Seiko Instruments Inc

Mitsuharu Iwamoto

Hiromitsu Goto

Shinji Kinoshita

Yukihiro Nakayama

Ryoji Yoneyama

Chihiro Tazawa

Toru Kumagai

Tetsuya Nagata

Tadao Iwaki

Naoki Kawawada

Takafumi Suzuki

A fluid injection apparatus for a bearing includes a bearing support surface for supporting the bearing so that a seal space is defined between the support surface and the bearing, a fluid injection passage comprised of an oil tank, a first conduit connecting the oil tank to the seal space, and an injection valve provided in the conduit, a decompression passage comprised of an oil recovery tank, a second conduit connecting the oil recovery tank to the seal space, a vacuum pump connected to the seal space through the oil recovery tank, and a decompression valve provided in the second conduit, and a sequence control unit for evacuating the bearing by closing the injection valve, opening the decompression valve, and turning on the vacuum pump, and then filling the bearing with lubricating oil by turning off the vacuum pump, closing the decompression valve, and opening the injection valve.

Fluid injection apparatus for fluid dynamic pressure bearing

In a hydraulic bearing motor, by means of dynamic pressure generating grooves provided on a thrust shaft with a larger diameter not only on the end face thereof but also on the shaft surface thereof, pressures generated in oil when rotating a shaft body are made to be applied not only in the axial direction but also in the radial direction with high magnitude. This can provide the hydraulic bearing motor as being capable of satisfying features of exhibiting small NRRO, and vibration and shock resistance even with a thinned hydraulic bearing motor.

Hydraulic bearing motor

A hydraulic dynamic pressure bearing motor has a rotational shaft mounted to undergo rotation about a rotational axis and having a shaft section and a flange section. A sleeve has a cavity for receiving the rotational shaft. A cover member is disposed over an open end of the sleeve cavity. A hydraulic dynamic pressure bearing includes minute radial and thrust clearances disposed between outer surface portions of the shaft and flange sections of the rotational shaft and inner surface portions of the sleeve and the cover member. A lubricating fluid is disposed in the minute radial and thrust clearances. The minute radial and thrust clearances are dimensioned so that during a non-rotational state of the rotational shaft, the flange section of the rotational shaft contacts preselected inner surface portions of the sleeve and the cover member while the shaft section of the rotational shaft does not contact any portion of the sleeve and an inner peripheral surface of the cover member.

Hydraulic dynamic pressure bearing motor

In a method for assembling a spindle motor having a liquid dynamic pressure bearing having a flanged shaft member formed by press-fitting a dynamic pressure ring member on a cylindrical member, a hub is press-fit on the flanged shaft member without causing deviation in the press-fit position of the dynamic pressure ring member. A hub press-fitting apparatus press fits a mount hole of the hub on a cylindrical end portion of the cylindrical member. The hub press-fitting apparatus comprises a hub holding member, a rotation shaft member, a coupling member, and an anti-rotation member. During assembly, a temporary coupling between the hub press-fitting apparatus and the liquid dynamic pressure bearing is made by screwing a threaded tap in a tap hole provided in an end face of the cylindrical member.

Spindle motor and method of formation

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Chiba, Japan

Mitsuharu Iwamoto