Automotive Engineering I	Exam 2-c	1st Semester 1427/28
Student Name:		Student Class No.    /

1- If a tire size marking has the following P205/75R15 95H

A- Find the tire free radius

 

 

 

B- What will be the car speed if the N_w = 1000 rpm, and the rolling radius is 85% of the free one.

 

 

 

C- What does 95 in size marking stand for?

 

 

 

2-What are the types of car live axles and stresses each one has?

Axle types	Axles’ stresses
-   -   -	-   -   -

3- What are the differences between the following(ما الفروق بين التالي) ?

- Two speed & Double reduction axle 

 

 

 

 

- Transaxle & Transfer gearbox

 

 

 

 

- Straight bevel & Hypoid final drive gears

 

 

4- Write down the relation between the following quantities (أكتب العلاقة بين الكميات التالية)

-Axle speed & wheel speed for a car with a hub reduction

 

 

- Gearbox input torque (T_input) & output torque (T_output)

 

 

5- If the input to gear A is equal to:

 N_input = N_A= 3000 rpm, T_input = T_A= 180 N.m, and the gearbox mechanical Efficiency is h_g= 90%.

Find:

A) The 1^st gear ratio                           

 

 

B) The N_output                                                

 

 

D) What type of gearbox is this one?           

 

 

 

E) If the final drive ratio i_f is 4.1 what is the overall gear ratio?

 

 

F) What is the car speed in the 1^st gear if the tire rolling radius is 0.3 m?

 

 

 

6- A transmission system for a vehicle is to have a first gear reduction ratio (i_g1) of 4.16:1 and final drive ratio (i_f) of 4.8:1. If the minimum to maximum speeds at each gear changes are (N_L) 2100 rpm and (N_H) 3000 rpm. Find

a- the minimum to maximum speed ratio (K)

 

 

b- the intermediate gearbox ratios (i_{g n,} i_{g 2}, i_g3, …….).