WO2020120659A1

WO2020120659A1 - Displacement machine according to the spiral principle, in particular a scroll compressor for a vehicle climate control system

Info

Publication number: WO2020120659A1
Application number: PCT/EP2019/084837
Authority: WO
Inventors: Dennis RYMA
Original assignee: Brose Fahrzeugteile SE & Co. Kommanditgesellschaft, Würzburg
Priority date: 2018-12-12
Filing date: 2019-12-12
Publication date: 2020-06-18
Also published as: EP3667086A1; CN113167273B; CN113167273A; EP3670915A1; EP3670915B1; EP3667086B1

Abstract

The invention relates to a scroll compressor (3) for refrigerant of a vehicle climate control system, comprising: a housing (12) having a high-pressure chamber (29) and having compressor chambers (24), and having a counter-pressure chamber (25); a stationary scroll (23), the base plate (23b) of which delimits the high-pressure chamber (29); and a movable scroll (21), the spiral wall (21a) of which engages in the spiral wall (23b) of the stationary scroll (23) and forms, together therewith, the compressor chambers (24), wherein the base plate (21b) of the movable scroll (21) delimits the counter-pressure chamber (25), and wherein a pressure line (35) connected to the compressor chambers (24) and to the high-pressure chamber (29) extends, at least in part, in the stationary scroll (23) and is connected via a first channel (36) to at least one of the compressor chambers (24) and via a second channel (37) to the high-pressure chamber (29).

Description

description

Displacement machine based on the spiral principle, in particular scroll compressors for a vehicle air conditioning system

The invention is in the field of positive displacement machines according to the spiral principle and relates to a scroll compressor, in particular an electric motor, as a refrigerant compressor for a vehicle air conditioning system, according to the preamble of claim 1. Such a displacement machine and in particular such a scroll compressor is known from DE 10 2017 1 10 913 B3.

Air conditioning systems are regularly installed in motor vehicles, which air condition the vehicle interior with the aid of a system which forms a refrigerant circuit. Such systems basically have a circuit in which a refrigerant is carried. The refrigerant, for example carbon dioxide (CO2) or R-134a (1, 1, 1, 2-tetrafluoroethane) or R-744 (carbon dioxide), is heated on an evaporator and compressed by means of a (refrigerant) compressor or compressor, the refrigerant then releases the absorbed heat again via a heat exchanger before it is again conducted to the evaporator via a throttle.

Scroll technology is often used as a refrigerant compressor to compress a refrigerant-oil mixture. The resulting gas-oil mixture is separated, with the separated gas being introduced into the air conditioning circuit, while the separated oil can optionally be introduced within the scroll compressor as a suitably electromotive driven refrigerant compressor for lubricating moving parts. The structure and operation of such a scroll compressor for the refrigerant or the cold medium-oil mixture of a motor vehicle air conditioning system is described in DE 10 2012 104 045 A1 and in “A Scroll Compressor for Air Conditioners”, Tojo et al. , Purdue e-Pubs (Purdue University), International Compressor Engineering Conference, 1984. A model calculation of a self-adjusting back preasure or counterpressure mechanism in a scroll compressor (scroll compressor) is in “Computer Modeling of Scroll Compressors with Seif Adjusting Back-Pressure Mechanism”, Tojo et al., Purdue e-Pubs (Purdue University), International Compressor Engineering Conference, 1986.

The essential components of the scroll compressor are a fixed scroll and a movable orbiting scroll. The scrolls are basically constructed in the same way and each have a base plate and a spiral-shaped wall that extends from the base plate in the axial direction (wrap). In the assembled state, the spiral walls of the two scrolls lie one inside the other and form a plurality of compression chambers between the scroll walls touching in sections.

When the movable scroll orbits, the sucked-in gas-oil mixture passes through an inlet to a first, radially outer compressor chamber and from there via further compressor chambers to the radially innermost compressor chamber and from there via a central outlet, for example in the form of a bore, and ge - If necessary, two adjacent auxiliary valves in the form of bores in the base plate of the fixed scroll in an outlet or flap pressure chamber. The chamber volume in the compressor chambers becomes smaller from the radially outside to the radially inside, and the pressure of the increasingly compressing medium increases. During operation of the scroll compressor, the pressure in the compression chambers increases from radially outside to radially inside.

The central gas-oil outlet (and, if applicable, each of the secondary valves or bores) is through on the back of the base plate of the fixed scroll Spring valve closed. The spring valve opens as a result of the pressure difference between the compression chambers and the flap pressure chamber. If necessary, the compressed gas-oil mixture flows into the high-pressure chamber of the scroll compressor (on the back of the fixed scroll) after the spring valve has been triggered, in order to be separated into oil and gas there. Then, when the pressure in the compression chambers opposite the high pressure chamber has dropped accordingly, the spring valve closes automatically.

During operation of the scroll compressor, due to the pressure generated in the compressor chambers and the axial force resulting therefrom, the scrolls are pressed apart, so that a gap and thus leakages can occur between the compressor chambers. To avoid this as far as possible, the orbiting scroll is pressed against the fixed 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 pressure chamber (back pressure chamber) in the base plate rear of the orbiting scroll in which a specific pressure is generated. According to DE 10 2012 104 045 A1 already mentioned, this can be achieved by introducing a medium-pressure channel (passage, opening, backpressure port) in the base plate of the orbiting scroll at a specific position, which channel forms at least one of the scrolls Compressor chambers with the back pressure chamber (back pressure chamber) connects, so that refrigerant gas from the compression process between the scroll spirals goes directly into the counter or medium pressure chamber. Due to the medium pressure channel in the movable scroll in connection with the back pressure chamber, the movable scroll is self-adjusting (automatically) pressed against the fixed scroll, so that there is sufficient tightness (axial tightness). Alternatively, the medium pressure channel can be arranged in the fixed scroll and can be guided around the movable scroll to the counter or medium pressure chamber. Depending on the positioning of the medium pressure channel (back pressure port), in the known scroll compressor the pressure in the back pressure chamber rises to, for example, about 6 bar to about 9 bar at a pressure ratio of, for example, 3 bar (low pressure) to 25 bar (high pressure) . In the known refrigerant scroll compressor for a motor vehicle air conditioning system, the medium-pressure duct is positioned at approximately 405 °, starting from the beginning of the scroll spiral (spiral wall) of the movable (orbiting) scroll.

In “Computer Modeling of Scroll Compressor with Seif Adjusting Back-Pressure Mechanism”, Tojo et al. , Purdue e-Pubs (Purdue University), International Compressor Engineering Conference, 1986, describes a model calculation of the self-adjusting back preasure mechanism for a scroll compressor. As a result of the investigation, an area of the relative compressor chamber volume is specified in FIG. 12, in which the back pressure port (with different port diameters) should be open (fluid-connected). This range is between 55% and approx. 100% of the (relative) chamber volume.

In “A Scroll Compressor for Air Conditioners”, Tojo et al., Purdue e-Pubs (Purdue University), International Compressor Engineering Conference, 1984, the practically identical pv diagram is shown in FIG. 11, with the range of the relative compression chamber volume there , in which the back pressure port should be open, is between 55% and approx. 95%.

In both p-v diagrams, a (relative) pressure drop or pressure increase by a factor of 2 (from 2.0 to 1.0 or from 1.0 to 2.0) can be seen in the volume range under consideration. The opening start value of the back pressure port is therefore approx. 100% or approx. 95% of the relative compressor chamber volume.

In “Computer Modeling of Scroll Compressor with Seif Adjusting Back-Pressure Mechanism”, Tojo et al., Purdue e-Pubs (Purdue University), International Compressor Engineering Conference, 1986, Figure 5 shows the course of the relative compressor chamber volume as a function of Rotation angle (roll or wave angle theta, Q) of the orbiting scroll. The course shown is divided into the suction process, which corresponds to the low pressure area, the compression process and the exhaust process. With the opening range of the port based on the relative volume between 55% and 100% or 95% from FIG. 12, there is an angular range from 0 ° to 335 ° (with 100% opening start volume) or 0 ° to 300 ° ( at 95% opening start volume) in which the port should be positioned.

In “Dynamics of Compliance Mechanisms in Scroll Compressors, Part I: Axial Compliance”, Nieter et al. , Purdue e-Pubs (Purdue University), International Compressor Engineering Conference, 1990, the angular position of the back pressure port (Figures 7 and 8) is discussed. From Figure 3 and page 309, penultimate paragraph, penultimate sentence, there is an angular range of 360 °, within which the counter or medium pressure channel (back pressure port) should be positioned. From EP 2 369 182 B1 a scroll compressor with a housing is known, in which a fixed scroll with a base plate and spiral formed thereon and a movable scroll rotating around a circumferential axis with a base plate and spiral formed thereon are arranged. A delivery chamber (flap pressure chamber) is formed between the base plate of the fixed scroll and a housing section. An arranged in the housing inter mediate wall with a shaft bearing delimits a suction or inlet chamber and forms a back pressure chamber (backpressure chamber) with the base plate of the movable scroll, which communicates via a delivery channel in the movable scroll with the compressor chamber between the scrolls. The dispensing chamber and the back pressure chamber are connected via a secondary delivery channel which extends essentially axially through an outer wall of the fixed scroll. The secondary delivery channel in the discharge chamber supplies oil or coolant gas separated by means of an oil separator to the counter-pressure chamber in order to restore the pressure in the counter-pressure chamber in a short time after a pressure drop.

The invention is based, a particularly suitable, in particular special electromotive driven or drivable scroll compressor, the task To specify cold medium compressors for a vehicle air conditioning system. In particular, the most flexible and effective possible adjustment of the pressure in the back pressure chamber (backpressure chamber) to working points of the scroll compressor for a vehicle air conditioning system, preferably in cooling and heat pump mode, is to be achieved by a suitable pressure channel system. Leakages should also be reduced as much as possible and friction losses between the fixed scroll and the orbiting scroll should be avoided or at least kept to a minimum. This object is achieved by the features of claim 1. Advantageous refinements and developments are the subject of the sub-claims.

In a housing with a high-pressure chamber and with compression chambers and with a counter-pressure chamber, the scroll compressor has a fixed scroll and a movable, i.e. H. in the driven state - i.e. in operation (compressor operation) - orbiting (oscillating) scroll. The scrolls or scroll parts each have a base plate and a spiral wall, the compression chambers being formed between the interlocking spiral walls of the two scrolls (scroll parts). The base plate of the fixed scroll limits the high pressure chamber and the base plate of the movable scroll limits the counter pressure chamber.

The back pressure chamber is connected to at least one of the compressor chambers via a pressure line running at least partially in the fixed scroll. The pressure line is connected to at least one of the compression chambers via a first channel and also to the high pressure chamber via a second channel. In this way, a static pressure also acting in the counter-pressure chamber arises in the pressure line, via which the counter-pressure chamber communicates fluidically with the high-pressure chamber and with the at least one compressor chamber. The scroll compressor is provided and set up in particular for refrigerants in a vehicle air conditioning system. Suitably at least one of the channels is arranged in the base plate of the fixed scroll. Preferably, the first channel connected to the compressor chamber and the second channel connected to the high pressure chamber are arranged in the base plate of the fixed scroll. In an advantageous embodiment, the second channel is arranged in a filter (filter insert) which is inserted in the high-pressure chamber in a bore opening which is introduced into the base plate on its high-pressure chamber plate side and there by a positioning and holding collar for the filter insert is surrounded. The pressure line expediently has at least a first line section which is arranged in the base plate of the fixed scroll and a second line section which is connected to the first line section and is arranged in a boundary wall of the fixed scroll. The boundary wall can be part of the fixed scroll or the housing.

According to a first alternative, the first line section can be introduced radially into the base plate and the second line section can run axially or obliquely in the boundary wall of the fixed scroll in the form of a bore, the bores within the base plate forming the pressure line flow into one another or merge into one another.

According to a second alternative, in which the second channel is arranged in or formed by a filter (filter insert), two obliquely extending, first line sections are provided starting from the bore opening in the base plate of the fixed scroll. One of these first line sections runs to the second line section in the boundary wall and opens into it. The other of these first line sections runs to the first channel, i. H. within the base plate of the fixed scroll in the direction of the (selected) position of the first channel.

The back pressure chamber is delimited by a partition from a low pressure chamber. In this intermediate wall, which suitably serves as a bearing plate for a shaft driving the movable scroll, a counter-pressure Chamber leading (third) line section of the pressure line arranged. This line section can in turn be designed in a simple manner as a radial bore in the intermediate wall. Alternatively, this line section of the pressure line is designed as a groove in the intermediate wall in connection with a plate covering this (wear plate).

The cross-sectional area of the pressure line is at least a factor of two (2) larger than the cross-sectional area of the first duct connected to the compression chamber and the second duct connected to the high-pressure chamber. The cross-sectional area of the first channel connected to the compressor chamber is advantageously again larger than the cross-sectional area of the second channel connected to the high-pressure chamber.

Suitably the ratio between the cross-sectional area of the first duct connected to the compression chamber and the cross-sectional area of the second duct connected to the high pressure chamber is between 3 (three) and 5 (five), preferably 4 (four). The cross-sectional areas of the two channels should expediently be as small as possible.

The cross-sectional area of the first duct connected to the compressor chamber is expediently between 0.03 mm ² and 1.5 mm ² , preferably 0.2 mm ² . The cross-sectional area of the second channel connected to the high-pressure chamber is advantageously between 0.008 mm ² and 0.2 mm ² , preferably 0.05 mm ² . Based on a circular channel cross section, the diameter of the first channel should be between 0.2 mm and 1 mm, preferably 0.5 mm, and that of the second channel between 0.1 mm and 0.5 mm, preferably 0.25 mm .

In an advantageous embodiment, the first and / or the second channel are designed as a drilling which opens into the pressure line. Due to the small wall thickness (wall thickness) of the base plate of the fixed scroll in the region of the two channels, the respective bore or channel thus acts as a baffle or throttle. This fluidic control and an effective adaptive adaptation of the pressure in the back pressure chamber to different operating points of the scroll compressor (in cooling or heat pump mode) is supported or can be further improved by the fact that the first channel connected to the compressor chamber - starting from a relative chamber volume of about 100% in the radially outermost compressor chamber and a rotation or shaft angle of 0 ° - at a rotation or shaft angle of (63.5 ± 5.5) ° is fully open and up to a rotation or shaft angle of (343.5 ± 5.5) ° remains open. This corresponds to a relative change in volume of the insulator chamber volume from (91, 15 ± 0.75) ° to (23.0 ± 0.3) °.

The radial distances between the two channels to a central outlet arranged in the fixed base plate and leading into the high-pressure chamber are suitably of different sizes, so that the operating channels are deliberately not arranged directly (axially) opposite one another. The radial distance of the second channel leading into the high-pressure chamber can be greater or smaller than the radial distance of the first channel connected to the compression chamber from the central outlet.

The advantages achieved by the invention are, in particular, that through the two flow-regulating channels in connection with the pressure line in the fixed scroll, an effective and self-adjusting adjustment of the pressure in the counter-pressure chamber to the respective operating point of the scroll compressor without additional flow-regulating components Flow restriction, such as valves, nozzles, throttles or other channels, holes or orifices.

The adaptive control of the pressure in the back pressure chamber is also reliably carried out by the two channels and the pressure line in the fixed scroll at a pressure ratio between suction pressure (low pressure) and high pressure of 5 (at a suction pressure of 3 bar and a high pressure of 15 bar) a setting as at a pressure ratio of about 8 (at a suction pressure of 3 bar and a high pressure of 25 bar) or 10 (at a suction pressure of 1.5 bar and a high pressure of 15 bar) for the refrigerant R-134A (operating point when operating as a heat pump). In addition, this two-channel pressure line system in the fixed scroll enables high process stability for series production. For example, the two channels in the fixed scroll are subject to virtually the same conditions in the course of a scroll coating, for example a color coating, so that tolerances which can lead to fluctuations in the counterpressure or backpressure level cancel each other out (cut out).

Furthermore, the scroll compressor can be operated with high efficiency due to the adaptive adjustment of the pressure in the back pressure chamber at operating points in the cooling and in the heat pump mode, because leaks in particular are reduced and friction losses between the scroll parts can be kept to a minimum. As a result of the self-adjusting pressure in the counter-pressure chamber, the axial force which is due to the adaptive adaptation is not, or always only by a small amount, greater than the sum of the axial forces in the compressor chambers, which typically have different pressures during compressor operation.

The particularly effective flow control and adaptive adjustment of the pressure in the back pressure chamber to different operating points of the scroll compressor is advantageously determined or influenced by the specified cross-sectional relationships of the pressure line and the two channels and their positioning in relation to the compressor chamber (s). The positioning is suitably chosen such that in particular the first channel opens at a relative volume of the compression chamber (compression chamber volume) of approx. 90% and remains open in the course of a relative pressure change up to a relative volume of the compression chamber of approx. 23%, before the respective channel is covered or overlapped by its spiral wall during the orbiting movement of the orbiting scroll and is connected (overlapping) to a compression chamber located radially further out. If the orbiting scroll typically takes 2.5 revolutions from the compression process of the cold medium-gas mixture in the compression chambers to the discharge process of the compressed cold medium-gas mixture into the high-pressure chamber of the scroll compressor - and thus between 0% and 100% relative ver seal chamber volume - passes through an angular range of 900 °, the first channel connecting the compressor chamber to the pressure line should be positioned in the fixed scroll at an angle (spiral angle cp) of 350 ° to 390 °, in particular 370 °, this angle cp starting from both The beginning and the end of the spiral wall (scroll spiral) of the fixed scroll can be measured.

The position of the second channel, which connects the pressure line to the high-pressure chamber within the housing of the scroll compressor, inevitably results along the same radius or angular line if the pressure line or its first line section is rectilinear. In the variant with obliquely running first line sections, the two axially spaced-apart channels can be arranged at different radial and / or azimuth positions.

An exemplary embodiment of the invention is explained in more detail below with reference to a drawing. In it show:

1 is a perspective side view of a scroll compressor with an electromotive drive module and with a compressor module,

2 schematically simplified in a sectional view the electromotively driven scroll compressor with a high pressure chamber and with a back pressure chamber (back-pressure chamber) and with the pressure line or channel system leading into it,

Fig. 3 is a sectional view of the scroll compressor with a stationary and a movable scroll in a compressor and with a pressure line leading to the back pressure chamber, each with a connecting channel (first channel and second channel) into the compression chambers formed between the scrolls, on the one hand, and into the high pressure chamber,

4 is a block diagram of the pressure feedback from the high pressure chamber and from the scroll-side compression chambers into the back pressure chamber and with an oil return into a suction or engine-side low pressure chamber,

5 is a perspective view of the fixed scroll with egg nem at a predetermined position within the scroll wall (scroll spiral) (angular position) in the base plate arranged channel (Boh tion) to the pressure line,

Fig. 6 in a plan view of the fixed scroll with two drawn

Angular positions (spiral angle) of the to a compressor chamber lead the first connection channel in the base plate, Fig. 7 shows a perspective view of the fixed scroll with a view of the high pressure chamber side plate surface (plate side), its base plate and the receiving opening arranged therein for a filter insert with the (second) Connecting channel to the high pressure chamber,

Fig. 8 shows the fixed scroll of FIG. 7 in a plan view, and

9 shows a section IX-IX from FIG. 8 with line sections of the pressure line starting from the receiving opening for the filter insert to the first connecting channel and to a line section in a (radially outer) boundary wall of the fixed scroll.

Corresponding parts and sizes are always provided with the same reference numerals in all figures. The cold medium compressor 1 shown in FIG. 1 is installed in a refrigerant circuit (not shown in more detail) of an air conditioning system of a motor vehicle. The electromotive refrigerant compressor 1 has an electrical (electromotive) drive module 2 and a compressor module coupled to it in the form of a scroll compressor 3. The scroll compressor 3 is connected to the drive module 2 in terms of drive technology via a mechanical interface 4 formed between the drive module 2 and the scroll compressor 3. The mechanical interface 4 serves as a drive-side end shield and forms an intermediate wall 5 (FIGS. 2 and 3). The scroll compressor 3 is connected (joined, screwed) to the drive module 2 by means of flange connections 6 distributed around the circumference and extending in the axial direction A of the refrigerant compressor 1.

A partial housing area of a drive housing 7 of the refrigerant compressor 1 is designed as a motor housing 7a for receiving an electric motor 13 (FIG. 2) and, on the one hand, through an integrated intermediate wall 7b (FIG. 2) to an electronics housing 7d provided with a housing cover 7c with an electric motor 13 driving motor electronics (electronics) 8 and on the other hand closed by the mechanical interface 4 with the bearing plate and the intermediate wall 5. The drive housing 7 has in the area of the electronics housing

7b has a connection section 9 with motor connections 9a and 9b leading to the electronics 8 for electrical contacting of the electronics 8 with an on-board electrical system of the motor vehicle. The drive housing 7 has a refrigerant inlet or refrigerant inlet 10 for connection to the refrigerant circuit and a refrigerant outlet 11. The outlet 11 is formed on the bottom of a compressor housing 12 of the scroll compressor 3. In the connected state, the inlet 10 forms the low pressure or suction side (suction gas side) and the outlet 11 forms the high pressure or pump side (pump side) of the refrigerant compressor 1.

Fig. 2 shows schematically the electromotive refrigerant compressor 1 in a sectional view along an axis of rotation 14 of the electric motor 13, which here is a brushless DC motor (BLDC) and has a cylindrical rotor 15. This is given around the circumference by means of a hollow cylindrical stator 16. The rotor 15 comprises a number of permanent magnets and is rotatably supported about the axis of rotation 14 by means of a shaft 17. The stator 16 has a number of electrical coils which are energized by means of the electronics 8, which in turn are connected, for example, to a bus system and the vehicle electrical system.

The electronics 8 is arranged in the electronics housing 7d of the drive housing 7, which is separated from the stator 16 and the rotor 15 by means of the intermediate wall 5. The housing cover 7c, which is detachably fastened to the electronics housing 7d by means of screws, closes an access opening of the electronics housing 7b. The motor electronics 8 has circuit boards 18, 19 which are arranged one above the other in the axial direction A. A bridge circuit of the printed circuit board 18, which is closest to the intermediate wall 7b, is in contact with the electrical coils of the stator 16 via current supply lines 19, which are led through the intermediate wall 7b. The bridge circuit is fed by means of the vehicle electrical system and controlled by means of a control circuit of the other printed circuit board 19, which is connected to the bus system in terms of signal technology.

As can be seen comparatively clearly in connection with FIG. 3, the scroll compressor 3 has a movable scroll (scroll part) 21 arranged in the compressor housing 12. This is coupled via an eccentric shaft journal 17a with, for example, two joining pins, of which only one joining journal 17b is visible, to the shaft 17 of the electric motor 13, which is guided into the mechanical interface 4 with the A-side end shield. The eccentric shaft journal 17a is mounted in a roller or ball bearing 22a held in the movable scroll 21. Another roller or ball bearing 22b supporting the shaft 17 is arranged in the mechanical interface 4 serving as the A-side bearing plate and there in the intermediate wall 5. The movable scroll (scroll part) 21 is driven orbiting during operation of the scroll compressor 3. The scroll compressor 3 also has a rigid scroll (scroll part) 23 fastened in the compressor housing 12. The two scrolls (scroll parts) 21, 23 engage with one another with their worm or spiral scroll walls (scroll spirals) 21 a, 23 a, which project axially from a respective base plate 21 b, 23 b. Between the scrolls 21, 23, ie between them Scroll walls or scroll spirals 21 a, 23 a and the base plates 21 b, 23 b form compression chambers 24, the volume of which is changed during operation of the electric motor 13.

A counterpressure chamber (backpressure chamber) 25 is located in the intermediate wall 5 between the A-side bearing plate and the movable scroll 21. This is in the compressor housing 12 of the base plate 21 b of the movable scroll 21 and / or - referred to simply as the housing below limited by an intermediate plate (wear plate) 5a (FIG. 3) in the form of a steel plate, which has good sliding properties for the orbiting scroll 21. The back pressure chamber 25 extends in some areas into the base plate 21 b of the movable scroll 21.

During operation, the refrigerant is introduced through the inlet 10 into the drive housing 7 and there into the motor housing 7a. This area of the drive housing 7 forms the suction or low-pressure side 26. By means of the intermediate wall 7b, penetration of the refrigerant into the electronics housing 7d is prevented. Within the drive housing 7, the refrigerant is mixed with oil present in the refrigerant circuit and is drawn along the rotor 15 and the stator 16 through an opening (or several openings, FIG. 3) 27 in the intermediate wall 5 to the scroll compressor 3. By means of the scroll compressor 3, the mixture of refrigerant and oil is compressed, the oil serving to lubricate the two scrolls 21, 23, so that friction is reduced and consequently efficiency is increased. The oil also serves as a seal in order to avoid an uncontrolled escape of the refrigerant located between the two scrolls (scroll parts) 21, 23.

The compressed mixture of refrigerant and oil is fed into a high-pressure chamber via a central outlet 28 in the base plate 23b of the fixed scroll 23 29 passed within the compressor housing 12. In the high-pressure chamber 29 there is an oil separator (cyclone separator) 30. Inside the oil separator 30, the mixture of refrigerant and oil is set into a rotational movement, the heavier oil due to the increased inertia and increased mass to the walls of the oil separator 30 passed and collected in a lower region of the oil separator 30, while the refrigerant is discharged upwards or laterally through the outlet 11.

As can be seen comparatively clearly in FIG. 3, the high-pressure chamber 29 is delimited within the housing 12 by means of the base plate 23b of the fixed scroll 23. The central outlet 28 in the high pressure or outlet chamber 29, which is located in the radially innermost chamber region 24 'of the compression chambers 24, is introduced into the base plate 23b of the fixed scroll 23 as a bore. Within the high-pressure chamber 29, the central outlet 28 is closed with a spring valve (finger spring valve) 33 as long as the pressure in the compression chambers 24 is lower than the pressure in the high-pressure chamber 29. If the pressure of the compressed refrigerant-oil mixture in the Compressor chambers 24, in particular in the central chamber area 24 ', greater than the pressure in the high-pressure chamber 29, the spring valve 33 opens quasi automatically.

A stop element 34, which is fixed in the high-pressure chamber 29 on the fixed scroll 23, for example on its base plate 23b, limits the stroke of the spring valve 33. When the pressure has dropped to below the pressure in the high-pressure chamber 29, the spring valve 33 closes the Outlet 28 again automatically due to its spring preload. In this way, the compressed refrigerant-oil mixture - depending on the speed of the shaft 17 or depending on the operating point of the scroll compressor 3 - passes continuously (through normal) or intermittently or pulsatingly through the central outlet 28 from the compressor chamber 24 into the high-pressure chamber 29 .

A pressure line 35 is provided in the fixed scroll 23, via which the compression chambers 24 and the high-pressure chamber 29 communicate with the counter-pressure chamber 25 in terms of flow. For this purpose, the pressure line 35 stands over a NEN first channel 36 with the Ver between the scroll walls 21 a, 23a formed compression chambers and via a second channel 37 with the high pressure chamber 29 in a region in connection, which in operation essentially contains the refrigerant tel and only a small amount of oil.

Fig. 4 shows schematically in a block diagram the fluidic or pressure-carrying connection of the back pressure chamber 25 via the pressure line 35 and the two channels 36, 37, which act as orifices or throttles, on the one hand with the high pressure chamber 29 and on the other hand with the compressor chambers 24. The first channel introduced into the base plate 23b of the fixed scroll 23, for example as a bore, is provided with the reference symbol 36, as is its orifice or throttle symbol.

Also shown in FIG. 4 is an oil return 38, shown as a broken (dashed) line, including throttle element 39, from the high-pressure chamber 29 in the region of the oil separator 30 into the low-pressure chamber

(Suction chamber) 26. This is fluidically connected via the suction gas opening 27 with the compressor chambers 24 of the scroll compressor 3, as illustrated by the broken arrow line 40.

In the embodiment according to FIG. 3, the pressure line 35 is formed from a first line section 35a, which is suitably made as a radial bore in the base plate 23b of the fixed scroll 23, and from a second line section 35b, which is suitably as an axial bore in a Pot-shaped boundary wall 23c of the fixed scroll 23 is arranged. The second line section 35 b can also be introduced into the (axial) housing wall of the compressor housing 12. The bores or line sections 35a, 35b open into one another within the base plate 23b or merge into one another. The inlet opening of the radial bore of the first line section 35a is closed on the circumference of the boundary wall 23c in a manner not shown in detail. The back pressure chamber 25 is delimited by the intermediate wall 5 from the suction or low pressure chamber 26. In the intermediate wall 5, which supports the bearings 22a and 22b for the shaft journal 17a and the shaft 17 as a bearing shield, a third line section 35c of the pressure line 35 leading to the back pressure chamber 25 is arranged. This line section 35c can be designed analogously as a radially running bore in the intermediate wall 5. Alternatively, the third line section 35c into the intermediate wall (interface) 5 can be designed as a groove which is open towards the orbiting scroll 21 and closed by the intermediate plate (commodity plate) 5a.

The cross-sectional area of the pressure line 35 is many times, for example ten times, smaller than the cross-sectional area of the central outlet 28. However, the cross-sectional area of the pressure line 35 is many times larger than the cross-sectional area of the two channels 36 and 37. In addition, the cross-sectional area is of the first duct 36 connected to the compression chambers 24 is larger than the cross-sectional area of the second duct 37 connected to the high pressure chamber 29.

The diameter of the central outlet 28 is between 5 mm and 10 mm. The diameter of the pressure line 35 is between 1 mm and 10 mm. The diameter of the first channel 36 is, for example, 0.5 mm, and the diameter of the second channel 37 is, for example, 0.25 mm, in each case with a circular bore or channel cross section.

The first channel 36 and the second channel 37 are designed as bores and (fluidically) act as an orifice or throttle. With this channel system formed from the pressure line 35 and the two channels 36, 37, a particularly effective fluidic regulation of the (static) pressure in the back pressure chamber 25 is achieved. The radial distance of the first channel 36 connected to the compressor chambers 24 to the central outlet 28 arranged in the base plate 23b of the fixed scroll 23 and leading into the high pressure chamber 29 is greater in the exemplary embodiment than the radial distance of the second channel 37 connected to the high pressure chamber 29 to the central Outlet 28. However, the second channel 37 can also be arranged closer to the central outlet 28 than the first channel 36. It is essential that the two channels 36 and 37 are not arranged directly axially opposite one another. Due to the static pressure prevailing in operation within the counterpressure chamber 25, the movable scroll 21 is pressurized and, as illustrated by the force arrows labeled FG, is pressed along the rotation axis 14 against the fixed scroll 23. This force (counterforce)

FG counteracts the axial force Fv illustrated by the force arrows, which in turn acts on the movable scroll 21 as a result of the pressure prevailing in the compression chambers 24. Together with the pressure transferred from the flap pressure chamber 29 via the pressure line 35 to the back pressure chamber 25 (passed on), an equilibrium of forces is established (FG = Fv) and thus the desired sealing effect between the two scrolls 21, 23.

FIGS. 5 and 6 show in a perspective representation or in a plan view the fixed scroll 23 with the first channel 36, which is arranged in the base plate 23b at an angle position PKI predetermined within the scroll wall (scroll spiral) 23a and there to the pressure line 35 , d. H. leads to the first line section 35a thereof running within the base plate 23b. The position PKI of the first channel 36 is located starting from the spiral beginning of the spiral wall 23a shown in FIG. 6 as the angular line f -is of the fixed scroll 23 preferably at the spiral angle cpi = 370 °. It is also expedient to position PK2 of the first channel 36 starting from the spiral end of the spiral wall 23a of the fixed scroll 23 shown in FIG. 6 as the angle line cp2s at the spiral angle y2 = 370. The channel outlet of the second line section 35b opening into the third line section 35c can also be seen within the, preferably circumferentially closed, boundary wall 23c of the fixed scroll 23.

Figures 7 and 8 show in a perspective view or in a plan view of the fixed scroll 23 with a view of the plate side of the base plate 23b located in the high pressure chamber 29. There is one Receiving opening 41 in the compression chambers 24. In this receiving opening 41, a filter (filter insert) 42 is received, which has a filter shaft 42a and a diaphragm or throttle head 42b, in which the second channel 37, for example as a central bore, is provided . The opening 41 is for receiving, positioning and / or stabilizing the aperture or Drosselkop fes 42b of the filter (filter insert) 42 from a wall 43 ben like a collar.

FIG. 9 shows a sectional illustration of the fixed scroll 23 along the lines IX-IX in FIG. 8. In this embodiment, the first line section 35a of the pressure line 35 is formed by two sections ai, a2 in the form of obliquely running bores which are formed by the Receiving opening 41 are introduced into the base plate 23b. The first section ai runs in the direction of the center or the central region of the base plate 23b. The second section a2 runs to the second line section 35b of the pressure line 35 in the boundary wall 35c of the fixed scroll 23 and opens there into the second line section 35b of the pressure line 35. The first channel 36 opens into the first section ai of the first line section 35a of the pressure line 35 Establishment of the (pressure and / or fluidic) connection of the compression chambers 24 to the pressure line 35 and via this to the back pressure chamber 25, not shown in FIG. 9.

The two flow-regulating channels 36, 37 and their connection to the pressure line 35 leading into the counter-pressure chamber 25 in the fixed scroll 23 enable a particularly effective, self-adjusting adjustment of the pressure in the counter-pressure chamber 25 in practically all working areas or points of the scroll compressor 3 reached. So the adaptive control of the pressure in the back pressure chamber 25 by means of the two channels 36, 37 and the pressure line 35 in the fixed scroll 23 at a suction pressure (low pressure) of 3 bar and a high pressure of 15 bar is just as reliable and self-adjusting as in a suction pressure of 3 bar and a high pressure of 25 bar or a suction pressure of 1.5 bar and a high pressure of 15 bar (operating point in heat pump operation). The scroll compressor 3 and thus the refrigerant compressor 1 can therefore be operated with high efficiency at operating points in the cooling and in the heat pump mode of a vehicle air conditioning system.

The flow control and adaptive adjustment of the pressure in the back pressure chamber 25, even at different operating points of the scroll compressor 3, can be achieved by the cross-sectional relationships of the pressure line 35 and the two channels 36, 37 and their positioning in relation to the compressor chamber (s). 24 can be influenced. The position PKI, PK2 of the first channel 36 is selected such that it opens at a relative volume of the compressor chamber 24 of approximately 90% and remains open up to a relative chamber volume of approximately 25%.

The orbiting scroll 21 typically runs through an angular range of 900 ° from the compression process of the refrigerant / gas mixture in the compression chambers 24 to the ejection process of the compressed refrigerant / gas mixture via the central outlet 28 into the high pressure chamber 29 of the scroll compressor 3. Therefore, the first channel 36 connecting the compressor chambers 24 to the pressure line 35 is suitably positioned in the fixed scroll 23 at the position PKI, PK2 illustrated in FIG. 4 at the corresponding helix angle f-1, 2 = 370 °.

In summary, the scroll compressor 3, which is provided and set up especially for refrigerants in a vehicle air-conditioning system, has a fixed scroll 23 and a movable scrolling device in the compressor mode in a compressor housing 12 with a high-pressure chamber 27 and with compressor chambers 24 and with a back pressure chamber (backpressure chamber) 25 (oscillating, rolling) scroll 21. The scrolls 21, 23, which each have a base plate 21 a, 23a and a scroll or spiral wall 21 a, which is integral therewith (formed on them), have between their intermeshing scroll or spiral walls 21 a and 23a the compression chamber (s) 24. The base plate 23b of the fixed scroll 23 delimits the high-pressure chamber 27, and the base plate 21b of the movable scroll 21 delimits the counter-pressure chamber 25. The back pressure chamber 25 is connected to at least one of the compressor chambers 24 via a pressure line 35 running at least partially in the fixed scroll 23 and a first channel 36 and to the high pressure chamber 27 via a second channel 37. This arises or prevails due to operational conditions in the pressure line 35, via which the counter-pressure chamber 25 communicates fluidically with the high-pressure chamber 27 and with the at least one of the compressor chambers 24, a pressure acting also in the counter-pressure chamber 25.

The claimed invention is not limited to the exemplary embodiments described above. Rather, other variants of the invention can also be derived therefrom by the person skilled in the art within the scope of the disclosed claims without departing from the subject matter of the claimed invention. In particular, all of the individual features described in connection with the various exemplary embodiments can also be combined in other ways within the scope of the disclosed claims without departing from the subject matter of the claimed invention.

Reference symbol list

1 refrigerant compressor

2 drive module

3 scroll compressors / compressor module

4 interface

5 end shield / partition

5a intermediate plate / ware plate

6 flange connection

7 drive housing

7a motor housing

7b partition wall

7c housing cover

7d electronics housing

8 Engine electronics

9 connection section

9a, b motor connection

10 inlet / inlet

11 outlet

12 compressor housing

13 electric motor

14 rotor axis

15 rotor

16 stator

17 wave

17a shaft journal

17b joining pin

18.19 circuit board

20 power supply line

21 movable / orbiting scroll / part

21 a Scroll wall / spiral

21 b base plate

22a, b roller / ball bearings 23 fixed scroll / part

23a scroll wall / spiral

23b base plate

23c boundary wall

24 compression chamber

24 'chamber area

25 back pressure chamber

26 Low pressure / suction side

27 opening

28 central outlet

29 High pressure / outlet chamber

30 oil separators

31 bypass channel

32 throttle device

33 spring valve

34 stop element

35 pressure line

35a first line section

35b second line section 35c third line section

36 first channel

37 second channel

38 Oil return

39 throttle device

40 (broken) arrow line

41 receiving opening

42 Filter / insert

42a filter shaft

42b throttle / orifice head in the first section

32 second section

fi, 2 spiral angles f-is spiral start cp2 _s spiral end A axial direction

FG counterforce Fv axial force

PKI, 2 position of 36

Claims

Expectations

1. Scroll compressor (3) for refrigerants of a vehicle air conditioning system, comprising

- a housing (12) with a high-pressure chamber (29) and with compression chambers (24) and with a counter-pressure chamber (25),

a fixed scroll (23) with a base plate (23b) and with a spiral wall (23a), the base plate (23b) of the fixed scroll (23) delimiting the high-pressure chamber (29),

- A movable scroll (21) with a base plate (21 b) and with a spiral wall (21 a) in the spiral wall (23b) of the fixed scroll

(23) engages and forms the compression chambers (24) with it, the base plate (21b) of the movable scroll (21) delimiting the counterpressure chamber (25),

characterized,

that the back pressure chamber (25) is connected via a pressure line (35) to the compressor chambers (24) and to the high pressure chamber (29), the pressure line (35) running at least partially in the fixed scroll (23) and via a first channel (36) with at least one of the compressor chambers (24) and via a second channel (37) with the high pressure chamber (29).

2. Scroll compressor (3) according to claim 1,

characterized,

that the first channel (36), which is connected to the at least one of the compressor chambers (24), and / or the second channel (37), which is connected to the high-pressure chamber (29), in the base plate (23b) of the fixed scroll (23 ) are arranged.

3. Scroll compressor (3) according to claim 1 or 2,

characterized,

- That the pressure line (35) has a first line section (35a) which is arranged in the base plate (23b) of the fixed scroll (23), and - That the pressure line (35) has a first line section (35a) connected to the second line section (35b), which is arranged in a boundary wall (23c) of the fixed scroll (23) or in a housing wall of the housing (12).

4. Scroll compressor (3) according to one of claims 1 to 3,

characterized,

that the back pressure chamber (25) is delimited by a low pressure chamber (26) by means of an intermediate wall (5) in which a third line section (35c) of the pressure line (35) leading to the back pressure chamber (25), in particular designed as a bore or groove, is arranged.

5. Scroll compressor (3) according to one of claims 1 to 4,

characterized,

that the ratio of the cross-sectional area of the pressure line (35) to the cross-sectional area of the first channel (36) connected to the compression chamber (24) is between 10 and 100, preferably between 15 and 70.

6. Scroll compressor (3) according to one of claims 1 to 4,

characterized,

that the ratio of the cross-sectional area of the pressure line (35) to the cross-sectional area of the second channel (36) connected to the high chamber (29) is between 50 and 500.

7. Scroll compressor (3) according to one of claims 1 to 6,

characterized,

that the cross-sectional area of the first channel (36) connected to the compressor chamber (24) is larger than the cross-sectional area of the second channel (37) connected to the high-pressure chamber (29).

8. Scroll compressor (3) according to one of claims 1 to 7,

characterized, that the cross-sectional area of the first channel (36) connected to the compressor chamber (24) is between 0.01 mm and 1 mm, preferably 0.25 mm. 9. Scroll compressor (3) according to one of claims 1 to 8,

characterized,

that the cross-sectional area of the second channel (37) connected to the high-pressure chamber (29) is between 0.01 mm and 2 mm, preferably 0.5 mm.

10. Scroll compressor (3) according to one of claims 1 to 9,

characterized,

that the ratio between the cross-sectional area of the first channel (36) connected to the compression chamber (24) and the cross-sectional area of the second channel connected to the high-pressure chamber (29)

(37) is between 2 and 10, preferably 4.

11. Scroll compressor (3) according to one of claims 1 to 10,

characterized,

that the first channel (36) and / or the second channel (37) is or are effective as a bore and / or as an orifice or throttle.

12. Scroll compressor (3) according to one of claims 1 to 11,

characterized,

that the first channel (36) connected to the compression chamber (24) starting from the beginning and / or end of the spiral wall (23a) of the fixed scroll (23) at a spiral angle (f-1,2) of 350 ° to 390 °, preferably 370 °, is arranged. 13. Scroll compressor (3) according to one of claims 1 to 12,

characterized,

that the radial distance of the first channel (36) connected to the compression chamber (24) to one in the base plate (23b) of the fixed one Scrolls (23) arranged and in the high pressure chamber (29) leading central outlet (28) is larger or smaller than the radial distance of the second channel (37) connected to the high pressure chamber (29) to the central outlet (28).

14. Scroll compressor (3) according to one of claims 1 to 13,

characterized,

that the second channel (37) is arranged in a filter (42) which is inserted into a receiving opening (41) which is introduced in the base plate (23b) on its plate side facing the high-pressure chamber (29).

15. Scroll compressor (3) according to claim 14,

characterized,

that starting from the receiving opening (41), two inclined sections (ai, a2) of the or a first line section (35a) of the pressure line (35) are provided, the first channel (36) opening into a first section (ai), and wherein the second section (a2) opens into or into a second line section (35b) of the pressure line (35).