Electric excitation brushless motor with axial magnetic field

Abstract

The utility model discloses an axial magnetic field electro-magnetic brushless motor, which comprises a casing, and a main generator, an alternating current exciter and a rectifying device which are arranged on the casing, the main generator comprises a rotating shaft, a stator disc and a rotor disc, the stator disc is fixed in the casing, the rotor disc is fixedly connected with the rotating shaft, the stator disc comprises a plurality of groups of armature windings, and the armature windings are arranged in the casing. The rotor disc comprises a plurality of groups of exciting windings, the alternating-current exciter stator is fixedly mounted in the casing, the alternating-current exciter rotor is mounted on the rotor disc, the windings of the alternating-current exciter rotor are connected with the input end of the rectifying device through wires, and the output end of the rectifying device is connected with the exciting windings through wires. The AC exciter stator is provided with a stator winding and / or a permanent magnet. According to the electro-magnetic synchronous motor, a collecting ring and an electric brush are omitted, the motor is compact in structure, light in weight, convenient to connect and higher in utilization rate, the magnetic field of the electro-magnetic synchronous motor is easy to adjust, and the magnetic field of the motor can be conveniently adjusted by adjusting the exciting current.

Description

Technical Field

[0001] The utility model belongs to the technical field of motors, in particular to an axial magnetic field electric excitation brushless motor. Background Art

[0002] Axial magnetic field motor is an efficient and reliable motor, which is often used in various occasions such as wind power generation and hydropower generation. Compared with radial magnetic field motor, axial magnetic field motor has short axial dimension, large diameter, more types of topological structure, relatively large torque density ratio and power density ratio, and can be designed according to different needs, with more and more flexible application scenarios. The axial permanent magnet motor, which is currently studied more, has a simple structure and high efficiency, but it is difficult for permanent magnet motor to adjust and control the magnetic field from the outside, and the rare earth materials commonly used in the manufacture of permanent magnet motor are an expensive non-renewable resource. Excessive development and utilization of rare earth resources will cause serious damage to the ecosystem. Considering this series of defects of permanent magnet motor, axial magnetic field electric excitation motor has received more and more attention. Traditional electric excitation motor requires collector rings and brushes to conduct current between rotating parts and stationary parts. Brushed motor has low production cost and relatively mature technology, but the brushes are constantly frictional and loss during motor operation, and there is a problem of easy heat and short service life. In addition, when the brushes of brushed motors come into contact with the rotor, sparks will be generated, resulting in electromagnetic interference, which reduces the efficiency of the motor. Utility Model Content

[0003] In view of the above-mentioned problems existing in the prior art, the purpose of the utility model is to provide an axial magnetic field electrically excited brushless motor, which is an electrically excited motor, and the collector ring and brushes are eliminated to realize the brushless excitation of the motor. Compared with the traditional radial magnetic field motor brushless excitation scheme, the motor has a compact structure, light weight, convenient connection, higher motor utilization rate, and the magnetic field of the electrically excited synchronous motor is easy to adjust. The magnetic field of the motor can be conveniently adjusted by adjusting the excitation current, which is convenient for maintenance. At the same time, the motor has good operating characteristics within a wider speed range.

[0004] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0005] An axial magnetic field electric excitation brushless motor comprises a casing and a main generator, an AC exciter and a rectifier mounted on the casing. The main generator comprises a rotating shaft, a stator disk and a rotor disk. The rotating shaft is rotatably mounted on the casing. The stator disk is fixed in the casing. The rotor disk is fixedly connected to the rotating shaft. The stator disk comprises a plurality of armature windings. The rotor disk comprises a plurality of excitation windings. The AC exciter comprises an AC exciter stator and an AC exciter rotor. The AC exciter stator is fixedly mounted in the casing. The AC exciter rotor is mounted on the rotor disk. The AC exciter rotor comprises a rotor winding. The rotor winding of the AC exciter rotor is connected to an input end of the rectifier through an electric wire. The output end of the rectifier is connected to the excitation winding through an electric wire. The AC exciter stator is provided with a stator winding and / or a permanent magnet. The stator winding can be connected to an external power supply and / or an armature winding.

[0006] As a further improvement of the above technical solution:

[0007] The rotor disk also includes a rotor yoke and a plurality of rotor teeth. The rotor yoke is in the shape of a disc and is parallel to a horizontal plane. The rotor yoke is fixedly connected to a rotating shaft and the rotating shaft is perpendicular to the horizontal plane. A plurality of rotor teeth are mounted on one surface of the rotor yoke and the plurality of rotor teeth are arranged in a circular array with the rotating shaft as the center line. A group of excitation windings are wound on each rotor tooth, and the AC exciter rotor is mounted on the rotor yoke.

[0008] The stator disk also includes a stator yoke and a plurality of stator teeth. The stator yoke is in the shape of a disc and is parallel to a horizontal plane. A plurality of stator teeth are mounted on both surfaces of the stator yoke. The plurality of stator teeth on each surface of the stator yoke are arranged in a circular array with the rotating shaft as the center line, and a group of armature windings are wound on each stator tooth.

[0009] The stator yoke is fixedly connected to the inner wall of the casing, the rotating shaft passes through the stator yoke, and a bearing is arranged between the rotating shaft and the stator yoke.

[0010] There are two rotor disks, which are respectively located on both sides of the stator disk. The two rotor yokes of the two rotor disks and the stator yoke are arranged in parallel and spaced apart. The two rotor yokes are respectively located on both sides of the stator yoke, and the side of the rotor yoke on which the rotor teeth are installed faces the stator yoke.

[0011] The AC exciter stator and the AC exciter rotor are located between the top cover of the casing and the rotor yoke above the stator yoke. The AC exciter stator is fixedly mounted on the inner surface of the casing top cover, and the AC exciter rotor is mounted on the side of the rotor yoke away from the stator disk.

[0012] There are multiple AC exciter stators and multiple AC exciter rotors, and the multiple AC exciter stators are arranged in a ring array with the rotating shaft as the center line, and the multiple AC exciter rotors are arranged in a ring array with the rotating shaft as the center line.

[0013] When permanent magnets are provided on the stators of the AC exciters, the polarities of the permanent magnets on the stators of the adjacent AC exciters are opposite.

[0014] The armature winding on one surface of the stator yoke is connected in parallel or in series with the armature winding on the other surface, and multiple groups of armature windings on the same surface of the stator yoke can be connected in series or in parallel.

[0015] When the stator winding is provided on the stator of the AC exciter, the stator winding can be connected to the armature winding through a rectifier. The rectifier connected to the stator winding of the stator of the AC exciter is fixedly installed in the casing, and the rectifier connected to the rotor winding of the rotor of the AC exciter is installed on the rotor yoke.

[0016] The beneficial effects of the utility model are:

[0017] (1) The motor is an electrically excited motor, which is a dual-rotor single-stator axial magnetic field motor. Concentrated windings are placed on two rotor disks, and the excitation winding, AC exciter rotor and rectifier are installed together on one disk. The motor has a simple and compact structure, light weight, convenient connection, easy manufacturing, reliable operation and low manufacturing cost.

[0018] (2) By using a single-stator single-rotor axial magnetic field AC exciter and a rectifier device, the collector ring and brushes are eliminated, realizing brushless excitation of the motor. Compared with the traditional radial magnetic field motor brushless excitation solution, the motor has a compact structure, light weight, easy connection, and higher motor utilization.

[0019] (3) The magnetic field of the electrically excited synchronous motor is easy to adjust. The magnetic field of the motor can be conveniently adjusted by adjusting the excitation current. The collector ring and brush are eliminated, which facilitates maintenance. At the same time, the motor has good operating characteristics within a wide speed range.

[0020] (4) The axial attraction between the AC exciter stator and the AC exciter rotor can offset the gravity of the rotor disk itself to a certain extent and reduce the force exerted by the rotor disk on the shaft. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a structural schematic diagram of the first embodiment of the utility model.

[0022] Figure 2 It is a structural schematic diagram of the stator disk and rotor disk of the main generator part of the first embodiment of the utility model. DETAILED DESCRIPTION

[0023] The specific implementation of the present invention is described in detail below in conjunction with the accompanying drawings. It should be understood that the specific implementation described here is only used to illustrate and explain the present invention, and is not used to limit the present invention.

[0024] For ease of description, spatially relative terms such as "above", "above", "on the upper surface of", "above", etc. may be used here to describe the spatial positional relationship between a device or feature and other devices or features as shown in the figure. It should be understood that spatially relative terms are intended to include different orientations of the device in use or operation in addition to the orientation described in the figure. For example, if the device in the accompanying drawings is inverted, the device described as "above other devices or structures" or "above other devices or structures" will be positioned as "below other devices or structures" or "below other devices or structures". Thus, the exemplary term "above" can include both "above" and "below". The device can also be positioned in other different ways (rotated 90 degrees or in other orientations), and the spatially relative descriptions used here are interpreted accordingly.

[0025] Embodiment 1

[0026] An axial magnetic field electrically excited brushless motor, such as Figure 1 and 2 As shown, it includes a casing 12 and a main generator, an AC exciter and a rectifier 4 mounted on the casing 12. The casing 12 has an internal cavity, and the internal cavity of the casing 12 is cylindrical, and the center line of the cylinder is perpendicular to the horizontal plane.

[0027] The main generator is an axial magnetic field generator with a single stator and two rotors, that is, it has one stator and two rotors. Specifically, the main generator includes a rotating shaft 1, a stator disk and two rotor disks, and the two rotor disks are arranged in parallel and spaced apart and are respectively located on both sides of the stator disk. The rotating shaft 1 is rotatably mounted on the casing 12, and the rotating shaft 1 is located on the center line of the internal cavity of the casing 12. In other words, the rotating shaft 1 is perpendicular to the horizontal plane. The lower end of the rotating shaft 1 is located in the casing 12, and the upper end passes through the top cover of the casing 12 and extends upward. A bearing is installed between the rotating shaft 1 and the top cover of the casing 12.

[0028] The stator disc is fixed inside the housing 12. The stator disc includes a stator yoke 9, a plurality of stator teeth 8 and a plurality of armature windings 10. The stator yoke 9 is disc-shaped and parallel to the horizontal plane. A plurality of stator teeth 8 are mounted on both surfaces of the stator yoke 9. The plurality of stator teeth 8 on each surface of the stator yoke 9 are arranged in a circular array with the rotating shaft 1 as the center line, and a group of armature windings 10 are wound on each stator tooth 8. The stator teeth 8 on one surface of the stator yoke 9 correspond to the stator teeth 8 on the other surface and are mounted back to back on the stator yoke 9. In other words, a stator tooth 8 on one surface of the stator yoke 9 and a stator tooth 8 on the other surface corresponding to the stator tooth 8 share a center line, and the center line is parallel to the rotating shaft 1. The armature winding 10 on one surface of the stator yoke 9 and the armature winding 10 on the other surface are connected in parallel or in series. The multiple groups of armature windings 10 on the same surface of the stator yoke can be connected in series or in parallel, and the specific design is set according to the specific application scenario.

[0029] The stator yoke 9 is fixedly connected to the inner wall of the housing 12, the rotating shaft 1 passes through the stator yoke 9, and a bearing 13 is provided between the rotating shaft 1 and the stator yoke 9 so that the stator yoke 9 does not interfere with the rotation of the rotating shaft 1. The bearing 13 is a thrust bearing 13 capable of bearing an axial load, the race of the bearing 13 is connected to the fixed part, i.e., the stator yoke 9, and the shaft race is connected to the rotating shaft 1.

[0030] In this embodiment, the circumferential side surface of the stator yoke 9 is fixedly connected to the inner wall of the casing 12 .

[0031] The rotor disk is located in the housing 12, and the rotor disk and the rotating shaft 1 are relatively fixed. Each rotor disk includes a rotor yoke, a plurality of rotor teeth 7 and a plurality of excitation windings 6. The rotor yoke is disc-shaped, and the rotor yoke is parallel to the horizontal plane. The rotor yoke is only mounted with a plurality of rotor teeth 7 on one surface, and the plurality of rotor teeth 7 are arranged in a circular array with the rotating shaft 1 as the center line, and a set of excitation windings 6 is wound on each rotor tooth 7. The plurality of excitation windings 6 can be connected in series or in parallel, and the specific design is set according to the specific application scenario. The rotor yoke is fixedly connected to the rotating shaft 1 and rotates synchronously with the rotating shaft 1, and the rotating shaft 1 passes through the rotor yoke. There is a distance between the circumferential side of the rotor yoke and the inner wall of the housing 12, so that the inner wall of the housing 12 does not interfere with the rotation of the rotor yoke. In other words, the rotor yoke is equivalent to being freely suspended in the housing 12. The rotor yoke is formed by laminating silicon steel sheets, and the rotor teeth 7 are pressed from soft magnetic composite materials.

[0032] The two rotor yokes are respectively located on both sides of the stator yoke 9 , and a rotor tooth portion 7 is provided on a surface of the rotor yoke facing or close to the stator yoke 9 .

[0033] In this embodiment, the two rotor yokes are respectively a first rotor yoke 5 and a second rotor yoke 11. The first rotor yoke 5 is located above the stator yoke 9, and the second rotor yoke 11 is located below the stator yoke 9.

[0034] In this embodiment, the distance between the rotor tooth portion 7 and the rotating shaft 1 is equal to the distance between the stator tooth portion 8 and the rotating shaft 1 .

[0035] The AC exciter and the rectifier 4 are both located in the housing 12. In this embodiment, the AC exciter and the rectifier 4 are both located between the top cover of the housing 12 and the first rotor yoke 5.

[0036] The AC exciter is an axial magnetic field motor with a single stator and single rotor structure. The AC exciter and the main generator are coaxially arranged and connected.

[0037] The AC exciter includes an AC exciter stator 2 and an AC exciter rotor 3. The AC exciter stator 2 is fixedly mounted on the inner surface of the top cover of the casing 12, and the AC exciter rotor 3 is mounted on the side of the first rotor yoke 5 away from the stator disk. There are multiple AC exciter stators 2 and multiple AC exciter rotors 3. Under the premise of considering the slot-pole matching, the number of AC exciter stators 2 and the number of AC exciter rotors 3 are designed according to the capacity of the main generator. The single-stator single-rotor structure means that the AC exciter consists of only one stator disk (casing + AC exciter stator) and one rotor disk (first rotor yoke + AC exciter rotor). When the motor is running, an axial magnetic pulling force is generated between the AC exciter rotor and the AC exciter stator, which acts on the AC exciter rotor as an upward pulling force, which can offset the gravity applied to the bearing by the rotating part of the motor to a certain extent. A plurality of AC exciter stators 2 are arranged in a circular array with the rotating shaft 1 as the center line, and a plurality of AC exciter rotors 3 are arranged in a circular array with the rotating shaft 1 as the center line. The distance from the AC exciter stator 2 to the rotating shaft 1 is equal to the distance from the AC exciter rotor 3 to the rotating shaft 1. The distance from the rotor tooth portion 7 to the rotating shaft 1 is greater than the distance from the AC exciter rotor 3 to the rotating shaft 1.

[0038] At least two rectifiers 4 are provided, at least one rectifier 4 is provided on a surface of the first rotor yoke 5 away from the stator disk, and at least one rectifier 4 is fixed on the housing 12. When a plurality of rectifiers 4 are provided on the first rotor yoke 5, the plurality of rectifiers 4 are arranged in a circular array with the rotating shaft 1 as the center line. The distance between the rectifier 4 and the rotating shaft 1 is greater than the distance between the AC exciter rotor 3 and the rotating shaft 1.

[0039] The AC exciter stator 2 includes stator teeth and stator windings wound around the stator teeth, and the AC exciter rotor 3 includes rotor teeth and rotor windings wound around the rotor teeth.

[0040] In this embodiment, the stator winding on the AC exciter stator 2 is connected to the external power supply through an electric wire. The rotor winding of the AC exciter rotor 3 is connected to the input end of the rectifier 4 on the first rotor yoke 5, and the output end of the rectifier 4 on the first rotor yoke 5 is connected to the main generator excitation winding 6 installed on the other side of the first rotor yoke 5. At the same time, the main generator excitation winding 6 on the second rotor yoke 11 is also connected to the output end of the rectifier 4. The AC exciter rotor 3, the rectifier 4 and the excitation winding 6 can be connected one by one, or one rectifier 4 can be matched with at least two excitation windings 6, and the specific number of matches can be specifically designed.

[0041] Based on the above structure, the working principle and process of the utility model are as follows: the motor is placed in a manner that the rotating shaft 1 is perpendicular to the horizontal plane. When the motor starts to run, the rotating shaft 1 drives the two rotor yokes to rotate, and the stator winding of the AC exciter stator 2 is powered by an external power supply, so that the stator winding is energized to generate a magnetic field. The rotor winding of the AC exciter rotor 3 generates current under the action of the magnetic field, which is rectified by the rectifier 4 and then transmitted to the excitation winding 6 installed on the first rotor yoke 5 and the second rotor yoke 11. Currents of the same magnitude and opposite directions are passed through the adjacent excitation windings 6 on the same rotor yoke to generate magnetic fluxes of the same magnitude and opposite directions. Currents of opposite directions can be passed through the opposite excitation windings 6 on the first rotor yoke 5 and the second rotor yoke 11 to form a series magnetic circuit or currents of the same direction can be passed through the opposite excitation windings 6 on the first rotor yoke 5 and the second rotor yoke 11 to form a parallel magnetic circuit. The design scheme is set according to the specific application scenario. As the rotating shaft 1 drives the two rotor disks to rotate, the armature winding 10 cuts the magnetic field generated by the excitation winding 6 to generate current. The current generated in the armature winding 10 is transmitted to the outside.

[0042] When the motor is in a stationary state, the gravity of the two rotor disks and the shaft 1 is applied to the bearing 13. When the motor starts to run, an axial magnetic pulling force is generated between the stator and the rotor, which partially offsets the gravity applied by the shaft 1 and the rotor disk on the bearing 13, greatly reducing the wear of the bearing 13 when the motor is running.

[0043] In this embodiment, the magnetic field of the electrically excited synchronous motor (i.e., the magnetic field generated by the stator winding of the AC exciter stator 2 and the magnetic field generated by the excitation winding 6) is easy to adjust. The magnetic field of the motor can be conveniently adjusted by adjusting the excitation current input into the stator winding of the AC exciter stator 2.

[0044] Embodiment 2

[0045] Different from the first embodiment, in this embodiment, each AC exciter stator 2 is also equipped with a small permanent magnet, and the small permanent magnets on adjacent AC exciter stators 2 have opposite polarities.

[0046] In this embodiment, during operation, the stator winding of the AC exciter stator 2 may not be connected to an external power source, and when the shaft 1 rotates, the rotor winding of the AC exciter rotor 3 generates current under the action of the small permanent magnet.

[0047] Embodiment 3

[0048] Different from the first or second embodiment, in this embodiment, the stator winding of the AC exciter stator 2 is connected to the armature winding 10 of the main generator through the rectifier 4 fixedly installed in the casing 12. The wire can pass through the gap between the first rotor yoke 5 and the casing 12, the gap between the second rotor yoke 11 and the casing 12, and directly pass through the stator yoke 9 to achieve the connection between different components.

[0049] In this embodiment, the current generated by the armature winding 10 is sent to the stator winding of the AC exciter stator 2 through the conductor buried in the casing 12 and the rectifier 4. The air gap magnetic field of the AC exciter is strengthened, and the current generated by the AC exciter rotor 3 also increases accordingly. Positive feedback is formed between the AC exciter and the main generator. In other words, when the motor enters the rated working state, part of the electric energy generated by the main generator is input into the AC exciter to generate excitation current, and part is sent to the power grid or for load operation. The excitation capacity of the generator is set according to the specific application scenario.

[0050] Finally, it is necessary to explain here that the above embodiments are only used to further illustrate the technical solution of the utility model in detail and cannot be understood as limiting the protection scope of the utility model. Some non-essential improvements and adjustments made by technicians in this field based on the above content of the utility model belong to the protection scope of the utility model.

Claims

1. An axial magnetic field electrically excited brushless motor, characterized in that: The invention comprises a casing (12) and a main generator, an AC exciter and a rectifier (4) mounted on the casing (12); the main generator comprises a rotating shaft (1), a stator disk and a rotor disk; the rotating shaft (1) is rotatably mounted on the casing (12); the stator disk is fixed in the casing (12); the rotor disk and the rotating shaft (1) are fixedly connected; the stator disk comprises a plurality of armature windings (10); the rotor disk comprises a plurality of excitation windings (6); the AC exciter comprises an AC exciter stator (2) and an AC exciter rotor (3), the AC exciter stator (2) is fixedly installed in the casing (12), the AC exciter rotor (3) is installed on the rotor disk, the AC exciter rotor (3) includes a rotor winding, the rotor winding of the AC exciter rotor (3) is connected to the input end of the rectifier (4) through an electric wire, and the output end of the rectifier (4) is connected to the excitation winding (6) through an electric wire. The AC exciter stator (2) is provided with a stator winding and / or a permanent magnet, and the stator winding can be connected to an external power supply and / or an armature winding (10).

2. The brushless motor according to claim 1, characterized in that: The rotor disk also includes a rotor yoke and a plurality of rotor teeth (7). The rotor yoke is in the shape of a disk and is parallel to a horizontal plane. The rotor yoke is fixedly connected to a rotating shaft (1), and the rotating shaft (1) is perpendicular to the horizontal plane. A plurality of rotor teeth (7) are mounted on one surface of the rotor yoke. The plurality of rotor teeth (7) are arranged in a circular array with the rotating shaft (1) as a center line. A group of excitation windings (6) are wound on each rotor tooth (7). The AC exciter rotor (3) is mounted on the rotor yoke.

3. The brushless motor according to claim 2, characterized in that: The stator disc also includes a stator yoke (9) and a plurality of stator teeth (8); the stator yoke (9) is disc-shaped and parallel to a horizontal plane; a plurality of stator teeth (8) are mounted on both surfaces of the stator yoke (9); the plurality of stator teeth (8) on each surface of the stator yoke (9) are arranged in a circular array with the rotating shaft (1) as the center line; and a group of armature windings (10) are wound around each stator tooth (8).

4. The brushless motor according to claim 3, characterized in that: The stator yoke (9) is fixedly connected to the inner wall of the casing (12), the rotating shaft (1) passes through the stator yoke (9), and a bearing (13) is provided between the rotating shaft (1) and the stator yoke (9).

5. The brushless motor according to claim 4, characterized in that: The rotor disks are provided with two rotor disks, which are respectively located on both sides of the stator disk; the two rotor yokes of the two rotor disks and the stator yoke (9) are arranged in parallel and spaced apart; the two rotor yokes are respectively located on both sides of the stator yoke (9); and a side of the rotor yoke on which the rotor tooth portion (7) is mounted faces the stator yoke (9).

6. The brushless motor according to claim 5, characterized in that: The AC exciter stator (2) and the AC exciter rotor (3) are located between the top cover of the casing (12) and the rotor yoke above the stator yoke (9); the AC exciter stator (2) is fixedly mounted on the inner surface of the top cover of the casing (12), and the AC exciter rotor (3) is mounted on a surface of the rotor yoke away from the stator disk.

7. The brushless motor according to claim 1, characterized in that: A plurality of AC exciter stators (2) and a plurality of AC exciter rotors (3) are provided, the plurality of AC exciter stators (2) being arranged in a ring array with the rotating shaft (1) as the center line, and the plurality of AC exciter rotors (3) being arranged in a ring array with the rotating shaft (1) as the center line.

8. The brushless motor according to claim 7, characterized in that: When permanent magnets are arranged on the stators (2) of the AC exciters, the polarities of the permanent magnets on the stators (2) of the adjacent AC exciters are opposite.

9. The brushless motor according to claim 3, characterized in that: The armature winding (10) on one surface of the stator yoke (9) and the armature winding (10) on the other surface are connected in parallel or in series, and multiple groups of armature windings (10) on the same surface of the stator yoke (9) can be connected in series or in parallel.

10. The brushless motor according to claim 2, characterized in that: When the stator winding is provided on the AC exciter stator (2), the stator winding can be connected to the armature winding (10) via a rectifier (4); the rectifier (4) connected to the stator winding of the AC exciter stator (2) is fixedly installed in a casing (12); and the rectifier (4) connected to the rotor winding of the AC exciter rotor (3) is installed on a rotor yoke.

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