problem with a pulley (i don't even know the name of the part)

[ALEX POLO]

I have this Ford explorer 2005 4.0 sportrac, and last night one of the pulleys started to spark and it smelled like burning metal.

I want to know if thats something easy to repair but, I don't even know the name of the part.

Can someone help/, picture attached

Thanks guys!!

/Users/johnfloyd/Desktop/100_0637.JPG/Users/johnfloyd/Desktop/100_0638.JPG/Users/johnfloyd/Desktop/100_0642.JPG

 

[ALEX POLO]

I dont know how to upload the pictures, I'm using a Mac

 

[ALEX POLO]

/Users/johnfloyd/Desktop/100_0642.JPG/Users/johnfloyd/Desktop/100_0638.JPG/Users/johnfloyd/Desktop/100_0637.JPG

 

[Clusterpup]

You need to host the photo someplace like photobucket or imageshack then link to it.