I need some creative input for a story i'm writing

AlphaLeague

So I'm writing a story that takes place in a dystopia steampunk setting. There are four branches of the city. The working class, military, aristocratic branch and the capital. I don't want to call them exactly by that and I want the names to be modeled after different parts of a machine. For example, the working class would be called the cogs, as they provide the basic function for the city, or machine. I was wondering if some really creative people here could help me contemplate some of the other names?

Blind Sniper

Crank or Regulator - Aristocratic Branch

Belt - Military

Reservoir - Capital

I got the part names from this link below. You can look at the list and see what else you find if you want to use something different instead of my suggestions.

http://www.macmillandictionary.com/us/thesaurus-category/american/parts-of-machines-and-machinery