KR20070119863A - Spindle motor - Google Patents

Abstract

A spindle motor is provided to prevent oil leakage by using an oil leakage suppressing cover on a coupling tube of a rotor yoke which is coupled with a rotation shaft. A bearing housing(110) has an open upper surface. A bearing(120) is implemented inside the bearing housing. Oil is applied to the bearing. A rotation shaft(130) is rotatably supported by the bearing. A stator(140) includes a core, which is fixed on an outer surface of the bearing housing, and a coil, which is wound around the core. A rotor(150) includes a rotor yoke which is fixed on the rotation shaft, and a magnet which is coupled with the rotor yoke. The rotor is rotated by an interaction between the rotor and the stator. A cover is formed on the rotor yoke and prevents leakage of the oil, which rises along an interface between the rotation shaft and the bearing, as the rotation shaft rotates.

Description

Spindle Motors {SPINDLE MOTOR}

1A is a cross-sectional view of a conventional spindle motor.

1B is an enlarged view of a portion “A” of FIG. 1A.

2A is a cross-sectional view of a spindle motor in accordance with one embodiment of the present invention.

2B is an enlarged view of a portion “B” of FIG. 2A.

Explanation of symbols on the main parts of the drawings

110: bearing housing 120: bearing

130: shaft 140: stator

150: rotor 160: turntable

170: cover

The present invention relates to a spindle motor.

FIG. 1A is a cross-sectional view of a conventional spindle motor, and FIG. 1B is an enlarged view of portion “A” of FIG. 1A, which will be described.

As shown, a bearing housing 13 is provided standing up on the base (11). The bearing 15 is press-fitted into the bearing housing 13, and the lower side of the rotating shaft 17 is supported and rotatably installed in the bearing 15.

A stator 19 having a core 19a and a coil 19b is fixed to an outer surface of the bearing housing 13, and a rotor yoke 21a and a rotor yoke 21a are formed at a portion of the rotating shaft 17 exposed to the upper side of the bearing housing 13. The rotor 21 having the magnet 21b is fixed. Thus, when a current is supplied to the coil 19b, the rotor 21 rotates by the action of the stator 19 and the rotor 21, thereby causing the rotation shaft 17 to rotate.

The bearing 15 is impregnated with oil. When the rotating shaft 17 rotates, the oil impregnated in the bearing 15 flows out to the interface between the bearing 15 and the rotating shaft 17 to form an oil film, whereby the rotating shaft 17 rotates smoothly.

At this time, the oil flowing out of the interface of the bearing 15 and the rotary shaft 17 is raised or lowered along the interface of the bearing 15 and the rotary shaft 17, the raised oil is to the upper outer side of the bearing housing (13) Leaks. In order to prevent this, the stopper 23 is press-fitted to the outer circumferential surface of the rotating shaft 17 above the bearing 15.

The conventional spindle motor as described above has a disadvantage in that the stopper 23 is separately provided and assembled to the rotary shaft 17, thereby increasing the cost by adding parts and adding an assembly process.

Reference numeral 25 denotes a turntable on which the disk 50 is mounted.

The present invention has been made to solve the problems of the prior art as described above, an object of the present invention to provide a spindle motor that can reduce the cost.

Spindle motor according to the present invention for achieving the above object, the bearing housing has an open upper surface; A bearing installed inside the bearing housing and impregnated with oil; A rotating shaft rotatably supported by the bearing; A stator having a core fixed to an outer surface of the bearing housing and a coil wound around the core; A rotor that is rotated by the action of the stator when the rotor yoke is fixed to the rotating shaft and the magnet is coupled to the rotor yoke; And a means formed in the rotor yoke and flowing out of the bearing as the rotary shaft rotates and rising along the interface between the rotary shaft and the bearing to prevent leakage of the outside of the bearing housing.

Hereinafter, a spindle motor according to embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Figure 2a is a cross-sectional view of the spindle motor according to an embodiment of the present invention, Figure 2b is an enlarged view "B" portion of Figure 2a.

As shown, the spindle motor according to the present embodiment has a bearing housing 110, which is provided in a cylindrical shape with an open top surface and is standing on the base 200.

In the bearing housing 110, a ring-shaped bearing 120 having a predetermined height is press-fitted and installed. At this time, the upper surface of the bearing 120 is located below the upper surface of the bearing housing 110. In addition, the bearing 120 is molded by sintering, and the sintered bearing has a plurality of pores formed therein, and the pores are impregnated with oil.

The lower side of the rotating shaft 130 is supported on the bearing 120 is rotatably installed. When the rotating shaft 130 rotates, oil impregnated in the bearing 120 flows out to the interface between the bearing 120 and the rotating shaft 130 to form an oil film. This rotates the rotating shaft 130 smoothly.

A stator 140 having a core 141 and a coil 145 is fixed to an outer surface of the bearing housing 110, and a metal rotor yoke 151 and a magnet are formed on an outer circumferential surface of the rotating shaft 130 above the bearing housing 110. The rotor 150 having 155 is fixed. Thus, when a current is supplied to the coil 145, the magnet 155 rotates due to the action of the electric field generated in the coil 145 and the magnetic field generated in the magnet 155, thereby, the rotor yoke 151 and The rotating shaft 130 rotates.

The turntable 160, on which the disk 50 is mounted, is fixed to a portion of the rotation shaft 130 above the rotor 150.

When the rotating shaft 130 rotates, oil impregnated in the bearing 120 flows out and rises or falls along the interface between the bearing 120 and the rotating shaft 130 by capillary action or fluid adhesion. Then, the oil raised to the upper surface of the bearing 120 is leaked to the outside of the bearing housing 110 by the centrifugal force.

The rotor yoke 151 of the spindle motor according to the present embodiment prevents oil flowing out of the bearing 120 and rising along the interface between the bearing 120 and the rotating shaft 130 to be leaked to the outside of the bearing housing 110. Means are provided.

In detail, the rotor yoke 151 is formed in a cylindrical shape having an open bottom and extends downward from an upper surface of the body 151 a and the body 151 a installed in a form surrounding the stator 140, and an upper side of the bearing housing 110. Rotating shaft 130 of the portion has a coupling pipe (151b) is pressed in combination.

The means extends outward from the outer circumferential surface of the lower end of the coupling pipe 151b and is provided as a ring-shaped cover 170 inserted into the upper end side of the bearing housing 110. Since the cover 170 is inserted into the upper end side of the bearing housing 110, the oil rising along the interface between the bearing 120 and the rotation shaft 130 is blocked by hitting the bottom surface of the cover 170. Therefore, leakage of oil is prevented.

Oil hitting the bottom of the cover 170 flows to the outer circumferential side of the cover 170 along the bottom of the cover 170 by centrifugal force. The oil flowing to the outer circumferential side of the cover 170 along the bottom of the cover 170 is covered by the cover ( Leakage in the gap between the outer peripheral surface of 170 and the inner peripheral surface of the bearing housing 110. In order to prevent this, the protruding frame 173 is formed on the bottom of the cover 170. Since the oil flowing toward the outer circumferential surface side of the cover 170 is blocked by the protruding frame 173 and falls to the upper surface of the bearing 120, leakage of oil is prevented.

Since the rotor yoke 151, the cover 170, and the protruding frame 173 are made of metal, the rotor yoke 151, the cover 170, and the protruding frame 173 may be easily formed by bending the outer circumferential surface of the cover 170.

As described above, the spindle motor according to the present invention is integrally formed with a cover to prevent the leakage of oil in the coupling pipe of the rotor yoke coupled to the rotating shaft, there is no need for a separate oil leakage component. In addition, since a separate process for coupling the component for oil leakage to the rotating shaft is unnecessary, cost is reduced.

In the above, the present invention has been described in accordance with one embodiment of the present invention, but those skilled in the art to which the present invention pertains have been changed and modified without departing from the spirit of the present invention. Of course.

Claims (3)

An open bearing housing; A bearing installed inside the bearing housing and impregnated with oil; A rotating shaft rotatably supported by the bearing; A stator having a core fixed to an outer surface of the bearing housing and a coil wound around the core; A rotor that is rotated by the action of the stator when the rotor yoke is fixed to the rotating shaft and the magnet is coupled to the rotor yoke; And a means formed in the rotor yoke and flowing out of the bearing as the rotary shaft rotates and rising along the interface between the rotary shaft and the bearing to prevent leakage of the oil to the outside of the bearing housing. The method of claim 1, The rotor yoke has a cylindrical body having an open bottom surface and a coupling tube formed on an upper surface of the body and coupled with the rotating shaft, The means is a spindle motor, characterized in that the cover extending from the coupling pipe inserted into the upper end side of the bearing housing. The method of claim 2, Spindle motor, characterized in that the bottom surface of the cover is formed with a protruding frame.

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