Device for regulating a mass flow rate of fluid for a device for compressing a gaseous fluid and device for compressing a gaseous fluid

Abstract

Device for regulating a mass flow rate of fluid for a device for compressing a gaseous fluid and device for compressing a gaseous fluid The invention relates to a device (1) for regulating a mass flow rate of fluid for a device for compressing a gaseous fluid from a low pressure level to a high pressure level, which is provided with a housing (2) provided with fluid connections (2a, 2b, 2c, 2d) subjected to different pressure levels, and with a closing element (3) arranged to be movable in translation within the housing (2) along a longitudinal axis (3a), provided with effective or active surfaces associated with the fluid connections (2a, 2b, 2c, 2d). The closing element (3) is configured to regulate a flow section of a flow path extending between a first fluid connection (2a) and a second fluid connection (2b).The housing (2) is provided with a receiving opening (11) for receiving the closing element (3), which is formed in at least two parts by a primary segment (3-1) and a secondary segment (3-2) which are each guided within the receiving opening (11) of the housing (2) and are each arranged to be completely surrounded by the housing (2). Figure to be published with the abstract: Fig. 3.

Description

Title of the invention: Device for regulating a mass flow rate of fluid for a device for compressing a gaseous fluid and device for compressing a gaseous fluid

[0001] The invention relates to a device for regulating a mass flow rate of fluid serving as a control flow rate for a device for compressing a gaseous fluid, more particularly a control valve for a spiral-orbital compressor. The device for regulating the control mass flow rate is provided with a housing provided with fluid connections subjected to different pressure levels, and with a closing element movable in translation within the housing along a longitudinal axis, provided with effective or active surfaces associated with the fluid connections. The closing element is configured to regulate a flow 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, more particularly a spiral-orbital compressor for compressing a refrigerant fluid, provided with a housing with a counter-wall and a compression mechanism with a stationary fixed scroll and a mobile orbital scroll driven by means of an eccentric drive. The spiral-orbital compressor is also called a scroll compressor.

[0003] Compressors for mobile applications known in the state of the art, more particularly for air conditioning systems of motor vehicles, intended to convey a refrigerant through a refrigerant circuit, also called refrigerant compressors, often take the form of variable displacement piston compressors or spiral orbital compressors, regardless of the refrigerant. The compressors are driven either by means of a pulley or electrically.

[0004] In addition to a housing, conventional spiral-orbital compressors are provided with a stationary fixed scroll having a disc-shaped base plate and a spiral-shaped wall extending from one side of the base plate and a movable orbiting scroll also having a disc-shaped base plate and a spiral-shaped wall extending from a front side of the base plate. The base plates are arranged with each other in such a way that the spiral-shaped walls interlock in the axial direction.

[0005] The fixed spiral and the orbiting spiral work together. The orbiting spiral describes a circular path thanks to an eccentric drive, so as to make the spiral-shaped walls touch at several points and to provide several successive sealed working spaces between the walls and the base plates. The volumes of adjacent working spaces are of variable size. The movement of the orbiting scroll relative to the fixed scroll changes the volumes and positions of the working spaces, so that the volumes of the working spaces gradually reduce towards the center of the spiral-shaped walls to thereby compress a gaseous fluid enclosed in the working spaces. The fluid thus compressed is discharged from the compression mechanism through at least one outlet. The associated increase in pressure in adjacent working spaces generates a force acting on the orbiting scroll, mainly in the axial direction, which also acts eccentrically on the orbiting scroll and thus generates a tilting moment.

[0006] Furthermore, the spaces provided in the axial direction between the fixed spiral and the orbiting spiral must be minimal to ensure sufficient internal sealing, this also being ensured by pressure of the orbiting spiral against the fixed spiral.

[0007] The spiral-orbital compressors belonging to the state of the art are provided with a wall arranged within the housing and firmly fixed thereto, and forming a boundary of a backpressure zone. This wall is therefore also called a counter-wall. Due to the backpressure prevailing within the backpressure zone arranged between the counter-wall and the orbiting scroll, more particularly a rear side of the base plate of the orbiting scroll, also called a backpressure chamber, the orbiting scroll is pressed against the fixed scroll, which, like the counter-wall, is fixed to the housing, by a force acting in the axial direction. The pressure force acting in the axial direction is regulated by the backpressure prevailing within the backpressure zone, also called contact pressure.In this respect, the contact pressure level represents an intermediate or medium pressure between the high pressure level, namely the discharge pressure, and the low pressure level, namely the suction pressure of the compressor. The contact pressure value should be adjusted so as, on the one hand, to close the axial sealing surfaces between the orbiting scroll and the fixed scroll and, on the other hand, to avoid excessive friction causing wear between the fixed scroll and the orbiting scroll.

[0008] The high-pressure and back-pressure and back-pressure and low-pressure zones of the compressor may, in each case, be connected to each other by flow channels incorporating expansion devices. A very limited mass flow rate of the compressed fluid in the compressor or of a mixture of the fluid and oil used as a compressor lubricant, also referred to as the control mass flow rate, flows through the flow channels. The conventional expansion devices take the form of nozzles in each case. At least one The relief device may also take the form of a spring-loaded mechanical regulating valve.

[0009] Document DE 10 2016 105 302 A1 describes a control flow regulating valve for scroll compressors in air conditioning systems for motor vehicles. The control flow regulating valve is provided with a housing and a closing element arranged inside the housing for adjusting the control flow. The housing is provided with fluid connections for high pressure, back pressure and suction pressure as well as ambient pressure. The closing element for the control flow is provided with effective or active surfaces associated with the respective fluid connections. A force resulting from the pressures acting on the closing element acts on the closing element so as to flow a control flow generating a back pressure from a zone in which the fluid is subjected to the high pressure to a zone in which the fluid is subjected to the suction pressure.A fluid-tight area, subject to ambient pressure, is also provided and sealed by means of a sheet metal membrane welded to the metal closing element or a vulcanized membrane. A spring element for producing an additional force acting on the closing element is also arranged inside the housing.

[0010] The balance of forces on the closure element and the position of the closure element, making it possible to obtain a required adjustment curve of the back pressure as a function of the high pressure and the suction pressure or the low pressure, are influenced by the pressures acting on the effective or active surfaces and by the flow rate passing through a passage opening cleared by the closure element.

[0011] The control flow control valve is provided with two elastomer membranes formed on the low-pressure side and the back-pressure side. The elasticity of the elastomer membrane allows axial mobility of the closure element within the housing. The elastomer membranes delimit a region of the control flow control valve in the axial direction which, due to the connection to the ambient pressure, is subjected to an atmospheric pressure independent of the low pressure and the back pressure. A fluid-tight and pressure-tight barrier is thus formed by the elastomer membranes between the low-pressure side and the back-pressure side. The fluid-tight connection of the elastomer membranes is ensured by vulcanization on the surrounding housing or on the closure element.

[0012] The devices, known in the state of the art, for regulating a mass flow rate of fluid serving as a control flow rate, more particularly for a device for compressing a gaseous fluid, are provided with a large number of components requiring very high manufacturing precision and low tolerances, connected together to form a complex structure, hence an assembly of great complexity. with a high number of assembly steps and correspondingly high assembly costs. For example, several seals are required to isolate the fluid-filled volumes from each other at different pressure levels. The individual elements must be aligned coaxially with each other. The large number of components results in a large space requirement, a high total weight, but also a high risk of errors during the assembly process. In addition, vulcanizing the membrane made of an elastomer onto metal, for example, is a particularly cumbersome and complex process that is particularly unsuitable for high-pressure applications, such as in systems using carbon dioxide as the fluid.Achieving a seal with vulcanized membranes also results in a high permeation surface which can lead to a very high release of fluid into the surrounding environment and therefore a very high loss of fluid over an overall operating period.

[0013] The setting of the device, more precisely of the closing element, on the corresponding operating point and the achievement of a high reproducibility require the stamping of the sealing seat. In this case, a defined force is applied by means of a press to the closing element during the stamping so as to provide, by plastic deformation of the material, a corresponding sealing seat on the housing. The stamping process usually comprises an iteration of stamping and testing steps until a setting on a desired pressure level is achieved and serves, for example according to document DE 10 2016 105 302 A1, to adjust a distance between the closing element and the elastomer membranes in order to eliminate the extension stresses of the elastomer membranes.

[0014] The object of the invention is to provide a device for regulating a mass flow rate of fluid serving as a control flow rate for a device for compressing a gaseous fluid, more particularly for the purpose of ensuring faultless operation and maximum service life of the fluid compression device. The device should comprise a minimum number of individual components and be simple to produce from a structural point of view, so as also to minimize assembly effort and costs during assembly. The device should have a minimal bulk, be lightweight and formed in a sealed manner to prevent any leakage or escape of fluid into the surrounding environment and therefore any loss of fluid from a system.

[0015] The aim is achieved firstly by a device for regulating a mass flow rate of fluid for a device for compressing a gaseous fluid from a low pressure level to a high pressure level, provided with a housing provided with fluid connections subjected to different pressure levels, and a closing element arranged within the housing so as to be movable in translation along a longitudinal axis and provided with effective or active surfaces associated with the fluid connections, the element closure element being configured to regulate a flow section of a flow path extending between a first fluid connection and a second fluid connection, characterized in that the housing is provided with a receiving opening for receiving the closure element, and the closure element is formed in at least two parts by a primary segment and a secondary segment, the primary segment and the secondary segment of the closure element each being guided within the receiving opening of the housing and each being arranged to be completely surrounded by the housing.

[0016] Thus, the intended purpose is achieved by a device according to the invention for regulating a mass flow rate of fluid serving as a control flow rate for a device for compressing a gaseous fluid from a low pressure level to a high pressure level. The device for regulating a mass flow rate of fluid is provided with a housing provided with fluid connections subjected to different pressure levels, and with a closing element movable in translation within the housing along a longitudinal axis, provided with effective or active surfaces (in terms of sealing) associated with the fluid connections. The closing element is configured to regulate a flow 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 housing is provided with a receiving opening for receiving the closure element, which is formed in at least two parts by a primary segment and a secondary segment. The primary segment and the secondary segment of the closure element are each guided within the receiving opening of the housing and are each arranged to be completely surrounded by the housing.

[0018] According to a further development of the invention, the primary segment of the closure element seals with the housing (in a fluid-tight and pressure-tight manner) by means of at least one first sealing element, while the secondary segment of the closure element seals with the housing (in a fluid-tight and pressure-tight manner) by means of at least one second sealing element, more particularly by means of at least two second sealing elements.

[0019] According to an advantageous embodiment of the invention, the housing is formed in at least two parts by a first housing element and a second housing element. The primary segment of the closure element is arranged to be guided within the first housing element and the secondary segment of the closure element is arranged to be guided within the second housing element. The receiving opening of the housing intended to receive the closure element is more particularly configured to overlap the housing element, so as to provide within the first housing element a first zone of the receiving opening intended to receive the primary segment of the closing element and to provide within the second housing element a second zone of the receiving opening intended to receive the secondary segment of the closing element.

[0020] According to a preferred design of the invention, the closure element is provided with a cylindrical shape, more particularly a circular cylindrical shape, with sections of different outer diameters, so that the closure element has steps between adjacent sections. Preferably, the primary segment of the closure element is provided with a primary segment diameter and the secondary segment of the closure element is provided with at least two sections each with different outer diameters. The primary segment diameter of the primary segment and the outer diameters of the secondary segment may also be different from each other.

[0021] The primary segment and the secondary segment of the closure element are advantageously each provided with an axis of symmetry, the axes of symmetry being, according to a first variant embodiment of the invention, arranged on the common longitudinal axis or, according to a second variant embodiment of the invention, arranged parallel and spaced apart from each other and parallel to the longitudinal axis.

[0022] An advantage of the invention lies in the fact that the closing element forms a sealing seat with the housing, more particularly with the first housing element, on a first end face, more particularly on a first end face of the primary segment.

[0023] The primary segment of the closure element is preferably aligned with a second end face, distal to the first end face, facing a first end face of the secondary segment of the closure element and, advantageously, rests against the first end face of the secondary segment of the closure element.

[0024] According to another advantageous design of the invention, a volume, delimited by the housing and the closure element provided with an annular effective or active surface having a first outer diameter of the closure element, more particularly of the secondary segment of the closure element, and the primary segment diameter of the closure element, more particularly of the primary segment of the closure element, as inner diameter, is subjected to the fluid at the low pressure level and is connected to a third fluid connection of the housing.

[0025] A volume, delimited by the housing, more particularly the second housing element, and a second end face of the closure element, distal to the first end face, more particularly a second end face of the secondary segment of the closure element, is preferably subjected to a level of ambient pressure, more precisely to ambient air, and is connected to the surrounding environment by means of a fourth fluid connection of the housing.

[0026] Furthermore, a volume, delimited by the housing and the closure element provided with an annular effective or active surface having the first outer diameter of the closure element and a second outer diameter of the closure element as an inner diameter, each more particularly of the secondary segment of the closure element, is advantageously subjected to the fluid at a counter-pressure level and is connected to the first fluid connection of the housing.

[0027] According to a further development of the invention, a first fluid connection is configured or formed (inside the housing) to extend from the first fluid connection to the volume delimited by the housing and the closure element provided with the annular effective or active surface having the first outer diameter of the closure element and the second outer diameter of the closure element as the inner diameter, each more particularly of the secondary segment of the closure element.

[0028] Within the housing, a second fluid connection may also be formed to extend from the first fluid connection to the volume delimited by the housing and the closure element provided with the annular effective or active surface having the first outer diameter of the closure element, more particularly of the secondary segment of the closure element, and the primary segment diameter of the closure element, more particularly of the primary segment of the closure element, as the inner diameter, or to the third fluid connection of the housing. The second fluid connection is advantageously provided with an expansion element, more particularly a throttle member, in other words an expansion element, more particularly a throttle member, is arranged within the second fluid connection.

[0029] The fluid mass flow control device serving as a control flow rate is advantageously configured such that the translational movement of the closure element, more particularly of the primary segment and the secondary segment, within the housing, more particularly within the first housing element and the second housing element, depends exclusively on pressures acting on the effective or active surfaces of the closure element and thus on pressure forces. The defined pressure forces or piston forces cause the movement of the closure element within sliding sealing elements, more particularly sealing elements in each case taking the form of O-rings. The primary segment and the secondary segment of the closure element may each be a metallic or non-metallic component.

[0030] According to another advantageous embodiment of the invention, the first fluid connection of the housing is subjected to the fluid at the back pressure level and the second fluid connection is subjected to the fluid at the high pressure level. Furthermore, the third fluid connection of the housing is subjected to the fluid at the low pressure level. The back pressure level represents an intermediate pressure level between the low pressure level and the high pressure level. A fourth fluid connection of the housing is preferably subjected to the ambient pressure level, more particularly to ambient air.

[0031] According to another preferred embodiment of the invention, the device for filtering the fluid to remove various particles therefrom is provided with a filter element which is integrated into the closure element, more particularly into the primary segment of the closure element, or which is arranged as a separate element within a flow passage opening of the second fluid connection and thus, in each case, at the inlet of the device.

[0032] The object is also achieved by a device for compressing a gaseous fluid from a low pressure level to a high pressure level, more particularly a compressor, more precisely a spiral-orbital compressor, provided with a housing with a counter-wall and a compression mechanism with a stationary fixed scroll and a mobile orbital scroll driven by means of an eccentric drive, the housing with the counter-wall and the orbital scroll being configured to enclose a counter-pressure chamber at least in certain areas, and a flow path extending from the high pressure area to the counter-pressure chamber being formed within the housing, characterized in that a device for regulating a mass flow rate of fluid as described above is formed within the flow path extending between the high pressure area and the counter-pressure chamber.

[0033] Thus, the invention also relates to a device for compressing a gaseous fluid from a low pressure level to a high pressure level, more particularly a spiral-orbital compressor for compressing a refrigerant. The fluid to be compressed is present in an inlet zone at the low pressure level and the compressed fluid is present in a high pressure zone, more particularly at an outlet of the compression device, at the high pressure level. The compression device is provided with a housing with a counter wall and a compression mechanism with a stationary fixed scroll and a movable orbiting scroll, driven by means of an eccentric drive. The housing with the counter wall and the orbiting scroll together at least partially surround a counter pressure chamber. In addition, a flow path extending from the high pressure zone up to the counter pressure chamber is provided within the housing.

[0034] According to the concept of the invention, a device according to the invention for controlling a fluid mass flow rate is formed within the flow path extending between the high-pressure region and the counter-pressure chamber. Thus, the device for controlling a fluid mass flow rate serving as a control flow control valve is preferably arranged in an integrated manner within the compressor housing. The device for controlling a fluid mass flow rate is therefore formed without the need for an additional housing.

[0035] According to a further development of the invention, the housing is provided with at least two housing elements. It is formed of a first housing element intended to receive a primary segment of the closing element of the fluid mass flow control device and a second housing element intended to receive a secondary segment of the closing element of the fluid mass flow control device.

[0036] The closure element is arranged with the primary segment and the secondary segment within the housing so as to be movable in translation to open and close the flow path. When the flow path is open, the fluid expands from a high pressure level to a required back pressure level. The back pressure level is determined by the position of the closure element, more particularly the primary segment of the closure element, and thus by the degree of opening of the fluid mass flow control device. The position of the closure element is adjusted by a balance of forces at the effective or active surfaces of the closure element, obtained from different pressure levels acting on the effective or active surfaces.

[0037] The closing element of the device for regulating the mass flow rate of fluid is advantageously arranged within a receiving opening provided in the housing of the device for compressing the gaseous fluid. The primary segment of the closing element is arranged within a first zone of the receiving opening, provided in the first housing element, and the secondary segment of the closing element is arranged within a second zone of the receiving opening, provided in the second housing element, more particularly to be movable in translation along a longitudinal axis.

[0038] Finally, the invention also relates to the use of a device for compressing a gaseous fluid provided with the device for regulating a mass flow rate of fluid as described previously in a refrigerant circuit of an air conditioning system of a motor vehicle.

[0039] Indeed, the advantageous design of the invention allows the use of the gaseous fluid compression device provided with the device for regulating a mass flow rate of fluid as a compressor in a refrigerant circuit of an air conditioning system of a motor vehicle. The compressor can be configured to be driven electrically or mechanically. In this case, the compression mechanism is driven by means of an electric motor or a pulley.

[0040] The device according to the invention for regulating a mass flow rate of fluid serving as a control flow rate for a device for compressing a gaseous fluid from a low pressure level to a high pressure level can therefore be configured as a control flow rate regulating valve, more particularly of a spiral-orbital compressor of a refrigerant circuit of an air conditioning system of a motor vehicle.

[0041] The device according to the invention for regulating a mass flow rate of fluid and the device for compressing a gaseous fluid provided with the device according to the invention for regulating a mass flow rate of fluid both have various additional advantages, namely: - minimal number of individual components and simple structure with high durability, resulting in minimal assembly effort, manufacturing effort and maintenance effort as well as minimal assembly costs, manufacturing costs and maintenance costs, - as an example, with a two-part design of the closure element, the requirement for coaxiality within the device is reduced, the spring element provided in the device in the state of the art is not necessary, and the sealing seat is integrated into the receiving element without the need for an additional shaping step, - minimal bulk and minimal total weight, - purely mechanical structure with automatic regulation within the device, and - maximum safety and tightness in operation due to the reduced number of potential leakage paths to the surrounding environment - presence of a single sealing point with the surrounding environment, therefore minimal escape of fluid, more particularly minimal escape of refrigerant from the compression device.

[0042] Other details, features and advantages of the invention will emerge from the following description of an illustrative embodiment with reference to the accompanying drawings. In the drawings:

[0043] [Fig. 1] a basic circuit diagram of a device for controlling a mass flow rate of fluid serving as a control flow rate for a compression device of a gaseous fluid with radial application of ambient pressure according to the state of the art,

[0044] [Fig.2] and [Fig.3] each a basic circuit diagram of a device according to the invention for regulating a mass flow rate of fluid serving as a control flow rate for a device for compressing a gaseous fluid, and

[0045] [Fig.4] a device for compressing a gaseous fluid incorporating a device for regulating a mass flow rate of fluid serving as a control flow rate, shown in side section.

[0046] [Fig.l] shows a basic circuit diagram of a device 1' for regulating a mass flow rate of fluid serving as a control flow rate, also called a control flow rate regulating valve, for a device for compressing a gaseous fluid from a suction pressure level to a high pressure level with radial application of ambient pressure according to the state of the art.

[0047] The device 1' is provided with a housing 2' with different fluid connections 2a', 2b', 2c', 2d'. Within the housing 2', a closure element 3' is arranged so as to be movable in translation along a longitudinal axis 3a which corresponds to an axis of symmetry of the closure element 3'. The device 1' is provided with a flow path which extends from a first fluid connection 2a' to a second fluid connection 2b' and the flow cross-section of which can be regulated by means of the closure element 3'. A control mass flow rate of the fluid is regulated by means of the closure element 3' from a high pressure level in the second fluid connection 2b' to a counter pressure level in the first fluid connection 2a'.

[0048] In addition, the housing 2' is provided with a third fluid connection 2c', the fluid being at a suction pressure level of the fluid compression device, also referred to as a low pressure level, and a fourth fluid connection 2d', at an ambient pressure level. The third fluid connection 2c' and fourth fluid connection 2d' each do not form any flow path. The third fluid connection 2c' and the fourth fluid connection 2d' serve to transmit the suction pressure levels and ambient pressure to corresponding effective or active surfaces of the closure element 3'.

[0049] Membrane sealing elements 4', arranged between the closure element 3' and the housing 2', delimit a zone of the device 1' in the direction of the longitudinal axis 3a and ensure the sealing of the device 1' with the ambient pressure. The atmospheric pressure of the zone delimited by the membrane sealing elements 4' is independent of the low pressure and the counter pressure due to the connection with the ambient pressure level. The membrane sealing elements 4' together form a fluid-tight and pressure-tight barrier between the low side pressure connected to the third fluid connection 2c' and the counter pressure side connected to the first fluid connection 2a'.

[0050] Since the membrane sealing elements 4' between the closure element 3' and the housing 2' in each case take the form of a welded sheet metal membrane or a vulcanized membrane, there is a high risk of leakage and thus a risk of the fluid escaping into the surrounding environment via the fourth fluid connection 2d'. The device 1' has four potential leakage paths for the fluid into the surrounding environment. The membrane sealing elements 4', each formed from an elastomer, are vulcanized onto the closure element 3'.

[0051] In a closed position of the device 1' shown in [Fig.l], the closure element 3' rests against a sealing seat 6 formed on the housing 2', having a sealing seat diameter dl. The sealing seat 6 is formed between the first fluid connection 2a' and the second fluid connection 2b'. The flow path extending between the fluid connections 2a', 2b' is closed. When a position of the device 1' deviates from the closed position, fluid flows from the second fluid connection 2b' to the first fluid connection 2a' via the flow path. A flow resistance is created by means of the regulated narrow sealing seat 6 which causes a loss of fluid pressure.

[0052] The device 1' is also provided with a spring element 5' which is arranged to act on the closure element 3' with a spring force aligned against the closed position of the closure element 3'. The spring element 5' is therefore configured to open the device 1', more particularly the flow path extending between the first fluid connection 2a' and the second fluid connection 2b', when the forces acting on the closure element 3' due to the different pressures balance out.

[0053] The closure element 3' bears, by a free end face of a primary segment 3-1' oriented in the direction of the longitudinal axis 3a, against the sealing seat 6 so as to close the flow path extending between the first fluid connection 2a' and the second fluid connection 2b'. The primary segment 3-1' of the closure element 3' cooperates with the sealing seat 6 and the second fluid connection 2b'.

[0054] The closure element 3' is geometrically formed in such a way that a primary segment diameter d2, a sealing seat diameter d1, a first effective diameter d3' from the suction pressure level to the ambient pressure level and a second effective diameter d4' from the back pressure level to the ambient pressure level are configured so that a resultant force acts on the closure element 3' depending on the respectively applied pressure levels and thus regulates the control mass flow rate of the fluid from the second fluid connection 2b' up to the first fluid connection 2a'. By means of a balance of forces, the closing element 3' is, in each case, brought into the corresponding position.

[0055] The device 1' is also provided with a first fluid connection 7 which extends from the first fluid connection 2a' to a volume enclosed by the closure element 3', more particularly an effective or active surface having the second effective diameter d4 from the back pressure level to the ambient pressure level, and the housing 2', for the purpose of thus involving the back pressure level in the balance of forces at the closure element 3'. Furthermore, a second fluid connection 8 is provided to connect the first fluid connection 2a' to the third fluid connection 2c' and extend between the first fluid connection 2a' and a volume enclosed by the closure element 3', more particularly an effective or active surface having the first effective diameter d3' from the suction pressure level to the ambient pressure level, and the housing 2'.A relaxation element 9, more precisely a throttling element or a throttle, is arranged within the second fluid connection 8.

[0056] The primary segment 3-1' of the closing element 3' seals with the housing 2' by means of a sealing element 10' taking the form of an O-ring.

[0057] Figures 2 and 3 show a basic circuit diagram of a device 1 according to the invention for regulating a mass flow rate of fluid serving as a control flow rate for a device for compressing a gaseous fluid from the suction pressure level to the high pressure level, with axial application of ambient pressure to an end face of a piston-shaped closing element 3 within the housing 2. Components identical to those of the device 1' of the prior art shown in [Fig.l] are each provided with the same reference numbers.

[0058] The device 1 is provided with the housing 2 provided with different fluid connections 2a, 2b, 2c, 2d. Fluid connections 2a, 2b, 2c, 2d should also be understood to mean flow channels provided in the components of the device 1.

[0059] The closure element 3 is integrated within the housing 2 and is movable in translation along the longitudinal axis 3a constituting the axis of symmetry of the closure element 3. The closure element 3 is arranged within a receiving opening 11 formed in the housing 2. As can be seen more particularly in [Fig. 3], the two-part closure element 3 is provided with a primary segment 3-1 arranged to be guided within a first housing element 2-1, more precisely within a first zone 11-1 of the receiving opening 11, and a secondary segment 3-2 arranged to be guided within a second housing element 2-2, more precisely within a second zone 11-2 of the receiving opening 11. The housing 2 is divided into two parts or formed of two parts by the first housing element 2-1 and the second housing element 2-2.

[0060] The primary segment 3-1 acting as a piston and the secondary segment 3-2 acting as an actuator, also called a control element, are each provided with a cylindrical shape, more particularly a circular cylindrical shape, with sections of different external diameters. The primary segment 3-1 and the secondary segment 3-2 may be made of the same material or different materials, such as a metallic or non-metallic material, more particularly a plastic material.

[0061] The device 1 is provided with a flow path extending between the first fluid connection 2a at the counter-pressure level and the second fluid connection 2b at the high-pressure level of the gaseous fluid compression device, the flow section of which can be regulated by movement of the closure element 3, more particularly of the primary segment 3-1 of the closure element 3. The control mass flow rate of the fluid taking the flow path is regulated by the closure element 3. The flow path is arranged within the first housing element 2-1.

[0062] The first free end face of the primary segment 3-1 of the closure element 3 oriented in the direction of the longitudinal axis 3a bears against a sealing seat 6 so as to close the flow path between the first fluid connection 2a and the second fluid connection 2b. The sealing seat 6 is arranged inside the first housing element 2-1 of the housing 2 of the device 1 in the form of a step or a rim. The primary segment 3-1 of the closure element 3 cooperates with the sealing seat 6 and the second fluid connection 2b.

[0063] The housing 2 is also provided with the third fluid connection 2c, the fluid being at the suction or low pressure level of the fluid compression device, and the fourth fluid connection 2d at the ambient pressure level. The third fluid connection 2c and the fourth fluid connection 2d serve only to transmit the suction and ambient pressure levels to corresponding effective or active surfaces of the closing element 3.

[0064] Sealing elements 10-1, 10-2 are arranged between the housing 2 and the closure element 3. According to [Fig. 3], a first sealing element 10-1 is arranged within the first zone 11-1 of the receiving opening 11 between the first housing element 2-1 and the primary segment 3-1 of the closure element 3, and two second sealing elements 10-2 are arranged within the second zone 11-2 of the receiving opening 11 between the second housing element 2-2 and the secondary segment 3-2 of the closure element 3, each delimiting volumes of the device 1 which are subjected to different pressures in the direction of the longitudinal axis 3a and sealing them against each other.

[0065] The primary segment 3-1 of the closure element 3 rests, by a second end face oriented in the direction of the longitudinal axis 3a and distal to the first end face, on a first end face of the secondary segment 3-2 of the closure element 3.

[0066] The piston-shaped secondary segment 3-2 of the closure element 3 is subjected to ambient pressure at a second end face, oriented in the direction of the longitudinal axis 3a and distal to the first end face oriented towards the primary segment 3-1 and towards the sealing seat 6. A volume delimited by the housing 2, more particularly by the second housing element 2-2, and the second end face of the secondary segment 3-2 of the closure element 3 is subjected to the ambient pressure level. The volume connected to the surrounding medium by the fourth fluid connection 2d is therefore subjected to a pressure level independent of the low pressure level and the back pressure level.

[0067] The primary segment 3-1 and the secondary segment 3-2 of the closing element 3 are in permanent mechanical contact after the filling, with a refrigerant, of the device for compressing a gaseous fluid and therefore also of the device 1 for regulating the mass flow rate of fluid due to the forces acting on the closing element 3.

[0068] In the closed position of the device 1, the closing element 3 rests, by the primary segment 3-1, against the sealing seat 6 having the sealing seat diameter dl, formed on the housing 2, more particularly on the first housing element 2-1. The flow path extending between the first fluid connection 2a and the second fluid connection 2b is closed.

[0069] The closing element 3 is geometrically formed in such a way that the primary segment diameter d2 of the primary segment 3-1 of the closing element 3, the sealing seat diameter d1, a first outer diameter d3 from the suction pressure level to the back pressure level and a second outer diameter d4 from the back pressure level to the ambient pressure level are configured so that a resultant force acts on the closing element 3 depending on the respectively applied pressures and thus regulates the control mass flow of the fluid from the second fluid connection 2b to the first fluid connection 2a. By means of a force balance, the closing element 3 is, in each case, brought into the corresponding position.The primary segment diameter d2 of the primary segment 3-1 and the outer diameters d3, d4 of the secondary segment 3-2 of the closing element 3 are each configured in such a way that the level of back pressure which is established is in particular in accordance with the required pressure of an orbiting scroll on a fixed scroll of a compression mechanism of a spiral-orbital compressor acting as a device for compressing a gaseous fluid.

[0070] The device 1 is also provided with the first fluid connection 7 which extends from the first fluid connection 2a to a volume enclosed by the closure element, more particularly an effective or active surface having the first outer diameter d3 from the back pressure level to the suction pressure level, and the housing 2, for the purpose of thus involving the back pressure level in the balance of forces at the closure element 3. Furthermore, the second fluid connection 8 is arranged to connect the first fluid connection 2a to the third fluid connection 2c and extend between the first fluid connection 2a and a volume enclosed by the closure element 3, more particularly an effective or active surface having the first effective diameter d3 from the suction pressure level to the back pressure level, and the housing 2. An expansion element 9 is arranged within the second fluid connection 8.

[0071] The volume enclosed by the second end face of the secondary segment 3-2 of the closure element 3 provided with the effective or active surface having the second outer diameter d4 and the housing 2, more particularly the second housing element 2-2, and connected to the fourth fluid connection 2d and therefore subjected to the ambient pressure level serves to reduce the effective or active surface of the counter-pressure acting in the closed position of the closure element 3.

[0072] On the first end face of the primary segment 3-1 of the closure element 3, the high pressure level prevailing in the second fluid connection 2b and the reduced counter-pressure level prevailing at the sealing seat 6 thanks to the sealing space provided between the primary segment 3-1 of the closure element 3 and the housing 2, more particularly the first housing element 2-1, also act against the closed position of the closure element 3.

[0073] The first fluid connection 2a is arranged to overlap the housing element by means of the first fluid connection 7, while the second fluid connection 2b extends within the first housing element 2-1 and the fourth fluid connection 2d extends within the second housing element 2-2. The third fluid connection 2c may be arranged within the first housing element 2-1 or within the second housing element 2-2.

[0074] The respective diameters of the closure element 3 are configured to establish a balance of forces to regulate the level of back pressure. The back pressure at the circular effective or active surface of the secondary segment 3-2 having the first outer diameter d3 and the second diameter d4 exerts a force oriented in the closing direction of the closure element 3, while the suction pressure at the circular effective or active surface of the secondary segment 3-2 having the first outer diameter d3 and the primary segment diameter d2 added to the high pressure at the circular effective or active surface having the sealing seat diameter dl exerts a counterforce oriented against the closing direction of the closing element 3. The counterforce is represented by a coefficient x for the suction pressure and by a coefficient y for the high pressure.

[0075] "Back pressure = x • Suction pressure + y • High pressure".

[0076] The coefficients x and y are adapted to establish a required back pressure or a desired back pressure curve according to a modification of the planes on which the individual pressures are exerted. The coefficients are adapted to modify ratios of the pressure surfaces between them, so that a variation of the coefficients causes a variation of the surface ratios and therefore a variation of the established back pressure depending on the degree of opening of the fluid mass flow control device.

[0077] The translational movement of the closure element 2, more precisely of the primary segment 3-1, defines a throttling space at the sealing seat 6 between the primary segment 3-1 and the housing 2, more particularly the first housing element 2-1, in which the fluid flowing through it undergoes a reduction from the high pressure level to the respective back pressure level. The primary segment 3-1 and the secondary segment 3-2 of the closure element 3 can both be aligned along the longitudinal axis 3a constituting an axis of symmetry and thus coaxially but also eccentrically with respect to the longitudinal axis 3a and thus parallel and spaced apart from each other.

[0078] The first sealing element 10-1, which takes the form of an O-ring, forms a fluid-tight and pressure-tight barrier between the volume subjected to the backpressure level and the first fluid connection 2a, while the second sealing elements 10-2, which take the form of O-rings, each form a fluid-tight and pressure-tight barrier between the volumes subjected to the ambient pressure level and the backpressure level and between the volumes subjected to the backpressure level and the suction pressure level. Thus, a single second sealing element 10-2 placed between the volumes subjected to the ambient pressure level and the backpressure level ensures the sealing of the device 1 with the surrounding environment.

[0079] [Fig. 4] shows, represented in side section, a device for compressing a gaseous fluid, more particularly an electrically driven compressor 20, more precisely a spiral orbital compressor, integrating a device 1 for regulating a mass flow rate of fluid serving as a control flow rate. The compressor 20 is provided with a compression mechanism 21 and an electric motor 22 intended to drive the compression mechanism 21.

[0080] The compression mechanism 21, which is provided with a fixed spiral 21a and an orbital spiral 21b, as well as the electric motor 22 are arranged within a volume enclosed by the housing 2. The housing 2 is formed of three housing elements 2-1, 2-2, 2-3, more particularly of the first housing element 2-1 intended to receive the primary segment 3-1 of the closing element 3 and the compression mechanism 21, of the second housing element 2-2 intended to receive the secondary segment 3-2 of the closing element 3 and of a third housing element 2-3 intended to receive the electric motor 22 and preferably made of a metal, for example aluminum.

[0081] The electric motor 22 is provided with a stator 22a having a substantially hollow cylindrical stator core and coils wound on the stator core, and a rotor 22b arranged inside the stator 22a. The rotor 22b is driven into rotation when the coils of the stator 22a are supplied with electrical energy. The rotor 22b is arranged coaxially within the stator 22a and rotatable about an axis of rotation 23. A drive shaft 24 may be an integral part of the rotor 22b or take the form of a separate element.

[0082] The orbital spiral 21b of the compression mechanism 21, in which the gaseous fluid, more particularly a refrigerant fluid, is compressed, is driven by the drive shaft 24 connected to the rotor 22b of the electric motor 22. The fluid compressed to the high pressure level when it passes through the compression mechanism 21 is discharged from the compression mechanism 21 by at least one outlet 25 to reach a zone of the high pressure level 20b of the compressor 20.

[0083] The compressor 20 is also provided with a wall which is arranged within the housing 2, more particularly the second housing element 2-2, and firmly connected to the housing 2, forming a boundary of a back pressure level area 20a of the compressor 20, also referred to as the back pressure area, and which is therefore also referred to as the counter wall 26. Within the back pressure level area 20a provided between the counter wall 26 and the orbiting scroll 21b, more particularly a rear side of a base plate of the orbiting scroll 21b, the fluid is subjected to the back pressure level, also present as a contact pressure level representing an intermediate pressure between the high pressure level, namely the discharge pressure, and the low pressure level, namely the suction pressure, of the compressor 20.The fluid is subjected to the low pressure level in a low pressure level zone 20c of the compressor 20, in which the electric motor 22 is also arranged. Since ambient pressure prevails outside the housing 2 of the compressor 20, the surrounding environment is also referred to as an ambient pressure level zone 20d of the compressor 20.

[0084] The device 1 for regulating a mass flow rate of fluid is integrated with the closure element 3 within the receiving opening 11 forming a cavity of the housing 2 of the device for compressing a gaseous fluid, more particularly of the compressor 20. The primary segment 3-1 of the closure element 3 is arranged within the first zone 11-1 of the receiving opening 11, formed in the first housing element 2-1, and the secondary segment 3-2 of the closure element 3 is arranged within the second zone 11-2 of the receiving opening 11, formed in the second housing element 2-2.

[0085] Between the primary segment 3-1 of the closure element 3 and the first housing element 2-1 is arranged the first sealing element 10-1, taking the form of an O-ring, while between the secondary segment 3-2 of the closure element 3 and the second housing element 2-2 are arranged the second sealing elements 10-2 taking the form of O-rings and sealingly isolating the corresponding pressure spaces from each other.

[0086] The first sealing element 10-1 forms a fluid-tight and pressure-tight barrier between volumes subjected to the suction pressure level and the back pressure level, more particularly between the low pressure level zone 20c and the back pressure level zone 20a of the compressor 20, while the second sealing elements 10-2 form a fluid-tight and pressure-tight barrier between volumes subjected to the suction pressure level and the back pressure level, more particularly between the low pressure level zone 20c and the back pressure level zone 20a of the compressor 20d, and between volumes subjected to the back pressure level and the ambient pressure level, more particularly between the back pressure level zone 20a and the ambient pressure level zone 20d of the compressor 20.

[0087] The elements, objects, indications and information illustrated in the figures are referenced as follows: 1.1' device 2, 2' housing 2-1 first housing segment 2-2 second housing segment 2-3 third housing segment 2a, 2a' first fluid connection at the back pressure level 2b, 2b' second fluid connection at the high pressure level 2c, 2c' third fluid connection at low pressure / suction pressure level 2d, 2d' fourth fluid connection at ambient pressure level 3, 3' closing element 3a longitudinal axis 3-1,3-r primary segment of closing element 3, 3' 3-2 secondary segment of closing element 3 4' diaphragm sealing element 5' spring element 6 sealing seat 7 first fluid connection 8 second fluid connection 9 expansion element 10-1 first sealing element 10-2 second sealing element 10' sealing element 11 receiving opening 11-1 first area of ​​receiving opening 11 11-2 second area of ​​receiving opening 11 20 compressor 20a back pressure level area 20b high pressure level area 20c low pressure / suction pressure level area 20d ambient pressure level zone 21 compression mechanism 21a fixed scroll 21b orbiting scroll 22 electric motor 22a stator 22b rotor 23 axis of rotation 24 drive shaft 25 output 26 counter wall dl sealing seat diameter d2 primary segment diameter d3 first outside diameter d3' first effective diameter d4 second outside diameter d4' second effective diameter

[0088] Of course, the invention is not limited to the embodiment described and shown in the attached drawings. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without departing from the scope of protection of the invention.

Claims

Claims

1. Device (1) for regulating a mass flow rate of fluid for a device for compressing a gaseous fluid from a low pressure level to a high pressure level, provided with a housing (2) provided with fluid connections (2a, 2b, 2c, 2d) subjected to different pressure levels, and with a closure element (3) arranged within the housing (2) so as to be movable in translation along a longitudinal axis (3a) and provided with effective or active surfaces associated with the fluid connections (2a, 2b, 2c, 2d), the closure element (3) being configured to regulate a flow section of a flow path extending between a first fluid connection (2a) and a second fluid connection (2b), characterized in that the housing (2) is provided with a receiving opening (11) intended to receive the closure element (3), and the closure element (3) is formed in at least two parts by a primary segment (3-1) and a secondary segment (3-2),the primary segment (3-1) and the secondary segment (3-2) of the closure element (3) each being guided within the receiving opening (11) of the housing (2) and each being arranged to be completely surrounded by the housing (2).,

2. Device (1) according to claim 1, characterized in that the primary segment (3-1) of the closure element (3) seals with the housing (2) by means of at least one first sealing element (10-1) and the secondary segment (3-2) of the closure element (3) seals with the housing (2) by means of at least one second sealing element (10-2), more particularly by means of at least two second sealing elements (10-2), each in a fluid-tight and pressure-tight manner.

3. Device (1) according to claim 1 or 2, characterized in that the housing (2) is formed in at least two parts by a first housing element (2-1) and a second housing element (2-2), the primary segment (3-1) of the closure element (3) being arranged to be guided within the first housing element (2-1) and the secondary segment (3-2) of the closure element (3) being arranged to be guided within the second housing element (2-2).

4. Device (1) according to any one of claims 1 to 3, characterized in that the closing element (3) is provided with a shape cylindrical, more particularly of a circular cylindrical shape, with sections of different external diameters.

5. Device (1) according to claim 4, characterized in that the primary segment (3-1) of the closing element (3) is provided with a primary segment diameter (d2) and the secondary segment (3-2) of the closing element (3) is provided with at least two sections having respective different outer diameters (d3, d4).

6. Device (1) according to claim 4 or 5, characterized in that the primary segment (3-1) and the secondary segment (3-2) of the closing element (3) are each provided with an axis of symmetry, the axes of symmetry being arranged on the common longitudinal axis (3a) or parallel and spaced apart from each other and parallel to the longitudinal axis (3a).

7. Device (1) according to any one of claims 4 to 6, characterized in that the closing element (3) forms a sealing seat (6) on a first end face, more particularly on a first end face of the primary segment (3-1), with the housing (2), more particularly with a first housing element (2-1).

8. Device (1) according to claim 7, characterized in that the primary segment (3-1) of the closure element (3) is aligned with a second end face, distal to the first end face, facing a first end face of the secondary segment (3-2) of the closure element (3), more particularly is arranged to rest against the first end face of the secondary segment (3-2) of the closure element (3).

9. Device (1) according to any one of claims 5 to 8, characterized in that a volume, delimited by the housing (2) and the closure element (3) provided with an annular effective or active surface having a first outer diameter (d3) of the closure element (3), more particularly of the secondary segment (3-2) of the closure element (3), and the primary segment diameter (d2) of the closure element (3), more particularly of the primary segment (3-1) of the closure element (3), as inner diameter, is subjected to the fluid at the low pressure level and is configured to be connected to a third fluid connection (2c) of the housing (2).

10. Device (1) according to claims 7 to 9, characterized in that a volume, delimited by the housing (2), more particularly a second housing element (2-2), and a second end face of the closure element (3), distal to the first end face, more particularly a second end face of the secondary segment (3-2) of the closure element (3), is subjected to an ambient pressure level and is configured to be connected to the surrounding environment by means of a fourth fluid connection (2d) of the housing (2).

11. Device (1) according to any one of claims 5 to 10, characterized in that a volume, delimited by the housing (2) and the closure element (3) provided with an annular effective or active surface having a first outer diameter (d3) of the closure element (3) and a second outer diameter (d4) of the closure element (3) as inner diameter, each more particularly of the secondary segment (3-2) of the closure element (3), is advantageously subjected to the fluid at a counter-pressure level and is configured to be connected to the first fluid connection (2a) of the housing (2).

12. Device (1) according to claim 11, characterized in that a first fluid connection (7) is configured to extend from the first fluid connection (2a) to the volume delimited by the housing (2) and the closure element (3) provided with the annular effective or active surface having the first outer diameter (d3) of the closure element (3) and the second outer diameter (d4) of the closure element (3) as inner diameter, each more particularly of the secondary segment (3-2) of the closure element (3).

13. Device (1) according to claims 9 to 12, characterized in that a second fluid connection (8) is configured to extend from the first fluid connection (2a) to the volume delimited by the housing (2) and the closure element (3) provided with the annular effective or active surface having the first outer diameter (d3) of the closure element (3), more particularly of the secondary segment (3-2) of the closure element (3), and the primary segment diameter (d2) of the closure element (3), more particularly of the primary segment (3-1) of the closure element (3), as inner diameter.

14. Device (1) according to claim 13, characterized in that a relaxation element (9), more particularly a member throttle, is arranged within the second fluid connection (8).

15. Device (1) according to any one of claims 1 to 14, characterized in that the sealing elements (10-1, 10-2) in each case take the form of an O-ring.

16. Device (1) according to any one of claims 1 to 15, characterized in that the first fluid connection (2a) of the housing (2) is configured to be subjected to the fluid at a counter-pressure level and the second fluid connection (2b) of the housing (2) is configured to be subjected to the fluid at the high pressure level.

17. Device (1) according to any one of claims 1 to 16, characterized in that a third fluid connection (2c) of the housing (2) is configured to be subjected to the fluid at the low pressure level.

18. Device (1) according to any one of claims 1 to 17, characterized in that a fourth fluid connection (2d) of the housing (2) is configured to be subjected to an ambient pressure level.

19. Device for compressing a gaseous fluid from a low pressure level to a high pressure level, more particularly a compressor (20), more precisely a spiral-orbital compressor, provided with a housing (2) with a counter wall (26) and a compression mechanism (21) with a stationary fixed scroll (21a) and a movable orbital scroll (21b) driven by means of an eccentric drive, the housing (2) with the counter wall (26) and the orbital scroll (21b) being configured to enclose a counter pressure chamber at least in certain areas, and a flow path extending from the high pressure area to the counter pressure chamber being formed within the housing (2), characterized in that a device (1) for regulating a mass flow of fluid according to any one of claims 1 to 18 is formed within the flow path extending between the high pressure zone and the counter pressure chamber.

20. Device according to claim 19, characterized in that the housing (2) is provided with at least two housing elements (2-1, 2-2, 2-3), a first housing element (2-1) being configured to receive a primary segment (3-1) of the closure element (3) of the device (1) for regulating the mass flow of fluid, and a second element housing (2-2) being configured to receive a secondary segment (3-2) of the closing element (3) of the device (1) for regulating the mass flow of fluid.

21. Device according to claim 20, characterized in that the closing element (3) of the device (1) for regulating the mass flow rate of fluid is arranged within a receiving opening (11) formed in the housing (2) of the device for compressing the gaseous fluid, the primary segment (3-1) of the closing element (3) being arranged within a first zone (11-1) of the receiving opening (11) formed in the first housing element (2-1) and the secondary segment (3-2) of the closing element (3) being arranged within a second zone (11-2) of the receiving opening (11) formed in the second housing element (2-2), more particularly movable in translation along a longitudinal axis.

22. Use of a device for compressing a gaseous fluid provided with the device (1) for regulating a mass flow rate of fluid according to any one of claims 19 to 21 in a refrigerant circuit of an air conditioning system of a motor vehicle.

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