Apparatus for clamping disk and spindle motor having the same
The disk clamp apparatus and a spindle motor having the same according to the present invention has an industrial applicability in that a radial force of a claw on a disk is greater than a radial force of an arm to the disk to prevent the radial force of the arm applying to the disk from affecting the disk, whereby matched center of the clamp body with a center of the disk by the law is not affected by an arm, such that the center of the disk comes to have a relatively smaller deviation from the center and to thereby enhance the reliability of the product.
1. A disk clamping apparatus comprising:
a clamp body configured to be inserted into an inner circumference of a disk;
at least two claws formed in a cantilever way on a lateral surface of the clamp body to apply pressure to an inner lateral surface of the disk with a first elasticity; and
at least two arms formed at a lateral surface of the clamp body to contact a corner formed by the inner circumference of the disk and an upper surface of the disk contacting the inner circumference of the disk and to apply pressure to the inner circumference of the disk with a second elasticity which is weaker than the first elasticity,
wherein a total sum of the first elasticity generated from each claw is greater than a total sum of the second elasticity generated by each arm.
2. The apparatus of claim 1 , wherein the first elasticity is 110% of the second elasticity.
3. The apparatus of claim 2 , wherein the first elasticity is 210% of the second elasticity.
4. The apparatus of claim 1 , wherein the first elasticity is 130˜170% of the second elasticity.
5. The apparatus of claim 1 , wherein a thickness of each claw is 0.45 mm˜0.50 mm.
6. The apparatus of claim 1 , wherein the arm includes a spring interposed between the clamp body and the arm to generate the second elasticity.
7. The apparatus of claim 1 , wherein at least three claws are formed on the clamp body at an even distance thereamong, and the arms are formed among the claws at an even distance thereamong.
8. The apparatus of claim 1 , wherein the claws and the arms are formed on the clamp body in the mutually same number.
9. A spindle motor having a disk clamping apparatus comprising:
a stator;
a rotor having a rotation shaft rotating relative to the stator;
a clamp body coupled to the rotation shaft and inserted into an inner circumference of a disk; at least two claws formed in a cantilever way on a lateral surface of the clamp body to apply pressure to an inner lateral surface of the disk with a first elasticity; and at least two arms formed at a lateral surface of the clamp body to contact a corner formed by the inner circumference of the disk and an upper surface of the disk contacting the inner circumference of the disk and to apply pressure to the inner circumference of the disk with a second elasticity which is weaker than the first elasticity,
wherein a total sum of the first elasticity generated from each claw is greater than a total sum of the second elasticity generated by each arm.
10. The spindle motor of claim 9 , wherein the first elasticity is 110%˜210% of the second elasticity.
11. The spindle motor of claim 10 , wherein the first elasticity is 130%˜170% of the second elasticity.
12. The spindle motor claim 9 , wherein thickness of each claw is 0.45 mm˜0.50 mm.
13. The spindle motor of claim 9 , wherein the arm includes a spring interposed between the clamp body and the arm to generate the second elasticity.
14. The spindle motor of claim 9 , wherein at least three claws are formed on the clamp body at an even distance thereamong, and the arms are formed among the claws at an even distance thereamong.
15. The spindle motor of claim 9 , wherein the claws and the arms are formed on the clamp body in the mutually same number.