This is because the two-way static and dynamic oil cushion has a wedge on both sides in the circumferential direction. When the table rotates counterclockwise, the small wedge-shaped port on the countercurrent side enters and the large port exits, resulting in unloading. However, there is no wedge on the countercurrent side of the one-way static and dynamic pressure oil cushion, so the oil film pressure of the two-way static and dynamic oil cushion is less than that of the one-way static and dynamic oil cushion.