Braking theory

Whatever the braking system and its use, a brake absorbs external mechanical energy, which may be either potential energy due to gravity (in the case of hoists), kinetic energy (in the case of vehicles), or both (in the case, for example, of a launched vehicle approaching a downhill gradient). The mechanical energy absorbed is returned by the brake in another form, depending on the braking system in question.

We'll confine ourselves to the study of brakes that convert mechanical energy into heat by friction between two solids, as these are the most widespread and economical braking systems: the slowing down or stopping of a moving machine or appliance is due to the frictional resistance generated in a friction member, by the pressure of a body against the rim of a moving rotor.

We can't stress enough the importance of braking, and the care that needs to be taken when choosing the right brakes. Braking systems account for only a small proportion of the cost of an installation, yet they determine both the serenity and smoothness of the machine's operation. They are a key factor in judging the seriousness of the construction.