CN101572467A - Highly efficient high-speed permanent magnetic synchronous motor - Google Patents

Abstract

A high-efficiency high-speed permanent magnet synchronous motor relates to the technical field of motors. It solves the problems of small leakage reactance, large winding current harmonic component, and high frequency loss of motor stator and rotor existing in the existing high-speed permanent magnet synchronous motor. The motor of the present invention includes a stator, a rotor and an air gap, and is an inner rotor structure. The rotor is composed of a permanent magnet, a permanent magnet sheath and a rotating shaft. The stator includes a stator core and a winding; A plurality of alveolar through holes, the alveolar through holes are used for embedding windings, the stator core can also be split, that is, the core is divided into a yoke core and a tooth core, the yoke core is cylindrical, The inside of the tooth core is cylindrical, and there are a plurality of tooth slots for embedding windings in the axial direction on its outer circumference; the tooth core is embedded in the yoke core to form the stator core. The synchronous motor of the invention can be used not only as a high-speed motor, but also as a high-speed generator, and has broad application prospects.

Description

High-efficiency high-speed permanent magnet synchronous motor

technical field

The invention belongs to the technical field of motors, and in particular relates to a structure of a permanent magnet synchronous motor.

Background technique

Due to the high speed and high power density of high-speed motors, the geometric size of high-speed motors is much smaller than that of low- and medium-speed motors of the same power, which has become a research hotspot in the field of motors. At present, the application fields of high-speed motors are becoming more and more extensive, such as high-speed grinding machines and other processing machine tools, high-speed flywheel energy storage systems, high-speed centrifugal compressors and blowers used in natural gas transmission and sewage treatment, etc. Recently, micro gas turbines driving high-speed generators for distributed power supply systems have received increasing attention. Permanent magnet motors are most suitable for high-speed motors due to their simple structure, high force-energy density, and no excitation loss.

Fig. 12 and Fig. 13 are the structure of the existing traditional high-speed permanent magnet synchronous motor. The rare earth permanent magnets generally used in high-speed motors are sintered NdFeB, which cannot withstand large tensile stresses. If there are no protective measures, the permanent magnets cannot withstand the huge centrifugal force generated when the rotor rotates at high speed. One of the methods to protect the permanent magnet is to add a high-strength non-magnetic metal protective sheath outside the permanent magnet, and an interference fit is used between the permanent magnet and the sheath. Another protection method is to use carbon fiber binding permanent magnets. The advantage of using a non-magnetic metal sheath is that it can shield the high-frequency magnetic field to a certain extent, and can reduce the high-frequency additional loss in the permanent magnet and the rotor yoke. At the same time, the thermal conductivity is good, which is conducive to the heat dissipation of the permanent magnet. ; The disadvantage is that the sheath is a conductor, which will generate eddy current loss. The advantage of the carbon fiber non-metallic sheath is that no eddy current will be generated in it. The disadvantage is that it has no shielding effect on the high-frequency magnetic field, and the high-frequency magnetic field will generate high-frequency additional losses in the permanent magnet and the rotor yoke.

Due to the uneven air gap caused by the cogging structure of the stator core and the harmonic component of the stator current armature reaction magnetic field, large additional losses will be generated in the permanent magnet rotor, rotor sheath and rotor yoke. In particular, the wind friction loss on the surface of the stator and rotor due to high-speed rotation occupies a large proportion of the total loss. At the same time, due to the small leakage reactance of the motor, the harmonic component of the winding current is large, the high-frequency loss of the motor stator and rotor increases, and the cogging torque caused by the slotting of the stator is large, resulting in large vibration and high noise of the motor. The efficiency and reliability of the entire high-speed motor are low, and the cooling of the motor is difficult.

Contents of the invention

In order to solve the problems existing in the existing high-speed permanent magnet synchronous motors such as small leakage reactance, large winding current harmonic components, and large high-frequency loss of the stator and rotor of the motor, the present invention proposes a high-efficiency high-speed permanent magnet synchronous motor.

The high-efficiency high-speed permanent magnet synchronous motor of the present invention has an inner rotor structure. The high-efficiency high-speed permanent magnet synchronous motor includes a stator, a rotor and an air gap. The rotor is composed of a permanent magnet, a permanent magnet sheath and a rotating shaft. The stator includes a stator core and a winding. , the stator core is cylindrical, and on the side of the stator core close to its inner wall, there are a plurality of slotted through holes in the axial direction, and the minimum radial thickness between the bottom of the slotted through holes and the inner wall of the stator core is less than 2mm , the armature winding is embedded in the alveolar through hole close to the axis side, and the armature winding is a centralized short-distance winding or a distributed winding.

In the high-speed permanent magnet synchronous motor according to the present invention, the side of the slotted through hole close to the shaft center is embedded in the winding, and the side away from the shaft center forms an axial ventilation hole to play the role of heat dissipation.

The inner surface of the armature core of the motor of the present invention is smooth, which effectively reduces the wind friction loss when the rotor rotates, greatly reduces the positioning torque, vibration and noise of the motor; reduces the high-order harmonic flux, and can effectively reduce the additional losses of the rotor; and the embedding process of the armature winding of the high-speed permanent magnet synchronous motor of the present invention is simple.

The high-efficiency high-speed permanent magnet synchronous motor of the present invention can be used not only as a motor, but also as a generator.

Description of drawings

Fig. 1 is a schematic structural view of a high-speed permanent magnet synchronous motor with an integrated iron core structure shown in the first embodiment; Fig. 2 is a high-speed permanent magnet synchronous motor with a stator structure without slots on the yoke core 11 shown in the second embodiment Schematic diagram of the structure; FIG. 3 is a schematic structural diagram of the yoke core 11 of the motor shown in FIG. 2; FIG. 4 is a schematic structural diagram of the tooth core 12 and the armature winding 4 of the motor shown in FIG. 2; FIG. 5 is the third specific embodiment Fig. 6 is a schematic structural view of the yoke core 11 of the motor shown in Fig. 5; Fig. 7 is a tooth core 12 of the motor shown in Fig. 5 and the motor A schematic structural view of the pivot winding 4; FIG. 8 is a schematic structural view of the rotor described in Embodiment 10; FIG. 9 is a schematic structural view of the rotor described in Embodiment 11; FIG. 10 is a schematic view of the rotor described in Embodiment 12 Fig. 11 is a schematic structural view of the rotor described in Embodiment 13; Fig. 12 is a schematic structural view of the stator core of an existing traditional high-speed permanent magnet synchronous motor; Fig. 13 is an existing traditional high-speed permanent magnet Schematic diagram of the rotor structure of a synchronous motor.

Detailed ways

Specific embodiment one: A kind of high-efficiency high-speed permanent magnet synchronous motor described in this embodiment has an inner rotor structure, which includes a stator, a rotor and an air gap. The rotor is composed of a permanent magnet 21, a permanent magnet sheath 23 and a rotating shaft 22. The stator Including the stator core and winding 4, the stator core 1 is cylindrical, and on the side close to the inner wall of the stator core 1, there are a plurality of cogged through holes 10 along the axial direction, the bottom of the cogged through holes 10 and the stator core 1 The minimum radial thickness of the inner wall is less than 2 mm, and the armature winding 4 is embedded in the alveolar through hole 10 near the axis side, and the armature winding 4 is concentrated short-distance winding or distributed winding.

When the winding 4 is a concentrated short-distance winding, it can be realized by a stringing process. Each phase winding is formed by a number of coils in series, and the coils are directly wound on the core teeth between two adjacent alveolar through holes 10 by a threading process. , the pitch of the coil is 1.

When the number of cogging through holes 10 in the stator core 1 of the high-speed permanent magnet synchronous motor described in this embodiment is 12, and the permanent magnet 21 of the rotor is 2 poles, the structure of the high-speed permanent magnet synchronous motor is shown in Figure 1 shown.

In the high-speed permanent magnet synchronous motor described in this embodiment, the side of the cogging through hole 10 close to the axis is embedded in the winding, and the side away from the axis forms an axial ventilation hole for heat dissipation.

The motor described in this embodiment is magnetized in the axial direction, and the rotating shaft 22 is made of magnetic materials.

Embodiment 2: The difference between this embodiment and the high-efficiency high-speed permanent magnet synchronous motor described in Embodiment 1 is that the stator core is a split structure, and the stator core is composed of a yoke core 11 and a tooth core 12. Composition, the yoke core 11 and the tooth core 12 are both cylindrical, and on the outer peripheral surface of the tooth core 12, there are a plurality of holes parallel to the central axis of the tooth core 12 along the axial direction. The tooth slot 121 , the armature winding 4 is embedded in the tooth slot 121 , the permanent magnet 21 in the rotor is fixed on the rotating shaft 22 , and the permanent magnet sheath 23 is fixed outside the permanent magnet 21 .

In this embodiment, the inner wall of the yoke core 11 and the tooth slot 121 on the tooth core 12 form the slot through hole 10 for embedding the winding. The yoke core 11 and the tooth core 12 can keep rotating synchronously. The end of the tooth 122 of the tooth core 12 may be connected with the inner wall of the yoke core 11 through a transition fit.

When the number of slots 121 of the high-speed permanent magnet synchronous motor described in this embodiment is 12, and the permanent magnets 21 of the rotor are 2 poles, the structure of the high-speed permanent magnet synchronous motor is shown in FIG. 2 to FIG. 4 . The stator core is a split structure, that is, the core is divided into two parts, the yoke core 11 and the tooth core 12. The yoke core 11 is cylindrical; the tooth core 12 is also cylindrical, and its outer diameter is the same as The diameter of the inner circle of the yoke core 11 is the same, and the outer circumferential surface of the tooth core 12 is axially provided with a tooth groove 121, and the armature winding 4 is embedded in the tooth groove 121; after the armature winding 4 is embedded The tooth core 12 is press-fitted into the yoke core 11.

The high-efficiency high-speed permanent magnet synchronous motor described in this embodiment adopts a split iron core structure, which can increase the leakage reactance of the motor, reduce the high-frequency current harmonics in the winding 4, and reduce the high-frequency copper loss and constant current of the motor winding 4. , Rotor high frequency iron loss.

Embodiment 3: The difference between this embodiment and the high-efficiency high-speed permanent magnet synchronous motor described in Embodiment 1 is that the stator core is a split structure, and the stator core is composed of a yoke core 11 and a tooth core 12. A plurality of straight slots 111 parallel to the central axis of the yoke core 11 are formed on the inner peripheral surface of the yoke core 11 in the axial direction. The number is the same; the shape of the end of the tooth 122 on the outer circumference of the tooth core 12 is the same as the shape of the inner wall of the straight groove 111 on the inner wall of the yoke core 11, and the end of the tooth 122 of the tooth core 12 is the same as that of the yoke The straight grooves 111 on the inner wall of the core 11 are engaged.

When the high-speed permanent magnet synchronous motor in this embodiment has 12 slots 121 and the permanent magnets 21 of the rotor have 2 poles, the structure of the high-speed permanent magnet synchronous motor is shown in FIG. 5 to FIG. 7 . On the inner peripheral surface of the yoke core 11, there are a plurality of straight slots 111 in the axial direction, and the number of the straight slots is the same as the number of the tooth grooves 121 in the tooth core 12; the teeth of the tooth core 12 The shape of 122 is the same as the internal shape of the straight slot 111 of the yoke core 11. After the winding 4 is embedded in the tooth slot 121 of the tooth core 12, the teeth of the tooth core 12 are meshed with the straight slot 111 of the yoke core 11. Press-fit into the yoke core 11.

Embodiment 4: The difference between this embodiment and the high-efficiency high-speed permanent magnet synchronous motor described in Embodiment 2 or 3 is that the distance between the groove bottom of the tooth groove 121 of the tooth core 12 and the inner circle of the tooth core 12 The minimum thickness is less than 2mm.

Embodiment 5: The difference between this embodiment and the high-efficiency high-speed permanent magnet synchronous motor described in Embodiment 1, 2, 3 or 4 is that the permanent magnet sheath 23 is a non-magnetic metal material. The outer surface of the permanent magnet sheath 23 is provided with several narrow grooves along the circumferential direction, the depth of the narrow grooves is smaller than the radial thickness of the permanent magnet sheath 23, and the width of the narrow grooves is 0.0mm-2.0mm.

Embodiment 6: The difference between this embodiment and the high-efficiency high-speed permanent magnet synchronous motor described in Embodiment 1, 2, 3, 4 or 5 is that the permanent magnet sheath 23 is a non-magnetic metal material. A thin metal layer with a thickness of 0.0 mm to 2 mm is fixed on the outer surface or inner surface of the permanent magnet sheath 23 , and the thin metal layer is a low-resistivity material.

Materials such as copper and silver may be used for the metal thin layer described in this embodiment. When the metal layer is relatively thin, for example, between 0.0 mm and 0.6 mm, the metal layer can be fixed on the outer surface or inner surface of the permanent magnet sheath 23 by using an existing surface coating process.

Embodiment 7: Metal layer The difference between this embodiment and the high-efficiency high-speed permanent magnet synchronous motor described in Embodiment 1, 2, 3, 4, 5 or 6 is that the permanent magnets 21 are elongated strips A permanent magnet, the permanent magnet 21 is stuck on the rotating shaft 22 in the axial direction.

Embodiment 8: The difference between this embodiment and the high-efficiency high-speed permanent magnet synchronous motor described in Embodiments 1, 2, 3, 4, 5 or 6 is that the permanent magnet 21 is a tile-shaped permanent magnet, The permanent magnet 21 is divided into several sections along the axial direction and pasted on the rotating shaft 22 .

Embodiment 9: The difference between this embodiment and the high-efficiency high-speed permanent magnet synchronous motor described in Embodiments 1, 2, 3, 4, 5, 6, 7 or 8 is that there is a motor with a thickness of 0mm-2.0mm metal layer, the metal layer is a low resistivity material.

Materials such as copper and silver may be used for the metal layer described in this embodiment. When the metal layer is relatively thin, for example, between 0.0 mm and 0.6 mm, an existing surface coating process can be used to fix the metal layer on the surface of the rotating shaft 22 .

Embodiment 10: The difference between this embodiment and the high-efficiency high-speed permanent magnet synchronous motor described in any one of Embodiments 1 to 9 is that there are shoulders 221 at both ends of the rotating shaft 22 in the rotor, and the permanent magnet 21 along the Axially stick between the two shoulders of the side wall of the rotating shaft 22, the permanent magnet sheath 23 is a metal sheath, the diameter of the shoulder 221 is less than or equal to the inner diameter of the permanent magnet sheath 23, the permanent magnet The axial length of the sheath 23 is greater than or equal to the length between the outer sides of the two shaft shoulders 221 , and the permanent magnet sheath 23 is fixedly connected to the shaft shoulders 221 .

The structure of the rotor described in this embodiment is shown in FIG. 8 . In this embodiment, the permanent magnet sheath 23 and the shaft shoulder 221 can be fixedly connected by welding.

Embodiment 11: The difference between this embodiment and the high-efficiency high-speed permanent magnet synchronous motor described in any one of Embodiments 1 to 9 is that one end of the rotating shaft 22 has a shoulder 221, and the permanent magnet sheath 23 is a circle. A cylindrical metal sheath, the outer diameter of one end of the permanent magnet sheath 23 is the same as the outer diameter of the shaft shoulder, and the other end has an inner end ring 230, the inner diameter of the inner end ring 230 is equal to the outer diameter of the rotating shaft 22; The magnet 21 is stuck on the outer surface of the rotating shaft 22 between the shaft shoulder 221 of the rotating shaft 22 and the inner end ring 230 in the axial direction, and the permanent magnet sheath 23 is fixedly connected with the shaft shoulder 221 .

The structure of the rotor in this embodiment is shown in FIG. 9 . In this embodiment, the permanent magnet sheath 23 and the shaft shoulder 221 can be fixedly connected by welding.

Embodiment 12: The difference between this embodiment and the high-efficiency high-speed permanent magnet synchronous motor described in any one of Embodiments 1 to 9 is that one end of the rotating shaft 22 has a shoulder 221, and the permanent magnet sheath 23 The outer diameter of the shaft shoulder 221 is the same; the permanent magnet sheath 23 is composed of a left sheath 231, a middle sheath 232 and a right sheath 233, wherein the left end of the left sheath 231 has an inner end ring; the middle sheath 232 There is an inner end ring in the middle; the right end of the right sheath 233 has an inner end ring; the inner diameter of all inner end rings is equal to the outer diameter of the rotating shaft 22; the permanent magnet 21 is stuck on the outer surface of the rotating shaft 22 in the axial direction, and is respectively located The right side of the inner end ring of the sleeve 231, the two sides of the inner end ring of the middle sheath 232 and the left side of the inner end ring of the right sheath 233, the left sheath 231, the middle sheath 232, the right sheath 233 It is fixedly connected with the shaft shoulder 221.

The structure of the rotor in this embodiment is shown in FIG. 10 . In this embodiment, the left sheath 231 , the middle sheath 232 , the right sheath 233 and the shaft shoulder 221 can be fixedly connected together by welding.

Embodiment 13: The difference between this embodiment and the high-efficiency high-speed permanent magnet synchronous motor described in any one of Embodiments 1 to 9 is that there is a shaft shoulder at one end of the rotating shaft 22, and the permanent magnet sheath 23 consists of four Metal cylinder 234 is formed, and the left end of described metal cylinder 234 has inner end ring, and the inner diameter of described inner end ring is identical with the diameter of rotating shaft 22, and the outer diameter of described metal cylinder 234 is identical with shaft shoulder diameter; Permanent magnet 21 is stuck on the outer surface of the rotating shaft 22 in the axial direction, and the permanent magnet 21 is located between the shoulder 221 and the inner end ring of the metal cylinder 234, or between the inner end rings of two metal cylinders 234, Between the four metal cylinders 234 and between the metal cylinders 234 and the shaft shoulder 221 are fixedly connected as a whole.

The structure of the rotor in this embodiment is shown in FIG. 11 . In this embodiment, the four metal cylinders 234 and the metal cylinders 234 and the shaft shoulder 221 can be fixedly connected together by welding.

The technical solution of the present invention is not limited to the structures described in the above embodiments, but also includes possible combinations of the structural features described in the above embodiments.

Claims (10)

1. High-efficiency high-speed permanent magnet synchronous motor, which is an inner rotor structure. The high-efficiency high-speed permanent magnet synchronous motor includes a stator, a rotor and an air gap, and the rotor consists of a permanent magnet (21), a permanent magnet sheath (23) and a rotating shaft ( 22) Composition, the stator includes a stator core and a winding (4), the stator core (1) is cylindrical, and it is characterized in that, on the side of the stator core (1) close to its inner wall, there are a plurality of slots along the axial direction A through hole (10), the minimum radial thickness between the bottom of the alveolar through hole (10) and the inner wall of the stator core (1) is less than 2 mm, and the armature winding (4) is embedded in the alveolar through hole (10) Near the side of the axis, the armature winding (4) is concentrated short-distance winding or distributed winding. 2. The high-efficiency high-speed permanent magnet synchronous motor according to claim 1, characterized in that the stator core is a split structure, and the stator core is composed of a yoke core (11) and a tooth core (12), Both the yoke core (11) and the tooth core (12) are cylindrical, and the outer peripheral surface of the tooth core (12) is axially opened with the tooth core (12). A plurality of tooth slots (121) parallel to the central axis, the permanent magnet (21) in the rotor in which the armature winding (4) is embedded in the tooth slot (121) is fixed on the rotating shaft (22), and the permanent magnet protects Cover (23) is fixed outside the permanent magnet (21). 3. The high-efficiency high-speed permanent magnet synchronous motor according to claim 1, characterized in that the stator core is a split structure, and the stator core is composed of a yoke core (11) and a tooth core (12), A plurality of straight slots (111) parallel to the central axis of the yoke core (11) are formed on the inner peripheral surface of the yoke core (11) in the axial direction, and the number of the straight slots (111) is the same as that of the teeth. The number of tooth slots (121) of the yoke core (12) is the same; the end shape of the teeth (122) on the outer circumference of the yoke core (12) is the same as the straight groove (111) on the inner wall of the yoke core (11) The inner walls have the same shape, and the ends of the teeth (122) of the tooth core (12) engage with the straight grooves (111) on the inner wall of the yoke core (11). 4. The high-efficiency high-speed permanent magnet synchronous motor according to claim 2 or 3, characterized in that the gap between the groove bottom of the tooth groove (121) of the tooth core (12) and the inner circle of the tooth core (12) The minimum thickness between them is less than 2mm. 5. The high-efficiency high-speed permanent magnet synchronous motor according to claim 1, 2 or 3, characterized in that, the permanent magnet sheath (23) is a non-magnetic metal material, and the permanent magnet sheath (23) ) is provided with several narrow grooves along the circumferential direction, the depth of the narrow grooves is less than the radial thickness of the permanent magnet sheath (23), and the width of the narrow grooves is 0.0mm-2.0mm. 6. The high-efficiency high-speed permanent magnet synchronous motor according to claim 1, 2 or 3, characterized in that, the permanent magnet sheath (23) is a non-magnetic metal material, and the permanent magnet sheath (23) ), or on the surface of the rotating shaft (22), a metal layer with a thickness of 0.0 mm to 2.0 mm is fixed, and the metal layer is a low-resistivity material. 7. The high-efficiency high-speed permanent magnet synchronous motor according to claim 1, 2 or 3, characterized in that there are shoulders (221) at both ends of the rotating shaft (22) in the rotor, and the permanent magnet (21) is axially Pasted between two shoulders of the side wall of the rotating shaft (22), the permanent magnet sheath (23) is a metal sheath, and the diameter of the shoulder (221) is less than or equal to that of the permanent magnet sheath (23). Inner diameter, the axial length of the permanent magnet sheath (23) is greater than or equal to the length between the outer sides of the two shaft shoulders (221), and the permanent magnet sheath (23) is fixedly connected to the shaft shoulders (221). 8. The high-efficiency high-speed permanent magnet synchronous motor according to claim 1, 2 or 3, characterized in that one end of the rotating shaft (22) has a shoulder (221), and the permanent magnet sheath (23) is cylindrical Metal sheath, the outer diameter of one end of the permanent magnet sheath (23) is the same as the outer diameter of the shaft shoulder, and the other end has an inner end ring (230), and the inner diameter of the inner end ring (230) is equal to the rotating shaft (22) The outer diameter of the outer diameter; the permanent magnet (21) is stuck on the outer surface of the rotating shaft (22) between the shaft shoulder (221) and the inner end ring (230) of the rotating shaft (22) in the axial direction, and the permanent magnet sheath (23 ) is fixedly connected with the shaft shoulder (221). 9. The high-efficiency high-speed permanent magnet synchronous motor according to claim 1, 2 or 3, characterized in that, one end of the rotating shaft (22) has a shoulder (221), and the outer diameter of the permanent magnet sheath (23) Same as the shaft shoulder (221); the permanent magnet sheath (23) is made up of a left sheath (231), a middle sheath (232) and a right sheath (233), wherein the left end of the left sheath (231) has Inner end ring; there is an inner end ring in the middle of the middle sheath (232); the right end of the right sheath (233) has an inner end ring; the inner diameter of all inner end rings is equal to the outer diameter of the rotating shaft (22); the permanent magnet (21) Stick on the outer surface of the rotating shaft (22) in the axial direction, and are respectively located on the right side of the inner end ring of the left sheath (231), on both sides of the inner end ring of the middle sheath (232) and on the right side of the right sheath (233 ), the left sheath (231), the middle sheath (232), the right sheath (233) and the shaft shoulder (221) are fixedly connected. 10. The high-efficiency high-speed permanent magnet synchronous motor according to claim 1, 2 or 3, characterized in that one end of the rotating shaft (22) has a shoulder, and the permanent magnet sheath (23) consists of four metal cylinders (234 ), the left end of the metal cylinder (234) has an inner end ring, the inner diameter of the inner end ring is the same as the diameter of the rotating shaft (22), and the outer diameter of the metal cylinder (234) is the same as the shaft shoulder diameter The permanent magnet (21) is stuck on the outer surface of the rotating shaft (22) in the axial direction, and the permanent magnet (21) is located between the inner end ring of the shaft shoulder (221) and the metal cylinder (234), or located Between the inner end rings of the two metal cylinders (234), between the four metal cylinders (234), and between the metal cylinders (234) and the shaft shoulder (221) are fixedly connected as a whole.

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