Matsushita Electric Industrial Co., Ltd.

Panasonic Corporation

Takeyoshi Yamamoto

Yasunori Tokuno

Masahiro Jyono

Taizo Ikegawa

Hiroaki Saito

Satoko Miki

Takao Yoshitsugu

Yoshihiro Ashizaki

Nobuhiro Yoshino

Highly reliable hydrodynamic bearing device and spindle motor are provided as a result of improving cleanliness by using an iron metal having austenite structure, which is a non-magnetic body, and solving the problem of lowering of abrasion resistance due to low hardness. A shaft is formed using an iron metal having austenite structure, and a surface treated layer dispersed with solid lubricant is formed on at least a part of the surface of a shaft facing a sleeve by spraying fine particles of solid lubricant. Cleanliness is improved since the shaft is formed using an iron metal having austenite structure, which is a non-magnetic body. Further, since the surface treated layer dispersed with solid lubricant is arranged on the bearing surface, the abrasion resistance is enhanced and excellent bearing reliability is obtained.

Hydrodynamic bearing device, spindle motor, and method for manufacturing hydrodynamic bearing device

A set of radial dynamic pressure generating grooves constitute a radial bearing, and an entire width (L) of the radial dynamic pressure generating groove is reduced. A set of thrust dynamic pressure generating grooves constituting a thrust bearing are formed so that an area where a maximal thrust dynamic pressure is generated (diameter) is increased, and a bearing angle stiffness of the thrust bearing is increased. The thrust bearing having the high bearing angle stiffness shares a moment load applied to a shaft to thereby compensate for a bearing angle stiffness of the radial bearing whose bearing stiffness is small because an entire width of the radial bearing is small. Thus, a thin-shaped hydrodynamic bearing capable of withstanding a large moment load is obtained.

Hydrodynamic bearing device and spindle motor having the bearing device, and recording and/or reproducing apparatus using the spindle motor

A magnet () for trapping abraded powder is disposed in a connecting passage between an opening of a sleeve and an opening of a hydrodynamic bearing motor, and a shaft (), a sleeve (), a thrust flange (), and a thrust main plate () are made of an austenitic stainless. With this configuration, since the austenitic stainless acting as a nonmagnetic substance is used, it is possible to increase a degree of cleaning. Further, abraded powder of the austenitic stainless is transformed into a magnetic substance, and thus a flow of the abraded powder to the outside can be prevented by providing the magnet for trapping abraded powder in the connecting passage between an opening of a bearing and the outside of the motor.

Dynamic pressure bearing motor

A fluid bearing device capable of responding to miniaturization while preventing an operating fluid such as a lubricating oil from leaking out to the outside. The fluid bearing device includes a shaft and a sleeve arranged on an outer periphery with respect to the shaft with a microscopic gap in between, and has an operating fluid filled in between the shaft and the sleeve. The shaft is formed by a sintered body, a radial dynamic pressure generating groove is formed on an outer peripheral surface of the shaft, and the sleeve is formed by a material not allowing the operating fluid to pass through. The shaft is thus covered by the sleeve formed by a material that does not penetrate the operating fluid such as lubricating oil from the outer periphery side, so that the operating fluid does not leak out to the outside even when the shaft is a porous body made of a sintered body.

Fluid bearing device and spindle motor

A spindle motor includes a shaft including a core spindle member with a large and a small diameter portions and an encircling annulus member attached to the small diameter portion; a rotor hub attached to the large diameter portion; a bearing member; a radial bearing portion provided with first dynamic pressure creating grooves and formed between the outer peripheral surface of the encircling annulus member and the inner peripheral surface of the bearing member; a thrust bearing portion provided with second dynamic pressure creating grooves and formed between a lower end of the encircling annulus member and the bottom of the bearing member; a first opening formed at a radially inner side of the thrust bearing portion; a second opening formed at a radially outer side of the large diameter portion; and a communication hole continuously formed from the first opening to the second opening.

Spindle motor and rotation device having dynamic pressure bearing

A spindle motor which allows appropriate formation of communicating hole for compensating a pressure difference due to an error in working of dynamic pressure generating grooves and other components, easy formation of dynamic pressure generating grooves and readily prevention of leakage of a lubrication fluid is provided. An outer cylindrical member is attached to a shaft, a radial hydrodynamic bearing and a thrust hydrodynamic bearing are provided between the outer cylindrical member and the sleeve, and communicating holes are formed between the shaft and the outer cylindrical member, and between the hub and the outer cylindrical member. Since the collared outer cylindrical member is attached to the shaft, the communicating holes can be readily formed. Also, since a thrust hydrodynamic bearing is formed between an opening of a communicating hole and a seal, a lubrication fluid is unlikely to leak from the seal portion. The outer cylindrical member having the collar portion also enables easy formation of a thrust dynamic pressure generating groove, using inexpensive methods such as pressing.

Spindle motor and rotation apparatus

A hydrodynamic bearing for a hard disk drive device is disclosed. An oil is filled in a clearance between an inner surface of the hub and an outer surface of the shaft, whereby a hydrodynamic radial bearing is formed between the inner periphery of the hub and the outer periphery of the shaft, and a hydrodynamic thrust bearing is formed between the top face of the shaft and the thrust plate. Between an outer peripheral part at the base end of the shaft and an inner peripheral part at the open end of the hub is formed a seal part in which a larger clearance is formed between the shaft and the hub than a clearance in the hydrodynamic radial bearing and in which the oil surface is positioned. An oil surface adjusting hole and a plug for sealing the hole are provided in the case opposite the seal part.

Hard disk drive device, and fluid dynamic bearing spindle motor and assembling method thereof

A dynamic pressure gas bearing motor in which a radial dynamic pressure gas bearing and a thrust dynamic pressure gas bearing are ensured to have sufficient length and diameter even though the clamping screw holes for introducing screws to reliably hold a disk are formed in the top wall of the motor rotation body. The top surface of the support shaft () has a downward recession, the motor rotation body () has a protruded part () facing the recession () of the support shaft and fitted therein with clearance, a radial dynamic pressure gas bearing () is formed by the inner periphery of the motor rotation body and the outer periphery of the support shaft, a thrust dynamic pressure gas bearing () is formed by the protruded part of the motor rotation body and the recession of the support shaft, the thrust dynamic pressure gas bearing is provided below the top end of the radial dynamic pressure gas bearing, and clam screw holes () for holding a disk are formed in the top wall of the motor rotation body above the recession of the support shaft.

Motor using dynamic gas bearings

An object of the present invention to provide a hydrodynamic bearing device and a motor having a high performance and reliability which prevents deterioration in a temperature property due to a difference in coefficients of linear expansion of a sleeve and a shaft and prevents abrasion of bearing surfaces of both the sleeve and the shaft. The sleeve is formed of a copper metal material or an iron metal material and is treated with electroless nickel plating at least on the surface which opposes the shaft. The shaft includes 0.2% by weight C, 0.3% by weight Si, 8% by weight Mn, 0.2% by weight S, 2.5% by weight Ni, and 14% by weight Cr, and a main component of the shaft is a manganese alloy steel including Fe.

Hydrodynamic bearing device and motor

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 gas dynamic bearing motor is provided that is capable of setting a bearing radius to a large value to obtain a sufficient radial stiffness, and preventing lock of the bearing and scattering of wear powder outside the bearing. An annular grooveis provided on a lower end surfaceof a hubto thereby enable a deformation of an inner circumferential surfaceof the hubwhen recording disksare loaded on the hubto be suppressed to a small value, thereby enabling partial contact in the radial bearing to be suppressed and lock of the bearing to be prevented. Further, a protrusionis provided on a basein a circumferential direction and fitted in the annular grooveto construct a labyrinth seal, thereby enabling scattering of wear powder generated on bearing surfaces outside the bearing to be prevented.

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Niihama, Japan

Takeyoshi Yamamoto