I don't know how limes are, but I have a miniature banana tree going on it's second year in a pot, without any fruit yet. I hear you have to fertilize the crap out of them though, basically every time you water or once a week, add fertilizer.

May be different for limes though...

What variety of lime is it?
Is it self fertile? Not all are, those that aren't may need help with pollination.
Is the tree outdoors? Do you see bees or other insects around it? If not you might need to hand pollinate it.
Keep in mind if the tree is or becomes stressed or is growing under less than optimal conditions it may drop whatever fruit it might have.