The present disclosure involves a belt drive mechanism which can be used to pay out or draw belt to or from a belt actuated system (or belt driven system). The mechanism features a self-winding spool which can automatically wind or unwind portions of the belt as they are withdrawn from, or fed to the belt actuated system. A second rotational axle (idler shaft), with one or more sheaves (e.g., pulley's or rollers) can be rotationally coupled to a capstan via a belt, and can be utilized to drive additional mechanisms in the belt drive mechanism, such as a winding mechanism.

A belt transmission mechanism includes two pulleys, first/second steel belts, and first/second covers. Each pulley includes first/second recesses recessed from the outer circumferential surface of the pulley. The first steel belt has an end fixed to a first block member disposed in the first recess. The first cover, fixed to the first recess to enclose the first block member, has an outer circumferential surface having the same diameter as the outer circumferential surface of the pulley. The second steel belt has an end fixed to a second block member disposed in the second recess. The second cover, fixed to the second recess to enclose the second block member, has an outer circumferential surface having the same diameter as the outer circumferential surface of the pulley.

In general, this disclosure involves a pulley system that includes a plurality of fixed sheaves arranged to at least partially encircle an output shaft, a plurality of traveling sheaves coupled to the output shaft. The output shaft can be configured to pass through the fixed sheaves and translate along an axis of travel and the plurality of traveling sheaves can be arranged such that a geometric average of belt tension created by spans of belt between the plurality of traveling sheaves and the plurality of fixed sheaves is approximately coincident with a centerline of the output shaft. The system further includes a belt extending between and around the plurality of fixed sheaves and the plurality of traveling sheaves such that the belt flexes toward a single surface of the belt.