Double-permanent-magnet double-armature motor

Abstract

The double-permanent-magnet double-armature motor comprises a primary and a secondary, the primary comprises a primary iron core, a primary armature winding and primary permanent magnets, the primary iron core is composed of primary iron core teeth and a primary iron core yoke, and the primary permanent magnets are located on the same single side of the tops of the primary iron core teeth; an included angle of-15 degrees to 15 degrees is formed between the magnetizing direction of the primary permanent magnets and the central axis of the primary iron core teeth where the primary permanent magnets are located; the secondary comprises a secondary iron core, a secondary armature winding and secondary permanent magnets, the secondary iron core is composed of secondary iron core teeth and a secondary iron core yoke, the secondary permanent magnets are located on the same single side of the tops of the secondary iron core teeth, and the magnetizing direction of the secondary permanent magnets and the central axis of the secondary iron core teeth where the secondary permanent magnets are located form an included angle of 30-90 degrees. The magnetic field phase difference generated by the primary permanent magnets and the secondary permanent magnets of the double-permanent-magnet double-armature motor is small, the permanent magnet torque or thrust generated by unit current can be improved, the power density of the motor is improved, and meanwhile the permanent magnet eddy current loss of the motor can be effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of electric machines, and in particular to a double permanent magnet double armature electric machine. BACKGROUND

[0002] As a core component in electromechanical energy conversion systems, electric machines have been the focus of attention and development for nearly a century, and have been successfully applied to national defense, energy, transportation, home and other industries. However, with the continuous development of the national economy, there is always a demand to improve the power density of electric machines. And while improving the power density, it is also necessary to suppress the loss of the electric machine, not only to ensure the efficiency of the electric machine, but also to control the temperature rise of the electric machine to avoid damage to the electric machine components due to overheating.

[0003] In existing electric machine design schemes, using multiple sets of permanent magnets and multiple sets of armature windings can effectively improve the electric load and magnetic load of the electric machine, thereby improving the power density of the electric machine. For example, the invention patent with publication number CN118646189A discloses a frame servo motor, which includes a primary and a secondary. The primary includes a primary core, a primary armature winding and a primary permanent magnet. The primary armature winding is located in the primary slot, and the primary permanent magnet is located at the top of each primary tooth. The secondary includes a secondary core, a secondary armature winding and a secondary permanent magnet. The secondary armature winding is located in the secondary slot, and the secondary permanent magnet is located at the top of each secondary tooth. The magnetization direction of the primary permanent magnet is parallel to the central axis of the primary tooth, and the magnetization direction of the secondary permanent magnet is parallel to the central axis of the secondary tooth.

[0004] The above-mentioned frame servo motor has two sets of permanent magnets and two sets of armature windings, which fully utilizes the internal space of the electric machine, and has higher electromagnetic load compared to traditional electric machines, thus having greater power density. However, the magnetization direction of the permanent magnets of the above-mentioned frame servo motor is single, the primary permanent magnet and the secondary permanent magnet are both parallel magnetized, and the magnetization directions of the two are the same or opposite. In order to avoid the mutual cancellation of the two-stage magnetic field, the magnetization direction must be completely the same or completely opposite in the traditional electric machine structure, which is a commonly used design method in the industry. However, through research, it is found that the magnetic field generated by the primary permanent magnet and the magnetic field generated by the secondary permanent magnet of the above-mentioned frame servo motor do not coincide in phase, and there is a large phase difference between them. In order to increase the permanent magnet torque or thrust that can be generated per unit current for the electric machine, the current phase angle needs to be adjusted so that the phase of the magnetic field generated by the armature winding and the phase of the magnetic field generated by the permanent magnet are as different as possible. 90°. If there is a phase difference between the magnetic fields generated by the primary permanent magnet and the secondary permanent magnet, then no matter how the current phase is adjusted, it will cause the phase of the magnetic field generated by at least one set of permanent magnets and the phase of the magnetic field generated by the armature winding to be less than 90°, thereby reducing the magnetic field utilization rate and limiting the further improvement of the power density. At the same time, the misaligned magnetic field will produce chaotic harmonic components, causing additional eddy current loss in the permanent magnet, increasing the heat generation of the permanent magnet, and reducing the efficiency of the electric machine. SUMMARY

[0005] The technical problem solved by the present application is to provide a double permanent magnet double armature motor which can further improve the power density of the motor, reduce the eddy current loss of the permanent magnet of the motor and improve the efficiency of the motor while ensuring the improvement of the electromagnetic load of the motor.

[0006] The technical solution adopted by the present application is a double permanent magnet double armature motor, comprising a primary and a secondary, wherein the primary comprises a primary iron core, a primary armature winding and a primary permanent magnet; the primary iron core is composed of a primary iron core tooth and a primary iron core yoke; the primary permanent magnets are located on the same single side of the top of the primary iron core tooth; the magnetization direction of the primary permanent magnet forms an angle θ with the central axis of the primary iron core tooth where the primary permanent magnet is located, and the value of the angle θ is in the range of -15°≤θ≤15°; the secondary comprises a secondary iron core, a secondary armature winding and a secondary permanent magnet; the secondary iron core is composed of a secondary iron core tooth and a secondary iron core yoke; the secondary permanent magnet is located on the same single side of the top of the secondary iron core tooth; the magnetization direction of the secondary permanent magnet forms an angle β with the central axis of the secondary iron core tooth where the secondary permanent magnet is located, and the value of the angle β is in the range of 30°≤β≤90°.

[0007] The beneficial effects of the present application are as follows: the double permanent magnet double armature motor has two sets of permanent magnets and two sets of armature windings, which can effectively improve the electric load and magnetic load of the motor, thereby improving the power density of the motor; at the same time, the magnetization directions of the primary permanent magnet and the secondary permanent magnet of the double permanent magnet double armature motor are no longer the same or opposite, and the magnetization directions of the two form a certain angle with the central axis of the iron core tooth where they are located, thereby changing the phase of the magnetic field of the permanent magnet and achieving the effect of reducing the phase difference between the primary permanent magnet magnetic field and the secondary permanent magnet magnetic field, thereby improving the power density of the motor. Due to the existence of the magnetic field modulation effect, the magnetic field generated by the permanent magnet can be decomposed into multiple magnetic field harmonic components, and the influence degree of changing the magnetization angle of the permanent magnet on the phase of each magnetic field harmonic component is different, and the permanent magnet torque and thrust of the motor are generated by multiple magnetic field harmonic components, therefore, when the magnetization directions of the two sets of permanent magnets of the double permanent magnet double armature motor satisfy a certain angle range, the torque density of the motor can be effectively improved and the eddy current loss of the permanent magnet can be reduced, thereby improving the efficiency of the motor.

[0008] As a preferred embodiment, the magnetization direction of the primary permanent magnet forms a 0° angle with the central axis of the primary iron core tooth where the primary permanent magnet is located, and the magnetization direction of the secondary permanent magnet forms a 60° angle with the central axis of the secondary iron core tooth where the secondary permanent magnet is located; by adopting this structure, the magnetic field phase adjustment effect of this kind of permanent magnet magnetization scheme on the two sets of permanent magnets is optimal in combination, which can make the motor obtain the maximum power density improvement effect, and also has obvious inhibition effect on the eddy current loss of the permanent magnet.

[0009] As preferred, the primary core further comprises primary core tooth tips close to the primary side of the secondary core, the primary core tooth tips and the primary core teeth form an integral inverted T-shaped structure, and primary slots are formed between every two adjacent inverted T-shaped structures, the primary armature winding is located in the primary slots, and the primary permanent magnets are located on the same single side of the primary core tooth tips. With this structure, the width of the primary permanent magnet is related to the width of the primary core tooth tip, and the width of the primary armature winding is related to the primary core tooth, that is, the width of the primary permanent magnet is no longer related to the width of the primary armature winding, thereby relieving the spatial competition relationship between the primary permanent magnet and the primary armature winding, so that the width of the primary permanent magnet can be increased without reducing the size of the primary armature winding as much as possible, thereby further improving the magnetic load of the motor, and finally realizing the further improvement of the power density of the motor. At the same time, the primary core tooth tip also helps to prevent the primary armature winding from falling off from the primary, and strengthens the mechanical strength of the motor.

[0010] As preferred, the primary core further comprises primary core tooth tips close to the primary side of the secondary core, the primary core tooth tips and the primary core teeth form an integral inverted T-shaped structure, and primary slots are formed between every two adjacent inverted T-shaped structures, the primary armature winding is located in the primary slots, and the primary permanent magnets are located on the same single side of the primary core tooth tips. With this structure, the width of the primary permanent magnet is related to the width of the primary core tooth tip, and the width of the primary armature winding is related to the primary core tooth, that is, the width of the primary permanent magnet is no longer related to the width of the primary armature winding, thereby relieving the spatial competition relationship between the primary permanent magnet and the primary armature winding, so that the width of the primary permanent magnet can be increased without reducing the size of the primary armature winding as much as possible, thereby further improving the magnetic load of the motor, and finally realizing the further improvement of the power density of the motor. At the same time, the primary core tooth tip also helps to prevent the primary armature winding from falling off from the primary, and strengthens the mechanical strength of the motor.

[0011] As preferred, the primary and the secondary are straight line structures. With this structure, the double permanent magnet double armature motor can be applied to occasions of straight line motion such as numerical control machine tools and logistics conveying lines. And the heat generated by the primary armature winding and the secondary armature winding due to loss can be respectively dissipated outward through the primary bottom plate and the secondary bottom plate, compared with the existing single set of armature winding straight motor, the double permanent magnet double armature motor has a larger effective heat dissipation area, thereby having a higher power density.

[0012] As preferred, the primary further comprises a left end auxiliary tooth at the left end thereof, a right end auxiliary tooth at the right end thereof, a left end permanent magnet at one side of the top of the left end auxiliary tooth, and a right end permanent magnet at one side of the top of the right end auxiliary tooth; the width of the left end auxiliary tooth and the right end auxiliary tooth is about half of the width of the teeth of the primary core. With this structure, the additional electromagnetic thrust fluctuation caused by the longitudinal end effect can be effectively reduced, and the stability of the output power of the double permanent magnet double armature motor can be ensured.

[0013] As preferred, the width of the left end permanent magnet is smaller than the width of the right end permanent magnet; and the width of the right end permanent magnet is smaller than the width of the primary permanent magnet. With this structure, the width of the left end permanent magnet and the right end permanent magnet is smaller than the width of the primary permanent magnet, and the width of the left end permanent magnet is smaller than the width of the right end permanent magnet, so that the additional electromagnetic thrust fluctuation caused by the longitudinal end effect can be reduced.

[0014] As preferred, the pole number of the primary is a multiple of 8; and the pole number of the secondary is a multiple of 9. With this structure, the phase number of the primary armature winding is 2, and the phase number of the secondary armature winding is 3, so that the two sets of armature windings can be powered by the existing three-phase full-bridge converter.

[0015] As preferred, the primary and the secondary are both rotary motor structures. With this structure, the double permanent magnet double armature motor can be applied to the control torque gyro frame servo system, high-end machine tool turntable system and other rotary motion occasions requiring large torque. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 FIG. 1 is a structural schematic diagram of a double permanent magnet double armature motor according to an embodiment of the present application; Figure 2 FIG. 2 is a structural schematic diagram of a frame servo motor in the prior art; Figure 3 FIG. 3 is a schematic diagram of the magnetic field harmonic phase change of the frame servo motor in the prior art; Figure 4 FIG. 4 is a schematic diagram of the magnetic field harmonic phase change of the motor according to the embodiment of the present application; Figure 5 FIG. 5 is a schematic diagram of the electromagnetic thrust waveform comparison between the motor according to the embodiment of the present application and the frame servo motor in the prior art; Figure 6 FIG. 6 is a schematic diagram of the permanent magnet loss comparison between the motor according to the embodiment of the present application and the frame servo motor in the prior art; Figure 7 FIG. 7 is a schematic diagram of the electromagnetic thrust curve of the motor according to the embodiment of the present application with the primary permanent magnet magnetization direction change; Figure 8 Fig. 1 is a schematic diagram of the electromagnetic thrust curve of a motor according to an embodiment of the present application varying with the magnetization direction of the secondary permanent magnet; Figure 9 Fig. 2 is a schematic diagram of the structure of a double-permanent-magnet double-armature motor according to an embodiment of the present application; Figure 10 Fig. 3 is a schematic diagram of the structure of a double-permanent-magnet double-armature motor according to an embodiment of the present application; As shown in the figure: 1, primary; 2, secondary; 11, primary core; 12, primary armature winding; 13, primary permanent magnet; 14, left end auxiliary tooth; 15, left end permanent magnet; 16, right end auxiliary tooth; 17, right end permanent magnet; 111, primary core tooth; 112, primary core yoke; 113, primary core tooth tip; 114, primary slot; 21, secondary core; 22, secondary armature winding; 23, secondary permanent magnet; 211, secondary core tooth; 212, secondary core yoke; 213, secondary core tooth tip; 214, secondary slot. DETAILED DESCRIPTION

[0017] The application will be further described with reference to the drawings and specific embodiments, so that those skilled in the art can implement the application according to the description, and the protection scope of the application is not limited to the specific embodiments.

[0018] Those skilled in the art should understand that in the disclosure of the present application, the orientations or positional relationships indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like are based on the orientations or positional relationships shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, therefore the above-mentioned terms cannot be understood as limiting the present application.

[0019] In addition, the terms "first", "second", "third" and the like are only used for differentiation in description and cannot be understood as indicating or implying relative importance.

[0020] In the description of the embodiments of the present application, it should also be noted that unless otherwise explicitly specified and limited, the terms "setting", "mounting", "connecting", "connection" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above-mentioned terms in the present application can be understood according to the specific circumstances.

[0021] Embodiment 1: The application relates to a double-permanent-magnet double-armature motor, as shown in the figure, comprising a primary 1 and a secondary 2. Figure 1 The primary 1 comprises a primary core 11, a primary armature winding 12 and a primary permanent magnet 13; the primary core 11 is composed of a primary core tooth 111 and a primary core yoke 112; each primary permanent magnet 13 is located on the same single side of the top of each primary core tooth 111; the magnetization direction of the primary permanent magnet 13 is at an angle of -15°-15° with the central axis of the primary core tooth 111 (the dashed line on the primary in the figure); the secondary 2 comprises a secondary core 21, a secondary armature winding 22 and a secondary permanent magnet 23; the secondary core 21 is composed of a secondary core tooth 211 and a secondary core yoke 212; each secondary permanent magnet 23 is located on the same single side of the top of each secondary core tooth 211; the magnetization direction of the secondary permanent magnet 23 is at an angle of 30°-90° with the central axis of the secondary core tooth 211 (the dashed line on the secondary in the figure).

[0022] Figure 1 In the specific embodiment, the magnetization direction of the primary permanent magnet 13 is at an angle of 0° with the central axis of the primary core tooth 111; the magnetization direction of the secondary permanent magnet 23 is at an angle of 60° with the central axis of the secondary core tooth 211. In this case, the motor can obtain the maximum power density improvement effect, that is, the phase adjustment effect of the magnetic field generated by the two sets of permanent magnets is optimal, and the eddy current loss of the permanent magnet is also obviously inhibited.

[0023] Figure 1 In the specific embodiment, the primary 1 and the secondary 2 are linear structures. The left side of the primary 1 has a left end auxiliary tooth 14 and a left end permanent magnet 15, and the left end permanent magnet 15 is located on the single side of the top of the left end auxiliary tooth 14; the right side of the primary 1 has a right end auxiliary tooth 16 and a right end permanent magnet 17, and the right end permanent magnet 17 is located on the single side of the top of the right end auxiliary tooth 16; the width of the left end permanent magnet 15 is smaller than the width of the right end permanent magnet 17; the width of the right end permanent magnet 17 is smaller than the width of the primary permanent magnet 13. That is, the sizes of the left end auxiliary tooth 14 and the left end permanent magnet 15 are similar to the right half of the primary core tooth 111 and the primary permanent magnet 13 respectively, and the sizes of the right end auxiliary tooth 16 and the right end permanent magnet 17 are similar to the left half of the primary core tooth 111 and the primary permanent magnet 13 respectively. By adopting this structure, the permanent magnet magnetic field originally leaked to the left end and the right end of the primary can be guided into the secondary, the low-frequency electromagnetic thrust fluctuation (edge magnetic field fluctuation is inhibited) caused by the longitudinal end effect is reduced, and the stability of the motor output power is ensured.

[0024] Figure 1In the embodiment, the number of poles of the primary 1 is 8, and the number of poles of the secondary 2 is 9, so that the number of phases of the primary armature winding 12 is 2, and the number of phases of the secondary armature winding 22 is 3. Both sets of armature windings can be powered by using an existing three-phase full-bridge inverter, without the need to develop an additional inverter adapted to the motor of the embodiment.

[0025] The advantages of the double-permanent-magnet double-armature motor of the embodiment are illustrated below by comparison with a frame servo motor in the prior art. The data are obtained through electromagnetic field two-dimensional finite element simulation calculation, electromagnetic field three-dimensional finite element simulation calculation and prototype performance measurement. In the comparison process, the two motors have the same outer envelope size, the same winding copper loss and the same movement speed.

[0026] As shown in FIG. 1, Figure 2 In the frame servo motor in the prior art, the magnetization directions of the primary permanent magnet 13 and the secondary permanent magnet 23 are the same, and the magnetization directions are respectively parallel to the central axis of the primary core tooth 111 and the central axis of the secondary core tooth 211. Figure 3 As shown in FIG. 2, it can be seen that there is a large phase difference (about 40°) between the magnetic field harmonics generated by the primary permanent magnet 13 and the magnetic field harmonics generated by the secondary permanent magnet 23. This causes the magnetic field phase generated by at least one set of permanent magnets and the magnetic field phase generated by the armature winding to be not 90° no matter how the current phase is adjusted. Since the phase difference between the two levels of magnetic fields is large, the current cannot be simultaneously coupled with the two levels of magnetic fields with high efficiency, so that the magnetic field utilization rate is reduced.

[0027] As shown in FIG. 3, Figure 4 In the motor of the embodiment, the magnetization direction of the permanent magnet and the central axis of the core tooth form an angle, that is, the angle between the magnetization direction of the primary permanent magnet 13 and the central axis of the primary core tooth 111 is 0° (perpendicular magnetization), and the angle between the magnetization direction of the secondary permanent magnet 23 and the central axis of the secondary core tooth 211 is 60° (inclined magnetization). The phase of the magnetic field harmonics generated by the primary permanent magnet 13 and the magnetic field harmonics generated by the secondary permanent magnet 23 changes. The inclination of the secondary permanent magnet causes the magnetic field harmonic waveform to shift to the left, reduces the phase difference with the primary magnetic field, and significantly reduces the phase difference between the primary magnetic field and the secondary magnetic field (about 20°), that is, the two sets of magnetic field harmonics tend to coincide, and the current can simultaneously drive the two levels of magnetic fields with high efficiency, thereby improving the magnetic field utilization rate and the motor power density. Similarly, other orders of magnetic field harmonic components also have similar change rules, the current can simultaneously drive the two levels of magnetic fields with high efficiency, and finally the overall magnetic field utilization rate is improved.

[0028] As shown in FIG. 4, Figure 5As shown, under the same motor outer envelope size, winding copper loss and movement speed, the average electromagnetic thrust of the motor in this embodiment is 15% higher than that of the existing frame servo motor. Furthermore, the electromagnetic thrust fluctuation of the motor in this embodiment is only 50% of that of the existing frame servo motor, that is, the motor of the present invention has a higher power density.

[0029] like Figure 6 As shown, the permanent magnet eddy current loss of the motor in this embodiment is only 60% of that of the existing frame servo motor, that is, the motor of the present invention has lower permanent magnet eddy current loss.

[0030] like Figure 7 As shown, in this embodiment of the motor, changing the magnetization direction of the primary permanent magnet 13 will change the average electromagnetic thrust generated by the motor. Figure 7 When the magnetization direction of the primary permanent magnet 13 is at an angle of 0° to the central axis of the primary iron core tooth 111, the motor has the maximum electromagnetic thrust; when the magnetization direction of the primary permanent magnet 13 is at an angle of -15° to 15° to the central axis of the primary iron core tooth 111, the electromagnetic thrust generated by the motor is not less than 95% of the maximum value.

[0031] like Figure 8 As shown, in this embodiment of the motor, changing the magnetization direction of the secondary permanent magnet 23 will change the average electromagnetic thrust generated by the motor. When the angle between the magnetization direction of the secondary permanent magnet 23 and the central axis of the secondary iron core tooth 211 is 60°, the motor has the maximum electromagnetic thrust; when the angle between the magnetization direction of the secondary permanent magnet 23 and the central axis of the secondary iron core tooth 211 is 30° to 90°, the electromagnetic thrust generated by the motor is not less than 95% of the maximum value.

[0032] Example 2: This invention relates to a dual permanent magnet dual armature motor, such as Figure 9 As shown, it includes a primary core 1 and a secondary core 2. The primary core 1 includes a primary core 11, a primary armature winding 12, and a primary permanent magnet 13; the primary core 11 is composed of primary core teeth 111 and a primary core yoke 112; the primary permanent magnet 13 is located on the same side of the top of the primary core teeth 111; the magnetization direction of the primary permanent magnet 13 forms a 0° angle with the central axis of the primary core teeth 111 (shown by the dashed line on the primary core in the figure); the secondary core 2 includes a secondary core 21, a secondary armature winding 22, and a secondary permanent magnet 23; the secondary core 21 is composed of secondary core teeth 211 and a secondary core yoke 212; the secondary permanent magnet 23 is located on the same side of the top of the secondary core teeth 211; the magnetization direction of the secondary permanent magnet 23 forms a 60° angle with the central axis of the secondary core teeth 211 (shown by the dashed line on the secondary core in the figure).

[0033] like Figure 9As shown, the primary core 11 further comprises primary core tooth tips 113 near the side of the secondary 2, the primary core tooth tips 113 and the primary core teeth 111 form an integral inverted T-shaped structure, and the primary slots 114 are formed between every two adjacent inverted T-shaped structures, the primary armature winding 12 is located in the primary slots 114, and the primary permanent magnets 13 are located on the same single side of the primary core tooth tips 113. The secondary core 21 further comprises secondary core tooth tips 213 near the side of the primary 1, each of the secondary core tooth tips 213 and each of the secondary core teeth 211 form an integral T-shaped structure, and the secondary slots 214 are formed between every two adjacent T-shaped structures, the secondary armature winding 22 is located in the secondary slots 214, and the secondary permanent magnets 23 are located on the same single side of the secondary core tooth tips 213. Figure 9 In this embodiment, because the primary core 11 has the primary core tooth tips 113 near the side of the secondary 2, and the secondary core 21 has the secondary core tooth tips 213 near the side of the primary 1, the width of the primary permanent magnets 13 and the width of the primary core teeth 111 are no longer related, when the width of the primary permanent magnets 13 increases, the width of the primary core teeth 111 does not need to increase, that is, the width of the primary armature winding 12 does not need to decrease because of the increase of the width of the primary permanent magnets 13, and the secondary core 21, the secondary permanent magnets 23 and the secondary armature winding 22 are the same. Therefore, by using this structure, the space competition relationship between the permanent magnets and the armature winding can be alleviated, the width of the primary permanent magnets 13 and the secondary permanent magnets 23 can be increased without reducing the size of the primary armature winding 12 and the secondary armature winding 22 as much as possible, thereby further improving the magnetic load of the motor, and finally realizing the further improvement of the power density of the motor. Compared with the first embodiment, the size of the permanent magnets in this embodiment is larger, and the size of the armature winding is similar (the height is smaller, but the width is larger), so the power density is higher than that of the first embodiment. At the same time, the primary core tooth tips 113 and the secondary core tooth tips 213 also help to prevent the primary armature winding 12 and the secondary armature winding 22 from falling out of the slots, and strengthen the mechanical strength of the motor.

[0034] Figure 9In the embodiment, the primary 1 and the secondary 2 are both straight structures. The left side of the primary 1 has a left end auxiliary tooth 14 and a left end permanent magnet 15, and the left end permanent magnet 15 is located on one side of the top of the left end auxiliary tooth 14. The right side of the primary 1 has a right end auxiliary tooth 16 and a right end permanent magnet 17, and the right end permanent magnet 17 is located on one side of the top of the right end auxiliary tooth 16. The width of the left end permanent magnet 15 is less than the width of the right end permanent magnet 17. The width of the right end permanent magnet 17 is less than the width of the primary permanent magnet 13. That is, the sizes of the left end auxiliary tooth 14 and the left end permanent magnet 15 are similar to the sizes of the primary core tooth 111 and the right half of the primary permanent magnet 13 respectively, and the sizes of the right end auxiliary tooth 16 and the right end permanent magnet 17 are similar to the sizes of the primary core tooth 111 and the left half of the primary permanent magnet 13 respectively. By adopting this structure, the permanent magnet magnetic field originally leaked to the left end and the right end of the primary can be guided into the secondary, the low-frequency electromagnetic thrust fluctuation caused by the longitudinal end effect can be reduced, and the smoothness of the motor output power can be ensured. The electromagnetic field finite element calculation result shows that, after the left end auxiliary tooth 14, the left end permanent magnet 15, the right end auxiliary tooth 16 and the right end permanent magnet 17 are adopted, the electromagnetic thrust fluctuation of the motor can be reduced from 30% to 10%.

[0035] Figure 9 In the embodiment, the number of poles of the primary 1 is 8, and the number of poles of the secondary 2 is 9, so that the number of phases of the primary armature winding 12 is 2, and the number of phases of the secondary armature winding 22 is 3. Both sets of armature windings can be powered by the existing three-phase full-bridge converter, without the need to develop an additional converter suitable for the motor of the embodiment.

[0036] Embodiment three: The application relates to a double-permanent-magnet double-armature motor. Figure 10 As shown in the figure, the motor comprises a primary 1 and a secondary 2. The primary 1 comprises a primary core 11, a primary armature winding 12 and a primary permanent magnet 13. The primary core 11 is composed of a primary core tooth 111 and a primary core yoke 112. The primary permanent magnet 13 is located on the same side of the top of the primary core tooth 111. The magnetization direction of the primary permanent magnet 13 forms a 0-degree angle with the central axis (shown by a dashed line in the figure) of the primary core tooth 111. The secondary 2 comprises a secondary core 21, a secondary armature winding 22 and a secondary permanent magnet 23. The secondary core 21 is composed of a secondary core tooth 211 and a secondary core yoke 212. The secondary permanent magnet 23 is located on the same side of the top of the secondary core tooth 211. The magnetization direction of the secondary permanent magnet 23 forms a 60-degree angle with the central axis (shown by a dashed line in the figure) of the secondary core tooth 211.

[0037] Figure 10In the embodiment, the number of poles of the primary 1 is 8, and the number of poles of the secondary 2 is 9, so that the number of phases of the primary armature winding 12 is 2, and the number of phases of the secondary armature winding 22 is 3, both of which can be powered by using the existing three-phase full-bridge converter, without the need to additionally develop a converter adapted to the motor of the embodiment.

[0038] Figure 10 In the embodiment, the primary 1 and the secondary 2 are both rotary motor structures, so that the motor of the embodiment can be applied to a control torque gyro frame servo system, a high-end machine tool turntable system and other rotary motion occasions requiring large torque.

Claims

1. A doubly permanent doubly salient electric machine comprising a primary (1) and a secondary (2), characterized in that: The primary (1) comprises a primary core (11), a primary armature winding (12) and a primary permanent magnet (13); the primary core (11) is composed of a primary core tooth (111) and a primary core yoke (112); the primary permanent magnet (13) is located on the same single side of the top of the primary core tooth (111); the magnetization direction of the primary permanent magnet (13) forms an angle θ with the central axis of the primary core tooth (111) where the primary permanent magnet (13) is located, and the angle θ is in the range of -15°≤θ≤15°; the secondary (2) comprises a secondary core (21), a secondary armature winding (22) and a secondary permanent magnet (23); the secondary core (21) is composed of a secondary core tooth (211) and a secondary core yoke (212); the secondary permanent magnet (23) is located on the same single side of the top of the secondary core tooth (211); the magnetization direction of the secondary permanent magnet (23) forms an angle β with the central axis of the secondary core tooth (211) where the secondary permanent magnet (23) is located, and the angle β is in the range of 30°≤β≤90°.

2. A dual permanent magnet dual armature machine according to claim 1, characterized in that: The magnetization direction of the primary permanent magnet (13) forms a 0° angle with the central axis of the primary core tooth (111) where the primary permanent magnet (13) is located; the magnetization direction of the secondary permanent magnet (23) forms a 60° angle with the central axis of the secondary core tooth (211) where the secondary permanent magnet (23) is located.

3. A dual permanent magnet dual armature electric machine according to claim 1 or 2, characterized in that: The primary core (21) further comprises a primary core tooth tip (113) near the side of the secondary (1), the primary core tooth tip (113) and the primary core tooth (111) form an integral inverted T-shaped structure, and primary slots (114) are formed between every two adjacent inverted T-shaped structures, the primary armature winding (12) is located in the primary slots (114), and the primary permanent magnets (13) are all located on the same single side of the primary core tooth tips (113).

4. A dual permanent magnet dual armature machine as claimed in claim 3, characterized in that: The secondary core (21) further comprises a secondary core tooth tip (213) near the side of the primary (1), each secondary core tooth tip (213) and each secondary core tooth (211) form an integral T-shaped structure, and secondary slots (214) are formed between every two adjacent T-shaped structures, the secondary armature winding (22) is located in the secondary slots (214), and the secondary permanent magnets (23) are all located on the same single side of the secondary core tooth tips (213).

5. A dual permanent magnet dual armature machine according to claim 2 or 4, characterized in that: The primary (1) and the secondary (2) are both linear structures.

6. A dual permanent magnet dual armature machine as claimed in claim 5, characterized in that: The primary (1) further comprises a left end auxiliary tooth (14) located at the left end thereof, a right end auxiliary tooth (16) located at the right end thereof, a left end permanent magnet (15) and a right end permanent magnet (17), the left end permanent magnet (15) is located on the single side of the top of the left end auxiliary tooth (16), and the right end permanent magnet (17) is located on the single side of the top of the right end auxiliary tooth (16); the width of the left end auxiliary tooth (14) and the right end auxiliary tooth (16) is about half of the width of the primary core tooth (111).

7. A dual permanent magnet dual armature electric machine according to claim 6, characterized in that: The width of the left end permanent magnet (15) is less than the width of the right end permanent magnet (17); the width of the right end permanent magnet (17) is less than the width of the primary permanent magnet (13).

8. A dual permanent magnet dual armature machine according to claim 2 or 4, characterized in that: The pole number of the primary (1) is a multiple of 8; the pole number of the secondary (2) is a multiple of 9.

9. A dual permanent magnet dual armature machine as claimed in claim 2 or 4, characterized in that: Both the primary (1) and the secondary (2) are rotating electric machine structures.

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