# US 8,572,638 B2 · Motor and optical disk drive using the same with chamfered and fractured parts on rotor case

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- Number: US 8,572,638 B2
- Document ID: US8572638B2
- Status: Granted
- Kind: B2
- Application number: 13/067,734
- Filed: 2011-06-22
- Published: 2012-03-29
- Granted: 2013-10-29
- Earliest claimed: 2010-09-28
- Assignees: Samsung Electro-Mechanics Co., Ltd.
- Applicants: Dong Yeon Shin; Dae Lyun Kang
- Inventors: Dong Yeon Shin; Dae Lyun Kang
- Web page: https://patentgrep.com/patent/US8572638B2

## CPC

- H02K 15/14: Casings; Enclosures; Supports
- G11B 19/2009: {Turntables, hubs and motors for disk drives; Mounting of motors in the drive (means for clamping of disk to turntable G11B17/022 and subgroups)}
- Y10T 29/49009: Dynamoelectric machine
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})
- G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R)
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

There are provided a motor capable of preventing scratches from occurring on an outer surface of a rotor case thereof, a method for manufacturing the same, and an optical disk drive using the same. The motor includes a shaft rotatably inserted into a bearing assembly; and a rotor case fixedly fastened to the shaft and rotating together with the shaft, wherein the rotor case is provided with a chamfered part along the outer peripheral edge of the bottom surface thereof. The rotor case includes a rotor hub fastened to an end of the shaft; an extending part extending in an outer-diameter direction from the rotor hub; and a vertical extending part formed to be vertically extended downwardly in a shaft direction from an outer peripheral edge of the extending part and having the chamfered part formed on the bottom end surface thereof.

## Claims

### Claim 1

A motor, comprising:
a shaft rotatably inserted into a bearing assembly; and
a rotor case fixedly fastened to the shaft, and the rotor case rotating together with the shaft and including a rotor hub fastened to an end of the shaft, an extending part extending in an outer-diameter direction from the rotor hub, a chamfered part along an outer peripheral edge of a bottom surface thereof, and a vertical extending part formed to be vertically extended downwardly in a shaft direction from an outer peripheral edge of the extending part and having the chamfered part formed on the bottom end surface thereof,
wherein a fracture part having a rough surface is formed to come into contact with the chamfered part at a top portion of the chamfered part along an outer peripheral edge of the vertical extending part.

### Claim 2 (depends on 1)

The motor of claim 1, wherein the fracture part is a cutting surface formed by pressurizing and cutting the rotor case by press machining.

### Claim 3 (depends on 1)

An optical disk drive, comprising:
a motor of claim 1; and
an optical pickup mechanism movably mounted in a lower space of a disk equipped in the motor and receiving data from the disk.

### Claim 4 (depends on 1)

The motor of claim 1, wherein the chamfered part is formed to have any one of an inclined surface, a curved surface, and a groove.