Abstract: A helicopter rotor head mounting assembly includes a rotor drive shaft and rotor hub splined to the shaft for rotation therewith. The rotor hub includes a central bore having an internal tapered portion which is forced downwardly upon a mating tapered portion of the rotor drive shaft. An annular split cone is mounted between the rotor shaft and the hub at a bottom portion of the hub bore and the split cone is forced upwardly into firm engagement with the hub and drive shaft by means of a plurality of individual loading means which are carried by an annular plate affixed to the bottom of the hub. The loading means are individually adjustable and apply loading force directly onto the split cone to thereby assure a secure, non-vibrational rotation of the hub with the rotor shaft.

Abstract: Both the disk and the blade retainer have a radially inward extending flange which axially abuts the other. A U-clip ring with its open side disposed radially outward is placed over the two flanges to hold them axially together and means is provided to maintain the U-clip ring in its holding position. In a preferred embodiment, the ring is constructed with its side farthest from the disk having a substantially greater radial height than that of the side closest the disk, and the circumferential length of the U-clip is so sized that there is a relatively small gap between its ends when it is in the installed position. With these features, the ring will remain in its assembled position without any other holding means. Removal can be effected by first radially moving one end of the ring inwardly with respect to the other and then axially moving it until it clears the other end.

Abstract: A plastic fan configured for attachment to a fan drive in a manner in which cooling air will be promoted to flow from the rear of the fan drive across the rear fins of the fan drive and through the blades of the fan. The flow of air across the rear fins increases heat dissipation from the fan drive. The fan has a plurality of radially extending circumferentially spaced blades secured to an axially extending hub portion. The hub portion is configured to be radially spaced from the fan drive to define an annular passage. Further, the front edge of the hub portion is spaced rearwardly from the forward portion of the rear fins of the fan drive to define a slot for cooling air to flow substantially unrestricted through the annular passage and to the blades of the fan.