Bearing system and spindle motor assembly adopting the same

• US 6,215,219 B1
• Filed: 07/20/1999
• Issued: 04/10/2001
• Est. Priority Date: 07/28/1998
• Status: Expired due to Term

• Current Assignee: Samsung Electronics Co. Ltd.
• Original Assignee: Samsung Electronics Co. Ltd.
• Inventors: Hwang, Tae-yeon
• Primary Examiner(s): NGUYEN, TRAN N
• Application Number:
  US09/358,391
• Time in Patent Office: 630 Days
• Field of Search: 310/90.5, 310/90, 310/91, 384/110-120, 384/100, 384/107, 298/980.2
• US Class Current: 310/90.5
• CPC Class Codes: F16C 39/063 Permanent magnets
• CPC Class Codes: Y10T 29/49639 Fluid bearing

Abstract

A bearing system and a spindle motor assembly adopting the same are provided. The bearing system includes a lower base on which a fixed shaft is installed, a cylindrical body fit on the fixed shaft, first and second magnetic bodies installed on the upper and lower ends of the cylindrical body, respectively; a third magnetic body installed so as to face the second magnetic body on the lower end of the cylindrical body, a fourth magnetic body facing the first magnetic body on the upper end of the cylindrical body at a predetermined space, and an upper base to which the fourth magnetic body is fixed and which is fixed to the upper portion of the fixed shaft. Accordingly, a vibration source which generates vibration during rotation due to defects of ball bearing components and cumulative processing errors caused upon conventional ball bearing support is removed by axially and radially supporting the rotating body in a non-contact way, thereby achieving a super-high rotation speed and super-accurate rotation of the rotating body.

Claims

1. A bearing system comprising:

a lower base on which a fixed shaft having a predetermined diameter is installed;

a cylindrical body having a larger inner diameter than the fixed shaft, fit around but unconnected to the fixed shaft;

first and second magnetic bodies installed on the upper and lower ends of the cylindrical body, respectively;

a third magnetic body installed on a lower portion of the fixed shaft so as to face the second magnetic body on the lower end of the cylindrical body, the third magnetic body having magnetic repulsion against the second magnetic body;

a fourth magnetic body facing the first magnetic body on the upper end of the cylindrical body, the fourth magnetic body having magnetic repulsion against the first magnetic body; and

an upper base to which the fourth magnetic body is fixed and which is fixed to the upper portion of the fixed shaft.

2. The bearing system as claimed in claim 1, wherein a predetermined number of wedge portions are formed on the inner circumferential surface of the cylindrical body, the predetermined number being the number of wedge portions required for the cylindrical body to become distant from the fixed shaft.

4. The bearing system as claimed in claim 2, wherein the cylindrical body is constituted of two cylindrical bodies, a maximum dynamic pressure is generated from the geometrical center of each of the upper and lower cylindrical bodies, and the rotating body is supported by the upper and lower cylindrical bodies.

5. The bearing system as claimed in claim 1, wherein the cylindrical body is constituted of two cylindrical bodies, a maximum dynamic pressure is generated from the geometrical center of each of the upper and lower cylindrical bodies, and the rotating body is supported by the upper and lower cylindrical bodies.

3. A bearing system comprising:

a lower base on which a fixed shaft having a predetermined diameter is installed;

a cylindrical body having a larger inner diameter than the fixed shaft, fit on the fixed shaft;

first and second magnetic bodies installed on the upper and lower ends of the cylindrical body, respectively;

a third magnetic body installed on a lower portion of the fixed shaft so as to face the second magnetic body on the lower end of the cylindrical body, the third magnetic body having magnetic repulsion against the second magnetic body;

a fourth magnetic body facing the first magnetic body on the upper end of the cylindrical body, the fourth magnetic body having magnetic repulsion against the first magnetic body; and

an upper base to which the fourth magnetic body is fixed and which is fixed to the upper portion of the fixed shaft, wherein a predetermined number of wedge portions are formed on the inner circumferential surface of the cylindrical body, the predetermined number being the number of wedge portions required for the cylindrical body to become distant from the fixed shaft, and

wherein the wedge portion includes;

an arc-typed flat portion having the same core as the core of the fixed shaft;

a tapered portion extending from the flat part to be distant from the fixed shaft; and

a groove portion extending from the tapered portion and formed so as to become distant from the center of the fixed shaft.

6. A bearing system comprising:

a fixed shaft having a predetermined diameter;

a base by which the fixed shaft is supported; and

a cylindrical body penetrated by the fixed shaft,

wherein the inner diameter of the cylindrical body is larger than the outer diameter of the fixed shaft, the cylindrical body includes a flat portion whose core is co-aligned with the core of the fixed shaft;

a tapered portion extending from the flat portion to be distant from the fixed shaft; and

a groove extending from the tapered portion and formed so as to become distant from the center of the fixed shaft, and the flat portion, the tapered portion, and the groove portion are formed on the inner circumferential surface of the cylindrical body.

7. The bearing system as claimed in claim 6, wherein the cylindrical body is constituted of two cylindrical bodies.

8. A spindle motor assembly comprising:

a spindle having a cylindrical part formed on a center of the spindle, and a rotor formed on a lower portion of the spindle;

a lower base which penetrates the cylindrical part of the spindle, and on which a fixed shaft having a predetermined diameter is installed, and on which a stator facing the rotor is installed;

a cylindrical body having a larger inner diameter than the fixed shaft, the fixed shaft penetrating the cylindrical body, the cylindrical body being disposed in and fixed to the cylindrical part of the spindle, the spindle and the cylindrical body fitting around and being unconnected to the fixed shaft;

first and second magnetic bodies installed on upper and lower ends of the cylindrical body, respectively;

a third magnetic body installed on a lower circumference of the fixed shaft so as to face the second magnetic body on the lower end of the cylindrical body, the third magnetic body having magnetic repulsion against the second magnetic body;

a fourth magnetic body facing the first magnetic body on the upper end of the cylindrical body, the fourth magnetic body having magnetic repulsion against the first magnetic body; and

an upper base to which the fourth magnetic body is fixed and which is fixed to the upper portion of the fixed shaft.

11. The spindle motor assembly as claimed in claim 8, wherein the cylindrical body is constituted of two cylindrical bodies.

9. A spindle motor assembly comprising:

a spindle having a cylindrical part formed on a center of the spindle, and a rotor formed on a lower portion of the spindle;

a lower base which penetrates the cylindrical part of the spindle, and on which a fixed shaft having a predetermined diameter is installed, and on which a stator facing the rotor is installed;

a cylindrical body having a larger inner diameter than the fixed shaft, the fixed shaft penetrating the cylindrical body, and being disposed in and fixed to the cylindrical part of the spindle;

first and second magnetic bodies installed on upper and lower ends of the cylindrical body, respectively;

a third magnetic body installed on a lower circumference of the fixed shaft so as to face the second magnetic body on the lower end of the cylindrical body, the third magnetic body having magnetic repulsion against the second magnetic body;

a fourth magnetic body facing the first magnetic body on the upper end of the cylindrical body, the fourth magnetic body having magnetic repulsion against the first magnetic body; and

an upper base to which the fourth magnetic body is fixed and which is fixed to the upper portion of the fixed shaft,

wherein the inner diameter of the cylindrical body is larger than the outer diameter of the fixed shaft, the cylindrical body includes a flat portion whose core is co-aligned with the core of the fixed shaft;

a tapered portion extending from the flat portion to be distant from the fixed shaft; and

a groove portion extending from the tapered portion and formed so as to become distant from the center of the fixed shaft, and a predetermined number of flat portions, tapered portions, and groove portions are formed on the inner circumferential surface of the cylindrical body, the predetermined number being the number of flat portions, tapered portions, and groove portions required for the cylindrical body to become distant from the fixed shaft.

10. The spindle motor assembly as claimed in claim 9, wherein the cylindrical body is constituted of two cylindrical bodies.

12. A spindle motor assembly comprising:

a spindle having a cylindrical part formed on a center of the spindle, and a rotor formed on a lower portion of the spindle;

a lower base which penetrates the cylindrical part of the spindle, and on which a fixed shaft having a predetermined diameter is installed, and on which a stator facing the rotor is installed;

a cylindrical body having a larger inner diameter than the fixed shaft, the fixed shaft penetrating the cylindrical body, the cylindrical body being disposed in and fixed to the cylindrical part of the spindle, the spindle and the cylindrical body fitting around and being unconnected to the fixed shaft;

first and second magnetic bodies installed on upper and lower ends of the cylindrical body, respectively;

a third magnetic body installed on a lower portion of the fixed shaft so as to face the second magnetic body on the lower end of the cylindrical body, the third magnetic body having magnetic repulsion against the second magnetic body;

a fourth magnetic body facing the first magnetic body on the upper end of the cylindrical body, the fourth magnetic body having magnetic repulsion against the first magnetic body; and

an upper base to which the fourth magnetic body is fixed and which is fixed to the upper portion of the fixed shaft,

wherein flanges are formed on far ends of the cylindrical portions, and the cylindrical part of the spindle is formed according to a shape of the outer circumferential surface of the cylindrical body and a shape of the flange installed on the cylindrical body.

13. A spindle motor assembly comprising:

a spindle having a cylindrical part formed on a center of the spindle, and a rotor formed on a lower portion of the spindle;

a lower base which penetrates the cylindrical part of the spindle, and on which a fixed shaft having a predetermined diameter is installed, and a stator facing the rotor is installed;

an upper base fixed to the upper part of the fixed shaft; and

a cylindrical body which has a larger inner diameter than an outer diameter of the fixed shaft disposed in and fixed to the cylindrical part of the spindle, the cylindrical body being penetrated by the fixed shaft,

wherein the cylindrical body includes a flat portion having a same core as a core of the fixed shaft, a tapered portion extending from the flat portion to be distant from the fixed shaft, and a groove extending from the tapered portion and formed so as to become distant from the center of the fixed shaft, and the flat portion, the tapered portion, and the groove portion being formed on an inner circumferential surface of the cylindrical body.