Positive displacement machine, method, vehicle air conditioning system, and vehicle

Abstract

To provide a positive displacement machine which enables an improvement in generation of a pressure for pressing a displacement spiral against a counter spiral, and which allows a simple and cost-preferable structure of the positive displacement machine.SOLUTION: A positive displacement machine comprises a high-pressure chamber, a low-pressure chamber, an orbiting displacement spiral 13, a counter spiral 14, and a counter-pressure chamber, the counter-pressure chamber being located between the low-pressure chamber and the displacement spiral 13, the displacement spiral engaging in the counter spiral 14 in such a way that at least one first compression chamber 16a and one second compression chamber 16b for receiving a working medium are formed, and the displacement spiral 13 having at least one passage opening 17 for fluidic connection to the counter-pressure chamber, the passage opening 17 being located in the displacement spiral 13 in such a manner that, due to the orbiting movement of the displacement spiral 13, at least sections of the passage opening 17 are temporarily arranged at least partially in the first compression chamber 16a and at least partially in the second compression chamber 16b.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a displacement machine based on the spiral principle as defined in the preamble of claim 1. Furthermore, the invention relates to a method, a vehicle air conditioning system and a vehicle. [Background technology]

[0002] A displacement machine of the aforementioned type is known from DE 10 2017 110 913 A1. DE 10 2017 110 913 A1 describes a scroll compressor having a discharge helix and a counter helix. The discharge helix engages within the counter helix. The orbiting discharge helix forms a compression chamber in which the refrigerant is compressed. To enable the refrigerant to be compressed, the discharge helix must be tightly attached to the counter helix. Therefore, it is advantageous if the discharge helix is ​​pressed against the counter helix. For this purpose, a back-pressure chamber is arranged on the side of the discharge helix opposite the counter helix. This type of back-pressure chamber is also known as a back-pressure chamber. The back-pressure chamber or counter-pressure chamber serves to build up pressure. For this purpose, the discharge helix has an opening that fluidly connects the back-pressure chamber or counter-pressure chamber with the compression chamber. Pressure within the counter pressure chamber provides a force on the displacement helix that presses it against the counter helix, thereby sealing the two helices fluid-tightly against one another.

[0003] In known scroll compressors of the type mentioned at the outset, the pressure in the back pressure chamber must be great enough to press the discharge helix against the counter helix so that the discharge helix abuts fluid-tightly against the counter helix, but not so great that friction forces are generated that would dampen the orbital motion of the discharge helix or result in power losses.

[0004] Providing a sufficiently high pressure for the back pressure chamber in order to press the discharge spiral onto the counter spiral and minimize power losses is associated with constructional effort and expense. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] German Patent Application Publication No. 102017110913 Summary of the Invention [Problem to be solved by the invention]

[0006] It is therefore an object of the present invention to provide a displacement machine which improves the generation of pressure that presses the discharge spiral against the counter spiral, thereby enabling a simple and cost-effective construction of the displacement machine.It is also an object of the present invention to provide a method, a vehicle air conditioning system and a vehicle. [Means for solving the problem]

[0007] According to the invention, this problem is solved by: - for the displacement machine, the subject matter of claim 1 - in respect of the method, according to the subject matter of claim 14, - for vehicle air conditioning systems, by the subject matter of claim 15, and - in respect of the vehicle, by the subject matter of claim 16 It will be resolved.

[0008] Specifically, the problem is solved by a displacement machine, in particular a scroll compressor, based on the helix principle, which has a high-pressure chamber, a low-pressure chamber, an orbiting discharge helix, a counter helix, and a back-pressure chamber, the back-pressure chamber being arranged between the low-pressure chamber and the discharge helix. The discharge helix engages with the counter helix so that, during operation, at least one first and second compression chambers for receiving a working medium are formed, and the discharge helix has at least one through-opening for fluid connection with the back-pressure chamber. The through-opening is arranged in the discharge helix so that, during operation, the orbital movement of the discharge helix causes the through-opening to be temporarily located at least partially in the first compression chamber and then temporarily located at least partially in the second compression chamber.

[0009] The high pressure chamber is the region into which the compressed working medium enters before being fed back into the circulation, for example the cooling circulation.

[0010] The low pressure chamber may also be referred to as a suction chamber. From the low pressure chamber, gas flows radially outward between the counter spiral and the discharge spiral.

[0011] The orbital motion of the discharge helix is ​​a circular locus of motion.

[0012] The working medium is preferably a cooling fluid, particularly preferably a gaseous cooling fluid, such as CO2.

[0013] Between the counter spiral and the discharge spiral there are arranged at least one first compression chamber and a second compression chamber in which a working medium, e.g., a fluid, is arranged during operation.

[0014] Compression chambers are formed in the radially outer region. They move radially inward. As they move, their volumes decrease, increasing the pressure in the chambers or compressing the working medium. Finally, the chambers merge and then dissolve. This process continues.

[0015] The through opening moves on a circular path due to the orbital movement of the discharge spiral, and the circular path of the through opening intersects with the first and second compression chambers in such a way that the through opening is temporarily located at least partially in the first compression chamber and thereafter in the second compression chamber, and a fluid connection is formed with the back pressure chamber.

[0016] In other words, the passage opening passes over the first compression chamber and the second compression chamber as follows, i.e., the passage opening is temporarily, at least partially, located in the first and subsequently the second compression chamber, so as to form a fluid connection with the back pressure chamber.

[0017] The passage opening changes location from the first compression chamber to the second compression chamber due to the orbital movement of the discharge helix, thereby causing the back pressure chamber to alternately and temporarily be fluidly connected with the first compression chamber and then with the second compression chamber.

[0018] It is also possible that more than two compression chambers are formed between the discharge spiral and the counter spiral and that the passage openings are temporarily arranged at least partially in more than two compression chambers.

[0019] The invention is advantageous because, by arranging the passage openings in at least two different compression chambers in temporary succession with one another, it is possible to minimize the frictional forces that generate in the backpressure chambers to press the discharge spiral against the counter-spiral, thereby braking or otherwise negatively affecting the orbital movement of the discharge spiral, while at the same time ensuring that the discharge spiral is arranged in a sufficiently fluid-tight manner on the counter-spiral. The force acting from the discharge spiral to the counter-spiral is provided by the pressure prevailing in the backpressure chamber.

[0020] Therefore, other fluid connections for supplying pressure to the back pressure chamber and / or regulating the pressure in the back pressure chamber can be omitted. In other words, the through opening in the discharge spiral is sufficient to generate sufficient pressure in the back pressure chamber. This allows for a compact construction shape, since other fluid connections can be omitted. Furthermore, time and costs are saved due to the lower manufacturing effort and costs.

[0021] Preferred embodiments of the invention are set forth in the subclaims.

[0022] In a particularly preferred embodiment, the counter spiral has a spiral section, and the passage opening passes through at least one spiral section when changing from the first compression chamber to the second compression chamber, the spiral section being located between two radially adjacent compression chambers.

[0023] The helix section is the section of the counter helix or discharge helix that defines the first and second compression chambers.

[0024] The passage of the spiral section is advantageous because in this way the transition between the compression chambers can be defined and the arrangement of the passage openings in the two compression chambers can be carried out directly one after the other in time.

[0025] The concept of passing means crossing the helical section in a radial direction or in a direction having a radial component. The helical section can be crossed completely and / or partially.

[0026] In another particularly preferred embodiment, the passage opening is arranged in the bottom section of the discharge spiral.

[0027] Arranging the passage opening at the bottom of the discharge spiral is advantageous because it facilitates passage of the passage opening through the spiral section, and in this way a direct and as short as possible connection to the back pressure chamber can be achieved.

[0028] The bottom is a base plate from which the spiral section extends perpendicularly.

[0029] It is advantageous if the passage opening has a circular, elliptical or oval cross section. This allows various preferred shapes of the passage opening for adjusting the flow characteristics of the working medium. For example, the area of ​​the passage opening that is initially exposed when the spiral section passes through during operation can have a cross section that is larger than the area still covered by the spiral section. This allows a good fluid connection with the back pressure chamber to be formed before the passage opening is fully opened.

[0030] In a preferred embodiment, the first compression chamber is in fluid-guiding connection with the backpressure chamber within an angular range of the rotation angle of the orbiting discharge helix between 120° and 400°, in particular between 247° and 367°.

[0031] In another preferred embodiment, the second compression chamber is connected in a fluid-guiding manner to the backpressure chamber within an angular range of the rotation angle of the orbiting discharge helix between 270° and 550°, in particular between 376° and 504°.

[0032] The angular range of rotation angles over which the first and second compression chambers are connected with the back pressure chamber is advantageous because it allows fluid connection of the compression chambers and the back pressure chamber over as large a range as possible of the rotation angle of the respective orbiting discharge helix.

[0033] The angular regions for the first and second compression chambers are selected in such a way that the compression chambers are fluidly connected with the back pressure chamber only when the pressure in the first and second compression chambers is large enough to generate sufficient pressure in the back pressure chamber and to press the discharge spiral fluid-tightly against the counter spiral with little power loss.

[0034] Particularly preferably, the first compression chamber is fluidly connected with the back pressure chamber in a relative volume of between 84% and 40%, in particular between 80% and 46%.

[0035] Even more particularly preferably, the second compression chamber is fluidly connected with the back pressure chamber in a relative volume of between 61% and 19%, in particular between 44% and 24%.

[0036] The relative volume of a compression chamber is the variable volume of the compression chamber at a given time during the compression cycle of the displacement machine relative to its initial volume at 0° rotation angle. The smaller the relative volume of the compression chamber, the greater the pressure in each compression chamber.

[0037] The compression cycle is a cyclical process characterized by constantly new compression chambers being formed.

[0038] The relative volume areas in which the first and second compression chambers are fluidly connected with the back pressure chamber are advantageous because they allow each compression chamber to be fluidly connected with the back pressure chamber only when the pressure in the respective compression chamber is high enough to allow the discharge spiral to be pressed fluid-tight against the counter spiral.

[0039] In an embodiment, the passage opening is closed during the angular range of 5° to 20° of rotation angle when passing through the spiral section when changing from the first compression chamber to the second compression chamber or vice versa.

[0040] This makes it possible to keep the period during which the passage opening is closed as small as possible, or more precisely, so short that the effect on the pressure in the back pressure chamber is minimal, and therefore the period during which the passage opening is closed has no effect on the pressure in the back pressure chamber or on the pressure on the discharge spiral and therefore on the function of the displacement machine.

[0041] In another embodiment, the passage opening has a control geometry, which is arranged in the surface of the discharge spiral facing towards the counter spiral.

[0042] The control geometry, for example, together with the helical section, defines a fluid passageway that fluidly connects the through opening with the compression chamber before the through opening is disposed within the compression chamber. The control geometry allows the through opening to be fluidly connected with the compression chamber earlier or for a longer period of time, thereby reducing the period during which the through opening is blocked by the helical section.

[0043] It is advantageous if the control geometry comprises recesses and / or cutouts, whereby the control geometry can be produced simply by known manufacturing means and with little effort.

[0044] In a preferred embodiment, the helical section of the counter helix has a radially inner helical wall and a radially outer helical wall, and the control geometry and / or the passage opening is arranged between the helical walls in the closed state.

[0045] That is, the control geometry is preferably configured such that the first and second passage openings are not in fluid communication with each other at any point during the compression cycle, thereby preventing a pressure drop in the compression chamber.

[0046] In a preferred embodiment, the discharge spiral and / or the counter spiral has at least a partial chamfer, which partially reduces the width of the spiral section, thereby reducing the range of the rotation angle over which the passage opening must move to pass through the spiral section. The chamfer therefore makes it possible to shorten the period during which the passage opening is closed.

[0047] Within the scope of the present invention, furthermore, a method for driving a displacement machine is disclosed and claimed, in which the through-opening is temporarily arranged at least partially in the first compression chamber and then temporarily at least partially in the second compression chamber by the orbital movement of the discharge spiral during driving, and the respective compression chamber is connected in a fluid-conducting manner with the back pressure chamber.

[0048] Within the scope of the present invention, a vehicle air conditioning system with a displacement machine is disclosed and claimed.

[0049] In another aspect of the present invention, a vehicle having a displacement machine or vehicle air conditioning system according to the present invention is disclosed and claimed.

[0050] The present invention will now be described in detail by way of examples with reference to the accompanying drawings. [Brief explanation of the drawings]

[0051] [Figure 1] FIG. 1 shows a schematic cross section of the counter spiral and the discharge spiral of an embodiment according to the invention of a displacement machine. [Figure 2] FIG. 2 shows a schematic cross section of the counter spiral and the discharge spiral of an embodiment of the displacement machine according to the invention at a rotation angle of 0° during the compression cycle. [Figure 3] FIG. 3 shows a schematic cross section of the displacement machine shown in FIG. 2 at a rotation angle of 60°. [Figure 4] FIG. 4 shows a schematic cross section of the displacement machine shown in FIG. 2 at a rotation angle of 160°. [Figure 5] FIG. 5 shows a schematic cross section of the displacement machine shown in FIG. 2 at a rotation angle of 300°. [Figure 6] FIG. 6 shows a schematic cross section of the displacement machine shown in FIG. 2 at a rotation angle of 400°. [Figure 7] FIG. 7 shows a schematic cross section of the displacement machine shown in FIG. 2 at a rotation angle of 460°. [Figure 8] FIG. 8 shows a schematic cross section of the displacement machine shown in FIG. 2 at a rotation angle of 560°. [Figure 9] FIG. 9 shows a cross section of the discharge spiral of an embodiment of the displacement machine according to the invention. [Figure 10] FIG. 10 shows a cross section of an embodiment of the displacement machine according to the invention. [Figure 11] FIG. 11 shows another cross section of the displacement machine shown in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0052] FIG. 1 shows diagrammatically the arrangement of the discharge spiral 13 and counter spiral 14 in the displacement machine 10 .

[0053] The discharge spiral 13 and the counter spiral 14 are interlocked. The discharge spiral 13 and the counter spiral 14 have spiral sections 18 that are disposed perpendicularly on a base plate or bottom. The bottom or base plate is circular. The spiral section 18 extends away from the bottom or base plate. In the assembled state, the spiral section of the discharge spiral 13 extends toward the counter section, and the spiral section 18 of the counter spiral 14 extends toward the discharge spiral 13.

[0054] The counter spiral 14 is arranged in a fixed or immovable manner within the displacement machine 10. The discharge spiral 13 is arranged in the displacement machine 10 so as to be capable of orbital movement within the counter spiral 14. The structure of the displacement machine 10 is explained in more detail in the description of Figures 10 and 11. Orbital movement is movement on a circular path.

[0055] In the region of the center or center point of the counter spiral there is arranged an outlet opening 22. The outlet opening 22 is arranged eccentrically in the counter spiral 14.

[0056] The position of the discharge helix 13 during a compression cycle can be indicated by the rotation angle of the orbital motion. A compression cycle is one pass or cycle of the continuously repeated compression process. That is, Figure 1 shows a point in the compression cycle of the displacement machine 10 at a rotation angle of 181° of the discharge helix 13.

[0057] A passage opening 17 is arranged in the discharge spiral 13. The passage opening 17 is arranged in the bottom or base plate of the discharge spiral 13. The passage opening 17 is arranged centrally between the two spiral sections 18 of the discharge spiral 13. The passage opening 17 extends perpendicular to the surface of the bottom. In the assembled state, the passage opening 17 extends between the side of the base plate facing the counter spiral 14 and the side of the base plate facing away from the counter spiral 14. The passage opening 17 has an opening on each side of the base plate, connecting the two sides of the bottom or base plate. In other words, the passage opening 17 forms a passage between the two sides of the base plate. The passage opening 17 has a circular cross section. Other shapes are also possible. The passage opening 17 preferably has a hole. The diameter of the passage opening 17 is preferably between 0.1 mm and 1 mm.

[0058] The through opening 17 has a control geometry 19 for controlling the flow characteristics of the working medium.

[0059] The control geometry 19 extends substantially in the radial direction of the discharge spiral 13. In other words, the direction in which the control geometry 19 extends has a radial component. Alternatively, other shapes and directions of the control geometry 19 are possible. The control geometry 19 extends radially outward of the discharge spiral 13, starting from the through opening 17.

[0060] The control geometry 19 is located at the bottom of the discharge spiral 13 or on the surface of the base plate. The control geometry 19 does not penetrate the bottom of the discharge spiral 13.

[0061] The control geometry 19 has a slit. The slit is straight. At its radially inner end, a through opening 17 is arranged. At its radially outer end, the control geometry has a circular section. Other shapes are also possible. The control geometry 19 is preferably formed as a milled hole or a cut-out hole.

[0062] The helical section 18 of the counter helix 14 has a radially inner helical wall 20a and a radially outer helical wall 20b. The dimensions of the control geometry 19 and the passage opening 17 extend between the radially inner helical wall 20a and the radially outer helical wall 20b. The control geometry 19 and the passage opening 17 do not extend beyond the helical walls 20a, 20b. In other words, when the control geometry 19 and the helical section 18 are overlapped, the control geometry 19 and the passage opening 17 do not extend beyond the side walls 20a, 20b and are completely covered.

[0063] Between the discharge spiral 13 and the counter spiral 14, a first compression chamber 16a and a second compression chamber 16b are formed. The compression chambers 16a and 16b are used to receive and compress a working medium, which can be, for example, a gaseous coolant. The compression chambers 16a and 16b will be described in more detail below.

[0064] The discharge spiral 13 and the counter spiral 14 each have a chamfer 21 along their spiral walls 20a, 20b. The chamfer 21 extends over the entire spiral turn. Alternatively, the chamfer 21 can be arranged partially in the spiral section 18, i.e., when alternating between the two compression chambers 16a, 16b, the chamfer 21 can be arranged only in the region of the spiral section 18 where the passage opening 17 passes through the spiral section 18.

[0065] 2 to 8 show diagrammatically the various states of the compression cycle of the displacement machine 10. In the following, the relative positions of the discharge spiral 13 and the counter spiral 14 with respect to each other are described as snapshots with a line of sight to the geometrical arrangement of the respective components.

[0066] FIG. 2 shows a diagrammatic representation of the compression cycle with the discharge spiral 13 and counter spiral 14 engaging with each other at a rotation angle of 0°.

[0067] At a rotation angle of 0°, the compression cycle of the displacement machine 10 begins. A rotation angle of 0° describes a state in which at least one of the two compression chambers 16a, 16b is closed. At 0°, it is possible for both compression chambers to be closed.

[0068] The compression chamber is closed when it is surrounded fluid-tight by the discharge spiral 14 and the counter spiral 14.

[0069] The first compression chamber 16a is still open. The second compression chamber 16b is closed. The compression chambers 16a, 16b are located in the radially outer region of the spirals 13, 14. The other two compression chambers from the previous compression cycle, the first compression chamber 16c and the second compression chamber 16d, are formed in the radially inner region of the discharge spiral 13 and the counter spiral 14. The relative volumes of the compression chambers 16a, 16b are greater than the relative volumes of the compression chambers 16c, 16d.

[0070] An inner compression chamber 23 is located in the central region of the arrangement of the discharge spiral 13 and the counter spiral 14. The inner compression chamber 23 is formed from two joined compression chambers.

[0071] Additionally, two secondary outlet openings 22a, 22b or front outlet openings are arranged between the outlet opening 22 and the radially outer region of the counter-helix 14. The secondary outlet openings 22a, 22b have different radial distances from the center of the counter-helix 14.

[0072] Arranged in the discharge spiral 13 is a passage opening 17 with a control geometry 19. The passage opening 17 and the control geometry 19 are covered by a spiral section 18 of the counter spiral 14. The passage opening 17 is therefore closed.

[0073] Figure 3 shows a snapshot of the compression cycle when the rotation angle of the discharge spiral 13 is 60°. In Figure 3, the two compression chambers 16a, 16b are closed. The relative volumes of the compression chambers 16a, 16b in Figure 3 are smaller than the relative volumes of the compression chambers 16a, 16b in Figure 2.

[0074] The passage opening 17 and the control geometry 19 are arranged in the compression chamber 16d, in other words the passage opening 17 is not covered or closed by the helical section 18.

[0075] Figure 4 shows the compression cycle at a rotation angle of 160°, the relative volumes of the compression chambers 16a, 16b being smaller than in the previous figures.

[0076] The passage opening 17 is covered by a helical section 18 of the counter helix 14. The control geometry 19 partially projects into the first compression chamber 16a, so that the passage opening 17 is fluidly connected to the first compression chamber 16a.

[0077] Compression chambers 16c, 16d combine to form inner compression chamber 23.

[0078] Figure 5 shows the compression cycle at 300° of rotation. The relative volumes of the first and second compression chambers 16a, 16b have further decreased. New compression chambers 16e, 16f have begun to form in the radially outer regions of the two spirals.

[0079] The passage opening 17 and the control geometry 19 are located entirely within the first compression chamber 16a.

[0080] Figure 6 shows the compression cycle at a rotation angle of 400°. Two new compression chambers 16e, 16f are formed in the radially outer regions of the discharge spirals 13, 14. The relative volumes of the compression chambers 16a, 16b are further reduced. The through opening 17 and a section of the control geometry 19 are located in the second compression chamber 16b. Part of the control geometry 19 is covered by the spiral section 8 of the counter spiral 14. The outlet opening 22 is located partly in the inner compression chamber 23 and partly in the second compression chamber 16b.

[0081] Figure 7 shows the compression cycle at a rotation angle of 460°. The relative volumes of the first compression chamber 16a and the second compression chamber 16b are further reduced. The passage opening 17 and the control geometry 19 are located entirely within the second compression chamber 16b. The outlet opening 22 is located within the second compression chamber 16b. The outlet opening 22 is partially covered by the discharge spiral 13.

[0082] 8 shows the compression cycle at a rotation angle of 560° of the discharge spiral 14. The first compression chamber 16a and the second compression chamber 16b merge into an inner compression chamber 23. The outlet opening 22 is located entirely within the inner compression chamber 23. The through opening 17 and the control geometry 19 are located entirely within the newly formed first compression chamber 16e.

[0083] 9 shows a cross section of the discharge spiral 13 in the region of the passage opening 17 and the control geometry 19. The passage opening 17 extends linearly. The passage opening 17 extends perpendicular to the surface of the discharge spiral 13, the surface facing the counter spiral 14.

[0084] The control geometry 19 is arranged in the surface of the discharge spiral 13. In other words, the control geometry 19 has a recess. Possible embodiments of the control geometry 19 include, for example, a cutout hole or a milled hole. It is possible for the control geometry 19 to have a gap that is open in the direction of the counter spiral 14 and closed in the direction of the discharge spiral 13. The control geometry 19 extends along the radial direction of the discharge spiral 13. Other orientations and geometries of the control geometry are also conceivable, i.e., it is also possible for the control geometry 19 not to extend in a straight line.

[0085] 10 and 11 each show a cross section of an embodiment of a displacement machine 10 according to the invention.

[0086] The displacement machine 10 has a housing 24. The housing 24 has a cylindrical shape. A drive 25 is arranged in the housing 24. The drive 25 can be, for example, an electric motor or a mechanical drive 25. The drive 25 is connected to a shaft 26 and drives the shaft 26.

[0087] The shaft 26 extends in the longitudinal direction of the housing 24. An eccentric bearing 27 with an eccentric pin is arranged at the axial end of the shaft 26. The eccentric bearing 27 connects the discharge spiral 13 to the shaft 26.

[0088] A counter spiral 14 is arranged in the housing 24 on the side of the discharge spiral 13 opposite the eccentric bearing 27. The counter spiral 14 is arranged fixedly and immovably in the housing 24 of the displacement machine 10. It is possible for the counter spiral 14 to be formed integrally with the housing 24.

[0089] A low pressure chamber 12 is located on the opposite side of the discharge spiral 13 from the counter spiral 14. Between the low pressure chamber 12 and the discharge spiral 13, a back pressure chamber 15 is located.

[0090] The discharge spiral 13 is arranged in the housing 24 so as to be movable in a direction parallel to the longitudinal direction of the axis 26. In other words, the discharge spiral 13 is slidable towards and away from the counter spiral 14. A through-opening 17 is arranged at the bottom of the discharge spiral 13. Through the through-opening 17, the compression chamber 16 can be connected to the back pressure chamber 15 in a fluid-conducting manner during operation.

[0091] A high pressure chamber 11 is arranged on the opposite side of the counter spiral 14 from the discharge spiral 13 .

[0092] The nested spirals 13, 14 form a compression chamber 16. In other words, the compression chamber 16 is defined by the spiral sections 18 of the discharge spiral 13 and the counter spiral 14.

[0093] At the start of the compression cycle, a working medium, e.g., a refrigerant, is drawn into the radially outer region of the helices 13, 14. The working medium is transferred into the compression chambers 16a, 16b between the discharge helix 13 and the counter helix 14.

[0094] During operation, the rotation of the shaft 26 and the eccentric coupling of the shaft 26 with the discharge spiral 13 results in an orbital movement of the discharge spiral 13 .

[0095] The orbital movement of the discharge spiral 13 reduces the relative volume of the compression chambers 16. The compression chambers 16 are temporary. They are continuously and repeatedly formed in the outer radial region of the spiral, then moved radially inward, and then dissolved in the inner radial region of the spiral. The path of movement of the compression chambers 16 is helical. In the embodiment shown in Figures 2-8, up to five compression chambers 16, 23 are possible: two pairs of first and second compression chambers 16 and one inner compression chamber 23. Furthermore, configurations with more or fewer compression chambers 16, 23 are also possible.

[0096] The through opening 17 forms a fluid connection between the first compression chamber 16a and the back pressure chamber 15 within an angular range of rotation angles between 147° and 367°. Within an angular range of rotation angles between 376° and 504°, the through opening 17 forms a fluid connection between the second compression chamber 16b and the back pressure chamber 15. Within an angular range of rotation angles between 367° and 376°, the through opening 17 is closed by the helical section 18 of the counter helix 14.

[0097] The passage opening 17 is located first in the first compression chamber 16a of a compression cycle and then in the second compression chamber 16b. The passage opening 17 is located in one of the compression chambers 16a, 16b once per compression cycle. After the second compression chamber 16b, the passage opening 17 moves to the first compression chamber 16c of the following compression cycle.

[0098] Part of the working medium flows into the back pressure chamber 15 through the through opening 17. This increases the pressure in the back pressure chamber 15. This pressure exerts an axial force on the discharge spiral 13. This force acts in the direction of the counter spiral 14. The discharge spiral 13 is axially movable, so that it presses against the counter spiral 14. Pressing the discharge spiral 13 against the counter spiral 14 results in compression of the working medium with as little power loss as possible.

[0099] The control geometry 19 forms a fluid-guiding passage together with the side of the counter spiral 14 facing the discharge spiral during operation, so that a fluid-guiding connection can be formed between the compression chamber 16 and the backpressure chamber 15 before the through-opening 17 is located completely or partially in the compression chamber 16.

[0100] Through the outlet opening 22, the compressed working medium flows into the high-pressure chamber 11. Through the high-pressure chamber 11, the working medium again enters the working circuit, in particular the cooling circuit. During operation, the secondary outlet openings 22a, 22b are located in different pressure zones of the displacement machine 10 due to their different distances from the center point of the counter-helix 14.

[0101] The compression cycle will now be described with reference to Figures 2 to 8. In particular, the compression chambers 16a, 16b will be considered.

[0102] 2 shows the compression cycle at a rotation angle of 0°. At this rotation angle, one of the at least two compression chambers 16a, 16b is closed. In FIG. 2, no fluid connection is formed between one of the compression chambers 16 and the back pressure chamber 15, because the through opening 17 with the control geometry 19 is completely covered by the helical section 18.

[0103] At a rotation angle of 60° (see Figure 3), the first compression chamber 16a and the second compression chamber 16b are closed. The relative volumes of the compression chambers 16a, 16b decrease with increasing rotation angle. The passage opening 17 and the control geometry 19 move on a circular locus.

[0104] At a rotation angle of 160° (see FIG. 4), the passage opening 17 has been moved further. The passage opening 17 is covered by a helical section 18, which separates the first and second compression chambers 16a, 16b. The passage opening 17 is no longer located in the first compression chamber 16a.

[0105] The control geometry 19 of the through opening 17 is located partially within the first compression chamber 16a. The control geometry 19 and the helical section 18 define a passageway by which the back pressure chamber 15 is fluidly connected to the first compression chamber 16a.

[0106] 5, the through-opening 17 and the control geometry 19 are located entirely within the first compression chamber 16a. The working medium can flow directly through the through-opening 17 into the back-pressure chamber 15.

[0107] The pressure in the first compression chamber 16a is higher in Figure 5 than in the first compression chamber 16a in Figure 4. The pressure in the compression chambers 16a, 16b increases as their relative volumes decrease.

[0108] 6 shows that at a rotation angle of 400°, the through opening 17 is located in the second compression chamber 16b. The through opening 17 and the control geometry 19 pass through the helical section 18 of the counter helix 14. While passing through the helical section 18, the through opening 17 is closed by the helical section 18.

[0109] During the period when the back pressure chamber 15 is not connected to any compression chamber 16, the pressure in the back pressure chamber 15 does not drop enough to cause the discharge spiral 13 to no longer be pressed fluid-tight against the counter spiral 14.

[0110] Figure 7 shows the state of the compression cycle at a rotation angle of 460°. The passage opening 17 and the control geometry 19 are located entirely within the second compression chamber 16b. The first and second compression chambers 16a, 16b merge immediately before them to form the inner compression chamber 23. It can be seen in Figure 7 that a new compression cycle begins simultaneously with the ongoing compression cycle.

[0111] At a rotation angle of 560° (see FIG. 8), the first compression chamber 16a and the second compression chamber 16b are combined into an inner compression chamber 23. The through opening 17 and the control geometry 19 are arranged in the subsequent first compression chamber 16e of the new compression cycle.

[0112] Multiple compression cycles can be performed in parallel, with the first and second compression chambers 16a and 16b, and the first and second compression chambers 16c and 16d, corresponding to different compression cycles. In other words, each compression cycle has a pair of first and second compression chambers 16a and 16b. [Explanation of symbols]

[0113] 10 Pushing Machine 11. High-Pressure Chamber 12 Low-pressure chamber 13 Discharge spiral part 14 Counter spiral 15 Back pressure chamber 16a First compression chamber 16b Second compression chamber 16c First compression chamber 16d Second compression chamber 16e First compression chamber 16f Second Compression Chamber 17 Passage opening 18 Spiral Section 19 Control Geometry Configuration 20a Radial inner spiral wall 20b Radial outer spiral wall 21 Chamfered part 22 Exit opening 22a Secondary exit opening 22b Secondary exit opening 23 Inner compression chamber 24 Housing 25 Drive 26 axes 27 Eccentric bearing

Claims

1. 1. A displacement machine based on the helical principle, in particular a scroll compressor, comprising a high-pressure chamber (11), a low-pressure chamber (12), an orbiting discharge helix (13), a counter-helix (14) and a back-pressure chamber (15), the back-pressure chamber being arranged between the low-pressure chamber (12) and the discharge helix (13), the discharge helix (13) engaging into the counter-helix (14) so ​​as to form, temporarily during operation, at least one first compression chamber (16a) and a second compression chamber (16b) for receiving a working medium, the discharge helix (13) having at least one through-opening (17) for fluid connection with the back-pressure chamber (15), the through-opening (17) is arranged in the discharge spiral (13) in such a way that, during operation, the orbital movement of the discharge spiral (13) causes the through-opening (17) to be temporarily at least partially located in the first compression chamber (16a) and then temporarily at least partially located in the second compression chamber (16b).

2. 2. A displacement machine according to claim 1, characterized in that the counter spiral (14) has a spiral section (18), the through opening (17) passes through at least one spiral section (18) when alternating from the first compression chamber (16a) to the second compression chamber (16b), and the spiral section is arranged between two diametrically adjacent compression chambers (16a, 16b).

3. 3. A displacement machine according to claim 1 or 2, characterized in that the passage opening (17) is arranged in the bottom section of the discharge spiral (13).

4. 4. A displacement machine according to claim 1, wherein the passage opening (17) has a circular, elliptical or oval cross section.

5. 5. A displacement machine according to any one of claims 1 to 4, characterized in that the first compression chamber (16a) is in fluid-guiding connection with the back-pressure chamber (15) within an angular range of the rotation angle of the orbiting discharge spiral (13) of 120° to 400°, in particular 247° to 367°.

6. 6. A displacement machine according to any one of claims 1 to 5, characterized in that the second compression chamber (16b) is in a fluid-guiding connection with the back-pressure chamber (15) within an angular range of the rotation angle of the orbiting discharge spiral (13) of 270° to 550°, in particular 376° to 504°.

7. 7. A displacement machine according to any one of claims 1 to 6, characterized in that the first compression chamber (16a) is fluidly connected with the back pressure chamber (15) in a relative volume of between 84% and 40%, in particular between 80% and 46%.

8. 8. A displacement machine according to any one of claims 1 to 7, characterized in that the second compression chamber (16b) is fluidly connected with the back pressure chamber (15) in a relative volume of between 61% and 19%, in particular between 44% and 24%.

9. 9. A displacement machine according to any one of the preceding claims, characterized in that the passage opening (17) is closed over an angular range of a rotation angle of 5° to 20° when passing through the spiral section (18) when alternating from the first compression chamber (16a) to the second compression chamber (16b) or vice versa.

10. 10. A displacement machine according to any one of claims 1 to 9, characterized in that the passage opening (17) has a control geometry (19), which is arranged in the surface of the discharge spiral (13) facing towards the counter spiral (14).

11. 11. A displacement machine according to claim 10, characterized in that the control geometry (19) comprises recesses and / or notches.

12. 12. A displacement machine according to claim 10 or 11, characterized in that the helical section (18) of the counter-helix (14) has a radially inner helical wall (20a) and a radially outer helical wall (20b), and the control geometry (19) and / or the passage opening (17) is arranged between the helical walls (20a, 20b) in the closed state.

13. 13. A displacement machine according to any one of the preceding claims, characterized in that the discharge spiral (13) and / or the counter spiral (14) at least partially have a chamfer (21).

14. A method for driving a displacement machine according to any one of claims 1 to 13, comprising: A method for driving a displacement machine, wherein the through-opening (17) is temporarily located at least partially in the first compression chamber (16a) and then temporarily located at least partially in the second compression chamber (16b) by the orbital movement of the discharge spiral (13) during operation, and each compression chamber (16a, 16b) is connected to a back pressure chamber (15) in a fluid-conducting manner.

15. Vehicle air conditioning installation comprising a displacement machine, in particular a scroll compressor, according to any one of the preceding claims.

16. A vehicle comprising a displacement machine according to any one of claims 1 to 13 or a vehicle air conditioning system according to claim 15.

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