How can I "combine" shapes with a stroke in Illustrator?

So I created a logo in Illustrator. I used multiple shapes and set the stroke to 1 px to get the white spacing.

The first example in the upper left corner shows it at the size I designed it. The example on the right side shows it if I make it larger. And when I make it smaller it looks light the example on the bottom.

I understand that it does that, because the stroke is always 1 px but the does not change proportionally when scaling the graphic.

What can I do to change this behaviour? Is it possible to combine the shapes or convert the stroke to a shape?

Thank you!