EP1442223B1 - Fan attachment with dynamic out-of-balance equalization - Google Patents

Abstract

The invention is based on an axial fan with a hub region ( 4, 27 ) for connecting the axial fan with a driven shaft ( 20 ) of an electrical drive ( 21 ), whereby the axial fan is statically balanced by means of a balancing weight ( 26 ). A flexurally soft connection is formed in the hub region ( 4, 27 ) between the axial fan ( 1 ) and the driven shaft ( 20 ) of an electrical drive ( 21 ).

Description

Technical area

The application relates to an axial fan as in the preamble of claim 1. Such an axial fan is eg from the DE-A-4143383 known.

With a view to the environment, great efforts are made to eliminate noise sources on motor vehicles as much as possible. In addition to the sound sources, such as tires and internal combustion engines, there are other sound sources in components of the internal combustion engine, such as in engine cooling fans. In general, such sound sources distinguish between airborne sound vibrations and the occurrence of structure-borne noise. The occurrence of structure-borne noise can be manifested, for example, in mass-excited vertical vibrations on the steering wheel of a motor vehicle.

State of the art

In today's conventional engine cooling fans is usually a balance of static imbalance in order to comply with the allowable limits can. A compensation of the dynamic imbalance (moment unbalance) is not possible or only with great effort in the often very flat design fans, since even the measurement weighs the small flat distance causes problems and not secure to compensate for the moment unbalance balancing masses on the unstable fan blades would. As a result, it is accepted that engine cooling fans are delivered with undefined dynamic imbalance. Depending on the respective installation situation in the vehicle, the structure-borne noise generated by the dynamic imbalance can lead to complaints as a result of perceptible vibrations in the passenger compartment. The remaining possibilities of intervention, such as the attachment of damping elements in the transmission path, or the post-processing of plastic fans to reduce their Eingangsunwuchten, on the one hand consuming and on the other hand, no satisfactory reduction of vibration to cause.

The mass forces - static and dynamic unbalances - are caused by inhomogeneous mass distributions of the rotating assemblies rotor / armature and fan as well as by form and position tolerances to the axis of rotation of the drive. Form and position tolerances cause rotational and Hauptenträgheitsachse no longer coincide. A parallel shift between the axis of rotation and the main axis of inertia, for example, a cooling fan with recorded on the armature or rotor shaft.

Fan, leads to a static imbalance, while a tilted axis of rotation to the main axis of inertia can produce a centrifugal moment, which equals in its effects of a momentum imbalance or dynamic imbalance.

Flexible connections between axial fan and drive shafts are from each of the Druchschriften GB-A-1376710 or US-A-2702087 or US-A-4917573 or DE-A-10058935 or DE-A-19958261 known.

Advantages of the invention

The advantages of the solution proposed according to the invention are, above all, to be seen in the fact that by means of a soft connection of the axial fan to the armature or rotor of an electric drive, the axial fan aligns with increasing speed in the direction of the axis of rotation. Thus, the disturbance, d. H. the unbalance torque is automatically reduced by the rotation of the axial fan with increasing speed. The influence of shape tolerances of the Axiallüfterrades occurs with respect to the dynamic centrifugal torque considerably, since a self-alignment of the Axiallüfterrades takes place with respect to the axis of rotation. Form and position tolerances of the Axiallüftemades are thereby mitkompensiert automatically with respect to the dynamic imbalance.

Since the dynamic imbalance of an axial fan is clearly dominated by the dynamic imbalance of the axial fan, a two-level imbalance compensation at the armature or rotor of the electric drive can be dispensed with. This in turn holds a considerable potential for savings, since the processing steps belonging to the two-level imbalance compensation can now be completely eliminated. Possibly can be completely dispensed with the anchor balancing by limiting the unbalance compensation to a purely static balancing an axial fan on Axiallüfterrad.

Due to the soft configuration of the hub of Axiallüfterrades, or the junction of Axiallüfterrades with the armature or the rotor shaft, can be dispensed with the installation of scarce space consuming additional damping systems. The modifications of the hub of the Axiallüfterrades in terms of greater bending softness can also be done in the context of retrofitting already delivered engine cooling fan in a simple way and very inexpensive.

drawing

With reference to the drawings, the invention will be explained in more detail below.

Figur 1

ein Axiallüfterrad, dessen Hauptträgheitsachse zur Rotationsachse verkippt ist,

Figur 2

die Schiefstellung des Axiallüfterrades an einem Ersatzmodell des Axiallüfterrades,

Figur 3

die Schiefstellung δ des Axiallüfters bei Drehzahl ω = 0,

Figur 4

die am Ersatzmodell des Axiallüfters angreifenden Kräfte und Momente und

Figur 5

die Seitenansicht eines Axiallüfters mit elektrischem Antrieb und

Figur 6

die Draufsicht auf die Nabe des Axiallüfterrades gemäß der Darstellung in Fig. 5,

Figur 7

eine weitere erfindungsgemäße Ausführungsvariante einer biegeweichen Aufnahme eines Axiallüfterrades an einem Antrieb,

Figur 8

eine dritte Ausführungsvariante einer biegeweichen Ankopplung eines Axiallüfterrades an einem Antrieb,

Figur 9

eine vierte Ausführungsvariante einer biegeweichen Ankopplung eines Axiallüfterrades am Antrieb mit Auslenkungsbereich und

Figur 9.1

die Ankopplungsstelle von Axiallüfterrad und Antrieb gemäß der Darstellung in Fig. 9 als in vergrößertem Maßstab wiedergegebene Einzelheit.

It shows:

FIG. 1

an axial fan whose main axis of inertia is tilted to the axis of rotation,

FIG. 2

the misalignment of the axial fan on a replacement model of the axial fan,

FIG. 3

the misalignment δ of the axial fan at rotational speed ω = 0,

FIG. 4

the forces and moments acting on the replacement model of the axial fan and

FIG. 5

the side view of an axial fan with electric drive and

FIG. 6

the top view of the hub of the Axiallüfterrades as shown in FIG Fig. 5 .

FIG. 7

a further variant of the invention a flexurally soft receiving a Axiallüfterrades on a drive,

FIG. 8

a third embodiment of a flexible coupling of a Axiallüfterrades on a drive,

FIG. 9

a fourth embodiment of a flexible coupling of a Axiallüfterrades on the drive with deflection and

Figure 9.1

the coupling point of Axiallüfterrad and drive as shown in FIG Fig. 9 as a detail reproduced on an enlarged scale.

design variants

Fig. 1 shows an axial fan whose main axis of inertia is tilted to the axis of rotation.

An axial fan wheel 1 comprises fan blades 2 and 3, which are arranged essentially on its outer circumferential region and are fastened on the circumference of a hub region 4. Preferably, an axial fan 1 as shown in FIG Fig. 1 manufactured as Kunststoffspritzgießbauteil. Such Axiallüfterrad is on an anchor or rotor shaft of an in Fig. 1 Not shown electric drive stored and the electrical Drive rotated. The Axiallüfterrad 1 has a Hauptenträgheitsachse, which in the illustration according to Fig. 1 with x - x is designated. Perpendicular to this extends another axis of inertia, which is denoted by y - y.

Moved to the mentioned axes of inertia x -x and y-y is a Rotationsachsenkoordinatensystem 8, which is characterized by the axis of rotation ξ-ξ and perpendicular to the axis η- η). Compared to the coordinate system spanned by the inertial axes, the rotation coordinate system 8 is slightly tilted. The axis of rotation ξ-ξ is rotatably mounted in bearings, of which a bearing is designed as a fixed bearing 5, which receives both axial and radial forces, while the other bearing 6 is designed as a floating bearing, which is only able to absorb radial forces and axial displacement of the Rotation axis ξ-ξ of Axiallüfterrades 1 permits.

Reference numeral 7 designates the center of gravity in which the axes of inertia x - x and y - y of the axial fan wheel 1 intersect. ω denotes the angular velocity with which the axial fan wheel, which is driven via the electric drive not shown here, rotates about the axis of rotation ξ-ξ.

Fig. 2 shows the misalignment of a Axiallüfterrades using a replacement model of Axiallüfterrades.

According to the in Fig. 2 model representation is the axial fan 1 is idealized as a rigid disk, while its connection region to the rotation axis ξ - ξ is modeled as an axially acting spring arrangement 9 and 10 respectively.

As shown in Fig. 2 is the unbalance _moment J _ξη · ω ² directed so that the Lüfterhauptträgheitsachse x - x with the rotation axis ξ- ξ is brought to coincide, so that the torque supplied by the electric drive, not shown here by forming the connection of the modeled as a rigid disk fan can be exploited at the hub region to reduce the given by the centrifugal Jξη · ω ² dynamic imbalance. In the modeled representation according to Fig. 2 the axis of rotation ξ-ξ is mounted in a fixed bearing 5 and in a floating bearing 6.

At the fixed bearing 5, the axial force F _Ax (11) and the radial direction engage the radial force F _Ay (12) in the axial direction. In contrast, the floating bearing 6 takes only forces in the radial direction characterized by F _By (13). The angle between the main axis of inertia x - x of the axial fan wheel 1 and its axis of rotation ξ - ξ is designated by δ.

The representation according to Fig. 3 is the inclination δ of the Axiallüfterrades at the speed ω = 0 refer to.

In an axial fan, centrifugal moments generate considerable forces and moments depending on the speed. At a maximum centrifugal moment of, for example, 45,000 gmm ² , the axial fan impeller ¹ has an unbalance torque of at 2,500 rpm $$\mathrm{M}={\mathrm{J}}_{\mathrm{\xi \eta }}\cdot {\mathrm{<figure-callout\; id="2"\; label="\omega "\; filenames="imgf0001.png,imgf0005.png"\; state="\{\{state\}\}">\omega </figure-callout>}}^2=45000{\mathrm{<figure-callout\; id="2"\; label="gmm"\; filenames="imgf0001.png,imgf0005.png"\; state="\{\{state\}\}">gmm</figure-callout>}}^2\cdot {\left(\frac{2500\cdot 2\pi }{60}\right)}^2{s}^{-2}=3.08\mathit{nm}$$

As shown in Fig. 3 engages the moment in the direction of the arrow on a perpendicular to the plane extending axis of the modeled as a rigid disk Axiallüfterrades. By this moment, the Axiallüfterrad 1 by the angle α in the position designated by δ - α, also designated by reference numeral 1 ', moved. As a result, the main axis of inertia x -x of the axial fan wheel 1 approaches the position of the axis of rotation ξ-ξ by which the axial fan 1 rotates at the angular speed ω. From the calculation derived above, it becomes clear that the resetting of the principal axis of inertia x - x with respect to the position of the axis of rotation ξ - ξ increases with increasing rotational speed, since this takes place quadratically in the torque calculation. This means that with increasing speed the angle α increases and consequently the skewed position δ at ω = 0 is reduced with increasing speed until, ideally, the angle δ-α assumes the value 0. In this case, the main axis of inertia x - x of the axial fan wheel 1 coincides with its axis of rotation ξ - ξ.

On the hub portion 4 of the modeled as a rigid disk axial fan wheel 1, the forces 15 designated by F _c attack which ξ- with respect to the rotation axis ξ of the axial fan 1 about the lever arm a, marked with reference numeral 14, attack and by the centrifugal J _ξη · ω ² counteract given moment. As the speed increases, the axial fan 1 is pressed in the direction of the axis of rotation ξ- _infolge due to the centrifugal _torque J _ξη · ω ² . It follows that as flexible bending design of the hub region, ie flexurally soft connection of the hub portion 4.27 of the Axiallüfterrades 1 with its axis of rotation ξ- ξ the self-adjusting and returning with the speed unbalance moment to return the main axis of inertia x - x of the Axiallüfterrades 1 in its axis of rotation ξ - ξ can be used for tilting at ω = 0.

Fig. 4 shows the forces and moments acting on the replacement model of the axial fan.

With δ minus α, the misalignment of the axial fan wheel 1, which is modeled as a rigid disk 1, is established at a given rotational speed ω 0. For resetting, ie for combining the main axis of inertia x - x with the axis of rotation ξ - ξ, the centrifugal _moment J _ξη · ω ^{2 is} utilized with increasing speed as a result of the soft connection of the hub region 5 to the axis of rotation ξ - ξ. To a provision of the in accordance with Fig. 4 Axially fan wheel 1, modeled as a rigid disk, into an angular position in which the angular difference δ - α assumes the value 0, the most flexible, self-aligning of the axial fan wheel 1 enabling connection of the hub region 4 to the axis of rotation ξ - ξ is desirable.

The torque relationship for the axial fan 1 that is established with respect to the axial fan 1 is as follows: $$\mathrm{.sigma..sub.m}\mathrm{=}\mathrm{0}\mathrm{.}\mathrm{d}\mathrm{,}\mathrm{H}\mathrm{,}{\mathrm{J}}_{\mathrm{\xi \eta }}\mathrm{\cdot }{\mathrm{<figure-callout\; id="2"\; label="\omega "\; filenames="imgf0001.png,imgf0005.png"\; state="\{\{state\}\}">\omega </figure-callout>}}^{\mathrm{2}}\mathrm{=}{\mathrm{F}}_{\mathrm{c}}\mathrm{\cdot }\mathrm{a}\mathrm{,}$$

If this relationship is satisfied, the axial fan 1 aligns during its rotation about the axis of rotation ξ - ξ so that the axis of rotation ξ - ξ and the main axis of inertia x - x of the axial fan 1 coincide. The axial or radial forces acting on the bearings 5 and 6 of the axis of rotation ξ - einstell by means of axial fan wheels 1 are shown in the illustration Fig. 4 denoted by reference numerals 11, 12 and 13.

The representation according to Fig. 5 shows the side view of an axial fan with electric drive.

According to the side view in Fig. 5 The axial fan 1 in its outer peripheral region comprises a number of fan blades 2 and 3, respectively, which are integrally formed on the circumference of a hub region 4. In the center of the hub region 4, the axial fan 1 is connected to an output shaft 20 of an electric drive 21. The electric drive 21 is accommodated in a housing 22, which protrudes partially into the cup-shaped hub region 4 of the axial fan wheel 1, to the axial length of the fan assembly as shown in FIG Fig. 5 To shorten. On the output shaft 20 of the electric drive 21, a disc 23 is accommodated from bendable, elastic material, which is connected to a plate-shaped or cup-shaped inverted inwardly portion 27 of the hub portion 4 of the Axiallüfterrades 1. To connect the recorded on the output shaft 20 of the electric drive 21 elastic disc 23 with the cup-shaped hub plate 27 of the hub portion 4 serve mounting screws 24. The mounting screws 24 are to increase the bending softness of the connection between the elastic disc 23 and hub plate 27 in the hub region 4 of the Axiallüfterrades 1 equipped with spring elements 30. The spring elements 30 may be provided on the fastening screws 24 either in the region of the cup-shaped recessed hub plate 27 or between the fastening screws 24 and the elastic disc 23.

Reference numeral 25 denotes holders with which the housing 22 of the electric drive 21 can be attached to a radiator assembly in the engine compartment of a motor vehicle.

Denoted at 26 is a balancing weight which is used for static balancing of the axial fan impeller 1 on a fan blade 3 on the circumference of the hub region 4 of the axial fan wheel 1 as shown in FIG Fig. 5 is included.

At the connection of the cup-shaped deepened hub plate 27 in the hub region 4 of the axial fan wheel 1 and the elastic disc 23 hub or disc holes 28 are formed in these two components, which are penetrated by the mounting screws 24 with optional spring elements 30 received thereon. The hub bores 28 are arranged on a Hubbohrungsteilkreis 29, which in Fig. 6 is shown in more detail.

The representation according to Fig. 6 shows the top view of the hub of the Axiallüfterrades according to Fig. 5 ,

The cup-shaped hub region 4 of the axial fan wheel as shown in FIG Fig. 5 here comprises 120 ° at the periphery of the hub portion offset from one another in the radial direction extending slots 31. The slots 31 are designed in a length 32 which exceeds the respective slot width 33 by a multiple. In addition to the radial slots 31 offset from one another here at an angle of 120 °, the formation of the hub region 4 of an axial fan wheel 1 is also possible with 4, 5, 6 or an even higher number of radial slots 31. Due to the formation of radial slots 31 in the wall of the hub region 4, which in the plane of the representation according to Fig. 6 is achieved, it is achieved that a self- _{alignment of the Axiallüfterrades} 1 by the centrifugal J _Jη · ω ^{2 is achieved} such that the main axis of inertia x -x of Axiallüfterrades 1 coincides with its axis of rotation ξ- ξ. In addition to a formation of radial slots 31 in the hub region 4 of the Axiallüfterrades 1, which in connection with the Fig. 5 already mentioned hub bores 28 are formed in the hub portion 4 on a Verschraubungsteilkreisdurchmesser 29, the diameter of which is less than half the diameter of the hub portion 4 of the Axiallüfterrades 1. The farther the hub bores 28, of which in the illustration according to Fig. 6 only three are arranged on the Verschraubungsteilkreisdurchmesser 29, in the direction of the bore 34, which is penetrated by the output shaft 20 of the electric drive 21 are arranged, the higher bending softness is in the hub region 4 of the axial fan 1 and promotes rotation of the axial fan 1 in angular velocity ω about the axis of rotation ξ - ξ the self-alignment and the Compensation of shape and position tolerances of the manufactured by a plastic injection molding axial fan 1.

An additional possibility of achieving a flexurally soft connection of the hub region 4 with the output shaft 20 of an electric drive 21 is to reduce the material thickness in the hub region 4 in the region of the cup-shaped hub plate 27. Furthermore, a more flexible connection of the hub region 4 to the output shaft 20 can be achieved of the electric drive 21 can be achieved in that on the spring elements 24, which connect the elastic disc 23 and the cup-shaped inverted hub plate 27 of the hub portion 4 together, spring elements are formed which generate depending on the deflection spring moments F _c · a, which with the rising Speed counteract increasing centrifugal J _ξη . If the two mentioned moments are in equilibrium, the axial fan 1 is aligned such that its principal axis of inertia x - x coincides with the axis of rotation ξ - und and no vibrations by structure-borne noise can be transmitted to other structural components in the engine compartment of a motor vehicle or to the interior of a motor vehicle.

Fig. 7 shows a further embodiment variant according to the invention a flexurally soft receiving a Axiallüfterrades on a drive.

As shown in Fig. 7 are at the armature shaft 20 of an electric drive, not shown here, an elastic driver 23 and connected to the elastic carrier 23 hub plate 27 of the Axiallüfterrades 1 is added. In the embodiment variant according to Fig. 7 the elastic driver 23 is provided with an S-shaped configured profiling 50 which extends on the elastic carrier 23 in its radial direction. The hub plate 27 of the Axiallüfterrades 1 is screwed in the region of the Verschraubungsteilkreises 29 via fastening screws 24 with screw threads of the elastic driver 23. Between the screw heads of the fastening screws 24 and the planverlaufenden end face of the driver 23 made of elastic material, a spacer bushing 37 is received. This lies with a contact surface 39 on the flat end face of the driver 23 made of elastic material. In the region of the spacer bushing 37, a peripheral recess 35 is received on the hub plate 27, in which an elastic element is embedded. The elastic member 36 may be, for example, as shown in FIG Fig. 7 shown as an O-ring that surrounds the spacer 37. In its undeformed, ie its unloaded state allows the recessed into the circumferential recess 35 O-ring deflection s, which in the illustration according to Fig. 7 identified by reference numeral 38. This means that the hub plate 27 of the Axiallüfterrades to the in Fig. 7 drawn tilt angle δ can move, characterized in that in the recess 35 recessed insert member 36 is a flexible connection between the elastic driver 23 and the hub plate 27 of the Axiallüfterrades 1 is created.

Fig. 8 shows a third embodiment of a flexible coupling of Axiallüfterrades on a drive.

The representation according to Fig. 8 are also provided with an S-shaped profiling 50 driver 23 made of elastic material and a fastening screws 24 connected thereto hub plate 27 can be seen. In modification of the Fig. 7 illustrated embodiment is according to the in Fig. 8 represented third embodiment in the circumferential recess 35 on the hub plate 27 of the Axiallüfterrades a corrugated disc 40 made of metallic material. The recessed into the circumferential recess 35 made of metallic material corrugated plate 40 also allows a flexible coupling of the hub plate 27 of the Axiallüfterrades 1 to the driver 23 made of elastic material. The representation according to Fig. 8 It can be seen that a deflection path s is set by the wave plate 40 shown in the rest state between the flat surfaces of the hub plate 27 and the elastic driver 23, which in the illustration according to Fig. 8 analogous to the representation according to Fig. 7 designated by reference numeral 38. The deflection s ensures that the hub plate 27 can move with the axial fan impeller 1 formed thereon by the angle δ, so that a relative movement of the hub plate 27 to the elastic carrier 23 accommodated on the armature shaft 20 is ensured. The fastening screws 24, with which the hub plate 27 of the Axiallüfterrades 1 are connected to the planverlaufenden end side of the elastic driver 23 are arranged in Verschraubungsteilkreis 29.

Fig. 9 shows a fourth embodiment of a flexible coupling of Axiallüfterrades on the drive with a deflection range.

The Axiallüfterrad 1 as shown in FIG Fig. 9 is received on the armature shaft 20 of an electric drive 21 with the interposition of a female member 42. The electric drive 21 is installed on here schematically illustrated holder 25 on a structural element of a vehicle. The axial fan 1 includes fan blades 2, in which balancing weights 26 may be arranged. On the housing 22 of the electric drive 21, the holder 25 are arranged, for example, at an angle of 120 ° to each other. The hub plate 27 of the axial fan wheel 1 encloses the electric drive 21 partially. The in Fig. 9 The area designated by the letter Y is shown in FIG Fig. 9.1 as reproduced in scale enlarged detail.

From the illustration according to Fig. 9.1 shows that in the area of a seat surface 46 of the armature shaft 20 of the electric drive 21, a female member 42 is received. The bushing element 42 is pressed against an abutment ring 47 by means of a clamping element 43 which is likewise supported on the armature shaft 20 in the region of an annular groove 45. The abutment ring 47 completely encloses the armature shaft 20 of the electric drive 21. The clamping element 43, which may be configured for example as a clamping disc, is supported with a leg on an edge of an introduced into the armature shaft 20 annular groove 45, while the farther outwardly extending leg of the clamping element 43 at the through the sleeve member 42 and the Hub plate 27 of the Axiallüfterrades 1 formed end face supported. The hub plate 27 and the socket member 42 are connected to each other via fastening screws 24. By the clamping element 43, the bearing 44 having a sleeve member 42 is provided in the axial direction against a contact surface 49 on the contact ring 47. As a result, the sleeve member 42 is fixed in the axial direction.

The armature shaft 20 of the electric drive 21 has a seat surface 46, on which the support 44 of the socket element 42 rests. The support 44 represents a tipping point of secured in the axial direction of the armature shaft 20, the tiltable in the radial direction bushing element 42. By a relative movement of the sleeve member 42 to the seat surface 46 of the armature shaft 20 may in the region of the approved tilting play 41 an inclined position of the on the tiltable mounted sleeve member 42 received hub plate 27 and thus the Axiallüfterrades 1 done. Self-adjusting dynamic imbalances are automatically compensated by this bearing of the sleeve member 42, acted upon by a clamping element 43 during the rotation of the armature shaft 20 of the electric drive 21.

errechnen. Daraus ergibt sich $$\delta =\frac{1}{2}\cdot \arcsin \left(\frac{2\cdot U_{\mathit{dyn}}}{\mathit{Jx}\mathit{-}\mathit{Jy}}\right),$$

mit einem Lüfterdurchmesser 390 mm und 463 g Lüftergewicht: $$\mathit{Jx}\mathit{-}\mathit{Jy}=m\frac{r^2}{4}=463g\frac{{195}^2{\mathit{mm}}^2}{4}=4401.{10}^{3}g{\mathit{mm}}^2$$

woraus sich ergibt $$\delta =\frac{1}{2}\cdot \arcsin \left(\frac{2\cdot U_{\mathit{dyn}}}{\mathit{Jx}\mathit{-}\mathit{Jy}}\right)=\frac{1}{2}\cdot \arcsin \left(\frac{2\cdot 25000{\mathit{gmm}}^2}{4401\cdot {10}^3{\mathit{gmm}}^2}\right)=0,32°\mathrm{.}$$

The required tilt angle can be calculated from the expected dynamic imbalance of the blower. This will be briefly explained on the basis of a sample calculation. For a fan with 25000 gmm ² expected dynamic imbalance, the required soft tilt angle can be determined by the relationship $$U_{\mathit{dyn}}=\frac{J_x-{\mathrm{<figure-callout\; id="2"\; label="J\; y"\; filenames="imgf0001.png,imgf0005.png"\; state="\{\{state\}\}">J\; </figure-callout>}}_y}{2}\cdot 2\mathrm{sin\delta }$$

calculate. This results in $$\delta =\frac{1}{2}\cdot \mathrm{<figure-callout\; id="2"\; label="arcsin"\; filenames="imgf0001.png,imgf0005.png"\; state="\{\{state\}\}">arcsin</figure-callout>}\left(\frac{2\cdot U_{\mathit{dyn}}}{\mathit{jx}\mathit{-}\mathit{jy}}\right).$$

with a fan diameter of 390 mm and 463 g fan weight: $$\mathit{jx}\mathit{-}\mathit{jy}=m\frac{{\mathrm{<figure-callout\; id="2"\; label="r"\; filenames="imgf0001.png,imgf0005.png"\; state="\{\{state\}\}">r</figure-callout>}}^2}{4}=463G\frac{{195}^2{\mathit{<figure-callout\; id="2"\; label="mm"\; filenames="imgf0001.png,imgf0005.png"\; state="\{\{state\}\}">mm</figure-callout>}}^2}{4}=\mathrm{4,401th}{10}^{3}G{\mathit{<figure-callout\; id="2"\; label="mm"\; filenames="imgf0001.png,imgf0005.png"\; state="\{\{state\}\}">mm</figure-callout>}}^2$$

from which results $$\delta =\frac{1}{2}\cdot \mathrm{<figure-callout\; id="2"\; label="arcsin"\; filenames="imgf0001.png,imgf0005.png"\; state="\{\{state\}\}">arcsin</figure-callout>}\left(\frac{2\cdot U_{\mathit{dyn}}}{\mathit{jx}\mathit{-}\mathit{jy}}\right)=\frac{1}{2}\cdot \arcsin \left(\frac{2\cdot 25000{\mathit{<figure-callout\; id="2"\; label="gmm"\; filenames="imgf0001.png,imgf0005.png"\; state="\{\{state\}\}">gmm</figure-callout>}}^2}{4401\cdot {10}^3{\mathit{gmm}}^2}\right)=0.32°\mathrm{,}$$

The calculated angle of 0.32 ° corresponds to a soft deflection of s = 50 · sin 0.32 ° = 0.28 mm, on the basis of a screw pitch circle 29 of 50 mm.

The design path s denoted by reference numeral 38 is about 3/10 mm based on this example calculation for the given example on the basis of the given data.

LIST OF REFERENCE NUMBERS

1

axial fan

1'

Axial fan in rotation

2

fan blades

3

fan blades

4

hub area

5

fixed bearing

6

movable bearing

7

main emphasis

8th

Rotating coordinate system

9

spring element

10

spring element

x -x

Fan axis (main axis of inertia)

y - y

Fan vertical axis

ξ - ξ

Rotary axis Axial fan

η - η

tilt

J _ξη · ω ² :

centrifugal

ω

angular velocity

δ

Misalignment at ω = 0

α

Deflection at ω ≠ 0

δ-α

Auslenkungsdifferenz

11

Axial force component fixed bearing 5

12

Radial force component fixed bearing 5

13

Radial force component floating bearing 6

14

Lever arm a

15

Spring force F _c

20

armature shaft

21

electric drive

22

casing

23

elastic disc

24

fixing screw

25

holder

26

balance weight

27

hub plate

28

hub bore

29

screw connections

30

spring element

31

radial slot

32

slot length

33

slot width

34

drilling

35

circumferential recess

36

insertion element

37

Distanzbuchse

38

Deflection s

39

contact surface

40

wave washer

41

Sideplay

42

female member

43

clamping element

44

In stock

45

ring groove

46

seat

47

Anlagenring

48

annulus

49

Contact surface bushing element

50

S-shaped driver profiling

Claims (20)

1. Axial fan with a hub region (4, 27) for connecting an axial-fan wheel (1) of the axial fan to an output shaft (20) of an electrical drive (21), the axial fan being balanced statically by means of a balancing weight (26), characterized in that, between the axial-fan wheel (1) and the output shaft (20) of the electrical drive (21), in the hub region (4, 27) a pliable connection is formed, which, within a flexible tilting angle, allows the deflection of the axial-fan wheel (1) in the direction of its main inertia axis, and the pliable connection in the hub region (4, 27) comprises radially extending orifices (31), by means of which the hub region (4, 27) is connected by means of fastening screws (24) to a driver (23) received on the output shaft (20) of the electrical drive (21) and consisting of elastic material, and spring elements (30) or elastic insert elements (36, 40) are assigned to the fastening screws (24) of the hub region (4, 27) on the elastic driver (23).
2. Axial fan according to Claim 1, characterized in that the length (32) of the orifices (31) in the radial direction exceeds their width (33).
3. Axial fan according to Claim 1, characterized in that the material thickness of the axial-fan wheel is reduced in the hub region (4, 27).
4. Axial fan according to Claim 1, characterized in that a dish-shaped hub depression (27) is formed in the hub region (4).
5. Axial fan according to Claim 1, characterized in that this is produced by the 2-component injection-moulding method, the component with pliable properties, as compared with the component injection-moulded on in the blade region (2, 3), being provided in the hub region (4, 27).
6. Axial fan according to Claim 1, characterized in that a screwing reference circle (29) in the hub region (4, 27) is designed with a diameter which is below half the diameter of the hub region (4, 27) of the axial fan.
7. Axial fan according to Claim 6, characterized in that the number of hub bores (28) on the screwing reference circle (29) amounts to 3 at most.
8. Axial fan according to Claim 1, characterized in that the spring elements (30) are arranged between the fastening screws (24) and the hub region (4, 27).
9. Axial fan according to Claim 1, characterized in that the spring elements (30) are provided between the elastic driver (23) and the fastening screws (24).
10. Axial fan according to Claim 1, characterized in that the driver (23) is formed from elastic material in an S-shaped profiling (50).
11. Axial fan according to Claim 10, characterized in that the S-shaped profiling (50) extends in the radial direction on the driver (23).
12. Axial fan according to Claim 1, characterized in that spacer bushes (37) are received between the elastic driver (23) and the hub dish (27) of the axial fan (1).
13. Axial fan according to Claim 12, characterized in that the spacer bushes are held in bearing (39) on the elastic driver (23) and arranged in the region of the screwing reference circle (29).
14. Axial fan according to Claim 12, characterized in that the spacer bushes (37) are assigned elastic insert elements (36, 40) surrounded by recesses (35) of the hub dish (27).
15. Axial fan according to Claim 14, characterized in that the insert elements (36) are designed as O-rings.
16. Axial fan according to Claim 14, characterized in that the insert elements (40) are constituted as corrugated resilient discs.
17. Axial fan according to Claim 1, characterized in that the hub dish (7) of the axial fan (1) is fastened to a bush element (42) mounted tiltably on the anchor shaft (20).
18. Axial fan according to Claim 17, characterized in that the bush element (42) is tensioned against a bearing ring (47) by means of a tension element (43) on the seat surface (46) of the anchor shaft (20).
19. Axial fan according to Claim 17, characterized in that the bush element (42) has a bearing (44) allowing a tilting play (41).
20. Axial fan according to Claim 18, characterized in that the tension element (43) tensioning the bush element (42) axially is supported in an annular groove (45) of the anchor shaft.

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