JPH0538115A - Spindle motor - Google Patents

Abstract

PURPOSE:To provide a spindle motor, which can be made thin and moreover is not inferior to usual ones in mechanical strength. CONSTITUTION:On a base plate 1, a plurality of window parts 19 are provided in the circumferential direction of the base plate 1 at predetermined pitches. A stator core 12 of a stator 5 is mounted on the base plate 1, and some parts of respective winding parts 14 of the stator 5 are made to penetrate the respective window parts 19 opposed thereto.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a spindle motor.

[0002]

2. Description of the Related Art A conventional spindle motor is shown in FIG.
There is an outer rotor type as shown in FIG. 2 and an inner rotor type as shown in FIG.

The spindle motor shown in FIG. 4 has a stator c externally fitted to a cylindrical portion b of a base plate a and a shaft member rotatably supported by the cylindrical portion b via bearings d and d. e and a hub f attached to the shaft member e
And a rotor magnet g attached to the inner peripheral surface of the hub f
And, it is equipped with. The stator c is composed of a stator core h and coils i wound around a plurality of teeth of the stator core h. In this case, the teeth protrude in the outer diameter direction.

Further, the spindle motor shown in FIG. 5 has a stator c fitted in an outer cylindrical portion k of a base plate a.
A shaft member e pivotally supported by an inner cylindrical portion m of the base plate a via bearings d, d, a hub n attached to the shaft member e, and an outer peripheral surface of a cylindrical holder portion r of the hub n. And a rotor magnet g attached to the. In this case, the teeth protrude in the inner diameter direction.

[0005]

In recent years, thin spindle motors have been demanded, and conventional spindle motors shown in FIGS. 4 and 5 have not been able to be made very thin.

That is, in the spindle motor shown in FIG. 4, a gap is provided between the base plate a and the winding portion p of the stator c, and the axial length L of this motor is correspondingly provided.
Could not be small. This is because the axial length L can be reduced by reducing the wall thickness dimension of the stator-corresponding portion of the base plate a, but the strength of the base plate a is inferior.

Also, in the spindle motor shown in FIG. 5, it is necessary to make the base plate a small in order to make it thin, and it is not possible to make it so thin.

Therefore, an object of the present invention is to provide a spindle motor which can be made thinner and whose base plate is not deteriorated in strength.

[0009]

In order to achieve the above-mentioned object, a spindle motor according to the present invention has a plurality of windows, through which a part of each winding portion of a stator enters, along a circumferential direction of a base plate. It was established at a predetermined pitch.

[0010]

[Function] A part of each winding part of the stator penetrates into the window formed in the base plate, and part of the winding part penetrates into the window without reducing the wall thickness of the base plate. Therefore, the overall axial length can be reduced.

[0011]

The present invention will be described in detail below with reference to the drawings illustrating the embodiments.

FIG. 1 shows a spindle motor according to the present invention. In this spindle motor, a shaft member 2 whose one end is fitted in a cylindrical portion 1a of a base plate 1 and bearings 3 and 3 are attached to the shaft member 2. A hub 4 rotatably supported via
And a stator 5 attached to the base plate 1 and a rotor magnet 6 that is internally fitted to the stator 5, and is a so-called inner rotor type motor.

The hub 4 is made of a magnetic material, and has a cylindrical portion 7, an outer flange portion 8 projecting from the outer peripheral surface 7a of the cylindrical portion 7, and an inner peripheral surface 7b of the cylindrical portion 7. The magnet holding portion includes an inner flange portion 9 provided and a cylindrical magnet holding portion 10 protruding from the cylindrical portion 7 to the plate 1 side.
A rotor magnet 6 is attached to the outer peripheral surface 10a of the rotor 10. A magnetic disk is attached to the outer collar portion 8.

As shown in FIG. 2, the stator 5 is a tooth arranged on the inner diameter side at a predetermined pitch along the circumferential direction.
A stator core 12 having 11 and a coil 13 wound around the teeth 11 of the stator core 12 are formed, and a winding portion 14 of the coil 13 is formed on the teeth 11. That is, the stator core 12 is composed of a ring-shaped main body portion 15 and teeth 11 protruding from the inner peripheral surface 15a of the main body portion 15 in the inner diameter direction. The teeth 11 are composed of a neck portion 11a and the neck portion 11a. It is composed of a head portion 11b continuously provided at the end portion of 11a.

Further, as shown in FIG. 1, the stator core 12 is formed by laminating a plurality of thin plate-shaped core laminations 16 having a plurality of teeth by superposition, and the tip end portions of the teeth of the core lamination 16 at the uppermost stage. On the rising side
17 are provided. That is, the rising piece portion 17 is formed to face the outer peripheral surface 6a of the rotor magnet 6, and reduces the magnetic resistance between the outer peripheral surface 6a of the rotor magnet 6 and the stator 5.

As shown in FIG. 2, the main body 15 of the stator core 12 is attached to the base plate 1 by fasteners 18 such as screws.

Thus, the base plate 1 is provided with windows 19 ... At a predetermined pitch along the circumferential direction.
As shown in FIG. 1, a part of each winding portion 14 of the stator 5 (that is, a portion projecting from the back surface 12a of the stator core 12) has entered into 19 ...

That is, the windows 19 are teeth of the stator 5.
2 are arranged at the same pitch as 11 ..., have a substantially square shape in plan view, and are set to be slightly larger than the winding portion 14, as shown in FIG. In this case, one surface 20 of the base plate 1 is provided with protruding ridges 21 ...
The stator 5 is attached to the base plate 1 in a state where the stator core 12 of the stator 5 is in contact with the protruding portions 21. As a result, the noise accompanying the electromagnetic vibration of the stator 5 and the vibration to the base plate 1 are reduced.

A cover 22 is provided on one surface 20 of the base plate 1 as a measure against leakage flux from the winding portion 14. That is, the cover 22 is made of, for example, a magnetic material such as stainless steel and has a flat plate portion 22 a facing the winding portion 14.
And a leg portion 22b vertically extending from the outer peripheral edge of the flat plate portion 22a,
The mounting piece portion 22c of the leg portion 22b is mounted on the base plate 1 by a fastener such as a screw.

Therefore, a part of the winding portion 14 of the stator 5 enters the window portion 19 opened in the base plate 1,
As a result, the axial length L can be reduced as a whole as compared with the conventional one, and the overall thickness can be reduced. In the present embodiment, the hub 4 has the cylindrical portion 7,
That is, since the holders of the bearings 3 and 3 are also used as the holders of the rotor magnet 6, the space in the radial direction can be effectively used and the weight can be reduced.

Next, FIG. 3 shows another embodiment. In this case, the spindle motor is of the shaft rotating type, whereas the spindle motor shown in FIG. 1 is of the shaft fixing type.

That is, in the spindle motor in this case, the base plate 1 is provided with the cylindrical portion 25, and the shaft member 2 is rotatably supported by the cylindrical portion 25 via the bearings 3 and 3. The hub 4 is attached.

In this case, however, the hub 4 has the disc portion 26.
A cylindrical portion 27 protruding from the disc portion 26, an outer flange portion 28 protruding from the outer peripheral surface of the cylindrical portion 27 in the outer radial direction, and the cylindrical portion.
A cylindrical magnet holding portion 29 that projects from the inner diameter side end surface of 27 to the base plate 1 side, the rotor magnet 6 is attached to the outer peripheral surface of the magnet holding portion 29, and the outer flange portion 28 has a magnetic disk. Is installed.

The stator 5 in this case is the same as that used in the spindle motor shown in FIG. 1, and the winding portion 14 of the stator 5 is attached to the base plate 1.
There is a window 19 ... where some of the ... penetrates.

That is, on one surface 20 of the base plate 1, there is formed a circumferential concave portion 30 arranged on the outer diameter side of the cylindrical portion 25,
The bottom surface 30a of the recess 30 is provided with through holes 31 ... Arranged at a predetermined pitch along the circumferential direction, and the through holes 31 serve as the window portion 19. In this case, the bottom surface 30a of the recess 30
Is provided with a ring-shaped convex ridge 32 on the outer peripheral edge thereof, and a ring-shaped convex ridge 33 is provided substantially at the center of the bottom surface 30a of the concave portion 30.
12 is in contact.

That is, a part of the winding portion 14 of the stator 5 (that is, a portion protruding from the back surface 12a of the stator core 12) is inserted into the window portion 19 as shown in the drawing, and the stator core 12 is recessed. Fit in 30. In this case, the stator core 12 may be fixed to the base plate 1 with an adhesive, the stator core 12 may be fixed to the base plate 1 with a screw, or the adhesive may be fixed with a screw. The outer peripheral surface 15b of the main body 15 is the peripheral surface 30 of the recess 30.
It is in contact with b.

Therefore, in this case as well, a part of the winding portion 14 of the stator 5 enters the window portion 19 of the base plate 1, so that the overall axial length L is reduced accordingly. be able to. It should be noted that in comparison with the one shown in FIG. 1, the one shown in FIG. 3 requires the hub 4 to be attached to the shaft member 2,
Although there is a drawback that the axial direction is lengthened by the mounting margin A, the axial length L can be made sufficiently small for the inner rotor type and the shaft rotating type.

The present invention is not limited to the above-mentioned embodiments, and the design can be freely changed without departing from the gist of the present invention. For example, in the embodiments, all are inner rotor type, but of course, The outer rotor type may be used. Further, the number of winding portions 14 of the stator 5 can be freely increased or decreased, and correspondingly, the number of window portions 19 can be freely increased or decreased. Further, the stator 5 may be one having teeth for interpolating between the teeth 11 and 11, and the number of core laminations 16 and the thickness dimension thereof can be freely changed.

[0029]

Since the present invention is configured as described above, it has the following effects.

It is possible to make the entire axial length L smaller than that of the conventional spindle motor by the amount of the part of the winding portion 14 entering the window portion 19 without reducing the wall thickness of the base plate 1. It can be made thin as a whole, and moreover,
It is not inferior in strength.

[Brief description of drawings]

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

FIG. 2 is a plan view of a main part of a stator.

FIG. 3 is a cross-sectional view of main parts of another embodiment.

FIG. 4 is a sectional view of a conventional example.

FIG. 5 is a cross-sectional view of another conventional example.

[Explanation of symbols]

 1 Base plate 5 Stator 14 Winding part 19 Window part

Claims (1)

Claims: 1. A plurality of windows (19) into which a part of each winding part (14) of the stator (5) penetrates are formed in the base plate (1) at a predetermined pitch along the circumferential direction. And spindle motor.