Device for controlling fluid mass flow for device for compressing gaseous fluid, and device for compressing gaseous fluid

Abstract

The invention relates to a device for controlling a fluid mass flow for a device for compressing a gaseous fluid from a low pressure level to a high pressure level. The device has a housing having a fluid interface and a closure element arranged in the housing so as to be translationally movable along a longitudinal axis, and the closure element has an active surface associated with the fluid interface. The closure element is designed to adjust a flow cross-section of a flow path extending between the first fluid connection and the second fluid connection. The device has a receiving element for receiving the closure element. The primary section as a first section of the closing element is surrounded by the receiving element and the secondary section as a second section of the closing element is surrounded by the housing and the receiving element by the housing. The secondary section is sealed with respect to the housing via a first sealing element and the primary section of the closure element is sealed with respect to the receiving element via a second sealing element and the receiving element is sealed with respect to the housing via a third sealing element in a fluid-tight and pressure-tight manner, respectively.

Description

Technical Field

[0001] The invention relates to a device for controlling a fluid mass flow of a device for compressing a gaseous fluid, in particular a regulating valve for a scroll compressor. The device for controlling a mass flow comprises a housing and a closing element which can be moved translationally along a longitudinal axis in the housing, the housing having a fluid connection loaded at different pressure levels, the closing element having an active surface associated with the fluid connection. The closing element is designed to adjust a flow cross section of a flow path extending between a first fluid connection and a second fluid connection.

[0002] The invention also relates to a device for compressing a gaseous fluid, in particular a scroll compressor for compressing a refrigerant, the device having a housing with a counter wall and a compression mechanism having an immovable fixed spiral and a movable coiled spiral driven via an eccentric drive. Scroll compressors are also called screw compressors. Background Art

[0003] Compressors known from the prior art for conveying refrigerant through a refrigerant circuit for mobile applications, in particular air conditioning systems of motor vehicles, also called refrigerant compressors, are usually designed in a refrigerant-independent manner as piston compressors with variable displacement or as scroll compressors. The compressors are driven via a belt pulley or electrically.

[0004] In addition to the housing, a conventional scroll compressor also has: an immovable fixed spiral part, which has a disk-shaped base plate and a spiral wall extending from one side of the base plate; and a movable coiled spiral part, which also has a disk-shaped base plate and a spiral wall extending from the front side of the base plate. Here, the base plates are arranged relative to each other so that the spiral walls engage with each other in the axial direction.

[0005] The fixed spiral portion and the coiled spiral portion act together. Here, the coiled spiral portion moves on a circular track with the aid of an eccentric drive, so that the spiral wall portion contacts at multiple locations, and a plurality of consecutive closed working spaces are formed between the wall portion and the base plate. The volumes of adjacent working spaces are not the same. Due to the movement of the coiled spiral portion relative to the fixed spiral portion, the volume and position of the working space change, so that the volume of the working space becomes smaller and smaller toward the center of the spiral wall portion, and the gaseous fluid enclosed in the working space is compressed. The fluid compressed in this way is discharged from the compression mechanism through at least one outlet. The associated pressure increase in the adjacent working space causes a force acting mainly in the axial direction on the coiled spiral portion, which also acts eccentrically on the coiled spiral portion, thereby generating a turning torque.

[0006] Furthermore, for sufficient internal sealing, the gap formed in the axial direction between the fixed spiral and the coiled spiral should be minimal, which is also ensured in conjunction with pressing the coiled spiral onto the fixed spiral.

[0007] The scroll compressor belonging to the prior art has a wall portion arranged in the housing and fixedly connected to the housing, which is formed as a delimiting portion of the back-pressure area, and is therefore also called a back-wall portion. Due to the back-pressure area, also called the back-pressure in the back-pressure chamber, formed between the back-wall portion and the coiled spiral portion, especially the back side of the substrate of the coiled spiral portion, the coiled spiral portion is pressed against the fixed spiral portion, which is also fixed to the housing like the back-wall portion, with a force acting in the axial direction. The pressure acting in the axial direction is regulated by the back-pressure, also called the pressing force, present in the back-pressure area. Here, the level of the pressing force as an intermediate pressure or medium pressure is between the level of the high pressure of the compressor as the outlet pressure and the level of the low pressure as the suction pressure. The value of the pressing force should be set so that on the one hand, the axial sealing surface between the coiled spiral portion and the fixed spiral portion is closed, and on the other hand, excessive friction between the fixed spiral portion and the coiled spiral portion that causes wear is avoided.

[0008] The areas of the compressor that are loaded with high pressure and counterpressure and the areas that are loaded with counterpressure and low pressure can each be connected to one another via flow channels with an integrated expansion device. A very limited mass flow of the fluid compressed in the compressor or a mixture of the fluid and oil as a lubricant for the compressor flows through the flow channels, which mass flow is also called the control mass flow. Conventional expansion devices are each designed as a nozzle. In this case, at least one expansion device can also be designed as a spring-loaded mechanical regulating valve.

[0009] A control flow regulating valve for a screw compressor in an air conditioning system of a motor vehicle is known from DE 10 2016 105 302 A1. The control flow regulating valve has a housing and a closing element arranged in the housing for setting the control flow. The housing is provided with fluid interfaces for high pressure, counterpressure, suction pressure and ambient pressure. The closing element for the control flow has an active surface associated with the corresponding fluid interface. Here, the force generated by the pressure applied to the closing element acts on the closing element, so that the control flow generating the counterpressure flows from the area of ​​the fluid loaded with the high pressure to the area of ​​the fluid loaded with the suction pressure. In addition, a fluid-tight area loaded with ambient pressure is formed, which is sealed by means of a metal sheet membrane or a vulcanized membrane welded to the metal closing element. A spring element is also provided in the housing, which is used to generate an additional force acting on the closing element.

[0010] The force balance at the closure element and its position for achieving the required counterpressure control curve in dependence on the high pressure and suction pressure or low pressure are influenced by the pressure exerted on the active surface and the flow through the through-opening released by the closure element.

[0011] The control flow regulating valve has two elastomer membranes formed on the low-pressure side and the counter-pressure side. The elasticity of the elastomer membranes enables the axial mobility of the closing element in the housing. The elastomer membranes delimit an area of ​​the control flow regulating valve in the axial direction which, due to the connection to the ambient pressure, has an atmospheric pressure that is independent of the low pressure and the counter-pressure. A fluid-tight and pressure-tight barrier is formed between the low-pressure side and the counter-pressure side by means of the elastomer membranes. The fluid-tight connection of the elastomer membranes is ensured by vulcanization on the surrounding housing or the closing element.

[0012] Devices known from the prior art for controlling a mass flow of a fluid as a control flow, in particular devices for compressing a gaseous fluid, have a large number of components connected to one another in a complex structure, which leads to a high complexity during installation with a large number of installation steps and thus to high installation costs. Thus, for example, a plurality of seals are required in order to separate different pressure levels from one another. In addition, the large number of components entails a high risk of errors occurring during the installation process. In addition, for example, vulcanizing membranes consisting of elastomers on metals is very expensive and complex and is particularly unsuitable for high-pressure applications, for example in systems with carbon dioxide as the fluid. Sealing with the aid of vulcanized membranes also leads to a high permeability surface, which can lead to a large outflow of fluid into the environment over the entire operating period, thus leading to very high losses of fluid.

[0013] In order to set the device, in particular the closing element, to the corresponding operating point and to achieve high reproducibility, it is necessary to emboss the sealing seat. During embossing, a defined force is applied to the closing element by means of a press, so that a corresponding sealing seat is formed on the housing by plastic deformation of the material. The embossing process usually consists of an iteration of embossing steps and tests until the desired pressure level is set, and, for example, according to DE 10 2016 105 302 A1, the embossing process is used to set the distance between the closing element and the elastomer film in order to relieve stresses in the elastomer film that occur due to stretching. Summary of the invention

[0014] The object of the present invention is to provide a device for controlling a fluid mass flow as a control flow of a device for compressing a gaseous fluid, in particular in order to ensure that the device for compressing a fluid operates without interruptions over a maximum service life. The device should have a minimum number of individual components and should be simple to implement in terms of construction, also in order to minimize the installation effort and costs during installation. The device should be designed to be fluid-tight in order to prevent leakage or outflow of the fluid into the environment, thereby preventing fluid losses in the system.

[0015] This object is achieved by the subject matter according to the invention. Improvements are provided in the invention.

[0016] The object is achieved by a device for controlling a fluid mass flow as a control flow according to the invention for compressing a gaseous fluid from a low pressure level to a high pressure level. The device for controlling a fluid mass flow comprises a housing and a closure element arranged in the housing so as to be translatably movable along a longitudinal axis, the housing having a fluid connection loaded at different pressure levels, the closure element having an active surface associated with the fluid connection. The closure element is designed to adjust the flow cross section of a flow path extending between a first fluid connection and a second fluid connection.

[0017] According to the concept of the invention, the device has a receiving element for receiving the closing element. The primary section as the first section of the closing element is surrounded by the receiving element and the secondary section as the second section of the closing element is surrounded by the housing. In addition, the receiving element is surrounded by the housing. Here, the secondary section of the closing element is sealed relative to the housing via at least one first sealing element, the primary section of the closing element is sealed relative to the receiving element via at least one second sealing element, and the receiving element is sealed relative to the housing via at least one third sealing element in a fluid-tight and pressure-tight manner.

[0018] The closing element is advantageously designed in one piece with the primary section and the secondary section as a continuous unit. The closing element and the receiving element can here each be a metallic or non-metallic component. The sealing element is preferably designed as an O-ring seal.

[0019] According to a refinement of the invention, the first fluid connection of the housing is loaded with fluid at a counterpressure level, the second fluid connection of the housing is loaded with fluid at a high pressure level, and the third fluid connection of the housing is loaded with fluid at a low pressure level. Here, the counterpressure level is an intermediate pressure level between the low pressure level and the high pressure level of the fluid. The fourth fluid connection of the housing is preferably loaded with an ambient pressure level, in particular ambient air.

[0020] According to a preferred development of the invention, the closure element is cylindrical, in particular circular cylindrical, with sections of different outer diameters, so that the closure element has a step between adjacent sections.

[0021] An advantage of the invention is that the closure element forms a sealing seat at a first end side, in particular an end side of the primary section, by means of the receiving element.

[0022] A volume bounded by the housing and a second end face of the closure element distal to the first end face, in particular the end face of the secondary section, is preferably acted upon by the ambient pressure level, in particular by ambient air, and is connected to the environment via a fourth fluid connection of the housing.

[0023] According to an advantageous design of the present invention, the primary section of the closure element is formed with a primary section diameter, and the secondary section of the closure element is formed with at least two sections having different outer diameters. Here, the primary section diameter of the closure element and the outer diameter of the secondary section can also be different from each other.

[0024] According to another preferred design of the present invention, a volume bounded by a housing, a receiving element and a closing element having an annular active surface is loaded with fluid at a low pressure level and is connected to a third fluid interface of the housing, wherein the active surface has a first outer diameter of the closing element and a primary section diameter of the closing element as an inner diameter.

[0025] Furthermore, a volume bounded by the housing and the closure element having an annular active surface having as inner diameters the first outer diameter and the second outer diameter of the closure element is acted upon by fluid at a counterpressure level and is connected to the first fluid connection of the housing.

[0026] According to a preferred improvement of the present invention, a first fluid connection is formed in the housing, which extends from the first fluid interface to a volume bounded by the housing and a closing element having an annular active surface, wherein the active surface has a first outer diameter of the closing element and a second outer diameter of the closing element as inner diameters.

[0027] A second fluid connection can also be provided in the housing, which extends from the first fluid connection to a volume bounded by the housing and a closure element having an annular active surface or to a third fluid connection of the housing, the active surface having as an inner diameter the first outer diameter of the closure element and the primary section diameter of the closure element. The second fluid connection is advantageously designed with an expansion element, in particular a throttle.

[0028] The device for controlling the fluid mass flow as the control flow is advantageously configured such that the translational movement of the closing element in the housing and the receiving element is based solely on the pressure acting on the effective surface of the closing element, thus on pressure. The defined pressure or piston force causes the closing element to move in a sliding seal, in particular in the form of an O-ring.

[0029] The object is also achieved by a device according to the invention for compressing a gaseous fluid from a low pressure level to a high pressure level, in particular a scroll compressor for compressing a refrigerant. Here, the fluid to be compressed is present in a suction region at a low pressure level, and the compressed fluid is present in a high pressure region at a high pressure level, specifically at the outlet of the device for compression. The device for compression has a housing with a counter-wall and a compression mechanism, the compression mechanism having an immovable fixed spiral portion and a movable coiled spiral portion driven via an eccentric drive. The housing with the counter-wall and the coiled spiral portion at least partially surround a counter-pressure chamber together. In addition, a flow path extending from the high pressure region to the counter-pressure chamber is formed.

[0030] According to the concept of the invention, the device according to the invention for controlling a fluid mass flow is formed in a flow path extending between a high-pressure region and a counter-pressure chamber.

[0031] An advantageous embodiment of the invention enables the use of a device for compressing a gaseous fluid as a compressor in a refrigerant circuit of an air conditioning system of a motor vehicle, the device having a device for controlling the mass flow of the fluid. The compressor can be designed to be electrically or mechanically driven. In this case, the compression mechanism is driven by means of an electric motor or a belt pulley.

[0032] Therefore, the device according to the invention for controlling a fluid mass flow as a control flow for compressing a gaseous fluid from a low pressure level to a high pressure level can be configured as a control flow regulating valve, in particular a control flow regulating valve of a scroll compressor of a refrigerant circuit of an air conditioning system of a motor vehicle.

[0033] In summary, the device according to the invention for controlling a fluid mass flow and the device for compressing a gaseous fluid having the device according to the invention for controlling a fluid mass flow have further diverse advantages:

[0034] - a minimum number of individual components and a simple design, thereby minimizing the complexity of assembly, production and maintenance and minimizing the costs of assembly, production and maintenance,

[0035] For example, no spring element is required in the device in contrast to the prior art, and the sealing seat is integrated into the receiving element without an additional molding step, and

[0036] - Maximum functional safety and tightness due to the minimum number of potential leakage paths to the environment - there is only one sealing point to the environment, which minimizes the outflow of refrigerant from the device for compression. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Further details, features and advantages of the invention are apparent from the following description of exemplary embodiments with reference to the accompanying drawings. The drawings show:

[0038] Figure 1 A schematic diagram of a device for controlling a fluid mass flow as a control flow of a device for compressing a gaseous fluid by means of an axial ambient pressure-impinging device according to the prior art is shown,

[0039] Figure 2 and Figure 3 1 and 2 show a schematic diagram of a device according to the invention for controlling a fluid mass flow as a control flow of a device for compressing a gaseous fluid,

[0040] Figure 4 The device according to the invention is shown in a perspective view, the device having a closing element and a receiving element, and

[0041] Figure 5 Show Figure 4 A top view of the device in FIG. 1 , and

[0042] Figure 6 The lateral sectional view shows a device for compressing a gaseous fluid having an integrated device for controlling a fluid mass flow as a control flow. DETAILED DESCRIPTION

[0043] from Figure 1 A schematic diagram of a device 1 ′ for controlling a fluid mass flow as a control flow, also referred to as a control flow regulating valve, is known from the prior art for compressing a gaseous fluid from a suction pressure level to a high pressure level by means of an axial ambient pressure loading device.

[0044] The device 1' has a housing 2', which has different fluid connections 2a', 2b', 2c', 2d'. A closing element 3' is arranged in the housing 2' so as to be translatably movable along a longitudinal axis 3a corresponding to the axis of symmetry of the closing element 3'. The device 1' is formed with a flow path, which extends from a first fluid connection 2a' to a second fluid connection 2b' and whose flow cross section can be adjusted by means of the closing element 3'. Here, the control flow of the fluid is adjusted from the high pressure level at the second fluid connection 2b' to the counterpressure level at the first fluid connection 2a' by means of the closing element 3'.

[0045] In addition, the housing 2' has a third fluid connection 2c', which has a suction pressure level of the device for compressing the fluid, also called a fluid at the low pressure level, and a fourth fluid connection 2d' with an ambient pressure level. In this case, the third fluid connection 2c' and the fourth fluid connection 2d' do not form a flow path. The third fluid connection 2c' and the fourth fluid connection 2d' are used to transmit the suction pressure level and the ambient pressure level to the corresponding active surfaces of the closure element 3'.

[0046] A membrane sealing element 4' is arranged between the closing element 3' and the housing 2', which delimits the area of ​​the device 1' in the direction of the longitudinal axis 3a and seals the device 1' with respect to the ambient pressure. Due to the connection to the ambient pressure level, the area delimited by the membrane sealing element 4' has an atmospheric pressure that is independent of the low pressure and the back pressure. The membrane sealing element 4' forms a fluid-tight and pressure-tight barrier in a combined manner between the low-pressure side connected to the third fluid connection 2c' and the back-pressure side connected to the first fluid connection 2a'.

[0047] Due to the membrane sealing element 4', which is designed as a welded sheet metal membrane or a vulcanized membrane between the closing element 3' and the housing 2', there is a high risk of leakage, so that there is a risk that the fluid will flow out into the environment via the fourth fluid connection 2d'. The device 1' has four potential leakage paths for the fluid into the environment. The membrane sealing element 4', which is made of an elastomer, is vulcanized on the closing element 3'.

[0048] In device 1' Figure 1 In the closed position shown in the figure, the closure element 3' is in contact with a sealing seat 6 formed at the housing 2', which has a sealing seat diameter d1. The sealing seat 6 is formed between the first fluid interface 2a' and the second fluid interface 2b'. The flow path extending between the fluid interfaces 2a', 2b' is closed. In a position of the device 1' that deviates from the closed position, the fluid flows from the second fluid interface 2b' to the first fluid interface 2a' through the flow path. Here, a flow resistance is generated by means of the adjusted narrow sealing seat 6, which causes a pressure loss of the fluid.

[0049] The device 1' further comprises a spring element 5', which is arranged in such a way that it acts on the closing element 3' by means of a spring force directed against the closed position of the closing element 3'. Thus, the spring element 5' forms a flow path extending between the device 1', in particular between the first fluid connection 2a' and the second fluid connection 2b', while compensating for forces acting on the closing element 3' due to different pressures.

[0050] The closure element 3' rests with the free end side of the primary section 3-1' oriented in the direction of the longitudinal axis 3a against the sealing seat 6 in such a way as to close the flow path extending between the first fluid connection 2a' and the second fluid connection 2b'. The primary section 3-1' of the closure element 3' interacts with the sealing seat 6 and the second fluid connection 2b'.

[0051] The closing element 3' is geometrically configured such that the primary section diameter d2, the sealing seat diameter d1, the first effective diameter d3' from the suction pressure level to the ambient pressure level, and the second effective diameter d4' from the back pressure level to the ambient pressure level are configured such that the generated force acts on the closing element 3' in a manner related to the respectively applied pressure level, thereby controlling the control flow of the fluid from the second fluid interface 2b' to the first fluid interface 2a'. The closing element 3' is brought to the corresponding position by force balance.

[0052] The device 1' is also provided with a first fluid connection 7, which extends from the first fluid interface 2a' to the volume surrounded by the closure element 3', in particular the following effective surface, and the housing 2', so that the counterpressure level is correspondingly incorporated into the force balance at the closure element 3', the effective surface having a second effective diameter d4' from the counterpressure level to the ambient pressure level. In addition, a second fluid connection 8 is provided, which connects the first fluid interface 2a' to the third fluid interface 2c' and extends between the first fluid interface 2a' and the volume surrounded by the closure element 3', in particular the following effective surface, and the housing 2', the effective surface having a first effective diameter d3' from the suction pressure level to the ambient pressure level. An expansion element 9, in particular a throttling element or a throttle valve, is arranged in the second fluid connection 8.

[0053] The primary section 3 - 1 ′ of the closure element 3 ′ is sealed relative to the housing 2 ′ by means of a sealing element 10 ′ designed as an O-ring.

[0054] exist Figure 2 and Figure 3 1 and 2 show the schematic circuit diagrams of a device 1 according to the invention for controlling a fluid mass flow as a control flow for compressing a gaseous fluid from a suction pressure level to a high pressure level by means of an axial ambient pressure loading device at the end side of a piston-shaped closure element 3 in a housing 2, while Figure 4 In the figure the device 1 according to the invention is shown in a perspective view with a closing element 3 and a receiving element 11 and in Figure 5 In FIG. 1 , the device 1 is shown in a top view of the receiving element 11 , without the housing 2 in each case. Figure 1 Compared to the device 1 ′ according to the prior art shown in FIG. 1 , identical components are respectively provided with the same reference numerals.

[0055] The device 1 has a housing 2, which has various fluid connections 2a, 2b, 2c, 2d. The fluid connections 2a, 2b, 2c, 2d are also to be understood as flow channels formed in components of the device 1. The closing element 3 and the connection for the closing element 3 are Figure 2 A receiving element 11 (not shown) is integrated into the housing 2 .

[0056] The closing element 3, which is partially arranged in the housing 2 and the receiving element 11, can be moved translationally along the longitudinal axis 3a as the symmetry axis of the closing element 3. The closing element 3 is formed with a primary section 3-1 guided in the receiving element 11 and a secondary section 3-2 guided in the housing 2. Here, the closing element 3 is provided with the primary section 3-1 in the receiving element 11, and the receiving element 11 is arranged in the housing 2, while the closing element 3 is provided with the secondary section 3-2 in the housing 2.

[0057] The closing element 3 is designed in one piece in the form of a cylinder, in particular a circular cylinder, with a primary section 3 - 1 and a secondary section 3 - 2 , with sections having different outer diameters.

[0058] The device 1 has a flow path extending between a first fluid connection 2a at the counterpressure level of the device and a second fluid connection 2b at the high pressure level for compressing a gaseous fluid, the flow cross section of which can be adjusted by moving a closing element 3. The closing element 3 is used to adjust the control flow of the fluid.

[0059] according to Figure 2 and Figure 3 The closure element 3 is abutted against the sealing seat 6 with a first free end side oriented in the direction of the longitudinal axis 3a in a manner closing the flow path extending between the first fluid connection 2a and the second fluid connection 2b. The sealing seat 6 is formed in the receiving element 11 of the device 1. The closure element 3 cooperates with the sealing seat 6 and the second fluid connection 2b.

[0060] The housing 2 also has a third fluid connection 2c, which has a fluid at the suction pressure level or low pressure level of the device for compressing the fluid, and a fourth fluid connection 2d with the ambient pressure level. The third fluid connection 2c and the fourth fluid connection 2d are only used to transmit the suction pressure level and the ambient pressure level to the corresponding active surfaces of the closure element 3.

[0061] Two first sealing elements 10-1 are arranged between the closing element 3 and the housing 2, a second sealing element 10-2 is arranged between the closing element 3 and the accommodating element 11, and a third sealing element 10-3 is arranged between the accommodating element 11 and the housing 2, and the third sealing elements 10-3 respectively limit the volumes of the device 1 loaded with different pressures in the direction of the longitudinal axis 3a and seal them relative to each other.

[0062] The piston-shaped closing element 3 is acted upon by ambient pressure at a second end side distal to a first end side, which is oriented relative to the sealing seat 6. In this case, the volume bounded by the housing 2 and the second end side of the closing element 3 is acted upon by the ambient pressure level. As a result, the volume connected to the environment via the fourth fluid connection 2d has a pressure level that is independent of the low pressure level and the counterpressure level.

[0063] On device 1 Figure 2 and Figure 3 In the closed position shown in FIG, the closure elements 3 each rest against a sealing seat 6 formed on the receiving element 11 and having a sealing seat diameter d1. The flow path extending between the first fluid port 2a and the second fluid port 2b is closed.

[0064] The closing element 3 is geometrically configured so that the primary section diameter d2, the sealing seat diameter d1, the first outer diameter d3 from the suction pressure level to the counterpressure level, and the second outer diameter d4 from the counterpressure level to the ambient pressure level are configured so that the generated force acts on the closing element 3 in a manner related to the pressure applied respectively, thereby controlling the control flow of the fluid from the second fluid interface 2b to the first fluid interface 2a. Through force balance, the closing element 3 is brought to the corresponding position respectively. The primary section diameter d2 and the outer diameters d3 and d4 of the closing element 3 are respectively configured so that the counterpressure level that occurs is particularly sufficient to press the coiled spiral portion as required to the fixed spiral portion of the compression mechanism of the scroll compressor as a device for compressing gaseous fluids.

[0065] according to Figure 2 and Figure 3 The device 1 also has a first fluid connection 7, which extends from the first fluid interface 2a to the volume surrounded by the closure element 3, in particular the following active surface and the housing 2, so that the counterpressure level is correspondingly included in the force balance at the closure element 3. In addition, a second fluid connection 8 is provided, which connects the first fluid interface 2a to the third fluid interface 2c and extends between the first fluid interface 2a and the volume surrounded by the closure element 3, in particular the following active surface and the housing 2, and the active surface has a first outer diameter d3 from the suction pressure level to the counterpressure level. An expansion element 9 is arranged in the second fluid connection 8.

[0066] The volume enclosed by the closure element 3 , in particular the second end side having the effective surface with the second outer diameter d4 , and the housing 2 and connected to the fourth fluid connection 2 d and thus loaded with the ambient pressure level serves to reduce the effective surface of the counterpressure acting in the closed position of the closure element 3 .

[0067] At the first end face of the closure element 3 , counter to the closed position of the closure element 3 , there also acts the high pressure level present in the second fluid connection 2 b and the reduced counterpressure level present at the sealing seat 6 due to the sealing gap formed between the closure element 3 and the receiving element 11 .

[0068] The first sealing element 10-1, which is designed as an O-ring, forms a fluid-tight and pressure-tight barrier between the volume loaded with the ambient pressure level and the counterpressure level and between the volume loaded with the counterpressure level and the suction pressure level, respectively, while the second sealing element 10-2, which is designed as an O-ring, forms a fluid-tight and pressure-tight barrier between the volume loaded with the suction pressure and the first fluid interface 2a. Thus, the first sealing element 10-1, which is arranged between the volume loaded with the ambient pressure level and the counterpressure level, only constitutes a sealing device of the device 1 relative to the environment.

[0069] exist Figure 6 1 shows a device for compressing a gaseous fluid, in particular an electrically driven compressor 20, specifically a scroll compressor, in a lateral sectional view, which has an integrated device 1 for controlling a fluid mass flow as a control flow. The compressor 20 is formed with a compression mechanism 21 and an electric motor 22 for driving the compression mechanism 21.

[0070] The compression mechanism 21 formed with a fixed spiral portion 21a and a coiled spiral portion 21b and the motor 22 are arranged in a volume surrounded by the housing 2. Here, the housing 2 is formed by housing elements, which are particularly used to accommodate the compression mechanism 21 and the motor 22, and the housing 2 is preferably formed of metal, such as aluminum.

[0071] The electric motor 22 has a stator 22a having a substantially hollow cylindrical stator core, a coil wound on the stator core, and a rotor 22b disposed in the stator 22a. When electric energy is supplied to the coil of the stator 22a, the rotor 22b is set in rotational motion. The rotor 22b is coaxially disposed in the stator 22a and is rotatably disposed around a rotation axis 23. The drive shaft 24 may be formed integrally with the rotor 22b or as a separate element.

[0072] The coiled spiral 21b of the compression mechanism 21, in which a gaseous fluid, in particular a refrigerant, is compressed, is driven via a drive shaft 24 connected to a rotor 22b of an electric motor 22. The fluid compressed to a high pressure level when flowing through the compression mechanism 21 is discharged from the compression mechanism 21 through at least one outlet 25 into a high pressure level region 20b of the compressor 20.

[0073] The compressor 20 also has a wall portion arranged in the housing 2 and fixedly connected to the housing 2, which wall portion is formed as a limit portion of the counter-pressure level region 20a of the compressor 20, which is also known as the counter-pressure region, and therefore the wall portion is also called the counter-wall portion 26. In the counter-pressure level region 20a formed between the counter-wall portion 26 and the coiled spiral portion 21b, in particular the back side of the base plate of the coiled spiral portion 21b, there is a fluid at the counter-pressure level, which is also the level of the pressing force as the intermediate pressure between the level of the high pressure as the outlet pressure and the level of the low pressure as the suction pressure of the compressor 20. Here, the fluid in the low-pressure level region 20c of the compressor 20 has a low-pressure level, and the electric motor 22 is also arranged in the low-pressure level region. There is an ambient pressure outside the housing 2 of the compressor 20, so that the environment is also called the ambient pressure level region 20d of the compressor 20.

[0074] The device 1 for controlling a fluid mass flow is preferably integrated in a cavity of a housing 2 of a device for compressing a gaseous fluid, in particular a compressor 20. In this case, a first sealing element 10-1 is arranged between the closing element 3 and the housing 2, and a second sealing element 10-2 is arranged between the closing element 3 and the receiving element 11, while the pressure space formed between the receiving element 11 and the housing 2 is sealed relative to each other by means of a third sealing element 10-3 formed as an O-ring. The receiving element 11 of the closing element 3 of the device 1 is sealed relative to the housing 2 via the third sealing element 10-3. In this case, the third sealing element 10-3 forms a fluid-tight and pressure-tight barrier between volumes loaded with a suction pressure level and a high pressure level, in particular between a low pressure level region 20c and a high pressure level region 20b of the compressor 20, and between volumes loaded with a high pressure level and a counterpressure level, in particular between a high pressure level region 20b and a counterpressure level region 20a of the compressor 20. The counterpressure level regions 20a are respectively connected to each other via a first fluid connection 7.

[0075] Reference numerals list

[0076] 1,1' equipment

[0077] 2,2' shell

[0078] 2a, 2a' First fluid connection at the back pressure level

[0079] 2b, 2b' Second fluid connection at high pressure level

[0080] 2c, 2c' Third fluid connection at low pressure / suction pressure level

[0081] 2d, 2d' Fourth fluid connection at ambient pressure level

[0082] 3,3' closing element

[0083] 3a Longitudinal axis

[0084] 3-1, 3-1' Primary section of closing element 3, 3'

[0085] 3-2 Secondary section of closing element 3

[0086] 4' membrane sealing element

[0087] 5' Spring element

[0088] 6 Sealing seat

[0089] 7 First fluid connection

[0090] 8 Second fluid connection

[0091] 9 Expansion element

[0092] 10-1 First sealing element

[0093] 10-2 Second sealing element

[0094] 10-3 Third sealing element

[0095] 10' Sealing element

[0096] 11 Accommodating components

[0097] 20 Compressor

[0098] 20a Back pressure level area

[0099] 20b High pressure horizontal area

[0100] 20c Low pressure / suction pressure level area

[0101] 20d Ambient pressure level area

[0102] 21 Compression mechanism

[0103] 21a Fixed spiral part

[0104] 21b Coiled helix

[0105] 22 Electric Motor

[0106] 22a Stator

[0107] 22b Rotor

[0108] 23 Rotation axis

[0109] 24 Drive shaft

[0110] 25 Exit

[0111] 26 Anti-wall

[0112] d1 Sealing seat diameter

[0113] d2 Primary section diameter

[0114] d3 first outer diameter

[0115] d3' first acting diameter

[0116] d4 Second outer diameter

[0117] d4' Second effective diameter

Claims

1. A device (1) for controlling a fluid mass flow, for compressing a gaseous fluid from a low pressure level to a high pressure level, the device for controlling a fluid mass flow comprising a housing (2) and a closing element (3) arranged in the housing (2) so as to be translatably movable along a longitudinal axis (3a), the housing having fluid interfaces (2a, 2b, 2c, 2d) loaded at different pressure levels, the closing element having an active surface associated with the fluid interfaces (2a, 2b, 2c, 2d), wherein the closing element (3) is designed to adjust a flow cross section of a flow path extending between a first fluid interface (2a) and a second fluid interface (2b), characterized in that The device (1) has a receiving element (11) for receiving the closure element (3), wherein a primary section (3-1) as a first section of the closure element (3) is surrounded by the receiving element (11) and a secondary section (3-2) as a second section of the closure element (3) is surrounded by the housing (2), and the receiving element (11) is surrounded by the housing (2), respectively, wherein the secondary section (3-2) of the closure element (3) is sealed relative to the housing (2) via at least one first sealing element (10-1), and the primary section (3-1) of the closure element (3) is sealed relative to the receiving element (11) via at least one second sealing element (10-2), and the receiving element (11) is sealed relative to the housing (2) via at least one third sealing element (10-3), respectively, in a fluid-tight and pressure-tight manner.

2. The device (1) according to claim 1, characterized in that The closure element (3) is formed integrally with the primary section (3-1) and the secondary section (3-2).

3. The device (1) according to claim 1 or 2, characterized in that The sealing elements (10-1, 10-2, 10-3) are each designed as an O-ring seal.

4. The device (1) according to any one of claims 1 to 3, characterized in that The first fluid connection (2a) of the housing (2) is designed for a fluid to be acted upon at a counter-pressure level, and the second fluid connection (2b) of the housing (2) is designed for a fluid to be acted upon at a high-pressure level.

5. The device (1) according to any one of claims 1 to 4, characterized in that The third fluid connection (2c) of the housing (2) is designed to be acted upon by a fluid at a low pressure level.

6. The device (1) according to any one of claims 1 to 5, characterized in that The fourth fluid connection (2d) of the housing (2) is designed to be acted upon by the ambient pressure level.

7. The device (1) according to any one of claims 1 to 6, characterized in that The closure element (3) is cylindrical, in particular circular cylindrical, with sections of different outer diameters.

8. The device (1) according to claim 7, characterized in that The closure element (3) forms a sealing seat (6) at a first end side by means of the receiving element (11).

9. The device (1) according to claim 8, characterized in that A volume delimited by the housing (2) and a second end face of the closure element (3) distal to the first end face is designed to be acted upon by the ambient pressure level and to be connected to the environment via a fourth fluid connection (2d) of the housing (2).

10. The device (1) according to any one of claims 7 to 9, characterized in that The primary section (3-1) of the closure element (3) is formed with a primary section diameter (d2), and the secondary section (3-2) of the closure element (3) is formed with at least two sections each having a different outer diameter (d3, d4).

11. The device (1) according to claim 10, characterized in that The volume bounded by the housing (2), the receiving element (11) and the closing element (3) having an annular active surface is constituted to be loaded with a fluid at a low pressure level and is connected to a third fluid interface (2c) of the housing (2), the active surface having a first outer diameter (d3) of the closing element (3) and a primary section diameter (d2) of the closing element (3) as an inner diameter.

12. The device (1) according to claim 10 or 11, characterized in that A volume bounded by the housing (2) and the closing element (3) having an annular active surface, the active surface having as an inner diameter a first outer diameter (d3) of the closing element (3) and a second outer diameter (d4) of the closing element (3), is formed to be loaded with a fluid at a counterpressure level and is connected to a first fluid connection (2a) of the housing (2).

13. The device (1) according to claim 12, characterized in that A first fluid connection (7) is formed, which extends from the first fluid connection (2a) to a volume bounded by the housing (2) and the closing element (3) having an annular active surface, the active surface having a first outer diameter (d3) of the closing element (3) and a second outer diameter (d4) of the closing element (3) as an inner diameter.

14. The device (1) according to any one of claims 11 to 13, characterized in that A second fluid connection (8) is formed, which extends from the first fluid connection (2a) to a volume bounded by the housing (2) and the closing element (3) having an annular active surface, the active surface having a first outer diameter (d3) of the closing element (3) and a primary section diameter (d2) of the closing element (3) as an inner diameter.

15. The device (1) according to claim 14, characterized in that An expansion element (9), in particular a throttle, is arranged in the second fluid connection (8).

16. A device for compressing a gaseous fluid from a low pressure level to a high pressure level, in particular a compressor (20), specifically a scroll compressor, the device having a housing (2) with a counter wall (26) and a compression mechanism (21), the compression mechanism having an immovable fixed spiral (21a) and a movable coiled spiral (21b) driven via an eccentric drive, wherein the housing (2) with the counter wall (26) and the coiled spiral (21b) are configured to at least partially surround a counter-pressure chamber, and a flow path extending from the high pressure area to the counter-pressure chamber is configured, characterized in that A device (1) for controlling a fluid mass flow according to any one of claims 1 to 15 is formed in the flow path extending between the high-pressure region and the counter-pressure chamber.

17. Use of a device according to claim 16 for compressing a gaseous fluid in a refrigerant circuit of an air-conditioning system of a motor vehicle, the device having a device (1) for controlling a fluid mass flow.

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