Fan and cooling structure for fan

Abstract

The present invention relates to a fan having an impeller and an electric motor, the electric motor including a stator, a rotor, and optionally an electronics pot, a cooling structure formed on a radially outer outer wall of the stator and / or the electronics pot, the cooling structure forming a flow path for a fluid, preferably air, such that a pressure difference generated by operation of the fan causes a flow that dissipates heat from the electric motor and / or the stator and / or the electronics pot. The present invention also relates to a corresponding cooling structure for the fan.

Description

[Technical Field]

[0001] The present invention relates to a fan having a specific cooling structure, and more particularly to a cooling structure that improves the cooling of an electric motor by creating a cooling flow between the cooling structure and the electric motor. [Background technology]

[0002] General-purpose fans are widely known in practice, see, for example, US Pat. No. 5,649,999.

[0003] Typically, the fan is subjected to high heat loads, for example, above 60°C. In particular, in the "suction" method in which hot air from the heat exchanger is sucked in through a fan, the accompanying rise in temperature is a significant disadvantage. In particular, the electronic components housed in the integrated electronic unit (in the EC fan), as well as components such as bearings, insulation, and windings, have certain temperature limits that limit the power output and / or rotational speed of the fan. Excessive temperature rise can lead to component damage.

[0004] Attempts have already been made in the prior art to avoid the above-mentioned problem of excessive temperature rise. An outer rotor EC motor with a built-in electronic unit already has a built-in cooling device. To adopt this structure, it is necessary to build a new motor. Also, the hub has penetrations and gaps that compromise efficiency. These penetrations and gaps have the effect of improving airflow around the motor.

[0005] Additionally, cooling systems with penetrations in the stator flange have already been put to practical use, but in this case too, it is necessary to modify the structure of the motor and stator. Additionally, additional components already exist to direct cooling air around the motor. This configuration is structurally complex and reduces efficiency. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] International Publication No. 2020 / 015792(A1) Summary of the Invention [Problem to be solved by the invention]

[0007] The object of the present invention is to overcome, at least to a large extent, the problems encountered in the prior art. Adequate cooling of the electric motor of the fan is achieved by simple means. It is also possible to retrofit the cooling structure required for cooling to improve heat dissipation from the motor and minimize any reduction in fan efficiency. Furthermore, the fan and cooling structure of the present invention must be differentiated from competing products. [Means for solving the problem]

[0008] The above-mentioned object of the invention is achieved by the features of claim 1. According to the features of claim 1, a cooling structure is formed or provided on the radially outer outer wall of the stator and / or the electronics pot. This cooling structure cooperates with the motor to form a flow path for a fluid (in the simplest case, ambient air). The operation of the fan creates a pressure differential which induces flow through this flow path. As a result, heat is dissipated from the electric motor and / or stator and / or electronics pot. In other words, cooling occurs by dissipating heat.

[0009] The cooling structure according to the present invention can be implemented in a variety of ways. It is important here that the flow path does not pass through any functionally relevant parts of the motor. Without the cooling structure, the motor will still function perfectly, but with reduced cooling capabilities. Therefore, the cooling structure can be retrofitted. For this purpose, cooling structures can be formed in specific components.

[0010] This cooling structure is then integrated into a cast streamer housing, which provides the cooling structure. Such a cooling structure has a pot surrounding the motor with a radial gap, and uses a fan-generated flow field to target the flow through the pot, improving heat dissipation from the motor. This approach can reduce the loss of fan efficiency.

[0011] When retrofitting a cooling structure, a hub pot with a larger diameter than the impeller hub must be provided, and this larger hub pot must be at least 105%, at most 130%, and preferably 115% of the size (diameter) of the conventional hub pot.

[0012] Furthermore, the cooling structure can be fixed directly or indirectly to the stator. When assembled with the stator, the cooling structure has at least one, and preferably three, axial penetrations or passages therein. These penetrations or passages provide a flow path in the axial direction, specifically from one side of the cooling structure to the opposite axial side. Preferably, at least one flow channel or multiple flow channels between one side and the other side of the cooling structure are formed with a special guide shape for guiding the cooling flow. The guide features form a flow path together with the outer wall of the motor, stator or electronics housing. The guide feature then extends axially along the motor, stator or electronics housing. During operation, the flow field created by the fan, and in particular the pressure differential between the axial sides of the cooling structure, causes "cold" ambient air to flow at relatively high velocity and with high turbulence through the channels in the cooling structure along the stator and / or electronics housing, thereby ensuring sufficient cooling of the motor and power electronics therein.

[0013] It should be noted that various possibilities exist for designing and improving the present invention. In this respect, reference is made on the one hand to the claims dependent on claims 1 and 12 and on the other hand to the following description of an embodiment of the fan according to the invention using the drawings. The improvements of the present invention will also be described in conjunction with the embodiments of the present invention using the drawings. [Brief explanation of the drawings]

[0014] [Figure 1] 1 shows a perspective view, seen from the outflow side, of a fan having a cooling structure according to the present invention, which is incorporated into a structural streamer unit having a housing, a streamer assembly and supporting blades. [Figure 2] The fan of FIG. 1 is shown in a perspective view as seen from the inlet side. [Figure 3] The fan having the structural streamer unit of FIGS. 1 and 2 is shown in an axial top view from the inlet side. [Figure 4] The fan having the structural streamer unit of FIGS. 1 to 3 is shown in an axial top view from the outflow side. [Figure 4a] 5 shows a detailed view of a region of the cooling structure of FIG. 4, with width dimensions indicated generally. [Figure 5] The fan with the structural streamer unit of Figures 1 to 4 is shown in side view and in cross section along a plane through the axis, with only the upper half of the fan axis being shown and dimensions being indicated approximately. [Figure 5a] 6 shows a detailed view of an area of ​​the cooling structure of FIG. 5, with further characteristic dimensions indicated schematically. [Figure 6a]5b shows a detailed view of a region of a cooling structure similar to FIG. 5a, illustrating a further embodiment of the cooling structure having an inlet region for the cooling flow path. [Figure 7] 1 shows a partial axial top view from the inlet side of a cooling arrangement according to the invention with externally integrated guide elements and an integrated electric motor; [Figure 8] 10 shows a further embodiment of a cooling structure for a fan with an electric motor built in, in which no cooling flow path is provided, in a perspective view seen from the stator side. [Figure 9] The cooling structure with the electric motor of FIG. 8 is shown in an axial top view from the stator side, with two dimensions indicated schematically. [Figure 10] The cooling structure with the electric motor of FIGS. 8 and 9 is shown in a side view and in a cross section along a plane passing through the axis. [Figure 11] A further embodiment of a fan with a cooling structure integrated into the inner streamer assembly is shown in a perspective view from the outflow side, where the support function is taken over by a metal support suspension and no structural streamer unit is provided. [Figure 12] 1 shows a further embodiment of the cooling structure of a radially configured fan in a perspective view from the outflow side, in which the cooling structure is integrated into the motor support plate of the support module. [Figure 13] The cooling structure with the electric motor of FIG. 12 is shown in a side view and in a partial cross-section of the area near the cooling structure along a plane passing through the axis. [Figure 13a] 14 shows a detailed view of an area of ​​the cooling structure of FIG. 13, with characteristic dimensions further indicated schematically. DETAILED DESCRIPTION OF THE INVENTION

[0015] FIG. 1 shows an axial flow structure type fan 57 having a cooling structure 40 according to the present invention in a perspective view from the outlet side, and this cooling structure 40 is incorporated into the structural streamer unit 1 so as to be integrated with the structural streamer unit 1. Structure The streamer unit 1 is composed of a housing 2, an intermediate ring 5, a hub ring 4, inner guide vanes 11 extending between the hub ring 4 and the intermediate ring 5, and support vanes 3 extending between the intermediate ring 5 and the housing 2 or each of the radially expanded regions 10 of the housing 2. The structural streamer unit 1 is manufactured in one piece by casting, advantageously by a plastic injection molding process.

[0016] The housing 2 defines the outer boundary of the fan flow that flows within the housing 2 . The housing 2 is made up of various regions, as viewed in the flow direction: first the inlet nozzle 9, then the cylindrical region 29 in which the impeller 19 with the blades 22 is arranged, and then the diameter-expanding region 10 in which the support blades 3 are fixed. Located within the housing 2 downstream of the impeller 19 is an inner streamer assembly consisting of fluidically effective inner streamer vanes 11 extending between the hub ring 4 and the intermediate ring 5 . The fluid effect of the inner streamer vanes 11 interacting with these intermediate rings 5 ​​and hub ring 4 results in a very high static efficiency and air output of the fan 57, particularly the static pressure rise at a specific conveying volume flow rate. And on the hub ring 4, radially inward of the hub ring 4 in a stator proximal receiving area 8 (also called a hub pot 8), a motor 34 having a stator 36 is fixed to a flange 54 of the cooling structure 40. This flange 54 also functions here as a motor fixing flange 59, so that the inner streamer vanes 11 and intermediate ring 5 also perform a structural function with respect to the motor 36 and ultimately to the impeller 19.

[0017] Outer support vanes 3 are provided to hold the motor 34 together with the impeller 19 and inner streamer assembly to the outer housing 2. The outer support vanes 3 have only a subordinate fluid function (if any) and primarily serve the function of securing the inner streamer assembly, and thus the motor 34 and impeller 19, to the outer housing 2. The outer support blades 3 are configured to be preferable from the standpoint of noise, and the presence of the outer support blades 3 generates no noise or only very little noise while the fan 57 is in operation. Overall, within the housing 2, when viewed in the span direction (from the hub ring 4 towards the radial expansion region 10), two distinct flow regions are formed in the axial region of the radial expansion region 10: an outer flow region 6 between the intermediate ring 5 and the wall of the radial expansion region 10 of the housing 2, and an inner flow region 7 between the hub ring 4 and the intermediate ring 5. This inner flow region 7 has a structural inner guide element 11 which has fluid functions (such as reducing vortices in the flow, increasing static pressure, and avoiding or reducing backflow on the hub) and, because it is located radially inward, generates almost no noise.

[0018] Furthermore, the outer flow region 6 also has structural support vanes 3, six in number, preferably four to eight, distributed around the circumference and configured for noise optimization. Structure The streamer unit 1 is provided with integral flanges in the peripheral areas of the inlet and outlet sides of the housing 2, which flanges are advantageously provided with various fixing means.

[0019] The inlet flange is provided with a fixture 20 for fixing the structural streamer unit 1 and fan 57 to a higher-level device or system, and similarly, the outlet flange is provided with a fixture 21 for fixing the structural streamer unit 1 to a higher-level device or system.

[0020] Furthermore, the outlet flange is provided with a fixing portion 25 for the contact protection mesh, and this fixing portion 25 may also be provided on the inlet flange in a similar manner. The contact protection mesh can be screwed into the area 29 in a recessed state so that it does not protrude axially from the structural streamer unit 1, which allows the fan 57 to be transported and stacked reliably.

[0021] The peripheral edge 12 on the outflow side of the intermediate ring 5 is formed in a wave-like shape, which may be formed in a sawtooth or groove-like shape. However, the intermediate ring 5 may be formed in a circular shape without a wavy shape.

[0022] In the stator-proximal receiving area 8 within the hub ring 4, the motor 34 is fixed to the structural streamer assembly 1 via an integrally formed motor fixing flange 59, which also serves as the flange 54 of the cooling structure 40. The stator proximal receiving area 8 is also provided with reinforcing ribs 58 that reinforce and stabilize the connection with the motor 34 . In particular, the stator proximate receiving area 8 is provided with means (eg, the illustrated cooling flow guides 14) to enhance the dissipation of heat from the motor 34.

[0023] The illustrated fan is formed with a cooling structure 40, which is incorporated into the structural streamer unit 1 so as to be integrated with the structural streamer unit 1. Then, during operation of the fan 57, a cooling flow passes through the cooling structure 40, and heat flow from the motor 34, stator 36 or electronics pot 13, respectively, is dissipated. The cooling structure 40 consists of a hub ring 4 and elements (in particular a cooling structure flange 54, which is also embodied here as a motor support flange 59) that are integrally arranged radially inside the hub ring 4, and has a special design that will be explained in the figures that follow, and advantageously has a cooling flow guide portion 14.

[0024] In the molding tool for manufacturing the structural streamer unit 1, an area within the hub ring 4, ie, the stator-near receiving area 8, is provided with an exchangeable insert. This allows for different interfaces to be realized for different motors and different embodiments of the cooling structure 40 which are here manufactured integrally with the structural streamer assembly 1. And the motor 34 The pitch circle for fixing the motor may vary, and further, the axial position of the fastening surface of the motor's axial screw, i.e., the cooling structure flange 54 / motor fixing flange 59 (e.g., within the stator proximal receiving area 8), may also vary. The presence and design of the cooling flow guides 14 may also vary.

[0025] The motor 34 is here an external rotor motor, furthermore advantageously embodied as an EC motor, advantageously with an integrated motor electronics unit, and a stator 36 is visible. Within this stator 36, a motor electronics unit is formed within the integrated electronics pot / electronics housing 13. The electronics pot / electronics housing 13 may also be secured to the stator 36 as a separate component. The cooling structure 40 functions to allow the dissipation of waste heat from the stator 36 of the motor 34, and in particular from the electronics pot 13 of the motor 34. As a result, cooling of the electronics is improved and the motor 34 is able to achieve higher torque and therefore higher power output at the same ambient or transport temperature.

[0026] The design of the cooling structure 40, which has the hub ring 4 within the hub pot 8, ensures that there is sufficient radial space at the end near the stator 36 between the outer contour of the stator 36 or the outer contour of the electronics pot 13. In particular, the outer diameter DN27 (see Figure 4a or Figure 5) of the hub ring 4 or cooling structure 40 is at least 15%, advantageously 30%, larger than the outer diameter DE63 (see Figure 5) of the electronics pot 13 in the region of the cable connector 53 (see also Figure 4a). This configuration allows easy connection of the necessary electrical cables to the stator 36 of the motor 34 and the electronics pot 13 during assembly.

[0027] FIG. 2 is a perspective view of the fan 57 of FIG. 1 as viewed from the inlet side. 1, the impeller 19 having blades 22 integrally secured to the hub 31 can be seen more clearly. A hub cap 37 is fixed to the hub 31 of the impeller 19 and is fastened by a latch hook. The hub cap 37 also interacts with the hub 31 to provide a fluidically favorable shape in the hub region of the impeller 19, which is advantageous for high efficiency and low noise. The rotor 35 of the motor 34 can be seen inside the hubcap 37, which has a large opening in its radially inner area. This design of the hub cap 37 with an internal opening ensures that the rotor 35 of the motor 34 is cooled. During operation of the fan 57, the impeller 19 is driven by the rotor 35 of the motor 34 to which the impeller 19 is fixed, and rotates in a direction of rotation 32, here for example clockwise. As a result, the conveying medium (often air) is conveyed by the fan 57 in the flow direction through the axial region as shown in the figure, from the inlet side through the inlet nozzle 9, the impeller region 29 and the radial expansion region 10 to the outlet side, which is axially opposite the inlet side. Energy is then transferred to the transport medium flow being transported in this way, which can be measured 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 19 , a first part flowing through the outer flow region 6 and a second part flowing through the inner flow region 7 .

[0028] FIG. 3 shows a fan 57 with the structural streamer unit 1 of FIGS. 1 and 2 in an axial top view from the inlet side. Further to the description of FIGS. 1 and 2, it can be seen that the hub ring 4 of the structural streamer unit 1, and therefore in particular the cooling structure 40, protrudes radially beyond the hub 37 of the impeller 19. This configuration is advantageous for the functioning mode of the cooling structure 40, which cools the motor 34, its stator 36 or its electronics pot 13, respectively. For example, the flow carried by the impeller 19 can enter the cooling structure 40 downstream of the impeller 19 through the radial region between the outer diameter of the hub 37 of the impeller 19 and the inner diameter of the hub ring 4 that forms the outer periphery of the cooling structure 40, thereby improving cooling of the motor 34.

[0029] FIG. 4 shows in axial top view, seen from the outlet side, a fan 57 with a cooling structure 40 integrated into the structural streamer unit 1 of FIGS. 1 to 3, the outer flow region 6 penetrated by the support vanes 3 and the inner flow region 7 having the inner guide vanes 11 can be easily seen. As shown in this figure, during operation of the fan 57, the impeller 19 carrying the blades 22 rotates in a counterclockwise direction 32 about the fan axis. The motor 34 in the cooling structure 40 is attached by fasteners 18 (preferably by screws) to a flange 54 (which also functions here as a motor fixing flange 59) of the cooling structure 40 in a stator-proximal receiving area 8 (also called a hub pot 8). During operation of the fan 57, the cooling structure 40 increases the heat dissipation from the motor 34, particularly the stator 36, and further from the electronics pot 13. Thus, in terms of cooling the motor 34, the cooling structure 40 interacts as a functional unit with the electric motor 34, the stator 36 or the electronics pot 13.

[0030] The radially expanding region 10 widens from the region 29 for the impeller 19 (see also FIG. 1) towards the outlet periphery of the housing 2 . The intermediate ring 5 extending from the impeller 19 also flares slightly towards its outlet periphery 12 (FIG. 5). As a result, the inner flow region 7 and the outer flow region 6 are designed to have an expanding diameter, i.e., to widen in the direction of flow. This design is advantageous in terms of increasing the rate of pressure recovery downstream of the impeller 19 and therefore increasing the static efficiency of the fan 57 . The increased static pressure is advantageous in the flow path between the impeller 19 and the outlet of the fan 57, and also in terms of potentially advantageous functioning modes of the cooling structure 40 for cooling the motor 34, stator 36 or electronics pot 13, respectively.

[0031] Specifically, the pressure differential, i.e., the static pressure at the outlet end (of the fan's main flow) of the cooling structure 40 is higher than the static pressure at the inlet end (of the fan's main flow), causing a cooling flow in the stator-proximal inner receiving region 8 within the cooling structure 40 to flow in a direction opposite to the main flow direction. This cooling flow passes through the motor 34, stator 36 or electronics pot 13, respectively, to further cool them. This cooling flow can flow in an inlet direction between the motor 34 and the cooling structure 40, and is further guided by the cooling flow guide 14 through a path within the area of ​​the cooling structure flange 54 to the opposite side of the cooling structure flange 54 (see particularly Figures 5 and 5a).

[0032] FIG. 4a is a detailed view of a region of the cooling structure 40 of FIG. 4, with width dimension B16 indicated generally. Here, the width dimension B16 represents the width of the cooling flow guide portion 14, that is, the dimension of the cooling flow guide portion 14 in a direction substantially perpendicular to the fan axis, that is, in the substantially circumferential direction. And since the cooling passage 42 (not shown here) passing through the cooling structure flange 54 has a similar dimension in the circumferential direction and corresponds to the cooling flow guide portion 14 (see Figures 5a and 7), the width dimension B16 can also be interpreted as the width of the cooling passage 42. In this embodiment, three cooling channels 42 are provided, each having a corresponding cooling flow guide 14 and arranged around the circumference. With this configuration, three areas on the radially outer surface of the electronics pot 13 of the motor 34 that are located radially opposite the cooling flow guide 14 are particularly well cooled because the cooling flow guide 14 and the cooling path 42 direct a cooling flow medium with a relatively high flow velocity and / or flow turbulence near the corresponding surfaces. These three areas are advantageously areas that are important to cool (e.g., associated with power electronic components that generate a lot of heat, such as the output stage (IGBT) and input stage, located inside the electronics pot 13, or temperature-sensitive components). When a cooling flow guide 14 is used, the width dimension B16 of the cooling flow guide 14, or the width dimension B16 of the cooling passage 42, is preferably in the range of 10% to 45% of the diameter DN27 of the stator-proximal receiving area 8 of the cooling structure 40.

[0033] In Figure 5, a fan 57 with the structural streamer unit 1 of Figures 1 to 4 is shown in side view and in cross section through an axial plane, with the dimensions in the area of ​​the cooling structure 40, the hub 31 of the impeller 19 and the inlet nozzle 9 being shown in outline. In addition to each figure, one can see the contour of the hub cap 37, which is aerodynamically rounded and transitions towards the hub 31 of the impeller 19 via a consistent tangent, and which is attached to the area of ​​the hub 31 of the impeller 19.

[0034] The motor 34, consisting of the stator 36 and rotor 35, is not shown in the cross-sectional view. The stator 36 also includes an electronics pod 13 and is secured within the stator-proximal receiving area 8 of the cooling structure 40 to a cooling structure flange 54 that also functions as a motor mounting flange 59 . Here, the cooling structure 40 is integrated into the structural streamer unit 1 . An impeller 19 having a hub 31 and blades 22 is fixed to a rotor 35 of the motor 34 . The radially outer end of the impeller 19 advantageously has a special profile, namely a winglet 38 . A small radial spacing is formed between the blades 22 of the impeller 19 having the winglets 38 and the impeller region 29 of the housing 2, creating a flow gap.

[0035] Fan 57 is a compact radial design. This means that the inlet diameter Da 45 of the inlet nozzle 9 is relatively small compared to the inner diameter Di 44, and the ratio thereof is Da / Di<1.1. This also makes the dimension e43 of the structural streamer unit 1 in a direction perpendicular to the fan axis relatively small (the dimension e43 is the length of the side of the square outline extending in a direction perpendicular to the fan axis, within which the structural streamer unit 1, and thus the fan 57, can be inserted). It is advantageous if e / Di<1.2. As a result, the fan 57 requires a relatively small installation space in terms of its inner diameter Di44 and thus the diameter of the impeller 19, as viewed in a direction perpendicular to its axis. Conversely, when installed in a given space, a fan 57 with a large inner diameter Di44, and therefore a fan 57 with a particularly large outer diameter of the impeller 19, can be used, which may provide acoustic advantages at a given operating point.

[0036] Since the inner diameter Di is relatively large relative to the outer dimension e43 that defines the radial installation space, a large flow passage cross-sectional area is essentially obtained, thereby realizing reduced acoustic characteristics and high static efficiency of the fan 57 at a given operating point. As a result, i.e. as a result of the relatively large cross-sectional flow area of ​​the fan 57 within the housing 2, it is possible to make the diameter DN27 of the cooling structure 40 larger compared to the diameter DL28 of the hub 31 of the impeller 19 without being excessively hindered by blocking effects, which is advantageous for the functioning mode of the cooling structure 40, as already explained with reference to Figure 3. Advantageously, DN / DL is in the range of 115% to 135%, and particularly advantageously is about 115%. Depending on the operating state of the fan 57, the secondary flow having a cooling effect can either enter the cooling structure 40 from the inlet side in the radial region between the hub 31 of the impeller 19 and the cooling structure 40, or conversely, can exit between the impeller hub 31 and the cooling structure 40 in a direction opposite to the main flow direction of the fan 57.

[0037] FIG. 5a is a detailed view of a region of the cooling structure 40 of FIG. 5, with further characteristic dimensions shown schematically. In this detailed view, the flow paths within the cooling structure 40 are easily visible. The cooling structure 40 within the hub ring 4 has a rotor proximate receiving area 46 and a stator proximate receiving area 8 . In a first operating state, flow can flow through the cooling structure 40 in the same direction as the main flow of the fan 57, from the rotor 35 side to the stator 36 side.

[0038] In a second operating state, flow can flow through the cooling structure 40 from the stator 36 side to the rotor 35 side in a direction opposite to the main flow direction of the fan 57 . This second operating state occurs when a significant static pressure increase is induced in the main flow of the fan 57 when the main flow of the fan 57 passes through the cooling structure 40, i.e., when the flow passes through a streamer wheel having inner streamer vanes 11 or when the flow passes through the inner flow region 7 and outer flow region 6 that expand radially in the flow direction (see Figure 4). As a result of the pressure difference thus created, a flow is generated through the cooling structure 40 in a direction opposite to the main flow direction of the fan 57, in this case from the stator 36 to the rotor 35, along the motor 34, stator 36 or electronics pot 13, respectively. In this way, in operating state 2, very efficient additional cooling of the motor 34, the stator 36 or the electronics pot 13, respectively, can be achieved.

[0039] Here, the flow path through the cooling structure 40 is from the main flow coming out of the fan 57 through the stator near-receiving area 8, then along the cooling flow duct 41 separated by the cooling flow guide 14 between the electronics pot 13 and the cooling flow guide 14, through the cooling passage 42 in the area of ​​the cooling structure flange 54 and into the rotor near-receiving area 46, where it finally leaves the cooling structure 40 and mixes with the main flow of the fan 57 (the reverse order is also conceivable). After passing through the cooling passage 42, the flow can optionally pass through a cooling system that is integrated into the motor 34, for example, the integrated motor cooling system including, among other things, stator cooling ribs 50 and a rotor cooling fan wheel 51. The cooling flow guide 14 integrated into the cooling structure 40, and thus the formation of correspondingly shaped cooling flow ducts 41 between the cooling flow guide 14 and the stator 36 or electronics pot 13, respectively, is particularly advantageous for heat dissipation, since high-velocity and / or high-turbulence flows are targeted and directed close to the surface of the motor 34 to be cooled. For this purpose, in the assembled state, a small gap t26 is formed along the cooling flow duct 41 in at least one area, i.e., between the cooling flow guide 14 and the stator 36 or the electronics pot 13, respectively. The width of this gap t, or this minimum gap t26, is advantageously between 2 mm and 15 mm, and in particular is advantageously about 5 mm.

[0040] The overlap length L24 between the cooling flow guide 14 and the stator 36 or the electronics pot 13, respectively, i.e., the axial length L24 of the cooling flow guide 14, is advantageously of sufficient length, for example at least 50% of the axial length Ls17 of the electronics pot 13 from the mounting surface of the stator flange 49 to the electronics cover (if present).

[0041] It should be noted that an embodiment in which the cooling flow guide portion 14 is not provided is also conceivable (see, for example, FIGS. 8 to 10). It is particularly advantageous if the cooling flow guide 14 and thus the cooling flow duct 41 are formed with a very small clearance from the centerline of the outer wall of the stator 36 or the outer wall of the electronics pot 13, respectively, in cross section. However, the provision of cooling passages 42 in at least the axial region of cooling structure flange 54 is particularly important to achieving the above-described flow through cooling structure 40 which interacts with electric motor 34 during operation of fan 57.

[0042] The cooling structure 40, including the cooling flow guide portion 14, is designed so that it can be released from a molding tool, particularly a plastic injection molding tool, without undercuts, and is specifically released by two shaping tool parts that are released axially (one on the right side, which is the direction of the fan inflow side in the figure, and the other on the left side, which is the direction of the fan outflow side in the figure). As a result, the narrowest point is located approximately at the periphery of the cooling flow guide 14 opposite the stator flange 49 , between the cooling flow guide 14 and the stator 36 or electronics pot 13 . This is particularly advantageous with respect to the economical manufacture of the corresponding tools and the economical mass production of the part (cooling structure 40).

[0043] FIG. 6 a is a similar detail view to FIG. 5 a showing a region of the cooling structure 40 in another embodiment of the cooling structure 40 . With respect to the embodiment of FIG. 5a, the cooling flow guide 14 is of a different design. The narrowest point between these cooling flow guides 14 and the stator 36 or electronics pot 13 is not at the peripheral edge of the cooling flow guides 14 opposite the stator flange 49, but at a location further towards the stator flange 49.

[0044] In the operating state 2, in which the cooling flow in the cooling structure 40 flows from the fan outlet side to the fan inlet side (from left to right in the figure), a special inflow area 47 is formed in the cooling flow duct 41 formed by the cooling flow guide portion 14, and the cooling flow duct 41, which extends from the peripheral portion of the cooling flow guide portion 14 near the stator toward the stator flange 49, first converges to its narrowest point and then further widens in the direction of the stator flange 49. This is particularly advantageous for the flow speed and / or turbulence in the cooling flow duct 41 and thus for the cooling of the stator 36 or electronics pot 13, respectively. However, if the cooling flow guide 14 is manufactured integrally with the cooling structure 40, a more complicated release from the molding tool is required due to the presence of an undercut in the axial direction of the fan, as shown.

[0045] In FIG. 7, a cooling structure 40 according to the invention is shown in a partial axial top view from the inlet side. In this cooling structure 40, the inner guide element 11 is integrated on the outside and incorporates, for example, an electric motor 34 according to the embodiment of FIGS. Here, the impeller 19 is not shown. This view shows the rotor-proximal receiving area 46 of the cooling structure 40 from the inlet side of the fan. Also shown is a rotor 35 of a motor 34, which is provided with a fixture 30 for fixing the impeller 19. Furthermore, three cooling channels 42 and the cooling flow guide 14 extending behind them and integrated into the cooling structure 40 can be seen radially outside the rotor 35 and inside the cooling structure 40 and hub ring 4, which form the boundary with the outer elements. Also, as previously described with respect to FIG. 4a, the cooling passage 42 has a characteristic width dimension B16 measured generally circumferentially, i.e., perpendicular to the fan axis. Reinforcing ribs (here, rotor-proximal reinforcing ribs 48 ) that reinforce the connection between the hub ring 4 and the motor support flange 59 are also formed in the rotor-proximal receiving area 46 . These reinforcing ribs are incorporated into the cooling structure 40 so as to be integrated with the cooling structure 40, similar to the cooling structure flange 54 implemented as the motor support flange 59.

[0046] FIG. 8 shows another embodiment of the cooling structure 40 for the fan 57 incorporating the electric motor 34, in a perspective view seen from the outflow side. In this electric motor 34, the stator 36 and the electronics pot 13 can be seen. The cooling structure 40 includes a hub ring 4 that radially separates the electric motor 34 from external elements. The cooling structure 40 also includes a flange 54 that connects the cooling structure 40 to the stator flange 49 of the stator 36 . This embodiment of the cooling structure 40 is not incorporated into other fan components, nor can it be used as a structural component in particular. This means that in the assembled state, another part such as a support strut or the like will need to take care of the connection between the motor 34 and the housing 2 or device or the like. Similar to the cooling structure 40, such support struts and the like can be secured to the stator flange 49 of the stator 36 by fasteners 18, particularly threaded connections, at attachment points circumferentially offset from the attachment points of the cooling structure flange 54, or at attachment points axially between the cooling structure 40 or its flange 54 and the stator flange 49.

[0047] It is important that, even in the assembled state, and even when performing the supporting function, a cooling path 42 is formed within the cooling structure 40 to guide the flow in the axial direction from the rotor 35 side to the stator 36 side, or in the opposite direction. Such cooling flow facilitates heat dissipation from the motor 34, its stator 36 or its electronics pot 13, respectively. Furthermore, no additional cooling flow guides 14 are provided to guide the cooling flow particularly near the stator 36 . This may also be advantageous in the case of a non-structural cooling structure 40, or a cooling structure 40 that is not integrated into other fan components.

[0048] It should be noted here that in operating state 2, if the cooling flow in the cooling structure 40 flows in the opposite direction to the main flow of the fan 57, the resulting return cooling flow reduces the effective conveying flow rate of the fan 57, thereby reducing the overall efficiency of the fan 57. It is therefore advantageous to carefully select the size and cross-sectional area of ​​the cooling passage 42 so as to provide good cooling while at the same time not unduly reducing the overall efficiency of the fan 57 . For example, when a cooling flow guide 14 is formed, as in the embodiment of Figures 1 to 5, the magnitude of the cooling flow can be easily controlled by the cooling flow guide 14 and the minimum spacing between the cooling flow guide 14 and the stator 36 of the motor 34 or the electronics pot 13, respectively.

[0049] In embodiments such as that shown in FIG. 8, which lack cooling flow guides, the magnitude of the cooling flow is controlled by carefully selecting the cross-sectional opening area of ​​the cooling passages 42 when assembled with the motor 34 . In this configuration without a cooling flow guide, it is advantageous if the opening cross-sectional area in the region of the cooling path 42 is less than 10% of the reference cross-sectional area of ​​the electronic device housing 13, which can be defined as π / 4*DE*DE using the outer diameter DE63 of the electronic device housing 13. This value also applies very generally to the cooling flow guide 14 implemented. This is the case when the narrowest cross-sectional area within the cooling flow path or cooling flow duct 41 through the cooling structure 40 assembled with the motor 34 is used as the overall opening cross-sectional area, where in embodiments having a cooling flow guide 14 (as shown in Figures 1 to 7), this narrowest cross-sectional area typically applies to the area where the gap between the stator 36 of the motor 34 or the electronics pot 13 and the cooling flow guide 14 is narrowest.

[0050] FIG. 9 shows a top axial view of the cooling structure 40 with the motor 34 of FIG. 8 as seen from the outflow side. In addition to FIG. 8, similar to FIG. 7, the width dimension B16 in the approximately circumferential direction of the cooling passage 42 in the assembled state with the motor 34 is shown. In particular, in embodiments without cooling flow guides 14, it is contemplated that the number of cooling passages 42 may be significantly increased and the width dimension B may be reduced, for example, up to 60 cooling passages 42 may be provided. The cooling passage 42 has an opening height h15 in the radial direction, which, together with the width dimension B, characterizes the opening cross-sectional area of ​​the single cooling passage 42. In this case, the opening cross-sectional area is the sum of the opening cross-sectional areas of all the cooling paths 42 .

[0051] In FIG. 10, the cooling structure 40 with the motor 34 of FIGS. 8 and 9 is shown in a side view and in cross section along a plane passing through the axis. The path of potential cooling flow through cooling flow ducts 41 within the cooling structure 40 or within the hub ring 4 of the cooling structure 40 can be easily traced. Again, within the cooling structure 40 are formed a stator proximal receiving region 8 and a rotor proximal receiving region 46, which are axially separated by a cooling structure flange 54, with the cooling passages 42 establishing fluid communication therebetween. In this way, the cooling medium within the cooling structure 40 can flow from the stator 36 to the rotor 35, or from the stator-proximal receiving area 8 through the cooling path 42 to the rotor-proximal receiving area 46, or vice versa, depending on external flow or pressure conditions.

[0052] In this way, a convection cooling system integrated into the motor 34 can also perform this function. Like the motor 34 of Figures 1 to 7, this motor 34 has a dedicated integrated cooling system with a rotating cooling fan wheel 51 fixed to the rotor 35 and heat dissipating cooling ribs 50 on the stator 36 or its stator flange 49, respectively. This cooling system allows basic heat dissipation in the motor 34, but the effect of the cooling structure 40 can significantly improve heat dissipation. In either case, the cooling flow within this cooling structure 40 can also be generated or enhanced by a cooling wheel 51 of the basic cooling system integrated into the motor 34 . However, the cooling flow is generated or enhanced directly or indirectly by the impeller 19 and / or vane wheel and / or radially expanding region 10 of the fan 57 .

[0053] FIG. 11 shows a further embodiment of a fan 57 with a cooling structure 40 according to the invention in a perspective view seen from the outflow side. The cooling structure 40 is incorporated into an inner streamer assembly consisting of an intermediate ring 5, a hub ring 4 and an inner guide element 11, and the supporting function is performed by a metallic support suspension 52. In this way, the structural streamer unit 1 is not implemented and the cooling structure 40 only has a partial structural function for the inner streamer assembly. The housing 2 is designed similarly to the housing 2 of the embodiment of Figures 1 to 7, but is constructed as a separate part and is connected to the motor 34 or its stator 36, respectively, via a metallic support assembly 52. For a description of the structure and associated mode of function of cooling structure 40, please refer to FIGS. 1-7 above and the associated discussion. In an assembled state, the cooling passage 42 has an effective cross-sectional area that is sufficient to allow flow through the cooling structure flange 54 in the cooling structure 40 from the stator 36 side to the rotor 35 side, or vice versa. Therefore, the potential shrouding effect of the support assembly 52 must be considered with respect to this cooling path 42 . This effect may reduce the effective cross-sectional area of ​​the cooling passages 42 in the assembled state.

[0054] Similar embodiments having a structural metal support assembly 52 without an inner streamer wheel, similar to the cooling structure 40 of FIGS. 8-10, are also contemplated. It is also contemplated that embodiments having structural metal support assemblies 52 and cooling flow guides 14 similar to the cooling flow guides 14 according to the embodiment of FIGS. 1-7 may be easily and very advantageously implemented. The cooling flow guide 14 according to the embodiment of Figures 1 to 7, together with the stator 36 of the motor 34 or the electronics pot 13, respectively, defines a cooling flow duct 41 having a narrow flow cross section within the cooling structure 40 between the cooling flow guide 14 and the outer wall of the stator 36 or the outer wall of the electronics pot 13, respectively.

[0055] FIG. 12 shows a further embodiment of a cooling structure 40 integrated into a radial structure fan 57 in a perspective view seen from the outflow side. The fan 57 has a radial structure impeller 19, and is essentially composed of a base disk 62, a cover disk 61, and blades 22 extending therebetween. Furthermore, the cover disc 61 has a central opening through which the inlet nozzle 9 projects. The inlet nozzle 9 is fixed to the nozzle plate 56 . The impeller 19 is fixed to the rotor 35 of the motor 36 (see also FIG. 13), and the stator 36 of the motor 34 is attached to a motor support plate 55 . Support posts 60 hold the motor support plate 55 on the nozzle plate 56 . Substantially the entire portion consisting of the nozzle plate 56, the support struts 60 and the motor support plate 55 is called a support module for the fan 57. The fan 57 can be fixed on its nozzle plate 56 to a host device or pneumatic system and is supported and operated thereby.

[0056] During operation of the fan 57, the motor 34 drives the impeller 19 via the rotor 35, and the rotational movement of the impeller 19 generates a flow of the conveying medium. The conveying medium flow enters the impeller 19 through the inlet nozzle 9 and flows radially outward, passing through the support struts 60 and exiting the fan 57 . As it passes through the fan 57, energy is transferred to the conveying medium flow, which causes a significant increase in total and / or static pressure. And, the support struts 60 have an aerodynamically favorable design to achieve high efficiency and low noise levels. In particular, the cross section of the support strut 60 is designed to resemble the cross section of an airfoil, being slightly elongated in the flow direction, with a rounded leading edge and a slightly thinner trailing edge.

[0057] When viewed radially, i.e. perpendicular to the axis, the motor support plate 55 projects beyond the impeller 19, which is beneficial to the static efficiency of the fan 57. As a result, a negative pressure is created in the interior area near the shaft and near the motor 34 relative to the static pressure level at the outlet of the fan 57 on the outflow side of the support strut 60 . Therefore, the static pressure inside the motor support plate 55 on the impeller 19 side is significantly lower than the static pressure on the opposite outside of the motor support plate 55, ie, outside of the fan 57 and the support module.

[0058] The cooling structure 40 is attached to the motor support plate 40 or is integrated into the motor support plate 55 in the area of ​​the stator 36 of the motor 34 . Here, the outer diameter of this cooling structure 40 can be defined by the outer diameter of the cooling passage 42 or the outer diameter of the cooling flow guide 14, respectively (see FIG. 13a). As a result of the pressure difference described above, the cooling flow from the outside of the support module flows between the stator 36 or the electronics pot 13, is guided axially by the cooling flow guide 14 and flows into the interior region of the support module through the motor support plate 55 with the integrated cooling structure flange 54 or the motor fixing flange 59. In the process, additional heat is dissipated from the motor 34, stator 36 or electronics pot 13, respectively, improving the cooling of the motor 34.

[0059] FIG. 13 shows a fan 57 with the cooling structure 40 of FIG. 12 in a side view and a partial cross-section of the area near the cooling structure 40 along a plane passing through the axis. FIG. 13a is a detailed view of a region of the cooling structure 40 of FIG. 13, with characteristic dimensions further outlined. The entire cooling structure 40 can be manufactured integrally on the motor support plate 55 if the motor support plate 55 is manufactured as a casting by a plastic injection molding process. The motor support plate 55 is also provided with a cooling structure flange 54 , which may be an integral or separate part, and is embodied as a motor fixing flange 59 to which the motor 34 is fixed. Furthermore, if each of the cooling structure flange 54 or the motor fixing flange 59 is implemented as a separate part relative to the motor support plate 56, and the screw fastening surfaces of the motor support plate 56 and the stator flange 49 are offset in the axial direction, the cooling structure 40 can also be integrated into this separate part.

[0060] Additionally, the cooling structure 40 may be secured to the motor support plate 56 as multiple separate components that define the cooling flow guide 14, for example. As can be seen particularly in Figure 13a, at least one cooling path 42 is provided, which establishes a fluid connection between the stator 36 side outside the cooling structure flange 54 (outside the fixing flange 54 in the case of a support module) and the rotor 35 side inside the cooling structure flange 54 (inside the motor fixing flange 59 in the case of a support module).

[0061] Due to the pressure difference generated during operation of the fan 57, the cooling flow in the cooling structure 40 flows at a relatively high flow rate between the cooling flow guide 14 and the stator 36 of the motor 34 or the electronics pot 13, respectively, and absorbs waste heat from the motor 34, the stator 36 or the electronics pot 13, respectively. The cooling flow then flows through cooling passages 42 into the interior of the support module and is discharged radially outward therefrom.

[0062] Similar to FIG. 5a, a minimum gap t26 between the cooling flow guide 14 and the outer wall of the stator 36 or the outer wall of the electronics pot 13, respectively, is shown. And the preferred value of this minimum gap t26 has already been specified in accordance with the description of FIG. 5a. The cooling flow ducts 41 formed by the cooling structures 40 or the cooling flow guides 14, respectively, can be characterized by imaginary centerlines in the cross-sectional views shown. As one moves from stator flange 49 toward stator 36 or electronics housing 13, i.e., to the right, this centerline has a profile toward the fan axis, changing from a larger radius to a smaller radius relative to the fan axis. In particular, the cooling flow guide 14 also has a similar profile as it progresses rightward from the stator flange 49 . Therefore, it is generally advantageous to design the cooling structure 40 with such cooling flow guides 14 . The cooling flow is guided radially outward through the stator flange 49 even though it does not form a channel on the stator flange 49, but the outer wall of the stator 36 or electronics pot 13, respectively, which is further radially inward, is particularly cooled. [Explanation of symbols]

[0063] 1. Structure Streamer Unit 2. Streamer unit housing 3 Support blade 4. Hub ring, outer ring with cooling structure 5. Streamer unit or middle ring of the diameter expansion area 6. Outer flow region 7. Inner flow region 8. Hub ring near-stator receiving area, hub pot 9. Inlet nozzle 10. Outer wall of the diameter expansion area 11 Inner guide element, guide vane 12 Outflow edge of intermediate ring 13 Stator pot, electronics housing 14...Cooling flow guide part 15 Cooling flow height h 16 Cooling flow guide section / cooling channel width B 17. Length of electronic device pot Ls 18 Fixtures in the receiving area 19 Impeller 20. Fixture for the inlet side of the streamer unit to the host system 21 Fixture for the outflow side of the streamer unit to the host system 22 Impeller blades 23 - Inlet side peripheral edge of intermediate ring of streamer unit 24. Overlapping length L between the cooling flow guide and the stator pot 25 Outlet protective mesh fixing device 26 Radial cooling flow guide clearance t from the stator (gap height) 27 Diameter of receiving area in hub DN / Diameter of hub pot DN 28 Impeller hub diameter DL 29 Impeller area 30 Motor fixing to impeller 31 Impeller hub 32 Impeller rotation direction 33 Fixture for suspension to housing 34 Motor 35 Motor rotor 36 Motor stator 37 Hubcap 38 Impeller blade winglets 39...not used 40...Cooling structure 41 Cooling flow duct 42 Cooling channels in the area of ​​the fastening flange 43 Dimension e of the streamer unit perpendicular to the fan axis 44 - Inner diameter Di of the housing of the streamer assembly in the region of the impeller 45 - outer diameter Da of the beginning of the outer curvature of the inlet nozzle 9 46 - Rotor near-receiving area with hub ring 47...Inlet region of cooling flow guide 48 Reinforcing rib in rotor near-receiving area 49 Stator flange 50 Cooling ribs on the stator 51 Cooling fan wheel on rotor 52...Suspension 53 Cable connector on motor stator or electronics housing 54 Cooling structure flange 55...support plate 56 Nozzle plate 57 Fan, axial fan 58 Reinforcing ribs in the motor receiving area 59 Motor fixing flange 60...Support strut 61 ···Cover disc 62 Base Disk 63 Outside diameter of electronic device housing DE

Claims

1. 1. A fan comprising an impeller and an electric motor, the electric motor including a stator, a rotor, and optionally an electronics pot, a cooling structure is formed or provided on a radially outer wall of the stator and / or the electronics pot; the cooling structure defines a flow path for a fluid, preferably air; the flow path being such that flow is induced by a pressure differential created by the operation of the fan; A fan, characterized in that the flow dissipates heat from the electric motor and / or the stator and / or the electronics pot.

2. 2. A fan according to claim 1, characterized in that the cooling structure is not formed by or penetrates functionally related parts of the electric motor.

3. 3. A fan according to claim 1 or claim 2, characterized in that the cooling structure is formed by a separate cooling unit arranged on or fixed to a stator flange (a flange that fixes the stator).

4. 4. The fan according to claim 1, wherein the separate cooling unit can be retrofitted to suit space requirements by using a large hub pot.

5. 4. A fan according to claim 1, wherein the cooling structure is mounted on or within a motor support plate of a radial or mixed flow fan, or is integrated into the mounting plate.

6. A streamer assembly having a streamer wheel is provided.

4. A fan according to claim 1, wherein the cooling structure is assigned to the streamer wheel and is preferably integrated into the streamer wheel so as to be integral therewith.

7. 7. A fan according to claim 6, wherein the streamer assembly has a structural function for the electric motor.

8. 8. The fan according to claim 1, wherein the cooling flow path extending in the cooling structure from the rotor side to the stator side (or vice versa) is formed by a cooling path passing through a cooling structure flange in the region of a motor support surface on the stator of the motor when assembled to the electric motor.

9. 9. A fan according to claim 1, wherein the flow path passes radially outside the stator flange (a flange that fixes the stator).

10. a narrowest flow region of the cooling flow in the flow path is formed between the outer wall of the stator of the motor or the outer wall of the electronic device pot, respectively, and the cooling structure or the cooling flow guide, 10. The fan according to claim 1, wherein the cooling flow is directed to pass at high speed near the outer wall of the stator or near the outer wall of the electronics pot, respectively, within the narrowest flow region.

11. 11. The fan according to claim 1, wherein the flow path or centerline of the flow path or the cooling flow guide portion extends from the stator flange in a direction toward the stator or electronics housing, towards the fan axis, and thus from a large radius to a small radius, thereby guiding the cooling flow close to a wall of the stator or a wall of the electronics housing.

12. A cooling structure for a fan having the features of the cooling structure according to any one of claims 1 to 11 for a fan having a fan hub and an electric motor including a stator, A cooling structure disposed between the fan hub and the stator.

Images