US 11,988,224 B2
Fan and fan blades
Marc Schneider, Dörzbach (DE); Andreas Lucius, Schwäbisch Hall (DE); and Marius Lehmann, Niedernhall (DE)
Assigned to ebm-papst Mulfingen GmbH & Co. KG, Mulfingen (DE)
Filed by ebm-papst Mulfingen GmbH & Co. KG, Mulfingen (DE)
Filed on Sep. 9, 2022, as Appl. No. 17/941,566.
Application 17/941,566 is a division of application No. 17/910,406, previously published as PCT/EP2021/055473, filed on Mar. 4, 2021.
Claims priority of application No. 102020106534.5 (DE), filed on Mar. 10, 2020.
Prior Publication US 2024/0084815 A1, Mar. 14, 2024
Int. Cl. F04D 29/28 (2006.01); F04D 29/32 (2006.01); F04D 29/38 (2006.01)
CPC F04D 29/38 (2013.01) [F04D 29/281 (2013.01); F04D 29/325 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A fan blade for a radial fan comprising:
an inflow edge and an outflow edge on the blade for the radial fan, the fan blade has, at least in one section of the inflow edge, a wavy inflow edge having a periodically repeating waveform of a period length λ, that is different from a sinusoidal waveform, and it is different from a sinusoidal waveform having equal period length λ;
the repeating waveform forms per period two adjacent wave troughs between two flanks extending toward one another obliquely to a flow direction and the two adjacent wave troughs have the same amplitude and/or depth;
a wave peak is located between the two adjacent wave troughs, the wave peak extends against the flow direction in the direction of an inflow-side front edge and a peak-trough value of the wave of the wave peak that is directly between the two adjacent wave troughs, is an absolute value approximately 10% to 80% of a peak-trough value of the directly adjacent wave peak(s); and
the blade profile, at least viewed in a profile section in a region of the wave peak, respectively has a bump protruding out of the suction side and a dent at the corresponding opposite position of the pressure side, a surface profile is respectively defined so that a surface curvature changes twice viewed in the flow direction.