JPH1070870A - Spindle motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent deformation of optical disc due to heat occurred in a spindle motor, by providing a stator core arranged oppositely to a rotor magnet with a predetermined gap between them and stator coils wound round a plurality of tooth poles, thereby constituting a stator, and by fixing the bearing of a rotation shaft by including the stator in a base. SOLUTION: Rotor magnets 4 are fixed along the outer face of circumference of a rotor 3 rotating around a rotation shaft as a center. And a stator is formed by a stator core 6 consisting of a plurality of tooth poles 7 made of a magnetic material arranged opposite to the rotor magnets 4 in radial direction with a predetermined gap provided between them. And the stator is included in a base 9 made of a resin and a bearing 2 of a rotation shaft 1 is fixed. By doing this, expansion or deformation of an optical disc due to heat generated by a spindle motor 11 can be prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a disk device for reproducing information recorded on a disk-shaped recording medium, and for example, to a spindle motor mounted on an optical disk device.

[0002]

2. Description of the Related Art FIG. 5 is an overall perspective view of a conventional optical disk device. In FIG. 5, reference numeral 40 denotes a spindle motor for rotating an optical disk (not shown). Details of the configuration will be described later. Reference numeral 41 denotes an optical pickup unit for reading information recorded on the optical disk, and reference numeral 42 denotes a tray for attaching and detaching the optical disk. The tray 42 is provided with a substantially U-shaped notch 42a for projecting a hub portion provided on the spindle motor 40 from an optical disk mounting portion of the tray 42. 43 is a spindle motor 40
Frame for attaching or storing the tray 42 or
Reference numeral 44 denotes an optical disk device, which includes the components denoted by reference numerals 40 to 43 described above.

FIG. 6 is a sectional view of the spindle motor 40 taken along a line AA 'shown in FIG. In FIG. 6, 40a
Is a rotating shaft, 40b is a bearing for the rotating shaft 40a, and 40c is a hub for chucking the optical disk, and is fixed to the tip of the rotating shaft 40a. 40d is a bearing 40
b is a laminated stator core fixed to b. Reference numeral 40e denotes a stator coil for generating a magnetic field, which is wound around the teeth of the stator core 40d. 40f is a rotor, which is fixed to the rotating shaft 40a. Reference numeral 40g denotes a rotor magnet attached to the inner peripheral surface of the rotor 40f, which is arranged to face the tooth pole of the stator core 40d from the inner peripheral surface. A base 40h fixes the bearing 40b by swaging or the like. Numeral 40 denotes a spindle motor, which includes a configuration to which reference numerals 40a to 40h are assigned. The spindle motor 40 is of a so-called outer rotor type in which a radial gap type in which a gap is provided between a tooth pole of a stator core 40d and a rotor magnet 40g and a rotor 40f as a rotor is provided outside the stator core 40d. It is a spindle motor.

Next, the operation will be described with reference to FIGS. The optical disk is placed on the tray 42 shown in FIG. 5, and the tray 42 is moved in the direction of the arrow. When the optical disk is stored in the optical disk device 44 together with the tray 42, the spindle motor 40 moves upward, and the hub 40c shown in FIG. The hub 40c protrudes from the notch 42a and chucks the optical disk.

When a current flows through the stator coil 40e shown in FIG. 6, the tooth poles of the stator core 40d are magnetized to generate a magnetic field, and this magnetic field causes the rotor 40f, to which the rotor magnet 40g is attached, to rotate about the rotating shaft 40a. Rotate. The rotation of the rotor 40f causes the optical disk chucked by the hub 40c to rotate. The information is reproduced by reading information recorded on the rotating optical disk by the optical pickup unit 41.

[0006]

In the conventional spindle motor 40 mounted on the conventional optical disk device 44, the temperature of the stator coil 40e and the stator core 40d rises mainly due to heat generated by the internal resistance of the stator coil 40e. In particular, the outer rotor type spindle motor 40
As shown in FIG. 6, the rotor 40f is
Since d and the stator coil 40e are covered, the temperature rise of the stator core 40d and the stator coil 40e becomes large. If the temperature becomes extremely high, there is a problem that the performance of the spindle motor 40 is adversely affected.
Further, since the spindle motor 40 is usually arranged at a position very close to the optical disk, the optical disk locally expands and deforms due to a local temperature rise near the spindle motor 40, and the optical disk rotates due to the expansion deformation. There is a problem that the surface deflection at the time becomes large, which adversely affects the reading accuracy of the optical pickup unit 41.

In particular, today, there is a demand for high-speed reading and high-speed transfer of information recorded on an optical disk, and therefore, a high-speed rotation of the spindle motor 40 is required. To rotate the spindle motor 40 at high speed,
It is sufficient to increase the value of the current flowing through the stator coil 40e. However, doing so increases the problem of heat generation described above.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problems, and has excellent heat radiation properties, and can prevent the heat generated by the spindle motor from adversely affecting the performance of the spindle motor and preventing the optical disk from expanding and deforming. The purpose is to obtain a spindle motor.

[0009]

A spindle motor according to the present invention comprises a rotor fixed to a rotating shaft and rotating about the rotating shaft, a rotor magnet fixed along the outer peripheral surface of the rotor, and the rotor A stator provided with a stator core made of a magnetic material provided with a plurality of tooth poles disposed to face each other with a predetermined gap in the radial direction between the magnet and a stator coil wound around the tooth poles, and including the stator; And a resin base to which the bearing of the rotary shaft is fixed.

Further, in the spindle motor according to the next invention, the base includes a coil lead and a coil terminal of the stator coil, and the coil terminal is arranged on a side surface so as to be electrically connectable.

[0011] The spindle motor according to the next invention is:
A rotor fixed to a rotating shaft and rotating about the rotating shaft, a rotor magnet fixed along a circumferential outer surface of the rotor, and a predetermined gap provided in a radial direction between the rotor magnet and the rotor magnet to face each other; A stator provided with a stator core made of a magnetic material provided with a plurality of tooth poles and a stator coil wound around the tooth poles, a mold stator obtained by resin-molding the stator, and the mold stator being closely attached to the inner wall of the recessed portion. And a metal base in which the bearing of the rotary shaft is fixed at the center of the inner diameter of the mold stator.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 FIG. An embodiment of the spindle motor according to the present invention will be described. FIG. 1 is an overall perspective view showing a spindle motor according to the first embodiment, and FIG. 2 is a cross-sectional view taken along a line BB ′ shown in FIG. 1 and 2,
1 is a rotating shaft, 2 is a bearing of the rotating shaft 1, 3 is a rotor fixed to the rotating shaft 1, and 4 is a rotor magnet fixed to the outer peripheral surface of the rotor 3 with an adhesive or the like. The above-described rotor 3 rotates around the rotating shaft 1 by obtaining a driving force by a magnetic field generated at a tooth pole of a stator core described later and a rotor magnet 4. Reference numeral 5 denotes a hub for chucking an optical disk (not shown), which is fixed to the tip of the rotating shaft 1. 6 is a stator core made of a magnetic material in which tooth poles 7 are arranged opposite to the rotor magnets 4 from outside the outer circumferential surface of the rotor 3 with a predetermined gap therebetween.
Reference numeral 8 denotes a stator coil wound around the tooth pole 7, and reference numeral 8a denotes a coil terminal such as a connector or a terminal block for connecting a coil lead of the stator coil 8. The stator is constituted by the stator core 6 and the stator coil 8 wound around the tooth pole 7. 9
Is a base made of epoxy resin, which is resin-molded with the above-mentioned stator included therein. However, the surface of the tooth pole 7 facing the rotor magnet 4 is not encapsulated by resin, and the coil terminal 8a is enclosed and disposed on the side surface to enable electrical connection with a motor control circuit (not shown). .
As shown in FIG. 1, the base 9 is provided with a substantially cylindrical depression 10 slightly larger than the outer diameter of the hub 5 along the surface facing the tooth pole 7. 2 is fixed and the rotor 3 is housed. Reference numeral 11 denotes a spindle motor, which includes the components denoted by reference numerals 1 to 10 described above.

This spindle motor 11 is of a radial gap type like the spindle motor 40 shown in FIG. 6, but is different from the spindle motor 40 in that a rotor 3 as a rotor is provided inside the stator core 6. Type spindle motor. The main part of the spindle motor 11 is such that the rotating shaft 1, the bearing 2, and the rotor 3 are housed in a recess 10 provided in a base 9 serving as a base and the stator core 6 and the stator coil 8 are included. Embedded in the base 9 to provide a built-in type spindle motor.

Next, the operation will be described with reference to the drawings. The spindle motor 11 according to the first embodiment is also used by being mounted on an optical disk device, similarly to the conventional spindle motor 40 shown in FIG. The driving principle of the spindle motor 11 is the same as that of the conventional spindle motor 40. That is, when a current flows through the stator coil 8 shown in FIG. 2, the tooth poles 7 of the stator core 6 are magnetized to generate a magnetic field, and the magnetic field drives the rotor magnet 4 to rotate the rotor 3 about the rotating shaft 1. . The rotation of the rotor 3 causes the optical disk chucked by the hub unit 5 to rotate.

Here, as shown in FIG. 2, since the whole of the stator coil 8 is included in the base 9, the heat generated in the stator coil 8 is efficiently conducted to the base 9. The base 9 serves as a heat sink, and the heat generated in the stator coil 8 is efficiently radiated by the base 9, so that the temperature rise of the stator coil 8 is suppressed. Therefore, the temperature rise of the spindle motor 11 is also suppressed.
Further, unlike the conventional spindle motor 40, since the rotor 3 does not cover the stator core 6 and the stator coil 8, there is no danger that heat will be trapped in the rotor 3 and the temperature rise of the spindle motor 11 will be further suppressed. Therefore, it is possible to suppress an increase in the internal temperature of the optical disk device itself on which the spindle motor 11 is mounted.

In the first embodiment, the base 9 is molded with an epoxy resin. However, the base 9 is not limited to an epoxy resin, but may be a thermosetting resin, and a resin having good heat conductivity is preferable. Further, in the first embodiment, the coil terminal 8a is arranged on the side surface of the base 9, but the position of the coil terminal 8a is not limited to the side surface of the base 9, and the motor control such as the upper surface and the lower surface of the base 9 is performed. It may be placed at a position where electrical connection with the circuit is easy.

As described above, according to the spindle motor 11 according to the first embodiment, the heat generated in the stator coil 8 by the base 9 including the stator coil 8 and the stator core 6 and molded with epoxy resin or the like is used. The heat is efficiently conducted to the base 9, and the heat radiation of the base 9 suppresses the temperature rise of the stator coil 8 and the stator core 6, so that the temperature rise of the disk drive motor 11 can be suppressed. Therefore, it is possible to prevent the performance of the disk drive motor 11 from being adversely affected by the temperature rise, and to suppress the expansion and deformation of the optical disk disposed close to the spindle motor 11 when the spindle motor 11 is mounted on the optical disk device.

Further, since the coil terminal 8a is included in the side surface of the base 9 so as to enable electrical connection, processing of the coil lead and the coil terminal can be facilitated, and electrical connection with the motor control circuit can be facilitated.

Embodiment 2 Another embodiment of the spindle motor according to the present invention will be described. FIG. 3 is an overall perspective view showing a spindle motor according to Embodiment 2.
FIG. 4 is a cross-sectional view taken along line CC ′ shown in FIG. 3 and 4, the same reference numerals as those in FIG. 1 or 2 denote the same or corresponding components, and a description thereof will be omitted. Reference numeral 12 denotes a mold stator formed by resin molding with an epoxy resin or the like, and includes a stator including a stator core 6 made of a magnetic material and a stator coil 8 wound around the tooth poles 7. However, the surface of the tooth pole 7 facing the rotor magnet 4 is not included in the resin. 12a is a hole provided on the inner diameter side of the mold stator 12, and this hole 12a
The rotor 3 is disposed with a predetermined gap between the rotor magnet 4 and the tooth pole 7. Reference numeral 13 denotes an aluminum base, which is provided with a concave portion 14 having the same shape as the outer shape of the side surface of the mold stator 12, and the mold stator 12 is fixed to the inner wall and the lower surface of the concave portion 14 with an adhesive, and the rotor is fixed. 3 is housed in the hole 12 a of the mold stator 12.
The bearing 2 is fixed at the center of the inner diameter a by caulking or the like. Reference numeral 11a denotes a spindle motor, which includes a configuration denoted by reference numerals 12 to 14 and a configuration denoted by reference numerals 1 to 8.

Next, the operation will be described with reference to the drawings. The spindle motor 11a according to the second embodiment is also used by being mounted on an optical disk device, similarly to the spindle motor 11 shown in FIG. The driving principle of the spindle motor 11a is the same as that of the conventional spindle motor 40 and the first embodiment.
Is the same as the spindle motor 11 described above. That is, FIG.
When a current flows through the stator coil 8 shown in FIG. 1, the tooth poles 7 of the stator core 6 are magnetized to generate a magnetic field, and the magnetic field drives the rotor magnet 4 to rotate the rotor 3 about the rotating shaft 1. Due to the rotation of the rotor 3, the optical disk (not shown) chucked by the hub 5 rotates.

As shown in FIG. 4, the mold stator 12 includes the stator coil 8 and is in close contact with the inner wall of the recess 14 of the base 13, so that the heat generated in the stator coil 8 is Is conducted to the base 13 via the resin forming the. The heat generated in the stator coil 8 is efficiently radiated by the base 13 through the resin forming the molded stator 12 by the aluminum base 13 serving as a heat radiating plate, so that the temperature of the stator coil 8 rises. Is suppressed. Therefore, the temperature rise of the spindle motor 11a is also suppressed. A conventional spindle motor 40 shown in FIG.
Unlike this, since the rotor 3 does not cover the stator core 6 and the stator coil 8, there is no possibility that heat is trapped in the rotor 3, and the temperature rise of the spindle motor 11a is further suppressed. Therefore, it is possible to suppress a rise in the internal temperature of the optical disk device (not shown) itself on which the spindle motor 11a is mounted.

In the second embodiment, the base 13 is made of aluminum. However, the present invention is not limited to this, and a metal having good heat conductivity may be used. In the second embodiment, the coil terminal 8a is pulled out to the upper side of the base 13. However, a hole penetrating below the base 13 is provided in the recessed portion 14, and the coil terminal 8a is pulled out to the lower side of the base 13. It doesn't matter.

As described above, according to the spindle motor 11a of the second embodiment, the mold stator 12 including the stator coil 8 and the stator core 6 is brought into close contact with the inner wall and the lower surface of the concave portion 14 of the base 13 so that the base 1
3, the heat generated in the stator coil 8 is conducted to the base 13 via the resin forming the molded stator 12, and the heat radiation of the aluminum base 13 causes the temperature rise of the stator coil 8 and the stator core 6 to increase. As a result, the temperature rise of the spindle motor 11a can be suppressed. Therefore, it is possible to prevent the performance of the spindle motor 11a from being adversely affected by a rise in temperature, and to suppress the expansion and deformation of the optical disk disposed close to the spindle motor 11a when the spindle motor 11a is mounted on the optical disk device.

Further, since the base 13 is made of aluminum and the rigidity of the base 13 is increased, it is possible to prevent adverse effects due to vibration and the like due to rotation as compared with the spindle motor 11 shown in the first embodiment, and to improve the reliability of the spindle motor 11a. Can be improved.

[0025]

As described above, the spindle motor according to the present invention includes a rotor fixed to a rotating shaft and rotating about the rotating shaft, a rotor magnet fixed along the outer circumferential surface of the rotor, and a rotor magnet. A stator provided with a stator core made of a magnetic material provided with a plurality of tooth poles disposed opposite to each other with a predetermined gap in the radial direction and a stator coil wound around the tooth poles, and including this stator. Since it is molded and has a resin base that fixes the bearing of the rotating shaft, the base becomes a radiator plate that radiates heat generated in the stator coil, and suppresses the temperature rise of the stator coil, thereby suppressing the temperature rise of the spindle motor. it can. Therefore, adverse effects on the performance of the spindle motor can be prevented,
Even when this spindle motor is mounted on an optical disk device and used, an effect is obtained that expansion and deformation of the optical disk can be suppressed.

Furthermore, in the spindle motor according to the next invention, since the base includes the coil lead and the coil terminal of the stator coil and the coil terminal is arranged on the side surface so as to be electrically connectable, the processing of the coil lead and the coil terminal is performed. And electrical connection becomes easy.

[0027] The spindle motor according to the next invention is:
A rotor fixed to the rotating shaft and rotating about the rotating shaft, a rotor magnet fixed along the outer circumferential surface of the rotor,
A stator provided with a stator core made of a magnetic material having a plurality of tooth poles arranged opposite to each other with a predetermined gap provided in the radial direction between the rotor magnet and a stator coil wound around the tooth poles; Since it has a molded mold stator and a metal base in which the mold stator is fixed in close contact with the inner wall of the recess and the bearing of the rotating shaft is fixed at the center position of the inner diameter of the mold stator,
The heat generated in the stator coil is conducted to the metal base via the resin of the molded stator, and the metal base serves as a radiator plate to suppress a rise in the temperature of the stator coil, thereby suppressing a rise in the temperature of the spindle motor. Therefore, adverse effects on the performance of the spindle motor can be prevented,
Even when this spindle motor is mounted on an optical disk device and used, an effect is obtained that expansion and deformation of the optical disk can be suppressed. Further, since the base for fixing the rotating shaft is made of metal and the rigidity of the base is increased, it is possible to prevent adverse effects due to vibration and the like due to rotation, and to improve the reliability of the spindle motor.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a spindle motor according to a first embodiment of the present invention.

FIG. 2 is a sectional view taken along line BB 'of FIG.

FIG. 3 is a perspective view showing a spindle motor according to a second embodiment of the present invention.

FIG. 4 is a sectional view taken along line CC ′ of FIG. 3;

FIG. 5 is an overall perspective view showing an optical disk device equipped with a conventional spindle motor.

FIG. 6 is a sectional view taken along line AA ′ of FIG. 5;

[Explanation of symbols]

9 Base, 11, 11a Spindle motor, 1
2 mold stator, 13 base

Claims (3)

[Claims] A rotor fixed to a rotating shaft and rotating about the rotating shaft; a rotor magnet fixed along a circumferential outer surface of the rotor; and a predetermined gap in a radial direction between the rotor magnet and the rotor magnet. A stator provided with a stator core made of a magnetic material provided with a plurality of tooth poles disposed opposite to each other and a stator coil wound around the tooth poles, and a stator enclosing and forming the stator, and a bearing for the rotating shaft being provided. A spindle motor comprising a fixed resin base. 2. The spindle motor according to claim 1, wherein the base includes a coil lead and a coil terminal of the stator coil, and the coil terminal is arranged to be electrically connectable to a side surface. 3. A rotor fixed to a rotating shaft and rotating around the rotating shaft, a rotor magnet fixed along a circumferential outer surface of the rotor, and a predetermined gap in a radial direction between the rotor magnet and the rotor magnet. A stator provided with a stator core made of a magnetic material provided with a plurality of tooth poles disposed opposite to each other and a stator coil wound around the tooth poles; a molded stator obtained by resin-molding the stator; A metal base fixed in close contact with an inner wall of the portion and a bearing of the rotating shaft fixed to a center position of an inner diameter of the mold stator.