JP3105393B2 - motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor,
In particular, it relates to fixing of a bearing and a stator core.

[0002]

2. Description of the Related Art For example, a motor used in a magnetic disk drive is disclosed in Japanese Utility Model Application No. 5-42992 filed earlier. An example of such a motor will be described with reference to the drawings. 6 and 7, the substrate 33
A thrust bearing 42 is attached substantially at the center. The outer periphery of the thrust bearing 42 has a flange shape, and the inner peripheral edge of the lower end surface of the bearing 32 is placed on this flange-like portion. The outer peripheral edge of the lower end surface of the bearing 32 protrudes downward, and is in contact with the upper end surface of the substrate 33. A core holder 41 is attached to the outer periphery of the bearing 32, and a stator core 39 is attached to the core holder 41. Stator core 39 is made up of a plurality of core elements, and has a plurality of salient poles on the outer periphery. A coil 40 is wound around each salient pole.

In FIGS. 8 and 9, a bearing 32 has a plurality of substantially semicircular notched recesses 32a formed on an outer peripheral surface thereof. On the other hand, a plurality of substantially semi-arc-shaped notched concave portions 39 are also provided on the inner peripheral surface of the stator core 39 attached to the outer periphery of the bearing 32.
a is formed. For this reason, by arranging the inner peripheral surface of the stator core 39 on the outer periphery of the bearing 32, a substantially circular fastening member insertion hole 45 is formed from each notch recess 32a and each notch recess 39a. The screw 34 as a fastening member is inserted into the hole 45.

In FIGS. 6 and 7, a fastening member insertion hole 45 is shown.
The screw 34 is screwed into the substrate 33 at the tip. When the tip of the screw 34 is screwed into the substrate 33, the upper end surfaces of the bearing 32 and the stator core 39 are pressed toward the substrate 33 by the head of the screw 34, and the bearing 32, the stator core 39, and the core holder 41 are attached to the substrate 33. Fixedly held on top.

[0005] A rotary shaft 31 is inserted into a center hole of the bearing 32. The tip of the rotating shaft 31 is in contact with a thrust bearing 42, and the rotating shaft 31 is supported by the thrust bearing 42 in the thrust direction. The rotating shaft 31 is supported in a radial direction by a bearing 32. The rotating shaft 31 is rotatable by the bearing 32 and the thrust bearing 42.

[0006] A cup-shaped rotor case 37 is attached to the outer periphery of the upper end side of the rotating shaft 31. A drive magnet 38 is attached to the inner surface of the peripheral wall of the rotor case 37.
9 and a certain gap. Therefore, by controlling the energization of the coil 40 wound around the salient poles of the stator core 39, the drive magnet 38 is biased and the rotor case 37 and the rotating shaft 31 are driven to rotate.

A hub 36 on which a magnetic disk is mounted is mounted above the rotor case 37 of the rotating shaft 31.

[0008]

The motor having the above-described structure does not use a bearing housing, and thus has an advantage that manufacturing costs and parts costs can be reduced. On the other hand, when the bearings 32 and the stator core 39 are fixed by screwing the screws 34 serving as the fastening members into the substrate 33, a bulge may occur in a portion of the substrate 33 around the screws 34. This occurs in the same manner as when the screw 34 is a self-tapping type screw, in which a female screw is formed in a hole in advance. When the climax occurs,
The bearing 33 directly attached to the substrate is pushed by the swelling, and the perpendicularity between the substrate 33 and the bearing 32 is impaired, or the substrate 33 is warped, which causes a decrease in the output of a frequency generator (not shown). In addition, the pressing force against the stator core 39 is insufficient, and problems such as rattling occur.

SUMMARY OF THE INVENTION The present invention has been made to solve the above problems, and has as its object to provide a motor in which the accuracy of mounting a bearing on a substrate is improved.

[0010]

According to the first aspect of the present invention,
A motor having a bearing for supporting the rotating shaft and a stator core disposed radially outside the bearing, wherein the stator core and the bearing are fixed on a substrate, and the outer peripheral surface of the bearing has a substantially semicircular arc shape. It has a notch recess, has a substantially semicircular notch recess on the inner peripheral surface of the stator core, and a notch recess of the bearing and a notch recess of the stator core constitute a fastening member insertion hole. It is characterized in that the peripheral edge on the substrate side of the cutout recess of the bearing to be formed is depressed.

[0011]

[0012]

When the fastening member is screwed into the board, a bulge occurs on the outer periphery of the fastening member on the board, and the bulge is absorbed by a depression in the periphery of the fastening member insertion portion on the board side.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a motor according to the present invention will be described. In FIGS. 1 and 2, a thrust bearing 12 is mounted substantially at the center of the substrate 3. The outer periphery of the thrust bearing 12 has a flange shape, and the inner peripheral edge of the lower end surface of the bearing 2 is placed on this flange-like portion. The outer peripheral edge of the lower end surface of the bearing 2 protrudes downward, and is in contact with the upper end surface of the substrate 3. A core holder 11 is attached to the outer periphery of the bearing 2, and a stator core 9 is attached to the core holder 11. Stator core 9 is made up of a plurality of core elements, and has a plurality of salient poles on the outer periphery. A coil 10 is wound around each salient pole.

In FIG. 3, the bearing 2 is formed with a plurality of substantially semicircular notched recesses 2a. A recess 2b is formed in an arc-shaped portion on the upper end surface side of each cutout recess 2a. When such a bearing 2 is attached to the substrate 3, the bearing 2 is attached in such a manner that the recess 2 b is on the substrate 3 side. On the other hand, a plurality of substantially semi-arc-shaped notched recesses 9a are also provided on the inner peripheral surface of the stator core 9 attached to the outer periphery of the bearing 2.
Are formed. For this reason, as shown in FIG. 4, each notch recess 2 a and each notch recess 9 a constitute a substantially circular fastening member insertion hole 15.

1 and 2, a fastening member insertion hole 15 is provided.
, A screw 4 as a fastening member is inserted. The tip of the screw 4 inserted into the fastening member insertion hole 15 is screwed into the substrate 3. For this reason, the upper end surfaces of the bearing 2 and the stator core 9 are pressed against the substrate 3 by the heads of the screws 4, and the bearing 2, the stator core 9, and the core holder 11 are fixed and held on the substrate 3.

The rotary shaft 1 is inserted into the center hole of the bearing 2. The tip of the rotating shaft 1 is in contact with a thrust bearing 12, and the rotating shaft 1 is supported by the thrust bearing 12 in the thrust direction. The rotating shaft 1 is supported by a bearing 2 in the radial direction. The rotating shaft 1 is rotatable by the bearing 2 and the thrust bearing 12.

A cup-shaped rotor case 7 is attached to the outer periphery of the rotating shaft 1 on the upper end side. A drive magnet 8 is mounted on the inner surface of the peripheral wall of the rotor case 7.
The inner peripheral surface of the drive magnet 8 faces the salient pole of the stator core 9 with a certain gap. Therefore, by controlling the energization of the coil 10 wound around the salient poles of the stator core 9, the drive magnet 8 is energized and the rotor case 7 is energized.
And the rotating shaft 1 is rotationally driven.

Above the rotor case 7 of the rotating shaft 1, a hub base 6 on which a magnetic disk is mounted is mounted.

According to the motor having the above-described configuration, the notch recess 2a on the outer peripheral surface of the bearing 2 and the notch recess 9a of the stator core 9 form the fastening member insertion hole 15, and the fastening member insertion hole 15 is a fastening member. Insert the screw 4 and insert the bearing 2
And stator core 9 and fastening member insertion hole 1
5 is formed in the periphery of the notch recess 2a constituting the substrate 5 on the substrate 3 side.
Is formed, when the tip of the screw 4 is screwed into the substrate 3, the bulge 3 generated on the outer peripheral portion of the screw 4 of the substrate 3 is formed.
a can be absorbed by the depression 2b. Therefore, the bearing 2 is not directly pushed by the bulge 3a, and the verticality of the bearing 2 is not impaired. Therefore,
The mounting accuracy of the bearing 2 to the substrate 3 can be improved. In addition, since the bulge 3a of the substrate 3 is absorbed by the depression 2b of the bearing 2, the warpage of the substrate 3 can be prevented. This also prevents the verticality of the bearing 2 from being impaired. It is possible to improve the mounting accuracy of the second substrate 3 to the substrate 3 and to prevent the output of the frequency generator (not shown) from decreasing.

The shape of the depression 2b is not particularly limited, and may be any shape as long as the protrusion 3a of the substrate 3 can be absorbed by the fastening member. For example, the depression 2b may be formed to be a groove having a constant width in the radial direction of the bearing 2.

As shown in FIG. 5, when the fastening member insertion hole 2d is formed only in the bearing 2, a depression 2b is formed in the periphery of the opening of the fastening portion insertion hole 2d on the substrate 3 side. The depression 2b may be configured to absorb the rise of the substrate 3. An effect similar to that of the above-described embodiment is obtained.

[0022]

According to the first aspect of the present invention, the outer peripheral surface of the bearing has a substantially semi-arc-shaped notch, and the inner peripheral surface of the stator core has a substantially semi-circular notch. The fastening member insertion hole is formed by the notch recess of the bearing and the notch recess of the stator core, and the fastening member is inserted into the fastening member insertion hole because the periphery of the notch recess of the bearing constituting the fastening member insertion hole on the substrate side is depressed. When the bearing is fixed on the substrate by doing so, the bulge generated around the fastening member of the substrate is absorbed by the recess, and the mounting accuracy of the bearing on the substrate can be improved.

[0023]

[Brief description of the drawings]

FIG. 1 is a sectional view showing an embodiment of a motor according to the present invention.

FIG. 2 is an enlarged sectional view of a main part of the same.

FIG. 3 is a perspective view showing an embodiment of a bearing applied to the motor.

FIG. 4 is an enlarged plan view showing a main part of the motor.

FIG. 5 is a sectional view showing another embodiment of the motor according to the present invention.

FIG. 6 is a sectional view showing an example of a conventional motor.

FIG. 7 is an enlarged sectional view of a main part of the above.

FIG. 8 is a perspective view showing an example of a bearing applied to the motor.

FIG. 9 is an enlarged plan view showing a main part of the motor.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Rotary shaft 2 Bearing 2a Notch recess 2b Depression 9 Stator core 9a Notch recess 15 Fastening member insertion hole

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int. Cl. ⁷ , DB name) H02K 29/00, 21/00 H02K 5/15 H02K 5/167

Claims (1)

(57) [Claims] 1. A motor having a bearing for supporting a rotating shaft and a stator core disposed radially outside of the bearing, wherein the stator core and the bearing are fixed on a substrate, and an outer periphery of the bearing is provided. The surface has a substantially semi-arc-shaped notch recess. The inner peripheral surface of the stator core has a substantially semi-arc-notch recess. A fastening member is inserted by the notch recess of the bearing and the notch recess of the stator core. A motor, wherein a hole is formed, and a peripheral edge of the notch recess of the bearing that forms the fastening member insertion hole on the substrate side is depressed.