High-torque-density magnetic harmonic speed reduction axial permanent magnet servo motor

Abstract

The invention discloses a high-torque-density magnetic harmonic deceleration axial permanent magnet servo motor, and an axial magnetic field modulation type motor comprises a stator, a motor left rotor, a motor right rotor, a permanent magnet and an armature winding. The radial magnetic harmonic reducer comprises a magnetic harmonic reducer stator, a magnetic harmonic reducer outer rotor, a magnetic harmonic reducer inner rotor, a permanent magnet and a ball bearing. Through the integrated structure of the magnetic harmonic reducer stator and the magnetic field modulation type motor stator, the magnetic harmonic reducer and the magnetic field modulation type motor are directly connected, a mechanical reducer structure of a traditional servo system is omitted, and the overall weight of the servo system is effectively reduced. The magnetic field modulation type motor adopts an axial structure so as to improve the torque density of the servo system. The magnetic harmonic reducer is embedded in a hollow position in the magnetic field modulation type motor by adopting a radial structure, so that the design of a light-weight high-integration servo system is realized. The magnetic field modulation type motor and the magnetic harmonic reducer both adopt a surface-mounted permanent magnet structure so as to reduce torque pulsation.

Description

Technical Field

[0001] The present invention belongs to the field of permanent magnet synchronous motors and servo motors, and in particular relates to a high torque density magnetic harmonic deceleration axial permanent magnet servo motor. Background Art

[0002] Traditional radial permanent magnet motors have similar stator and rotor pole counts. As the number of rotor poles increases, the number of stator slots increases accordingly, leading to increased slot leakage and a reduced slot fill rate. This necessitates a larger motor size to meet output requirements, resulting in reduced motor efficiency and torque density. In contrast, radial magnetic field modulation motors, with their high torque density and low torque ripple, easily meet the low-speed, high-torque requirements of servo systems within space constraints. This type of motor achieves "self-deceleration" by modulating the air gap magnetic field through the introduction of modulation poles. However, due to the performance limitations of permanent magnet materials, their torque density at high reduction ratios still cannot meet application requirements.

[0003] To further improve torque density, the flattening characteristics of axial magnetic field modulation motors at the same torque output can offset the reduced torque density caused by wasted end space in traditional radial magnetic field modulation motors. However, at current research levels, the maximum reduction ratio of axial magnetic field modulation motors is still far inferior to that of mechanical reducers. A single axial field modulation motor cannot replace the traditional servo motor plus mechanical reducer combination. In addition, the insufficient space utilization of the hollow area of the motor means that the lightweight and high torque density design of axial field modulation motors needs further optimization. Therefore, how to further improve the torque density of servo motors on this basis remains a pressing issue. Summary of the Invention

[0004] In response to the problems existing in the prior art, the present invention provides a high-torque-density magnetic harmonic deceleration axial permanent magnet servo motor, which can improve the space utilization rate of the hollow part of the motor and enhance the torque density of the servo motor.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions: a high torque density magnetic harmonic reduction axial permanent magnet servo motor, comprising: an axial magnetic field modulation type motor and a radial magnetic harmonic reducer;

[0006] The axial magnetic field modulation type motor includes a stator, a right rotor and a left rotor, wherein the right rotor 4 and the left rotor are distributed on both sides of the stator;

[0007] The stator is provided with an armature winding; the right rotor of the motor is provided with a right rotor permanent magnet; the left rotor of the motor is provided with a left rotor permanent magnet;

[0008] The radial magnetic harmonic reducer includes a magnetic harmonic reducer stator, a magnetic harmonic reducer outer rotor, a magnetic harmonic reducer inner rotor and a ball bearing. The magnetic harmonic reducer stator is provided with a magnetic harmonic reducer stator permanent magnet; the magnetic harmonic reducer outer rotor is provided with a magnetic harmonic reducer outer rotor permanent magnet, and the magnetic harmonic reducer outer rotor and the magnetic harmonic reducer inner rotor are connected through a ball bearing;

[0009] The magnetic harmonic reduction axial permanent magnet servo motor directly mechanically couples the motor stator with the magnetic harmonic reduction device stator to form an integrated stator structure.

[0010] Furthermore, the aforementioned stator adopts a yokeless partial block stator structure, that is, stator teeth are provided in the stator, and the armature winding is wound on the stator teeth.

[0011] Furthermore, the stator tooth ends of the stator teeth extending into the air gap are extended in the circumferential direction, so as to improve the utilization rate of the armature winding ends and reduce magnetic leakage.

[0012] Furthermore, the armature winding is distributed along the circumference of the stator using drum-shaped windings and uses rectangular cross-section wires to reduce the possibility of short circuits.

[0013] Furthermore, the number of pole pairs of the permanent magnets of the right rotor of the motor is equal to that of the permanent magnets of the left rotor of the motor, forming a single-stator-double-rotor structure with the stator to reduce the axial unbalanced magnetic pull.

[0014] Furthermore, the aforementioned motor right rotor permanent magnet, motor left rotor permanent magnet and stator armature winding) have different pole pairs and are designed using the magnetic field modulation principle.

[0015] Furthermore, the aforementioned high torque density magnetic harmonic deceleration axial permanent magnet servo motor has auxiliary slots on the stator teeth (32) to form a stator split tooth structure for air gap magnetic field modulation.

[0016] Furthermore, the auxiliary slots on the aforementioned stator teeth form teeth of equal width distributed along the circumference, and the stator teeth have two split small teeth.

[0017] Compared with the prior art, the beneficial technical effects of the present invention using the above technical solution are as follows:

[0018] 1. The present invention directly couples an axial magnetic field modulation motor with a radial magnetic harmonic reducer, thereby reducing mechanical losses by eliminating the transmission shaft. Through the "two-stage self-deceleration" of the servo motor system, low-speed and high-torque output is achieved without a mechanical reducer, thereby increasing the torque density of the servo motor and realizing an integrated design of the drive motor and reducer.

[0019] 2. The axial magnetic field modulation motor of the present invention adopts a single stator and dual rotor design, which greatly reduces the impact of axial unbalanced magnetic pull on motor performance; the magnetic poles are directly coupled with the stator. Since the number of permanent magnet pole pairs is much larger than the number of armature winding pole pairs, the torque output is improved while achieving self-deceleration, and the axial length of the motor is further reduced, which is conducive to further improving the torque density of the motor.

[0020] 3. The axial magnetic field modulation motor of the present invention adopts a yokeless partial block stator core, drum winding, split teeth and other structures, which makes the stator easy to modularize, convenient for transportation and installation, while reducing end leakage and improving motor efficiency.

[0021] 4. The output port of the magnetic harmonic reduction axial permanent magnet servo motor of the present invention is the outer rotor port of the magnetic harmonic reducer, which can be used as a frameless rotor to directly drive the load, further reducing the mechanical friction loss of the system.

[0022] 5. The stator teeth, rotor and permanent magnet surfaces of the axial magnetic field modulation motor of the present invention all adopt an unequal radius design method, which achieves spatial symmetry of the motor magnetic field, thereby increasing the motor output torque while reducing torque fluctuations. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is a structural diagram of a high torque density magnetic harmonic deceleration axial permanent magnet servo motor of the present invention;

[0024] Figure 2 This is an exploded view of the motor structure of the present invention;

[0025] Figure 3 This is a schematic diagram of the axial magnetic field modulation type motor structure of the present invention;

[0026] Figure 4 Schematic diagram of the radial magnetic harmonic reducer structure of the motor structure of the present invention;

[0027] Figure 5 This is a structural diagram of the magnetic harmonic deceleration axial permanent magnet servo motor of the present invention;

[0028] Figure 6 Schematic diagram of the split tooth structure of the present invention;

[0029] Figure 7 It is a schematic diagram of the ring winding structure of the present invention.

[0030] Figure numerals: 1. Axial magnetic field modulation type motor; 2. Radial magnetic harmonic reducer; 3. Stator; 31. Armature winding; 32. Stator teeth; 33. Magnetic harmonic reducer stator; 34. Magnetic harmonic reducer stator permanent magnet; 35. Stator split teeth; 4. Motor right rotor; 41. Motor right rotor permanent magnet; 5. Motor left rotor; 51. Motor left rotor permanent magnet; 6. Magnetic harmonic reducer outer rotor; 61. Magnetic harmonic reducer outer rotor permanent magnet; 7. Magnetic harmonic reducer inner rotor; 8. Ball bearing. DETAILED DESCRIPTION

[0031] In order to better understand the technical content of the present invention, specific embodiments are given and described below with reference to the accompanying drawings.

[0032] Various aspects of the present invention are described herein with reference to the accompanying drawings, which show a number of illustrative embodiments. The embodiments of the present invention are not limited to those described in the accompanying drawings. It should be understood that the present invention can be implemented by any of the various concepts and embodiments described above, as well as the concepts and implementations described in detail below, because the concepts and embodiments disclosed herein are not limited to any particular implementation. In addition, some aspects disclosed herein may be used alone or in any appropriate combination with other aspects disclosed herein.

[0033] Ginseng Figures 1 to 5 This embodiment provides a high torque density magnetic harmonic reduction axial permanent magnet servo motor, comprising an axial magnetic field modulation motor 1 and a radial magnetic harmonic reducer 2.

[0034] The axial magnetic field modulation type motor 1 includes a stator 3, a right motor rotor 4 and a left motor rotor 5, which are distributed on both sides of the stator 3; an armature winding 31 is provided on the stator 3; a right motor rotor permanent magnet 41 is provided on the right motor rotor 4; and a left motor rotor permanent magnet 51 is provided on the left motor rotor 5.

[0035] In the axial magnetic field modulation type motor 1, the permanent magnets 41 of the right rotor of the motor and the permanent magnets 51 of the left rotor of the motor are both surface-mounted, and the magnetization direction is axial magnetization, which is beneficial to reducing torque pulsation; at the same time, in order to improve the torque output capacity, the magnetic field modulation principle is applied, and the pole pairs of the unequal armature winding 31 and the pole pairs of the permanent magnets 41 of the right rotor of the motor and the permanent magnets 51 of the left rotor of the motor are modulated through the stator teeth 32, so as to achieve the effect of deceleration and torque increase.

[0036] The principle is as follows.

[0037] If the number of stator teeth is P s , the number of pole pairs of the armature winding is P a , then the number of pole pairs P of the permanent magnets of the left and right rotors of the motor is r Should meet the following requirements:

[0038] P r =|P s ±P a |

[0039] Therefore, the expression of the average output torque of the axial magnetic field modulation motor can be written as:

[0040]

[0041] Where B g is the single-side air gap magnetic flux amplitude; N s is the number of winding turns; I rms is the effective value of the winding phase current; k w1 is the fundamental wave winding coefficient; D i is the inner diameter of the stator core; D o is the outer diameter of the stator core. Compared with ordinary axial permanent magnet synchronous motors, the torque formula of axial magnetic field modulation motors has The magnification factor shows that the axial magnetic field modulation motor has a higher torque density than the ordinary axial motor.

[0042] The stator 3 of the axial magnetic field modulation type motor adopts a modular design, with each stator core 32 and armature winding 31 as each sub-unit, which is convenient for installation and transportation while reducing electromagnetic loss and improving motor efficiency.

[0043] The radial magnetic harmonic reducer 2 includes a magnetic harmonic reducer stator 33, a magnetic harmonic reducer outer rotor 6, a magnetic harmonic reducer inner rotor 7 and a ball bearing 8. The magnetic harmonic reducer stator 33 is provided with a magnetic harmonic reducer stator permanent magnet 34; the magnetic harmonic reducer outer rotor 6 is provided with a magnetic harmonic reducer outer rotor permanent magnet 61.

[0044] The radial magnetic harmonic reducer has different magnetic harmonic reducer outer rotor permanent magnet 61 pole pairs P o The stator permanent magnet of the magnetic harmonic reducer has 34 pole pairs (P o -1) Realize the transmission from stator to outer rotor The torque gain effect.

[0045] The magnetic harmonic reduction axial permanent magnet servo motor directly couples the motor stator 3 with the magnetic harmonic reducer stator 33 to form an integrated stator structure, thereby achieving two-stage self-deceleration and even reaching the reduction ratio that can be output by current mechanical reducers.

[0046] In summary, the torque output gain ratio λ of the magnetic harmonic deceleration axial permanent magnet servo motor is

[0047]

[0048] Example 2

[0049] like Figure 6 As shown, the axial magnetic field modulation type motor adopts a stator split tooth 35 structure, that is, auxiliary slots are opened on the stator teeth 32 to form equal-width teeth distributed along the circumference, which plays the role of air gap magnetic field modulation. Each stator tooth has two split small teeth, thereby improving the motor torque output capacity while ensuring that its power factor is not too low; the armature winding 31 adopts a drum winding, thereby effectively improving the utilization rate of the winding end, reducing copper loss, and improving the motor efficiency.

[0050] After adopting the split tooth structure, the modulation ratio of the axial magnetic field modulation motor is

[0051]

[0052] Then the expression of the average torque output by the axial magnetic field modulation motor can be written as:

[0053] T=3α(B pm +αB epm )N s I rms k w1 D i (D o -D i )

[0054] Where B pm is the fundamental amplitude of the no-load air gap magnetic flux density; B epm is the effective harmonic amplitude of the no-load air gap magnetic flux density.

[0055] Example 3

[0056] like Figure 7 As shown, the axial magnetic field modulation type motor adopts a ring winding 31 structure, so that when the motor diameter is large and the number of armature winding pole pairs is small, the amount of copper wire used can be reduced, thereby reducing copper loss while reducing costs and improving motor operating efficiency.

[0057] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0058] The basic principles, main features, and advantages of the present invention are shown and described above. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present invention. Various changes and modifications may be made to the present invention without departing from the spirit and scope of the present invention, and such changes and modifications are intended to fall within the scope of the present invention.

[0059] While the present invention has been described above with reference to preferred embodiments, this is not intended to limit the present invention. Persons skilled in the art will readily appreciate that various modifications and variations can be made without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention shall be determined by the claims.

Claims

1. A high torque density magnetic harmonic deceleration axial permanent magnet servo motor, comprising: An axial magnetic field modulation type motor (1) and a radial magnetic harmonic reducer (2); characterized in that: The axial magnetic field modulation type motor (1) comprises a stator (3), a right motor rotor (4) and a left motor rotor (5), wherein the right motor rotor (4) and the left motor rotor (5) are distributed on both sides of the stator (3); The stator (3) is provided with an armature winding (31); the motor right rotor (4) is provided with a motor right rotor permanent magnet (41); the motor left rotor (5) is provided with a motor left rotor permanent magnet (51); The radial magnetic harmonic reducer (2) comprises a magnetic harmonic reducer stator (33), a magnetic harmonic reducer outer rotor (6), a magnetic harmonic reducer inner rotor (7) and a ball bearing (8); the magnetic harmonic reducer stator (33) is provided with a magnetic harmonic reducer stator permanent magnet (34); the magnetic harmonic reducer outer rotor (6) is provided with a magnetic harmonic reducer outer rotor permanent magnet (61); the magnetic harmonic reducer outer rotor (6) and the magnetic harmonic reducer inner rotor (7) are connected via a ball bearing (8); The magnetic harmonic reduction axial permanent magnet servo motor directly mechanically couples the motor stator (3) with the magnetic harmonic reduction device stator (33) to form an integrated stator structure.

2. The high torque density magnetic harmonic deceleration axial permanent magnet servo motor according to claim 1, characterized in that: The stator (3) adopts a yokeless partial block stator structure, that is, stator teeth (32) are arranged in the stator (3), and the armature winding (31) is wound on the stator teeth (32).

3. The high torque density magnetic harmonic deceleration axial permanent magnet servo motor according to claim 2, characterized in that: The stator tooth end portion of the stator tooth (32) extending into the air gap is extended in the circumferential direction, so as to improve the utilization rate of the end portion of the armature winding (31) and reduce magnetic leakage.

4. The high torque density magnetic harmonic deceleration axial permanent magnet servo motor according to claim 1, characterized in that: The armature winding (31) is distributed along the circumference of the stator using a drum-shaped winding and uses a rectangular cross-section wire to reduce the possibility of short circuit.

5. The high torque density magnetic harmonic deceleration axial permanent magnet servo motor according to claim 1, characterized in that: The motor right rotor permanent magnet (41) and the motor left rotor permanent magnet (51) have the same number of pole pairs, and form a single stator-double rotor structure with the stator (3) to reduce axial unbalanced magnetic pulling force.

6. The high torque density magnetic harmonic deceleration axial permanent magnet servo motor according to claim 1, characterized in that: The motor right rotor permanent magnet (41), the motor left rotor permanent magnet (51) and the stator armature winding (31) have different pole pairs and are designed using the magnetic field modulation principle.

7. The high torque density magnetic harmonic deceleration axial permanent magnet servo motor according to claim 2, characterized in that: Auxiliary slots are opened on the stator teeth (32) to form a stator split tooth (35) structure for air gap magnetic field modulation.

8. The high torque density magnetic harmonic deceleration axial permanent magnet servo motor according to claim 7, characterized in that: Auxiliary slots are formed on the stator teeth (32) to form teeth of equal width distributed along a circumference, and the stator teeth are provided with two split small teeth.

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