Nidec Corporation

Shozo Ibara

Shigeharu Sumi

Yoshito Oku

Hiromasa Fujii

A motor having a bracket with a stator coil for generating a magnetic field and a rotor hub with rotor magnets for receiving a rotation force from the magnetic field generated by the coil. Upper and lower dynamic pressure radial bearings are formed in between the sleeve and the rotary shaft. The lower end surface of the rotary shaft is formed with a spiral groove in which a lubricating fluid is filled to form a dynamic pressure thrust bearing. The spiral groove is formed by a circular hole at the center of the shaft, and a plurality of curved grooves each curving from the circular hole to the direction opposite to the rotation direction of the shaft and gradually increasing its width toward the outer circumference of the lower end surface of the shaft without reaching the circumference. The spiral groove functions to move the lubricating fluid outward in the radial direction from the center of the shaft, when the shaft rotates.

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Kyoto, Japan

Shozo Ibara