JPS5924621B2 - synchronous motor - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a synchronous motor, and its purpose is to be able to automatically start a permanent magnet rotor in one direction without the need for accessory parts such as a shade coil, and to be easy to manufacture. The object of the present invention is to provide an efficient synchronous motor.

FIG. 1 shows a cross-sectional view of a synchronous motor that forms the basis of this invention.

In the figure, 1 is a surface-facing rotor block, 2 is a disc-shaped multi-pole magnetized permanent magnet rotor which is the main part of the rotor block 1, 3 is a motor shaft, 4 is a bearing mechanism, 5(/
'i Stator yoke made by drawing from a magnetic iron plate, 6 is the main excitation coil, γ is the center magnetic path of the stator yoke 5,
Reference numeral 8 denotes a stator magnetic pole tooth plate, which is a disk-shaped plate made by punching an iron plate and has multi-pole magnetic pole teeth.

This stator magnetic pole tooth plate 8 faces the surface of the multipolar permanent magnet rotor 2 to constitute a multipolar synchronous motor.

The stator magnetic pole tooth plate 8 has 36 poles, and as shown in Fig. 2, it is manufactured from a single magnetic iron plate by the photographic corrosion method or by punching.The stator magnetic pole tooth plate outer frame has 9 pieces. 18 stator magnetic pole teeth 10 radially equidistantly spaced toward the center
27 are provided in a protruding manner, and a portion of the tip of each of the magnetic pole teeth 10 to 27 is integrally connected to the inner frame 28 of the stator magnetic pole tooth plate.

In addition, the stator inner frame 287) is arranged such that 18 magnetic pole teeth 29 to 46 having a magnetic pole tooth width wider than the magnetic pole tooth width of the stator magnetic pole teeth 10 to 27 are arranged at equal intervals in the direction of the stator outer frame 9. The magnetic pole teeth 29 to 4 are protruded radially so as to alternately enter the magnetic pole teeth 29 to 27.
A portion of the tip of the stator 6 is partially integrally connected to the stator outer frame 9.

The rotor rotation direction (
The stator magnetic pole teeth 29 to 46, which are adjacent to each other in the counterclockwise direction, are spaced apart by an angle α from the center lines of the stator magnetic pole teeth 29 to 46, each having a wide magnetic pole tooth width.

Further, the center line of the stator magnetic pole teeth 10 to 27 and the center line of the wide stator magnetic pole teeth 29 to 46, which are adjacent to each other in the opposite rotational direction to the stator magnetic pole teeth 10 to 21, are arranged at an angle β. It is set up.

α is designed to be slightly smaller than β, and the width of stator magnetic pole teeth 29 to 46 is approximately twice the width of stator magnetic pole teeth 10 to 2γ, and α and β are electrical angles α<180 °
, β) 18CP.

” The arrangement is such that the length L=1800.

Next, as shown in FIG. 3, the magnetic pole surface of the disc-shaped rotor 2 used to face the stator magnetic pole tooth plate 8 having the structure shown in FIG. 2 is made of a disc-shaped hard magnetic material. A total of 36 magnetic poles, the same number as the number of motor poles, are magnetized alternately N and S at equal intervals at an angle of a+1i.

This rotor 2 has a stator outer frame 9 and a stator inner frame 28.
The rotor 2 and the stator magnetic poles are always connected by the magnetic force of the permanent magnets of the rotor 2. The structure is such that an attractive force acts between the rotor 2 and the toothed plate 8, and the gap between the rotor 2 and the stator magnetic pole toothed plate 8 is kept constant (see FIG. 1).

Next, the operation of the rotor when starting up will be explained with reference to figures in which the stator magnetic pole teeth and the rotor magnetic pole teeth are developed in a line as shown in FIGS. 4a-e.

In Fig. 4, 35, 36, and 37 indicate all representative stator magnetic pole teeth with wide width, and 16, 17, and 18 indicate representative stator magnetic pole teeth with narrow width. α and β
In experiments, it was found that the angle α of the white side was 130 to 150 degrees in electrical angle, and therefore β was in the range of 210 to 230 degrees in terms of characteristics.

Note that the distance between adjacent N and S magnetic poles of opposite polarity on the rotor 2 is exempt from tax.

First, in a state where no excitation current is passed through the excitation coil 6 (Fig. 1), stator magnetic pole teeth 10 to 27 and 29 to
Since 46 is also in a non-excited state, no magnetic flux is generated, and the magnetic pole width of the stator magnetic pole teeth 10 to 2γ is the same as the stator magnetic pole teeth 29 to 4.
The center line of each of the stator magnetic pole teeth 10 to 2T and the center line of the stator magnetic pole teeth 29 to 46 that are adjacent to each other in the rotation direction of the rotor 20 for each of the stator magnetic pole teeth 10 to 27. An angle α between the center line of each of the descendant pole teeth 10 to 27 and the center line of the stator magnetic pole teeth 29 to 46 adjacent to each of the stator magnetic pole teeth 10 to 21 on the opposite rotation direction side of the rotor 2 Since the angle β is smaller than the angle β, the magnetic flux of the adjacent magnetic poles of opposite polarity of the rotor 2 is smaller than the angle β, so that the magnetic flux of the adjacent magnetic poles of opposite polarity of the rotor 2 is smaller than the magnetic flux of the adjacent stator magnetic pole teeth 2 with an angle α interval, as shown in FIG.
9 to 46 and 10 to 27, that is, the rotor 2
In order for the magnetic flux of adjacent magnetic poles of opposite polarity to take a path such that the magnetic resistance is minimized, the rotor 2 is provided with the stator magnetic pole teeth substantially opposite to each other as shown in FIG. Stop in position.

When the rotor 2tri is shifted, the positional forces shown in Figure 4 a'E and ub create a torque (due to static magnetic force) between each magnetic flux of the magnetic poles of the rotor 2 and each of the stator magnetic pole teeth. is automatically returned to the positional relationship shown in FIG. 4 a'E or b.

Note that this static magnetic force always works even when current flows through the exciting coil and the stator magnetic pole teeth are excited.

Next, when an AC voltage is applied to the excitation coil, the stator magnetic pole teeth 29 to 46 and 10 to 27 are always excited with opposite magnetism. Assuming that it is excited to the north pole when applying ,
Since each of the S poles of the rotor 2 is S pole almost directly opposite the stator magnetic pole teeth 10 to 27 as shown in FIG. 4a, rotational torque is generated. However, each of the rotor 2 ON poles is opposed to the stator magnetic pole teeth 29 to 46 by being displaced in the rotation direction of the rotor 20 as indicated by the arrow P in the figure, and the stator magnetic pole teeth 29 to 46 are opposed to the stator magnetic pole teeth 29 to 46. Since each of the north poles of the rotor is a pole, the stator magnetic pole tooth 2 is a north pole.
9 to 46, each of the S poles of the rotor 2 has an angle α smaller than β, so the stator magnetic pole teeth 29 to 46, which are close to each other in the direction of rotor rotation among the N poles, Each is attracted and generates rotational torque, and the rotor 2 rotates in the direction of arrow P, which is the rotation direction side. As the rotor 2 rotates, each of the S poles of the rotor 2 becomes a stator magnetic pole, which is an S pole. Teeth 10-27
Each of the S poles of the rotor 2 is displaced in the rotational direction and opposed to the stator magnetic pole teeth 29-46, and is also displaced in the counter-rotational direction to the stator magnetic pole teeth 29-46. 2
A rotational torque is generated which is repelled by the stator magnetic pole teeth 29 to 46 and is attracted to the stator magnetic pole teeth 29 to 46, and the rotor 2 (/'i rotation generates rotational torque in the lateral direction and rotates as shown in FIG. 4C). It rotates with a certain positional relationship.

At that time, the position of the rotor 2 is such that each of the N poles of the rotor 2 faces the stator magnetic pole teeth 10 to 27 with a slight displacement in the opposite rotation direction, and each of the S poles of the rotor 2 faces the stator magnetic pole teeth 10 to 27. It faces the magnetic pole teeth 29 to 46 in the rotational direction, and is therefore substantially the same as the resting position of the rotor 2 during so-called non-excitation, when no current flows through the exciting coil 6.

Therefore, the force attracted in the rotational direction by the stator magnetic pole teeth 10 to 2T in which each of the north poles of the rotor 2 is an south pole, and the stator magnetic pole teeth in which each of the south poles of the rotor 2 is a north pole. 29-46
The rotor 2 comes to rest in the positional relationship shown in FIG. 4C at a position where the three forces, the force attracted in the opposite rotational direction and the static magnetic force described above, are balanced.

After that, when the direction of the current flowing through the coil 6 is reversed by the AC voltage applied to the excitation coil 6, the magnetic flux of each of the stator magnetic pole teeth almost disappears, so as described above, the magnetic flux of each of the magnetic poles of the rotor 2 and A torque is generated between each of the stator magnetic pole teeth due to the static magnetic force, and the rotor 2 rotates a little in the direction of rotation and moves to the position shown in FIG. 4.

Thereafter, when the direction of the current flowing through the coil is reversed by the alternating current voltage, stator magnetic pole teeth 29 to 46 become S poles, stator magnetic pole teeth 10 to 27 (/'iN poles), and rotor 2
Each of the S poles of the rotor 2 repels the stator magnetic pole teeth 29 to 46, which are S poles, and each of the N poles of the rotor 2 has an S pole stator magnetic pole tooth 29 that is closer to the rotating direction side because α is smaller than β. ~ 46, the rotor 2 rotates in the rotational direction, and the rotor 2
As the rotor 2 rotates, each of the north poles of the rotor 2 is repelled by the stator magnetic pole teeth 10 to 21, which are north poles, and rotates further to the position shown in FIG. 4d.

At the position shown in FIG. 4d, each of the ON poles of the rotor 2 is attracted by the stator magnetic pole teeth 29 to 46, which are S poles, in the opposite rotation direction, and each of the S poles of the rotor 2 is N A force that is attracted to the stator magnetic pole teeth 10 to 27, which are poles, in the rotation direction,
The three static magnetic forces mentioned above are balanced.

After that, when the direction of the current flowing through the coil 6 is reversed again by the AC voltage applied to the excitation coil 6, the magnetic flux of each of the stator magnetic pole teeth almost disappears, so that the magnetic flux of each of the magnetic poles of the rotor 2 and A torque is generated between each of the stator magnetic pole teeth due to the static magnetic force, and the rotor 2 rotates a little in the direction of rotation and stops again at the position shown in FIG. 4a.

Therefore, for every 1 Hz of the AC voltage applied to the excitation coil 6, the rotor 2 rotates in the rotation direction by an angle corresponding to twice the pinch between adjacent magnetic poles of opposite polarity, that is, α+β.

Next, if the stator magnetic pole teeth 29 to 46 are excited to the S pole when AC voltage is applied to the excitation coil 6 in FIG. 4a, each of the S poles of the rotor 2 (/'i Since the child magnetic pole teeth 10 to 27 are almost directly opposed to each other, no rotational torque is generated, but each of the rotor 2ON poles is S
Since the stator magnetic pole teeth 29 to 46, which are poles, are displaced in the direction of rotation and are opposed to each other, rotational torque is generated, and the rotor 2
receives a force in the counter-rotation direction and rotates to the position shown in Fig. 4e, but as the rotor 2 rotates, each of the S poles of the rotor 2 rotates counter-rotated with respect to the stator magnetic pole teeth 10 to 27. Since they are displaced in the opposite rotational direction, each of the north poles of the rotor 2 is an south pole, and the force attracted to the stator magnetic pole teeth 29 to 46 in the counter-rotation direction, and each of the south poles of the rotor 2 is The rotor 2 cannot rotate any further in the opposite rotational direction because the force that is attracted to the stator magnetic pole teeth 10 to 27, which is the N pole, in the rotational direction and the static magnetic force described above are balanced. First, the rotors 2 come to rest in the mutual positional relationship shown in FIG. 4e.

After that, when the direction of the current flowing through the coil 6 is reversed by the AC voltage applied to the excitation coil 6, the magnetic flux of each of the stator magnetic pole teeth almost disappears, so as mentioned above, the magnetic flux of each of the magnetic poles of the rotor 2 is fixed. Torque is generated by each of the child magnetic pole teeth due to the static magnetic force, and the rotor 2 rotates slightly in the rotational direction due to the mutual positional relationship force shown in FIG. 4e, as shown in FIG. 4a.
It stops at the mutual positional relationship shown in .

Thereafter, when the direction of the current flowing through the coil is reversed by the alternating current voltage, the stator magnetic pole teeth 29 to 46 are excited to the north pole, so that the stator magnetic pole teeth 29 to 46 become the north pole when the alternating current voltage is applied in FIG. Exactly as when the rotor 2 is excited, the rotor 2 rotates in the direction of rotation by an angle corresponding to twice the pinch between adjacent magnetic poles of the rotor 2, that is, α+β, for every 1 Hz of the alternating voltage.

Furthermore, even when the rotor 2 is stationary in the mutual positional relationship shown in FIG. 2/ri is automatically activated and rotates in the rotation direction by an angle corresponding to twice the pinch between adjacent magnetic poles of opposite polarity of the rotor 2, that is, α+β, for every 1 Hz of the AC voltage.

In this way, one-way self-starting characteristics and synchronous rotation of the rotor 2 are obtained.

In the synchronous motor having the above configuration, the width of each of the stator magnetic pole teeth 10 to 27 is set to the width of the stator magnetic pole teeth 2, although it varies somewhat depending on the length of the air gap between the rotor magnetic poles and the stator magnetic poles.
Based on the equation of motion and experimental power, it is clear from the equation of motion and experimental power that the starting performance is good if the width of each of the magnetic rods 9 to 46 is approximately half, and the angle β is approximately 1.6 times as large as α. It became a sword.

In this way, the magnetic pole width of the stator magnetic pole teeth 10 to 27 of one polarity is made smaller than the magnetic pole width of the stator magnetic pole teeth 29 to 46 of the other polarity, and the stator magnetic pole teeth 10 having the small magnetic pole width are
27 in the rotor 20 rotation direction side, the stator magnetic pole teeth 10 to 27 having a small magnetic pole width and the widths adjacent to the stator magnetic pole teeth 10 to 27 in the rotor rotation direction side having a small magnetic pole width. The distance α between the wide magnetic pole teeth 29 to 46 is set to the stator magnetic pole teeth 10 to 27 having a small magnetic pole width and the wide adjacent magnetic pole teeth 10 to 21 having a small magnetic pole width on the side opposite to the rotor rotation direction. Since the spacing between the magnetic pole teeth 29 to 46 is smaller than β, the rotation of the adjacent magnetic poles of opposite polarity on the rotor is caused by each of the stator magnetic pole teeth 10 to 21 and the stator magnetic pole teeth 10 to 27, each having a small magnetic pole width. The rotor 2 can be made to almost face each of the stator magnetic pole teeth so as to pass through the stator magnetic pole teeth 29 to 46, which have wide magnetic pole widths adjacent to each other in the child rotation direction, so that the rotor 2 is fully automatically started. At the same time, the starting direction can be made constant.

However, as shown in FIG. 2, the more the number of poles in the magnetic pole tooth plate 8, the denser the magnetic pole teeth become, making it difficult to punch out.

By the way, it was particularly difficult to master the example because it was small with an outer diameter of 25 mm as shown in FIG.

In order to solve this problem, when the magnet rotor is placed face-to-face, the area ratio of each inner and outer magnetic pole tooth facing the rotor magnetic pole face is maintained, and the magnetic pole teeth of each deer and the other are as shown in Figure 2. To prevent them from fitting together alternately, press the outer magnetic pole teeth with short force.
We proposed a stator with a new magnetic pole tooth arrangement.

An example of such a stator is shown in FIG.

The rotation principle of the stator with this magnetic pole tooth arrangement is the same as that shown in Fig. 2, but the punching process has become easier.

However, in the arrangement shown in FIG. 5, there is a sufficient distance between the outer magnetic pole tooth tip 41 and the inner magnetic pole tooth tip 48 for punching, so the air gap between the two magnetic pole tooth tips 47 and 48 It has been found that the magnetic resistance of the magnetic pole teeth is larger than in the case shown in FIG. 2, and when used as an electric motor, the starting excitation current becomes too strong, resulting in low efficiency.

In order to improve this problem, we invented a stator magnetic pole tooth plate having a magnetic pole tooth arrangement as shown in FIG.

This is also basically the same as the magnetic pole teeth shown in FIG.
the inner magnetic pole tooth 5 of the outer magnetic pole tooth 49
By making the pitch of 0 equal to the thickness of the entire magnetic pole tooth plate,
The motor excitation current was set to 20% or less of that using the magnetic pole tooth sheet metal shown in FIG. 5, and the same starting excitation current as that using the magnetic pole tooth sheet metal shown in FIG. 2 was obtained.

In the end, by keeping the principle of the magnetic pole tooth plate force and the like shown in Fig. 2, and proposing the magnetic pole tooth arrangement shown in Fig. 5, and then reimproving it as shown in Fig. 6, the motor efficiency was as shown in Fig. 2. It is no different from using a conventional material, but it is easier to process the force and material, and it is also easier to make multi-poles.

Incidentally, FIGS. 5 and 6 show a structure with 48 poles.

In this case, the optimal values of α' and β' are different from the α and β values explained in Figure 2, and should be set at α' = 95 to 105 electrical angles and β' = 255 to 265 electrical angles. As a result, the starting voltage of the motor of the present invention can be made the same as that of the motors described in Figures 1 and 4.

Experiments have revealed that the voltage range that allows for stable synchronous rotation is sufficient for practical use.

It has been experimentally found that the rotation of the motor becomes more stable when the width of each magnetic pole tooth exceeds 180 electrical degrees by about 5 to 10 electrical degrees, that is, about 190 electrical degrees.

In the process of improving the magnetic pole tooth force shown in Figure 5 to that shown in Figure 6, the characteristics improved more than in the case of Figure 2.
It has become easier to make the magnetic poles multiplier, and the magnetic pole arrangement has been improved to make it easier to process.

Note that the tips of the outer magnetic pole teeth 49 and the inner magnetic pole teeth 50 are inclined so that the tips of the inner magnetic pole teeth 50 are on the rotation direction P side in FIG. Even if the angle is tilted to , there is no effect because the magnetic resistance of the magnetic pole teeth is reduced.

As described above, according to the present invention, it is possible to realize a synchronous motor that can be started automatically without using accessory parts such as a shade coil, is easy to manufacture, and has high power and efficiency.

[Brief explanation of drawings]

FIG. 1 is a longitudinal cross-sectional view of a synchronous motor that is the basis of this invention.
Fig. 2 is a plan view of the stator magnetic pole tooth plate, Fig. 3 is a plan view of the rotor, Fig. 4 is an explanatory diagram of the operating principle of the synchronous motor of Fig. 1, and Fig. 5 is the basis of this invention. FIG. 6 is a partial plan view of an example of the magnetic pole tooth plate used in the synchronous motor of the present invention. 49...Outer magnetic pole tooth, 50...Inner magnetic pole tooth.

Claims (1)

[Claims] 1 A plurality of inner magnetic pole teeth extending radially outward from the inner magnetic pole teeth, and a plurality of inner magnetic pole teeth extending inward from the outer force so as to be arranged at positions shifted by a predetermined angle with respect to the inner magnetic pole teeth. and inclined facing portions formed at the tips of the inner and outer magnetic pole teeth such that adjacent tips of the inner and outer magnetic pole teeth face each other at a constant angle with respect to the circumferential direction. In a synchronous motor having a magnetic pole tooth plate, the angles formed between the center of the inner magnetic pole tooth and the center of the outer magnetic pole tooth adjacent thereto are set to 95 to 105 electrical degrees and 225 to 265 electrical degrees, respectively, A synchronous motor, wherein the angle of the inclined facing portions of the inner and outer magnetic pole teeth with respect to the circumferential direction is set to 25 degrees or more.