Matsushita Electric Industrial Co., Ltd.

Nobuhiro Yoshino

Takeyoshi Yamamoto

Shinichi Minakuchi

A spindle motor is provided in which an end portion of a winding of a coil maintains insulation from a base and the end portion of the winding of the coil can be easily threaded through a hole of a printed circuit board when the end portion of the winding of the coil is drawn out. For this, the spindle motor includes a base fixed with a stator having a coil, an insulating sheet provided between the stator and the base, and a printed circuit board provided in the base on an outer side of the motor. Holes are formed in the base, insulating sheet and printed circuit board so as to communicate with each other, and an winding end portion of the coil is led out to the outside of the motor. The diameter C of the holein the printed circuit board and the diameter B of the holeof the insulating sheet are smaller than the diameter A of the holeof the base, and the diameter C of the holeis larger than the diameter B of the hole

Spindle motor

A motor having a dynamic-pressure type bearing device includes a cylindrical sleeve fixedly secured to a base, a shaft rotatably inserted into a hollow of the cylindrical sleeve, a hub fixedly secured to an end portion of the shaft, a ring-like rotor magnet fixedly secured to the hub, and an armature fixedly secured onto the base to be in opposed relation to the rotor magnet so as to constitute a motor driving device. Further, the motor has a disc-like plate coaxially and fixedly secured to an end portion of the shaft to have a diameter of the disc-like plate greater than a diameter of the shaft and a plate disposed in opposed relation to a surface of the disc-like plate. The bearing device includes a radial dynamic-pressure groove assembly having a predetermined groove configuration to generate a radial dynamic pressure in a radial direction of the shaft and an axial dynamic-pressure groove assembly having a predetermined groove configuration to generate an axial dynamic pressure in an axial direction of the shaft. The radial dynamic-pressure groove assembly is formed in at least one of an outer circumferential surface of the shaft and an inner surface of the cylindrical sleeve which face each other and the axial dynamic-pressure groove assembly is formed in at least one of the surface of the disc-like plate and a surface of the plate disposed in opposed relation to the surface of the disc-like plate.

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Matsuyama, Japan

Nobuhiro Yoshino