Patent ID: 7699529

Claim:
A fluid dynamic radial bearing having pressure-generating surface patterns, having at least two bearing parts ( 1 , 2 ) that are rotatable with respect to each other and form a bearing gap ( 3 ) filled with a bearing fluid between associated bearing surfaces, the surface patterns being disposed on at least one bearing surface and generating hydrodynamic pressure within the bearing gap when the bearing parts rotate with respect to each other, each surface pattern ( 9 ; 10 ; 11 ; 12 ; 13 ) comprises at least three sections ( 9 a , 9 b , 9 c ; 10 a , 10 b , 10 c ; 11 a , 11 b , 11 c ), bent with respect to each other, each section having a different length compared to the length of the other sections and generating a pumping action in a defined direction, and the pumping actions of adjacent sections being substantially directed in opposite directions, the surface patterns ( 9 ; 10 ; 11 ; 12 ; 13 ) being developed asymmetrically and generating a pumping action substantially directed in one direction of the bearing gap ( 3 ), the different lengths of the at least three sections of each surface pattern decreasing in the one direction of the bearing gap ( 3 ), whereby there are at least three sections with the third section generating a pumping action equidirectional to the first section.