JP3507245B2 - motor - Google Patents

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a polygon mirror,
The present invention relates to a mechanism for suppressing vibration noise in a dynamic pressure bearing motor that rotates an optical disk and the like.

[0002]

2. Description of the Related Art As a motor for rotating a polygon mirror or the like, an outer rotor type motor employing an air dynamic pressure bearing is used. A motor of this type will be described with reference to FIG.
And a rotor assembly 3, and a rotor body such as a polygon mirror 4 is rotationally driven by the rotor assembly 3.

The stator assembly 2 includes a fixed shaft 21 extending along the motor rotation center axis 1a and the fixed shaft 21.
A motor frame 22 is formed integrally with one end (lower end in the figure) of the motor frame 22 and extends outward in the radial direction. Further, a stator substrate 23 mounted and fixed to the motor frame 22, a cylindrical core frame 24 mounted and fixed to the inner peripheral edge of the stator substrate 23, and a stator core mounted on the outer periphery of the core frame 24. 25
It has and.

The rotor assembly 3 is provided with a rotor 31 having a shaft hole through which the fixed shaft 21 on the side of the stator assembly 2 is rotatably passed, and the inner peripheral surface of this shaft hole and the outer periphery of the fixed shaft 21. Air dynamic bearings are formed between the surfaces. The rotor 31 includes an annular end wall portion 33 that extends radially outward from the outer circumference thereof, and a cylindrical outer peripheral wall portion 34 that is continuous with the outer peripheral edge of the end wall portion. A ring-shaped drive magnet 36 is adhesively fixed to the inner peripheral surface of the outer peripheral wall portion 34 via a back yoke 35 so as to surround the stator core 25 on the stator assembly 2 side.

[0005]

Generally, when the motor rotation speed increases, the vibration on the stator core 21 side also increases accordingly. In the motor having the above configuration,
The stator core 21 includes a stator substrate 23 attached to a motor frame 22 via a cylindrical core frame 24.
Supported by. Therefore, the stator core 21
The vibration generated on the side is transmitted to the motor frame 22 via the core frame 24 and the stator substrate 23.

Since the motor frame 22 is fixed to a motor mounting chassis or the like, the vibration transmitted to the motor frame 22 is transmitted to an external member such as the chassis via this. When the vibration generated on the stator core 21 side is transmitted to each part in this way, each part vibrates and a large noise is generated.

In view of this point, an object of the present invention is to propose a motor capable of suppressing the vibration generated on the side of the stator core from being transmitted to other portions and suppressing the generation of a large noise. is there.

[0008]

In order to solve the above problems, the present invention provides a fixed shaft, a cylindrical core frame that holds a stator core, and an inner peripheral side part that holds the core frame. And a stator mounting substrate that is in contact with any one of the front and back surfaces of the stator substrate,
In a motor having a motor frame having the stator substrate mounted and fixed on the substrate mounting surface, the fixing
The shaft is molded integrally with the motor frame,
The core frame is installed on the inner peripheral side of the stator substrate.
It is fixed only, and the inner peripheral part of the board mounting surface is
The core frame is located on the outer peripheral side of the outer peripheral portion, and a flange is formed on the motor frame so as to surround the outer periphery of the substrate mounting surface, and the outer peripheral end face of the stator substrate and the outer peripheral end face face each other. Between the inner peripheral surface of the flange and the inner peripheral surface of the flange, in a direction along the outer peripheral end surface of the stator substrate , of the continuous gap and the discontinuous gap .
It is characterized in that either one of the gaps is formed.
It

[0009] with forming such a gap, the stator substrate itself may form a discontinuous slit group along its outer peripheral edge.

In the motor of the present invention, the edge between the outer peripheral surface of the stator substrate and the motor frame is completely or substantially cut off. As a result, it is possible to prevent or suppress the vibration generated on the stator core side from being transmitted to the motor frame side via the stator substrate. In particular, it is possible to effectively prevent the longitudinal wave component of the vibration propagating through the stator substrate from being transmitted to the motor frame side. The cause of the vibration noise depends more on the propagation of the longitudinal wave component than on the propagation of the transverse wave component. Therefore, by adopting the configuration of the present invention, it is possible to effectively prevent the vibration generated on the stator core side from being transmitted to the motor mounting member side such as the chassis via the motor frame to generate a large noise. .

Here, the vibration propagating through the stator substrate is
It propagates to the motor frame side via fasteners that attach and fix the stator substrate to the motor frame side. Therefore, it is desirable to block or suppress the propagation of vibrations via the fasteners. For this purpose, the fastener and the stator substrate may be configured so as not to be in surface contact with each other. In other words, between the fastener and the stator board,
The contact may be made in line contact or point contact.

Screws are commonly used as fasteners. In this case, if a flat head screw whose constricted portion of the screw head is a tapered outer peripheral surface is used, the flat head of the flat head screw will be inserted into the inner peripheral edge of the circular screw hole formed on the stator substrate side. The outer peripheral surfaces can be brought into line contact with each other.

[0013]

BEST MODE FOR CARRYING OUT THE INVENTION An outer rotor type motor of the air dynamic pressure bearing type for rotating a polygon mirror according to the present invention will be described below with reference to the drawings.

FIG. 1 is a side view showing the outer rotor type motor of this type in a right half section. As shown in this figure, the motor 1 has a stator assembly 2 and a rotor assembly 3, and the polygon mirror 4 is rotationally driven by the rotor assembly 3.

The stator assembly 2 includes a fixed shaft 21 extending along the motor rotation center axis 1a, and the fixed shaft 21.
A motor frame 22 is formed integrally with one end (lower end in the figure) of the motor frame 22 and extends outward in the radial direction. Further, the stator assembly 2 includes a stator board 23 made of a circuit board for mounting and fixing the motor frame 22, and
A cylindrical core frame 24 is attached and fixed to the inner peripheral edge of the stator substrate 23, and a stator core 25 is attached to the outer periphery of the core frame 24.

The rotor assembly 3 includes a rotor 31 having a shaft hole through which the fixed shaft 21 on the side of the stator assembly 2 is rotatably passed. The rotor 31 has an inner peripheral surface and an outer periphery of the fixed shaft 21. Air dynamic bearings are formed between the surfaces. The rotor 31 includes an annular end wall portion 33 that extends radially outward from the outer periphery of the cylindrical rotor body portion 32, and a cylindrical outer peripheral wall portion 34 that is continuous with the outer peripheral edge of the end wall portion. I have it. A ring-shaped drive magnet 36 is adhesively fixed to the inner peripheral surface of the outer peripheral wall portion 34 via a back yoke 35 so as to surround the stator core 25 on the stator assembly 2 side.

At the center of the annular end wall portion 33 of the rotor 31, a pedestal 33a having an annular end surface for mounting the polygon mirror 4 is formed. From the tip side of the cylindrical rotor body portion 32 of the rotor 31, the end surface of the polygon mirror 4 mounted on the rotor body portion 32 is in contact with the pedestal 33a. In this state, the polygon mirror 4 is pressed and fixed to the rotor body portion 32 by the balance plate 42 fitted to the tip of the rotor body portion 32 via the pressing spring 41.

Here, the stator board 23 is a disk-shaped circuit board having a central hole 23a formed therein, and the ends of the coils wound around the stator core 25 are connected to the circuit board. The circuit of the board 23 is adapted to be connected to an external circuit through a connector 28 which is connected and fixed to the board. A lower end 24a of a cylindrical core frame 24 is fitted into and bonded and fixed to the central hole 23a of the stator substrate. On the other hand, on the motor frame 22 side, an annular flat substrate mounting surface 22a to which the stator substrate 23 is mounted is formed. This board mounting surface 2
A mounting groove 22b for mounting the connector 28 or the like, which is a stator board mounting component, is partially formed in 2a.

An annular flange 22c for mounting and fixing the motor 1 on a chassis or the like is formed on the motor frame 22 so as to surround the outer periphery of the board mounting surface 22a. The inner peripheral surface 22d of the flange 22c faces the outer peripheral end surface 23b of the disk-shaped stator substrate 23.
In the present example, the outer peripheral end surface 23b of the stator substrate 23 faces the inner peripheral surface 22d of the flange on the motor frame side with a constant gap 5 left open. In other words, the outer peripheral end surface 23b of the stator substrate 23 and the inner peripheral surface 2 on the motor frame side.
A gap 5 having a constant width and continuous along the outer peripheral end surface 23b is formed between 2d (the surface facing the substrate). The gap 5 may be sealed with a resin having elasticity.

In this example, the stator board 23 is mounted on the motor frame side board mounting surface 22a by a plurality of flat head screws 6.
Has been concluded. That is, on the stator substrate 23,
Circular screw through holes 2 at predetermined angular intervals in the circumferential direction
3f is formed. 22 f of screw holes are formed in the board | substrate mounting surface 22a by the side of a motor frame in the position which opposes these screw through-holes 23f. Stator board 2
The inner diameter of the screw through hole 23f formed in No. 3 has a tapered outer peripheral surface 6 connecting the head and leg of the flat head screw 6 with each other.
It is set so as to come into line contact with the middle position of a.

In the motor 1 thus constructed,
As with a general motor, the vibration on the side of the stator core 25 increases as the motor speed increases. Stator core 2
The vibration generated on the side of No. 5 is transmitted through the core frame 24 having the cylindrical shape to which the core frame 24 is attached.
Propagates to the stator substrate 23 directly attached thereto.

The vibration propagated to the stator substrate 23 is transmitted to the motor frame 22 side via the stator substrate 23. However, in this example, the outer peripheral end surface 23b of the stator substrate 23 and the motor frame 22 are formed.
Further, a gap 5 is formed between the inner peripheral surface 22d of the flange 22c , and the edge is completely cut. Therefore, the vibration propagating through the stator substrate 23, especially the longitudinal wave component, is prevented or suppressed from being transmitted to the motor frame 22 side.

Here, the back surface of the stator substrate 23 and the substrate mounting surface 22a on the motor frame side are in surface contact with each other, and these contact surfaces are aligned in the vibration direction of the longitudinal wave component of the vibration propagating through the stator substrate 23. I am doing it. Therefore, the longitudinal wave component of the vibration on the stator substrate 23 side is hardly transmitted to the motor frame 22 side via these contact surfaces.

Further, in this example, the flat head screws 6 are used to fasten the stator substrate 23 to the substrate mounting surface 22a on the motor frame side. Then, the tapered outer peripheral surface 6a of the head of the flat head screw 6 has a screw through hole 23f in the stator substrate 23.
Is in line contact with the inner peripheral edge of. As described above, since the contact portions of the inner peripheral surfaces of the through holes 23f of both members are made as small as possible, the flat plate screws 6 as fasteners are used to move the stator frame 23 side to the motor frame 22 side. It is possible to effectively prevent or suppress the transmission of vibration to the.

As described above, the motor 1 of this embodiment employs a structure capable of suppressing vibration transmission from the stator substrate 23 to the motor frame 22 side. Therefore, it is possible to avoid or suppress the adverse effect that the vibration generated on the stator core 25 side is transmitted to other members via the motor frame and causes a large noise.

(Other Embodiments) The above description is an example in the case where the present invention is applied to an outer rotor type motor of a pneumatic bearing type. The present invention can be similarly applied to motors of other types. That is, in the case of a motor of a type in which a vibration transmission path in which vibration generated on the stator core side is transmitted to the motor frame side is configured, it is possible to prevent or suppress the generation of vibration noise by applying the present invention. it can.

In the above description, a gap is formed between the outer peripheral end surface of the stator board and the board-facing surface of the motor frame. With this configuration, as shown in FIG. 2, a plurality of discontinuous slits 7 may be formed along the outer peripheral end surface 23b of the disk-shaped stator substrate 23. Also in this case, it is possible to prevent or suppress the longitudinal wave component of the vibration propagating through the stator substrate 23 from being blocked by the slits 7 and transmitted to the motor frame 24 side. Of course, the slit 7 may have a linear shape instead of the arc shape shown in the drawing .

On the other hand, in the above description, the flat head screw 6 is used as the fastener. A screw having a shape other than this may be used to form a protrusion or an inclined surface on the stator substrate 23 side that makes point contact or line contact with the screw head.

[0029]

As described above, the motor of the present invention employs a structure in which a gap is formed between the outer peripheral end surface of the stator substrate and the substrate facing surface on the side of the motor frame to which the stator substrate is mounted. ing. In addition, this configuration and co
In addition, a configuration is adopted in which discontinuous slits are formed in the stator substrate itself along the outer peripheral end surface of the stator substrate. Therefore, according to the present invention, these gaps or slits can prevent or suppress the vibration generated on the stator core side and propagated to the stator substrate from being transmitted to the motor frame side. Therefore, it is possible to prevent generation of unacceptably large vibration noise even if the motor rotation speed increases.

Further, in the motor of the present invention, the fastener for fastening the stator substrate to the motor frame is brought into contact with the stator substrate in a point contact state or a line contact state. Therefore, it is possible to effectively prevent vibration transmission from the stator substrate to the motor frame side.

[Brief description of drawings]

FIG. 1 is a half cross-sectional side view of an outer rotor type motor of an air dynamic bearing type to which the present invention is applied.

FIG. 2 is an explanatory diagram showing a modified example of the stator substrate of FIG.

[Explanation of symbols]

1 motor 2 Stator assembly 21 fixed axis 22 Motor frame 22a Board mounting surface 22d Inner end face of motor frame (substrate facing side) 22f screw hole 23 Stator board 23b Peripheral end face of stator substrate 23f screw through hole 24 core frame 25 stator core 3 rotor assembly 31 rotor 32 rotor body 36 Drive magnet 4 polygon mirror 5 gap 6 Flat head screws (fasteners) 6a Tapered outer peripheral surface

─────────────────────────────────────────────────── ─── Continuation of the front page (56) Reference JP 58-108513 (JP, A) JP 8-154356 (JP, A) JP 8-47229 (JP, A) JP 5- 209622 (JP, A) JP-A-4-178148 (JP, A) JP-A-4-8153 (JP, A) Actual Kaihei 3-1674 (JP, U) (58) Fields investigated (Int.Cl. ⁷ , DB name) H02K 21/22 H02K 29/00 H02K 5/24

Claims (4)

(57) [Claims] 1. A fixed shaft, a cylindrical core frame holding a stator core, a stator substrate holding the core frame at an inner peripheral side, and one of front and back surfaces of the stator substrate. A motor frame having a substrate mounting surface that abuts against the motor frame, and the stator substrate is mounted and fixed to the substrate mounting surface, the fixed shaft is formed integrally with the motor frame.
And the core frame is a portion on the inner peripheral side of the stator substrate.
It is fixed only to the outer peripheral part of the core frame.
A flange is formed on the outer peripheral side of the motor frame so as to surround the outer periphery of the substrate mounting surface, and the outer peripheral end face of the stator substrate and the outer peripheral end face of the flange face each other. A motor characterized in that, between the inner peripheral surface and the inner peripheral surface, one of a continuous clearance and a discontinuous clearance is formed in a direction along the outer peripheral end surface of the stator substrate. . 2. The motor according to claim 1, wherein the stator substrate includes a discontinuous slit group formed along an outer peripheral end surface of the stator substrate. 3. The stay according to claim 1 or 2,
Fasten the motor board to the board mounting surface of the motor frame
A fixing fastener, the fastener and the stator
There is no line contact or point contact with the board.
A motor characterized by 4. The fastener according to claim 3, wherein the fastener is a flat head screw.
The inner peripheral edge of the screw hole formed in the stator substrate.
On the other hand, when the outer peripheral surface of the head of the flat head screw comes into contact with
A motor characterized by being installed.