Patent ID: 8512084

Claim:
An underwater thruster comprising: a housing unit defining a retaining space therein and having a first opening in spatial communication with said retaining space; a cover unit connected water-tightly to said housing unit, covering said first opening, and defining a protective space therein that communicates spatially with said first opening; a supporting unit connected to said housing unit and disposed in said protective space; a motor disposed in said retaining space and having a driving shaft that extends through said first opening along an axis; a magnetic core unit that is connected co-rotatably to said driving shaft and that extends along the axis into said protective space; a plurality of magnetic intermediate units that are disposed on said supporting unit, that surround said magnetic core unit, and that are driven rotatably and magnetically by said magnetic core unit when said magnetic core unit rotates; a magnetic surrounding unit that surrounds said cover unit, that is driven rotatably and magnetically by said magnetic intermediate units when said magnetic intermediate units rotate, and that has a rotational speed lower than that of said magnetic core unit; and a propelling unit connected co-rotatably to said magnetic surrounding unit, and having a plurality of angularly spaced-apart blades that surround the axis.