Fluid dynamic bearing, fluid dynamic bearing device, and motor

A fluid dynamic bearing comprising a first dynamic pressure generating part and a second dynamic pressure generating part that are provided in an inner peripheral surface so as to be spaced apart from each other in an axial direction, wherein

• each of the first and second dynamic pressure generating parts includes a first part and a second part, the first part having dynamic pressure generating grooves that are tilted in a direction to be displaced to one side in a circumferential direction as going toward one axial direction, and the second part having dynamic pressure generating grooves that are tilted in a direction to be displaced to the one side in the circumferential direction as going toward another axial direction,
• the first dynamic pressure generating part also includes an annular hill part located axially between the first part and second part of the first dynamic pressure generating part,
• the dynamic pressure generating grooves of the first part and the second part of the second dynamic pressure generating part are continuous in the axial direction, and the second dynamic pressure generating part does not include an annular hill part located axially between the first part and second part of the second dynamic pressure generating part,
• a tilt angle, with respect to the circumferential direction, of the dynamic pressure generating grooves of the first part and the second part of the first dynamic pressure generating part is 20 degrees or less, and
• a tilt angle, with respect to the circumferential direction, of the dynamic pressure generating grooves of the first part and the second part of the second dynamic pressure generating part is more than 20 degrees and 40 degrees or less.