electric machine

Abstract

The present application relates to a kind of motor stator, belong to motor field.A kind of motor stator, inside rotor, including core, shape is annular, for magnetic conduction and setting winding;Three-phase winding, spiral winding is wound on the core.The structural design of the motor stator is optimized, provides the possibility of technical improvement, which will allow the torque density of motor to increase.

Description

Technical Field

[0001] This invention relates to the field of electric motors, and in particular to an electric motor stator capable of providing high torque density and power density. Background Technology

[0002] Electric motor drives have a wide range of applications, and their performance largely depends on the weight of the motor itself. Examples include aircraft propeller motors, spacecraft equipment, wind turbines, and electric drive systems within automobile wheels. Designing and manufacturing electric motors with high power density and high performance is a growing trend.

[0003] The closest prior art to this invention is the electric motor disclosed in U.S. Patent No. 20040194286, which includes a rotor consisting of at least two permanent magnet assemblies with different polarities, and a stator with three-phase windings spirally wound on an iron core. However, this machine has the disadvantage of being large and heavy due to the poor ergonomics of the stator and rotor unit arrangement inside the housing and the shape of the permanent magnets, making it difficult to reduce the motor's mass without reducing the torque value. Summary of the Invention

[0004] The purpose of this invention is to provide a motor stator whose structural design is optimized, providing the possibility of technical improvements that will allow for an increase in the torque density of the motor.

[0005] This application provides a motor stator located inside the rotor, including...

[0006] The iron core, which is ring-shaped, is used for conducting magnetism and setting up the windings;

[0007] The three-phase winding is spirally wound around the iron core. It has a simple structure and is easy to manufacture industrially.

[0008] Furthermore, the three-phase windings cover the entire surface of the core to prevent magnetic leakage.

[0009] Furthermore, the three-phase winding consists of independent coils for each phase, and each coil can provide a sinusoidal or trapezoidal AC voltage with a phase difference of 120°.

[0010] Furthermore, each phase includes at least one conductor, the configuration of which reduces eddy currents.

[0011] Furthermore, the cross-section of the coil in each phase is circular or square.

[0012] Furthermore, channels for coolant flow are formed inside the core.

[0013] Furthermore, the core is made of anisotropic silicon steel sheets stacked together, or of isotropic silicon steel sheets stacked together, or of amorphous layered foil, or of high permeability material, or of insulating powdered soft magnetic composite material.

[0014] Furthermore, including

[0015] A material comprising epoxy resin, or reinforced epoxy resin, or polyimide;

[0016] The material is used to bond the three-phase windings.

[0017] Furthermore, the conductive portion of the three-phase winding is made of materials including copper, silver, aluminum, carbon nanotubes, nickel, or steel.

[0018] Furthermore, the conductive parts of the three-phase windings are made of aluminum, and the insulation of the three-phase windings is made of micro-arc-oxidized ceramic. The use of aluminum for the conductive parts makes the stator lighter.

[0019] Furthermore, the conductor is a Litz-type conductor, which contains many conductive wires. This can reduce eddy currents.

[0020] Furthermore, the core is provided with slots, the height of which is 0% to 100% of the height of the conductive portion of each phase in the insulated three-phase winding. This makes it easy to fix the insulated conductive portion.

[0021] Furthermore, the three-phase winding coils are at least partially located in slots.

[0022] An electric motor includes a rotor consisting of at least two permanent magnet assemblies with different polarities, and a stator located inside the rotor, the stator having an iron core and a three-phase winding spirally wound around the iron core, wherein the permanent magnets form a spiral around the stator, each portion of the spiral including at least one permanent magnet of the same polarity.

[0023] First, the technical result is achieved because the permanent magnet forms a dense spiral around the stator. Combined with the stator windings that are spirally wound on the iron core, the magnetic circuit can be shortened, thereby increasing the tension strength of the gap between the rotor permanent magnet and the spiral windings on the stator iron core.

[0024] In some implementations, the three-phase winding is represented by three independent coils for each phase, with a sinusoidal or trapezoidal AC voltage applied to each coil, phased by 120°, wherein each phase contains at least one conductor, and the three-phase winding covers the entire surface of the core to reduce eddy currents.

[0025] In some embodiments, the number of permanent magnets on the rotor should be even, wherein the permanent magnet assembly includes at least one pole pair and the permanent magnet assembly is supported by a permanent magnet support.

[0026] In some embodiments, the ratio of the number of helically arranged permanent magnets to the number of helical windings is 2:6, wherein the permanent magnet support is made of ferromagnetic steel.

[0027] Furthermore, the permanent magnet assembly is a Halbach permanent magnet assembly, wherein the ratio of the number of helically arranged permanent magnets to the number of helical windings is 4:6, and the material of the permanent magnet support is selected by the applicant through experiments, including aluminum alloy, magnesium alloy, titanium alloy, carbon fiber, and plastic.

[0028] In some embodiments, the permanent magnets in the permanent magnet assembly are interconnected by an adhesive and bonded to a permanent magnet support.

[0029] In some implementations, the cross-section of the coil for each phase is typically circular or square.

[0030] In some embodiments, channels for coolant flow are formed within the core, and the core itself is made of anisotropic silicon steel sheets stacked together, or isotropic silicon steel sheets stacked together, or amorphous layered foil, or a high-permeability material, or an insulating powdered soft magnetic composite material.

[0031] In some implementations, the conductive parts of the three-phase winding are made of materials including copper, silver, aluminum, carbon nanotubes, nickel, and steel. If the conductive parts of the three-phase winding are made of aluminum, then its insulation is made of micro-arc-oxidized ceramic.

[0032] In some embodiments, the material connecting the three-phase winding coils is epoxy resin, or reinforced epoxy resin, or polyimide.

[0033] In some implementations, the height of the slots on the core can be 0% to 100% of the height of the conductive portion of each phase in the insulated three-phase winding, with the three-phase winding coils at least partially located in the slots.

[0034] Furthermore, the motor is made in a ring shape.

[0035] However, it will be apparent to those skilled in the art that the listed embodiments describing the principal features of the claimed electric machine are merely exemplary and not limiting or exclusive. The dimensions, scales, shapes, and outlines of elements in the illustrations given in this document are illustrative and may vary in embodiments of the machine depending on the design and desired functionality. Attached Figure Description

[0036] Figure 1a1b and 1c are cross-sectional views of an electric motor with a circular rotor and stator, and axial and radial configurations, respectively.

[0037] Figure 2 - An exploded view of an electric motor according to the present invention.

[0038] Figure 3 - Exploded longitudinal section view of the permanent magnet assembly and permanent magnet support.

[0039] Figure 4 - A longitudinal cross-sectional view of the Halbach permanent magnet arrangement of the present invention.

[0040] Figure 5 - A longitudinal cross-sectional view of the standard type permanent magnet assembly of the present invention.

[0041] Figure 6 - Exploded view of the stator.

[0042] Figure 7-3 A schematic diagram of the spiral winding of the phase winding.

[0043] Figure 8 - A schematic diagram of a coil with a typical circular cross-section.

[0044] Figure 9 - A schematic diagram of a coil with a typical square cross-section.

[0045] Figure 10a 10b, 10c, 10d - Schematic diagram of iron core structure with slots.

[0046] Figure 11 - A schematic diagram of a monopole permanent magnet structure.

[0047] The attached diagram will be explained in detail below with reference to specific implementation cases. Detailed Implementation

[0048] The following embodiments are described to aid in understanding this application. These embodiments are not, and should not be construed as, limiting the scope of protection of this application. Various modifications and improvements can be made without departing from the inventive concept, and all such modifications and improvements fall within the scope of protection of this invention.

[0049] Figures 1A to 1C show three embodiments of the invention. The three configurations have the same construction structure, but different shapes of the rotor (1) and stator (2): a circular structure, an axial structure, and a radial structure.

[0050] Figure 2An exploded cross-sectional view of an electric motor is shown, including: a permanent magnet support (4), a stator (2) inside the rotor (1), an iron core (5), a channel (6) inside the iron core for coolant flow, a three-phase winding (7) spirally wound on the iron core, the sides (8) and bottom (9) being the walls of the motor housing, and a drive shaft (10) fixed inside the motor by bearings (11) and (12), the rotational motion of the drive shaft being transmitted by the rotor (1).

[0051] Figure 3 An exploded longitudinal section view of the permanent magnet assembly (3) and the permanent magnet support (4) is shown.

[0052] Figure 4 A longitudinal cross-sectional view of the Halbach permanent magnet assembly (3) is shown, where the arrows indicate the polarity of the magnets in the permanent magnet assembly (3). All permanent magnets have the same shape but four different polarities: two radial (13), (14) and two tangential (15), (16). Therefore, the magnetic field is concentrated on one side of the permanent magnet assembly, while the other side is suppressed. The use of ferromagnetic material is unnecessary for the magnetic circuit in the permanent magnet support (4). The minimum number of permanent magnets in the Halbach permanent magnet assembly is four, and the maximum number is unlimited.

[0053] Figure 5 A longitudinal cross-sectional view of a standard arrangement type magnet assembly (3) is shown, where arrows indicate the polarity of the magnets in the permanent magnet assembly (3). In the case of the standard permanent magnet assembly (3), only two opposing radial polarities (17) and (18) are used. In this case, the permanent magnet support (4) should be made of ferromagnetic material to form the magnetic field. The number of permanent magnets is at least twice that of a Halbach arrangement type permanent magnet assembly. The minimum number of permanent magnets is 2, and the maximum number is unlimited.

[0054] Figure 6 The exploded view of the stator is shown, including the iron core (5). First, the three-phase windings (7) form a rigid frame. Second, there are channels for coolant flow in the iron core (not shown in this figure), in which channels for circulating coolant flow are formed (not shown in the figure). Third, the magnetic field of the permanent magnet is ring-shaped. Figure 6 It is also shown that the element (19) includes an inlet (20) and an outlet (21) for the flow of coolant, which is connected to the core (5) and arranged around the periphery of the stator connecting pin (22) to secure the stator in the motor housing.

[0055] Figure 7A view of the three-phase winding spiral is shown, where each coil (23) is connected to a controller (not shown) that sequentially excites the phase windings, causing the rotor to rotate relative to the stator. The number of turns in each spiral on each coil (23) is equal to the number of poles in the rotor's permanent magnets. Theoretically, the minimum number is two, and the maximum is limited only by the motor design.

[0056] The cross-sectional shape of the coil in each phase is generally circular. Figure 8 ). and square (Fig. 9). To reduce losses caused by eddy currents inside the conductor, Litz type conductors should be used, which contain many conductive wires (24). The helical shape of the three-phase windings on the core enables it to achieve a very high space factor and is fully used for torque generation.

[0057] Figure 10a , 10b Views 10c and 10d show exemplary configurations of slots (25) for laying three-phase windings on the core, where their height can be smoothly varied from 0% to 100% of the conductive portion of the insulated three-phase windings.

[0058] Figure 11 A general view showing the structure of a monopole permanent magnet.

[0059] The motor operates as follows:

[0060] This invention relates to electric motors, and more particularly to slotted and slotless electric motors and generators. The operating principle of such motors is based on the Lorentz force acting on a conductor in a magnetic field. The permanent magnet assembly (3) of the rotor (1) generates a concentrated alternating magnetic field within three-phase windings (7), which are helically wound around an iron core (5) within the stator. The number of permanent magnets is even, and they are placed in pairs, maintaining equal distances. The number of poles of the rotor (1) depends on the size of the motor and the torque it should provide. The magnetic field circulates through the iron core (5) in the stator (2). The three-phase windings (7) of the stator (2) comprise three coils (23), each providing a sinusoidal or trapezoidal AC voltage with a 120° phase difference. The current in the coils (23) of the stator (2) generates a tangential Lorentz force from the alternating voltage within the magnetic field of the rotor (1), causing the rotor to rotate. During current changes, the rotor (1) rotates according to the two magnetic poles of the magnets. To operate the motor, a standard controller for a PMSM (Permanent Magnet Synchronous Motor) can be used.

[0061] Up to 95% of the coils, except for their upper portions, are in the magnetic field and participate in torque generation. For all existing electric motors, the recommended design has the maximum possible ratio of active to stationary working winding portions. Various motor models can be created by varying the slot height from 0 to the diameter of the winding wires. Due to the low losses in the core, slotless motors can achieve high power density, while slotted motors can achieve high torque at low speeds.

[0062] Therefore, the present invention is an electric motor whose structural design will provide opportunities to achieve a technological achievement, including optimizing the rotor and stator unit design, which will increase the torque density of the motor.

Claims

1. An electric motor, comprising a stator and a rotor, characterized in that, The stator is located inside the rotor. The stator includes an iron core, which is ring-shaped and used for magnetic conduction and setting up the windings. Channels for coolant flow are formed inside the iron core. The three-phase windings are spirally wound on the iron core and cover the entire surface of the iron core. The rotor consists of at least two permanent magnet assemblies with different polarities. The permanent magnets are densely arranged in a helical pattern around the stator. The permanent magnet assemblies are Halbach permanent magnet assemblies, and the ratio of the number of helical permanent magnets to the number of helical windings is 4:

6.

2. The motor according to claim 1, characterized in that: The three-phase winding consists of independent coils for each phase, and each coil can provide a sinusoidal or trapezoidal AC voltage with a phase difference of 120°.

3. The motor according to claim 2, characterized in that, The cross-section of the coil in each phase is circular or square.

4. The motor according to claim 1, characterized in that, The conductive portion of the three-phase winding is made of aluminum, and the insulation of the three-phase winding is made of micro-arc-oxidized ceramic.

5. The motor according to claim 1, characterized in that, The core is provided with slots, the height of which is 0% to 100% of the height of the conductive part of each phase in the insulated three-phase winding.

6. The motor according to claim 5, characterized in that, The three-phase winding coils are at least partially located in slots.

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