CHUCKING MECHANISM, BRUSHLESS MOTOR HAVING THE CHUCKING MECHANISM, AND DISK DRIVING APPARATUS HAVING THE BRUSHLESS MOTOR

• US 20080046905A1
• Filed: 08/20/2007
• Published: 02/21/2008
• Est. Priority Date: 08/21/2006
• Status: Active Grant

• Current Assignee: Nidec Corporation
• Original Assignee: Nidec Corporation
• Inventors: Kuramoto, Satoru, Uchimura, Tomoya, Iwai, Yusuke, Takaki, Hitoshi
• Granted Patent: US 7,921,438 B2
• Time in Patent Office: Days
• US Class Current: 720/707
• CPC Class Codes: G11B 17/0282 by means provided on the turntable

Abstract

A claw member includes at a radially inward surface thereof a protrusion inclined surface in order to minimize deformation occurring in an axial direction to an elastic member which is a coil spring. The protrusion inclined surface is preferably inclined, when a tip portion of the claw member is at an axially lowest point, to be substantially perpendicular to the central axis, or such that the further radially inward a portion thereof is the axially lower the portion is. By virtue of such configuration, the protrusion inclined surface minimizes deformation occurring to the elastic member in the axial direction.

Claims

1. A chucking mechanism operable to detachably set thereon a discoid disk including a central opening portion, the chucking mechanism comprising:

a center case arranged concentrically with a predetermined central axis, including a cylindrical portion which fits the central opening portion, a top plate covering an axially upper side of the cylindrical portion, and a plurality of openings arranged in a circumferential direction extending from the cylindrical portion to an outer circumferential side of the top plate portion;

a claw member movable with respect to the opening, protruding in a radially outward direction from the cylindrical portion, and making contact with the central opening portion of the disk;

a coil spring providing radial force to the claw member; and

a turn table including a disk setting surface setting thereon the disk, wherein

a tip portion arranged at a radially outmost portion of the claw member continues to move in an axially downward direction and a radially inward direction until the disk is set on the disk setting surface,

a protrusion which fits the coil spring is arranged at a surface of the claw member making contact with the coil spring, and the protrusion includes a protrusion inclined surface inclined such that the further radially inward a portion thereof is the axially lower the portion is, and arranged so as not to force the coil spring to be pressed in the axial direction when the tip portion moves in the axially downward direction.

2. The chucking mechanism according to claim 1, wherein a diameter of an area connecting the protrusion and the inner circumferential surface of the claw member is substantially equal to a diameter of the coil spring.

3. The chucking mechanism according to claim 1, wherein the protrusion inclined surface is inclined to be substantially perpendicular to the central axis, or such that the further radially inward a portion thereof is the axially lower the portion is when the tip portion is at an axially lowest point.

4. The chucking mechanism according to claim 1, wherein the claw member includes at a portion on the inner circumferential surface of the claw member below the protrusion in the axial direction an inner circumferential inclined surface inclined such that the further radially outward a portion thereof is the axially lower the portion is, and the inner circumferential inclined surface is substantially parallel with the central axis when the tip portion is at an axially lowest point.

5. The chucking mechanism according to claim 1, wherein the protrusion inclined surface is such that the further radially outward a portion thereof is the smaller the circumferential width is.

6. The chucking mechanism according to claim 1, wherein the center case includes a base portion including a surface making contact with the coil spring,

the turn table includes a leveled portion having a diameter substantially equal to that of the surface, and

the surface makes contact with the base portion and the leveled portion.

7. The chucking mechanism according to claim 6, wherein the surface includes a movement restricting indent portion restricting movement of the coil spring in the circumferential direction, and

the top plate portion includes at a portion below a bottom surface thereof a lower contact surface restricts elastic member from making contact with the top plate.

8. The chucking mechanism according to claim 7, wherein the surface of the base portion includes a plane surface perpendicular to a direction the coil spring extends.

14. A brushless motor including the chucking mechanism according to claim 1, the motor comprising:

a rotor portion having therein a rotor magnet rotating concentrically with the central axis, and

a stator portion having therein a stator arranged opposite from the rotor magnet rotatably supporting the rotor portion.

15. A brushless motor including the chucking mechanism according to claim 2, the motor comprising:

a rotor portion having therein a rotor magnet rotating concentrically with the central axis, and

a stator portion having therein a stator arranged opposite from the rotor magnet rotatably supporting the rotor portion.

16. A disk driving apparatus including the brushless motor according to claim 14, the apparatus comprising:

an optical unit optically storing data on the disk and reproducing data on the disk, and

a gear mechanism moving the optical unit in the radial direction.

17. A disk driving apparatus including the brushless motor according to claim 15, the apparatus comprising:

an optical unit optically strong data on the disk and reproducing data on the disk, and

a gear mechanism moving the optical unit in the radial direction.

9. A chucking mechanism operable to detachably set thereon a discoid disk including a central opening portion, the chucking mechanism comprising:

a center case arranged concentrically with a predetermined central axis, including a cylindrical portion which fits the central opening portion, a top plate covering an axially upper side of the cylindrical portion, and a plurality of openings arranged in a circumferential direction extending from the cylindrical portion to an outer circumferential side of the top plate portion;

a claw member movable with respect to the opening, protruding in a radially outward direction from the cylindrical portion, and making contact with the central opening portion of the disk;

a coil spring providing radial force to the claw member; and

a turn table including a disk setting surface setting thereon the disk, wherein

a tip portion arranged at a radially outmost portion of the claw member continues to move in an axially downward direction and a radially inward direction until the disk is set on the disk setting surface,

the claw member includes at a radially inner surface thereof below the protrusion in the axial direction an inner circumferential inclined surface inclined such that the further radially outward a portion thereof the axially lower the portion is, and

the inner circumferential inclined surface is substantially parallel with the central axis when the tip portion is at an axially lowest point.

10. The chucking mechanism according to claim 9, wherein the center case includes a base portion having a surface making contact with the coil spring,

the turn table includes a leveled portion having a diameter substantially equal to that of the surface, and

the surface makes contact with the base portion and the leveled portion.

11. The chucking mechanism according to claim 10, wherein the surface includes a movement restricting indent portion restricting movement of the coil spring in the circumferential direction, and

the top plate portion includes at a portion below a bottom surface thereof a lower contact surface restricts elastic member from making contact with the top plate.

12. The chucking mechanism according to claim 11, wherein the surface of the base portion includes a plane surface perpendicular to a direction the coil spring extends.

13. A chucking mechanism operable to detachably set thereon a discoid disk including a central opening portion, the chucking mechanism comprising:

a center case arranged concentrically with a predetermined central axis, including a cylindrical portion which fits the central opening portion, a top plate covering an axially upper side of the cylindrical portion, and a plurality of openings arranged in a circumferential direction extending from the cylindrical portion to an outer circumferential side of the top plate portion;

a claw member movable with respect to the opening, protruding in a radially outward direction from the cylindrical portion, and making contact with the central opening portion of the disk;

a coil spring providing radial force to the claw member; and

a turn table including a disk setting surface setting thereon the disk, wherein

a tip portion arranged at a radially outmost portion of the claw member continues to move in an axially downward direction and a radially inward direction until the disk is set on the disk setting surface,

a protrusion is which fits the coil spring is arranged at a surface of the claw member making contact with the coil spring, and

the protrusion includes a step portion inclined such that the further radially inward a portion thereof is the axially lower the portion is indented, and arranged so as not the force the coil spring to be pressed in the axial direction when the tip portion moves in the axially downward direction.