JP4543415B2 - Core structure of smooth armature winding AC servo motor and smooth armature winding AC servo motor using this core structure - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a core structure of a smooth armature wound AC servo motor obtained by mounting a coil for forming a rotating magnetic field on a slotless annular stator core, and a smooth armature wound AC servo motor using this core structure. About.
[0002]
[Prior art]
Conventionally, a smooth armature winding type AC servo motor is generally well known as one that can suppress the modulation of the field magnetic flux by the stator slot and has a characteristic of small torque ripple. Such a smooth armature wound AC servo motor is a stator core for a motor, and is formed by laminating a large number of electromagnetic steel plates in a ring shape, and the inner or outer peripheral surface of a cylindrical laminated core having no slots. In addition, a plurality of coils curved to fit the core shape are fixed to the core via an insulating layer and molded by resin. Alternatively, a plurality of coils are assembled to a cylindrical laminated core and assembled into a cylindrical shape, and the outer periphery is molded with resin, and then fitted and fixed to the cylindrical laminated core via an insulating layer.
[0003]
[Problems to be solved by the invention]
However, the conventional technique has the following problems.
(1) In a stator in which a large number of cylindrical electromagnetic steel sheets are laminated, the yield of the stator core is very poor.
(2) In order to improve the yield of the stator core material, there is a method of laminating long electromagnetic steel sheets by helical winding. However, in this method, strain stress is applied to the electromagnetic steel sheets, so the magnetic properties of the electromagnetic steel sheets Will fall.
(3) In order to restore the magnetic properties of the magnetic steel sheet, strain relief annealing is required after the core lamination, and the ratio of the stator core outer diameter to the stator thickness is restricted due to the bending of the stator core. Occurs, and the degree of freedom of shape as a motor is restricted. Therefore, a method of configuring the stator core as a wound iron core is conceivable. However, although it is easy to manufacture, the eddy current loss inside the core increases, so that the efficiency of the motor decreases.
(4) FIG. 4 is an explanatory view showing a conventional frame and stator core insertion process. For example, as shown in FIG. 4, when a cylindrical stator core 12 formed by laminating ring-shaped silicon steel plates 11 is inserted into and fixed to the outer frame 10, the stator is usually fitted by shrink fitting or adhesion. Since the core 12 is fixed to the frame 10, if there is an error such as roundness between the frame 10 and the stator core 12, there is a problem that positioning and fixing cannot be performed properly, or the stator core is attached to the frame 10. When 12 is inserted, the thickness of the entire circumference of the stator core 12 becomes uneven, the magnetic characteristics change, and cogging occurs. Therefore, the present invention uses a core structure of a smooth armature winding AC servo motor that has a good yield of the stator core material, is easy to manufacture and assemble, and has low loss and excellent magnetic characteristics, and this core structure is used. An object of the present invention is to provide a smooth armature winding AC servo motor.
[0004]
[Means for Solving the Problems]
In order to solve the above problem, the present invention according to claim 1 is characterized in that a substantially cylindrical frame and a rotating magnetic field formed on the inner peripheral surface or outer peripheral surface of the cylindrical stator core are fitted and fixed to the frame. An n-phase (m is a natural number) stator that is provided with n armature coils (n is a natural number and a multiple of m), and the stator and a magnetic gap are provided. And a rotor having a permanent magnet having P magnetic poles (P is an even number that is a natural number of 2 or more) having different polarities, and the plate material constituting the stator core is the longitudinal length of the plate material. A plurality of V-shaped cut portions formed toward the direction, and formed of silicon steel plates formed at the tips of the cut portions and provided with protrusions for positioning and fixing to the frame; The stator core is formed on the silicon steel plate. In a smooth armature winding AC servo motor that forms an annular body that is helically wound and laminated by bending a notch, the frame has a stator core protrusion formed by laminating the silicon steel plates. A plurality of recesses are provided so as to be fitted to each other, and the number of cut portions per circumference of the silicon steel plate constituting the annular body by stacking is a (where a is not a multiple of the phase number m) , all SANYO that the number a of the cut portion and the number of magnetic poles P has a prime number of relations, the least common multiple X of the number a and the number of magnetic poles P of the slit portion is, X> 10 × to have P relationship: It is characterized by .
According to a second aspect of the present invention, in the core structure of the smooth armature wound AC servo motor according to the first aspect, the cut portions are provided at unequal intervals in the longitudinal direction of the silicon steel plate. .
According to a third aspect of the present invention, there is provided a smooth armature winding type AC servo motor including the core structure stator according to the first or second aspect.
By the above means, the distortion of the core due to the bending is concentrated at the tip of the V-shaped cut-out portion, so that the magnetic property can be extremely reduced even if it is formed into a cylindrical shape. Moreover, the yield of electromagnetic steel sheets is also improved. The core formed into a cylindrical shape by bending has a number of cuts due to the cuts, and cogging occurs due to magnetic field modulation generated by the cuts, but the number of cuts a is a prime number relative to the number of magnetic poles P. By doing so, the basic order of cogging becomes high and the amplitude of cogging torque can be kept small.
[0005]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 is a smooth armature winding AC servomotor showing an embodiment of the present invention, in which (a) is a front sectional view thereof and (b) is a partially enlarged view of a silicon steel plate constituting a stator core. In this embodiment, an explanation will be given using an example of an inner rotor type smooth armature winding AC servo motor having 8 magnetic poles and 6 armature coils. In the figure, 1 is a substantially cylindrical frame, 2 is a stator fitted inside the frame 1, 3 is a cylindrical core, and a stator core formed by laminating silicon steel plates to be described later, 4 is an armature coil. In addition, the stator core 3 is disposed on the inner peripheral surface of the stator core 3 at equal intervals through an insulating layer (not shown). The armature coils 4 are molded with a resin (not shown). Reference numeral 5 denotes a rotor, 6 denotes a shaft, and 7 denotes a rotor core in which silicon steel plates are laminated. Reference numeral 8 denotes a permanent magnet that is bonded and fixed at equal intervals on the surface of the rotor core 7 so as to have different polarities alternately, and is provided via the armature coil 4 and a magnetic gap. Next, the feature of the shape given to the silicon steel plate which comprises the stator core 3 is demonstrated using FIG.1 (b). In the figure, 9 is a silicon steel plate having a strip shape, 9A is a V-shaped cut portion provided at equal intervals along the longitudinal direction of the silicon steel plate 9, 9B is a mating surface of the cut portions 9A, and 9C is a plurality of cuts. This is a projection provided for positioning when connecting and fixing the silicon steel plate 9A divided by the portion 9A to the frame 1. In such a silicon steel plate 9, the number of the cut portions 9 </ b> A per circumference of the silicon steel plate 9 constituting the annular body by stacking so as to be the number of magnetic salient poles of the stator core 3 is a, and the number of magnetic poles is P. In this case, the number of notches 9A and the number of magnetic poles have a prime number relationship with each other. In general, the cogging torque of the inner rotor type motor is generated by the field magnetic flux changing due to the positional relationship between the rotor and the stator core due to the magnetic saliency of the stator core. It becomes the least common multiple of the number of magnetic salient poles of the stator core, and the higher the order, the smaller the amplitude of the cogging torque tends to be. Thus, in the present embodiment, the number of notches 9A (a = 11) and the number of magnetic poles (P = 8), which are the number of magnetic salient poles of the stator core, are in a prime relationship with each other. By setting the least common multiple higher, the order of the cogging torque can be increased and the amplitude of the cogging torque can be reduced. Next, manufacturing and assembling processes of such a smooth armature winding AC servomotor will be described. FIG. 2 is a schematic view showing a bending process of a band-shaped silicon steel plate. FIG. 3 is an explanatory view showing an insertion process of the frame and the stator core. First, in the silicon steel plate 9 having an infinitely long band shape, a cut portion 9A and a protruding portion 9C are formed. That is, as shown in FIG. 1B, the band-shaped silicon steel sheet 9 is cut so that the core outer diameter after bending is Do and the core inner diameter is Di. At this time, the cut portion 9A is cut so that a circular arc having an angle of 2π / 11 radians obtained by dividing the entire circumference into 11 equal parts, and a protrusion 9C is formed at the tip of the cut portion 9A. Next, as shown in FIG. 2, the slit 9A of the silicon steel sheet 9 formed into a predetermined shape is wound in a helical shape while being bent, laminated to have a predetermined thickness, and cylindrical by bonding or the like. Mold. Thereafter, at this time, the silicon steel plate 9 bent at the notch 9A is connected by a protrusion 9C at the tip of the notch 9A. Then, as shown in FIG. 3, the stator core 3 is fixed to the frame 1 while the projection 9 </ b> C is positioned in the recess 1 </ b> A provided in the frame 1 using the projection 9 </ b> C. Accordingly, a smoothing electric machine comprising a stator having an armature coil for forming a rotating magnetic field on the inner or outer peripheral surface of a cylindrical stator core, and a rotor having a permanent magnet having P magnetic poles. In the slave winding AC servo motor, the rotor core is formed by forming a plurality of V-shaped notches on a silicon steel plate and bending them at the notches to form a cylindrical shape, and the number of notches a Since the number P of magnetic poles is in a prime relationship with each other, a smooth armature wound AC servo motor with good core material yield, easy manufacture and assembly, and low cogging torque can be realized. If the number of V-shaped cuts is a, the least common multiple X of a and the number of magnetic poles P preferably satisfies the relationship X> 10 × P. In this embodiment, X = 88>. 10 × 8 = 10P. Thereby, the order of cogging torque can be increased and the amplitude of cogging torque can be reduced. In this embodiment, the V-shaped cut portions are provided on the silicon plate or the like at equal intervals. However, the cut portions may be provided at unequal intervals. Further, in this embodiment, the core structure of the smooth armature winding AC servo motor has been described using the example of the surface magnet type motor in which the permanent magnet is disposed on the surface of the rotor core. You may apply to the internal magnet type motor of the structure with which it mounted | wore inside.
[0006]
【The invention's effect】
As described above, according to the present invention, an m-phase stator obtained by mounting n coils for forming a rotating magnetic field on the inner peripheral surface or outer peripheral surface of a cylindrical stator core, and P pieces In a smooth armature wound AC servo motor comprising a rotor having a permanent magnet having the number of magnetic poles, the stator core is provided with a plurality of V-shaped cut portions in a silicon steel plate formed in a strip shape. Bending is formed into a cylindrical shape, and the number of cuts (a) and the number of magnetic poles (p) are in a prime relationship with each other, so the yield of the core material is good, and manufacturing and assembly are easy. There is an effect that a smooth armature winding type AC servo motor with a small cogging torque can be realized.
[Brief description of the drawings]
FIG. 1 is a smooth armature wound AC servomotor showing an embodiment of the present invention, in which (a) is a front sectional view thereof, and (b) is a partially enlarged view of a silicon steel plate constituting a stator core. .
FIG. 2 is a schematic view showing a process of bending a band-shaped silicon steel plate.
FIG. 3 is an explanatory diagram showing an insertion process of a frame and a stator core according to the present embodiment.
FIG. 4 is an explanatory view showing a conventional frame and stator core insertion step.
[Explanation of symbols]
1: Frame 1A: Recess 2: Stator 3: Stator core 4: Armature coil 5: Rotor 6: Shaft 7: Rotor core 8: Permanent magnet 9: Silicon steel plate 9A: Cut 9B: Mating surface 9C: protrusion

Claims (3)

A substantially cylindrical frame;
N armature coils (n is a natural number and a multiple of m) for forming a rotating magnetic field are fitted and fixed to the frame and are formed on the inner or outer peripheral surface of a cylindrical stator core. A m-phase stator (m is a natural number)
A rotor provided with permanent magnets having P poles (P is an even number that is a natural number equal to or greater than 2) magnetic poles alternately provided with a magnetic gap and the stator.
The plate material constituting the stator core includes a plurality of V-shaped cut portions formed in the longitudinal direction of the plate material, and protrusions formed at the tips of the cut portions for positioning and fixing to the frame. It is composed of a silicon steel plate with a part,
In the smooth armature coiled AC servo motor, the stator core is formed in an annular body formed by winding and laminating helically by bending a notch formed in the silicon steel plate,
The frame is provided with a plurality of recesses so as to fit into the protrusions of the stator core formed by laminating the silicon steel plates,
The number of notches per round of the silicon steel plates constituting the annular body by laminating is a (where a is not a multiple of the number of phases m), and the number of notches a and the number of magnetic poles P are all SANYO with a prime number of relationships,
The core structure of a smooth armature wound AC servo motor, wherein the number a of the notches and the least common multiple X of the number P of magnetic poles have a relationship of X> 10 × P 2. The core structure of a smooth armature wound AC servo motor according to claim 1, wherein the cut portions are provided at unequal intervals in the longitudinal direction of the silicon steel plate. A smooth armature winding type AC servo motor comprising the stator having the core structure according to claim 1.

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