求机械专业英语翻译Gear type are determined largely by the disposition

求机械专业英语翻译
Gear type are determined largely by the disposition of the shafts; in addition, certain types are better suited than others for large speed changes. This means that if a specific disposition of the shafts is required, the type of gear will more or less be fixed. On the other hand, if a required speed change demands a certain type, the shaft positions will also be fixed.
Spur gears and helical gears.A gear have tooth elements that are straight and parallel to its axis is known as a spur gear. A spur pair can be used to connect parallel shafts only.
If an involute spur pinion were made of rubber and twisted uniformly so that the ends rotated about the axis relative to one another, the elements of the teeth, initially straight and parallel to the axis, would become helices. The pinion the in effect would become a helical gear.
Worm and bevel gears. In order to achieve line contact and improve the load carrying capacity of the crossed axis helical gears, the gear can be made to curve partially around the pinion, in somewhat the same way that a nut envelops a screw. The result would be a cylindrical worm and gear. Worms are also made in the shape of an further increase in load-carrying capacity.
Worm gears provide the simplest means of obtaining large ratios in a single pair. They are usually less efficient than parallel-shaft gears, however, because of an additional sliding movement along the teeth.
不要用在线翻译软件的那种肯本就不准确的翻译！

Gear type are determined largely by the disposition of the shafts; in addition, certain types are better suited than others for large speed changes. This means that if a specific disposition of the shafts is required, the type of gear will more or less be fixed. On the other hand, if a required speed change demands a certain type, the shaft positions will also be fixed.
　　齿轮的使用型号很大程度上取决于轮轴的位置。而且，齿轮是否使用得当还取决于转动速度。这就是说，如果轮轴的位置固定了，就相当于齿轮的型号也相应固定了。另外，如果按需求规定了轮轴转速，齿轮的型号也就被确定了，轴的位置也相应调整。
　　Spur gears and helical gears.A gear have tooth elements that are straight and parallel to its axis is known as a spur gear. A spur pair can be used to connect parallel shafts only.
　　If an involute spur pinion were made of rubber and twisted uniformly so that the ends rotated about the axis relative to one another, the elements of the teeth, initially straight and parallel to the axis, would become helices. The pinion the in effect would become a helical gear.
　　正齿轮和斜齿轮：齿尖正对轴心的齿轮称为正齿轮。正齿轮只能用于链接水平轮轴。如果橡胶材料的渐开线小齿轮一起转动，连带轴周围的末端齿轮一起转动，那么正齿轮要换用斜齿轮，实际操作中，小齿轮也应换用斜齿轮。
　　Worm and bevel gears. In order to achieve line contact and improve the load carrying capacity of the crossed axis helical gears, the gear can be made to curve partially around the pinion, in somewhat the same way that a nut envelops a screw. The result would be a cylindrical worm and gear.Worms are also made in the shape of an further increase in load-carrying capacity.Worm gears provide the simplest means of obtaining large ratios in a single pair. They are usually less efficient than parallel-shaft gears, however, because of an additional sliding movement along the teeth.
　　涡轮和锥齿轮：为了善用线接触作用并达到改进轴的承载负荷能力的效果，斜齿轮可以根据部分周围小齿轮来更改其弯曲度，与螺帽配对螺钉是一个道理。这一装置就变成了柱形蜗杆和圆柱齿轮。螺纹的设计也是为了增加承载负荷能力。一对简单的涡轮转动装置就能获得高效率。由于涡轮齿边易滑动，因此涡轮不比平行轴齿轮好。