JP3340607B2 - Brushless motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to information and communication equipment,
The present invention relates to a small brushless motor used for video / audio equipment and the like.

[0002]

2. Description of the Related Art Recently, with the demand for miniaturization, high accuracy, and high reliability of information / communication equipment and video / audio equipment, a shift from a motor with a brush to a brushless motor has been advanced. With brush motors becoming smaller and thinner, motors with cores use cylindrical frame cases to oval frame cases, and coreless motors also change from cylindrical to oval or square motors. A motor with a mold frame case has been developed and used as a motor for portable communication devices. Battery-powered motors for portable devices are strictly regulated in the thickness direction and have low current consumption due to battery life.The conventional oval or cylindrical configuration requires a high energy product. Even with magnets,
Increasing motor efficiency is becoming more difficult.

[0003] A conventional motor will be described below.

(Conventional Example 1) FIG. 43 (a) is a cross-sectional view of a conventional oval type sectioned motor with a core for a portable pager, and FIG. 43 (b) is a cross-sectional view on a plane perpendicular to an axis. It is shown.

In FIG. 43, 101 is a frame case, 102 is a magnet, 103 is a shaft, 104,
105 is a sintered bearing, 106 is a core, 107 is a coil (winding), 108 is a commutator terminal block, 109 is a commutator, 110
Is a brush and 111 is a bracket.

As shown in FIG. 43, a motor core 106 (also referred to as an iron core) in which a silicon steel sheet is laminated on a shaft 103 is provided.
Is fixed, an insulator resin-molded into a core shape is inserted into the core 106, and the commutator terminal block 108 is
Press into 3. Further, a coil 107 is wound around the core 106, and a current-carrying portion of the coil 107 is connected to the commutator terminal block 1.
08 at a predetermined position, conduct with solder,
Make an amateur winding assembly. Next, the commutator surface of the commutator terminal block 108 of the amateur winding assembly is subjected to a lapping process to clean the entire amateur winding assembly. Frame
A sintered bearing 105 is fixed to the center of the rubber case 101, and the frame case 101 has an oval shape, and arc-shaped magnets 102 are individually mounted on the inner peripheral side of the frame case 101 in the two arc portions. 10 magnets
Magnetic poles are magnetized to different polarities inside 2. The shaft 103 of the cleaned armature winding assembly is inserted into the sintered bearing 104, and the bracket 111 having the brush 110 and the sintered bearing 105 is attached to the frame case 101 to assemble the motor.

[0007] The magnetic flux of the magnet 102 exits from one magnet inner surface, passes through the motor core 106, then enters the other magnet 102 inner surface, and returns to the first magnet 102 through the frame case 101. Configuration. This is a magnetic circuit configuration on a plane perpendicular to the axis.

(Conventional Example 2) FIG. 44 shows a square-section coreless motor as a motor for portable communication equipment.
Is a plan view thereof, and (b) is a sectional view thereof.

In FIG. 44, a shaft 121 is fixed to a coreless coil group 123 via a commutator 122. Reference numeral 124 denotes a hollow cylindrical magnet which is fixed to the housing 126 and has a space inside the coil group 123. Reference numeral 125 denotes a frame case having a flat portion on the outer periphery. The frame case 125 fixes a housing 126 to which the cylindrical magnet 124 is fixed so as to be arranged with a space inside the coil group 123, and a magnetic circuit between the housing 126 and the cylindrical magnet 124. Is composed. 127 is a bearing, which is fixed to the housing 126 and has a shaft 121
Is rotatably supported. A brush assembly 128 energizes the coil group 123 via the commutator 122.

(Conventional Example 3) FIG. 45 is a sectional view of an inner rotor type brushless motor.

In FIG. 45, 141 is a cylindrical core having three salient poles, 142 is a coil, 143 is a magnet, 144 is a shaft, 145 is a frame case, 14
6 and 147 are bearings and 148 is a circuit board on which electronic components are mounted.

As shown in FIG. 45, the inner cylindrical portion of the hollow cylindrical magnet 143 is inserted and fixed to the shaft 144,
One end of the shaft 144 is supported by a bearing 146 attached to the frame case 145, and the other shaft end is an inner rotor of a double-sided support structure supported by a bearing 147. A magnet 143 attached to a shaft 144 rotatably held by bearings 146 and 147 is magnetized to two poles, and a rotor magnet is formed by a magnetic flux generated when a coil 142 wound around a salient pole of the core 141 is energized. Rotates. The magnet 143 has two poles, and the salient poles of the core 141 are U-phase and V-phase, respectively.
This is a three-phase winding structure that is a three-phase and W-phase winding. The circuit is energized and driven such that the phases of the induced voltages generated in the three phases are shifted by 120 ° each. That is, it is driven as a three-phase brushless motor.

[0013]

However, in the above-mentioned conventional structure, the size of the equipment has been reduced, and the demand for a small, high-efficiency, and high-reliability motor has been reduced (Conventional Example 1).
Is less reliable than a brushless motor because it has a brush, and it becomes difficult to make a small-sized motor for winding if the motor is small.

(Conventional Example 2) has a coreless type brush, so its reliability is lower than that of a brushless type, and the smaller the size is, the smaller the amount of output torque to be taken out is compared with the coreless type. The realization of a small coreless motor with high efficiency becomes difficult as the diameter decreases. The coil wire used for the coil group must also use 0.01 to 0.02 mm, so that the yield of machining the coil group is deteriorated and the motor cannot be supplied at low cost.

[0015] (Conventional example 3) is an inner rotor type brushless motor, which is a cylindrical core. Therefore, if the dimension in a plane perpendicular to the rotation axis of the motor is restricted, a winding part is secured to some extent. Otherwise, the winding operation cannot be performed, and if the rotor magnet diameter becomes small, the operation becomes extremely difficult.

[0016]

In order to solve the above-mentioned problems, a brushless motor according to the present invention has K stages (where K is an integer of 2 or more) in which the magnetization positions of the N and S poles in the circumferential direction are shifted from each other in each stage. ), A core provided with K coil-wound salient poles corresponding to the magnet bodies of each stage in a single row in parallel to the axial direction of the rotor magnet, and a core provided in the axial direction of the rotor magnet. A flat outer package having a pair of long sides facing each other at a right angle in cross section and a pair of short sides facing each other, a rotor magnet penetrating a center portion of the outer package, and at least one short side of the outer package is provided. A core is arranged on the side and the terminal of the coil wound around the salient pole is printed
Conduction treatment is performed on the substrate, and this printed circuit board is
At least one side is composed, and the driving circuit
Child is implemented, or each stage
K stage where the magnetization positions of the N and S poles in the circumferential direction are shifted from each other
Rotor with magnet body (K is an integer of 2 or more)
Gnet and coil winding corresponding to the magnet body of each stage
The salient poles are K in one row parallel to the rotor magnet axis.
And a cut perpendicular to the axial direction of the rotor magnet.
From a pair of long sides facing each other and a pair of short sides facing each other
With a flat outer casing, and the central part of the outer casing is low.
Cores penetrate through each of the short sides of the exterior body.
And a pair of short sides and one long side of the exterior body
Flexible printed circuit board so that it is continuous on the three surfaces
It is characterized by being arranged .

[0017]

(Embodiment 1) Hereinafter, Embodiment 1 of the present invention will be described with reference to the drawings.

FIG. 1A is an axial sectional view of a pager motor for mobile communication, and FIG. 1B is a vertical sectional view of the pager motor for mobile communication. .

In FIG. 1, reference numeral 18 denotes three salient poles 1a, 1
a first core 19 composed of b, 1c and a yoke plate 11 for coupling these, and a second core 19 composed of three salient poles 2a, 2b, 2c and a yoke plate 12 for coupling these , 3
Is a rotor magnet composed of three magnet bodies 3a, 3b, 3c and spacers 8a, 8b interposed between the magnet bodies and the shaft 4, 5 and 6 are bearings, and 7 is salient pole 1.
a to 1c, coils wound around 2a to 2c, 9 is a weight for imbalance, 10 is a thrust plate, 13 and 14 are brackets, 15 is a printed circuit board, 16 is a drive IC, 1
7 is a sheet.

The outer casing 90 of the motor according to the present embodiment has a flat rectangular cross section perpendicular to the axial direction of the rotor magnet 3, and a pair of short sides 90a, 90a of which are both the yoke plate 11, And a pair of long sides 90
b and 90b are composed of the printed circuit board 15 and the sheet 17. The cross-sectional shape of the exterior body 90 may be a flat cross-sectional shape such as an oval shape.

In FIG. 1, salient poles 1a, 1b, 1c, 2
Each of a, 2b, 2c is insulated by electrodeposition coating,
A coil 7 is wound from above the insulating layer. The three salient poles 1a, 1b, and 1c around which the coil 7 is wound are attached to the yoke plate 11 at intervals in the axial direction of the shaft 4 to form a first core (core assembly) 18. Also,
Opposite the shaft 4 there is a second core (core assembly) 19. The second core 19 has a configuration in which three salient poles 2 a, 2 b, and 2 c around which the coil 7 is wound are attached to the yoke plate 12 at intervals in the axial direction of the shaft 4.

Each magnet body 3 of the rotor magnet 3
Reference numerals a, 3b, and 3c denote hollow cylindrical radially anisotropic sintered magnets which are magnetized to N and S poles, respectively. As shown in FIG. 2, three magnet bodies 3a, 3b, 3c
Are arranged with their polarities shifted by 120 degrees, the shaft 4 is inserted into the hollow cylindrical portions of the magnet bodies 3a, 3b, 3c, and further, the spacers 8a, 8b are inserted between the magnet bodies 3a, 3b, 3c. In this state, the three magnet bodies 3a, 3b, 3c are fixed to the shaft 4 at intervals.

Since the present embodiment is a vibration calling pager motor for mobile communication, an unbalanced weight whose center of gravity is located at a position distant from the center of rotation (shaft center) in order to extract the vibration generated by the motor. With the provision of 9, the centrifugal force of the center of gravity of the weight 9 due to the rotation utilizes the energy transmitted to the stator side of the motor. In the above case, the greater the radial load acting on the bearing 6, the greater the vibration. Therefore, in order to increase the load acting on the bearing 6, the center of gravity is separated from the center of rotation so that the spacers 8a and 8b also have eccentric loads. . The radial load applied to the bearing 6 becomes a reaction force with the unbalance force acting. The influence of the position of the center of gravity of the weight 9 and the position of the center of gravity of the spacers 8a and 8b on the magnitude of the reaction force will be described with reference to the explanatory diagram of FIG. When the center of gravity of the object having the mass m is eccentric by r from the rotation axis and the axis rotates at the rotation angular velocity ω, the centrifugal force F is expressed by (Equation 1).

F = m · rω ² (1) When the elastic deformation ρ of the rotor is examined by the centrifugal force, the total centrifugal force F is expressed by (Equation 2).

F = m (r + ρ) ω ² (2) Since the elastic deformation ρ is negligible compared to r, the centrifugal force F is given by (Equation 1).

The weights from the bearing 5 9, spacers 8a, the distance to the spacer _{8b L 1, L 2, L} 3, the distance from the bearing 5 to the bearing 6 L, X axis the axis center, the axis perpendicular to the X axis Is the Y axis. When the centrifugal forces F ₁ , F ₂ , and F ₃ of the weight 9 and the spacers 8a and 8b are disassembled in the X and Y axis directions, the equation (3) is obtained.

F _1x = m ₁ r ₁ ω ² = F ₁ F _1y = 0 F _2x = m ₂ r ₂ ω ² cos θ ₂ = F ₂ cos θ ₂ F _2y = m ₂ r ₂ ω ² sin θ ₂ = F ₂ sin θ ₂ F _3x = m ₃ r ₃ ω ² cos θ ₃ = F ₃ cos θ ₃ F _3y = m ₃ r ₃ ω ² sin θ ₃ = F ₃ sin θ ₃ (3) If the reaction force of the bearing 6 is R, The reaction force R is also decomposed in the X and Y directions, and the moment is considered with the bearing 5 as a fulcrum, as shown in (Equation 4).

LR _x = L ₁ F _1x + L ₂ F _2x + L ₃ F _3x LR _y = L ₁ F _1y + L ₂ F _2y + L ₃ F _3y (4) Components R _X , R _{Y of the} reaction force R Are combined as shown in (Equation 5).

R ² = R _x ² + R _y ² (5) Accordingly, the square of the reaction force R is represented by (Equation 6).

[0030] _{^{R 2 = R x 2 + R}} y 2 = (F 1x · (L 1 / L) + F 2x · (L 2 / L) + F 3x · (L 3 / L)) 2 + (F 1y · (L _{1 / L) + F 2y ·} (L 2 / L) + F 3y · (L 3 / L)) 2 = (F 1 · (L 1 / L) + F 2 cosθ 2 · (L 2 / L) + F 3 cosθ 3・ (L ₃ / L)) ² + (F ₂ sin θ ₂ · (L ₂ / L) + F ₃ sin θ ₃ · (L ₃ / L)) ² ... (6) R is the maximum when R ² is the maximum. It is. In (Equation 6),
The rotational angular velocity ω, masses m ₁ , m ₂ , m ₃ , eccentric distance r ₁ ,
r ₂ , r ₃ and the spans L ₁ , L ₂ , L _{3 in the} axial direction are known by design, and the unknowns are the angles θ ₂ , θ ₃ . R is maximized when θ ₂ = θ ₃ = 0. That is, the centrifugal force of the spacer is in the same direction as the centrifugal force of the weight.

From the above description, it is preferable that the eccentric direction of the spacer is the same as the eccentric direction of the weight, and the rotor portion of the present embodiment is also configured in such a manner. Therefore, the unbalanced load acting on the bearing 6 can be made large.

Since the shape of the weight 9 has an important influence on vibration, a weight model as shown in FIG. 4 is considered.
The weight 9 has a sector shape with a reduced angle of 2α from the semicircle, and the outermost diameter of the weight 9 is D,
This is hereinafter referred to as the weight outer diameter. FIGS. 5A, 5B, and 5C show the relationship between the weight outer diameter D / shaft diameter d, the center of gravity deviation g of the weight 9, the area A of the weight 9, and the centrifugal force F ₄ using the angle α as a parameter. ). However,
The shaft diameter d = 1, the thickness of the weight 9, the specific gravity of the weight 9, and the square of the rotation speed were unchanged. The amount of deviation of the center of gravity of the sector weight 9 is determined by the ratio (D / D) of the weight outer diameter D to the shaft diameter d.
d) is expressed by a linear expression. The area A of the weight 9 is expressed by a higher-order equation with respect to the ratio (D / d) between the weight outer diameter D and the shaft diameter d. Since the centrifugal force is expressed by (Equation 1), the centrifugal force F ₄ is proportional to the product of the area A of the weight 9 and the amount of displacement g of the center of gravity.

To increase the vibration caused by the weight 9,
It can be said from FIG. 5 that the outer diameter of the weight 9 is preferably as large as possible, but as shown in FIG. 1, in a motor having a flat cross-sectional shape, the weight outer diameter D is equal to or longer than the length of the short side 90a. There is very little to do except in special cases. In a motor having a flat cross section as shown in FIG. 1, the outer diameter D of the weight 9 is defined as follows.

The length of the short side 90a is represented by a (FIG. 1 (b)
), The weight outer diameter D is regulated as shown in (Equation 7).

0.6 × a <D <a (7) Further, it is preferable that the sheet 17 and the printed circuit board 15 are thinner in terms of the characteristics of the motor.
_{Assuming m} , it is preferable that the weight outer diameter D be selected as shown in (Equation 8).

0.8 × D _m <D <1.1 × D _m (8) As shown in FIG. 6, the bearing 5 is a cylindrical bearing that receives a radial load, and the load in the thrust direction is It is constituted by a pivot bearing of the arc at the tip of the shaft 4 and the thrust plate 10. A low sliding resin material is used for the thrust plate 10.

The radius of the spherical shape at the tip of the shaft 4 is represented by r.
When, the friction torque T _p the maximum surface pressure P _max (Equation 9)
Is required.

P _max = a × r ^−2/3 T _p = b × r ^1/3 (9) where a is a coefficient, b is a coefficient, and the maximum surface pressure P _max and friction in the case of a certain radius r _O Torque T _p
FIG. 7 shows the relationship between the respective ratios of the maximum surface pressure and the friction torque, where is set to 1. Since the friction torque T _p and reduce the radius r of the tip of the shaft is lowered although the surface pressure P _max is large, it is sometimes rather impairing the reliability that the thrust plate 10 in the case of the resin is increased much surface pressure. Also, increasing the radius r, but the surface pressure P _max drops, because the loss torque is increasing frictional torque T _p is the temperature becomes heat sometimes lowered and the reliability by increasing, in 2000rpm rotation faster than The pivot bearing is designed so that the relationship between the radius r of the shaft tip of the thrust bearing and the shaft diameter d is expressed by (Equation 10).

10 × d>r> 1.5 × d / 2 (10) The thrust plate 10 is made of a general polymer material. However, when a motor is used in a battery-powered, portable type device, it is preferable to use a polyacetal resin having excellent lubricity for the thrust plate 10 in order to reduce long-term friction torque. When using at high temperatures often, use polyimide resin or Teflon resin, which has excellent heat resistance.

Further, to exhibit the relationship of the outer diameter D _s and the shaft outer diameter d of the thrust plate 10 in (Equation 11).

D _s > d (11) By doing so, the thrust plate 10 does not fall off the bearing 5 when the shaft is inserted, so that the work is stabilized. Even if the shaft 4 moves in the thrust direction, the thrust plate 10 does not move in close contact with the bracket 14 due to the lubricating oil and the oil of the bearing 5, but may move in the surface direction to reduce bearing loss. May need to regulate movement. By adopting the relationship of (Equation 11), the contact area is increased and it is difficult to move, and the diameter can be regulated by the diameter of the cylindrical portion of the bearing 5. By inserting the thrust plate 10 into the bracket 14 and fixing and assembling the bearing 5, a bearing having the relationship of (Equation 27) can be formed.

When the size of the motor becomes smaller, the ratio of the bearing loss to the generated torque increases. Therefore, it is necessary to reduce the bearing loss. The bearings 5 and 6 use oil-impregnated sintered bearings. The viscosity of the oil containing oil is 10 cst to 50.
Use the one of cst.

Also, if a sintered material is mixed with a resin having a low friction, for example, fine powder of Teflon having a particle size of 1 μm or less, and a bearing is made, Teflon intervenes in a metal gap and acts as a binder. In addition, the resin is scattered on the bearing surface with respect to the shaft 4, so that the bearing loss can be reduced more than in the case of using only oil. In addition to being able to start the motor at a low voltage, the battery life can be extended.

Further, if the shape of the inner diameter of the bearing is formed into an arc-shaped cross section as shown in FIG. 8, bearing loss can be reduced. FIG. 8A is a view showing a state in which the shaft 4 has penetrated the bearing 6 on the weight side, and FIG. 8B is a view showing a part of the bearing 5 on the pivot bearing side. FIG. 8A shows that even though the shaft perpendicularity to the bracket 13 is slightly deteriorated due to assembling of the shaft 4 or bending of the shaft 4 due to imbalance, the inner diameter of the bearing 6 is arcuate, so that the arc 6a and the shaft 4 Is a point contact, and the bearing 6 has a self-aligning property. In the case of FIG. 8B as well, contact between the bearing 5 and the shaft 4 due to bending of the shaft 4 due to assembling or unbalance during assembly makes a point contact at one point of the inner diameter arc 5 a of the bearing 5. By making the inner diameters of the bearings 6 and 5 arc-shaped so as to make point contact with the shaft 4, bearing loss can be reduced.

The lands of the printed circuit board 15 constituting one long side 90b of the exterior body 90 have respective salient poles 1a to 1
c, the terminals of the coil 7 wound around 2a to 2c are indirectly or directly conducted. Printed circuit board 1 of the present embodiment
Reference numeral 5 denotes a flexible printed circuit board, on which a driving circuit electronic component such as a driving IC 16 is mounted, and a land 15a for connection to a power supply on the apparatus side is provided.

Since the flexible printed circuit board is disposed on one surface on the long side 90b side as in this embodiment, a relatively large board shape is obtained for a thin motor, and the drive circuit components are used for the flexible printed circuit board. It is easy to mount on top, and a thin and small brushless motor can be configured.

Further, a sheet 17 is attached on the side opposite to the printed circuit board 15. By pasting the sheet 17,
Since the inside of the motor has a sealed structure, no dust enters the inside of the motor, and the rotor magnet 3 and the cores 18 and 19 are free from dust.
This eliminates the possibility that dust from the outside will be trapped in between them and the rotation of the rotor will not be reduced. That is, it is a dustproof measure. Further, since the serial number and the name of the manufacturer are described on the sheet 17, it can be used reasonably.

The salient poles 1a, 1b, 1c, 2
a, 2b, 2c and the yoke plates 11, 12 are not integrated, and the salient poles 1a to 1c, 2a to 2c are individually formed into separate pieces. The salient poles 1a made into pieces
One example of 1c, 2a to 2c has a structure as shown in FIG. When the salient pole in FIG.
The surface 21a facing the one rotor magnet 3 is an arc surface along the radius of curvature centered on the rotation axis. A back surface 21b of a surface 21a of the protruding portion 21 facing the rotor magnet 3 has a curved surface portion, and a tooth portion 22 having a cylindrical cross section for winding the coil 7 is formed on the surface 21b. Assuming that the diameter of the cross section is h1, h1
A cylindrical portion 23 having a smaller cross-sectional diameter is formed at the tip of the teeth portion 22. The cylindrical portion 23 is to be engaged and inserted into a hole formed in the yoke plates 11 and 12, and is smaller than the cylindrical portion diameter of the teeth portion 22 by inserting and positioning the yoke plates 11 and 12 at the step portion. This is because the air gap between the rotor magnet 3 and the facing surface 21a can be made uniform in each salient pole 20. The distal end surface of the cylindrical portion 23 is concave. The salient poles 20 are connected to yoke plates 11 and 12
Is fixed to the yoke plates 11 and 12 by caulking the outer peripheral portion of the concave surface of the cylindrical portion 23 in a state of being inserted into the cylindrical portion 23. Salient pole 20 and yoke 1
There are methods other than caulking for fixing 1 and 12, such as press-fitting and bonding.

Piece-shaped salient poles 1a-1c, 2a-2
c has an example of a shape as shown in FIG. When the salient poles in FIG. 10 are represented by reference numeral 24, a surface 25a of the protruding portion 25 of the core 24 facing the rotor magnet 3 is an arc surface along a radius of curvature centered on the rotation axis. The back surface 25b of the surface 25a of the protruding portion 25 facing the rotor magnet 3 has a curved surface portion, and the surface 25b is formed with a teeth portion 26 having a rectangular cross section around which the coil 7 is wound. Let h _{2 be} the length in the direction perpendicular to the rotation axis and h _{3 be} the length in the direction of the rotation axis.
6 has the relationship shown in (Equation 12).

H ₂ ≒ h ₃ (12) The cylindrical portion 27 having a sectional diameter smaller than the length of the side of the square.
Are formed before the teeth 26. The cylindrical portion 27 is to be engaged and inserted into a hole formed in the yoke plates 11 and 12. The cylindrical portion 27 is smaller than the cross section of the teeth portion 26. This is to make the air gap between 3 and the opposing surface 25a uniform in each salient pole 24.

Piece-shaped salient poles 1a-1c, 2a-2
c has an example of a shape as shown in FIG. 11, the surface 29a of the protruding portion 29 of the salient pole 28 facing the rotor magnet 3 is an arc surface along the radius of curvature centered on the rotation axis. The rear surface 29b of the surface 29a of the protruding portion 28 facing the rotor magnet 3 has a curved surface portion, on which a tooth portion 30 having a rectangular cross section for winding the coil 7 is formed. It is formed integrally. Assuming that the length of the square section of the tooth portion 30 in the direction perpendicular to the rotation axis is h ₄ and the length in the rotation axis direction is h ₅ , the tooth portion 30 in FIG. 11 is a rectangle having a relationship shown in (Equation 13). .

H ₄ <h ₅ (13) As shown in the equation (13), in the motor having a flat rectangular cross section, the teeth 30 of the salient pole 28 have a long dimension parallel to the axial direction. Has the following advantages. That is, in FIGS. 9, 10, and 11, when the coil 7 is wound around the teeth 22, 26, and 30, the length in the width direction of the teeth 22, 26, and 30 is the same. That is, as shown in (Equation 14).

H ₁ = h ₂ = h ₄ (14) As a result, the equation (15) is obtained, and the tooth cross-sectional area in FIG. 11 becomes the maximum as compared with those shown in FIGS. 9 and 10. .

(Π / 4) h ₁ ² <h ₂ · h ₃ <h ₄ · h ₅ (15) Therefore, if the teeth have the same sectional area, the length of the salient pole in the width direction is shown in FIG. since 11 h ₄ is small, the coil 7
Can have a large winding height, and a large number of turns can be involved.

Since the salient poles 1a to 1c and 2a to 2c are made into pieces, an example of a method for manufacturing the pieces will be described. The mixture of metal powder and resin was molded by injection molding and baked after molding to remove the resin.
Salient pole 1a by so-called metal injection manufacturing method
To 1c and 2a to 2c. Compared to cutting and polishing,
Since the curvature of the facing surfaces 21a, 25a, and 29a with respect to the rotor magnet 3 shown in FIGS. 9 to 11 is within the tolerance range of the required dimensions after firing, variations in motor characteristics are reduced.

When the salient poles 1a to 1c and 2a to 2c are made by using a metal injection (also referred to as metal powder injection molding) technique, a small salient pole having a complicated shape as shown in FIGS. A final shape that does not require post-finishing can be obtained. Fe-Si is an example of a powder material used for salient poles.
Although there is a system material, post-processing is hardly possible because it is difficult to process. In the case of a salient pole having a caulking process, a pure iron powder material is used. In the metal injection manufacturing process, the raw metal powder of each component of the chemical composition regulated by reduction and reduction and the binder of the resin are weighed, mixed and kneaded with the sieved set particle size to create a material that can be injection molded,
The resin is removed from the binder by injection molding using a mold. After the resin is removed, sufficient interatomic bonds are formed between the particles by heating, and the powder metal is sintered to form a metal sintering bond. There is a state in which the pores 32 exist as shown in FIG. If there are many pores 32, the size after sintering changes, so that parts having strict accuracy such as salient poles have fine powder particles and uniform particle diameter to increase the density. Pores 32
Is reduced and the density of the salient poles is increased, whereby a structure capable of coping with a portion where the magnetic flux density of the salient poles is large can be obtained. The resin is impregnated in the final step or a small amount of binder resin is left so that an insulating film of resin is formed on the sintered metal surface and the pores. The generation of the eddy current can be suppressed by the insulating film having the internal structure of the salient pole.

Another example of a method for manufacturing the salient poles 1a to 1c and 2a to 2c will be described.

When salient poles are formed by forging, the salient poles are formed into pieces and small, so that the salient poles can be mass-produced with a small forging machine. In the forging, the corners are rounded, and in the salient poles 28 as shown in FIG. 11, the corners are rounded, but the curvature of the surface 29a facing the rotor magnet 3 is not affected. No difference occurs in the characteristics of the motor due to the salient pole shape. FIG. 13 shows a directional flow chart of the metal composition of the forged salient pole. Since the magnetic flux flows in the same direction as the direction of the composition flow K as shown in FIG. 13, the magnetic flux does not result in a loss, but a loss occurs due to distortion of the metal crystal particles due to forging. The salient pole is annealed to coarsen the crystal grains and reduce the loss.

Next, how to assemble the motor (FIG. 1) of the present embodiment will be described with reference to FIG. A first core formed by assembling three salient poles in which a coil 7 is wound around a yoke plate 11 from the axial direction at one notch 14a of a bracket 14 on which a thrust plate 10 is mounted and a bearing 5 is fixed by press-fitting. 18
The lower protrusion 1 of the second core 19 in which three salient poles are assembled to the yoke plate 12 is fitted.
9a is fitted into the other cutout 14b of the bracket 14. The magnets 3a, 3b, 3c and the spacer 8
The rotor magnet 3 is assembled by fixing a and 8b to the shaft 4 with a predetermined number and a predetermined position. The lower end of the shaft 4 of the rotor magnet 3 is inserted into the bearing 5 of the bracket 14. Next, the upper protrusion 18b of the first core 18
Is fitted into one notch 13a of the bracket 13, and the upper projection 19b of the second core 19 is fitted into the other notch 13b of the bracket 13. The bracket 13 is assembled after first inserting the upper end of the shaft 4 into the bearing 6 of the bracket 13. The above assembly can be built in from the axial direction.
When the frame of the motor is completed, a weight 9 for imbalance is attached to the shaft 4, a printed board 15 on which electronic components are mounted is attached, and a coil terminal is soldered to a land 15 a on the printed board 15. Further, the sheet 17 is attached.

Next, the principle of rotation of the motor of this embodiment will be described with reference to FIG.
1 and FIG. 42.

FIG. 41 shows the magnets 3a, 3b, 3
FIG. 4 is a diagram schematically illustrating a relationship between the coil 7 (referred to as 7a, 7b, and 7c in order from the top), and salient poles 1a to 1c, 2a to 2c.

As shown in FIG. 41, the salient poles 1a to 1c,
2a to 2c are arranged at the same circumferential position in each of the cores 18 and 19 so as to form one vertical line, and in each stage, the coils 7a, 7b and 7c are continuously connected to the two cores 1 by one conductor.
8 and 19 are wound in the same direction around the salient poles 1a to 1c and 2a to 2c. The winding directions of the coils 7a, 7b, 7c in each stage are the same as shown in FIG.

FIG. 42 is a diagram showing a waveform of an induced voltage generated in each coil when the rotor magnet 3 rotates with this configuration.

As shown in FIG. 42, coils 7a, 7b, 7
The induced voltages Va, Vb, and Vc generated in c have waveforms whose phases are shifted by 120 ° because the angles of the magnet bodies 3a, 3b, and 3c are shifted by 120 °.
Here, one end of each of the coils 7a, 7b, 7c is commonly connected as COM, three phases are distributed to the other ends thereof, and an electric circuit is driven by an electronic circuit on the printed circuit board 15 in accordance with the induced voltages of the three phases. Occurs and the magnet body 3
a, 3b, 3c rotate. That is, it is driven as a three-phase brushless motor. The electronic circuit is supplied with current from a DC power supply. The motors of the following embodiments also rotate on the same principle.

In the present embodiment, the motor has a three-stage structure. However, a K-stage (n = 2, 3, 4,...) Magnet body and salient poles make it possible to use a K-phase brushless motor. Generally, it can be widely used.

(Embodiment 2) Hereinafter, Embodiment 2 of the present invention will be described with reference to the drawings.

FIG. 15A is an axial sectional view of a pager motor for mobile communication, and FIG. 15B is an axial vertical sectional view of a pager motor for mobile communication. .

In the second embodiment, the same points as those in the first embodiment will not be described, and only the differences will be described. 15, the same reference numerals are used for parts common to those in FIG.

The exterior body 90 of the second embodiment has a flat rectangular cross section perpendicular to the axial direction of the rotor magnet 3, and its short sides 90a, 90a are constituted by a pair of yoke plates 11, 12. One of the long sides 90b, 90b is open, and the other is constituted by the plate 35 and the flexible printed board 34.

In FIG. 15, 37 is a bracket on the side of the weight 9, 33 is a bearing bracket, 34 is a flexible printed circuit board, 35 is a plate, and 36 is a terminal plate.

The magnet bodies 3a, 3b and 3c constituting the rotor magnet 3 of the motor are hollow cylindrical magnets, each of which is divided into N and S2 poles and magnetized.
As shown in FIG. 16, three magnet bodies 3a, 3b,
3c is arranged in a state where the polarity is shifted by 120 ° between the stages, and the shaft 4 is inserted and fixed in the hollow cylindrical portions of the magnet bodies 3a to 3c. It can be regarded as an integral rotor magnet 3 whose surface magnetic pole distribution is layered in the axial direction.

As shown in FIG. 17, the three magnet bodies 3a, 3b, and 3c are respectively provided with three magnet bodies 3a, 3b, and 3c to determine the angles of the polarities of the three magnet bodies 3a to 3c. The projections and depressions 92 and 91 are provided with irregularities.
3c is shifted by exactly 120 °.
According to this configuration, a predetermined magnetic pole can be obtained simply by magnetizing the magnet bodies 3a to 3c on the basis of the irregularities and combining them so that the irregularities match, thereby facilitating the assembly. Further, as in the first embodiment, a spacer may be provided between the magnets, and the spacer may be provided with a positioning mechanism. An example will be described below.

FIG. 18 shows three magnet bodies 3a, 3
b, 3c and spacers 37a, 37b provided between them. The three magnets 3a, 3b, and 3c are provided with a concave portion 94, and the two spacers 37a and 37b are provided with a convex portion 93 corresponding to the magnet. Spacer 3
The projections 93 of 7a and 37b are provided at positions vertically shifted by 120 °, and when the magnets and the spacers are combined in combination, the magnets 3a to 3c
Are shifted by exactly 120 °. According to this configuration, a predetermined magnetic pole can be obtained simply by magnetizing the magnet body based on the concave portion and combining the magnet body and the spacer so that the unevenness of the spacer is matched, so that the assembly is easy and suitable for mass production. . Spacers 37a, 37
The b serves as a weight for imbalance and also serves as a positioning between the magnet bodies, and can prevent the leakage of magnetic flux between the upper and lower magnet bodies.

Since the present embodiment is a vibration calling pager motor for mobile communication, the unbalanced weight 9 has its center of gravity separated from the center of rotation (axial center) in order to extract the vibration generated by the motor. Position.

To increase the vibration caused by the weight 9,
It is preferable that the outer diameter of the weight 9 is as large as possible. In the present embodiment, when the dimension of the short side 90a of the exterior body 90 is a (see FIG. 15B), the outer diameter D of the weight 9 is as shown in (Equation 16).

0.6 × a <D <a (16) Further, although the center of the shaft is not necessarily located at the center of the side surface of the bracket, the rotor magnet 3 rotates, so that the magnet bodies 3a, 3b The relationship between the diameter of 3c and the diameter of the weight 9 may be selected as shown in (Equation 17). Here, the outer diameter of the magnet body is D _m , and the outer diameter of the unbalance weight is D.

0.8 × D _m <D <1.1 × D _m (17) The bearing portion 37a of the bracket 37 is formed by making the peripheral portion of the bearing hole thinner, and FIG. As shown in FIG. 7, a low friction resin layer 38 is coated on the inner peripheral surface.
Therefore, the shaft 4 has a small bearing loss in contact with the low friction coating material 38 and the thickness of the low friction coating material 38 is, for example, 100 μm or less, and the shaft 4 functions as strong rigidity. The force acting on the bearing is transmitted as vibration to the outer shell of the motor without attenuation. Table 1 shows examples of materials of the low friction coating material used.

[0078]

[Table 1]

The bracket 33 is made of a low-friction resin, and a bearing 33a having a spherical concave portion is also integrally formed.
Since the bracket 33 is an injection-molded product, a complicated shape around the bearing is possible.

For example, as the low friction resin, any one of a fluororesin, a polyacetal resin and a polyimide resin is used. Fluororesins have chemical resistance, heat resistance, and non-adhesive properties in addition to low friction properties, and are used in a wide range of fields.

When the bracket 33 is made of a metal material, the bearing 37a of the bracket 37 can be coated with the low-friction coating material used to form a pivot bearing.

The flexible printed circuit board 34 on which the drive circuit electronic components such as the drive IC 16 are mounted is attached to a plate 35 and fixed. The flexible printed circuit board 34 has coils 7 wound around the salient poles 1a to 1c and 2a to 2c.
Is connected to the terminal board 36, and the terminal is electrically connected to the land on the flexible printed board 34 via the terminal board 36. When the flexible printed circuit board 34 is configured with the surface of the long side 90b as in the present embodiment, it is easy to mount the drive circuit components on the flexible printed circuit board 34, even though the thickness of the motor is thin. A small brushless motor can be configured. The opposite side of the printed circuit board 34 is open.

The salient poles 1a to 1c, 2a to 2c of the present embodiment
Also, the yoke plates 11 and 12 are not integral with each other, but have a configuration in which salient poles are individually made into separate pieces. An example of the pieced salient pole has a structure as shown in FIG.
When the salient pole in FIG. 19 is represented by reference numeral 39, the surface 40 a of the projecting portion 40 of the salient pole 39 facing the rotor magnet 3 is not an arc having a curvature centered on the axis 43 of the rotor magnet 3, but is farther from the axis 43. Is an arc surface having a center of curvature. It becomes flat when the radius R ₂ of the circular arc surface is infinite.

The rear surface portion 40b of the surface 40a of the protruding portion 40 facing the rotor magnet 3 is flat, and the teeth portion 4
Since the cross-sectional shape of 1 is rectangular, when winding the coil 7 having a flat rectangular cross-section, there is little winding deviation, and a winding process with a clean winding shape and high reliability can be performed. FIG. 20 shows the salient pole 39 of FIG. 19 wound with the coil 7 having a flat rectangular cross section.

The salient pole 39 shown in FIG.
Since the shape of the hole to be inserted into the first and second holes 12 is not a circle but a quadrangle, the cross-sectional shape of the joint 42 of the salient pole 39 to be engaged is also a quadrangle. When the shape to be inserted is a polygon other than a circle, positioning for inserting the salient poles 39 into the yoke plates 11 and 12 becomes possible.

In FIG. 15, salient poles 1a, 1b, 1c,
Each of 2a, 2b and 2c is insulated by electrodeposition coating. When the coil 7 is wound around each salient pole from above the insulating layer, the coil 7 is wound in a state where the terminal plate 36 is press-fitted into the yoke plate insertion portion and assembled, and the coil terminal is connected to the terminal plate 3.
6 is connected by pressure contact near the salient pole. FIG. 21 shows a state in which the terminal plate 36 is attached to the salient pole 39 formed into pieces. The terminal plate 36 is formed by integrally molding a metal plate 43 and an insulating resin 44. The metal plate 43 has two components for the salient poles 39. , The pieced salient pole 39 is in the form of a component that is easy to mount like a chip resistor in a state where the winding is applied.

Next, how to assemble the motor (FIG. 15) of the present embodiment will be described with reference to FIG. A flexible printed circuit board 34 on which electronic components such as the drive IC 16 are mounted is attached on a plate 35, and the rotor magnet 3, which is an assembly of the magnet bodies 3 a, 3 b, 3 c and the shaft 4, is attached to the plate 35. The bracket 33 is assembled from the direction perpendicular to the axis in a state of being inserted into the bearing, and the other bracket 33 is also assembled slightly obliquely from the axis so that the bearing is fitted to the shaft 4. In this state, a first core in which salient poles 1 a, 1 b, and 1 c wound with the coil 7 and subjected to terminal treatment on the respective terminal plates 36 are attached to the yoke plate 11 at intervals in the axial direction of the shaft 4. 1
8 and a second core 19 in which salient poles 2 a, 2 b, 2 c, etc. are attached to the yoke plate 12
7 is assembled.

The above assembling can be built in from a direction perpendicular to the axis. When the frame of the motor is completed, a weight 9 for imbalance is attached to the shaft 4.

(Embodiment 3) Embodiment 3 of the present invention will be described below with reference to the drawings.

FIG. 23 (a) is an axial sectional view of a mobile communication pager motor according to Embodiment 3 of the present invention, and FIG. 23 (b) is an axial vertical direction of the mobile communication pager motor. FIG.

In the third embodiment, the points common to the first embodiment will not be described, and only the differences will be described. FIG.
The same reference numerals are used for the parts numbers used in 3 in the case of parts common to FIG.

In FIG. 23, 3 is a rotor magnet,
45 and 46 are bearing brackets, 47 is a flexible printed circuit board, 48 is a terminal board, and 49 and 50 are bearing bushes.

The rotor magnet 3 of the motor is a cylindrical magnet having an integral structure. In the first and second embodiments, the rotor magnet 3 has three magnet bodies 3a to 3c.
However, in the present embodiment, it is an integral rotor magnet. However, since the magnetized state is the same as in the first and second embodiments, in FIG. 24, the rotor magnet 3 is divided into three stages for the sake of explanation, and the phases of the magnetic poles of the three magnets are 1
It is shown as being magnetized with a shift of 20 °. Since the rotor magnet 3 is integrated, operations such as magnetic pole positioning can be eliminated. Both ends of the rotor magnet 3 have a cylindrical portion 71 having a small outer diameter, and ring-shaped bearing bushes 49 and 50 are press-fitted and fixed to the cylindrical portion 71.

The bearing bushes 49 and 50 are shown in FIGS.
As shown in FIG. 4, thick semicircular portions 49a and 50a are used to generate an unbalance force accompanying rotation. The bearing bushes 49, 50 have bearing holes 49b, 50b at the center. At the center of each of the upper and lower bearing brackets 45, 46, a bearing pin (bearing convex portion) 45a, 46a is protruded, and the bearing hole (bearing concave portion) 49b, 50b is fitted into the bearing pin. The rotor magnet 3 is rotatably supported by upper and lower bearing brackets 45 and 46.

Since the present embodiment is a vibration call pager motor for mobile communication, the bearing bushes 49, 50 whose center of gravity is located away from the center of rotation (shaft center) in order to extract the vibration generated by the motor. , The centrifugal force of the center of gravity of the bearing bushes 49 and 50 due to the rotation utilizes the energy transmitted to the stator side of the motor. In the above case, the larger the radial load acting on the bearing pins 45a and 46a, the greater the vibration.
The loads acting on 5a and 46a will be described with reference to the model diagram of FIG.

The distance from the bearing pin 46a to the bearing bush 49 and the bearing bush 50 is L5 and L6, the distance from the bearing pin 46a to the bearing pin 45a is L, and the distance between the center of gravity of the bearing bush 49 and the shaft center is r. _5. The distance between the center of gravity of the bearing bush 50 and the shaft center is r ₆ . The X axis is the axis center, and the Y axis is perpendicular to the X axis. When disassembling the centrifugal force F _5, F ₆ of the bearing bushes 49, 50 X, the Y-axis direction, represented in (Equation 18). Where ω is the rotational angular velocity,
m ₅ and m ₆ are the masses of the bearing bush 49 and the bearing bush 50, respectively.

F _5x = m ₅ r ₅ ω ² = F ₅ F _5y = 0 F _6x = m ₆ r ₆ ω ² cos θ ₆ = F ₆ cos θ ₆ F _6y = m ₆ r ₆ ω ² sin θ ₆ = F ₆ sin θ ₆ ... (18) The reaction force of the bearing pin 45a against the bearing bush 49 is expressed by R ₃
Then, R _3x and R _3y are obtained by decomposing the reaction force R ₃ in the X and Y directions.
Considering the moment about the bearing pin 46a of the bearing bush 50 as a fulcrum, (Equation 19) is obtained.

LR _3x = L ₅ F _5x + L ₆ F _6x LR _3y = L ₅ F _5y + L ₆ F _6y (19) The square of the reaction force R ₃ is represented by (Equation 20).

R ₃ ² = R _3x ² + R _3y ² = (F _5x · (L ₅ / L) + F _6x · (L ₆ / L)) ² + (F _5y · (L ₅ / L) + F _6y · ( (L ₆ / L)) ² = (F ₅ · (L ₅ / L) + F ₆ cos θ ₆ · (L6 / L)) ² + (F ₆ sin θ ₆ · (L ₆ / L)) ² (20) ) In (Equation 20), the rotational angular velocity, the mass of the bearing bush,
The eccentric distance and the axial span are known by design, and the unknown is the angle θ ₆ . The maximum of R ₃ is θ ₆ = 0. That is, this is a case where the centrifugal forces of the two bearing bushes 49 and 50 are in the same direction.

From the above description, in order to greatly increase the unbalanced load acting on the bearing pin 45a corresponding to the bearing bush 49, the two bearing bushes 49, 5
It is necessary to configure the eccentric direction of the center of gravity 0 to be the same direction. Actually, the relationship of (Equation 21) is obtained due to the relationship of assembly accuracy.

[0102] | theta ₆ | as a fulcrum <30 ° ......... (21) bearing pin 45a corresponding to the bearing bushing 49, a reaction force acting on the bearing pin 46a corresponding to the bearing bush 50 when obtaining the R _4, (Equation 22) is obtained.

R ₄ ² = R _4x ² + R _4y ² = (F _5x · ((L−L ₅ ) / L) + F _6x · ((L−L ₆ ) / L)) ² + (F _5y · (( (L−L ₅ ) / L) + F _6y · ((L−L ₆ ) / L)) ² = (F ₅ · ((L−L ₅ ) / L) + F ₆ cos θ ₆ • ((L−L ₆ ) / L)) ² + (F ₆ sin θ ₆ · ((L−L ₆ ) / L)) ² (22) where R _4x and R _4y are the component of the reaction force R _{4 in} the X and Y directions. .

[0103] From equation (22), the reaction force R ₄ bearing pin 46a corresponding to the bearing bushing 50 is maximized is when the eccentric angle of the center of gravity of the bearing bushing are matched.

In order to increase the vibration due to unbalance, it is preferable that the product of the unbalance mass and the center of gravity is as large as possible.
Since the dimensions must not be in contact with the outer casing 90 of the motor, if the outer diameter of the rotor magnet 3 is Dm and the outermost diameter of the bearing bush is Db, the relationship is _expressed by (Equation 23).

0.8 × D _m <D _b <1.1 × D _m (23) The dimensions of the unbalanced bearing bushes 49 and 50 are regulated by the dimensions of the short side 90 a of the exterior body 90. You need to choose as follows. The dimension of the short side 90a is a (see FIG. 23B), the bearing bush 49,
When the outermost diameter of 50 to D _b, is selected as (Equation 24).

0.6a <D _b <a (24) The salient poles 1a to 1c and 2a to 2c of this embodiment are also yoke plates 1.
1 and 12 are not integrated, but have a configuration in which salient poles are individually made into separate pieces. As shown in FIG. 26, the coil 7 is wound around the pieced salient poles 1a to 1c and 2a to 2c, and a terminal plate 52 in which a metal piece 51 is integrally formed with resin is installed at the time of winding. The terminal of the coil 7 is connected to the metal piece 51 of 52. The end of the coil 7 is connected to the metal piece 51 by fusing heat pressure welding, and the winding start and end of the coil 7 are connected. Salient poles 1a-1
The projections 53 of c, 2a to 2c have arc-shaped surfaces facing the rotor magnet 3. The salient pole is Yoke 1
It has a cylindrical portion 54 for positioning and inserting into 1 and 12.

As shown in FIG. 27, both sides of the flexible printed circuit board 47 are fixed on the yoke plates 11 and 12,
A predetermined number of salient poles 1 a to 1 c and 2 a to 2 c are arranged, and these cylindrical portions 54 are inserted into holes 57 provided in the yoke plates 11 and 12. Cream solder is applied to the flexible printed circuit board 47 in advance, and electronic components such as the drive IC 55 are mounted thereon. Accordingly, the metal pieces 51 of the terminal plate 52 are placed on the lands 56 of the flexible printed circuit board 47, and thereafter, the electronic components and the coils can be made conductive by passing through the reflow furnace.

Next, how to assemble the motor of this embodiment (FIG. 23) will be described. After the conduction process is completed, salient pole 1a
1c, 1a, 2a-2c, etc.
2 are erected from both sides, respectively.
0 is attached to the rotor magnet 3 and the two iron plates 1
Place between 1 and 12. In this state, the bearing brackets 45 and 46 are inserted from both upper and lower sides in the axial direction, and the rotor magnet 3 is assembled and fixed to both the yoke plates 11 and 12. Further, a sheet 58 is attached. By adhering the sheet 58, the inside of the motor has a closed structure.

FIG. 28 shows the bearing brackets 45 and 46.
As shown in FIG. 7, bearing pins 45a and 46a are provided. The rotor magnet 3 of the present embodiment has a solid cylindrical shape, and has a structure without a shaft unlike the first and second embodiments. Therefore, the bearing bushes 49 and 50 are inserted from both upper and lower sides of the rotor magnet 3. These bearing holes 49b and 50b form a bearing portion. The portions that engage with the bearings are bearing pins 45a, 46a provided on the bearing brackets 45, 46. The bearing pin 45
When the bearing brackets 45 and 46 are formed of a metal plate, they can be integrally formed by a coining press. Further, by pressing the tip of the projection 60 into a spherical shape as shown in FIG. 29, a metal press pivot bearing with less bearing loss can be configured.

(Embodiment 4) Embodiment 4 of the present invention will be described with reference to the drawings.

FIG. 30A shows an axial sectional view of a pager motor for mobile communication in the present embodiment, and FIG. 30B shows an axial vertical sectional view of the pager motor for mobile communication. It shows.

In FIG. 30, reference numeral 61 denotes three salient poles 67.
a, a, 67b, 67c are arranged in parallel to the axial direction,
62 is a resin insulator integrally formed with the core 61, 63 is a back yoke paired with the core 61, 64 is a rotor magnet, 65 is a shaft, 66a and 66b are bearings, 68 is a coil, 69 and 70 are brackets, 71 Is a printed circuit board, 72 and 73 are weights for imbalance,
74 is a dustproof cover. In the motor of the present embodiment, the core 61 and the back yoke 63 are arranged to face each other with the rotor magnet 64 interposed therebetween. Three salient poles 67a,
In a motor in which 67b and 67c are arranged in parallel to the axial direction, the case where two cores 61 are arranged symmetrically with respect to the rotor magnet 64 as in Embodiments 1 to 3 is good in balance, but the coil 68 is Since the number of coils is six, the number of terminals of the coil 68 is also twelve (in FIG. 41, the number of terminals is six even in such a case). Therefore, in the motor of the present embodiment, the core 61
And one back core instead of another core
3 is attached. With this configuration, the number of coils 68 is three, and the terminals of the coil 68 are also six, so that the winding and the connection of the terminals are greatly reduced, and the cost is reduced.

The rotor magnet 64 has the same construction as that shown in FIG. 16, and has three vertical magnet bodies 64a,
Each of the magnets 64a to 64c is magnetized in a state where the polarities are shifted by 120 ° in three stages, and the magnet bodies 64a to 64c are divided into three stages.
The shaft 65 is inserted into the hollow cylindrical portion 4c.

Both ends of the shaft 65 are rotatably held by bearings 66a, 66b inserted and fixed to upper and lower brackets 69, 70.

A printed board 71 is fixed to the core 61, the back yoke 63, the brackets 69 and 70, respectively.
Finally, the dust cover 74 is covered.

The motor exterior body 90 of this embodiment has a flat rectangular cross section perpendicular to the axial direction of the rotor magnet 64, one long side 90 b of which is formed by the printed circuit board 71, and the other side 90 b is formed by the printed board 71. Long side 90b and a pair of short sides 9
The three sides 0a and 90a are configured with dustproof covers 74.

FIG. 31 is a view showing the structure of the core 61. As shown in FIG. FIG. 31A is a diagram of the core 61 as viewed from the side, and FIG. 31B is a vertical cross-sectional view thereof. The core 61 is configured by joining two core components 61a and 61b of the same shape, which are divided in half by a motor center axis and a plane formed by the core 61. Each of the core components 61a and 61b may be manufactured by laminating a plurality of silicon steel plates, or may be manufactured from a single metal plate.

When the core 61 is manufactured by laminating silicon steel plates, the efficiency is best when the core 61 is laminated along a plane parallel to the direction in which the magnetic flux flows, due to the eddy current loss of the core 61. 3
In the case of a motor in which three salient poles 67a to 67c are arranged in parallel to the axial direction, the magnetic flux flows in the salient poles 67a to 67c in a radial direction with respect to the axis, as shown by an arrow in FIG. At the portions where the salient poles 67a to 67c are connected, magnetic flux flows in a direction parallel to the axis. Therefore, in the case of the present embodiment, the efficiency is highest when the layers are stacked in a direction perpendicular to the plane formed by the shaft and the core.

In the case of the present embodiment, the core 61 has a structure in which two core parts 61a and 61b are stacked in exactly this direction, and the eddy current loss is smaller and the efficiency is higher than in the case where a single molding is performed.

The core 61 is composed of two core parts 6 of the same shape which are divided in half by a plane formed by the shaft and the core 61.
Since it is divided into 1a and 61b, it can be manufactured only by bending and cutting using a plate material. As a result, it can be easily manufactured by the press manufacturing method, and can be compared even when using a silicon steel sheet which is not suitable for drawing, forging, etc. It can be easily manufactured.

FIG. 32 is a view showing the structure of the core 61 and the resin insulator 62. The two core components 61a and 61b of the core 61 are integrally fixed to an insulating resin insulator 62 by resin molding.
An insulating layer is formed on the winding portion of the first substrate, and a pin 75 for press-fitting and fixing the printed circuit board 71 is formed on the printed circuit board side of the core 61.

With this configuration, the core parts 61a, 61b
Since the fastening of the core 61 and the insulation of the core 61 can be performed at the same time, the configuration is suitable for mass production with less labor required for manufacturing. Furthermore, resin integral molding takes advantage of the high degree of freedom in the shape of resin molding,
It is easy to have other functions.

Further, according to this configuration, when fixing the core 61, it is only necessary to press-fit the pin 75, and at the same time,
The core 61 can be positioned with respect to the printed board 71.

The motor of this embodiment is driven by a battery because it is a pager motor for mobile communication. For this reason, it is necessary to reliably start at a low voltage of about 1.2 to 3.3 V. Factors attributable to the starting voltage of the motor include:
There are a shaft loss, a cogging torque generated by an attractive force between the core and the magnet, a voltage drop in the drive circuit, and the like. In the present embodiment, the following measures are taken to reduce the cogging torque.

FIG. 33 shows a core 61, a back yoke 63,
FIG. 4 is a diagram schematically illustrating a relationship between rotor magnets 64. The angle α of the portion of the salient poles 67 a to 67 c of the core 61 shown in FIG. 33 facing the rotor magnet 64 and the angle β of the back yoke 63 have a close relationship with the cogging torque.

FIG. 34 is a diagram showing the relationship between α and cogging torque when the angle α is changed with α = β. As shown in FIG. 34, the cogging torque is minimized at two points around 90 ° and around 150 °. Therefore, α is 90 ° or 1
By setting the angle around 50 °, the cogging torque can be suppressed. However, when the angle is set to 90 °, the magnetic efficiency is deteriorated because the leakage of the magnetic flux increases, and the case where the angle is set to 150 ° is more excellent.

Further, it has been shown above that the angle α of the salient poles 67a to 67c of the core 61 and the angle β of the back yoke 63 are closely related to the cogging torque.
Is different from the cogging torque in the same manner.

FIG. 35 is a diagram showing an example in which α-β is changed while α + β is kept constant. As shown in FIG. 35, the cogging torque is minimized near ± 30 ° and ± 90 °. However, when the angle is ± 90 °, the magnetic efficiency is poor due to poor balance on both sides, and the case where the angle is ± 30 ° is more excellent.

In this embodiment, the case where the core and the back yoke are used is shown. However, when two cores are used as in the first to third embodiments, the difference between the angles of the two cores is similarly ± 30.
By setting 得, the same effect can be obtained.

Next, weights 72 and 73 for imbalance are provided.
Will be described.

Since the present embodiment relates to a pager motor for mobile communication, in order to extract vibration from the motor, centrifugation of the weights 72, 73 is provided by providing weights 72, 73 whose centers of gravity are separated from the axis. It utilizes the energy transmitted to the stator side.

As shown in FIG. 36, the rotor magnet 64
, The unbalanced weights 72 and 73 are fixed by caulking to both ends of the shaft 65, and the unbalanced weights are fixed to both ends of the rotor magnet 64 using adhesives 72 a and 73 a. 7
2, 73 are adhered and fixed.

FIG. 37 is a diagram showing the relationship between the center of gravity of the unbalance weight 72 (73) with respect to the bearings 66a and 66b. FIG. 37 (a) shows that the center of gravity G of the weight 72 (73) for unbalance is set to the two bearings 66a and 66.
37 (b), the center of gravity G of the unbalance weight 72 (73) is connected to the two bearings 66.
a and 66b. Double bearing 66a, 6
When the distance between the bearings 6b is L ₁ , the axial distance from one bearing 66a to the center of gravity G is L ₂ with the direction of the other bearing 66b being positive, and the load due to centrifugal force is F, bearings 66a and 66b respectively. The loads F ₆ and F ₇ applied to
As shown in (Equation 25).

F ₆ = ((L ₁ −L ₂ ) / L ₁ ) · F F ₇ = (L ₂ / L ₁ ) · F (25) Here, as shown in FIG. The center of gravity G of the unbalance weight 72 (73) is connected to the two bearings 66a and 66b.
F ₇ becomes negative if the installed outside. This indicates that the direction of the load is reversed.

Generally, the bearing loss torque _Tr is
The load is approximated as f (Expression 26) as f.

T _r = T _c + kf (26) Here, T _c is a constant component regardless of the load, and k is a proportional constant.

Therefore, the total loss torque of the two bearings 66a and 66b is as shown in (Equation 27).

T _r = T _c + k (| F ₆ | + | F ₇ |) (27) FIG. 38 is a diagram showing the relationship between the loss torque T _n and L ₁ and L ₂ .

[0139] Two bearings 66a the center of gravity G of FIG. 38 from L ₂ is 0 and the weight 72 for clogging imbalance between L ₁ (73), when installed between 66b is less loss torque T _r.

Further, considering the life of the bearing, the bearing 6
It is desirable that the loads F ₆ and F ₇ applied to the respective 6a and 66b be smaller, respectively. In the case shown in (Equation 28), that is, the imbalance weight 72 (73)
Two bearings 66a the center of gravity G of, when installed in the middle between 66b, F ₆ and F ₇ are advantageous in terms of both reduced lifetime.

L ₂ = L _1/2 (28) In FIG. 37, the weights 72 (7
Although the position of the center of gravity of 3) was considered, when two or more weights for imbalance are used as in the motor of the present embodiment,
What is necessary is just to consider the center of gravity G of the unbalance weight 72 (73). In the motor of this embodiment, the center of gravity G of the entire unbalance weight 72 (73) is
The motor is installed in the middle between 6a and 66b, and is a motor that is advantageous in both shaft loss and life.

In order to further reduce the shaft loss, reducing the diameter of the shaft 65 is a very effective means. However, when the shaft 65 is made thin, the deflection of the shaft 65 cannot be ignored, and problems such as contact with the rotor occur.

FIG. 39 shows a weight 72 for imbalance.
It is the figure which showed the load applied to the shaft 65 by (73). FIG. 39A shows an unbalance weight 72.
FIG. 39B shows the case where one (73) is used and the case where two unbalance weights 72 and 73 are used.

When the shaft 65 is considered to be a rigid body, FIG.
(A) and (b) of FIG. 39 are completely equivalent, but are slightly different when the deflection of the shaft 65 is considered.

As shown in FIG. 39 (a), when one weight 72 (73) for unbalance is used, the shaft 65 is used.
Is as shown in (Equation 29).

[0146] ^{_{δ = FL 1 3 / 48EI .........}} (29) where E is the modulus of longitudinal elasticity of the shaft, I is a cross-sectional second moment of the shaft. Similarly, when two unbalance weights 72 and 73 are used as shown in FIG. 39B, the deflection δ of the shaft 65 is from the bearings 66a and 66b to the unbalance weights 72 and 73 on one side. the axial distance, when L ₃ other bearing 66b, the direction of 66a as a positive, as shown in (equation 30).

[0147] ^{_{δ = (FL 3 2 (L}} 1 -L 3) 2) / 3L 1 EI ......... (30) FIG. 40 is a diagram showing the relationship between the deflection [delta] and L _3. In the figure, the dotted line shows the deflection of the shaft 65 when one weight is used for comparison.

As shown in FIG. 40, when L ₃ is 0, the deflection δ is 0.
This is the best but practically impossible because of the bearings 66a and 66b. Therefore, the smallest deflection δ is caused by the unbalance weights 72, 73 being mounted on the bearings 66a, 66.
This is the case where it is arranged closest to b.

In the motor according to the present embodiment, the weights 72 and 73 for imbalance are attached to both ends of the rotor magnet 64, so that the deflection δ of the shaft 65 is small, and the shaft loss is reduced by using the thinner shaft 65. Is being planned.

As described above, the motor according to the present embodiment uses the thin shaft 65 for reducing the shaft loss. However, when the shaft 65 is thin, the weights 72 and 73 for imbalance with respect to the shaft 65 and the rotor magnet are used. The mounting of 64 is disadvantageous in terms of fixing strength over thick shafts.

[0151] The caulking fixing, which is commonly used,
Taking the case of press-fitting and fixing as an example, the release strength F _n ,
The relationship shown in (Equation 31) exists between the rotation torque _Tn and the shaft diameter d.

F _n ∝d T _n ∝d ² (31) Accordingly, when the shaft 65 is thin, the rotational torque T _n is particularly large.
It is difficult to secure strength.

In particular, many rotor magnets 64 have lower mechanical strength than metal or the like, and it is more difficult to secure the strength.

Therefore, in the motor of this embodiment, the shaft 65 is penetrated by the rotor magnet 64, and the unbalanced weights 72, 73 are fixed to both ends of the magnet 64 of the shaft 65 by caulking. by securing the pull-out strength F _n for 65, further bonded and fixed to both end portions of the rotor magnet 64 to the weight 72 and 73 for imbalance, to ensure the rotational torque T _n for weights 72 and 73 of the rotor magnet 64 I have.

[0155] Since this embodiment is a pager motor for mobile communications, it is not necessary to take out the output shaft to the outside of the motor, the rotor magnet 64 weights for strength F _n and unbalanced loss relative to the shaft 65 72, 73 rotational torque T _n is not a problem if it is ensured against. The configuration of this embodiment is the rotor magnet 64, a configuration suitable for and pager motor obtained by minimally maintained rotational torque to the weight 72 and 73 for strength F _n and unbalanced loss with respect to the shaft.

In the present embodiment, the core 61 and the back yoke 63 are provided as a pair. However, it is also possible to adopt a configuration having only the core 61.

[0157]

According to the present invention, a motor having high reliability, high efficiency, and suitable for thinning can be provided.

[Brief description of the drawings]

1A and 1B show a pager motor for mobile communication according to a first embodiment of the present invention, wherein FIG.
(B) is a sectional view in the direction perpendicular to the axis.

FIG. 2 is a perspective view illustrating a magnetic pole positional relationship of a rotor magnet.

FIG. 3 is a model diagram illustrating an unbalance amount.

FIG. 4 is a perspective view showing a weight for imbalance.

5 shows an unbalanced relationship, (a) is a graph showing a relationship between D / d and g, (b) is a graph showing a relationship between D / d and A, and (c) is a graph showing D / d and centrifugation. It is a graph which shows the relationship of force F.

FIG. 6 is an enlarged sectional view of a pivot bearing.

FIG. 7 is a graph showing the relationship between r / r ₀ and P _max and T _p of the pivot bearing.

8A and 8B show a self-aligning bearing, in which FIG. 8A is a cross-sectional view of the upper end of the shaft, and FIG. 8B is a cross-sectional view of the lower end of the shaft.

FIG. 9 is a perspective view of an example of salient poles.

FIG. 10 is a perspective view of another example of salient poles.

FIG. 11 is a perspective view of yet another example of salient poles.

FIG. 12 is a sectional view of a metal powder molded product.

FIG. 13 is a sectional view of a forged salient pole.

FIG. 14 is an exploded perspective view illustrating the assembly of the motor.

15A and 15B show a pager motor for mobile communication according to a second embodiment of the present invention, wherein FIG.
(B) is a sectional view in the direction perpendicular to the axis.

FIG. 16 is a perspective view illustrating a magnetic pole position relationship of a rotor magnet.

FIG. 17 is an exploded perspective view illustrating the magnetic pole positioning of the rotor magnet.

FIG. 18 is a perspective view of another example illustrating magnetic pole positioning of a rotor magnet.

FIG. 19 is a perspective view of an example of salient poles.

FIG. 20 is a perspective view of a salient pole on which a coil is wound.

FIG. 21 is a perspective view of a salient pole to which a terminal plate is attached.

FIG. 22 is an exploded perspective view illustrating the assembly of the motor.

23A and 23B show a pager motor for mobile communication according to a third embodiment of the present invention, wherein FIG.
(B) is a sectional view in the direction perpendicular to the axis.

FIG. 24 is a perspective view of a rotor magnet on which a bearing bush is mounted.

FIG. 25 is a model diagram illustrating an imbalance amount.

FIG. 26 is a perspective view of a salient pole in which a coil is wound and a terminal plate is incorporated.

FIG. 27 is an exploded perspective view illustrating assembly of the motor.

FIG. 28 is a perspective view of a bracket.

FIG. 29 is a cross-sectional view of another example of a bracket.

30A and 30B show a pager motor for mobile communication according to a fourth embodiment of the present invention, wherein FIG.
(B) is a sectional view in the direction perpendicular to the axis.

FIG. 31 shows a configuration of a core, (a) is a side view thereof,
(B) is a plan view thereof.

FIG. 32 shows a configuration of a core and a resin insulator,
(A) is a front view, (b) is a side view, and (c) is a plan view.

FIG. 33 is a view schematically showing a relationship among a core, a back yoke, and a rotor magnet.

FIG. 34 is a view showing a relationship between an angle α and a cogging torque.

FIG. 35 is a diagram showing a relationship between angles α-β and cogging torque.

36A and 36B show a configuration of a rotor magnet, wherein FIG. 36A is a front view thereof, and FIG. 36B is a bottom view thereof.

37A and 37B show the relationship between the positions of the centers of gravity of the unbalance weights with respect to the bearings, FIG. 37A shows a case where the centers of gravity of the weights are installed outside the two bearings, and FIG. It is a figure showing the case where it is installed between bearings.

FIG. 38 is a diagram showing a relationship between loss torque and L ₁ and L ₂ .

39A and 39B show a load applied to a shaft by an unbalance weight, FIG. 39A is a diagram showing a case where one weight is used, and FIG. 39B is a diagram showing a case where two weights are used.

FIG. 40 is a diagram showing a relationship between shaft deflection δ and L ₃ .

FIG. 41 is a view showing a motor rotation principle of the present invention.

FIG. 42 is a diagram showing a voltage waveform of an induced voltage.

43A and 43B show a structure of a motor of Conventional Example 1, in which FIG. 43A is a partially cutaway sectional view, and FIG. 43B is a transverse sectional view thereof.

44 (a) and 44 (b) show the structure of a motor of Conventional Example 2, wherein FIG. 44 (a) is a plan view thereof, and FIG.

FIG. 45 is a cross-sectional view showing the structure of a motor of Conventional Example 3.

[Explanation of symbols]

1a, 1b, 1c, 2a, 2b, 2c, 67a, 67
b, 67c Salient pole 3, 64 Rotor magnet 3a, 3b, 3c, 64a, 64b, 64c Magnet 4, 65 Shaft 5, 6, 66a, 66b Bearing 7, 7a, 7b, 7c, 68 Coil 8a, 8b, 37a , 37b Spacer 9, 72, 73 Weight 10 Thrust plate 11, 12 Yoke plate 13, 14, 33, 37, 45, 46, 69, 70 Bracket 15, 34, 47, 71 Printed circuit board 16, 55 Drive IC 17, 58 , 74 seats 18, 19, 61 cores 22, 26, 30, 41 teeth 35 plate 36, 48, 52 terminal plate 38 low friction coating material 49, 50 bearing bush 49b, 50b bearing hole in bearing bush 51 metal piece 61a, 61b Core component 62 Resin insulator 63 Back yoke 75 Pin 90 Outside Body 90a short side 90b long side

────────────────────────────────────────────────── ─── Continued on the front page (72) Inventor Miyuki Furuya 1006 Kazuma Kadoma, Kadoma, Osaka Prefecture Matsushita Electric Industrial Co., Ltd. (56) References JP-A-7-46802 (JP, A) JP-A-7- 245928 (JP, A) JP-A-7-70606 (JP, A) JP-A-6-136404 (JP, A) JP-A-7-75267 (JP, A) JP-A-60-131039 (JP, A) JP-A-6-1133491 (JP, A) JP-A-5-49192 (JP, A) JP-A-1-278242 (JP, A) JP-A-60-167637 (JP, A) JP-A-3-226258 (JP, A) JP-A-3-139150 (JP, A) JP-A-59-92757 (JP, A) JP-A-6-261506 (JP, A) JP-A-6-153428 (JP, A) JP-A-61-199446 (JP, A) JP-A-2-214452 (JP, A) JP-A-62-114456 (JP, A) ) Fully open 1979-37704 (JP, U) Fully open 1979-47570 (JP, U) Fully open 1979-95104 (JP, U) Fully open 6-31359 (JP, U) Fully open 4 17675 (JP, U) Japanese Utility Model 3-70072 (JP, U) Japanese Utility Model Utility Model 57-1082 (JP, U) Japanese Utility Model Utility Model 60-59753 (JP, U) Japanese Utility Model Utility Model 62-51965 (JP, U) Hikaru 1-64964 (JP, U) Jiko 31-15517 (JP, Y1) WO 94/5074 (WO, A1) (58) Fields investigated (Int. Cl. ⁷ , DB name) H02K 29 / 00 H02K 16/00 H02K 21/14

Claims (5)

(57) [Claims] 1. A rotor magnet having K-stage (K is an integer of 2 or more) magnet bodies in which the magnetization positions of the N and S poles in the circumferential direction are shifted from each other in each stage, and a rotor magnet corresponding to each stage. A core having K coil-wound salient poles arranged in a row in parallel with the axial direction of the rotor magnet in a row, and a pair of long sides opposed to a pair of long sides having a cross-section perpendicular to the axial direction of the rotor magnet. A coil having a flat outer casing made of short sides, a rotor magnet penetrating the center of the outer casing, a core disposed on at least one short side of the outer casing , and a coil wound around a salient pole. Terminal leads to the printed circuit board
This printed circuit board is at least one of
Drive circuit elements mounted on this printed circuit board
Brushless motor, characterized in that it is. 2. Magnetization positions of N and S poles in the circumferential direction at each stage
The magnets of K stages (K is an integer of 2 or more)
A rotor magnet with a magnet body and coil-wound salient poles
Core with K pieces in a single row parallel to the axial direction of the magnet
And the cross section perpendicular to the axial direction of the rotor magnet faces
Outside a flat shape consisting of a pair of short sides facing a pair of long sides
The rotor magnet penetrates the center of the exterior body,
A core is provided on each of the two short sides, and is connected to three surfaces of the pair of short sides and one long side of the exterior body.
Flexible printed circuit board is arranged to continue
A brushless motor. 3. A metal piece is integrally molded with each salient pole.
The terminal plate was inserted and fixed and wound around the teeth of the salient pole
With the end of the coil connected to the metal piece,
The brushless motor according to claim 1, wherein the metal piece and the printed board are electrically connected . 4. A terminal of a coil is connected to a metal piece by thermal pressure welding.
4. The brushless motor according to claim 3 , wherein the brushless motor is continuously processed . 5. The method according to claim 5, wherein the metal piece and the printed circuit board are pressed by heat.
5. The brushless motor according to claim 3, which is connected .