JP2002118993A - Stator structure of inner-rotor motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stator used for an inner-rotor motor, which is satisfactory in efficiency and can enhance the motor efficiency. SOLUTION: This stator structure of an inner-rotor motor is equipped with a stator, having an annular inside periphery and an outside periphery equipped with projections projected outward in the radial directions and is provided at specified intervals in circumferential direction and made by stacking steel sheets, coils mounted on the projections, and a cylindrical yoke engaging with the outside periphery of the stator.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an inner rotor type AC motor (induction motor,
The present invention relates to a stator structure widely applicable to a synchronous motor, an AC servomotor, a brushless DC motor, and the like.

[0002]

2. Description of the Related Art Conventionally, inner rotor type motors such as brushless DC motors and AC motors have been used as motors for industrial machines and automobiles.

FIG. 7 is a partial sectional front view of a conventional brushless DC motor 100 of the inner rotor type. A cylindrical stator iron core (stator structure) 104 is fixed to an inner peripheral surface of a frame 102 of the brushless DC motor 100,
A cylindrical rotor yoke 108 is rotatably disposed inside the stator core 104. Rotor yoke 10
A permanent magnet 106 is mounted on the outer peripheral surface of the stator 8 so as to face the inner periphery of the stator core 104. A rotating shaft 112 is fitted on the inner periphery of the rotor yoke 108, and the rotating shaft 112 supported by the bearing 116 rotates integrally with the rotor yoke 108.

The teeth of the stator core 104 have coils 110
Is installed. As can be seen from FIG. 7, the brushless DC motor 100 has a coil end 11 for inserting a coil wound around a frame from an inner slot of a stator iron core.
8 is longer in the axial direction.

FIG. 8 is a sectional view of an inner rotor type induction motor 200 conventionally used. The configuration is substantially the same as that of the above-described brushless DC motor 100. A stator iron core 204 on which a winding 207 is wound is fixed to an inner peripheral surface of a frame 202, and a rotor iron core 214 having a cage type conductor 208 is provided. Are disposed facing each other within the inner diameter of the stator core 204. Further, the inner circumference of the rotor core 214 is fitted to the rotation shaft 212, and the rotation shaft 212 supported by the bearing 216 rotates integrally with the rotor core 214. FIGS. 9A and 9B show general configurations of the stator iron core and the rotor used in the above-described inner rotor type brushless DC motor 100. FIG.

FIG. 9 shows a state in which the stator iron core 304 and the rotor are combined, and FIG. 9A is a front view thereof.
FIG. 10B is a cross-sectional view taken along a line bb in FIG.

The inner periphery of the stator core 304 is open, and the teeth 316 and the grooves 320 having a T-shaped cross section in the radial direction are alternately arranged at substantially equal intervals in the circumferential direction. That is, the slot open 322 exists between the teeth 316 adjacent in the circumferential direction. The windings are wound around each tooth 316, but are not shown for clarity.

FIG. 10A shows a method of winding a winding.
The coil 410 (FIG. 10 (b)) wound in advance using the winding frame 420 shown in FIG.
6 (see FIG. 9), a method in which the stator is formed by welding or bonding after dividing and winding the teeth, or a method in which the stator is directly wound on the teeth of the stator iron core using a winding machine. A winding method and the like are employed.

[0009]

However, in a conventional stator structure of an inner rotor type motor, when a coil wound by a winding frame is inserted, an operation for inserting the coil is performed because a circumferential width of a slot open is narrow. Not good. When a coil is inserted by a machine, an expensive coil insertion machine that can be used even when the slot open is narrow is required. Furthermore, when a coil is manually inserted, since the circumferential width of the slot open is narrow, skill is required for the operation, and it is difficult to increase productivity. When winding a coil (copper wire) directly on a tooth, a special winding machine that can be used even in a narrow slot open state is required to wind one tooth at a time, and this also requires a large investment. Since there is a slot open in the inner periphery of the stator core, the air gap of the magnetic circuit becomes long, and the motor efficiency is not good.
Furthermore, since many harmonic components are found in the magnetic flux distribution due to the slot open, torque loss becomes remarkable especially in a synchronous motor. When making a motor that is long (elongated) in the axial direction with respect to the radial direction, it is difficult to directly wind a winding or insert a coil in a structure in which the inner periphery of the stator iron core is open. The present invention has been made in view of the problems inherent in such a conventional structure, and has as its object to provide a stator structure of an inner rotor type motor in which motor workability is good and motor efficiency is improved. I do.

[0010]

According to a first aspect of the present invention, there is provided a stator structure for an inner rotor type motor, comprising an annular inner periphery and a radially outer portion. A stator formed by laminating steel plates and having an outer periphery having protruding portions provided at predetermined intervals in a circumferential direction, a coil mounted on the protruding portion, and fitted to the outer periphery of the stator And a cylindrical yoke to be combined.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS One aspect of the present invention is to laminate steel plates having an annular inner periphery and an outer periphery having radially outwardly projecting portions provided at predetermined intervals in the circumferential direction. A stator structure for an inner rotor type motor, comprising: a stator formed as described above; a coil mounted on the protrusion; and a cylindrical yoke fitted on the outer periphery of the stator.

Further, in the stator structure of the inner rotor type motor according to the above aspect, the yoke is formed by laminating laminated steel sheets.

Further, in the stator structure of the inner rotor type motor according to the above aspect, the yoke is formed of soft ferrite. This is an aspect in which it is possible to prevent dimensional accuracy from deteriorating due to uneven thickness in the axial direction due to the accumulation of the sheet pressure deviation of the silicon steel sheet.

Further, there is provided a stator structure for an inner rotor type motor, wherein reinforcing rings made of a non-magnetic metal are fixed to both axial sides of the stator. This is a preferred embodiment when it is necessary to increase the mechanical strength of the stator.

[0015]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In general, an inner rotor type motor comprises a stator on which a drive coil is mounted, and a rotor rotatably disposed in the inner periphery of the stator. The stator structure of the inner rotor type motor of the present invention is used for such an inner rotor type motor. Hereinafter, a stator structure of an inner rotor type motor according to the present invention will be described with reference to the drawings.
In the drawings, the same members are denoted by the same reference numerals.

FIGS. 1A and 1B show a stator core of the present invention. FIGS. 1A and 1B are a front view of the stator core and a line bb in FIG. 1A, respectively. FIG.

The stator iron core 1 is formed by laminating a predetermined number of silicon steel plates in the axial direction. The outer periphery of the stator core 1 has an open groove shape that opens radially outward, and has a cylindrical portion and teeth 16 provided at regular intervals in the circumferential direction of the cylindrical portion and protruding radially outward. The winding is wound around this tooth 16. Grooves 22 are defined between circumferentially adjacent teeth 16.

The radial cross section of the teeth 16 is rectangular, and has substantially parallel end surfaces 16a and 16b, an arc-shaped outer peripheral surface 16c,
It has side surfaces 16d and 16e opposed in the axial direction. This is a stator structure in which a yoke (to be described later) is fitted to the outer peripheral surface 16c.

Surfaces 22c and 22d constituting the bottom surface of the groove 22
Are connected at substantially the center (A part) between the teeth 16 adjacent in the circumferential direction, and define a V-shaped bottom surface in a radial cross section. In addition,
The wall thickness of the cylindrical portion is configured to be the thinnest at the portion A.

FIGS. 2A and 2B show a state in which a coil 10 wound by a bobbin (not shown) is mounted on the stator iron core 1 of the present invention. FIGS. FIG. 3 is a front view of the iron core and a cross-sectional view taken along line bb in FIG. As shown in the drawing, in the winding operation, regardless of whether the winding is wound directly on the teeth 16 or the coil wound in advance is mounted, the outer circumference of the stator core 1 Because it is an open groove shape,
The workability is very good, and the coil can be easily and quickly mounted. Also, in the work of mounting the coil,
It is possible to prevent the coil from being damaged because no excessive force is applied to the coil.

FIG. 3 shows a yoke 20 used in the stator structure according to the present invention. 3A and 3B are front views of the yoke, respectively, and FIG.
FIG. 4 is a cross-sectional view taken along line bb of FIG.

The cylindrical yoke 20 is the same as the stator iron core 1 described above.
Similarly to the above, a predetermined number of silicon steel plates are laminated in the axial direction. The axial length of the yoke 20 is substantially the same as that of the stator core 1. The inner diameter of the yoke 20 is dimensioned so that it can be fitted to the outer periphery of the stator core 1. Further, the inner diameter of the yoke 20 may be slightly smaller than the outer diameter of the stator core 1 and dimensioned so that the yoke can be press-fitted into the stator core.

FIG. 4 shows a stator structure of the present invention.
4A and 4B are a front view of the stator structure and a cross-sectional view taken along line bb in FIG. 4A, respectively.

The stator structure 21 is in a state where the yoke shown in FIG. 3 is fitted to the outer periphery of the stator core 1 having the coil shown in FIG. The stator structure 21 is used as an exciting coil, and a rotor (not shown) is arranged so as to face the inner periphery of the exciting coil, thereby forming an inner rotor type motor.

As shown in FIG.
Since the groove of the conventional configuration is not provided on the inner peripheral surface of the magnetic flux generating portion, the magnetic flux generating portion is not divided. Therefore, as compared with the conventional stator structure in which the inner circumference is grooved, even if the inner diameter of the stator structure is the same, it is possible to increase the size of the magnetic flux generating portion.

FIGS. 5A and 5B are views showing a yoke according to another embodiment of the present invention. FIGS. 5A and 5B are a front view and a drawing of a yoke according to another embodiment, respectively. Line b of 5 (a)
It is sectional drawing which followed -b. The shape of the yoke 40 is the same as that of the yoke 20 shown in FIG. However, the yoke 40 is made of soft ferrite and has a different material from the yoke 20 of FIG.

By the way, in the yoke 20 formed by laminating the silicon steel sheets shown in FIG. 3, when the number of the laminated silicon steel sheets is large, the thickness deviation is accumulated and the thickness unevenness in the axial direction occurs. Dimensional accuracy may be reduced. Therefore, in order to obtain a predetermined length in the axial direction of the yoke, it is preferable to use the soft ferrite yoke 40 rather than increasing the number of silicon steel sheets to be laminated.

FIG. 6 shows FIG. 1 with the reinforcing ring attached.
FIGS. 6A and 6B are front views of a stator core with a reinforcing ring and FIGS. 6A and 6B, respectively.
FIG. 4 is a cross-sectional view taken along line bb of FIG.

When designing the stator core, magnetic leakage prevention,
From the viewpoint of the type of motor, the number of poles, the number of grooves, and the like, it may be necessary to make the radial thickness of the portion A (see FIG. 1) extremely small. On the other hand, if the thickness of the portion A is reduced, the mechanical strength of the stator iron core itself may be insufficient. In order to secure the strength, it is effective to crimp a pair of annular reinforcing rings 50 integrally on both sides of the stator core 1 in the axial direction.
As a material of the reinforcing ring 50, a non-magnetic metal is preferable.

As described above, the mechanical strength of the stator iron core can be ensured by using the reinforcing ring. Note that the stator structure according to the present invention is not limited to the number and shape of the grooves provided in the stator core, the shape of the yoke and the coil as described in the above embodiment, and Needless to say, it can be changed and improved as needed.

[0031]

According to the stator structure of the inner rotor type motor of the present invention, since the outer peripheral side of the stator is open, when the coil wound by the winding frame is inserted, the circumferential width of the slot open is large. The workability of coil insertion is improved. When inserting the coil into the teeth, no excessive force is applied to the coil, so there is no risk of damaging the coil. Therefore,
The occurrence of defects such as coil insulation failure and disconnection can be reduced,
The quality of the motor can be improved. Further, even when the coil is manually inserted, the operation can be easily performed, and the productivity can be improved. Even when the winding is wound directly on the teeth, there is no narrow slot open, so it is easy to wind and the copper wire is less damaged. Since the inner circumference of the stator is annular, the air gap in the magnetic circuit is shortened, and the motor efficiency can be increased. Furthermore, in the conventional stator iron core, although many harmonic components caused by slot open were observed in the magnetic flux distribution, this problem can be solved. In particular, the synchronous motor has a remarkable improvement in torque. Furthermore, by making the inner periphery of the stator annular, it is possible to increase the area of the magnetic flux generating portion. Therefore, this is equivalent to shortening the magnetic path length of the stator in which the inner circumferential side is grooved in the related art, motor efficiency can be increased, and the motor can be made compact. Further, since the motor efficiency is improved, it is possible to reduce the number of turns of the winding required for the conventional stator iron core, and the coil end can be reduced as compared with the conventional stator structure. Therefore, since the DC resistance of the coil can be reduced, the motor efficiency can be increased. When making an elongated motor, it becomes easy to insert a coil as in the case of winding a winding straight.

[Brief description of the drawings]

FIG. 1 is a diagram showing a stator core of the present invention, wherein (a) and (b) are a front view of the stator core and a cross-sectional view taken along line bb of (a), respectively. .

FIGS. 2A and 2B are diagrams showing a stator core on which a coil of the present invention is wound, and FIGS. 2A and 2B are front views of the stator core and lines bb in FIG. It is sectional drawing along.

FIGS. 3A and 3B are views showing a yoke fitted to the stator iron core of the present invention, wherein FIGS. 3A and 3B are respectively a front view of the yoke and a line bb of FIG. It is sectional drawing.

FIG. 4 is a view showing a stator structure of the present invention, and (a).
And (b) are a front view of the stator structure and (a)
FIG. 4 is a cross-sectional view taken along line bb of FIG.

FIG. 5 is a view showing a yoke according to another embodiment of the present invention, wherein (a) and (b) are a front view of the yoke and a cross-sectional view taken along line bb of (a), respectively. is there.

FIGS. 6A and 6B are diagrams showing the stator core of FIG. 1 to which a reinforcing ring is attached, wherein FIGS. 6A and 6B are a front view of the stator core with the reinforcing ring and a line of FIG. It is sectional drawing in alignment with bb.

FIG. 7 shows a conventional inner rotor type brushless DC.
It is a partial section front view showing a motor.

FIG. 8 is a partial sectional front view showing a conventional inner rotor type induction motor.

FIG. 9 is a diagram showing a state where a conventional stator iron core and a rotor are combined, wherein (a) and (b) are a front view and a cross-sectional view taken along line bb in (a), respectively. It is.

FIGS. 10 (a) and (b) are a bobbin (wound form),
It is a figure which shows the example of a winding coil.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Stator iron core 10 Coil 16 Teeth 20, 40 Yoke 22 Groove 50 Reinforcing ring

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 5H002 AA02 AA03 AA07 AA08 AA09 AB01 AB06 AC06 AE07 5H603 AA03 BB01 BB05 BB12 CA01 CA05 CB02 CB26 CC11 CD01 CD04 CD11 CD22 CD32 CE05 EE12 EE13 5H615 AA01 QBQ12 Q12 SS05 SS09 SS11 SS19

Claims (1)

[Claims] In a stator structure of an inner rotor type motor, steel plates having an annular inner periphery and an outer periphery having a radially outwardly projecting portion provided at predetermined intervals in a circumferential direction are laminated. A stator structure for an inner rotor type motor, comprising: a stator formed as described above; a coil mounted on the protrusion; and a cylindrical yoke fitted on the outer periphery of the stator.