JP2006060879A - Permanent-magnet rotary electric machine and manufacturing method for same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a manufacturing method for a rotary electric machine having a split core that is so constructed that cogging having variation in various phases, produced in manufacturing, can be removed by adjustment after assembly and can be easily adjusted after assembly. <P>SOLUTION: The permanent-magnet rotary electric machine includes: a rotor 3 having a cylindrical permanent magnet 2 magnetized in multiple poles; and a stator 4 constructed of a split core that is placed with an air gap between it and the permanent magnet 2 and is split into multiple pieces in the circumferential direction. The rotary electric machine is provided with multiple cogging compensators 10a and 10b that are individually movable in the axial direction in proximity to the side end face of the permanent magnet 2 in the axial direction. The cogging compensators are so disposed that the spacing between the adjoining cogging compensators 10a and 10b is (90/P)+(360m/P) degrees in the relative angle relative to the rotation axis of the rotor, where P is the number of poles and m is an integer smaller than P. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  TECHNICAL FIELD The present invention relates to a permanent magnet type rotating electrical machine and a method for manufacturing a permanent magnet type rotating electrical machine, and in particular, a microscopic variation that occurs due to magnetic asymmetry of a stator generated on a machine in a rotating electrical machine in which a stator core is divided. The present invention relates to a compensation mechanism for compensating cogging and an adjustment method thereof.

In a rotating electrical machine equipped with a plurality of magnetic poles formed of permanent magnets, there is a magnetic pulsation caused by the interaction between the magnet and the stator slot, so-called cogging torque, which causes deterioration of controllability. It was. As a method for reducing the cogging torque, it is desirable to make the magnetic field close to a sine wave. For example, a method of reducing the cogging by chamfering the circumferential end face of the magnetic pole has been considered. For high-precision control motors, for example, a method of canceling cogging in the axial direction by continuous or discrete skew has been considered. For cogging with a period determined by the least common multiple of the number of magnetic poles and the number of slots generated between the magnet and the stator, a magnetic body is arranged near the magnet, and the same period as the above period is reversed between the magnetic body and the magnet. A method of reducing the cogging torque by generating and canceling the cogging torque of the phase has been considered (for example, see Patent Document 1).
These methods are based on the premise that the magnetic circuit of the stator is isotropic as viewed from the rotor as a principle of cogging reduction. The inner diameter of the stator is a perfect circle, and the magnetic resistance of the teeth and yokes is It was assumed that it would not change depending on the location.

  On the other hand, as a problem different from low cogging, a control motor is often incorporated in an apparatus, and miniaturization and low loss are required at the same time. Therefore, in recent years, in order to perform high-density winding in permanent magnet motors, a part of the stator core or all of the cores that have been wound are divided, and winding is performed in advance for each of the divided cores. It is widely practiced to form a stator by combining wire.

Japanese Patent Laid-Open No. 11-89199 (page 3, FIG. 1)

In the conventional permanent magnet type rotating electrical machine, in which the stator is composed of the divided cores as described above, after winding the divided cores, the divided cores are arranged radially in the circumferential direction by means such as welding or fraying. Although it is necessary to integrate them, there is a work limit in an actual motor, so there is a minute gap on the joint surface of the split core, and the gap amount can be made completely the same depending on the position in the circumferential direction. was difficult. In particular, in a rotating electrical machine having a small gap, nonuniformity in the gap amount causes nonuniformity in the stator magnetic circuit, and the magnitude of the gap magnetic flux varies from pole to pole. In addition, when a split core is punched out with a press or the like, a perfect circle is formed because processing errors occur in units of several to several tens of microns with slight variations in processing with respect to the ideal dimensions. I couldn't.
As a result, even if the above-described measures for reducing cogging are used, there are problems such as non-uniform gaps in the stator magnetic circuit caused by non-uniform gaps, and the stator inner diameter does not become a perfect circle. There was a problem that cogging newly occurred. Cogging generated due to such a working error of the stator occurs in the same cycle as the number of poles of the magnet, and its amplitude is approximately 1% or less in rated torque ratio, and its phase is indefinite. In a high-precision control motor, it is necessary to adjust the cogging generated several times per revolution of the motor to make the cogging almost zero. Therefore, when adjusting the cogging generated due to such a work error to make it close to zero, it is conceivable to adjust the cogging after assembling the motor.
In Patent Document 1, when a plurality of magnetic bodies can be moved in the radial direction, and these magnetic bodies can be moved in the circumferential direction, and the cogging torque between the magnet and the stator deviates from the basic waveform due to a work error, It describes that the cogging torque is reduced by finely adjusting the position of the magnetic body. However, the above-described cogging caused by the number of poles per one rotation of the motor due to a working error has different cogging phases and amplitudes for each rotating electrical machine and lot, and it is difficult to reduce the cogging. is there. In other words, as described above, the configuration of Patent Document 1 is intended for cogging with a period determined by the number of magnetic poles and the number of slots, and does not take into account cogging reduction of the pole period based on a machining error, and thus occurs in a split core. It is not always possible to adjust the cogging torque of various phases with variations. In addition, when there are too many magnetic materials for cogging compensation, there is a problem in that the degree of freedom becomes excessive when cogging is reduced, and adjustment takes a long time.

  The present invention has been made to solve the above-described problems, and in a rotating electric machine having a split core, cogging having various phases and variations caused by machining is removed by adjustment after assembling. An object of the present invention is to provide a method for manufacturing a rotating electrical machine that can easily perform adjustment after assembly.

The permanent magnet type rotating electrical machine according to the present invention is a rotor having a cylindrical permanent magnet magnetized in multiple poles, and a division divided into a plurality of portions in the circumferential direction, arranged through the permanent magnet and a gap. In a permanent magnet type rotating electrical machine having a stator composed of a core, a plurality of cogging compensators are provided which are adjacent to the end surface on the axial direction side of the permanent magnet and can be independently moved in the axial direction, and are adjacent to each other. The cogging compensator spacing is relative to the rotor rotation axis.
(90 / P) degree + (360 m / P) degree
However, P is the number of poles, and m is an integer less than P.

  Further, the permanent magnet type rotating electrical machine according to the present invention is provided with a rotor having a cylindrical permanent magnet magnetized in multiple poles, the permanent magnet and a gap, and is divided into a plurality in the circumferential direction. In a permanent magnet type rotating electrical machine having a stator constituted by a split core, each of the permanent magnets can be moved independently in the axial direction in the vicinity of the end surface on the axial direction side of the permanent magnet, and can be independently moved in the circumferential direction. One or more movable cogging compensators are provided.

  Further, the permanent magnet type rotating electrical machine according to the present invention is provided with a rotor having a cylindrical permanent magnet magnetized in multiple poles, the permanent magnet and a gap, and is divided into a plurality in the circumferential direction. In a permanent magnet type rotating electrical machine, in which currents having different phases flow through the windings applied to the respective divided cores, currents having different phases flow among the plurality of divided cores. Each cogging compensator is inserted in a plurality of split cores in the radial direction so that each cogging compensator is arranged close to the permanent magnet, and each cogging compensator is independently movable in the radial direction. It was made possible.

  In addition, a method of manufacturing a permanent magnet type rotating electrical machine according to the present invention includes a rotor having a cylindrical permanent magnet magnetized in multiple poles, a plurality of permanent magnets arranged in the circumferential direction with the permanent magnet interposed therebetween. A step of manufacturing a permanent magnet type rotating electrical machine having a stator composed of divided cores, a step of measuring cogging generated by the rotating electrical machine, and separating the measured cogging for each frequency component. A step of extracting the phase and amplitude information of the pole period component; and the cogging compensator according to claim 1 is installed in the rotating electric machine, and the cogging compensator measured in advance with the phase and amplitude information. And adjusting the position of the cogging compensator so as to cancel the cogging having the phase and amplitude of the pole period component based on the cogging information obtained by the above.

  According to the present invention, cogging torque generated by a plurality of cogging compensators can be arranged at positions where they are represented by orthogonal vectors, and cogging of a pole period with a phase variation, which is generated due to a work error, Can be canceled. Further, since the adjustment amount of the cogging compensator can be uniquely determined, it is possible to compensate for cogging simply and accurately.

  In addition, according to the present invention, one or more cogging compensators can be independently moved in the axial direction and movable in the circumferential direction. It is possible to cancel the cogging of the pole period with the phase variation.

  In addition, according to the present invention, a plurality of cogging compensators are inserted into the split core in the radial direction and movable in the radial direction, so that cogging of a pole period with a phase variation caused by a work error is generated. Can be canceled. In addition, since the cogging compensators are arranged at a known relative angle with respect to each other, the amount of adjustment of the cogging compensator can be uniquely determined, and cogging can be compensated simply and accurately. Become.

  Further, according to the present invention, the cogging is measured after the divided core is molded on the circumference, the measured cogging is separated for each frequency component, and the phase and amplitude information of the pole period component is extracted and recorded, and then Install a cogging compensator in which information about the cogging that occurs is measured in advance, and the cogging compensator suppresses the cogging variation specific to the split core based on the information above. There is an effect that it can be derived immediately.

Embodiment 1 FIG.
1 is a perspective view showing a permanent magnet type rotating electrical machine according to Embodiment 1 of the present invention, FIG. 2 is a cross-sectional configuration view taken along the plane AA of FIG. 1, and FIG. 3 is a cross section taken along line BB of FIG. It is a block diagram. 1 to 3, a cylindrical rotor 3 is provided inside the motor 1, and the rotor 3 is supported by a frame 9 at both ends of a shaft via brackets 8 by bearings 7. A permanent magnet 2 is attached to the circumferential surface of the cylindrical rotor 3 so that N poles and S poles are alternately arranged in the circumferential direction. A stator 4 is disposed on the outer periphery of the rotor 3 via a permanent magnet 2 and a minute gap of the rotor 3. The stator 4 has a configuration in which a winding 6 is applied to a stator core 5. In the first embodiment of the present invention, the stator 4 is divided into a plurality of stator cores for each core to which the winding 6 is applied. ing. The stator 4 is formed by combining pre-wound windings (teeth) with respect to each of the divided stator cores. The teeth 4 are arranged in the circumferential direction, and as shown in FIG. The core is molded. In such a configuration, the permanent magnet 2 of the rotor 3 generates a magnetic flux in the gap radial direction and operates as a general permanent magnet type rotating electrical machine by interaction with the stator 4.

Since the stator 4 of the present embodiment is configured by combining the stator cores divided as described above, there is a small gap 4a in the radial direction between the divided cores as shown in FIG. Exists. Furthermore, it is difficult to make this minute gap 4a uniform depending on the location in the circumferential direction due to assembly reasons. For example, as shown in the gap 4b in FIG. Can happen. This is a phenomenon peculiar to the split core and does not occur in a motor manufactured without a break in the yoke portion of the stator core, such as a general induction type rotating electric machine.
The core in which such a large gap 4 b is generated causes nonuniformity in the magnetic circuit of the stator 4. The non-uniformity of the stator magnetic circuit mainly causes polar period cogging. In addition, since the cogging of a new pole period generated by this divided core differs depending on the size and position of the gap 4b, there are many cases in which both the phase and the amplitude vary from motor to motor. This cogging becomes a problem when used in applications such as high-precision NC machining because the motor acts as pulsating torque when controlling the speed and torque.

In order to reduce such cogging, in the first embodiment, two magnetic bodies (first cogging compensator and second cogging compensator) 10a and 10b for cogging compensation are used in the blanket 8 or the frame 9. Provided. The two magnetic bodies 10a and 10b are disposed along the axial direction of the rotor 3 so as to be close to the vicinity of the end surface of the rotor 3 on the permanent magnet 2 side, and are configured to be movable in the axial direction of the rotor 3, respectively. It has become. Further, the positions of the two magnetic bodies 10a and 10 are set such that the relative angle of each magnetic body with respect to the rotation axis of the rotor 3 forms a predetermined angle represented by a formula described later.
Since the two magnetic bodies 10a and 10b are each in a stable position when facing the positions between the poles of the plurality of permanent magnets 2, cogging of a new pole period occurs according to the relative position with the rotor. . The cogging of this polar period is from the end face of the permanent magnet and is a little less than about 1% of the rated torque. However, the cogging with variations caused by the split core is similar and can be offset. If the positional relationship of the arrangement of the magnetic bodies 10a and 10b is set to a predetermined angle as described below, it is possible to easily cope with the reduction of the cogging, which has a variation in both phase and amplitude for each motor.

The cogging compensation operation of the present invention will be described in detail below.
If Fc is a cogging torque having a variation that occurs in the work, Fc is expressed by equation (1) in consideration of the pole period. Here, θ is the rotor position when one rotation is 2π, P is the number of poles, α is the amplitude of the cogging torque Fc, and β is the phase. Although there is a DC component due to friction and iron loss, it is not considered here. Since the amplitude α and the phase β have variations, they vary depending on individual motors.
Fc = αsin (Pθ + β) (1)
On the other hand, the cogging torque Fa generated by the magnetic body 10a and the permanent magnet 2 is expressed by equation (2). A is the amplitude of the cogging torque Fa.
Fa = Asin (Pθ) (2)
Another magnetic body 10b is provided, and the cogging torque Fb generated between the magnetic body 10b and the permanent magnet 2 is 90 degrees out of phase with the cogging torque Fa generated between the magnetic body 10a and the permanent magnet 2, that is, , Fb is represented by equation (3). B is the amplitude of the cogging torque Fb.
Fb = Bcos (Pθ) (3)
The condition for establishing such a relationship between Fa and Fb is that the relative positional relationship between the magnetic body 10a and the magnetic body 10b is
(2π / P) × (m + 0.25)
Here, m = integer, that is, an angle that is an integral multiple of the angle of one pole plus an angle of 1/4 of one pole.
The sum of the formulas (2) and (3) is the total cogging generated by the two magnetic bodies 10a and 10b, and is the formula (4).

  When Fc = Fa + Fb, cogging caused by variation can be canceled out, so if the above equations (1) to (3) are substituted,

  Therefore, if α and β are known, A and B satisfying the relationship of equation (5) can be found. If the amplitude A of the cogging torque Fa generated by the magnetic body 10a and the permanent magnet 2 and the amplitude B of the cogging torque Fb generated by the magnetic body 10b and the permanent magnet 2 are adjusted based on the obtained A and B, the variation The generated cogging can be easily offset.

Hereinafter, a method for simply performing the cogging adjustment will be described in detail.
First, the relationship between the distance r between each magnetic body 10a, 10b and the side end face of the permanent magnet 2 and the magnitude of cogging torque (amplitude A, B) generated by each magnetic body 10a, 10b is shown for each magnetic body. As shown in FIG. 4, it is grasped separately beforehand.
Further, the cogging torque of the motor is measured without the magnetic bodies 10a and 10b, and the amplitude α and phase β are measured. From the obtained α and β, A and B satisfying the equation (5) are obtained. From the data shown in FIG. 4, the optimum adjustment amounts 10a and 10b can be obtained immediately by obtaining the distance r at which predetermined A and B can be obtained. As shown in FIG. 5, A and B are solutions for A and B at the intersection of a straight line having an inclination of B = (β + π) A and a circle satisfying A ² + B ² = α ² . In FIG. 5, each cogging torque is shown as a vector, and Fa and Fb are set to have a positional relationship in which they are orthogonally arranged. Therefore, if the amplitude α and phase β of the target cogging Fc are known, Cogging Fc can be canceled as a vector sum of Fa and Fb for any phase Fc.
However, since A and B can take only positive values as shown in FIG. 4, the adjustment range is a quarter period of the cogging waveform. In FIG. 5, Fc is in the third quadrant (β = 180 to 270). The degree). The cogging Fc variation is large, and the phase range is 3 when the adjustment range is ½ period with respect to the pole period, and 4 when coping with the pole period. Prepare your body and use any two of them.

For example, in the case of a 6-pole rotor, since one cycle of generated cogging is 60 degrees, the positional relationship of magnetic bodies that generate orthogonal cogging Fa and cogging Fb to cancel out this cogging Fc is: It is sufficient that the angle is 1/4 of 60 degrees, that is, 15 degrees,
The position of the first cogging compensator is at least one of 0, 60, 120, 180, 240, and 300 degrees;
The position of the second cogging compensator is at least one of the angles of 15, 75, 135, 195, 255, 315;
The position of the third cogging compensator is at least one of the angles of 30, 90, 150, 210, 270, 330;
When the position of the fourth cogging compensator is at least one of the angles of 45, 105, 165, 225, 285, 345,
If the second or fourth cogging compensator is arranged with respect to at least the first cogging compensator, even if the phase of the cogging torque generated in the polar period varies by ¼ of the polar period, Can be canceled as the vector sum of the cogging torque by the cogging compensator and the cogging torque by the second or fourth cogging compensator (however, the phase range that can be compensated is 180 to 270 degrees, or 90 to 180 degrees). Further, if the second or fourth cogging compensator is arranged with respect to the third cogging compensator, it can be canceled even if it fluctuates by 1/4 of the pole period (however, the phase range that can be compensated is 270). ~ 360 degrees, or 0-90 degrees). For example, as shown in FIG. 6, if the second cogging compensator 10b is disposed at a position 135 degrees away from the first cogging compensator 10a, the cogging torque generated in the polar cycle as described in FIG. The cogging torque by the first cogging compensator and the cogging torque by the second cogging compensator are used for the cogging having a phase variation of ¼ period (in this case, a phase range of 180 ° to 270 °) and an amplitude variation. Can be canceled as a vector sum of
Furthermore, if any three of the first to fourth cogging compensators are arranged, two of the three compensators can be moved even if the phase of the cogging varies by 1/2 of the polar period. If it does, it can cancel as a vector sum of cogging torque by two cogging compensators. For example, if a second cogging compensator and a fourth cogging compensator are arranged with respect to the first cogging compensator, the first cogging compensator and the second cogging compensator, or the first cogging compensator. The compensator and the fourth cogging compensator are moved to have a phase variation of 1/2 period of cogging torque generated in a polar cycle (in this case, a phase range of 90 to 270 degrees) and an amplitude variation. Cogging can be canceled. Alternatively, if the second cogging compensator and the fourth cogging compensator are arranged with respect to the third cogging compensator, the third cogging compensator and the second cogging compensator, or the third cogging compensator. The compensator and the fourth cogging compensator are moved to have a phase variation of 1/2 period of cogging torque generated in a polar period (in this case, a phase range of −90 to 90 degrees) and an amplitude variation. Can cancel cogging.
Further, if the first to fourth cogging compensators are arranged and two of them are moved, the cogging of the opposite phase is generated by these two cogging compensators with respect to the variation of the cogging of an arbitrary phase. Cogging can be offset and reduced.

Generalizing the above, when P is the number of poles and m is an integer less than P, the position of the first cogging compensator is at least one position of 360 m / P degrees,
The position of the second cogging compensator is at least one position of (90 / P) + (360 m / P) degrees,
The position of the third cogging compensator is at least one of (180 / P) + (360 m / P) degrees;
When the position of the fourth cogging compensator is at least one of (270 / P) + (360 m / P) degrees,
When the variation range of the cogging phase is 90 degrees or less, any two of the first to fourth cogging compensators (excluding the first and third, and the second and fourth combinations) When the cogging variation range is more than 90 degrees and less than 180 degrees, any three of the first to fourth cogging compensators are arranged, and the cogging variation range exceeds 180 degrees If all of the first to fourth cogging compensators are provided, it is possible to perform compensation according to the variation range of the cogging phase.

As described above, according to the first embodiment, if the phase of cogging and the range of phase variation are known, it is possible to cancel the cogging with variation with the minimum number of cogging compensators.
If the amplitude and phase of the cogging are known, the cogging can be canceled by adjusting only the two cogging compensators, and the amount of adjustment can be determined uniquely from the phase and amplitude of the cogging. The effect that it can be performed is obtained.

  In addition, in the said embodiment, although what divided | segmented all the stator cores 5 to which the winding 6 was given was shown, it is applicable also to what divided | segmented a part of stator core.

1 to 3 has the stator 4 arranged on the outer periphery of the rotor 3, but the same configuration is applied to the rotary electric machine in which the rotor is arranged on the outer periphery of the stator. By doing so, the same effect as in the above embodiment can be obtained. 7 (a) and 7 (b) show such a configuration.
In the above embodiment, a magnetic material is used as the cogging compensator. Instead, a magnet piece may be used, and the cogging of the pole period is generated by the interaction with the rotor permanent magnet. .

Embodiment 2. FIG.
8 is an exploded perspective view showing a part of a permanent magnet type rotating electrical machine according to Embodiment 2 of the present invention, and FIG. 9 is a cross-sectional configuration diagram of the permanent magnet type rotating electrical machine according to Embodiment 2 of the present invention.
In the second embodiment, a magnetic body (first cogging compensator) 11a is arranged in an arc-shaped slit 8a provided in the blanket 8, and the first cogging compensator 11a is arranged not only in the axial direction but also in the circumferential direction. Was also movable.
FIG. 10 shows a method of cogging adjustment by the first cogging compensator 11a. In FIG. 10, a curve A is a cogging waveform generated by the motor, and is a waveform having an amplitude α and a phase β. Curve B is a cogging waveform generated by the first cogging compensator 11a before cogging adjustment, and curve C is a cogging waveform generated by the first cogging compensator 11a after cogging adjustment. A curve C is a waveform in which positive and negative are reversed from those of the curve A, and is a waveform that cancels cogging generated by the motor. First, the first cogging compensator 11a is moved in the circumferential direction so that the phase of the cogging waveform by the first cogging compensator 11a matches the phase of the curve C. If the movable range in the circumferential direction is 1/4 of the pole period, the phase adjustment range by the cogging compensator 11a is 90 degrees. Next, the cogging compensator 11a is moved in the axial direction. If the amplitude a of the cogging waveform by the first cogging compensator 11a is larger than the amplitude α of the curve C, the cogging compensator 11a is moved away from the magnet 2, and if smaller, it is moved closer. Thus, the amplitude a of the cogging waveform by the first cogging compensator 11a is made to coincide with the amplitude α of the curve C. The order of movement in the axial direction and movement in the circumferential direction may be reversed.

  In this way, the cogging generated by the cogging compensator is measured by measuring the amplitude α and the phase β of the cogging generated on the work and moving one cogging compensator in the axial direction based on the amplitude α and the phase β. The cogging that can counteract the cogging that occurs in the work can be generated by adjusting the amplitude of the cogging and changing the cogging phase generated by the cogging compensator by moving in the circumferential direction. Further, since the amount of adjustment is also uniquely determined from the amplitude α and the phase β, an effect that the adjustment can be performed immediately and accurately is obtained.

  The movable range in the circumferential direction is not limited to the above embodiment. What is necessary is just to design according to a phase adjustment range.

In the above embodiment, the cogging compensator 11a reduces the cogging of the pole period generated in the work, but FIG. 11 shows a rotating electric machine having two cogging compensators movable in the axial direction and the circumferential direction. FIG. 12 and FIG. 13 are diagrams for explaining the operation. Two magnetic bodies (a first cogging compensator and a second cogging compensator) 11a and 11b are close to the vicinity of the end surface of the permanent magnet 2 side of the rotor 3 along the axial direction of the hexapole rotor 3. Each of them is configured to be movable in the axial direction of the rotor 3. The two magnetic bodies 11a and 11b are configured to be independently movable in the circumferential direction along the arc-shaped slits 8a and 8b, respectively, and the movable ranges of the magnetic bodies 11a and 11b are each 360 / (2 × 6) = The interval is 30 degrees so that the arrangement angle of the movable center is (360/6) + 360 / (2 × 6) = 90 degrees. In this way, the first and second cogging compensators 11a and 11b generate pole-period cogging torques Fa and Fb, respectively, and move the respective cogging compensators 11a and 11b in the circumferential direction. As shown in FIG. 12, each cogging vector can be changed in a phase range corresponding to ½ period of the polar period. Moreover, the movable ranges of the cogging vectors do not overlap each other. Therefore, the first cogging compensator and the second cogging compensator are independently moved in the circumferential direction and the axial direction, respectively, and are generated by the cogging torque Fa generated by the first cogging compensator and the second cogging compensator. The vector sum with the cogging torque Fb to be performed cancels the cogging torque Fc generated on the work as shown in FIG.
In this way, even if the cogging waveform varies in any phase range, the cogging can be offset and reduced by the two cogging compensators.

In addition, when n cogging compensators that can move in the axial direction and the circumferential direction are provided, each cogging compensator can be moved independently in the circumferential direction, and its movable range is 360 / nP, respectively.
And the distance between the movable centers of each cogging compensator is (360 / nP) + (360 m / P) relative to the rotation axis of the rotor.
Then, similarly, even if the cogging waveform varies in any phase range, the cogging can be canceled and reduced by the two cogging compensators. Here, P is the number of poles, and m is an integer less than P.

In the present embodiment, the same effect can be obtained by adopting the same configuration for the rotating electrical machine in which the rotor is disposed on the outer periphery of the stator.
Further, a magnet piece may be used as the cogging compensator.

Embodiment 3 FIG.
The optimum location of the cogging compensator in each of the above embodiments will be described. A motor is usually used by being connected to another load, but there are many load devices that apply a load to a bearing such as a pulley. In that case, it is necessary to increase the bearing size of the motor, but generally only the bearing size on the load side is increased. In that case, the bearing interferes with the cogging compensator of the present invention. Avoiding this increases the axial dimension of the motor. Therefore, if a cogging compensator is attached to the anti-load side which is a small bearing portion, an increase in the axial size can be minimized even if the cogging compensator is provided, and a small servo motor with a cogging compensator can be obtained.

Embodiment 4 FIG.
14 is a sectional view showing a permanent magnet type rotating electric machine according to Embodiment 4 of the present invention, and FIG. 15 is a top view showing teeth according to Embodiment 4 of the present invention. The stator 4 is constituted by divided cores, and each divided core (tooth) is constituted by laminating iron cores 5a. That is, as shown in FIG. 15, the a part of the teeth is formed by laminating iron cores pressed into a normal tooth shape, while the b part is constituted by laminating two divided iron cores 5b, and the through hole 5c. Have The through hole 5c penetrates in the radial direction of the motor. As shown in FIG. 14, the magnetic body 12a (first cogging compensator) or the magnetic body 12b (second cogging compensator) passes through the stator core 5. It is configured to penetrate and protrude into the gap between the rotor 3. With such a configuration, a new cogging torque for cogging compensation can be generated locally, and the magnitude of the cogging can be adjusted by the amount of protrusion of the magnetic bodies 12a and 12b into the gap. Moreover, the permanent magnet type rotating electrical machine of the present embodiment is a three-phase motor, and the teeth into which the magnetic body 12a and the magnetic body 12b are inserted are teeth of different phases. By doing so, it is possible to cancel out cogging torque having a phase variation caused by a work error.

Hereinafter, the operation of the present embodiment will be described.
In general, when the number of stator slots is s and the number of poles is P, the phase difference between teeth with respect to the cogging waveform is 360 P / s. Therefore, for example, if the first cogging compensator 12a is inserted in the teeth position of the energized U phase and the second cogging compensator 12b is inserted in the V or W phase where the energized phases of the coils are different, the first cogging compensator The cogging torque Fa generated by 12a and the cogging torque Fb generated by the second cogging compensator 12b are not in phase because the phase of the 120 ° cogging torque is different. Therefore, as in the case of canceling cogging with the two orthogonal vectors described in the first embodiment, a plurality of vectors (in this case, a vector having an angle of 120 degrees) can be combined to cancel the cogging torque having a phase variation. It becomes. That is, when the cogging compensators 12a and 12b are arranged at, for example, the U-phase tooth position and the V-phase tooth position, cogging torques Fa and Fb are generated as shown in FIG. Since the size of Fa and Fb can be adjusted by the amount of magnetic material inserted into the air gap, for example, even if there is cogging Fc with variations, the size of Fa and Fb is adjusted so as to cancel out with the combined vector of Fa + Fb. Thus, the cogging Fc due to the working error of the rotating electrical machine can be canceled.

As described above, by inserting a plurality of magnetic bodies into teeth portions of different phases in the stator and making the magnetic body movable in the radial direction, cogging with variations in phase and amplitude is achieved. Can also be canceled by the vector sum of the cogging torque generated by the plurality of cogging compensators.
In addition, since multiple cogging compensators are arranged at known relative angles with respect to each other, cogging adjustment can be performed uniquely, and cogging can be compensated simply and accurately without requiring a large amount of adjustment time. Is possible.
Also, providing a cogging compensator in the stator core has the effect of allowing the adjustable cogging compensator to be inserted and removed even when there is no dimensional margin in the axial bracket or frame.

Embodiment 5. FIG.
Using the cogging compensator shown in the first to fourth embodiments, a method that can easily implement cogging in a rotating electric machine configured with a split core is shown below.
First, a permanent magnet type rotating electrical machine composed of a rotor and a stator having divided cores is manufactured (step 1), and then cogging is measured with this motor alone (step 2). Further, the measured cogging is separated for each frequency component by FFT analysis or the like, and the phase and amplitude of the pole period component are detected and recorded for each motor (step 3). Thereafter, a cogging compensator is installed, and the cogging compensator is adjusted based on the record (step 4).

As a method for measuring cogging in step 2, a method using a torque meter and an angle detector is generally used. However, since it takes time to attach and detach the torque meter and it is more difficult after the device is assembled, a method for performing this simply will be disclosed below.
The control device drives the motor with a minute torque command so that the motor becomes extremely low speed. Since the cogging torque Fc becomes a disturbance at the time of a minute constant torque command, the speed fluctuation occurs. Therefore, when ω is the speed and J is the inertia moment of the rotating shaft, the speed fluctuation is measured as dω / dt to measure the cogging Fc. Fc = J · dω / dt
As observable.
As another method, when speed feedback control is performed with a constant speed as a target value, the cogging torque is roughly measured and recorded from the control amount required to operate at a constant speed.
Until recently, these methods were often used exclusively as cogging suppression means by correcting the control amount. However, in the present invention, cogging is suppressed by adjusting the cogging compensator.

  In step 3, the cogging waveform measured by any of the above methods is separated for each frequency component by FFT or the like, and the amplitude and phase information of the pole period component is recorded and attached as motor information. Specifically, it is recorded in a memory mounted on the motor, or is labeled and pasted as a barcode for individual motor recognition. In particular, when a label is attached, there is an effect that reading is easy and cogging information can be easily obtained in a motor mass production line process.

In step 4, using the stored information and the relationship between the cogging compensator position measured in advance and the magnitude and phase of the cogging torque to be generated, for example, the method as described in the first embodiment. Thus, the adjustment position of the cogging compensator for canceling the cogging torque caused by the machining error is obtained. As a result, the adjustment position of the cogging compensator is uniquely determined, and even in the case of automation, there is an effect that adjustment can be performed quickly and accurately without the difficulty of adjustment due to multiple degrees of freedom.
For example, after reading a bar code label attached to a motor, cogging compensation is performed using information read by an automated robot and cogging compensator information stored in advance (information on cogging torque generated by the cogging compensator). If the amount of rotation of the adjusting screw of the machine or the amount of rotation and the amount of movement in the circumferential direction is determined, there is an effect that automatic adjustment of cogging reduction can be performed in the production line.

It is a perspective view which shows the permanent magnet type rotary electric machine by Embodiment 1 of this invention. It is a cross-sectional block diagram in the AA surface of FIG. It is a cross-sectional block diagram in the BB line of FIG. It is a figure which shows the characteristic of the magnetic body concerning Embodiment 1 of this invention. It is a figure explaining operation | movement of the permanent-magnet-type rotary electric machine by Embodiment 1 of this invention. It is a figure which shows the example of arrangement | positioning of the magnetic body concerning Embodiment 1 of this invention. It is a figure which shows the other permanent magnet type rotary electric machine by Embodiment 1 of this invention. It is a perspective view which decomposes | disassembles and shows a part of permanent magnet type rotary electric machine by Embodiment 2 of this invention. It is a cross-sectional block diagram which shows the permanent magnet type rotary electric machine by Embodiment 2 of this invention. It is a figure explaining operation | movement of the permanent-magnet-type rotary electric machine by Embodiment 2 of this invention. It is a block diagram which shows the other permanent magnet type rotary electric machine by Embodiment 2 of this invention. It is a figure explaining operation | movement of the other permanent magnet type rotary electric machine by Embodiment 2 of this invention. It is a figure explaining operation | movement of the other permanent magnet type rotary electric machine by Embodiment 2 of this invention. It is a cross-sectional block diagram which shows the permanent magnet type rotary electric machine by Embodiment 4 of this invention. It is a top view which shows the teeth concerning Embodiment 4 of this invention. It is a figure explaining operation | movement of the permanent-magnet-type rotary electric machine by Embodiment 4 of this invention.

Explanation of symbols

  1 motor, 2 permanent magnets, 3 rotors, 4 stators, 5 stator cores, 6 windings, 7 bearings, 8 blankets, 9 frames, 10a, 10b, 11a, 11b, 12a, 12b magnetic body.

Claims (6)

A rotor having a cylindrical permanent magnet magnetized in multiple poles, and a stator that is arranged via the permanent magnet and a gap and is divided into a plurality of divided cores in the circumferential direction. In the permanent magnet type rotating electrical machine, a plurality of cogging compensators that are each independently movable in the axial direction in the vicinity of the end surface on the axial direction side of the permanent magnet are provided, and the interval between adjacent cogging compensators is Relative to the axis of rotation
(90 / P) degree + (360 m / P) degree
However, the permanent magnet type rotating electric machine is characterized in that P is arranged so as to form a number of poles and m is an integer less than P. A rotor having a cylindrical permanent magnet magnetized in multiple poles, and a stator that is arranged via the permanent magnet and a gap and is divided into a plurality of divided cores in the circumferential direction. In the permanent magnet type rotating electrical machine, one or more cogging compensators are provided that are each independently movable in the axial direction in the vicinity of the end surface on the axial direction side of the permanent magnet and that are independently movable in the circumferential direction. A permanent magnet type rotating electrical machine. When n cogging compensators are provided, the n cogging compensators have a circumferential movable range.
(360 / nP) degrees
However, P is the number of poles, and the distance between the movable centers of adjacent cogging compensators is relative to the rotation axis of the rotor.
(360 / nP) + (360 m / P)
However, the permanent magnet type rotating electrical machine according to claim 2, wherein m is an integer less than P. The rotor is supported by bearings at both ends in the axial direction, and when one of the bearings is a load side and the other is an anti-load side, a cogging compensator is attached to the anti-load side. Item 4. The permanent magnet type rotating electrical machine according to any one of Items 1 to 3. A rotor having a cylindrical permanent magnet magnetized in multiple poles, and a stator that is arranged through the permanent magnet and a gap and is divided into a plurality of divided cores in the circumferential direction; In a permanent magnet type rotating electrical machine that allows currents having different phases to flow through the windings applied to each split core, a cogging compensator is provided in each of the plurality of split cores to which currents having different phases flow. A permanent magnet that is inserted in a radial direction and is configured such that each cogging compensator is disposed in proximity to the permanent magnet, and each cogging compensator is independently movable in the radial direction. Rotary electric machine. A rotor having a cylindrical permanent magnet magnetized in multiple poles, and a stator that is arranged via the permanent magnet and a gap and is divided into a plurality of divided cores in the circumferential direction. A step of manufacturing a permanent magnet type rotating electrical machine, a step of measuring cogging generated by the rotating electrical machine, a step of separating the measured cogging for each frequency component, extracting phase and amplitude information of a pole period component, and the rotation The cogging compensator according to any one of claims 1 to 5 is installed in an electric machine, and the phase and amplitude of the polar periodic component are determined based on the phase and amplitude information and information on cogging by the cogging compensator measured in advance. And a step of adjusting the position of the cogging compensator so as to cancel the cogging. The method of manufacturing a permanent magnet type rotating electrical machine.

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