| 摘要 |
<p>A phase change mechanism comprises concentric drive (18) and driven (14) members, and two gears (22, 24) the first (22) being an internally toothed gear ring and the second (24) being an externally toothed gear of smaller diameter but having teeth of the same pitch as the teeth of the first gear which mesh with the internal teeth of the first gear ring (22) over only part of the circumference of the second gear (24). Each of the gears is coupled for rotation with a respective one of the drive and driven members, one of the gears (22) being mounted for rotation about the same axis as the drive and driven members (18, 14) and the other (24) being journalled for rotation about an eccentric crank (26) serving as the actuating member, rotation of the crank (26) being effective to cause trochoidal movement of the gear (24) journalled thereon relative to the other gear (22) so as to bring about a phase shift between the drive and driven members.</p> |
