Task 4
Task 4:
The three types that we need to provide here, must be made of dry friction material according to task NO 1.
1- Cast iron on cast iron:
First of all, it is a dry friction with 0.21 coefficient friction. This is suitable because it is easy to made and provide our clutch coefficient with 0.21which is near to our demand as with 150 maximum temperature engineering view. But as economy, iron is the cheapest between iron materials and casting is also a cheap way to manufactured.
2- Steel on steel:
Here, steel on steel provides a dry friction coefficient with 0.3. As engineering view this consider as suitable material because it is easy to be manufactured.
And this suitable for economy because of steel consider one of the affordable cost of iron materials comparing to others.
3- Cast iron on steel:
Comes with 0.15 to 0.20 coefficient of friction and consider as dry friction. This actually goes between the first two types, so which is stabile for economy and engineering with 250 temperature.
The best types of the three mentioned above is NO 3 cast iron on steel. Why? Because in our design we are looking for not high coefficient friction not more 0.20 and ability to reach to 250 degree Celsius as it would be longer life span comparing to them.
To make the choice easiest we can find out first the exact coefficient of friction if all the known are available by using this formula: T = n * μ * w * R
Where T is torque transmitted, n number of sides, μ coefficient of friction, and R is mean radius.
The three types that we need to provide here, must be made of dry friction material according to task NO 1.
1- Cast iron on cast iron:
First of all, it is a dry friction with 0.21 coefficient friction. This is suitable because it is easy to made and provide our clutch coefficient with 0.21which is near to our demand as with 150 maximum temperature engineering view. But as economy, iron is the cheapest between iron materials and casting is also a cheap way to manufactured.
2- Steel on steel:
Here, steel on steel provides a dry friction coefficient with 0.3. As engineering view this consider as suitable material because it is easy to be manufactured.
And this suitable for economy because of steel consider one of the affordable cost of iron materials comparing to others.
3- Cast iron on steel:
Comes with 0.15 to 0.20 coefficient of friction and consider as dry friction. This actually goes between the first two types, so which is stabile for economy and engineering with 250 temperature.
The best types of the three mentioned above is NO 3 cast iron on steel. Why? Because in our design we are looking for not high coefficient friction not more 0.20 and ability to reach to 250 degree Celsius as it would be longer life span comparing to them.
To make the choice easiest we can find out first the exact coefficient of friction if all the known are available by using this formula: T = n * μ * w * R
Where T is torque transmitted, n number of sides, μ coefficient of friction, and R is mean radius.