The dynamic element can be driven to generate the aspiration movement as soon as the tapespool rotates, so the number of the dynamic elements can be increased.
由于带盘每旋转一次动力元件都会驱动一下产生抽吸动作，因而还可增加动力元件的数量。
2
A device, such as a cylinder, spool, or frame, that turns on an axis and is used for winding and storing rope, tape, film, or other flexible materials.
卷轴：一种如卷筒、卷轴或框，绕轴旋转装置，用于卷起和贮存绳索、磁带、胶片或其它带弹性的物质。
3
On dictation equipment, a spool on which magnetic tape is wound.