Grinding my gears

[Speaking clock]

I was cleaning the garage the other day when I stumbled upon some gears my father found years ago in the north folk southern Sharon yard. They are larger than a quarter but smaller than a half dollar. They have pentagon shaped holes in the center.I shall try to get a good picture of them online soon. Does anybody know what these gears were used for? 

Note: they were lying in the ballast alongside a bolt, which leads us to think an engine broke down and dropped its gears or something like that. We had permission to enter etc.

[ndbprr]

They definitely would not be gears for moving a locomotive. Without knowing the timeframe and the type locomotive as well as any markings any answer would be speculative. Possibly an event recorder or lubricator but they may not even be from a locomotive.

[Speaking clock]

Thanks, I can't find the gears but they're half an inch thick and they're about as big as a half dollar. They had a decent amount of grease when I found them so a lubricator seems a logical source.