United Technologies Corporation

Sikorsky Aircraft Corporation

Robert J Durwin

Jules G Kish

William L Noehren

Lee N Hager

Ralph D Costanzo

Timothy L Krantz

Joseph H Mancini

A method for fabricating a split path transmission system that achieves equal torque splitting between the forward and aft split load paths of each gear train thereof at a predefined operating point by providing an intentional timing difference between gears and pinions of the forward and aft split load paths of each gear train of the split path transmission system is disclosed. The method includes the steps of identifying the torque distribution curves of the forward and aft split load paths of one gear train of the split path transmission system. The method further includes a step of selecting a predefined operating point for the split path transmission system wherein equal torque splitting between the forward and aft split load paths of the one gear train is desired. Next, the forward and aft torque distribution curves are analytically modified as required to pass through the predefined operating point. The interception point with the abscissa of the analytically-modified forward or aft torque distribution curve having the steeper slope is then identified to quantify an input torque range. Finally, the timing relationship of the gears and pinions of the split load path represented by the analytically-modified torque distribution curve having the steeper slope is altered to provide an intentional timing difference between the gears and pinions of the forward and aft split load paths, respectively, of the one gear train such that during operation of the split path transmission system the other split load path transmits all torque input to the main rotor shaft over the input torque range.

Method for fabricating a split path transmission system providing equal

A retractable helicopter rotor in which the rotor and its blades, the swashplate and the pitch change rods are retracted and extended as a unit during the helicopter rotor retraction/extension mode of operation, wherein the connection between the rotor support system and the fuselage constitutes a single interface between overlapping circumferentially extending flanges of each, and with the bolts joining those flanges being loaded in compression.

Retractable helicopter rotor

A shaft bearing retention means comprises a segmented ring having a conical inner surface which is placed about a large diameter shaft having a corresponding conical indentation about its periphery to receive the ring. The segments are retained in assembled position on the shaft by joining pins extended through interengaging lapped tongues on the ends of each segment and by attaching one or more flanged retaining rings thereto by screws or bolts. Additional clamping screws or bolts pass through the retaining ring and are threaded into the segments, projecting beyond the latter so as to bear against a thrust ring through which the shaft passes. The axially adjustable thrust ring engages a bearing assembly which is fixed against axial movement by a shoulder on the shaft. Axial force is produced against the bearing assembly by the clamping bolts due to wedging action of the mating conical surfaces on the shaft and the segmented ring.

Threadless locking device

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Trumbull, CT, United States of America

Robert J Durwin