WO2021125567A1

WO2021125567A1 - Device for controlling a flow rate and expanding a fluid in a fluid circuit and method for operating the device

Info

Publication number: WO2021125567A1
Application number: PCT/KR2020/015840
Authority: WO
Inventors: Carsten Ohrem; Jürgen Nothbaum; Oliver Fischer
Original assignee: Hanon Systems
Priority date: 2019-12-16
Filing date: 2020-11-12
Publication date: 2021-06-24
Also published as: DE102019134523A1

Abstract

The invention relates to a device (1) for controlling a flow rate and expanding a fluid in a fluid circuit. The device (1) has an enclosure (2) and a valve element (6) arranged inside the enclosure (2) as well as an actuator (4) and a transmission assembly (5) for transmitting a rotational movement (4a) of the actuator (4) about a longitudinal axis into a linear movement (6a) of the valve element (6) in the direction of the longitudinal axis relative to the enclosure (2). The valve element (6) is mounted rotatably about the longitudinal axis in a rotational movement (6d). The valve element (6) is mechanically connected to the actuator (4) via a sliding rotary assembly (8). The sliding rotary assembly (8) is formed in such a way so as to transmit the rotational movement (4a) of the actuator (4) to the valve element (6). The invention also relates to a method for operating a device (1) for controlling a flow rate and expanding a fluid in a fluid circuit.

Description

DEVICE FOR CONTROLLING A FLOW RATE AND EXPANDING A FLUID IN A FLUID CIRCUIT AND METHOD FOR OPERATING THE DEVICE

The invention relates to a device for controlling a flow rate and expanding a fluid in a fluid circuit, in particular a coolant in a coolant circuit of an air conditioning system of a motor vehicle. The device has an enclosure and a valve element arranged in the interior of the enclosure, as well as an actuator and a transmission assembly for transmitting a rotational movement of the actuator about a longitudinal axis into a linear movement of the valve element in the direction of the longitudinal axis relative to the enclosure.

The invention also relates to a method for operating the device.

A valve as a device for controlling a flow rate and expanding a coolant, in particular an expansion valve, fulfills the functions of sealing, controlling a mass flow or expanding the coolant according to a characteristic curve, as well as letting it through at full load with the flow cross-section open to the maximum. Operation with the flow cross-section of the valve open to the maximum enables the coolant to flow through with minimal or no significant pressure loss.

In addition to the functions mentioned, the valve should also meet other criteria. The transition between the sealing and controlling or expanding functions should take place as continuously as possible and therefore without a jump within the corresponding characteristic curve. Sealing must also be ensured in a de-energized state of a valve driven by an electric motor; the valve should consequently be formed to be self-sealing or self-locking. The valve must be configured for a pressure gradient applied on both sides. The pressure difference can be up to 100　bar. The valve should be usable in a temperature range of - 40　 ^oC to + 120　 ^oC.

DE 10 2016 013 492 A1 discloses an electrically driven expansion valve and shut-off valve for operation with the coolant R744. The valve has a valve body arranged in a valve body chamber as well as a sealing seat and a seal which are aligned along an axial direction of movement of the valve body within the valve. The valve is formed in such a way that in a closed state there is a pressure bypass to the valve body chamber. The valve body is provided with a passage aperture extending substantially in the axial direction as a component of the pressure bypass. The pressure bypass extends from a connection through the valve body to the valve body chamber.

Devices 1' known from the prior art for controlling a flow rate and expanding a coolant with an electric drive, as shown in Figs. 1a to 1d, are formed with an enclosure 2' and an electric motor 3 which sets a drive shaft provided as an actuator 4' in a rotational movement 4a. Using a transmission assembly 5' provided on the drive shaft 4' oriented in an axial direction, in particular a thread, specifically a so-called movement thread, the rotational movement 4a of the drive shaft 4' about its longitudinal axis is transmitted into a translatory stroke movement of a valve element 6' which is preferably formed as a valve needle. The translatory stroke movement thus corresponds to a linear movement 6a of the valve element 6' in the axial direction, that is to say, in the direction of the longitudinal axis of the drive shaft 4'.

The mating threads of the transmission assembly 5' are provided between the drive shaft 4' and the valve element 6'. The drive shaft 4', which substantially has the shape of a cylindrical rod, in particular a round rod with sections of different diameters, is inserted with a free end into an aperture 6b' formed in the valve element 6'. The free end of the drive shaft 4' is arranged distally to an end connected to the electric motor 3. The drive shaft 4' thus has a male thread at the free end as the first element of the mating threads, while a female thread is formed as the second element of the mating threads inside the aperture 6b' of the valve element 6'.

The valve element 6' is arranged in a valve seat element 7. The valve element 6', which is moved linearly in the axial direction and substantially extends in the axial direction, is held by a sliding rotary lock assembly 8' which prevents a rotational movement of the valve element 6' about the axial direction or the longitudinal axis of the valve element 6' and allows the linear movement 6a in the axial direction.

The valve element 6' has formations 6c' in the area sliding along inside the enclosure 2'. The formations 6c' are formed on an end of the valve element 6' oriented towards the electric motor 3 and protrude in pairs opposite from the valve element 6', which can be seen in particular from Figs. 1c and 1d. The valve element 6' thus has a T-shape in a cross-section through the longitudinal axis.

In the area of the formations 6c' of the valve element 6' the enclosure 2' is formed with notch-shaped or groove-like recesses 2a' arranged opposite one another with respect to the longitudinal axis of the valve element 6', which, in each case, correspond in shape to a formation 6c' of the valve element 6'. The shapes of the recesses 2a' of the enclosure 2' each correspond to the outer shape of the formations 6c' of the valve element 6' plus a play for sliding movement of the valve element 6' within the enclosure 2' in the axial direction.

By arranging the formations 6c' of the cross-sectionally T-shaped valve element 6' within the notch-shaped or groove-like recesses 2a' of the enclosure 2', a rotational movement of the valve element 6', driven by the actuator 4' rotating about the longitudinal axis, is prevented. The valve element 6' is thus moved by the rotational movement 4a of the actuator 4' without its own rotation about the longitudinal axis in the linear movement 6a.

The device is also formed with a first port 9 and a second port 10. A passage aperture 9a of the first port is oriented in the radial direction to the valve element 6', while a passage aperture 10a of the second port 10 is oriented in the axial direction of the valve element 6'. The passage aperture 9a of the first port 9 is pressurized by coolant at a first pressure p1, so that the pressure p1 acts on the valve element 6′' substantially in the radial direction. The passage aperture 10a of the second port 10 is pressurized by coolant at a second pressure p2, so that pressure p2 acts on the valve 6' substantially in the axial direction. All the pressurized surfaces of the valve 6' are configured in such a way that valve 6' is arranged in an almost isostatic state. The pressure forces acting on the valve 6' are in equilibrium.

Due to the dimensioning of the electric drive, only a limited force is available for moving the valve element 6', that is to say the valve needle. In addition, a tight fit of the valve element 6' within the valve seat element 7 in the de-energized state of the electric motor 3 and at temperatures of -40　 ^oC to + 120　 ^oC must be ensured. By generating a force acting on the valve element 6' and thus pressing the valve element 6' into the valve seat element 7, the valve element 6' can be held by the transmission assembly 5' formed as a self-locking movement thread. However, a combination of the force pressing the valve element 6' into the valve seat element 7 and a change in temperature and the associated different expansion of the components of the valve 1' leads to jamming of the components, so that the valve element 6' is immovably fixed.

Another possibility of forming the valve 1' is a defined clamping of the valve element 6' on the valve seat element 7, in particular on a sealing element arranged between the enclosure 2', the valve seat element 7 and the valve element 6', which sealing element is also referred to as a valve seat seal. An angle of a sealing cone should be selected in such a way that self-locking is achieved in the sealing area and the movement thread is thus relieved. However, this requires a very detailed and precise design of the sealing contour, since an angle of the sealing cone that is too small will result in jamming the valve element 6' within the valve seat seal, and an angle of the sealing cone that is too large will result in leaks between the valve element 6' and the valve seat seal. In addition, such a concept requires very high manufacturing standards, especially with regard to surfaces and geometric tolerances. Such manufacturing and measuring is very complex and costly.

The movement thread as a transmission assembly 5' is formed depending on the dimension of the valve element 6', for example with a fine thread M3/M4 and thus at the limit of the load capacity. Deviations in quality and external influences, such as changes in temperature and the associated different expansions of the components and manufacturing tolerances, can lead to jamming and thus to failure of the valve 1'.

The introduction of a section 5a' formed as a flattened area of the thread of the actuator 4', which otherwise has a circular cross-section, according to Figs. 1c and 1d, reduces the load capacity and leads to an uneven load. The section 5a' formed in the area of the thread as a throughflow aperture in combination with the aperture 6b' of the valve element 6' formed as a through-hole ensures the pressure equalization in the axial direction with respect to the second pressure p2 within the valve 1'. The formation of the section 5a' as a flattened area carries the risk of the formation of a burr on the edges and the transition from the surface to the thread during the manufacturing process, which in turn damages the movement thread as a transmission assembly 5'.

Due to the mounting of the drive shaft 4' within the enclosure 2' and the assembly of the valve element 6' within the valve seat element 7, a number of interconnected tolerances of several components result. Alignment errors and other assembly inaccuracies are compensated for by a clearance fit of the threaded connection, which leads to a further indefinable load on the transmission assembly 5' and thus to possible overloads.

The object of the invention is to provide and improve a device for controlling a flow rate and expanding a fluid in a fluid circuit, in particular in a coolant circuit, especially an air conditioning system of a motor vehicle, which meets the above-mentioned requirements. In particular, the configuration of the device with regard to the transmission of the movement of the actuator to the valve element with regard to a defined and uniform load, especially in the area of the transmission assembly, should be improved. The forces acting on the transmission assembly should be minimal. The assembly inaccuracies between the actuator and the valve element should also be minimized. In addition, the production should be simple and thus the production costs should be minimal. The device should be able to be operated reliably in every application, that is to say, in a large temperature range and pressure range.

The object is achieved by the subjects with the features of the independent claims. Further developments are set forth in the dependent claims.

The object is achieved by a device for controlling a flow rate and expanding a fluid in a fluid circuit, in particular a coolant in a coolant circuit. The device has an enclosure and a valve element arranged in the interior of the enclosure, as well as an actuator and a transmission assembly for transmitting a rotational movement of the actuator about a longitudinal axis into a linear movement of the valve element in the direction of the longitudinal axis relative to the enclosure.

According to the conception of the invention, the valve element is arranged rotatably mounted about the longitudinal axis in a rotational movement. The valve element is mechanically connected to the actuator via a sliding rotary assembly. The sliding rotary assembly is formed in such a way so as to transmit the rotational movement of the actuator to the valve element and advantageously to enable a relative movement between the actuator and the valve element in the direction of the longitudinal axis.

The actuator is preferably formed as a drive shaft. The drive shaft is preferably connected to an electric motor, in particular a stepping motor or a servomotor, which can set the drive shaft in a rotational movement about the longitudinal axis. One advantage of the invention is that the drive shaft is fixed in the axial direction within the enclosure.

According to a further development of the invention, the sliding rotary assembly has an aperture formed in the valve element and an end section of the drive shaft. The end section of the drive shaft is preferably arranged distally to an end of the drive shaft connected to the electric motor.

According to a preferred configuration of the invention, the aperture formed in the valve element extends in the direction of the longitudinal axis. The end section of the drive shaft is arranged movably inserted into the aperture of the valve element in the direction of the longitudinal axis. The aperture of the valve element can be provided as a through hole.

The sliding rotary assembly is advantageously formed as a form-fitting sliding contour. A shape of a wall surrounding the aperture of the valve element and an outer shape of the end section of the drive shaft are formed and arranged to correspond to one another and to interlock. The sliding rotary assembly also preferably has a polygonal or multi-edged shape, in particular a hexagon, a star, a polygon or the like.

The sliding rotary assembly is preferably formed with a free cross-section between the drive shaft and the valve element, for example in order to ensure pressure equalization around the valve element, in particular in the axial direction.

According to an advantageous configuration of the invention, the transmission assembly is formed as mating threads between the enclosure and the valve element. In this case, a male thread is preferably provided on an outside of the rotationally symmetrical valve element, and a female thread is provided inside the enclosure. The male thread and the female thread are preferably each formed over their entire circumference.

The male thread of the valve element can be arranged specifically on an end of the valve element which is oriented towards the actuator.

According to a further development of the invention, the valve element is arranged for guiding and holding inside a valve seat element which allows the rotational movement of the valve element about the longitudinal axis and the linear movement of the valve element in the axial direction.

The valve element is preferably arranged sealingly via two sealing elements to the enclosure and to the valve seat element. A first sealing element is preferably formed as a sliding seal, sealing the valve element from the enclosure, while a second sealing element is formed as a valve seat seal, sealing the valve element from the enclosure and from the valve seat element.

Another advantage of the invention is that the valve element in a closed state of the device abuts the second sealing element in a sealing area and that the valve element in an open state is arranged forming a fully circumferential gap between the valve element and the second sealing element.

The sealing area preferably has a first sealing surface which is formed circumferentially on the second sealing element and a second sealing surface which is formed circumferentially on the valve element. The first sealing surface and the second sealing surface are aligned conically to the longitudinal axis in a like-minded manner. The first sealing surface can be oriented at an angle α in the range from 20° to 45° to the longitudinal axis, while the second sealing surface can be oriented at an angle β in the range from 3° to 10° to the longitudinal axis.

According to a further preferred configuration of the invention, the valve element has a circumferentially formed control surface on a lateral surface. The control surface is preferably conical and oriented at an angle γ in the range from 0.5° to 2° to the longitudinal axis.

The control surface advantageously extends from the second sealing surface of the sealing area to an end face of the valve element.

Another advantage of the invention is that the enclosure is formed with ports for connecting to fluid lines, which are each connected to the interior of the enclosure via a passage aperture. In this case, axes of symmetry of the passage apertures of the ports of the enclosure have a common point of intersection where the valve element is arranged.

The passage aperture of the first port of the enclosure is preferably oriented in a radial direction to the longitudinal axis, while the passage aperture of the second port of the enclosure is arranged on an opposite side of the actuator to the valve element. In addition, the axis of symmetry of the passage aperture of the second port of the enclosure and the longitudinal axis or the axis of rotation of the valve element can be arranged coaxially aligned with one another.

The object is also achieved by a method according to the invention for operating an aforementioned device for controlling a flow rate and expanding a fluid in a fluid circuit, in particular a coolant in a coolant circuit. The method consists of the following steps:

- setting an actuator in a rotational movement about a longitudinal axis,

- transmitting the rotational movement of the actuator by means of a sliding rotary assembly to a valve element, so that the valve element together with the actuator rotates about the longitudinal axis in a rotational movement,

- transmitting the rotational movement of the valve element by means of a transmission assembly into a linear movement of the valve element in the direction of the longitudinal axis relative to the enclosure, so that the valve element is moved linearly along the longitudinal axis, the device being opened or closed depending on the direction of rotation of the actuator.

The advantageous configuration of the invention enables the device to be used for controlling a flow rate and for expanding a fluid in a coolant circuit of an air conditioning system of a motor vehicle.

The device according to the invention and the method for operating the device for controlling a flow rate and expanding a fluid in a fluid circuit have, in summary, further diverse advantages:

- transferring the movement of the actuator to the valve element with a minimum number of degrees of freedom with a defined and uniform load, especially in the area of the transmission assembly where the forces acting are minimal, and

- minimal assembly inaccuracies between the actuator and the valve element, therefore

- reliable operation in a wide temperature range and pressure range, and

- simple production with minimal production costs.

Further details, features and advantages of configurations of the invention emerge from the following description of exemplary embodiments with reference to the associated drawings.

Figs. 2a and 2b: show a device for controlling a flow rate and expanding a fluid in a fluid circuit, in particular a coolant circuit of an air conditioning system of a motor vehicle, with an enclosure and valve element arranged within the enclosure, as well as an actuator with a transmission assembly in the closed as well as open state, each in a lateral sectional illustration,

Fig. 3: shows the actuator and the valve element as individual components in an exploded illustration and perspective view, and

Figs. 4a and 4b: each show a detailed view of the assembly of the valve element within the valve seat element and the second sealing element, respectively.

Figs. 2a and 2b each show a device 1 for controlling a flow rate and expansion of a fluid in a fluid circuit, in particular a valve 1, especially in a coolant circuit of an air conditioning system of a motor vehicle, with an enclosure 2 and a valve element 6 arranged in the interior of the enclosure 2, as well as an actuator 4 with a transmission assembly 5 in a closed as well as an open state of the device 1, each shown in a lateral sectional illustration. The device 1, in particular a valve, is driven via an electric motor 3. With the electric motor 3, a drive shaft formed as an actuator 4 is set in a rotational movement 4a.

The rotational movement 4a and a torque of the drive shaft 4 are transmitted to the valve element 6 via a sliding rotary assembly 8, which is thus rotated in a rotational movement 6d, equal to the rotational movement 4a of the drive shaft 4. The sliding rotary assembly 8 is also formed according to Fig. 3 such that the drive shaft 4, which substantially has the shape of a cylindrical rod, in particular a round rod with sections of different diameters, is inserted with a free end in an aperture 6b formed in the valve element 6 as a first component of the sliding rotary assembly 8. The free end of the drive shaft 4, which is also referred to as the end section 8a of the drive shaft 4 and is formed as a second component of the sliding rotary assembly 8, is arranged distally to an end of the drive shaft 4 connected to the electric motor 3. The aperture 6b provided within the valve element 6 is formed as a through hole which extends along the axis of rotation or the longitudinal axis of the valve element 6.

The torque is transmitted via the sliding rotary assembly 8, which is formed with a form-fitting sliding contour. The form-fitting sliding contour is preferably formed as a shaft-hub connection or a notch-pin connection that can be linearly displaced or that enables a linear movement 6a and transmits a rotational movement 4a. Especially in the area of the aperture 6b provided in the valve element 6 in conjunction with the end section 8a of the drive shaft 4 inserted in the aperture 6b, the sliding rotary assembly 8 can have various form-fitting sliding contours, such as a hexagon, a star, a polygon or the like, which are suitable for transmitting momenta, in particular torques, and enable a relative displacement of the drive shaft 4 and valve element 6 to one another or a sliding of the drive shaft 4 and valve element 6 along one another in the direction of the longitudinal axis of the drive shaft 4. The shape of the wall surrounding the aperture 6b of the valve element 6 and the outer shape of the end section 8a of the drive shaft 4 are formed to correspond to one another and to interlock. The shape of the wall surrounding the aperture 6b of the valve element 6 corresponds to the outer shape of the end section 8a of the drive shaft 4 plus a play for sliding movement of the valve element 6 on the end section of the drive shaft 4 in the axial direction. The drive shaft 4 is fixed in the axial direction.

The sliding rotary assembly 8 is formed with a free cross-section to compensate for the pressure p2 and to compensate for assembly inaccuracies between the drive shaft 4 and the valve element 6. The wall surrounding the aperture 6b of the valve element 6 and the wall of the end section 8a of the drive shaft 4 do not abut completely fluid-tight. According to Fig. 3, the form-fitting sliding contour of the sliding rotary assembly 8 has, for example, an embodiment according to an elongated square with rounded transitions on the side surfaces, that is, a slot contour of the aperture 6b and two opposite parallel surfaces on the shaft of the drive shaft 4.

Using a transmission assembly 5 formed on an outside of the rotationally symmetrical valve element 6, in particular a thread, specifically a movement thread, the rotational movement 6d of the valve element 6 about the longitudinal axis is transmitted into a translatory stroke movement of the valve element 6 which is preferably formed as a valve needle. The translatory stroke movement corresponds to the linear movement 6a of the valve element 6 in the axial direction and thus in the direction of the longitudinal axis.

The mating threads of the transmission assembly 5 is provided between the enclosure 2 and the valve element 6. The valve element 6b as the first element of the mating threads has a male thread at an end facing the drive shaft 4, while the enclosure 2 is formed in the area of the assembly of the valve element 6 with a female thread as the second element of the mating threads.

The valve element 6 is displaced as a result of the formation of the sliding rotary assembly 8 in combination with the transmission assembly 5 by the rotational movement 4a of the actuator 4 with its own rotation in rotational movement 6d about the longitudinal axis in the linear movement 6a.

The valve element 6 is arranged within a valve seat element 7, which allows both the rotational movement 6d of the valve element 6 about the longitudinal axis and the linear movement 6a of the valve element 6 in the axial direction.

The device 1 is also formed with a first port 9 and a second port 10 for connecting to fluid lines. A passage aperture 9a of the first port 9 is oriented in the radial direction to the valve element 6, while a passage aperture 10a of the second port 10 is oriented in the axial direction of the valve element 6. The passage aperture 9a of the first port 9 is pressurized by coolant at a first pressure p1, so that the pressure p1 acts on the valve element 6 substantially in the radial direction. The passage aperture 10a of the second port 10 is pressurized by coolant at a second pressure p2, so that the pressure p2 acts on the valve element 6 substantially in the axial direction. All the pressurized surfaces of the valve body 6 are configured in such a way that the valve element 6 is arranged in an almost isostatic state. The pressure forces acting on the valve element 6 are in equilibrium. The pressure equalization with respect to the pressure p2 acting in the axial direction is ensured by the formation of the sliding rotary assembly 8 with the free cross-section between the drive shaft 4 and the valve element 6, in particular between the wall surrounding the aperture 6b of the valve element 6 and the wall of the end section 8a of the drive shaft 4.

The valve element 6 is also arranged sealingly via two sealing

elements

11, 12, in particular a first, dynamic sealing element 11 to the enclosure 2 and a second, static sealing element 12 to the enclosure 2 and the valve seat element 7. The first sealing element 11 is formed as a sliding seal, in particular a rod seal, in the form of an axial seal or an annular seal, while the second sealing element 12 is formed as a seat seal, in particular as a valve seat seal. The second sealing element 12 is consequently arranged between the enclosure 2, the valve element 6 and the valve seat element 7.

Figs. 4a and 4b each show a detailed view of the assembly of the valve element 6 inside the valve seat element 7 and inside the second seal element 12, respectively.

In the closed state of the device 1, according to Fig. 2a, the valve element 6 abuts the second sealing element 12 in a sealing area 13, while the valve element 6 in the open state of the device 1, according to Fig. 2b, is displaced in the axial direction with respect to the second sealing element 12 in such a way that a fully circumferential gap is formed between the valve element 6 and the second sealing element 12.

The sealing area 13 has a first, circumferential sealing surface 13a on the second sealing element 12 and a second, circumferential second sealing surface 13b on the valve element 6, which are formed conically in a like-minded manner to the longitudinal axis and correlate with one another. In the closed state of the device 1 the first sealing surface 13a of the second sealing element 12, which is also sealingly connected to the enclosure 2 and the valve seat element 7, abuts the second sealing surface 13b of the valve element 6 in a fluid-tight manner.

The conically formed first sealing surface 13a of the second sealing element 12 is oriented at an angle a in the range of 20° to 45° to the longitudinal axis, while the conically formed second sealing surface 13b of the valve element 6 is oriented at an angle β in the range of 3° to 10° to the longitudinal axis. As a result of the conical formation of the sealing

surfaces

13a, 13b, the valve element 6 can be inserted into the second sealing element 12 in a centered manner during the process of closing the device 1.

In the open state of the device 1, the sealing

surfaces

13a, 13b are arranged at a distance from one another. After a process of opening the device 1, during which the valve element 6 is moved away from the second sealing element 12, the device 1 is brought directly into a control area.

The valve element 6 has a circumferential control surface 14 besides the second sealing surface 13b of the sealing area 13 on the lateral surface, which are arranged adjacent to one another in the axial direction and differ in an extension in the axial direction. The control surface 14, which extends over a larger area than the sealing surface 13b, is, like the sealing surface 13b, formed conically and oriented at an angle γ in the range from 0.5° to 2° to the longitudinal axis. The control surface 14 extends from the sealing surface 13b to the end face of the valve element 6.

The conical formations of the second sealing surface 13b and the control surface 14 are oriented in the same way. Due to the conical formation of the control surface 14 in the direction of the longitudinal axis of the valve element 6, the flow cross-section for the fluid to be passed through the device 1 is continuously changed with the linear movement 6a of the valve element 6 in the axial direction until the valve element 6 is completely removed from the second sealing element 12 or the device 1 is closed and the valve element 6 abuts the second sealing element 12 in a fluid-tight manner. By means of the linear movement 6a of the valve element 6 in relation to the second sealing element 12, in combination with the control surface 14, the mass flow of the fluid through the device 1 is controlled.

The lateral surface of the valve element 6 is substantially formed in the sequence mentioned below with an area formed with the transmission assembly 5, an area having the shape of a straight circular cylinder, the second sealing surface 13b and the control area with the control surface 14.

List of reference numerals

1, 1' device, valve

2, 2' enclosure

2a' recess of the enclosure 2'

3 electric motor

4, 4' actuator, drive shaft

4a rotational movement of the actuator 4, 4'

5, 5' transmission assembly

5a' section

6, 6' valve element

6a linear movement of the valve element 6, 6'

6b, 6b' aperture of the valve element 6, 6'

6c' formation of the valve element 6'

6d rotational movement of the valve element 6

7 valve seat element

8 sliding rotary assembly

8a end section of the drive shaft 4

8' sliding rotary lock assembly

9 first port

9a passage aperture of the first port 9

10 second port

10a passage aperture of the second port 10

11 first sealing element

12 second sealing element

13 sealing area

13a first sealing surface of the second sealing element 12

13b second sealing surface of the valve element 6

14 control surface

p1, p2 pressure

α angle of the first sealing surface 13a of the second sealing element 12

β angle of the second sealing surface 13b of the valve element 6

γ angle of the control surface 14

Claims

A device (1) for controlling a flow rate and expanding a fluid in a fluid circuit, comprising an enclosure (2) and a valve element (6) arranged in the interior of the enclosure (2), as well as an actuator (4) and a transmission assembly (5) for transmitting a rotational movement (4a) of the actuator (4) about a longitudinal axis into a linear movement (6a) of the valve element (6) in the direction of the longitudinal axis relative to the enclosure (2), characterized in that the valve element (6) is arranged rotatably mounted about the longitudinal axis in a rotational movement (6d), wherein the valve element (6) is mechanically connected to the actuator (4) via a sliding rotary assembly (8) and the sliding rotary assembly (8) is formed in such a way so as to transmit the rotational movement (4a) of the actuator (4) to the valve element (6).
The device (1) according to claim 1, characterized in that the actuator (4) is formed as a drive shaft.
The device (1) according to claim 2, characterized in that the drive shaft (4) is formed to be connected to an electric motor (3).
The device (1) according to claim 2 or 3, characterized in that the sliding rotary assembly (8) has an aperture (6b) formed in the valve element (6) and an end section (8a) of the drive shaft (4).
The device (1) according to claim 4, characterized in that the aperture (6b) formed in the valve element (6) is formed to extend in the direction of the longitudinal axis and the end section (8a) of the drive shaft (4) is arranged movably inserted into the aperture (6b) of the valve element (6) in the direction of the longitudinal axis.
The device (1) according to claim 4 or 5, characterized in that the sliding rotary assembly (8) is formed as a form-fitting sliding contour, with a shape of a wall surrounding the aperture (6b) of the valve element (6) and an outer shape of the end section (8a) of the drive shaft (4) are formed and arranged to correspond to one another and to interlock.
The device (1) according to claim 6, characterized in that the sliding rotary assembly (8) has a polygonal shape.
The device (1) according to any one of claims 2 to 7, characterized in that the sliding rotary assembly (8) is formed with a free cross-section between the drive shaft (4) and the valve element (6).
The device (1) according to any one of claims 4 to 8, characterized in that the aperture (6b) of the valve element (6) is formed as a through hole.
The device (1) according to any of claims 1 to 9, characterized in that the transmission assembly (5) is formed as mating threads between the enclosure (2) and the valve element (6).
The device (1) according to claim 10, characterized in that a male thread is formed on an outer side of the rotationally symmetrical valve element (6) and a female thread is formed within the enclosure (2).
The device (1) according to claim 11, characterized in that the male thread and the female thread are each formed over their entire circumference.
The device (1) according to claim 11 or 12, characterized in that the male thread of the valve element (6) is arranged at an end which is oriented towards the actuator (4).
The device (1) according to any one of claims 1 to 13, characterized in that the valve element (6) is arranged within a valve seat element (7).
The device (1) according to claim 14, characterized in that the valve element (6) is arranged sealingly via two sealing elements (11, 12) to the enclosure (2) and to the valve seat element (7).
The device (1) according to claim 15, characterized in that a first sealing element (11) is formed as a sliding seal, sealing the valve element (6) from the enclosure (2).
The device (1) according to claim 15 or 16, characterized in that a second sealing element (12) is formed as a valve seat seal, sealing the valve element (6) from the enclosure (2) and from the valve seat element (7).
The device (1) according to claim 17, characterized in that the valve element (6) in a closed state of the device (1) is arranged in a sealing area (13) adjacent to the second sealing element (12) and that the valve element (6) in an open state of the device (1) is arranged forming a fully circumferential gap between the valve element (6) and the second sealing element (12).
The device (1) according to claim 18, characterized in that the sealing area (13) has a first sealing surface (13a) formed circumferentially on the second sealing element (12) and a second sealing surface (13b) formed circumferentially on the valve element (6).
The device (1) according to claim 19, characterized in that the first sealing surface (13a) and the second sealing surface (13b) are formed in a like-minded manner, conically aligned with the longitudinal axis.
The device (1) according to claim 20, characterized in that the first sealing surface (13a) is oriented at an angle α in the range from 20° to 45° to the longitudinal axis.
The device (1) according to claim 20 or 21, characterized in that the second sealing surface (13b) is oriented at an angle β in the range from 3° to 10° to the longitudinal axis.
The device (1) according to any one of claims 1 to 22, characterized in that the valve element (6) has a circumferentially formed control surface (14) on a lateral surface.
The device (1) according to claim 23, characterized in that the control surface (14) is conical and oriented at an angle γ in the range from 0.5° to 2° to the longitudinal axis.
A method for operating a device (1) for controlling a flow rate and expanding a fluid in a fluid circuit according to any one of claims 1 to 24, comprising the following steps:

- setting an actuator (4) in a rotational movement (4a) about a longitudinal axis,

- transmitting the rotational movement (4a) of the actuator (4) by means of a sliding rotary assembly (8) to a valve element (6), so that the valve element (6) rotates about the longitudinal axis in a rotational movement (6d),

- transmitting the rotational movement (6d) of the valve element (6) by means of a transmission assembly (5) into a linear movement (6a) of the valve element (6) in the direction of the longitudinal axis relative to the enclosure (2), so that the valve element (6) is moved linearly along the longitudinal axis, the device (1) being opened or closed depending on the direction of rotation of the actuator (4).
Use of a device (1) for controlling a flow rate and expanding a fluid according to any one of claims 1 to 24 in a coolant circuit of an air conditioning system of a motor vehicle.