V-belts and Ropes PPT

Question 1

is mostly used where a great amount of power is to be transmitted from one pulley to another when the two pulleys are very near to each other.

are made of fabric and cords moulded in rubber and covered with fabric and rubber. These belts are moulded to a trapezoidal shape and are made endless.

Answer 1

V-belt

Question 2

The included angle for the V-belt is usually from

Answer 2

30° to 40°

Question 3

Usually the groove angles of _____ are used.

Answer 3

32° to 38°

Question 4

The power is transmitted by the __________ between the belt and the ________ in the pulley or sheave.

Answer 4

wedging action, V-groove

Question 5

A ______ must be provided at the bottom of the groove in order to prevent touching of the bottom as it becomes narrower from wear.

Answer 5

clearance

Question 6

When one of the set of belts break, the entire set should be
________ at the same time.

Answer 6

replaced

Question 7

is defined as the circumferential length of the belt at the pitch width (i.e. the width at the neutral axis) of the belt.

Answer 7

Pitch length

Question 8

The pitch lengths are obtained by adding to inside length:

36 mm for

Answer 8

type A

Question 9

The pitch lengths are obtained by adding to inside length:

43 mm for

Answer 9

type B

Question 10

The pitch lengths are obtained by adding to inside length:

56 mm for

Answer 10

type C

Question 11

The pitch lengths are obtained by adding to inside length:

79 mm for

Answer 11

type D

Question 12

The pitch lengths are obtained by adding to inside length:

92 mm for

Answer 12

type E

Question 13

are widely used where a large amount of power is to be transmitted, from one pulley to another, over a considerable distance.

Answer 13

rope drives

Question 14

is limited for the transmission of moderate power from one pulley to another when the two pulleys are not more than 8 metres apart.

Answer 14

Flat belt

Question 15

The rope drives use the following two types of ropes:

Answer 15

1. Fiber ropes
2. Wire ropes

Question 16

are usually made from fibrous materials such as hemp, manila (abaca plant fibres) and cotton.

Answer 16

ropes for transmitting power

Question 17

Since the hemp and manila fibres are rough, therefore
the ropes made from these fibres are not very flexible
and possesses ___________

Answer 17

poor mechanical properties

Question 18

have less strength as compared to manila ropes.

Answer 18

hemp ropes

Question 19

very soft and smooth

Answer 19

cotton ropes

Question 20

The diameter of manila and cotton ropes usually ranges from 38 mm to 50 mm. The size of the rope is usually designated by its circumference or

Answer 20

girth

Question 21

For manila ropes, the average value of the ultimate tensile breaking load may be taken as

Answer 21

500 d^2 kN

Question 22

For cotton ropes, it may be taken as ________, where d is the diameter of rope in mm.

Answer 22

350 d^2 kN

Question 23

are usually circular in cross-section.

Answer 23

fiber ropes

Question 24

The groove angle of the pulley or sheave for rope drives is usually

Answer 24

45°

Question 25

The proper size of sheave wheels is _____ and the minimum size is ______, where d is the diameter of rope in cm.

Answer 25

40 d, 36 d

Question 26

The number of grooves should not be more than _____

Answer 26

24