JP2002064950A - Motor, manufacturing method therefor, and electric vacuum cleaner - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a permanent magnet-field dc motor that is inexpensive and efficient. SOLUTION: The permanent magnet-field dc motor comprises a plurality of stator cores arranged so that the stator cores are adjacent to one another in the circumferential direction and form a circle, a plurality of field magnets secured inside the stator cores opposite to one another so that the substantially center position of the width thereof in the circumferential direction is positioned between the adjacent stator cores, and a rotor placed inside the plurality of the field magnets with a gap in-between and provided between slots with armature winding.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electric motor using a permanent magnet on the field side, a method for manufacturing the same, and an electric vacuum cleaner.

[0002]

2. Description of the Related Art FIG. 14 is a view showing a cross section of a conventional permanent magnet field type DC motor (hereinafter, DC motor).
FIG. 5 is a view showing the arrangement of the stator core piece and the rotor core piece when the stator core piece of the stator core of the conventional DC motor and the rotor core piece of the rotor are punched from a magnetic steel sheet as a material. . 14 and 15, reference numeral 1 denotes a stator core formed by laminating electromagnetic steel sheets, 2 denotes a field magnet fixed inside the stator core 1, and 130 denotes an electromagnetic field disposed inside the field magnet 2 This is a rotor formed by stacking steel plates. Reference numeral 11 denotes a stator core piece of the stator core 1, 131 denotes a rotor core piece of the rotor 130, 101 denotes a steel plate as a material, 1
01a and 101b are discarded in an extra space when the stator core piece 11 and the rotor core piece 131 are punched from the steel plate 101 of the material.

In FIG. 1, a stator core 1 is generally formed by laminating a predetermined number of stator core pieces 11 punched from a thin electromagnetic steel plate 101 as a material in a thickness direction (axial direction). The stator of the DC motor is configured by fixing the field magnet 2 so as to face the inside of the stator core 1. Similarly to the stator core 1, the rotor 3 is formed by laminating rotor core pieces 131 punched out of a magnetic steel sheet 101 as a material. As shown in FIG. 14, the stator core pieces 11 and the rotor core pieces are formed. 131 is laminated by punching out the same electromagnetic steel plate 101.

[0004]

With the above configuration, the conventional DC motor has the following problems. When the stator core piece 11 and the rotor core piece 131 are punched by using the same electromagnetic steel plate 101, there is an extra space 101a in a portion where the field magnet 2 is disposed, so that the stator core piece 11 and the rotor core piece 131 are punched out. The minimum area of the electromagnetic steel sheet 101 required to obtain one sheet of steel sheet was required to be very large as shown by the dotted line in FIG. For this reason, there is a large amount of extra space 101a corresponding to a discarded portion, that is, a portion to which the field magnet 2 is to be fixed, and extra cost is required. As a result, there is a problem that the DC motor becomes expensive.

[0005] Japanese Patent Application Laid-Open No. 4-347567 discloses an example in which a split type stator structure using a pair of stator cores is used. In the DC motor described in Japanese Patent Application Laid-Open No. 4-347567, a field magnet is used for the stator, but the cross section is a rectangular field magnet, and both poles (N pole and S pole) of the field magnet are fixed. It is fixed so that it is covered with a child core. Therefore, since both poles (N pole and S pole) of the field magnet are covered with the stator core, it is necessary to increase the size of the field magnet to increase the output of the DC motor. There was a problem that it became large and expensive.

An object of the present invention is to provide a motor which is inexpensive, highly efficient and easy to assemble, and a method of manufacturing the same. Another object is to provide an inexpensive and highly efficient vacuum cleaner. Another object is to provide a highly reliable electric motor and vacuum cleaner.

[0007]

According to a first aspect of the present invention, there is provided an electric motor comprising a plurality of stator cores which are circumferentially adjacent to each other and arranged so as to form a circle; A plurality of field magnets fixed to the inside of the stator core facing each other so that the approximate center position of the circumferential width comes to And a rotor on which armature windings are provided.

In the electric motor according to a second aspect of the present invention, a plurality of stator cores adjacent to each other in the circumferential direction and arranged so as to form a circle are fixed to the outer peripheral side, and the adjacent stator cores are fixed. A frame in which a plurality of field magnets arranged opposite to each other are fixed to the inner peripheral side so that a substantially central position of the circumferential width comes therebetween, and a gap is formed inside the plurality of field magnets fixed to the frame. And a rotor provided with an armature winding between the slots.

A motor according to a third aspect of the present invention includes a frame having a positioning projection on at least one of an inner peripheral side and an outer peripheral side, and at least one of a plurality of stator cores or a plurality of field magnets. The positioning is performed by bringing one of the two into contact with the positioning projection.

A motor according to a fourth aspect of the present invention has a frame having a field magnet on the inner peripheral side and a stator core on the outer peripheral side, and an armature winding inside the field magnet. The output power is changed by changing the ratio of the axial thickness of the stator core to the axial thickness of the rotor.

Further, in the electric motor according to a fifth aspect of the present invention, a gap is provided between stator cores adjacent in the circumferential direction.

Further, in the electric motor according to a sixth aspect of the present invention, the size of the gap between the adjacent stator cores is set to an angle of 10 degrees or less with respect to the center of the stator in a cross section substantially perpendicular to the axial direction of the stator. Things.

The electric motor according to a seventh aspect of the present invention has a field magnet fixed inside a stator core and an armature winding disposed between the field magnets and slots. And a ratio of the thickness of the minimum thickness portion to the outer diameter of the rotor in a cross section substantially perpendicular to the axial direction of the stator core is set to a predetermined value or more at which the torque generated by the motor does not decrease. is there.

Further, in the electric motor according to an eighth aspect of the present invention, the predetermined value is set to 3.5% or more, preferably 4% or more.

A motor according to a ninth aspect of the present invention includes a rotor formed by laminating rotor core pieces, and a stator core formed by laminating stator core pieces. The thickness of the stator core piece is made larger than the thickness of the rotor core piece.

Further, a vacuum cleaner according to a tenth aspect of the present invention includes the electric motor according to any one of the first to tenth aspects.

Further, according to an eleventh aspect of the present invention, there is provided a method of manufacturing an electric motor, comprising: a plurality of stator cores formed by laminating stator core pieces in an axial direction; A magnetic magnet and a stator formed by arranging a plurality of stator cores adjacent to each other in a circumferential direction, forming a circle, and fixing a plurality of field magnets inside. When a core piece is punched from a material, a pair of stator core pieces are arranged so as to be shifted in a direction in which the width of the material is reduced.

A method for manufacturing a motor according to a twelfth aspect of the present invention includes a rotor formed by laminating rotor core pieces, and punches the rotor core pieces and a pair of stator core pieces from a material. In this case, a pair of stator core pieces are staggered with the rotor sandwiched in the direction in which the width of the material is reduced.

The vacuum cleaner according to a thirteenth aspect of the present invention is characterized in that a plurality of stator cores arranged adjacent to each other in the circumferential direction to form a circle have a circumferential width between adjacent stator cores. A stator having a field magnet disposed so as to face the approximate center position of the stator, a rotor having an armature winding and a commutator connected to the armature winding, and an electric power while contacting the commutator. And an electric motor having a brush for supplying the same in the main body.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 Hereinafter, the invention according to the first embodiment will be described with reference to the drawings. FIG. 1 is a diagram illustrating a cross section of a permanent magnet field type DC motor according to the first embodiment of the present invention. In the figure, 21a and 21b are stator cores divided into two in the axial direction, and 2 is a field magnet. 2
The stator cores 21a and 21b divided into two
1c and 21d are arranged so as to be adjacent to each other in the circumferential direction and to face each other, and form a circle. Further, the stator cores 21a and 21b are fixed with an adhesive or the like via the field magnets 2 arranged opposite to each other to form the stator 20, and the inside of the field magnet 2 is shown in FIG. A rotor core 130 (not shown) similar to the above exists. The rotor core forms a rotor by applying an armature winding to a slot.

A normal stator core 21 is formed by combining the mating surfaces 21c and 21d of the stator cores 21a and 21b. One of the N-poles or S-poles of the field magnets 2 facing each other has a stator core 2.
It is not in contact with 1a, 21b, and is exposed to the rotor 130 (not shown). Therefore, Japanese Patent Application Laid-Open No. 4-347
As disclosed in Japanese Patent No. 567, both the N pole and the S pole are not covered with the stator core, so that there is no need to increase the size of the field magnet, and an inexpensive and highly efficient motor can be obtained.

Here, since the approximate center position of the circumferential width of the field magnet is arranged at the position between the adjacent stator cores (matching surface), there is a mating surface of the stator cores. It does not hinder the flow of the magnetic flux of the field magnet.
That is, since the magnetic flux flows to the left and right in the circumferential direction from the mating surface of the field magnet, a highly reliable electric motor can be obtained without obstructing the flow by the mating surface.

FIG. 2 is a view showing the arrangement of the respective core pieces when the stator core piece and the rotor core piece of the DC motor according to the first embodiment are punched from a steel plate. In the drawing, reference numerals 121a and 121b denote stator cores 21a and 21b.
And 131 are rotor core pieces constituting the rotor core 130. 100 is the stator core piece 1
It is an electromagnetic steel plate which is a material for punching out 21a, 121b and the rotor core piece 131. By dividing the stator core 21 (stator cores 21a, 21b), the stator core pieces 121a, 121 of the stator cores 21a, 21b are formed.
When the rotor core piece 131 and the rotor core piece 131 of the rotor core 130 are punched from the same magnetic steel sheet 100, a pair of stator core pieces 1
21a and 121b are discarded portions (100
The rotor core pieces 131 are staggered so as to sandwich the rotor core pieces 131 in such a manner that a, 100b) is as small as possible.

That is, when a conventional stator core piece 11 that has not been divided is punched from a raw material, the width of the steel plate of the raw material needs to be L, but the stator core is divided (121a, 121b).
The width of the material steel plate 100 is LB (LB = L−
LA), the availability of the material steel plate itself is improved, and it can be obtained at low cost.

Therefore, the field magnet 2 conventionally discarded
Space 101a corresponding to the above and four corner spaces 1
01b can be made as small as the space of 100a and 100b in the present invention. As a result, the area of the magnetic steel sheet 100 required to obtain the pair of stator core pieces 121a and 121b and the rotor core piece 131 can be reduced, and the scrap portion to be discarded can be reduced, so that the cost can be reduced. Since the size of the magnetic steel sheet of the material can be small, the storage space can be small.

Compared with the size of the conventional material (FIG. 12), the combination of the stator 20 and the rotor core 130 of the present embodiment requires about 92% of the required area, so that the required material of the electromagnetic steel sheet is small. In other words, material removal is improved. Further, since the width of the material is small, the capacity of the machine may be small, so that mass production is possible, and as a result, an inexpensive electric motor can be obtained.

Further, in this motor, since the stator is not provided with a winding, the stator can be easily disassembled, and can be easily disassembled even when the motor is discarded, thereby improving the recyclability. Is obtained. FIG. 3 is a diagram illustrating a cross section of another DC motor according to the present embodiment.
Numerals 1a and 31b denote stator cores, and 31c and 31d denote cut portions. The stator 30 is configured by fixing a pair of stator cores 31a and 31b through the field magnet 2 inside.

In the electric motor shown in FIG. 3, adjacent mating surfaces of a pair of stator cores 31a and 31b are cut obliquely. If the mating surface is cut in this way, in addition to the above-described effects, the required amount of the magnetic steel sheet as the material can be further reduced, so that further cost reduction can be obtained. Further, since the air passage is formed in the axial direction by the cut portions 31a and 31b, even when a frame or the like is present on the outer periphery, the air passage becomes an air passage and a cooling effect can be obtained.

Embodiment 2 FIG. 4 is a diagram illustrating a cross section of a permanent magnet field type DC motor according to a second embodiment of the present invention. In the figure, the same or corresponding parts as those in FIG. 1 shown in the first embodiment are denoted by the same reference numerals, and description thereof will be omitted. In the figure, 41a and 41b are stator cores,
To form a stator 40. represents the gap angle between the adjacent ends 41c and 41d of the stator cores 41a and 41b, and the center thereof is the axis center 45 of the stator 40 in a cross section substantially perpendicular to the axial direction. The shaft center 45 corresponds to a substantially rotation center position of the stator 40.

In this embodiment, a gap θ is provided between 41c and 41d corresponding to the mating surfaces 21c and 21d described with reference to FIG.
Is provided. Therefore, similarly to the case described with reference to FIG. 2, when the stator core pieces are punched from the material steel plate, the shift amount of the pair of stator core pieces may be larger than that in FIG. 2 by an amount corresponding to θ minutes. As a result, the size of the magnetic steel plate as the material can be further reduced than the size described in the first embodiment, and an inexpensive electric motor can be obtained. In the present embodiment as well, similar to the first embodiment, the substantially central portion in the circumferential direction of the field magnet is arranged near the mating surface of the stator core, so that the flow of the magnetic flux is not hindered.

As the gap θ between the stator cores 41a and 41b increases, the generated torque decreases.
In the present embodiment, the size of the gap θ is selected such that the amount of reduction in the generated torque is small and the range is not affected.

FIG. 5 is a diagram showing the ratio of the generated torque to the clearance angle (θ) of the stator of the electric motor according to the present embodiment. In the figure, the horizontal axis represents the clearance angle (θ) between the stator core 41a and the stator core 41b, and the vertical axis represents the clearance angle (θ) with respect to the generated torque when the clearance angle (θ) is 0 ° (no clearance). ) Indicates the ratio of the generated torque when the value is increased. As shown in the figure, when the gap angle (θ) is increased, the generated torque for θ of 0 degree decreases.

For example, when θ is 10 degrees, it means that the generated torque is 3% lower than when θ is 0 degrees, that is, the efficiency of the motor is 3% lower.
As the gap angle is further increased, the torque is greatly reduced. Therefore, in this embodiment, the gap angle (θ) is set to 10 degrees or less so as not to cause a problem in practical use. By reducing the angle to 10 degrees or less, the efficiency of the motor decreases by 3%.
Therefore, the efficiency can be kept high, and a highly efficient DC motor can be obtained.

FIG. 6 is a diagram showing the arrangement of the core pieces when the stator core piece and the rotor core piece of the DC motor according to the present embodiment are punched from a steel plate. In the figure,
141a and 141b are stator core pieces constituting the stator cores 41a and 41b, and 131 is a rotor core piece constituting the rotor core. 110 is a stator core piece 141
a, 141 b and a magnetic steel sheet which is a material for punching the rotor core piece 131. Since the stator core 40 is divided (stator cores 141a and 141b), the stator core pieces 141a and 141 of the stator cores 41a and 41b are formed.
When the rotor core piece 131 and the rotor core piece 131 of the rotor core 130 are punched from the same electromagnetic steel plate, a pair of stator core pieces 141 are used.
a, 141b are discarded parts (110a,
The rotor core pieces 131 are staggered so as to sandwich the rotor core pieces 131 so as to reduce the number of parts 110b) as much as possible.

The figure shows an example in which the gap angle (θ) is set to 6 degrees. When the gap is provided by the gap angle (θ), the area of the material steel plate required to obtain one iron core piece can be further reduced as compared with the case of the first embodiment (for example, FIG. 2). Compared with the conventional case (FIG. 14), for example, when the gap angle (θ) is 6 degrees, the required area of the material steel plate can be reduced to about 89%.
Therefore, material removal is further improved by an amount corresponding to the gap between the stator cores 141a and 141b, and the cost of the material can be reduced, and an inexpensive DC motor can be obtained. Further, the volume of iron having a high specific gravity is reduced by the amount of the gap, so that the weight of the DC motor can be reduced.

Further, since there is a gap corresponding to the gap angle (θ) between the stator cores 41a and 41b, the gap becomes an air flow path through which the wind flows. Therefore, when this motor is used as a blower, The air flowing through the air passage enhances the cooling effect of the electric motor, thereby reducing the loss of the electric motor and improving the performance of the blower.

Embodiment 3 FIG. 7 is a diagram illustrating an arrangement of core pieces when a stator and a rotor core of a permanent magnet field type DC motor according to the third embodiment are punched from a steel plate. In the drawings, the same or corresponding parts as those in the drawings shown in the first embodiment or the second embodiment are denoted by the same reference numerals, and description thereof is omitted. In the figure, 121a and 121b are stator core pieces,
131 is a rotor core piece, 105 is a stator core piece 121
a, a steel plate as a material for punching 121b, 106
Is an electromagnetic steel plate of a material for punching the rotor core piece 131.

In this embodiment, the stator core pieces 121a,
121b and the rotor core piece 131 are made of different materials 105, 10
Since the blanks are separately punched from 6, the material of the steel plate can be changed. When the motor rotates, the direction of the magnetic field inside the rotor core 130 changes (the magnetic field alternates) in the rotor core 130 according to the number of rotations. Therefore, in order to increase the efficiency of the DC motor, a thin plate (for example, 0.35 mm) is used.
It is necessary to reduce the iron loss by using the electromagnetic steel sheet.

On the other hand, since the direction of the magnetic field inside the stator core 21 is constant and the magnetic field does not alternate, it is not necessary to use a thin electromagnetic steel plate. Use has little effect on efficiency. Since magnetic steel sheets generally increase in cost when they become thinner, in the embodiment of the present invention, the stator core piece and the rotor core piece are made of separate magnetic steel sheets, and a thicker steel plate can be used at low cost. By increasing the thickness, a DC motor with low cost and high efficiency can be obtained.

Embodiment 4 FIG. FIG. 8 is a cross-sectional view of the permanent magnet field type DC motor according to the fourth embodiment, which is perpendicular to the axial direction. FIG. 9 is a cross-sectional view taken along the line AA of FIG. 8, and FIG.
FIG. 11 is a cross-sectional view perpendicular to the axial direction of a permanent magnet field type DC motor showing another example of FIG. 8 to 11, the same or corresponding parts as those shown in the first to third embodiments are denoted by the same reference numerals, and description thereof is omitted. 8 to 11, 4
Is an electric motor frame, 5 is an armature winding provided on the slot 130a of the rotor core 130, 6 is a commutator connected to the armature winding 5, 8 is a positioning projection provided on the outer peripheral portion of the frame 4. , 9 are abutment portions for positioning the field magnet 2 in the axial direction. In FIGS. 10 and 11, 7a and 7b are divided stator cores.

Reference numeral 4 denotes a frame which is formed by drawing and pressing an iron plate, and has a positioning projection 8 on its outer peripheral portion.
And the inner peripheral portion is provided with a stop portion 9. First, as shown in FIGS. 8 and 9, the axial position of the field magnet 2 when the field magnet 2 is inserted is determined by the abutment 9, and the field magnet 2 is fixed at that position. At this time, the positioning in the circumferential direction may be performed by similarly providing a positioning projection on the frame 4 or by using a jig or the like. An adhesive is often used for fixing the field magnet 2 and the frame 4, but any method such as a method of fixing with resin may be used.

Next, stator cores 7a and 7b for generating a magnetic circuit are fixed to the outer peripheral side of the frame 4. At the time of fixing, the positioning of the stator cores 7a and 7b in the circumferential direction is performed by positioning projections 8 provided on the outer peripheral portion of the frame 4. At this time, the positioning in the axial direction may be performed by similarly providing a positioning projection on the frame 4 or by using a jig or the like. As for the fixing method, any method such as integrally molding (solidifying) with an adhesive or resin may be used as in the case of fixing the field magnet 2. Conversely, the field magnet 2 and the stator core 7
Positioning projections may be provided on a and 7b. The frame 4 includes a field magnet 2 and a stator core 7.
A similar effect can be obtained by providing a concave portion in which the positioning projections provided on the a and 7b are fitted. Also, in the present embodiment, as in the first embodiment, since the substantially central portion in the circumferential direction of the field magnet is arranged near the mating surface of the stator core, the flow of magnetic flux can be prevented. Absent.

Here, a method of assembling the electric motor of the present invention will be described with reference to FIG. FIG. 12 is a flowchart illustrating the method for assembling the electric motor according to the present invention. In the figure,
ST1 is a step of fixing the field magnet 2 to the frame 4,
ST2 is a step of mounting the rotor sub-assembly, ST3 is a step of fixing the stator cores 7a and 7b to the frame 4,
ST4 is a step of fixing the bracket 400 to the frame 4, ST5 is a step of fixing the brush 440 to the frame 4, ST11 is a step of fixing the rotor core 130 to the drive shaft 500, and ST12 is a step of fixing the commutator 6 to the drive shaft 500.
, ST13 is a step of applying the armature winding 5 of the rotor core 130, and ST14 is a step of attaching a bearing to the end face side of the drive shaft 500.

In each of the steps ST11 to ST14, the rotor sub-assembly is performed. First, in ST11, the drive shaft 50
The rotor core 130 is fixed to zero by shrink fitting or press fitting. Next, the commutator 6 is similarly fixed to the drive shaft 500 in ST12. In ST13, the armature winding 5 is applied to the rotor 130. At this time, the armature winding 5 is applied to the rotor 130 while the armature winding 5 is hooked on the commutator 6. Then, by attaching bearings (rolling bearings) 410 and 420 to both ends of the drive shaft 500 in ST14, the rotor subassembly is completed.

In step ST1, the field magnet 2 is brought into contact with the inner peripheral side of the frame 4 in the axial direction by the stopper 9 and the adhesive is formed while positioning in the circumferential direction by the positioning projections (not shown). Or by resin molding. The rotor sub-assembly is attached to the frame 4 to which the field magnet 2 is fixed in ST2, and the stator cores 7a and 7b are positioned in the circumferential direction by the positioning projections 8 provided in the frame 4 in ST3. It is fixed to the outer periphery of the frame 4 by an adhesive or the like while being positioned by a positioning projection (not shown) in the direction.

Thereafter, in step ST4, the bracket 400 is positioned by the positioning projection 401 provided on the outer peripheral side of the frame 4 and then fixed with bolts or the like. Absent. Finally, in step ST5, the brush 440 is inserted from outside the frame 4 and fixed to the frame 4 with bolts or the like, thereby completing the electric motor. Here, the brush 440 may not be on the BB section of FIG. 10, but is usually provided on the section without the field magnet 2.

With the above configuration, the size of the frame 4 can be reduced as compared with the case where the frame 4 is arranged outside the stator core, and therefore, the weight of the DC motor can be reduced. Can be. Further, since the stator cores 7a and 7b are arranged outside the frame 4, the size of the stator cores 7a and 7b can be arbitrarily changed. For example, when the output of the DC motor is small, high efficiency can be maintained even when the amount of magnetic flux is small. Therefore, the volume of the stator cores 7a and 7b can be reduced. Stator core 7a,
If the output of the stator cores 7a and 7b is reduced, the volume of the stator cores 7a and 7b can be reduced.
A DC motor having a size corresponding to the output of the motor can be obtained.

Therefore, the stator core may be changed according to the required output of the motor, so that parts can be shared and a low-cost motor can be obtained. Further, the stator cores 7a and 7b may be simultaneously punched from the same material as the rotor core 130 as described in the second embodiment,
As shown in the third embodiment, separate electromagnetic steel sheets having different thicknesses may be punched in order to reduce the cost of the stator core pieces.

In the first to fourth embodiments, the stator core is divided into two parts. However, the stator core is not necessarily divided into two parts. The effect is obtained. Further, if the stator cores are arranged on a circle and the substantially central part of the circumferential width of the field magnet is arranged at the mating surface position of the adjacent stator cores as in the first embodiment, the magnetic flux is reduced. A high-performance and highly reliable electric motor can be obtained without obstructing the flow of air.

Embodiment 5 FIG. 13 is a diagram showing the characteristics of the permanent magnet field type DC motor according to the fifth embodiment, and shows the thinnest portion of the stator core (of the stator) when a ferrite magnet is used as an example of the material of the field magnet. The relationship between the ratio of the thinnest portion of the stator core in a substantially perpendicular cross section in the axial direction to the diameter of the rotor (hereinafter referred to as the iron core thin portion) and the torque generated by the DC motor is shown.

The thinnest portion, that is, the minimum thickness portion (also referred to as the iron core thin portion), corresponds to the portion where the substantially central portion of the circumferential width of the field magnet 2 is disposed, and corresponds to a portion in the axial direction of the stator core. FIG. 1 shows the thickness in a substantially right-angle cross section in the axial direction near the mating surface of the stator core 21 in FIG. This also applies to the case where the stator core is not divided. In FIG. 14, the minimum thickness portion corresponds to the portion where the substantially central portion of the field magnet 2 in the circumferential direction is arranged. It represents the thickness (X-dimension portion) of the iron core in a substantially right-angle cross section in the axial direction. In FIG. 13, the horizontal axis represents the ratio between the iron core thin portion and the rotor outer diameter in percentage, and the vertical axis represents the ratio of the generated torque.

From FIG. 13, if the outer diameter of the rotor is assumed to be constant, for example, if the dimension of the thin portion of the iron core is reduced, that is, if the ratio of the thin portion of the core to the outer diameter of the rotor is reduced, 3 When it becomes less than about 0.5%, the generated torque sharply decreases. Therefore, in the present embodiment, the ratio of the iron core thin portion to the rotor outer diameter is set to 3.5% or more, which is a point at which the torque sharply decreases.
By doing so, the reduction in the generated torque of the motor can be small (1% or less), high efficiency can be maintained, and a highly reliable DC motor with reduced heat generation due to loss of the motor can be obtained. . Further, since the strength of the thin portion is ensured, a highly reliable electric motor can be obtained. here,
If the ratio of the iron core thin portion to the rotor outer diameter is set to 4.0% or more, the torque generated by the electric motor does not decrease, so that the strength of the thin portion is further secured than when it is set to 3.5% or more. Therefore, a highly reliable electric motor can be obtained.

When the electric motor is mounted on an electric vacuum cleaner, the efficiency of the electric motor for blowing air is high, so that the work efficiency of the electric vacuum cleaner is high, and a high-performance electric vacuum cleaner having a high suction power. You can get the machine. Since an inexpensive electric motor is used, a low-cost vacuum cleaner can be obtained.

[0054]

According to the first aspect of the present invention, a plurality of stator cores adjacent to each other in the circumferential direction and arranged so as to form a circle, and a circumferential width between the adjacent stator cores is reduced. A plurality of field magnets are fixed to the inside of the stator core so as to face each other so that the approximate center position is located, and an armature winding is arranged between the slots, with a plurality of field magnets disposed inside the plurality of field magnets. And a rotor provided with a rotor, so that the stator core material width can be small without obstructing the flow of magnetic flux of the field magnet, and a material-efficient motor can be obtained regardless of the size of the material. Can be.

The invention according to claim 2 of the present invention provides:
A plurality of stator cores that are adjacent to each other in the circumferential direction and are arranged so as to form a circle are fixed to the outer peripheral side, and are opposed to each other so that the substantially central position of the circumferential width comes between the adjacent stator cores. A frame in which a plurality of arranged field magnets are fixed on the inner peripheral side, and a rotation in which an armature winding is provided between the slots and arranged inside the plurality of field magnets fixed to the frame via a gap. Since the field magnet is fixed, it is easier to fix the field magnet to the frame than to the divided stator core, and it is possible to obtain an electric motor with good assemblability.

The invention according to claim 3 of the present invention provides:
Since a frame having a positioning protrusion on at least one of the inner peripheral side and the outer peripheral side is provided, and at least one of the plurality of stator cores or the plurality of field magnets is positioned so as to contact the positioning protrusion, An electric motor with good assemblability that can easily position the field magnet and the stator core in the axial direction or the circumferential direction can be obtained.

The invention according to claim 4 of the present invention provides:
A frame having a field magnet on the inner peripheral side and having a stator core on the outer peripheral side, and a rotor having an armature winding inside the field magnet, fixed to the axial thickness of the rotor Since the magnitude of the output is changed by making the ratio of the axial thickness of the iron core variable, a low-cost electric motor with common parts can be obtained.

The invention according to claim 5 of the present invention provides:
Since a gap is provided between the stator cores that are adjacent in the circumferential direction, the volume of the stator core can be small, so that a lightweight and inexpensive motor can be obtained.

The invention according to claim 6 of the present invention provides:
Since the size of the gap between the adjacent stator cores is set to 10 degrees or less with respect to the center of the shaft in a substantially perpendicular cross-section in the axial direction of the stator, it is possible to obtain a highly reliable motor with little reduction in torque of the motor. it can.

The invention according to claim 7 of the present invention provides:
A field magnet fixed inside the stator core, and a rotor disposed inside the field magnet and having an armature winding between slots, substantially perpendicular to the axial direction of the stator core Since the ratio of the thickness of the minimum thickness portion to the outer diameter of the rotor in the cross section is set to a predetermined value or more at which the torque generated by the motor does not decrease, a highly reliable motor that can be set so that the torque of the motor does not decrease. Can be obtained.

The invention according to claim 8 of the present invention provides:
Since the predetermined value is set to 3.5% or more, preferably 4% or more, it is possible to obtain a highly reliable electric motor in which the torque of the electric motor does not decrease.

The invention according to claim 9 of the present invention provides:
A rotor formed by laminating the rotor core pieces, and a stator core formed by laminating the stator core pieces, wherein the thickness of the stator core pieces is greater than the thickness of the rotor core pieces. Since the thickness is increased, a stator core piece having a lower material cost than the rotor core piece can be obtained, and a low-cost electric motor that can be made of any material can be obtained.

According to the tenth aspect of the present invention, since the electric motor according to the first to eighth aspects is provided, a high-performance vacuum cleaner having a high suction force can be obtained.

The invention according to claim 11 of the present invention is characterized in that a plurality of stator cores formed by axially laminating stator core pieces, a plurality of field magnets provided to face each other, A stator formed by arranging a plurality of stator cores adjacent to each other in a circumferential direction to form a circle and fixing a plurality of field magnets inside, When punching more, the pair of stator core pieces are shifted in the direction in which the width of the material is reduced, so that the size of the material can be reduced and an inexpensive stator core piece can be obtained. An inexpensive motor manufacturing method can be obtained.

Further, the invention according to claim 12 of the present invention comprises a rotor formed by laminating rotor core pieces, and when a rotor core piece and a pair of stator core pieces are punched out of a material, a pair Since the stator core pieces were shifted with the rotor sandwiched in the direction in which the width of the material became smaller,
In addition to the stator core pieces, the rotor core pieces can be manufactured inexpensively, and a low-cost electric motor manufacturing method with less wasted parts can be obtained.

Further, the invention according to claim 13 of the present invention is characterized in that a plurality of stator cores arranged adjacent to each other in the circumferential direction so as to form a circle have a substantially central circumferential width between adjacent stator cores. A stator having field magnets arranged opposite to each other, a rotor having an armature winding and a commutator connected to the armature winding, and supplying power while contacting the commutator. Since the electric motor having the brush is provided in the main body, a small and highly reliable vacuum cleaner having a large suction force can be obtained.

[Brief description of the drawings]

FIG. 1 is a diagram illustrating a cross section of a permanent magnet field type DC motor according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating an arrangement of respective core pieces when punching a stator core piece and a rotor core piece of a DC motor according to the first embodiment of the present invention from a steel plate.

FIG. 3 is a diagram showing a cross section of another DC motor representing the first embodiment of the present invention.

FIG. 4 is a diagram illustrating a cross section of a permanent magnet field type DC motor according to a second embodiment of the present invention.

FIG. 5 is a diagram illustrating a ratio of a generated torque to a gap angle (θ) of a stator of the electric motor according to the second embodiment of the present invention.

FIG. 6 is a diagram illustrating an arrangement of respective core pieces when a stator core piece and a rotor core piece of a DC motor according to a second embodiment of the present invention are punched from a steel plate.

FIG. 7 is a diagram illustrating an arrangement of core pieces when a stator and a rotor core of a permanent magnet field type DC motor according to a third embodiment of the present invention are punched from a steel plate.

FIG. 8 is a cross-sectional view of a permanent magnet field type DC motor according to a fourth embodiment of the present invention, which is perpendicular to the axial direction.

FIG. 9 is a diagram illustrating a cross section taken along line AA of FIG. 8 illustrating the fourth embodiment of the present invention.

FIG. 10 is a cross-sectional view perpendicular to the axial direction of a permanent magnet field type DC motor that represents another example that represents the fourth embodiment of the present invention.

FIG. 11 is a cross-sectional view taken on line B- in FIG. 10 illustrating the fourth embodiment of the present invention;
It is a figure showing B section.

FIG. 12 is a flowchart illustrating an electric motor assembling method according to a fourth embodiment of the present invention.

FIG. 13 is a diagram illustrating characteristics of a permanent magnet field type DC motor according to a fifth embodiment of the present invention.

FIG. 14 is a diagram showing a cross section of a conventional permanent magnet field type DC motor.

FIG. 15 is a view showing the arrangement of each core piece when punching a stator core piece and a rotor core piece of a conventional DC motor from a steel plate.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Fixed iron core, 2 field magnets, 4 frames, 5 armature windings, 6 commutators, 7a, 7b stator cores, 8 positioning protrusions, 9 abutment portions, 11 stator core pieces, 2
0 stator, 21 stator core, 21a, 21b stator core, 21c, 21d mating surface, 30 stator, 31
Stator core, 31a, 31b Stator core, 31c,
31d cut part, 40 stator, 41 stator core,
41a, 41b Stator core, 41c, 41b Cut part, 45 axis, 100 steel plate, 100a, 100b
Space, 105, 106 steel plate, 110 steel plate, 11
0a, 110b space, 121a, 121b stator core pieces, 121c, 121d mating surface, 130 rotor core, 130a slot, 131 rotor core pieces, 141a, 141b stator core pieces, 400 bracket, 401 positioning protrusion, 410, 420 bearings, 440 brushes, 500 drive shafts.

Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat II (Reference) H02K 23/04 H02K 23/04 5H623 (72) Inventor Hitoshi Kawaguchi 2-3-2 Marunouchi 2-chome, Chiyoda-ku, Tokyo Mitsubishi Electric (72) Inventor Yuji Takahashi 1728-1 Komaeda, Hanazono-cho, Osato-gun, Saitama F-term (reference) 3B006 FA01 5H002 AA07 AA09 AC04 AC08 5H605 AA08 BB05 BB09 CC01 CC07 DD03 GG01 5H615 AA01 BB01 BB04 BB14 PP01 PP06 PP26 SS03 SS05 SS18 TT04 5H622 AA03 CA02 CA10 CB01 PP10 PP19 5H623 AA10 BB07 GG13 GG22 GG28 JJ01 JJ06 LL02 LL09

Claims (13)

[Claims] 1. A plurality of stator cores which are adjacent to each other in a circumferential direction and are arranged so as to form a circle, and face each other such that a substantially central position of a circumferential width is between the adjacent stator cores. A plurality of field magnets fixed inside the stator core, and a rotor disposed inside the plurality of field magnets via a gap and having an armature winding between slots. An electric motor, comprising: 2. A plurality of stator cores adjacent to each other in the circumferential direction and arranged so as to form one circle are fixed to the outer peripheral side, and a substantially central position of a circumferential width comes between the adjacent stator cores. A plurality of field magnets arranged opposite to each other are fixed to the inner peripheral side, and an electric motor is disposed between the slots, and is arranged inside the plurality of field magnets fixed to the frame via a gap. An electric motor comprising: a rotor on which a child winding is applied. 3. A frame having a positioning projection on at least one of an inner peripheral side and an outer peripheral side, wherein at least one of the plurality of stator cores or the plurality of field magnets is brought into contact with the positioning projection. The electric motor according to claim 2, wherein the electric motor is positioned by positioning. 4. A rotor having a field magnet on an inner peripheral side and having a stator core on an outer peripheral side, and a rotor having an armature winding inside the field magnet. The motor according to claim 2 or 3, wherein the magnitude of the output is changed by changing the ratio of the axial thickness of the stator core to the axial thickness of the stator core. 5. The electric motor according to claim 1, wherein a gap is provided between stator cores circumferentially adjacent to each other. 6. The electric motor according to claim 5, wherein the size of the gap between the adjacent stator cores is not more than 10 degrees as an angle with respect to the center of the stator in a substantially perpendicular cross section in the axial direction of the stator. . 7. A stator core forming one circle, a field magnet fixed inside the stator core, and an armature winding disposed between the slots and having an armature winding between slots. And a ratio of the thickness of the minimum thickness portion to the outer diameter of the rotor in a cross section substantially perpendicular to the axial direction of the stator core is set to a predetermined value or more at which the torque generated by the motor does not decrease. Motor. 8. The predetermined value is set to 3.5% or more, preferably 4%.
The electric motor according to claim 7, wherein the electric motor is set as described above. 9. A rotor, comprising: a rotor core formed by laminating rotor core pieces; and a stator core formed by laminating stator core pieces, wherein the thickness of the stator core piece is adjusted by the rotation. The electric motor according to any one of claims 1 to 8, wherein the thickness is greater than a thickness of the core iron piece. 10. An electric vacuum cleaner comprising the electric motor according to claim 1. Description: 11. A plurality of stator cores formed by laminating stator core pieces in an axial direction, a plurality of field magnets provided to face each other, and a plurality of stator cores adjacent to each other in a circumferential direction. And a stator formed by fixing the plurality of field magnets inside, arranged to form a circle,
Comprising, when punching the stator core piece from the material,
A method for manufacturing an electric motor, wherein the pair of stator core pieces are displaced in a direction in which the width of the material is reduced. 12. When a rotor is formed by laminating rotor core pieces, and when the rotor core piece and a pair of stator core pieces are punched from a material, the pair of stator core pieces are made of the material. The method of manufacturing an electric motor according to claim 11, wherein the rotors are staggered in a state of sandwiching the rotors in a direction in which the width decreases. 13. A plurality of stator cores which are arranged so as to be adjacent to each other in the circumferential direction so as to form a circle, and are arranged to face each other such that a substantially central position in a circumferential direction comes between adjacent stator cores. A motor having a stator having a field magnet, a rotor having an armature winding and a commutator connected to the armature winding, and a brush for supplying electric power while contacting the commutator, is provided in the main body. An electric vacuum cleaner comprising: