How Clutches Work
By Mike Bumbeck/autoMedia.com
Clutch is one of those words that sounds more or less like what it means.
Onomatopoetic, such as it is. Linguistically we'll be dealing with its noun
form here. While one can certainly be caught in the clutches of sin, or the
talons of an eagle, the clutches we'll be focusing on are of the mechanical
variety. These clutches are any of various devices for engaging and
disengaging two moving parts of a shaft, or of a shaft and a driving
mechanism. While many different things in the world contain clutches of some
sort, we'll be focusing on the type that sits between the engine and the
transmission of an automobile equipped with a manual transmission.
The two moving parts in this case are the engine crankshaft and the
transmission input shaft. The engine is the driving mechanism, and the
transmission is the driven mechanism. Since the engine rotates at varying
speeds, and the manual transmission has gears that need to be shifted to
transfer the power of the engine to the wheels, the clutch has a crucial task
when it comes to carefree motoring. By nature of the clutch's hidden location,
it can be difficult to visualize how it works.
A Fork, a Plate, and a Helping of Bearings
While a clutch assembly consists of many small parts, there are five major
components. The first of these is the flywheel. The flywheel is connected
directly to the engine crankshaft and, therefore, spins, as does the engine.
Bolted to the flywheel itself is the second major component, the clutch
pressure plate. The spring-loaded pressure plate has two jobs. One is to hold
the clutch assembly together, and the other is to release its tension to allow
the assembly to rotate freely.