DE102016226118A1 - scroll compressor - Google Patents

Abstract

A scroll compressor with a stator spiral (10), with an orbiting drivable rotor spiral (18) and with one of the stator spiral (10) and the rotor spiral (18) associated bottom (14, 28), wherein the bottoms (14, 28) pressure chambers which are bounded in the radial direction with respect to an orbital axis (16) of the rotor spiral (18) by the stator spiral (10) and the rotor spiral (18) in the axial direction with respect to the orbital axis (16), characterized in that the rotor spiral ( 18) relative to the associated bottom (28) is arranged relatively movable. Consequently, the bottom (28) associated with the rotor spiral (18) is not intended to participate in orbiting movement of the rotor spiral (18), allowing it to be statically integrated into the scroll compressor and, in particular, a housing of the scroll compressor, thereby advantageously providing axially directed support Forces that arise due to a pneumatic overpressure in the pressure chambers, can be achieved. Complex measures for compensating axially acting on a moving bottom of the rotor spiral compressive forces, for example by the integration of a so-called medium-pressure space, can be dispensed with.

Description

The invention relates to a scroll compressor, which may be provided in particular for use as a refrigerant compressor for an air conditioning system of a motor vehicle.

In principle, scroll compressors have a number of advantages compared with compressors of other types, for example piston compressors, which predestine them for use as refrigerant compressors in an air conditioning system of a motor vehicle. For example, spiral compressors are relatively robust, efficient and can also be produced inexpensively. Furthermore, these can be formed due to their radial direction of action in the compression of the gas provided for this purpose with comparatively small dimensions, in particular along the axis of rotation of a drive shaft of the scroll compressor.

Spiral compressor (see eg US 2013/0115123 A1 ) basically comprise one or more pairs of spirals, each interlocking with each other in an eccentric arrangement interlocked and thereby delimit several mutually separated, spiral or sickle-shaped pressure chambers. In an orbiting relative movement of the spirals (each pair of spirals) to each other, the pressure chambers are first opened at its radially outer end to a low pressure section of the scroll compressor, which can flow into the gas to be compressed in this. With a further relative movement of the spirals, the individual, then closed pressure chambers move on a spiral path in the direction of a central region, wherein the sizes of the pressure chambers are increasingly reduced. This is a compression of the enclosed gas in the pressure chambers connected according to the displacement principle. The central portion of the scrolls is typically connected to a high pressure section of the scroll compressor with the interposition of a self-actuated valve into which the compressed gas is ejected upon reaching the maximum compression pressure due to a reduction in the sizes of the pressure chambers. A relative movement of the two spirals (each spiral pair) is usually achieved by the orbital drive of a (rotor) spiral, while the other (stator) spiral is stationary.

To achieve the highest possible efficiency of a scroll compressor, it is important that the rotor spiral (s) and the stator spiral (s) in the contact points to each other are sealed as well as possible. In this case, sealing of the gaps formed between the end edges of the spiral walls of the spirals and the bottoms of the associated partner spirals is often problematic because the compression of the gas in the compaction pockets with the consequent high pressure leads to compressive forces pushing the spirals away from each other along the orbit relationship , It is obvious that the higher the compression ratio achieved by means of a scroll compressor, the more this problem arises. For refrigerant compressors for motor vehicle air conditioning systems, therefore, this problem arises in particular for those which require much higher system pressures for use with refrigerants such as carbon dioxide (R744) than for the previously used conventional synthetic refrigerants (for example R134a , R1234yfF, R12) is the case. Furthermore, carbon dioxide as a refrigerant has a relatively small molecule size, which can result in a significant leakage even at relatively small gaps.

It is known to provide a so-called medium pressure space between the spirals of a spiral pair of a scroll compressor to produce the best possible and operating load-dependent axial contact pressure, which is in fluid communication with one or more of the pressure chambers by means of one or more medium pressure channels. In this case, the one or more medium-pressure channels on relatively small opening cross sections, whereby they serve as a throttle for between the pressure chambers and the medium pressure space overflowing gas. As a result of the fluid-conducting connection with one or more pressure chambers, a mean pressure arises in the medium-pressure space, the height of which lies between the suction pressure and the compression end pressure and which fluctuates significantly less as a result of the throttling action of the medium-pressure ducts than for the pressure of the gas or gaseous refrigerant in the pressure chambers applies. This present in the medium-pressure space medium pressure acts on the bottom of one of the spirals of a pair of spirals and pushes them axially against the associated partner spiral.

The DE 10 2013 200 807 A1 discloses a scroll compressor in which the rotor coil is connected to an inner ring of a pendulum slide mechanism, wherein the inner ring is also rotatably mounted on an eccentric end of a drive shaft. The inner ring is further connected via a plurality of pendulums with a fixed outer ring. The pendulum slide mechanism ensures that the rotating drive through the drive shaft only leads to an orbiting movement of the rotor spiral, without this also rotating with respect to the stator spiral.

The invention had the object of providing a scroll compressor, despite a simple and therefore cost-effective constructive Design ensures a good seal limited by the spirals and the associated bottoms pressure chambers.

This object is achieved by means of a scroll compressor according to the patent claim 1. Advantageous embodiments of the scroll compressor according to the invention are objects of the other claims and / or will become apparent from the following description of the invention.

According to the invention, a spiral compressor is provided with a stator spiral, with an orbitally drivable rotor spiral and with a respective bottom of the stator spiral and the rotor spiral, the bottoms pressure chambers being movable radially with respect to an orbit axis of the rotor spiral (about which the rotor spiral can orbitingly be moved). are limited by the spirals, at least partially, preferably completely in the axial direction with respect to the orbit axis limit. It is provided that the rotor coil is arranged relative to the ground associated therewith relatively movable. Consequently, the bottom should not interfere with orbital motion of the rotor spiral, allowing it to be statically integrated into the scroll compressor, and more particularly into a housing of the scroll compressor, advantageously providing support for axially directed forces due to pneumatic overpressure in the pressure chambers can be achieved. Accordingly, it may be provided, in particular, that the rotor spiral is provided as orbitally as possible, while the stator spiral and the two plates associated with the spirals are statically integrated into the scroll compressor. In this way, an overpressure in the pressure chambers of the scroll compressor substantially does not lead to axially directed forces acting on the rotor spiral, whereby their sealing, which is required in a spiral compressor according to the invention for both spirals even opposite to both floors, in a simple manner. Consequently, in a scroll compressor according to the invention can be dispensed with elaborate design measures to compensate for an orbiting with a rotor spiral mitbewegten moving bottom pressure forces that lead without such measures to a lack of tightness of the scroll compressor, and in particular to the integration of a so-called medium-pressure space, whereby the constructive Effort and thus the manufacturing cost of a scroll compressor according to the invention can be kept low. Furthermore, a spiral compressor according to the invention is characterized by a relatively small orbiting moving mass, which can have an advantageous effect on the efficiency and / or the acoustic operating behavior of the scroll compressor. Another advantage, which may arise due to an embodiment of a scroll compressor according to the invention, lies in relatively low friction losses and thus again in a relatively high efficiency.

In a preferred embodiment of a scroll compressor according to the invention it can be provided that the bottom of the rotor spiral is at least in the axial direction with respect to the orbital axis immovable (indirectly or preferably directly) connected to the stator spiral and / or to the bottom of the stator spiral. In this way, a particularly advantageous support of caused by a pneumatic overpressure in the pressure chambers pressure forces in the axial direction with respect to the orbital axis can be achieved. A particularly advantageous support can be achieved if the two bottoms and consequently those components which are acted upon directly in the axial direction with respect to the orbital axis with the compressive forces, are connected to each other directly, for example via a screw.

Further preferably, it is provided that the bottom associated with the stator spiral and / or the bottom assigned to the rotor spiral form a section of a housing of the spiral compressor. It can also be provided in particular that their respective side facing away from the associated spiral side represents an outer side of the housing or the scroll compressor. Such a scroll compressor according to the invention can be characterized by a particularly compact and thus by a claim only a relatively small space configuration.

In order to achieve the best possible sealing of the spirals with respect to the bottoms and thus also the best possible sealing of a spiral compressor according to the invention, it can be provided that the rotor spiral and the stator spiral are arranged in the axial direction as free of play as possible between the trays. As a result of an inventively enabled static integration of both floors in the scroll compressor can be adjusted in a structurally relatively simple way the smallest possible clearance, which is largely independent of the pressure conditions in the pressure chambers by an adapted design of the soil interconnecting components. Due to manufacturing tolerances, however, it is often not possible to achieve a far-reaching backlash. In addition, if necessary, different thermal expansion of the components of the scroll compressor in operation must be taken into account, by which the distances of the floors to each other and to the spirals can change. In order to ensure at all times during operation of a scroll compressor according to the invention the best possible sealing of the spirals with respect to the floors should therefore preferably Additional measures may be provided, for example, even at thermally induced strains at any time ensure a backlash-free arrangement of the spirals between the floors, but at the same time keep friction losses due to the relative movements of the floors to the spirals as low as possible. For this purpose, it can preferably be provided that the rotor spiral and / or the stator spiral is flexible and in particular elastic, at least in the axial direction with respect to the orbital axis. For this purpose, it may be provided that the spiral wall of the rotor spiral and / or the stator spiral itself are formed at least partially from a flexible or preferably elastic material, for example an elastomer or a thermoplastic plastic. Alternatively or additionally, there is also the possibility of integrating one or more separate sealing elements, which are arranged at least in the axial direction movable on a spiral wall forming body of the respective spiral and supported for example by means of one or more prestressed spring elements on the base body and thereby against an adjacent floor are charged.

In a further preferred embodiment of a scroll compressor according to the invention can be provided that a rotational axis of a drive for the rotor spiral radially offset with respect to the orbital axis is arranged. In this way, an embodiment for the rotor spiral associated soil can be achieved in an advantageous manner, which is as free of passage openings and in particular can be integrally formed, which is positive in terms of sealing the pressure chambers and / or in terms of supporting axially directed pressure forces can affect.

Furthermore, it can preferably be provided that the rotor spiral is connected to a guide element which surrounds the latter at least partially peripherally and forms an anti-twist device for the rotor spiral. The rotation ensures that generation of an orbiting movement of the rotor spiral by means of a drive is not connected to a relevant rotation of the rotor spiral relative to the stator spiral. For this function of the guide element, it may be sufficient if this extends only in a relatively small portion (for example by a maximum of 180 °, by a maximum of 120 ° or by a maximum of 90 ° with respect to the orbital axis of the rotor spiral) circumferentially of the rotor spiral. A relatively small guide element can in turn have an advantageous effect with regard to the size of the orbiting mass moved as well as with regard to the friction losses and thus with regard to the efficiency and the acoustic operating behavior of a scroll compressor according to the invention. In this case, it can furthermore preferably be provided that the guide element is arranged exclusively circumferentially of the rotor spiral, so that the entire inside area of the rotor spiral, in which this limits pressure chambers in cooperation with the stator spiral, can be covered in the axial direction by the associated floor, which is turn may be advantageous in terms of sealing the pressure chambers and / or in terms of supporting axially directed pressure forces.

The preferably provided guide element of a scroll compressor according to the invention can also be preferred for transmitting an orbital drive movement, which is arranged by a central drive (ie, the axis of rotation of the drive coaxial with respect to the orbital axis) or preferably a decentralized drive (ie the axis of rotation of the drive is radially offset with respect the orbital axis arranged) is effected, serve on the rotor spiral, so that can be dispensed with additional transmission means, which in turn can be advantageous in terms of achieving the least orbiting moving mass and in terms of the lowest possible friction losses.

For a scroll compressor according to the invention may be provided in a preferred manner, a drive with an electric drive motor, because this u.a. In a particularly simple way allows a demand-based power control for the scroll compressor. Compared to a mechanically driven scroll compressor according to the invention then can be dispensed with, for example, an integration of a clutch for power control. Such a power control may be required or at least desirable, for example, in a preferably provided use of a scroll compressor according to the invention as a refrigerant compressor for an air conditioning of a motor vehicle, the energy consumption for the scroll compressor and thus the fuel consumption of an internal combustion engine directly or indirectly providing the energy for the operation of the scroll compressor of the motor vehicle as low as possible. Furthermore, such an electric motor-driven scroll compressor allows use in motor vehicles with partially or fully electrified powertrain (regardless of the operation of an optionally existing internal combustion engine).

Due to the advantageous support of compressive forces in the axial direction, which is made possible by an inventive design of a scroll compressor, and consequently due to a good sealability of the pressure chambers, an inventive scroll compressor is advantageously also for generating a relatively large pressure ratio of For example, at least 15, preferably of at least 25. Thus, such a scroll compressor is particularly suitable for use as a refrigerant compressor of an air conditioning system of a motor vehicle, in which a refrigerant is used, which, such as carbon dioxide (R744), correspondingly high system pressures required to To ensure proper functioning of the air conditioner. Accordingly, a configuration can be provided for a scroll compressor according to the invention, by means of which correspondingly high system pressures can be realized.

It can also be provided that the spiral compressor according to the invention is designed in one stage and consequently has only one spiral pair consisting of stator spiral and rotor spiral. As a result, although the entire compression ratio must be realized by means of a compression stage, which correspondingly high demands on this compression stage, in particular with regard to the thermal load and also to the seal between the stator and the rotor spiral of this compression stage, but at the same time can the design complexity and also the space of the scroll compressor are kept low, which makes this relatively inexpensive to produce and advantageous usable. Multi-stage compressors according to the invention are also possible.

The indefinite articles ("a", "an", "an" and "an"), in particular in the patent claims and in the description generally describing the claims, are to be understood as such and not as numerical words. Corresponding to this concretized components are thus to be understood that they are present at least once and may be present more than once.

• 1: einen erfindungsgemäßen Spiralverdichter in einer perspektivischen Explosionsdarstellung; und
• 2: eine perspektivische, teilweise transparente Ansicht des Spiralverdichters.

The present invention will be explained in more detail with reference to embodiments shown in the drawings. In the drawings shows, in a simplified representation:

• 1 : a scroll compressor according to the invention in a perspective exploded view; and
• 2 a perspective, partially transparent view of the scroll compressor.

The Indian 1 The scroll compressor shown comprises a multi-part housing into which a double-walled stator spiral 10 is immovably integrated. The stator spiral 10 is in one piece and thereby completely gap-free with a flat, substantially circular housing portion 14 a first housing part 12 connected, said housing portion 14 one of the stator spiral 10 assigned ground 14 forms, through the pressure chambers, between the stator spiral 10 and one eccentric with respect to an orbital axis 16 into the stator spiral 10 engaging rotor spiral 18 formed and that of the stator spiral 10 and the rotor spiral 18 in the radial direction with respect to the orbital axis 16 are limited in one of the axial directions with respect to the orbital axis 16 are limited. The stator spiral 10 is still of a circular peripheral boundary wall 42 surrounded, which also in one piece and thus gap-free with the flat housing section 14 of the first housing part 12 connected is. The first housing part 14 still includes a jacket-shaped, the stator spiral 10 and the boundary wall 42 circumferentially (fully) surrounding housing section 20 , In these are connection openings 24 for (for example, two in the illustrated embodiment) in the boundary wall 42 opening inlet channels 22 integrated, can be introduced via the gas to be compressed in the pressure chambers.

The housing further comprises a second housing part 26 , which also has a flat housing section 28 has, which is formed approximately circular segment-shaped. This housing section 28 forms one of the rotor spiral 18 assigned ground 28 through which the pressure chambers in the other of the axial directions with respect to the orbital axis 16 are limited. Furthermore, the second housing part forms 26 also a jacket-shaped housing section 30 out. In the assembled state of the scroll compressor (see. 2 ) are the two housing parts 12 . 26 not shown connecting elements, such as fittings, directly connected to each other, wherein the shell-shaped housing sections 20 . 30 the two housing parts 12 . 26 support each other.

The second housing part 26 forms due to the only part-circular design of the flat housing portion 28 a section 32 out, which is the shape of a roughly 120 ° around the orbital axis 16 having extending circular arc. In this section 32 is a guide element 34 which also takes the form of a roughly 120 ° around the orbital axis 16 Having extending annular arc and fixed and in particular integrally with an adjacent, specifically with a at the radially outer end of the rotor spiral 18 located section of the rotor spiral 18 connected is. This is the guide element 34 with respect to the axial direction (relative to the orbital axis 16 ) next to the rotor spiral and with respect to the radial direction (relative to the orbital axis 16 ) outside the rotor spiral 18 so that the whole of the rotor spiral 18 limited, spiral internal volumes exclusively (on the corresponding side) of the rotor spiral 18 assigned ground 28 and not also of the guide element 34 is covered.

A function of the guide element 34 lies therein, an orbiting motion of the rotor spiral 18 , which is caused by means of a drive, not shown, to lead and thereby rotation of the rotor spiral 18 relative to the stator spiral 10 (to the relevant extent) to avoid, whereby an anti-rotation is realized. For this purpose, it is provided that the guide element 34 a plurality of cylindrical guide grooves 36 forms into the cylindrical guide pins 38 of the first housing part 12 intervention. The guide pins 38 extend from a further housing section 40 that in overlapping with the cutout 32 of the second housing part 26 arranged portion of the first housing part 12 is provided and in an approximately parallel orientation with respect to the flat housing portion 14 the local edge portion of the shell-shaped housing portion 20 with the local section of the boundary wall 42 of the first housing part 12 connects and thereby a support and guide surface for the guide element 34 formed. The (for all management pits 36 identically dimensioned) diameter of the guide recesses 36 is significantly larger than the (for all guide pins 38 identically dimensioned) diameter of the guide pins 38 , An orbiting movement of the guide element 34 and thus the rotor spiral 18 can be achieved by sliding the guide pins 38 on the peripheral surfaces of the guide grooves 36 be guided.

Another function of the guide element 34 lies therein, as a transmission element of an orbiting motion, which is imposed by the drive, not shown, on the rotor spiral 18 transferred to.

An orbiting motion of the rotor spiral 18 relative to the stator spiral 10 leads in a known manner to the fact that the pressure chambers each on a spiral path in the direction of a central portion of the stator spiral 10 shift and thereby become continuously smaller, which are increasingly compressed in the pressure chambers subsets of a gas or a gas-oil mixture. In a proposed compression of a gas-oil mixture, the gas was added to the gas before or at the beginning of the compression, to lubricate by means of this in particular between the stator spiral 10 and the rotor spiral 18 To realize trained contact surfaces, whereby relatively low friction losses can be achieved. The individual pressure chambers reach the central section of the stator spiral 10 , The compressed subsets of the gas or the gas-oil mixture over in the present embodiment three in the stator spiral 10 assigned ground 14 integrated outlets ejected. It is assigned by means of the outlet openings, automatically pressure-controlled valves 44 (Check valves) reaches the best possible, pressure-dependent outflow of the compressed gas or gas-oil mixture from the pressure chambers.

The ejection of the compressed gas or gas-oil mixture via the outlet openings can also take place in a high-pressure space (not shown) formed, for example, by the housing, from which the compressed gas is then removed centrally. If a gas-oil mixture was or is compressed in the pressure chambers, an oil separator (not shown), for example formed as a centrifugal separator, can be integrated into this high-pressure chamber, by which the oil is separated as completely as possible from the gas and fed to a new use ( ie this is again introduced into a gas still to be compressed).

The valves 44 can, as shown, be designed in the form of finger or lamella valves, to which they each have a spring tab 46 include, with its one end on the outside of the stator spiral 10 assigned soil 14 or of this soil 14 forming housing section 14 of the first housing part 12 by means of, for example, a respective screw (not shown) are fastened, while in each case the free end of the spring tabs 46 is arranged in overlap with the associated outlet opening and this in the unloaded state of the spring tabs 46 closes. In the case of an overpressure within the pressure chambers in fluid communication with the outlet openings in comparison to the pressure on the outside of the valves 44 open the valves 44, with the free ends of the spring tabs 46 be deflected elastically. On the other hand, an overpressure on the outside leads to an increased pressure of the free ends of the spring tabs 46 on the portions of the bottom surrounding the outlet openings 14 , whereby the valves 44 securely close the outlet openings.

Due to the inventive design of the scroll compressor, due to a relatively movable arrangement of the rotor spiral 18 assigned soil 28 with respect to the rotor spiral 18 a static integration of this soil 28 allows in the scroll compressor, resulting from an overpressure in the pressure chambers resulting pressure forces in the axial direction with respect to the orbital axis 16 are aligned, in an advantageous manner by the formed as sections of the housing floors 14 . 28 be supported while on the rotor spiral 18 or on the unit made of rotor spiral 18 and guide element 34 no axially directed pressure forces (in relevant height) act. A good seal between the spirals 10 . 18 and the floors 14 . 28 trained column is therefore in structurally relatively simple manner possible, since pressure-dependent widths of these gaps, as would occur in generic scroll compressors according to the prior art without complex compensation measures, such as the integration of a so-called medium pressure space, simply and safely by a suitable dimensioning of the housing parts 12 . 26 and thus the floors 14 . 28 connecting connecting means can be avoided.

LIST OF REFERENCE NUMBERS

10

Statorspirale

12

first housing part

14

flat housing section of the first housing part / bottom of the stator spiral

16

orbit axis

18

rotor spiral

20

shell-shaped housing portion of the first housing part

22

inlet channel

24

Connection opening of the inlet channel

26

second housing part

28

flat housing section of the second housing part / bottom of the rotor spiral

30

shell-shaped housing portion of the second housing part

32

Section of the second housing part

34

guide element

36

Guide recess of the guide element

38

guide pin

40

further housing section of the first housing part

42

boundary wall

44

Valve

46

Spring tab of the valve

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• US 2013/0115123 A1 [0003]
• DE 102013200807 A1 [0006]

Claims (8)

Spiral compressor with a stator spiral (10), with an orbiting drivable rotor spiral (18) and with one of the stator spiral (10) and the rotor spiral (18) associated bottom (14, 28), wherein the bottoms (14, 28) pressure chambers, the in the radial direction with respect to an orbital axis (16) of the rotor spiral (18) through the stator spiral (10) and the rotor spiral (18) are limited in the axial direction with respect to the orbital axis (16), characterized in that the rotor spiral (18) with respect the associated bottom (28) is arranged relatively movable. Spiral compressor according to Claim 1 , characterized in that the rotor spiral (18) and the stator spiral (10) in the axial direction with respect to the orbital axis (16) as free of play between the plates (14, 28) are arranged. Spiral compressor according to Claim 1 or 2 , characterized in that the rotor spiral (18) and / or the stator spiral (10) at least in the axial direction with respect to the orbital axis (16) is flexible and in particular elastically formed / are. Scroll compressor according to one of the preceding claims, characterized in that the bottom (28) of the rotor spiral (18) at least in the axial direction with respect to the orbital axis (16) immovable with the stator spiral (10) and / or with the bottom of the stator spiral (10) (14) is connected. Scroll compressor according to one of the preceding claims, characterized in that the base (14) associated with the stator spiral (10) and / or the bottom (28) associated with the rotor spiral (18) form a section of a housing of the spiral compressor. Scroll compressor according to one of the preceding claims, characterized in that a rotational axis of a drive for the rotor spiral (18) radially offset with respect to the orbital axis (16) is arranged. Scroll compressor according to one of the preceding claims, characterized in that the rotor spiral (18) is connected to a guide element (34), which surrounds this at least partially peripherally and forms an anti-twist device for the rotor spiral (18). Spiral compressor according to Claim 7 , characterized in that a drive for the rotor spiral (18) acts on the guide element (34).

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