Nippon Densan Corporation

Nippon Densen Corporation

Yoichi Mori

Hiroyuki Yonei

Itsuo Miyaji

Kihachiro Ohta

Kiyoyoshi Takegami

Tadahiro Tanaka

Kiyoharu Noguchi

Hirotada Itoi

Yoshiyuki Kodaira

Takashi Yokoyama

A low airflow hard disk apparatus comprises a base, a cover member, a rotational portion disposed in a disk chamber, a hard disk held by and rotatable with the rotational portion, a first projection portion disposed on the lower surface of the cover member and facing toward the upper surface of the hard disk, and a second projection portion disposed on the upper surface of the base and facing toward the lower surface of the hard disk. The first and second projection portions, preferably radially extending fins, prevent an air flow from generating by the rotation of the hard disk.

Low airflow hard disk apparatus

A circuit and a method of driving a DC motor is provided in which a DC power to be supplied to the DC motor is oscillated in phase for producing a variable torque. As the torque is varied, its peak value increases while its average remains unchanged. Hence, the maximum torque needed for starting rotation will successfully be obtained. Once the rotation starts, a lower torque is accepted for continuous rotation of a load. The rotation can thus be conducted by a lower amplitude of the variable torque. Accordingly, when the rotating torque of the motor becomes low due to increase in unwanted load or declination in capability, the motor can remain operable without troublesome repair or replacement.

Circuit and method of driving a DC motor

A spindle motor includes a housing, a shaft member fixed in the housing, a rotor rotatably supported on the shaft member, a rotor magnet mounted on the rotor, and a stator placed facing with the rotor magnet. The housing and the shaft member are made of materials different in hardness and a sleeve having substantially the same level of hardness as the shaft member is placed between the housing and the shaft member. A bushing is provided between bearing members and the rotor which is rotatably supported by the bearing members. The bushing and a yoke which is mounted on the rotor are secured together in the axial middle part of the bushing. In addition, through holes which enable communications between the interior and exterior area of the motor are provided in the bushing.

Motor

A spindle motor comprises a housing, a hub arranged for rotation on the housing, a couple of bearings interposed between the housing and the hub, a rotor magnet mounted to the hub, and a stator mounted to the housing so as to face the rotor magnet, in which at least one of the two bearings is of single seal type having a seal at one side. Also, a flexible pc film is provided for supply of electric energy to the stator and arranged for improved connection to an armature coil of the stator.

Spindle motor

Growing community of inventors

Shiga, Japan

Yoichi Mori