Fan and cooling structure for fan

Abstract

The invention relates to a fan having an impeller and an electric machine, the electric machine comprising a stator, a rotor and optionally an electronics compartment, the stator and / or the outer wall of the electronics compartment being formed or provided with a cooling structure which forms a flow path for a fluid, preferably air, through the flow path, a flow stream is caused based on a pressure difference generated by fan operation, and the flow stream discharges heat from the motor and / or the stator and / or the electronic component cabin. The invention also relates to a corresponding cooling structure for a fan.

Description

Technical Field

[0001] The present invention relates to a fan with a special cooling structure and a cooling structure, in particular for improving the cooling of an electric motor based on a cooling flow generated between the cooling structure and the electric motor. Background Art

[0002] Fans of this type are already sufficiently known from practice. For this purpose, reference may be made merely by way of example to WO 2020 / 015792 A1.

[0003] Fans are usually subject to high thermal loads, for example ≥ 60°C. Especially in "suction" arrangements, where, for example, hot air from a heat exchanger is sucked in by the fan, the corresponding temperature has a significant negative impact. In particular, electronic components (in EC fans) and other components such as bearings, insulation materials, winding wires, etc. in the integrated electronic system are subject to certain temperature limits, which limit the performance and / or speed of the fan. Excessive temperatures lead to damage to components.

[0004] There are already solutions in the prior art for avoiding the aforementioned overheating problems. EC external rotor motors have therefore already been equipped with integrated electronics with integrated cooling systems. This requires a redesign of the motor. In addition, there are also hubs with perforations or cutouts, which cause efficiency losses. In this way, it is possible to encourage better air flow around the motor.

[0005] In practice, there are also known cooling systems with perforations on the stator flange, but this also requires modifications to the motor or the stator. In addition, there are already additional components for guiding cooling air on or around the motor. This is complex in structure and inefficient. Summary of the invention

[0006] The object of the invention is to at least largely eliminate the disadvantages that occur in the prior art. Adequate cooling of the motor of the fan should be achieved by simple means. It should also be possible to add the required cooling structure for cooling, so as to improve the heat dissipation of the motor and minimize the efficiency loss of the fan. In addition, the fan according to the invention and the cooling structure according to the invention should be distinguished from competitive products on the market.

[0007] The aforementioned object is achieved by the features of claim 1, according to which a cooling structure is constructed or provided on the radially outer outer wall of the stator and / or the electronic component compartment. The cooling structure, together with the motor, forms a flow path for a fluid medium, in the simplest case, ambient air. A flow stream is induced through this flow path by a pressure difference due to the operation of the fan. As a result, heat is discharged from the motor and / or the stator and / or the electronic component compartment. In other words, cooling is achieved by heat removal.

[0008] The cooling structure according to the invention can be implemented in completely different ways. What is important here is that the flow path does not pass through components of the motor that are important for its function. Even without the cooling structure, such a motor can operate fully, but the cooling capacity is reduced. Accordingly, a cooling structure can be added. For this purpose, the cooling structure can be configured in special components.

[0009] It is also conceivable to integrate the cooling structure into an outlet guide housing, which is preferably injection-molded, and to provide it through this outlet guide housing. Such a cooling structure includes a housing that surrounds the motor at a radial distance from the motor, and this housing is purposefully flowed through by the flow field generated by the fan, so as to improve the heat dissipation of the motor. By this measure, the efficiency loss of the fan can be reduced.

[0010] If the cooling structure is retrofitted, a preparatory device for a hub cover with a diameter larger than that of the impeller hub is required. This enlarged hub cover should be at least 105% and at most 130%, preferably 115%, of the size (diameter) of the conventional hub cover.

[0011] The cooling structure can be directly or indirectly fastened to the stator. In the assembled state with the stator, the cooling structure has at least one, preferably three, axial perforations or channels inside the cooling structure. These axial perforations or channels form a flow path axially, that is, they extend from one side of the cooling structure to its axially opposite side. At least one or more flow paths between one side and the other side of the cooling structure are advantageously configured as a cooling flow guide part by means of a special guiding profile, and this cooling flow guide part interacts with the outer wall of the motor or the stator or the electronic component housing to form a flow path. These flow paths extend axially along the motor or the stator or the electronic component housing. Based on the flow field generated during the operation of the fan, especially the pressure difference between the two axially opposite sides of the cooling structure, "cold" ambient air flows through the flow path inside the cooling structure at a higher flow rate and turbulence, flows along the stator or the electronic component housing, and cools the motor and its built-in power electronic components sufficiently. Description of the Drawings

[0012] There are various possibilities for beneficially designing and improving the teachings of the present invention. For this purpose, on the one hand, reference can be made to the dependent claims of claims 1 and 12, and on the other hand, reference can be made to the following explanation of the preferred embodiments of the fan according to the present invention through the drawings. In combination with the explanation of the preferred embodiments of the present invention with the aid of the drawings, the generally preferred design solutions and improvement solutions of the said teachings are also explained. In the drawings:

[0013] Figure 1Perspective view showing the fan with the cooling structure according to the invention, seen from the outflow side, the cooling structure being integrated in a load-bearing outlet guide unit having a housing, an outlet guide device and stay vanes;

[0014] Figure 2 Perspective view showing the fan seen from the oncoming flow side Figure 1 of the fan shown;

[0015] Figure 3 Perspective view showing the fan seen from the oncoming flow side Figure 1 and 2 axial plane top view of the fan shown with a load-bearing outlet guide unit;

[0016] Figure 4 Perspective view showing the fan seen from the outflow side Figures 1 to 3 axial plane top view of the fan shown with a load-bearing outlet guide unit;

[0017] Figure 4a Shows Figure 4 detail view in the area of the cooling structure, where the width dimension is schematically marked;

[0018] Figure 5 Shows Figures 1 to 4 side view and section in a plane passing through the axis of the fan shown with a load-bearing outlet guide unit, where only the upper half of the fan axis is shown, and where dimensions are schematically marked;

[0019] Figure 5a Shows Figure 5 detail view in the area of the cooling structure, where additional characteristic dimensions are schematically shown;

[0020] Figure 6a Similarly shows Figure 5a detail view in the area of the cooling structure, which shows another embodiment of the cooling structure having an inlet area of the cooling flow guide;

[0021] Figure 7 axial plane top view of a part of the cooling structure according to the invention, seen from the oncoming flow side, which has a guide element integrally formed on the outside thereof and a configured electric machine;

[0022] Figure 8 Perspective view showing another embodiment of the cooling structure for a fan, seen from the stator side, which has an electric machine configured therein and where no cooling flow guide is provided;

[0023] Figure 9 Perspective view showing the fan seen from the stator side Figure 8 axial plane top view of the cooling structure with an electric machine shown, where two dimensions are schematically marked;

[0024] Figure 10 Show Figure 8 And 9 Side view of the shown motor - equipped cooling structure and cross - section in a plane passing through the axis;

[0025] Figure 11 Perspective view of a fan with a cooling structure according to another embodiment, viewed from the outflow side, the cooling structure being integrated in a built - in outlet guide device, where the load - bearing function is borne by a metal brace suspension device and no load - bearing type outlet guide unit is designed;

[0026] Figure 12 Perspective view of another embodiment of the cooling structure of a radial - flow fan, viewed from the outflow side, where the cooling structure is integrated in the motor support plate of a load - bearing module;

[0027] Figure 13 Show Figure 12 Side view of the shown motor - equipped cooling structure and partial cross - section in a plane passing through the axis in a region near the cooling structure;

[0028] Figure 13a Show Figure 13 Detail view in the region of the cooling structure, where characteristic dimensions are additionally schematically marked. Detailed implementation mode

[0029] Figure 1 Perspective view of an axial - flow fan 57, viewed from the outflow side, which has a cooling structure 40 according to an embodiment of the present invention, the cooling structure being integrally integrated in a load - bearing type outlet guide unit 1 here. The outlet guide unit 1 particularly includes a housing 2, an intermediate ring 5, a hub ring 4, internal guide vanes 11 extending between the hub ring 4 and the intermediate ring 5, and brace vanes 3 extending between the intermediate ring 5 and the housing 2 or its diffuser region 10. The outlet guide unit 1 is advantageously manufactured in one piece by an injection molding method, preferably an injection molding method.

[0030] The housing 2 defines the outer boundary of a fan flow path extending within the housing 2. The housing 2 includes a plurality of regions: first an inlet nozzle 9 in the flow-through direction, then a preferably cylindrical region 29 and a diffuser region 10. An impeller 19 and its blades 22 are provided within the cylindrical region, and the strut blades 3 are fastened to the diffuser region. An internal outlet guide device is provided downstream of the impeller 19 inside the housing 2. This internal outlet guide device particularly includes internal outlet guide vanes 11 that are hydraulically effective. These internal outlet guide vanes extend between the hub ring 4 and the intermediate ring 5. Due to the hydrodynamic effect generated by the cooperation of the internal outlet guide vanes 11 with the intermediate ring 5 and the hub ring 4, the fan 57 has a particularly high static efficiency and air volume power, especially a particularly high static pressure rise when the delivered volume flow is determined. A motor 34 is fastened on the hub ring 4 on its radially inner side in the stator-side receiving region 8 (also called the hub housing 8). The motor has its stator 36 on the flange 54 of the cooling structure 40. This flange also serves as the motor fastening flange 59 here, so that the internal outlet guide vanes 11 and the intermediate ring 5 also have the function of supporting the motor 36 and also the impeller 19.

[0031] In order to hold the motor 34 together with the impeller 19 and the internal outlet guide device on the outer housing 2, external strut blades 3 are provided. These external strut blades have at most a secondary hydrodynamic function and are mainly used to fasten the internal outlet guide device, and thus the motor 34 and the impeller 19, to the outer housing 2. These external strut blades are designed with low noise, and due to their presence, the fan 57 does not generate or only generates a small amount of additional noise during operation. In summary, two different flow path regions are constructed in the axial region of the diffuser 10 inside the housing 2 when observed in the spanwise direction (observed from the hub 4 to the diffuser 10): an external flow path region 6 located between the intermediate ring 5 and the diffuser wall 10 of the housing 2 and an internal flow path region 7 located between the hub ring 4 and the intermediate ring 5.

[0032] The internal flow path region 7 has load-bearing internal guide elements 11. These load-bearing internal guide elements have hydrodynamic functions and, for example, reduce air flow vortices, promote the construction of static pressure, avoid or reduce hub backflow, and these load-bearing internal guide elements only generate weak noise due to their radially inner position.

[0033] The external flow path region 6 is provided with strut blades 3 that are also load-bearing. In this embodiment, there are a total of 6, and beneficially 4 to 8, which are distributed circumferentially. These strut blades are optimized in terms of noise. On the load-bearing outlet guide unit 1, flanges are integrally provided on the edge region of the housing 2 on the upstream side and the outflow side. These flanges beneficially have a variety of fastening preparation devices.

[0034] On the upstream-side flange, there is a fastening preparation device 20 for fastening the outlet guide unit 1 and thus also the fan 57 to a higher-level instrument or system. Similarly, on the downstream-side flange, there is a fastening preparation device 21 for fastening the outlet guide unit 1 to a higher-level instrument or system.

[0035] Furthermore, on the downstream-side flange, there is also a fastening preparation device 25 for an anti-touch grille, and these fastening preparation devices can also be similarly provided on the upstream-side flange. The anti-touch grille can be countersunk and screwed in the area 25 such that it does not axially protrude beyond the outlet guide unit 1, which achieves good operability and good stackability of multiple fans 57.

[0036] The intermediate ring 5 has a wavy design at its downstream-side edge 12 and can also have a serrated or slotted structure. It can also be designed as a circle without a wavy structure.

[0037] Inside the hub ring 4, in the stator-side accommodation area 8, the motor is fastened to an integrally arranged motor-bearing flange 59 on the load-bearing outlet guide device 1, and this motor-bearing flange is simultaneously the flange 54 of the cooling structure. To enhance and stabilize the connection with the motor, reinforcing ribs 58 are also arranged inside the stator-side accommodation area 8. In particular, in the stator-side accommodation area 8, there are preparation devices for improving the heat dissipation of the motor, such as the cooling flow guide part 14 recognizable here.

[0038] On the illustrated fan, a cooling structure 40 is constructed, and in this embodiment, it is integrally formed in the load-bearing outlet guide unit 1. The cooling structure 40 is penetrated by a cooling flow during the operation of the fan 57, which conducts the additional heat flow from the motor 34 or rather the stator 36 or the electronic component compartment 13. In this embodiment, it includes the hub ring 4, elements integrally installed radially inside the hub ring, in particular the cooling structure flange 59 with a special shape, which is also designed as the motor-bearing flange 59 here, and advantageously also includes a cooling flow guide part 14 as in the illustrated embodiment, and the special configuration will be detailed in the subsequent figures.

[0039] It is conceivable that in the molding die for manufacturing the load-bearing outlet guide unit 1, replaceable inserts are provided in the area inside the hub ring 4, i.e., in the stator-side accommodation area 8, to achieve different interfaces for the cooling structure 40 integrally formed with the load-bearing outlet guide device 1 here for relatively different motors and / or different embodiments. Here, in addition to the bolt hole pitch circle for fastening the motor, there is also an axial tightening plane for the motor, which changes the axial position of the cooling structure flange / motor-bearing flange 54, 59 in the accommodation area 8. The presence or shape of the cooling flow guide part 14 can also be changed.

[0040] The stator 36 can be seen from the electric motor 34, which is an external rotor motor here and is also advantageously designed as an EC motor with integrated motor electronics. In the stator 36, the motor electronics are constructed in an integrated electronics compartment / electronics housing 13. The electronics compartment / electronics housing can also be fastened to the stator as a separate component. The cooling structure 40 promotes the removal of waste heat from the stator 36 of the electric motor 34 and in this embodiment, in particular the electronics compartment 13, by its operating principle. This allows better cooling of the electronic components and enables the electric motor to achieve higher torques and thus higher powers at the same ambient medium temperature or conveying medium temperature.

[0041] Due to the design of the cooling structure 40 together with the hub ring 4 in the hub shell 8 at the stator-side end, there is sufficient space in the radial direction between the outer contours of the stator 36 or the electronic component compartment 13. In particular, the outer diameter D of the hub ring 4 or the cooling structure is N 27 (See Figure 4a or 5) than the electronic component compartment 13 at the cable connector 53 (see also Figure 4a ) in the area of ​​the outer diameter D E 63 (See Figure 5 ) is at least 15%, preferably 30%. This is beneficial and can simply connect the required cables to the stator 36 of the motor 34 or the electronic component compartment 13 during assembly.

[0042] Figure 2 Shown from the upstream side Figure 1 A perspective view of the fan 57 is shown. Figure 1 As shown, the impeller 19 and its blades 22 fastened in one piece to the hub 31 can also be clearly seen here. A hub cap 37 is fastened to the hub 31 of the impeller 22 and is advantageously locked with a snap-on hook. The hub cap 37 forms a favorable contour for the flow in the hub region of the impeller 19 by cooperating with the hub 37, which is beneficial for high efficiency and low noise levels. The rotor 35 of the motor 34 can be seen inside this hub cap 37, which has a large opening in the radial inner region. This design of the hub cap 37 with an inner opening ensures good cooling of the rotor 35 of the motor 34. When the fan 57 is in operation, the impeller 19 (which is fastened to the rotor) is driven by the rotor 35 of the motor 34 to rotate in the direction of rotation 32, here, for example, in the clockwise direction. The conveying medium (usually air) is thus conveyed by the fan 57 from the incident flow side (visible here) in the flow direction through the inlet nozzle 9, the impeller region 29 and the diffuser 10 to the outflow side axially opposite the incident flow side. In particular, energy is transferred to the conveying medium flow conveyed in this way, which is measurable in the form of a pressure increase, in particular a total pressure increase and / or a static pressure increase. The conveying medium flow is divided into two main parts downstream of the impeller: one part flows through the outer flow channel region 6 and the second part flows through the inner flow channel region 7.

[0043] Figure 3 shown as viewed from the upstream side Figure 1 and 2 axial plane top view of the fan 57 with the load-bearing outlet guide unit 1 shown. As a supplement to Figure 1 and 2 the description, the hub 4 of the outlet guide unit 1 and in particular the cooling structure 40 can be seen here. The cooling structure radially exceeds the hub 37 of the impeller 19. This design is beneficial for the cooling structure 40 to cool the motor 34 or its stator 36 or its electronic component compartment 13. For example: The flow conveyed by the impeller 19 can flow into the cooling structure 40 between the outer radius of the hub 37 of the impeller 19 and the inner radius of the hub 4 forming the outer edge of the cooling structure 40 downstream of the impeller 19, and improve the motor cooling effect.

[0044] Figure 4 shown as viewed from the outflow side Figures 1 to 3 axial top view of the fan 57 with the cooling structure 40 shown, which is integrated in the load-bearing outlet guide unit 1. As a supplement to Figures 1 to 3 the shown embodiment, the external flow path region 6 penetrated by the diagonal support blades 3 and the internal flow path region 7 with the internal guide blades 11 can be clearly observed. When the fan 57 operates, the impeller 22 with the blades 19 rotates around the fan axis in the rotational direction 32 (counterclockwise in the view). The motor 34 is accommodated on the stator side in the accommodation region 8, also called the hub cover 8, of the cooling structure 40 and is mounted on the flange 54, which also serves as the motor bearing flange of the cooling structure 40, through the fastening preparation means 18, preferably threaded parts. When the fan 57 operates, the cooling structure 40 improves the heat dissipation of the motor 36, in particular its stator 36 and in particular its electronic component compartment 13, and in this way serves as a functional unit for motor cooling in combination with the motor 34 or the stator 26 or the electronic component compartment 13.

[0045] The diffusion region 10 expands from the region 29 for the impeller 19 (see Figure 1 ) towards the outflow side edge of the housing 2. The intermediate ring 5 also slightly expands from the impeller 19 towards its outflow side edge 12 (see Figure 5 ). Thus, in this embodiment, both the internal flow path region 7 and the external flow path region 6 are configured to be diffusive, that is, widened along the flow-through direction. This is beneficial for the high pressure recovery downstream of the impeller 19 and thus the high static efficiency of the fan 57. Particularly beneficial is that the static pressure rise in the flow path between the impeller 19 and the outlet of the fan 57 is also used for the possible beneficial principle of action of the cooling structure 40, that is, for cooling the motor 34 or the stator 36 or the electronic component compartment 13.

[0046] In the cooling structure 40, a cooling flow opposite to the mainstream direction is induced in the inner accommodation area 8 on the stator side by a pressure difference, that is, a higher static pressure at the outflow side end (with respect to the fan mainstream) of the cooling structure 40 relative to its upstream side end (with respect to the fan mainstream). This cooling flow additionally cools the motor 34, that is, the stator 36 or the electronic component compartment 13 by flowing past them. Here, this cooling flow can be additionally guided between the motor 34 and the cooling structure 40 through the cooling flow guide 14, through the channels in the cooling structure flange 54 until it flows to the upstream side direction on the opposite side of the cooling structure flange 54 (especially see Figure 5 , 5a ).

[0047] Figure 4a For Figure 4 a detail view in the area of the cooling structure 40, in which the width dimension B16 is schematically marked. Here, B16 represents the width of the cooling flow guide 14, that is, its extension in a direction substantially transverse to the fan axis and substantially circumferentially. Since the cooling channels 42 that are not visible here correspond to the cooling flow guide 16 through the cooling structure flange 54 with a similar circumferential extension (especially see Figure 5a , Figure 7 ), B can thus also be understood as the width of the cooling channels 42. In this embodiment, three cooling channels (42) distributed on the circumference are provided with corresponding cooling flow guides 14. Based on this configuration, three areas radially opposite to the cooling flow guides 14 at the radially outward-facing surface of the electronic component compartment 13 of the motor 34 are particularly well cooled because, due to the cooling flow guides 14 and the cooling channels 42, the cooling medium flows past the corresponding surfaces at a relatively high flow rate and / or in a turbulent manner. Advantageously, areas where good cooling is particularly important, such as opposite to the power electronic components that generate particularly a lot of heat in the electronic component compartment, such as the output stage (IGBT) or the input stage, or opposite to components that are particularly temperature-sensitive. When the cooling flow guide 14 is used, its width B16 or the width B16 of the cooling channels 42 is advantageously 10% - 45% of the diameter D N of the stator side accommodation area 8 of the cooling structure 40.

[0048] Figure 5 Shows Figures 1 to 4 a side view and a cross-section in a plane passing through the axis of the fan 57 with a load-bearing outlet guide unit 1, in which the dimensions in the areas of the cooling structure 40, the impeller hub 31, and the inlet nozzle 9 are schematically marked. In addition to the relevant drawings, the contour of the hub cover 37 can be seen particularly clearly here. It is designed to transition to the hub 31 of the impeller 19 in an aerodynamically suitable manner with a tangential side rounded, and this hub cover is installed in the hub area of the impeller 19.

[0049] The electric motor 34 (including a stator 36 and a rotor 35) is shown here without sectioning. The stator 36 (which also includes the electronic component compartment 13 here) is fastened in the stator-side receiving region 8 of the cooling structure 40 integrated in the load-bearing outlet guide unit 1 by means of a cooling structure flange 54 which also serves as an electric motor fastening flange 59. The impeller 19 is fastened to the rotor 35 of the electric motor 34 via its hub 31 and the blades 22, the radially outer ends of said blades advantageously having a special profile, namely so-called winglets 38, wherein there is a small radial spacing and a flow gap between the impeller blades 22 with winglets 38 and the impeller region 29 of the housing 2.

[0050] The fan 57 is designed particularly compactly in the radial direction. This means that: the ratio of the inlet diameter Da45 of the inlet nozzle 9 to the inner diameter Di44 is small, advantageously Da / Di < 1.1. As a result, a small extension e43 of the outlet guide unit transverse to the fan axis can also be achieved (the extension e43 can in particular be understood as the side length of a square profile extending transverse to the fan axis into which the load-bearing outlet guide unit 1 and thus the fan 57 can be inserted). Advantageously, e / Di < 1.2. The fan 57 thus occupies a particularly small installation space in terms of its inner diameter Di44 when viewed transverse to its axis and thus also in terms of the diameter of its impeller 19. Conversely, when the installation space is pre-given, a fan 57 with a particularly large inner diameter Di44 and thus a particularly large outer diameter of its impeller 19 can be used, which would be acoustically beneficial at a pre-given operating point.

[0051] Due to the relatively large outer extension e43 which relatively confines the radial structural space, a relatively large flow cross-section can in principle be provided, which is very beneficial for reducing the noise of the fan 57 and increasing its static efficiency at a given operating point. Due to the relatively large flow cross-section of the fan existing inside the housing 2, it is also beneficial to achieve a relatively large diameter D i of the cooling structure 40 even without unduly influencing the blocking effect, N wherein the diameter D L 27 of the cooling structure 40 is relatively large compared to the diameter D Figure 3 of the hub 31 of the impeller 19, which is beneficial for the principle of operation of the cooling structure 40, as already described N by L way of. Preferably, D N / D L is in the range from 115% to 135%, particularly preferably approximately 115%. Depending on the operating state of the fan 57, the flow diversion for cooling can flow into the cooling structure 40 in the radial region between the impeller hub 31 and the cooling structure 40 starting from the upstream side, or vice versa in the direction opposite to the main flow direction of the fan between the impeller hub 31 and the cooling structure towards the impeller 19.

[0052] Figure 5a is shown Figure 5Detail view in the region of the cooling structure 40, in which additional characteristic dimensions are schematically indicated. In this detail view, the flow path inside the cooling structure 40 can be clearly observed. In the present embodiment, the cooling structure 40 here has a rotor-side receiving region 46 and a stator-side receiving region 8 inside the hub ring 4. In the first operating state, the flow can pass through the cooling structure 40 from the rotor side to the stator side in a direction parallel to the main flow of the fan.

[0053] In the second operating state, the flow can pass through the cooling structure 40 from the stator side to the rotor side in a direction opposite to the main flow of the fan. This second operating state occurs especially when the main flow of the fan passes through the cooling structure 40, in particular through the outlet guide wheel with the internal outlet guide vanes 11, or when passing through the internal 7 and external flow channel regions 6 that widen diffusively in the flow direction (see Figure 4 ), where a significantly increased static pressure is generated. The resulting pressure difference then drives the flow in a direction opposite to the main flow of the fan, here from the stator 36 towards the rotor 35, along the electric machine 34 or the stator 36 or the electronic component housing 13 through the cooling structure 40. Especially in this second operating state, efficient additional cooling of the electric machine 34 or the stator 36 or the electronic component housing 13 can be achieved.

[0054] The flow path through the cooling structure here (in the following order or in reverse) is from the outflowing main flow of the fan through the stator-side receiving region 8, then along the cooling flow channel 41 delimited here by the cooling flow guide 14 between the electronic component housing 13 and the cooling flow guide 14 to the region of the cooling channel 42 in the cooling structure flange 54 in the rotor-side receiving region 46, in order to finally flow out of the cooling structure 40 from there and mix with the main flow of the fan. After passing through the cooling channel 42, the fluid can possibly also flow through a cooling system integrated in the electric machine 34, as shown in the present embodiment, where the integrated electric machine cooling system especially includes stator cooling ribs 50 and a rotor cooling fan wheel 51. The embodiment in which the cooling flow guide 14 is integrated in the cooling structure 40 and thus forms a cooling flow channel 41 of a corresponding form between the cooling flow guide 14 and the stator 36 or the electronic component housing 13 is particularly beneficial for heat dissipation, because the flow passes through the vicinity of the surface to be cooled of the electric machine at a targeted high speed and / or high turbulence. For this purpose, in the assembled state, it is beneficial that at least one region with a small gap, i.e., a minimum distance t26 between the cooling flow guide 14 and the stator 36 or the electronic component housing 13, is designed along the cooling flow channel 41. Advantageously, this gap width or this minimum distance t26 is between 2 and 15 mm, particularly advantageously approximately 5 mm.

[0055] The overlapping length L24 of the cooling flow guide portion 14 with the stator 36 or the electronic component compartment 13, in other words the axial length L24 of the cooling flow guide portion 14, is advantageously large enough, for example at least 50% of the axial length Ls17 of the electronic component compartment 13, where the measurement is taken from the connection plane of the stator flange 49 up to the electronic component cover plate (if present).

[0056] It should be noted that embodiments without the cooling flow guide portion 14 can also be considered, for example see Figures 8 to 10 . However, it is particularly advantageous that the cooling flow guide portion 14 and thus the cooling channel 41 (which relates to its cross-sectional center line) are at least partially constructed with a very small distance from the outer wall of the stator 36 or the electronic component compartment 13. However, at least important is the design of the cooling channel 42 in the axial region of the cooling structure flange 54 to ensure the described flow through the cooling structure 40 and the electric machine 34 during fan operation.

[0057] In the present embodiment, the cooling structure 40 is designed such that in its integrated structure including the cooling flow guide portion 14, it can be demolded from the injection molding die, especially from the injection molding die, in one piece without undercuts, and it has two molding die parts that are demolded from the member along the axial direction of the member, one of which is demolded in the direction of the fan upstream side to the right in the view, and one is demolded in the direction of the fan downstream side to the left in the view. Thus, the narrowest part between the cooling flow guide portion 14 and the stator 36 or the electronic component compartment 13 is approximately located on the edge of the cooling flow guide portion 14 that faces away from the stator flange 49. This is particularly beneficial for the economical manufacture of the corresponding die and the economical manufacture of the member (cooling structure 40) in mass production.

[0058] Figure 6a And Figure 5a A detail view of the cooling structure 40 in the region of the cooling structure 40 similar to another embodiment is shown. Different from the Figure 5a embodiment, the cooling flow guide portion 14 has a different design structure. The narrowest part between the cooling flow guide portion 14 and the stator 36 or the electronic component compartment 13 is no longer at the edge of the cooling flow guide portion 14 that faces away from the stator flange 49, but is further shifted in the direction of the stator flange 49.

[0059] For operating state 2 in which the cooling flow flows from the fan outlet side to the fan inlet side (from left to right in the view) within the cooling structure 40, a special inflow region 47 is configured in the cooling flow channel 41 formed by the cooling flow guide 14 such that the cooling flow channel 41 converges from the stator side edge of the cooling flow guide 14 towards the stator flange 49 to the narrowest part first and then diverges again in the further extension towards the stator flange 49. This would be particularly beneficial for the flow velocity and / or turbulence in the cooling flow channel 41 and thus for the cooling of the stator 36 or the electronic component compartment 13. However, in the case of integrally one-piece manufacturing of the cooling flow guide 14 and the cooling structure 40, this implementation requires a particularly complex demolding from the injection mold, especially when it no longer has undercuts relative to the fan axis direction as in the illustrated implementation.

[0060] Figure 7 Shows an axial plane top view of a part of the cooling structure 40 according to the invention as viewed from the inlet side, which cooling structure is externally integrated with a flow guiding element 11 with a motor 34 built thereon, for example according to Figures 1 to 5 the illustrated implementation. The impeller is not shown here. Inside the rotor side receiving region 46 of the cooling structure 40 as seen from the fan inlet side. The rotor 35 of the motor 34 can be seen, which rotor has fastening preparation means 30 for fastening the impeller. Three cooling channels 42 can be seen radially outside the rotor 35, inside the cooling structure 40 and inside the hub ring 4 bounded on the outside of this cooling structure, and the cooling flow guide 14 integrated in the cooling structure 40 extending behind them. The cooling channels 42, as described by Figure 4a have a characteristic width B16 measured approximately in the circumferential direction or perpendicular to the fan axis. In order to strengthen the connection between the hub ring 4 and the motor bearing flange 49, rotor side reinforcing ribs 58, here rotor side reinforcing ribs 48, are also configured in the rotor side receiving region 46, and these rotor side reinforcing ribs are beneficially integrally integrated with the cooling structure flange 54 designed as the motor bearing flange 59 on the cooling structure 40.

[0061] Figure 8A perspective view of another embodiment of a cooling structure 40 for a fan, as viewed from the outflow side, is shown, which has a motor 34 constructed therein, where the stator 36 or the electronic component housing 13 is visible. The cooling structure 40 has a hub ring 4 and a flange 54, the hub ring bounding the cooling structure radially on the outside, and the cooling structure is connected to the flange 49 of the stator 36 via the flange. This embodiment of the cooling structure 40 does not integrate other fan components and is not particularly suitable for bearing loads, that is, in the assembled state, other components, such as support ribs, must be responsible for connecting the motor to the housing or instrument or the like. Such support ribs or the like can be fastened to the flange 49 of the stator, like the cooling structure 40, by means of fastening preparation means 18, in particular a threaded connection, or at a connection location offset circumferentially relative to the connection location of the cooling structure flange 54, or axially between the cooling structure 40 or its flange 54 and the stator flange 49.

[0062] The key point is that in the assembled state (including the suspension device), cooling channels 42 are formed, which enable the cooling structure 40 to be flowed through axially from the rotor side to the stator side or vice versa. This cooling flow promotes the heat dissipation of the motor 34 or its stator 36 or its electronic component housing 13. In this embodiment, no additional cooling flow guiding portion is provided for the cooling flow to flow through the stator particularly close to the stator 36. This can also be beneficially considered in a non-load-bearing or non-integrated cooling structure 40 into other fan components.

[0063] It should be noted here that especially in operating state 2, when the cooling flow in the cooling structure 40 is opposite to the main flow of the fan, the effective delivery volume flow of the fan is thereby reduced by the return cooling flow and the total efficiency of the fan is decreased. Therefore, it is beneficial to carefully select the size or cross-section of the cooling channels 42, thereby achieving a good cooling effect and at the same time not overly affecting the total efficiency of the fan. When constructing the cooling flow guiding portion 14 as in the embodiment shown in Figures 1 to 5 the size of the cooling flow can also be well controlled via the cooling flow guiding portion 14 and the minimum distance between the cooling flow guiding portion and the stator 36 or the electronic component housing 14 of the motor 34.

[0064] In Figure 8 the embodiment shown without a cooling flow guiding portion, the careful selection of the open cross-section of the cooling channels 42 must be controlled in the assembled state with the motor 34. In a construction without a cooling flow guiding portion, it is beneficial that the total open cross-section in the region of the channels 42 is not greater than 10% of the reference cross-section of the electronic component housing 13, which can be defined via its outer diameter D E 63 as π / 4×D E ×D EWhen the narrowest cross section in the flow path or cooling channel 41 of the cooling flow flowing through the cooling structure 40 is used as the total open cross section in the assembled state with the electric machine 34 (the narrowest cross section is, for example, Figures 1 to 7 In the embodiment shown with the cooling flow guide 14, this is usually obtained in the area where the cooling flow guide 14 has a minimum distance from the stator 36 of the motor 34 or the electronic component compartment 13), this value is completely universal and also applies to the case of a designed cooling flow guide 14.

[0065] Figure 9 Shown from the outflow side Figure 8 The cooling structure 40 with the motor 34 is shown in an axial plan view. Figure 8 As shown, here and Figure 7 Similarly, the width B16 of the cooling channel 42 in the assembled state with the electric machine 34 is additionally indicated approximately in the circumferential direction. In particular, in embodiments without cooling flow guides 14, it is also conceivable to provide a significantly larger number of cooling channels 42, for which the width B is smaller, for example up to 60 cooling channels. The cooling channels 42 also have an open height h15 in the radial direction, which together with the width B characterizes the open cross-sectional area of ​​an individual cooling channel 42, while the open cross-sectional area is the sum of all open cross-sectional areas of all cooling channels 42.

[0066] Figure 10 Show Figure 8 and 9 A side view of a cooling structure 40 with an electric motor 34 and a cross section on a plane passing through the axis are shown. The path of a possible cooling flow through the cooling channel 41 in the cooling structure 40 or its hub ring 4 can be clearly understood. Here, the stator-side receiving area 8 and the rotor-side receiving area 46 can also be constructed in the cooling structure 40, which are separated on one side in the axial direction by a cooling structure flange 54, wherein the cooling channel 42 establishes fluid communication. In this way, the cooling medium can flow from the stator 36 to the rotor 35 in the cooling structure 40, or from the stator-side receiving area 8 through the cooling channel 42 to the rotor-side receiving area 46, or vice versa, which is determined by the external flow flow conditions or pressure conditions.

[0067] Here, the convection cooling system integrated in the electric motor 34 can also play a role. Figures 1 to 7Like the electric machine in the illustrated embodiment, the illustrated electric machine has its own integrated cooling system and cooling ribs 50 for heat dissipation on the stator 36 or its flange 49. The integrated cooling system includes a rotating cooling fan wheel 51 fastened to the rotor 35. This cooling system ensures the basic heat dissipation of the electric machine 34, but this basic heat dissipation can be significantly improved by the action of the cooling structure 40. The cooling flow in the cooling structure 40 can at least also be generated or promoted by the cooling wheel 51 of the basic cooling system integrated in the electric machine 34. However, it is particularly advantageous that the cooling flow is directly or indirectly caused or enhanced by the impeller and / or guide wheel and / or diffuser of the fan.

[0068] Figure 11 A perspective view of a fan 57 of another embodiment as viewed from the outflow side is shown. The fan has a cooling structure 40 according to the present invention integrated in a built-in outlet guide device. The built-in outlet guide device particularly includes an intermediate ring 5, a hub ring 4, and a guide element 11, and the metal strut suspension device 52 bears the load-bearing function. Thus, no load-bearing outlet guide unit is designed, and the cooling structure 40 also only bears part of the load-bearing function, that is, for the built-in outlet guide device. The design of the housing 2 is similar to Figures 1 to 7 the housing in the illustrated embodiment, but is connected to the electric machine 34 or its stator 36 as an independent component via a preferably metal strut device 52. For the description of the structure and related functions of the cooling structure 40, reference can be made to the foregoing Figures 1 to 7 and its description content. The cooling channel 42 only has an effective cross-section that can enable the cooling flow to flow through the cooling structure flange 54 from the stator side to the rotor side (or vice versa) inside the cooling structure 40 in the assembled state. Therefore, the shielding effect that the strut suspension device 52 may have on the cooling channel 42 must be considered, and this shielding effect will reduce the effective cross-section of the cooling channel 42 in the assembled state.

[0069] In a similar embodiment with a load-bearing metal strut device 52, it is also possible to consider not providing an internal outlet guide wheel, which is similar to Figures 8 to 10 the illustrated cooling structure. It is also feasible and very beneficial to consider: an embodiment with a load-bearing metal strut device 52 and a cooling flow guiding portion similar to Figures 1 to 7 the cooling flow guiding portion 14 in the illustrated embodiment. This embodiment defines a cooling flow path 41 in the cooling structure 40 through the stator 36 of the electric machine 34 or the electronic component compartment 13. The cooling flow path has a narrow flow path cross-section between the cooling flow guiding portion 14 and the outer wall of the stator 36 or the electronic component compartment 13.

[0070] Figure 12A perspective view of a cooling structure 40 integrated on a radial fan 57 according to another embodiment, as viewed from the outflow side. The fan 57 has a radial impeller 19 which mainly includes a bottom plate 62, a cover plate 61 and blades 22 extending therebetween. The cover plate 61 is provided with a central opening into which an inlet nozzle 9 is inserted. The inlet nozzle 9 is fastened to a nozzle plate 56. The impeller 19 is in turn fastened to the rotor 35 of an electric motor 36 (see also Figure 13 ), and the stator 36 of the electric motor is assembled on a motor support plate 55. Support ribs 60 hold the motor support plate 55 on the nozzle plate 56. Substantially, the nozzle plate 56, the support ribs 60 and the motor support plate 55 are integrally marked as the load-bearing module of the fan 57. The fan 57 can be fastened on a ventilation system or a superior instrument on its nozzle plate 56, thereby achieving support and operation.

[0071] During the operation of the fan 57, the electric motor 34 drives the impeller 19 through its rotor 35, and a flow of conveying medium is generated based on the rotational movement of the impeller. The flow of conveying medium enters the impeller 19 through the inlet nozzle 9, flows radially outward, and is discharged from the fan 57 after passing by the support ribs 60. When the flow of conveying medium flows through the fan 57, energy is transferred to the flow of conveying medium, which is manifested as an increase in the total pressure and / or static pressure. In this embodiment, the support ribs 60 have a beneficial design structure in terms of aerodynamics to achieve high efficiency and low noise values. In particular, the cross-section of the support ribs 60 is similar to the cross-section of an airfoil, that is, it is elongated along the flow direction, has a rounded leading edge and a thin trailing edge.

[0072] Viewed in the radial direction, that is, in a direction transverse to the axis, the motor support plate 55 extends beyond the impeller 19, which is beneficial to the static efficiency of the fan 57. Thus, a negative pressure is generated in the inner region near the axis and the electric motor 34 relative to the static pressure level at the outlet of the fan 57 downstream of the support ribs 60. Therefore, the static pressure on the impeller side inside the motor support plate 55 is significantly lower than the static pressure on the opposite outer side of the motor support plate 55, that is, outside the fan 57 or outside the load-bearing module.

[0073] The cooling structure 40 is now mounted on the motor support plate 40 or integrated in the region of the stator 36 of the electric motor 34. The outer diameter of the cooling structure 40 can be defined here by the outer diameter of the cooling channel 42 or the cooling flow guide 14 (see Figure 13a ). By means of the pressure difference, the cooling flow starts from outside the load-bearing module and, under the guidance of the cooling flow guide 14, axially passes through the motor mounting plate 55 having an integrated cooling structure flange 54 or a motor fastening flange 59 into the inner region of the load-bearing module. Here, additional heat is taken away from the electric motor 34 or its stator 36 or the electronic component bin 13, thereby improving the cooling of the electric motor 34.

[0074] Figure 13 ShownFigure 12 Side view of the fan 57 with the cooling structure 40 and partial cross-sectional view in a plane passing through the axis in the region near the cooling structure 40. Figure 13a For Figure 13 Detail view in the region of the cooling structure 40, in which the characteristic dimensions are also schematically marked. The cooling structure 40 can be integrally and monolithically integrated into the motor carrier plate 59, especially when the motor carrier plate 56 is advantageously manufactured as an injection-molded part in an injection molding process. A cooling structure flange 54 is also integrally integrated or mounted as a separate component on the motor carrier plate 56, and the cooling structure flange is designed as a fastening flange 59 for fastening the motor 34. If the cooling structure flange 54, or rather the fastening flange 59, is designed as an independent component relative to the motor carrier plate 56 (possibly in the case of achieving an axial offset between the screwing plane of the motor carrier plate 56 and the stator flange 49), the cooling structure 40 can also be integrated into this independent component.

[0075] The cooling structure 40 can also be fastened to the motor carrier plate 56 in the form of multiple independent components, for example, in the form of the cooling flow guide 14. In particular, as Figure 13a shown, there is provided at least one cooling channel 42, which establishes a fluid connection between the stator side outside the cooling structure flange 54, or rather the fastening flange 59, in the load-bearing module and the rotor side inside the cooling structure flange 54, or rather the fastening flange 59, in the load-bearing module.

[0076] Due to the pressure difference generated during the operation of the fan 57, the cooling flow flows through the cooling structure 40 at a relatively high flow rate between the cooling flow guide 14 and the stator 36 of the motor 34, or rather the electronic component compartment 13, and takes away the waste heat from the motor 34, or rather its stator 36, or rather its electronic component compartment 13. Subsequently, the cooling flow enters the interior of the load-bearing module through the cooling channel 42 and is discharged radially outward from there.

[0077] Similar to Figure 5a that, the minimum distance t between the cooling flow guide 14 and the outer wall of the stator 36, or rather the electronic component compartment 13, is shown. Regarding the appropriate value of t, Figure 5ahas been given in the description. The cooling flow path 41 formed by the cooling structure 40 or the cooling flow guide 14 can be characterized by the imaginary center line in the shown cross-section. When moving away from the stator flange 49 towards the stator side or the electronic component housing side, here to the right, this center line shows an extension towards the fan axis, i.e., the larger radius with respect to the fan axis decreases. In particular, the cooling flow guide 14 also has this extension starting from the stator flange 49. The design of the cooling structure 40 with such a cooling flow guide 14 has general advantages. The cooling flow passes through the radial outside of the stator flange 49 without the need to provide channels in the stator flange 49, however, in particular, cooling the radially further inward outer wall of the stator 36 or the electronic component compartment 13.

[0078] List of reference numerals

[0079] 1 Load-bearing outlet guide unit

[0080] 2 Housing of the outlet guide unit

[0081] 3 Diagonal support vane

[0082] 4 Hub ring, outer ring of the cooling structure

[0083] 5 Intermediate ring of the outlet guide unit or diffuser

[0084] 6 Outer flow path region

[0085] 7 Inner flow path region

[0086] 8 Stator-side accommodation region inside the hub ring, hub head

[0087] 9 Inlet nozzle

[0088] 10 Outer diffuser wall

[0089] 11 Inner guide element, guide vane

[0090] 12 Outflow edge of the intermediate ring

[0091] 13 Stator compartment, electronic component housing

[0092] 14 Cooling flow guide

[0093] 15 Height h of the cooling flow perforation

[0094] 16 Width B of the cooling flow guide / cooling channel

[0095] 17 Length Ls of the electronic component compartment

[0096] 18 Fastening preparation means in the accommodation region

[0097] 19 Impeller

[0098] 20 Upstream fastening preparation device of the outlet guide element on the superior system

[0099] 21 Downstream fastening preparation device of the outlet guide unit element on the superior system

[0100] 22 Blades of the impeller

[0101] 23 Upstream edge of the intermediate ring of the outlet guide unit

[0102] 24 Overlap length L of the cooling flow guide - stator chamber

[0103] 25 Downstream fastening preparation device for the protective grille

[0104] 26 Radial distance t (clearance height) between the cooling flow guide and the stator

[0105] 27 Diameter D of the accommodation area in the hub / hub housing N

[0106] 28 Diameter D of the impeller hub L

[0107] 29 Area for the impeller

[0108] 30 Fastening preparation device for the motor on the impeller

[0109] 31 Hub of the impeller

[0110] 32 Rotation direction of the impeller

[0111] 33 Fastening device of the suspension device on the housing

[0112] 34 Motor

[0113] 35 Rotor of the motor

[0114] 36 Stator of the motor

[0115] 37 Hub cover

[0116] 38 Winglets at the tips of the impeller blades

[0117] 39 Not defined

[0118] 40 Cooling structure

[0119] 41 Cooling flow channel

[0120] 42 Cooling channel in the fastening flange area

[0121] 43 Extension e of the outlet guide unit transverse to the fan axis

[0122] 44 Inner diameter Di of the housing of the outlet guide device in the area of the impeller

[0123] Outer diameter Da at the outer starting point of the bent section of the 45 inlet nozzle 9

[0124] 46 Rotor-side accommodation area within the hub ring

[0125] 47 Inflow area of the cooling flow guide

[0126] 48 Reinforcing ribs in the rotor-side accommodation area

[0127] 49 Flange of the stator

[0128] 50 Cooling ribs on the stator

[0129] 51 Cooling fan wheel on the rotor

[0130] 52 Suspension device

[0131] 53 Cable connector on the stator or on the electronic component housing of the motor

[0132] 54 Flange of the cooling structure

[0133] 55 Carrier plate

[0134] 56 Nozzle plate

[0135] 57 Fan, axial-flow fan

[0136] 58 Reinforcing ribs in the accommodation area for the motor

[0137] 59 Fastening flange for the motor

[0138] 60 Support ribs

[0139] 61 Cover plate

[0140] 62 Bottom plate

[0141] 63 Outer diameter D of the electronic component housing E

Claims

1. A fan, the fan having an impeller and an electric motor, wherein, the electric motor includes a stator, a rotor and, if necessary, an electronic component chamber, and is characterized in that a cooling structure is constructed or provided radially externally on the outer wall of the stator and / or the electronic component chamber, the cooling structure constituting a flow path for a fluid, preferably air, through which a flow stream is caused to flow based on a pressure difference generated by the operation of the fan, and the flow stream discharges heat from the electric motor and / or the stator and / or the electronic component chamber.

2. The fan according to claim 1, characterized in that, the cooling structure is not constituted by and does not pass through functionally important components of the electric motor.

3. The fan according to claim 1 or 2, characterized in that, the cooling structure is constituted by a separate cooling unit, and the cooling unit is provided or fastened to a stator flange (a flange for fastening the stator).

4. The fan according to any one of claims 1 to 3, characterized in that, if necessary, the separate cooling unit can be added by adapting to spatial conditions, for example, by using an enlarged hub housing.

5. The fan according to any one of claims 1 to 3, characterized in that, the cooling structure is arranged on, in or integrated into a motor carrier plate of a radial-flow or mixed-flow fan.

6. The fan according to any one of claims 1 to 3, wherein, an outlet guide device having an outlet guide wheel is provided, and is characterized in that the cooling structure is assigned to the outlet guide wheel and is preferably integrally formed in the outlet guide wheel in one piece.

7. The fan according to claim 6, characterized in that, the outlet guide device has a supporting function for the electric motor.

8. The fan according to any one of claims 1 to 7, characterized in that, in the assembled state with the electric motor, a flow path for a cooling flow extending inside the cooling structure is formed, the cooling flow flowing from the rotor side through a cooling channel to the stator side (or vice versa), and the cooling channel passes through a cooling structure flange in a region of a motor suspension plane on the stator of the electric motor.

9. The fan according to any one of claims 1 to 8, characterized in that, the flow path passes radially externally of the stator flange (a flange for fastening the stator).

10. The fan according to any one of claims 1 to 9, characterized in that, for the cooling flow in the flow path, a narrowest flow channel region is constructed between the outer wall of the stator of the electric motor or the electronic component chamber and the cooling structure or the cooling flow guide portion, and through the narrowest flow channel region, the cooling flow passes near the outer wall of the stator or the electronic component chamber at a high flow velocity.

11. The fan according to any one of claims 1 to 10, characterized in that, the center line of the flow path or its portion for the cooling flow or the cooling flow guide portion extends from the stator flange towards the stator side or the electronic component chamber side, towards the fan axis, that is, from a larger radial position to a smaller radial position, so as to guide the cooling flow to pass near the wall of the stator or the electronic component chamber.

12. Cooling structure for a fan, the fan having a fan hub and an electric motor with a stator, the fan in particular having a cooling structure with the features according to one of claims 1 to 11, wherein, the cooling structure is arranged between the fan hub and the stator.

Images