New to gears.. let us see the introduction to gears, later on we will discuss about the type of gears and the machines used in manufacturing gears..
There was a need for us to develop a gear box with a speed reduction ratio of 128:1 for my project, but there was no one to guide us in designing a gear box. Later on, i sought the help of some teachers in a polytechnic college and completed my gear box. I will now share my ideas regarding how to design a gear box (using spur gears) which will be useful to you. First let us see about the introduction to gears. The below figure shows our gear reduction box.
A gear is a component within a transmission device that transmits rotational force to another gear of device. Gears are the most common means of transmitting power in mechanical engineering. There are tiny gears for devices like wrist watches and there are large gears that some of you might have noticed in the movie Titanic. Gears form vital elements of mechanisms in many machines such as vehicles, metal tooling machine tools, rolling mills, hoisting and transmitting machinery, marine engines, and the like. Toothed gears are used to change the speed, power and direction between an input and output shaft. A gears most important feature is that gears of unequal sizes can be combined to produce a mechanical advantage, so that the rotational speed and torque of the second gear are different from that of the first.
The desired speed reduction (128:1) was obtained by a combination of software and hardware. By hardware, we designed a gear box with a speed reduction ratio of 64:1 (4x4x4) using three gear trains each having a gear ratio of 4:1. By software, we made the stepper motor to run in half step mode, thus achieving the final gear reduction of 128:1(64x2). That is for every 128 rotations of the gear attached to the shaft of stepper motor, the final gear will rotate only once.