Axial fan

Abstract

The present invention relates to an axial fan, comprising a fan impeller and an outlet guide device downstream of the impeller in a housing / flow channel, wherein the outlet guide device includes outlet guide blades extending only on a portion of the housing / flow channel when viewed in the spanwise direction or radial direction, wherein the outlet guide device has a structure serving as a diffuser and has a gradually expanding flow cross-section when viewed in the flow direction, wherein two flow areas are formed downstream of the impeller: an inner flow area closer to the axis when viewed in the spanwise direction, the inner flow area being defined by a hub ring of the outlet guide device and an outer ring of the outlet guide device; and an outer flow area away from the axis when viewed in the spanwise direction, the outer flow area being defined by the outer ring of the outlet guide device and the wall of the housing.

Description

Technical Field

[0001] The invention relates to a fan, in particular an axial, radial or diagonal fan, having a fan wheel and an outlet guide device arranged downstream thereof in a housing / flow channel, the outlet guide device having outlet guide vanes. Background Art

[0002] Free-running diagonal or radial fans, especially those with backward curved blades, are well known in practical use. In such fans, no guides such as spiral housings, outlet guide vanes, diffusers, etc. are located downstream of the impeller outlet. The air flow leaves the impeller at a high flow rate. The dynamic pressure associated with these flow rates cannot be used for free-running diagonal or radial fans. This means pressure and energy losses. As a result, such fans have insufficient pressure increments, insufficient air performance, and insufficient efficiency. Moreover, these high flow rates at the outlet produce excessively high noise emissions. In addition, struts are usually used to attach the motor fan wheel to the nozzle plate, and these struts usually pass very close to the impeller outlet. Therefore, they constitute obstacles in the flow path and have additional negative effects on air performance, efficiency and acoustics. However, free-running diagonal or radial fans are usually compact, which means that they occupy a small space in higher-level systems, are usually square, and are inexpensive to produce.

[0003] A radial fan is known from EP 2 792 885 A1, which has a circular blade outlet guide wheel on the air outlet side to improve air circulation. The outlet guide wheel also serves as a suspension, but does not contribute to improving efficiency. The outlet guide wheel comprises a cover plate and a base plate, which extend the corresponding cover plate or base plate of the impeller in the installed state, respectively, and comprises guide blades, which are partially arranged between the cover plate and the base plate of the outlet guide wheel, but extend beyond its outer edge when viewed in the flow direction. As a result, the outlet guide wheel generates a lot of noise. Another disadvantage of the known radial fan is that, when viewed in the flow direction, the guide device cover plate and the guide device base plate are basically separated from each other, that is, the flow cross section is significantly widened in the flow direction. This leads to turbulence in the area of ​​the guide device, where it increases the generation of noise, while reducing the air performance and thus the efficiency. Summary of the invention

[0004] The object of the present invention is to configure and improve a conventional ventilator in such a way that the problems arising in the prior art are at least largely eliminated. The static efficiency should be increased over a wide range of the performance curve while maintaining a minimum noise level. In addition, the ventilator according to the invention should be distinguished from competitive products.

[0005] Corresponding exit guidance equipment will also be specified.

[0006] The above objects are achieved by the ventilator according to the present invention. According to the present invention, the outlet guide device of the general ventilator has a specific structural design; specifically, when viewed in the span direction, the outlet guide vanes extend only over a portion of the flow area.

[0007] Alternatively, two flow areas are formed downstream of the impeller: an inner flow area closer to the axis when viewed in the span direction is defined by the hub ring of the guide device and by the outer ring of the guide device, and an outer flow area further away from the axis when viewed in the span direction is defined by the outer ring of the guide device and the wall of the casing.

[0008] The exit guide device according to the invention is configured accordingly.

[0009] In addition to improving static efficiency or keeping noise levels low, the compact configuration of the outlet guide device, whose outlet guide vanes extend substantially only over a portion of the span of the associated impeller, has a positive effect on tool and part costs. Due to the relatively small diameter of the outlet guide device, which is based on a given impeller diameter, the tool size of the associated injection molding tool is smaller than would otherwise be normally required. This is particularly true in the case of axial fans.

[0010] Furthermore, a correspondingly configured radial fan is particularly suitable for installation in narrow channels with an axial flow path.

[0011] Since various exemplary embodiments of the present invention will be described in high detail below with further reference to the accompanying drawings, a general description of the present invention is omitted herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] There are various options for advantageous embodiments and improvements of the invention. In this regard, reference is made to the following detailed description of a preferred exemplary embodiment of a ventilator according to the invention with reference to a set of drawings. In conjunction with the detailed description of a preferred exemplary embodiment of the invention with reference to this set of drawings, preferred configurations and improvements of the present teaching will also be described. The drawings show:

[0013] Figure 1 is a perspective view of a guide device and a housing of an exemplary embodiment of an axially designed ventilator according to the invention, seen from the outflow side;

[0014] Figure 2 Viewed from the outflow side Figure 1 An axial plan view of the guide device and the housing;

[0015] Figure 3 yes Figure 1 and 2 A side cross-sectional view of the guide device and the housing along a plane passing through the axis;

[0016] Figure 3a yes Figures 1 to 3 A side sectional view of the guide device and the housing along a plane passing through the axis with the impeller mounted and the motor schematically shown;

[0017] Figure 4 yes Figures 1 to 3 A side cross-sectional view of the guide device and the housing along a plane parallel to the axis;

[0018] Figure 5 Based on the view from the entrance side Figures 1 to 4 A perspective view of the guide device and the housing;

[0019] Figure 6 Based on the view from the entrance side Figures 1 to 5 An axial plan view of the guide device and the housing;

[0020] Figure 7 is a perspective view of a guide device according to a further exemplary embodiment of a radially or diagonally designed ventilator according to the invention, seen from the outflow side;

[0021] Figure 8 Based on the outflow side Figure 7 A perspective view of a guide device with an associated impeller of radial design;

[0022] Fig. 9 Based on the outflow side Figure 7 An axial plan view of the guide device;

[0023] Fig.10 Based on the outflow side Figure 8 Axial plan view of the guide device and impeller;

[0024] Fig.11 is based on Figure 8 and 10 A side sectional view of the guide device and the impeller along a plane passing through the axis;

[0025] Fig.12 is based on Figure 8 and 10 a side cross-sectional view of a guide device and an impeller along a plane passing through the axis, mounted in a discharge side casing, with an inlet nozzle associated with the impeller;

[0026] Fig.12a is an axial plan view of a housing, a guide device and an impeller of a further embodiment of a ventilator according to the invention, seen from the outflow side, showing a suspension mounting in which a plurality of guide elements of the guide device are integrated;

[0027] Fig.13is a perspective view of a guide device and a housing of a further exemplary embodiment of an axially designed fan according to the invention, seen from the outflow side;

[0028] Fig.14 Based on the view from the entrance side Fig.13 An axial plan view of the guide device and the housing;

[0029] Fig.15 is based on Fig.13 and 14 A side cross-sectional view of the guide device and the housing along a plane passing through the axis;

[0030] Fig.16 is an axial plan view of a housing, a guide device and an impeller of a further embodiment of a ventilator according to the invention, seen from the outflow side, wherein the guide device is made of sheet metal;

[0031] Fig.17 is based on Fig.16 A side sectional view of the casing, the guide device and the impeller along a plane passing through the axis;

[0032] Fig.18 An axial plan view of a housing, a guide device and an impeller of a further exemplary embodiment of a ventilator according to the invention, seen from the outflow side, wherein the guide device is produced from sheet metal and the guide element has an adjusted section. DETAILED DESCRIPTION

[0033] Figure 1A perspective view of a guide device 1 according to the invention used as an outlet guide device and a housing 2 of an exemplary embodiment of an axially designed fan is shown. The guide device 1 essentially comprises a hub ring 4, an outer ring 5 and guide vanes 3 extending therebetween. When the fan according to the invention is in the assembled state, the guide device 1 is arranged downstream of an impeller (not shown) in the housing 2, so that a part of the air flowing outward from the impeller is generated between the guide device 1 or its outer ring 5 and the wall of the housing 2 through which an air channel 6 (outer flow area) is guided. Another part of the air flowing outward from the impeller is guided through an inner flow area bounded by the hub ring 4 towards the axis when viewed in the spanwise direction and by the outer ring 5 towards the outer flow area 6 when viewed in the spanwise direction. The inner flow area 7 is interspersed with guide vanes / guide elements 3 (13 of these elements in these embodiments, advantageously 3-19 of these elements), which stabilize the vortex leaving the impeller by reducing the vortex in the flow. This improves efficiency. The hub ring 4 and the outer ring 5 extend substantially over the entire circumference around the axis. The hub ring 4 surrounds an inner receiving area 8, in which, for example, a drive motor for a ventilator can be arranged. No air flows through the receiving area 8, or advantageously only a small air volume flow (0.1%-2% of the total air volume flow) passes through the area to allow the heat generated by the motor to be carried away.

[0034] When viewed in the spanwise direction, the outer flow region 6 as a whole is substantially free of further guide elements, at least over a large area. As a result, no or almost no additional noise is generated in this region due to the interaction of the flow leaving the impeller and the guide elements. This leads to highly noise-reduced operation, since the flow velocities are high, in particular in this outer region 6. It is not essential for the efficiency of the fan that the guide elements stabilize the flow in the outer flow region 6. Thus, a fan is obtained which is low-noise, in particular due to the fact that there are substantially no guide elements in the outer flow region 6, or that only a small number of guide elements are present there, compared to the inner flow region 7. In addition, due to the flow stabilization produced by the guide element 3 in the inner flow region 7, the fan according to the invention has a high efficiency.

[0035] Figure 2 The axial plan view shows the Figure 1The guide device 1 and the housing 2. The outer flow area 6 without guide elements and the inner flow area 7 with the guide elements 3 in the exemplary embodiment are clearly visible. In this illustration, the connection between the guide device 1 and the housing 2 is not shown. In practice, however, such a connection is necessary for attaching the guide device 1 to the housing 2. This can be achieved with the help of a flat or rod-shaped metal material or with the help of an element configured to assist the flow, which connects the guide device 1 to the housing 2. This necessary suspension must also extend through the outer flow area 6 and cannot be regarded as an actual guide element and does not change the statement that the outer flow area 6 is essentially free of additional guide elements.

[0036] In the exemplary embodiment, both the wall of the housing 2 and the hub ring 4 have a conical shape towards the outflow end. Therefore, the outer diffuser 10 is integrated into the housing 2. Therefore, both the inner flow area 7 and the outer flow area 6 are configured as diffusers, which expand their flow cross-section towards their outflow end. This is very advantageous for static efficiency, in particular for axial fans. In the exemplary embodiment, the outer ring 5 of the guide device 1 is designed in the form of a cylindrical shell aligned in the axial direction. This is particularly advantageous when the guide device is produced as a casting, because in this case, the demoulding of the guide element 3, which is attached to the outer ring 5 at its outer end 12, is greatly simplified. For the same reason, it is also conceivable to configure the hub ring 4, which is connected to the hub ring 4 at its inner end 11 in the form of a cylindrical shell.

[0037] Measures enabling mounting, such as mounting flanges, can advantageously be integrated or attached to the housing 2 and / or the guide device 1 both on the inlet side and on the outlet side, so that the ventilator can be installed in a higher-level system, such as an air conditioning system.

[0038] Figure 3 Shown in the Figure 1 and 2 Side view and section view in the plane of the axis of the guide device 1 and the housing 2. In the section view, an outer flow section 6 without guide elements, an inner flow section 7 with guide elements 3 and a receiving section 8 in the hub ring 4 can be seen. After assembly, the impeller (not shown) is arranged in the section 29 upstream of the guide device 1. When the fan is in operation, as can be seen from this view approximately from left to right, the air first flows through the inlet nozzle 9 integrated with the housing 2, and then through the impeller (not shown), after which it is divided between the outer flow section 6 and the inner flow section 7, where the flow is stabilized (mainly in the inner flow section 7) and where the kinetic energy of the flow is converted into pressure energy. In the area of ​​the receiving section 8 in the hub ring 4, there is an arrangement or simulation device 18 for fastening the motor.

[0039] Basically, there are two different bearing concepts for the motor with impeller. On the one hand, the guide device 1 can be adapted to load-bearing. This means that it is stably connected to the housing in the region of its outer ring 5 (by means of struts, flat stock or aerodynamically optimized metal sheets or plastic elements) and the motor together with the impeller is held on a motor fastening arrangement 18 in the inner section 8 of the guide device 1. On the other hand, the guide device 1 may not be adapted to load-bearing, which means that the motor is fastened to the housing 2 by means of a bearing arrangement (in particular made of bar stock or flat stock), whereupon the non-load-bearing guide device 1 is fastened to the motor or to the associated bearing arrangement, or to the housing 2 by means of a separate bearing device. In any case, parts of the bearing arrangement must pass through the outer flow section 6, which should not change the statement that the outer flow section 6 is essentially free of guide elements over a large part of its spanwise extension.

[0040] In the exemplary embodiment, the guide elements 3 have a special and advantageous configuration. In the inflow section, they comprise an inclined portion 16 adapted to the inflow direction, in the outflow section, an axially aligned portion 15, and a transition section 17 between the portions 15 and 16. Here, the transition section 17 is simply implemented as a bend. An inflow that is as smooth as possible in the region of the leading edge 13 of the guide vane 3 is advantageous for achieving high efficiency and low sound generation. This is ensured by the inclined portion 16 of the guide vane 3, which is oriented approximately parallel to the direction of the swirling inflow from the impeller (see also Figure 4 ). However, in combination with a conically configured hub ring 4, demoulding of inclined, i.e. non-axially aligned, guide vanes will be much more difficult due to the undercut. Therefore, the section 15 of the guide vane 3 located in the region of the conically configured hub ring is designed as an axially aligned section. Figure 2 This can also be easily seen in the region where the inner end 11 of the guide element 3 abuts against the conical section of the hub ring 4. Thus, if the guide device 1 is a casting, preferably produced by injection molding, the hub ring 4 and the guide element 3 together with the outer ring 5 can be demoulded parallel to their orientation without undercuts. In order to demould the one-piece guide device 1 from the molding die without undercuts, it is advantageous if the hub ring 4 does not extend conically in the region of the inclined section 16 of the guide blades 3, but rather is cylindrical, as in the exemplary embodiment shown. Thus, in this exemplary embodiment, the hub ring 4 extends in the shape of a cylinder in a first section and does not extend relatively conically in a second section.

[0041] Figure 3a Shown in the Figures 1 to 31 and sectional views in a plane of the axis of the guide device 1 and the housing 2, in which an axial type impeller 19 is mounted and a motor 34 is schematically shown, which comprises in particular a rotor 35 and a stator 36. The impeller comprises a hub ring 38, on which advantageously 3 to 13 impeller blades 22 are fastened. The impeller 19 runs in the housing 2 so that there are only small gaps between the impeller blades 22 and the housing 2. The impeller 19 is fastened by its hub ring 38 to the rotor 35 of the motor 34 driving the impeller 19. The guide device 1 is fastened to the stator 36 of the motor 34. In a load-bearing embodiment, the guide device 1 is firmly connected to the housing 2 by its outer ring 5 by means of suspension elements (not shown), and in a non-load-bearing embodiment, the motor 34 is firmly connected to the housing 2 by means of its stator 36 by means of suspension elements (not shown).

[0042] Advantageously, the outer contour of the impeller hub 38 has, at least at the ends facing each other, an outer diameter that is the same or similar to the outer contour of the hub ring 4 of the guide device 1. This creates a substantially continuous restriction contour towards the inner section close to the axis, which is very advantageous for high efficiency and low noise generation. Furthermore, in the exemplary embodiment, a hub cap 37 is attached to the hub ring 38 of the impeller 19 on the inflow side, which hub cap 37 can have, for example, a semi-elliptical outer contour and forms a continuous inner restriction contour with the hub ring 38.

[0043] In the exemplary embodiment, the motor 34 is an outer rotor motor which is attached in the hub ring 38 and 4 (or also in the receiving section 8 in the hub ring 4 ), resulting in a space-saving solution and a compact ventilator design.

[0044] Advantageously, suitable measures (openings, holes, slots or the like) produce a small air volume flow in the hub rings 38 and 4 (or also in the receiving section 8 in the hub ring 4 ) in order to better dissipate the waste heat of the motor 34 .

[0045] Figure 4 shows that in parallel with Figures 1 to 3 The side view and the cross-sectional view are in the plane of the axis of the guide device 1 and the housing 2. The section plane does not pass through the axis, but is at a distance from the axis that is within the range of the average radius of the guide blade 3. Therefore, some cross-sectional views of the guide blade 3 can be seen, and as reference Figure 3Its structure, which has been described, can be seen more clearly. The guide vane 3 has a leading edge 13 on the inflow side and a corresponding trailing edge 14 on the outflow side. In particular, in the region of the leading edge 13, the inclined section 16 of the guide vane 3 is almost parallel to the flow direction of the swirling flow from the impeller. The axially aligned portion 15 of the guide vane is formed towards the trailing edge 14. This configuration significantly facilitates the demoulding of the guide device 1 having a conically configured hub ring 4 and / or a conically configured outer ring 5 from the molding die. In the exemplary embodiment, the transition 17 between the portions 15 and 16 of the guide vane 3 is implemented as a curved portion, but can also be configured as a blunt rounded section with a constant tangent or a constant curvature, for example. The angle of the inclined portion 16 of the guide vane 3 at the leading edge 13, for example, toward a line parallel to the axis, is advantageously in the range between 20° and 50°. Advantageously, as in the exemplary embodiment, the inclined portion 16 of the guide vane 3 has an airfoil profile in its cross section.

[0046] Figure 5 Shows the flow from the inflow side. Figures 1 to 4 1 and a perspective view of the guide device 1 and the housing 2. In operation, air flows into the housing 2 through the inlet nozzle 9. From its leading edge, the flow channel defined by the wall of the housing 2 or the nozzle 9 tapers in the region of the nozzle 9 as the air passes through until the narrowest cross section, thereby accelerating the air. The impeller is arranged approximately at the level of the narrowest cross section of the housing 2. This exemplary embodiment is particularly suitable for axial-type impellers. Figure 5 The fastening flange 18 in the hub ring 4 is clearly shown, which fastening flange 18 has a hole for fastening the motor.

[0047] Advantageously, the guide device 1 is made in one piece by plastic injection molding. Compared with known outlet guide vanes extending to the outer contour of the housing 2, significantly smaller injection molds are required, and due to the small outer diameter of the guide device 1, mold costs and production costs are saved. Advantageously, the housing 2 including the integrated inlet nozzle 9 and the integrated outer diffuser 10 can itself be made of sheet metal in a cost-effective manner. Here, it can be supplemented by one or even a plurality of sheet metal parts, which are then connected by screws, welding, rivets or other means.

[0048] Figure 6 Based on the inflow side Figures 1 to 5 1 and the housing. This clearly shows the outer flow section 6 and the inner flow section 7, which are separated from each other by the outer ring 5 of the guide device 1. The outer ring 5 is suitable for axial alignment. A fastening flange 18 for fastening the motor is arranged in the receiving section 8. For this embodiment of the guide vane 3, the figure only shows the inclined section 16 up to the transition section 17.

[0049] In the embodiment shown, the guide vanes 3 are configured in a crescent shape, i.e. the leading edge 13 of the guide vanes 3 is adapted to be curved in this view. Seen in the circumferential direction, the end of the leading edge 13 located at the outer ring 5 is offset from the end of the leading edge 13 located at the hub ring 4 in the opposite direction to the direction of rotation of the impeller. In this case, the direction of rotation of the impeller (not shown) relative to a given viewing direction is clockwise.

[0050] Figure 7 A perspective view of a guide device 1 of another exemplary embodiment of a centrifugal or mixed flow fan according to the invention, seen from the outflow side, is shown. The guide device 1 has four guide elements 3, which extend radially along a curved path from a hub ring 4 to an outer ring 5. A fastening flange 18 for fastening the motor is attached inside the hub ring 4. In the exemplary embodiment, the guide elements 3 are configured to be aligned in the axial direction and can advantageously be made of a metal sheet. In the exemplary embodiment, the outer ring 5 has the geometry of a solid body that rotates around an axis.

[0051] Figure 8 The flow rate from the outflow side is shown. Figure 7 1 , with an associated centrifugal-type impeller 19. In this exemplary embodiment, the centrifugal impeller 19 essentially comprises a cover plate 20, a base plate 21 and blades 22 extending therebetween. The motor is not shown. It can be fastened on the stator side to a fastening flange 18 in the hub ring 4 of the guide device and on the rotor side to a corresponding fastening arrangement 30 on the impeller 19. The guide device 1 is arranged downstream after the flow outlet 31 of the centrifugal impeller 19; however, it does not extend from the impeller 19 across the entire span at the flow outlet 31, but only across a section closer to the base plate 21. In this exemplary embodiment, the profile of the outer ring 5 of the guide device 1 leads to a more axial deflection of the air radially leaving the centrifugal impeller 19 into a direction more parallel to the axis.

[0052] Fig. 9 Shown according to Figure 7 Axial top view of the guide device from the outflow side. The figure clearly shows that the guide element 3 is aligned in the axial direction, only its trailing edge 14 is visible. A fastening arrangement 18 is attached in the receiving section 8 in the hub ring 4. In plan view, the guide element 3 is adapted to be curved, the curvature starting from the inside at the hub ring 4 and extending in the direction of the outer ring 5 opposite to the rotation of the impeller. In the exemplary embodiment shown in this figure, the direction of rotation of the impeller is clockwise. Advantageously, the inclination angle of the guide element 3 from the corresponding centrifugal direction has its maximum value at the outer ring 5, its magnitude being greater than 20°, advantageously greater than 35°.

[0053] Fig.10 Shown according to Figure 81 is an axial top view of the guide device 1 and the impeller 19 as seen from the outflow side. For the configuration of the guide device 1, see, for example Fig. 9 The outer diameter of the outer edge 24 of the base plate 21 of the impeller 19 is smaller than the outer diameter of the inflow-side edge 23 of the outer ring 5 of the guide device 1. This makes it possible to push the guide device 1 onto the base plate 21 of the impeller, thus allowing a better assembly of the fan. In this figure, a portion of the blade 22 can be seen between the outer edge 24 of the base plate 21 of the impeller 19 and the inflow-side edge 23 of the outer ring 5 of the guide device 1, which, seen along its trailing edge or its path towards the cover plate 20, can be placed radially further outwards than the outer edge 24 of the base plate 21. The direction of rotation of the impeller 19 is clockwise.

[0054] Fig.11 Shown in the Figure 8 and 10 The side view and the cross-sectional view in the plane of the axis of the guide device 1 and the impeller 19. The cross-sectional view clearly shows the contour of the outer ring 5 of the guide device 1, which is connected to the radial outer end 12 of the guide element 3. This outer ring 5 is severely bent towards its inflow-side end 23, so that there is no or only a small angle of attack relative to the flow flowing in the radial direction from the impeller 19 at the inflow-side end 23 of the outer ring 5. On its path, this actually deflects the flow in the axial direction. Therefore, it extends parallel to the axis at the outflow-side edge 28. According to this exemplary embodiment, only the outer ring 5 (without the guide element 3) can be demoulded from the molding die without an undercut. Then, the guide element 3, which is advantageously made of a metal sheet in the exemplary embodiment, can be fastened to the outer ring 5 of the guide device 1, for example by screwing or snapping it thereon. When viewed in the spanwise direction of the impeller 19, the guide device 1 with the outer ring 5 extends only from the impeller 19 across a part of the flow outlet 31. With respect to the outlet width of the impeller 19 (=width of the outlet 31 of the impeller 19 measured axially from the cover plate 20 to the base plate 21 in axial cross section), the axial position of the inflow side edge 23 of the outer ring 5 of the guide device 1 is approximately in the range of 50%-70% of the width measured from the cover plate 20. In the exemplary embodiment, the guide element 3 has a relatively small axial extension, which is approximately 20%-60% of the axial width of the outlet 31 of the impeller 19, thereby achieving an axially compact design.

[0055] Fig.12 Shown in accordance with Figure 8 and 101 to 11, side view and sectional view on the plane of the axis of the guide device 1 and the impeller 19, wherein the inlet nozzle 9 is installed in a housing 2 implemented as a pressure side air duct. In this housing 2, downstream of the impeller 19, the air continues (flows) in a direction roughly parallel to the axis. The guide device 1 shown can be used particularly advantageously for this configuration. The air leaving the impeller 19 at the outlet 31 is divided between two flow sections, on the one hand on the outer flow section 6 and on the other hand on the inner flow section 7. The outer ring 5 of the guide device 1 represents a separator between the two flow sections 6 and 7. Over a large part of its span, the outer flow section 6 is essentially free of other guide elements. On the contrary, the inner flow section 7 has those 4 guide elements 3 in the exemplary embodiment, which stabilize the vortex air from the impeller 19 in the flow section 7 closer to the axis by reducing the vortex. A particularly significant increase in efficiency can be achieved if the side walls of the housing 2 are relatively close to the outlet 31 of the impeller 19, and in particular if the width of the duct (= the width of the housing 2 seen in cross section and in radial direction at the level of the outlet 31) is less than 1.6 times the maximum diameter of the impeller 19 at least in some sections, which is generally due to a compact design of such a housing 2.

[0056] The guide device 1 must be fastened to the housing 2 by means of a suspension (not shown). Advantageously, this can be achieved by extending one, several or all guide elements 3 to the wall of the housing 2.

[0057] Fig.12a The axial top view of the housing 2, the guide device 1 and the impeller 19 of another embodiment of the fan is shown from the outflow side. The outer edge 24 of the base plate 21 of the impeller 19 is located within the inflow side edge 23 of the outer ring 5 of the guide device 1. This allows the guide device 1 to be pushed onto the base plate 21. Figure 7 Unlike the embodiment of FIG. 1-12, the guide element 3 has no bends. This significantly facilitates the manufacture of the guide element 3 from sheet metal. In order to still obtain good flow characteristics, high efficiency and low noise levels, the guide element 3 is twisted or tilted relative to the radial direction. In the radial section of the inflow-side end 23 of the outer ring 5, the twist angle from the local radial line is about 30°, advantageously 15°-45°. In the exemplary embodiment, the guide element 3 connects to the hub ring 4 at an acute angle at the inner end 11. The hub ring 4 and the guide element 3 are advantageously made of sheet metal and are connected to each other by welding or screws. Since its profile is a solid of revolution (similar to Figure 7 -12), the outer ring 5 is advantageously manufactured as a shell, in particular as an injection-molded part. The guide element 3 is advantageously connected to the outer ring 5 at its outer end 12 by snapping them thereon, screwing, rivets or the like. A corresponding arrangement may be present on the injection-molded part.

[0058] The suspension of the guide device 1 and therefore the suspension of the motor and the impeller 19 at the housing 2 is realized by means of a suspension 32, which integrates some of the functions of the guide elements. The geometry of the suspension 32 in the radial direction within the outer ring 5 of the guide device 1 corresponds approximately to the geometry of the remaining guide elements 3. Advantageously, the suspension 32 is made of sheet metal and is fastened to the housing 2 using fastening means 33, advantageously by means of screws or rivets. This functional integration leads to particularly economical and efficient production. The suspension 32 with integrated guide element function also passes through the outer flow section 6. Due to the additional guide elements 3 in the inner flow section 7, the fact that the outer flow section 6 is essentially free of guide elements, at least in comparison with the inner flow section 7, also applies to this embodiment. Advantageously, no more than half of the number of suspension-specific elements extends in the outer flow section 6. This is not much compared to the inner flow section 7, because the outer flow section 6 also has a significantly larger cross-sectional area than the inner flow section 7, and when considering the integrated suspension / guide elements 32, the distance between adjacent suspensions 32 in the circumferential direction is greater than the distance between adjacent guide elements 3 in the inner flow section 7.

[0059] Fig.13 A perspective view of a guide device 1 and a housing 2 of another exemplary embodiment of an axial type ventilator according to the present invention, viewed from the outflow side, is shown. A suspension strut 25 is schematically shown, which forms a connection between the guide device 1 and the housing 2 in this load-bearing embodiment of the guide device 1. The suspension strut 25 can be made of a metal sheet, a bar stock or molded, and is then advantageously provided with a flow-optimized shape. For suspension struts 25 made of flat material, it is also conceivable that they are not axially aligned, but attached at a fluidically favorable angle to the axial direction. Despite the presence of the suspension strut 25, the outer flow section 6 should be considered to be essentially free of guide elements, at least compared to the inner flow section 7. The suspension strut 25 can be connected to the outer ring 5 of the housing 2 and / or the guide device 1 by screws, rivets, welding or the like. It is also conceivable to manufacture the entire housing 2 and the guide device 1 in a one-piece, single-piece, integral manner, which has the suspension strut 25 as a casting.

[0060] Similar to Figure 1 In the exemplary embodiment of the invention, the guide vane 3 has an inclined portion 16 on the inflow side, an axially aligned portion 15 on the outflow side, and a transition portion 17 to combine the realization of a flow-optimized inflow angle with the easy demoulding of the guide device 1, in particular the hub ring 4 and / or the outer ring 5 of the guide device 1 have a conical profile in at least some sections. Here, the transition section 17 is formed as a blunted section, which connects the inclined portion 16 and the axially aligned portion 15 via a constant tangent.

[0061] Fig.14 Shows the flow from the inflow side. Fig.13Axial top view of the guide device 1 and the housing 2. The guide device 1 has 11 guide elements 3. The 4 suspension struts 25 are distributed slightly irregularly on the circumference, since they are always arranged approximately between adjacent guide elements 3 in their circumferential position. Figure 1 In the embodiment shown in FIGS. 12 and 12a, the outer ring 5 of the guide device 1 is not implemented as a solid body of revolution. However, it still extends over the entire circumference and connects the individual guide elements 3 to each other at their outer ends 12. The outer ring 5 is not adapted for axial alignment, but is substantially conical in the vicinity of the guide blades 3 with specially configured demoulding sections 26, which are operable to allow or facilitate demoulding of the guide device 3 from the molding die. That is, the outer ring 5 is adapted for local axial alignment in this demoulding section 26, which is necessary for demoulding without undercuts in the axial direction.

[0062] Between the axially aligned section 26 and the conical section 27 of the outer ring 5, a transition section with a constant tangent is formed in the section between adjacent guide blades 3 on the one hand, and a step-like transition section is formed in this section of the guide blade 3 on the other hand, wherein the shape of the step corresponds approximately to the continuation of the contour of the guide blade 3. In other words, the section of the guide blade 3 close to its outer end 12 connects the axially aligned part 26 of the outer ring 5 to the conical section 27 of the outer ring 5. Here, reference has been made to Fig.13 The described special configuration of the guide element with the inclined portion 16 and the axially aligned portion 15 leads in particular to a small circumferential extension of the guide vanes 3, in particular close to the outer end 12. This minimizes the circumferential section in which the outer ring 5 must be configured in the form of a cylindrical demoulding section 26 to achieve demouldability without undercuts, which is particularly beneficial to efficiency.

[0063] Fig.14 The outer flow section 6 with a small number of guide elements and the inner flow section 7 with a large number of guide elements are clearly shown. Here, the section inside the hub ring 4 is not shown in detail, but can be similar to that according to Figure 1 –12 and 12a.

[0064] Fig.15 Shown in accordance with Fig.13 and 14Side view and sectional view on the plane of the axis of the guide device 1 and the housing 2. The at least partially conical configuration of the outer ring 5 of the guide device 1 can be clearly seen. In the embodiment shown, the outer ring 5 is configured so that when viewed in the flow direction, the radius of the profile (the distance from the axis) decreases instead. In contrast, the hub ring 4 is configured here in the shape of an axially aligned cylinder. Therefore, the cross section of the inner flow section 7 defined by the hub ring 4 toward the axis and by the outer ring 5 toward the outer flow section 6 (in the shown figure) tapers from left to right in the flow direction. Therefore, the inner flow section 7 is formed as a mixing guide (confusor). This configuration leads to additional stabilization of the vortex close to the axis from the impeller (not shown), thereby achieving an additional increase in efficiency. In addition, a particularly advantageous long-term infusion of the air from the flow sections 6 and 7 on the outflow side to the open exit is achieved, that is, the air jet remains compact over a long distance and has a high air speed over a long distance in the imaginary continuous area of ​​the axis, which is advantageous for certain fan applications.

[0065] This conical configuration of the outer ring 5 of the guide device 1 also affects the cross-sectional profile of the outer flow section 6. As a result, the flow section 6 has more diffuser characteristics. Therefore, in order to obtain an optimal cross-sectional expansion of the flow section 6, the conical hole angle of the outer diffuser wall 10 integrated in the housing 2 must be selected to be smaller than the configuration of the cylindrical outer ring 5. This reduces the outer diameter at the outlet of the housing 10 on the outflow side, thereby achieving a compact design. If necessary, with the help of this conical configuration of the inner ring 5, it is even possible to omit the formation of the diffuser 10 on the housing 2, that is, the housing 2 can be configured with a cylindrical axial alignment profile towards its outflow side end, thereby simplifying the manufacture of the housing 2.

[0066] The sectional view clearly shows the structure of the guide vane 3 with the inclined portion 16, the axially aligned portion 15 and the transition section with constant tangent 17. Since the axially aligned suspension struts 25 are irregularly distributed over the circumference in the exemplary embodiment, the sectional view shows only the upper one of the struts 25; the others are not visible. Fig.15 The receiving section 8 with the fastening arrangement 18 for the motor of the fan is shown in the hub ring 4 .

[0067] Fig.16An axial top view of a housing 2, a guide device 1 and an impeller 19 of another embodiment of a ventilator according to the invention from the outflow side is shown. In this embodiment, the guide device 1 is essentially made of sheet metal and is therefore advantageously composed of essentially planar subsections. In particular, there is no flat section with a significant curvature. The impeller 19 shown is a centrifugal impeller, in which the base plate 21, the cover plate 20 and the blades 19 are partially visible. The housing 2 is a flow duct with a quadrilateral cross section, in which the air that has left the impeller 19 or the guide device 1 is further guided in the axial direction in the direction toward the observer. In this viewing direction, the outer contour of the guide element 1 or its outer ring 5 also has a quadrilateral contour. It is rotationally symmetrical, divided into four parts, but in this case is not a solid body of rotation. This can be advantageous for constructing the guide element 1 from a planar section, which is essentially advantageous for manufacturing the guide element 1 from a sheet metal. In addition, if the housing 2 also has a quadrilateral cross section, the quadrilateral outer contour of the guide element 1 is particularly suitable in terms of fluid. This results in the outer flow-through section 6 having a substantially constant width, which is defined by the distance of the outer ring 5 of the guide device 1 from the wall of the housing 2 , forming the inner and outer boundaries of the outer flow-through section 6 , respectively.

[0068] The inner flow section 7, which is delimited radially inwardly by the hub ring 4 and radially outwardly by the outer ring 5, is interspersed with guide elements 3. In accordance with the easy manufacture from sheet metal, they are also implemented as planar sections. In the exemplary embodiment, they are implemented as axially aligned sections 15, i.e. parallel to the fan axis. In addition, the hub ring 4 has a fluidically favorable quadrilateral contour, which is parallel to the contour of the housing 2 or to the contour of the outer ring 5. A fastening section 18 for the stator side of a motor (not shown) is provided at the hub ring 4. The fastening arrangement 30 for the rotor side of the motor can be seen on the base plate 21 of the impeller 19.

[0069] The outer ring 5 is also essentially made of planar sections 5a, 5b, 5c. A circular inflow flank 23 is associated with the planar section 5c extending perpendicularly to the fan axis. This ensures a favorable inflow angle relative to the flow leaving the impeller 19 in a substantially radial direction. The outflow flank 28 is associated with the planar section 5a, which is parallel to the fan axis and therefore parallel to the air flow direction in the housing or flow duct 2 in the implemented section. Between the planar sections 5c and 5a, planar transition sections 5b are also formed, which promote low-loss deflection of the air leaving the impeller 19 in the radial to axial direction.

[0070] In this embodiment, as can be seen in this view, the outer length of the guide device 1 is about 1.15 times, advantageously 1.1-1.2 times, the outer diameter at the outer edge 24 of the base plate 21 of the impeller 19. This ratio is particularly suitable for tight installation spaces, i.e. the side length of the housing 2 seen in cross section is less than 1.6 or 1.5 times the average diameter of the trailing edge of the blades 22 of the impeller 19 relative to the fan axis.

[0071] Fig.17 The side view and the cross-sectional view on the plane passing through the axis are shown according to Fig.16 The housing 2, guide device 1 and impeller 19 of the embodiment of the present invention are shown in the sectional view. The planar sections of the outer ring 5 of the guide device 1 are clearly shown. The axially parallel section 5a, the planar transition section 5b and the inflow section 5c on the outflow side are bounded internally by the inflow side edge 23 of the outer ring 5.

[0072] In the exemplary embodiment, when viewed in the span direction of the impeller 19, for about 75% (advantageously 60%-80%) of the span as seen from the cover, the inflow side edge 23 of the outer ring 5 of the guide device 1 is closer to the base plate 21 than to the cover plate 20. This is also advantageous for the tight installation space of the impeller 19 relative to the housing 2, i.e. the side length of the housing 2 seen in the cross section is less than 1.6 times or 1.5 times the average diameter of the trailing edge of the blade 22 of the impeller 19 relative to the fan axis. In any other respects, reference is made to the description of other embodiments, for example according to Fig.12 .

[0073] Fig.17 The guide device 1 of the embodiment shown in the figure can be easily made of sheet metal because it is composed of planar sections. To this end, one or more sheet metal pieces are cut or punched, appropriately tilted, and combined when necessary, for example by welding, lugs, studs, rivets or screws.

[0074] The guide device 1 may be adapted to be load-bearing or non-load-bearing. The necessary suspension elements, which fasten the impeller 19 and the guide device 1 to the housing 2, are not shown.

[0075] Fig.18 FIG. 1 shows an axial top view of a housing 2, a guide device 1 and an impeller 19 of a further embodiment of a ventilator according to the invention, viewed from the outflow side. Fig.16 and 17 The exemplary embodiment of the invention is very similar; however, the guide element 3 is formed with an inclined section 16 which is connected to the axially aligned section 15 on the inflow side. Thus, the inflow losses of the guide device 1 can be reduced by a more suitable inflow angle of the swirling flow leaving the impeller 19. The inclined section 16 is also embodied as a planar section. In any other respects, reference is made to the description of Fig.16 and 17The explanation made.

[0076] With regard to further advantageous embodiments of the ventilator according to the invention and of the guide device according to the invention, reference is made to the common sections of the description in order to avoid repetitions.

[0077] Finally, it is important to point out that the exemplary embodiments of the ventilator according to the invention and of the guide device according to the invention described above are presented merely for the purpose of discussion and teaching, without restricting them to the exemplary embodiments.

[0078] Reference numerals list

[0079] 1 Guidance device, exit guidance device

[0080] 2 Housing

[0081] 3 Guide elements, guide vanes, outlet guide vanes

[0082] 4 Hub ring and inner ring of the guide device

[0083] 5 Outer ring of the guide device, annular flow element

[0084] 5a, b, c Flat section of the outer ring of the guide

[0085] 6 Outflow section

[0086] 7 Internal circulation section

[0087] 8 Receiving section in hub ring

[0088] 9 Inlet nozzle

[0089] 10 External Diffuser

[0090] 11 Inner end of guide element

[0091] 12 Outer end of guide element

[0092] 13 Leading edge of guide element

[0093] 14 Trailing edge of guide element

[0094] 15 Axial alignment portion of the guide element

[0095] 16 Inclined section of guide element

[0096] 17 Transition section of the guide element

[0097] 18 Fastening arrangement in receiving section

[0098] 19 Impeller

[0099] 20 Impeller cover

[0100] 21 Impeller base plate

[0101] 22 Impeller blades

[0102] 23 Inflow side edge of the outer ring of the guide device

[0103] 24 Outer edge of impeller base plate

[0104] 25 Suspension strut

[0105] 26 Axial alignment section and demoulding section of the outer ring

[0106] 27 Conical section of outer ring

[0107] 28 Outflow side edge of the outer ring of the guide device

[0108] 29 Impeller segment

[0109] 30 Fastening arrangement of motor on impeller

[0110] 31 Impeller outlet

[0111] 32 Suspension

[0112] 33 Fastening of suspension to housing

[0113] 34 Motor

[0114] 35 Motor rotor

[0115] 36 Motor stator

[0116] 37 Hub Cap

[0117] 38 Impeller hub ring

Claims

1. An axial fan having a fan impeller in a housing / flow channel and an outlet guide device downstream of the impeller, wherein: The outlet guide device comprises outlet guide vanes extending only over a portion of the housing / flow channel when viewed in the spanwise direction or radial direction, wherein the outlet guide device has a structure serving as a diffuser, and when viewed in the flow direction, the outlet guide device has a gradually expanding flow cross section, wherein two flow areas are formed downstream of the impeller: an inner flow area closer to the axis when viewed in the spanwise direction, the inner flow area being defined by the hub ring of the outlet guide device and the annular flow element / outer ring of the outlet guide device; and an outer flow area away from the axis when viewed in the spanwise direction, the outer flow area being defined by the annular flow element / the outer ring of the outlet guide device and the wall of the housing, wherein the outlet guide device forms at least a part of the suspension, wherein the suspension comprises a suspension strut, the suspension strut forming a connection between the outlet guide device and the housing, and Therein, the housing and the outlet guide device are produced together with the suspension strut in one piece, in one piece, integrally as a cast part.

2. The ventilator according to claim 1, characterized in that The outlet guide vanes extend across the entire radial, span-wise half of the casing / flow passage.

3. The ventilator according to claim 1, characterized in that The diameter of the outlet guide device is smaller than the diameter of the fan wheel.

4. The ventilator according to claim 1, characterized in that The outlet guide vanes are connected in circumferential direction to the annular flow element / the outer ring, which extends around the circumference.

5. The ventilator according to claim 1, characterized in that The outlet guide vanes are connected at the outer ends in the circumferential direction to the annular flow element / the outer ring, which extends around the circumference.

6. The ventilator according to claim 4, characterized in that The annular flow element / the outer ring is configured and arranged as a body of rotation or is configured and arranged rotationally symmetrically with respect to the fan axis.

7. The ventilator according to claim 4, characterized in that The annular flow element / the outer ring is designed as an element which tapers conically from the inlet side to the outlet side, so that the region in the vicinity of the outlet guide vanes is suitable for demoulding from the casting mold without undercuts when viewed in the axial direction.

8. The ventilator according to claim 6, characterized in that The annular flow element / the outer ring is designed as an element which tapers conically from the inlet side to the outlet side, so that the region in the vicinity of the outlet guide vanes is suitable for demoulding from the casting mold without undercuts when viewed in the axial direction.

9. The ventilator according to any one of claims 4 to 8, characterized in that: The contour of the annular flow element / the outer ring is increasingly curved from its outflow-side end to its inlet-side end, so that it has no or only a small angle of incidence with respect to the flow emerging from the impeller and deflects the flow.

10. The ventilator according to any one of claims 4 to 8, characterized in that The contour of the annular flow element / the outer ring is increasingly curved from its outflow-side end to its inlet-side end, so that it has no or only a small angle of incidence with respect to the radial flow emerging from the impeller and deflects the radial flow.

11. The ventilator according to claim 1, characterized in that The outlet guide vanes have a curved profile in their radial extension.

12. The ventilator according to claim 11, characterized in that The curved profile is a sickle-shaped profile.

13. The ventilator according to claim 11, characterized in that The outlet guide vanes have, at least in a radially outer region, an inclination angle greater than 30° relative to the radial direction.

14. The ventilator according to claim 11, characterized in that The outlet guide vanes have, at least in a radially outer region, an inclination angle greater than 45° relative to the radial direction.

15. The ventilator according to claim 11 or 13, characterized in that: The outlet guide vane has an inlet side region and an outlet side region, wherein the inlet side region can have an airfoil profile cross section, the airfoil profile cross section having an inlet angle in the range of 20° to 50° relative to the fan axis at the leading edge of the profile centerline, and / or wherein the outlet side region can be parallel to the fan axis, and / or wherein the transition between the inlet side region and the outlet side region can be configured to be tangentially constant or tangentially non-constant like a curved portion.

16. The ventilator according to claim 1, characterized in that The outlet guide device has means for its own suspension on its outer contour.

17. The ventilator according to claim 1, characterized in that A flange for attaching a motor is provided on the inlet side at the inner contour of the outlet guide device, wherein the motor is suspended on the housing / flow channel by the outlet guide device.

18. The ventilator according to claim 16, characterized in that A flange for attaching a motor is provided on the inlet side at the inner contour of the outlet guide device, wherein the motor is suspended on the housing / flow channel by the outlet guide device.

19. The ventilator according to claim 17 or 18, characterized in that The motor together with the associated fan wheel is suspended on the housing / flow channel via the outlet guide device.

20. The ventilator according to claim 1, 16, 17 or 18, characterized in that The suspension struts extend between the annular flow element / the outer ring and the housing / the wall of the flow channel and are arranged upright when viewed in the axial direction and / or can be bent and / or tilted.

21. The ventilator according to claim 20, characterized in that The suspension strut is made of a flat material.

22. The ventilator according to claim 1, 16, 17 or 18, characterized in that For attachment to the outlet guide device, one or more outlet guide vanes are extended towards the outside as far as the wall of the air guide channel or the outer casing, thereby producing an integral attachment arrangement.

23. The ventilator according to claim 1, characterized in that The outlet guide device is made of sheet metal and consists of planar areas.

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