WIRE ROPES PPT

Question 1

Wire Ropes are made from _____________ that are first wrapped into strands; then wrapped into helices around a core or central element, which is usually hemp or pulp.

Answer 1

cold-drawn wires

Question 2

Often, the core or central element is an independent wire rope core (IWRC) which makes the rope much

Answer 2

more resistant to crushing

Question 3

IWRC, compared to hemp core, is ______________________, has about ________________ and has ____________________.

Answer 3

high-temperature resistant, 7.5% greater strength, smaller elongation under load

Question 4

are used when a large amount of power is to be transmitted
over long distances from one pulley to another (i.e. when the pulleys are up to 150 metres apart).

are widely used in elevators, mine hoists, cranes, conveyors, hauling devices and suspension bridges.

run on grooved pulleys but they rest on the bottom of
the grooves and are not wedged between the sides of the grooves.

Answer 4

Wire ropes

Question 5

the direction of twist of wires in the strands is opposite to the direction of twist of the strands; such type of ropes are most popular.

Answer 5

Cross or regular lay ropes

Question 6

the direction of twist of the wires in the strands is same as that of strands in the rope

Answer 6

Parallel or lang lay ropes

Question 7

the wires in the two adjacent strands are twisted in the opposite direction.

Answer 7

Composite or reverse laid ropes

Question 8

The _______________ should be fairly large in order to reduce the bending stresses in the ropes when they bend around the sheaves or pulleys.

Answer 8

sheave diameter

Question 9

should be employed which give better and more economical service, if space allows so.

Answer 9

Large diameters

Question 10

For light and medium service, the sheaves are made of __________, but for heavy crane service they are often made of __________.

Answer 10

cast iron, steel castings