JP2002354719A - Stator core structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a stator core structure wherein precision is improved impendent of such conditions as laminating thickness (lamination), length, shape, and the number of slots of the stator core. SOLUTION: There are provided at least one chained thin plates 10 in which T-like unit plates 1, comprising an arc part 1b and a tooth piece part 1a protruding on the inner peripheral side of it, are connected at a connection part 2 at the edge of the outer peripheral side of the arc part 1b. T-like independent unit plates 9, comprising an arc part 9b and a tooth piece part 9a protruding on the inner peripheral side of it, are so laminated as to correspond to the unit plates 1 of the chained thin plates 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a stator core structure in an inner rotor motor (such as a brushless motor).

[0002]

2. Description of the Related Art As shown in a plan view of FIG. 9, a conventional stator core structure has a substantially T-shape including an arc portion 41b and a tooth piece portion 41a protruding from an inner peripheral side of the arc portion 41b. A chain-like thin plate 40 formed by connecting a predetermined number of base plates 41 at connecting portions 42 on the outer peripheral side edge of the arc portion 41b is provided, and a plan view of FIG.
As shown in the side view of (b), a plurality of laminated thin plates (laminations) 40 are laminated to form a laminate 43, and as shown in the plan view of FIG. It was configured by joining at 44 to form a cylindrical stator core 45. The chain-like thin plates 40 are connected to each other by the engagement of the projection coupling portions 46 formed on the base plates 41.

[0003] A coil (not shown) is wound around a tooth (teeth) 47 formed by laminating the respective tooth pieces 41a ... to form a stator. Inside the stator (not shown). ) A rotor is provided to constitute an inner rotor motor.

[0004]

However, in the conventional stator core structure, when the stacked body 43 is rolled (curled) to form the stator core 45 into a cylindrical shape, the spring effect of the connecting portions 42. Biasing force)
It is pushed back by the spring force (spring back),
The inner and outer diameters of the stator core 45 were round, concentric, and coaxial with low accuracy. And the effect is that the stator core 45
As the stack thickness (lamination) increased, the influence of springback was adversely affected, and the accuracy decreased. On the other hand, when the stator core 45 is forcibly corrected, an excessive stress is applied to the projection joints 46 for fixing the respective chain-like thin plates 40 or to the welded joint by laser welding (not shown, which is another fixing method). It could be damaged.

More specifically, as shown in FIG.
The conventional stator core 45 affected by springback (indicated by a solid line) has a roundness of inner and outer diameters (due to eccentricity) and coaxiality compared to a regular stator core in which a perfect circle is maintained (indicated by a broken line). Accuracy such as degree has decreased,
The gap between the inner peripheral surface portion 47a of the teeth 47 and the outer peripheral surface of the rotor (not shown) becomes unbalanced (unequal), and cogging torque, torque ripple, vibration, and noise are generated, which adversely affects motor characteristics. Had been hit. In particular, in the above-mentioned conventional stator core structure, a motor having a long stack thickness (lamination) of the stator core 45 or a large number of slots (teeth 47) (multi-slots)
It is not suitable for a motor, and the deterioration of motor characteristics becomes remarkable.

Therefore, an object of the present invention is to improve the roundness, coaxiality, and concentricity tolerance of the stator core without being restricted by the conditions such as the stack thickness (lamination) length, shape, and number of slots of the stator core. Another object is to improve the motor characteristics.

[0007]

In order to achieve the above-mentioned object, a stator core structure according to the present invention has a substantially T-shape comprising an arc portion and a tooth piece protruding from an inner peripheral side of the arc portion. At least one chain-like thin plate formed by connecting a plurality of base plates at a connection portion of an outer peripheral edge of the arc portion, and an arc portion and a tooth piece protruding from an inner periphery of the arc portion. Are laminated in a manner corresponding to each of the above-described chain-shaped thin plates.

[0008] With this configuration, when the stacked body in the initial stage formed by stacking the chain-like thin plate and the independent base plate is curled (rolled) to form the stator core, the spring by the connecting portion is formed. Since the influence of the back is small, it is possible to improve the accuracy of the inner and outer diameters of the stator core, such as roundness, coaxiality, and concentricity. For this reason, the gap between the inner peripheral surface of the teeth of the stator core and the outer peripheral surface of the rotor can be maintained in a balanced (uniform) manner.
Thus, the characteristics of the motor can be improved. Vibration and noise can be reduced. Cogging torque and torque ripple can be reduced. Rotation unevenness can be reduced. High efficiency of motor load characteristics can be achieved. In particular, it is suitable for a motor having a long stack thickness (lamination) of a stator core or a motor having a large number of slots (teeth) (multi-slots), and the motor characteristics are significantly improved.

In addition, the contact surfaces of the corresponding laminated base plates and the base plates are connected to each other by projection connection, welding, or the like, so that each independent base plate is indirectly or directly connected to the chain-like thin plate. Is what it is. Therefore, each independent base plate does not fall apart, and the cylindrical shape of the stator core can be reliably held.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the drawings showing embodiments.

FIG. 1 shows an embodiment of a motor having a stator core structure according to the present invention, which is a low-voltage, high-output type, large-current three-phase inner rotor motor (such as a brushless motor) for an industrial machine or the like. A lead wire 26 connected to an external connector (not shown) is connected (connected) to the coil 12 via a collecting plate (bus bar) 27 of a predetermined phase. The power supply from the external connector excites the coil 12 of the stator 11.

As shown in FIGS. 1 and 2, the stator 11
A 9-slot stator core 5 composed of a cylindrical laminated iron core and protruding nine teeth 7 in the inner circumferential direction, and a coil 12 wound around the stator core teeth 7 via an insulator 14. , Have.

More specifically, the motor section 20 includes a flange section 31 and a housing 25, and the rotary shaft 21 is mounted inside the flange section 31 and the housing 25 via a pair of upper and lower bearings 24,24. . A multi-pole rotor 13 composed of a rotor core of a laminated iron core and a rotor magnet is fixed to the rotating shaft 21, and surrounds the rotor 13.
The stator 11 (comprising the stator core 5 and the coil 12) is fixed to the housing 25. Further, a sensor magnet 23 magnetized, for example, to have the same number of poles as the rotor 13 is fixed to a portion above the rotary shaft 21 via a sensor holder 22 also serving as a back yoke.

A position detecting element 28 (such as a Hall element, a Hall IC, or a magnetoresistive element) is attached to a substrate 29 so as to face the upper surface of the sensor magnet 23.

The rotation of the rotor 13 with respect to the stator 11 is detected by detecting the magnetic pole of the sensor magnet 23 by the position detection element 28, and a predetermined signal is applied to each phase coil 12 of the stator 11 based on the detection signal. By sending the current, a rotating magnetic field is generated, and the rotor 13 can be rotated in a desired direction.

The stator core 5 is formed by joining both ends of the laminated body 3 shown in FIG. 4 at a joint 4 to form a cylindrical shape as shown in FIG.

The laminate 3 is shown in the plan view of FIG.
As shown in the front view of (b), at least one chain-like thin plate 10 is provided, and the independent base plates 9 are stacked in the thickness direction of the chain-like thin plate 10. More specifically, one to a small number of chain-like thin plates 10, 10, 10 are respectively disposed at the upper end, the middle, and the lower end to form three layers A, A, A, and a large number of independent sheets are formed. The base plate 9 is laminated, and two other layers B,
B is formed.

As shown in FIG. 3A, the chain-like thin plate 10 is a substantially T-shaped base plate having an arc portion 1b and a tooth portion 1a protruding from the inner periphery of the arc portion 1b. 1 is a predetermined number (9 in this embodiment) at the connecting portion 2 on the outer peripheral edge of the arc portion 1b.
) Are connected.

The arc portion 1b of the base plate 1 has an arc shape having a central angle of 40 °, one end of which is formed in a convex shape, the other end of which is formed in a concave shape, and a connecting portion having a minute width on the outer peripheral side. 2, the concave end portion of one of the base plates 1 and the convex end portion of the other base plate 1 are separated from each other in the arc portion 1b of the adjacent base plates 1, 1. In a state where both ends of the 3 (chain-like thin plate 10) are joined and formed into a cylindrical shape, the concave end portion and the convex end portion are fitted with each other, and the cylindrical shape of the laminate 3 (the chain-like thin plate 10) ( Annular).

As shown in FIG. 3B, the independent base plate 9 has a substantially T-shape comprising an arc portion 9b and a tooth portion 9a protruding from the inner periphery of the arc portion 9b. The layers B of the laminated body 3 are formed as shown in FIG. As can be seen from FIGS. 3 and 4, the single independent element plates 9 stacked are juxtaposed in the linearly developed state so as to have a minute gap S with the adjacent independent element plates 9, 9. I have. In other words, the independent base plates 9 of the layer B of the laminated body 3 are formed by connecting the base plates 1 of the chain-like thin plate 10 (of FIG. And are configured to be separated and independent from each other. The shape of the arc portion 9b of the independent base plate 9 is
Of the circular arc portion 1b.

In short, when the laminate 3 is in the linearly unfolded state shown in FIG. 4, in the partial layers A, the base plates 1 are connected (coupled) at the connecting portions 2. In B ..., the individual base plates 9 are independent at the minute gaps S, and if they are formed in a cylindrical shape as shown in FIG. Similar to the fitting of the concave end portion and the convex end portion of the chain-like thin plate 10 described above, the fitting of the concave end portion and the convex end portion of the independent base plates 9, 9 causes the minute gap S to be eliminated. )Contact. It can be said that the fitting of the concave end portion and the convex end portion provides an effect of arranging the independent base plates 9 at accurate inner and outer radial positions.

Note that the chain-like thin plates 10 and the independent raw plates 9.
Is a projection coupling portion 6 provided (by embossing or the like).
Are mechanically connected by the mutual engagement of each other. In other words, the independent base plates 9 and the chain-like thin plates 10 are connected to each other by the projection connection of the contact surfaces, and each independent base plate 9 Are connected indirectly or directly to the chain-like thin plate 10 so that the cylindrical shape of the stator core 5 (shown in FIG. 5) can be surely held so that the...

The chain-like thin plate 10 and the independent raw plate 9 are
A thin plate made of a magnetic material is formed by punching into a predetermined shape by press working.
Since the sheet material has a substantially straight shape, unnecessary portions of the plate material after punching are extremely reduced, and waste is reduced.

When the thus configured laminated body 3 is curled (rolled) to form the stator core 5 shown in FIG. 5, the number of the connecting parts 2 in the laminating direction of the laminated body 3 is small. 2 reduces the influence of springback, and improves the accuracy of the inner and outer diameters of the stator core 5, such as roundness, coaxiality, concentricity, and the like.

Further, even if the stator core 5 is forcibly corrected in order to improve the accuracy, the independent plates 9 in the layers B.
Are not connected between adjacent teeth, so that excessive stress is not applied to the projection coupling portions 6, and damage can be prevented.

Next, a method of forming the stator 11 shown in FIG. 2 will be described. In the laminated body 3 (substantially linear in plan view) shown in FIG. 4, tooth pieces 1a,. A coil 12 is wound around the tooth 7 thus formed, and then the laminated body 3 is curled and both ends thereof are joined to form a stator 11 shown in FIG.

In the motor to which the stator 11 is applied (shown in FIG. 1), the gap between the inner peripheral surface of the teeth 7 of the stator core 5 and the outer peripheral surface of the rotor 13 can be maintained in a balanced (uniform) manner.・ Noise reduction, cogging torque
Motor characteristics such as reduction of torque ripple, reduction of rotation unevenness, and higher efficiency of motor load characteristics can be improved. In particular, it is suitable for a motor having a long stator core stack thickness (lamination) or a motor having a large number of slots (teeth) (multi-slot) (that is, a type having a small bending angle of the connecting portion 2), and the motor characteristics are remarkably improved. Becomes

Next, FIG. 6 shows another embodiment of the present invention, and the following configuration is clearly different from FIG. That is, in FIG. 6, the chain-like thin plates 10 and the independent blanks 9 are connected to each other by welding joints 8 (by laser welding or the like).
Are connected to each other. As described above, since each independent base plate 9 is indirectly or directly connected to the chain-like thin plate 10, each independent base plate 9 does not fall apart, and the cylindrical shape of the stator core is ensured. Can be held.

Next, FIG. 7 shows another embodiment of the present invention. In the laminate 3, the chain-like thin plates 10 (one to a few sheets) form one intermediate layer A, and Form plates 9 are arranged on both sides to form two layers B, B. As described above, since the chain-like thin plates 10 are provided only in the middle of the stacked body 3 in the stacking direction, the influence of the springback caused by the connecting portions 2 is further reduced, and the accuracy of the stator core can be improved.

Next, FIG. 8 shows still another embodiment of the present invention. In the laminate 3 (one to a few sheets)
The chain-like thin plate 10 forms two layers A, A on the upper end surface and the lower end surface, and the independent base plate 9 is disposed therebetween to form one layer B. Therefore, since the chain-like thin plates 10 are provided only on the upper end face and the lower end face in the stacking direction of the stacked body 3, the cylindrical shape of the stator core can be reliably held, and
The influence of the springback by the connecting portions 2 can be reduced.

Here, in other words, the present invention relates to a laminated body 43 formed by laminating a plurality of chain-like thin plates 40 (see the conventional example of FIG. 10). body
Each of the base plates 41 of all the chain-like thin plates 40 except for at least one of the chain-like thin plates 40 out of 43 plural chain-like thin plates 40.
Can be said to be separated and independent.

The present invention is not limited to the above-described embodiment, but includes a method for connecting the chain-like thin plate 10 and the independent raw plate 9 to each other, and a method for forming the chain-like thin plate 10 and the independent raw plate 9 The number, shape, and the like of the base plates 9 can be changed in design without departing from the gist of the present invention.

[0033]

According to the present invention, the inner and outer diameters of the stator core, such as roundness, coaxiality, concentricity, etc., are not restricted by the conditions such as the stack thickness (lamination) length, shape, and number of slots of the stator core. Accuracy can be improved, and motor characteristics can be improved.

[Brief description of the drawings]

FIG. 1 is a sectional view showing an application example of the present invention.

FIG. 2 is a plan view showing an embodiment of the present invention.

FIG. 3 is a plan view showing a constituent member of the present invention.

FIG. 4 is a configuration explanatory view showing a laminated body.

FIG. 5 is a plan view showing a stator core.

FIG. 6 is a configuration explanatory view showing another embodiment of the present invention.

FIG. 7 is a front view showing another embodiment of the present invention.

FIG. 8 is a front view showing still another embodiment of the present invention.

FIG. 9 is a plan view showing a conventional constituent member.

FIG. 10 is a configuration explanatory view showing a conventional laminate.

FIG. 11 is a plan view showing a conventional stator core.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 base plate 1 a tooth section 1 b arc section 2 connecting section 3 laminated body 5 stator core 9 independent base plate 9 a tooth section 9 b arc section 10 linked thin plate S minute gap

Claims (2)

[Claims] 1. A substantially T-shaped base plate comprising an arc portion and a tooth piece protruding from an inner peripheral side of the arc portion is connected at a connecting portion of an outer peripheral edge of the arc portion. At least one continuous sheet
A plurality of independent T-shaped base plates each comprising an arc portion and a tooth piece portion protruding from an inner peripheral side of the arc portion are laminated so as to correspond to the respective base plates of the chain-like thin plate. A stator core structure. 2. The contact surfaces of the correspondingly laminated base plates and the base plates are connected to each other by projection connection, welding, or the like, so that each independent base plate is indirectly or directly connected to the chain-like thin plate. The stator core structure according to claim 1.