Industrial axial-flow fan having offset airfoil-to-hub mounting system for improved aerodynamic performance

摘要

An industrial fan (1) having a plurality of blades (2) attached to a common hub (21), wherein each blade (2) has a substantially uniform aerodynamic shape the lenght thereof including its root, by virtue of novel attachment means which do not require added strengthening of the root deforming its aerodynamic shape, thereby improving overall performance. The attachment means include an intermediate member (13) of each blade (2) coupled to the hub (9) and clamped against one of the faces of the associated blade (2). Radial pivot means are provided between each intermediate member (13) and the hub (9) according to feathering axes offset from the blade longitudinal axes, for manually adjusting the pitch (angle of incidence) of the blades according to a required flow. The invention also includes a pneumatic system (30) for varying the position (pitch) of the fan blades in motion.