EP3667086A1 - Spiral-type displacement machine, in particular a displacement machine for a vehicle air-conditioning system - Google Patents

Abstract

The disclosure relates to a scroll compressor (3) for refrigerants of a vehicle air conditioning system, comprising a housing (12) with a high pressure chamber (29) and with compressor chambers (24) and with a counter pressure chamber (25), a fixed scroll (23), the base plate (23b ) 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 fixed scroll (23) and forms the compression chambers (24) with it, the base plate (21b) of the movable scroll (21) delimits the back pressure chamber (25), and a pressure line (35) connected to the compression chambers (24) and to the high pressure chamber (29) runs 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).

Description

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 positive displacement machine and in particular such a scroll compressor is known from DE 10 2017 110 913 B3 known.

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 (CO ₂ ) 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, whereby the refrigerant then releases the absorbed heat again via a heat exchanger before it is again led 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, the separated gas being introduced into the air conditioning circuit, while the separated oil can optionally be introduced to the scroll compressor as a suitably electromotive-driven refrigerant compressor for the lubrication of moving parts.

The structure and mode of operation of such a scroll compressor for the refrigerant or the refrigerant-oil mixture of a motor vehicle air conditioning system is shown, for example, in US Pat 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 , described. A model calculation of a self-adjusting back preasure or counterpressure mechanism in a scroll compressor (scroll compressor) is in " Computer Modeling of Scroll Compressor with Self Adjusting Back-Pressure Mechanism ", Tojo et al., Purdue e-Pubs (Purdue University), International Compressor Engineering Conference, 1986 , described.

The essential components of the scroll compressor are a fixed scroll and a movable orbiting scroll. The two scrolls are basically constructed in the same way and each have a base plate and a spiral-shaped wall (wrap) extending from the base plate in the axial direction. 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 if appropriate two adjacent auxiliary valves in the form of bores in the base plate of the fixed scroll in an outlet or high 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 due to the pressure difference between the compression chambers and the high 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 there into oil and gas. Then, when the pressure in the compression chambers opposite the high pressure chamber has dropped accordingly, the spring valve closes automatically.

During the operation of the scroll compressor, the two scrolls are pressed apart due to the pressure generated in the compressor chambers and the axial force caused thereby, so that a gap and thus leaks can occur between the compressor chambers. In order 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) on the back of the base of the orbiting scroll in which a specific pressure is generated.

This can be done according to the previously mentioned DE 10 2012 104 045 A1 in that a medium pressure channel (passage, opening, backpressure port) is introduced at a certain position in the base plate of the orbiting scroll, which connects at least one of the compression chambers formed by the scrolls to the back pressure chamber (back pressure chamber), 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 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 channel is positioned at about 405 °, starting from the beginning of the scroll spiral (spiral wall) of the movable (orbiting) scroll.

In " Computer Modeling of Scroll Compressor with Self Adjusting Back-Pressure Mechanism ", Tojo et al., Purdue e-Pubs (Purdue University), International Compressor Engineering Conference, 1986 , a model calculation of the self-adjusting back preasure mechanism for a scroll compressor is described. As a result of the investigation, a range 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 11 shows the practically the same pv diagram, the range of the relative compressor chamber volume in which the back pressure port is to be open being 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 Self Adjusting Back-Pressure Mechanism ", Tojo et al., Purdue e-Pubs (Purdue University), International Compressor Engineering Conference, 1986 , shows Figure 5 the course of the relative compressor chamber volume as a function of the rotation angle (roll or shaft angle theta, θ) of the orbiting scroll. The course shown is divided into the suction process corresponding to the low pressure area, the compression process and the exhaust process. With the opening range of the port relative to 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 ° (with 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 , is the angular position of the back pressure port ( Figures 7 and 8 ) discussed. Out 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 the EP 2 369 182 B1 A scroll compressor with a housing is known in which a fixed scroll with a base plate and a spiral formed thereon and a movable scroll rotating around a circumferential axis with a base plate and a spiral formed thereon are arranged. A discharge chamber (high pressure chamber) is formed between the base plate of the fixed scroll and a housing section. A bearing partition in the housing 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 with the compressor chamber between the scrolls via a delivery channel in the movable scroll. 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 delivery chamber supplies oil or coolant gas separated by means of an oil separator to the back pressure chamber in order to restore the pressure in the back pressure chamber after a pressure drop in a short time.

The invention is based on the object of a particularly suitable scroll compressor, in particular driven or driven by an electric motor To specify refrigerant compressors for a vehicle air conditioning system. In particular, a suitable pressure channel system is intended to achieve the most flexible and effective possible adaptation of the pressure in the back pressure chamber (backpressure chamber) to operating points of the scroll compressor for a vehicle air conditioning system, preferably in the cooling and heat pump mode. 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 according to the invention by the features of claim 1. Advantageous refinements and developments are the subject of the dependent 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 defines the high pressure chamber and the base plate of the movable scroll defines 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 compressor 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 back pressure chamber is created in the pressure line, via which the back pressure chamber communicates in terms of flow with the high pressure chamber and with the at least one compression 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. The first channel connected to the compression chamber and the second channel connected to the high-pressure chamber are preferably 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 from 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 which 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 made radially into the base plate and the second line section axially or obliquely into the boundary wall of the fixed scroll in the form of a hole, the holes opening into the base plate to form the pressure line . merge.

According to a second alternative, in which the second channel is arranged in or formed by a filter (filter insert), two obliquely running, 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, there is 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 it (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 expediently 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 bore 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 an orifice 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 one Chamber volume of approximately 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 compressor 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 for flow restriction, such as valves, nozzles, throttles or other channels, bores or orifices.

The adaptive control of the pressure in the back pressure chamber is also reliably self-adjusting by means of 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), as with 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. Thus, 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 that can lead to fluctuations in the counterpressure or backpressure level cancel each other out (shorten them).

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 in particular leakages can be reduced and friction losses between the scroll parts can be kept to a minimum. Because of the adaptive adaptation, the axial force that is effective as a result of the self-adjusting pressure in the counterpressure chamber 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 fluidic control and adaptive adaptation 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% 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 from the compression process of the refrigerant-gas mixture in the compressor chambers to the ejection process of the compressed refrigerant-gas mixture into the high-pressure chamber of the scroll compressor typically 2.5 revolutions - and thus between 0% and 100% relative compressor chamber volume - 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 ϕ) of 350 ° to 390 °, in particular 370 °, this angle ϕ starting from both the beginning and the end the spiral wall (scroll spiral) of the fixed scroll can be measured (applied).

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 inclined first line sections, the two axially spaced channels can be arranged at different radial and / or azimuthal positions.

Fig. 1

in einer perspektivischen Seitenansicht einen Scrollverdichter mit einem elektromotorischen Antriebsmodul und mit einem Verdichtermodul,

Fig. 2

in einer Schnittdarstellung schematisch vereinfacht den elektromotorisch angetrieben Scrollverdichter mit einer Hochdruckkammer und mit einer Gegendruckkamer (Back-Pressure-Kammer) sowie mit in diese führendem Druckleitungs- bzw. Kanalsystem,

Fig. 3

in einer Schnittdarstellung den Scrollverdichter mit in einem Verdichtergehäuse einem feststehenden und einem beweglichen Scroll sowie mit einer zur Gegendruckkammer führenden Druckleitung mit jeweils einem Verbindungskanal (erster Kanal und zweiter Kanal) in die zwischen den Scrolls gebildeten Verdichterkammern einerseits und in die Hochdruckkammer andererseits,

Fig. 4

in einem Blockschaltbild die Druckrückführung aus der Hochdruckkammer und aus den scrollseitigen Verdichterkammern in die Gegendruckkammer sowie mit einer Ölrückführung in eine saug- bzw. motorseitige Niederdruckkammer,

Fig. 5

in einer perspektivischen Darstellung den feststehenden Scroll mit einem an einer innerhalb der Scrollwand (Scrollspirale) vorbestimmten Position (Winkel-Position) in der Basisplatte angeordneten Kanal (Bohrung) zur Druckleitung,

Fig. 6

in einer Draufsicht den feststehenden Scroll mit zwei eingezeichneten Winkelpositionen (Spiralwinkel) des zu einer Verdichterkammer führenden ersten Verbindungskanals in der Basisplatte,

Fig. 7

in einer perspektivischen Darstellung den feststehenden Scroll mit Blick auf die hochdruckkammerseitige Plattenfläche (Plattenseite) dessen Basisplatte und darin angeordneter Aufnahmeöffnung für einen Filtereinsatz mit dem (zweiten) Verbindungskanal zur Hochdruckkammer,

Fig. 8

den feststehenden Scroll gemäß Fig. 7 in einer Draufsicht, und

Fig. 9

einen Schnitt IX-IX aus Fig. 8 mit von der Aufnahmeöffnung für den Filtereinsatz ausgehenden Leitungsabschnitten der Druckleitung zum ersten Verbindungskanal und zu einem Leitungsabschnitt in einer (radial äußeren) Begrenzungswand des feststehenden Scrolls.

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

Fig. 1

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

Fig. 2

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

Fig. 3

in a sectional view the scroll compressor with a fixed and a movable scroll in a compressor housing 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 on the other hand,

Fig. 4

in a block diagram, the pressure return from the high pressure chamber and from the scroll-side compressor chambers to the back pressure chamber and with an oil return to a suction or motor-side low pressure chamber,

Fig. 5

a perspective view of the fixed scroll with a channel (bore) to the pressure line arranged at a predetermined position (angular position) in the base plate within the scroll wall (scroll spiral),

Fig. 6

in a plan view the fixed scroll with two drawn-in angular positions (spiral angle) of the first connecting duct leading to a compression chamber in the base plate,

Fig. 7

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

according to the fixed scroll Fig. 7 in a top view, and

Fig. 9

a section IX-IX Fig. 8 with line sections of the pressure line extending 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 symbols in all figures.

The in Fig. 1 The refrigerant compressor 1 shown 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 ( Figures 2 and 3rd ). 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 by an integrated partition wall 7b ( Fig. 2 ) to an electronics housing 7d provided with a housing cover 7c with motor electronics (electronics) 8 controlling the electric motor 13 and on the other hand closed by the mechanical interface 4 with the end shield and the intermediate wall 5. In the area of the electronics housing 7b, the drive housing 7 has a connection section 9 with motor connections 9a and 9b leading to the electronics 8 for electrical contacting of the electronics 8 to an 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 schematically shows 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 circumferentially surrounded by 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 have printed 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 passed 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 in connection with Fig. 3 Is comparatively clearly visible, the scroll compressor 3 has a movable scroll (scroll part) 21 arranged in the compressor housing 12. This is coupled to the shaft 17 of the electric motor 13 via an eccentric shaft journal 17a with, for example, two joining pins, of which only one joint journal 17b is visible, which shaft is guided into the mechanical interface 4 with an A-side bearing plate. 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 fixed scroll (scroll part) 23 fixed rigidly in the compressor housing 12. The two scrolls (scroll parts) 21, 23 engage with one another with their helical or spiral scroll walls (scroll spirals) 21a, 23a, which project axially from a respective base plate 21b, 23b. Between the scrolls 21, 23, i.e. H. Compressor chambers 24 are formed between their scroll walls or scroll spirals 21a, 23a and the base plates 21b, 23b, the volume of which is changed when the electric motor 13 is in operation.

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 - hereinafter simply referred to as the housing - from the base plate 21b of the movable scroll 21 and / or an intermediate plate (wear plate) 5a ( Fig. 3 ) limited 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 21b 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 region of the drive housing 7 forms the suction or low-pressure side 26. The intermediate wall 7b prevents the refrigerant from penetrating into the electronics housing 7d. Within the drive housing 7, the refrigerant is mixed with oil present in the refrigerant circuit and 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. The mixture of refrigerant and oil is compressed by means of the scroll compressor 3, the oil being used 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 in a rotational movement, the heavier oil being guided to the walls of the oil separator 30 and in one because of the increased inertia and increased mass lower region of the oil separator 30 is collected while the refrigerant is discharged upwards or laterally through the outlet 11.

As in Fig. 3 can be seen comparatively clearly, the high-pressure chamber 29 is limited 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 drilled into the base plate 23b of the fixed scroll 23. 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. The pressure of the compressed refrigerant-oil mixture in the compression chambers 24, in particular in the central chamber region 24 ', greater than the pressure in the high-pressure chamber 29, the spring valve 33 opens quasi automatically.

A stop element 34, which is fastened in the high-pressure chamber 29 to the fixed scroll 23, for example on its base plate 23b, limits the stroke of the spring valve 33. When the pressure has dropped 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 (continuously) 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 is above a first channel 36 with the compression chambers 24 formed between the scroll walls 21a, 23a and via a second channel 37 with the high-pressure chamber 29 in a region in connection which in operation essentially contains the refrigerant and only a small amount of oil.

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

Also in Fig. 4 An oil return 38, including the throttle element 39, is shown as a broken line (dashed line) from the high-pressure chamber 29 in the area of the oil separator 30 to the low-pressure chamber (suction chamber) 26. This is connected to the compression chambers 24 of the scroll compressor 3 in terms of flow technology via the suction gas opening 27 , 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 introduced into the base plate 23b of the fixed scroll 23 as a radial bore, and from a second line section 35b, which is suitably as an axial bore into a cup-shaped boundary wall 23c of the fixed scroll 23 is arranged. The second line section 35b 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. A third line section 35c of the pressure line 35 leading to the counter pressure chamber 25 is arranged in the intermediate wall 5, which receives the bearings 22a and 22b for the shaft journal 17a and the shaft 17 as a bearing plate. 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 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 compression 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 from the central one 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 during operation within the counter-pressure chamber 25, the movable scroll 21 is pressurized and, as illustrated by the force arrows labeled F _G, is pressed against the fixed scroll 23 along the axis of rotation 14. This force (counterforce) F _G counteracts the axial force F _V 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 transmitted (passed on) from the high-pressure chamber 29 via the pressure line 35 to the counter-pressure chamber 25, an equilibrium of forces is established (F _G = F _V ) and thus the desired sealing effect between the two scrolls 21, 23.

The Figures 5 and 6 show in a perspective view 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 P _K1 predetermined within the scroll wall (scroll spiral) 23a and there to the pressure line 35, ie to the inside thereof of the base plate 23b extends first line section 35a. The position P _{K1 of} the first channel 36 is based on the in Fig. 6 Spiral beginning of the spiral wall 23a of the fixed scroll 23 drawn in as the angular line ϕ _1s, preferably at the spiral angle ϕ ₁ = 370 °. A position P _{K2 of} the first channel 36 is also based on FIG Fig. 6 the spiral end of the spiral wall 23a of the fixed scroll 23 drawn in as the angular line ϕ _{2s is} expedient at the spiral angle ϕ ₂ = 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.

The Figures 7 and 8 show in a perspective view or in a plan view 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 an orifice or throttle head 42b, in which the second channel 37 is provided, for example as a central bore. The opening 41 is surrounded by a wall 43 for receiving, positioning and / or stabilizing the aperture or throttle head 42b of the filter (filter insert) 42.

Fig. 9 shows a sectional view 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 a ₁ , a ₂ in the form of obliquely running bores which are introduced into the base plate 23b from the receiving opening 41. The first section a ₁ runs in the direction of the center or the central region of the base plate 23b. The second section a ₂ 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 opens into the first section a _{1 of} the first line section 35a of the pressure line 35 36 producing the (pressure and / or fluidic) connection of the compression chambers 24 with the pressure line 35 and via this with the in Figure 9 Back pressure chamber 25, not shown.

Due to 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, a particularly effective, self-adjusting adjustment of the pressure in the counter-pressure chamber 25 is achieved in practically all working areas or 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 and the pressure line 35 in the fixed scroll 23 takes place with a suction pressure (low pressure) of 3 bar and a high pressure of 15 bar as reliably and self-adjusting as with one 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 influenced 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. The position P _K1 , P _{K2 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 in the fixed scroll 23 connecting the compression chambers 24 to the pressure line 35 is suitably on the one in FIG Fig. 4 illustrated position P _K1 , P _{K2 positioned} at the corresponding helix angle ϕ _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 (or oscillating (oscillating) oscillator during compressor operation) 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 , scroll 21). The scrolls 21, 23, which each have a base plate 21a, 23a and a scroll or spiral wall 21a which is integral therewith (formed on them), form the compression chamber (s) 24 between their intermeshing scroll or spiral walls 21a and 23a The base plate 23b of the fixed scroll 23 defines the high pressure chamber 27, and the base plate 21b of the movable scroll 21 defines the 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 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. A static pressure also acts or prevails in the pressure line 35, via which the back pressure chamber 25 communicates fluidically with the high pressure chamber 27 and with the at least one of the compression chambers 24.

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 compressors

2nd

Drive module

3rd

Scroll compressor / compressor module

4th

interface

5

End shield / partition

5a

Intermediate plate / ware plate

6

Flange connection

7

Drive housing

7a

Engine housing

7b

Partition wall

7c

Housing cover

7d

Electronics housing

8th

Engine electronics

9

Connection section

9a, b

Motor connection

10th

Inlet / inlet

11

Outlet

12

Compressor housing

13

Electric motor

14

Rotor axis

15

rotor

16

stator

17th

wave

17a

Shaft journal

17b

Joining pin

18.19

Circuit board

20th

Power line

21st

movable / orbiting scroll / part

21a

Scroll wall / spiral

21b

Base plate

22a, b

Rolling / ball bearings

23

fixed scroll / part

23a

Scroll wall / spiral

23b

Base plate

23c

Boundary wall

24th

Compressor chamber

24 '

Chamber area

25th

Back pressure chamber

26

Low pressure / suction side

27th

opening

28

central outlet

29

High pressure / outlet chamber

30th

Oil separator

31

Bypass channel

32

Throttling 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

Throttling device

40

(broken) arrow line

41

Receiving opening

42

Filter / insert

42a

Filter shaft

42b

Throttle / orifice head

a ₁

first section

a ₂

second part

ϕ _1.2

Spiral angle

ϕ _1s

Spiral start

s2 _s

Spiral end

A

Axial direction

F _G

Drag

F _V

Axial force

P _K1.2

Position of 36

Claims (15)

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 (21b) and with a spiral wall (21a) which engages in the spiral wall (23b) of the fixed scroll (23) and forms the compression chambers (24) therewith, the base plate (21b ) of the movable scroll (21) limits the back pressure chamber (25), characterized,
that the back pressure chamber (25) is connected to the compressor chambers (24) and to the high pressure chamber (29) via a pressure line (35), 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). Scroll compressor (3) according to claim 1,
characterized,
that the first channel (36), which is connected to the at least one of the compression chambers (24), and / or the second channel (37), which is connected to the high-pressure chamber (29), is arranged in the base plate (23b) of the fixed scroll (23) are or is. 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 second line section (35b) connected to the first line section (35a), which is arranged in a boundary wall (23c) of the fixed scroll (23) or in a housing wall of the housing (12). 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 . 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. 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. 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 compression chamber (24) is larger than the cross-sectional area of the second channel (37) connected to the high-pressure chamber (29). 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. 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. 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 (37) connected to the high-pressure chamber (29) is between 2 and 10, preferably 4. Scroll compressor (3) according to one of claims 1 to 10,
characterized,
that the first channel (36) and / or the second channel (37) is designed as a bore and / or is or are effective as an orifice or throttle. Scroll compressor (3) according to one of claims 1 to 11,
characterized,
that the first channel (36) connected to the compressor chamber (24) preferably starting from the beginning and / or end of the spiral wall (23a) of the fixed scroll (23) at a spiral angle (ϕ _1.2 ) of 350 ° to 390 ° 370 °, is arranged. 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 leading into the high pressure chamber (29) 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). 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). Scroll compressor (3) according to claim 14,
characterized,
that, starting from the receiving opening (41), two inclined sections (a ₁ , a ₂ ) of the or a first line section (35a) of the pressure line (35) are provided, the first channel (36) being divided into a first section (a ₁ ) opens, and wherein the second section (a ₂ ) opens into or into a second line section (35b) of the pressure line (35).

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