What you're looking for is the electromagnet (solenoid). which turns the first gear in the gear train.

你要找的是电磁体（螺线管），在传动机构中驱动第一齿轮。

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The influence of the main designed parameters on floating displacement was analyzed. The reference was supplied for designing the basic floating part of star gear train.

分析系统主要设计参数对各构件浮动位移的影响，为星型齿轮传动系统浮动机构的设计提供依据。

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This equation is useful in determining the kinematic linkage between the lathe spindle and the lead screw and enables proper selection of the gear train between them.

这公式在决定车床心轴和丝杆之间的运动学关系时很有用，并且提供了正确挑选它们之间轮系的方法。

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The Mini was one of the first cars to popularize the use of the universal joint in the drive train, previously used in submarine control gear.

CNN: A design classic

Instead of vast maneuver grounds and lots of instructors and equipment, soldiers can train with small but high-tech gear such as Dismounted Soldier Training System, or they can practice techniques, such as squad tactics or IED recognition, using a training game on a laptop or even smartphones.

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As much as selling gear, it is laying the rails before the train can proceed, as it were.

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