JPH04108373U - motor - Google Patents

Abstract

(57) [Summary] [Purpose] The purpose is to easily and reliably position a position detection magnet at a predetermined position, and to solve the problem of detachment caused by temperature changes. [Structure] A motor comprising a housing 2, a rotor rotatable relative to the housing 2, a rotor magnet 6 attached to the rotor, and a stator 5 disposed opposite the rotor magnet 6. An annular recess 94 is formed in the rotor, and a position detection magnet 95 is attached to this annular recess 94. A positioning protrusion 98 is provided on the inner circumferential surface and/or outer circumferential surface of the annular recess 94 (or the inner circumferential surface and/or outer circumferential surface of the position detection magnet 95) for positioning the magnet 95 at a predetermined position. ing.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

The present invention relates to motors such as spindle motors.

0002

[Conventional technology]

A spindle motor as an example of a motor has a housing and a It includes a hub member (rotor) that is rotatable relative to the rotor. to the hub member The rotor magnet is attached and the stator is placed opposite the rotor magnet. It is. In addition, the hub member has a position detection device for detecting its rotational angular position. A magnet is attached, and a hole is placed at a predetermined position opposite to this position detection magnet. A detection sensor such as a control element is provided. And a position detection magnet is accommodated in an annular recess formed in the hub member.

0003

[Problem that the idea aims to solve]

However, this type of motor has the following problems to be solved. Generally, the hub member is formed from a metallic material such as aluminum, while the hub member is The magnet is made of synthetic resin or rubber containing magnetic powder, and the coefficient of thermal expansion of the hub member is smaller than the position detection magnet. Therefore, temperature changes in the atmosphere in which the motor is used When the thermal expansion coefficient is large, the position An annular recess (formed in the hub member) that accommodates the width of the detection magnet. is smaller than the width of

0004 By reducing the width of the position detection magnet, this magnet can be placed inside the annular recess. It becomes difficult to accurately position them concentrically. And the magnet is out of position. In this case, the output of the detection sensor will vary depending on the rotational angular position of the hub member, and the It is not possible to accurately detect the rotational angular position of the knob member. Also, the position may shift and the If the magnet comes into contact with the inner or outer circumferential surface of the annular recess of the hub member, the Changes in ambient temperature create a relatively large thermal stress between the two, which causes A problem arises in which the detection magnet separates from the hub member.

[0005] The problem of this invention is to easily and reliably position the position detection magnet in a predetermined position. A motor that can be used in a variety of applications, and can also solve disengagement caused by temperature changes. The goal is to provide the following.

[0006]

[Means to solve the problem]

In the first motor of the present invention, the inner peripheral surface of the annular recess provided in the rotor and/or is equipped with a positioning protrusion that protrudes toward the position detection magnet on the outer circumferential surface. It is.

[0007] In the second motor of the present invention, the inner circumferential surface and/or outer circumferential surface of the position detection magnet protrudes toward the inner circumferential surface and/or outer circumferential surface of the annular recess provided in the rotor. A positioning protrusion is provided.

[0008]

[Effect]

In the first motor of the present invention, the rotor is provided with a positioning protrusion. Therefore, the position detection magnet can be easily aligned concentrically by the action of the positioning protrusion. It can be positioned in In addition, what actually acts on the position detection magnet is Since this is the only positioning protrusion, even if thermal stress occurs due to temperature changes, this will not occur. The deformation of the magnet from the rotor can be absorbed by the elastic deformation of the magnet. Departure is prevented.

[0009] In the second motor of the present invention, a positioning protrusion is provided on the position detection magnet. The position detecting magnet is not affected by the action of the positioning projection. can be easily positioned concentrically. In addition, an annular recess provided in the rotor It is only the positioning protrusion that acts on the inner circumferential surface or outer circumferential surface of the Even if thermal stress occurs due to temperature changes, it is absorbed by the elastic deformation of the positioning protrusion. This prevents the magnet from detaching from the rotor.

0010

【Example】

An embodiment of the motor according to the present invention will be described below with reference to the accompanying drawings. .

[0011] FIG. 1 shows an embodiment of a spindle motor according to the present invention. In FIG. 1, the illustrated motor has a housing 2 and a A hub member 8 is provided which is relatively rotatable. The housing 2 is approximately disk-shaped. The outer circumference of the housing body 24 has a radial direction. A flange portion 25 projecting outward is integrally provided. This flange portion 25 , fixed to the disk drive frame (not shown) by means such as mounting screws. It will be done.

0012 A shaft member 1 is fixed to the center of the housing body 24, and a pair of shaft members 1 are fixed to the center of the housing body 24. A hub member 8 is rotatably supported via bearing members 3 and 4. hub parts 8 has a cylindrical hub body 81, and one end (upper end) of this hub body 81 is connected to one side. is rotatably supported via the bearing member 3 of the hub body 81, and the other end (lower end ) is rotatably supported via the annular bushing member 41 and the other bearing member 4. ing.

[0013] A flange portion 83 is also integrally provided at the other end of the hub body 81. A plurality of magnets are mounted on the upper surface of this flange portion 83 via a spacer member (not shown). An air disk (not shown) is placed thereon.

[0014] An annular yoke member 7 is attached to the inner peripheral surface of the hub body 81, and this yoke member 7 An annular rotor magnet 6 is attached to the inner peripheral surface of the rotor. On the other hand, the rotor magnet A stator 5 is disposed opposite the cut 6. The stator 5 is attached to the shaft member 1. stator core 51 and coils wound around this stator core 51 as required. 52. By supplying a driving current to this coil 52 as required, Then, the hub member 8 (magnetic disk The rotor magnet 6) is rotated in a predetermined direction. In this example, As can be easily understood, the hub member 8, the yoke member 7, the rotor magnet 6 and the The annular bushing member 41 constitutes a rotor.

[0015] A magnetic fluid sealing mechanism 9 is provided on the outside of one of the bearing members 3 . illustrated The magnetic fluid seal mechanism 9 includes an annular permanent magnet 91 attached to the hub member 8 and a ring-shaped permanent magnet 91 attached to the hub member 8. A pair of pole pieces 92 are provided on both sides of a shaped magnet 91. 2 and the shaft member 1 is filled with magnetic fluid. Modification of the above-mentioned magnetic fluid seal mechanism 9 A cap member 93 is attached to the outside.

[0016] A labyrinth seal structure 12 is provided on the outside of the other bearing member 4 . The illustrated labyrinth seal structure 12 has a ring formed on the inner surface of the housing body 24. from the annular protrusion 87 provided on the lower surface of the flange portion 83 of the hub member 8. The annular protrusion 87 is received in the annular recess 88 .

[0017] The coil 52 of the stator 5 is led out to the outside as follows. Shaft member 1 A recess 14 extending in the axial direction is formed in a part of the outer peripheral surface of the recess 14 . Also, Howe The ring body 24 has a through hole that communicates with the lead-out space defined by the recess 14. A hole 31 is formed. The lower surface (outer surface) of the housing body 24 has a predetermined shape. A recess is formed, and circuit boards 54 and 55 are disposed within the recess. . The lead wire 56 from the coil 52 passes through the recess 14 and the through hole 31 to the outside. The end portion thereof is electrically connected to the terminal portion of the circuit board 55. Also , an elongated flexible board 53 extends from the circuit board 54. A flexible board 53 is electrically connected to a terminal portion of the disk drive device. Furthermore, implementation In the example, the recess formed in the housing body 24 is closed by the seal member 77. , the circuit boards 54 and 55 are covered by this seal member 77.

[0018] The hub member 8 (i.e., the rotor magnet 6) in such a spindle motor The rotational angular position is detected as follows. Referring to FIG. 2 in conjunction with FIG. An annular housing recess is provided on the lower surface (outer surface) of the annular bushing member 41 that constitutes a part of the 94 is formed. A position detection magnet 9 is placed inside this housing recess 94. 5 is housed and secured by means such as adhesive. Magnet for position detection The groove 95 is annular and has a width smaller than the width of the accommodation recess 94 of the bushing member 41. When positioned concentrically, the inner circumferential side of the magnet 94 (its inner circumferential surface and the housing recess) (between the inner circumferential surface of the housing recess 94) and the outer circumferential side (between the outer circumferential surface and the outer circumferential surface of the housing recess 94) ).

[0019] In the embodiment, the hub member 8 is formed from aluminum and includes an annular bushing member 41. is made of a magnetic material such as iron, and the magnet 95 is made of plastic containing magnetic powder. It is formed from magnets. This magnet 95 is the same as the rotor magnet 6. Similarly, for example, it is magnetized into 8 poles as shown in Figure 2 (N and S poles in Figure 2 are , showing the magnetic poles magnetized on the bottom surface of the magnet 95 in FIG. 1). And low The magnetic poles of the magnet 6 and the magnetic poles of the position detection magnet 95 are substantially aligned in the axial direction. The magnet 95 is attached to the bushing member 41 so as to match.

[0020] On the other hand, a substantially rectangular recess 97 is provided at a predetermined portion on the lower surface of the housing body 24. is formed, and the detection sensor 23 such as a Hall element provided on the circuit board 54 is connected to the circuit board 54. It is received in the recess 97 of. The detection sensor 23 is a position detection magnet 95 The magnet 95 for position detection, and therefore the rotation of the hub member 8, Detect rotation angle position.

[0021] In the embodiment, the outer peripheral surface of the position detection magnet 95 is provided with substantially equal intervals (90 degree angles). Four positioning protrusions 98 are integrally provided at intervals (intervals). Positioning protrusion 98 has a substantially semicircular shape, and the diameter of the circle connecting the tips is the same as that of the accommodation recess 9. The diameter is set to be substantially the same as the diameter of the outer circumferential surface of No. 4. It is structured like this Therefore, when attaching the magnet 95, it is necessary to align it with the outer circumferential surface of the housing recess 94. The magnet 95 is positioned by the action of the protrusion 98, and the magnet 95 is positioned in the accommodation recess 94. When attached to the storage recess 94, the magnet 95 is positioned exactly concentrically within the housing recess 94. It will be done. In the embodiment, as shown in FIG. 2, a protrusion 98 is provided corresponding to the N pole of the magnet 95. By using this protrusion 98 as a mark of the N pole, the position of the magnet 95 can be determined. Easy to install. Instead of these N poles, there are protrusions corresponding to the S poles or the boundaries of both poles. 98 may be provided.

[0022] In the embodiment, four positioning protrusions 98 are provided on the outer peripheral surface of the positioning magnet 95. However, three or five or more may be provided. In addition, in the example, It is provided on the outer peripheral surface of the magnet 95, but instead of this, the same is provided on the inner peripheral surface. It may also be provided.

[0023] By providing the positioning protrusion 98 as in the embodiment, the following features occur. . That is, as described above, the positioning is performed by the action of the accommodation recess 94 and the positioning protrusion 98. The position detection magnets 95 can be easily positioned concentrically. Also, Figure 2 As can be easily understood from the above, the outside of the accommodation recess 94 provided in the bushing member 41 Since it is essentially only the positioning protrusion 98 that acts on the circumferential surface, it is not affected by temperature changes. Even if thermal stress is generated due to this, it can be absorbed by the elastic deformation of the positioning protrusion 98. This prevents thermal stress from acting on the entire magnet 95.

[0024] An embodiment of the motor according to the present invention has been described above, but the present invention is The invention is not limited to the examples, and various modifications and modifications may be made without departing from the scope of the invention. Correct is possible. For example, in the illustrated embodiment, the positioning protrusion 98 is provided on the position detection magnet 95. However, instead of or in addition to this, the housing recess 9 of the bushing member 41 is provided. A positioning protrusion may be provided on the inner circumferential surface and/or outer circumferential surface of 4. containment When provided on the inner circumferential surface (or outer circumferential surface) of the recess 94, the positioning protrusion can be used for position detection. It comes to act on the inner circumferential surface (or outer circumferential surface) of the output magnet 95, and this inner circumferential surface (or the outer circumferential surface) to position the magnet 95 at a concentric predetermined position. . In addition, in such cases, even if thermal stress occurs due to temperature changes, position Due to elastic deformation of the portion of the output magnet 95 on which the positioning protrusion 98 acts. The same effect as in the above embodiment can be achieved.

[0025] In each of the above examples, the position detection magnet 95 is mounted on the bushing member 41. This includes, but is not limited to, other members forming part of the rotor, For example, a position detection magnet 95 is attached to the hub member 8 (for example, the flange portion 83). You can do it like this.

[0026]

[Effect of the idea]

As detailed above, in the first motor of the present invention, the rotor has a positioning protrusion. is provided, the position detection magnet is capacitated by the action of the positioning protrusion. They can be easily positioned concentrically. It also acts on the position detection magnet. Since it is essentially only the positioning protrusion, thermal stress is not generated due to temperature changes. Even so, the absorption is caused by the elastic deformation of a part of the magnet (the part where the protrusion acts). This prevents the magnet from coming off.

[0027] In the second motor of the present invention, a positioning protrusion is provided on the position detection magnet. The position detection magnet can be easily moved by the action of the positioning protrusion. Can be positioned concentrically. In addition, the amount that actually acts on the rotor is Since there is only a positioning protrusion, even if thermal stress occurs due to temperature changes, the positioning protrusion This can be absorbed by the elastic deformation of the magnet, preventing the magnet from detaching.

[Brief explanation of drawings]

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

FIG. 2 is a bottom view of the bushing member and position detection magnet in the motor of FIG. 1, viewed from below.

[Explanation of symbols]

2 Housing 5 Stator 6 Rotor magnet 8 Hub member 23 Detection sensor 41 Bush member 94 Accommodation recess 95 Position detection magnet 98 Positioning protrusion

Claims (2)

[Scope of utility model registration request] 1. A rotor comprising: a housing; a rotor rotatable relative to the housing; a rotor magnet attached to the rotor; and a stator disposed opposite the rotor magnet. In a motor in which an annular recess is formed in the rotor and a position detection magnet is attached to the annular recess, the inner circumferential surface and/or outer circumferential surface of the annular recess protrudes toward the position detection magnet. A motor characterized in that it is provided with a positioning protrusion. 2. A rotor comprising a housing, a rotor rotatable relative to the housing, a rotor magnet attached to the rotor, and a stator disposed opposite to the rotor magnet, In a motor in which an annular recess is formed in the rotor and a position detecting magnet is attached to the annular recess, the inner circumferential surface and/or outer circumferential surface of the position detecting magnet have an inner circumferential surface and/or an outer circumferential surface of the annular recess. /
Or a motor characterized by being provided with a positioning protrusion that protrudes toward the outer peripheral surface.