CN217642912U - Eccentric rotor with pole shoe for three-phase permanent magnet servo motor - Google Patents
Eccentric rotor with pole shoe for three-phase permanent magnet servo motor Download PDFInfo
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- CN217642912U CN217642912U CN202220744206.5U CN202220744206U CN217642912U CN 217642912 U CN217642912 U CN 217642912U CN 202220744206 U CN202220744206 U CN 202220744206U CN 217642912 U CN217642912 U CN 217642912U
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Abstract
The utility model discloses a three-phase permanent magnet servo motor is with eccentric rotor of taking pole shoe, rotor include pole shoe, rotor end piece and rotor yoke, and rotor yoke both ends are provided with a slice rotor end piece respectively, and the pole shoe is fixed to be set up around the rotor yoke outside. The utility model discloses a method that the cooperation of two eccentric structures of rotor increases the pole shoe, suppression positioning torque that can be very good reduces air gap harmonic magnetic field, promotes the performance in each aspect of motor comprehensively, and this method is all suitable for two types of permanent-magnet machine of square wave and sine wave, the major diameter torque motor in the direct drive system of also specially adapted.
Description
Technical Field
The utility model discloses a three-phase permanent magnetism servo motor, especially a three-phase permanent magnetism servo motor is with eccentric rotor who takes pole shoe.
Background
Permanent magnet motors can be classified into two broad categories, sine waves and square waves, according to the drive current and back emf waveforms.
The torque fluctuation of the sine wave permanent magnet motor is much smaller than that of the square wave permanent magnet motor, and the sine wave permanent magnet motor becomes the mainstream of industrial application nowadays. However, in order to reduce torque ripple of the conventional sine wave permanent magnet motor, a "fractional-slot distributed winding structure" is adopted. The air gap harmonic magnetic field and the positioning torque of the 'fractional-slot distributed winding motor' are small, but the structure and the manufacturing process of the motor are complicated, and in addition, the control system of the sine wave permanent magnet motor is complicated, so that the cost of the motor is greatly increased, and more importantly, the force and energy indexes of the motor are also reduced.
In order to solve the problems of high cost, complicated structure and process of the fractional-slot distributed winding motor, when the sinusoidal wave permanent magnet motor starts to adopt the fractional-slot concentrated winding structure, the most typical examples are as follows: a 10 pole, 12 slot "fractional slot concentrated winding motor". Because the pole number of the fractional-slot concentrated winding motor is very close to the slot number, and the positioning torque (cogging positioning torque) of the fractional-slot concentrated winding motor is relatively large, the greatest design and manufacturing difficulties of the concentrated winding motor are as follows: how to reduce its cogging torque. Although the research is not few at home and abroad, the methods are numerous, but the methods all need to pay the premise of sacrificing other properties and have poor effect. The reason is analyzed as follows:
because the pole number of the fractional slot concentrated winding motor is very close to the slot number, the winding coefficient of the fractional slot concentrated winding motor is very large, namely the winding utilization rate is very high, the winding end is minimized, the copper loss of the motor is small, and the efficiency is high. But the cogging torque of a fractional slot concentrated winding motor can be very large and difficult to suppress. In the limit condition, the positioning torque reaches the maximum value when the number of poles is equal to the number of grooves. The traditional method is as follows: the method for restraining the positioning torque is characterized by selecting reasonable tooth groove matching, adopting a closed groove or a small groove opening, properly enlarging an air gap, adopting a rotor inclined groove, adopting rotor eccentricity and the like. However, the above method causes the winding coefficient to be smaller, the magnetic leakage to be larger, the air gap magnetic density to be smaller, and the utilization rate of the motor material to be reduced, so that the mechanical performance index and performance of the motor are sacrificed, and the positioning torque is not enough to be inhibited to be less than several ten-thousandths of an order of magnitude. Even if the above methods are used simultaneously in many electrical machines for engineering applications, it is difficult to suppress the cogging torque to less than several tens of thousands of parts. Therefore, restraining the cogging torque remains a big problem in the design and manufacture of the current permanent magnet motor. In particular, the conventional "fractional-slot distributed winding structure" is still adopted in the large-diameter torque motor in the direct drive system, although the motor structure and the manufacturing process are complicated and the production cost is high.
Disclosure of Invention
The shortcoming that can not compromise to permanent-magnet machine positioning torque among the above-mentioned prior art and power ability index, the utility model provides a three-phase permanent magnet servo motor is with the eccentric rotor of taking the pole shoe, its method that increases the pole shoe through the cooperation of rotor eccentric structure, suppression positioning torque that can be very good reduces air gap harmonic magnetic field, promotes the performance of motor each side comprehensively.
The utility model provides a technical scheme that its technical problem adopted is: the rotor comprises pole shoes, rotor end sheets and a rotor yoke, wherein two ends of the rotor yoke (3) are respectively provided with one rotor end sheet, and the pole shoes are fixedly arranged on the periphery of the outer side of the rotor yoke.
The utility model provides a technical scheme that its technical problem adopted further still includes:
the pole shoe is arranged on the rotor yoke through square magnetic steel.
The rotor end sheet is in a form that a pole shoe and a rotor yoke are integrated.
The rotor end plate is made of silicon steel plate or other high-strength metal or nonmetal composite materials.
The rotor yoke is formed by overlapping the rotor punching sheets.
The thickness of the rotor end plate is 0.35-2.1 mm.
A magnetic bridge is arranged between the adjacent pole shoes, and the width of the magnetic bridge is 0.3-0.4 mm.
Grooves are respectively formed in the pole shoe and the rotor yoke.
And wedge grooves for inserting the rotor yoke of the T-shaped wedge blocks are formed in the two sides of the rotor yoke, and the T-shaped wedge blocks are inserted into the wedge grooves of the rotor yoke along the axial direction.
The rotor is an eccentric rotor with the eccentricity ratio P r ＝r 1 /r 2 = (1.05- (1 +1.5 delta cos (180 °/2P))), wherein r 1 Is the rotor radius, r 2 Is the eccentric rotor radius and 2P is the motor pole number.
The utility model has the advantages that: the utility model discloses a method that the cooperation of two eccentric structures of rotor increases the pole shoe reduces air gap harmonic magnetic field, promotes the performance in each aspect of motor comprehensively, and this method is all suitable for two types of permanent-magnet machine of square wave and sine wave, the major diameter torque motor in the also specially adapted direct drive system.
The present invention will be further described with reference to the accompanying drawings and the detailed description.
Drawings
Fig. 1 is a front view of the structure of the present invention.
Fig. 2 is a schematic view of the rotor end piece structure of the present invention.
Fig. 3 is a schematic view of the tangent plane structure of the present invention.
Fig. 4 is a schematic view of a magnetic pole structure of a first embodiment of the rotor with pole shoe according to the present invention.
Fig. 5 is a schematic view of a magnetic pole structure of a second embodiment of the rotor with pole shoe according to the present invention.
Fig. 6 is a schematic view of a first embodiment of a rotor yoke with pole pieces according to the present invention.
Fig. 7 is a schematic view of a second embodiment of a rotor yoke with pole pieces according to the present invention.
Fig. 8 is a schematic view of the structure of the utility model in use.
Fig. 9 is a diagram of a cogging torque waveform for a pole shoe without eccentricity of one pole.
Fig. 10 is a plot of cogging torque waveforms for the next pole with pole shoes using rotor eccentricity.
Fig. 11 is a diagram of the cogging torque waveform for the next pole with the pole shoe using double eccentricity of the rotor and stator.
In the figure, 1-stator iron core, 2-rotor iron core, 3-rotor yoke, 4-pole shoe, 5-rotor end piece, 6-square magnetic steel, 7-magnetic bridge, 8-rotor punching sheet and 9-wedge groove.
Detailed Description
The embodiment is a preferred embodiment of the present invention, and other principles and basic structures are the same as or similar to those of the embodiment, and are within the protection scope of the present invention.
The utility model discloses solve the problem that current square wave permanent-magnet motor and sine wave permanent-magnet motor exist, provide a three-phase permanent-magnet servomotor with the eccentric rotor of taking the pole shoe, it can cooperate eccentric stator to realize new design principle, new construction, high performance, low cost, adopt the two eccentric non-uniform air gap three-phase permanent-magnet servomotor of stator and rotor of fraction groove concentrated winding.
The utility model discloses in, the rotor includes pole shoe 4, rotor end piece 5 and rotor yoke 3, and 3 both ends of rotor yoke are provided with a slice rotor end piece 5 respectively, and pole shoe 4 sets up around 3 outsides of rotor yoke. More importantly, the principle electromagnetic air gap of the motor is greatly reduced after the rotor is provided with the pole shoes 4. The reason is that if the rotor does not have the pole shoe 4, the magnetic permeability of the magnetic steel is close to that of air, so the principle electromagnetic air gap of the radial magnetic circuit should include the thickness of the magnetic steel, and therefore, after the rotor is provided with the pole shoe 4, the principle electromagnetic air gap of the motor is reduced by one thickness of the magnetic steel, so that the thickness of the magnetic steel is greatly reduced. Obviously, when the principle electromagnetic air gap is small, the relative change of the eccentricity to the principle electromagnetic air gap is large by adopting the eccentricity of the rotor and the stator, so that the eccentricity is more sensitive to restraining the positioning moment. Namely, the optimal design of the positioning moment and the better optimization effect can be achieved through smaller eccentricity change. The eccentricity change is little, and the influence of the air gap flux density of course is also littleer, so the utility model discloses after the rotor had pole shoe 4, rotor and stator are two eccentric, and is littleer than traditional motor to the influence of air gap flux density.
In this embodiment, the pole shoes 4 are mounted on the rotor yoke 3 by square magnets 6. The utility model discloses after the rotor had pole shoe 4, can use square magnet steel 6, the magnet steel cost can descend about 25%.
In this embodiment, the rotor end plate 5 is a form in which the pole shoe 4 and the rotor yoke 3 are integrated, and the square magnetic steel 6, the pole shoe 4 and the rotor yoke 3 are embedded into each other through the rotor end plate 5 to form the integrated rotor core 2.
In this embodiment, the rotor end plate 5 may be a silicon steel plate or other high-strength metal or non-metal composite material.
In this embodiment, the rotor sheets 8 are disposed between the adjacent rotor end pieces 5, or the rotor yoke 3 is formed by overlapping the rotor sheets 8, that is, for a motor with a longer axial length, in order to increase the strength, the number of the rotor end pieces 5 with the pole shoes 4 and the rotor yoke 3 integrated is not limited to 2-3, or even more, and the thickness of the rotor end pieces 5 is 0.35-2.1 mm.
In this embodiment, in order to simplify and maintain the consistency of the process, in the three-phase permanent magnet servo motor, the rotor end plates 5 are made of silicon steel sheets the same as the rotor yoke 3, magnetic bridges 7 are arranged between adjacent pole shoes 4, the width Q of each magnetic bridge 7 is not greater than δ in order to reduce magnetic leakage, the air gap δ =0.4mm, and the width Q of each magnetic bridge 7 is 0.3-0.4 mm.
In this embodiment, the pole shoe 4 and the rotor yoke 3 are respectively provided with a groove so that the pole shoe 4 and the rotor yoke 3 can be bonded and embedded together through the square magnetic steel 6, in order to simplify the assembly, both sides of the groove for mounting the magnetic steel on the rotor yoke 3 are provided with wedge grooves 9 for inserting the rotor yoke 3 of the T-shaped wedge, when the T-shaped wedge is inserted into the wedge grooves 9 of the rotor yoke 3 along the axial direction, the square magnetic steel 6, the pole shoe 4 and the rotor yoke 3 can be embedded and embedded together to form a firm rotor core 2 which is integrally embedded and embedded together, and in order to increase the strength, anaerobic glue or epoxy glue can still be applied to each joint part.
In this embodiment, the pole shoe 4 is made of one of low-carbon steel, cast steel, a silicon steel sheet, ferrite, SMC composite soft magnetic material or other soft magnetic materials, grooves are respectively formed in the pole shoe 4 and the rotor yoke 3, so that the pole shoe 4 and the rotor yoke 3 are bonded into the integral rotor core 2 through the square magnetic steel 6, and the used bonding agent can be anaerobic adhesive or epoxy adhesive special for the magnetic steel; in order to simplify the production process or for a small-sized motor, the square magnetic steel 6, the pole shoe 4 and the rotor yoke 3 can be bonded after being positioned by a die, and at the moment, no groove can be arranged on the pole shoe 4 and the rotor yoke 3.
As analyzed above, since the influence of eccentricity is more sensitive after the pole shoe 4 is provided, the rotor core 2 of the motor is the eccentric rotor core 2, and the rotor eccentricity Pr = r1/r2= (1.05 ÷ (1 +1.5 δ cos (180 °/2P))) of the motor with the pole shoe 4, where r1 is the rotor radius, r2 is the eccentric rotor radius, and 2P is the number of motor poles.
To further illustrate the effect of the eccentricity after the rotor has the pole shoe 4, the effect of the eccentricity on the suppression of the positioning torque is analyzed, and a motor with a slot number Z =12, a pole number 2p =10, an air gap δ =0.4mm, a notch opening 0.2mm, and an outer diameter 110mm is taken as an example.
(1) When the motor rotor is provided with the pole shoe 4, eccentricity is not adopted, and the gap is uniform, because the number of slots is close to the number of poles, even if the optimal pole slot matching is adopted, the optimal gap is matched with the size of the notch, the positioning torque of the motor is still 0.010Nm, the motor is not practical, and the positioning torque waveform under one magnetic pole is as shown in figure 9. The positioning torque waveform mainly comprises the following components: a primary wave with larger amplitude is superposed with a secondary wave with smaller amplitude caused by slotting, and the positioning moment wave is a double-frequency harmonic wave relative to a pair of magnetic pole waves.
(2) When the rotor is provided with the pole shoes 4, the rotor eccentricity is adopted, even if the eccentricity ratio is larger, the optimal positioning moment is 0.001Nm, the waveform of the positioning moment is as shown in figure 10, but the amplitude of the positioning moment is reduced by 10 times, and secondary waves caused by slotting are basically and completely inhibited. The positioning torque index of the high-performance motor is not optimal enough.
(3) When the motor rotor is provided with the pole shoe 4, the rotor and the stator are adopted to be double eccentric, even if the eccentricity is not too large, the positioning torque can be designed to be 0.00059Nm, the waveform of the positioning torque is as shown in figure 11, the amplitude of the positioning torque is reduced by 17.6 times compared with that of the positioning torque without eccentricity, and the frequency is multiplied. It can be seen that rotor area pole shoe 4, the effect of restraining positioning torque after rotor and stator double eccentricity is better, moreover because rotor and stator eccentricity is not too big, and inhomogeneous air gap does not have obvious change with the even air gap of no eccentricity, consequently the utility model discloses the average air gap magnetic density of inhomogeneous air gap motor is almost the same with when having no eccentric even air gap. That is, the average air gap flux density is reduced very little by adopting the motor with double eccentric rotor and stator.
The utility model discloses a method that the cooperation of two eccentric structures of rotor increases the pole shoe, suppression positioning torque that can be very good reduces air gap harmonic magnetic field, promotes the performance in each aspect of motor comprehensively, and this method is all suitable for two types of permanent-magnet machine of square wave and sine wave, the major diameter torque motor in the direct drive system of also specially adapted.
Claims (10)
1. The utility model provides an eccentric rotor of taking pole shoe for three-phase permanent magnetism servo motor which characterized by: the rotor comprises pole shoes (4), rotor end pieces (5) and a rotor yoke (3), wherein the two ends of the rotor yoke (3) are respectively provided with one rotor end piece (5), and the pole shoes (4) are fixedly arranged on the periphery of the outer side of the rotor yoke (3).
2. The eccentric rotor with pole pieces for a three-phase permanent magnet servomotor according to claim 1, wherein: the pole shoe (4) is arranged on the rotor yoke (3) through square magnetic steel (6).
3. The eccentric rotor with pole pieces for a three-phase permanent magnet servomotor according to claim 1, wherein: the rotor end plate (5) is in a form that a pole shoe (4) and a rotor yoke (3) are integrated.
4. The eccentric rotor with pole pieces for a three-phase permanent magnet servomotor according to claim 1, wherein: the rotor end sheet (5) is made of silicon steel sheets.
5. The eccentric rotor with pole pieces for a three-phase permanent magnet servomotor according to claim 1, wherein: the rotor yoke (3) is formed by mutually overlapping rotor punching sheets (8).
6. The eccentric rotor with pole pieces for a three-phase permanent magnet servomotor according to claim 1, wherein: the thickness of the rotor end sheet (5) is 0.35 to 2.1mm.
7. The eccentric rotor with pole pieces for a three-phase permanent magnet servomotor according to claim 1, wherein: a magnetic bridge (7) is arranged between the adjacent pole shoes (4), and the width of the magnetic bridge (7) is 0.3 to 0.4mm.
8. The eccentric rotor with pole pieces for a three-phase permanent magnet servomotor according to claim 1, wherein: grooves are respectively formed in the pole shoe (4) and the rotor yoke (3).
9. The eccentric rotor with pole pieces for a three-phase permanent magnet servomotor according to claim 1, wherein: and wedge grooves (9) for inserting the rotor yoke (3) of the T-shaped wedge blocks are formed in the two sides of the rotor yoke (3), and the T-shaped wedge blocks are inserted into the wedge grooves (9) of the rotor yoke (3) along the axial direction.
10. The eccentric rotor with pole pieces for a three-phase permanent magnet servomotor according to claim 1, wherein: the rotor is an eccentric rotor with the eccentricity ratio P r =r 1 /r 2 = (1.05- (+ 1.5 delta cos (180 °/2P))), wherein r 1 Is the rotor radius, r 2 Is the eccentric rotor radius and 2P is the motor pole number.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220744206.5U CN217642912U (en) | 2022-04-01 | 2022-04-01 | Eccentric rotor with pole shoe for three-phase permanent magnet servo motor |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202220744206.5U CN217642912U (en) | 2022-04-01 | 2022-04-01 | Eccentric rotor with pole shoe for three-phase permanent magnet servo motor |
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| Publication Number | Publication Date |
|---|---|
| CN217642912U true CN217642912U (en) | 2022-10-21 |
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| Application Number | Title | Priority Date | Filing Date |
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| CN202220744206.5U Active CN217642912U (en) | 2022-04-01 | 2022-04-01 | Eccentric rotor with pole shoe for three-phase permanent magnet servo motor |
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| CN (1) | CN217642912U (en) |
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- 2022-04-01 CN CN202220744206.5U patent/CN217642912U/en active Active
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