SCROLL MACHINE AND VEHICLE AIR-CONDITIONING SYSTEM

Abstract

A scroll machine is particularly suited as a scroll compressor for refrigerant in a vehicle air-conditioning system. First and second scrolls are each formed with a base plate and with a spiral wall that projects from the base plate and follows a spiral line. The spiral wall of the second scroll engages in a spiral path formed by the first scroll and the spiral walls form a number of compressor chambers. The spiral walls have respective wall surface profiles in regions on their wall surfaces, with the wall surface profile being superposed on the spiral line. As the facing wall surface profile contacts a respective other spiral wall a contact normal at a point of contact, which contact normal extends obliquely with respect to a corresponding local normal of the corresponding first or second spiral line.

Claims

1. A scroll machine, comprising: a first scroll having a first base plate and a first spiral wall projecting from said first base plate, said first spiral wall following a first spiral line and forming a first spiral passage; a second scroll having a second base plate and a second spiral wall projecting from said second base plate, said second spiral wall following a second spiral line, engaging into said first spiral passage of said first scroll, and forming a number of conveying chambers together with said first spiral wall; said first and second spiral walls, in certain regions on an inner wall surface and an outer wall surface thereof, being formed with a wall surface profile that is superposed on the respective said spiral line and that is matched to a facing wall surface profile of the respectively opposite spiral wall, so that, during intended operation, a contact point between said mutually opposite spiral walls has a contact normal that extends obliquely relative to a corresponding local normal of the corresponding said first or second spiral line.

2. The scroll machine according to claim 1, wherein said wall surface profile defines a type of toothing between said first spiral wall and said second spiral wall during compressor operation.

3. The scroll machine according to claim 1, wherein the respective said wall surface profile is of continuous design.

4. The scroll machine according to claim 1, wherein the respective said wall surface profile is formed by a superposition of the respective said spiral line with a continuous wave shape.

5. The scroll machine according to claim 4, wherein the spiral line has a sinusoidal wave shape.

6. The scroll machine according to claim 1, wherein said first and second scrolls are co-rotating scrolls.

7. The scroll machine according to claim 6, wherein mutually facing wall surface profiles of said first and second spiral walls are matched to one another taking account of an orbiting radius.

8. The scroll machine according to claim 1, wherein a radial projection of the respective said wall surface profile undershoots a ratio of a radial height thereof to an orbiting radius.

9. The scroll machine according to claim 1, wherein, in a region of the superposed wall surface profiles, a contact region between said first and second spiral wall extends over an angular range of between zero and 30 degrees.

10. The scroll machine according to claim 9, wherein the angular range is 15 to 20 degrees.

11. The scroll machine according to claim 1, wherein the superposed said wall surface profiles extend over an angular range of at least 360 degrees.

12. The scroll machine according to claim 11, wherein the superposed said wall surface profiles extend over at least 360 degrees from an inlet in a compression direction.

13. The scroll machine according to claim 11, wherein a spiral center of said first and second spiral walls, said spiral center preferably covering an angular range of at least 90 degrees, is free from the respective said superposed wall surface profile.

14. The scroll machine according to claim 13, wherein said spiral center covers an angular range of at least 90 degrees.

15. The scroll machine according to claim 1 configured for a refrigerant of a vehicle air-conditioning system.

16. A vehicle air-conditioning system, comprising a scroll machine according to claim 1.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0045] FIG. 1 schematically shows a partial sectional detail illustration of a scroll machine according to the prior art;

[0046] FIG. 2 schematically shows a perspective illustration of a fixed scroll according to the prior art;

[0047] FIG. 3 schematically shows a partial sectional illustration of a section taken along the line III-Ill in FIG. 1 of the fixed scroll in a plan view of the latter and of a movable scroll inserted therein according to the prior art;

[0048] FIG. 4 shows a perspective side view of one exemplary embodiment of a according to the invention with an electromotive drive module and with a compressor module; and

[0049] FIG. 5 shows a view according to FIG. 3 of a part of the scroll machine according to FIG. 4.

[0050] Mutually corresponding parts and dimensions are provided with the same reference designations throughout the figures.

DETAILED DESCRIPTION OF THE INVENTION

[0051] Referring now to the figures of the drawing in detail and first, in particular, to FIGS. 1-3 thereof, there is shown customary, prior art scroll machine. Here, the scroll machine is used as a scroll compressor 2. The scroll compressor 2 is shown in a schematic partial sectional illustration in FIG. 1. The scroll compressor 2 has a movable scroll arranged in a (compressor) housing 4 (referred to as O-scroll 6). The O-scroll 6 is coupled eccentrically with respect to a drive shaft 7 by means of a shaft journal 8, which is in turn coupled by means of a joining pin 10, to the drive shaft 7 of an electric motor. The eccentric shaft journal 8 is mounted in a roller or ball bearing 12 held in the O-scroll 6. During (compressor) operation of the scroll compressor 2, the O-scroll 6 is driven in orbiting fashion on account of its eccentric coupling to the drive shaft 7.

[0052] The scroll compressor 2 also has a fixed scroll rigidly fastened in the housing 4 (referred to as F-scroll 14). Each of the two scrolls 6, 14 has a worm-shaped or spiral-shaped spiral wall (scroll spiral) 6a, 14a. These are each designed so as to follow an assigned spiral line 6b, 14b (see FIG. 3), which in the present exemplary embodiment represent an Archimedean spiral. The spiral walls 6a, 14a protrude axially from a respective base plate 6c, 14c. The spiral wall 14a of the F-scroll 14 forms an assigned spiral passage 14d. The spiral wall 6a of the O-scroll 6 engages into the latter. The F-scroll 14 furthermore has a peripherally closed delimiting wall 14e. Between the scrolls 6, 14, this means between the spiral walls 6a, 14a thereof and the base plates 6c, 14c, conveying chambers, referred to here as compressor chambers 16, are formed, the volume of which is changed during operation of the scroll compressor 2, specifically is reduced during compressor operation.

[0053] During operation, a gas-oil mixture is increasingly compressed due to the change in volume of the compressor chambers 16, as a result of which radial, azimuthal (tangential) and axial fluid forces act on the scroll parts 6, 14. In FIG. 1, the radial forces are illustrated as horizontal arrows and the axial forces as vertical arrows, the azimuthal forces acting approximately perpendicular to the plane of the drawing. The individual forces in the compressor chambers 16 result in a radial force FR and an axial force FA and a tangential force (not shown in any more detail). As a result of these forces, torques are also generated during operation, which act on the movably mounted O-scroll 6. Here, in particular, a torque which tilts the movable scroll 6 is generated, which causes an axial tilting or rolling motion of the movable scroll 6. This tilting is partially prevented by the base plate 6c of the O-scroll 6 being supported on the spiral wall 14a of the F-scroll 14. However, the tangential force leads to an intrinsic rotation of the O-scroll 6, which must be prevented.

[0054] In order to be able to better absorb the radially inwardly increasing pressure, the spiral wall 6a and the spiral wall 14a are formed with a wall thickness that increases inwardly toward the spiral center.

[0055] FIG. 2 shows a perspective illustration of the fixed F-scroll 14 of the scroll compressor 2, FIG. 3 showing the fixed scroll 14 with the inserted spiral wall 6a of the movable O-scroll 6 in a partial sectional illustration III-Ill. Two inlets 18a, 18b as entry openings for the gas-oil mixture are introduced into the delimiting wall 14e, a central outlet 20 as exit opening being arranged approximately centrally in the base plate 14c. As is apparent in particular in FIG. 3, the inlets 18a, 18b are arranged on a respective spiral start of the spiral walls 6a, 14a.

[0056] Between the delimiting wall 14e and the spiral outer side of the spiral profile of the spiral wall 14a, a radial chamber closure 22 is customarily provided, which extends from the inlet 18a in the spiral direction to the inlet 18b. As is apparent in particular in the plan view of FIG. 3, the F-scroll 14 has substantially no axial support for the base plate 6c of the O-scroll 6 in an angular range between the inlets 18a and 18b.

[0057] Referring now to FIGS. 4 and 5, we shall now describe an exemplary embodiment of a scroll compressor according to the invention in more detail. As will be seen, a tendency in particular of the O-scroll 6 toward intrinsic rotation, caused by the above-described tangential force, is avoided.

[0058] FIG. 4 shows one exemplary embodiment of the scroll compressor 2 designed according to the invention, which is installed for example as a refrigerant compressor in a refrigerant circuit of an air-conditioning system of a motor vehicle. The scroll compressor 2, which is an electromotive scroll compressor, has an electrical (electromotive) drive module 26 and a compressor module 28 coupled thereto. The compressor module 28 is connected in terms of a drive connection to the drive module 26 by way of a mechanical interface 30 formed between the drive module 26 and the compressor module 28. The mechanical interface 30 serves as an output-side (O-side) end shield and forms an intermediate wall 32 (see also FIG. 1). The compressor module 28 is connected (joined, screwed) to the drive module 26 by means of peripherally distributed flange connections 36 extending in an axial direction A of the scroll compressor 2.

[0059] A housing subregion of a drive housing 38 of the scroll compressor 2 is in the form of a motor housing 38a for receiving an electric motor (not shown in any more detail) and is closed on the one side by an integrated housing intermediate wall (not shown) to an electronics housing 38c which is provided with a housing cover 38b and which has a set of motor electronics (electronics) 40 controlling the electric motor and on the other side by the mechanical interface 30 with the end shield. The drive housing 38 has, in the region of the electronics housing 38c, a connection portion 42 with motor connections 42a and 42b, guided to the electronics 40, for the electrical contacting of the motor electronics 40 to an on-board electrical system of the motor vehicle.

[0060] The drive housing 38 has a refrigerant inlet or refrigerant feed 44 for connection to the refrigerant circuit and a refrigerant outlet 46. The outlet 46 is integrally formed on the bottom of the above-described (compressor) housing 4 of the compressor module 28. In the connected state, the inlet 44 forms the low-pressure side or suction side (suction-gas side) and the outlet 46 forms the high-pressure side or pump side of the scroll compressor 2.

[0061] Between the O-side end shield and the O-scroll 6, a counterpressure chamber (backpressure chamber) 50 is located in the intermediate wall 32 formed by the end shield (see FIG. 1). During operation, the refrigerant is introduced through the feed 44 into the drive housing 38 and there into the motor housing 38a. This region of the drive housing 38 forms the suction side or low-pressure side. Penetration of the refrigerant into the electronics housing 38c is prevented by means of the integrated housing intermediate wall. Within the drive housing 38, the refrigerant mixes with oil (usually oil mist) that is present in the refrigerant circuit, in particular in the region within the drive housing 38, and is sucked along the rotor and the stator of the electric motor through an opening (or multiple openings) in the intermediate wall 32 to the compressor module 28. The mixture of refrigerant and oil is compressed by means of the compressor module 28, wherein the oil serves to lubricate the two scrolls 6, 14, such that friction is reduced and efficiency is consequently increased. The oil also serves for sealing, in order to avoid uncontrolled escape of the refrigerant located between the two scrolls (scroll parts) 6, 14.

[0062] The compressed mixture of refrigerant and oil is conducted via the central outlet 20 in the base plate 14c of the fixed F-scroll 14 into a high-pressure chamber 52 (see FIG. 1) within the compressor housing 4. For example an oil separator (cyclone separator) is located in the high-pressure chamber 52. Within the oil separator, the mixture of refrigerant and oil is set into a rotational movement, wherein the oil, on account of its higher density compared with the gaseous refrigerant, is conducted to the walls of the oil separator and collected in a lower region of the oil separator, while the refrigerant is discharged upward or laterally through the outlet 46.

[0063] In order to then prevent the above-described intrinsic rotation of the O-scroll 6, according to the invention, as illustrated in FIG. 5, the spiral wall 6a and the spiral wall 14a are changed in relation to the embodiment according to FIGS. 2 and 3. In this case, the F-scroll 14 represents a first scroll and the O-scroll 6 represents a second scroll. The spiral wall 6a has an inner wall surface 60 and an outer wall surface 62. Correspondingly, the spiral wall 14a also has an inner wall surface 64 and an outer wall surface 66. Both the respective inner wall surface 60 and 64, respectively, and the respective outer wall surface 62, 66 have a profile (wall surface profile 68) which, by means of a superposition of the correspondingly assigned spiral line 6b and 14b, respectively, is formed with a further function or shape in such a way that contact between the two spiral walls 6a, 14a is not effected normal to the respective spiral line 6b and 14b, but rather at an angle. In other words, at this point an assigned contact normal 69 is oblique with respect to a normal 70 of the spiral line 6b, 14b at this point. As a result, at the contact point a tangentially acting force can be form-fittingly introduced into the two spiral walls 6a, 14a and thus a rotation of the two scrolls 6 and 14 in relation to one another can be prevented.

[0064] In the exemplary embodiment illustrated, the wall surface profiles 68 are formed in that a sinusoidal wave shape is superposed on the contourand thus also the respective spiral line 6b and 14bof the wall surfaces 60, 62, 64, 66. The roughly radially oriented projections 71 produced here by the wave crests form a type of tooth which, during intended compressor operation, slides on the inner side of the spiral wall 6a or 46a in the region of a corresponding recess 72 (a wave trough). It has been found that this increases a form-fitting engagement for the avoidance of the intrinsic rotation. In the present exemplary embodiment, such contact points between the two spiral walls 6a, 14a are present at two such points.

[0065] As is also apparent in FIG. 5, the amplitude, in particular the height or the spacing in relation to the respective spiral line 6b, 14b, of the wall surface profile 68 formed by the superposition is selected to be comparatively flat. The production of dead spaces when the two spiral walls 6a and 14a are sliding against one another is avoided as a result.

[0066] The wall surface profiles 68 of the respective mutually facing wall surfaces, that is to say of the wall surfaces 60 and 66 and of the wall surfaces 62 and 64, are also matched to one another. The respective recess 72 is thus designed to be larger, for example with a greater radius, so that the respectively assigned projection 71 (of the other spiral wall 6a or 14a) can slide therein. The dimensions of the recesses 72 differ here by the orbiting radius from the dimensions of the corresponding projections 71, specifically are enlarged by the orbiting radius. Here, the (dimensions of the) individual projections 71 are selected in such a way that the correspondingly enlarged recesses 72 do not reach as far as the spiral lines 6b, 14b.

[0067] The respective superposed wall surface profile 68 also extends merely over an angular range of approximately 360 degrees from a free or outer end of the respective spiral wall 6a or 14a in the direction of the spiral center. As a result, on the one hand, for a full revolution, a fit of the two spiral walls 6a and 14a against one another that prevents the intrinsic rotation is made possible, and, on the other hand, a situation is avoided in which, on account of the increasing curvature of the respective spiral wall 6a or 14a, the wavelength of the sinusoidal wave shape would be shortened and thus also the relative tooth height of the projections 71 would be increased, which is undesirable. Furthermore, by way of the projections 71 and recesses 72 being arranged on the outer side, a comparatively large lever arm can be used in order to prevent the intrinsic rotation by means of the form-fitting contacts.

[0068] It is recognized that a region specifically of the spiral wall 14a, in the region in which no contact by the O-scroll 6 can be effected on the outer side, does not need to be equipped with the wall surface profile 68 on the outer side.

[0069] It will be understood that the subject matter of the invention is not limited to the exemplary embodiments described above. Rather, other embodiments of the invention may be derived from the preceding description by a person skilled in the art. In particular, the individual features of the invention that are described on the basis of the various exemplary embodiments and the design variants thereof may also be combined with one another in some other way.

[0070] The following is a summary list of reference numerals and the corresponding structure used in the above description of the invention: [0071] 2 Scroll compressor [0072] 4 Housing [0073] 6 O-scroll [0074] 6a Spiral wall [0075] 6b Spiral line [0076] 6c Base plate [0077] 8 Shaft journal [0078] 10 Joining pin [0079] 12 Ball bearing [0080] 14 F-scroll [0081] 14a Spiral wall [0082] 14b Spiral line [0083] 14c Base plate [0084] 14d Spiral passage [0085] 14e Delimiting wall [0086] 16 Compressor chamber [0087] 18a Inlet [0088] 18b Inlet [0089] 20 Outlet [0090] 22 Chamber closure [0091] 26 Drive module [0092] 28 Compressor module [0093] 30 Interface [0094] 32 Intermediate wall [0095] 36 Flange connection [0096] 38 Drive housing [0097] 38a Motor housing [0098] 38b Housing cover [0099] 38c Electronics housing [0100] 40 Motor electronics [0101] 42 Connection portion [0102] 42a Motor connection [0103] 42b Motor connection [0104] 44 Refrigerant inlet [0105] 46 Refrigerant outlet [0106] 50 Counterpressure chamber [0107] 52 High-pressure chamber [0108] 60 Wall surface [0109] 62 Wall surface [0110] 64 Wall surface [0111] 66 Wall surface [0112] 68 Wall surface profile [0113] 69 Contact normal [0114] 70 Normal [0115] 71 Projection [0116] 72 Recess [0117] A Axial direction [0118] FA Axial force [0119] FR Radial force