JPH10201214A - motor - Google Patents

Abstract

(57) [Summary] (with correction) [Problem] A first yoke and a second yoke which have good workability and high strength.
It has a yoke and provides a low-cost motor. SOLUTION: A first coil which is equally divided in a circumferential direction and is arranged concentrically with a rotor made of a cylindrical permanent magnet 1 in which different poles are alternately magnetized and sandwiches the rotor in the axial direction. 3 and a first yoke 5 and a second yoke 6 which are inserted into the respective inner diameters of the second coil 4 and are opposed to the rotor with a gap therebetween, and each of which has one end connected to the first or second yoke. And third and fourth yokes 8 and 9 which cover the outer diameter of the first or second coil and have a magnetic pole part whose other end faces a part of the outer peripheral part of the rotor. A connecting member made of a non-magnetic material for concentrically holding the yoke; and a section of the first yoke or the second yoke in a portion facing the inner diameter portion of the rotor in a direction perpendicular to the axis being outside. Alternate between the range where the diameter is large and the range where the outside diameter is small Arrange them.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art As a small cylindrical step motor,
There is one shown in FIG. A stator coil 105 is concentrically wound around the bobbin 101, and the bobbin 101 is fixedly held by two stator yokes 106 in the axial direction, and the stator yoke 106 has stator teeth 106a in the circumferential direction of the inner diameter surface of the bobbin 101. The stators 106 b are alternately arranged, and the stator yoke 106 integrated with the stator teeth 106 a or 106 b is fixed to the case 103 to form the stator 102.

One of two cases 103 has a flange 1
15 and the bearing 108 are fixed, and another bearing 108 is fixed to the other case 103. Rotor 109
The rotor magnet 111 is fixed to the rotor shaft 110, forms a radial gap with the stator yoke 106 a of the stator 102, and is both supported by the bearing 108.

[0004]

However, in the above conventional example, the case 103 and the bobbin 10
1. Since the stator coil 105, the stator yoke 106 and the like are arranged concentrically, there is a disadvantage that the outer diameter of the motor becomes large. Further, the magnetic flux generated by energizing the stator coil 105 mainly passes between the end faces of the stator teeth 106a and 106b, and thus does not effectively act on the rotor magnet 111. Therefore, there is a disadvantage that the output does not increase. The present applicant has proposed a motor which has solved the above-mentioned drawbacks of the conventional example in Japanese Patent Application Laid-Open No. 8-186672. It is described below.

[0005] A rotor made of a cylindrical permanent magnet equally divided in the circumferential direction and having different poles alternately magnetized, and a first rotor arranged concentrically with the rotor and sandwiching the rotor in the axial direction. And a first yoke made of a soft magnetic material inserted into the inner diameter of the first coil and facing the inner diameter portion of the rotor with a gap therebetween. A second yoke, which is inserted and is made of a soft magnetic material facing the inside of the rotor with a gap between the inner diameters of the rotor, one end connected to the first yoke and covering an outer diameter of the first coil; A third yoke having a magnetic pole portion whose end faces the outer peripheral portion of the rotor, one end connected to the second yoke and covering the outer peripheral portion of the second coil, and the other end having an outer peripheral portion of the rotor A fourth yoke having a magnetic pole portion facing the portion; Is made of a connecting member made of non-magnetic material for holding said third yoke and said fourth yoke concentrically.

FIGS. 8 and 9 show an embodiment thereof. Reference numeral 1 denotes a cylindrical permanent magnet, a first magnetized layer composed of 1a, 1b, 1c, and 1d in which the circumference is divided into four and S and N poles are alternately magnetized; Split to S pole N
It comprises a second magnetized layer composed of 1e, 1f, 1g, and 1h whose poles are alternately magnetized. The phases of the first magnetized layer and the second magnetized layer are magnetized with a shift of 45 °.

[0007] The first magnetized layer 1a, 1c and the second magnetized layer 1e, 1g are magnetized so that the outer peripheral surface becomes an S pole and the inner peripheral surface becomes an N pole. 1b and 1d of the magnetic layer and the second
The magnetized layers are magnetized such that the outer peripheral surfaces of 1f and 1h become N poles and the inner peripheral surface becomes S poles.

Reference numeral 2 denotes a rotating shaft to which a permanent magnet 1 is fixed. The rotating shaft 2 and the permanent magnet 1 constitute a rotor. Reference numerals 3 and 4 denote coils, which are arranged concentrically with the permanent magnet 1 and at positions sandwiching the permanent magnet 1 in the axial direction. Reference numeral 15 denotes a first yoke made of a soft magnetic material.
15d portion inserted into the inner diameter portion 3a of the permanent magnet 1
Has the teeth 15b and 15c facing the inner diameter of the first magnetized layer. The teeth 15b and 15c are formed so as to be out of phase by 180 ° with respect to the poles of the first magnetized layer. The hole 15a of the first yoke and the portion 2a of the rotating shaft 2 are rotatably fitted.

Reference numeral 16 denotes a second yoke made of a soft magnetic material.
A 16d portion inserted into the inner diameter portion 4a of the coil 4, a tooth 16b facing the inner diameter portion of the second magnetized layer of the permanent magnet 1,
16c. The teeth 16b and 16c are formed so as to be out of phase with each other by 180 ° so as to have the same phase with respect to the pole of the second magnetized layer. The hole 16a of the second yoke 16 and the portion 2b of the rotating shaft 2 are rotatably fitted.

The teeth 15b and 15c of the first yoke 15 and the teeth 16b and 16c of the second yoke 16 are in the same phase, that is, located at positions opposing each other in the axial direction.

Reference numeral 8 denotes a first outer yoke made of a soft magnetic material, and the teeth 8a and 8b are used as the teeth 15b and 15c of the first yoke 15.
Are formed at positions sandwiching the first magnetized layer of the permanent magnet 1. 9 is a second outer yoke made of a soft magnetic material,
The teeth 9a, 9b are the teeth 16b, 16c of the second yoke 16,
The permanent magnet 1 is formed at a position sandwiching the second magnetized layer.

Reference numeral 10 denotes a connecting ring made of a non-magnetic material, and the teeth 8a, 8 of the first outer yoke 8 are provided in the grooves 10a, 10b.
b fits into the teeth 10 of the second outer yoke 9 in the grooves 10c and 10d.
The first and second outer yokes 8 and 9 are fixed to each other by a known method such as bonding. The first outer yoke 8 and the second outer yoke 9 are connected to 10 e of the connecting ring 10,
It is fixed at a predetermined interval by a 10f portion. The teeth 8a and 8b of the first outer yoke 8 are arranged so as to face the teeth 9a and 9b of the second outer yoke 9. Also, the first
As shown in FIG. 9, one end of the outer yoke 8 is
, And covers the outer diameter portion of the coil 3, and the other ends of the teeth 8 a and 8 b face the outer peripheral portion of the permanent magnet 1 with a predetermined gap. As shown in FIG. 9, the second outer yoke 9 has one end connected to the second yoke 16 and covers the outer diameter of the coil 4, and the other ends 9 a and 9 b of the permanent magnet 1
Are opposed to each other with a predetermined gap.

According to these constructions, the output is high and the outer diameter of the motor can be made small. However, since the diameters of the first yoke 15 and the second yoke 16 are small, the teeth 15b, In the case where the processing of 15c and the teeth 16b and 16c is performed by pressing, the processing becomes difficult due to problems such as the strength of the mold and the discharge of cutting chips. Also, the strength of the teeth is weak,
Deformation can occur during assembly.

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a motor having good workability and strong first and second yokes and low cost.

[0015]

In order to achieve the above object, a motor according to the present invention is characterized in that a cross section of the first yoke or the second yoke at a portion facing an inner diameter portion of the rotor in a direction perpendicular to an axis. It is characterized in that the shape is formed by alternately arranging a range in which the outer diameter is large and a range in which the outer diameter is small. In the above configuration, the first yoke and the second yoke have good workability and high strength due to the cross-sectional shape.

[0016]

【Example】

(Embodiment 1) FIGS. 1 to 4 show the first embodiment. Reference numeral 1 denotes a cylindrical permanent magnet, a first magnetized layer composed of 1a, 1b, 1c, and 1d in which the circumference is divided into four and S and N poles are alternately magnetized; Split to S pole N
It comprises a second magnetized layer composed of 1e, 1f, 1g, and 1h whose poles are alternately magnetized. The phases of the first magnetized layer and the second magnetized layer are magnetized with a phase shift of 45 °.

The first and second magnetized layers 1a, 1c and 1e, 1g of the second magnetized layer are magnetized so that the outer peripheral surface is an S pole and the inner peripheral surface is an N pole. 1b and 1d of the magnetic layer and the second
The magnetized layers are magnetized such that the outer peripheral surfaces of 1f and 1h become N poles and the inner peripheral surface becomes S poles.

Reference numeral 2 denotes a rotating shaft to which the permanent magnet 1 is fixed. The rotating shaft 2 and the permanent magnet 1 constitute a rotor. Reference numerals 3 and 4 denote coils, which are arranged concentrically with the permanent magnet 1 and at positions sandwiching the permanent magnet 1 in the axial direction. Reference numeral 5 denotes a first yoke made of a soft magnetic material, which has a 5d portion inserted into the inner diameter portion 3a of the coil 3 and a magnetic pole portion facing the inner diameter portion of the first magnetized layer of the permanent magnet 1.

As shown in FIG. 4, the magnetic pole portion has a large outer diameter 5b, 5c in a cross section perpendicular to the axis.
The portions and the portions 5e and 5f having small outer diameters are formed alternately. The portions 5b and 5c correspond to the poles of the first magnetized layer.
They are formed to have the same phase. That is, the portion 5b and the portion 5c are positioned 180 ° from each other. First
The hole 5a of the yoke and the portion 2a of the rotating shaft 2 are rotatably fitted.

Reference numeral 6 denotes a second yoke made of a soft magnetic material, having a 6d portion inserted into the inner diameter portion 4a of the coil 4, and a magnetic pole portion facing the inner diameter portion of the second magnetized layer of the permanent magnet 1. .
The magnetic pole portion has a large outer diameter 6 like the first yoke 5.
Parts b and 6c and parts 6e and 6f having small outer diameters are formed alternately. The portions 6b and 6c are formed to have the same phase with respect to the pole of the second magnetized layer. That is,
The portions 6b and 6c are shifted from each other by 180 °. The hole 6a of the second yoke and the portion 2b of the rotating shaft 2 are rotatably fitted. The large diameter portions 5b and 5c of the first yoke 5 and the large diameter portions 6b and 6c of the second yoke 6 are in the same phase, that is, at positions facing each other in the axial direction.

Reference numeral 8 denotes a first outer yoke made of a soft magnetic material. The teeth 8a and 8b are formed at positions where the 5b and 5c portions of the first yoke 5 and the first magnetized layer of the permanent magnet 1 are sandwiched. I have.
Reference numeral 9 denotes a second outer yoke made of a soft magnetic material.
9 b is formed at a position sandwiching the 6 b portion and 6 c portion of the second yoke 6 and the second magnetized layer of the permanent magnet 1.

Numeral 10 denotes a connecting ring made of a non-magnetic material, and the teeth 8a, 8b of the first outer yoke 8 are provided in the grooves 10a, 10b.
Are fitted, and the teeth 9a of the second outer yoke are inserted into the grooves 10c and 10d.
9b are fitted, and the first outer yoke 8 and the second outer yoke 9 are fixed by a known method such as bonding. First outer yoke 8
And the second outer yoke 9 are connected to the connecting ring 10 by 10e, 10f.
The parts are fixed at predetermined intervals. The teeth 8a and 8b of the first outer yoke 8 are
a, 9b.

As shown in FIG. 2, the first outer yoke 8 has one end connected to the first yoke 5, covers the outer diameter of the coil 3, and the other ends 8a and 8b have permanent magnets. 1 with a predetermined gap. As shown in FIG. 2, the second outer yoke 9 has one end connected to the second yoke 6, covers the outer diameter of the coil 4, and has a tooth 9 at the other end.
a, 9b face the outer peripheral portion of the permanent magnet 1 with a predetermined gap.

FIG. 2 is a cross-sectional view after assembly. FIGS. 3A, 3B, 3C, and 3D show cross sections taken along the line AA in FIG. 2, and FIGS. f), (g) and (h) are shown in FIG.
2 shows a BB cross section. 3 (a) and 3 (e) are cross-sectional views at the same point, FIGS. 3 (b) and 3 (f) are cross-sectional views at the same point, and FIGS. g) is a cross-sectional view at the same time, and FIGS. 3D and 3H are cross-sectional views at the same time. FIG. 3 (a),
From the state of (e), the coils 3 and 4 are energized, and the magnetic pole portions 5b, 5c, 5d, and 5e of the first yoke 5
b and 5c, the portions 8a and 8b of the third yoke 8
And the magnetic pole portions 6b, 6c, 6d, 6e of the second yoke 6 are S
When the 9a, 9b portion of the fourth yoke 9 facing the poles, 6b, 6c is excited to the N pole, the permanent magnet 1 rotates 45 ° to the left,
The state shown in FIGS. 3B and 3F is obtained.

Of the magnetic pole portions of the first yoke 5, the smaller diameter 5
d and 5e are farther from the inner peripheral surface of the first magnetized layer than 5b and 5c, and the polarity generated there hardly acts on the first magnetized layer, and the generated driving force Has little effect. Accordingly, the first yoke 5 can perform the same operation as the conventional first yoke 15 shown in FIGS. 8 and 9 having only the teeth 15b and 15c. When the first yoke 5 is manufactured by press working, since no chips are generated, it is not necessary to consider the discharge of the chips and the manufacturing is easy. Also, 5b, 5d, 5c,
5e is connected, so the strength is high,
There is no risk of deformation during assembly.

The same applies to the second yoke 6, and the smaller diameters 6d and 6e of the magnetic pole portions of the second yoke 6 are further away from the inner peripheral surface of the second magnetized layer as compared with 6b and 6c. Therefore, the polarity generated there hardly acts on the second magnetized layer, and hardly affects the generated driving force. Therefore, the second yoke 6 is the same as the conventional second yoke 1 shown in FIGS.
The same operation can be performed as when only the six teeth 16b and 16c are used. When the second yoke 6 is manufactured by press working, since no chips are generated, it is not necessary to consider the discharge of the chips and the manufacturing is easy. Further, since the structure is such that 6b, 6d, 6c, and 6e are connected over the entire circumference, the strength is high, and there is no possibility of deformation during assembly.

Next, the power supply to the coil 3 is reversed,
The magnetic pole portions 5b, 5c, 5d, and 5e of the yoke 5 are
The 8a and 8b portions of the third yoke opposed to b and 5c are S poles,
The magnetic pole portions 6b, 6c, 6d, 6e of the second yoke 6 are S poles,
When the portions 9a and 9b of the fourth yoke opposed to 6b and 6c are excited to the N pole, the permanent magnet 1 further rotates counterclockwise by 45 °, and the state shown in FIGS. 3 (c) and 3 (g) is obtained.

Next, the power supply to the coil 4 is reversed,
The magnetic pole portions 6b, 6c, 6d and 6e of the yoke 6 are
When the portions 9a and 9b of the fourth yoke opposed to b and 6c are excited to the S pole, the permanent magnet 1 further rotates counterclockwise by 45 °. As described above, by sequentially switching the energizing direction to the coil 3 and the coil 4, the permanent magnet 1 and the rotating shaft 2 are switched.
Is rotated to a position corresponding to the energizing phase.

(Embodiment 2) FIGS. 5 and 6 are views showing Embodiment 2. FIG. FIG. 5 is a perspective view of the first yoke, in which a magnetic pole portion facing the inner peripheral surface of the first magnetized layer has an ellipse 5g (a major axis is A, and a minor axis is B) in a section perpendicular to the axis. , A> B)
It is configured so that FIG. 6 shows the first yoke 6.
FIG. 3 is a cross-sectional view of the motor in which the motor is incorporated. The first yoke 6 is arranged such that the major axis A faces a position facing the teeth 8a, 8b of the first outer yoke 8. Similarly, although not shown, at least the outer peripheral surface of the magnetic pole portion of the second yoke has an elliptical shape with a major axis A and a minor axis B (A> B).
The long axis is arranged so as to face a position facing the teeth 9a and 9b of the second outer yoke.

Since the outer peripheral surfaces of the first yoke 5 and the second yoke 6 in the short axis direction are separated from the circumferential surfaces of the first and second magnetized layers, respectively, 5e of the first embodiment is used. , 5f, 6e,
As in 6f, the output of the motor is not adversely affected. Further, since the magnetic pole portions of the first yoke and the second yoke are connected over the entire circumference, the strength is large, and no cutting powder is generated at the time of press working, so that the workability is good.

[0031]

As described above, according to the present invention,
Since it is possible to form a yoke shape having good workability and high strength, it is possible to provide a low-cost motor.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view illustrating a configuration of main components of a first embodiment.

FIG. 2 is a cross-sectional view of the first embodiment.

FIG. 3 is a cross-sectional view of the first embodiment.

FIG. 4 is a perspective view of a first yoke according to the first embodiment.

FIG. 5 is a sectional view of a second embodiment.

FIG. 6 is a perspective view of a first yoke according to the second embodiment.

FIG. 7 is a sectional view showing a conventional motor structure.

FIG. 8 is a configuration diagram of a conventional motor.

FIG. 9 is a sectional view of a conventional motor.

[Description of Signs] 1 Permanent magnet 2 Rotary shaft 3 Coil 4 Coil 5 First yoke 6 Second yoke 8 First outer yoke 9 Second outer yoke 10 Connecting rings 5b, 5c Magnetic pole part with small diameter 5g Magnetic pole part with elliptical cross section

Claims (2)

[Claims] 1. A rotor made of a cylindrical permanent magnet equally divided in a circumferential direction and having different poles alternately magnetized, and disposed at a position concentric with the rotor and sandwiching the rotor in the axial direction. A first coil, a second coil, a first yoke made of a soft magnetic material inserted into the inner diameter of the first coil and opposed to the inner diameter of the rotor with a gap therebetween; A second soft magnetic material inserted into the inner diameter and opposed to the rotor with a gap between the inner diameters of the rotor;
And a third yoke having one end connected to the first yoke and covering the outer diameter of the first coil, and the other end having a magnetic pole portion facing a part of the outer peripheral portion of the rotor. A fourth yoke having one end connected to the second yoke and covering the outer peripheral portion of the second coil, and the other end having a magnetic pole portion facing a part of the outer peripheral portion of the rotor; A portion of the first yoke or the second yoke facing the inner diameter portion of the rotor, comprising a connection member made of a non-magnetic material for holding the third yoke and the fourth yoke concentrically; A motor characterized in that the cross-sectional shape in the direction perpendicular to the axis is formed by alternately arranging a range in which the outer diameter is large and a range in which the outer diameter is small. 2. A motor according to claim 1, wherein the first yoke or the second yoke has a major axis A, a minor axis, and a cross section perpendicular to the axis at a portion facing the inner diameter of the rotor. A yoke having an elliptical shape consisting of B (A> B), wherein the major axis A is configured to be located opposite to the magnetic poles of the third yoke and the fourth yoke.