There’s a tradeoff between torque and speed. Imagine if you’re running – there’s a tradeoff between speed and endurance. The only way to improve both is to get more fit/more muscles. Or if you’re riding a bike, you can put it in a high gear to go fast, but you can’t go up hills. If you want to go up hills, you need a higher torque at the cost of lower speed. You can’t increase both speed and torque. The only way to increase both is to have a more powerful engine (or legs, on a bike). You use gear trains to change the torque/speed tradeoff in the event you want a different ratio for your specific application. For example, a Dremel spins really fast so you want to shift the tradeoff so you get more speed, even though you have less torque.
Torque is kinda like force if you don’t do anything to change the end part (I.e. Bicycle wheel, Dremel bit, a car tire).
Types Of Gear Train –
1-Simple gear train: In this type, there is only one gear is mounted on each shaft.
2-Compound gear train: In this type, two or more gears are mounted on each shaft.
3-Riveted gear train: The compound gear train in which input and output shafts are collinear to each other.
4-Epicyclic gear train: In this type, one gear is moving upon and around another gear.