| 摘要 |
A key pulley segment in a synchronized, segmentally interchanging pulley transmission system is either first or last in a pulley segment set to engage an endless member. The first or last key segment teeth to engage or disengage, respectively, are shortened or completely trimmed, and the adjacent pulley segment to the key segment is elongated such that the inward portion of the tooth profile extends toward the key segment. Shortened tooth or teeth and an elongated adjacent segment together allow for many pulley segments to be designed as key segments. Completely trimmed teeth may be engineered to create a supporting surface for the endless member on the key segment. The elongated adjacent segment may have an extending portion which slidably mates with the supporting surface of the key segment, thereby receiving radial support therefrom. Multiple pulley segments from different pulley segment sets may be connected or constructed to move together in a unified stack, and may be staggered such that any one segment may be in an engaging position with the endless member when the unified stack is moved along the axis of rotation. Unified stacks may have guiding rails on both inner and outer radial surfaces, and the pulley assembly may have mating features that receive such guiding rails. Any number of the pulley segments in a unified stack may be key pulley segments. Pulley segments of a stack may be vertically separated into one or more unified stacks. Unified stacks may be moved by way of a cam or roller cam system, where each unified stack has a slidably or ratably attached roller and roller-arm. Chassis-mounted cams engage the rollers outside of the contact zone, rollers and roller-arms are moved into and out of engagement with the cams, and individual segments of a unified stack are moved into or out of engagement. Rollers may be actuated into and out of engagement by electromagnets, fixably mounted in an array. Rollers may discretely engage with multiple cams, by way of several electromagnet-arrays, and thereby complete several stack axial motions. Electromagnets in an array may be selectively energized to move selected rollers to an active position in order to effect key pulley segment engagement, stack axial movement and transition. |
