Drive train tractive effort and vehicle speed

After having dealt with the configuration of the drivetrain, this section deals with the tractive effort . The torque transmitted from the power plant to the driven wheels (T_w) is given by:

(1)

The tractive effort on the driven wheels (Figure 9) is expressed as

                                                                  (2)

Substituting value of T_w from Equation 1 into Equation 2 gives

                                                                                                             (3)

The total mechanical efficiency of the transmission between the engine output shaft and driven wheels is the product of the efficiencies of all the components of the drive train.

The rotating speed of the driven wheel is given by

                                          (4)

The rotatational speed N_p of the transmission is equal to the engine speed in the vehicle with a manual transmission and the turbine speed of a torque converter in the vehicle with an automatic transmission. The translation speed of the wheel ( vehicle speed ) is expressed as

                                                                                                 (5)

By substituting the value of N_w from equation 4 into equation 5 , the vehicle speed can be expressed as

                                                                                                (6)