbon dioxide generates high compression pressures, particularly exceeding 40 bar, which act on the displacer spiral and the counter-spiral. The resulting axial forces place a particular load on the displacer spiral and an axial sliding bearing located between the displacer spiral and the housing partition. Due to these high axial forces, the axial sliding bearing is subject to significant wear.

The object of the invention is to provide a scroll compressor for compressing high-pressure refrigerants, which exhibits low wear and simultaneously ensures a good seal between the displacement spiral and the counter-spiral. Furthermore, it is an object of the invention to provide a vehicle air conditioning system with such a scroll compressor.

According to the invention, this problem is solved with regard to the scroll compressor by the subject matter of claim 1 and with regard to the vehicle air conditioning system by the subject matter of claim 13.

Specifically, the problem is solved by a scroll compressor for compressing high-pressure refrigerants, particularly for automotive applications, which has a drive chamber in which a drive unit is located. Furthermore, the scroll compressor has a compression chamber separated from the drive chamber by a housing partition, in which an orbiting displacer spiral is arranged. The orbiting displacer spiral engages with a counter-spiral such that at least one variable compression chamber for compressing the high-pressure refrigerant is formed between the displacer spiral and the counter-spiral. An axial gap is formed between the displacer spiral and the counter-spiral, which is sealed by a tip seal. According to the invention, a pressure chamber is formed between the displacer spiral and the housing partition, which is fluidly connectable to or fluidly connected with the compression chamber, at least temporarily.

The present invention thus supplements a scroll compressor, whose displacement spiral and counter-spiral are sealed against each other by a tip seal, with a pressure chamber between the displacement spiral and the housing partition. Such a pressure chamber is similar to a technology also known as a backpressure system. The pressure chamber, which can be at least temporarily fluidically connected to the compression chamber, can therefore be pressurized with the refrigerant undergoing compression. The pressure of the refrigerant generated in the compression chamber is thus used to exert a back pressure on the displacement spiral, thereby reducing the load on the axial bearing.

Generally, high pressures are generated in the compression chamber, causing the displacer spiral to be forced towards the housing partition. The pressure chamber then generates a counter-pressure that acts axially against the compression pressure between the displacer spiral and the counter-spiral. This reduces the contact pressure of the displacer spiral against the housing partition, thus reducing wear, which occurs particularly in the area of an axial sliding bearing between the housing partition and the displacer spiral.

In a scroll compressor, the refrigerant to be compressed is introduced into the compression chamber at a radially outer point of the displacement spiral. It then flows spirally through the compression chamber to the center of the counter-spiral and is compressed along the way. Since the refrigerant pressure increases from the radially outer inlet to the radially inner outlet, the different compression chambers of the displacement spiral and the counter-spiral act upon each other in a radial direction. Different pressure differentials occur in the direction of the pressure difference. A top seal is used to seal these large pressure differences.

In general, the displacer spiral can be provided with a first tip sealing element that seals an axial gap between the displacer spiral and a counter-spiral base. Furthermore, the counter-spiral can have a second tip sealing element that seals against a displacer spiral base, in particular an axial gap between the counter-spiral and the displacer spiral base. The axial gap between the displacer spiral and the counter-spiral can thus be formed, on the one hand, between a free end face of spiral walls of the displacer spiral and the counter-spiral base, and on the other hand, between a free end face of spiral walls of the counter-spiral and the displacer spiral base. The tip seal that seals this axial gap can, in particular, be designed in two parts and comprise a first tip sealing element and a second tip sealing element, wherein the first tip sealing element is associated with the displacer spiral and a second tip sealing element with the counter-spiral.

In a preferred embodiment of the invention, the displacer spiral has at least one through-channel that establishes a fluid connection between the compression chamber and the pressure chamber. The through-channel is preferably adapted so that the pressure chamber can be pressurized with high-pressure refrigerant from the compression chamber. The through-channel thus enables the transfer of the pressure generated in the compression chamber to the pressure chamber, so that the pressure can act accordingly on the displacer spiral. In particular, the pressure acts between the displacer spiral and the housing partition. By forming the through-channel in the displacer spiral, it is also ensured that a sufficiently high pressure, generated by the compression in the compression chamber, reaches the pressure chamber and can effect the corresponding force reduction on the displacer spiral in order to reduce frictional forces in the area of the axial sliding bearing.

In a further preferred embodiment of the scroll compressor according to the invention, the through-channel is formed in a section of the displacement spiral in such a way that, in the activated state of the scroll compressor, the through-channel is open when 70%–100%, in particular 90%–100%, and in particular 95%, of the relative compression chamber volume is reached, and remains open during a subsequent rotation of the displacement spiral by a rotation angle of 120°–360°, in particular 255°–315°, and in particular 270°. In this embodiment, it is particularly preferred if the displacement spiral has a single, i.e., only one, through-channel.

Generally, the through-channel is preferably formed in a displacement spiral base. The displacement spiral walls are preferably free of through-passes.

The arrangement of the through-channel in a section, particularly a bottom section, of the displacement spiral, such that the through-channel opens at a specific compression chamber volume, essentially means that the through-channel is not covered by the spiral element or a spiral wall of the counter-spiral in this open state. Rather, in the open state, the through-channel provides a free fluid connection between the compression chamber and the pressure chamber. The invention particularly provides that the open state of the through-channel is maintained for a specific time or over a specific rotation angle of the displacement spiral. In other words, after the through-channel has opened, the displacement spiral can be rotated by a further 120°–360°, particularly a further 255°–315°, and especially a further 270°, while the through-channel remains open. The zero point of the rotation angle, i.e., a rotation angle of 0°, occurs when the compression begins between the displacer spiral and the counter-spiral. The starting point of the compression is therefore essentially the 0° angle alignment.

The previously described design of the displacer spiral, and in particular the positioning of the through-channel, is advantageous because it allows for precise control of the pressure in the pressure chamber. The pressure is adjusted by the position of the through-channel to ensure that a sufficient counterforce from the pressure chamber acts on the displacer spiral to counteract wear-related abrasion. This counterforce is preferably set or adjustable to reduce the frictional force exerted by the displacer spiral on the axial sliding bearing, thereby minimizing wear on the axial sliding bearing. Furthermore, the counterforce is preferably set to maintain constant contact between the displacer spiral and the housing partition wall to ensure proper guidance of the displacer spiral by the axial sliding bearing.

In one embodiment of the invention, the through-channel in the displacement spiral can be arranged such that, during operation, the orbiting movement of the displacement spiral The through-channel is temporarily arranged, at least partially, in a first compression chamber and subsequently, at least partially, in a second compression chamber. In this variant, it is preferred if only a single through-channel is formed in the displacement spiral, particularly in the base of the displacement spiral. Preferably, at least two compression chambers, namely a first compression chamber and a second compression chamber, are formed between the displacement spiral and the counter-spiral. Both compression chambers are variable, meaning their volume changes due to the rotation of the orbiting displacement spiral. In particular, the compression chambers migrate radially inward due to the orbiting movement of the displacement spiral, thereby reducing their volume. The pressure in the compression chambers is thereby increased, thus compressing the high-pressure refrigerant. At the center of the counter-spiral, the compression chambers merge and thus dissolve. The high-pressure refrigerant is then expelled through an opening in the counter-spiral.

The through-channel moves along a defined path due to the orbiting motion of the displacer spiral. This defined path of the through-channel overlaps with the first and second compression chambers. This overlap can be adjusted so that the through-channel is temporarily located, at least partially, in the first and then in the second compression chamber. In this way, a fluid connection is established with the pressure chamber in each case, with the fluid connection existing with the first compression chamber on one side and with the second compression chamber on the other. The counterforce on the displacer spiral can be adjusted by positioning the through-channel. The counterforce is preferably set or adjustable to reduce the frictional force exerted by the displacer spiral on the axial sliding bearing, thereby reducing wear on the axial sliding bearing. The counterforce can be adjusted so that a constant contact between the displacer spiral and the housing partition is maintained to ensure good guidance of the displacer spiral by the axial sliding bearing.

Alternatively or additionally, the displacement spiral can have a first and a second through-channel. The first through-channel can be located primarily in a central section, and the second through-channel in an initial region of the displacement spiral. Both through-channels are preferably arranged in the base of the displacement spiral. This variant allows for alternative pressure adjustment in the pressure chamber to create back pressure on the displacement spiral and thus reduce wear. The variant with two through-channels therefore provides an alternative operating principle, although the effect is similar to that of the variants mentioned above.

In a preferred embodiment of the scroll compressor according to the invention, the displacement spiral slides over a center plate arranged between the housing partition and the displacement spiral. The axial sliding bearing can be arranged between the center plate and the displacement spiral. The center plate can essentially be designed as an additional element of the housing partition or rest on the housing partition. The center plate, also called the "center plate," is preferably formed by a flat plate, which is characterized in particular by a flat surface. The displacement spiral slides on this flat surface during its orbiting movement. Therefore, the center plate is preferably made of a material that offers low sliding friction.

The axial sliding bearing can be formed, in particular, by a corresponding sliding ring arranged in or on the base of the displacer spiral and between the displacer spiral and the central plate. Preferably, the axial sliding bearing is located in a radially outer region of the displacer spiral base.

The displacer spiral can further have several cylindrical blind holes in its base region, each of which interacts with pins arranged in the housing partition to form an anti-rotation mechanism. In general, an anti-rotation mechanism can thus be arranged between the intermediate plate and the displacer spiral. A preferred variant of such an anti-rotation mechanism is a so-called pin-ring system. In this system, the displacer spiral includes corresponding blind holes with a circular diameter in its base, with corresponding pins formed on the intermediate plate that engage in the blind holes in the base of the displacer spiral. The pins, together with the blind holes, prevent the displacer spiral from rotating. Instead, the pin-ring system forces the displacer spiral into an orbiting motion. Other embodiments of anti-rotation mechanisms are also possible.

With regard to the tip seal, it is preferably provided that it is arranged such that it covers, preferably exclusively, closed component areas. In other words, it is provided that the tips The seal, in particular both tip sealing elements, slide over surfaces of the displacement spiral and the counter spiral that are free of openings. This ensures continuous sealing. Furthermore, this method ensures that the tip seal only rubs against smooth surfaces, thus minimizing wear on the tip seal and ensuring uniform action across the entire tip seal.

Generally, it is advantageous if the tip seal is made of or consists of a plastic material. Materials such as polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), or polyetheretherketone (PEEK) are particularly preferred. The plastic material may be enriched with fillers.

Furthermore, the tip seal may be designed to have a thickness between 1 mm and 3 mm, in particular 2 mm. In this context, thickness refers to the height of the tip seal, extending from the respective spiral wall of the displacer spiral or counter-spiral to the opposite base of the counter-spiral or displacer spiral.

With regard to the axial sliding bearing, it is advantageous if it also comprises or consists of a plastic material. Preferably, plastics such as polytetrafluoroethylene (PTFE), polyphenylene sulfide (PPS), polyetheretherketone (PEEK), polyetherketone (PEK), or polyaryletherketone (PAEK) are used for the axial sliding bearing. It is also preferred if such plastic materials are enriched with fillers. Furthermore, it is conceivable to use a plastic material made from a combination of the aforementioned plastics.

Preferably, the axial sliding bearing has a rectangular cross-section. The rectangular cross-section preferably has a long and a short side, with the aspect ratio between the short and long sides preferably being between 0.2 and 0.6. The long side makes contact with the displacer spiral or the center plate. The short side forms the radial outer circumferential surface or the radial inner circumferential surface of the axial sliding bearing.

In a preferred embodiment, the scroll compressor is generally configured to compress high-pressure refrigerant, particularly _CO₂ , to a pressure of at least 40 bar, particularly at least 50 bar, and more specifically at least 60 bar, preferably up to a maximum of 180 bar. It is particularly preferred that the scroll compressor be configured to compress the high-pressure refrigerant to a pressure between 60 bar and 180 bar, particularly between 90 bar and 150 bar, and preferably to 120 bar.

A subordinate aspect of the invention relates to a vehicle air conditioning system, in particular a vehicle air conditioning system with _CO2 as a refrigerant, wherein the vehicle air conditioning system has a scroll compressor as previously described.

• 1 eine Querschnittsansicht eines erfindungsgemäßen Scrollverdichters nach einem bevorzugten Ausführungsbeispiel;
• 2 eine Querschnittsansicht eines erfindungsgemäßen Scrollverdichters nach einem weiteren bevorzugten Ausführungsbeispiel;
• 3 eine Querschnittsansicht eines erfindungsgemäßen Scrollverdichters nach einem weiteren bevorzugten Ausführungsbeispiel; und
• 4A - 4C Detailansichten unterschiedlicher Varianten von Axialgleitlagern für einen erfindungsgemäßen Scrollverdichter nach bevorzugten Ausführungsbeispielen.

The invention is explained in more detail below with reference to the accompanying schematic drawings. These show:

• 1 a cross-sectional view of a scroll compressor according to the invention in a preferred embodiment;
• 2 a cross-sectional view of a scroll compressor according to the invention in a further preferred embodiment;
• 3 a cross-sectional view of a scroll compressor according to the invention in a further preferred embodiment; and
• 4A - 4C Detailed views of different variants of axial sliding bearings for a scroll compressor according to the invention, based on preferred embodiments.

In the 1 - 3 Figure 1 shows a cross-sectional view of a scroll compressor according to the invention, which has a drive chamber 10 and a compression chamber 20. The drive chamber 10 and the compression chamber 20 are bounded by a housing 14. The housing 14 can be made up of multiple parts and in particular has a central housing body and a cover closing it. The housing 14 is preferably gas-tight.

The separation between the drive chamber 10 and the compression chamber 20 is achieved by a housing partition 15. The housing partition 15 can, in particular, be arranged in a main housing part 14a, which is axially closed by a housing cover 14b. The housing cover 14b forms an outer boundary of the compression chamber 20.

A drive 11, preferably an electric motor, is arranged in the drive chamber 10. The drive 11 drives a drive shaft 12, which extends through the housing partition 15 into the compression chamber 20. The drive shaft 12 is appropriately sealed against the housing partition 15 and supported in a rolling bearing 13, which is fixed in the housing partition 15.

The drive shaft 12 has an eccentric pin that engages with an orbiting displacement spiral 21. The orbiting displacement spiral 21 is arranged together with a counter-spiral 22 in the compression chamber 20. The displacement spiral 21 comprises one or more spiral walls that engage with the counter-spiral 22. The counter-spiral 22 has corresponding, counter-rotating spiral walls. Thus, the displacement spiral 21 and the counter-spiral 22 are arranged in an interlocking configuration. The counter-spiral 22 is rigidly connected to the housing 14. The counter-spiral 22 preferably does not move during operation of the scroll compressor.

The eccentric pin 19 imparts an orbiting motion to the displacer spiral 21. To ensure that the displacer spiral 21 does not rotate in a circular path, an anti-rotation mechanism 50 is provided, which in the embodiments shown here is designed as a pin-ring system. For this purpose, several cylindrical blind bores or blind openings are provided in the displacer spiral 21, which open towards the drive chamber 10. Pins, fixed in a central plate 16, engage in these blind openings. The central plate 16 is located between the displacer spiral 21 and the housing intermediate wall 15. To ensure smooth sliding of the pins along the inner walls of the blind bores, the inner walls of the blind bores are preferably equipped with a ring element 28. The ring element 28 is preferably frictionally and/or positively locked in the blind bore of the displacer spiral 21.

Between the displacement spiral 21 and the counter-spiral 22, one or more compression chambers 30 are formed. The compression chambers are bounded by the respective bottoms of the displacement spiral 21 and the counter-spiral 22, as well as by the spiral walls of the displacement spiral 21 and the counter-spiral 22. The compression chambers 30 are variable, meaning their volume changes during operation of the scroll compressor. This volume change is used to compress a refrigerant.

The refrigerant is typically introduced into the compression chambers 30 from a radially outer edge region of the compression chamber 20. The refrigerant is compressed by the orbiting motion of the displacement spiral 21 between the spiral walls of the displacement spiral 21 and the counter-spiral 22, and simultaneously conveyed towards the center of the counter-spiral 22. Maximum compression is reached at the center of the counter-spiral 22, and the compressed refrigerant can escape through an outlet opening 25 into a high-pressure region 29. The high-pressure region 29 can be formed in the housing cover 14b. From the high-pressure region 29, the compressed refrigerant can then exit the scroll compressor.

In the exemplary embodiments shown here, in the 1 - 3 The displacer spiral 21 and the counter-spiral 22 each have an axial gap. This means that the spiral walls of the displacer spiral 21 do not directly and immediately abut the base of the counter-spiral 22. Conversely, the spiral walls of the counter-spiral 22 do not directly abut the base of the displacer spiral 21. To prevent refrigerant from escaping the compression chambers 30 through this axial gap, a peak seal 23, 24 is provided. The displacer spiral 21 has a first peak seal element 23, and the counter-spiral 22 has a second peak seal element 24. The peak seals 23, 24 each bridge the axial gap between the displacer spiral 21 and the counter-spiral 22, thus effectively sealing the two spirals against each other.

The scroll compressor according to the invention is particularly intended for use in the compression of high-pressure refrigerants, especially _CO₂ . With such refrigerants, very high pressures, which can reach up to 180 bar, are generated in the compression chamber 30. The pressure of the refrigerant acts on the displacer spiral 21 and the counter spiral 22 such that the displacer spiral 21 and the counter spiral 22 are forced apart. To prevent the displacer spiral 21 from lifting away from the counter spiral 22 under this pressure, thereby reducing or eliminating the sealing effect of the tip seal 23, 24, the displacer spiral 21 is supported by the axial sliding bearing 17.

The pressure generated in the compression chamber 30 between the displacer spiral 21 and the counter-spiral 22 results in an axially acting compression force F_{_V} , which forces the displacer spiral 21 against the housing partition 15, specifically the intermediate plate 16. Although the intermediate plate 16 preferably has a smooth surface to facilitate the sliding of the displacer spiral 21 in its orbiting motion on the intermediate plate 16, the axial sliding bearing 17 arranged between the displacer spiral 21 and the housing partition 15, in particular the intermediate plate 16, is subjected to a high frictional force when the displacer spiral 21 moves, which would lead to high wear.

To reduce this wear, in the embodiments of the scroll compressor according to the invention, it is provided that there is a space between the displacement spiral 21 and the housing space. Wall 15 forms a pressure chamber 40, which is at least temporarily fluidly connected to or fluidly connected to the compression chamber 30. Through this fluid connection, refrigerant, which has been compressed to a high pressure by the displacement coil 21, is directed into the pressure chamber 40, so that the pressurized refrigerant presses against the back of the displacement coil 21. The fluid pressure prevailing in the pressure chamber 40 thus generates an axial counterforce F _G , which acts on the displacement coil 21 and relieves it. The frictional force acting on the axial sliding bearing 17 is thus reduced, thereby decreasing the wear of the axial sliding bearing 17.

In 1 The forces acting in opposite directions on the displacement spiral 21, namely the compressor force F_{_V} and the counterforce F_{_G} , are represented by corresponding arrows. It is also evident that the ratio between the compressor force F_{_V} and the counterforce F_{_G} is adjusted such that the forces do not completely cancel each other out, but rather the compressor force F_{_V} generally predominates. However, it is preferable for the difference between the compressor force F_{_V} and the counterforce F_{_G} to be as small as possible in order to minimize the friction on the axial sliding bearing 17.

The in the 1 - 3 The illustrated embodiments of the scroll compressor according to the invention essentially have the aforementioned design features and differ only in the way in which the fluid connection between the compression chamber 30 and the pressure chamber 40 is achieved.

Thus, in the exemplary embodiment according to 1 It is provided that a single through-channel 33 is arranged in the displacement spiral 21, which connects the compression chamber 30 to the pressure chamber 40 with fluid at least temporarily, i.e., during certain time intervals during the movement of the displacement spiral 21. Additionally, in the embodiment according to 1 It is provided that a return channel 34 runs from the high-pressure area 29 through a throttle 35 into the pressure chamber 40. The return channel 34 extends through the housing 14 and the housing partition 15. The pressure chamber 40 is pressurized essentially continuously via the return channel 34. This base pressure is subject to only minor fluctuations and is, in a broad sense, constant. The base pressure is preferably between the suction and high pressure.

A substantially constant base pressure can be set in the pressure chamber 40 via the return channel 34. The peak pressure exceeding the base pressure is reduced in the pressure chamber 40 by the passage channel 33 establishing a direct connection between the compression chamber 30 and the pressure chamber 40 at predetermined positions during the orbiting movement of the displacement spiral 21.

2 shows another variant, which is essentially the same as the variant according to 1 This corresponds to the exception that the feedback channel 34 is omitted. In the embodiment according to 2 The single through-channel 33 is solely responsible for the fluid connection between the compression chamber 30 and the pressure chamber 40. The through-channel 33 is preferably positioned such that, in the activated state of the scroll compressor, it establishes a fluid connection with the pressure chamber 40 when the relative volume of the compression chamber reaches between 70% and 100%, particularly between 90% and 100%, and especially 95%. Specifically, the through-channel 33 can be positioned such that, outside of the aforementioned value ranges, it is generally covered by a spiral wall of the counter-spiral 22, thus preventing any fluid connection. However, as soon as the relative volume of the compression chamber reaches 75% to 100%, and especially 95%, the fluid connection to the pressure chamber 40 is established by the opening of the through-channel 33. Preferably, the through-channel 33 remains open while the displacer spiral 21 rotates through an angle of 120° - 360°, particularly 270°. Only then does the through-channel 33 close again or is covered by the counter-spiral 22.

In the variant according to 3 Unlike the scroll compressors described above, the displacement spiral 21 does not have a single through-channel 33, but rather two through-channels 31, 32. The first through-channel 31 is located near the center of the displacement spiral 21. The second through-channel 32 is located in a radially outer section of the displacement spiral 21. This radial outer region is also referred to as the initial region, as this is where the refrigerant compression begins. The central region of the displacement spiral 21 essentially corresponds to a middle area where the refrigerant has the highest pressure.

An advantageous aspect of the scroll compressor according to the invention is the reduction of wear in the area of the axial sliding bearing 17. Several forces act on the axial sliding bearing 17. On the one hand, the compressor force F _V acts on the axial sliding bearing 17, which results from the refrigerant pressure generated in the compressor chamber 30 between the displacement spiral 21 and the counter spiral 22. In addition, a rotating tilting moment acts on the Displacement spiral 21 places an additional load on the axial sliding bearing 17. To maintain the stability of the axial sliding bearing 17, different versions of the axial sliding bearing are provided. In all versions, however, the pressure setting in the pressure chamber 40 is a crucial factor. By adjusting the pressure in the pressure chamber 40 so that the counterforce F _G does not exceed the compressor force F _V , it is ensured that the displacement spiral 21 continuously bears against the housing intermediate wall 15 or the center plate 16 and is thus well guided.

In 4a Figure 1 shows one way to position the axial sliding bearing 17 between the displacement spiral 21 and the center plate 16. To ensure that the axial sliding bearing 17 follows the orbiting movement of the displacement spiral 21, it is particularly advantageous to position the axial sliding bearing 17 in a bearing groove 26. The bearing groove 26 is bounded on a radial inner and a radial outer side by a radial flange 27. The axial sliding bearing 17 is inserted into the bearing groove 26 and secured laterally by the radial flanges 27. It is specifically designed that the axial sliding bearing 17 projects beyond the radial flanges 27 to ensure that essentially only the axial sliding bearing 17 is in contact with the center plate 16. The central plate 16 and the axial sliding bearing 17 are preferably made of materials that slide well against each other, for example plastics, so that low friction is achieved while ensuring sufficient sealing.

4b Figure 1 shows an alternative arrangement of the axial sliding bearing 17. In this variant, the displacement spiral 21 has only a radially outer flange 27, which radially delimits the axial sliding bearing 17. On an inner side, the axial sliding bearing 17 projects with an overhang 18 into a blind opening in the displacement spiral 21. The blind opening is part of the anti-rotation mechanism 50. A ring element 28 is arranged in the blind opening. The axial sliding bearing 17, with its overhang 18, projects beyond the edge of the blind opening and essentially covers an axial portion of the ring element 28. In this way, the overhang 18 essentially forms an axial retainer or an axial positive locking mechanism for the ring element 28. Simultaneously, in the variant according to Figure 1, 4b This resulted in the axial sliding bearing 17 having an increased width. In this way, the sliding contact area between the axial sliding bearing 17 and the center plate 16 is increased. This helps the axial sliding bearing 17 to effectively absorb not only the contact pressure of the displacement spiral 21, but also, in particular, tilting moments.

The variant according to 4c The design provides that the displacement spiral 21 has a radial flange 21 only on one inner side, in particular on a side facing a blind hole of the anti-rotation mechanism 50. The radial flange 21 prevents radial slippage of the axial sliding bearing 17. On a radially outer side of the displacement spiral 21, the axial sliding bearing 17 projects beyond the outer circumferential surface of the displacement spiral 21 with an overhang 18. The overhang 18 is designed to have a length less than half the length of the axial sliding bearing 17 to prevent tilting of the axial sliding bearing 17. In the variant according to 4c The focus is particularly on compensating tilting moments. The arrangement of the axial sliding bearing 17 in a radially outer region of the displacement spiral 21, especially in the maximally radial outer region of the displacement spiral 21, ensures good support of the displacement spiral 21 against tilting moments. Furthermore, the overhang 18 can serve to support the displacement spiral 21 against the counter spiral 22 in the radial direction.

In general, all embodiments may include an additional compensation mechanism for the scroll compressor, located in the area of the eccentric pin 19, which reduces vibrations in the scroll compressor that can occur due to gas forces and manufacturing tolerances. Such a compensation mechanism, also called a swing link, is exemplified in WO 2022/033 934 A1 described, to which full reference is hereby made.

The scroll compressor described here is particularly suitable as a compression machine for a vehicle air conditioning system that uses _CO₂ as a refrigerant. Especially with regard to electromobility, it is preferably provided that the drive 11 of the scroll compressor is formed by an electric motor. The drive 11 is preferably also arranged in the housing 14, in particular in the main housing part 14a, of the scroll compressor.

List of reference symbols

10

Engine compartment

11

drive

12

drive shaft

13

Rolling bearings

14

Housing

14a

Main housing part

14b

Housing cover

15

Housing partition

16

center plate

17

Axial plain bearing

18

Overhang

19

eccentric pin

20

Congestion area

21

Displacement spiral

22

Counter-spiral

23

first top seal

24

second top seal

25

outlet opening

26

bearing groove

27

radial flange

28

Ring element

29

High-pressure area

30

Compression chamber

31

first through channel

32

second through channel

33

through channel

34

Return channel

35

throttle

40

pressure chamber

50

Antirotation mechanism

QUOTES CONTAINED IN THE DESCRIPTION

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

• EP 3 309 399 A1 [0001, 0002]
• WO 2022/033 934 A1 [0051]

Claims (13)

Scroll compressor for compressing high-pressure refrigerant, particularly for automotive applications, comprising a drive chamber (10) in which a drive (11) is arranged, and a compression chamber (20) separated from the drive chamber (10) by a housing partition (15), in which an orbiting displacer spiral (21) is arranged, which engages with a counter-spiral (22) such that at least one variable compression chamber (30) for compressing the high-pressure refrigerant is formed between the displacer spiral (21) and the counter-spiral (22), wherein an axial gap is formed between the displacer spiral (21) and the counter-spiral (22), which is sealed by a tip seal (23, 24), characterized in that a pressure chamber (40) is formed between the displacer spiral (21) and the housing partition (15), which is at least temporarily connected to the Compression chamber (30) is fluid-connectable or fluid-connected. Scroll compressor after Claim 1 characterized in that the displacement spiral (21) has at least one through-channel (31, 32, 33) which establishes a fluid connection between the compression chamber (30) and the pressure chamber (40), so that the pressure chamber (40) can be supplied with high-pressure refrigerant from the compression chamber (30). Scroll compressor after Claim 2 characterized in that the through-channel (31, 32, 33) is formed in such a section of the displacement spiral (21) in which the through-channel (31, 32, 33) is open in the activated state of the scroll compressor when reaching 70% - 100%, in particular 90% - 100%, in particular 95%, of the relative compression chamber volume and remains open during a rotation of the displacement spiral (21) by a rotation angle of 120° - 360°, in particular 255° - 315°, in particular 270°, following the opening. Scroll compressor after Claim 2 or 3 characterized in that the through-channel (31, 32, 33) in the displacement spiral (21) is arranged such that during operation, the through-channel (31, 32, 33) is temporarily arranged at least sectionally in a first compression chamber and subsequently at least sectionally in a second compression chamber due to the orbiting movement of the displacement spiral (21). Scroll compressor according to one of the preceding claims characterized in that the displacement spiral (21) has a first through-channel (31) and a second through-channel (32), wherein the first through-channel (31) is formed substantially in a middle section and the second through-channel (32) is formed in an initial region of the displacement spiral (21). Scroll compressor according to one of the preceding claims characterized in that the displacement spiral (21) slides over a central plate (16) which is arranged between the housing intermediate wall (15) and the displacement spiral (21), wherein an axial sliding bearing (17) is arranged between the central plate (16) and the displacement spiral (21). Scroll compressor after Claim 6 characterized in that an antirotation mechanism (50) is arranged between the middle plate (16) and the displacement spiral (21). Scroll compressor according to one of the preceding claims characterized in that the tip seal (23, 24) comprises or consists of a plastic material, in particular polytetrafluoroethylene, polyphenylene sulfide or polyetheretherketone, preferably each enriched by fillers. Scroll compressor according to one of the preceding claims characterized in that the tip seal (23, 24) has a thickness between 1 mm and 3 mm, in particular 2 mm. Scroll compressor according to one of the Claims 6 until 9 characterized in that the axial sliding bearing (17) comprises or consists of a plastic material, in particular polytetrafluoroethylene, polyphenylene sulfide, polyetheretherketone, polyetherketone, polyaryletherketone, preferably each enriched by fillers. Scroll compressor according to one of the Claims 6 until 10 characterized in that the axial sliding bearing (17) has a rectangular cross-section with an aspect ratio between 0.2 and 0.6. Scroll compressor according to one of the preceding claims characterized in that the scroll compressor is configured to compress high-pressure refrigerant to a pressure of at least 40 bar, in particular at least 50 bar, in particular at least 60 bar, preferably up to a maximum of 180 bar. Vehicle air conditioning system, in particular vehicle air conditioning system with _CO2 as refrigerant, with a Scroll compressor according to one of the preceding claims.