Disc clamp with balancers providing improved durability and balance and spindle motor having the same
A disc clamp and a spindle motor having the same is provided, the disc clamp according to an exemplary embodiment comprising: a disc clamp body; a first disc balancer projected from the disc clamp body in the horizontal direction and configured to have a first thickness; and a second disc balancer bent downwards from an end of the first disc balancer to fix the disc and configured to have a second thickness, wherein an angle between a horizontal surface of the first disc balancer and the second disc balancer is in the range of 92° to 95°.
1. A disc clamp, comprising:
a disc clamp body;
a first disc balancer formed in a plate shape having an upper surface and a bottom surface, wherein the first disc balancer is extended from a side of the disc clamp body in a horizontal direction and configured to have a first uniform thickness; and
a second disc balancer formed in a plate shape having an inner side surface and an outer side surface, wherein the second disc balancer is straightly and downwardly extended from an edge portion of the first disc balancer and configured to have a second uniform thickness,
wherein the edge portion formed between the upper surface of the first disc balancer and the outer side surface of the second disc balancer along an entire periphery of the disc clamp body has a curved surface,
wherein the second disc balancer has an angle θ1 arranged obliquely in a range of 2.0° to 5.0° clockwise with respect to a vertical direction,
wherein an angle (θ) between the upper surface of the first disc balancer and the outer side surface of the second disc balancer is in a range of 92° to 95°, and
wherein a ratio of the first thickness to the second thickness is in a range of 1.5 to 1.8.
2. The disc clamp according to claim 1 , wherein a balance ratio formed by the angle (θ) of the first and second disc balancers is from 60 μm to 70 μm, and an insertion force of the disc clamp is from 200 [gf] to 300 [gf].
3. A spindle motor, comprising:
a stator configured to include a bearing housing engaged with a base plate, a bearing inserted into the bearing housing, a core engaged with an outer circumferential surface of the bearing housing, and a coil wound around the core;
a rotational axis rotatabiy engaged with the bearing;
a rotor configured to include a yoke engaged with the rotational axis, and a magnet fixed inside the yoke and facing the core; and
a disc clamp including;
a disc clamp body;
a first disc balancer formed in a plate shape having an upper surface and a bottom surface, wherein the first disc balancer is extended from a side of the disc clamp body in a horizontal direction and configured to have a first uniform thickness; and
a second disc balancer formed in a plate shape having an inner side surface and an outer side surface, wherein the second disc balancer is straightly and downwardly extended from an edge portion of the first disc balancer and configured to have a second uniform thickness,
wherein the edge portion formed between the upper surface of the first disc balancer and the outer side surface of the second disc balancer along an entire periphery of the disc clamp body has a curved surface,
wherein the second disc balancer has an angle θ1 arranged obliquely in a range of 2.0° to 5.0° clockwise with respect to a vertical direction,
wherein an angle (θ) between the upper surface of the first disc balancer and the outer side surface the second disc balancer is in a range of 92° to 95°, and
wherein a ratio of the first thickness to the second thickness is in a range of 1.5 to 1.8.
4. The disc clamp according to claim 3 , wherein a balance ratio made by the angle (θ) of the first and second disc balancers is from 60 μm to 70 μm, and an insertion force of the disc clamp is from 200 [gf] to 300 [gf].