Variable effective diameter pulleys for variable speed transmission of power

摘要

Variable effective diameter pulleys comprise identical interleaved sheaves mounted on identical hubs that in turn engage balls in key ways or splines. A single helical spring within the pulley assembly urges the hubs apart to thereby increase the effective pulley diameter. The pulley design is symmetric about the central pulley plane perpendicular to the axis of the pulley. In one embodiment all of the pulley parts with the exception of the spring and balls are conveniently formed with simple sheet metal stampings. Permanent assembly requires only circumferential external welding or circumferential mechanical fastening near the periphery of each sheave. In another embodiment the stamped parts may alternatively be die cast or otherwise formed and welded together. Both embodiments of the pulley are particularly suited to automated assembly and mass production. Also disclosed are governor assemblies attachable to the pulley to provide constant speed operation of the pulley regardless of input belt speed and alternative hub and rim constructions for high volume mass production and assembly to shafts.