Why can it mesh with gears of different sizes?

Customer question:Why can it mesh with gears of different sizes?

EP answer:althoughgearThe size of the index circle is different from that of the gear, but as long as the tooth profile is the same, meshing transmission can be carried out.To indicate whether the tooth profile is the same or not, the value obtained by dividing the index circle diameter d (mm) by the number of teeth z (pieces) is the modulus.The modulus (m) has a relationship of m=d/z with the index circle diameter and the number of teeth.

The size of the gear is expressed by the diameter of the addendum circle, the diameter of the root circle, the thickness of the tooth, and the width of the tooth.The point where the gear and the gear mesh with each other is called the meshing point, and the trajectory of this point is called the meshing circle.In order for the gears to mesh smoothly, there must be a moderate tooth gap.

将直径尺寸不同的齿轮组合进行啮合，能够改变传递的旋转速度。设传递运动的主动齿轮与被传递运动的被动齿轮的旋转速度分别为n1和n2、齿数分别为z1和z2、分度圆直径分别为d1和d2，使用模数就能推导出下式所示的传递速度比i的计算式。

Even if the number of meshing gears increases, the formula for this relationship holds (n3 is the rotation speed of the third driven gear, and z3 is the number of teeth of the third driven gear).

That is to say, the gear transmission speed ratio is determined by the gear ratio of the driving gear and the driven gear, and has nothing to do with the number of gears in between.

In addition, the center distance a of the two gear shafts can be expressed by the following formula.

In order to make the gear meshing smoothly, it is necessary to conduct a more in-depth study on the shape of the gear teeth. At present, in the JIS standard, the involute with simple processing method and high production efficiency is used to study the meshing transmission of standard gear teeth.

For more information about gears and gear meshing, please consult EP Technology for free. Ever-Power Transmission- is a brand with 10 years of customized precision gear processing, complete product models and specifications, welcome to buy.