BASEPLATE FOR DISK DRIVE SUSPENSION AND METHOD FOR MANUFACTURING BASEPLATE

• US 20130100556A1
• Filed: 12/06/2012
• Published: 04/25/2013
• Est. Priority Date: 05/08/2009
• Status: Active Grant

• Current Assignee: NHK Spring Company Limited, Ogaki Seiko Co., Ltd.
• Original Assignee: NHK Spring Company Limited, Ogaki Seiko Co., Ltd.
• Inventors: YABU, Ryosuke, SUGINO, Masakazu
• Granted Patent: US 8,537,498 B2
• Time in Patent Office: Days
• US Class Current: 360/294.6
• CPC Class Codes: G11B 5/4833 Structure of the arm assembly, e.g. load beams, flexures, parts of the arm adapted for controlling vertical force on the head G11B5/484 takes precedence
• CPC Class Codes: G11B 5/484 Integrated arm assemblies, e.g. formed by material deposition or by etching from single piece of metal or by lamination of materials forming a single arm/suspension/head unit
• CPC Class Codes: G11B 5/56 with provision for moving the head support for the purpose of adjusting the position of the head relative to the record carrier, e.g. manual adjustment for azimuth correction or track centering G11B5/52, G11B5/54, G11B5/58 take precedence
• CPC Class Codes: Y10T 29/49938 Radially expanding part in cavity, aperture, or hollow body

Abstract

A cylindrical boss portion is press-formed on a baseplate of a disk drive suspension. The boss portion is penetrated by a ball insertion hole relative to the thickness of the baseplate. The baseplate is formed of stainless steel. A chemically-polished surface is formed on an inner circumferential wall of the ball insertion hole by chemically polishing the baseplate after heat-treating it. The boss portion is inserted into a mounting hole of an actuator arm. A ball having a diameter larger than the inside diameter of the ball insertion hole is passed through the ball insertion hole. As the diameter of the boss portion is enlarged by the ball, the boss portion is fixed to the actuator arm.

Claims

1. A baseplate of a suspension fixed to an actuator arm of a disk drive, the baseplate comprising a cylindrical boss portion configured to be inserted into a mounting hole formed in the actuator arm,

the boss portion comprising a ball insertion hole, which penetrates the boss portion along an axis thereof, and a chemically-polished surface formed on an inner circumferential wall of the ball insertion hole.

2. A baseplate of a suspension fixed to an actuator arm of a disk drive, the baseplate being formed from heat-treated austenite stainless steel and comprising a cylindrical boss portion configured to be inserted into a mounting hole formed in the actuator arm,

the boss portion comprising a ball insertion hole, which penetrates the boss portion along an axis thereof, and a chemically-polished surface formed on an inner circumferential wall of the ball insertion hole,

the chemically-polished surface having an oxygen-rich layer of which an oxygen concentration is higher than a chromium concentration near a surface,

a thickness of the oxygen-rich layer is thinner than a thickness of a oxygen-rich layer of a non-chemically polished surface, and

a frictional resistance when a ball is inserted in a direction in which the boss portion is pulled is smaller than a frictional resistance when the ball is inserted in a direction in which the boss portion is compressed.