How do you isolate an animated object so you can animate a separate movement?

http://postimage.org/image/45q5os0rr/
I have Created a propeller on a shaft that rotates 360° over 7 frames. I now need the propeller and shaft to slide in and out, but I cannot figure out how to do this because my propeller is animated only in the first 7 fames and I need to add more frames for the shaft to move in and out. I’m sure this can’t be that hard, but I just cant figure out how to do it.
blend file
http://www.pasteall.org/blend/10788
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