齿条的英文：
rack
spline

参考例句：

A steering rack,eg on a cable car
转向齿条(如缆车上的).

The four main types of gears (spur, helical, worm, and bevel)and a rack and pinion are shown in Figure 7
图7所示是四种主要的齿轮(巨齿轮，斜齿轮，蜗轮和伞齿轮)以及齿条和小齿轮。

rack是什么意思：
n. 支架，架子
v. 使痛苦不堪，使受折磨；把...放在架子上

You should rack these bottles of wine.
你应该把那几瓶酒放到架子上。

They have been racked by bitter quarrels.
激烈的争吵使他们不得安生。

The cough seemed to rack his body.
他咳得全身震动。

And the coughing will rack his ancient chest.
咳嗽会绞紧他的年老的胸膛。

So they elect to get a roof rack.
因此，他们选择车顶行李架。

spline是什么意思：
n. 云形规,齿条,制转楔,花键
vt. 装以角栓,开键槽

The general technical specifications for involute splines hobs
渐开线花键滚刀通用技术条件

This paper applies B -- spline to fit the curve of plane wing, and according to geometrycaculation, an equation of wing surface is setted up.
本文应用三次b样条曲线对机翼直纹区曲面的翼型曲线进行拟合，并用简单的几何推算方法，建立简单翼面直纹区曲面的参数方程。

"Turn the shaft, if the clutch-disk hub splines. Put Bolts in place, and tighten them to the correct tension."
如果与离合器从动盘轮彀的花键相连,可转动传动轴,把螺栓就位,并适度拧紧。