Protective grille with improved efficiency and noise characteristics

A protective grille comprising

• attachment means for placement on a fan, and
• a grille web structure, which in the circumferential direction has spaced-apart radial webs and in the radial direction has spaced-apart circumferential webs arranged coaxially, the radial webs and/or the circumferential webs have a rectangular cross section,
• the protective grille at least has a radially outer region and a central region about a central axis of the protective grille,
• an envelope surface, spanning from the radial outer region to the central region, is configured convexly curved in the radial outer region and planar in the central region, parallel to a radial plane of the protective grille, the convexly curved envelope surface in the radial outer region, in a lateral cross section, determines a partially elliptical contour that has a ratio of a radial length (a), of the outer region, to a radius (c), of the protective grille, of a/c >0.25, and
• radial web ends terminating independently from one another so that the radial web ends are discrete, unconnected and spaced from one another;
• the circumferential webs are each placed in a radial direction at a radial distance r to the axial center of the protective grille and each has a surface positioned on a varied angular position with respect to an axial plane of the protective grille, and
• the attachment means including a plurality of attachment portions spaced apart in a circumferential direction, the attachment portions partially formed from at least a pair of adjacent radial webs ends so that the attachment portion is formed by an attachment web spanning between, both circumferential and radially, at least the pair of adjacent radial web ends so that the at least a pair of adjacent radial web ends are only directly connected by the attachment web.