Valve drive and valve arrangement for controlling a fluid flow

Abstract

This invention provides a valve actuation device and a valve assembly for controlling fluid flow. The valve actuation device comprises: a linear actuator including a shaft operatively coupled to an electric motor; a fluid-sealed enclosure housing the shaft and a rotor of the electric motor; a control unit located outside the enclosure; and a housing containing the linear actuator, the enclosure, and the control unit. According to the invention, the housing has a heat shield between the enclosure and the control unit. The heat shield may have a wall portion molded or mounted on the inner side of the housing, wherein the wall portion may circumferentially surround a front closed end of the enclosure.

Description

Technical Field

[0001] This invention relates to a valve actuation device for controlling fluid flow as described in the preamble of claim 1. Such a device is described, for example, in DE 10 2017 110 343 A1. Background Technology

[0002] One application area of ​​this invention is valve devices for regulating fluid flow in fluid passages, particularly valve devices with linear actuators (German: Linearstellantrieb), for providing a regulating or control valve for controlling fluid flow in a fluid passage. This valve can, for example, be configured as an expansion valve or a throttle valve. Fluid flow can refer to a liquid flow, a gas flow, and / or a combination thereof. In one example, the fluid flow is a coolant flow.

[0003] In recent years, CO2 has been introduced as a coolant into automotive cooling circuits and / or air conditioning systems. As a coolant for automotive air conditioning systems, CO2 is a climate-friendly alternative to the tetrafluoroethane coolant currently used. CO2 has high cooling performance, is non-flammable, does not form any decomposition products, and can be used worldwide at low cost. In the industry, the natural coolant carbon dioxide (CO2) is known by the abbreviation R744. Heat pumps can also operate using CO2, thus enabling its efficient use for heating and energy-saving operation through a cooling / heating concept.

[0004] The heat input in the vehicle's engine compartment is primarily caused by the drive motor, which can be an internal combustion engine and / or an electric motor. Experience shows that under continuous operation, the temperature of a vehicle's cooling circuit is typically around 160°C to 165°C, briefly reaching 180°C. Therefore, the cooling circuit must be designed for temperatures that may occur during operation (including cold starts), assuming a minimum of -40°C. To enable the use of CO2 as a coolant in the cooling circuit and / or air conditioning system, the coolant flow must be maintained at high pressure, for example, on the order of approximately 130 to 25 bar, to maintain CO2 in a liquid or gaseous, or preferably supercritical, state under conditions where the overall temperature during vehicle operation is approximately -40°C to 165°C, briefly reaching 180°C. For safety reasons, the system should be designed to withstand higher pressures, for example, not exceeding 225 bar according to the regulations of the TÜV (Technische überwachungsverrein) Technical Inspection Association (German Technical Inspection Association). To achieve high efficiency, the high-pressure side pressure of the refrigeration circuit in an air conditioning system should be on the order of approximately 60 to 130 bar. This is equivalent to several times the pressure of conventional refrigerants.

[0005] The pressure can be set according to the ambient temperature to maintain CO2 coolant in a liquid, gaseous, or supercritical state. Supercriticality is achieved from a temperature of approximately 30°C and a pressure of approximately 75 bar. More precisely, the critical temperature of CO2 is 31°C, and the critical pressure is 74 bar. The properties of supercritical CO2 are between those of a gas and a liquid. Supercritical CO2 has the same density as a liquid but the same viscosity as a gas. Therefore, supercritical CO2 is a very flexible substance based on its fluidity and has proven suitable for use as a coolant.

[0006] In order for a cooling or air conditioning system to operate using CO2, the system must be designed to withstand a maximum operating pressure of 130 bar and a burst pressure of 340 bar. This also applies to regulating devices in the refrigerant circuit, including valves.

[0007] A car's cooling system must be able to operate at temperatures ranging from approximately -40°C to approximately 165°C, with brief periods reaching 180°C, depending on the vehicle and engine. The thermostatic valves in the coolant circuit typically open between approximately 75°C and 90°C. However, when designing the regulating device, in addition to the heat generated by the vehicle's drive motor, it is also necessary to consider that the actuation of valve devices with electric actuators can generate a significant amount of heat.

[0008] To better understand the heat input into such an actuator, an exemplary valve device can be observed.

[0009] The valve assembly may, for example, include: a linear actuator having a shaft operatively coupled to an electric motor; and a fluid-sealed enclosure or protective cover housing the electric motor shaft and rotor. The electric motor stator may be arranged outside the enclosure and coaxially surround the rotor. The walls of the enclosure are located within the working gas gap (working gas gap) between the rotor and stator. A control unit is arranged outside the enclosure and may have a housing to house the linear actuator, the enclosure, and the control unit. The shaft may be coupled to an actuator, for example, to the closing element of a needle valve to control coolant flow.

[0010] The valve assembly may also include a valve assembly containing fluid passages and sealing elements, and an adapter block for connecting an isolation shield to the valve assembly. The valve assembly, adapter block, and isolation shield are typically made of metal, thereby transferring heat from the coolant flow and the electric actuator to other parts of the valve assembly. The isolation shield prevents coolant that could penetrate the rotor through the shaft bearings via the valve assembly and adapter block from reaching the stator and control unit areas.

[0011] Heat is primarily transferred to the motor within the enclosure via refrigerant. Therefore, the rotor temperature during operation will, for example, remain permanently at approximately 165°C, and briefly reach even approximately 180°C during peak operating times (e.g., for about 10 minutes). This is because the enclosure is filled with coolant. The rotor assembly transfers heat to the stator assembly. The stator generates additional self-heating, which can lead to further temperature rises that must be considered when designing the electronics and the entire system. From the control unit's perspective, the enclosure represents a heat source. Summary of the Invention

[0012] Therefore, the object of the present invention is to provide a valve device for controlling fluid flow, particularly for cooling circuits or air conditioning systems in automobiles, thereby protecting temperature-sensitive components from overheating during operation. The solution of the present invention to achieve the above object lies in the valve actuation device according to claim 1 and the valve device according to claim 13. Preferred solutions are described in the dependent claims.

[0013] This invention proposes a valve drive device for controlling fluid flow, comprising: a linear actuator including a shaft operatively coupled to an electric motor; a fluid-sealed isolation or protective cover housing the shaft and the rotor of the electric motor; a control unit located outside the isolation cover; and a housing housing the linear actuator, the isolation cover, and the control unit. According to the invention, the housing has a heat shield between the isolation cover and the control unit. This heat shield may have a wall portion molded or mounted on the inner side of the housing, the wall portion circumferentially surrounding the front closed end of the isolation cover.

[0014] By isolating the control unit, which contains the rotor, from the heat source of the valve actuation device, the control unit can be isolated. A heat shield located between the control unit and the isolation enclosure acts as a barrier to block all heat, which is diffused through the isolation enclosure via the heat conduction of the coolant and released by the enclosure as thermal radiation.

[0015] A particularly simple and advantageous solution is to form the heat shield as a wall directly molded into the inside of the housing and oriented such that the wall is positioned between the insulation shield and the control unit, but does not contact either of them. Therefore, the heat shield is preferably arranged at a distance from both the insulation shield and the control unit. This distance serves as a mounting tolerance and provides additional insulation.

[0016] Similar to the housing, the heat shield can also be made of plastic, such as polyamide. Furthermore, the housing may have openings in the wall region that at least partially overlaps with the shield to allow for outward heat dissipation. Alternatively or additionally, the housing may have metal in the wall region that at least partially overlaps with the shield, or be connected to a metal body, to allow for outward heat dissipation.

[0017] The shaft can be mounted at a first end facing the actuator (German: Stellglied) via a ball bearing and at a second end away from the actuator via a sliding bearing for supporting the shaft, with axial and / or radial clearance. In the described application examples, this clearance-supported shaft allows compensation for different thermal expansions of the valve assembly components and tolerances during operation. Furthermore, the clearance-supported support prevents system over-stability when the valve is closed and the actuator is against the valve seat. In one example, the actuator has a valve piston of a needle valve.

[0018] In addition, a valve device is provided having a valve assembly having a fluid passage and a sealing element therein, and an adapter block for connecting the isolation shield to the valve assembly, wherein the valve assembly, the adapter block and the isolation shield are made of metal or have metal, and therefore have thermal conductivity.

[0019] In one application example, the valve device is used to control the CO2 fluid flow in an automotive coolant circuit or automotive air conditioning system, wherein the isolation cover is made of metal, particularly stainless steel, and is connected to the adapter block in a fluid-tight manner. Attached Figure Description

[0020] The other features and details of the valve device are described below with reference to the accompanying drawings and examples. Wherein:

[0021] Figure 1 A cross-sectional view of a valve device according to one embodiment;

[0022] Figure 2 This is a partial cross-sectional view of a valve actuation device according to one embodiment;

[0023] Figure 3 For illustrating temperature distribution similar to Figure 2 A three-dimensional image. Detailed Implementation

[0024] Figure 1 This is a cross-sectional view of a valve device according to an example. The valve device includes a linear actuator 10 having a shaft 12 and an electric motor including a rotor 14 and a stator 16. The electric motor is, for example, a stepper motor or an asynchronous motor, particularly a brushless DC motor.

[0025] The rotor 14 may have a rotor support 14' and a rotor magnet 14' held therein, wherein the rotor support 14' may be press-fitted or molded onto the shaft 12. Figure 1In the example shown, knurling 12' is formed on the outer periphery of shaft 12 in the middle section of the shaft to torsionally connect rotor 14 to shaft 12. Shaft 12 may be press-fitted into the area of ​​knurling 12' by rotor support 14', or the rotor support may be press-fitted onto shaft 12. Rotor support 14' may be made of plastic, wherein the plastic may be glass fiber reinforced plastic and / or metal particles may be embedded in the plastic to form a circuit. Rotor magnet 14" may be, for example, NdFeB magnet and may be press-fitted, depending on the situation. Stator 16 has stator stack 16' and stator winding 16"". In the example shown, stator stack 16' and stator winding 16" are electrically isolated by slot insulation 18.

[0026] The rotor 14 is housed within a housing 20, which provides a pressure-sealed and fluid-sealed enclosure for both the shaft 12 and the rotor 14. Figure 1 In the example shown, the isolation shield 20 is substantially cylindrical, having cylindrical walls 20' and a dome-shaped dome 20' located at the end of the linear actuator 10. As an alternative to the dome 20", the isolation shield 20 may also be flattened at its ends or have other shapes; the dome shape has proven to be particularly advantageous in terms of uniform heat dissipation, stability, and manufacturing technology. In one example, the isolation shield 20 is made of stainless steel. The cylindrical walls 20' extend through the working air gap between the rotor 14 and the stator 16.

[0027] The valve assembly described above also includes a valve assembly 30 and an adapter block 40. The valve assembly 30 and the adapter block 40 may each be made of metal as die-cast parts and are fluid-tightly connected by material joining (e.g., by laser welding or screwing). A linear actuator 10 with an isolation shroud 20 is connected to the valve assembly 30 via the adapter block 40. A passage 32 for coolant flow is formed in the valve assembly 30. As described below, the passage 32 has a valve seat 34 in the region of which the passage 32 can be opened and closed.

[0028] The adapter block 40 connects the linear actuator 10 to the valve assembly 30. In the illustrated example, the adapter block also supports the shaft 12 and guides the actuator 50 of the valve assembly. Furthermore, the adapter block 40 is adapted to convert the rotational motion of the shaft 12 into the linear regulating motion of the actuator 50.

[0029] To establish a pressure- and fluid-tight connection between the valve assembly 30 and the linear actuator 10, the adapter block 40 can be screwed to the valve assembly 30, for example, screwed into the valve assembly 30, and a seal 36, such as an O-ring, can be formed between the valve assembly 30 and the adapter block 40. Furthermore, the isolation cover 20 can be connected to the adapter block 40 by material bonding, for example, through laser welding, and / or via a corresponding flange. Additional seals and / or welding are provided.

[0030] In the adapter block 40 according to this example, a bearing housing 44 for receiving the ball bearing 60 is also formed so as to rotatably support the shaft 12 at the first end of the shaft. The ball bearing 60 can be press-fitted onto the shaft 12 by means of its inner ring (not shown) and can be retained in the bearing housing 44 by means of its outer ring (not shown). A retaining ring 62 can secure the ball bearing 60 in the bearing housing 44.

[0031] The shaft 12 can be mounted in a sliding bearing at its opposite end (hereinafter referred to as the second end), for which the bearing body 64 can be embedded (e.g., pressed into) the dome 20” of the isolation cover 20. The shaft 12 may have a bearing pin 66 at its second end, which is integrally formed with the shaft 12 at its end face. The bearing pin 66 is inserted into the cylindrical recess 68 of the bearing body 64 in a clearance fit. The cylindrical recess 68 may have a tapered extension in its exit region to allow for easy insertion of the bearing pin 66 and to provide a lubricant reservoir as needed.

[0032] The bearing pin 66 is supported at its axial outer end by a pointed bearing or a pivot bearing. For this purpose, a spherical or dome-shaped contact surface 108 is formed at the bottom of the recess 68 of the bearing body 64.

[0033] The bearing body 64 can be made of plastic as an injection molded part, such as PPS (polyphenylene sulfide), wherein a metal ball can be injected or another metal reinforcement material can be provided in the area of ​​the tip bearing.

[0034] exist Figure 1 In the example shown, the actuator 50 is formed as the valve piston of a needle valve. The actuator 50 can be cylindrical with a flat front end or a truncated conical end. Flattening can facilitate pressure equalization. The actuator 50 can be made of metal, particularly steel.

[0035] The actuator 50 has an internal thread 104. The actuator 50 is torsionally resistant and axially movable via an adapter block 40. An external thread 106, engaging the internal thread 104 of the actuator 50, is arranged on a coupling element 70. The coupling element 70 is torsionally connected to a rod 74, which is unthreaded and torsionally (i.e., non-rotatably) connected to or integrally formed with the shaft 12. The shaft 12, rod 74, and coupling element 70 do not undergo axial movement during operation of the linear actuator 10, but only rotational movement. When the shaft 12 rotates, the rod 74 and coupling element 70 rotate accordingly. The rotational movement of the shaft 12 is converted into axial movement of the actuator 50 by the external thread 106 of the coupling element 70, which engages with the internal thread 104 of the actuator 50.

[0036] Therefore, depending on the rotation direction of shaft 12, actuator 50 can move in the closing or opening direction. In particular, the valve piston (actuator 50) can be moved until it abuts against valve seat 34 to completely close fluid passage 32, and the valve piston can be moved in the opposite direction to fully or gradually open fluid passage 32.

[0037] like Figure 1 As shown, the actuator 50 is linearly movably supported in the valve assembly 30; the shaft 12 is rotatably supported in the adapter block 40 via a ball bearing 60. Because the actuator 50, coupling element 70, and shaft 12 move relative to the valve assembly 30 and adapter block 40, at least a capillary gap is formed at the interface through which coolant can seep from the channel 32 into the inner cavity of the isolation shield 20. The ball bearing 60 is also permeable to coolant. Furthermore, coolant can also permeate into the bearing housing 64 through the air gap formed between the rotor 14 and the isolation shield 20. It can be assumed that the inner cavity of the isolation shield 20 contains coolant during operation, which can be in a liquid, gaseous, or supercritical state. This coolant can be atomized into fine particles and deposited as a thin film on the assembly. In this case, the coolant can also provide a lubricating film for the bearing.

[0038] As mentioned above, the coolant, especially when using CO2 as the coolant, is under relatively high pressure during operation, with operating pressures typically on the order of approximately 130 bar. Due to coolant seepage into the isolation shroud 20, pressures up to 130 bar may also exist within the shroud 20. For safety reasons, the entire system should be designed to operate normally at pressures up to approximately 225 bar.

[0039] Figure 1The illustrated valve assembly also includes a control unit 80, which in this example has a printed circuit board 82 (e.g., a printed circuit board); and control electronics 84. Control electronics 84 includes, for example, controllers, drivers, transformers, transistors, and other passive and active control components and sensors, such as Hall effect sensors. These electronic components do not require high temperature stability and may malfunction or even fail under thermal loads due to ambient temperature and the self-heating of the linear actuator.

[0040] In the illustrated example, the printed circuit board 82 extends substantially across and beyond the entire end face of the linear actuator 10 to provide a contact plug 86 on the side of the linear actuator 10 and to enable its connection to the control unit 80 in a straightforward manner. The stator 16 and the contact plug 86 can be connected to the circuitry on the printed circuit board 82 via plug-in contacts, piercing contacts 78, etc.

[0041] In the illustrated example, the printed circuit board 82 has a notch 88 through which a portion of the linear actuator 10 extends via a shield 20. In the illustrated example, the dome-shaped dome 20” of the shield 20 extends through the notch 88. This allows for a particularly compact arrangement.

[0042] The linear actuator 10 is housed in a housing 90, which in the illustrated example has a housing base 92 and a housing cover 94. The housing base 92 surrounds the linear actuator 10, including the outer periphery of the stator 16, and forms a socket for the plug 86. The housing base 92 is fluid-tight and pressure-tightly connected to the adapter block 40, wherein a flange 96 of the housing base 92 abuts against the outer periphery of the adapter block 40. A sealing ring 98 can be inserted between the flange 96 of the housing base 92 and the adapter block 40 to seal the housing 90 and prevent water leakage.

[0043] The housing cover 94 is permanently attached to the housing base 92, for example, by means of adhesive or welding. A heat shield 100 is formed or mounted on the inside of the housing cover 94. In the illustrated example, the heat shield 100 has the shape of a wall portion that is molded to the inside of the housing cover 94. Alternatively, the heat shield 100 may also be formed by a separate wall portion mounted on the inside of the housing cover 94. The heat shield 100 is located between the shield 20 and the control unit 80 and protects the control unit from most of the heat radiation emitted by the shield 20.

[0044] exist Figure 1In the example shown, the heat shield 100 is specifically formed as an annular wall that circumferentially surrounds the front end of the isolation shield 20 in the area of ​​the dome-shaped dome 20". In this case, the wall of the heat shield 100 specifically shields the following parts of the isolation shield 20: the notch 88 protruding from the printed circuit board 82 and the heat that would otherwise be directly dissipated to the control unit 80 without the heat shield.

[0045] In the illustrated example, the heat shield 100 defines a shielded space 102 that absorbs the heat radiated by the isolation enclosure 20. Specifically, in the illustrated example, the shielded space 102 is defined by the peripheral wall of the heat shield 100 and the inner side of the cover section included therein. In the illustrated example, when the valve device is viewed in a side view perpendicular to the longitudinal direction of the valve device or perpendicular to the axis of rotation of axis 12, the heat shield 100 partially overlaps with the isolation enclosure 20. In other words, the dome 20” of the isolation enclosure 20 extends into the shielded space 102. During operation, the heat emitted by the isolation enclosure 20 rises upwards; therefore, according to Figure 1 The installation position of the valve device shown is also effective with the following heat shield 100, that is, the heat shield defines the shielding space 102, but has a wall portion that does not overlap with the isolation cover 20 in the side view.

[0046] like Figure 1 As shown, the valve assembly is positioned such that the control unit 80 is arranged above the linear actuator 10. As explained, in this position, heat generated by the linear actuator 10 and, where appropriate, by the coolant flowing through the channel 32, rises upward and is radiated upward by the dome 20” of the shield 20, thereby causing the heated air to rise further and accumulate in the shielded space 102. Through the shielded space 102, heat can be dissipated to the external environment through the housing cover 94. This protects the electronic components of the control unit 80 from thermal radiation.

[0047] Similar to the housing cover 94, the heat shield 100 can also be made of plastic, particularly polyamide. The housing cover 94 may have metal in the section defined by the heat shield 100 and at least partially overlapping with the shield 20, or may be connected to a metal body (not shown) to optimize heat dissipation to the external environment. In the area defined by the heat shield 100 of the housing cover 94, a heat sink or heat exchanger may be arranged, for example, on the outside of the housing cover 94.

[0048] As a supplement or alternative, the housing cover 94 may have one or more openings (not shown) in the wall region defined by the heat shield 100 and at least partially overlapping with the isolation shroud 20 to allow direct outward heat dissipation. To seal the housing, such openings must be closed in a fluid-tight manner, for example, by an integrated membrane seal.

[0049] like Figure 1 As shown, the heat shield 100 is arranged at a distance from the isolation cover 20 and the control unit 80 to avoid thermal bridging. The air between the heat shield 100 and the control unit 80 provides supplemental insulation. Figure 1 Unlike the illustrations, the heat shield 100 does not necessarily have to surround the entire circumference of the isolation shield 20. For example, it can be configured such that the heat shield is provided only on one side of the isolation shield 20 between the isolation shield 20 and the control electronics 84, and the shielding space 102 is open to the opposite side, so that heat can also be dissipated to one side of the valve device.

[0050] Figure 2 and 3 Shown in side view and perspective view respectively Figure 1 The valve actuator shown includes a valve device with a linear actuator 10. The valve actuator includes the linear actuator 10, partially covered by a housing 20, a control unit 80, an adapter block 40, and a housing 90 having a housing base 92 and a housing cover 94. See full reference. Figure 1 A detailed description. For clarity, in Figure 2 and Figure 3 In the figure, only the main components of the valve drive device are marked with reference numerals.

[0051] Figure 2 The diagram schematically illustrates the heat radiated by the shielding enclosure 20, particularly in its upper dome-shaped region, with the shielded space 102 indicated by shading. It can be seen that most of the heat radiated by the shielding enclosure 20 rises upwards and is isolated from the control unit 80 by the heat shield 100. This controls and reduces the heat input to the control unit 80, thus preventing temperature-related malfunctions or failures of the electronic components of the control unit 80.

[0052] In the test setup, temperature measurements were performed on a valve actuation device with a heat shield 100 according to the invention. Operating conditions corresponding to the use of the valve actuation device in the engine compartment of a vehicle were simulated in an artificial climate chamber, assuming that the valve actuation device is used to control the flow of CO2 coolant, which has a temperature on the order of approximately 165°C during continuous operation. The ambient temperature of the engine compartment was assumed to be approximately 80°C, and corresponding settings were implemented in the artificial climate chamber.

[0053] Measurements were taken in six regions, which were in Figure 3 The diagram is labeled I through VI. Region I corresponds to the environment of the valve actuation device in the engine compartment of an automobile, with a preset temperature of 80°C. Region II corresponds to the area inside the housing 90 where the control unit 80 is housed. In this experimental example, the temperature measured at the control unit 80 is approximately 90°C.

[0054] The highest temperature of the valve actuation device was measured in Zone III, assuming this zone is located outside the adapter block 40, where the adapter block 40 is in direct contact with the valve assembly guiding the coolant. During operation, the temperature of the adapter block in Zone III is approximately 140°C to 150°C. Another zone IV is defined inside the lower section of the shield 20, where the shield 20 is in contact with the adapter block 40. In this zone, heat is dissipated from the adapter block 40 to the shield 20, and also through the stator 16 of the motor. Temperature measurements show that the operating temperature in Zone IV is approximately 130°C. Another zone V is defined outside the upper section of the shield 20, i.e., at the end of the shield 20, away from the adapter block 40, from which heat is dissipated into the shielded space 102. Temperature measurements taken outside the shield 20 in Zone V indicate a temperature of approximately 110°C to 120°C.

[0055] The temperature on the isolation enclosure 20 is generated on the one hand by the heat input of the coolant, the temperature of which is transferred to the isolation enclosure 20 through the valve assembly 30 and the adapter block 40, and on the other hand by the operation of the electric motor. Another heat source is the ambient air of the valve actuation device in the engine compartment of the vehicle.

[0056] Another region VI for temperature measurement is defined within the shielded space 102, near the inside of the housing cover 94, in which the housing cover 94 radiates heat outward. During operation, the temperature in region VI is approximately 110°C.

[0057] It can be assumed that without the heat shield 100, the temperature of the upper section of the housing 90 would be similar to the temperature in the shielded space 102 (i.e., in region VI). Therefore, compared to the case without the heat shield, the temperature in region II of the housing 90, where the control unit 80 is installed, can be reduced by approximately 20°C with the aid of the heat shield. In the illustrated example, the temperature in region II, expressed in absolute value, is approximately 90°C, rather than the approximately 110°C in region VI (i.e., above the isolation shield 20 within the housing 90). Temperatures below 100°C are non-critical for most electronic components; therefore, in the valve actuation device according to the invention, under normal operating conditions, the temperature within the control unit area can be maintained at a temperature that will not periodically malfunction.

[0058] Therefore, this invention proposes an actuation device for a valve used to control fluid flow and related valve devices, particularly for automotive air conditioning systems or coolant circuits, and more specifically for controlling CO2 coolant flow. The valve devices minimize the thermal load on the electronic components used to control the actuation device by a simple means. Heat sources generated by the heated coolant and / or the self-heating of the actuation device are isolated from the electronic components of the control unit by an integrated heat shield located inside the housing cover of the actuation device, thereby protecting these electronic components from thermal radiation. The housing cover can be designed to dissipate heat to the external environment of the valve device through thermal conduction and / or thermal radiation.

[0059] Explanation of reference numerals in the attached figures

[0060] 10 Linear actuator; 12 shaft; 12' knurled; 14 rotor; 14' rotor support; 14” rotor magnet; 16 stator; 16' stator stack; 16” stator winding; 18 slot insulation; 20 isolation enclosure; 20' cylindrical wall; 20” dome; 30 valve assembly; 32 passage in valve assembly; 34 valve seat; 36 seal; 40 adapter block; 44 bearing housing; 50 actuator; 60 ball bearing; 62 retaining ring; 64 bearing body; 66 Bearing pin; 68 Recess in bearing housing; 70 Coupling element; 74 Rod; 78 Piercing contact, plug-in contact; 80 Control unit; 82 Printed circuit board; 84 Control electronics; 86 Contact plug; 88 Recess in printed circuit board; 90 Housing; 92 Housing base; 94 Housing cover; 96 Flange of housing base; 98 Sealing ring; 100 Heat shield; 102 Shielding space; 104 Internal thread; 106 External thread; 108 Contact surface.

Claims

1. A valve actuation device for controlling fluid flow, comprising: Linear actuator (10) having a shaft (12) operatively coupled to an electric motor. A fluid-sealed enclosure (20) housing the shaft (12) and the rotor (14) of the motor. Control unit (80), which is located outside the isolation enclosure (20); and The housing (90) houses the linear actuator (10), the isolation shield (20), and the control unit (80). Its features are, The housing (90) has a heat shield (100) between the isolation cover (20) and the control unit (80). The housing (90) has a housing base (92) and a housing cover (94). The heat insulation screen (100) has a wall portion that is molded or installed on the inside of the housing cover (94).

2. The valve driving device according to claim 1, wherein, The heat insulation screen (100) has a wall portion that surrounds the front closed end of the isolation cover (20) circumferentially.

3. The valve driving device according to any one of the preceding claims, wherein, The heat insulation screen (100) is made of plastic.

4. The valve driving device according to claim 3, wherein, The heat insulation screen (100) is made of polyamide.

5. The valve driving device according to claim 3, wherein, The housing (90) has an opening in a wall region that at least partially overlaps with the isolation shield (20) to allow for heat dissipation.

6. The valve driving device according to claim 3, wherein, The housing (90) has metal or is connected to a metal body in a wall region that at least partially overlaps with the isolation shield (20) in order to dissipate heat outward.

7. The valve actuation device according to claim 1 or 2, wherein, The heat insulation screen (100) is arranged at a certain distance from the isolation cover (20) and the control unit (80).

8. The valve actuation device according to claim 1 or 2, wherein, The shaft (12) is mounted at a first shaft end facing the actuator (50) by ball bearings (60) and at a second shaft end facing away from the actuator by sliding bearings for supporting the shaft (12), with axial and / or radial clearance.

9. The valve actuation device according to claim 8, wherein, The inner ring of the ball bearing (60) is press-fitted onto the shaft (12).

10. The valve actuation device according to claim 8, wherein, The shaft (12) is mounted in a bearing body (64) at its second end, the bearing body (64) being fixed to the front end of the isolation cover (20).

11. The valve actuation device according to claim 10, wherein, The shaft (12) is installed in the bearing body (64) with a clearance.

12. The valve actuation device according to claim 10, wherein, The shaft (12) is axially supported in the bearing body (64).

13. A valve device comprising the valve actuation device according to any one of the preceding claims, the valve device further comprising: Valve assembly (30), which houses a fluid passage (32) and an actuator (50), and An adapter block (40) is used to connect the isolation shield (20) to the valve assembly (30), the valve assembly (30), the adapter block (40) and the isolation shield (20) being of metal.

14. The valve device according to claim 13, the valve device being used to control the CO2 fluid flow of an automotive air conditioning system or an automotive coolant circuit, the isolation cover (20) being made of metal and being connected to the adapter block (40) in a fluid-tight manner.

15. The valve device according to claim 13 or 14, wherein the isolation cover (20) is made of stainless steel.

16. The valve device according to claim 13 or 14, having an actuating element (50) having a valve piston of a needle valve.

Images