CN113167273B

CN113167273B - Positive displacement machine according to the spiral principle, in particular a scroll compressor for a vehicle air conditioning system

Info

Publication number: CN113167273B
Application number: CN201980080121.2A
Authority: CN
Inventors: 丹尼斯·里马
Original assignee: Bozewalsburg Automotive Parts Europe
Current assignee: Bozewalsburg Automotive Parts Europe
Priority date: 2018-12-12
Filing date: 2019-12-12
Publication date: 2023-06-27
Anticipated expiration: 2039-12-12
Also published as: EP3667086B1; WO2020120659A1; EP3670915A1; EP3670915B1; EP3667086A1; CN113167273A

Abstract

The present disclosure relates to a scroll compressor (3) for a refrigerant of a vehicle air conditioning unit, having: comprises a housing (12) having a high-pressure chamber (29), a compressor chamber (24), and a back-pressure chamber (25); a stationary scroll (23) whose bottom plate (23 b) delimits a high-pressure chamber (29); and a movable scroll (21), the spiral wall (21 a) of which is embedded in the spiral wall (23 b) of the stationary scroll (23) and forms a compressor chamber (24) therewith, wherein the floor (21 b) of the movable scroll (21) delimits a back pressure chamber (25), and wherein a pressure line (35) connected to the compressor chamber (24) and the high pressure chamber (29) extends at least partially in the stationary scroll (23) and is connected to at least one of the compressor chambers (24) via a first channel (36) and to the high pressure chamber (39) via a second channel (37).

Description

Positive displacement machine according to the spiral principle, in particular a scroll compressor for a vehicle air conditioning system

Technical Field

The present invention is in the field of positive displacement machines according to the spiral principle and relates to scroll compressors, in particular electric motors, as refrigerant compressors for vehicle air conditioning units. Such a positive-displacement machine and in particular such a scroll compressor are known from DE 10 2017 1 10 913 B3.

Background

In motor vehicles, an air conditioning unit is usually installed, which adjusts the temperature of the vehicle interior by means of the unit forming a refrigerant circuit. Such a unit basically has a circuit in which the refrigerant is guided. Refrigerants, e.g. carbon dioxide (CO) ₂ ) Or R-134a (1, 2-tetrafluoroethane) or R-774%Carbon dioxide) is heated in the evaporator and compressed by means of a (refrigerant) compressor or extruder, wherein the refrigerant then releases the absorbed heat again via a heat exchanger and is then redirected via a throttle to the evaporator.

Scroll technology is often used in refrigerant compressors to compress the refrigerant-oil mixture. The oil-gas mixture formed in this way is separated, wherein the separated gas is introduced into the air conditioning circuit, and the separated oil can be guided, if appropriate, to the moving parts for lubrication purposes within a scroll compressor, which is a refrigerant compressor driven by an electric motor in a suitable manner.

The construction and operation of such a scroll compressor for a refrigerant or refrigerant-oil mixture of an air conditioning unit of a motor vehicle is described, for example, in DE 10 2012 104 045A1 and Tojo et al, purdee-Pubs (university of Purperage) in "A Scroll Compressor for Air Conditioners (International conference on compressor engineering)" made in International Compressor Engineering Conferenz (1984). Model calculations of a self-setting back pressure or back pressure mechanism in a scroll compressor (scroll extruder) are described in Tojo et al, purde e-Pubs (university of Pudu) in International Compressor Engineering Conferenz (International conference on compressor engineering) 1986, "Computer Modeling ofScroll Compressor with Self Adjusting Back-Pressure Mechanism (computer modeling of scroll compressors with self-setting back pressure mechanism)".

The main components of the scroll compressor are a stationary scroll (stationary scroll) and a movable orbiting scroll (movable orbiting scroll). The two scrolls (scroll elements) are in principle identically constructed and each have a base plate and a spiral wall (wrap) extending from the base plate in the axial direction. In the assembled state, the spiral walls of the two scrolls are interleaved with each other and a plurality of compressor chambers are formed between the section-contacted scroll walls.

When the movable scroll moves in an orbital manner, the sucked-in oil-gas mixture reaches the radially outer first compressor chamber via the inlet and from there the radially innermost compressor chamber via the further compressor chamber and from there the outlet chamber or the high-pressure chamber via the central outlet, for example in the form of a bore, and possibly two adjacent auxiliary valves, likewise in the form of bores in the base plate of the stationary scroll. The chamber volume in the compressor chamber decreases from the radially outer portion to the radially inner portion and causes the pressure of the increasingly compressed medium to increase. Thus, during operation of the scroll compressor, the pressure in the compressor chamber increases from radially outside to radially inside.

The central oil and gas outlet (and possibly each auxiliary valve or aperture therein) is closed by a spring valve on the back side of the base plate of the stationary scroll. The spring valve opens due to the pressure difference between the compressor chamber and the high pressure chamber. After triggering the spring valve, if necessary, the compressed oil-gas mixture (on the back side of the stationary scroll) flows into the high-pressure chamber of the scroll compressor, where it is separated into oil and gas. The spring valve is then automatically closed when the pressure in the compressor chamber opposite the high-pressure chamber decreases accordingly.

During operation of the scroll compressor, the two scrolls are squeezed apart due to the pressure and thus axial force generated in the compressor chambers, so that a gap and thus a leak can be generated between the compressor chambers. In order to avoid this as much as possible, the orbiting scroll is pushed against the stationary scroll in addition to the oil film between the friction surfaces of the two scrolls if necessary. A corresponding axial force (reaction force) is generated by providing a pressure chamber (back pressure chamber, back pressure chamber (back pressure chamber)) on the back side of the base plate of the orbiting scroll, in which a specific pressure is generated.

According to DE 10 2012 104 045A1 already mentioned, this can be achieved by introducing a medium-pressure channel (through, opening, back pressure port) in the base plate of the orbiting scroll at a specific location, which medium-pressure channel connects at least one of the compressor chambers formed by the scroll with a back pressure chamber (back pressure chamber), so that the refrigerant gas from the compression process reaches the back pressure or medium pressure chamber directly between the scroll spirals. Since the intermediate pressure passage in the movable scroll is connected to the back pressure chamber (back pressure chamber), the movable scroll will be pushed from the setting (automatically) toward the stationary scroll, thereby providing sufficient sealing (axial sealing). Alternatively, the medium pressure channel may be arranged in the stationary scroll and open into the back pressure or medium pressure chamber around the movable scroll.

In known scroll compressors, the pressure in the back pressure chamber will rise to, for example, about 6 bar to about 9 bar at a pressure of, for example, 3 bar (low pressure) to 25 bar (high pressure) depending on the positioning of the medium pressure passage (back pressure port). In the known refrigerant scroll compressors for motor vehicle air conditioning units, the medium pressure channel is located in approximately 405 ° starting from the start of the scroll spiral (spiral wall) of the movable (orbiting) scroll.

In Tojo et al, purde e-Pubs (university of Pudu) in International Compressor Engineering Conferenz (International conference on compressor engineering) 1986, "Computer Modeling ofScroll Compressor with Self Adjusting Back-Pressure Mechanism (computer modeling of a scroll compressor with a self-setting back pressure mechanism)", model calculations of a self-setting back pressure mechanism in a scroll compressor are described. In the results of the study, a range of opposed compressor chamber volumes is shown in fig. 12, where the back pressure ports (at different port diameters) should be open (fluidly connected). This range is between 55% and about 100% of the (relative) chamber volume.

In "AScroll Compressor for Air Conditioners (scroll compressor for air conditioning)" by Tojo et al, purde e-Pubs (university of Purperance) in International Compressor Engineering Conferenz (International conference on compressor engineering) in 1984, nearly identical p-v diagrams are shown in FIG. 11, where the range of opposing compressor chamber volumes (where the back pressure ports should be open) should be between 55% and about 95% here.

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

In Tojo et al, purde e-Pubs (university of Purperance) in International Compressor Engineering Conferenz (International conference on compressor engineering) 1986, "Computer Modeling ofScroll Compressor with Self Adjusting Back-Pressure Mechanism (computer modeling of scroll compressor with self-setting back pressure mechanism)", FIG. 5 shows the trend of the rotation angle (roll angle or shaft angle Theta) of the orbiting-dependent scroll relative to the compressor chamber volume. The illustrated trend is divided into a pumping process (corresponding to a low pressure range), a compression process and a discharge process. Over a port opening range of between 55% and 100% or 95% for the relative volume in fig. 12, an angular range in which the port should be positioned (at 100% of the opening start volume) is 0 ° to 335 ° or (at 95% of the opening start volume) is 0 ° to 300 °.

The angular positioning of the back pressure ports is discussed in Nieter et al, purde e-Pubs (university of Purpura) at International Compressor Engineering Conferenz (International conference on compressor engineering) 1990, "Dynamics of Compliance Mechanisms in Scroll Compressors, part I: axial company" (FIGS. 7 and 8). From the penultimate sentence of the penultimate paragraph of fig. 3 and page 309, an angular range of 360 ° is obtained, within which the back pressure or medium pressure channel (back pressure port) should be positioned.

A scroll compressor having a housing in which a stationary scroll having a base plate and a spiral formed on the base plate and a movable scroll which also has a base plate and a spiral formed on the base plate and which is rotatable about a rotational axis are known from EP 2 369 182b 1. An output chamber (high-pressure chamber) is formed between the base plate of the stationary scroll and the housing section. A bearing intermediate wall with a shaft bearing arranged in the housing delimits the suction or inlet chamber and forms, together with the base plate of the movable scroll, a back pressure chamber (back pressure chamber) which communicates with the compressor chamber between the scrolls via a conveying channel in the movable scroll. The outlet chamber and the back pressure chamber are connected via a secondary transfer passage extending substantially axially through the outer wall of the stationary scroll. The secondary delivery passage delivers the oil or coolant gas separated in the output chamber by the oil separator into the back pressure chamber so as to reestablish the pressure in the back pressure chamber in a short time after the pressure drops.

Disclosure of Invention

The object of the present invention is to provide a particularly suitable scroll compressor, in particular an electric motor or an electric motor-drivable scroll compressor, as a refrigerant compressor for a vehicle air conditioning system. In particular, by means of a suitable pressure channel system, it is to be achieved that the pressure in the back pressure chamber (back pressure space) is adapted as flexibly and effectively as possible to the operating points of the scroll compressor for the vehicle air conditioning unit, which are preferably in cooling mode and heat pump mode. Leakage should also be minimized and frictional losses between the stationary scroll and the orbiting scroll should be avoided or at least kept as small as possible.

According to the invention, this object is achieved by the features of the invention.

The scroll compressor has a stationary scroll and an orbiting (oscillating) scroll (in the driven state, i.e., in operation (compressor operation)) in a compressor housing having a high-pressure chamber, a compressor chamber, and a back-pressure chamber. The scroll portions or scroll members have a base plate and spiral walls, respectively, wherein a compressor chamber is formed between the nested spiral walls of the two scroll portions (scroll members). The base plate of the stationary scroll defines a high pressure chamber and the base plate of the movable scroll defines a back pressure chamber.

The back pressure chamber is in communication with at least one of the compressor chambers via a pressure line extending at least partially in the stationary scroll. The pressure line is connected via a first channel to at least one of the compressor chambers and is also connected via a second channel to the high-pressure chamber. In this way, a static pressure is generated in the pressure line which fluidly connects the back pressure chamber with the high pressure chamber and with the at least one compressor chamber, which static pressure also will act in the back pressure chamber. The scroll compressor is provided and set up in particular as a refrigerant for a vehicle air conditioning unit.

Suitably, at least one of the channels is arranged in the base plate of the stationary scroll. Preferably, a first passage connected to the compressor chamber and a second passage connected to the high pressure chamber are arranged in the base plate of the stationary scroll. In an advantageous embodiment, the second channel is arranged in a filter (filter insert) which is inserted in the high-pressure chamber into a bore opening which is introduced into the base plate on the high-pressure chamber plate side of the base plate and is surrounded there by a positioning and retaining collar for the filter insert.

The pressure line expediently has at least one first line section arranged in the base plate of the stationary scroll and a second line section connected to the first line section, the second line section being arranged in the limiting wall of the stationary scroll. The delimiting wall may be an integral part of the stationary scroll or an integral part of the housing.

According to a first alternative, the first line sections are each introduced radially into the base plate in the form of bores in a simple manner, and the second line sections are introduced axially or obliquely into the delimiting walls of the stationary scroll, wherein the bores open into each other or transition into each other within the base plate for forming the pressure line.

According to a second alternative, two obliquely extending first line sections are provided starting from the bore openings in the base plate of the stationary scroll, wherein the second channel is arranged in or formed by a filter (filter insert). One of the first line sections extends into a second line section in the limiting wall and opens into it. The other of these first line sections extends into the first channel, that is to say into the base plate of the stationary scroll in the (selected) positioning direction of the first channel.

The back pressure chamber is separated from the low pressure chamber by an intermediate wall. A (third) line section of the pressure line leading to the back pressure chamber is arranged in an intermediate wall, which suitably serves as a bearing end cap for driving the shaft of the movable scroll. The line section can in turn be embodied in a simple manner as a radial hole in the intermediate wall. Alternatively, this line section of the pressure line is embodied as a groove in the intermediate wall, which is connected to a plate (wear plate) covering it.

The cross-sectional area of the pressure line is at least two (2) times larger than the cross-sectional area of the first channel connected to the compressor chamber and the second channel connected to the high pressure chamber. Advantageously, the cross-sectional area of the first passage connected to the compressor chamber is larger than the cross-sectional area of the second passage connected to the high pressure chamber.

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

Suitably, the first passage connecting with the compressor chamber has a cross-sectional area of 0.03mm ² And 1.5mm ² Preferably 0.2mm ² . Suitably, the cross-sectional area of the second passage connected to the high pressure chamber is 0.008mm ² And 0.2mm ² Preferably 0.05mm ² . With respect to the circular channel cross section, the diameter of the first channel should be between 0.2mm and 1mm, preferably 0.5mm, and the diameter of the second channel should be between 0.1mm and 0.5mm, preferably 0.25mm.

In an advantageous embodiment, the first and/or the second channel is embodied as a bore opening into the pressure line. Since the wall thickness (wall thickness) of the base plate of the stationary scroll in the region of the two channels is small, the respective bore or the respective channel acts as a throttle plate or throttle.

The fluidic adjustment and efficient and adaptive adaptation of the pressure in the back pressure chamber to the different operating points of the scroll compressor (in cooling or heat pump mode) is supported or can be further improved by letting the first channel connected to the compressor chamber open completely at a rotation angle or shaft angle (starting from about 100% of the opposite chamber volume and a rotation angle or shaft angle of 0 ° in the radially outermost compressor chamber) of (63.5±5.5) °, and keeping open until the rotation angle or shaft angle is (343.5 ±5.5) °. This corresponds to a relative volumetric change in compressor chamber volume from (91.15±0.75) ° to (23.0±0.3) °.

Suitably, the radial distance between the two channels and a central outlet opening into the high-pressure chamber, which is arranged in the stationary base plate, is of different size, so that the two channels are intentionally not arranged directly (axially) opposite each other. The radial distance between the second channel opening into the high-pressure chamber and the central outlet may be greater or smaller than the radial distance between the first channel connected to the compressor chamber and the central outlet.

The advantages achieved with the invention are, inter alia, that by the two fluid-regulated channels in the stationary scroll being in connection with the pressure lines, an efficient and self-setting adaptation of the pressure in the back pressure chamber to the operating points of the scroll compressor is achieved without additional fluid-regulated components for restricting the flow, such as valves, nozzles, throttles or further channels, holes or throttle plates.

By means of the two channels and the pressure lines in the stationary scroll, the adaptive regulation of the pressure in the back pressure chamber is achieved equally reliably and self-setting at a pressure ratio between suction pressure (low pressure) and high pressure of 5 (suction pressure of 3 bar and high pressure of 15 bar), as is the case for refrigerant R-134A (operating point when operating as a heat pump) at a pressure ratio of about 8 (suction pressure of 3 bar and high pressure of 25 bar) or 10 (suction pressure of 1.5 bar and high pressure of 15 bar).

Furthermore, with such a two-channel pressure line system in the stationary scroll, high process stability can be achieved for mass production. Thus, during the coating of the scroll portion (e.g., color coating), the two passages in the stationary scroll portion are subjected to approximately the same conditions, such that tolerances that may cause back pressure or back pressure level fluctuations cancel (decrease) each other.

Furthermore, due to the adaptive matching of the pressure in the back pressure chamber at the operating points in the cooling mode and the heat pump mode, the scroll compressor can be operated efficiently, since in particular leakage can be reduced and frictional losses between the scroll members can be kept to a minimum. As a result, the self-regulating pressure in the back pressure chamber is adapted such that the axial force due to the self-regulating pressure in the back pressure chamber is not greater than the sum of the axial forces in the compressor chambers or is always only a small amount greater than this, in which compressor chambers typically different pressures prevail in the compression operation.

Advantageously, the pressure in the back pressure chamber is particularly effective for and is regulated and adapted in terms of flow technology to the different operating points of the scroll compressor, determined by the ratio of the given cross sections of the pressure lines and of the two channels and their positioning relative to the compressor chamber(s) or affected by it. The positioning is thus suitably selected in such a way that the first channels are opened, in particular when the relative volume of the compressor chambers (compressor chamber volume) is about 90%, and remain open during the relative pressure change until the relative volume of the compressor chambers is about 23%, after which the respective channels are covered or bridged by their spiral walls during the orbital movement of the orbital scroll and are in connection (cover) with the radially further outer compressor chambers.

When the orbiting scroll typically runs at 2.5 revolutions (and thus between 0% and 10% of the opposing compressor chamber volume) through an angular range of 900 ° from the compression of the refrigerant-gas mixture in the compressor chamber until the injection of the compressed refrigerant-gas mixture into the high pressure chamber of the scroll compressor, the first passage in the stationary scroll connecting the compressor chamber with the pressure line should be positioned at an angle of 350 ° to 390 °, in particular 370 ° (helix angle

) Wherein the angle->

The measurement may be started not only from the start point of the spiral wall of the stationary scroll portion (spiral portion) but also from the end point thereof (creation).

When the pressure line or its first line section is straight, it is practically unavoidable that the positioning of the second channel connecting the pressure line with the high pressure chamber within the housing of the scroll compressor is obtained along the same radius or angle line. In a variant with a first line section extending obliquely, the two axially spaced-apart channels can be arranged at different radial and/or azimuthal positions from one another.

Drawings

Embodiments of the present invention are described in detail below with reference to the accompanying drawings. Wherein:

FIG. 1 illustrates a perspective side view of a scroll compressor having an electric motor type drive module and having a compressor module;

fig. 2 shows, in a schematic simplified cross-sectional view, an electric motor-driven scroll compressor with a high-pressure chamber, a back-pressure chamber (back-pressure chamber) and a pressure line or channel system leading into them;

fig. 3 shows a scroll compressor in a sectional view, with stationary and movable scrolls in the compressor housing and with pressure lines leading to a back pressure chamber, which pressure lines each have a connecting channel (first channel and second channel) which on the one hand enters the compressor chamber formed between the scrolls and on the other hand into the high-pressure chamber;

figure 4 shows in block diagram form the pressure return from the high pressure chamber and from the compressor chamber on the scroll side to the back pressure chamber and the oil return with the low pressure chamber to the suction side or motor side,

fig. 5 shows in perspective view a stationary scroll with a passage (hole) leading to a pressure line arranged in a predetermined position (angular position) in the base plate within the scroll wall (scroll wrap);

FIG. 6 shows a stationary scroll in top view with two noted angular orientations (helix angles) of a first connecting passage in the base plate to the compressor chamber;

Fig. 7 shows a stationary swirl part and a receiving opening for a filter insert arranged therein in a perspective view from the plate surface (plate side) facing the high-pressure chamber side of the base plate of the swirl part, the receiving opening having a (second) connection channel to the high-pressure chamber;

FIG. 8 shows the stationary scroll of FIG. 7 in top view and

fig. 9 shows the section IX-IX of fig. 8 with the line section of the pressure line leading from the receiving opening for the filter insert to the first connecting channel and to the line section in the (radially outer) delimiting wall of the stationary scroll.

Throughout the drawings, components and dimensions that correspond to each other are provided with the same reference numerals.

Detailed Description

The refrigerant compressor 1 shown in fig. 1 is installed in a refrigerant circuit, not shown in detail, of an air conditioning unit of a motor vehicle. The electric motor-type refrigerant compressor 1 has an electric (electric motor-type) drive module 2 and a compressor module in the form of a scroll compressor 3 coupled thereto. In terms of drive technology, the scroll compressor 3 is docked to the drive module 2 via a mechanical interface 4 formed between the drive module 2 and the scroll compressor 3. The mechanical interface 4 serves as a bearing end cap on the drive side and forms an intermediate wall 5 (fig. 2 and 3). The scroll compressor 3 is connected (joined, screwed) to the drive module 2 by means of a flange connection 6 extending in the axial direction a of the refrigerant compressor 1 in a circumferentially distributed manner.

The housing area of the drive housing 7 of the refrigerant compressor 1 is designed as a motor housing 7a for accommodating the electric motor 13 (fig. 2), and is closed off by an integrated housing intermediate wall 7b (fig. 2) on the one hand with respect to an electronics housing 7d provided with a housing cover 7c and having motor electronics (electronics) 8 for driving the electric motor 13, and on the other hand by a mechanical interface 4 with an end cap and intermediate wall 5. The drive housing 7 has a coupling section 9 in the region of the electronics housing 7b, which has motor coupling ends 9a and 9b to the electronics 8 for electrically contacting the electronics 8 with the on-board electrical system of the motor vehicle.

The driver housing 7 has a refrigerant inlet or refrigerant inflow end 10 for coupling with a refrigerant circuit and has a refrigerant outlet 11. The outlet 11 is formed in the bottom of the compressor housing 12 of the scroll compressor 3. In the coupled state, the inlet 10 forms the low pressure or suction side (suction side) of the refrigerant compressor 1, while the outlet 11 forms the high pressure or pump side (pumping side).

Fig. 2 shows schematically in a sectional view along the rotational axis 14 of an electric motor 13, which is here a brushless direct current electric motor (BLDC) and has a cylindrical rotor 15, the refrigerant compressor 1. The rotor being hollow on the circumferential side the cylindrical stator 16 surrounds. The rotor 15 comprises a number of permanent magnets and is supported rotatably about the rotation axis 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 the bus system and the on-board electrical system of the motor vehicle.

The electronics 8 are arranged in an electronics housing 7d of the drive housing 7, which electronics housing is separated from the stator 16 and the rotor 15 by means of the intermediate wall 5. The housing cover 7c detachably fastened to the electronics housing 7d by means of screws closes the access opening of the electronics housing 7 b. The motor electronics 8 have circuit boards 18, 19 which are arranged one after the other in the axial direction a. The bridge circuit of the circuit board 18 closest to the housing intermediate wall 7b is in contact with the electrical coils of the stator 16 via energizing lines 19 led through the housing intermediate wall 7 b. The bridge circuit is supplied with power by the on-board electrical system and is controlled by a drive circuit of a further circuit board 19 which is connected to the bus system in signal technology.

As is more clearly seen in connection with fig. 3, the scroll compressor 3 has a movable scroll (scroll member) 21 arranged in the compressor housing 12. Which is coupled via eccentric journals 17a with, for example, two engagement pins, only one of which 17b is visible, to a shaft 17 of the electric motor 13 which leads into the mechanical interface 4 with the a-side bearing end cap. The eccentric journal 17a is supported in a rolling or ball bearing 22a held in a movable scroll 21. A further rolling or ball bearing 22b supporting the shaft 17 is arranged in the mechanical interface 4 serving as a-side bearing end cap and there in the intermediate wall 5. The movable scroll (scroll member) 21 is driven in an orbital motion preventing manner when the scroll compressor 3 is in operation.

The scroll compressor 3 also has a stationary scroll (scroll member) 23 firmly secured in the compressor housing 12. The two scroll portions (scroll members) 21, 23 are nested with each other with their scroll-like or spiral-like scroll walls (scroll spiral portions) 21a, 23a axially protruding from the

respective bottom plates

21b, 23 b. Between the

scroll parts

21, 23, i.e. between their scroll walls or

spiral parts

21a, 23a and the

base plates

21b, 23b, compressor chambers 24 are formed, the volume of which changes when the electric motor 13 is running.

A back pressure chamber 25 is present in the intermediate wall 5 between the a-side bearing cap and the movable scroll 21. The back pressure chamber is delimited in the compressor housing 12 (hereinafter simply referred to as housing) by a base plate 21b of the movable scroll 21 and/or an intermediate plate (wear plate) 5a (fig. 3) in the form of a steel plate having good sliding properties for the orbiting scroll 21. The back pressure chamber 25 extends partially into the bottom plate 21b of the movable scroll 21.

In operation, refrigerant is introduced into the drive housing 7 via the inflow end 10 and into the electric motor housing 7a there. This region of the driver housing 7 forms the suction or low pressure side 26. By means of the housing intermediate wall 7b, the intrusion of refrigerant into the electronics housing 7d is prevented. Within the driver housing 7, the refrigerant is mixed with oil present in the refrigerant circuit and sucked along the rotor 15 and the stator 16 to the scroll compressor 3 through the opening (or openings, fig. 3) 27 in the intermediate wall 5. The mixture of refrigerant and oil is compressed by means of the scroll compressor 3, wherein the oil serves to lubricate the two

scrolls

21, 23, thereby reducing friction and thus improving efficiency. The oil also acts as a seal to avoid uncontrolled escape of refrigerant located between the two scrolls (scroll members) 21, 23.

The compressed mixture of refrigerant and oil is directed via a central outlet 28 in the bottom plate 23b of the stationary scroll 23 into a high pressure chamber 29 within the compressor housing 12. An oil separator (cyclone) 30 is present in the high-pressure chamber 29. Within the oil separator 30, a mixture of refrigerant and oil is put into rotational motion, wherein the heavier oil is guided to the walls of the oil separator 30 due to high inertia and high mass and is collected in the lower region of the oil separator 30, while the refrigerant is discharged upwards or laterally through the outlet 11.

As can be seen more clearly in fig. 3, the high-pressure chamber 29 is delimited within the housing 12 by the base plate 23b of the stationary scroll 23. A central outlet 28 into the high-pressure or outlet chamber 29, which is located in the radially innermost chamber region 24' of the compressor chamber 24, is introduced as a bore into the bottom plate 23b of the stationary scroll 23. Within high pressure chamber 29, central outlet 28 is closed by a spring valve 33 as long as the pressure in compressor chamber 24 is lower than the pressure in high pressure chamber 29. If the pressure of the compressed refrigerant-oil mixture in the compressor chamber 24, in particular in the central chamber region 24', is greater than the pressure in the high-pressure chamber 29, the spring valve 33 opens approximately automatically.

The stop element 34 limits the travel of the spring valve 33, which is fastened in the high-pressure chamber 29 to the stationary scroll 23, for example to its base plate 23 b. When the pressure drops below the pressure in the high pressure chamber 29, the spring valve 33 closes the outlet 28 again by itself due to its spring pretension. In this way, the rotational speed of the shaft 17 is dependent on the operating point of the scroll compressor 3, so that the compressed refrigerant-oil mixture passes continuously (constantly) or intermittently or pulsed from the compressor chamber 24 into the high-pressure chamber 29 via the central outlet 28.

A pressure line 35 is provided in the stationary scroll 23, via which pressure line 35 the compressor chamber 24 and the high-pressure chamber 29 are in fluid communication with the back pressure chamber 25. For this purpose, the pressure line 35 is connected via a first channel 36 to the compressor chamber 24 formed between the

scroll walls

21a, 23a and via a second channel 37 to the high-pressure chamber 29 in a region which in operation has essentially refrigerant and a small amount of oil.

Fig. 4 shows schematically in a block diagram that the back pressure chamber 25 is fluidically or pressure-guided connected to the high pressure chamber 29 on the one hand and to the compressor chamber 24 on the other hand via a pressure line 35 and two

channels

36, 37 acting as a throttle plate or throttle. The first channel, which is introduced into the base plate 23b of the stationary scroll 23, for example as a bore, is provided with the reference number 36 as is its throttle plate or throttle element.

Also shown in fig. 4 is an oil return 38, shown as a broken line, which includes a throttle 39, which passes from the high-pressure chamber 29 into the low-pressure chamber (suction chamber) 26 in the region of the oil separator 30. The low-pressure chamber is fluidically connected to the compressor chamber 24 of the scroll compressor 3 via a suction opening 27, as indicated by the broken arrow line 40.

In the embodiment according to fig. 3, the pressure line 35 is formed by a first line section 35a, which is suitably introduced as a radially extending bore into the base plate 23b of the stationary scroll 23, and a second line section, which is suitably introduced as an axially extending bore into the tank-shaped bounding wall 23c of the stationary scroll 23. The second line section 35b can also be introduced into the (axial) housing wall of the compressor housing 12. The holes or

line sections

35a, 35b open into each other or merge into each other within the base plate 23 b. The inlet opening of the radial bore of the first line section 35a is closed over the circumference of the limiting wall 23c in a manner not shown in detail.

The back pressure chamber 25 is separated from the suction or low pressure chamber 26 by means of the intermediate wall 5. The third line section 35c of the pressure line 35, which opens into the back pressure chamber 25, is arranged into the intermediate wall 5 as a bearing end cap, which accommodates the

bearings

22a and 22b for the journal 17a and the shaft 17. The line section 35c may similarly be embodied as a radially extending bore in the intermediate wall 5. Alternatively, the third line section 35c into the intermediate wall (interface) 5 may be embodied as a groove which opens into the orbiting scroll 21 and is closed by the intermediate plate (partition) 5 a.

The cross-sectional area of the pressure line 35 is many times smaller, 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 areas of the two

channels

36 and 37. Furthermore, the cross-sectional area of the first passage 36 connected to the compressor chamber 24 is larger than the cross-sectional area of the second passage 37 connected to the high-pressure chamber 29.

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

The first channel 36 and the second channel 37 are embodied as bores and act (in terms of flow technology) as a throttle plate or throttle. With the channel system formed by the pressure line 35 and the two

channels

36, 37, a particularly effective regulation of the flow technique of the (static) pressure in the back pressure chamber 25 is achieved. In one embodiment, the first passage 36 connected to the compressor chamber 24 is disposed opposite the base plate 23b of the stationary scroll 23 and the radial spacing between the central outlets 28 leading into the high pressure chamber 29 is greater than the radial spacing between the second passage 37 connected to the high pressure chamber 29 opposite the central outlets 28. However, the second channel 37 may also be arranged closer to the central outlet 28 than the first channel 36. Importantly, the two

channels

36 and 37 are not directly disposed axially opposite each other.

The movable scroll 21 is pressurized due to the static pressure existing in the back pressure chamber 25 during operation, and is forced by F _G Indicated by the force arrows, is pressed along the rotation axis 14 towards the stationary scroll 23. The force (counterforce) F _G Counteracting the axial force F indicated by the force arrow _V This axial force acts again on the movable scroll 21 due to the pressure generated in the compressor chamber 24. Together with the pressure transferred (transferred) from the high-pressure chamber 29 to the back-pressure chamber 25 via the pressure line 35, a force balance (F) occurs _G ＝F _V ) And thus the desired sealing action between the two

scrolls

21, 23.

Fig. 5 and 6 show in perspective and top view a stationary scroll 23 with a first channel 36 arranged in a base plate 23b at a predetermined angular position P within a scroll wall (spiral) 23a _K1 Where it leads to the pressure line 35, i.e. to its first line section 35a extending within the bottom plate 23 b. First channel 36 positioning P _K1 From FIG. 6 of the spiral wall 23a of the stationary scroll 23

The marked helical start point preferably starts at the helix angle

Where it is located. Also suitably, the positioning P of the first channel 36 _K2 From fig. 6 of the spiral wall 23a of the stationary vortex part 23, the angle line +. >

The indicated helical end point is preferably at helix angle +.>

Where it is located. It can also be seen that the channel section of the second line section 35b leading into the third line section 35c is within the preferably circumferentially closed limiting wall 23c of the stationary scroll 23.

Fig. 7 and 8 show the stationary scroll 23 in perspective and in top view from the side of the plate located in the high-pressure chamber 29 towards the base plate 23b of the scroll. There is a receiving opening 41 into the compressor chamber 24. Into which a filter (cartridge) 42 is accommodated, which has a filter rod 42a and a throttle plate or throttle head 42b, in which a second channel 37 is provided, for example as a central bore. The opening 41 is surrounded by a collar-like wall 43 for receiving and positioning a throttle plate or throttle head 42b of the filter (cartridge) 42 and/or stabilizing its position.

Fig. 9 shows a cross-sectional view of the stationary scroll 23 along line IX-IX in fig. 8. In this embodiment, the first line section 35a of the pressure line 35 is composed of two sections a in the form of obliquely extending bores ₁ 、a ₂ Formed, they are introduced into the bottom plate 23b from the accommodation opening 41. First section a ₁ Toward the center or toward the middle region of the bottom plate 23 b. Second section a ₂ The second line section 35b of the pressure line 35 in the limiting wall 35c of the stationary scroll 23 extends and opens thereInto the second line section 35b of the pressure line 35. The first channel 36 opens into a first section a of the first line section 35a of the pressure line 35 ₁ To establish a connection (in terms of pressure technology and/or fluid technology) of the compressor chamber 24 with a pressure line 35 and via this pressure line with a back pressure chamber 25 not shown in fig. 9.

By means of the two flow-regulated

channels

36, 37 in the stationary scroll 23 and their connection to the pressure line 35 leading into the back pressure chamber 25, a particularly effective, self-setting adaptation of the pressure in the back pressure chamber 25 is achieved in almost all operating ranges or operating points of the scroll compressor 3. The adaptive regulation of the pressure in the back pressure chamber 25 by means of the two

channels

36, 37 in the stationary scroll 23 and the pressure line 35 is thus likewise reliably and self-setting effected at a suction pressure of 3 bar (low pressure) and a high pressure of 15 bar, as is the case at 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 the operation of the heat pump). Thus, in operation in the cooling and heat pump modes of the vehicle air conditioning unit, the scroll compressor 3 and thus the refrigerant compressor 1 can be operated efficiently.

The adjustment and adaptation of the pressure in the back pressure chamber 25 to the different operating points of the scroll compressor 3 in terms of flow is also influenced by the ratio of the cross sections of the pressure line 35 and the two

channels

36, 37 and by their positioning relative to the compressor chamber(s) 24. Thus, the position P of the first channel 36 is selected as follows _K1 、P _K2 I.e. such that it is open at about 90% of the relative volume of the compressor compartment 24 and remains open up to about 25% of the relative compartment volume.

The orbiting scroll 21 typically passes through an angular range of 900 ° from the compression process of the refrigerant-gas mixture in the compressor chamber 24 until the injection process of the compressed refrigerant-gas mixture into the high pressure chamber 29 of the scroll compressor 3 via the central outlet 28. Thus, the first passage 36 in the stationary scroll 23 connecting the compressor chamber 24 with the pressure line 35 is suitably positioned as shown in fig. 4 at the corresponding helix angle

Positioning P of (2) _K1 、P _K2 Where it is located.

In summary, in particular, the scroll compressor 3 provided and set up for the refrigerant in the vehicle air conditioning system has a stationary scroll 23 and an orbiting (oscillating, executing a rolling motion) scroll 21 in a compression operation in a compressor housing 12 having a high-pressure chamber 27, a compressor chamber 24 and a back-pressure chamber (back-pressure chamber) 25. The

scroll parts

21, 23 here each have a

base plate

21a, 23a and a scroll or spiral wall 21a which is one-piece with the base plate (formed onto the base plate), and between their mutually nested scroll or

spiral walls

21a or 23a, respectively, compressor chamber(s) 24 are formed. The bottom plate 23b of the stationary scroll 23 defines a high pressure chamber 27, and the bottom plate 21b of the movable scroll 21 defines a back pressure chamber 25.

The back pressure chamber 25 is connected to at least one of the compressor chambers 24 via a pressure line 35 and a first channel 36 extending at least partially in the stationary scroll 23, and to the high pressure chamber 27 via a second channel 37. Here, for operational reasons, a static pressure is generated or present in a pressure line 35 which fluidically connects the back pressure chamber 25 to the high-pressure chamber 27 and to at least one of the compressor chambers 24, which static pressure also acts in the back pressure chamber 25.

The claimed invention is not limited to the embodiments described above.

List of reference numerals

1. Refrigerant compressor

2. Driving module

3. Scroll compressor/compressor module

4. Interface

5. Bearing end cap/intermediate wall

5a intermediate plate/separator plate

6. Flange connecting part

7. Driver housing

7a motor housing

7b intermediate wall of housing

7c housing cover

7d electronic device housing

8. Motor electronics

9. Coupling section

9a, b motor coupling

10. Inlet/inflow end

11. An outlet

12. Compressor shell

13. Electric motor

14. Rotor shaft

15. Rotor

16. Stator

17. Shaft

17a journal

17b dowel pin

18. 19 circuit board

20. Power-on line

21. Movable/orbiting scroll/member

21a spiral wall/helix

21b bottom plate

22a, b rolling/ball bearing

23. Stationary scroll/member

23a spiral wall/helix

23b bottom plate

23c bounding wall

24. Compressor chamber

24' Chamber region

25. Back pressure chamber

26. Low pressure/suction side

27. An opening

28. Central outlet

29. High pressure/outlet chamber

30. Oil separator

31. Bypass channel

32. Throttling mechanism

33. Spring valve

34. Stop element

35. Pressure circuit

35a first line section

35b second line section

35c third line section

36. A first channel

37. Second channel

38. Oil return portion

39. Throttling mechanism

40 Arrow line (interrupted)

41. Accommodating opening

42. Filter cartridge/insert

42a filter rod

42b throttle/throttle plate head

a ₁ First section

a ₂ Second section

Helix angle

Start point of spiral part

Spiral end point

Aaxial direction

F _G Reaction force

F _V Axial force

P

_K1,2 36, positioning of

Claims

1. A scroll compressor (3) for a refrigerant of a vehicle air conditioning unit, the scroll compressor having:

a housing (12) having a high-pressure chamber (29), a compressor chamber (24) and a back-pressure chamber (25),

a stationary scroll (23) having a base plate (23 b) and a spiral wall (23 a), wherein the base plate (23 b) of the stationary scroll (23) delimits the high-pressure chamber (29),

-a movable scroll (21) having a base plate (21 b) and a spiral wall (21 a), the spiral wall of the movable scroll (21) being embedded in the spiral wall (23 b) of the stationary scroll (23) and forming the compressor chamber (24) therewith, wherein the base plate (21 b) of the movable scroll (21) delimits the back pressure chamber (25),

it is characterized in that the method comprises the steps of,

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

The cross-sectional area of the pressure line (35) is at least 2 times greater than the cross-sectional area of the first channel (36) connected to the compressor chamber (24) and the second channel (37) connected to the high-pressure chamber, and/or

A first passage (36) connected to the compressor chamber (24) has a larger cross-sectional area than a second passage (37) connected to the high-pressure chamber (29).

2. The scroll compressor (3) according to claim 1,

it is characterized in that the method comprises the steps of,

a first channel (36) connected to at least one of the compressor chambers (24) and/or a second channel (37) connected to the high-pressure chamber (29) is arranged in the floor (23 b) of the stationary scroll (23).

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

it is characterized in that the method comprises the steps of,

-the pressure line (35) has a first line section (35 a) arranged in a bottom plate (23 b) of the stationary scroll (23), and

-the pressure line (35) has a second line section (35 b) connected to the first line section (35 a), which is arranged in a delimiting wall (23 c) of the stationary scroll (23) or in a housing wall of the housing (12).

4. The scroll compressor (3) according to any one of claims 1 to 2,

It is characterized in that the method comprises the steps of,

the back pressure chamber (25) is separated from the low pressure chamber (26) by an intermediate wall (5) in which a third line section (35 c) of the pressure line (35) leading to the back pressure chamber (25) is arranged.

5. The scroll compressor (3) according to any one of claims 1 to 2,

it is characterized in that the method comprises the steps of,

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 compressor chamber (24) is between 10 and 100.

6. The scroll compressor (3) according to any one of claims 1 to 2,

it is characterized in that the method comprises the steps of,

the ratio of the cross-sectional area of the pressure line (35) to the cross-sectional area of the second channel (37) connected to the high-pressure chamber (29) is between 50 and 500.

7. The scroll compressor (3) according to claim 4,

it is characterized in that the method comprises the steps of,

the third line section (35 c) is formed as a hole or slot.

8. The scroll compressor (3) according to any one of claims 1 to 2,

it is characterized in that the method comprises the steps of,

the first passage (36) connected to the compressor chamber (24) has a cross-sectional area of between 0.01mm and 1 mm.

9. The scroll compressor (3) according to any one of claims 1 to 2,

It is characterized in that the method comprises the steps of,

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

10. The scroll compressor (3) according to any one of claims 1 to 2,

it is characterized in that the method comprises the steps of,

the ratio of the cross-sectional area of a first passage (36) connected to the compressor chamber (24) to the cross-sectional area of a second passage (37) connected to the high-pressure chamber (29) is between 2 and 10.

11. The scroll compressor (3) according to any one of claims 1 to 2,

it is characterized in that the method comprises the steps of,

the first channel (36) and/or the second channel (37) are embodied as holes and/or function as a throttle plate.

12. The scroll compressor (3) according to any one of claims 1 to 2,

it is characterized in that the method comprises the steps of,

a first channel (36) connected to the compressor chamber (24) is arranged at a helix angle (phi) of 350 DEG to 390 DEG starting from the start and/or end of the spiral wall (23 a) of the stationary scroll (23) _1,2 )。

13. The scroll compressor (3) according to any one of claims 1 to 2,

it is characterized in that the method comprises the steps of,

a first channel (36) connected to the compressor chamber (24) is arranged opposite the base plate (23 b) of the stationary scroll (23) and the radial distance between the central outlets (28) leading into the high-pressure chamber (29) is greater or smaller than the radial distance between a second channel (37) connected to the high-pressure chamber (29) opposite the central outlets (28).

14. The scroll compressor (3) according to any one of claims 1 to 2,

it is characterized in that the method comprises the steps of,

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

15. The scroll compressor (3) according to claim 14,

it is characterized in that the method comprises the steps of,

starting from the receiving opening (41), two obliquely extending sections (a) of a first line section (35 a) of the pressure line (35) are provided ₁ 、a ₂ ) Wherein the first channel (36) opens into the first section (a) ₁ ) And wherein the second section (a ₂ ) Into a second line section (35 b) of the pressure line (35).

16. The scroll compressor (3) according to any one of claims 1 to 2,

it is characterized in that the method comprises the steps of,

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 compressor chamber (24) is between 15 and 70.

17. The scroll compressor (3) according to any one of claims 1 to 2,

it is characterized in that the method comprises the steps of,

the cross-sectional area of the first passage (36) connected to the compressor chamber (24) is 0.25mm.

18. The scroll compressor (3) according to any one of claims 1 to 2,

it is characterized in that the method comprises the steps of,

the cross-sectional area of the second channel (37) connected to the high-pressure chamber (29) is 0.5mm.

19. The scroll compressor (3) according to any one of claims 1 to 2,

it is characterized in that the method comprises the steps of,

the ratio of the cross-sectional area of the first passage (36) connected to the compressor chamber (24) to the cross-sectional area of the second passage (37) connected to the high-pressure chamber (29) is 4.

20. The scroll compressor (3) according to any one of claims 1 to 2,

it is characterized in that the method comprises the steps of,

a first channel (36) connected to the compressor chamber (24) is arranged at a helix angle (phi) of 370 DEG starting from the start and/or end of the spiral wall (23 a) of the stationary scroll (23) _1,2 )。

21. The scroll compressor (3) according to any one of claims 1 to 2,

it is characterized in that the method comprises the steps of,

the first channel (36) and/or the second channel (37) are embodied as holes and/or function as a throttle.