Patent Application
20250188932
This patent application claims the benefit of and priority to German Patent Application No. DE 2024 129 639.9, filed on Oct. 14, 2024, and German Patent Application No. DE 10 2023 134 115.4, filed on Dec. 6, 2023, the entire contents of each of which are incorporated herein by reference for all purposes.
The invention relates to a device for controlling a fluid mass flow as a control flow for a device for compressing a gaseous fluid, in particular a control valve for a scroll compressor. The device for controlling the control mass flow has a housing with fluid connections impinged upon at different pressure levels and a closure element which can be moved in a translatory manner within the housing along a longitudinal axis, with effective surfaces assigned to the fluid connections. The closure element is formed such as to regulate a flow cross-section of a flow path extending between a first fluid connection and a second fluid connection.
The invention also relates to a device for compressing a gaseous fluid, in particular a scroll compressor for compressing a refrigerant, which has a housing with a counter wall and a compression mechanism with an immobile, fixed spiral and a movable, orbiting spiral driven via an eccentric drive. The scroll compressor is also referred to as a spiral compressor.
Compressors for mobile applications known from the prior art, in particular for air-conditioning systems of motor vehicles, for conveying refrigerant through a refrigerant circuit, also referred to as refrigerant compressors, are often formed as piston compressors with variable displacement or as scroll compressors irrespective of the refrigerant. The compressors are driven either via a pulley or electrically.
In addition to a housing, conventional scroll compressors have an immobile, fixed spiral with a disc-shaped base plate and a spiral-shaped wall extending from one side of the base plate as well as a movable orbiting spiral also with a disc-shaped base plate and a spiral-shaped wall extending from a front side of the base plate. The base plates are arranged relative to one another such that the spiral-shaped walls engage with one another in the axial direction.
The fixed spiral and the orbiting spiral work together. The orbiting spiral is moved on a circular path by means of an eccentric drive such that the spiral-shaped walls touch at several points and several successive, sealed working spaces are formed between the walls and the base plates. The volumes of adjacent working spaces vary in size. As a result of the movement of the orbiting spiral relative to the fixed spiral, the volumes and the positions of the working spaces are changed such that the volumes of the working spaces become progressively smaller towards the centre of the spiral-shaped walls and a gaseous fluid enclosed within the working spaces is compressed. The fluid compressed in this way is discharged from the compression mechanism through at least one outlet. The associated increase in pressure in adjacently arranged working spaces causes a force acting on the orbiting spiral, predominantly in the axial direction, which also acts eccentrically on the orbiting spiral and thus generates a tilting moment.
In addition, gaps formed in the axial direction between the fixed spiral and the orbiting spiral should be minimal for sufficient internal tightness, which is also guaranteed in connection with pressing the orbiting spiral against the fixed spiral.
The scroll compressors belonging to the prior art have a wall which is arranged within the housing and firmly connected to the housing and which is formed as a boundary of a counter pressure area and is consequently also referred to as a counter wall. Due to the counterpressure prevailing within the counter-pressure region formed between the counter wall and the orbiting spiral, in particular a rear side of the base plate of the orbiting spiral, also referred to as counter pressure chamber, the orbiting spiral is pressed against the fixed spiral, which is fixed on the housing like the counter wall, through a force acting in the axial direction. The pressure force acting in the axial direction is regulated by the counter pressure present within the counter pressure region, also referred to as a contact pressure. As such, as an intermediate pressure or medium pressure, the contact pressure level is between the levels of the high pressure as the outlet pressure and the low pressure as the suction pressure of the compressor. The value of the contact pressure is to be adjusted such that, on the one hand, the axial sealing surfaces between the orbiting spiral and the fixed spiral are closed and, on the other hand, excessive friction causing wear between the fixed spiral and the orbiting spiral is avoided.
The regions of the compressor which are acted upon by high pressure and counter pressure as well as by counter pressure and low pressure can in each case be connected to one another via flow channels with integrated expansion devices. A very limited mass flow of the fluid compressed in the compressor or of a mixture of the fluid and oil as lubricant of the compressor, which is also referred to as control mass flow, flows through the flow channels. Conventional expansion devices are in each case formed as nozzles. At least one expansion device can also be formed as a spring-loaded mechanical regulating valve.
DE 10 2016 105 302 A1 discloses a control flow regulating valve for spiral compressors in air-conditioning systems for motor vehicles. The control flow regulating valve has a housing and a closure element arranged inside the housing for adjusting the control flow. The housing is formed with fluid connections for the high pressure, the counter pressure and the suction pressure as well as the ambient pressure. The closure element for the control flow has effective surfaces associated with the respective fluid connections. A force resulting from the pressures applied to the closure element acts on the closure element such that a control flow generating a counter pressure flows from a region to which fluid is applied to high pressure to a region to which fluid is applied to suction pressure. In addition, a fluid-tight region, to which ambient pressure is applied, is formed and is sealed by means of a sheet metal membrane welded to the metallic closure element or vulcanised membrane. A spring element for generating an additional force acting on the closure element is also arranged inside the housing.
The equilibrium of forces on the closure element and the position of the closure element for achieving a required control curve of the counter pressure as a function of the high pressure and the suction pressure or low pressure is influenced by the pressures on the effective surfaces and by the flow through a passage opening released by the closure element.
The control flow regulating valve has two elastomer membranes which are formed on the low pressure side and the counter pressure side. The elasticity of the elastomer membrane permits axial mobility of the closure element within the housing. The elastomer membranes delimit a region of the control flow regulating valve in the axial direction which, due to a connection to the ambient pressure, has an atmospheric pressure independent of the low pressure and the counter pressure. A fluid-tight and pressure-tight barrier is formed with the elastomer membranes between the low pressure side and the counter pressure side. The fluid-tight connection of the elastomer membranes is guaranteed by vulcanisation to the surrounding housing or the closure element.
The devices known from the prior art for controlling a fluid mass flow as a control flow, in particular for a device for compressing a gaseous fluid, have a large number of components to be made in a very precise manner and with low tolerance, which are connected to one another in a complex structure, which causes a high complexity during assembly with a high number of assembly steps and thus high assembly costs. Thus, for example, several seals are also required in order to separate volumes charged with the fluid at different pressure levels from one another. Individual elements must be aligned coaxially to one another. The large number of components requires a large installation space, causes a high total weight and also carries a high risk of errors during the assembly process. Furthermore, vulcanising the membrane of an elastomer on metal, for example, is very complicated and complex and is unsuitable in particular for high pressure applications, such as in systems for carbon dioxide as a fluid. Sealing with vulcanised membranes also causes a high permeation surface, which can lead to a very high discharge of the fluid into the environment and thus to a very high loss of the fluid over a total operating time.
In order to adjust the device, especially the closure element, to the corresponding operating point and to achieve a high reproducibility, the sealing seat must be embossed. In this case, a defined force is applied to the closure element during embossing 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 testing until a desired pressure level is adjusted and serves, for example according to DE 10 2016 105 302 A1, for adjusting a distance between the closure element and the elastomer membranes in order to eliminate stresses of the elastomer membranes which occur as a result of extension.
The object of the invention is to provide a device for controlling a fluid mass flow as a control flow for a device for compressing a gaseous fluid, in particular in order to guarantee trouble-free operation with maximum service life of the device for compressing the fluid. The device should have a minimum number of individual components and be structurally simple to realise, also in order to minimise the assembly effort and costs during assembly. The device is to require minimum installation space, have a low weight and be formed in a fluid-tight manner in order to prevent leakage or the escape of fluid into the environment and thus the loss of fluid from a system.
The object is achieved by the subject matters having the features of the independent claims. Further developments are indicated in the dependent claims.
The object is achieved by a device according to the invention for controlling a fluid mass flow as a control flow for a device for compressing a gaseous fluid from a low pressure level to a high pressure level. The device for controlling a fluid mass flow has a housing with fluid connections impinged upon at different pressure levels and a closure element which can be moved in a translatory manner within the housing along a longitudinal axis, with effective surfaces assigned to the fluid connections. The closure element is formed such as to regulate a flow cross-section of a flow path extending between a first fluid connection and a second fluid connection.
According to the concept of the invention, the housing has a receiving opening for receiving the closure element, which is formed from a primary segment and a secondary segment in at least two pieces. The primary segment and the secondary segment of the closure element are each guided within the receiving opening of the housing and each arranged completely surrounded by the housing.
According to a further development of the invention, the primary segment of the closure element is sealed to the housing in a fluid-tight and pressure-tight manner via at least one first sealing element, while the secondary segment of the closure element is sealed to the housing in a fluid-tight and pressure-tight manner via at least one second sealing element, in particular via at least two second sealing elements.
According to an advantageous embodiment of the invention, the housing is formed from a first housing element and a second housing element in at least two parts. The primary segment of the closure element is guided within the first housing element and the secondary segment of the closure element is guided within the second housing element. The receiving opening of the housing for receiving the closure element is formed in particular to overlap the housing element, so that a first region of the receiving opening for receiving the primary segment of the closure element is provided within the first housing element and a second region of the receiving opening for receiving the secondary segment of the closure element is provided within the second housing element.
According to a preferred design of the invention, the closure element is formed to be cylindrical, in particular circular cylindrical, 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 formed with a primary segment diameter and the secondary segment of the closure element is formed with at least two sections each having different outer diameters. The primary segment diameter of the primary segment and the outer diameters of the secondary segment of the closure element can also differ from one another.
The primary segment and the secondary segment of the closure element advantageously each have an axis of symmetry which, according to a first alternative embodiment of the invention, are arranged on the common longitudinal axis or, according to a second alternative embodiment of the invention, are arranged parallel and spaced apart from one another and parallel to the longitudinal axis.
An advantage of the invention is that the closure element forms a sealing seat with the housing, in particular with the first housing element, on a first end face, in particular on a first end face of the primary segment.
The primary segment of the closure element is preferably aligned with a second end face, distal to the first end face, pointing towards 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.
According to a further advantageous design of the invention, a volume, which is limited by the housing and the closure element with an annular effective surface with a first outer diameter of the closure element, in particular of the secondary segment of the closure element, and the primary segment diameter of the closure element, in particular of the primary segment of the closure element, as an inner diameter, is acted upon by the fluid at the low pressure level and is connected to a third fluid connection of the housing.
A volume delimited by the housing, in particular the second housing element, and a second end face of the closure element, distal to the first end face, in particular a second end face of the secondary segment of the closure element, is preferably subjected to a level of an ambient pressure, specifically with ambient air, and is connected to the environment via a fourth fluid connection of the housing.
In addition, a volume, which is limited by the housing and the closure element with an annular effective surface with the first outer diameter of the closure element and a second outer diameter of the closure element as an inner diameter, each in particular of the secondary segment of the closure element, is advantageously acted upon by the fluid at the level of a counter pressure and is connected to the first fluid connection of the housing.
According to a further development of the invention, a first fluid connection is formed inside the housing, which extends from the first fluid connection to the volume limited by the housing and the closure element with the annular effective surface with the first outer diameter of the closure element and the second outer diameter of the closure element as the inner diameter, each in particular of the secondary segment of the closure element.
Within the housing, a second fluid connection can also be provided which extends from the first fluid connection to the volume limited by the housing and the closure element with the annular effective surface with the first outer diameter of the closure element, in particular of the secondary segment of the closure element, and the primary segment diameter of the closure element, in particular the primary segment of the closure element, as an inner diameter or to the third fluid connection of the housing. The second fluid connection is advantageously formed with an expansion element, in particular a throttle member.
The device for controlling the fluid mass flow as a control flow is advantageously configured such that the translatory movement of the closure element, in particular of the primary segment and of the secondary segment, within the housing, in particular within the first housing element and the second housing element, is based exclusively on pressures acting on the effective 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, in particular the sealing elements formed as O-rings. The primary segment and the secondary segment of the closure element can each be a metallic or a non-metallic component.
According to a further advantageous embodiment of the invention, the first fluid connection of the housing is acted upon by the fluid at the counter pressure level and the second fluid connection of the housing is acted upon by the fluid at the high pressure level, while the third fluid connection of the housing is acted upon by the fluid at the low pressure level. The counter pressure level represents an intermediate pressure level between the low pressure level and the high pressure level of the fluid. A fourth fluid connection of the housing is preferably acted upon by the level of the ambient pressure, in particular the ambient air.
According to a further preferred embodiment of the invention, the device for filtering out various particles from the fluid has a filter element which is integrated within the closure element, in particular within the primary segment of the closure element, or is arranged as a separate element within a flow-through opening of the second fluid connection and thus in each case at the inlet of the device.
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. The fluid to be compressed is present in an intake region at the low pressure level and the compressed fluid is present in a high pressure region, especially at an outlet of the device for compressing, at the high pressure level. The device for compressing has a housing with a counter wall and a compression mechanism with an immobile, fixed spiral and a movable, orbiting spiral driven via an eccentric drive. The housing with the counter wall and the orbiting spiral 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 within the housing.
According to the concept of the invention, a device according to the invention for controlling a fluid mass flow 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 as a control flow regulating valve is preferably arranged integrated within the housing of the compressor. The device for controlling a fluid mass flow is consequently formed without an additional housing.
According to a further development of the invention, the housing has at least two housing elements. A first housing element for receiving a primary segment of the closure element of the device for controlling the fluid mass flow and a second housing element for receiving a secondary segment of the closure element of the device for controlling the fluid mass flow are formed.
The closure element is arranged with the primary segment and the secondary segment within the housing so as to be movable in translation in order to open and close the flow path. When the flow path is open, the fluid is expanded from a high pressure level to a required counter pressure level. The level of the counter-pressure is determined by the position of the closure element, in particular of the primary segment of the closure element, and thus the degree of opening of the device for controlling the fluid mass flow. The position of the closure element is adjusted by an equilibrium of forces at the effective surfaces of the closure element, which is obtained from different pressure levels acting on the effective surfaces.
The closure element of the device for controlling the fluid mass flow is advantageously arranged within a receiving opening formed in the housing of the device for compressing the gaseous fluid. The primary segment of the closure element is arranged within a first region of the receiving opening, which is formed in the first housing element, and the secondary segment of the closure element is arranged within a second region of the receiving opening, which is formed in the second housing element, in particular such that it can be moved in translation along a longitudinal axis.
The advantageous design of the invention allows for the use of the device for compressing the gaseous fluid with the device for controlling a fluid mass flow as a compressor in a refrigerant circuit of an air-conditioning system of a motor vehicle. The compressor can be formed to be driven electrically or mechanically. In this case, the compression mechanism is driven by means of an electric motor or a pulley.
The device according to the invention for controlling a fluid mass flow as a control flow for a device for compressing a gaseous fluid from a low pressure level to a high pressure level can consequently be formed as a control flow regulating valve, in particular of a scroll compressor of a refrigerant circuit of an air-conditioning system of a motor vehicle.
The device according to the invention for controlling a fluid mass flow and the device for compressing a gaseous fluid with the device according to the invention for controlling a fluid mass flow together have further diverse advantages:
Further details, features and advantages of the invention will become apparent from the following description of an exemplary embodiment with reference to the accompanying drawings. In the drawings:
The device 1′ has 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 a translatory manner along a longitudinal axis 3a which corresponds to a symmetry axis of the closure 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 regulated by means of the closure element 3′. A control mass flow of the fluid is regulated by means of the closure element 3′ from a level of the high pressure at the second fluid connection 2b′ to a counter pressure level at the first fluid connection 2a′.
In addition, the housing 2′ has a third fluid connection 2c′ with the fluid at a level of the suction pressure of the device for compressing the fluid, also referred to as a level of the low pressure, and a fourth fluid connection 2d′ with a level of the ambient pressure. The third fluid connection 2c′ and the fourth fluid connection 2d′ each form no flow path. The third fluid connection 2c′ and the fourth fluid connection 2d′ serve to transmit the levels of the suction pressure and the ambient pressure to corresponding effective surfaces of the closure element 3′.
Between the closure element 3′ and the housing 2′, membrane sealing elements 4′ are arranged which delimit a region of the device 1′in the direction of the longitudinal axis 3a and seal the device 1′ to the ambient pressure. The region delimited by the membrane sealing elements 4′ has an atmospheric pressure independent of the low pressure and the counter pressure due to a connection to the ambient pressure level. The membrane sealing elements 4′ form in combination a fluid-tight and pressure-tight barrier between the low pressure side connected to the third fluid connection 2c′ and the counter pressure side connected to the first fluid connection 2a′.
Due to the membrane sealing elements 4′ formed between the closure element 3′ and the housing 2′ in each case as a welded sheet metal membrane or a vulcanised membrane, there is a high risk of leakage and thus the risk of fluid flowing 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 elements 4′, each formed from an elastomer, are vulcanised onto the closure element 3′.
In a closed position of the device 1′ shown in
The device 1′ also has a spring element 5′ which is arranged to act on the closure element 3′ with a spring force aligned counter to the closed position of the closure element 3′. The spring element 5′ is consequently formed for opening the device 1′, in particular 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 are balanced.
The closure element 3′ bears with a free end face of a primary segment 3-1′ orientated in the direction of the longitudinal axis 3a against the sealing seat 6 in a manner closing 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′.
The closure element 3′ is geometrically formed such that a primary segment diameter d2, the sealing seat diameter d1, a first effective diameter d3′ of the suction pressure level to the ambient pressure level and a second effective diameter d4′ of the counter pressure level to the ambient pressure level are configured such that a resulting force acts on the closure element 3′ as a function of the respectively applied pressure levels and thus controls 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 closure element 3′ is brought into the corresponding position in each case.
The device 1′ is also formed with a first fluid connection 7 which extends from the first fluid connection 2a′ to a volume enclosed by the closure element 3′, in particular an effective surface with the second effective diameter d4′ of the counter pressure level to the ambient pressure level, and the housing 2′, in order to include the counter pressure level correspondingly in the force balance at the closure element 3′. In addition, a second fluid connection 8 is provided which connects the first fluid connection 2a′ to the third fluid connection 2c′ and extends between the first fluid connection 2a′ and a volume enclosed by the closure element 3′, in particular an effective surface with the first effective diameter d3′ of the suction pressure level to the ambient pressure level, and the housing 2′. An expansion element 9, especially a throttle element or a throttle, is arranged within the second fluid connection 8.
The primary segment 3-1′ of the closure element 3′ is sealed off from the housing 2′ by means of a sealing element 10′ formed as an O-ring.
In
The device 1 has the housing 2 with different fluid connections 2a, 2b, 2c, 2d. The fluid connections 2a, 2b, 2c, 2d are also to be understood as meaning flow channels formed in the components of the device 1.
The closure element 3 is integrated within the housing 2 and can be moved in translation along the longitudinal axis 3a as 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 in particular from
The primary segment 3-1 as a piston and the secondary segment 3-2 as an actuator, also referred to as a control element, each have the shape of a cylinder, in particular a circular cylinder, with sections of different outer diameters. The primary segment 3-1 and the secondary segment 3-2 can be made of the same material or different materials, such as metal or non-metal, in particular plastic.
The device 1 has the 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 device for compressing the gaseous fluid, the flow cross-section of which can be regulated with the movement of the closure element 3, in particular of the primary segment 3-1 of the closure element 3. The control mass flow of the fluid through the flow path is regulated by the closure element 3. The flow path is formed within the first housing element 2-1.
The free first end face of the primary segment 3-1 of the closure element 3 orientated in the direction of the longitudinal axis 3a bears against a sealing seat 6 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 inside the first housing element 2-1 of the housing 2 of the device 1 in the form of a step or edge. The primary segment 3-1 of the closure element 3 cooperates with the sealing seat 6 and the second fluid connection 2b.
The housing 2 also has the third fluid connection 2c with the fluid at the level of the suction pressure or the low pressure of the device for compressing the fluid and the fourth fluid connection 2d with the level of the ambient pressure. The third fluid connection 2c and the fourth fluid connection 2d only serve to transmit the levels of the suction pressure and the ambient pressure to corresponding effective surfaces of the closure element 3.
Sealing elements 10-1, 10-2 are arranged between the housing 2 and the closure element 3. According to
The primary segment 3-1 of the closure element 3 rests with a second end face, which is orientated in the direction of the longitudinal axis 3a and is distal to the first end face, on a first end face of the secondary segment 3-2 of the closure element 3.
The piston-shaped secondary segment 3-2 of the closure element 3 is subjected to ambient pressure at a second end face, which is orientated in the direction of the longitudinal axis 3a and is distal to the first end face orientated to the primary segment 3-1 and to the sealing seat 6. A volume delimited by the housing 2, in particular the second housing element 2-2, and the second end face of the secondary element 3-2 of the closure element 3 is acted upon by the ambient pressure level. The volume connected to the environment via the fourth fluid connection 2d thus has a pressure level which is independent of the low pressure level and the counter pressure level.
The primary segment 3-1 and the secondary segment 3-2 of the closure element 3 are always in mechanical contact after the filling of the device for compressing a gaseous fluid and thus also of the device 1 for controlling the fluid mass flow with refrigerant due to the forces acting on the closure element 3.
In the closed position of the device 1, the closure element 3 with the primary segment 3-1 rests against the sealing seat 6 with the sealing seat diameter d1, which is formed on the housing 2, in particular the first housing element 2-1. The flow path extending between the first fluid connection 2a and the second fluid connection 2b is closed.
The closure element 3 is geometrically formed such that the primary segment diameter d2 of the primary segment 3-1 of the closure element 3, the sealing seat diameter d1, a first outer diameter d3 of the suction pressure level to the counter pressure level and a second outer diameter d4 of the counter pressure level to the ambient pressure level are configured such that a resulting force acts on the closure element 3 as a function of the respectively applied pressures and thus controls 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 closure element 3 is brought into the corresponding position in each case. 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 closure element 3 are each configured such that the counter pressure level which is established in particular satisfies the required pressure of an orbiting spiral on a fixed spiral of a compression mechanism of a scroll compressor as a device for compressing a gaseous fluid.
The device 1 is also formed with the first fluid connection 7 which extends from the first fluid connection 2a to a volume enclosed by the closure element 3, in particular an effective surface with the first outer diameter d3 of the counter pressure level to the suction pressure level, and the housing 2, in order to include the counter pressure level correspondingly in the force balance at the closure element 3. In addition, the second fluid connection 8 is provided which connects the first fluid connection 2a to the third fluid connection 2c and extends between the first fluid connection 2a and a volume enclosed by the closure element 3, in particular an effective surface with the first effective diameter d3 of the suction pressure level to the counter pressure level, and the housing 2. The expansion element 9 is arranged within the second fluid connection 8.
The volume enclosed by the second end face of the secondary element 3-2 of the closure element 3 with the effective surface with the second outer diameter d4 and the housing 2, in particular the second housing element 2-2, and connected to the fourth fluid connection 2d and thus acted upon with the ambient pressure level serves to reduce the effective surface of the counter pressure acting in the closed position of the closure element 3.
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 by means of the sealing gap formed between the primary segment 3-1 of the closure element 3 and the housing 2, in particular the first housing element 2-1 also act counter to the closed position of the closure element 3.
The first fluid connection 2a is formed to overlap the housing element with 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 can be formed within the first housing element 2-1 or within the second housing element 2-2.
The respective diameters of the closure element 3 are formed with the aim of establishing the equilibrium of forces in such a way that the level of the counter-pressure is regulated. The counter-pressure at the circular effective surface of the secondary segment 3-2 with the first outer diameter d3 and the second outer diameter d4 effects a force orientated in the closing direction of the closure element 3, while the suction pressure at the circular effective surface of the secondary segment 3-2 with the first outer diameter d3 and the primary segment diameter d2 plus the high pressure at the circular effective surface with the sealing seat diameter d1 effects a counter-force orientated counter to the closing direction of the closure element 3. The counterforce is imaged by means of a coefficient x for the suction pressure and a coefficient y for the high pressure.
The coefficients x and y are adapted for setting a required back pressure or a desired back pressure curve with a change of the planes on which the individual pressures act. The coefficients are adapted to changed ratios of the pressurised surfaces to one another, so that a variation of the coefficients results in a variation of the surface ratios and consequently a variation of the set back pressure as a function of the degree of opening of the device for controlling the fluid mass flow.
With the translatory movement of the closure element 3, specifically of the primary segment 3-1, a throttle gap is set at the sealing seat 6 between the primary segment 3-1 and the housing 2, in particular the first housing element 2-1, in which the fluid is reduced from the level of the high pressure to the respective level of the counter pressure when flowing through. The primary segment 3-1 and the secondary segment 3-2 of the closure element 3 can be aligned both along the longitudinal axis 3a as an axis of symmetry and thus coaxially and also eccentrically with respect to the longitudinal axis 3a and thus parallel and spaced apart from one another.
The first sealing element 10-1, which is formed as an O-ring, formed a fluid-tight and pressure-tight barrier between the volume impinged upon by the level of the suction pressure and the first fluid connection 2a, while the second sealing elements 10-2, which are formed as O-rings, each form a fluid-tight and pressure-tight barrier between the volumes impinged upon by the ambient pressure level and the counter pressure level and between the volumes impinged upon by the counter pressure level and the suction pressure level. Thus, only a second sealing element 10-2 provided between the volumes impinged upon by the ambient pressure level and the counter pressure level is formed as a sealing of the device 1 to the environment.
In
The compression mechanism 21, which is formed with a fixed spiral 21a and an orbiting spiral 21b, and the electric motor 22 are arranged within a volume enclosed by the housing 2. The housing 2 is formed from three housing elements 2-1, 2-2, 2-3, in particular the first housing element 2-1 for receiving the primary segment 3-1 of the closure element 3 and the compression mechanism 21, the second housing element 2-2 for receiving the secondary segment 3-2 of the closure element 3 and a third housing element 2-3 for receiving the electric motor 22 and preferably formed from a metal, for example from an aluminium.
The electric motor 22 has a stator 22a with an essentially hollow cylindrical stator core and coils wound on the stator core, and a rotor 22b arranged inside the stator 22a. The rotor 22b is set into a rotational movement when electrical energy is supplied to the coils of the stator 22a. The rotor 22b is arranged coaxially within the stator 22a and rotatable about an axis of rotation 23. A drive shaft 24 can be formed integrally with the rotor 22b or as a separate element.
The orbiting spiral 21b of the compression mechanism 21, in which the gaseous fluid, especially a refrigerant, is compressed, is driven via the drive shaft 24 connected to the rotor 22b of the electric motor 22. The fluid compressed to the high pressure level when flowing through the compression mechanism 21 is discharged through at least one outlet 25 from the compression mechanism 21 into a region of the high pressure level 20b of the compressor 20.
The compressor 20 also has a wall arranged within the housing 2, in particular the second housing element 2-2, and fixedly connected to the housing 2, which is formed as a boundary of a region of the counter pressure level 20a of the compressor 20, also known as the counter pressure region, and is consequently also referred to as a counter wall 26. Within the region of the counter pressure level 20a formed between the counter wall 26 and the orbiting spiral 21b, in particular a rear side of a base plate of the orbiting spiral 21b, the fluid is present at the counter pressure level, which is also present as a level of the contact pressure as an intermediate pressure between the levels of the high pressure as outlet pressure and of the low pressure as suction pressure of the compressor 20. The fluid has the low pressure level in a region of the low pressure level 20c of the compressor 20, in which the electric motor 22 is also arranged. Outside the housing 2 of the compressor 20, the ambient pressure prevails, so that the environment is also designated as a region of the ambient pressure level 20d of the compressor 20.
The device 1 for controlling a fluid mass flow is integrated with the closure element 3 within the receiving opening 11 as a cavity of the housing 2 of the device for compressing a gaseous fluid, in particular of the compressor 20. The primary segment 3-1 of the closure element 3 is arranged within the first region 11-1 of the receiving opening 11, which is formed in the first housing element 2-1, and the secondary segment 3-2 of the closure element 3 is arranged within the second region 11-2 of the receiving opening 11, which is formed in the second housing element 2-2.
Between the primary segment 3-1 of the closure element 3 and the first housing element 2-1, the first sealing element 10-1, which is formed as an O-ring, is arranged, while between the secondary segment 3-2 of the closure element 3 and the second housing element 2-2, the second sealing elements 10-2, which are formed as O-rings and seal off the corresponding pressure spaces from one another, are arranged.
The first sealing element 10-1 forms a fluid-tight and pressure-tight barrier between volumes acted upon with the level of the suction pressure and the level of the back pressure, in particular between the region of the level of the low pressure 20c and the region of the level of the back pressure 20a of the compressor 20, while the second sealing elements 10-2 form a fluid-tight and pressure-tight barrier between volumes acted upon with the level of the suction pressure and the level of the back pressure, in particular between the region of the level of the low pressure 20c and the region of the level of the back pressure 20a of the compressor 20d, and between volumes acted upon with the level of the back pressure and the level of the ambient pressure. in particular between the region of the level of the counter pressure 20a and the region of the level of the ambient pressure 20d of the compressor 20.
| Number | Date | Country | Kind |
|---|---|---|---|
| 102023134115.4 | Dec 2023 | DE | national |
| 102024129639.9 | Oct 2024 | DE | national |
