Permanent magnet arc motor adopting bilateral axial compensation

Abstract

The invention discloses a permanent magnet arc motor adopting bilateral axial compensation, and belongs to the technical field of electromechanics. The permanent magnet arc-shaped motor comprises a rotor and at least one arc-shaped stator. The arc-shaped stator comprises a radial stator iron core, a radial main winding, a double-side axial compensation device and a stator connecting structure; the double-side axial compensation device comprises a double-side axial iron core and a double-side axial compensation winding; the rotor comprises rotor magnetic steel and a rotor iron core; the radial main winding is fixedly arranged on the radial stator iron core, the radial stator iron core is fixedly connected with the stator connecting structure, symmetrical double-side axial iron cores are additionally arranged at spare positions on two sides of the end part of the radial main winding, the double-side axial iron cores are fixedly connected with the stator connecting structure, double-side axial compensation windings are symmetrically and fixedly arranged on the double-side axial iron cores, and the double-side axial compensation windings are fixedly connected with the stator connecting structure. An air gap is arranged between the bilateral axial iron core and the rotor magnetic steel, and the rotor magnetic steel is fixedly arranged on the outer side face of the rotor iron core. The utilization rate of the end space of the winding is improved through the double-side axial compensation device, and the output torque characteristic of the arc-shaped motor is improved.

Description

Technical Field

[0001] The invention belongs to the field of electromechanical technology, and in particular relates to a permanent magnet arc motor which adopts double-side axial compensation to improve the motor torque characteristics. Background Art

[0002] Permanent magnet arc motors have the characteristics of simple structure, fast dynamic response, high torque density and direct drive. They are widely used in astronomical observation, national defense weapons, robots, mining and other fields.

[0003] Permanent magnet arc motors are usually used in large diameter, low speed scenes, such as astronomical telescopes, radars, etc. Figure 3 The characteristics of the arc-shaped motor are: larger outer diameter and smaller axial length. The axial length of the end windings on both sides of the arc-shaped motor is often greater than the axial length of the motor core. The relatively long winding ends cause a large waste of space inside the motor, low space utilization, and low motor torque density. Summary of the invention

[0004] The purpose of the present invention is to solve the above problems existing in the prior art and to provide a permanent magnet arc motor with double-sided axial compensation.

[0005] The new structure of the permanent magnet arc motor proposed in the present invention can improve the utilization rate of the winding end space through the double-sided axial compensation device; improve the output torque characteristics of the arc motor; in addition, the double-sided axial compensation device can also use a weak magnetic method to widen the speed operating range, which is helpful to adjust the output torque and speed characteristics of the motor.

[0006] To achieve the above object, the technical solution adopted by the present invention is:

[0007] A permanent magnet arc motor adopting double-sided axial compensation comprises a rotor and at least one arc-shaped stator; the arc-shaped stator comprises a radial stator core, a radial main winding, a double-sided axial compensation device and a stator connection structure, the double-sided axial compensation device comprises a double-sided axial core and a double-sided axial compensation winding; the rotor comprises a rotor magnetic steel and a rotor core; the radial main winding is fixedly mounted on the radial stator core, the radial stator core is fixedly connected to the stator connection structure, symmetrical double-sided axial cores are installed at the free positions on both sides of the ends of the radial main winding, the double-sided axial cores are fixedly connected to the stator connection structure, the double-sided axial compensation windings are symmetrically fixedly mounted on the double-sided axial cores, an air gap is provided between the double-sided axial cores and the rotor magnetic steel, and the rotor magnetic steel is fixedly mounted on the outer surface of the rotor core.

[0008] Furthermore, the rotor magnet is a surface-mounted magnet, and each pole of the surface-mounted magnet is divided into three sections; the middle magnetization direction is radial and is the radial main magnet, and the magnetization directions on both sides are axial and are the axial compensation magnets; when the magnetization direction of the radial main magnet is radially outward, the magnetization directions of the axial compensation magnets on both sides are respectively axially outward; when the magnetization direction of the radial main magnet is radially inward, the magnetization directions of the axial compensation magnets on both sides are respectively axially inward.

[0009] Furthermore, the rotor magnet is a magnetic focusing structure, and the rotor magnet of the magnetic focusing structure includes radial main magnets and magnetic focusing magnet blocks. The NS poles of the radial main magnets are circumferentially magnetized and arranged oppositely. The magnetic focusing magnet blocks are arranged between the NS poles of the radial main magnets. The radial main magnets and the magnetic focusing magnet blocks are arranged alternately in sequence according to the radial main magnet N pole → magnetic focusing magnet block → radial main magnet S pole → magnetic focusing magnet block as a pair of pole pitches.

[0010] Furthermore, there are multiple arc-shaped stators, and the multiple arc-shaped stators are evenly distributed along the circumference of the rotor core.

[0011] Furthermore, the number of the arc-shaped stator is one.

[0012] Furthermore, the arc width of the arc-shaped stator is (n+1 / 2) times the pole pitch, where n is an arbitrary positive integer.

[0013] Furthermore, the distance between two adjacent arc-shaped stators is (n±1 / m) times the pole pitch, where n is an arbitrary positive integer and m is the number of arc-shaped stators.

[0014] Furthermore, the number of tooth slots of the bilateral axial core and the distribution of the bilateral axial compensation windings are the same as the number of tooth slots of the radial stator core and the distribution of the radial main windings of the main magnetic circuit.

[0015] Furthermore, a magnetic steel isolation core is arranged between the radial main magnetic steel and the axial compensation magnetic steel.

[0016] Furthermore, outer baffles are fixed at both ends of the arc-shaped stator.

[0017] The beneficial effects of the present invention relative to the prior art are:

[0018] 1. Compared with conventional permanent magnet arc motors, the permanent magnet arc motor with double-sided axial compensation proposed in the present invention can improve the space utilization rate of the radial main winding ends; when the same current as the radial main winding is passed through the double-sided axial compensation windings, the space utilization rate of the radial main winding ends can be improved; the output torque is increased, and the output torque characteristics of the arc motor are improved.

[0019] 2. When a current with a phase opposite to that of the radial main winding is passed through, it can play a role in magnetic weakening. The use of magnetic weakening can broaden the speed operating range and help adjust the output torque and speed characteristics of the motor.

[0020] 3. A rotor magnetic concentration structure is proposed, that is, the NS poles are magnetized circumferentially and arranged oppositely, with a magnetic concentration magnet block in the middle, which increases the air gap flux density and the torque density of the motor.

[0021] 4. The permanent magnet arc motor with double-sided axial compensation proposed in the present invention can improve the torque characteristics of the permanent magnet arc motor from the perspective of the motor body structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of a permanent magnet arc motor adopting double-side axial compensation according to the present invention;

[0023] Figure 2 A cross-sectional view of a permanent magnet arc motor using double-side axial compensation according to the present invention;

[0024] Figure 3 This is a schematic diagram of a permanent magnet arc motor without a double-sided axial compensation device installed;

[0025] Figure 4 It is a structural schematic diagram of the double-sided axial compensation device of the present invention;

[0026] Figure 5 Schematic diagram of the structure and magnetization direction of the rotor magnetic steel;

[0027] Figure 6 It is a schematic diagram of the rotor magnetic steel structure, where: Figure 6 (a) is a schematic diagram of the three-dimensional structure of a surface-mounted magnetic steel; Figure 6 (b) is a schematic diagram of the rotor magnetic steel adopting a magnetic concentrating structure;

[0028] Figure 7 This is a schematic diagram of the auxiliary winding and the radial winding being connected in reverse series.

[0029] The names and reference numerals of the components involved in the above drawings are summarized as follows:

[0030] 1- radial stator core, 2- double-sided axial core, 3- radial main winding, 4- double-sided axial compensation winding, 5- radial main magnetic steel, 6- rotor core, 7- axial compensation magnetic steel, 8- stator connection structure, 9- outer baffle, 10- magnetic steel isolation core, 11- magnet block, 12- double-sided axial core connection structure. DETAILED DESCRIPTION

[0031] Specific implementation method 1: Figure 1 , Figure 2As shown, this embodiment discloses a permanent magnet arc motor with bilateral axial compensation, including a rotor and at least one arc-shaped stator; the arc-shaped stator includes a radial stator core 1, a radial main winding 3, a bilateral axial compensation device and a stator connection structure 8, and the bilateral axial compensation device includes a bilateral axial core 2 and a bilateral axial compensation winding 4; the rotor includes a rotor magnetic steel and a rotor core 6; the radial main winding 3 (which is an arc-shaped stator winding) is fixedly mounted on the radial stator core 1, and the radial stator core 1 is fixedly connected to the stator connection structure 8, and symmetrical bilateral axial cores 2 are added to the vacant positions on both sides of the ends of the radial main winding 3, and the bilateral axial cores 2 are fixedly connected to the stator connection structure 8, and the bilateral axial compensation windings 4 are symmetrically fixedly mounted on the bilateral axial core connection structure 12 of the bilateral axial core 2, and an air gap (which is an axial air gap) is provided between the bilateral axial core 2 and the rotor magnetic steel, and the rotor magnetic steel is fixedly mounted on the outer surface of the rotor core 6. There are two structural forms of rotor magnets:

[0032] Structural form 1: The rotor magnet is a surface mounted magnet, each pole of which is divided into three sections; the radial main magnet 5 is in the middle, and the axial compensation magnet 7 is in the two sides (the structure and magnetization direction of the rotor magnet are shown in the figure). Figure 5 and Figure 6 (a)); when the magnetization direction of the radial main magnetic steel 5 is radially outward, the magnetization directions of the axial compensation magnetic steels 7 on both sides are axially outward; when the magnetization direction of the radial main magnetic steel 5 is radially inward, the magnetization directions of the axial compensation magnetic steels 7 on both sides are axially inward (the radial main magnetic steel 5 and the axial compensation magnetic steel 7 are arranged on the outer surface of the rotor core 6 according to this rule).

[0033] The double-sided axial core 2 plays a positioning and supporting role, so that the double-sided axial compensation device and the axial compensation magnetic steel 7 of the rotor maintain an appropriate air gap, and provide a flow channel for the magnetic circuit inside the double-sided axial compensation device.

[0034] A three-phase symmetrical current is passed through the radial main winding 3, which is consistent with the driving form of a conventional arc-shaped motor. The double-sided axial compensation winding 4 in the double-sided axial compensation device passes the same current as the radial main winding 3. At this time, the double-sided axial compensation device will generate an additional torque, which can improve the utilization rate of the space at the end of the radial main winding 3 and improve the output torque characteristics of the arc-shaped motor.

[0035] When a current in the opposite direction to that in the radial main winding 3 is passed through the bilateral axial compensation winding 4, the bilateral axial compensation winding 4 interacts with the radial main winding 3 to produce a weak magnetic effect. The weak magnetic method is used to widen the speed operating range, which helps to adjust the output torque and speed characteristics of the motor.

[0036] The auxiliary winding (A) and the auxiliary winding (B) (i.e., the double-sided axial compensation winding 4) of the present invention are connected in reverse series with the radial winding (i.e., the radial main winding 3), such as Figure 7 As shown, the induced potential generated by the auxiliary winding and the radial winding can be in the opposite direction, which effectively reduces the value of the DC bus voltage. The reduction of the DC bus voltage can effectively reduce the size of the drive and reduce the cost.

[0037] Furthermore, a magnetic steel isolation core 10 is provided between the radial main magnetic steel 5 and the axial compensation magnetic steel 7, such as Figure 6 (a) shown.

[0038] Structural form II: The rotor magnetic steel is a magnetic focusing structure, and the rotor magnetic steel of the magnetic focusing structure includes radial main magnetic steel 5 and magnetic focusing magnet block 11. The NS poles of the radial main magnetic steel 5 are circumferentially magnetized and arranged oppositely. The magnetic focusing magnet block 11 is arranged between the NS poles of the radial main magnetic steel 5. The radial main magnetic steel 5 and the magnetic focusing magnet block 11 are arranged alternately in sequence according to the radial main magnetic steel 5 N pole → magnetic focusing magnet block 11 → radial main magnetic steel 5 S pole → magnetic focusing magnet block 11 as a pair of pole pitches, such as Figure 6 (b) as shown.

[0039] The rotor magnet adopts this magnetic focusing structure to further improve the utilization rate of the radial main winding 3 end space and the magnetic flux utilization rate of the permanent magnet, provide additional magnetic resistance torque, and improve the torque density of the arc-type permanent magnet motor. Because the effect of this magnetic focusing effect no longer requires the double-sided axial compensation magnetic steel 7, the radial length of the rotor magnet is further reduced; the magnetic focusing effect increases the air gap magnetic flux density of the motor, and the magnetic circuit flows in the radial direction and the axial direction of the two ends. The additional magnetic resistance torque improves the overall torque density of the arc-type motor.

[0040] Such an arrangement increases the air gap flux density and effectively improves the torque density of the motor. The rotor magnetic concentration structure of the present invention provides a new path for the magnetic field, and the magnetic circuit can be divided into a radial magnetic circuit and an axial magnetic circuit. The magnetic circuit provides additional reluctance torque to improve the torque density of the arc-type permanent magnet motor. Therefore, a permanent magnet arc-type motor using double-sided axial compensation of the present invention can improve the torque characteristics of the permanent magnet arc-type motor.

[0041] Furthermore, there are multiple arc-shaped stators, which are evenly distributed along the circumference of the rotor core 6 .

[0042] Furthermore, the number of the arc-shaped stator is one.

[0043] Furthermore, the arc width of the arc-shaped stator is (n+1 / 2) times the pole pitch, where n is an arbitrary positive integer.

[0044] The arc-shaped motor stator has two ends due to its structural characteristics, which causes the air gap magnetic resistance to be distorted at the ends and produces serious end effect. The end effect will produce a large end torque when the arc-shaped motor is running, causing the arc-shaped motor to produce a large output torque pulsation. When the central angle of the arc-shaped stator is adjusted to (n+1 / 2) times the pole pitch, the fundamental components of the end torque generated by the two ends of the arc-shaped stator can offset each other, thereby suppressing the fundamental component of the end torque and greatly suppressing the output torque pulsation of the arc-shaped motor.

[0045] Furthermore, when there are multiple arc-shaped stators, the distance between two adjacent arc-shaped stators is (n±1 / m) times the pole pitch, where n is an arbitrary positive integer and m is the number of arc-shaped stators.

[0046] The stator end effect of the arc-shaped motor will produce a large end torque, and the fundamental component can be suppressed by adjusting the stator center angle; when the arc-shaped motor is spliced ​​with multiple arc-shaped stators, the second harmonic components in the end torque of each arc-shaped stator will be superimposed on each other to form a large torque pulsation; when the distance between each stator is (n±1 / m) times the pole pitch (m is the number of arc-shaped stators), the second harmonics of the end torque of each arc-shaped stator will be superimposed and cancel each other out, further suppressing the end torque, further suppressing the output torque pulsation of the arc-shaped motor, and improving the output torque characteristics of the arc-shaped motor.

[0047] Furthermore, the number of tooth slots of the bilateral axial core 2 and the distribution form of the bilateral axial compensation windings 4 are the same as the number of tooth slots of the radial stator core 1 and the distribution form of the radial main windings 3 of the main magnetic circuit.

[0048] The radial main winding 3 and the bilateral axial compensation winding 4 adopt the same distribution form, which is conducive to the application of the excitation current and the switching of the compensation function; when the bilateral axial compensation device is needed to increase the output torque, the bilateral axial compensation winding 4 is passed with a current in phase with the radial main winding 3 or the bilateral axial compensation winding 4 is connected in series with each phase of the radial main winding 3 to achieve the increase of the output torque, which is conducive to improving the output torque characteristics of the arc motor; when the bilateral axial compensation device is needed to play a role in magnetic weakening, the bilateral axial compensation winding 4 is passed with a current in phase with the radial main winding 3 or the bilateral axial compensation winding 4 is connected in series with each phase of the radial main winding 3 to achieve the effect of magnetic weakening, and the speed operation range is widened by using magnetic weakening, which is conducive to adjusting the output torque and speed characteristics of the motor. In general, the radial main winding 3 and the bilateral axial compensation winding 4 adopt the same distribution form, which is conducive to the application of the excitation current and the switching of the effect of the bilateral axial compensation device.

[0049] Furthermore, outer baffles 9 are fixed at both ends of the arc-shaped stator.

[0050] The present invention adopts a double-sided axial compensation device, which can improve the torque characteristics of the permanent magnet arc motor and form a new permanent magnet arc motor structure. The length of the winding end of the conventional permanent magnet arc motor is often greater than the length of the core, and the space utilization rate is low; a double-sided axial compensation device is installed in the space vacated at the end of the winding, and the device includes a double-sided axial core 2 and a double-sided axial compensation winding 4. The double-sided axial compensation device can improve the utilization rate of the space at the end of the radial main winding 3; improve the output torque characteristics of the arc motor; in addition, the double-sided axial compensation device can also use a weak magnetic method to widen the speed operation range, which is helpful to adjust the output torque and speed characteristics of the motor.

[0051] The present invention proposes a permanent magnet arc motor with double-sided axial compensation. Among them, the distribution form of the double-sided axial compensation winding 4 is the same as that of the radial main winding 3. When the current of the same phase as that in the radial main winding 3 is passed, the utilization rate of the space at the end of the radial main winding 3 can be improved; and the output torque characteristics of the arc motor are improved. When the current of the opposite phase to the radial main winding 3 is passed, it can play a weak magnetic effect, and the speed operation range is widened by weak magnetic method, which is helpful to adjust the output torque and speed characteristics of the motor; when the rotor magnetic concentration structure is adopted, the magnetic circuit provides additional reluctance torque, which improves the torque density of the arc permanent magnet motor. Therefore, the new permanent magnet arc motor with double-sided axial compensation in the present invention can improve the torque characteristics of the permanent magnet arc motor.

[0052] The above are only preferred specific implementation modes of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical solutions and inventive concepts of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A permanent magnet arc motor with double-sided axial compensation, characterized in that: The invention comprises a rotor and at least one arc-shaped stator; the arc-shaped stator comprises a radial stator core (1), a radial main winding (3), a double-sided axial compensation device and a stator connection structure (8); the double-sided axial compensation device comprises a double-sided axial core (2) and a double-sided axial compensation winding (4); the rotor comprises a rotor magnetic steel and a rotor core (6); the radial main winding (3) is fixedly mounted on the radial stator core (1); the radial stator core (1) is fixedly connected to the stator connection structure (8); symmetrical double-sided axial cores (2) are installed at the free positions on both sides of the ends of the radial main winding (3); the double-sided axial cores (2) are fixedly connected to the stator connection structure (8); the double-sided axial compensation windings (4) are symmetrically fixedly mounted on the double-sided axial cores (2); an air gap is provided between the double-sided axial cores (2) and the rotor magnetic steel; the rotor magnetic steel is fixedly mounted on the outer surface of the rotor core (6).

2. A permanent magnet arc motor with double-sided axial compensation according to claim 1, characterized in that: The rotor magnet is a surface mounted magnet, and each pole of the surface mounted magnet is divided into three sections; the middle magnetization direction is radial, which is the radial main magnet (5), and the magnetization directions on both sides are axial, which are the axial compensation magnets (7); when the magnetization direction of the radial main magnet (5) is radially outward, the magnetization directions of the axial compensation magnets (7) on both sides are axially outward; when the magnetization direction of the radial main magnet (5) is radially inward, the magnetization directions of the axial compensation magnets (7) on both sides are axially inward.

3. The permanent magnet arc motor with double-sided axial compensation according to claim 1, characterized in that: The rotor magnetic steel is a magnetic focusing structure, and the rotor magnetic steel of the magnetic focusing structure comprises radial main magnetic steel (5) and a magnetic focusing magnet block (11), the N poles of the radial main magnetic steel (5) are circumferentially magnetized and arranged oppositely, the magnetic focusing magnet block (11) is arranged between the N poles of the radial main magnetic steel (5), and the radial main magnetic steel (5) and the magnetic focusing magnet block (11) are arranged alternately in sequence according to the radial main magnetic steel (5) N pole → magnetic focusing magnet block (11) → radial main magnetic steel (5) S pole → magnetic focusing magnet block (11) as a pair of pole pitches.

4. The permanent magnet arc motor with double-sided axial compensation according to claim 1, characterized in that: There are multiple arc-shaped stators, which are evenly distributed along the circumference of the rotor core (6).

5. The permanent magnet arc motor with double-sided axial compensation according to claim 1, characterized in that: The number of the arc-shaped stator is one.

6. A permanent magnet arc motor with double-sided axial compensation according to claim 1, 4 or 5, characterized in that: The arc width of the arc-shaped stator is (n+1 / 2) times the pole pitch, where n is an arbitrary positive integer.

7. The permanent magnet arc motor with double-sided axial compensation according to claim 4, characterized in that: The distance between two adjacent arc-shaped stators is (n±1 / m) times the pole pitch, where n is an arbitrary positive integer and m is the number of arc-shaped stators.

8. The permanent magnet arc motor with double-sided axial compensation according to claim 1, characterized in that: The number of tooth slots of the bilateral axial core (2) and the distribution form of the bilateral axial compensation windings (4) are the same as the number of tooth slots of the radial stator core (1) and the distribution form of the radial main windings (3) of the main magnetic circuit.

9. The permanent magnet arc motor with double-sided axial compensation according to claim 2, characterized in that: A magnetic steel isolation core (10) is arranged between the radial main magnetic steel (5) and the axial compensation magnetic steel (7).

10. The permanent magnet arc motor with double-sided axial compensation according to claim 1, characterized in that: Outer baffles (9) are fixed at both ends of the arc-shaped stator.

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