Duct fan

Abstract

A duct fan (1) with a housing (80) in which a motor (10) and an impeller (11) are accommodated, wherein a tubular intake nozzle (52) for the fastening arrangement of a duct arrangement is arranged or formed adjacent to the housing (80) as seen in the axial flow direction, wherein a groove-like depression (90) is provided at a transition between the housing (80) and the tubular intake nozzle (52), which is designed to receive an end section of the duct arrangement.

Description

The invention relates to a pipe fan with an optimized pipe connection possibility.Duct fans are used to generate air flow through the duct within a duct assembly of predetermined duct diameter. A distinction is made here between so-called in-line pipe fans, in which the maximum housing diameter of the pipe fan corresponds to that of the pipe diameter of the pipe arrangement. For this application, axial fans and diagonal fans are used in particular. Its advantage lies in the compact construction with good flow guidance. However, they do not achieve the pressure and efficiency of a radial fan. Therefore, axial fans and diagonal fans are used for high volume flows at low pressures.When using an axially aspirating and radially inflating radial fan to achieve higher pressures, the housing diameter of the housing accommodating the radial fan is always significantly larger than the tube diameter of the tube arrangement. An in-line variant is therefore not possible in radial fans. It is known in the prior art to construct the housing of the tubular fans in multiple parts and to integrate the motor holder for the motor of the radial fan into the housing part on the blowing-out side. The radial impeller of the radial fan conveys a volume flow which is blown unaffected into the blower-side housing part and subsequently into the adjacent pipe arrangement. This results in recirculation zones and separation of the flow in the housing part on the exhaust side, which have a negative effect both on the efficiency and on the noise formation.Furthermore, the fastening connection of the pipe fan to the pipe arrangement is always a critical point. In the prior art, a connecting section for fastening a pipe or a pipe arrangement is provided on the housing of the pipe fan, from which connecting section the pipe fan / s draws. The tube is pushed with its free end section onto the suction section of the tube fan and is fastened in a sealed manner. The tube or tube arrangement then lies on its outer wall usually at right angles to the housing. The sealing is complex in this case. In addition, there are outwardly free edges on the pipe or the pipe arrangement, which entail a risk of injury.From the prior art and for example from the document US 2018 / 0242799 A1, pipe fans without a depression according to the invention at the transition between the housing and an intake connection are already known.The object of the invention is therefore to provide a ducted fan which offers improved integration of the duct arrangement to be connected. With a further development of the pipe fan, its flow guidance is also to be improved in such a way that its efficiency is increased and at the same time the noise formation is reduced.This object is achieved by the combination of features according to claim 1.According to the invention, a ducted fan having a housing in which a motor and an impeller are accommodated is proposed. A tubular intake connection is arranged or formed adjacent to the housing as viewed in the axial flow direction for the fastening arrangement of a pipe arrangement. In addition, at a transition between the housing and the tubular intake connector, a groove-like or groove-shaped depression is provided, which is designed to receive an end section of the pipe arrangement.The specially created transition between the housing and the tubular intake connection as a groove-like depression makes it possible that the end section of the pipe arrangement, which is usually designed as an intake pipe or hose pipe, is not exposed in the assembled state and therefore does not have any free edges. According to the invention, the pipe end is inserted into the groove-like depression and can be glued therein, for example. It is advantageous here that an adhesive and / or a sealant can be introduced into the groove-like depression in a targeted manner without it being distributed over the lateral surface of the housing.An advantageous embodiment of the pipe fan additionally provides that the housing extends rounded and without edges into the groove-like depression. Thus, the end portion of the pipe arrangement can be slid onto the suction connection without the risk that the free edge of the end portion tilts at the groove-like depression.Furthermore, an embodiment variant of the pipe fan is characterized in that the groove-like depression has a cross section which narrows as seen in the axial direction. This allows the free end section of the pipe arrangement to be pre-fixed and centered in the depression in a positive-locking manner.A further development of the pipe fan provides, moreover, that at the groove-like depression the pipe suction connection has an axial extension which extends into the housing. The axial extension ensures on the one hand an increased stability exactly at the position of the groove-like depression, on the other hand it can serve as an inlet nozzle of the suction connection piece, which extends, for example, into a suction opening of a radial impeller.The groove-like depression preferably has an axial depression depth which is several times smaller than an axial length of the tubular intake connector. The pipe arrangement is first pushed over a certain axial length of the tubular intake connection and only engages in the groove-like depression in the last, comparatively short axial end section.The tubular fan presented also has fluidic advantages. It is preferably designed as a radial fan. The housing has a suction-side suction cup, which defines a suction section with the suction port and accommodates the radial impeller, and a blowing-side blowing cup, which defines a blowing section. A cup-shaped motor holder for the fixed accommodation of the motor is arranged in the blow-out cup. Between the motor holder and the blow-out shell, a continuous flow channel to the blow-out section is formed, through which a flow generated by the radial impeller during operation is guided.The casing of the duct fan is attached to the adjacent duct assembly, as in the prior art, through which the flow is to pass. The suction shell and the exhaust shell determine the diameter which is enlarged compared to the pipe arrangement. The respective shell shape of the suction shell and blow-out shell provides the expansion to an enlarged diameter as seen in the direction of flow and the subsequent narrowing with the reduction of the diameter to that of the pipe arrangement. Due to the motor holder in the blow-out shell, which is also at least partially shell-shaped, the flow channel is generated for the flow generated by the radial fan and thus a defined flow guidance from the radial impeller towards the blow-out section, which minimizes recirculation zones and flow separations. This has a positive effect on the efficiency and reduces the noise formation.An advantageous further development of the pipe fan additionally provides that a plurality of follow-up struts arranged distributed in the circumferential direction are arranged in the flow channel. The follow-up struts are preferably designed as radial struts with guide surfaces for the flow extending through the flow channel.In this case, an embodiment of the pipe fan is advantageous in which the follow-up struts extend from an outer lateral surface of the motor holder to an inner wall surface of the blow-out shell and divide the flow duct into a plurality of individual ducts in the circumferential direction. Due to the radial extension of the follow-up struts from wall to wall, the individual channels are closed and are preferably joined together again only in the blow-out section.A preferred embodiment variant is characterized in that the follow-up struts are formed integrally on the motor holder. This reduces the number of parts and the assembly effort of the motor mounting on the outer shell.In the prior art, the motor holder could frequently be formed integrally with the blow-out shell. In the present ducted fan, however, the motor holder is designed as a separate part. Nevertheless, for an advantageous and simple installation possibility, it is provided that receiving grooves for the fastened insertion of fastening webs formed on the motor holder are provided on the blow-out shell. The motor holder can thus be fixed in position in the blow-out shell, but is at the same time detachably fastened. The receiving grooves are preferably formed in a tubular end portion of the blow-out shell which defines the blow-out portion. In this region, the receiving grooves practically do not influence the flow.An embodiment variant of the pipe fan is particularly advantageous in which the fastening webs on the motor holder are formed by the follow-up struts. The follow-up struts thus assume the function of both guiding the flow through the flow duct and of fastening the motor holder to the blow-out shell.The flow channel between the blow-out shell and the motor holder is ensured by their two shell-shaped wall sections. The engine mount comprises a shell with a cross section tapering in the flow direction, wherein the tapering corresponds substantially to that of the outer shell, so that the flow channel has substantially a constant flow width. The follow-up struts preferably extend in the axial flow direction beyond the shell of the engine mount forming the flow channel, in particular into the exhaust section, and thus guide the flow into the adjacent pipe arrangement.On the axial side facing the radial impeller, the shell of the motor holder forming the flow channel has, in an advantageous embodiment, an axial projection running circumferentially. The axial protrusion defines an inlet section of the flow channel and protrudes axially in the direction of the radial impeller with respect to the follow-up struts. In other words, the follow-up struts begin to extend in the flow channel axially spaced apart from an axial outer edge of the shell of the motor holder.A fluidically favorable embodiment of the pipe fan additionally provides that the follow-up guide struts extend in sections curved in the circumferential direction. A curved curve is particularly preferred. The curved path is provided in particular in the region of the engine mount in which the shell is located. In the adjoining section, the follow-up struts end running in the axial flow direction, i.e. parallel to the axis of rotation of the radial fan.The noise reduction of the pipe fan is positively enhanced by a development in which a wall section of the shell of the motor mount forming the flow duct is formed perforated with through holes. Noise-insulating insulating material can then be introduced into the shell. In a favorable embodiment, the shell of the motor holder has an axle-central motor base for holding the motor and defines an accommodation space between an inner wall surface of the perforated wall section and the motor base. This receiving space can be used in the same way for arranging sound-insulating insulating material.A development for noise reduction of the tubular fan, in particular in the region of the outer shell, is likewise provided. For this purpose, the blow-out shell has, in the region of the flow duct, in each case, viewed in the circumferential direction, a radial widening between the follow-up struts, which widening is designed to accommodate noise-insulating insulation material. In an axial plan view, the widenings of the blow-out shell distributed in the circumferential direction result in a type of flower shape. The radial expansions follow the extension between two of the follow-up struts in each case and are thus preferably also curved or twisted in an arc shape in the circumferential direction. Preferably, the noise-insulating insulation material is injected directly into the radial widenings on the blow-out shell. As insulating material, for example, insulating foam can be used.For an advantageous inflow of the air flow generated by the radial impeller into the flow channel, the tubular fan is characterized in that a suction-side maximum outer diameter of the shell of the motor holder is greater than an outer diameter of the radial impeller.In an advantageous further development, the pipe fan also provides that the suction shell and the exhaust shell can be fixed to one another by a fastening device, placed on one another, and thereby fix a position of the motor holder in the exhaust shell. Clamps or a bayonet lock can serve as the fastening device, for example. The motor holder is positioned in particular between the suction shell and the exhaust shell and is also fixed when they are fixed.Other advantageous developments of the invention are characterized in the dependent claims or are illustrated in more detail below together with the description of the preferred embodiment of the invention on the basis of the figure. It shows: FIG. 1 shows a sectional view of an embodiment variant of the tubular fan according to the invention; FIG. 2 shows an enlarged detail view from FIG. 1.FIG. 1 shows a pipe fan 1 designed as a radial fan in a cut-away view. FIG. 2 shows the upper detail from FIG. 1 in enlarged form. The pipe fan 1 comprises the housing 80 formed from the two housing parts of a suction-side suction shell 2 and a discharge-side discharge shell 3. the suction shell 2 comprises the tubular suction connection piece 52 formed in one piece, the discharge shell 3 comprises the tubular discharge section 53, via which the pipe fan 1 is attached to an external pipe arrangement on the suction side and on the discharge side.On the intake shell 2 of the housing 80, the tubular intake connection 52 is formed for the fastening arrangement of the pipe arrangement, as viewed in the axial flow direction SR. However, variants are also included in which the intake connection piece 52 is fastened as a separate component to the intake shell 2. In the transition between the intake shell 2 of the housing 80 and the tubular intake connector 52, the circumferentially encircling groove-like depression 90 is provided, in which the end section of the pipe arrangement (not shown) to be pushed onto the intake connector 52 is received. The groove width is adapted to the geometry of the end section of the pipe arrangement. The depth of depression relative to an axial end plane EE of the intake shell 2 perpendicular to the flow direction SR is significantly reduced relative to the axial length of the intake connection piece 52, so that only the end section of the pipe arrangement is inserted into the depression 90. At the same time, the depression depth is large enough that free pipe edges of the pipe arrangement can be introduced completely into the depression 90, so that they cannot be seen further or touched on the outside. Otherwise, the pipe arrangement in the assembled state bears coaxially against the intake connection 52. A sealing compound and / or adhesive can be introduced into the depression 90 in order to produce the connection between the pipe fan 1 and the pipe arrangement to be connected thereto as free of losses as possible. Alternatively, it is also possible to use a sleeve or an adhesive tape for fastening and sealing. A sleeve for connecting the duct fan 1 and the duct assembly as frequently used in the prior art is not necessary due to the provision of the depression 90.It can be clearly seen in FIG. 2 how the circumferential surface 91 of the suction shell 2 of the housing 80 extends rounded and without edges into the groove-like depression 90. The cross section of the depression 90 narrows in its extension in the axial flow direction SR as far as the lowest point. The deepest portion in the groove-like depression 90 preferably has a constant cross section corresponding to the shape of the end portion of the pipe arrangement, so that a form-fitting connection is formed in the depression 90. Starting from the lowest point of the groove-like depression 90, the axial extension 19 is formed on its rear side, which extends as far as the interior of the suction cup 2 and into the interior of the radial impeller 11.Referring again to Fig. 1, in the suction shell 2 is disposed the centrifugal fan with its motor 10 and its centrifugal impeller 11 driven by the motor 10. The radial impeller 11 comprises a cover disk, a bottom disk and impeller blades running therebetween. In operation, the radial impeller 11 draws a flow S axially through the suction portion 52 and blows it out radially toward the inner wall surface of the suction cup 2.The motor 10 is mounted on the center-axis motor base 22 of the cup-shaped motor bracket 5, which is in turn accommodated and fixed in the blow-out cup 3. The shell-shaped motor mount 5 comprises the shell 6, on which the axle-central motor base 22 is formed in one piece, and the follow-up struts 4, which are preferably also formed in one piece on the outside of the shell 6 in the circumferential direction. The continuous flow channel 20 to the blowing-out section 53 is formed between the shell 6 of the motor mount 5 and the blowing-out shell 3, through which flow S generated by the radial impeller 11 during operation is guided. The flow channel 20 is divided by the follow-up struts 4 into a plurality of individual channels, since the follow-up struts 4 extend continuously from the outer circumferential surface of the shell 6 of the engine mount 5 as far as the inner wall surface of the blow-out shell 3. In the downstream region of the shell 6, the individual channels are then joined together again to form a flow channel. The follow-up struts 4 extend in the axial flow direction beyond the shell 6 of the motor holder 5 forming the flow channel 20 as far as into the tubular blow-out section 53. The axial projection 12 extends parallel to the axis of rotation of the radial fan 11 The inflow into the flow duct 20 is therefore initially determined only by the shell 6 and the blow-out shell 3. Only within the region of the flow channel 20 in which the shell 6 begins to reduce its cross section is the flow guided via the follow-up struts 4.The follow-up struts 4 are for this purpose curved in sections in the circumferential direction. The preferably arcuate curvature 63 is particularly advantageous, but other continuous curvatures including an S-shaped course can also be provided as required. The direction of curvature is preferably coordinated with the direction of rotation of the radial fan 11. The flow S is guided by the follow-up struts 4 through the flow channel 20 along the shell 6 of the engine mount 5 and the exhaust shell 3.In the blow-out section 53, a plurality of receiving grooves 9 are formed for the fastening reception of the follow-up guide struts 4. The follow-up struts 4 are inserted into the receiving grooves 9 for mounting the motor mount 5 in the blow-out shell 3 and thus fix the motor mount 5 in the blow-out shell 3. The suction shell 2 and the exhaust shell 3 are placed on top of each other and fixed to each other by clamps 51. The motor holder 5 is positioned with a part of the follow-up struts 4 between the housing parts of the suction shell 2 and the exhaust shell 3, fixed and fixed in position by fastening them. In particular, it is ensured that the follow-up struts 4 are completely inserted into the receiving grooves 9 when the clamps 51 are fixed.A wall portion of the shell 6 of the motor mount 5 has a plurality of through holes 8 forming a perforation. The size of the through holes 8 decreases as viewed in the direction of flow. Sound-insulating insulation material (not shown) is introduced into the receiving space 15 between the shell 6 of the motor holder 5 and the motor base 22, in order to minimize the sound formation of the flow along the shell 6. The perforation through the through-holes 8 increases the effect of the sound-insulating insulation material. In addition, radial widenings 7 are formed on the blow-out shell 3 in the regions between the follow-up struts 4, which widenings have a course in the circumferential direction and in the axial direction which corresponds to that of the follow-up struts 4. Noise-insulating insulating material (at reference numeral 77, but not shown) is likewise introduced into the widenings 7, preferably injected by injection molding. Thus, noise reduction is also achieved at the blow-out shell 3.

Claims

A pipe fan (1) having a housing (80) in which a motor (10) and an impeller (11) are accommodated, wherein a tubular intake connection (52) for the fastening arrangement of a pipe arrangement is arranged or formed adjacent to the housing (80) as viewed in the axial flow direction, wherein a groove-like depression (90) is provided at a transition between the housing (80) and the tubular intake connection (52), which depression is formed to accommodate an end section of the pipe arrangement.The pipe fan (1) according to claim 1, characterized in that the housing (80) extends in a rounded and edge-free manner into the groove-like depression (90).The pipe fan (1) according to claim 1 or 2, characterized in that the groove-like depression (90) has a cross section which narrows as seen in the axial direction.The pipe fan (1) according to any one of the preceding claims, characterized in that at the groove-like depression (90) the pipe-like suction connection (52) has an axial extension (19), which extends into the housing (80).The pipe fan (1) according to any one of the preceding claims, characterized in that the groove-like depression (90) has an axial depression depth which is several times smaller than an axial length of the tubular intake connection piece (52).Pipe fan (1) according to one of the preceding claims, in particular designed as a radial fan, with and with the impeller (11) designed as a radial impeller, comprising the housing (80) formed from a suction-side suction shell (2) which determines the suction connection piece (52) and accommodates the radial impeller (11), and a blowing-side blowing shell (3) which determines a blowing section (53), wherein a shell-shaped motor holder (5) for the fixed accommodation of the motor (10) is arranged in the blowing shell (3), and wherein a continuous flow duct (20) is formed between the motor holder (5) and the blowing shell (3) to the blowing section (53), through which flow (S) generated by the radial impeller (11) during operation is guided.The pipe fan (1) according to claim 6, characterized in that a plurality of follow-up struts (4) arranged distributed in the circumferential direction are arranged in the flow channel (20), wherein the follow-up struts (4) extend from an outer circumferential surface of the motor holder (5) to an inner wall surface of the blow-out shell (3) and divide the flow channel (20) into a plurality of individual channels in the circumferential direction.The pipe fan (1) according to claim 7, characterized in that the follow-up struts (4) are formed integrally on the motor holder (5).Pipe fan (1) according to one of the preceding claims 6 to 8, characterized in that receiving grooves (9) for the fastened insertion of fastening webs formed on the motor holder (5) are provided on the blow-out shell (3).Pipe fan (1) according to Claim 9, characterized in that the fastening webs are formed by the follow-up struts (4).The pipe fan (1) according to any one of the preceding claims 6 to 10, characterized in that a wall section of a shell (6) of the motor holder (5) forming the flow channel (20) is formed perforated with through holes (8).The pipe fan (1) according to the preceding claim, characterized in that the shell (6) of the motor holder (5) has an axle-central motor base (22) for holding the motor (10) and defines between an inner wall surface of the perforated wall section of the shell (6) and the motor base (22) a receiving space (15) for arranging sound-insulating insulation material.Pipe fan (1) according to one of the preceding claims 7 to 12, characterized in that the blow-out shell (3) has in the region of the flow duct (20), in each case as viewed in the circumferential direction, between the outlet guide struts (4) a radial widening (7) in each case, which is designed to receive sound-insulating insulation material.Pipe fan (1) according to one of the preceding claims 6 to 13 characterised in that the suction shell (2) and the exhaust shell (3) can be fixed to one another in a manner mounted on one another by a fastening device and thereby fix a position of the motor holder (5) in the exhaust shell (3).

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