Automotive Engineering I	Time 2 hrs.
Student Name:	Student Number:

1- Answer only 4 of the requirements in each of the questions 1-A and 1-B. In case there are more than 4 answers and you don’t indicate what your choices are, the first four answers will be marked.

 

A) What are the differences between?

a- Work and torque.

i)                                                                           ii)

b- Manual gearbox and torque converter.

i)                                                                           ii)

c- Manual gearbox and planetary gearbox.

i)                                                                           ii)

d- Universal joints and constant velocity (CV) joints.

i)                                                                           ii)

e- Semi floating axle and fully floating axle.

i)                                                                           ii)

 

 

B- What are the parameters which contribute to INCREASE in the following?

a- Engine Torque (T_e):

i)                                                                           ii)

b- Car tractive effort (TE):

i)                                                                           ii)

c- Car speed (v):

i)                                                                           ii)

d- Air resistance (AR):    

i)                                                                            ii)

e- Rolling resistance (RR):        

i)                                                                           ii)

 

 

 

 

2- A) Complete the following table:

 

Part	Job	Types
Gear box	1-	1-
	2-	2-
Drive axle	1-	1-
	2-	2-

 

B) Find:

i) the tire radius if the size marking on the tire is 225/65R16 97W SP SPORT 270

 

 

 

 

 

ii) the speed of output shaft [the carrier (c)]of planetary gearbox.

The annulus (ring) gear (a) is the input shaft and the sun gear (s) is the fixed shaft.

The number of gears teeth are a = 100, s = 40. The input shaft speed is 2800 rpm.

 

 

 

 

 

 

3- The figure shows an arrangement of gearwheels. The input shaft runs at 2000 rpm with an input torque (T_in) of 175 N.m. The efficiency of the gearing is 90%. Calculate:

a) the gearbox reduction ratio (ig)
b) the output torque (Tout).

c) the input power (P_in)

 

 

 

 

d) the car speed (v) if the back axle ratio is 4.32 and final reduction efficiency is 80% and the tire radius (R_w) is 0.38 m

 

 

 

 

e) the car tractive effort (TE).

 

 

 

 

4- A car having the following characteristics:

- engine develops its maximum power at 6000 rpm.

- car mass (m) of 1200 kg.

- car frontal area (A_f) 2.4 m²

- car coefficient of air resistance (0.4).

- car rolling radius (R_w) 0.36 m

- coefficient of wheel rolling resistance (f_r) is 0.02

and the air density (r) is 1.2 kg/m³

a) Find the car air resistance (AR) at a car speed (v) of 180 km/h.

 

 

 

b) the rolling resistance (RR) at the same car speed.

 

 

 

c) the car tractive effort (TE) if the car maximum speed on the direct drive is 180 km/h

 

 

 

e) the back axle ratio of the car (i_f).

 

 

 

f) the car maximum power (P_max).