KR100533585B1 - A fluid dynamic bearing motor - Google Patents

Abstract

 Disclosed is a hydrodynamic bearing motor which has a journal bearing length in spite of miniaturization and suppresses conical vibration. It has a coupling hole is formed in the center, the housing 110 is provided with a core 130 concentric with the coupling hole; A hollow lower sleeve 121 fixed to a coupling hole and having a first inner diameter surface 121d and a first hemispherical inner peripheral surface 121c concentrically formed therein; A shaft 140 having a lower end rotatably coupled to the lower sleeve 121; A bearing block 310 fixed to the shaft 140 and having a circumferential surface 313 having a predetermined length between the upper spherical surface 311 and the lower spherical surface 312 and the upper and lower spherical surfaces 311 and 312; Coupled and fixed to the lower sleeve 121 to form a space portion of the shape corresponding to the shape of the bearing block 310 together with the lower sleeve 121, therein the second inner diameter surface (122b) and the second hemispherical inner peripheral surface ( An upper sleeve 122 in which 122a) is formed; A hub 150 whose center is connected to the shaft 140 and is rotated together and has a magnet 160 attached thereto to generate an electromagnetic force by interacting with the core 130 on the inner end surface of the extended end portion; The thrust cover 180 is fixedly coupled to the lower end of the lower sleeve 121 to support the shaft 140.

Such a hydrodynamic bearing motor adopts a spherical bearing in addition to the journal bearing to enable the motor to be miniaturized without significantly reducing the length of the journal bearing, and to have a stable driving characteristic of the motor by suppressing conical vibration. .

Description

A fluid dynamic bearing motor

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fluid dynamic bearing spindle motor, and more particularly, to a fluid hydrodynamic bearing motor having a journal bearing length in spite of miniaturization and suppressing conical vibration.

In general, hydrodynamic bearings that maintain the motor's shaft only by centrifugal lubricating oil pressure have no metal friction because they are based on centrifugal force. The high speed rotation of the disk is also better suited to smoother and higher end hard disk products than ball bearings.

Hydrodynamic bearings in spindle motors typically produce herringbone or spiral hydrodynamic pressure grooves on the inner surface of the sleeve or on the mating surface of the thrust plate, respectively. And the oil is filled into the bearing clearance formed between the shaft and the sleeve or the thrust plate and the sleeve, and the friction members are not in contact with each other due to the dynamic pressure in the bearing clearance. It is a configuration that the frictional load is reduced by making the state.

An example of a motor employing such a hydrodynamic bearing is shown in FIG. 1.

It consists of a fixing member consisting of the housing 10, the sleeve 20 and the core 30, and a rotating member composed of the shaft 40, the hub 50 and the magnet 60.

The sleeve 20 is formed in a hollow shape so that the shaft 40 is rotatably inserted, and a groove (not shown) for generating dynamic pressure is formed on the inner diameter surface thereof so that the fluid dynamic pressure in the radial direction of the shaft 40 can be obtained. Generates. That is, a journal bearing is formed between the sleeve 20 and the shaft 40 to support the rotating members in the radial direction.

In addition, an annular thrust plate 70 is fixedly coupled to the lower end of the shaft 40 so as to be rotatable with the shaft 40 at the inner diameter of the sleeve 20, and at the inner center of the housing 10. The core 30 on which the coil is wound is fixedly mounted.

The thrust plate 70 is formed so that the fluid dynamic pressure in the axial direction is formed by the groove (not shown) for generating the dynamic pressure on the upper surface and the lower surface.

On the other hand, the lower end of the sleeve 20, the inner diameter is shielded by the cover plate 80 is blocked from the outside, the thrust plate 70 is rotated relative to the upper side of the cover plate (80). Therefore, the thrust plate 70 is interposed between the sleeve 20 and the cover plate 80 to form a thrust bearing.

In addition, a hub 50 is integrally coupled to an upper end of the shaft 40 rotatably inserted into the inner diameter portion of the sleeve 20, and the hub 50 has an inner diameter of an extended end portion as a cap shape opened downward. The magnet 60 is installed on the surface to face the outer diameter surface of the core 30.

In such a structure, a fine oil gap is formed between the inner diameter surface of the sleeve 20 and the shaft 40 and the thrust 70, and the oil gap is filled with oil having a predetermined viscosity. .

The oil in the oil gap generates dynamic pressure between the fixing member and the rotating member which is rotated against the surface thereof so that the shaft 40 can be stably driven.

However, in the motor employing the hydrodynamic bearing of the above structure, when the motor is miniaturized, the length of the journal bearing is reduced while the overall height of the motor is reduced. In particular, when the thrust bearing is formed by employing the thrust plate 70 as described above, the length of the journal bearing is further reduced.

In order to suppress the conical vibration, it is required to secure the length of the journal bearing. However, in the above-described configuration, the length of the journal bearing cannot be secured when the motor is designed to be compact.

The present invention has been made to solve the above problems, and despite the miniaturized design, the object of the present invention is to provide a hydrodynamic bearing motor having an improved structure so as to secure a journal bearing length and suppress conical vibration. have.

In the fluid dynamic bearing motor of the present invention to achieve the above object is a fluid dynamic bearing motor in which the rotating member is rotatably supported by the fluid bearing means to the fixed member,

The fluid bearing means is provided with a journal bearing for supporting the rotating member in the direction perpendicular to the axial direction, and a spherical bearing for supporting the rotating member radially,

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A housing having a coupling hole formed at the center thereof, and having a core concentric with the coupling hole;

A hollow lower sleeve fixed to the coupling hole and having a first inner diameter surface and a first hemispherical inner peripheral surface concentrically formed therein;

A shaft having a lower end rotatably coupled to the lower sleeve;

A bearing block fixed to the shaft and having a circumferential surface having a predetermined length between an upper spherical surface and a lower spherical surface and an upper and lower spherical surface;

An upper sleeve coupled to the lower sleeve to form a space having a shape corresponding to the shape of the bearing block together with the lower sleeve, and having a second inner diameter surface and a second hemispherical inner peripheral surface formed therein;

A hub having a magnet attached to the shaft, the magnet being rotated together and having a magnet which generates an electromagnetic force by interaction with the core on an inner end surface of the extended end portion extending downward;

A thrust cover fixed to the lower end of the lower sleeve and rotatably supporting the shaft,

A spherical bearing is formed between the upper / lower spherical surface of the bearing block and the hemispherical inner circumferential surface of the upper / lower sleeve by interposing oil between the upper and lower sleeves and the bearing block, and the inner diameter surface of the upper / lower sleeve. And a journal bearing is formed between the circumferential surface of the bearing block.

In addition, the present invention to achieve the above object is a hydrodynamic bearing motor in which a rotating member is rotatably supported by a fluid bearing means to a fixed member, wherein the fluid bearing means is a journal for supporting the rotating member in the axial direction at right angles. A housing having a bearing and a spherical bearing radially supporting the rotating member, wherein a coupling hole is formed at the center thereof and a core is provided concentrically with the coupling hole;

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A hollow lower sleeve fixed to the coupling hole and having a first hemispherical inner circumferential surface concentrically formed therein;

A shaft having a lower end rotatably coupled to the lower sleeve;

A bearing block fixed to the shaft and having an upper spherical surface and a lower spherical surface;

A third inner diameter surface is fixed to the lower sleeve and a second hemispherical inner peripheral surface is formed therein to form a space portion having a shape corresponding to the shape of the bearing block together with the lower sleeve, and the shaft is rotatably coupled. An upper sleeve formed thereon;

A hub having a magnet attached to the shaft, the magnet being rotated together and having a magnet which generates an electromagnetic force by interaction with the core on an inner end surface of the extended end portion extending downward;

A thrust cover fixed to the lower end of the lower sleeve and rotatably supporting the shaft,

A spherical bearing is formed between the upper / lower spherical surface of the bearing block and the hemispherical inner circumferential surface of the upper / lower sleeve by interposing oil between the upper and lower sleeves and the bearing block, and the third inner diameter surface of the upper sleeve. And a journal bearing is formed between the outer peripheral surface of the shaft and oil.

According to the characteristics of the present invention, the hydrodynamic bearing motor of the present invention employs a spherical bearing in addition to the journal bearing, enabling the motor to be miniaturized design without significantly reducing the length of the journal bearing and to suppress the conical vibration motor To have stable driving characteristics.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

The hydrodynamic bearing motor of the embodiment of the present invention ensures the length of the journal bearing to suppress the occurrence of conical vibration despite the miniaturized design of the motor.

2 and 3 illustrate a motor of an embodiment for realizing the characteristics of the present invention.

The rotating member is rotatably supported by the fluid bearing means on the stationary member, and the fluid bearing means is provided with a journal bearing for supporting the rotating member in a direction perpendicular to the axial direction, and a spherical bearing for supporting the rotating member radially. Has a structure.

The fluid bearing means has a coupling hole is formed in the center, the housing 110 is provided with a core 130 concentric with the coupling hole; A hollow lower sleeve 121 fixed to the coupling hole and having a first inner diameter surface 121d and a first hemispherical inner peripheral surface 121c formed concentrically; A shaft 140 having a lower end rotatably coupled to the lower sleeve 121; A bearing block 310 fixed to the shaft 140 and having a circumferential surface 313 having a predetermined length between an upper spherical surface 311 and a lower spherical surface 312 and upper and lower spherical surfaces 311 and 312; Coupled and fixed to the lower sleeve 121 to form a space having a shape corresponding to the shape of the bearing block 310 together with the lower sleeve 121, the second inner diameter surface 122b and the second inside An upper sleeve 122 in which a hemispherical inner circumferential surface 122a is formed; A hub 150 whose center is connected to the shaft 140 and is rotated together and has a magnet 160 that generates electromagnetic force by interacting with the core 130 at an extended end inner diameter surface thereof; The thrust cover 180 is fixedly coupled to the lower end of the lower sleeve 121 to support the shaft 140.

The lower sleeve 121 is formed with a first coupling groove 121a to which the upper sleeve 122 is coupled, and a second coupling groove 121b to which the thrust cover 180 is coupled.

On the other hand, between the upper and lower sleeves 122, 121 and the bearing block 310 to form a hydrodynamic bearing through the oil. That is, spherical bearings 124 and 123 between the upper and lower spherical surfaces 311 and 312 of the bearing block 310 and the hemispherical inner peripheral surfaces 122a and 121c of the upper and lower sleeves 122 and 121. The journal bearing 125 is formed between the inner diameter surfaces 122b and 121d of the upper and lower sleeves 122 and 121 and the circumferential surface 313 of the bearing block 310.

A fluid groove (not shown) is formed on the outer circumferential surface of the bearing block forming the journal bearing or the inner diameter surface of the sleeve.

The spherical bearings 124 and 123 rotate and support the load of the rotating member including the shaft 140, the hub 150, and a platter, which is a component of the horizontal component and the vertical component. Journal bearing and thrust bearing are adopted at the same time to simultaneously support the load.

Fluid grooves (not shown) are formed on the outer circumferential surface of the bearing block forming the spherical bearing or the inner circumferential surface of the sleeve.

In the motor having the above-described configuration, a rotating member consisting of a shaft 140 and a hub 150 is provided in a core with respect to a fixing member formed of a housing 110, an upper / lower sleeve 122, 121, and a thrust cover 180. It is driven to rotate by the electromagnetic force by the 130 and the magnet (160).

In addition, by adopting the journal bearing 125 between the upper and lower spherical bearings (124, 123), it is possible to suppress the conical vibration, and furthermore, through the spherical bearings (124, 123) simultaneously journal bearing and thrust bearing Therefore, even though the motor is designed to be miniaturized, a separate space for the thrust bearing installation is not required, and thus the overall length of the journal bearing can be used relatively long. Therefore, despite the miniaturized design of the motor, it is possible to stably drive the motor by suppressing conical vibration.

4 and 5 show another embodiment of the fluid hydrodynamic bearing motor of the present invention. In the following description, the same components as those of the hydrodynamic bearing motor of the embodiment will be described with the same reference numerals and the same names.

The fluid bearing means of the hydrodynamic bearing motor of this embodiment includes a housing 110 in which a coupling hole is formed at a center thereof, and a core 130 is provided concentrically with the coupling hole; A hollow lower sleeve 121 fixed to the coupling hole and having a first hemispherical inner peripheral surface 121c concentrically formed therein; A shaft 140 having a lower end rotatably coupled to the lower sleeve 121; A bearing block 310 fixed to the shaft 140 and having an upper spherical surface 311 and a lower spherical surface 312 formed therein; A second hemispherical inner circumferential surface 122a is formed therein and fixed to the lower sleeve 121 to form a space having a shape corresponding to that of the bearing block 310 together with the lower sleeve 121. An upper sleeve 122 having a third inner diameter surface 122c to which the shaft 140 is rotatably coupled; A hub 150 whose center is connected to the shaft 140 and is rotated together and has a magnet 160 that generates electromagnetic force by interacting with the core 130 at an extended end inner diameter surface thereof; The thrust cover 180 is fixedly coupled to the lower end of the lower sleeve 121 to support the shaft 140.

The difference between this embodiment and the above embodiment is that the circumferential surface is not formed in the bearing block 310, and thus, the journal bearing is not formed between the bearing block 310 and the upper / lower sleeves 122 and 121.

In this embodiment, the journal bearing 126 is formed between the third inner diameter surface 122c of the upper sleeve 122 and the outer diameter surface of the shaft 140 by oil.

That is, in this embodiment, the hydrodynamic bearing is provided between the upper and lower sleeves 122 and 121 and the bearing block 310, so that the upper and lower spherical surfaces 311 of the bearing block 310 are separated. Spherical bearings 124 and 123 are formed between the 312 and the hemispherical inner peripheral surfaces 122a and 121c of the upper and lower sleeves 122 and 121, and the third inner diameter surface of the upper sleeve 122 is formed. The journal bearing 126 is formed between oil 122c and the outer peripheral surface of the shaft 140 via the oil.

In this embodiment, the journal bearing and the thrust bearing are formed through the spherical bearings 124 and 123, and the journal bearing 126 is formed on the spherical bearings 124 and 123, thereby reducing the motor size. Nevertheless, the overall length of the journal bearing is not reduced. Accordingly, despite the miniaturization of the motor, conical vibration is suppressed to enable stable driving of the motor.

The present invention as described above is not limited to the above embodiments without departing from the spirit and scope of the present application can be practiced with a number of modifications.

The fluid hydrodynamic bearing motor of the present invention as described above employs a spherical bearing together with a journal bearing to enable the motor to be miniaturized without significantly reducing the length of the journal bearing, and to suppress conical vibration, thereby stably driving the motor. Have characteristics.

1 is a cross-sectional view showing a conventional hydrodynamic bearing motor,

2 is a cross-sectional view showing a hydrodynamic bearing motor of an embodiment of the present invention;

3 is an exploded view of the main part of FIG.

4 is a cross-sectional view showing a hydrodynamic bearing motor of another embodiment of the present invention;

5 is an exploded view illustrating main parts of FIG. 4.

* Explanation of symbols for main parts of the drawings

110 ... housing 121 ... lower sleeve

121a ... first coupling groove (in lower sleeve) 121b ... second coupling groove (in lower sleeve)

121c ... hemispherical inner peripheral surface (lower sleeve) 122 ... upper sleeve

123,124 ... Spherical Bearings 125,126 ... Journal Bearings

130 ... core 140 ... shaft

150 ... hub 160 ... magnet

180 ... Thrust cover 310 ... Bearing block

Claims (3)

delete In a fluid dynamic bearing motor in which a rotating member is rotatably supported by a fluid bearing means to a fixed member, The fluid bearing means is provided with a journal bearing for supporting the rotating member in the direction perpendicular to the axial direction, and a spherical bearing for supporting the rotating member radially, A coupling hole is formed in the center, and the housing 110 is provided with a core 130 concentrically with the coupling hole; A hollow lower sleeve 121 fixed to the coupling hole and having a first inner diameter surface 121d and a first hemispherical inner peripheral surface 121c formed concentrically; A shaft 140 having a lower end rotatably coupled to the lower sleeve 121; A bearing block 310 fixed to the shaft 140 and having a circumferential surface 313 having a predetermined length between an upper spherical surface 311 and a lower spherical surface 312 and upper and lower spherical surfaces 311 and 312; Coupled and fixed to the lower sleeve 121 to form a space having a shape corresponding to the shape of the bearing block 310 together with the lower sleeve 121, the second inner diameter surface 122b and the second inside An upper sleeve 122 in which a hemispherical inner circumferential surface 122a is formed; A hub 150 whose center is connected to the shaft 140 and is rotated together and has a magnet 160 that generates electromagnetic force by interacting with the core 130 at an extended end inner diameter surface thereof; The thrust cover 180 is fixedly coupled to the lower end of the lower sleeve 121 to support the shaft 140. Spherical bearings between the upper and lower spherical surfaces 311 and 312 of the bearing block and the hemispherical inner circumferential surfaces 122a and 121c of the upper and lower sleeves with oil interposed between the upper and lower sleeves and the bearing block. 124, 123, and a hydrodynamic bearing characterized in that the journal bearing 125 is formed between the inner diameter surfaces 122b and 121d of the upper and lower sleeves and the circumferential surface 313 of the bearing block. motor. In a fluid dynamic bearing motor in which a rotating member is rotatably supported by a fluid bearing means to a fixed member, The fluid bearing means is provided with a journal bearing for supporting the rotating member in the direction perpendicular to the axial direction, and a spherical bearing for supporting the rotating member radially, A coupling hole is formed in the center, and the housing 110 is provided with a core 130 concentrically with the coupling hole; A hollow lower sleeve 121 fixed to the coupling hole and having a first hemispherical inner peripheral surface 121c concentrically formed therein; A shaft 140 having a lower end rotatably coupled to the lower sleeve 121; A bearing block 310 fixed to the shaft 140 and having an upper spherical surface 311 and a lower spherical surface 312 formed therein; A second hemispherical inner circumferential surface 122a is formed therein and fixed to the lower sleeve 121 to form a space having a shape corresponding to that of the bearing block 310 together with the lower sleeve 121. An upper sleeve 122 having a third inner diameter surface 122c to which the shaft 140 is rotatably coupled; A hub 150 whose center is connected to the shaft 140 and is rotated together and has a magnet 160 that generates electromagnetic force by interacting with the core 130 at an extended end inner diameter surface thereof; The thrust cover 180 is fixedly coupled to the lower end of the lower sleeve 121 to support the shaft 140. Spherical bearings between the upper / lower spherical surfaces 311 and 312 of the bearing block and the hemispherical inner circumferential surfaces 122a and 121c of the upper and lower sleeves with oil interposed between the upper and lower sleeves and the bearing block. And a journal bearing (126) between the third inner diameter surface (122c) of the upper sleeve and the outer peripheral surface of the shaft.