A four-phase double-stator double-salient-pole motor

Abstract

The present invention relates to the field of motor technology, and in particular to a four-phase dual-stator double-salient pole motor, comprising an outer stator, a rotor and an inner stator coaxially arranged from the outside to the inside, wherein the outer stator comprises an outer stator core and an excitation device, a plurality of pairs of outer stator slots are uniformly opened circumferentially on the outer stator core, and the radial sections of each pair of outer stator slots are mutually symmetrical, and the excitation device is embedded in the outer stator slots; the rotor comprises a non-magnetic connection structure and a rotor core block; the inner stator comprises an inner stator core yoke, inner stator core teeth and an armature winding; the radial axis of the excitation device is collinear with the bisector of the angle formed by the radial axes of two adjacent inner stator core teeth; the number of teeth N of the inner stator core is 1 / 4 of the inner stator core; s =8k, the number of rotor core blocks N r =6k or 10k, the number of excitation devices N pm =2k, where k is a positive integer. This motor can effectively solve the low torque density problem existing in traditional structures and reduce the risk of thermal demagnetization of permanent magnets.

Description

Technical field

[0001] The present invention belongs to the technical field of motors, and in particular relates to a four-phase dual-stator double-salient-pole motor. [Background Technology]

[0002] The doubly salient permanent magnet motor is a stator-type permanent magnet motor. Compared with the traditional three-phase six-stator slot four-rotor tooth motor, the four-phase eight-stator slot six-rotor tooth motor has obvious advantages, such as higher power density, wider speed range, smaller torque ripple and lower current amplitude. Therefore, it has received widespread attention from people in the electrical engineering field.

[0003] However, the permanent magnets and armature windings of this type of motor are placed on the stator, which will result in insufficient utilization of the internal space of the motor, causing the motor's torque output capacity to remain poor, thereby limiting the promotion and application of this type of motor in the industrial field.

[0004] For example, Chinese patent publication number CN102130564A discloses a four-phase doubly salient-pole motor consisting of a stator and rotor mounted on the same shaft. The stator has 8n salient-pole teeth evenly distributed. Every fourth salient-pole tooth slot on the stator houses an excitation winding or a permanent magnet. Furthermore, each stator salient-pole tooth is fitted with a concentrated armature winding. The armature windings on salient-pole teeth at the same position in the magnetic field are connected in series to form a single-phase winding. The rotor has 6n rotor poles evenly distributed, where n is a positive integer and n ≥ 1. This motor unit has an 8 / 6 structure, with a stator pole pitch that is three times the stator pole arc length and a rotor pole width that is equal to or greater than the stator pole width. When the rotor poles are widened to a pole arc coefficient of 1 / 3, the motor achieves maximum output power when used as a generator. Compared to a corresponding three-phase 6n / 4n-pole doubly salient-pole motor of the same size, this technical invention offers higher power density, lower winding copper losses, a wider speed regulation range, and lower torque ripple. However, the motor described in the prior invention has the following shortcomings:

[0005] 1) Sinusoidal alternating current flows through the armature winding, generating copper loss. The heat is mainly conducted through the stator core. The permanent magnets are embedded in the stator core yoke and must simultaneously withstand their own eddy current loss heat and the heat conducted to the stator core by the windings. This greatly increases the risk of thermal demagnetization of the permanent magnets.

[0006] 2) The rotor only has a rotor yoke and salient pole rotor teeth, and the internal space utilization of the motor is not high.

[0007] 3) The size of the permanent magnet in the tangential magnetization direction is adjustable, but the size in the radial direction is limited by the thickness of the stator core yoke. The amount of permanent magnets used is not easy to select, and it is not easy to accommodate more permanent magnets, which limits the torque output capacity of the motor.

[0008] 4) The permanent magnets and armature windings are located on the stator core yoke and stator core teeth respectively. There is a spatial competition between the two, resulting in competition between the electric load and the magnetic load, which in turn limits the torque output capacity of the motor. [Summary of the invention]

[0009] Based on the deficiencies in the existing technology, the present invention provides a four-phase dual-stator double-salient pole motor, which can better solve the low torque density problem existing in the traditional structure, and at the same time, can also reduce the risk of thermal demagnetization of permanent magnets.

[0010] To achieve the above-mentioned object, the present invention provides the following technical solution: a four-phase dual-stator double-salient-pole motor, comprising a coaxially arranged outer stator, a rotor and an inner stator, wherein the rotor is located between the outer stator and the inner stator, the outer stator comprises an outer stator core and an excitation device, the outer stator core is uniformly provided with a plurality of outer stator slots in pairs, and the radial sections of each pair of the outer stator slots are mutually symmetrical, and the excitation device is embedded in the corresponding outer stator slot; the rotor comprises a non-magnetic connection structure and The rotor core block is uniformly embedded in the non-magnetic connection structure along the circumferential direction; the inner stator includes an inner stator core yoke, inner stator core teeth uniformly fixed on the outer side of the inner stator core yoke along the circumferential direction, and an armature winding wound on the inner stator core teeth; the radial axis of the excitation device is collinear with the bisector of the angle formed by the radial axes of two adjacent inner stator core teeth, and the number of inner stator core teeth sandwiched by the radial axes of two adjacent excitation devices is the number of phases of the motor; the number of inner stator core teeth N s =8k, the number of rotor core blocks N r =6k or 10k, the number of excitation devices N pm =2k, where k is a positive integer.

[0011] This invention improves the stator structure, transforming the conventional single-stator design into a dual-stator structure, and placing the excitation device and armature windings on the inner and outer stators. This effectively increases the internal space utilization of the motor, thereby enhancing the motor's torque output capacity. Furthermore, there is no direct contact between the excitation device and the armature windings. When the excitation device is a permanent magnet, the heat it experiences is solely due to its own eddy current losses, which can be effectively dissipated through the housing, significantly reducing the risk of thermal demagnetization. When the excitation device is a field coil, the risk of thermal insulation loss in the copper wire is reduced.

[0012] Furthermore, the excitation device is a permanent magnet and / or an excitation coil, that is, the excitation device can be a permanent magnet, an excitation coil, or a hybrid excitation in which the excitation coil and the permanent magnet together form a magnetic source. Optionally, when the excitation device is a permanent magnet, the heat borne by the permanent magnet is only caused by its own eddy current loss, and can be effectively discharged by the casing, so the risk of thermal demagnetization is significantly reduced; optionally, when the excitation device is an excitation coil, the motor's weak magnetic speed regulation capability can be improved; optionally, when the excitation device is a combination of a permanent magnet and an excitation coil, that is, a hybrid excitation in which the permanent magnet and the excitation coil together form a magnetic source, this can simultaneously take into account the motor's torque output performance and weak magnetic speed regulation performance.

[0013] Furthermore, a heat sink is provided at the center of the inner stator to enhance the heat dissipation of the armature windings. The heat sink can be an air-cooled structure, a liquid-cooled structure, or a combination of the two. Specifically, the air-cooled structure can be a fan located at the end of the inner stator core, while the liquid-cooled structure can be a water-cooling channel axially opened in the center of the inner stator. The heat sink is used to enhance the heat dissipation capacity of the motor, allowing heat generated by the armature windings in the motor to be quickly dissipated through the inner stator core teeth and the inner stator core yoke to the heat sink, achieving a cooling effect.

[0014] Furthermore, the rotor core blocks are arranged with skew poles, which can effectively suppress torque pulsation.

[0015] Furthermore, the outer contour of the radial section of the outer stator core is olive-shaped. This configuration increases the radial length of the permanent magnets, increasing the amount of permanent magnet material used, thereby improving magnetic load levels and enhancing torque capacity. Furthermore, the outer contour of the radial section of the outer stator core can also be circular, rectangular, or polygonal. The motor's mechanical structure is either rotary, linear, or a combination of the two.

[0016] Furthermore, the inner stator core yoke and the inner stator core teeth are integrally formed, making the inner stator more firm and durable.

[0017] Compared with the prior art, the beneficial effects of the present invention include at least:

[0018] In this invention, the stator is dual-stator: an inner stator and an outer stator. Compared to existing single-stator solutions, the excitation device and armature windings of the motor are located on both the outer and inner stators. This effectively alleviates the spatial competition between them, effectively improving the motor's space utilization, which helps increase the electrical and magnetic load levels, and thus improve the motor's torque output capacity.

[0019] In this invention, the excitation device (including permanent magnets and excitation coils) and the armature coils are separated into the inner and outer stators. Compared to existing solutions (where permanent magnets are embedded in the stator core yoke, subjecting them to both their own eddy current losses and heat conducted to the stator core by the windings), the present structure avoids physical contact between the excitation device and the armature windings, effectively reducing the risk of thermal demagnetization of the permanent magnets.

[0020] In the present invention, the excitation device can adopt three excitation forms: permanent magnet excitation alone, excitation coil excitation alone, and "permanent magnet + excitation coil" mixed excitation. The excitation form is selected according to the application scenario requirements. Permanent magnet excitation alone can make the motor output a larger torque, excitation coil excitation alone can make the motor have good weak magnetic speed regulation capability, and permanent magnet + excitation coil mixed excitation can make the motor take into account both torque output capability and weak magnetic speed regulation capability.

[0021] In this invention, the outer stator core has an olive-shaped cross-section, eliminating the constraints imposed by the stator yoke thickness on the size of the permanent magnets in existing solutions. This allows for increased permanent magnet material usage and improved torque density. A heat sink is inserted into the inner stator ring, facilitating heat dissipation. Furthermore, the motor of this invention utilizes a skewed rotor pole design to suppress torque ripple.

Brief Description of the Drawings

[0022] Figure 1 Schematic diagram of the structure of the motor of the present invention;

[0023] Figure 2 A schematic diagram of the motor structure with a permanent magnet external magnetic field concentration design added to the present invention;

[0024] Figure 3 The present invention adopts a motor structure with excitation coil excitation;

[0025] Figure 4 This is a schematic diagram of the motor structure in which the excitation device of the present invention adopts "permanent magnet + excitation coil";

[0026] Among them, 1-external stator, 11-external stator core, 12-permanent magnet, 13-excitation coil, 2-rotor, 21-rotor core block, 22-non-magnetic connection structure, 3-inner stator, 31-inner stator core teeth, 32-inner stator core yoke, 33-armature winding. [Specific implementation method]

[0027] The present invention will be further described in detail below through specific embodiments in conjunction with the accompanying drawings, but the present invention is not limited to the following specific embodiments.

[0028] A four-phase double-stator double-salient-pole motor, such as Figures 1 to 4As shown, it includes a coaxially arranged outer stator 1, a rotor 2 and an inner stator 3, the rotor 2 is located between the outer stator 1 and the inner stator 3, the outer stator 1 includes an outer stator core 11 and an excitation device, the outer stator core 11 is evenly opened with a plurality of outer stator slots in pairs, and the radial sections of each pair of the outer stator slots are centrally symmetrical to each other, and the excitation device is embedded in the corresponding outer stator slot; the rotor 2 includes a non-magnetic connection structure 22 and a rotor core block 21, the rotor core block 21 is evenly embedded in the non-magnetic connection structure 22 along the circumferential direction, specifically, the rotor 2 is connected to the non-magnetic connection structure 22 through the rotor core block 21. The inner diameter of the rotor core block 21 is equal to the inner diameter of the non-magnetic connection structure 22, and the outer diameter of the rotor core block 21 is equal to the outer diameter of the non-magnetic connection structure 22; the inner stator 3 includes an inner stator core yoke 32, inner stator core teeth 31 uniformly fixed circumferentially on the outside of the inner stator core yoke 32, and an armature winding 33 wound on the inner stator core teeth 31; the radial axis l2 of the excitation device is collinear with the bisector of the angle formed by the radial axes l1 and l3 of two adjacent inner stator core teeth 31, and the number of inner stator core teeth 31 sandwiched by the radial axes of two adjacent excitation devices is the number of phases of the motor. For further reference, Figure 1 、 Figure 2 or Figure 4 As shown, in this embodiment, the number of phases of the motor is 4; the number of the inner stator core teeth 31 is N s =8k, the number of the rotor core blocks 21 is N r =6k or 10k, the number of excitation devices N pm =2k, where k is a positive integer. In this embodiment, a preferred embodiment is that the number of teeth of the inner stator core is 8, the number of rotor core blocks is 6, the number of excitation devices is 2 and the excitation devices can be two permanent magnets 12, such as Figure 1 、 Figure 2 As shown, there may also be two sets of excitation coils 13, such as Figure 3 Another preferred embodiment is that the number of teeth of the inner stator core is 16, the number of rotor core blocks is 12, the number of excitation devices is 4 and the excitation device is two permanent magnets 12 provided on a pair of outer stator slots and two sets of excitation coils 13 provided on another outer stator slot, as shown. Figure 4 shown.

[0029] Preferably, in this embodiment, the excitation device can be either a permanent magnet 12 or an excitation coil 13 , or a hybrid excitation device in which the permanent magnet 12 and the excitation coil 13 together form a magnetic source.

[0030] Preferably, in this embodiment, a heat sink is provided at the center of the inner stator 3 to enhance the heat dissipation of the armature winding 33. The heat sink can be an air-cooled structure, a liquid-cooled structure, or a combination of the two. Specifically, the air-cooled structure can be a fan located at the end of the inner stator core, while the liquid-cooled structure can be a water-cooling channel axially extending through the center of the inner stator. The heat sink is used to enhance the heat dissipation capacity of the motor, allowing heat generated by the armature winding in the motor to be rapidly dissipated through the inner stator core teeth and the inner stator core yoke to the heat sink, achieving a cooling effect.

[0031] Preferably, in this embodiment, the rotor core blocks 21 are arranged with skew poles.

[0032] Preferably, if Figure 2 As shown, in this embodiment, the outer contour of the radial section of the outer stator core 11 is olive-shaped, circular, rectangular or polygonal.

[0033] In this embodiment, the mechanical structure of the motor is in the form of rotation, linear or a combination of the two.

[0034] In this embodiment, the inner stator core yoke 32 and the inner stator core teeth 31 are integrally formed.

[0035] The above is only a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or replacements within the technical scope disclosed by the present invention, which should be included in the scope of protection of the present invention. In addition, the technical solutions between the various embodiments of the present invention can be combined with each other, but it must be based on the ability of ordinary technicians in this field to implement. When the combination of technical solutions is contradictory or cannot be implemented, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection required by the present invention. Therefore, the scope of protection of the present invention shall be based on the scope of protection of the claims.

Claims

1. A four-phase double-stator double-salient-pole motor, comprising an outer stator (1), a rotor (2), and an inner stator (3) arranged coaxially, wherein the rotor (2) is located between the outer stator (1) and the inner stator (3), and characterized in that: The outer stator (1) comprises an outer stator core (11) and an excitation device, wherein a plurality of outer stator slots in pairs are evenly opened on the outer stator core (11) in a circumferential direction, and radial sections of each pair of the outer stator slots are centrally symmetrical to each other, and the excitation device is embedded in the corresponding outer stator slot; The rotor (2) comprises a rotor core block (21) and a non-magnetic conductive connection structure (22), wherein the rotor core block (21) is uniformly embedded in the non-magnetic conductive connection structure (22) along the circumferential direction; The inner stator (3) comprises an inner stator core yoke (32), inner stator core teeth (31) uniformly fixed circumferentially on the outside of the inner stator core yoke (32), and an armature winding (33) wound on the inner stator core teeth (31); The radial axis (l2) of the excitation device and the bisector of the angle formed by the radial axes (l1, l3) of two adjacent inner stator core teeth (31) are collinear, and the number of inner stator core teeth (31) sandwiched between the radial axes of the two adjacent excitation devices is the number of phases of the motor; The number of the inner stator core teeth (31) is N s =8k, the number of the rotor core blocks (21) is N r =6k or 10k, the number of excitation devices N pm =2k, where k is a positive integer.

2. The four-phase dual-stator double-salient-pole motor according to claim 1, characterized in that: The excitation device is a permanent magnet (12) and / or an excitation coil (13).

3. The four-phase dual-stator double-salient-pole motor according to claim 1, characterized in that: A heat dissipation device is provided at the center of the inner stator (3).

4. The four-phase dual-stator double-salient-pole motor according to claim 1, characterized in that: The rotor core block (21) adopts an oblique pole arrangement.

5. The four-phase dual-stator double-salient-pole motor according to claim 1, characterized in that: The outer contour of the radial section of the outer stator core (11) is olive-shaped, circular or polygonal.

6. The four-phase dual-stator double-salient-pole motor according to claim 1, characterized in that: The mechanical structure of the motor is in the form of rotation, linear or a combination of the two.

7. The four-phase dual-stator double-salient-pole motor according to claim 1, characterized in that: The inner stator iron core yoke (32) and the inner stator iron core teeth (31) are integrally formed.

Images