JPS6041545B2 - commutatorless motor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a field winding of a rotor in which a field winding is inserted into a slot provided on the outer periphery of a cylindrical rotating field core that does not become a magnetic pole part, and a rectangular wave current. This relates to a commutatorless motor in which the current phase relationship to the armature windings supplied with current is set constant, and in particular to improve the commutation characteristics by increasing the commutation margin angle of the square wave armature current. The present invention relates to an improvement in the above-mentioned rotor purchasing method.

Conventionally, as a rotor structure of a rotary field type commutatorless motor, one of two types in a synchronous machine is generally used, namely, a cylindrical rotor and a salient pole rotor.

Figure 1a shows a conventional cylindrical rotor type commutatorless motor (4
Fig. 1b is a cross-sectional view taken along line A-A in Fig. 1a, and Fig. 1c is an enlarged view of section B in Fig. 1b. Show the diagram. In the figure, 1 is a field core with a uniform circular outer peripheral surface, 2 is a field coil embedded in a slot of field core 1, and 3 is a field core embedded in a damper slot of field core 1. 4 is a shorting plate that electrically shorts the damper rod 3 at both ends; 5 is an armature core;
6 is the armature coil, g' is the field core 1 and the armature core 5
The gap length between the two is uniform over the entire circumference. next,
The operation will be explained using a vector diagram of the electric motor.

Figure 2 shows the voltage and current of the conventional non-commutator motor shown in Figure 1.
FIG. 2 is a known vector diagram regarding the fundamental wave component of magnetomotive force.
In the figure, the direct axis (d axis) is the direction of the field magnetic pole, and the machine axis (q
The axis) indicates the direction perpendicular to the field magnetic pole. When the field current IF is applied to the field coil 2, the field magnetomotive force AT is generated in the vertical direction.
F occurs. When armature current is passed through the armature coil 6, the armature reaction magnetomotive force ATa is generated by its fundamental wave component la.
occurs, and its direction has an electrical angle (BO-wife side) phase relative to the field magnetomotive force ATF, as shown in the figure. Here, the angle 8o represents the starting phase of the rectangular wave armature current of the commutatorless motor, and is the setting control advance angle of the distributor (not shown) of the commutatorless motor. Further, the angle u indicates the load commutation overlap angle of the commutatorless motor. Next, we will focus on the relationship between magnetomotive force and magnetic flux within the motor. The field magnetic flux ■F generated by the field magnetomotive force ATF is generated in the same direction as the ATF. On the other hand, the armature reaction magnetic flux ■a generated by the armature reaction magnetomotive force ATa is also generated because the outer peripheral surface of the field core of the rotor is a uniform circle and the air gap length g of the motor is uniform over the entire circumference. , the magnetic reluctance of the vertical axis magnetic circuit and the magnetic resistance of the horizontal axis magnetic circuit are equal and therefore occur in the same direction as ATa. As a result, the air gap length g. ,■F and■
There is a vector composite magnetic flux ■g of a, and an induced electromotive force Ea proportional to this ■g and the rotational speed of the motor is generated, and its direction is ahead of ■g by 90 electrical degrees and in phase. The terminal voltage Vt of the motor is determined by the voltage drop (ra+k,
) la is the vector composite value. Further, the torque of the electric motor is generated by the interaction between the armature current la and the air gap magnetic flux g. However, in a non-commutator motor, the phase at which the commutation of the square wave armature current is completed is (8) than the field magnetic force ATF.

It is essential for commutation that the line ○P, which is in phase advanced by -u19 and ), is in phase advanced by more than the minimum necessary commutation margin angle than the phase of terminal voltage Vt. As mentioned above, the field core of the rotor is a circle with a uniform outer peripheral surface, and since the air gap length of the motor is uniform over the entire circumference, the magnetic resistance of the Naoto magnetic circuit and the magnetic resistance of the machine shaft magnetic circuit are As a result, the armature reaction magnetic flux ■a is generated in the same direction as the armature reaction magnetomotive force ATa, and as the load torque increases, the angle between the terminal voltage Vt and the line ○P tends to decrease significantly. This was a hindrance to reducing the size and weight of the non-commutated Viscount motive. The present invention was made in order to eliminate the drawbacks of the conventional ones as described above, and the outer peripheral surface of the cylindrical rotating field iron core is made uneven to reduce the influence of armature reaction, thereby reducing the size and weight. The purpose is to provide a commutatorless motor.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 3a is a longitudinal sectional view showing the structure of a commutatorless motor according to the present invention, and FIG. 3b is a sectional view taken along line A--A in FIG. 3a. Further, FIG. 3c shows an enlarged view of section B in FIG. 3b. In the figure, 1 is a field whose outer peripheral surface is processed unevenly so that the radius of the arc in the part where the field coil slot exists is smaller than the radius of the arc in the magnetic pole part where the field coil slot does not exist. Magnetic core, 2
3 is a field coil embedded in a slot of field core 1, 3 is a damper twill embedded in a damper slot of field core 1, and 4 is a field coil embedded in a slot of field core 1.
is a short-circuit plate that electrically short-circuits the damper rod 8 at both ends thereof;
5 is an armature core, and 6 is an armature coil. Next, the operation will be explained.

Figure 4, similar to Figure 2, shows the fundamental wave components of voltage, current, and magnetomotive force, with the direct axis (d-axis) in the direction of the field magnetic pole and the horizontal axis (q-axis) in the direction perpendicular to the field magnetic pole. Shows a vector diagram. In the figure, field current IF, field magnetomotive force ATF, fundamental wave component la of armature current, and armature reaction magnetomotive force ATa
The relationship is the same as in FIG. Next, we will focus on the relationship between magnetomotive force and magnetic flux within the motor. The field magnetic flux ■F generated by the field magnetomotive force ATF is generated in the same direction as the ATF. However, the armature reaction magnetic flux 1a generated by the armature reaction magnetomotive force ATa is not generated in the same direction as ATa. That is, the armature reaction magnetomotive force ATa is the field magnetomotive force ATF
The armature reaction magnetic flux (a) has an electrical angle that is (8.-90) degrees more advanced in phase than the armature reaction magnetomotive force. This is because the magnetic resistance of the vertical magnetic circuit D shown by the solid line in FIG. Since the length of the air gap is 2×&, which is 4×, it shows a value smaller than the magnetic resistance of the wisteria shaft magnetic circuit Q. Therefore, the component of the armature reaction magnetic flux generated in the machine axis direction where the magnetic resistance is large is considerably suppressed. Furthermore, in the air gap of the motor, there is a vector composite magnetic flux g of the field magnetic flux F and the armature reaction magnetic flux a, and this composite magnetic flux g and the induced electromotive force Ea proportional to the rotational speed of the motor are combined. The magnetic flux ■ is generated at an electrical angle position that is 90 degrees ahead of the phase g. The motor terminal voltage Vt is determined by the above induced electromotive force Ea and the armature leakage impedance (ra+ix,
) is the vector composite value of the voltage drop (ra + 戊, )la, and the motor torque is the armature current la and the air gap magnetic flux ■
It is generated by the electromagnetic action of g. A remarkable feature of the embodiments of the present invention is that the generation of the axis component of the armature reaction magnetic flux is considerably suppressed, so that the phase of the induced electromotive force Ea that accompanies an increase in load torque, that is, an increase in armature current la, is significantly suppressed. Changes are reduced. Therefore, the rate of decrease of the angle y between the phase at which commutation of the square wave armature current is completed (line ○P in Figure 4) and the phase of the motor terminal voltage V as the load torque increases is Therefore, the load torque limit at which the commutatorless motor can operate stably increases. As described above, according to the present invention, the field winding of the rotor is formed by embedding the field winding in the slot provided on the outer periphery of the cylindrical rotating field iron which does not become the magnetic pole part, and the rectangular wave. In a commutatorless motor in which the energization phase relationship to the armature windings to which current is supplied is set constant, the radius of the arc of the portion of the cylindrical rotating field iron core that becomes the magnetic pole portion is defined as the portion that does not become the magnetic pole portion. Since the radius of the arc is larger than that of the arc and its outer peripheral surface is processed unevenly, the armature reaction magnetic flux can be made to have a phase leading than the armature reaction magnetomotive force, and the commutation margin angle of the rectangular wave electric machine viscous current can be It can be increased to improve commutation characteristics.

This increases the load torque limit of the commutatorless motor, making it easier to reduce the size and weight of the motor.

[BRIEF DESCRIPTION OF THE DRAWINGS] FIG. 1a is a longitudinal sectional view showing the configuration of a conventional non-commutator motor, FIG. 1b is a sectional view taken along line A-A in FIG. 1a, Figure 1c is an enlarged view of section B in Figure 1b, Figure 2 is a vector diagram of voltage, current and magnetomotive force in Figure 1, Figure 3a is
3 is a vertical cross-sectional view showing the configuration of the commutatorless motor of the present invention.
Figure b is a cross-sectional view taken along line A-A in Figure 3a, Figure 3c is an enlarged view of section B in Figure 3b, and Figure 4 is the voltage, current and FIG. 3 is a diagram showing a vector diagram of magnetomotive force. 1...Field iron core, 2...Field coil,
g,, g2...Gap In the drawings, the same reference numerals indicate the same or corresponding parts. Figure 1 Figure 2 Figure 4 Figure 3

Claims (1)

[Claims] 1 A damper rod with both ends short-circuited with a short-circuit plate is embedded in a slot provided only near the outer periphery of the portion that will become the magnetic pole of a cylindrical rotating field core, and a damper rod is provided only near the outer periphery of the portion that will not become the magnetic pole. A commutatorless motor in which a field winding of a rotor is constructed by embedding a field winding in a slot, and the energization phase relationship between the field winding of the rotor and the armature winding to which a square wave current is supplied is set constant. In the cylindrical rotating field iron core, the radius of the circular arc of the part that becomes the magnetic pole part is made larger than the radius of the circular arc of the part that does not become the magnetic pole part, so that the armature reaction magnetic flux has a phase leading than the armature reaction magnetomotive force. A commutatorless motor characterized by increasing the commutation margin angle of the square wave armature current and increasing the load torque limit.