WO2019092024A1

WO2019092024A1 - Scroll compressor with an optimized closing pressure

Info

Publication number: WO2019092024A1
Application number: PCT/EP2018/080482
Authority: WO
Inventors: Manuel Wagner
Original assignee: SANDEN International Europe Ltd.
Priority date: 2017-11-07
Filing date: 2018-11-07
Publication date: 2019-05-16
Also published as: DE102017125968A1

Abstract

Scroll compressor having a fixed disc (1) and a fixed scroll (2) on a fixed base surface (3) of the fixed disc (1), which fixed scroll (2) configures a spiral compressor channel (6) which extends from an outer end (5) of the fixed scroll (2) as far as an outlet opening (7) at an inner end (4) of the fixed scroll (2). An orbiting disc (11) with an orbiting scroll (12) can orbit along a compression direction (100) relative to the fixed disc (1). At least one compression chamber (20a, 20a', 20a'', 20b, 20b') is delimited between the discs. Furthermore, an outlet pressure chamber (30) in a fluidic connection with the outlet opening (7) and a closing pressure chamber (40) are provided, which closing pressure chamber (40) is loaded with a closing pressure during compression operation, wherein the orbiting disc (11) is pressed against the fixed disc (1) by way of the closing pressure. The scroll compressor has a return connection (33) which configures a fluidic connection from the outlet pressure chamber (30) to the closing pressure chamber (40), a reference opening (50) which is arranged in the fixed base surface (3) within the compressor channel (6), and a reference connection (51) which configures a fluidic connection between the closing pressure chamber (40) and the reference opening (50) for influencing the closing pressure on the basis of a reference pressure which prevails at the reference opening (50) during compression operation.

Description

Spiral compressor with optimized contact pressure

The invention relates to a scroll compressor for the compression of a fluid. Scroll compressors typically include a stationary disk with a stationary scroll and an orbital disk with an orbital scroll. By orbiting the Orbitierscheibe relative to the stationary disc, a fluid - in particular a gas - is compressed by the scroll compressor. For this purpose, the Orbitierspirale and the stationary spiral are arranged interleaved in such a way that they form compression spaces for the gas between them. With respect to the stationary spiral, each compression space with the gas trapped therein moves from an outer area of the stationary spiral to the center thereof. At the same time, the space available for the gas becomes increasingly smaller and the gas is compressed. The Orbitierscheibe with the Orbitierspirale and the stationary disk with the stationary spiral together form a compressor unit.

The gas enters the compressor unit at a suction pressure and is led out of it at a significantly higher outlet pressure.

Scroll compressors are used, for example, as compressors in air conditioning systems, in particular in air conditioning systems for motor vehicles. Furthermore, they are used as heat pumps. They are distinguished from other types of compressor by a particularly uniform, low-vibration and quiet running.

The gas in the compressor unit, which is increasingly compressed within the scroll compressor, forces apart the orbital disk and the stationary disk. Therefore, a lift-off force acts on the orbital disk. The strength of this lifting force depends in particular on the suction pressure, the Outlet pressure and the geometry of the compressor unit together. The strength of the lifting force depends on the outlet and suction pressure, with the variance outweighing the suction pressure. So that the Orbitierscheibe is pressed firmly and sealingly on the stationary disc and no gas escapes from the compressor unit, the Orbitierscheibe is acted upon with a pressure on its side of the stationary disc opposite side with a contact pressure. The contact pressure presses the orbital disk with a contact force in the direction of the stationary disk. The contact force counteracts the lifting force and must be greater than the latter. Otherwise, the orbital disk would be pushed away from the stationary disk by the lifting force.

In conventional scroll compressors a difference of the contact pressure to the suction pressure is always the same in the compression mode, more precisely independent of the suction pressure and the outlet pressure. It must be so large that the force acting on the Orbitierscheibe contact pressure is sufficient even at maximum intake pressure and maximum outlet pressure to securely press the orbital disk sealing against the stationary disc.

A common method for adjusting the contact pressure is to pressurize a contact pressure chamber and to limit the pressure upward by a pressure control valve with respect to the suction pressure. The pressure control valve opens a fluid communication between the pressure application chamber and a suction pressure range when the pressure exceeds the suction pressure plus a desired difference (for example, about 0.3 MPa). The pressurization of the pressure chamber at the same time ensures that the contact pressure does not fall below this setpoint. Since the repulsive force counteracting the contact pressure decreases nonlinearly with a smaller suction pressure, in most operating states a higher contact pressure and thus a higher contact pressure act on the orbital disk than would be necessary. This leads to increased friction of the moving Orbitierscheibe. Electrically driven scroll compressors typically operate in a speed range of 500 to 12000 rpm ^-1. High friction is noticeable by a reduced efficiency.

Document DE 10 2013 020 762 A2 discloses a scrolling machine with a controllable by means of a control device and controllable lifting device by which an eccentric of the scrolling machine can be acted upon by a contact force opposite pressing force or with the contact pressure can be reduced. The lifting device is designed as a 2/3-way valve. By opening the valve, the pressure in the back pressure chamber is equalized to a pressure in a low pressure space. Through targeted control of the valve, the frictional force between the eccentric disc and a stator disc can be minimized. However, this solution is complicated and expensive, since the control or controllable 2/3-way valve and the additional control device are required. In addition, energy is lost unused by the pressure equalization when opening the valve.

Also in the scroll compressor of JP 2014-31795 A, an orbital disk is pressed by a contact pressure against a stationary disk, wherein the contact pressure between an intake pressure and an outlet pressure is. Due to a difference between the outlet pressure and the contact pressure, oil flows from an oil reservoir into a longitudinal bore in a drive shaft. Part of the oil is fed from the drive shaft for lubrication in a first bearing of the drive shaft. This part of the oil then flows into a contact pressure chamber. Another part of the oil passes from the drive shaft into an orbital storage chamber. The Orbitierlagerkammer serves, among other things, Press the orbital disc against the stationary disc by the outlet pressure. The contact pressure can also serve to press the orbital disk with the contact pressure against the stationary disc. The oil that flows through the first bearing in the contact pressure chamber, is still almost below the outlet pressure and thus acts on the contact pressure chamber with pressure. It lubricates an Oldham ring and then flows through a compression chamber passage into a compression chamber and through a suction passage into a suction area of the scroll compressor. As a result, the contact pressure is maintained at a medium pressure. A contact pressure valve in the compression chamber passage opens when the contact pressure is greater than a pressure in the compression chamber. Also, this device is complicated and expensive, since the compression chamber passage with the contact pressure, the intake area passage and next to the suction pressure chamber and the Orbitierlagerkammer are necessary. In addition, the actual contact force of the orbital disk is influenced by many different factors and can not be adjusted specifically for different operating states.

The object of the present invention is to provide a simple structure, easier to produce and economic scroll compressor, which operates efficiently in various operating conditions.

The above object is achieved by a scroll compressor for compressing a fluid

a stationary disk having a stationary scroll, wherein the stationary scroll is disposed on a stationary base of the stationary disk and forms a spiral compressor passage extending from an outer end of the stationary scroll to a compressed fluid outlet port at an inner end of the stationary scroll;

an orbital disk having an orbital spiral, the orbital spiral being disposed on an orbital ground surface of the orbiting disk, the orbital disk being orbitable relative to the stationary disk along a compression direction,

furthermore, the orbital spiral and the stationary spiral are arranged interlaced in such a way that at least one compression space is bounded by the stationary base surface and the stationary spiral as well as the orbital base surface and the orbital spiral,

wherein the compression space shifts from an intake area of the compressor passage to an outlet area of the compressor passage, thereby decreasing its volume, when the orbit disk is orbiting relative to the stationary disk along the compression direction;

an outlet pressure chamber in fluid communication with the outlet port;

a contact pressure chamber, which is acted upon in the compression mode with a contact pressure, wherein the orbital disk is pressed by the contact pressure against the stationary disk;

a return connection forming a fluid connection from the discharge pressure chamber to the pressure application chamber;

a reference opening disposed in the stationary base within the compressor duct; and

a reference connection, which forms a fluid connection between the contact pressure chamber and the reference opening for influencing the contact pressure by means of a reference pressure applied to the reference opening in the compression mode. The suction pressure and the outlet pressure are determined in the compression mode usually by a connected to the scroll compressor system, which is traversed by the compressed fluid in the scroll compressor. Such a system may, for example, be a heat exchanger of an air conditioning system. From the outlet pressure chamber, the compressed te fluid are discharged from the scroll compressor, for example, through the outlet connection and the outlet port.

At the outlet port is the outlet pressure, at the suction port of the suction pressure. The outlet pressure chamber, the contact pressure chamber, the orbital disk, the stationary disk, the return connection and the reference connection are preferably arranged in the suction pressure chamber. As a result, all these components are securely enclosed by the suction pressure chamber. The suction port and the outlet port may in this case be arranged on the suction pressure chamber, wherein the outlet port is pressure-tight in fluid communication with the outlet pressure chamber.

A maximum outlet pressure of the scroll compressor results from the geometry of the compressor unit (the stationary and Orbitierscheibe nested one inside the other) and the respective intake pressure. The higher the suction pressure, the higher the maximum outlet pressure. For a given suction pressure, the maximum outlet pressure results from the compression of the fluid which can be achieved in terms of geometry in the compressor unit on the basis of the known fluid equations, for example the equation for ideal gases or the van der Waals equation.

The (actual) outlet pressure is usually lower than the maximum outlet pressure. As soon as the outlet pressure, which is predetermined, for example, by the connected system, is attained, the scroll compressor no longer compresses the fluid, but pushes it out of the compressor unit through the outlet opening into the outlet pressure chamber. At the outlet opening, a check device (such as a check valve or a check valve) may be arranged. This prevents fluid from the outlet pressure chamber from flowing back through the outlet port if the outlet pressure in the outlet pressure chamber is higher than the pressure at the outlet opening in the compressor unit.

With the present invention, the contact pressure is influenced directly by the reference pressure. The reference pressure again depends strongly on the suction pressure and possibly also on the outlet pressure given the position of the reference opening in the compressor channel. In this respect, a difference between the contact pressure and the intake pressure adapts itself to an operating state of the scroll compressor. A complex, external, prone and expensive control of the contact pressure is not required. In particular, no actively variably adjustable pressure control valve for adjusting and regulating the contact pressure is needed. Due to the interaction of the return connection and the reference connection, a pressure equilibrium is established in the contact pressure chamber. If the contact pressure is greater than the reference pressure, fluid and / or oil flows from the contact pressure chamber through the reference connection and the reference opening in the compressor unit, more precisely in the compression space, when it is just in fluid communication with the reference opening. This reduces the contact pressure. On the other hand, fluid and / or oil is led out of the outlet chamber or the oil filter into the contact pressure chamber via the return connection. This feedback increases the contact pressure, unless the pressure loss caused by the reference connection is greater or equal. Put simply, the return connection serves for the subsequent delivery of fluid and / or oil into the contact pressure chamber, while the reference connection with the reference opening effects the adjustment or regulation of the contact pressure. The oil and / or fluid flowing into the compressor unit via the reference connection must be further compressed, but only from the level of the contact pressure until the high pressure is reached. The oil also contributes to their lubrication where appropriate. This improves the durability of the scroll compressor. The reference pressure depends on how much the fluid in the compressor unit is compressed when the compression chamber reaches and sweeps over the reference port. Changing the position of the reference opening in the compressor channel generally changes the reference pressure applied to the reference opening in the compression mode and, consequently, the resulting contact pressure. In other words, can be determined by the positioning of the reference opening of the adjusting contact pressure.

By the targeted design and coordination of the return connection and the reference connection and the reference opening, in particular the exact positioning of the reference opening in the compressor channel, the automatic adjustment of different, respectively desired contact pressures for different operating states of the scroll compressor is achieved. Accordingly, the contact pressure with which the orbital disk is pressed by the contact pressure on the stationary disk is adjusted for different operating states to the lifting force acting on the orbital disk in the respective operating state. In particular, a comparatively low contact pressure acts when the contact pressure and / or the outlet pressure are low. This improves the efficiency of the scroll compressor when the scroll compressor is operating in such a condition. In addition, the startup and rotation of the scroll compressor is greatly facilitated by the dependent on the operating state contact pressure.

In the compression mode, the pressing force acting on the orbital disk is preferably at least 10 percent greater in every operating state than the lifting force acting on the orbital disk, particularly preferably at least 15 percent. In this way, the orbital disk is securely pressed against the stationary disk and no fluid can escape from the compressor unit. Alternatively and / or additionally, in the compression mode, the contact force acting on the orbital disk in each operating state is preferably at most 30 percent greater than the lift-off force acting on the orbital disk, particularly preferably at most 20 percent greater. This avoids unnecessarily high friction due to excessive contact pressure. This allows energy-efficient operation of the scroll compressor in all operating conditions.

The contact pressure with which the orbital disk is pressed onto the stationary disk by the contact pressure depends on an effective area of the orbital disk on which the contact pressure in the direction of the orbital disk can act. On the other hand, the lift-off force is related to the suction pressure, the discharge pressure and the geometry of the compressor unit. Therefore, the design and tuning of the return connection and the reference connection and the reference opening, in particular their exact positioning in the compressor channel, which is required for a desired ratio of contact pressure and lifting force, for different embodiments of the scroll compressor differ.

In other words, if the orbiting disc orbits relative to the stationary disc, it means that the orbiting disc is eccentrically displaced relative to the stationary disc in a circular path. Preferably, the orbital disk orbits on a circular path around a stationary central axis of the stationary disk, the stationary central axis being perpendicular to the stationary base surface and extending through a center of the stationary scroll.

The stationary spiral may be formed of a wall which extends parallel to the stationary central axis away from the stationary base surface from the stationary base surface. Preferably, an end surface of the stationary spiral remote from the stationary base surface along the stationary central axis is flat and parallel to the stationary base surface. The stationary spiral and the Orbitierspirale each have a spiral arm.

The intake area of the compressor passage is composed of all areas of the compressor passage that at least temporarily are in direct fluid communication with a fluid inlet when the orbital disk is orbiting relative to the stationary disk along the compression direction. The fluid inlet - for example in the form of the suction port - serves to supply the fluid to be compressed to the scroll compressor.

In the compression mode, the fluid in the at least one compression space is compressed, moved in the direction of the outlet opening and finally pushed into the outlet opening. The discharge area of the compressor duct comprises all areas of the compressor duct that at least temporarily are in direct fluid communication with the outlet opening for the fluid when the orbiting disk is orbiting relative to the stationary disk along the direction of compression. The central area of the compressor duct comprises all areas of the compressor duct which can not be in direct fluid communication with either the inlet area or the outlet area.

In an advantageous embodiment of the invention, the reference opening is arranged in the middle area and / or in the outlet area of the compressor channel. Thus, the reference port is not located in the inlet area of the compressor passage. During operation of the scroll compressor, this does not result in an immediate fluid connection between the fluid inlet and the reference opening and no fluid can flow from the reference opening directly into the suction area and / or the fluid inlet. Such an unwanted Pressure loss would lead to a deterioration in the efficiency of the scroll compressor.

For the purposes of this application, an innermost turn or first turn of a spiral means an area of this spiral that extends from its inner end to the point where it once wrapped around its center. The inner end of the stationary spiral is assigned a position angle of 0 °. The position angle increases continuously to the outer end of the stationary spiral along the extension of the stationary spiral. A spiral angle of the stationary spiral is given by its outer end. The spiral angle thus corresponds to the largest position angle of the stationary spiral.

This is illustrated by way of example for a stationary spiral with two turns: The first turn of the stationary spiral begins with the inner end of the stationary spiral at a position angle of 0 ° and ends at a position angle of 360 °. The second and outermost winding begins at a position angle of 360 ° and ends at spiral angle of 720 ° with the outer end of the stationary spiral. Correspondingly, position angles are defined in the compressor channel. An outer end of the spiral compressor passage is defined by an inlet port of the compressor passage formed between the outer end of the stationary scroll and a start of the outermost turn of the stationary scroll.

For the purposes of this application, an outer side of a region of a spiral is the side of this region of the spiral which faces away from the center of the spiral in a radial direction. Correspondingly, an inner side of the region of the spiral is the side of this region of the spiral which faces the center of the spiral in the radial direction. At this point it should be emphasized that the definitions concerning the compressor channel are independent of the definition of the compression space. In particular, the compression space need not be completely in the compressor channel at all times. For example, the compression space may be formed by contacting an outer end of the orbiting scroll with an outer side of the outermost turn of the stationary scroll. By this seal the compression space is closed and sealed. On the other hand, when the compression space is closed by having an outer side of the orbiting scroll contact the outer end of the stationary scroll, the compression space is already completely within the compressor duct at that time.

With the return connection, the high outlet pressure is used to pressurize the contact pressure chamber. The contact pressure presses the Orbitierscheibe against the stationary disc, so that these two discs are securely sealing each other and in particular the compression chamber is securely sealed. A rear side of the orbital disk, which faces away from the orbital base, may form part of a boundary of the contact pressure chamber. The return connection preferably leads from the contact pressure chamber (or a component in the contact pressure chamber) directly to the contact pressure chamber. This ensures a simple construction and that the spiral compressor is easier to produce. The reference pressure varies during operation of the scroll compressor, even in a continuous compression mode. As soon as a new compression chamber reaches the reference opening, the reference pressure drops to the current pressure in this compression chamber. As the compression space continues to move and reduce in the direction of the outlet opening, the pressure of the fluid in the compression space and hence the reference pressure increase continuously. borrowed. At the moment when the compression space just barely covers the reference opening, the reference pressure is maximum. Thereafter, the reference opening is covered by the Orbitierspirale and covered, so closed. Thereafter, a new compression chamber reaches the reference port, and reference pressure decreases. Depending on the position of the reference opening, it can be covered and covered once or twice by the orbital spiral during one revolution of the orbital disk.

Due to the volumes of the reference connection and the contact pressure chamber, however, the effect of these fluctuations is partially reduced and damped. In addition, due to the typically high speed at which the orbital disk is orbiting, the fluctuations are very fast and essentially a mean reference pressure can be considered. The mean reference pressure results from the integral of the reference pressure over the orbital period which the orbiting spiral requires for a full turn divided by this orbital period. Correspondingly, mean pressures other than time average over one revolution are defined, in particular an average pressure difference between the contact pressure and the suction pressure. In a preferred embodiment of the invention, the scroll compressor has two compression spaces, wherein the reference opening is arranged in the compressor passage during compression of the orbital disk for a first part of the circulation time with a last stage compression space and for another part of the time required for the circulation is directly in fluid communication with a compression chamber of penultimate stage. In this case, the first part and the other part together do not have to give the total time required for the circulation. Rather, there may be other parts. This targeted positioning of the reference opening in the compressor channel ensures that even a high-pressure region of the scroll compressor has an influence on the contact pressure and the contact pressure in the compression mode always remains high enough in each operating state, so that the contact pressure on the orbital disk is sufficiently greater than that lifting force. The Orbitierscheibe is thereby pressed in compression mode in each operating state sealingly on the stationary disc.

The compression chamber last stage is characterized by the fact that the fluid in it is still performed at least partially in the discharge opening in compression operation within this orbit of the Orbitierscheibe. The compression chamber penultimate stage is characterized by the fact that the fluid in it is in compression operation within the next orbit of the Orbitierscheibe at least partially out into the outlet. There may be several last-stage compression rooms and several second-to-last compression rooms. The compression chamber penultimate stage and the compression chambers penultimate stage follows or follow in the compressor channel opposite to the direction of compression of the compression chamber last stage or the compression chambers last stage.

Within one revolution, the orbital disc orbits exactly once (ie, 360 °) relative to the stationary disc. One end of the circulation is defined by the operating point in which the fluid (in particular refrigerant) is ejected last into the outlet opening. This is the moment when a compression cycle is completed. This operating point also defines an end of the last stage. A beginning of this last step is a full rotation of the orbital disk around the stationary disk beforehand, ie 360 ° before, defined.

This is explained by way of example for a scroll compressor, which compresses the fluid in compression operation within two revolutions (by 720 °) and into which Outlet opening leads: The first and penultimate stage begins when an amount of the fluid to be compressed has just been trapped in the compression space. It ends after a first full round (360 °) of the orbital disk around the stationary disk. At the same time, the second and final stage begins for the fluid currently being carried in this compression space. The final stage ends with the second complete revolution (720 °) of the orbital disk when the fluid has been completely directed into the exhaust port.

Preferably, the stationary spiral has a spiral angle of more than 360 °, wherein the reference opening is arranged in the compressor passage at a positional angle from the inner end of the stationary scroll, the at least

315 ° / (0.5 - helix angle / 360 °) ° · ¹

and maximum

435 ° ^* (0.5 - helix angle / 360 °) ⁰ - ²

is, preferably at least

345 ° / (0.5 ^■ helix angle / 360 °) ⁰ - ¹

and maximum

405 ° ^* (0.5 - helix angle / 360 °) ^{0 2} .

This positioning of the reference opening has proven to be particularly advantageous for achieving the stated advantages of the invention. On the one hand, a sufficiently large influence of the high-pressure region near the outlet opening is ensured, so that the contact pressure can not become too low. On the other hand, the reference pressure in this area is still low enough that no unnecessarily large contact force acts on the orbital disk. This benefits the efficiency of the scroll compressor.

Basically, the smaller the position angle in which the reference opening is arranged, the higher the mean reference pressure in the compression mode. Because the smaller the position angle of the reference opening, the closer the reference opening is located at the outlet opening. Accordingly, the fluid in the compression space is more compressed when the compression space reaches the reference opening. In addition, the average reference pressure generally also depends on other factors, in particular the suction pressure and the outlet pressure. In addition, the average reference pressure at the same position angle of the reference opening may also depend on whether the reference opening is arranged in the radial direction further inside or further out in the compressor duct.

In a development of the invention, the stationary spiral has at least 1.25 turns. This corresponds to a spiral angle of the stationary spiral of at least 450 °. This ensures sufficient maximum compression of the scroll compressor for common applications.

Alternatively and / or additionally, the stationary spiral preferably has a maximum of 2.5 turns. This corresponds to a spiral angle of the stationary spiral of a maximum of 900 °. So the scroll compressor remains compact, easy and cheap to produce.

Particularly preferably, the stationary spiral has two turns, wherein the reference opening in the compressor duct is arranged at a positional angle from the inner end of the stationary spiral which is at least 315 ° and at most 435 °, more preferably at least 345 ° and at most 405 °. This arrangement has proven to be particularly practical.

In a development of the invention, in the compression mode, an average pressure difference between the contact pressure and a suction pressure increases with increasing suction pressure, if the outlet pressure remains at least substantially constant. When the contact pressure and / or the outlet pressure increase, the lift-off force also increases on the orbital disk. On the one hand to ensure a sufficiently high contact pressure with a low suction pressure and on the other hand with a high suction pressure on the other hand, it is advantageous if the contact pressure increases with increasing suction pressure.

In a further advantageous embodiment of the invention, the scroll compressor has a flow valve provided in the return connection. The flow control valve influences the effect of the return connection. This makes it easier to tune and adjust the contact pressure.

Particularly preferably, the flow control valve is designed as a throttle valve. In this application, a throttle valve means an element which generates a pressure difference between the valve inlet and outlet (and does not throttle the mass flow). Thus, the vote of the contact pressure by the return connection and the reference connection is much easier. This increases the efficiency of the scroll compressor compared to versions without a throttle valve.

Preferably, a damping element is provided in the reference connection between the reference opening and the contact pressure chamber. The damping element damps the fluctuations of the reference pressure in addition. The contact pressure is kept more stable and can be adjusted more precisely. This further improves the efficiency of the scroll compressor. Since the damping element takes over at least a substantial part of the damping of the reference pressure, other parts of the reference connection can be designed with a small cross-section. As a result, unnecessarily large mass flows of fluid through the reference connection are avoided. The reference compound may, for example, have a cross-sectional area that lies in one of the regions, which are proposed below for the opening area of the reference opening.

Particularly preferably, the damping element is designed as a damping chamber. Such a damping chamber can be produced particularly easily, quickly and inexpensively. Due to the additional volume of the damping chamber between the reference port and the Anpressdruckkammer the amplitude of the reference pressure is attenuated as described above. Most preferably, the damping chamber has a volume of 5 cm ³ to 6 cm ³ . This size has proved to be particularly advantageous. On the one hand, the damping chamber is then large enough to dampen the fluctuations of the reference pressure sufficiently strong to achieve the aforementioned advantages. On the other hand, it is still so compact that it requires little space and can be provided with little effort in the reference compound.

In a preferred embodiment of the invention, the reference opening in the stationary base area has an opening area between 0.5 mm ² and 8.05 mm ² , preferably between 1, 13 mm ² and 3.15 mm ² . The reference opening must on the one hand be large enough to allow the desired influence of the contact pressure by the reference pressure by a sufficiently fast and strong fluid exchange between the contact pressure chamber and the reference opening overstreifendem compression space. On the other hand, the reference opening may be maximally so large that it is completely closed by the orbital spiral when the orbital spiral sweeps over the reference opening. Otherwise, two consecutive compression spaces could fluidly communicate with each other via the reference port, which could result in undesirable pressure equalization between these two compression spaces. Apart from that, the reference opening and the reference connection should have the smallest possible cross section. This avoids that in the compression mode by the fluctuation of the reference pressure unnecessarily much fluid in the reference compound is pushed back and forth or compressed and relaxed again. A small cross section of the reference opening and / or the reference connection thus ensures a better efficiency of the scroll compressor.

In a highly advantageous embodiment of the invention, the reference opening in the stationary base is formed as a round hole with a diameter between 0.4 mm and 1.6 mm, preferably between 0.6 mm and 1.0 mm. Such a hole can be produced with little effort, quickly and easily reproducible through a hole. The above-mentioned cross sections for the reference opening and the corresponding advantages are thus achieved particularly easily. In a development of the invention, the scroll compressor has an oil separator in the outlet pressure chamber and an oil reservoir, wherein the return connection leads from the oil reservoir to the contact pressure chamber.

The oil lubricates and protects the orbital disk and the stationary disk which move relative to each other during compression operation. However, part of the oil passes through the outlet port into the outlet pressure chamber. With the oil separator ensures that the oil is separated and collected in the oil reservoir. Thus, no oil passes out of the scroll compressor into a system connected to it, for example a heat exchanger. The oil would wet the heat exchanger from the inside and worsen the heat transfer.

At least a portion of the separated oil can then be recycled via the return connection via the oil separator. The oil or part of the oil can continue through the reference connection and the reference opening in the Compressor unit are introduced. So it is used again for lubrication and protection of the compressor unit. The oil return improves the efficiency and reliability of the scroll compressor. Preferably, the reference connection between the contact pressure chamber and the reference opening is always permeable in both directions. As a result, the reference opening and the contact pressure chamber are always in unimpeded fluid connection via the reference connection. The contact pressure is set by the reference opening and the reference connection depending on the operating state, without further mechanical components such as flaps or valves for controlling a fluid flow in the reference connection are necessary. The proposed system is therefore particularly inexpensive and reliable.

In a particularly preferred embodiment of the invention, no valve is provided in the reference connection.

With the present invention, no valve in the reference connection is necessary due to the selected position of the reference orifice in the compressor passage. Thus, the reference compound can be produced particularly easily and inexpensively. The absence of a valve makes for a lighter scroll compressor. In addition, such a scroll compressor is more reliable because the valve would be a potential source of error.

In a further advantageous embodiment of the invention, a pressure control valve is provided in the reference connection, which closes the fluid connection between the contact pressure chamber and the reference opening when the reference pressure is at least 0.2 bar greater than the contact pressure, preferably at least 0 , 8 bar. Due to the pressure control valve, pressure equalization and fluid flow through the reference junction will not occur when the reference pressure has reached or exceeds the appropriate magnitude. The pressure control valve prevents the contact pressure from becoming too great when the reference pressure is very high. Too large contact pressure is disadvantageous because the friction increases. The pressure control valve prevents in particular that pressure peaks of the reference pressure lead to damage to an axial sealing surface of the orbital disk. In addition, it opens up additional possibilities for regulating contact pressure. The reference opening can be positioned closer to the outlet opening in the compressor channel, that is to say be arranged at a smaller position angle, without the contact pressure becoming undesirably large. If both the pressure control valve and the damping element are provided in the reference connection, the damping element is particularly preferably arranged between the reference opening and the pressure control valve. As a result, the pressure control valve is exposed to less strong pressure fluctuations. This allows the use of a finer, responsive pressure control valve and more accurate adjustment of the pressure differential between the contact pressure and the mean reference pressure. In addition, the number of opening and closing operations of the pressure control valve is reduced during operation damping of the reference pressure, in particular of extremes of the reference pressure. As a result, the life expectancy of the Druckkontrollven- tils higher and the reliability of the scroll compressor increases.

The scroll compressor preferably has an electric motor for driving the orbital disk. The integration of the electric motor into the scroll compressor enables a particularly precise and efficient operation of the scroll compressor. The operation of the electric motor can be accurate to the specific scroll compressor be matched. In particular, the drive of the scroll compressor is then not dependent on an operating state of other external units. Most preferably, the electric motor is disposed within the suction chamber. Alternatively and / or additionally, the scroll compressor can also have a power transmission device for driving the orbital disk by means of an external drive unit. The external drive unit may be, for example, an internal combustion engine. The power transmission device may include a clutch (such as a magnetic clutch).

Optionally, the scroll compressor can for example also be used in a heat pump system. This is of particular interest for the air conditioning of electric vehicles and / or full hybrid vehicles. The invention further relates to an air conditioning system with a scroll compressor according to the invention. In particular, it may be an air conditioning system for a motor vehicle.

The described embodiment and advantages for the scroll compressor apply accordingly to the system.

In one development of the invention, the air-conditioning system has a refrigerant, which is compressed by the scroll compressor in the compression mode, wherein the refrigerant is sucked into the scroll compressor with a suction pressure p _s and leaves the scroll compressor with an outlet pressure pd, and wherein the reference opening in such the compressor passage is arranged to adjust the following conditions in the compression operation of the scroll compressor:

• a first quotient Qi, defined by a contact pressure pb.max, when the suction pressure p _s , max an evaporation pressure p _v , max of the refrigerant at a temperature of 15.7 ° C, divided by a contact pressure pb.min, when a suction pressure p _s , _m in an evaporation pressure p _v , min of the refrigerant at a temperature of -26.4 ° C corresponds to lies in one Range from 2.4 to 4 (that is:

2.4 <Ql = Pb, max (Ps, max = Pv, max (15.7 ° C)) / Pb, min (P _S, p = min _v, min (-26.4 ° C))

* 4);

A second quotient Q2 defined by the contact pressure pb.max when the outlet pressure pd.max corresponds to a condensation pressure p _c , max of the refrigerant at a temperature of 72.6 ° C divided by a contact pressure Pb.min when an outlet pressure pd .min corresponds to a condensation pressure p _c , min of the refrigerant at a temperature of 34.4 ° C, is in a range of 1, 1 to 1, 4 (that is:

1, 1 <Q ₂ = Pb, min (Pd, max = Pc, max (72.6 ° C)) / Pb, min (Pd, min = Pc, min (34.4 ° C))

* 1, 4):

A product of the first quotient Q1 with the second quotient Q2 is within a range of 2.6 to 5.6 for an operating range of the scroll compressor (that is, 2.6 <Q1 ^■ Q ₂ <5.6, if p _v , min (-26.4 ° C) <p _s <p _v , max (15.7 ° C) and on the other hand p _c , min (34.4 ° C) <p _d

For a sufficient adjustment of the contact pressure in dependence on the respective operating condition of the air conditioning system is ensured. The suction pressure p _s and the outlet pressure pd are essentially determined by a temperature-dependent evaporation pressure p _v and a temperature-dependent condensation pressure p _{c of} the refrigerant. The temperatures of the refrigerant at a suction port of the scroll compressor and at an outlet port of the scroll compressor in turn depend on a temperature of the region to be cooled and a temperature of an environment to which heat is to be discharged. For a particularly preferred air-conditioning system with the coolant R134a, the following values apply, for example, approximately: p _v , min (-26.4 ° C.) = 0.1 MPa, p _v , max (15.7 ° C.) = 0, 5 MPa, p _c , min (34.4 ° C) = 1.0 MPa and p _c , max (72.6 ° C) = 2.5 MPa.

In general, other fluorine-based refrigerants can also be used, for example R1234yF. For fluorine-based refrigerants, the relevant pressures typically range from 0.1 to 3 MPa. It is also possible to use other refrigerants, for example R744 (CO2, pressures typically in the range of 2.0 to 13.0 MPa) or butane.

The invention will be explained below with reference to embodiments and with reference to the figures. All described and / or illustrated features alone or in any combination form the subject matter of the invention, regardless of their summary in the claims or their back references.

1 shows a first embodiment of a spiral compressor according to the invention in a longitudinal section;

2 shows a second embodiment of a spiral compressor according to the invention, which has a damping chamber in a reference connection compared with the first embodiment from FIG. 1, in a longitudinal section;

3A shows a cross section through a compressor unit of a spiral compressor according to the invention with a stationary spiral with 2.25 winch fertilize after an orbital disc has completed a circulation around the stationary disc to one-eighth;

Fig. 3B is the cross section of Fig. 3B, after the Orbitierscheibe the

Circulation around the stationary disk has been completed to a quarter;

4A shows a plan view of an embodiment of a stationary disk of a spiral compressor according to the invention in the direction of the stationary spiral and a stationary base surface of the stationary spiral, wherein the stationary spiral has two windings;

Fig. 4B is the plan view of Fig. 4A with a highlighted representation of in

Fig. 4A angle shown.

1, a stationary disk 1, an orbital disk 11, an outlet pressure chamber 30, a contact pressure chamber 40 and an electric motor 70 are arranged within a suction pressure chamber 60. The electric motor 70 has a rotor 71 and a stator 72 and is connected to an inverter 80 provided outside the suction pressure chamber 60.

At the suction pressure chamber 60, a suction port 61 and an outlet port 62 are provided, via which the scroll compressor can be connected to an external air conditioning system, for example a heat exchanger of a vehicle air conditioning system. The outlet port 62 is pressure-tightly in fluid communication with the outlet pressure chamber 30 via an outlet connection 63.

The stationary disk 1 and the Orbitierscheibe 1 1 are arranged interleaved in such a way that they form a compressor unit. It is the Stationary disc 1 of the outlet pressure can 30 faces, while the Orbi- animal disk 1 1 of Ansaugdruckkannnner 40 faces. The compressor unit is in fluid communication via an outlet opening 7 with the outlet pressure chamber 30. A check valve 8 prevents refrigerant from the discharge pressure chamber 30 from flowing back into the compressor unit.

In the outlet pressure chamber, an oil separator 31 and an oil reservoir 32 are provided. A return connection 33 leads from the oil reservoir 32 directly to the contact pressure chamber 40. Through the return connection 33, a fluid connection is made from the discharge pressure chamber 30 to the contact pressure chamber 40. A throttle valve 34 in the return link 33 provides a pressure difference between an outlet pressure in the outlet chamber 30 and a pressure applied to the pressure-applying chamber 40. The contact pressure chamber 40 is at the same time connected via a reference connection 51 to a reference opening in a stationary base surface (not shown in FIG. 1) of the stationary disk 1.

In the compression mode, an outlet pressure applied to the outlet port 62 prevails in the outlet pressure chamber 30, and in the suction pressure chamber 60, a suction pressure applied to the suction port 61 and lower than the outlet pressure.

Through the suction port 61, the refrigerant passes under the suction pressure into the suction pressure chamber 60 and is sucked by the compressor unit. In compression chambers (not shown in Fig. 1), which are formed in the compressor unit between the stationary disk 1 and the Orbitierscheibe 1 1, the refrigerant is compressed until it has reached outlet pressure. Subsequently, it is conveyed through the check valve 8 and the outlet port 7 into the discharge pressure chamber 30. In the discharge pressure chamber 30, the oil separator 31 separates oil carried in the refrigerant. The separated oil is collected in the oil reservoir 32. The refrigerant freed from the oil and under the discharge pressure is led out of the discharge pressure chamber 30 through the outlet connection 63 and the outlet port 62 from the scroll compressor.

The trapped in the compression chambers and increasingly compressed refrigerant causes a lifting force on the Orbitierscheibe 1 1. Without a counterforce this lifting force would push the Orbitierscheibe 1 1 away from the stationary disc 1. The two discs would then no longer seal against each other and the compression chambers would not be sealed. The refrigerant could escape from the compressor unit into the suction pressure chamber 60. To prevent this, there is a contact pressure in the contact pressure chamber 40 in the compression mode, which presses the orbital disk 11 with a contact force against the stationary disk 1. Thus, the Orbitierscheibe 1 1 is pressed tightly sealingly against the stationary disk 1. Fig. 2 shows a second embodiment of a scroll compressor according to the invention. The second embodiment corresponds to the first embodiment with the only difference that, in addition to the first embodiment, a damping chamber 52 is provided in the reference connection 51. A volume of the damping chamber 52 is 5 cm ³ to 6 cm ³ . This additional volume in the reference compound 51 attenuates fluctuations in the reference pressure at a reference port (not shown in FIG. 2). Accordingly, the contact pressure is kept more stable and the Orbitierscheibe 1 1 is pressed uniformly against the stationary disk 1. FIG. 3A shows a cross section through a compressor unit of a spiral compressor according to the invention, for example the scroll compressor from FIG. 1 or FIG. 2. Accordingly, the same reference numerals are used for the same features. A sectional area for FIG. 3A lies between the orbital disk 11 and the stationary disk 1 in FIG. 1 or FIG. 2 and extends parallel to a stationary base area 3 of the stationary disk 1. On the stationary base 3 a stationary spiral 2 is arranged with 2.25 turns. Accordingly, an outer end 5 of the stationary spiral 2 is arranged at a spiral angle of 810 ° from an inner end 4 of the stationary spiral 2.

Of the Orbitierscheibe 1 1 is due to the cross section in Fig. 3A, only an Orbitierspirale 12 can be seen, which is arranged on a Orbitiergrundfläche (not shown) of the Orbitierscheibe 1 1. The Orbitierspirale 12 has (like the stationary spiral 2) 2.25 turns on.

The stationary disk 1 and the Orbitierscheibe 1 1 are arranged nested. In compression operation, the Orbitierscheibe 1 1 is pressed by the contact pressure in the contact pressure chamber 40 (see Fig. 1 and Fig. 2) on the stationary disk 1. As a result, on the one hand, an end of the orbital spiral 12 facing away from the orbital ground surface seals against the stationary base surface 3 and, on the other hand, an end of the stationary spiral 2 facing away from the stationary base surface 3 seals against the orbit base. The stationary base 3, the stationary spiral 2, the Orbitiergrundfläche and Orbitierspirale 12 thereby limit several compression spaces. In the position of the Orbitierscheibe 1 1 and the Orbitierspirale 12 shown in Fig. 3A are in this way in a compressor duct 6, which is formed between the turns of the stationary spiral 2, just a compression space last stage 20a, 20a ', 20a "and two Compression spaces penultimate stage 20b, 20b 'limited, wherein the compression space last stage 20a, 20a', 20a 'from a first sub-area 20a, a second sub-area 20a' and a third 3A, which are in fluid communication with each other in Fig. 3A through narrow gaps (not visible) between the stationary scroll 2 and the orbiting scroll 12. On the right side of Fig. 3A, there is shown a phasor diagram representing a recirculation angle 103 of the orbital disk 1 1 (and thus the Orbitierspirale 12) and their direction of rotation or compression direction 100. The Orbitierscheibe 1 1 begins a new round when its circulating position 103 in the vector diagram is just at a orbital angle of 0 ° 101. Then touches the Orbi- spiral spiral 12th At the same time, an outer end 15 of the orbiting scroll 12 contacts an outer side of an outermost turn of the stationary scroll 12, thereby closing the compression space of the penultimate step 20b ' has the orbital disc starting from the orbital angle 101 of 0 ° entla ng the circulation direction 100 already moved to the circulation position 103 of 45 °.

In the compressor channel 6, a reference opening 50 in the stationary base 3 is arranged at a positional angle of 360 ° to the inner end 4 of the stationary spiral 2. It is just swept over in Fig. 3A by the sub-area 20a "of the last-stage compression space 20a, 20a ', 20a" and is in fluid communication with the entire last-stage compression space 20a, 20a', 20a. "Referring to Fig. 3A, the orbital disk orbits further along the direction of rotation 100 about a center of the stationary spiral 2.

In Fig. 3B, the Orbitierscheibe 1 1 has ended the circulation to a quarter. Its circulation position 103 is now at a rotation angle 102 of 90 °. The two compression spaces of the penultimate stage 20b, 20b 'from FIG. 3A are propagated along the compression direction 100 in the compressor duct 6 further in the direction of the center of the stationary scroll 2. They have each reduced their volume and the enclosed refrigerant in them was compressed accordingly. Also, the volume of the last-stage compression space 20a, 20a ', 20a "has become smaller The sub-area 20a of the last-stage compression space 20a, 20a', 20a" of Fig. 3A has largely collapsed and the outlet opening 7 in the stationary base 3 is straight an inner end 14 of Orbitierspirale 12 hidden. The reference opening 50 is still swept over by the subregion 20a 'in FIG. 3B.

At an orbital angle between 90 ° and 180 °, the subregions 20a 'and 20a "unite. When the orbital disk 1 1, starting from Fig. 3B, orbits by another 270 ° along the compression direction 100 relative to the stationary disk 1, it reaches a 0 recirculation position The refrigerant which had been located in the last stage compression chamber 20a, 20a ', 20a "at the beginning of the revolution in Fig. 3A has been led into the outlet port 7 to a large extent. The merged sub-regions 20a 'and 20a "form the new sub-region 20a' for the following new cycle The second-to-last compression chamber 20b of Figures 3A and 3B becomes the new sub-region 20a ', the second-to-last compression chamber 20b' will oppose to the new sub-hole 20a "and the orbital disk 1 1 starts the new round.

The refrigerant located in the last-stage compression chambers 20b, 20b 'in FIG. 3A does not (yet) enter into fluid communication with the outlet port 7 until the beginning of the new cycle, but only during this new cycle. At 0 ° orbital angle 101 at the beginning of the new cycle, the new subregions 20a, 20a ', 20a "are not yet in fluid communication, but as soon as the orbital disk 11 continues to orbit, the new subregions 20a, 20a', 20a" are narrow Column in fluid communication with each other and together form the new compression space last stage 20a, 20a ', 20a "for the new circulation When in the new circulation the circulation position 103 of 45 ° is reached, the state shown in Fig. 3A again.

The reference opening 50 is swept over and closed by the Orbitierspirale 12 during a revolution of the Orbitierscheibe 1 1 to a first part of the time required for the circulation (hereinafter also "orbital period"). Then, in a second part of the circulation time, it is in fluid communication with the sub-region 20a "and consequently with the entire first-stage compression chamber 20a, 20a ', 20" (see Figs. 3A and 3B). Subsequently, during a third part of the circulation time, it is again swept over by the orbital spiral 12 and closed. Thereafter, in a fourth part of the circulation time, it is in fluid communication with the compression space of the penultimate stage 20b '. Finally, during a fifth part of the orbital period until the end of this cycle, it is again covered and closed by the orbital spiral 12.

This is due to the reference port 50 during the second part of a rising high pressure. This is because the refrigerant in the last-stage compression chamber 20a, 20a ', 20a "is already compressed to some extent when it fluidly communicates with the reference port 50. At the beginning of the fourth part, when the second-to-last compression chamber 20b' In fluid communication with the reference port 50, the reference pressure decreases to a minimum value and then continuously increases again during the fourth part 16. During the first, third and fifth portions, the reference pressure at the reference port 50 remains approximately unchanged since the references - zöffnung 50 is closed. A mean reference pressure results as the integral of the reference pressure over the orbital period divided by the orbital period.

If the reference opening 50 is arranged on an inner side or on an outer side of the compressor channel 6, deviating from the illustration in FIGS. 3A and 3B, the reference opening 50 is covered and closed only once by the Orbitierspirale 12 during the circulation time. For example, if it is at the same positional angle as in FIGS. 3A and 3B, but on the inside in the compressor duct 6, it will be obscured only once by the orbiting scroll 12 and will not be in fluid communication with the penultimate stage compression chamber 20b the other compression space penultimate stage 20b '.

It will now be explained with reference to FIGS. 4A and 4B in which position angle the reference opening 50 should be arranged. 4A shows a plan view of a further embodiment of a stationary disk 1 of a spiral compressor according to the invention, for example for the embodiments shown in FIGS. 2 and 2A, with a stationary spiral 2 with two windings. The same reference numerals are retained for the same features, even if the stationary disk 1 of FIGS. 4A and 4B differs in detail from the stationary disk 1 of FIGS. 3A and 3B.

A position angle 58 of 0 ° is determined by the inner end 4 of the stationary spiral 2. It should be noted that a Abschlusswulst 4A 'of the inner end 4 for determining the position angle of 0 ° is irrelevant.

Since the stationary spiral 2 has two turns in FIG. 4A, its outer end 5 is arranged at a position angle or a spiral angle 9 of 720 °. Accordingly, there is an inlet opening of a compressor channel 6, which is located between the outer end 5 and a beginning of an outer turn the stationary spiral 2 extends at a position angle of 360 °, at the spiral angle 720 °.

Depending on the spiral angle 9, the reference opening 50 should be arranged in the hatched area 55. The region 55 extends in the compressor duct 6 between a minimum position angle 56 for the reference opening 50 and a maximum position angle 57 for the reference opening 50. Starting from an arbitrary spiral angle greater than or equal to 450 °, the minimum position angle 56 is calculated from the formula 315 ° / (0.5 ^■ Spiral angle / 360 °) ° ¹ and the maximum position angle 57 from the formula 435 ° / (0.5 ^■ Spiral angle / 360 ⁰ ) ^{0 2} . In the present case, the minimum position angle 56 is therefore 315 ° and the maximum position angle 57 is therefore 435 °. The reference opening 50 is exemplarily provided in a position angle 54 of 375 ° in the region 55 in FIGS. 4A and 4B.

In Fig. 4B, the minimum position angle 56, the position angle 54 of the reference opening 50, the maximum position angle 57 and the helix angle 9 are again particularly emphasized. When the contact pressure is greater than the reference pressure, oil and / or refrigerant flows from the contact pressure chamber 40 through the reference connection 51 and the reference opening 50 into the compressor unit. As a result, the contact pressure 40 is reduced. In this case, this oil and / or coolant, which is already under the contact pressure, reintroduced into the compression process and not simply blown into a lower pressure level outside the compressor unit and relaxed. Thus, the compression work stored therein is used to increase the pressure in the compression space 20a, 20a ', 20b, 20b', which is in fluid communication with the reference port 50, and is not wasted. The following Table 1 shows an example of an air conditioning system with a scroll compressor according to the invention according to FIG. 2 and a refrigerant R134a, how the contact pressure pb (in MPa) in dependence on the suction pressure p _s and the outlet pressure pd adjusts. p _d (MPa)

1, 0 1, 5 2.0 2.05

0.5 0.84 0.88 0.91 0.99

0.4 0.73 0.77 0.8 0.88

Q_

0,6 0.3 0.61 0.65 0.69 0.77

w

CL 0.2 0.45 0.49 0.52 0.56

0.1 0.31 0.29 0.34 0.45

Table 1: pt (MPa) as a function of p _s (MPa) and pd (MPa)

From Table 1 it can be seen that a pressure difference between the contact pressure PB and the intake pressure p _s increases with increasing inlet pressure p _s, if the discharge pressure Pd does not decrease. In addition, this pressure difference tends to increase with increasing outlet pressure pd, unless p _s decreases.

A total force F, with which the orbital disk 1 1 is pressed against the stationary disk 1, results from the contact force pd caused by the contact pressure minus the lifting force directed counter to it. The following Table 2 exemplifies the total force F (in N) for the air conditioning system, to which Table 1 refers. p _d (MPa)

1, 0 1, 5 2.0 2.05

0.5 1352 1003 955 940

0.4 895 778 772 820 O

Q_

53 0.3 536 508 575 629

w

CL 0.2 31 1 329 455 607

0.1 372 216 400 713

Table 2: F (N) as a function of p _s (MPa) and pd (MPa)

The friction between the Orbitierscheibe 1 1 and the stationary disk 1 in the compression mode depends (at least approximately) linearly from the total force F. From Table 2, it can be seen that the total force F with the present invention tends to increase with increasing discharge pressure p _s at a given discharge pressure p d. In particular, there is generally only a small total force F at low intake pressure p _s. Correspondingly, the friction between the orbital disk 1 1 and the stationary disk 1 is low at a low intake pressure p _s and the orbital disk 1 1 can be moved in a particularly effortless manner. This also facilitates turning on, turning on and turning up the orbital disk 1 1. At the same time, the invention ensures low friction at low suction pressure p _s and low outlet pressure pd.

The total force F remains significantly greater than 0 over an entire operating range. The lifting force and thus the contact force required to overcome it increase sharply with increasing suction pressure p _s when the outlet pressure pd does not drop, and increase with increasing outlet pressure pd when the suction pressure p _s does not sink. In order to ensure a reliable sealing of the compressor unit with constant percentage fluctuations of the lifting force and / or the contact force, therefore, with the present invention, the total force F at high outlet pressure pd and / or at high Suction pressure p _s total greater than in the case when both the outlet pressure pd and the suction pressure p _{s are} low.

In summary, the present invention provides a simple and inexpensive, but effective adjustment of the contact pressure as a function of the operating state of the scroll compressor. It ensures a reliable, safe and efficient operation of the scroll compressor in different operating conditions.

LIST OF REFERENCE NUMBERS

1 stationary disc

2 stationary spiral

3 stationary base area

4 inner end

4a end bead

5 outer end

6 compressor channel

7 outlet opening

8 check valve

9 spiral angles

1 1 Orbital disk

12 Orbital spiral

15 outer end

20a subarea

20a 'sub-area

20a "subarea

20b, 20b 'compression room penultimate stage

30 outlet pressure chamber

31 oil separator

32 oil reservoir

33 feedback connection

34 throttle valve

40 contact pressure chamber

50 reference opening

51 reference connection

52 damping chamber

54 position angle

55 area 56 Minimum position angle

57 Maximum position angle

58 position angle

60 intake pressure chamber

61 suction connection

62 outlet connection

63 outlet connection

70 electric motor

71 rotor

72 stator

80 inverters

100 revolution direction

101 orbital angle

102 orbital angle

103 circulation position

Claims

claims:

1 . Scroll compressor for compressing a fluid with

a stationary disk (1) with a stationary spiral (2), wherein the stationary spiral (2) is arranged on a stationary base surface (3) of the stationary disk (1) and forms a spiral compressor channel (6) extending from an outer end (5 ) the stationary scroll (2) extends to a compressed fluid outlet port (7) at an inner end (4) of the stationary scroll (2);

an orbital disk (11) having an orbital spiral (12), the orbital spiral (12) being arranged on an orbit base surface of the orbital disk (11),

wherein the orbital disk (1 1) is orbitable relative to the stationary disk (1) along a compression direction (100),

wherein the Orbitierspirale (12) and the stationary spiral (2) are arranged interleaved in such a way that of the stationary base (3) and the stationary spiral (2) and the Orbitiergrundfläche (12) and the Orbitierspirale at least one compression space (20a, 20a ' 20a ", 20b, 20b ') is limited,

wherein the compression space (20a, 20a ', 20a ", 20b, 20b') of a

Suction range of the compressor passage (6) shifts toward an outlet region of the compressor duct (6) and thereby reduces its volume when the Orbitierscheibe (1 1) orbiting relative to the stationary disk (1) along the compression direction (100);

an outlet pressure chamber (30) in fluid communication with the outlet port (7);

a contact pressure chamber (40) which is acted upon in the compression mode with a contact pressure, wherein the Orbitierscheibe (1 1) is pressed by the contact pressure against the stationary disc (1); a return connection (33) which forms a fluid connection from the outlet pressure chamber (30) to the contact pressure chamber (40);

a reference opening (50) disposed in the stationary base (3) within the compressor duct (6); and

a reference connection (51) providing fluid communication between the

Contact pressure chamber (40) and the reference opening (50) for influencing the contact pressure on the basis of a in the compression mode at the reference opening (50) applied reference pressure forms.

2. Scroll compressor according to claim 1, characterized by at least two compression spaces (20a, 20a ', 20a ", 20b, 20b'),

wherein the reference opening (50) is arranged in the compressor passage (6) such that the reference opening (50) in the compression mode during a circulation of the orbital disk (1 1) for a first part of the circulation time with a last-stage compression space (20a , 20a ', 20a ") and for a further part of the time required for the circulation with a compression chamber penultimate stage (20b, 20b') is directly in fluid communication.

3. scroll compressor according to claim 1 or 2, characterized in that the stationary spiral (2) has a spiral angle (9) of more than 450 °,

wherein the reference port (50) is disposed in the compressor passage (6) at a positional angle (54) from the inner end (4) of the stationary scroll (2) which is at least 315 ° / (0.5 ° ^helix angle / 360 °) ⁰ '. ¹ and a maximum of 435 ° ^* (0.5 ^■ helix angle / 360 °) ° ^<2 ,

preferably at least 345 ° / (0.5 ^■ helix angle / 360 °) ° ¹ and a maximum of 405 ° ^* (0.5 helix angle / 360 °) ° ^<2 .

4. scroll compressor according to one of the preceding claims, characterized in that in the compression operation, a mean pressure difference between the contact pressure and a suction pressure with increasing suction pressure begins when the outlet pressure remains at least substantially constant.

5. Scroll compressor according to one of the preceding claims, characterized by a in the return connection (51) provided in the flow valve, preferably a throttle valve (34).

6. scroll compressor according to one of the preceding claims, characterized in that in the reference compound (51) between the reference opening (50) and the contact pressure chamber (40), a damping element (52) is provided.

7. scroll compressor according to one of the preceding claims, characterized in that the reference opening (50) in the stationary base surface (3) has an opening area between 0.5 mm ² and 8.05 mm ² , preferably between 1, 13 mm ² and 3, 15 mm ² .

8. Scroll compressor according to one of the preceding claims, characterized by an oil separator (31) in the outlet pressure chamber (30) and an oil reservoir (32), wherein the return connection (33) from the oil reservoir (32) to the contact pressure chamber (40) leads ,

9. scroll compressor according to one of the preceding claims, characterized in that in the reference connection (51) no valve is provided.

10. Scroll compressor according to one of claims 1 to 8, characterized in that in the reference connection (51), a pressure control valve is provided which the fluid connection between the contact pressure chamber (40). and the reference opening (50) closes when the reference pressure is greater by at least 0.2 bar than the contact pressure, preferably by at least 0.8 bar.