Disk device and unbalance correcting method thereof
View Patent ↗In a disk device, having disks 2 and a hub 4 for holding thereof, to be attached onto a shaft 5 of a spindle motor, for rotary drive thereof, a groove 42 is formed on a bottom surface of a flange portion 41 of the hub 4 , for receiving therein. A balance weight 8 to be received in this groove 42 has elasticity and an outer configuration of about “C”, and further, in a portion thereof is attached at least one (1) piece of an auxiliary weight or more, thereby achieving unbalance correction at high accuracy with an aid of the balance weight. After being attached with one (1) piece or more of the “U” shaped auxiliary weight(s) directing it/them from an inner periphery to an outer periphery thereof, the “C” shaped balance weight is inserted or fitted into, while being suppressed a little bit in an inside thereof. Therefore, a disk device and the unbalance correcting method for that, can be obtained, in which spaces necessary for attaching and detaching are less, but enabling the balance correction at high accuracy.
1. A disk device, to be attached onto a spindle motor for rotary drive thereof, comprising:
a disk recording medium; and
a rotary portion, having an essentially cylindrical shape, for holding said disk recording medium;
wherein a balance weight receiving portion having a recess for a balance weight is formed on at least one of both end surfaces of said rotary portion about an axis of rotation thereof;
wherein said balance weight to be received in said balance weight receiving portion is substantially in the shape of the letter “C”; and
wherein at least one auxiliary weight is attached to a portion of said balance weight, said auxiliary weight having a rectangular shape and being smaller than said balance weight.
2. A disk device as described in claim 1 , wherein said auxiliary weight has an substantially “U” shaped cross-section and is attached to the portion of said balance weight in such a direction that an opening portion of said “U” shape directs from an inner periphery to an outer periphery of said “C” shaped balance weight.
3. A disk device as described in claim 2 , wherein said auxiliary weight has an elasticity and is attached to said balance weight such that a portion of said balance weight is between the “U” shaped cross-section thereof.
4. A disk device as described in claim 2 , wherein said auxiliary weight is attached onto the portion of said balance weight through welding.
5. A disk device as described in claim 2 , wherein said auxiliary weight is attached onto the portion of said balance weight through bonding.
6. An unbalance correcting method for a disk device having a disk recording medium and a rotary portion, having substantially cylindrical shape, for holding said disk recording medium, wherein a balance weight receiving portion having a recess for a balance weight is formed on at least one of both end surfaces of said rotary portion about an axis of rotation thereof, comprising the following steps of:
preparing a balance weight in substantially the shape of the letter “C”;
measuring an unbalance of said rotary portion;
attaching at least one auxiliary weight to a portion of said balance weight based upon the measured unbalance; and
attaching said balance weight, having said at least one auxiliary weight attached thereto, into said recess of said balance weight receiving portion.
7. An unbalance correcting method for a disk device as described in claim 6 , wherein:
said balance weight has an elasticity; and
said balance weight is inserted into said recess while being compressed.
8. An unbalance correcting method for a disk device as described in claim 6 , wherein said “C” shaped balance weight forms an arc having a center angle greater than or equal to 180 degrees.
9. An unbalance correcting method for a disk device as described in claim 6 , wherein said disk recording medium is one of an optical disk or a magnetic disk.
10. An unbalance correcting method for a disk device as described in claim 6 , wherein said “C” shaped balance weight is removable from said rotary portion.
11. A disk device as described in claim 1 , wherein said “C” shaped balance weight forms an arc having a center angle greater than or equal to 180 degrees.
12. A disk device as described in claim 1 , wherein said disk recording medium is one of an optical disk or a magnetic disk.
13. A disk device as described in claim 1 , wherein said “C” shaped balance weight is detachable from said rotary portion.
14. A disk device, to be attached onto a spindle motor for rotary drive thereof, comprising:
a disk recording medium; and
a rotary portion, having a substantially cylindrical shape, for holding said disk recording medium;
wherein a balance weight receiving portion having a recess for a balance weight is formed on at least one of both end surfaces of said rotary portion in a direction of rotation thereof;
wherein said balance weight to be received in said balance weight receiving portion is formed from a metal plate cut substantially in the shape of the letter “C”; and
wherein at least one auxiliary weight is attached to a portion of said balance weight, said auxiliary weight having a rectangular shape and being smaller than said balance weight.
15. A disk device as described in claim 14 , wherein said “C” shaped balance weight forms an arc having a center angle greater than or equal to 180 degrees.
16. A disk device as described in claim 14 , wherein said disk recording medium is one of an optical disk or a magnetic disk.
17. A disk device as described in claim 14 , wherein said “C” shaped balance weight is removable from said rotary portion.