This is only very rough guessing as I haven't dismantled the Canon A490 before myself but here is what I think it is. Where I have circled Auto-focus drive/gears, were there gears and a lens element attached to a spiral rod? If so, then that's the auto-focus mechanism. If not, I'm not 100% what it is.
I TAKE NO RESPONSIBILITY FOR ANY DAMAGE DONE.
If you want to look further, it looks like all you need to do is rotate the most outer barrel, past the home position and time it so it pops out. It should have teeth visible where I've circled Zoom drive. Keep turning the teeth so the barrel comes towards you but be vary careful not to break or damage the flex.
It was found that the auto-focus mechanism was fixed to the CCD frame and not viewable in the original image
If the zoom and auto-focus gears move freely, I'd consider that OK and reassemble it. There shouldn't be any other flexes, unless the auto-focus mechanism is done more internally (which I doubt), but I can not see where it is.
The apreture and shutter should be OK. The actual blinds/aperture ring is under the element where I have pointed but not circled.
Report back if you'd like just by commenting.
EDIT: So, there will be more moving parts, but not gears. Just arms that sit in the grooves/tracks.
And here is the flip side of the moving piece:
Thanks to Bernd Jendrissek for the image
One might notice that the aperture is only one hole and not made up of blades to change the size of it. That is because most compact cameras have a fixed aperture. If you find that you get different aperture values in the EXIF data, that's due to zooming. As the hole moves away from the sensor, it appears bigger, creating a kind of "pseudo" aperture.