VARIABLE PITCH FAN BLADE RETENTION SYSTEM IN WHICH CENTRIFUGAL LOADS ARE TRANSMITTED BY A RING-SHAPED KEY HAVING INCLINED CONTACT SURFACES FOR REDUCED STRESS CONCENTRATION

摘要

A variable pitch fan (38) for a gas turbine engine includes a fan blade (40) defining a pitch axis (P) and attached at a radially inner end to a trunnion mechanism (92). The variable pitch fan (38) also includes a disk (42) having a disk segment (90) with the trunnion mechanism (92) extending at least partially through the disk segment (90). A key (110) is positioned at least partially in a key slot (128) defined in a base (126) of the trunnion mechanism (92), and further positioned adjacent to a support member of the disk segment (90). The key (110) defines a first contact line (130) between the key (110) and the key slot (128) and a second contact line (132) between the key (110) and the support member. The first and second contact lines (132) respectively define a first contact reference line (134) in a second contact reference line (136). The first and second contact reference lines (134, 136) define an angle with the pitch axis (P) of the fan blade (40) greater than zero degrees and less than ninety degrees.