Patent ID: 7794151

Claim:
A fluid dynamic bearing system particularly for the purpose of rotatably supporting a spindle motor, having a first bearing part that comprises a bearing sleeve ( 1 ), and a second bearing part that comprises a shaft ( 2 ), the two bearing parts being spaced apart from one another by a bearing gap ( 5 ) and being rotatable with respect to each other, wherein the bearing sleeve ( 1 ) is closed at one end by a counter plate ( 4 ) that is accommodated in an annular recess in the bearing sleeve and connected to the bearing sleeve by a joint ( 6 ), characterized in that the counter plate ( 4 ) has a thickness (D 1 ) at its middle region and a reduced thickness (D 2 ) at its outer edge and that it is affixed in the region of its reduced thickness (D 2 ) to the bearing sleeve ( 1 ), wherein the reduced thickness (D 2 ) is at most one half of the thickness(D 1 ), wherein the joint ( 6 ) comprises at least one laser or electron beam weld seam having a width, length, depth and continuity consistent with a single laser or electron beam pulse having a pulse power greater than or equal to 200 watts and a feed speed at the weld seam greater than or equal to 300 mm/s.