JP2001186694A - Stator for electric motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stator for electric motors that interacts with a rotor magnetically. SOLUTION: A first yoke 20 having a plurality of circumferential wall members 21 that are arranged in a circumferential shape to receive a rotor 3, and a radius wall member 23 that projects radially from the outer-periphery surface of the circumferential wall members 21; a cylindrical second yoke 30 that is provided separately from the first yoke 20 and is arranged so that it surrounds the first yoke 20, and has an inner-periphery surface in that the terminal of the radius wall member 23 of the first yoke 20 touches; and a plurality of excitation coils 28 that are wound around the radius wall members 23 of the first yoke 20; are included. As a result, a coil is easily wound around the first yoke 20 of a stator 9, thus improving working efficiency, reducing torque change being generated when an electric motor is operated, and hence reducing vibration and noise and improving the performance of the electric motor.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a motor, and more particularly, to a stator for a motor.

[0002]

2. Description of the Related Art An electric motor is a device for converting electrical energy into mechanical energy. Generally, a motor has a stator having an exciting coil for generating a magnetic force, and the stator is magnetically interacted with the stator. And a rotor that rotates within.

FIG. 7 is an exploded perspective view of a conventional motor stator and rotor, and FIG. 8 is a plan view of FIG. As shown in these drawings, the conventional electric motor includes the rotor 103
And a stator 109 that receives the rotor 103.

The rotor 103 has a cylindrical shape and is formed by laminating many core plates (not shown). Rotor 10
A rotation shaft hole 105 to which a rotation shaft (not shown) for transmitting the rotation force of the rotor 103 to the outside is formed at the center of 3. On the outer peripheral surface of the rotor 103, a permanent magnet 107 that magnetically interacts with the stator 109 is mounted.

The stator 109 has a cylindrical first yoke portion 1.
13, a plurality of second yoke portions 111 radially extended at equal intervals from the inner peripheral surface of the first yoke portion 113, and an exciting coil 117 wound around the second yoke portion 111. Each second yoke portion 111 includes a radial wall member 111a extending radially from the inner peripheral surface of the first yoke portion 113, a circumferential wall member 111b extending circumferentially from an inner end of the radial wall member 111a, and , Consists of Excitation coil 1
Reference numeral 17 is wound vertically on the radial wall member 111a of the second yoke portion 111.

With such a configuration, when power is supplied to the motor from a power supply device (not shown), the stator 109
Excitation coil 1 wound around second yoke portion 111
An electric current flows through 17, thereby generating a magnetic field. At this time, since the plurality of second yoke portions 111 are arranged in the radial direction and form a circular shape as a whole, a rotating magnetic flux is generated. Thus, the rotor 103 of the electric motor rotates by the rotational force of the rotating magnetic flux.

FIG. 9 is a graph showing a torque distribution of an electric motor using a conventional stator, and shows a torque change according to a rotation time in an arbitrarily selected rotation section. Here, the vertical axis indicates torque, and the horizontal axis indicates time.

FIG. 10 is a graph showing the distribution of the magnetic flux density of a motor using a conventional stator, and shows the magnetic flux density of the rotor 103 with respect to a specific rotation time when the rotor 103 rotates. is there. Here, the horizontal axis indicates the rotation angle, and the vertical axis indicates the magnetic flux density. Further, in this graph, since the directions of the N pole and the S pole of the permanent magnet 107 mounted for generating the rotating force on the rotor 103 are opposite, one of the magnetic flux densities is indicated by a negative sign (-). It is. FIG.
0 shows both a graph (A) showing a normal state and a graph (B) showing a magnitude state. Here, a normal state and a magnitude state are shown separately by different forms and installation methods of the magnets.

However, in such a conventional motor, it is not easy to wind up the exciting coil 117 in a narrow space because the second yoke portion 111 protrudes from the first yoke portion 113 toward the rotor 103. Was. Further, the circumferential wall member 111b of the second yoke portion 111 is
Since the end portion 11a is formed so as to protrude along the circumferential direction, a bobbin could not be used to wind up the exciting coil 117.

Further, in such a conventional motor, since a gap is formed between the circumferential wall members 111b of the second yoke portion 111, the torque generated when the motor operates is as shown in FIG. 5 shows a waveform that repeats rising and falling, and the rising width and the falling width are not constant.

As shown in FIG. 10, the range of change between the maximum value and the minimum value of the magnetic flux density is relatively large, the magnetic flux density fluctuates drastically, the torque ripple is large, and the noise and vibration are increased. However, there is a disadvantage that the efficiency of the electric motor may be reduced.

[0012]

SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a stator for an electric motor in which an exciting coil can be easily wound around a second yoke portion of the stator and a change in magnetic flux density due to the exciting coil can be reduced. To provide.

[0013]

SUMMARY OF THE INVENTION According to the present invention, there is provided, in accordance with the present invention, a motor stator that magnetically interacts with a rotor, wherein the plurality of circumferential walls are arranged circumferentially to receive the rotor. A first yoke portion having a member and a radial wall member radially protruding from an outer peripheral surface of the circumferential wall member; provided separately from the first yoke portion and arranged so as to surround the first yoke portion; A second cylindrical yoke having an inner peripheral surface in contact with a distal end of the radial wall member of the first yoke;
And a plurality of excitation coils wound around a radial wall member of the first yoke portion.

Here, it is preferable that the bobbin further includes a bobbin coupled to the radial wall member of the first yoke portion, and the exciting coil is wound around the bobbin.

[0015] The first yoke portion may further include a connecting member provided between the circumferential wall members, the connecting member being thinner than the circumferential wall members and forming a depression between the circumferential wall members. Is preferred.

A meshing groove is formed at one of the end of the radial wall member of the first yoke portion and the inner peripheral surface of the second yoke portion, and the other is formed with the meshing groove. It is preferable that an extension protrusion which is mutually connected to the groove is formed.

Further, according to the present invention, there is provided a motor stator which magnetically interacts with a rotor, comprising: a cylindrical cylinder member; and a plurality of radial walls protruding from an inner peripheral surface of the cylinder member. A second yoke portion having a plurality of circumferential wall members disposed concentrically with the first yoke portion inside the first yoke portion and in contact with an end portion of the radial wall member. The present invention is also achieved by a motor stator, comprising: a yoke portion; and a plurality of excitation coils wound around a radial wall member of the first yoke portion.

Here, it is preferable that the bobbin further includes a bobbin coupled to the radial wall member of the first yoke portion, and the exciting coil is wound around the bobbin.

Further, the second yoke portion may further include a connecting member provided between the circumferential wall members, the connecting member having a thickness smaller than that of the circumferential wall members and forming a depression between the circumferential wall members. Is preferred.

An engaging groove is formed on one of the end of the radial wall member of the first yoke portion and the outer peripheral surface of the circumferential wall member of the second yoke portion, and the other is provided with the other. It is effective that the extension protrusion is formed to be mutually connected with the meshing groove.

[0021]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings. FIG. 1 is an exploded perspective view of a motor stator and a rotor according to an embodiment of the present invention, and FIG. 2 is a plan view of FIG. The electric motor according to the present invention includes a rotor 3 and a stator 9 that receives the rotor 3.

The rotor 3 is formed in a cylindrical shape, and is formed by laminating many core plates (not shown). At the center of the rotor 3 is a rotating shaft (not shown) for transmitting the rotating force of the rotor 3 to the outside.
Is formed with the rotating shaft hole 5 to which the. Permanent magnet 7 magnetically interacting with stator 9 is provided on the outer peripheral surface of rotor 3.
Is installed. In the present embodiment, an arc-shaped permanent magnet
Twelve are mounted so that the N pole and the S pole are alternately arranged.

The stator 9 includes a first yoke part 20 for receiving the rotor 3 and a cylindrical second yoke part 30 surrounding the first yoke part 20. The first yoke part 20 is the second yoke part 3
0, a plurality of circumferential wall members 21 concentrically arranged, a plurality of radial wall members 23 protruding from the outer peripheral surface of the circumferential wall member 21, and a circumferential wall member 2 formed between the circumferential wall members 21.
A plurality of connecting members 27 forming a cylinder together with one; a plurality of extension protrusions 25 formed at the end of the radial wall member 23;
Having. The thickness of the connecting member 27 is thinner than the thickness of the circumferential wall member 21, and a depression 27 a is formed between the circumferential wall members 21. The depressed portion 27 a is necessary for using magnetic characteristics in which a magnetic force is concentrated at the end of the circumferential wall member 27.

On the inner peripheral surface of the second yoke portion 30, there is formed a vertical engagement groove 31 corresponding to the extension protrusion 25 of the first yoke portion 20. The thickness of the extension protrusion 25 is formed smaller than the thickness of the radial wall member 23, and the width of the engagement groove 31 is formed so as to match the thickness of the extension protrusion 25.

A bobbin is connected to the radial wall member 23 of the first yoke portion 20, and an exciting coil 28 for generating a magnetic force is wound on the bobbin 29.

FIG. 3 is an exploded perspective view of a motor stator and a rotor according to another embodiment of the present invention, and FIG. 4 is a plan view of FIG. As shown in FIG. 3 and FIG.
The first yoke part 40 and the first yoke part 4 are substantially cylindrical.
0, and a second yoke part 50 arranged concentrically with the first yoke part 40. The first yoke portion 40 is formed at a distal end of the cylinder member 41, a radial wall member 43 extending in a radial direction from an inner peripheral surface of the cylinder member 41, and has a thickness greater than that of the radial wall member 43. Thin extension protrusion 4
And 5.

The second yoke portion 50 has a plurality of circumferential wall members 51 arranged in the circumferential direction, and a plurality of connecting members 53 formed between the circumferential wall members 51. Circumferential wall member 51
A groove 51a is formed on the outer peripheral surface of the first yoke portion 40 at a position corresponding to the extension protrusion 45 so as to receive the extension protrusion 45.

The thickness of the connecting member 53 of the second yoke portion 50 is smaller than the thickness of the peripheral wall member 51,
A depression 53a is formed therebetween. This depression 53a
Is necessary to use the magnetic characteristic in which the magnetic force is concentrated at the end of the circumferential wall member 51 as in the above-described embodiment.

The radial wall member 43 of the first yoke portion 40 includes
A bobbin 49 is connected, and an exciting coil 48 for generating a magnetic force is wound on the bobbin 49.

In the embodiment of the present invention, the bobbins 29 and 49 in which the exciting coils 28 and 48 are wound in advance on the radial wall members 23 and 43 of the first yoke portions 20 and 40 can be assembled. The winding operation of the exciting coils 28 and 48 is very easily performed. Also, when the first yoke portions 20 and 40 and the second yoke portions 30 and 50 are connected, the extension protrusions 2 formed on the first yoke portions 20 and 40 are formed.
Since the engagement grooves 31 and 51a of the second yoke portions 30 and 50 engage with each other, the connection is firmly performed.

FIG. 5 is a graph showing a torque distribution state of a motor using a stator according to the present invention, showing a torque change according to a rotation time in an arbitrarily selected rotation section. Here, the horizontal axis indicates time, and the vertical axis indicates a torque value due to driving of the electric motor.

FIG. 6 is a graph showing the distribution of the magnetic flux density of a motor using the stator according to the present invention, which is provided around the rotor 3 at an arbitrarily selected specific rotation time. This shows the magnetic flux density depending on the position of the permanent magnet 7. Here, the horizontal axis indicates the position where the permanent magnet is located by an angle, and the vertical axis indicates the magnetic flux density.

In FIG. 6, the magnetic flux density due to the pole of a specific permanent magnet is indicated as positive (+), and the magnetic flux density due to the permanent magnet having the opposite pole is indicated as negative (-). FIG.
Is a graph (A ') showing a normal state and a graph (B') showing a magnitude state.
Are shown together. Here, the normal state and the magnitude state are shown separately by different types and arrangements of the magnets.

According to the stator 9 according to the present invention, since the circumferential wall members 21 and 51 are integrally connected, it is possible to solve the torque failure caused by the gap between the adjacent radial wall members 23 and 43. it can. That is, as shown in FIG. 5, by changing the torque in a substantially gentle curve, it is possible to find the optimum torque value according to the rotation time of the rotor 3.

Further, as shown in FIG. 6, when the stator 9 according to the present invention is provided, the variation width of the magnetic flux density depending on the position of the permanent magnet 7 can be minimized to maintain the magnetic flux density.

In the above embodiment, the bobbin 2
The structure in which the excitation coils 28 and 48 are wound around the windings 9 and 49 and the bobbins 29 and 49 are connected to the radial wall members 23 and 43 has been described. The conventional problem can be solved even by directly winding.

In the above-described embodiment, the extension protrusions 25, 45 are formed on the radial wall members 23, 43, and the second yoke portions 30, 50 are engaged with the grooves 31, 51a.
Has been described, but the extension protrusions 25 and 45 are formed on the second yoke portions 30 and 50, and the engagement grooves 31 and 51 a that receive the extension protrusions 25 and 45 on the radial wall members 23 and 43. Can also be formed. Alternatively, the first yoke and the second yoke may be press-fitted and assembled so that the first yoke and the second yoke are closely bonded to each other even if there is no extension protrusion or engagement groove between the first yoke and the second yoke. It is possible.

[0038]

As described above, according to the present invention, the coil can be easily wound around the first yoke portion of the stator, so that the assemblability can be improved.

Further, according to the present invention, noise and vibration can be eliminated by finding the optimum torque value and reducing the torque ripple, so that the efficiency of the motor can be improved as compared with the conventional motor.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view of a motor stator and a rotor according to an embodiment of the present invention.

FIG. 2 is a plan view of FIG.

FIG. 3 is an exploded perspective view of a motor stator and a rotor according to another embodiment of the present invention.

FIG. 4 is a plan view of FIG. 3;

FIG. 5 is a graph showing a torque distribution of an electric motor using a stator according to the present invention.

FIG. 6 is a graph showing a magnetic flux density distribution of an electric motor using a stator according to the present invention.

FIG. 7 is an exploded perspective view of a conventional motor stator and rotor.

FIG. 8 is a plan view of FIG. 7;

FIG. 9 is a graph showing a torque distribution of a motor using a conventional stator.

FIG. 10 is a graph showing a magnetic flux density distribution of a motor using a conventional stator.

[Description of Signs] 3 Rotor 5 Rotating shaft hole 7 Permanent magnet 9 Stator 20, 40 First yoke part 41 Cylinder member 21, 51 Circular wall member 23, 43 Radial wall member 25, 45 Extension protrusion 27, 53 Connecting member 27a, 53a Depressed portions 28, 48 Excitation coils 29, 49 Bobbins 30, 50 Second yoke portions 31, 51a Meshing grooves

Claims (8)

[Claims] 1. A stator for an electric motor that magnetically interacts with a rotor, comprising: a plurality of circumferential wall members circumferentially arranged to receive the rotor; and a radially extending outer circumferential surface of the circumferential wall member. A first yoke portion having a radial wall member protruding from the first yoke portion; a first yoke portion provided separately from the first yoke portion and disposed so as to surround the first yoke portion; A stator for an electric motor, comprising: a cylindrical second yoke portion having an inner peripheral surface to be brought into contact; and a plurality of excitation coils wound around a radial wall member of the first yoke portion. 2. The stator for an electric motor according to claim 1, further comprising a bobbin coupled to a radial wall member of the first yoke portion, wherein the exciting coil is wound around the bobbin. 3. The first yoke portion further includes a connecting member provided between the circumferential wall members, the connecting member being thinner than the circumferential wall members and forming a depression between the circumferential wall members. The stator according to claim 1, wherein: 4. An engaging groove is formed at one of an end portion of the radial wall member of the first yoke portion and an inner peripheral surface of the second yoke portion, and the other is engaged with the engaging groove. The stator for an electric motor according to claim 1, wherein an extension protrusion interconnected with the groove is formed. 5. A motor stator that magnetically interacts with a rotor, comprising: a first yoke having a cylindrical cylinder member and a plurality of radial wall members protruding from an inner peripheral surface of the cylinder member. A second yoke portion having a plurality of circumferential wall members disposed concentrically with the first yoke portion inside the first yoke portion and contacting an end of the radial wall member; and the first yoke A plurality of exciting coils wound on a radial wall member of the section;
A stator for an electric motor, comprising: 6. The motor stator according to claim 5, further comprising a bobbin coupled to a radial wall member of the first yoke portion, wherein the exciting coil is wound around the bobbin. 7. The second yoke portion further includes a connecting member provided between the circumferential wall members, the connecting member being thinner than the circumferential wall members and forming a depression between the circumferential wall members. The stator for an electric motor according to claim 5, characterized in that: 8. An engaging groove is formed on one of an end portion of a radial wall member of the first yoke portion and an outer peripheral surface of a circumferential wall member of the second yoke portion, and the other is provided with an engaging groove. The stator for an electric motor according to claim 5, wherein an extension protrusion is formed to be interconnected with the engagement groove.