29. Wire Ropes
Construction: A rope is generally made up of number of strands twisted
around a core. The strands are themselves formed from a number of wires
twisted in a helical fashion. The wires are first formed into strands and then
strands laid around a core to make a rope.
Example: 6X36 (IS: 2266/89). This description means that there are 6
strands in the rope, each consisting of 36 wires.
strength/ load bearing capacity of the wire rope. Usually, if you procure a
rope as per IS specifications, the usual designations are 1770 N/mm2,
1960 N/mm2, or 2160 N/mm2.
30.
31. The manner of laying the strands around the core is termed as lay of the rope
34. The belt conveyor is an endless belt moving over two end pulleys at
fixed positions and used for transporting material horizontally or at
an incline up or down.
The main components of a belt conveyor are:
• The belt that forms the moving and supporting surface on which the
conveyed material rides. It is the tractive element. The belt should
be selected considering the material to be transported.
• The idlers, which form the supports for the carrying and return
stands of the belt.
• The pulleys that support and move the belt and controls its tension.
• The drive that imparts power to one or more pulleys to move the
belt and its loads.
• The structure that supports and maintains the alignments of the
idlers and pulleys and support the driving machinery.
Belt Conveyor
39. Tire nomenclature.
Tread - The part of the tire in contact with the ground. It must provide traction,
long wear and cut resistance. The tread depth and design vary based on site and
application.
Carcass - Contains the inflation medium. The greater its strength, the greater the
pressure it can hold. Bias and bias/belted tire carcasses use many angled plies of
fabric to achieve strength. Radials have one ply of steel wire.
Breakers (Belts) - These are placed between the tread and carcass. They help to
join these parts. They also distribute road shock to protect the carcass. In
bias/belted and radial constructions, they control the diameter of the tire. They
also impart superior tread impact and penetration resistance.
Bead - Bundles of high tensile steel wire. They anchor the tire to the rim. Bias and
bias/belted tires may have several bead bundles. Radials have one large bead
bundle.
Sidewalls - The protective rubber cover on the side of a tire. The rubber is
compounded to flex without cracking. It also resists cuts and forms a barrier to
protect the carcass from the weather.
Inner Liner - Especially formulated rubber compound inside the tire that minimizes
permeation. It works with the rim and O-ring to contain the inflation medium in
tubeless designs
40. TYRE CODING
• 175 - Tyre width
• 80 – Aspect ratio
• R – Radial construction
• 14 – Wheel rim diameter
• 88 – Load index
• H – Speed rating
(The aspect ratio or profile of the tyre is calculated as the
sidewall height expressed as a percentage of the tyre width.
So a tyre with an aspect ratio of 80 is a tyre whose height
is equal to 80% of its width)
175/80 R14 88H
43. Proper tire maintenance
1. Proper inflation
• Over inflation
• under inflation
2. Proper loading
3. Proper speed
44. 4. Effect on heat on tires
• Overloading
• Over speed
• Under inflation
• Quick stops and starts
• Insufficient spacing
between dual tires
5. Driving habits
6. wheel misalignment
7. Storing of tires
8. Road conditions
45. TYRE PATTERN FOR ROAD CONDITIONS
A. Car moderate speed radial.
B. Car high speed radial.
C. Car very high speed radial.
D. Car wet weather radial.
E. Car winter radial with moulded stud
holes.
F. Car winter radial.
G. Light vehicles off I on road winter
tread.
H. Truck steer axle tread.
I. Truck drive axle tread.
J. Truck rough ground tyre.
K. Truck cross-country tyre.
L. Tractor cross country tyre
48. pushing speed= 2.5kmph, return speed = 5kmph,loading time = 0.30min
Note: swell = The ratio of the volume of loose excavation material to the volume of the
same material in place