The name is the plain Hebrew word for wheels. Ezekiel 1:15-21 places one beside each of the four living creatures of the opening vision: a wheel upon the earth, its construction described as a wheel in the middle of a wheel, its rims high and dreadful and full of eyes round about. The wheels go wherever the creatures go and rise with them, and they do not turn as they go, because the spirit of the living creature is in them.
That single passage is the whole of the scriptural warrant. Nothing else in the Hebrew Bible describes the ophanim, and nothing in Ezekiel calls them a rank of angels; they are part of the apparatus of the throne-chariot, the merkabah, rather than a separate order of beings with duties of their own. The later reading, which turns them into the second rank of a ten-rank hierarchy, is an inference drawn from the vision by readers who wanted a hierarchy, not a statement the vision makes.
What the passage does give is an image of unusual precision, and it is the reason the ophanim are one of the few angelic ranks with a fixed visual form. A wheel that contains another wheel set across it can move in any direction without pivoting, which is exactly the property Ezekiel insists on, and the eyes set around the rim make the mechanism a seeing thing rather than merely a turning one. Chariot mysticism, the tradition of contemplative ascent that took Ezekiel's first chapter as its founding text, kept both details.