types of transmissions
When it comes to transmissions, we can organize our models into several disparate categories. Firstly and most importantly, a transmission can be synchronized or nonsynchronized. This refers to how easy it is to make gears mesh while shifting gears. Whenever a gear is shifted, one pair of gears has to disengage, and another pair has to engage. in synchronized transmissions, these gears can engage at any speed and any position ; in nonsynchronized transmissions, engagement is a matter of making their teeth meet properly, which can succeed or fail, depending on the gears positions and on the difference of their teeth meet properly , they grid their teeth, and we have to try to shift the gear again. We can assume that gears will always engage in synchronized transmissions; in nonchronized ones ones, successful shifting is a matter of the shape of the gears teeth, the speed of shifting, and a degree of luck Some types of gear mesh more easily in nonsynchronized transmissions than others. For example, double-bevel gears, because they are beveled, engage more easily than typical spur gears. Naturally, it's much easier to shift a nonsynchronized transmission while while its input stopped; in a synchronized transmission, it makes no difference.
Secondly, tranmissions can be categorized as sequentail or regular. Sequentail (or linear) tranamissions can only be shifted from one gear to the next closest one. That is, they can be shifted from 2nd to 3rd gear, but they can't beshifted from 2nd to 4th gear directly; instead, they have to shift from 2nd to 3rd and then to 4th. Regular (or nonlinear) transmissions, and they often use elaborate shift sticks, like the one in Figure 17-2. They can shift even from 10 th to 1st gear directly, even though it may be dangerous to change the gear ratio so much so quickly. in real life, sequential transmissions are common in bicycles and motorbikes, while regular ones are found in cars