Patent ID: 6543781
Filing Date: 2003-04-08
Classification: F16C,G11B,H02K

Abstract:
A spindle-drive motor for hard drives having a baseplate, a shaft and one or more bearings for rotational mounting of a rotationally driven rotor, said motor comprising: at least one magnetic fluid seal arranged between the stationary part and the rotating part of said spindle-drive motor, said magnetic fluid seal comprising:an outer part including one upper and one lower yoke lamination and a magnet disk between said yoke laminations being attached to one of the two parts of said spindle-drive motor that can rotate relative to one another, and where the inside of the magnet disk together with the inner areas of the yoke laminations forms a concentric chamber which is open toward the inside on one side to hold a magnetically conducting fluid; a flux concentrating lamination projecting into the chamber and radially overlapping the yoke laminations; said bearing comprising an inner bearing ring having an end face, said flux concentrating lamination being directly in contact with said end face; said bearing comprising an outer bearing ring having an end face, and said magnetic fluid seal outer part being in direct contact with said end face of said outer bearing ring.