Table of Contents

What is Gear Train

Gears are used for power transmission from one shaft to another. Sometimes, two or more gears are made to mesh with each other to transmit power from one shaft to another. Such a combination is called a齿轮火车或齿轮火车。

齿轮系取决于以下因素：

轴轴的相对位置。
所需的速度比。

Gear train and its types

以下是不同类型的齿轮列车，这取决于车轮的排列：
1.简单的齿轮系，
2. Compound gear train,
3. Reverted gear train, and
4. Epicyclic gear train.

In the first three types of gear trains, the axes of the shafts over which the gears are mounted are fixed relative to each other. But in case of epicyclic gear trains, the axes of the shafts on which the gears are mounted may move relative to a fixed axis.

简单的齿轮火车

当每个轴上只有一个齿轮时，它被称为简单的齿轮系。
When the distance between the two shafts is small, the two gears 1 and 2 are made to mesh with each other to transmit motion from one shaft to the other, as shown in Fig. 1. Since the gear 1 drives the gear 2, therefore gear 1 is called the driver and the gear 2 is called the driven or follower.
It may be noted that the motion of the driven gear is opposite to the motion of driving gear.

Sometimes, the distance between the two gears is large. The motion from one gear to another, in such a case, maybe transmitted by either of the following two methods :
1. By providing the large-sized gear, or
2. By providing one or more intermediate gears.
The idle gears ( Gear number 2 in fig . b ) are used for the following two purposes:
1. To connect gears where a large center distance is required, and
2.获得从动齿轮的所需运动方向（即顺时针或逆时针）
让N1 = R.P.M中的齿轮1（或驾驶员）的速度。
N2 = R.P.M中的齿轮2（或驱动或追随者）的速度，
T1 =齿轮1上的齿数，和
T2 = Number of teeth on gear 2.

由于齿轮系的速度比（或速度比）是驾驶员的速度与驱动或跟随器的速度的比率，并且在网眼中的任何一对齿轮的速度比的比率是它们的齿数的倒数，所以

速比=（n1 / n2 = t2 / t1）

速度比=（驱动驾驶员/速度的速度）=（驱动/驾驶员齿号的齿数）

复合轮系:

When there is more than one gear on a shaft, as shown in Fig. , it is called a compound train of gear.
我们在上一节中看到了空闲齿轮，在简单的齿轮中的齿轮中不会影响系统的速度比。但这些齿轮可用于桥接驾驶员和驱动之间的空间。但是，只要驾驶员和驱动或从动件之间的距离必须通过中间齿轮桥接并且同时需要大（或更小）的速度比，因此通过提供复合齿轮即可加强中间齿轮的优点中间轴。
In this case, each intermediate shaft has two gears rigidly fixed to it so that they may have the same speed. One of these two gears meshes with the driver and the other with the driven or follower attached to the next shaft as shown in Fig.

复合系通过简单齿轮系的优点是可以用小齿轮获得从第一轴到最后轴的更大减速。如果使用简单的齿轮系来减速，则最后一轮必须非常大。通常为了减速超过7比1的速度，不使用简单的火车，并且采用复合列车或蜗杆传动装置。

速比=（最后驱动的第一驾驶员/速度的速度）=（驱动/产品的齿数的牙齿驾驶员数量的速度）

恢复了齿轮火车

Reverted Gear Train:When the axes of the first gear (i.e. first driver) and the last gear (i.e. last driven or follower) are co-axial, then the gear train is known as reverted gear train as shown in Fig.
恢复齿轮系非常像复合齿轮系一样。当速度或功率输出的巨大变化的欲望时，它们都使用它们，但是限制了用于容纳多个齿轮的空间。
A reverted gear train is also a compound gear train, having the input and output shafts on the same axis (Co-axial). If these two gears are mounted on the same shaft, one of them must be loosely mounted. And also the distance between the centers of the two gears in each pair must be the same.
The gear transmission ratio is calculated similarly like a compound gear train.

环状齿轮火车：

Epicyclic gearing also called as planetary gearing. It is a gear system that consists of one or more outer gear (planet gear) rotating about a central (sun gear). The planet gear is mounted on a moveable arm (carrier) which itself may rotate relative to the sun gear. Epicyclic gearing systems may also incorporate the use of an outer ring gear or annulus, which meshes with the planet gears.

该图示出了环状传动装置的示例。它用于提高输出速度。行星齿轮架由输入扭矩驱动。太阳齿轮提供输出扭矩，而环形齿轮是固定的。