I am in the middle of the game and turn the world. I am trying to do the bridge control but seems i dont have on of the gears to put in the unit. just where did i miss getting one andhow do I go back to get it

It is in the workshop in another time. So time travel and see.

How do I travel back in time

Use the time key in the lock on the wall.

I am near the endof the game and I am tryhing to open the flower buds but I am confused of what to do. i dont know which way to turn the wheels and what to do after that.

1. You have 2 flower buds: one at level 2 and other at level 4. Each of them have alpha, beta and gamma on a part of the bud. If you click the metal stick on any of those parts, you make a sound.
To make the bud open you have to reproduce the sounds that those buds make.

2. Enhance sounds:
There are 3 strings in level 2. They are used to reproduce the sounds. The lever on this strings have to be lowered to make a sound. You can raise a lever of a stand to listen to just one of the strings.
They are also alpha, beta and gamma in order.
At level 3, go to far left and see a harp at end of a long bars - this is the wind collector. You have to adjust this to get maximum sound for the strings.
At level 4, outside go left and look at the wall. See a lever, pull that so that the sound is enhanced.

3. Make sounds.
At level 3, see 3 stands; left to right - alpha, beta and gamma.
Now is the hard part - hit alpha on a metal bud, run here and turn the knob of the left alpha stand to hear if that is the same sound. If not, turn the wheel until you know it is similar to the sound of the metal bud's alpha.
Do this for beta and gamma of that bud.

If the 3 stands reproduce the sound of the metal bud - then it will open.