Electronic device with active cooling function

Abstract

The invention relates to an electronic device (1) with active cooling. In order to make a compact design of the electronic device possible and also to ensure a high level of ESD / EMC protection and a high level of IP protection, according to the invention the housing (2) of the electronic device (1) is connected to a body (10) of a fan (4). When the body (10) is in a connected state with the housing (2), an opening to the interior of the housing (2) is closed. The body (10) is also connected to a hub (6) on which a fan rotor (7) is mounted for rotation. In the connected state, a chamber (14) is also formed which is separated from the interior of the housing (2) and in which the fan rotor (7) is arranged. Here, the chamber (14) forms a housing for the fan rotor (7).

Description

TECHNICAL FIELD

[0001] The present application relates to an electronic device having a housing and at least one electronic component to be cooled, which is arranged on a device circuit board inside the housing. At least one of the electronic components serves to implement a function of the electronic device. BACKGROUND

[0002] In order to dissipate the heat generated as a result of power losses at the electronic parts or components, active convection solutions are known from the prior art, in which air is moved by means of a fan. In the solutions known from the prior art, the fan is usually installed as a complete assembly (i.e. together with a fan housing, cables and plug connectors) inside or on the outside of the device housing.

[0003] If the fan is located inside the housing, the air flow is guided through the device and the heat is dissipated directly from the components by the air flow. In this case, dust, dirt, moist air and / or liquids can enter the interior of the device with the air flow. These can contaminate the electronic parts, which in turn can lead to malfunctions, for example as a result of electromigration.

[0004] If the fan is fastened from the outside to the device, the air flow takes place outside the device, wherein the heat is conducted away from the parts to be cooled, usually by means of a thermal connection to the housing, and is conducted away to the ambient air via external cooling fins. Here, the problem is that a mechanical protection device for preventing access to the fan rotor is required as an additional component part. Furthermore, the electrical contact, which is achieved by means of cable connections and plug connectors, is usually made by means of a tedious manual cable laying and contact process. This requires additional expenditure on the components and associated additional part costs, as well as additional expenditure on assembly steps and associated additional costs of the assembly process. Furthermore, the fan housing component and the electrical connection achieved by means of cables and plug connectors additionally occupy installation space, which limits the utilization of the available device installation space.

[0005] Fans usually have a moving rotating part (i.e. the fan rotor) and a fixed part (i.e. the stator). The operation of the fan requires at least one electrical connection for the stator. For this purpose, two lines are provided, i.e. a ground connection and a voltage connection. Furthermore, in the case of modern fans, a third line is also always used, for a rotational speed sensor mechanism and thus for determining the rotational speed of the fan. Furthermore, PWM (pulse width modulation) fans also have a fourth line, which is provided, inter alia, for cooling a CPU. The fourth line is used for the electronics of the rotational speed controller. Here, the fan electronics and the fan sensor mechanism are typically installed on a fan circuit board, which limits the installation space of the fan.

[0006] In the case where the fan is installed within the housing, in order to prevent dust, dirt, moist air and / or liquids from entering the interior of the device with the air flow and thus being able to damage the electronic components, it is known from the prior art to lay a specially designed air flow guide through the housing in a cumbersome manner. Furthermore, it is known to filter the drawn-in air before it enters the interior of the housing. However, all of this requires additional expenditure on components and additional assembly steps, each with associated additional costs.

[0007] Furthermore, it is important not only to protect the electronic components within the housing from the ingress of dust, dirt, moist air and / or liquids, but also to protect them from the penetration of electromagnetic radiation. This is referred to as EMC (electromagnetic compatibility) protection.

[0008] For example, DE 10 2018 120 053 A1 is known. The document describes an existing electronic device. In detail, the document describes an electronic device having an axial fan and a housing having a heat sink with cooling fins. The axial fan is accommodated in a receiving space of the housing, which has openings on both sides, so that air is drawn in from one side and discharged to the opposite side. The cooling fins are arranged spaced apart from the receiving space enclosing the fan on the side from which air is discharged from the axial fan. Here, the axial fan is accommodated as a whole assembly, i.e. together with the fan housing, in the receiving space. The fan housing is intended to ensure that the openings present in the receiving space are substantially closed towards the interior of the housing. In this way, it is intended to prevent dust, dirt, moist air and / or liquids from entering the interior of the electronic device and thus into the electronic components. However, DE 10 2018 120 053 A1 also discloses that a complete sealing of the receiving space with respect to the interior of the housing is only possible if a frame, a sealing element or the like, which seals with respect to the inner contour of the receiving space, is additionally arranged around the fan housing. The disadvantage is therefore that, in order to protect the interior from the ingress of dust, dirt, moist air and / or liquids, the space requirement of the fan is increased due to the required fan housing. Furthermore, additional sealing elements have to be used in order to actually ensure that, even with the fan housing, no dust, dirt, moist air and / or liquids can enter the interior of the electronic device. Depending on the construction of the fan housing, which is typically made of plastic, and the sealing elements, electromagnetic radiation which penetrates through the openings on both sides into the receiving space can additionally penetrate into the interior of the housing. Adequate EMC protection is then no longer guaranteed. SUMMARY

[0009] Therefore, it is an object of the present application to provide an electronic device with active cooling function which overcomes at least one of the above-mentioned drawbacks. In particular, it is an object of the present application to provide an electronic device with active cooling function which allows to achieve a compact design as well as a high level of ESD (Electro Static Discharge) / EMC protection and a high level of IP (Intrusion Protection) protection, i.e. to ensure protection against intrusion of dust, dirt, humid air, liquids and / or prevention of contact.

[0010] At least one of these objects is achieved by an electronic device as described hereinafter. Preferred developments of the present application are subject matter of the following description.

[0011] According to the invention, the housing of the electronic device is connected to the main body of the fan. Here, the fan does not have an additional, dedicated fan housing, such as a plastic housing. Thus, the fan also does not have any housing parts that are formed by the fan and that partially enclose the fan blades of the fan rotor in any way. The main body is thus not to be confused with a dedicated fan housing that belongs to the fan. The main body is preferably of a plate-like configuration. The main body is particularly preferably composed of one or more plastics. When the main body is in the connected state with the housing, an opening into the interior of the housing is closed. When the main body is in the connected state with the housing, a chamber is also formed in the housing that is separated from the interior of the housing. Furthermore, the main body is connected to a hub on which the fan rotor of the fan is mounted for rotation. Here, the hub forms a protrusion that extends from the main body. In order to facilitate a compact design, it is preferred that the main body and the housing are connected to and arranged relative to each other such that the axis of rotation of the fan rotor extends in a direction that is perpendicular to the extension of the region of the housing to which the main body is connected and on which the heat sink is arranged. Here, during assembly, the main body and the housing are connected from the inside of the housing, i.e. via the region in which the device circuit board is arranged. Thus, in one step during the assembly process, the connection between the main body and the housing is first established to form the chamber, and the fan rotor is arranged in said chamber. Then, in a subsequent step, the device circuit board is arranged in the region of the electronic device that forms the interior of the housing. Due to the configuration of the chamber and the specified assembly direction, this can be kept overall small, so that the electronic device can be made very compact. When the main body is in the connected state with the housing, the fan rotor is arranged within the chamber. The chamber or the housing of the electronic device is configured such that, when connected to the main body, it forms a housing for the fan rotor of the electronic device. In this way, as has already been discussed above, a dedicated fan housing is dispensed with, and the air inlet and the air outlet can be freely designed. The air inlet and the air outlet are formed in the chamber by the housing geometry of the electronic device, wherein the air flow can be guided in a targeted manner by the housing geometry. In this way, for example, the flow noise of the fan can be reduced. Due to the chamber being separated from the interior of the housing, a spatial separation from the interior of the housing and from the region in which the fan rotor is arranged is also achieved. In this way, the device circuit board and the electronic components in the interior of the housing can be effectively and easily protected from the ingress of dust, dirt, moist air and liquids, as well as from the penetration of electromagnetic radiation. By the configuration of the chamber, and due to the dispensing with a dedicated fan housing, an overall compact configuration of the electronic device can be achieved. Furthermore, the chamber is overall configured to serve as a region through which the air flow is guided and generated through the fan, while being encapsulated with respect to the electronic components that are located in the interior of the device, and as a cover to protect against mechanical erosion.

[0012] The bushing is configured such that the fan rotor is mounted to rotate on the bushing. Here, the bushing can be configured as a bearing or can have a bearing, such that the fan rotor can be mounted to rotate on the bushing. In one embodiment of the application, the connection of the bushing to the main body is realized by fastening means. For example, as fastening means, adhesives and / or screws and / or rivets and / or clamping and / or detent means can be used. The advantage of such an embodiment, in which the bushing and the main body are configured as two parts and have to be connected by fastening means, is that the bushing can have a standardized design and the main body can have a device-specific design. In this way, production costs can be reduced. In a preferred embodiment of the application, the bushing and the main body are configured as a single piece. The single-piece configuration facilitates simplification and improvement of the implementation of ESD / EMC protection and prevention of the intrusion of dirt, dust and / or the like.

[0013] In a preferred embodiment of the application, the main body consists of an electrically conductive substance or material. The main body can consist, for example, of a metal, for example a metal plate. The main body is preferably composed of an electrically conductive plastic. The use of electrically conductive materials also has an advantageous effect on EMC protection. Furthermore, a main body composed of a plastic with electrically conductive properties can additionally have thermally conductive properties. In this way, the dissipation of heat can additionally be promoted.

[0014] In one embodiment of the application, there is a direct connection between the main body and the housing. The direct connection of the main body to the housing is realized, for example, by fastening means that connect the main body and the housing directly to one another. For example, as fastening means, adhesives and / or screws and / or rivets and / or clamping and / or detent means can be used. It goes without saying that, in this embodiment, the opening to the interior of the housing is closed by the main body.

[0015] In a particularly preferred embodiment, the main body has an electrically conductive connection to the housing. The connection between the main body and the housing can be realized, for example, by a screw connection, a clamping connection, a rivet connection, a clamp connection, a caulking connection, a snap connection, a solder connection or the like. Especially in the case of embodiments in which the main body consists of an electrically conductive material and thus produces an essentially enclosing electrical contact between the main body and the housing, the electrically conductive connection between the main body and the housing can have an advantageous effect on ESD / EMC protection.

[0016] In a particularly preferred embodiment of the application, the main body has an electrically conductive adhesive connection to the housing. The electrically conductive adhesive connection preferably additionally has sound-deadening properties. For example, the electrically conductive adhesive connection can have electrical conductivity and have an elastomeric consistency. The adhesive connection can then additionally ensure and / or facilitate the acoustic decoupling of the fan relative to the housing.

[0017] In one embodiment of the application, the body is composed of a spritzguss part. In a preferred embodiment of the application, the body is composed of a mehrkomponenten spritzguss part. The body is preferably composed of a plastic part produced in a mehrkomponenten spritzguss process. The embodiment of the mehrkomponenten spritzguss part offers a simple means of forming a body with different physical properties. For example, it is thus possible to form a single-piece body which comprises a first spritzguss component part with electrically conductive properties and a second spritzguss component part with electrically conductive properties and sound-deadening properties. Preferably, the first spritzguss component part has an electrically conductive and thermally conductive material, preferably an electrically conductive and thermally conductive plastic, preferably polycaprolactam. The second spritzguss component part preferably has an electrically conductive and sound-deadening material, for example a thermoplastic and electrically conductive elastomer. The body is thus adapted in a personalized manner to the electronics and the housing. It goes without saying that the body and the bushing can be configured as a single piece, and the bushing can for example be formed from a plastic which does not have electrically conductive properties. The materials can thus be used optimally, which additionally contributes to cost savings.

[0018] In one preferred embodiment of the application, there is an indirect connection between the body and the housing. There is an indirect connection of the body and the housing if an adapter element is additionally fitted between the body and the housing. The connection of the body and the housing is then effected via the adapter element. The body is thus connected to the adapter element, and the adapter element is connected to the housing. The adapter element is connected to the housing by fastening means, for example by adhesive and / or screws and / or rivets and / or clamping and / or arresting means. The body is connected to the adapter element by fastening means, for example by adhesive and / or screws and / or rivets and / or clamping and / or arresting means. It goes without saying that in this embodiment the opening to the interior of the housing is significantly closed off by the adapter element. The adapter element preferably has a substantially plate-like or ring-like configuration. The adapter element is preferably composed of one or more plastics and is produced in a spritzguss process, a mehrkomponenten spritzguss process or an assembly process. It goes without saying that the adapter element and the body can be produced from different materials with different physical properties. For example, the body can be produced from an electrically conductive plastic, while the adapter element can be composed of an electrically conductive material and an elastomer material with sound-deadening properties. Furthermore, the connection of the body and the housing can be simplified by the adapter element. A preconfigured fan assembly with the body, the bushing, the fan rotor, the stator, the fan sensor mechanism and optionally the fan circuit board with the fan electronics can thus be standardized. Furthermore, the body, in the embodiment with the adapter element and as part of the fan assembly, can be dimensioned overall to be smaller, whereby material for the body can be saved, for example in the case of a standardized fan assembly. Only the adapter element is then adapted in a device-specific manner.

[0019] In a preferred embodiment of the application, the adapter element is composed of a multi-component injection-molded part having a first part and a second part. Here, the first part has an electrically and thermally conductive material, preferably an electrically and thermally conductive plastic, for example polycaprolactam. The second part has an electrically conductive and sound-damping material, for example a thermoplastic and electrically conductive elastomer. The first part and the second part preferably have a plate-like configuration. Alternatively, at least one of the two parts can be in a ring-like configuration.

[0020] The main body preferably has a receiving area in which the bushing is arranged and which is also preferably configured such that the stator and, optionally, the fan sensor mechanism can also be arranged thereon. The bushing can optionally be configured as a holder for the stator. Thus, the stator, and optionally the fan sensor mechanism, for example in the form of a Hall sensor, are located in a region that is just as spaced apart from the interior of the housing as the fan rotor. Optionally, the receiving area can also be configured for receiving a fan circuit board.

[0021] In an embodiment of the application, the fan or fan rotor, the stator and / or the fan sensor mechanism are arranged on the bushing and / or the receiving area of the main body. It goes without saying that the fan rotor is mounted to rotate on the bushing. Preferably, a fan circuit board with fan electronics is also arranged on the main body, preferably at the receiving area of the main body. In an embodiment of the application, the fan circuit board is arranged on the side of the main body that is directed towards the chamber. This makes the contact and mounting of the fan on the main body particularly simple. In an alternative embodiment of the application, the fan circuit board is arranged on the side of the main body that is directed towards the interior of the housing after the main body has been connected with the housing. The embodiments described in connection with the arrangement of these fan components allow the corresponding fan components to be preassembled on the main body. Furthermore, standardization and scalability of the fan assembly with fan rotor, stator, fan sensor mechanism, bushing, main body and, optionally, fan circuit board with fan electronics can be achieved. Furthermore, these embodiments allow the fan assembly as a whole to be simplified for assembly in the electronic device.

[0022] In an embodiment of the application, at least one electronic component of the fan is arranged in the interior of the housing. As an electronic component of the fan, here in particular the electronic components of the speed controller are considered. Mounting the electronic components of the fan to the interior of the housing offers the advantage that the installation space of the fan itself can be reduced. Thus, in particular, the chamber in which the fan rotor is located can be made more compact. Furthermore, the components arranged in the interior of the housing can additionally be better protected from dust, dirt, humid air and / or liquids. Furthermore, the electronic components in the interior of the housing can additionally be better protected from the penetration of electromagnetic radiation.

[0023] In a preferred embodiment of the application, at least one electronic component of the fan, in particular a component of the fan electronics, is mounted on the device circuit board. For example, due to the integration of the control electronics of the fan onto the device circuit board, a reduction in the number of contacts for the electrical connection of the fan to the device circuit board and a minimization of the fan mounting space can be advantageously achieved. In a particularly preferred embodiment of the application, the fan electronics are arranged entirely on the device circuit board. Thus, the fan circuit board can be completely dispensed with. Since the fan electronics are moved into or onto the device circuit board, only three robust current leads are still required. In addition, the evaluation of the rotor position and the rotational speed for the control can be carried out in the existing processor on the device circuit board, which additionally contributes to a reduction in costs.

[0024] In an embodiment of the application, the fan is configured as an axial fan. In a preferred embodiment of the application, the fan is configured as a mixed flow fan. In a particularly preferred embodiment of the application, the fan is configured as a radial fan. Here, the rotational axis of the fan rotor of the respective fan preferably extends in a direction perpendicular to the extension of the region of the housing to which the main body is connected and on which the heat sink is arranged. Since the rotational axis of the fan rotor of the respective fan extends perpendicular to the extension of the region of the housing to which the main body is connected and on which the heat sink is arranged, a particularly compact and thin construction of the electronics can be ensured.

[0025] In a particularly preferred embodiment of the application, the rotational axis of the fan is arranged perpendicular to the device circuit board of the electronics. Thus, the electrical contacting of the fan to the device circuit board can be simplified, for example by push-in contacts.

[0026] The heat sink preferably has at least one cooling fin, preferably a plurality of cooling fins arranged parallel to one another. The fan and the heat sink are then arranged and configured such that the air flow generated by the fan rotor flows through one cooling fin or a plurality of cooling fins arranged parallel to one another.

[0027] In an embodiment of the application, the housing and the heat sink are configured as a single piece. In a further embodiment of the application, the heat sink is connected to the housing in a thermally conductive manner as a separate component. The housing and the heat sink can consist of a metal or a metal alloy, for example an aluminum or magnesium alloy, and, for example, be formed as a metal casting. For example, the two parts can be produced in separate aluminum die casting processes or magnesium die casting processes, or, for the single piece embodiment, in one common aluminum die casting process or magnesium die casting process. Alternatively, the housing and / or the heat sink can be made of one or more plastics having different physical properties. For example, the housing and / or the heat sink can be produced in an injection molding process, for example in a multi-component injection molding process. It is particularly preferred that at least the heat sink consists of a plastic having thermally conductive properties. The plastic of the heat sink can additionally also have electrically conductive properties.

[0028] In a particularly preferred embodiment of the application, the chamber is designed to form an air inlet for the fan, the direction of which is parallel to the rotational axis of the fan rotor, and an air outlet, which is substantially perpendicular to the rotational axis of the fan rotor, and wherein the heat sink is arranged at the air outlet. This type of chamber configuration allows an efficient air flow guidance to be achieved and at the same time a very compact design of the electronic device.

[0029] In a further particularly preferred embodiment of the application, in order to form the chamber, the housing has a wall and a cover, the wall partially enclosing the fan rotor. Here, the wall has at least one hole at the location where the heat sink is arranged. The at least one hole forms an air outlet for the air flow guidance of the fan. The cover is located on the wall. The cover has a plurality of openings, which form an air inlet for the air flow guidance of the fan. Here, the openings in the cover can have any desired shape and can consist of, for example, slots, polygonal openings and / or circular holes. Here, the design of the openings is not limited to any geometry and can be chosen taking into account the air flow guidance through the openings and / or with regard to acoustic aspects. It goes without saying that the housing, the wall and the cover are configured as a single piece. Thus, the wall and the cover are integrally connected to each other. The air flow guidance of the fan is determined by the design of the wall and the cover. This embodiment makes it possible for the fan rotor to draw in air from a direction parallel to its rotational axis and to discharge the drawn-in air via the at least one hole in the wall, which is located in a direction substantially perpendicular to the rotational axis of the fan rotor, i.e. in the radial direction of the fan rotor. The air flow generated by the fan rotor is thus guided over the heat sink, which is arranged adjoin the hole forming the air outlet.

[0030] In a further particularly preferred embodiment of the application, in order to form the chamber, the housing has a cover, which is located at or on cooling fins of the heat sink, the cooling fins being arranged at the air outlet. Furthermore, the cover has a plurality of openings forming the air inlet. It goes without saying that in this embodiment the cooling fins, the heat sink and the cover are an integral part of the housing. The cooling fins are integrally connected to the cover. The chamber is then substantially formed by the cooling fins, the cover and the connection of the main body to the housing. This embodiment facilitates an even more compact design of the electronic device according to the application. It goes without saying that in this embodiment no partially enclosing wall is required. For example, the cooling fins can be arranged radially in all directions of the chamber. However, in this embodiment a partially enclosing wall can be formed, for example, by the cooling fins as an integral part of the housing.

[0031] In a further particularly preferred embodiment of the application, the chamber is arranged between cooling fins of the heat sink. Here, the cooling fins adjoin the chamber and extend from the chamber in two opposite directions perpendicular to the rotation axis of the fan rotor. Here, the heat sink is configured as an integral component of the housing and the cooling fins are configured as cooling fins of the heat sink which are arranged parallel to one another. This embodiment has the advantage of a large-area cooling. Thus, a plurality of electronic components in the interior of the housing can be actively cooled at the same time or more heat can be removed at the same time. The air flow generated by the fan can thus be used optimally for cooling the electronic components arranged on multiple sides of the chamber in the interior of the housing.

[0032] The electronic device according to the application can in principle be used for heat dissipation by forced convection achieved by the air flow provided by the fan and ensures that the higher requirements for EMC / ESD and IP protection are met in a simple and economic manner. In particular, the application is intended for electronic devices in vehicles, for example high-performance computers or head-up displays installed in vehicles.

[0033] Further features of the present application will become apparent from the following description and the accompanying drawings. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 A first embodiment of an electronic device according to the application is shown schematically,

[0035] Figure 2 A second embodiment of an electronic device according to the application is shown schematically,

[0036] Figure 3 A third embodiment of an electronic device according to the application is shown schematically, and

[0037] Figure 4 The third embodiment shown in Figure 3 is shown in a slightly different view. DETAILED DESCRIPTION

[0038] For a better understanding of the principles of the application, embodiments of the application will be explained in more detail below with reference to the accompanying drawings. The same reference signs will be used in the drawings for the same or functionally equivalent elements, and a repeated description will not necessarily be described again. It should be understood that the application is not limited to the embodiments shown and that the described features can also be combined or modified without departing from the scope of protection of the application as defined in the attached claims.

[0039] Figure 1 is a schematic representation of a first embodiment of an electronic device 1 according to the application. The electronic device 1 has a housing 2, a device circuit board 3, a heat sink 8 with cooling fins, and a fan 4 configured as a radial fan.

[0040] The device circuit board 3 is disposed inside the electronic device 1 and has electronic components 5 that implement the functions of the electronic device 1.

[0041] The heat sink 8 is integrally formed with the housing 2, but the heat sink 8 can alternatively be configured as a separate component and thermally connected to the housing 2. The heat sink 8 and the electronic component 5 are arranged relative to each other such that the heat sink 8 absorbs heat from the electronic component 5. For this purpose, the heat sink 8 and the electronic component 5 are thermally coupled.

[0042] The fan 4 has a plate-shaped body 10, a bushing 6, a fan rotor 7, a stator (not shown), a Hall sensor (not shown), and a fan circuit board 11 on which the fan electronics are arranged. The fan 4 used here is a PWM fan. In this case, the bushing 6 and the body 10 are made as a single piece of conductive plastic in an injection molding process. Alternatively, the bushing 6 and the body 10 can also be configured as two parts and connected to each other using fasteners. In the two-part configuration, the bushing 6 can be made of a relatively inexpensive plastic without specific conductive properties. The plate-shaped body 10 has a recess configured as a receiving area for the stator (not shown) and the bushing 6. The bushing 6 is used to rotatably mount the fan rotor 7, protrudes from the recess on one side, and receives the stator in the receiving area.

[0043] The main body 10, bushing 6, fan rotor 7, stator, Hall sensor, and fan circuit board 11 (on which the fan electronics are arranged) together form a fan assembly. This fan assembly is pre-configured such that the fan components are arranged on the main body 10 before being installed into the electronic device 1. Here, the connection between the main body 10 and the housing 2 is achieved through an area that forms the interior of the housing 2 and where the device circuit board 3 is arranged. Therefore, the entire pre-configured fan assembly is arranged within the electronic device 1. In this case, the main body 10 and the housing 2 are directly connected to each other by fastening devices, i.e., there are no additional adapter elements between the main body 10 and the housing 2. Here, the connection between the main body 10 and the housing 2 is a conductive connection. The fastening device is equivalent to a conductive adhesive device, in this case, a completely enclosed conductive and sound-absorbing adhesive connection 12 at the connection point between the main body 10 and the housing 2. The housing 2 and the heat sink 8 are made of aluminum alloy or magnesium alloy and are produced in a die-casting process. Alternatively, the housing 2 and the heat sink 8 can be made of thermally conductive plastic and manufactured, for example, in an injection molding process or a multi-component injection molding process.

[0044] The housing 2 of the electronic device 1 has a wall 9 which partially surrounds the fan rotor 7 and a cover 13 which is located on the wall 9. In this case, the wall 9 and the cover 13 are formed integrally with the housing 2. When the main body 10 is in the connected state with the housing 2, the wall and the cover form, together with the main body 10, a chamber 14 in which the fan rotor 7, the stator and the Hall sensor are arranged. At the location at which the heat sink 8 is arranged, the wall 9 has a hole which forms an air outlet 16. The cover 13 also has a plurality of circular openings which form air inlets 15 in the chamber 14. During operation of the fan 4, the rotation of the fan rotor 7 causes air to be drawn in from a direction parallel to the axis of rotation R of the fan rotor 7 via the openings in the cover 13 which form the air inlets 15. The air flow generated by the fan rotor 4 is then discharged in a direction which is substantially perpendicular to the axis of rotation R of the fan rotor 7 via the hole in the wall 9 which forms the air outlet 16. The air flow is discharged such that it flows over or along a plurality of cooling fins of the heat sink 8 which are arranged parallel to one another, the heat sink being arranged adjoin the hole. The chamber 14, the fan rotor 7 and the heat sink 8 are in this case configured and arranged relative to one another such that the air flow flows over as large an area of the heat sink 8 as possible. The chamber 14 therefore also extends beyond the extent of the fan rotor 7 in the direction of the hole, such that the generated air flow flows over the heat sink 8 or the cooling fins in the form of a laminar flow as far as possible without turbulence. The axis of rotation R of the fan rotor 4 is arranged perpendicular to the device circuit board 3 of the electronic device 1 and extends in a direction which is perpendicular to the extension of the region of the housing 2 to which the main body 10 is connected and on which the heat sink 8 is arranged.

[0045] When the main body 10 is in the connected state with the housing 2, the main body 10 closes the opening to the interior of the housing 2. In this way, the bushing 6, the fan rotor 7, the stator and the Hall sensor are arranged in the chamber 14 and in a region which is separated from the interior of the housing 2. Furthermore, the chamber 14, or the wall 9, the cover 13 and the main body 10 form a housing for the fan rotor 7.

[0046] The fan circuit board 11, on which the fan electronics, in this case a rotational speed controller, are located, is arranged on the side of the main body 10 which faces the interior of the housing 2. In this way, the electronic components of the fan 4 are arranged in the interior of the housing 2. The fan circuit board 11 and the device circuit board 3 are in mechanical and electrical contact with one another via a plug connection 17, for example a board-to-board plug connection. Alternatively, the fan circuit board 11 and the device circuit board 3 can also be electrically and / or mechanically connected to one another, for example by a cable connection and / or a plug connection and / or a snap connection and / or by a connection of a one-piece connector. Optionally, at least one electronic component of the fan 4 is mounted to the device circuit board 3. Optionally, all electronic components of the fan 4 are mounted to the device circuit board 3, so that the fan circuit board 11 can be dispensed with.

[0047] Figure 2 A second embodiment of the electronic device 1 according to the present invention is illustrated schematically. Figure 2 The illustrated embodiments and Figure 1 The difference in the illustrated embodiment is that, Figure 2 The chamber 14 shown (formed by the housing 2 and body 10 of the electronic device 1) is arranged between the cooling fins of the heat sink 8. Here, the cooling fins of the heat sink 8 are adjacent to the chamber 14 and extend from the chamber 14 in two opposite directions perpendicular to the rotation axis R of the fan rotor 7. In this way, heat is dissipated from the electronic components 5, 5', which are arranged on several sides of the chamber 14 inside the housing 2, on the device circuit board 3, and thermally connected to the heat sink 8. Figure 2 In the middle, the partially enclosed wall 9 is formed by cooling fins of the radiator 8 extending along the chamber 14. Figure 2 In this configuration, the cover 13 of the chamber 14 is located on or adjacent to the cooling fins of the radiator 8, and is integrally connected to the cooling fins. Figure 2 In the middle, the cover 13 has multiple openings in the form of trapezoidal slots.

[0048] exist Figure 2 In this configuration, fan 4 is configured as a diagonal-flow fan. Alternatively, this fan can be configured as an axial-flow fan.

[0049] Furthermore, the body 10 is composed of a multi-component injection-molded component and has two injection-molded components 18 and 19. The first injection-molded component 18 is plate-shaped and made of a conductive and thermally conductive material, such as polycaprolactam. The second injection-molded component 19 is annular in shape and made of a conductive and sound-absorbing material, such as a thermoplastic and conductive elastomer. Alternatively, the second injection-molded component 19 may have a plate-shaped configuration like the first injection-molded component 18. A bushing 6 is disposed on the first injection-molded component 18. The body 10 is directly connected to the housing 2 of the electronic device 1 via the second injection-molded component 19. The connection between the body 10 and the housing 2 is achieved by a conductive adhesive connection 12 in the form of an adhesive layer disposed in the L-shaped transition region between the first injection-molded component 18 and the second injection-molded component 19.

[0050] exist Figure 2 In this configuration, the fan circuit board 11 is also guided into the interior of the chamber 14. In this case, the fan circuit board 11 is arranged between the body 10 and the stator or fan rotor 7. Here, all the electronic components and sensor components of the fan are located on the fan circuit board 11. Alternatively, the electronic components of the fan can also be housed on a device circuit board 3 inside the housing 2.

[0051] Figure 3 andFigure 4 A third embodiment of the electronic device 1 according to the application is schematically shown. Figure 4 Herein differs from Figure 3 in that slightly different views of the third embodiment are shown. For the sake of clarity, Figure 3 and Figure 4 the device circuit board and the electronic components are not shown. Figure 3 and Figure 4 differ from the embodiment shown in Figure 1 in that the main body 10 and the housing 2 are indirectly connected to each other. Herein, the main body 10 and the housing 2 are connected to each other by means of a plate-like adapter element 20. Herein, the main body 10 is connected to the adapter element 20 and the adapter element 20 is connected to the housing 2. In Figure 3 and Figure 4 the embodiment shown, the opening to the interior of the housing 2 is closed by the adapter element 20 when the housing 2 and the main body 10 are in the connected state.

[0052] The adapter element 20 consists of a multi-component injection molded part and has a first part 21 and a second part 22. Herein, both parts 21, 22 have a plate-like form. The first part 21 consists of an electrically and thermally conductive material, in this case an electrically and thermally conductive plastic. The second part 22 consists of an electrically conductive and sound-deadening material, in this case a thermoplastic and electrically conductive elastomer. The first part 21 and the second part 22 are arranged in a layered manner relative to each other, wherein the second part 22 is arranged in the direction of the chamber 14 and the first part 21 is arranged in the direction of the interior of the housing 2 when the main body 10 and the housing 2 are in the connected state. The housing 2 is supported on the second part 22 when the housing 2 and the main body 10 are in the connected state. The connection of the main body 2 to the adapter element 20 is made here by means of a clearance. As can be seen in the representation of Figure 4 , a clearance pin 25 is used as a fastening means, which in this case is formed as an integral component part of the main body 10 and is driven through both parts 22, 23 of the adapter element 20. The acoustic decoupling between the housing 2 and the fan assembly, which has the main body 10, the bushing 6, the fan rotor 7, the stator (not shown) and the fan circuit board 11, is achieved by the elastomer material of the second part 22 during operation of the fan 4. Here, the clearance pin 25 allows a vibration along the extension of the clearance pin 25 during operation of the fan 4, which is damped in a sound-deadening manner by the elastomer material of the second part 22. The connection of the housing 2 to the adapter element 20 is made here by means of a threaded connection.

[0053] In Figure 3 and Figure 4 , the fan circuit board 11 is as Figure 2As in the embodiment shown, the cable is guided to the interior of the chamber 14. In this case, the fan circuit board 11 is arranged between the main body 10 and the stator or fan rotor 7. Here, all electronic components and sensor components of the fan 4 are located on the fan circuit board 11. Alternatively, the electronic components of the fan 4 can also be accommodated on the device circuit board 3 inside the housing 2. Here, the electrical contact of the fan circuit board 11 to the device circuit board is effected by means of a cable and plug connection (not shown). Here, the cable for electrical contact to the device circuit board is arranged on the side of the fan circuit board 11 which faces into the interior of the housing 2. The cable is guided through an opening in the main body 10, which is concealed in the direction of the chamber 14 by the fan circuit board 11. The second portion 22 of the adapter element 20 is arranged adjoined to the main body 10. The second portion 22 has a slot-like passage 24 for the passage of the cable, which passage abuts the cable guided therethrough and significantly closes the opening in the second portion 22 due to the elastomeric material used. For the passage of the cable through the first portion 21, the first portion has an open region 23 which adjoins the passage 24 in the second portion 22. This can be seen in particular in Figure 3

[0054] Due to the configuration of the adapter element 20 with the first portion 21 and the second portion 22, the main body 10 and the bushing 6 can be formed as a single-piece injection-molded part and made of a relatively inexpensive material, for example plastic, which does not have specific electrically conductive properties.

[0055] A further difference from the embodiment shown in Figure 1 Figure 3 The cover 13 in the embodiment shown in Figure 4

[0056] List of reference signs

[0057] 1 electronic device

[0058] 2 housing

[0059] 3 device circuit board

[0060] 4 fan

[0061] 5, 5' electronic components

[0062] 6 bushing

[0063] 7 fan rotor

[0064] 8 heat sink

[0065] 9 wall

[0066] 10 main body

[0067] 11 fan circuit board​​​

[0068] 12 electrically conductive adhesive connection

[0069] 13 cover

[0070] 14 chamber

[0071] 15 air inlet

[0072] 16 air outlet

[0073] 17 plug connection

[0074] 18 first injection-molded component

[0075] 19 second injection-molded component

[0076] 20 adapter element

[0077] 21 first part

[0078] 22 second part

[0079] 23 open area

[0080] 24 through-passage

[0081] 25 shimming pin

[0082] R rotational axis of the fan

Claims

1. Electronic device (1) having a housing (2), at least one device circuit board (3), a heat sink (8), and a fan (4) with a fan rotor (7), wherein the at least one device circuit board (3) being arranged in the interior of the housing (2) and having at least one electronic component (5, 5'), and wherein at least one electronic component (5, 5') implements a function of the electronic device (1), wherein the heat sink (8) absorbs heat from the at least one electronic component (5, 5') and is cooled by an air flow generated by the fan rotor (7) and flowing through the heat sink (8), wherein the housing (2) is connected to a main body (10) of the fan (4), wherein an opening to the interior of the housing (2) is closed when the main body (10) is in a connected state with the housing (2), wherein the main body (10) is connected to a bushing (6) on which the fan rotor (7) is mounted for rotation, wherein in the connected state a chamber (14) is formed which is separated from the interior of the housing (2) and in which the fan rotor (7) is arranged, and wherein the chamber (14) forms a housing for the fan rotor (7), in order to form the chamber (14), the housing (2) has a wall (9) which partially surrounds the fan rotor (7), wherein the wall has at least one hole at the location where the heat sink (8) is arranged, and a cover (13), wherein the cover is located on the wall (9) and has a plurality of openings which form an air inlet for the fan (4).

2. The electronic device (1) as defined in claim 1, wherein The fan (4) is configured as an axial fan, wherein the rotational axis (R) of the fan rotor (7) of the respective fan (4) extends in a direction which is perpendicular to the extension of the region of the housing (2) to which the main body (10) is connected and on which the heat sink (8) is arranged.

3. The electronic device (1) according to one of claims 1 and 2, wherein The chamber (14) is designed to form an air inlet (15) and an air outlet (16) for the fan (4), the air inlet being oriented parallel to the rotational axis (R) of the fan rotor (7), the air outlet being oriented substantially perpendicular to the rotational axis (R) of the fan rotor (7), and wherein the heat sink (8) is arranged at the air outlet (16).

4. The electronic device (1) as claimed in claim 3, wherein The cover (13) is located at or on cooling fins of the heat sink (8), said cooling fins being arranged at the air outlet (16).

5. The electronic device (1) as claimed in claim 1 or 2, wherein The chamber (14) is arranged between cooling fins of the heat sink (8), said cooling fins abutting the chamber (14) and extending from the chamber (14) in two opposite directions perpendicular to the rotational axis (R) of the fan rotor (7).

6. The electronic device (1) as claimed in claim 1 or 2, wherein The main body (10) is composed of an electrically conductive material.

7. The electronic device (1) as claimed in claim 1 or 2, wherein The main body (10) has an electrically conductive connection to the housing (2).

8. The electronic device (1) as claimed in claim 1 or 2, wherein The main body (10) and the housing (2) are connected to each other by an adapter element (20).

9. The electronic device (1) as claimed in claim 8, wherein The adapter element (20) is composed of a multi-component injection-molded part having a first part (21) with an electrically and thermally conductive material and a second part (22) with an electrically conductive and sound-damping material.

10. The electronic device (1) as claimed in claim 1 or 2, wherein At least one electronic component of the fan (4) is arranged in the interior of the housing (2).

11. The electronic device (1) as claimed in claim 1 or 2, wherein At least one electronic component of the fan (4) is positioned on the device circuit board (3).

12. The electronic device (1) as claimed in claim 1, wherein The fan (4) is configured as an axial fan.

13. The electronic device (1) as claimed in claim 1, wherein The fan (4) is configured as a radial fan.

14. The electronic device (1) as claimed in claim 7, wherein The main body (10) has an electrically conductive adhesive connection with the housing (2).

15. The electronic device (1) as claimed in claim 7, wherein The main body (10) has an electrically conductive and sound-damping adhesive connection (12) with the housing (2).

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