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 Nw = 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 (Tinput) & output torque (Toutput)

 

 

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

 Ninput = NA= 3000 rpm, Tinput = TA= 180 N.m, and the gearbox mechanical Efficiency is hg= 90%.

Find:

A) The 1st gear ratio                           

 

 

B) The Noutput                                                

 

 

D) What type of gearbox is this one?           

 

 

 

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

 

 

F) What is the car speed in the 1st 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 (ig1) of 4.16:1 and final drive ratio (if) of 4.8:1. If the minimum to maximum speeds at each gear changes are (NL) 2100 rpm and (NH) 3000 rpm. Find

a- the minimum to maximum speed ratio (K)

 

 

b- the intermediate gearbox ratios (ig n, ig 2, ig3, …….).