JPH01234038A - Revolving-field type synchronous machine - Google Patents

Abstract

PURPOSE:To decrease a machining cost and to increase an output, by bonding a hexagonal columnar permanent magnet comprising a rare earth material wherein the long side of the cross section of a rectangular parallelopiped is the base of an isosceles trapezoid on the surface of a rotor which is freely rotated in a cylindrical stator. CONSTITUTION:Many sheets of steel plates in which a plurality of slots 14 are blanked are laminated, and pole pieces 15 are formed. A coil 16 is wound, and a three-phase stator 12 is formed. A rotor 17 which is supported with bearings so that it is freely rotated is inserted into the stator 12. The rotor 17 is formed by bonding or coupling a permanent magnet 1 comprising a rare each material on the surface of an octagonal rotor core 18. The permanent magnet 1 has a hexagonal column shape. A long side BC of the rectangular parallelopiped of the cross section of the magnet is equal to a base AD of the isosceles trapezoid of the cross section. The magnet is magnetized in the direction of the thickness so that the polarities are alternately reversed. The interval between the points E and F of the trapezoid and the pole piece 15 is made minimum, and the interval between the point A and D of the trapezoid is made maximum. Thus, the machining cost of the permanent magnet is decreased, and a synchronous machine characterized by the large output and the small cogging is obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION Object of the Invention [Field of Industrial Application] The present invention relates to a rotating field type synchronous motor in which the rotor rotates at a constant speed during steady operation.

[Prior Art] Conventionally, in order to maintain the rotational characteristics of the rotor, various methods have been used to maintain the magnetic interaction between the permanent magnets attached to the cylindrical rotor and the rotating magnetic field of the stator in a good state. has been proposed. For example, a permanent magnet with a cross section orthogonal to the rotation axis or an arcuate permanent magnet with a substantially triangular notch on the outside of both ends in the direction of rotation (the magnetic flux density of the equipment is reduced and the magnetic flux distribution is brought to an ideal state). A technique for making the waveform approximate to a beaten sine waveform is disclosed in Japanese Utility Model Application Laid-Open No. 61-104776.

Furthermore, although the surface of the cross section facing the magnetic pole surface is arcuate, the length of the gap is increased toward the outside of both ends (Utility Model Application No. 61-149).
No. 971). FIG. 7 shows a motor 30 according to these conventional techniques, in which a permanent magnet 31 as described above is used.

In addition, it was common to use ferrite permanent [65] for permanent LAD, but in recent years, rare permanent magnets with older magnetic properties than ferrite permanent magnets, that is, large residual magnetic flux density and coercive force, have been used. Magnets are being used.

[Problem to be Solved by the Invention 1 The above conventional technology is a preferable technology that can achieve rotation in synchronization with the rotating magnetic field of the synchronous rotor, smooth rotation, and suppress the occurrence of cogging. Problems remain.

Including cases where rare earth permanent magnets are used in synchronous machines instead of ferrite permanent magnets, permanent magnets have a shape or curve, often a combination of circular arcs that match the diameter of the rotor. This resulted in a loss of 1 to 10% in the molding process. Furthermore, permanent magnets must be molded for each different rotor diameter, which is also a factor in increasing the manufacturing cost of the synchronous machine.

(In order to reduce the iron cost, it is possible to make the permanent 1a5 a simple shape based on straight lines, but simply making it a simple shape will not meet the characteristics required for the 1111 aircraft, i.e. During steady operation, it is difficult to achieve constant rotation synchronized with the rotating field, smooth rotation, high responsiveness, etc.

The present invention has been made to solve the above problems, and its purpose is to reduce manufacturing costs including reducing the cost of molding permanent magnets, and to make the IU1 using the permanent magnets An object of the present invention is to provide a rotating field type synchronous machine that can improve rotational characteristics.

Structure of the Invention [Means for Solving the Problem] The means used in the present invention to achieve the above object are as follows: An armature winding is applied to magnetic poles arranged in a circle, and a rotating magnetic field is generated inside the circle. In a rotating field type synchronous machine having a stator and a rotor rotatably supported in the rotating magnetic field and having permanent magnets attached thereto for coordinating magnetic action with the rotating magnetic field, the permanent magnet is made of a rare earth metal. It is a permanent magnet, and its shape is a polygonal columnar body, and its cross section perpendicular to the rotation axis of the rotor is a hexagon consisting of a rectangle and an isosceles trapezoid whose base is the long side of the rectangle, and The length of the long side of the rectangle is approximately equal to the length of the arc of the magnetic pole face of the magnetic pole of the rotor, and the length of the upper side of the trapezoid is 1/3 of the arc of the magnetic pole face of the stator. 2/3 of the gap between the permanent magnet and the magnetic pole, which is the mounting surface of the permanent magnet on the rotor or the side surface including the long side of the rectangle of the polygonal columnar body, and the gap between the permanent magnet and the magnetic pole. The length is the minimum value at both of the upper sides of the trapezoid, and the value is 0.1 to Q, 3 mm, and the maximum length is one straight at the inscription 1 of each leg of the trapezoid, The gist thereof is a rotating field type synchronous machine characterized in that the value is 4 to 6 times the minimum value.

"Operation" The stator of the present invention generates a rotating magnetic field by sequentially exciting the magnetic poles using an armature winding around which the magnetic poles are wound.

The rotor supported within the rotating magnetic field is rotated by the magnetic action of the attached permanent fa6 and the rotating magnetic field.

Since the permanent magnet used in the rotating field type synchronous machine according to the present invention is a simple polygon+1-shaped body formed by combining planes, the work of forming the permanent magnet into the shape of the columnar body is simplified. In addition, each permanent lamination stone attached to the rotor 4 has a side surface including the upper side of the cap trapezoid and two sides including each leg of the isosceles trapezoid facing the magnet 1 of each magnetic pole of the stator. Avoid facing. Each permanent magnet, which is a rare earth permanent magnet, has a large residual magnetic flux density and coercive force. Moreover, the length of the cap with the magnetic pole face should be a minimum value of 0.1 to 0.8 mm at both ends of the upper side of the isosceles trapezoid, and a maximum value of 4 to 6 times the above minimum value at the end of each leg of the isosceles trapezoid. The length of the upper side is 1/3 to 2/3 of the length of the arc of the magnetic pole surface.

Therefore, the rotating field shape 1lIJ machine of the present invention secures sufficient magnetic flux between 1" and 1", and since the surface of the permanent magnet facing the magnetic pole surface is flat, the cap By setting the length to the above value, a magnetic flux distribution approximating a sine wave is provided between the caps.

[Embodiment] Next, an embodiment of the present invention will be described based on the drawings.

Figure 1 shows the rare earth permanent magnet (hereinafter referred to as
FIG. 2 shows a vertical cross-sectional view of a three-phase synchronous motor (hereinafter simply referred to as a motor) using the magnet.

As shown in the figure, the magnet 1 has a rectangle ABCD (ArB+
C1D+) and an isosceles trapezoid ADEF (AlDlElFl) whose base is the long side AD (AI Dl) of the rectangle.
It is a hexagonal columnar body with F1) as the upper and lower surfaces, and the side surface FE
It is a magnet magnetized from F1F1 toward side surface BCC1B1 or in the opposite direction.

The stator 12 of the motor 10 using l'EIil having the above-mentioned shape is a laminated body of thin iron plates, and a substantially cylindrical internal space 13 is formed in the center of the stator 12. A predetermined number of slots 14 are formed in the peripheral wall of the internal space 13 along the stacking direction of the thin iron plates, and approximately T-shaped pole teeth 15 protrude toward the internal space 13. slot 1
4, an armature winding 16 for generating a rotating magnetic field in the internal space 13 is wound across the three pole teeth 15 as shown in the figure to alternately form U-phase, ■-phase, and W-phase. Moreover, each adjacent phase shares one pole tooth with each other.

A rotor 17 is rotatably supported within the interior space 13 with the central axis of the interior space 13 and the rotation axis aligned. The rotor 17 is composed of a rotor core 18 having a substantially regular octagonal prism shape and eight magnets 1 mounted on the outer periphery of the rotor core 18 at equal intervals in the following manner. A protrusion 19 is provided at each vertex of the outer circumference of the rotor core 8 to protrude along the direction of the rotation axis of the rotor 17 . Eight magnets 1 are fitted and adhered in respective recesses 20 formed by both side surfaces of adjacent protrusions 19 and the outer circumferential plane of rotor core 18, with the direction of magnetization alternated.

Note that the magnet 1 has a length corresponding to the cylindrical height of the rotor core 18.

Side surface EEE1 of IUil of the columnar body assembled in this way
F+ faces the arcuate end surface 15a of the pole tooth 15. The length of the side FE (FlEl) of this side surface is 1/2 of the arc of the magnetic pole surface of the Ila pole of each phase formed by the three poles @15 and the armature winding 16. On the other hand, mounting surface B of magnet 1
The length of the side BC (B1C1) of CC1B1 is set to be approximately equal to the length of the arc of the magnetic pole. Moreover, the length of the gap is the side EE1 of magnet 1. The minimum value (indicated by MIN in the figure) is 0.4rnm between FF1 and the arc of the magnetic pole face.
, and the side AA1 of magnet 1 is AA1. The maximum value (indicated by MAX in the figure) occurs between DD+ and the arc of the magnetic pole face, and that value is the minimum value of 5.
2 mm.

The motor 10 configured as described above has an internal space 13 of the stator 12.
The rotor 17 is rotated by the magnetic action of the rotating magnetic field generated by the magnetic field and the magnet 51.

Magnetic? 51 is a simple hexagonal columnar shape that is entirely formed of flat surfaces, so its forming process is simplified and processed]
It is possible to reduce the amount of 1~. Furthermore, since the magnet 1 has a simple shape, the rotor core 18 to which the magnet 1 is assembled also has a simple shape. Therefore, the rotor core 18 can be easily formed by ordinary machining such as planing, and the processing cost can be reduced. That is, in this embodiment, the recess 20 into which the magnet 1 fits is simply formed by groove machining with an end mill along the rotational axis direction on the outer periphery of the cylindrical shaft.

In addition, in order to assemble the magnet 1, it is only necessary to fit it into the recess 20, so that the magnet 1 can be easily assembled and the assembly cost can be reduced.

In other words, the motor 10 using the magnet 1 is a motor that can reduce manufacturing costs such as magnet processing costs.

Furthermore, since the magnet 1 is a rare earth permanent magnet and has a large residual magnetic flux density, the peripheral wall of the inner space 13 and the magnet 1
Sufficient magnetic flux is secured in the gap. Therefore, the output of the motor 10 becomes large. Since the gap becomes larger toward the side surfaces ABB1A1 and DCC1D1 of the magnet 1, the magnetic flux density on both side surfaces decreases.

In FIG. 3, when the motor 108 is driven before power generation,
The output waveform of the induced voltage of 1q from one armature winding is shown. This graph is very similar to the induced voltage output obtained when performing a similar operation on a conventional motor 30 as shown in FIG. Since the induced voltage thus measured is extremely close to a sine wave, the magnetic flux 7F generated in the gap between [il and la4=M has a waveform close to a sine wave. Therefore [-
The Ta 10 rotates smoothly without any uneven rotation such as kings (similar to the conventional Ta 30 that uses permanent magnets with external or curved surfaces), and rotates at a constant rotation speed during steady operation. It's Tanabata.

Moreover, since each magnet 1 is fitted into the recess 20,
The side surface of the protrusion 19 and the side surface of the magnet 1 are in contact with each other along the rotation axis direction. Therefore, the protrusions 19 prevent a reaction force from acting against a force that attempts to move the magnet 1 in the same or opposite direction to the rotational direction of the rotor 17. Therefore, the force is canceled out and magnet 1
The force acting on is apparently canceled. Therefore, one protrusion prevents the magnet 1 from shifting and peeling 3(t).In addition, the magnetic F
The assembly position of i1 is uniformly determined by the formation (O position) of the recesses 20 formed at equal intervals on the outer periphery of the rotor core 17. Therefore, it is difficult to assemble the magnet 1 with high precision. In addition, the reassembly performance of reassembling the magnet 1 due to overhaul or the like can be ensured with high precision.

Next, FIGS. 4 to 6 show another embodiment in which the shape of the protrusion, that is, the shape of the recess, which suppresses movements such as sliding and peeling of the magnet is different from that of the embodiment described above. The upper figure in each figure is a view of one assembled permanent magnet viewed from a direction perpendicular to the rotating shaft, and the lower figure is a sectional view taken along line >I of the upper figure. Note that constituent members having the same shape or the same function as those in the above embodiments are indicated with subscripts.

FIG. 3 shows a case in which the protrusion 19 of the motor 10 is replaced by two protrusions '19a which are respectively protruded from the apex of the end of the rotor core 18a along the direction of the rotation axis. Since each protrusion 19a is in contact with the side surface of the magnet 1a,
This protrusion 18a has the same function and effect as the protrusion 19 described above.

In this embodiment, the protrusion 19a can be easily protruded and the manufacturing cost can be reduced.

In place of the above-mentioned protrusions 19a that contact the side surfaces of the magnets, FIG. In this embodiment, the protrusion 19b has the same function and effect as the protrusion 19,
In addition, movement of the permanent magnet 1b along the direction of the rotation axis can also be prevented.

Figure 6 shows both sides of the magnet =: protrusion 19b that fits into the notch.
moss, and a protrusion puJ is formed on the outer peripheral surface of the rotor core 18c so as to fit into the two single-arrow holes drilled in the magnet 1C.
This shows an opening using a protruding pin 19G instead. In this embodiment as well, the protruding pin 19C is for 1'1 similar to the protruding strip 19.
In addition, it is possible to prevent the magnet 1C from moving along the direction of the rotation axis.

This embodiment is not limited to the above embodiment, and can be implemented in any manner without departing from the gist thereof.

In addition, the length of the side EF, E+F+ of the magnet 1 or Ii of the embodiment
! If it is shorter than J, the waveform of the induced voltage shown in Figure 3 will be:
Each vertex approaches a triangular waveform with an acute angle, and the above sides EF, E
When +F+ becomes smaller, the waveform approaches a rectangular waveform in which each vertex is flattened. Therefore, in order to maintain various characteristics such as rotational smoothness required of a synchronous machine, the sides EF, E+Fl are adjusted so that an output waveform as shown in FIG. 3 is obtained.
Now that we have determined the length etc. The applicant has sides EF, E+
The length of Fl is 1/3 of the length of the arc on both sides
~2/3, and the minimum length of the gap is 0.
．． 1~Q, 8mm, and the maximum value is the minimum value of 4~G (8), it was experimentally shown that the output waveform and effective value of the induced voltage comparable to the conventional motor shown in Figure 7 can be increased by 1. I've confirmed it.

Effects of the Invention As described above in detail including the embodiments, the rotating field type synchronous machine of the present invention uses a permanent magnet that is made of a polygon consisting of a rectangle and an isosceles trapezoid whose base is the long side of the rectangle. Since it is a polygonal columnar body with a rectangular (hexagonal) top and bottom, it becomes a synchronous machine with low processing costs for permanent magnets, and low silkiness.

Historically, the permanent magnet 5 is made of the polygonal columnar rare earth permanent magnet, and the length of the cap, the width of the surface facing the magnetic pole surface, etc. are optimized, so that the output is not too large and the sheer force for cogging is small. This is a synchronous machine that maintains rotational characteristics such as smooth fetal movement, smooth rotation, and constant speed rotation during steady operation.

In addition, since the permanent la5 has a simple shape, it is suitable for production in Italy and has little variation in shape, making it possible to make the rotational characteristics of the synchronous machine uniform.

[Brief explanation of the drawing]

Fig. 1 is a perspective view of a permanent magnet used in the rotating field type synchronous machine of the present invention, Fig. 2 is a longitudinal sectional view of a motor using the permanent LAD, and Fig. 3 is for explaining the effects of the embodiment. FIGS. 4 to 6 are explanatory views used to explain another embodiment 11, and FIG. 7 is an explanatory view used to show an example of the conventional technique. 1... Permanent EIIE 10... Motor 12
...Stake 15...Pole tooth 16...Electric)
Real child winding 17...Rotor 19...Protrusions
19a, 19b...Protrusion 19C...Protrusion pin

Claims (1)

[Scope of Claims] 1. A stator having armature windings applied to magnetic poles arranged in a circle and generating a rotating magnetic field inside the circle; A rotating field type synchronous machine having a rotor having a permanent magnet attached thereto which exhibits a magnetic effect, wherein the permanent magnet is a rare earth permanent magnet, the shape is a polygonal columnar body, and the rotor The cross section perpendicular to the rotation axis of the stator is a hexagonal shape consisting of a rectangle and an isosceles trapezoid whose base is the long side of the rectangle, and the length of the long side of the rectangle is equal to the arc of the magnetic pole face of the magnetic pole of the stator. , the length of the upper side of the trapezoid is 1/3 to 2/3 of the arc of the magnetic pole face of the stator, and the permanent magnet is attached to the rotor. The design surface is a side surface including the long side of the rectangle of the polygonal columnar body, and the length of the gap between the permanent magnet and the magnetic pole has a minimum value at both ends of the upper side of the trapezoid, and that value is 0. 1 to 0.8 mm, and has a maximum value at the end of each leg of the trapezoid, and the value is 4 to 6 times the minimum value.