JP3865210B2 - Spindle motor - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a pattern of FG relates spin dollar motor provided frequency generator (hereinafter FG) pole of the magnet on the inner peripheral side of the coil, which is in particular an external high FG signal S / N ratio which is not affected by noise resulting it relates to Luz-pin dollar motor having a.
[0002]
[Prior art]
In recent years, flexible disk drives have been increasingly reduced in size and weight, and the spindle motor for flexible disk drives, which is the main component, has been required to have small, thin, high precision and high performance characteristics.
Hereinafter, a conventional example of a spindle motor for a 1/2 inch height flexible disk drive will be described in order with reference to FIGS.
[0003]
FIG. 5 is a perspective view of an example of a spindle motor for a flexible disk drive,
FIG. 7 is a stator diagram of an example of a conventional spindle motor for a flexible disk drive.
FIG. 8 is an enlarged half-sectional view of an example of a conventional spindle motor for a flexible disk drive.
The spindle motor for flexible disk drive includes a rotor 30 and a stator 24.
[0004]
In FIG. 8, a rotor 30 as an example of a conventional flexible disk drive spindle motor includes a rotor yoke 16, a resin FG magnet (magnet) 22, a disk positioning portion 8, a drive magnet (magnet) 13, and a motor shaft 1. .
A sheet 18 is attached to the outer periphery of the motor shaft 1 at the inner peripheral portion of the rotor yoke 16 so as to securely clamp the disc (not shown).
[0005]
The rotor yoke 16 is an iron plate material made of a galvanized steel plate, and an FG magnet 22 made of resin for detecting the rotational speed is formed on the outer peripheral portion thereof by outsert molding, and one round is magnetized to 96 poles. The metal base printed circuit board (stator yoke) 2 is provided with FG patterns 27 shown in FIG. 7 at predetermined intervals.
[0006]
The FG pattern 27 must cross the FG pattern 27 to connect the coil 9 terminal and the circuit terminal (not shown).
For this reason, the FG pattern 27 cannot be provided continuously over substantially the entire circumference, and the FG pattern cutout portion 20 as shown in FIG. 7 is provided.
[0007]
7 and 8, a stator 24 as an example of a conventional spindle motor for a flexible disk drive includes a sintered oil-impregnated bearing 5, a metal base printed board 2, and a plurality of coils 9. A rotor position detecting Hall element 11 and other electronic components (not shown) are arranged.
The coils 9 are flat coils and are fixed to the metal base printed board 2 by bonding 12 large and small.
The sintered oil-impregnated bearing 5 is held by caulking the lower end to the metal base printed board 2.
[0008]
When the rotor 30 in which the motor shaft 1 is press-fitted and fixed to the rotor yoke 16 is mounted on the sintered oil-impregnated bearing 5, the sintered oil-impregnated bearing 5 and the thrust ball bearing 14 are attracted by magnetic attraction between the drive magnet 13 and the metal base printed board 2 of the stator 24. Thus, the rotor 30 is held rotatably.
[0009]
The rotor 30 rotates at a rotation speed of 300 or 360 r / min around the motor shaft 1 by a three-phase drive current applied to the coil 9. An input information signal is recorded and reproduced (detected) by a magnetic head 17 that moves in the axial direction (arrow direction in FIG. 7) along the surface of a recording / reproducing disk (not shown).
[0010]
[Problems to be solved by the invention]
In the conventional spindle motor for flexible disk drive, since the FG magnet 22 is disposed on the outer peripheral portion of the rotor 30, it is difficult to reduce the size of the spindle motor.
[0011]
Further, since the FG pattern 27 is arranged on the outer peripheral portion of the stator 24 corresponding to the FG magnet 22, the FG signal is vulnerable to external noise and easily affected by noise from the head of the flexible disk drive.
On the other hand, since it is necessary to provide a copper foil pattern for connection between the terminal of the coil 9 and the control circuit terminal etc. on the inner periphery of the FG pattern 27, the FG pattern 27 is provided over substantially the entire circumference. Can not be done, it is necessary to cut out some.
For this reason, there exists a subject from which the effect of the pattern of a perimeter integral type FG cannot fully be acquired.
[0012]
Therefore, the present invention has been made in view of the above problems, and in particular, a thrust plate in which the FG pattern 7A is arranged on the inner peripheral side of the plurality of coils 9 so as to face the magnetic pole 15 of the FG magnet 12. 19 spin dollar motor substantially disposed over the entire circumference on, and the magnetic pole 15 of the FG magnet 12, and an object thereof is to provide a spin dollar motor provided on the inner peripheral portion of the rotary drive magnet 13B .
[0013]
[Means for Solving the Problems]
In order to achieve the above object, the present invention has the following configurations 1) and 2).
1) rotor a spin dollars motor driven rotating relative to the stator,
The rotor is supported in the thrust direction by the thrust ball bearing with respect to the stator, shaft and a rotor yoke shaft is fixed to the center, the thrust ball bearing is fixed to an inner peripheral side of the rotor yoke The first thrust plate that contacts, the ring-shaped drive magnet fixed to the outer peripheral side of the rotor yoke, and the frequency at which a plurality of poles are magnetized in the circumferential direction fixed between the thrust plate and the drive magnet has a magnet generator, wherein the stator includes a substrate, a second thrust preparative plate the thrust ball bearing is fixed to the substrate is in contact, it is fixed so as to face the driving magnet to the substrate includes a plurality of flat coils, a, together with the second thrust plate faces the said first magnet thrust plate and the frequency generator, wherein A feature and be Luz pin dollars motor that has a frequency generator pattern provided substantially over the entire circumference so as to face a plurality of poles of the magnet for the wave number generator.
2) A spindle motor whose rotor is driven to rotate with respect to the stator,
The rotor is supported in the thrust direction by a thrust ball bearing with respect to the stator, and has a shaft, a rotor yoke fixed to the shaft at the center, and an inner peripheral side of the rotor yoke. A first thrust plate that is in contact with the ring, and a ring-shaped drive magnet fixed to the outer peripheral side of the rotor yoke, and the stator is fixed to the substrate and the thrust ball bearing abuts against the substrate. A thrust plate and a plurality of flat plate coils fixed to the substrate so as to face the drive magnet, and a magnetic pole for a frequency generator is magnetized on a portion on the inner peripheral side of the drive magnet, The second thrust plate opposes the first thrust plate and the inner peripheral portion of the drive magnet, and opposes the frequency generator magnetic pole. Yo a substantially spindle motor, characterized in that it has a pattern frequency generator provided over the entire circumference.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
Per embodiments of spin dollar motor of the present invention, the preferred embodiment will be described in conjunction with FIG below.
Is an embodiment of the present invention with a 1/2 inch height flexible disk drive spindle motor will be described below in conjunction with FIGS. 1-5.
In addition, the same code | symbol is attached | subjected to the same component as the structure mentioned above, and the description is abbreviate | omitted.
[0015]
Figure 1 is a scan stator view of a spindle motor for a flexible disk drive embodiment, FIG 2 is a half cross-sectional enlarged view of a spindle motor for a flexible disk drive embodiment, FIG. 3 is a flexible disk drive according to another embodiment FIG. 4 is a half sectional enlarged view of a spindle motor for a flexible disk drive according to another embodiment , and FIG. 5 is a perspective view of the spindle motor for a flexible disk drive . FIG. 6 is a diagram schematically showing a magnetic pole surface of a drive magnet of a spindle motor for a flexible disk drive according to another embodiment .
The flexible disk drive spindle motor of the embodiment is composed of a rotor 10 and a stator 4.
[0016]
1 to 4, the rotor 10 is composed of a galvanized steel rotor yoke 16. A thrust plate 29 for the thrust ball bearing 14 is fixed to the inner peripheral side of the rotor yoke 16, and a plurality of coils are provided on the outer peripheral side of the rotor yoke 16. An Ne—Fe—B-based sintered drive magnet 13A, which is a ring-shaped rare earth element facing 9 is magnetized in 16 poles (8 pole pairs).
[0017]
A sheet 18 is attached to the outer peripheral portion of the inner peripheral shaft 1 to securely clamp the disc (not shown).
The resin-made FG magnet 12 for detecting the rotation speed is fixed to the rotor yoke 16 with an adhesive on the inner peripheral portion of the drive magnet 13A and is magnetized to 96 poles per round.
[0018]
The stator 4 includes a metal base printed circuit board (stator yoke) 2, a plurality of coils 9, an FG pattern 7 </ b> A provided over the entire circumference facing the FG magnet 12, a sintered oil-impregnated bearing 5, and a thrust ball bearing. It is composed of the thrust plate 19 for 14.
[0019]
The FG pattern 7A facing the FG magnet 12 is provided on the thrust plate 19 on the metal base print 2 side of the thrust ball bearing 14, and an FG signal is generated from the FG pattern 7A.
[0020]
As shown in FIG. 1, since the FG pattern 7A is provided over substantially the entire circumference, the effect of the all-round integration is obtained, and a highly accurate FG signal is obtained.
Further, since the FG pattern 7A is provided on the inner periphery of the plurality of coils 9, it is less affected by noise from the magnetic head 17 moving in the direction of the arrow in FIG. 1, and a highly accurate FG signal is obtained. It is done.
[0021]
Then, with the flexible disk drive spindle motor of another embodiment, it illustrates a scan stator of another embodiment flexible disk drive spindle motor of FIG. 3, half-sectional enlarged view of FIG. 4, FIG. 6 The magnetic pole surface (surface having both the FG magnetic pole and the rotational drive magnetic pole) of the drive magnet will be described below with a diagram schematically showing.
The stator 4 includes a sintered oil-impregnated bearing 5, a metal base printed circuit board (stator yoke) 2, and a plurality of coils 9. The metal base printed circuit board 2 has a rotor position detecting hall element 11 and other elements not shown. Electronic components are arranged.
[0022]
The plurality of coils 9 are flat-plate coils and are fixed to the metal base printed board 2 by adhesion.
The sintered oil-impregnated bearing 5 holds the metal base printed circuit board 2 at the lower end.
The rotor 10 includes a rotor yoke 16, a disk positioning portion 8, and a ring-shaped rare earth Ne—Fe—B based sintered drive magnet 13 </ b> B facing the plurality of coils 9, and includes a thrust ball bearing 14 and a sintered bearing. 5, the stator 4 can rotate freely.
[0023]
The FG signal is generated by the 96-pole FG magnetic pole 15 provided on the inner peripheral side portion of the drive magnet 13 </ b> B and the FG pattern 7 </ b> B provided on the outer peripheral portion of the thrust plate 19 facing the FG magnetic pole 15.
[0024]
As shown in the magnetic pole surface of the drive magnet in FIG. 6, the 96-pole FG magnetic pole 15 is provided on the inner peripheral portion of the drive magnet 13B, and the 16-pole drive magnetic pole is provided on the outer peripheral portion of the drive magnet 13B. It is magnetized.
[0025]
In this embodiment, the width of the FG pattern 7B is configured such that the FG magnet is also used by the drive magnet 13B, and the width of the FG pattern 7B is narrower than the width of the FG pattern 7A, but the FG pattern 7B. Is slightly larger than the FG pattern 7A.
[0026]
Also in this embodiment, the FG pattern 7B is provided over substantially the entire circumference as can be seen from the FG pattern 7B shown in FIG. A signal is obtained.
Further, in this embodiment, since only the drive magnet 13B is provided and no FG magnet is required, the number of parts can be reduced and the cost of providing the FG magnet can be eliminated.
[0027]
On the other hand, noise jumping from the magnetic head 17 due to movement in the direction of the arrow in FIG. 3 can be less affected as compared with the conventional case because the FG pattern 7B is provided on the inner periphery of the plurality of coils 9.
The rotor 10 is rotated about the motor shaft 1 by current applied to the plurality of coils 9, and the rotation speed of the rotor 10 is 300 or 360 r / min (5 or 6 r / sec).
[0028]
【The invention's effect】
As described above in detail, the present invention has a configuration in which the FG pattern is not provided on the outer peripheral portion but is provided on the inner peripheral side of the plurality of coils. An FG signal is obtained.
[0029]
Further, according to the present invention, since the FG pattern is provided over substantially the entire circumference, the effect of the whole circumference integration is obtained, and a highly accurate FG signal with less noise can be obtained.
[0030]
Moreover, since FG is arrange | positioned at the internal peripheral surface of a coil, since this invention can enlarge an outer peripheral diameter, performances, such as rotational torque, can be improved.
[0031]
The invention of spin dollar motor according to claim 2, there is no need for a separate FG magnet since is serves the FG magnet drive magnet can delete the cost of the FG magnet.
[Brief description of the drawings]
FIG. 1 is a stator diagram in which an FG pattern in a spindle motor for a flexible disk drive of an embodiment is provided on the inner circumference of a coil.
2 is a half-sectional enlarged view of the scan last plate provided the pattern of FG in the flexible disk drive spindle motor of the embodiment.
FIG. 3 is a view showing a stator in which an FG pattern is provided on the inner circumference of a coil in a spindle motor for a flexible disk drive of another embodiment .
FIG. 4 is an enlarged half-sectional view in which an FG magnetic pole is provided on a rotary drive magnet in a spindle motor for a flexible disk drive of another embodiment .
FIG. 5 is a perspective view of an example of a general flexible disk drive spindle motor.
FIG. 6 is a diagram schematically showing a magnetic pole surface (a surface having both an FG magnetic pole and a rotational drive magnetic pole) of a drive magnet in a spindle motor for a flexible disk drive of another embodiment .
FIG. 7 is a view showing a stator as an example of a conventional spindle motor for a flexible disk drive.
FIG. 8 is an enlarged half-sectional view of an example of a conventional spindle motor for a flexible disk drive.

Claims (2)

Rotor a spin dollars motor driven rotating relative to the stator,
The rotor is supported in the thrust direction by the thrust ball bearing with respect to the stator, shaft and a rotor yoke shaft is fixed to the center, the thrust ball bearing is fixed to an inner peripheral side of the rotor yoke The first thrust plate that contacts, the ring-shaped drive magnet fixed to the outer peripheral side of the rotor yoke, and the frequency at which a plurality of poles are magnetized in the circumferential direction fixed between the thrust plate and the drive magnet has a magnet generator, the,
The stator includes a substrate, a second thrust preparative plate the thrust ball bearing is fixed to the substrate is in contact, and a plurality of flat coils which are secured to opposed to the drive magnet to said substrate,
Said second thrust plate is adapted to face the said first thrust plate and magnet the frequency generator, provided substantially over the entire circumference so as to face a plurality of poles of the magnet for the frequency generator features and to Luz pin dollars motor that has a pattern frequency generator. A spindle motor whose rotor is driven to rotate relative to the stator,
The rotor is supported in the thrust direction by a thrust ball bearing with respect to the stator, and has a shaft, a rotor yoke fixed to the shaft at the center, and an inner peripheral side of the rotor yoke. A first thrust plate in contact with the ring-shaped drive magnet fixed to the outer peripheral side of the rotor yoke;
The stator has a substrate, a second thrust plate fixed to the substrate and abutted against the thrust ball bearing, and a plurality of flat coils fixed to the substrate so as to face the drive magnet,
A magnetic pole for a frequency generator is magnetized on the inner peripheral side of the drive magnet,
The second thrust plate is provided over substantially the entire circumference so as to face the first thrust plate and the inner peripheral portion of the drive magnet and to face the frequency generator magnetic pole. features and to Luz pin dollars motor that has a pattern frequency generator.

Images