This, from Alan Sokal (yes, that Sokal, of the "hoax" fame) is excellent on the relationship between philosophy of science and science:
... you know the famous quote from Feynman which says ‘philosophy of science is about as useful for scientists as ornithology is for birds.’ Most people would see that as denigration of philosophy of science, but I don’t see it that way at all. Ornithology is not intended to be useful for birds. In principle ornithologists might, by studying the physics of how birds fly, come up with some suggestions to birds about how they could fly more efficiently, except that natural selection has probably beaten them to it anyway. In the same way, philosophy of science could come up with suggestions for working scientists, but that’s not necessarily its major goal. I like that Feynman quote precisely because it’s not, in my view, pejorative towards philosophers of science. It’s saying that the philosophy of science is different. It clarifies what scientists do whether or not it helps scientists.
There's more where that came from -- here.