According to the spool thread shape difference, the axis may divide into the crank and the straight axle two kinds.

依据轴线外形的不同，轴可以分为曲轴和直轴两类。

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AXIS, an imaginary straight line or an actual physical component (such as an axle) around which a body can rotate.

轴线，可让物体围绕着作旋转运动的一个想像的直线或实际存在的部件(如轴)。

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But if the coupler's locomotive traction on the ramp is same as on the straight road, the axle load transfer will be a increase slightly.

但如果在坡道上机车承担的车钩牵引力与平直道的车钩牵引力相同，则轴重转移会有少量的增加。

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Each had its own way of moving through the land and each had its own odor of passage: the railway tracks cut straight ahead, asking no questions of the bedrock through which it sliced, the wrought-iron rails smelling of axle grease and the wooden slats of rancid, licorice-scented shellac.

NPR: Excerpt: 'The Selected Works of T.S. Spivet'