In the whole engine system, when a crankshaft is rotated, a resisting force is generated against the crank shaft caused by the EDT (Equivalent Drive Train), which is connected with a crank shaft. The EDT can include a transmission, clutch, drive shaft, chain, wheel, tire and so on. It is represented as relationship of components such as a EMI (Equivalent Moment of Inertia), stiffness including speed ratio, Drive and Driven body. In general, three types of EDT are used in automotive system. These are a direct-drive, gear-drive and belt-drive type.
(a) Direct Drive Type
(b) Gear Drive Type
(c) Belt Drive Type
Figure 1 Types of Drive System