DE7038013U - AXIAL FAN IMPELLER - Google Patents

Description

I) It. XXCi. K. HOFFM MNN DIPL. * N <5. W. IiITLE · DH, KER. NAT. K. HOFFMANN

FATIiNTAKWiLTK ] \

D.8000 MUNICH 81 ■ AR *> BE LLASTRAESE a ■ TELEFON (OB!]) 911037

70 3> 8o 13.1 July 19, 1972

Aktiebolaget Svenska Fläktfabriken in Nacka / Sweden

Axial fan impeller

The innovation relates to an axial fan impeller with at least two adjustably arranged on a hub Blades made up of two or more in a radial direction; elements lying one behind the other are formed.

In the case of axial fans, the fan blades can be adjusted in so far as desirable as the losses in applied mechanical energy by the fan strongly depend on the prevailing operating conditions, and these can only be kept low if the angle of incidence of the blades in relation to the flowing medium is optimally adapted to the relevant operating conditions will.

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Axial fans of the type mentioned are known in which the blades are arranged on the impeller hub ro so that they are adjusted about their longitudinal axis v: earth Ιί'οΤχΓιΒΐϊ. BiCGC Art CLer / Inp2.S SlUlS? R nntprc ^ hipriHt-h ^ Befcriebsbedingungen is, however, a rough approximation, since the change in the angle of attack of the blades is the same at every point on the blade longitudinal axis and thus the flow losses are only reduced to a minimum in a limited blade area be reduced. There are also known Gobläselaufräder (DT-AS 1 083 482, DT-PS 374 482 and 646 614 as well as FR-PS 1 195 124)., In which the above-mentioned adjustable blades are composed of several uniform elements lying one behind the other in the radial direction , whereby the transition from one element to the adjacent takes place steadily and without changing the angle of attack, so that the same fluidic effect occurs as with a blade made from one piece.

The aim of the Neverung, on the other hand, is axial fan impellers to create in which the blades are optimally adapted to the respective prevailing operating conditions can be.

According to the innovation, this is done in the case of a fan impeller with blades made of two or more elements according to the introduction of the type mentioned achieved in that the elements are partly adjustable with one another and partly with respect to the hub are arranged. This ensures that fan impellers are preferably made of blade elements that are similar to one another composed and optimally adapted in a simple manner to completely different operating conditions • .-. 'Can ground. Depending on the requirements, the Joining elements together by fixed or detachable connections, with the advantage of the latter connection type, aa £ in cases of doubt, the most favorable in terms of flow technology The angle of incidence of the individual elements at the place of use of the device is determined and adjusted through practical tests can be.

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To one at the transition from a Schaufelelcrment to the Adjacent possible gas flow in the radial direction are to be avoided according to a further development of the innovation between the blade elements, disc-shaped segments, perpendicular or essentially perpendicular to the longitudinal axis of the blades arranged above the outer contour edges of the blade elements protrude.

Appropriate embodiments of the innovation are in reproduced in the drawing and in the description below. Show it:

Fig. 1 is a built up of elements and attached to a hub arranged impeller blade according to the innovation;

FIG. 2 shows a section through the blade according to FIG. 1; Fig. 2a shows a section along line A-A in Fig. 2;

Fig. 5 is a section through one blade in another Embodiment;

4 shows a further embodiment of a blade.

1 shows a blade composed of mutually similar elements 1, 2, 3, which is arranged on a hub 4 with side surfaces 5 designed as a polygon. The individual elements 1, 2, 2 can be set separately from one another at angles of incidence β1, β2 and β ^ which are appropriate for a specific operating state. The direction of rotation of the fan impeller is indicated by 7 and the direction of flow of the medium through the fan is indicated by 7 '. If the fan impeller is to be used under different operating conditions, the elements can be joined together by a detachable connection. For example, in the case of the

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The illustrated embodiment ο form with ο In around the sealing element on element 3 > the elements with each other and with the hub H by a L / "; threaded bolts and nuts lü, il screwed onto them.

In the case of fan impellers, which are under only slightly fluctuating operating conditions should, can the blade elements 1, 2, 3 are joined together by flange connections, as shown in FIG. 3. the Blade elements 1, 2, 3 here have at their ends Flanges 12 which can be connected by screw connections, rivets, welding or the like. Serve flanges 12 also serve the purpose of ensuring a radially directed flow of the medium at the transitions from a blade element to prevent another.

When in ^Fig.] \ Illustrated embodiment, discs 13 are provided between the Schaufelelementun whose area the cross-sectional area of the blade elements projects somewhat beyond. These disks 13 likewise prevent, in the manner corresponding to the flanges 12 in FIG. 3, a radially directed flow of the medium during the transition from one blade element to another.

The at the radially outermost Schauf ⁿ - element 3 arranged packer 6 serves to seal the zviischen this vane member and the casing surrounding the Gebiäselaufrad resulting gap.

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Claims (3)

Protection claims 1. Axial fan impeller with at least two adjustable blades arranged on a hub, which are formed from two or more elements lying one behind the other in the radial direction, characterized in that the elements (1, 2 _} 3) partly with each other and ^ eiis opposite the hub ( 4) are arranged to be adjustable. 2. Axial fan impeller according to claim 1, characterized in that that between the '^ bucket elements disc-shaped segments perpendicular or substantially perpendicular are arranged to the longitudinal axis of the blades, which protrude beyond the outer contour edges of the blade elements. 3. Axialgebiäselaufrad according to claim 1 or 2, characterized characterized in that the display elements (1, 2, 3) with one another are essentially congruent. 703801323.11.72