WO2011012352A1

WO2011012352A1 - Entering geometry for half-axial fan wheels

Info

Publication number: WO2011012352A1
Application number: PCT/EP2010/057625
Authority: WO
Inventors: Andreas Schiel; Andreas Kockler
Original assignee: Robert Bosch Gmbh
Priority date: 2009-07-30
Filing date: 2010-06-01
Publication date: 2011-02-03
Also published as: DE102009028125A1

Abstract

The invention relates to a fan with a fan wheel comprising suction blades extending in radial and axial directions with a leading edge facing an axial input direction of the fan wheel, wherein at least one suction blade has at the leading edge thereof a swirling device for generating microturbulences.

Description

description

title

Entry geometry for semi-axial fan wheels The invention relates to a fan with a fan wheel. In particular, the invention relates to a fan of a fan for use in a motor vehicle.

PRIOR ART Fan systems in motor vehicles usually comprise an intake tract for

Suction of outside air, a fan for conveying the air, as well as a distribution tract for transporting and distributing the conveyed air in the interior of the motor vehicle. In addition, such fan systems may include a heat exchanger for heating, a condenser for cooling, a filter for cleaning and a number of flaps and valves for selectively conducting the air.

A problem with existing ventilation or air conditioning systems is that conventional fans with fan wheels can inherently generate speed-dependent noise that can propagate in the distribution tract, so that they are audible in the interior of the motor vehicle, where they are perceived as disturbing by inmates can. By overlaying with other noises, an increased noise level in the interior of the motor vehicle can arise.

Known fans have a stepped or continuously variable speed control, by means of which the fan speed can be set according to a quantity of air to be delivered. Transitioning between different speeds can cause noisy or whining sounds in fans that produce speed-dependent sounds, which are often perceived as even more unpleasant than constant noises. The invention is therefore based on the object of specifying a fan with reduced speed-dependent noise.

Disclosure of the invention

The object is achieved by a fan with a fan wheel according to claim 1 and by a motor vehicle according to claim 9. Subclaims indicate possible or advantageous embodiments.

According to a first aspect, a fan of a fan in a radial and axial direction extending suction vanes with an inlet edge, which faces an axial inlet direction of the fan, at least one suction pad in the region of the leading edge has a swirling device for the generation of microturbulence.

A fan of a narrow frequency range ("monofrequent noises") depends on a speed of the fan wheel and a number of impeller fan blades (order) .The vortexer can effectively suppress this noise, but a turbulizer can cause a noise The position and extent of the swirling device can therefore be chosen so that the intensity of the monofrequent noises is effectively reduced in the interior of the motor vehicle and at the same time the noise of

Inmates are not perceived as disturbing.

At least one suction vane of the fan wheel may be formed integrally with a discharge vane. As a result, the flow surfaces of the air along the fan blades are edge-free, so that additional noise sources can be avoided.

The swirling device may be formed by a recess in the suction paddle. The recess may, for example, have an elliptical or partially elliptical shape. In particular, the recess may be in the form of a vertical tion of the leading edge of the suction pad or in the form of an enclosed opening through the suction pad in the region of the leading edge be realized.

The swirling device can also be formed by a two spaced-apart recesses in the suction paddle. In particular, it has been found that the area between spaced recesses can produce a microturbulent wake that effectively suppresses the tendency of the fan to produce monofrequency noises. It is also possible to use several turbulizers in the area of the leading edge.

Adjacent suction paddles may differ in the position and / or shape of their turbulator. By avoiding an overly regular sequence of turbulators of adjacent suction vanes in the circumferential direction of the fan wheel, monofrequency noises made possible by the turbulizer itself can be prevented.

One another with respect to the position and / or the shape of their Verwirbelungs- device corresponding suction vanes may be repeated periodically over the circumference of the fan. In particular, the turbulators may be distributed on the suction vanes of the fan wheel so that they lie on one or more arms of a (imaginary) spiral. If a strictly regular sequence of suction vanes corresponding to one another is not practical, for example because the number of suction vanes is a prime number, it is easy to deviate from the arrangement principle at one or more points without significantly impairing the effect of the swirling devices. This can be done for example by two successive, corresponding suction vanes.

A position and / or extent of the swirling device may be determined as a function of a ratio of the length of the suction scoop to the length of the outflow scoop. The mentioned aspect ratio is one of the most determining factors in the design of the ratio of the delivery rate of the suction vanes to the delivery rate of the discharge vanes. The

Flow load of the suction paddles, and thus a tendency of the suction shoveling to produce monofrequency noises may depend on this ratio of conveyances.

The impeller may include outflow vanes with trailing edges facing a radial outlet direction of the impeller. Such a design is known as a semi-axial fan. Halbaxiale fan wheels have a particularly good efficiency, since the air to be conveyed is promoted both in the suction direction by the suction vanes, as well as in the outflow through the discharge vanes. By the downstream of the suction vanes outflow vanes is a flow load of the suction vanes by the passing air higher than in a purely axial structure of the fan. By means of the described turbulence device in the region of the flow-technically highly loaded leading edge of a suction pad, a tendency of a semi-axial fan wheel to produce speed-dependent or order-dependent noises can be counteracted particularly efficiently. In addition, the noise due to the microturbulences is effectively damped by the conveying action of the discharge vanes, so that noises caused by the turbulizer do not propagate significantly through the distribution tract. According to a second aspect, a motor vehicle includes a fan system comprising a fan with fan as described above.

Brief description of the drawings

The invention will be described below with reference to the accompanying drawings, wherein

Figure 1 is a schematic representation of a fan system in a motor vehicle;

Figure 2 is a plan view of a fan wheel for use in the fan system of

FIG. 1;

Figure 3 is an isometric sectional view of the fan wheel of Figure 2; and

Figure 4 is a side sectional view of the fan wheel of Figure 2 represents. 1 shows a schematic representation of a motor vehicle fan system 100. A motor vehicle 110 includes an intake tract 120, a fan 130 and a distribution tract 140. The fan 130 comprises a fan wheel 150 and a fan motor 160. In the representation of FIG included are optional elements of the automotive cooling system 100, such as filters, flaps, valves, heat exchangers, capacitors and other elements that are not relevant in the present context. The fan motor 160 rotates the fan wheel 150, so that air is drawn into the fan wheel 150 from the outside of the motor vehicle 110 through the intake section 120 and then discharged through the distribution section 140 to an inside of the motor vehicle 140.

Frequently, the intake tract 120 and the distribution tract 140 are designed to be integrated with one another and the ventilator 130 can be inserted into the integrated tract in the manner of a cartridge. The tract may also comprise elements which convert a radial flow direction of air discharged from the fan wheel 150 into a uniform flow direction, for example a so-called pressure-increasing spiral. FIG. 2 shows the fan wheel 150 shown only as a function block in FIG. 1 in a plan view. The fan wheel 150 comprises a hub 210, from which extends to a stiffening surface 220 on the circumference of the fan wheel 150, a number of suction paddles 230. The suction paddles 230 comprise two different embodiments, of which a first embodiment comprises only one swirling device 250 and a second embodiment comprises two spaced-apart swirling devices 250. Suction cups 230 of the first and second embodiments are alternately arranged in the circumferential direction of the fan wheel 150, except for an irregularity in the range of the 1 o'clock position of the fan wheel 150, where two

Suction blades 230 of the second embodiment are adjacent. Since the fan wheel 150 comprises a total of 23 suction paddles 230, it is not possible to arrange suction paddles 230 of several different types in a closed cyclic sequence along the circumference of the fan wheel 150 (if the cycle length is neither 1 nor 23). The irregularity shown has little or no effect on the function of the swirling device. tions 250 to minimize noise by the generation of microturbulences, which are dependent on the rotational speed of the fan wheel 150.

The illustrated turbulators 250 include pairs of half-circular shape recesses. However, the location, position and dimensions of the swirlers 250 can be varied. For example, instead of the semicircular shape, the shape of an elliptical segment may also be used more generally. It is also possible to provide the leading edge 240 of a suction pad 230 with a greater or lesser number of recesses over part or all of its length. In another embodiment, it is possible to provide raised turbulators 250 with respect to a surface of the suction paddles 230. The raised turbulators 250 may extend from the entry edges 240 in a tangential or axial direction or in both directions. In yet another embodiment, the turbulizer 250 may include a breakthrough in the region of the leading edge 240 enclosed by a suction pad 230. In all cases, turbulators 250 may be arranged in the same or different sizes, positions and shapes on different suction paddles 230.

FIG. 3 shows the fan wheel 150 from FIG. 2 in an isometric sectional view. It can be seen how each of the suction vanes 230 continues in the axial direction and in each case merges into a discharge vane 210 with a trailing edge 320. Air that has passed through the suction paddles 230 is accelerated by the outflow blades 310 about the axis of rotation of the fan wheel 150, so that it leaves the fan wheel 150 in the radial direction due to a centrifugal force. In addition, the discharge vanes 310 are curved to assist in the outflow of air. It can also be seen that the hub 210 and the stiffening surface 220 are integrally formed with the suction paddles 230 and the discharge blades 310. Thereby, the fan 150 can be manufactured in a single casting or injection molding process. In a further embodiment, the fan wheel 150 may also be cast or sprayed around a hub 210 of another material, such as bronze or steel. The hub

210 is for receiving an axle or shaft or a corresponding bearing educated. An attachment to the hub 210 can be done for example by screwing, gluing, riveting or pressing. The illustrated configuration of turbulators 250 aids in the production of molding or injection molding by not providing the suction paddles 230 with additional undercuts that may hinder a demolding process of the fan wheel 150 from a permanent mold.

The stiffening surface 220 has a front inlet ring 330 and an outer end ring 340. The inlet ring 330 closes the fan wheel 150 against a surrounding structure, for example the intake tract 120, and is shaped such that a gap remaining between these elements is as little as possible disturbing the air flowing past it. The closure ring 340 may perform a similar function, wherein the surrounding structure may also be the distribution manifold 140. Runs the closing ring 340 in a groove of the surrounding structure, so a labyrinth seal can be constructed. In addition, the end ring 340 may stiffen the fan 150 against deformation, for example, at high speeds.

Figure 4 shows a side sectional view of the fan wheel 150 of Figure 2. In this illustration, the one-piece construction of the fan wheel 150 so that it can be advantageously prepared in a casting or injection molding process, well visible.

If the fan wheel 150 is inserted into a fan 130, there is a deflecting element at the lower ends of the discharge blades 310 in the illustration of FIG. 4, which deflects air which has passed through the suction blades 230 to the outflow blades 310. A fan motor 160 is usually located beyond (below) this baffle and transmits torque to the fan 150 by means of a drive shaft leading into the hub 210.

Such a fan 130 is particularly suitable for use in ventilation and air conditioning systems, especially of passenger cars. The fan wheel shown by way of example in FIGS. 2 to 4 has an outer diameter of approximately 20 cm.

Claims

claims

1. Fan (130) with fan (150), the

suction vanes (230) extending in the radial and axial directions, with an inlet edge (240) facing an axial inlet direction of the fan wheel (150),

characterized in that

- At least one suction pad (230) in the region of its leading edge (240) has a swirling device (250) for generating micro-turbulence.

2. Fan (130) according to claim 1, characterized in that at least one suction pad (230) is formed integrally with a discharge vane (310).

3. fan (130) according to claim 1 or 2, characterized in that the

Whirling device (250) is formed by a recess in the suction paddle (230).

4. fan (130) according to claim 1 or 2, characterized in that the swirling device (250) is formed by two spaced-apart recesses in the suction pad (230).

5. Fan (130) according to any preceding claim, characterized in that adjacent suction vanes (230) differ with respect to the position and / or shape of their swirling device (250).

6. fan (130) according to claim 5, characterized in that with respect to the position and / or shape of their swirling device (250) corresponding suction vanes (230) are repeated periodically over the circumference of the fan wheel (150).

7. fan (130) according to any one of the preceding claims, characterized in that the position and / or the extent of the Verwirbelungsein- direction (250) depending on an aspect ratio of a suction pad (230) to a discharge vane (310) is determined.

8. fan (130) according to any one of the preceding claims, characterized in that the fan wheel (150) outflow blades (310) having a trailing edge (320) which faces a radial outlet direction of the fan wheel (150) comprises.

9. Motor vehicle (110) with a fan system (100), which comprises a fan (130) according to one of claims 1 to 8.