Fan blade mounting

摘要

A fan blade mounting system for large air-moving fans includes a radially extending hub strut, a blade root member pivotally coupled to an end of the hub strut for receiving a blade skin, and a tube end located between the blade root member and the hub strut. A pair of resilient mounts are utilized in the blade root member to effectively pivotally couple the blades to the hub, thus relieving most of the vertical bending moment transferred to the hub and eliminating critical frequencies associated with the fan. The hub strut is connected to the hub of the fan by a stud having right- and left-handed threads and a wall thickness adjacent to the threads sufficient for distributing the stresses substantially uniformly on the threads, thereby improving fatigue resistance. The resilient mounts comprise a metal core and metal sleeve with a resilient elastomeric layer between the core and sleeve. The sleeves are connected to the blade root member and the cores of the two mounts are clamped to the tube end.