JP2003259581A - Motor component, manufacturing method for motor component, and motor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor that hardly exerts a adverse effects caused by a faulty connection of a permanent magnet and a support member for the magnet, and to provide a motor component by which the motor can be provided, and a manufacturing method for the motor component. <P>SOLUTION: A rotor 1 comprises a yoke 2, the permanent magnet 3, a hub 4, and a sleeve 5. The permanent magnet 3 is constituted of a magnet body 31 and a metallic layer 32 formed on at least a part of the surface of the body. The yoke 2 and the permanent magnet 3 are jointed and fixed by heat-calking or press-insertion. The metallic layer 32 is composed of a material containing Ni. The average thickness of the metallic layer 32 is 1 to 50 μm. The yoke 2 is composed of a material containing Fe or Al as a main component. When the inside diameter of the yoke 2 in a natural condition at the vicinity of room temperature is set D<SB>1</SB>(mm), and when the outside diameter of the permanent magnet 3 in a natural condition at the vicinity of room temperature is set D<SB>2</SB>(mm), a relation of 1.00025≤D<SB>2</SB>/D<SB>1</SB>≤1.00105 is satisfied. <P>COPYRIGHT: (C)2003,JPO

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a method of manufacturing a motor component, a motor component, and a motor.

[0002]

2. Description of the Related Art Generally, a motor has a rotor and a stator. Some rotors have a structure in which a permanent magnet is fixed to a yoke.

In such a conventional rotor, the permanent magnet and the yoke are joined by an organic adhesive. However, with conventional adhesives, the adhesive strength varies widely, and in some cases, some or all of the joints may peel off during long-term operation. When such peeling occurs, problems such as abnormal noise and abnormal vibration occurring when the motor is driven, and deterioration of the torque characteristics of the motor occur.
Further, when the above-mentioned peeling progresses, the permanent magnet and the yoke are separated from each other, which causes a problem that the motor is broken or damaged.

Further, in the conventional rotor as described above, in the manufacturing process, the excess organic adhesive sometimes squeezes out from between the permanent magnet and the yoke to the rotor end surface. Such an excess organic adhesive is usually designed with a motor structure in which the excess adhesive is dimensionally tolerable, but the excess adhesive on the end face is subjected to centrifugal force, vibration, and torque fluctuation due to the rotation of the rotor. Since it is directly subjected to the circumferential acceleration due to, peeling, breakage, and falling occur. A part of the adhesive that has fallen off may remain in the motor and adversely affect the motor.

Further, since an organic adhesive is used to bond the permanent magnet and the yoke, the bonding position causes variations in the bonding position, and the unbalance amount of the center of gravity of the rotor (rotational unbalance amount) is reduced. Was difficult.

[0006]

SUMMARY OF THE INVENTION An object of the present invention is to provide a motor which is less likely to be adversely affected by a defective joint between a permanent magnet and a supporting member thereof, and a motor component which can provide the motor. It is to provide a method for manufacturing a motor component.

[0007]

The above objects are achieved by the present invention described in (1) to (26) below.

(1) A motor component having a permanent magnet whose surface is at least partially covered with a metal layer, and a support member for supporting the permanent magnet, the component being for heat caulking.
A motor component, wherein the permanent magnet is supported and fixed to the support member.

(2) The coefficient of thermal expansion (coefficient of linear expansion) of the constituent material of the supporting member near room temperature is 4 to 30 [× 10 ^−6]
K ^-1 ], The motor component as described in (1) above.

(3) A motor component having a permanent magnet having at least a part of its surface coated with a metal layer, and a support member for supporting the permanent magnet, wherein the permanent magnet is made to support the permanent magnet by press fitting. A motor component characterized by being supported and fixed to.

(4) The motor component according to (3), wherein the friction coefficient μ of the metal layer measured by the ball-on-disk method is 0.1 to 0.7.

(5) The permanent magnet is composed of a magnet body and the metal layer, and the coefficient of thermal expansion (linear expansion coefficient) of the magnet body near room temperature is α ₁ [× 10 ^{− 6} K
^-1], the thermal expansion coefficient at near room temperature of the material of the metal layer (coefficient of linear expansion) α ₂ [× ^{10 -} when a 6 ^{K -1],}
| Α ₂ −α ₁ | is the motor component according to any one of the above (1) to (4), which is 15 [× 10 ⁻⁶ K ⁻¹ ] or less.

(6) The motor component according to any one of (1) to (5), wherein the permanent magnet is supported and fixed to the inner peripheral side of the support member.

(7) Vickers hardness Hv of the metal layer
The motor component according to any one of (1) to (6) above, wherein the value is 150 or more.

(8) The motor component according to any one of (1) to (7), wherein the metal layer is made of a material containing Ni.

(9) The average thickness of the metal layer is 1 to 5
The motor component according to any one of (1) to (8), which has a thickness of 0 μm.

(10) The motor component according to any one of the above (1) to (9), wherein the metal layer is formed by electroplating and / or electroless plating.

(11) The support member is at least
The motor component according to any one of the above (1) to (10), wherein the portion to be coupled with the permanent magnet is made of a metal or an alloy material.

(12) The motor component according to any one of (1) to (11), wherein the permanent magnet is a bonded magnet.

(13) The motor component according to any one of (1) to (12), wherein the permanent magnet is chamfered.

(14) The motor component according to any one of (1) to (13) above, which is a rotor.

(15) The motor component according to the above (14), wherein the rotational unbalance amount of the rotor is 0.005 g · cm or less.

(16) A method for manufacturing a motor component having a permanent magnet having at least a part of its surface coated with a metal layer, and a supporting member for supporting the permanent magnet, wherein the permanent magnet is formed by thermal caulking. Is supported and fixed to the support member, and a method for manufacturing a motor component.

(17) The thermal expansion coefficient (linear expansion coefficient) of the constituent material of the supporting member at around room temperature is 4 to 30 [× 10
^-6 K ^-1 ], the method for producing a motor component as described in (16) above.

(18) A method of manufacturing a motor component having a permanent magnet, at least a portion of the surface of which is coated with a metal layer, and a support member for supporting the permanent magnet, wherein the permanent magnet is formed by press fitting. A method of manufacturing a motor component, comprising supporting and fixing the support member.

(19) The method of manufacturing a motor component according to (18), wherein the friction coefficient μ of the metal layer measured by the ball-on-disk method is 0.1 to 0.7.

(20) The permanent magnet is supported and fixed on the inner peripheral side of the supporting member, and the permanent magnets (16) to (19) are fixed.
A method for manufacturing a motor component according to any one of 1.

(21) When the inner diameter of the supporting member in the natural state near room temperature is D ₁ [mm] and the outer diameter of the permanent magnet in the natural state near room temperature is D ₂ [mm], the following formula The method of manufacturing a motor component according to (20) above, which satisfies the relationship (I). 1.00025 ≤ D ₂ / D ₁ ≤ 1.00105 (I)

(22) Vickers hardness H of the metal layer
v is 150 or more, The manufacturing method of the parts for motors in any one of said (16) thru | or (21).

(23) The method of manufacturing a motor component according to any one of (16) to (22), wherein the permanent magnet is chamfered.

(24) A motor comprising the motor component described in any one of (1) to (15) above.

(25) The motor according to the above (23), which is used in a region where the maximum rotation speed is 4000 rpm or more.

(26) The motor according to the above (23) or (24) used in a hard disk drive.

[0034]

BEST MODE FOR CARRYING OUT THE INVENTION Preferred embodiments of a motor component, a motor component manufacturing method, and a motor of the present invention will be described below with reference to the accompanying drawings.

First, preferred embodiments of the motor component and the manufacturing method thereof according to the present invention will be described.

FIG. 1 shows a motor component (rotor) of the present invention.
It is a cross-sectional side view showing a preferred embodiment of the. Below, Figure 1
The middle and lower sides will be described as "base ends" and the upper sides as "tips".

As shown in FIG. 1, a rotor (rotor) 1
Is a hub 4, a sleeve 5 joined to the inner surface of the hub 4 on the tip end side, a yoke 2 joined to the inner surface of the hub 4 on the base end side, and an inner surface side of the yoke 2 (support member). The permanent magnet 3 is joined and fixed.

The sleeve 5 has a substantially cylindrical shape, and has a groove (middle escape portion) 53 on the inner surface side thereof. The sleeve 5 functions as a bearing (dynamic pressure fluid bearing) when used for manufacturing the motor 11 as described later. That is, the sleeve 5 has bearing portions 51 and 52 protruding inward at two different locations in the longitudinal direction (vertical direction in FIG. 1).
When the bearing is such a hydrodynamic fluid bearing (sliding bearing), it can be suitably applied to a motor used in a high rotation range as described later.

As a constituent material of the sleeve 5, for example,
Copper alloy such as copper or brass, aluminum, iron alloy such as iron or stainless steel, or a metal sintered body using them as a powder raw material, Al ₂ O ₃ (alumina), titania (TiO ₂ ), zirconia (ZrO ₂ ) Examples include ceramics containing as a main component, synthetic resins, and the like.

The yoke 2 has a substantially cylindrical shape and is joined and fixed to the inner surface of the hub 4 on the base end side.

The constituent material of the yoke 2 is not particularly limited, but is usually composed of a metal or alloy material. York 2
Examples of the material for forming are Fe, Al, free-cutting steel, stainless steel, brass, sintered alloys, alloys containing at least one of these, and the like. It is preferably composed of a material mainly containing Al. This allows the yoke 2
Is a metal layer 3 having sufficient mechanical strength and described later.
The bonding strength (adhesion) with 2 becomes particularly excellent.

Further, the constituent material of the yoke 2 has a coefficient of thermal expansion (linear expansion coefficient) in the vicinity of room temperature of 4 to 30 [× 10 ⁻⁶ K].
⁻¹ ] is preferable, and 8 to 25 [× 10 ⁻⁶ K
⁻¹ ] is more preferable.

When the coefficient of thermal expansion (linear expansion coefficient) of the constituent material of the yoke 2 is less than the lower limit value, for example, when the permanent magnet 3 and the yoke 2 are joined by thermal caulking, the yoke is manufactured in the manufacturing process. Unless the temperature of 2 is set to a relatively high temperature, it may be difficult to insert the permanent magnet 3 into the hollow portion of the yoke 2.

On the other hand, when the coefficient of thermal expansion (linear expansion coefficient) of the constituent material of the yoke 2 exceeds the upper limit value, the adhesion between the permanent magnet 3 and the yoke 2 when the rotor 1 is exposed to a high temperature environment. May decrease.

The surface roughness Ra of the yoke 2 is preferably 0.5 to 10.0 μm, and 1.0 to 1.0 μm.
More preferably, it is 5.0 μm.

When the surface roughness Ra of the yoke 2 is within the above range, for example, when the permanent magnet 3 and the yoke 2 are joined by press fitting, the operation can be easily performed. Further, it is possible to more effectively prevent the surface of the permanent magnet 3 from being scratched during press fitting. As a result, the permanent magnet 3 is prevented from being corroded and the mechanical strength is prevented from being lowered, and as a result, the long-term stability of the motor is improved.

On the other hand, if the surface roughness Ra of the yoke 2 is less than the lower limit value, the adhesion (bonding strength) between the permanent magnet 3 and the yoke 2 may be reduced.

If the surface roughness Ra of the yoke 2 exceeds the upper limit value, the above effect may not be sufficiently obtained.

The permanent magnet 3 is a ring-shaped magnet body 3
1 and a metal layer 32 formed on the surface thereof.

The magnet body 31 is magnetized in multiple poles. As the magnet body 31, for example, any magnet such as a cast magnet, a sintered magnet, a bonded magnet, or a magnet obtained by a method such as rolling, forging, or hot extrusion may be used. Is preferably a bonded magnet whose shape can be manufactured at low cost. Thereby, excellent magnetic characteristics can be stably obtained.

The bonded magnet is mainly composed of magnet powder and a binding resin (binder).

As the magnetic powder constituting the bonded magnet,
For example, a rare earth magnet powder containing a rare earth element, a transition metal and boron as basic components is preferably used.

Rare earth magnet powder (hereinafter, simply “magnet powder”)
(Also referred to as) is preferably made of an alloy containing a rare earth element and a transition metal, and particularly, the following [1] to [6]
Is preferred.

[1] An alloy containing R (where R is at least one of rare earth elements including Y) and a transition metal mainly containing Co as basic components (hereinafter referred to as an R—Co alloy). ).

[2] R (where R is at least one of rare earth elements including Y), a transition metal (TM) mainly containing Fe, and B as basic components (hereinafter,
R-TM-B type alloy).

[3] R (provided that R is at least one of rare earth elements containing Y), a transition metal (TM) containing Fe as a main component, and an interstitial element containing N as a basic component. (Hereinafter, referred to as R-TM-N alloy).

[4] R (where R is at least one of rare earth elements including Y) and a transition metal (T
M) as a basic component, and a soft magnetic phase and a hard magnetic phase are adjacent to each other (including a case where they are adjacent to each other through a grain boundary phase) (in particular, there is a nanocomposite structure) With.

[5] A mixture of at least two of the compositions [1] to [4]. In this case, it is possible to have the advantages of each magnet powder to be mixed, and it is possible to easily obtain desired magnetic characteristics.

[6] The composition of the above [1] to [4]
Of these, at least one and ferrite powder (for example, B
aO ・ 6Fe_TwoO_ThreeSuch as Ba-ferrite, SrO ・ 6
Fe _TwoO_ThreeSuch as Sr-ferrite and some of these
Transition metals, those substituted with rare earth elements, etc.)
thing. In this case, it has the advantages of each magnet powder to be mixed.
It is possible to obtain desired magnetic characteristics easily.
It

Typical R-Co alloys are:
Examples thereof include SmCo ₅ and Sm ₂ TM ₁₇ (where TM is a transition metal).

Typical R-TM-B type alloys are Nd-Fe-B type alloys, Pr-Fe-B type alloys, and N-type alloys.
d-Pr-Fe-B type alloy, Nd-Dy-Fe-B type alloy, Ce-Nd-Fe-B type alloy, Ce-Pr-Nd-
Fe-B based alloys, some of Fe in these are Co, N
Examples thereof include those substituted with other transition metals such as i.

A typical R-TM-N-based alloy is Sm ₂ Fe ₁₇ N produced by nitriding an Sm ₂ Fe ₁₇ alloy.
_3, TbCu ₇ type phase as the main phase Sm-Zr-Fe-Co
-N-based alloys may be mentioned.

The rare earth elements include Y, La and C.
e, Pr, Nd, Pm, Sm, Eu, Gd, Tb, D
Examples thereof include y, Ho, Er, Tm, Yb, Lu, and misch metal, and one or more of these may be included. Examples of the transition metal include Fe, Co, Ni and the like, and one or more of these may be included.

In order to improve the magnetic properties such as the coercive force and the maximum magnetic energy product, or to improve the heat resistance and the corrosion resistance, the magnetic material may contain A if necessary.
l, Cu, Ga, Si, Ti, V, Ta, Zr, Nb,
It is also possible to contain Mo, Hf, Ag, Zn, P, Ge, Cr, W and the like.

As the binder resin (binder),
Examples thereof include thermoplastic resins and thermosetting resins.

Examples of the thermoplastic resin include polyamide (eg, nylon 6, nylon 46, nylon 66, nylon 610, nylon 612, nylon 11, nylon 12, nylon 6-12, nylon 6-66), thermoplastic polyimide. , Liquid crystal polymers such as aromatic polyester, polyphenylene oxide, polyphenylene sulfide, polyethylene, polypropylene, polyolefin such as ethylene-vinyl acetate copolymer, modified polyolefin, polycarbonate, polymethyl methacrylate, polyethylene terephthalate, polyester such as polybutylene terephthalate, poly Ether, polyetheretherketone, polyetherimide, polyacetal, etc.
Further, copolymers, blends, polymer alloys and the like containing these as main constituents may be mentioned, and one kind or a mixture of two or more kinds thereof may be used.

Such a thermoplastic resin can be selected in a wide range depending on its type, copolymerization and the like, for example, one with an emphasis on moldability, one with an emphasis on heat resistance and mechanical strength. There is an advantage.

On the other hand, as the thermosetting resin, for example, various epoxy resins such as bisphenol type, novolac type, naphthalene type, phenol resin, urea resin, melamine resin, polyester (unsaturated polyester) resin, polyimide resin, silicone resin , Polyurethane resin, etc., and one kind or a mixture of two or more kinds of them can be used.

The thermosetting resin used (uncured)
May be liquid at room temperature or solid (powdered).

The magnetic characteristics of the magnet body 31 are not particularly limited, but the magnetic energy product (BH) _max is 32.
kJ / ^{m 3} is preferably more than one, more preferably 48kJ / ^{m 3} or more of, more preferably 64kJ / ^{m 3} or more.

Further, the magnet body 31 may be chamfered at the corners (at least the corners on the outer peripheral side of the tip) of the ends thereof. Thereby, for example, when the permanent magnet 3 and the yoke 2 are joined by press fitting, the operation can be easily performed. Also, when performing the press-fitting operation,
It is possible to more effectively prevent the surface of the permanent magnet 3 from being scratched. As a result, the permanent magnet 3 is prevented from being corroded and the mechanical strength is prevented from being lowered, and as a result, the long-term stability of the motor is improved.

A metal layer 32 is formed on the surface of the magnet body 31.
Are formed. The metal layer 32 is mainly composed of a metal material.

By providing such a metal layer 32, the mechanical strength of the permanent magnet 3 becomes particularly excellent. As a result, the permanent magnet 3 and the yoke 2 can be joined by thermal crimping or press fitting as will be described in detail later. This allows the permanent magnet 3 to be supported and fixed to the yoke 2 with sufficient adhesion (bonding strength). As described above, when the permanent magnet 3 and the yoke 2 are joined with sufficiently high strength, the rotor 1 is connected to the motor (particularly,
When applied to a motor used in a high rotation range, a motor used repeatedly, a motor used continuously for a long period of time, etc., the occurrence of defective joint between the permanent magnet 3 and the yoke 2 is more effective. To be prevented. As a result, it is possible to more effectively prevent problems such as the generation of abnormal noise during driving of the motor and the deterioration of the torque characteristics of the motor. Further, by effectively preventing the above-mentioned bonding failure,
The motor 11 having the yoke 2 is less likely to be damaged or damaged and has excellent reliability.

As described above, by providing the metal layer 32, the permanent magnet 3 and the yoke 2 can be joined by thermal crimping or press fitting, so that the permanent magnet 3 and the yoke 2 can be joined together. However, sufficient bonding strength can be obtained without using an organic adhesive which has been conventionally used. As described above, when the permanent magnet 3 and the yoke 2 are joined without using the organic adhesive, it is not necessary to provide a space for inserting the organic adhesive between the permanent magnet 3 and the yoke 2, and thus the rotor 1 The unbalance amount of the center of gravity (rotational unbalance amount) can be made particularly small. As a result, the motor 11 to which the rotor 1 is applied is less likely to generate vibration due to shaft shake and noise (abnormal noise) even when used in a high rotation range, for example.

Further, by providing the metal layer 32, the corrosion of the magnet body 31 can be prevented more effectively. As a result, the motor 11 has stable characteristics over a long period of time.

As the metal material forming the metal layer 32,
For example, Ni, Cu, Cr, Fe, Zn, Cd, Sn,
Examples thereof include Pb, Al, Au, Ag, Pd, Pt, Rh, and the like, and alloys containing at least one of these. Among these, it is preferable that the metal material of the metal layer 32 is mainly Ni. As a result, the above-described effect (in particular, the improvement in the adhesion (bonding strength) with the magnet body 31 and the yoke 2) becomes more remarkable.

The average thickness of the metal layer 32 is not particularly limited, but is preferably 1 to 50 μm, and 5 to 40 μm.
Is more preferable.

When the average thickness of the metal layer 32 is within the above range, the above effect (in particular, the improvement of the mechanical strength of the permanent magnet 3) becomes more remarkable.

The metal layer 32 has a Vickers hardness Hv.
Is preferably 150 or more, more preferably 200 or more.

The Vickers hardness Hv of the metal layer 32 is 150.
If it is above, the mechanical strength of the permanent magnet 3 will be especially excellent.

When the Vickers hardness Hv of the metal layer 32 is 150 or more, for example, when the permanent magnet 3 and the yoke 2 are joined by press fitting, the surface of the permanent magnet 3 is scratched in the process. Can be prevented more effectively. As a result, the permanent magnet 3 is prevented from being corroded and the mechanical strength is prevented from being lowered, and as a result, the long-term stability of the motor is improved.

The metal layer 32 preferably has an appropriate lubricity. Thereby, for example, when the permanent magnet 3 and the yoke 2 are joined by press fitting, the operation can be easily performed. Further, it is possible to more effectively prevent the surface of the permanent magnet 3 from being scratched during press fitting. As a result, the permanent magnet 3 is prevented from being corroded and the mechanical strength is prevented from being lowered, and as a result, the long-term stability of the motor is improved.

As an index showing lubricity, for example, JI
The friction coefficient μ in the ball-on-disk method, which is measured according to S R 1613, and the like can be mentioned. The friction coefficient μ of the metal layer 32 measured by the ball-on-disk method is 0.
It is preferably about 1 to 0.7, and more preferably about 0.2 to 0.6.

If the friction coefficient μ of the metal layer 32 is less than the lower limit value, the adhesion (bonding strength) between the permanent magnet 3 and the yoke 2 may be reduced.

On the other hand, if the friction coefficient μ of the metal layer 32 exceeds the upper limit value, the above effect may not be sufficiently obtained.

In the illustrated configuration, the metal layer 32 is formed on the entire surface of the magnet body 31, but, for example, at least a part of the surface of the magnet body 31 (the yoke 2).
It may be formed on a portion (contacting with).

As a method of forming the metal layer 32, for example,
Wet plating methods such as electroplating, immersion plating, electroless plating, vacuum deposition, sputtering, thermal CVD, plasma C
Examples include chemical vapor deposition (CVD) such as VD and laser CVD, dry plating such as ion plating, and thermal spraying. Among these, wet plating is preferable, electroplating,
Electroless plating is more preferred. By using wet plating as a method of forming the metal layer 32, a uniform metal layer 32 having excellent adhesion (bonding strength) to the magnet body 31 and the yoke 2 (support member) can be formed with a relatively simple apparatus. It can be easily formed. Such an effect becomes more remarkable when electroplating or electroless plating is used.

In electroplating and electroless plating, the composition of the metal layer (metal plating layer) 32 to be formed can be easily adjusted by adjusting the composition of the plating solution. As a result, for example, the physical properties of the metal layer 32 (for example,
Mechanical strength, hardness, friction coefficient, coefficient of thermal expansion, corrosion resistance, etc.)
Alternatively, the affinity of the metal layer 32 with respect to the magnet main body 31 and the yoke 2 (support member) can be easily adjusted.

In electroplating, the film thickness, density, etc. of the metal layer 32 can be easily adjusted by adjusting the plating conditions such as the current density. As a result, the metal layer 3
The physical properties of 2 (for example, mechanical strength, hardness, friction coefficient, corrosion resistance, etc.) can be easily adjusted.

The electroplating is preferably performed under the following conditions, for example. The bath temperature during electroplating is not particularly limited, but is preferably 20 to 70 ° C,
It is more preferably 40 to 65 ° C.

When the bath temperature is less than the lower limit value described above, a decrease in plating rate, uneven gloss, and abnormal precipitation are likely to occur.

On the other hand, if the bath temperature exceeds the above upper limit, abnormal precipitation and decomposition of the brightener are likely to occur.

The current density during electroplating is
It is not particularly limited, but is preferably 0.1~8.0A / dm ^2, and more preferably 0.5~6.0A / dm ^2.

When the current density is within the above range, the metal layer 32 having excellent adhesion (bonding strength) with the magnet body 31 and the yoke 2 (supporting member), and a uniform and dense metal layer 32 can be efficiently formed. can do.

In electroless plating, the film thickness and density of the metal layer (metal plating layer) 32 to be formed can be easily adjusted by adjusting the liquid temperature, the plating time and the like. As a result, for example, the corrosion resistance physical properties of the metal layer 32,
The affinity to the magnet body 31 and the yoke 2 (support member) can be easily adjusted.

Further, in the electroless plating, the metal layer 32 having a uniform film thickness can be formed on a cylindrical material to be plated such as the magnet body 31 without any special adjustment.

The electroless plating is preferably performed under the following conditions, for example. The bath temperature during electroless plating is not particularly limited, but as an example, in the case of nickel-boron-based electroless plating, it is preferably 50 to 70 ° C, and more preferably 55 to 65 ° C.

When the bath temperature is less than the lower limit value described above, the plating rate tends to decrease and abnormal precipitation tends to occur. On the other hand, the bath temperature is
When it exceeds the upper limit, the bath solution is likely to be decomposed.

Prior to the formation of the metal layer 32, the surface of the magnet body 31 may be subjected to pretreatment. Examples of the pretreatment include blast treatment, alkali washing (alkali degreasing treatment), acid washing, water washing (including pure water washing), organic solvent washing, ultrasonic washing, and bombarding. By performing such pretreatment, for example, the adhesion between the magnet body 31 and the metal layer 32 can be further improved.

The composition of each portion of the metal layer 32 may or may not be constant. For example, the metal layer 32 may be one whose composition changes gradually (gradient material) along its thickness direction.

The metal layer 32 is formed by, for example, a forming method,
It may be a laminate of a plurality of layers having different formation conditions and compositions.

The permanent magnet 3 as described above is fixed to the yoke 2 (support member) by heat caulking or press fitting.

As a result, the permanent magnet 3 is supported and fixed to the yoke 2 with sufficient adhesion (bonding strength).
In this way, when the permanent magnet 3 and the yoke 2 are joined with a sufficiently high strength, the rotor 1 can be used as a motor (especially for a motor used in a high rotation range, a motor used repeatedly, and a long term). When applied to a continuously used motor or the like), the occurrence of defective joint between the permanent magnet 3 and the yoke 2 can be more effectively prevented. As a result, it is possible to more effectively prevent problems such as the generation of abnormal noise during driving of the motor and the deterioration of the torque characteristics of the motor. Further, by effectively preventing the above-mentioned joining failure, the motor 11 having the yoke 2 is less likely to be damaged or damaged, and has excellent reliability.

As described above, the permanent magnet 3 and the yoke 2 are joined by thermal caulking or press fitting,
Sufficient bonding strength can be obtained without using an organic adhesive, which has been conventionally used, at the bonding portion between the permanent magnet 3 and the yoke 2. Thus, when the permanent magnet 3 and the yoke 2 are joined without using the organic adhesive, the unbalance amount (rotational unbalance amount) of the center of gravity of the rotor 1 can be made particularly small. As a result, the motor 11 to which the rotor 1 is applied is less likely to generate vibration due to shaft shake and noise (abnormal noise) even when used in a high rotation range, for example.

The permanent magnet 3 preferably satisfies the following relationship.

That is, the heat of the magnet body 31 near room temperature
Expansion coefficient (linear expansion coefficient) is α₁[× 10 ^-6K^-1],metal
Thermal expansion coefficient (linear expansion coefficient) of the constituent material of the layer 32 near room temperature
Α _Two[× 10^-6K^-1] | Α_Two-Α₁
| Is 15 [× 10^-6K^{− 1}] The following is preferred
10 [× 10^-6K^-1] It is more preferable that
Good

| Α ₂ −α ₁ | is 15 [× 10
^-6 K ^-1 ] or less, even when the amount of change in the temperature of the permanent magnet 3 during manufacture or use of the rotor 1 and the motor 11 is relatively large, the metal layer 32 causes the magnet body 3 to have a large amount of change.
The peeling from No. 1 can be more effectively prevented. As a result, corrosion of the permanent magnets 3, deterioration of mechanical strength, and increase in the amount of unbalance of the center of gravity of the rotor 1 (rotational unbalance amount) are prevented, and as a result, long-term stability of the motor is improved.

The measurement of the unbalance amount of the rotor 1 as described above can be generally regarded as the periodic stress generation in the radial direction accompanying the rotation of the rotor 1. By electrically converting this stress, it can be measured as an unbalance amount. This rotational unbalance amount is 0.
It is preferably 005 g · cm or less, and 0.004 g
-It is more preferable that it is not more than cm.

The rotational unbalance amount of the rotor 1 is 0.00
When it is 5 g · cm or less, even when applied to a motor used in a high rotation range, vibration due to shaft shake and noise (abnormal noise) are less likely to occur.

The rotor (motor component) 1 as described above is obtained by supporting and fixing the permanent magnet 3 to the yoke (support member) 2 by thermal crimping or press fitting.

First, a method of supporting and fixing the permanent magnet 3 to the yoke 2 by thermal caulking will be described.

Thermal caulking is performed by inserting the permanent magnet 3 into the hollow portion of the yoke 2 which is at a higher temperature than the permanent magnet 3 and then cooling the yoke 2.

The temperature of the yoke 2 when inserting the permanent magnet 3 is preferably 180 to 220 ° C., and 190 to 2
It is more preferably 10 ° C. When the temperature of the yoke 2 is a value within the above range, the joining strength between the permanent magnet 3 and the yoke 2 in the rotor 1 becomes particularly excellent.

On the other hand, if the temperature of the yoke 2 is less than the lower limit value, depending on the coefficient of thermal expansion of the constituent material of the yoke 2 and the like,
It becomes difficult to insert the permanent magnet 3 into the hollow portion of the yoke 2. In addition, the permanent magnet 3 and the yoke 2 in the rotor 1
Shows a tendency that the bonding strength with

Further, if the temperature of the yoke 2 exceeds the upper limit value, the temperature history given to the permanent magnet 3 joined to the yoke 2 becomes large, and the magnetic characteristics of the permanent magnet 3 may be deteriorated.

Further, the yoke 2 when the permanent magnet 3 is inserted
The temperature of T₁[° C.], the temperature of the permanent magnet 3 is T_Two[℃]
When you do, T₁-T_TwoIf it satisfies the relation of> 0
It ’s good, but 140 <T₁-T_Two<220 relationship is satisfied
160 <T ₁-T_Two<200 relationships
It is more preferable to be satisfied. (T₁-T_Two) Is the above range
If the value is within the range, the permanent magnet 3 and the yoke in the rotor 1
The bonding strength with 2 is particularly excellent.

On the other hand, if the value of (T ₁ -T ₂ ) is less than the lower limit value, the operation of inserting the permanent magnet 3 into the hollow portion of the yoke 2 may be performed depending on the coefficient of thermal expansion of the constituent material of the yoke 2. Will be difficult. Also, the bonding strength between the permanent magnet 3 and the yoke 2 in the rotor 1 tends to decrease.

If the value of (T ₁ -T ₂ ) exceeds the upper limit value, the temperature history given to the permanent magnet 3 joined to the yoke 2 becomes large, and the magnetic characteristics of the permanent magnet 3 may be deteriorated. There is.

The heat crimping is performed, for example, by inserting the cooled permanent magnet 3 into the hollow portion of the yoke 2 which is at a higher temperature than the permanent magnet 3, and then raising the temperature of the permanent magnet 3. Good.

Next, the permanent magnet 3 is attached to the yoke 2 by press fitting.
A method of supporting and fixing the sheet on the substrate will be described.

When the permanent magnet 3 and the yoke 2 are joined by press fitting, the relative moving speed (approaching speed) of the permanent magnet 3 and the yoke 2 in the axial direction (vertical direction in the figure) is
It is preferably 0.2 to 20 cm / sec, and 0.5 to 1
More preferably, it is 0 cm / sec.

When the relative moving speed of the permanent magnet 3 and the yoke 2 is within the above range, the surface of the permanent magnet 3 is effectively prevented from being scratched, and the permanent magnet 3 is efficiently moved. Can be pressed. In this way, by preventing the surface of the permanent magnet 3 from being scratched, corrosion of the permanent magnet 3 and deterioration of mechanical strength are prevented, and as a result, long-term stability of the motor is improved.

When the permanent magnet 3 and the yoke 2 are joined by press fitting, the corner of the end of the permanent magnet 3 (magnet body 31) (at least the corner on the outer peripheral side of the tip) is chamfered. It is preferably one. This makes it possible to perform the press-fitting operation more easily. Further, it is possible to more effectively prevent the surface of the permanent magnet 3 from being scratched when performing the press-fitting operation. As a result, the permanent magnet 3 is prevented from being corroded and the mechanical strength is prevented from being lowered, and as a result, the long-term stability of the motor is improved.

The permanent magnet 3 joined by thermal caulking and press fitting as described above has an outer diameter in a natural state (state before joining to the yoke 2) in a natural state (permanent magnet) of a corresponding portion of the yoke 2. It is larger than the inner diameter in the state before joining with No. 3). Thereby, the permanent magnet 3 in the obtained rotor 1 is obtained.
The joining strength between the yoke 2 and the yoke 2 is sufficiently large.

In particular, the inner diameter of the yoke 2 in the natural state (before being joined to the permanent magnet 3) near room temperature is D
₁ [mm], the outer diameter of the permanent magnet 3 in the natural state (before joining with the yoke 2) near room temperature is D ₂ [m
m], it is preferable to satisfy the relationship of the following formula (I).

1.00025 ≦ D ₂ / D ₁ ≦ 1.00105 (I) As a result, the above-described thermal crimping and press-fitting can be easily performed, and the permanent magnet 3 in the obtained rotor 1 is obtained. The joining strength between the yoke 2 and the yoke 2 is particularly excellent.

Further, it is more preferable that the relation of the formula (II) is satisfied instead of the formula (I), and it is further preferable that the relation of the formula (III) is satisfied. As a result, the effects described above become more prominent. 1.00031 ≦ D ₂ / D ₁ ≦ 1.00095 (II) 1.00037 ≦ D ₂ / D ₁ ≦ 1.00085 (III)

When the permanent magnet 3 and the yoke 2 are joined by thermal crimping or press fitting, the yoke 2 is fixed to the hub 4.
May or may not be joined to the.

The method of joining the permanent magnet 3 and the yoke 2 has been described above in detail. Examples of such joining methods include joining the yoke 2 and the hub 4, and joining the hub 4 and the sleeve 5.
It can also be applied to joining with. As a result, even when the rotor 1 is applied to a motor used in a high rotation range, vibrations due to shaft shake and noise (abnormal noise) hardly occur, and the rotor 1 has particularly stable characteristics.

Next, a preferred embodiment of the motor of the present invention will be described. FIG. 2 is a sectional side view of a motor having the motor component (rotor) shown in FIG.

As shown in FIG. 2, a motor (motor for hard disk drive) 11 includes a rotor (rotor) 1, a shaft (axis) 7, and a stator (stator) 6 described above.
And a base portion (frame) 8.

The shaft 7 rotatably supports the rotor 1. The shaft 7 is usually made of a metal material such as stainless steel. As stainless steel, for example, S
US304, SUS303, SUS316, SUS31
Fe such as 6L, SUS316J1 and SUS316J1L
-Cr-Ni system alloy, SUS405, SUS420J
2, SUS430, 434, SUS444, SUS42
9, Fe—Cr alloys such as SUS430F, and the like.

The stator 6 is arranged so as to face the outer peripheral surface of the permanent magnet 3 with a predetermined gap (gap). The stator 6 is composed of a core 61 made of a laminate of silicon steel plates punched into a desired shape, and a coil (three-phase coil) 62 formed by winding the core 61.

The base portion 8 has a shape having a hollow portion, and the shaft 7 is firmly fixed to the inner surface side thereof by a method such as press fitting. The stator 6 is supported and fixed to the outer surface side of the base portion 8.

A thrust receiving plate 10 is fixed together with the flange 9 on the front end side of the sleeve 5, and the thrust receiving plate 10 is in contact with the front end portion of the shaft 7.

In such a motor 11, the core 61 is excited by energizing the coil 62 of the stator 6 via a conductor (not shown), and torque is generated in the rotor 1. In this case, the energization of the coil 62 is controlled based on the detection signal from the rotor position sensor that detects the position of the rotor 1, preferably by motor drive control means (not shown) including an inverter.

As described above, in the present invention, since the permanent magnet 3 and the yoke 2 (support member) are joined by heat caulking or press fitting, even when torque is generated in the rotor 1, the permanent magnet 3 It is difficult for a defective joint between the yoke 3 and the yoke 2 to occur. As a result, it is possible to more effectively prevent problems such as the generation of abnormal noise during driving of the motor and the deterioration of the torque characteristics of the motor. Further, by effectively preventing the above-mentioned joining failure, the motor 11 having the yoke 2 is less likely to be damaged or damaged, and has excellent reliability.

As described above, the motor 11 of the present invention
Then, since the permanent magnet 3 and the yoke 2 are joined by heat caulking or press fitting, it is sufficient that the joining portion between the permanent magnet 3 and the yoke 2 does not use an organic adhesive which is conventionally used. Good bonding strength can be obtained. Thus, when the permanent magnet 3 and the yoke 2 are joined without using the organic adhesive, the unbalance amount (rotational unbalance amount) of the center of gravity of the rotor 1 can be made particularly small.
As a result, the motor 11 to which the rotor 1 is applied is, for example,
Even when used in a high rotation range, vibration and noise (abnormal noise) due to shaft shake are less likely to occur.

By the way, in the conventional manufacturing method using the organic adhesive as described above, from between the permanent magnet and the yoke,
Excessive organic adhesive sometimes squeezed out on the end face of the rotor. Such an excess organic adhesive is usually designed with a motor structure in which the excess adhesive is dimensionally tolerable, but the excess adhesive on the end face is subjected to centrifugal force, vibration, and torque fluctuation due to the rotation of the rotor. Since it is directly subjected to the circumferential acceleration due to, peeling, breakage, and falling occur. A part of the adhesive that has fallen off may remain in the motor and adversely affect the motor.

On the other hand, in the present invention, since sufficient bonding strength can be obtained without using an organic adhesive, the occurrence of such a problem can be avoided. Therefore, the present invention can be suitably applied to, for example, a motor for a hard disk drive, which requires removal of extremely fine foreign matter.

The maximum rotation speed of the motor 11 is 4000 rp.
It is preferably used in a region of m or more.
It is more preferably used in the range of 000 rpm or higher, and even more preferably used in the range of 7,000 rpm or higher.

When the motor 11 is a motor having such a maximum rotation speed, the effect of the present invention becomes more remarkable.

That is, as in the prior art, when the bonding strength between the permanent magnet and its supporting member is small, it is difficult to realize a high rotation type motor which has been difficult to realize due to problems such as reliability. The invention can be preferably applied.

Further, in a high rotation type motor, in order to prevent or suppress the generation of vibration and noise (abnormal noise) due to shaft runout, it is further required to reduce the unbalance amount of the center of gravity of the rotor. According to this, since it is not necessary to use an organic adhesive, it is possible to easily achieve reduction in the unbalance amount of the center of gravity of the rotor. Therefore, according to the present invention, it is possible to easily avoid the above-mentioned problems that may occur in a high rotation type motor.

In the illustrated configuration, the motor 11 is a motor used in a hard disk drive (hard disk drive motor). If the motor 11 is such a hard disk drive motor, the effect of the present invention becomes more remarkable.

That is, since a hard disk drive motor is generally used in a high rotation region and has a very high magnetic recording density, reduction of vibration is one of the most important problems. The occurrence of such a problem can be easily avoided.

Further, according to the present invention, since sufficient bonding strength can be obtained without using an organic adhesive, it is possible to eliminate foreign matter from the motor due to the excess organic adhesive falling off or the like. However, it is suitable for hard disk drive motors.

As described above, according to the present invention,
It is possible to easily prevent and suppress the occurrence of vibration due to shaft shake. Therefore, when the motor according to the present invention is used for a hard disk drive, it is possible to prolong the service life and increase the density of the hard disk drive device.

Although the motor component and the motor of the present invention have been described above based on the illustrated embodiment, the present invention is not limited to this.

For example, in the above-described embodiment, the metal layer 3
Although 2 covers the entire surface of the magnet main body 31, it may be formed on at least a part of the surface of the magnet main body 31 (at least a part of the portion in contact with the yoke (support member) 2). In this case, the metal layer 32 is preferably formed on at least the entire inner surface side of the magnet body 31.

The motor component of the present invention is not limited to the rotor, and may be any component.

Further, the motor to which the present invention is applied is not limited to the outer rotor type motor as described above, and may be, for example, an inner rotor type or disc type motor.

The motor to which the present invention is applied is not limited to the hard disk drive motor, and may be of any type.

Further, in the above-mentioned embodiment, the structure in which the supporting member is the yoke has been described, but the supporting member is not limited to this, and may be, for example, a shaft (shaft), a hub, a casing or the like.

Further, in the above-described embodiment, the one having the dynamic pressure fluid bearing structure has been described, but the bearing structure may be any one. For example, a hydrostatic bearing such as a self-lubricating bearing, an orifice bearing, or a pocket bearing may be used. In addition to the sliding bearing as described above, for example, a rolling bearing (ball bearing), a magnetic bearing, or the like may be used.

[0156]

EXAMPLES Next, specific examples of the present invention will be described.

[Manufacture of Rotor (Motor Parts)] (Example 1) A rotor (motor parts) as shown in FIG. 1 was manufactured as follows.

First, a magnet powder having an alloy composition of R-TM-B type alloy (MQPI-B powder manufactured by MQI),
An epoxy resin and a small amount of a hydrazine-based antioxidant were mixed, and these were kneaded at room temperature for 30 minutes to prepare a composition (compound) for a bonded magnet.

At this time, the compounding ratio (weight ratio) of the magnet powder, the epoxy resin and the hydrazine antioxidant was 95 wt%, 4 wt% and 1 wt%, respectively.

Next, this compound was weighed and filled in a mold of a press machine, compression molded at room temperature in the absence of a magnetic field at a pressure of 1370 MPa, and then the epoxy resin was heat-cured at 170 ° C., A cylindrical bonded magnet was obtained.
This bond magnet was subjected to a polishing treatment in the height direction. Then, the bonded magnet was polished by a barrel polishing method until each edge became R0.2, and this was used as a magnet body.

The coefficient of thermal expansion (linear expansion coefficient) α ₁ of the obtained magnet body at 20 ° C. was 12.4 [× 10 ⁻⁶ K].
⁻¹ ].

Next, the obtained magnet body was washed. As the cleaning of the magnet body, first, alkali cleaning (alkali degreasing treatment) is performed at 50 ° C. for 10 minutes, followed by pure water ultrasonic cleaning for 1 minute, acid cleaning (5 wt% hydrochloric acid) for 1 minute, and pure water ultrasonic cleaning. Washing was carried out for 2 minutes.

A metal layer made of Ni was formed on the surface of the magnet main body which was washed in this way.

The metal layer was formed as follows. First, the magnet body washed as described above is
i Electroless plating was performed. For this electroless plating, Top Chemialoy (manufactured by Okuno Chemical Industries Co., Ltd.) was used as a plating solution, and the bath temperature and the immersion time of the plating solution were 65 ° C. and
It was 60 minutes.

After performing the electroless plating, the surface of the formed plating layer is subjected to pure water ultrasonic cleaning for 2 minutes, and thereafter,
Further, electroplating treatment was performed. This electroplating was performed by a barrel method in which a rotating barrel jig was used to rotate the barrel and an electric current was passed through an electrode installed in the barrel. The bath temperature of the plating solution, the immersion time, and the current density during electroplating were 50 ° C. and 180 minutes, respectively.
It was 0.7 A / dm ² .

The thus-formed metal layer had an average thickness on the outer surface side of 31.5 μm and an average thickness on the inner surface side of 20 μm.

The thermal expansion coefficient (linear expansion coefficient) α ₂ of the formed metal layer at 20 ° C. is 13.3 [× 10 ⁻⁶ K
⁻¹ ].

The coefficient of friction μ and the Vickers hardness Hv of the formed metal layer were measured.

The friction coefficient μ is measured according to JIS R 161.
According to 3, the measurement was performed by the ball-on-disk method. Ce as a ball-on-disk type friction and wear tester
ntreSuisse D'Electronique et de Microtechnique
"CSEM TRIBOMETER" manufactured by SA was used. As a result, the measured value of the friction coefficient μ of the metal layer was 0.3.
It was 5.

The Vickers hardness Hv of the metal layer was measured with a measuring load of 25 gf. As a result, the measured value of Vickers hardness Hv of the metal layer was 150.

The bonded magnet on which the metal layer was formed as described above was magnetized into 8 poles to obtain a permanent magnet.

The permanent magnet thus obtained has an outer diameter of 19.001 mm × inner diameter of 17.024 mm × height of 4.0.
It had a cylindrical shape of 2 mm (room temperature (20 ° C.), natural state). The maximum magnetic energy product (BH) _max of the obtained permanent magnet was 75.3 kJ / m ³ .

Further, a yoke was obtained by preparing a substantially cylindrical member made of free-cutting steel material (SUM21) and subjecting it to cutting work.

The yoke thus obtained has an outer diameter of 2
0.503 mm x inner diameter 18.990 mm (excluding the vicinity of the tip) x height 4.20 mm approximately cylindrical (at room temperature (20
℃), the natural state). The surface roughness Ra (inner surface) of the yoke was 1.9 μm. Further, the thermal expansion coefficient (linear expansion coefficient) of the yoke at 20 ° C. is
It was 11.7 [ ^{x10-6K- 1} ].

The yoke thus obtained and the permanent magnet were joined by thermal crimping. The joining by thermal crimping was performed as follows.

First, the temperature of the yoke is set to 200 on the heating table.
Heated to 0 ° C. The inner diameter of the yoke at this time is
It was 19.03 mm.

In this state, a permanent magnet was inserted into the hollow portion from the base end side of the yoke using a jig whose position in the height direction was determined. The temperature of the permanent magnet at this time was 20 ° C.

After that, the heating table was moved from the heating table to the cooling table, and the yoke in which the permanent magnet was inserted was cooled to 20 ° C.

A rotor (motor component) as shown in FIG. 1 was obtained by using the bonded body of the permanent magnet and the yoke obtained as described above.

Free-cutting steel (SUM21), aluminum, and brass were used as the constituent materials of the yoke, the hub, and the sleeve, and the yoke and the hub and the hub and the sleeve were joined by press fitting. Went by.

Example 2 A rotor (motor component) as shown in FIG. 1 was manufactured as follows.

First, a magnet body (bonded magnet) was manufactured in the same manner as in Example 1, and the obtained magnet body was washed. To clean the magnet body, first carry out alkali cleaning (alkali degreasing treatment) at 50 ° C for 10 minutes, and then
Ultrasonic cleaning with pure water for 1 minute, acid cleaning (5 wt% hydrochloric acid) for 1 minute
Ultrasonic cleaning with pure water was performed for 2 minutes.

A metal layer made of Ni was formed on the surface of the magnet main body that was washed in this way.

The metal layer was formed as follows. First, the magnet body washed as described above is
i Electroless plating was performed. For this electroless plating, Top Chemialoy (manufactured by Okuno Chemical Industries Co., Ltd.) was used as a plating solution, and the bath temperature and the immersion time of the plating solution were 65 ° C. and
It was 60 minutes.

After the electroless plating, the surface of the formed plating layer is subjected to pure water ultrasonic cleaning for 2 minutes, and thereafter,
Further, electroplating treatment was performed. This electroplating was performed by a barrel method in which a rotating barrel jig was used to rotate the barrel and an electric current was passed through an electrode installed in the barrel. The bath temperature of the plating solution, the immersion time, and the current density during electroplating were 50 ° C. and 180 minutes, respectively.
It was 0.7 A / dm ² .

The metal layer thus formed has an average thickness on the outer surface side of 33 μm and an average thickness on the inner surface side of 21 μm.
was μm.

The thermal expansion coefficient (linear expansion coefficient) α ₂ of the formed metal layer at 20 ° C. is 13.3 [× 10 ⁻⁶ K].
⁻¹ ].

With respect to the formed metal layer, the friction coefficient μ and the Vickers hardness Hv were set in the same manner as in Example 1 above.
Was measured.

As a result, the measured value of the friction coefficient μ of the metal layer was 0.35, and the measured value of the Vickers hardness Hv was 150.
Met.

The bonded magnet having the metal layer formed as described above was magnetized into 8 poles to obtain a permanent magnet.

The permanent magnet thus obtained had an outer diameter of 19.003 mm, an inner diameter of 17.25 mm, and a height of 4.0.
It had a cylindrical shape of 1 mm (room temperature (20 ° C.), natural state). The maximum magnetic energy product (BH) _max of the obtained permanent magnet was 75.5 kJ / m ³ .

Further, a yoke was obtained by preparing a substantially cylindrical member made of free-cutting steel material (SUM21) and subjecting it to cutting work.

The yoke thus obtained has an outer diameter of 2
0.502 mm × inner diameter 18.991 mm (excluding the vicinity of the tip) × height 4.20 mm approximately cylindrical (room temperature (20
℃), the natural state). The surface roughness Ra (inner surface) of the yoke was 1.9 μm. Further, the thermal expansion coefficient (linear expansion coefficient) of the yoke at 20 ° C. is
It was 11.7 [ ^{x10-6K- 1} ].

The permanent magnet was pressed into the hollow portion of the yoke obtained as described above. The permanent magnet was press-fitted by a hydraulic press using a positioning jig so that the permanent magnet would not tilt with respect to the yoke.

At this time, the relative moving speed (approaching speed) between the permanent magnet and the yoke was 5 cm / sec.

A rotor (motor component) as shown in FIG. 1 was obtained by using the joined body of the permanent magnet and the yoke obtained as described above.

Free-cutting steel (SUM21), aluminum, and brass were used as the constituent materials of the yoke, the hub, and the sleeve, respectively, and the joining of the yoke and the hub and the joining of the hub and the sleeve were performed as described above. The same heat caulking was performed.

Comparative Example 1 A magnet body (bonded magnet) was manufactured in the same manner as in Example 1, and the obtained magnet body was washed. For cleaning the magnet body, first, alkali cleaning (alkali degreasing treatment) is performed at 50 ° C. for 10 minutes, followed by pure water ultrasonic cleaning for 1 minute and acid cleaning (5 wt% hydrochloric acid).
1 minute, and pure water ultrasonic cleaning was performed for 2 minutes.

On the surface of the magnet main body thus washed, a resin film was formed by spray coating with a paint containing an epoxy resin as a main component. The average thickness of the formed resin coating (on the outer surface side of the permanent magnet) was 16 μm.

The permanent magnet thus obtained had an outer diameter of 19.002 mm × inner diameter of 17.25 mm × height of 4.0.
It had a cylindrical shape of 1 mm (room temperature (20 ° C.), natural state).

Further, a yoke was obtained by preparing a substantially cylindrical member made of free-cutting steel material (SUM21) and subjecting it to cutting work.

The yoke thus obtained has an outer diameter of 2
0.502 mm × inner diameter 18.991 mm (excluding the vicinity of the tip) × height 4.20 mm cylindrical (room temperature (20 ° C.),
It was a natural state). The surface roughness Ra (inner surface) of the yoke was 1.9 μm.

When the yoke thus obtained and the permanent magnet were tried to be joined by thermal crimping in the same manner as in Example 1, a step of cooling the yoke in which the permanent magnet was inserted was conducted. In the above, the permanent magnet was destroyed by the contracting force of the yoke, and the rotor could not be manufactured.

Comparative Example 2 A magnet body (bonded magnet) was manufactured in the same manner as in Example 1, and the obtained magnet body was washed. For cleaning the magnet body, first, alkali cleaning (alkali degreasing treatment) is performed at 50 ° C. for 10 minutes, followed by pure water ultrasonic cleaning for 1 minute and acid cleaning (5 wt% hydrochloric acid).
1 minute, and pure water ultrasonic cleaning was performed for 2 minutes.

On the surface of the magnet body thus washed, a resin film was formed by spray coating with a paint containing an epoxy resin as a main component. The average thickness of the formed resin coating (on the outer surface side of the permanent magnet) was 15 μm.

The permanent magnet thus obtained had an outer diameter of 19.002 mm, an inner diameter of 17.024 mm, and a height of 4.0.
It had a cylindrical shape of 1 mm (room temperature (20 ° C.), natural state).

Further, a yoke was obtained by preparing a substantially cylindrical member made of free-cutting steel material (SUM21) and subjecting it to cutting work.

The yoke thus obtained has an outer diameter of 2
0.503 mm × inner diameter 18.991 mm (excluding the vicinity of the tip) × height 4.20 mm cylindrical (room temperature (20 ° C.),
It was a natural state). The surface roughness Ra (inner surface) of the yoke was 1.9 μm.

An attempt was made to join the yoke thus obtained and the permanent magnet by press fitting in the same manner as in Example 2, and the resin coating formed on the surface of the permanent magnet and the magnet body A part of the outer surface side was scraped by the yoke. When an attempt was made to remove the resin coating film and the shavings of the magnet body thus generated, most of the shavings adhered to the yoke or the like and could not be removed.

A rotor (motor component) was manufactured in the same manner as in Example 2 using the bonded body of the permanent magnet and the yoke obtained as described above.

Comparative Example 3 A magnet body (bonded magnet) was manufactured in the same manner as in Example 1, and the obtained magnet body was washed. For cleaning the magnet body, first, alkali cleaning (alkali degreasing treatment) is performed at 50 ° C. for 10 minutes, followed by pure water ultrasonic cleaning for 1 minute and acid cleaning (5 wt% hydrochloric acid).
1 minute, and pure water ultrasonic cleaning was performed for 2 minutes.

On the surface of the magnet body thus washed, a resin film was formed by spray coating with a paint containing an epoxy resin as a main component. The average thickness of the formed resin coating (on the outer surface side of the permanent magnet) was 16 μm.

The permanent magnet thus obtained had an outer diameter of 19.003 mm, an inner diameter of 17.022 mm, and a height of 4.0.
It had a cylindrical shape of 1 mm (room temperature (20 ° C.), natural state).

Further, a yoke was obtained by preparing a substantially cylindrical member made of free-cutting steel material (SUM21) and subjecting it to cutting work.

The yoke thus obtained has an outer diameter of 2
0.509 mm x inner diameter 19.025 mm (excluding the vicinity of the tip) x height 4.20 mm cylindrical (room temperature (20 ° C),
It was a natural state). The surface roughness Ra (inner surface) of the yoke was 1.9 μm. An organic adhesive made of epoxy resin was applied to the inner surface of this yoke.

In this state, a permanent magnet was inserted into the hollow portion from the base end side of the yoke using a jig whose position in the height direction was determined.

After that, the yoke in which the permanent magnet was inserted was heated to 150 ° C. and left in this state for 1 hour to thermally cure the organic adhesive and bond the permanent magnet and the yoke.

After the bonding, it was confirmed that the excess adhesive protruding from between the permanent magnet and the yoke did not interfere with other members, and no particular treatment such as shaving was performed.

A rotor (motor component) was manufactured in the same manner as in Example 2 using the bonded body of the permanent magnet and the yoke obtained as described above.

[Evaluation and Manufacture of Motor] With respect to each rotor manufactured as described above, the amount of rotational imbalance was measured using a dynamic balance tester (VC003T type) manufactured by Shimadzu Corporation. The rotation speed at that time is 3600 rp
m.

Next, a motor as shown in FIG. 2 was manufactured by using the rotor manufactured in each of the examples and the comparative examples (excluding the comparative example 1 in which the motor could not be manufactured).

For each of the motors thus obtained, the operation of energizing the coils of the stator (energizing time: 30 seconds, maximum rotation speed: 7200 rpm) was repeated.

In the motor of the present invention, vibration and noise during driving were relatively small, whereas in the motor of the comparative example, vibration and noise during driving were large.

Further, in the motor of the comparative example, vibration and noise (abnormal noise) became more severe after the number of energizing operations reached about 30,000 times.

After performing the above energization operation 50,000 times,
Each motor was disassembled. As a result, residues such as an organic adhesive were present inside the motors of Comparative Examples 1 to 3. In particular, many such residues were present inside the motors of Comparative Examples 1 and 3.

Take out the rotor from each disassembled motor,
For these, the bonding strength between the permanent magnet and the yoke was measured. The bonding strength was measured using a precision universal testing machine (AGS-1000A) manufactured by Shimadzu Corporation. The relative moving speed (drawing speed) of the permanent magnet and the yoke at this time was set to 5 cm / sec. The results are shown in Table 1.

[0227]

[Table 1]

As is clear from Table 1, in the rotor (motor component) obtained in the present invention, the bonding strength between the permanent magnet and the yoke (support member) was large.

From these results, it is understood that according to the present invention, it is possible to provide a motor having excellent reliability, in which adverse effects due to defective joining of the permanent magnet and the yoke (support member) are unlikely to occur.

On the other hand, in the rotor (motor component) obtained in the comparative example, the bonding strength between the permanent magnet and the yoke (support member) was small.

[0231]

As described above, according to the present invention, it is possible to provide a motor which is unlikely to be adversely affected by a defective joint between a permanent magnet and a supporting member thereof, and a motor for which the motor can be provided. Parts can be provided.

Further, according to the present invention, it is possible to provide a motor in which the amount of rotational imbalance of the rotor is small and vibration and noise are unlikely to occur. Therefore, it can be suitably applied to a motor used in a high rotation range.

Further, since sufficient bonding strength can be obtained without using an organic adhesive, it can be suitably applied to a motor for a hard disk drive, which requires elimination of foreign matter (including very fine foreign matter). .

Further, the reliability of the motor is further improved by appropriately selecting the constituent material of the supporting member, the constituent material of the metal layer, the forming conditions of the metal layer, and the like and combining them.

[Brief description of drawings]

FIG. 1 is a cross-sectional side view showing a preferred embodiment of a motor component (rotor) of the present invention.

FIG. 2 is a cross-sectional side view of a motor having the motor component (rotor) shown in FIG.

[Explanation of symbols]

1 ... Rotor 2 ... Yoke 3 ... Permanent magnet 31 ...
… Magnet body 32 …… Metal layer 4 …… Hub 5 …… Sleeve 51 …… Bearing part 52 …… Bearing part 53 …… Groove 6 …… Stator 61 …… Core 62 ……
Coil 7 ... Shaft 8 ... Base 9 ... Flange 10 ... Thrust receiving plate 11 ... Motor

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Isao Kokonoki             Seiko, 3-3-3 Yamato, Suwa City, Nagano Prefecture             -In Epson Corporation (72) Inventor Tadashi Kobe             Seiko, 3-3-3 Yamato, Suwa City, Nagano Prefecture             -In Epson Corporation F-term (reference) 5H621 BB07 JK01 JK03 JK08                 5H622 DD02 PP11 PP12 QA02 QA08

Claims (26)

[Claims] 1. A motor component comprising a permanent magnet having at least a part of its surface coated with a metal layer, and a support member for supporting the permanent magnet, wherein the permanent magnet is supported by thermal caulking. A motor component characterized by being supported and fixed to. 2. The coefficient of thermal expansion (linear expansion coefficient) of the constituent material of the supporting member near room temperature is 4 to 30 [× 10].
^-6 K ^-1 ], The motor component according to claim 1. 3. A motor component having a permanent magnet having at least a part of its surface coated with a metal layer, and a support member for supporting the permanent magnet, wherein the permanent magnet is attached to the support member by press fitting. Motor parts characterized by being supported and fixed. 4. The motor component according to claim 3, wherein a friction coefficient μ of the metal layer measured by a ball-on-disk method is 0.1 to 0.7. 5. The permanent magnet comprises a magnet body and the metal layer, and the coefficient of thermal expansion (linear expansion coefficient) of the magnet body near room temperature is α.
_{^{1 [× 10 -6 K -1]}} , coefficient of thermal expansion around room temperature of the material of the metal layer (coefficient of linear expansion) alpha ₂ ^- when the ^{[× 10 6 K -1],} | α 2 -
The motor component according to any one of claims 1 to 4, wherein α ₁ | is 15 [× 10 ⁻⁶ K ⁻¹ ] or less. 6. The motor component according to claim 1, wherein the permanent magnet is supported and fixed to the inner peripheral side of the support member. 7. The Vickers hardness Hv of the metal layer is 15
The motor component according to any one of claims 1 to 6, which is 0 or more. 8. The motor component according to claim 1, wherein the metal layer is made of a material containing Ni. 9. The average thickness of the metal layer is 1 to 50 μm.
9. The motor component according to any one of claims 1 to 8. 10. The motor component according to claim 1, wherein the metal layer is formed by electroplating and / or electroless plating. 11. The motor component according to claim 1, wherein at least a portion of the support member that is coupled to the permanent magnet is made of a metal or an alloy material. 12. The motor component according to claim 1, wherein the permanent magnet is a bond magnet. 13. The motor component according to claim 1, wherein the permanent magnet is chamfered. 14. The motor component according to claim 1, wherein the motor component is a rotor. 15. The rotational unbalance amount of the rotor is
The motor component according to claim 14, which has a weight of 0.005 g · cm or less. 16. A method for manufacturing a motor component, comprising: a permanent magnet having at least a part of its surface coated with a metal layer; and a support member for supporting the permanent magnet, wherein the permanent magnet is formed by thermal caulking. A method of manufacturing a motor component, comprising supporting and fixing the support member. 17. The thermal expansion coefficient (linear expansion coefficient) of the constituent material of the supporting member at around room temperature is 4 to 30 [× 10 ⁻⁶ K].
⁻¹ ]. The method for manufacturing a motor component according to claim 16. 18. A method for manufacturing a motor component, comprising: a permanent magnet having at least a part of its surface coated with a metal layer; and a support member for supporting the permanent magnet, the press-fitting of the permanent magnet A method for manufacturing a motor component, which comprises supporting and fixing to a support member. 19. The method of manufacturing a motor component according to claim 18, wherein a friction coefficient μ of the metal layer measured by a ball-on-disk method is 0.1 to 0.7. 20. The method of manufacturing a motor component according to claim 16, wherein the permanent magnet is supported and fixed to the inner peripheral side of the support member. 21. When the inner diameter of the support member in the natural state near room temperature is D ₁ [mm] and the outer diameter of the permanent magnet in the natural state near room temperature is D ₂ [mm],
The method of manufacturing a motor component according to claim 20, wherein the relationship of the following formula (I) is satisfied. 1.00025 ≤ D ₂ / D ₁ ≤ 1.00105 (I) 22. The Vickers hardness Hv of the metal layer is 1
The method for manufacturing a motor component according to any one of claims 16 to 21, wherein the number is 50 or more. 23. The method for manufacturing a motor component according to claim 16, wherein the permanent magnet is chamfered. 24. A motor comprising the motor component according to any one of claims 1 to 15. 25. The motor according to claim 23, which is used in a region where the maximum rotation speed is 4000 rpm or more. 26. The motor according to claim 23, which is used in a hard disk drive.