Cooling device with two separately flowable end surfaces

Description

[0001] The invention relates to a cooling device, particularly for motor vehicles, comprising a heat exchanger unit through which air can flow and a fan arranged on the heat exchanger unit forming a radial gap to generate an airflow through the heat exchanger unit. The fan is arranged at the front of the heat exchanger unit or adjacent to an end face of the heat exchanger unit, so that the fan covers part of the end face and thereby divides it into two or at least two sub-surfaces, which can be separately exposed to an airflow.

[0002] A variety of cooling devices with a heat exchanger unit and fans arranged on it are known from the prior art, wherein a heat exchanger unit can have one or more heat exchangers, and in particular several heat exchangers arranged in series. It is usually provided that the fans generate an airflow through the heat exchanger unit, so that the air is heated as it flows through the heat exchanger unit and the air carries heat away from the heat exchanger unit.

[0003] For this purpose, the fans are usually positioned directly adjacent to the heat exchanger unit, so that no structure obstructing the flow lies between the fan and the heat exchanger unit. However, such a fan is usually not directly against or on top of the heat exchanger unit, but is offset or spaced axially from the heat exchanger unit, creating a radial gap, i.e., a gap open in the radial direction, between the heat exchanger unit and the fan.

[0004] This radial gap allows air to flow in and out of the space between the fan and the heat exchanger unit. This also allows air to flow back from the pressure side of the fan (the side where the fan blows air out and thus creates positive pressure) to the suction side (the side where the fan draws in air), which is disadvantageous in several respects. This backflow of air can also be described as bypass flow.

[0005] If a bypass flow is present, so that not all of the airflow generated by the fan is conveyed through the heat exchanger, the fan must be operated at a higher power or a more powerful fan must be installed compared to a solution with less or no bypass flow, which leads to higher power consumption and higher noise levels during operation.

[0006] Furthermore, air can be drawn in again by the fan through this radial gap. Since the bypass flow mainly consists of turbulent air, this repeated intake generates additional noise and thus leads to undesirable acoustics.

[0007] In addition, the air drawn in again via the bypass flow may already have been heated by passing along the heat exchanger, so that drawing in the already heated air again leads to a deterioration in cooling performance and thus to a reduced efficiency of the cooling device.

[0008] To solve this problem, covers are known in the prior art, which can be described as "hoods" or "air hoods" and which enclose the fan on the side facing a heat exchanger or heat exchanger unit and completely cover the heat exchanger so that no air can flow back from the pressure side to the suction side of the fan. Such hoods are proposed, for example, in documents EP 0 098 397 A1 and AT 522 171 A4.

[0009] However, if such cooling devices with scoops are to be used in motor vehicles, for example to enable cooling of the heat exchanger unit even when the vehicle is stationary, the heat exchangers or other coolers located behind a first cooling level of the heat exchanger unit, such as combustion engine coolers or charge air coolers, cannot be directly cooled by the airflow while driving, but only via the fan, since the remaining front surface of the heat exchanger unit is covered by the scoop and cannot be directly cooled.

[0010] To solve this problem, the fan, for example, must be sufficiently large to guarantee adequate cooling both without and with airflow, which usually leads to higher costs, higher energy consumption and higher noise levels.

[0011] To solve this problem, WO 2013 / 160832 A1, for example, proposes a cowl equipped with flaps which can be opened while driving, so that airflow can pass through the heat exchanger unit through the open flaps.

[0012] However, such a solution, equipped with movable and partly sensory and actuator elements, is complex and subject to wear and tear, and therefore also disadvantageous.

[0013] Other cooling devices with air-flowing heat exchanger elements or aspects of such devices are also known from documents US 4 685 513 A, US 5 597 038 A, FR 2 189 697 A2, US 5 771 961 A and US 2007 / 209613 A1.

[0014] The invention is therefore based on the objective of overcoming the aforementioned disadvantages and providing a cooling device which can easily provide efficient and sufficient cooling both when a vehicle is moving and when it is stationary.

[0015] This problem is solved by the combination of features according to patent claim 1.

[0016] According to the invention, a cooling device, particularly for motor vehicles, is provided, comprising a heat exchanger unit through which air flows and at least one fan arranged on the heat exchanger unit with a radial gap to generate an airflow through the heat exchanger unit. The heat exchanger unit preferably has at least one heat exchanger, and several heat exchangers can also be arranged one behind the other in the direction of airflow.The fan, which is formed in particular and essentially from an impeller rotatable about an axis of rotation and a housing surrounding the impeller circumferentially around the axis of rotation, and which has an air outlet towards the heat exchanger unit, is arranged at the end face and preferably directly adjacent to the heat exchanger unit, so that no structures obstructing airflow between the fan and the heat exchanger unit are located between them. Since the heat exchanger unit and the fan are thus spaced apart from each other in the axial direction with respect to the axis of rotation, without being in contact with each other, a gap open in the radial direction with respect to the axis of rotation is formed between the heat exchanger unit and the fan, which is referred to as a radial gap. Analogous to a gap open in the radial direction and referred to as a radial gap, a gap open in the axial direction is referred to as an axial gap.Alternatively, the radial and axial gaps can be defined such that an axial gap extends parallel to the axis of rotation and / or is permeable to airflow parallel to the axis of rotation, and that a radial gap extends orthogonally to the axis of rotation and / or is permeable to airflow orthogonally to the axis of rotation. According to the invention, it is further provided that the heat exchanger unit, and in particular a heat exchanger of the heat exchanger unit located closest to the fan, has an end face facing the fan and permeable to airflow, which is partially covered by the fan, such that the end face is divided into a first partial surface covered at least partially by the fan and a second partial surface free from the fan.If the base area of ​​the fan is projected onto the front face of the heat exchanger unit parallel to the axis of rotation, the base area projected onto the front face lies within the first sub-area and outside the second sub-area, with the second sub-area bordering the first sub-area and surrounding it, for example, in a frame-like manner. Although the first sub-area can be equal to the base area projected onto the front face, it can also be larger than the base area projected onto the front face. It is essential that the cooling device according to the invention has a guide sleeve, which can also be referred to as an air guide sleeve. The guide sleeve is designed to allow airflow, particularly in the axial direction, i.e., along or parallel to the axis of rotation, and is thus configured to guide air or a flow.Furthermore, the guide sleeve is arranged between the heat exchanger unit and the fan, closing the radial gap between them at least partially, and forms an airflow channel leading from an air outlet of the fan to the first section of the end face of the heat exchanger unit. "Arranged between the heat exchanger unit and the fan" means that the guide sleeve extends axially at least partially between the end face of the heat exchanger unit and the fan, and in particular, may also partially cover or overlap the fan. The radial gap is closed or covered at least partially by the guide sleeve on its radial outward side. Preferably, the guide sleeve completely closes the radial gap between the heat exchanger unit and the fan.Furthermore, the guide sleeve fluidically connects the fan's air outlet to the first section of the front face and fluidically separates the air outlet from the second section. Fluidic separation can also be understood as a situation where the flow from the air outlet to the second section is negligibly small compared to the flow from the air outlet to the first section, for example, less than 5% of the flow from the air outlet to the first section. This means that the airflow generated by the fan can be directed directly onto or through the first section of the front face of the heat exchanger unit via the guide sleeve or the flow channel it forms, while backflow from a pressure side at the fan's air outlet to a suction side of the fan through the radial gap is minimized.Furthermore, the second part of the front surface of the heat exchanger unit preferably remains free of the guide sleeve and thus allows flow through it, so that a flow independent of the fan, such as driving wind, can flow onto or through the second part of the surface unhindered, at least by the guide sleeve.

[0017] Preferably, the guide sleeve is arranged on the end face in or at a boundary between the first partial surface and the second partial surface, so that these are structurally separated from each other by the guide sleeves.

[0018] If multiple fans are used, they can be arranged side-by-side on the heat exchanger unit, so that each fan defines a first partial area on the front face of the heat exchanger unit. A guide sleeve is provided for each fan, connecting the respective air outlet to the respective first partial area.

[0019] In addition to other possible training methods, an advantageous further development provides that the guide sleeve is hollow cylindrical and / or rotationally symmetrical, with the guide sleeve being arranged coaxially to the axis of rotation of the impeller of the fan.

[0020] As an alternative to a hollow cylindrical shape, the guide sleeve can also be funnel-shaped or designed as a hollow truncated cone, the diameter of which preferably increases from the air outlet of the fan to the end face of the heat exchanger unit.

[0021] Several different variants are possible for the guide sleeve. The guide sleeve can be designed as a separate component from the heat exchanger unit and fan, positioned between the heat exchanger unit and the fan, and optionally making contact with the heat exchanger unit and / or the fan. Furthermore, the guide sleeve can be integrally or integrally formed with the heat exchanger unit and extend towards the fan. Alternatively, the guide sleeve can be integrally or integrally formed with the fan and extend towards the heat exchanger unit. Additionally, a first part of the guide sleeve can also be separately, integrally, or integrally formed with the heat exchanger unit or fan.a heat exchanger of the heat exchanger unit and a second part of the guide sleeve being formed separately or integrally or in one piece with the fan, wherein the first part of the guide sleeve and the second part of the guide sleeve overlap or abut each other on their facing sides.

[0022] One particularly advantageous variant involves the guide sleeve being integrally formed by the heat exchanger unit or being integrally connected to it. The guide sleeve can also be attached, for example, by material, form, or force-fit connection to the end face of the heat exchanger within the heat exchanger unit closest to the fan.

[0023] The guide sleeve can be in direct contact with the fan, or it can have a radial gap to the fan due to a distance from the fan in the axial direction, or it can have an axial gap to the fan, for example, due to a larger inner diameter than the outer diameter of the fan.

[0024] A sealing element can also be provided in such a radial or axial gap to close the respective gap. Furthermore, it is advantageous if the flowable area of ​​the radial or axial gap between the guide sleeve and the fan is smaller than the flowable area of ​​the radial gap between the fan and the heat exchanger unit, thus minimizing the backflow of air from a pressure side to a suction side of the fan.

[0025] If a sealing element is provided, it can also be designed as a bellows or skirt and, in particular, be flexible or deformable in the axial direction. By moving the fan or guide sleeve towards the end face of the heat exchanger unit, the skirt / bellows / sealing element can be elastically compressed, so that essentially no force acts on the end face, while the gap between the end face of the heat exchanger unit and the guide sleeve remains closed.

[0026] According to the invention, the fan has a wall on the heat exchanger side that extends circumferentially around the axis of rotation and overlaps the guide sleeve axially along the axis of rotation, such that the guide sleeve completely surrounds the fan wall in the circumferential direction, or the fan wall completely surrounds the guide sleeve in the circumferential direction. The fan wall is part of a housing for the fan and defines an interior space through which air can flow in the axial direction.

[0027] If the guide sleeve is designed to overlap and rest against the fan wall, a stop can be provided on the guide sleeve to limit its movement relative to the fan or its wall. Furthermore, the surfaces of the guide sleeve and the fan wall that face each other and are in direct contact can be designed as a fit, and in particular as a transition or press fit, so that the guide sleeve and the fan can be inserted into each other without any additional fasteners and in a substantially flow-tight manner, i.e., preventing airflow.

[0028] Furthermore, a variant of the cooling device in which the guide sleeve is integrally formed by the fan or, for example, bonded to it as a single unit is also particularly advantageous. Alternatively, the guide sleeve can also be connected to the fan by material, force, or form-fitting means.

[0029] Here too, the guide sleeve can be in direct contact with the heat exchanger unit or, by means of an axial distance, have a radial gap to the heat exchanger unit. A sealing element can also be provided in such a radial gap. Furthermore, it is advantageous here as well if the flow area of ​​the radial gap between the guide sleeve and the heat exchanger unit is smaller than the flow area of ​​the radial gap between the fan and the heat exchanger unit, so that the backflow of air from a pressure side to a suction side of the fan is minimized.

[0030] A sealing element as described above can also be arranged in a radial gap between the heat exchanger unit and the air guide sleeve, by which the radial gap is at least partially closed.

[0031] A particularly advantageous variant provides that the sealing element is shaped as a bellows or apron and has a first end fixed axially to the guide sleeve and a free second end opposite it in the axial direction. Furthermore, the sealing element is designed to be stretched axially by the airflow generated by the fan from an undeformed first position to a deformed second position, so that the radial gap is completely closed in the second position.

[0032] For example, in its undeformed position, the sealing element can create flow resistance in or on the flow channel from the fan's air outlet to the end face of the heat exchanger unit. If a predetermined force is applied to the section of the sealing element that provides the flow resistance by the airflow, or a sufficiently large airflow as intended, the sealing element can be deformed and thus stretched in the axial direction. In the deformed second position, the sealing element can also rest directly against the end face. If the airflow decreases, the sealing element is preferably compressed from the second position back into the first position by its elasticity. Furthermore, the deformation behavior can be influenced by a suitably matched elasticity and / or stiffness of the sealing element, as well as by the geometry of the section of the sealing element extending into the flow channel.The stretch can be determined depending on the airflow generated by the fan.

[0033] Such a sealing element, designed as a bellows or apron, can be formed in particular by a film made of, for example, plastic.

[0034] An advantageous further development of the cooling device also provides that the guide sleeve is dimensionally stable or rigid and, for example, made of plastic, whereby rigid or dimensionally stable is understood to mean that the guide sleeve is not deformed or cannot be deformed when used as intended.

[0035] In a different embodiment, the guide sleeve could also be designed to be flexible or elastic, at least in sections, which is the case, for example, if a sealing element is injection-molded directly onto a dimensionally stable or rigid section of the guide sleeve.

[0036] To simplify the connection of the guide sleeve to the heat exchanger unit and / or the fan, and to dissipate forces over a larger area, an advantageous variant of the cooling device provides that the guide sleeve has a circumferential wall and a flange extending radially beyond the wall on the heat exchanger and / or fan side. The guide sleeve can be manufactured as a single piece or, in particular, as a single-piece assembly. The flange provides a connection surface for joining the adjacent heat exchanger unit or fan, which is larger than the end face of the guide sleeve wall. The flange can be fixed to the end face via this connection surface, for example, by material, form, or force-fit.

[0037] The flange can extend radially inwards and / or radially outwards beyond the wall.

[0038] The wall and flange can be bonded together, so that the flange is an integral part of the guide sleeve. Alternatively, the flange can also be designed as a separate component and separate from the guide sleeve, in which case the flange must be fixed to the wall of the guide sleeve.

[0039] If the guide sleeve is integrally formed with the fan, the wall of the guide sleeve can also be the wall of the fan.

[0040] A further advantageous embodiment provides that the flange has a deformation element and / or a multitude of bristles on its end face, which allow the flange to penetrate the heat exchanger unit or the heat exchanger of the heat exchanger unit located immediately adjacent to the flange. This allows the flange to be fixed to the end face of the heat exchanger unit, at least with respect to movement parallel to it, and further reduces the radial gap between the end face and the fan. The bristles can be made of an elastic material.

[0041] A flange on the heat exchanger side can serve not only for connection but also for improved pressure and force distribution to the heat exchanger unit or the heat exchanger closest to the fan. The heat exchanger can be extremely delicate and therefore sensitive. If a force transmitted from the guide sleeve to the heat exchanger were distributed over too small an area—for example, the end face of the wall—the heat exchanger could be damaged. To prevent such damage, the force can be distributed over a larger area by the flange's surface facing the heat exchanger compared to a solution without a flange. This reduces the pressure acting on the heat exchanger and its end face, allowing the heat exchanger to withstand the pressure.

[0042] Preferably, the rotation axis of the fan impeller can also be provided that it is coaxial with a central axis of the heat exchanger unit that is orthogonal to the end face and runs centrally through the end face, so that the fan is positioned centrally on the heat exchanger unit. Accordingly, the cooler is positioned centrally on the end face. "Directly through the end face" is understood to mean, in particular, passing through the geometric center of gravity of the end face. Such a central arrangement or fixation of the fan on the end face is intended to suppress or prevent opposing vibrations in the fan that could cause excessive movement and damage the heat exchanger unit.

[0043] For example, vibrations or oscillations in general on the fan can cause the fan to move in an axial direction, which can cause the fan to hit the front surface and be pressed into the heat exchanger unit.

[0044] A guide sleeve, which is fixed to the heat exchanger unit via a flange and rests directly on the end face, and has an axial gap to the fan, can be particularly advantageous if it features a stop element on the heat exchanger side designed to limit the maximum axial movement of the fan relative to the guide sleeve. If the fan experiences an oscillation or vibration that causes axial movement, it can move freely through the axial gap to the guide sleeve. If the axial movement becomes too great, such that the fan would strike the end face, the fan instead rests against the contact element of the guide sleeve. This prevents the fan from striking the heat exchanger unit, and instead allows the force that would otherwise act directly on the end face to be dissipated over a large area of ​​the end face via the flange.

[0045] In order to be able to fix the fan to the heat exchanger unit, the cooling device preferably also has a fan holding element which is designed to fix the fan in a position fixed relative to the heat exchanger unit and to form the radial gap relative to the fan.

[0046] If the heat exchanger unit is designed for use with a guide sleeve, the heat exchanger unit, and in particular the heat exchanger of the heat exchanger unit closest to the fan, may also have a support structure on which the guide sleeve can rest over its entire surface and which is designed to withstand and / or dissipate a force transmitted from the guide sleeve to the heat exchanger.

[0047] The guide sleeve can also be pressed resiliently against the end face by spring elements or be resilient itself.

[0048] The features disclosed above can be combined in any way, provided that this is technically possible and they do not contradict each other.

[0049] Other advantageous embodiments of the invention are characterized in the dependent claims or are described in more detail below together with the description of the preferred embodiment of the invention with reference to the figures. The figures show: Fig. 1 a first prior art; Fig. 2 side view of the first prior art; Fig. 3 a second prior art; Fig. 4 a detail of a first embodiment of the cooling device; Fig. 5 a detail of a second embodiment of the cooling device; Fig. 6 a detail of a third embodiment of the cooling device; Fig. 7A a detail of an embodiment with a sealing element; Fig. 7B a detail of the embodiment with a sealing element; Fig. 8 a detail of an embodiment with bristles.

[0050] The figures are schematic examples. Identical reference symbols in the figures indicate identical functional and / or structural features.

[0051] Figures 1 and 2 Figure 1 shows a cooling device for a motor vehicle, as known in the prior art, which forms the starting point for the inventive proposal. The cooling device is shown in Figure 1 perspective and in Figure 2 shown in a side view.

[0052] The heat exchanger unit 10 consists, for example, of several components or several individual heat exchangers, and here of a condenser 12 for an air conditioning system, a charge air cooler 13, and a water cooler 14. The heat exchanger unit 10 can also have other components, as well as more or fewer components, whereby at least one cooling element or heat exchanger, here the condenser 12, is provided directly adjacent to the fan 20.

[0053] A fan 20 is arranged immediately adjacent to the heat exchanger unit 10 or to the condenser 12, but offset in the axial direction X from the latter, i.e. spaced away from an end face 11 of the heat exchanger unit 10, so that a radial gap 2 extending in the radial direction Y is formed between the heat exchanger unit 10 and the fan 20.

[0054] The fan 20, which can also be called a ventilator, essentially consists of an impeller 21, which can be driven, for example, by an electric motor, and which is arranged inside a housing through which air can flow in the axial direction X, and which is rotatable about an axis of rotation R, wherein the axial direction X runs along or parallel to the axis of rotation R.

[0055] Furthermore, the fan 20 is held in a fixed position relative to the heat exchanger unit 10 by a fan retaining element 40. If the surrounding structure allows the fan 20 to be fixed in a fixed position relative to the heat exchanger unit 10 in another way, for example on other components of a vehicle, such a fan retaining element 40 can be omitted.

[0056] The fan retaining element 40 has four (first) struts 41 which extend radially outwards from a ring element or fan frame 42 which surrounds the fan 20 in circumferential direction U around the axis of rotation R, over the end face 11 and thus span the end face 11.

[0057] The fan 20 partially covers the front surface 11 of the heat exchanger unit when viewed along the axis of rotation R, so that the front surface 11, as in Figure 2The area is shown to be divided into a first sub-area 11A and a second sub-area 11B. The first sub-area 11A corresponds to the base area of ​​the fan 20 projected onto the front surface 11, and the second sub-area 11B corresponds to the remaining area of ​​the front surface 11 of the heat exchanger unit 10, which here surrounds the first sub-area 11A in a frame-like manner.

[0058] When the motor vehicle moves (drives) at a sufficiently high speed, the cooling device is exposed to a resulting airflow parallel to the axis of rotation R or in the axial direction X, so that the airflow passes through the interior of the fan 20, which can flow through it in the axial direction X, onto the first partial surface 11A and outside the fan 20 onto the second partial surface 11B, passes through the heat exchanger unit 10 and can provide sufficient cooling of the heat exchanger unit 10.

[0059] When the vehicle is stationary, at least some of the components of the heat exchanger unit 10 should continue to be cooled, for example, to enable the vehicle's air conditioning system to operate even when stationary or to continue cooling the engine. Since no airflow passes through the heat exchanger unit 10 when the vehicle is stationary, the fan 20, or rather its impeller 21, is driven, thereby generating an airflow at least at the first partial surface 11A, which then flows through the heat exchanger unit 10.

[0060] Due to the radial gap 2, a backflow S occurs from a pressure side to a suction side of the fan 20, so that part of the flow generated by the fan does not pass through the heat exchanger unit 10 as bypass flow or backflow S. To compensate for this backflow S, a more powerful fan 20 must be used, or the fan 20 must be operated at a higher speed or with higher power, which, in addition to increased energy consumption, leads to a higher noise level.

[0061] To solve this problem, an exemplary solution is available in the prior art. Figure 3 The hood 43 shown is known, through which the pressure side is separated from the suction side of the fan 20, so that no backflow S is possible and the entire airflow generated by the fan 20 passes through the heat exchanger unit 10 in a cooling manner.

[0062] This is in Figure 3However, the solution shown is only advantageous when the vehicle is stationary, since at sufficient speed the vehicle's airflow can no longer directly affect the second sub-area 11 B, so that even with sufficient speed or sufficient airflow, cooling is only possible via an airflow affecting the first sub-area 11A or by a flow passing through the fan 20.

[0063] These problem-solving cooling devices 1 are shown in sections and perspectives in various design variants in the Figures 4 to 6 depicted, with each figure representing a variant. The basic structure corresponds to that in Figure 1 and Figure 2 Depicted, so that the associated explanation of the Figures 1 and 2 The same applies analogously to the cooling devices 1, as they are described in the Figures 4 to 6 are shown. The essential difference compared to the cooling device accordingly Figures 1 and 2 is involved, that the cooling devices 1 of the Figures 4 to 6 each has a guide sleeve 30 which completely or at least partially closes the radial gap 2 and thereby completely prevents or at least minimizes a backflow S from the pressure side of the fan 20 to the suction side of the fan 20.

[0064] This includes in the Figures 4 to 6 Only the uppermost component (condenser 12) of the heat exchanger unit 10, which forms the front surface 11 and is immediately adjacent to the fan 20, is shown, whereby further levels or components of the heat exchanger unit 10 may also be provided on the side of the component (condenser 12) facing away from the fan 20 (e.g. charge air cooler 13 and / or water cooler 14).

[0065] At the Figure 4The solution shown provides that the guide sleeve 30 rests against the heat exchanger unit 10 on its side facing the heat exchanger unit 10 and that its heat exchanger-side end face rests substantially over its entire surface on the end face 11 of the heat exchanger unit 10 or the component nearest the fan. On its side facing the fan 20, the guide sleeve 30 overlaps the wall 22 of the fan 20 in axial direction X, so that the interior of the fan 20, through which flow can occur in axial direction X, transitions directly and, in particular, tightly into the flow channel formed by the guide sleeve 30.

[0066] Although in Figure 4Alternatively, it can be provided that the guide sleeve 30 bears against a radially outer surface of the wall 22 of the fan 20 with a radially inner surface. Furthermore, stops limiting the overlap and displacement of the guide sleeve 30 on the fan 20 can be provided on the radially inner surface and / or the radially outer surface of the guide sleeve 30 and / or the wall 22.

[0067] In Figure 4 The guide sleeve 30 can, for example, be fixed in place on the heat exchanger unit 10 and the fan 20 can be movable relative to the guide sleeve 30, or fixed in place on the fan 20 and movable relative to the heat exchanger unit 10.

[0068] Furthermore, the guide sleeve 30 can also be movable relative to both the heat exchanger unit 10 and the fan 20, wherein the guide sleeve 30 is pressed resiliently against the end face 11 of the heat exchanger unit 10 by spring elements not shown from the side of the fan 20.

[0069] The radial gap 2 is completely closed in each case, so that the backflow S through the radial gap 2 is essentially completely blocked or suppressed.

[0070] The in Figure 5 The variant shown differs from the one in only this respect. Figure 4In the illustrated embodiment, the guide sleeve 30 has, in addition to a wall 31 extending in the axial direction X and enclosing or circumferencing the wall 22 of the fan 20 in the circumferential direction U, a flange 32 extending radially Y beyond the wall 31 of the guide sleeve 30, thereby increasing the contact area of ​​the guide sleeve 30 against the end face 11 of the heat exchanger unit 10. The flange 32 extends both radially inwards and radially outwards beyond the wall 31 of the guide sleeve 30, although it is also possible for it to extend only radially outwards or radially inwards.

[0071] This is advantageous in several respects. If, for example, the guide sleeve 30 is bonded in one piece to the heat exchanger unit 10 or the end face by adhesive, the flange 32 increases the bonding surface and thus the stability of the connection. Alternatively, if the guide sleeve 30 is fixedly connected to the fan 20, the guide sleeve 30 resting on the end face 11 of the heat exchanger unit 10 must not exert excessive force or pressure on the end face 11, as this could damage the heat exchanger unit 10. The flange 32 increases the contact area, thereby distributing the force over a larger area and reducing the pressure on the end face 11 or on the heat exchanger unit 10.

[0072] Even in the variant according to Figure 6 The guide sleeve 30 has a flange 32, the essential difference being compared to the embodiment of the Figure 5The guide sleeve 30 has an inner diameter larger than the outer diameter of the wall 22 of the fan 20, so that the guide sleeve 30 overlaps the wall 22 of the fan 20 in the axial direction X, but they do not touch each other, and an axial gap 3 is formed between them. The guide sleeve 30 is preferably fixed to the heat exchanger unit 10, for example by gluing it to the end face 11 of the heat exchanger unit 10, so that the fan 20 can move freely relative to the guide sleeve 30 through the axial gap 3, at least along the axial direction X. Therefore, vibration of the fan 20, which causes axial movement of the fan 20, does not cause the fan 20 or the guide sleeve 30 to be pressed against the end face 11 of the heat exchanger unit 10 and thus damage it, or only does this occur in the case of very strong vibrations.Furthermore, it is essential that the flowable area of ​​the axial gap 3 is smaller than the flowable area of ​​the radial gap 2 between heat exchanger unit 10 and fan 20, so that the backflow S is not completely prevented, but minimized.

[0073] The Figures 7A and 7B Figure 1 shows an enlarged section of a variant in which a remaining gap between the wall 31 of the guide sleeve 30 and the end face 11 can be closed by a sealing element 50 that is elastically deformable in the axial direction X, or is automatically closed by a sufficiently strong airflow. According to the [reference to the figure] Figures 7A and 7BIn the depicted variant, the guide sleeve 30 of the cooling device is arranged with a radial gap to the heat exchanger unit 10 or its end face 11. Furthermore, a sealing element 50, shaped as a bellows or bellows-like film, is arranged between the guide sleeve 30 and the heat exchanger unit 10, closing the radial gap. The sealing element 50 has a first end fixed in the axial direction X to the guide sleeve 30 or to the wall 31 of the guide sleeve 30, and a second free end opposite in the axial direction X. If the fan 20 does not generate an airflow or generates an airflow below a predetermined limit, the sealing element 50 is in its closed position. Figure 7AThe initial position (first position) is shown. In this position, the sealing element 50 extends with a section 51 into the airflow channel from the air outlet of the fan 20 to the end face 11 of the heat exchanger unit 10, thereby forming a flow resistance. If the airflow generated by the fan 20 exceeds a predetermined lower limit, such that a force acting on the section 51 of the sealing element 50 due to the airflow exceeds a predetermined value, the sealing element 50 is deformed depending on the airflow and stretched in the axial direction X from its fixed end (or the end fixed to the guide sleeve 30) to its free end, so that the sealing element 50 completely or at least partially closes the radial gap as soon as the airflow exceeds a predetermined upper limit. Figure 7BThe sealing element 50 is in its second fully deformed or stretched position, in which it rests against the end face 11. It should be noted that the deformation, i.e., the stretching of the sealing element 50, is greater the larger the airflow becomes, so that the radial gap is closed depending on the airflow generated by the fan 20.

[0074] The sealing element 50 is bellows-shaped, so that when the guide sleeve 30 moves towards the end face 11, the sealing element 50 is compressed and further closes the gap without exerting a force on the end face 11 that would damage the heat exchanger unit 10. In this process, Figure 7A a condition is shown in which the sealing element 50 is essentially undeformed. Figure 7B The guide sleeve 30 is displaced in the axial direction X in the direction of the end face 11 and the sealing element 50 is deformed accordingly.

[0075] Figure 8corresponds to a variant according to Figure 5 , wherein bristles are provided on a side or surface of the flange 32 facing the end face 11, which penetrate into the heat exchanger unit 10 or here the condenser 12 and thereby fix the flange 32 to the heat exchanger unit 10 with respect to a movement parallel to the end face 11.

Claims

1. A cooling device (1) with a heat exchanger unit (10) through which air can flow and at least one fan (20) that is arranged on the heat exchanger unit (10), forming a radial gap (2) for generating an airflow through the heat exchanger unit (10), wherein the heat exchanger unit (10) has a front face (11) through which air can flow which points toward the fan (20) and which is covered in portions by the fan (20), so that the front face (11) is divided into a first subface (11A) that is at least partially covered by the fan (20) and a second subface (11B) that is free of the fan, wherein the fan (20) has a housing having a wall (22) on the heat exchanger side which extends in the circumferential direction (U), said wall delimiting an interior of the fan through which air can flow in the axial direction characterized in that the cooling device (1) has a guide sleeve (30) which is arranged between the heat exchanger unit (10) and the fan (20) so as to close the radial gap (2) at least in portions, the wall (22) overlaps with the guide sleeve (30) in the axial direction (X), so that the guide sleeve (30) covers the wall (22) of the fan (20) in the circumferential direction (U) or the wall (22) of the fan (20) extends around the guide sleeve (30) in the circumferential direction (U), forms a flow channel leading from an air outlet of the fan (20) to the first subface (11A) of the front face (11), and fluidically connects the air outlet of the fan (20) to the first subface (11A) of the front face (11) and fluidically separates the same from the second subface (11B).

2. The cooling device as set forth in claim 1, wherein the guide sleeve (30) is embodied as a hollow cylinder and / or is rotationally symmetrical, and wherein the guide sleeve (30) is arranged coaxially with an axis of rotation (R) of an impeller (21) of the fan (20).

3. The cooling device as set forth in claim 1 or 2, wherein the guide sleeve (30) is formed integrally by the heat exchanger unit (10) or is connected thereto in a single piece.

4. The cooling device as set forth in one of claims 1 to 3, wherein the guide sleeve (30) rests directly against the fan (20) or is arranged with a radial gap relative to the fan (20) or is arranged with an axial gap (3) relative to the fan (20).

5. The cooling device as set forth in claim 1 or 2, wherein the guide sleeve (30) is formed integrally by the fan (20) or is connected thereto in a single piece.

6. The cooling device as set forth in one of claims 1, 2, 4 or 5, wherein the guide sleeve (30) rests directly against the heat exchanger unit (10) or is arranged with a radial gap (2) relative to the heat exchanger unit (10).

7. The cooling device as set forth in one of claims 1, 2, 4 or 5, wherein the guide sleeve (30) is arranged with a radial gap (2) relative to the heat exchanger unit (10) and a sealing element (50) which closes the radial gap (2) is arranged between the guide sleeve (30) and the heat exchanger unit (10).

8. The cooling device as set forth in the preceding claim, wherein the sealing element (50) is embodied as a bellows or skirt, has a first end that is secured in the axial direction (X) to the guide sleeve (30) and a free second end that is oppositely situated in the axial direction (X) and is designed to be stretched by the airflow generated by the fan (20) in the axial direction (X) from a non-deformed first position into a deformed second position, so that the radial gap (2) is particularly completely closed in the second position.

9. The cooling device as set forth in one of the preceding claims, wherein the guide sleeve (30) is dimensionally stable and particularly rigid.

10. The cooling device as set forth in one of the preceding claims, wherein the guide sleeve (30) has a wall (31) that extends around in the circumferential direction (U) and a flange (32) that extends beyond the wall (31) in the radial direction (Y) on the heat exchanger side and / or fan side.

11. The cooling device as set forth in the preceding claim, wherein the flange (32) has a deformation element and / or a plurality of bristles toward the front face (11) by means of which the flange (32) is designed to penetrate through the front face (11) into the heat exchanger unit (10).

12. The cooling device as set forth in one of the preceding claims, wherein an axis of rotation (R) of an impeller (21) of the fan (20) is coaxial with a central axis of the heat exchanger unit (10), which is orthogonal to the front face (11) and extends centrally through the front face (11).

13. The cooling device as set forth in one of the preceding claims, further comprising a fan holding element (40) that is designed to secure the fan (20) in a fixed position relative to the heat exchanger unit (10).