Stator core and spindle motor including the same

• US 8,912,703 B2
• Filed: 04/09/2012
• Issued: 12/16/2014
• Est. Priority Date: 09/22/2011
• Status: Expired due to Fees

• Current Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Original Assignee: Samsung Electro-Mechanics Co., Ltd. (Samsung Group)
• Inventors: Oh, Song Bon, Oh, Jong Ryeol
• Primary Examiner(s): Lam, Thanh
• Application Number:
  US13/442,362
• Publication Number:
  US 20130076196A1
• Time in Patent Office: 981 Days
• Field of Search: 310/51, 310216093-216094, 310/216.106, 310/216.001, 310/216.008
• US Class Current: 310/216.106
• CPC Class Codes: H02K 1/146 consisting of a generally annular yoke with salient poles
• CPC Class Codes: H02K 21/222 Flywheel magnetos
• CPC Class Codes: H02K 29/03 with a magnetic circuit specially adapted for avoiding torque ripples or self-starting problems

Abstract

There is provided a stator core formed by stacking a plurality of single core sheets, each including a coreback having a central hole formed therein, a plurality of tooth parts extended from the coreback in a radial direction, and extension parts extended from the plurality of respective tooth parts in a circumferential direction, wherein at least one of the plurality of single core sheets includes through-holes formed therein in order to reduce cogging torque, the through-holes being formed in the extension parts.

Claims

1. A stator core, comprising:

a plurality of stacked single core sheets, each single core sheet including a coreback having a central hole formed therein, a plurality of tooth parts extended from the coreback in a radial direction, and extension parts extended from the plurality of respective tooth parts in a circumferential direction,

wherein at least one of the plurality of single core sheets includes through-holes formed therein in order to reduce cogging torque, the through-holes being formed in the extension parts and being closed at one end, and

wherein, among the plurality of single core sheets, an uppermost single core sheet closes the through-holes formed in the remainder single core sheets stacked therebelow.

2. The stator core of claim 1, wherein the through-holes are formed in an axial direction in order to reduce cogging torque.

3. The stator core of claim 1, wherein each through-hole has a circular shape, and a ratio of a diameter of each through-hole to an interval between the extension parts is within a range of 0.5˜

1;

1.

4. A spindle motor comprising:

a rotor part including a rotor hub having a magnet mounted on an inner surface thereof; and

a stator part rotatably supporting the rotor part and including a stator core disposed to face the magnet,

wherein the stator core is formed by stacking a plurality of single core sheets, each single core sheet including a coreback having a central hole formed therein, a plurality of tooth parts extended from the coreback in a radial direction, and extension parts extended from the plurality of respective tooth parts in a circumferential direction, and

at least one of the plurality of single core sheets includes through-holes formed therein in order to reduce cogging torque, the through-holes being formed in the extension parts and being closed at one end, and

among the plurality of single core sheets, an uppermost single core sheet closes the through-holes formed in the remainder single core sheets stacked therebelow.

5. The spindle motor of claim 4, wherein the through-holes are formed in an axial direction in order to reduce cogging torque.

6. The spindle motor of claim 4, wherein each through-hole has a circular shape, and a ratio of a diameter of each through-hole to an interval between the extension parts is within a range of 0.5˜

1;

1.

7. The spindle motor of claim 4, wherein the stator part further includes:

a base member including an installing part having the stator core mounted thereon; and

a sleeve fixed to the installing part, and

the stator core is fixed to an outer peripheral surface of the installing part in order that front edges of the extension parts are disposed to face the magnet.

8. The spindle motor of claim 7, wherein the rotor part further includes a shaft rotatably inserted into the sleeve and having the rotor hub mounted on an upper end portion thereof to thereby rotate together therewith, and

the through-hole is formed to be parallel with the shaft.

9. The spindle motor of claim 4, wherein the through-holes are disposed on extension lines extended from the plurality of tooth parts, and formed in the extension parts.