The Name, as it is pronounced, is known, and can be known. Ask any rabbi, or cohen who is observant. It is just not said, except twice, on Yom Kippur, and only by the High Priest, and only when a Temple is in existence, in obedience to the command "Do not profane My Holy Name." How is it profaned? When it is not holy. Therefore to make his Name common, from this logic, is to profane it.
However, as a living example of the Torah, I tend to take the position and thus engage in the living example of our Master, Rabbi Yeshua, who when reading from the scroll of Isaiah in the synagogue concerning a passage that was directly fulfilled in the hearing of their hears, used a circumlocution written as "Kurios" in the Greek, translated as Adonai in Hebrew, or simply "Lord" in English. Had Yeshua pronounced the Name as written (and he certainly knew it), he probably would have been thrown out of the synagogue, and the Greek translator/writer of the gospel would have left evidence of this in an attempt to transliterate what Yeshua said rather than serve a translation.
So then, since my Master used a circumlocution even when reading from the scripture in a synagogue, even as it was fulfilled by its reading, then how much more so I will use circumlocutions for anything else less than that.
We also find Moshe using circumlocution when addressing HaShem directly, but I'll have to look up the verse for you. In short, the Torah teaches us to use circumlocution as well.
Shalom,
Josephus