JP2860812B2 - motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is to detect a rotation speed, a rotation position, and the like of a rotor in an annular groove provided in a rotating portion that rotates integrally with the rotor. In which an annular permanent magnet body is fixed via an adhesive substance.

[Prior Art] Conventionally, when an annular permanent magnet body a for detecting a rotation speed, a rotation position, and the like of a rotor is fixed to a spindle motor as shown in FIG. 7, for example, the magnetic force of the annular permanent magnet body a is reduced. An annular permanent magnet body a for detection is provided in an annular groove c formed by a yoke b or the like made of a ferromagnetic material provided for improving the magnetic flux in a certain direction.
Was tightly fitted with an adhesive d.

[Problem to be Solved by the Invention] In this way, it is apparent that the ring-shaped permanent magnet body is firmly fitted in the groove-like portion in a state in which the permanent magnet body is tightly fitted. Adhesives are not always applied to the required areas to ensure reliable adhesion.
Adhesive strength may be insufficient due to uneven application or insufficient amount of adhesive. In such a case, if the annular permanent magnet body is fitted exactly into the groove, it is difficult to check the bonding state from the outside, and this has been a problem in finding a poorly bonded product.

The present invention has been made in view of the above-described problems in the related art, and an object of the present invention is to provide a product in which an annular permanent magnet body is securely fixed in a groove-shaped portion. It is an object of the present invention to provide a motor that can be manufactured more efficiently than the above.

[Means for Solving the Problems] In order to achieve the above object, a motor according to the present invention is arranged such that a rotational speed, a rotational position, and the like of a rotor are provided in an annular groove provided in a rotating portion integrally rotating of the rotor. In a motor in which an annular permanent magnet body for detecting a state is fixed via an adhesive substance, any one of the inner circumferences or the outer circumferences of the annular permanent magnet body and the groove-shaped portion is one of The annular permanent magnet body is positioned in the radial direction with respect to the groove-shaped portion by being configured in close contact, the other is separated via a gap, the gap is filled with an adhesive substance, and is present, The annular body is fixed in the groove by the adhesive substance.

[Effect] One of the inner peripheral portions and the outer peripheral portions of the annular permanent magnet body and the groove portion is configured to be in close contact with each other, so that the annular permanent magnet body is radially oriented with respect to the groove portion. It is positioned at. The other one of the inner peripheral portions or the outer peripheral portions of the annular permanent magnet body and the groove portion is separated via an interval, and the interval is filled with an adhesive substance, and the adhesive substance is present. As a result, the annular body is fixed in the groove-shaped portion, so that at least the state of adhesion between the annular permanent magnet body and the groove-shaped portion by the adhesive substance filled in the space can be easily confirmed from the outside.

Then, by detecting magnetic fluctuation due to rotation of the annular permanent magnet body fixed to the rotating portion that rotates integrally with the rotor, the rotation speed and the rotation position of the rotor are detected.

Embodiment An embodiment of the motor according to the present invention will be described with reference to FIGS.

FIG. 1 is a half sectional view of a main part of a spindle motor for driving a hard disk.

In FIG. 1, reference numeral 10 denotes a fixed shaft, 12 denotes a stator fixed to the fixed shaft 10, and 14 denotes a bearing.

Reference numeral 16 denotes a hub made of a non-magnetic material (refers to a paramagnetic material or a diamagnetic material; the same applies hereinafter). Reference numeral 18 denotes a cylindrical yoke made of a ferromagnetic material for a rotor magnet,
Is fixed inside. Inside the cylindrical yoke 18,
The rotor magnet 20 is fixed. Reference numeral 22 denotes an annular member press-fitted between the hub 16 and the bearing 14. The hub 16 and the annular member 22 include a bearing 14 and a lower bearing (not shown).
And is rotatably supported on the fixed shaft 10 via the. twenty four
Is a labyrinth-shaped seal member provided above the bearing 14. The seal member 24 is fixed to the fixed shaft 10 in a state where the top ends of the upper and lower two throttle pieces 26 and 28 are close to the inner peripheral portion of the annular member 22, and a groove is formed between the two throttle pieces 26 and 28. 30 are formed.

32 is an annular permanent magnet body. This annular permanent magnet body
This is for detecting the rotation speed of the rotor 34, and is magnetized with alternating polarity over the entire circumference. 36 is an annular yoke made of a ferromagnetic material for an annular permanent magnet body, and 38 is an adhesive. The annular yoke 36 has a protrusion 36b on the outer peripheral portion of the annular plate portion 36a.
Is formed.

An annular notch 40 is formed in the outer peripheral portion of the upper end of the annular member 22, and the bottom surface of the notch 40 and the upper end surface of the hub 16 are continuous to form an annular flat portion 42.

The inner peripheral wall surface 44 of the notch 40 is formed vertically (that is, parallel to the axial direction).

The annular yoke 36 is adhered such that the bottom surface is in contact with the annular flat portion 42 and the inner peripheral portion is in contact with the inner peripheral wall surface 44 of the cutout portion 40.

The annular yoke 36 and the inner peripheral wall surface 44 of the notch 40 in the annular member 22 form an annular groove-like portion 46, in which the annular permanent magnet body 32 is attached via an adhesive 38. Fixed. The inner peripheral wall surface 48 of the annular permanent magnet body 32 is also formed vertically.

Since the outer peripheral portions of the annular permanent magnet body 32 and the groove-shaped portion 46 are formed in close contact with each other, the positioning of the annular permanent magnet 32 with respect to the groove-shaped portion 46 is easy, and the annular permanent magnet body 32 and the groove-shaped portion 46 are formed. Are separated from each other via a space 50, and the space 50 is filled with an adhesive 38, so that the annular permanent magnet body 32 and the groove 46 The state of adhesion with can be easily confirmed from the outside.

After the annular permanent magnet body 32 is adhered to the annular yoke 36, the annular yoke 36 is adhered to the annular plane portion 42, and then the gap portion 50 is filled with the adhesive 38. .

52 is a hard disk, 54 is an adjacent hard disk
It is a spacer inserted between 52 and 52.

By forming a rotating magnetic field with the stator 12, the rotor magnet 20, the cylindrical yoke 18, the hub 16, and the annular member are formed.
The rotating portion consisting of 22 is driven to rotate together with the ring-shaped permanent magnet body 32 and the ring-shaped yoke 36, and the change in magnetic flux due to the rotation of the ring-shaped permanent magnet body 32 is detected by a coil pattern (not shown), etc. An AC electric signal having a frequency corresponding to the frequency can be obtained.

In addition, the airflow that flows out of the bearing 14 through the seal member 24 during rotation through the seal member 24, after passing between the lower throttle piece 26 and the annular member 22, expands in the groove 30 to cause stagnation,
Lubricant particles and the like scattered from the bearings fall in order from the heaviest one, and scattering to the outside is suppressed.

2 to 5 are cross-sectional views of a main part of a spindle motor for driving a hard disk.

In FIG. 2, a notch is further provided in the inner peripheral wall of the cutout portion 40 in the annular member 22, and a part of the inner peripheral wall surface 44 is inclined inward and downward by this notch.
The inner peripheral wall surface 48 of the annular permanent magnet body 32 is formed vertically.

With such a configuration, the adhesive filled in the space portion 50
38 are prevented from falling off.

In FIG. 3, the inner peripheral wall surface 44 of the cutout portion 40 in the annular member 22 is formed vertically, and the inner peripheral wall surface 48 of the annular permanent magnet body 32 is formed to be inclined inward and downward.

With such a configuration, the adhesive filled in the space portion 50
38 enhances the effect of preventing the annular permanent magnet body 32 from falling off.

In FIG. 4, a part of the inner peripheral wall 44 of the notch 40 in the annular member 22 is formed to be inclined inward and downward, and the inner peripheral wall 48 of the annular permanent magnet body 32 is 44
Is formed to have an inward and downward inclination at a shallower angle than the inward and downward inclination angle.

With such a configuration, the adhesive filled in the space portion 50
This prevents the falling off of the annular permanent magnet body 32 by the adhesive 38 filled in the space 50, while preventing the falling off of the annular permanent magnet 32.

In FIG. 5, the inner peripheral wall surface 44 of the notch 40 in the annular member 22 is formed to be inclined inward and downward,
An interval is also provided between the inner periphery of the annular yoke 36 and the inner peripheral wall surface 44 of the notch 40, and the space is also filled with the adhesive 38.

By doing so, it is easy to confirm not only the annular permanent magnet body 32 but also the bonding state of the annular yoke 36.

Further, as shown in FIG. 6, a notch 56 is provided in the inner peripheral portion of the annular flat portion of the annular yoke 36, and an adhesive is filled in the notch 56 to prevent the annular yoke 36 from rotating with respect to the annular flat portion 42. In addition, the effect of ensuring the adhesion and fixing can be obtained.

In the above example, the outer peripheral portions of the annular permanent magnet body and the groove-shaped portion are configured to be in close contact with each other, but the inner peripheral portions thereof are configured to be in close contact with each other, and the outer peripheral portions thereof are filled with an adhesive. Of course, there is no problem even if they are separated via the spaced portion.

Further, the annular permanent magnet body may be magnetized at an alternate polarity over the entire circumference, or may be magnetized at only one location.

[Effects of the Invention] In the motor according to the present invention, one of the inner peripheral portion and the outer peripheral portion of the annular permanent magnet body and the groove portion is configured to be in close contact with each other, so that the annular permanent magnet body is formed. Are positioned in the radial direction with respect to the groove-shaped portion, the other is separated via a gap, and the gap is filled with an adhesive substance, and the annular body is fixed in the groove-shaped section by the adhesive substance. Therefore, the state of adhesion between the annular permanent magnet body and the groove-shaped portion by at least the adhesive substance filled in the space can be easily confirmed from the outside. Therefore, a product in which the annular permanent magnet body is securely fixed in the groove portion can be manufactured more efficiently than in the past, and the annular permanent magnet body for detecting the rotation speed, the rotation position, and the like of the rotor. It is highly effective in preventing troubles such as falling off.

[Brief description of the drawings]

1 to 6 relate to an embodiment of the motor of the present invention. 1 is a half sectional view of a main part of a spindle motor for driving a hard disk, FIGS. 2 to 5 are cross-sectional views of a main part of a spindle motor for driving a hard disk, and FIG.
It is a perspective view of an annular yoke. FIG. 7 is a half sectional view of a main part of a conventional spindle motor for driving a hard disk. In the drawing, 32 is an annular permanent magnet body, 34 is a rotor, 38 is an adhesive, 46 is a groove-like portion, and 50 is a spacing portion.

──────────────────────────────────────────────────続 き Continued on front page (58) Field surveyed (Int.Cl. ⁶ , DB name) H02K 11/00

Claims (1)

(57) [Claims] An annular permanent magnet for detecting a rotation speed, a rotation position, and the like of a rotor is fixed in an annular groove-shaped portion provided on a rotating portion that rotates integrally with the rotor via an adhesive substance. In the motor, any one of the inner peripheral portions or the outer peripheral portions of the annular permanent magnet body and the groove-shaped portion is configured to be in close contact with each other so that the annular permanent magnet body has a groove-like shape. Is positioned in the radial direction with respect to the portion, and the other is separated by a gap, and the gap is filled with an adhesive substance, and the annular body is fixed in the groove-shaped section by the adhesive substance. A motor characterized in that: