I am not 100% sure what you are asking, but the link you attached is a chain guide. I've never messed with putting a chain guide on any bike, they usually are put on 1X(8,9) speed bikes. I have found a few pics that show people using the one you listed on 3 speed cranks, but I am not exactly sure how that works. Maybe some of the riders that are more experience with single speed cranks will be able to help you.
The bottom bracket is the piece that goes into your frame and holds the crank onto the bike and allows the crank to spin.
Hope this helps a little. you might wanna make a new thread and put the title as "Need help with chain guide" rather than asking about "screw shackle".
Also here is an image of it the piece that you are calling a screw shackle attached to a bike. Is this what you are wanting to do?
Yes, that's it. Translator said that "screw shackle" is correct. So, I'll make new thread. Very thanks