How to keep my coworkers at arms length without them realizing it?

I'm very tired of being involved in the gossip of my work place because I don't care about who is doing what. I keep talking about my life because my coworkers keep asking and if I don't tell they consider me cold has anyone mastered the art of keeping coworkers at arms legnth and working without people knowing your there, yet they know you do your job and your good at it too? Can anyone explain the art of disguise of a working cna/ Victorian ninja doll? In a step by step process?

Answer: 
It's very common for co-workers to be interested in each other's personal lives. It gives an illusion of friendship. However, you recognize that this type of "friendship" is not the real thing. My suggestion: Bore them stiff with prattle about what groceries you bought yesterday, the pattern of your dishes, the trouble you had with your Hoover, and similar impersonal topics. If they zero in with questions about your personal problems or relationships, just be vague and say, "Oh, there's really nothing to tell – I get along fine with my friends and family." There's nothing wrong with having a reserved personality. As you say, though, things run more smoothly when you know subtle ways of deflecting nosy questions.