Hitachi Global Storage Technologies Netherlands B.v.

Yuji Ishima

Masaru Muranishi

Kazuyoshi Hanada

Kenji Tomida

Embodiments of the invention provide a magnetic disk drive promoting even higher densities, greater capacities, and further reduction in size, while relaxing component accuracy requirements. In one embodiment, the magnetic disk drive includes a magnetic disk receiving member and a magnetic disk holding member, a magnetic disk being rotatably held with the magnetic disk clamped therebetween. The receiving member makes a line contact with a surface of the magnetic disk on a circumference of a circle formed around a rotational axis of the magnetic disk.

Magnetic disk drive with line contact

Embodiments of the invention prevent trouble caused by an increase in viscosity of grease generated when a ball bearing operates at a low temperature, and fretting that an inner ring and/or an outer ring comes in contact with balls to produce wear when vibration is applied thereto. In one embodiment, a ball bearing is configured such that a plurality of balls are arranged between an outer ring and an inner ring. Grease is filled between the balls, the inner ring and the outer ring. A holder is provided with a spring plate, and an extreme end thereof is always in contact with the balls. The spring plate is formed of a sufficiently softer material than the balls so as not to damage the balls. The mounted direction is one along the direction in which the balls are desired to be rotated. Appropriate spring pressurization can be applied to the balls at an angle defined by the holder and the spring plate in the root at which the holder is attached to the spring plate.

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Kanagawa, Japan

Yuji Ishima