Motor

Abstract

The present invention provides a motor with permanent magnets, which can provide high torque density and high power density for a motor or generator, and the motor includes a rotor and a stator, the rotor and the stator have a spiral shape, and the stator is located inside the rotor. The rotor includes at least two permanent magnet components of different polarities, forming a spiral around the stator; the stator includes an iron core and a three-phase winding spirally wound on the iron core, and this structure allows almost the entire winding to participate in torque generation. Cooling with a coolant inside the iron core can eliminate heat over the entire length of the winding, thereby greatly improving work efficiency.

Description

Technical Field

[0001] The present invention relates to the field of electric motors, in particular to an electric motor or generator with a permanent magnet and a stator and a rotor with a spiral structure, which can provide high torque density and high power density. Background Art

[0002] There are many application areas for motor-driven devices, and their performance depends largely on the weight of the motor itself. Examples include aircraft propeller motors, spacecraft equipment, wind turbines, electric drive systems inside car wheels, etc. It is a trend to design and manufacture electric motors with high power density and high performance.

[0003] The closest prior art to the present invention is the motor disclosed in U.S. Patent No. 20040194286, which includes: a rotor composed of at least two permanent magnet assemblies with different polarities, and a stator with three-phase windings spirally wound on an iron core. The disadvantage of this machine is that due to the low ergonomics of the arrangement of the stator and rotor units inside the casing and the shape of the permanent magnets, the size and weight of the motor structure are large, which is not conducive to reducing the mass of the motor without reducing the torque value. Summary of the invention

[0004] The object of the present invention is to provide an electric machine which, by optimizing the structural design of the rotor and the stator, offers the possibility of technical improvement, which will allow increasing the torque density of the electric machine.

[0005] The present application provides an electric motor, which includes a rotor composed of at least two permanent magnet assemblies with different polarities, and a stator located inside the rotor, wherein the stator has an iron core and a three-phase winding spirally wound on the iron core, wherein the permanent magnets form a spiral around the stator, and each part of the spiral includes at least one permanent magnet with the same polarity.

[0006] Firstly, the technical result can be achieved because the permanent magnets form a dense spiral around the stator, which, combined with the stator windings spirally wound on the core, can shorten the magnetic path, thereby increasing the tension strength of the gap between the rotor permanent magnets and the spiral windings on the stator core.

[0007] In some embodiments, the three-phase winding is represented by three independent coils per phase, a sinusoidal or trapezoidal AC voltage is applied to each coil with a phase difference of 120°, wherein each phase includes at least one wire, and to reduce eddy currents, the three-phase winding covers the entire surface of the core.

[0008] In some embodiments, the number of permanent magnets on the rotor should be an even number, wherein the permanent magnet assembly includes at least one pole pair, and the permanent magnet assembly is supported by a permanent magnet support.

[0009] In some embodiments, the ratio of the number of the spirally arranged permanent magnets to the number of the spiral windings is 2:6, wherein the permanent magnet bracket is made of ferromagnetic steel.

[0010] Furthermore, the permanent magnet assembly is a Halbach permanent magnet assembly, in which the ratio of the number of spirally arranged permanent magnets to the number of spiral windings is 4:6, and the material of the permanent magnet bracket is selected by the applicant through experiments, including aluminum alloy, magnesium alloy, titanium alloy, carbon fiber, and plastic.

[0011] In some embodiments, the permanent magnets in the permanent magnet assembly are connected to each other by an adhesive and bonded to the permanent magnet bracket.

[0012] In some embodiments, the cross-section of the coil of each phase is generally circular or square.

[0013] In some embodiments, channels for coolant flow are formed in the core, and the core itself is made of laminated anisotropic silicon steel sheets, or laminated isotropic silicon steel sheets, or amorphous layered foil, or high magnetic permeability material, or insulating powdered soft magnetic composite material.

[0014] In some embodiments, the material of the conductive part of the three-phase winding includes copper, silver, aluminum, carbon nanotubes, nickel, steel, and if the conductive part of the three-phase winding is made of aluminum, then its insulation is made of micro-arc oxidized ceramic.

[0015] In some embodiments, the material connecting the three-phase winding coils is epoxy resin, or reinforced epoxy resin, or polyimide.

[0016] In some embodiments, the height of the slots on the core may be 0% to 100% of the height of the conductive portion of each phase in the insulated three-phase winding, and the three-phase winding coils are at least partially located in the slots.

[0017] Furthermore, the motor is manufactured in a ring shape.

[0018] However, it is obvious to a person skilled in the art that the listed embodiments describing the main features of the claimed electric machine are only exemplary and not limiting and / or exclusive. The sizes, proportions, shapes and outlines of the elements on the illustrations given in this document are schematic and may vary in the embodiments of the machine, depending on the design and the required functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] 1a, 1b, 1c - are transverse cross-sectional views of an electric motor with circular, axial and radial configurations of the rotor and stator, respectively.

[0020] Figure 2 - An exploded view of an electric motor according to the present invention.

[0021] Figure 3 - Exploded longitudinal section of the permanent magnet assembly and permanent magnet support.

[0022] Figure 4 - Longitudinal cross-section of a Halbach permanent magnet arrangement according to the invention.

[0023] Figure 5 - A longitudinal cross-section of a permanent magnet assembly of the standard type according to the invention.

[0024] Figure 6 - Exploded view of the stator.

[0025] Figure 7-3 Schematic diagram of the helically wound phase winding.

[0026] Figure 8 -Schematic diagram of a coil having a generally circular cross-section.

[0027] Fig. 9 -Schematic diagram of a coil with a generally square cross-section.

[0028] Fig.10a , 10b, 10c, 10d- Schematic diagram of the core structure with slots.

[0029] Fig.11 -Schematic diagram of the monopole permanent magnet structure.

[0030] The accompanying drawings will be described in detail below in conjunction with specific implementation cases. DETAILED DESCRIPTION

[0031] The following embodiments are described to assist understanding of the present application, and the embodiments are not and should not be interpreted in any way as limiting the protection scope of the present application. Without departing from the concept of the present invention, several modifications and improvements can be made, which all belong to the protection scope of the present invention.

[0032] In Figures 1A to 1C, three embodiments of the invention are shown. The three configurations have the same construction, but with different shapes of the rotor (1) and the stator (2): a circular configuration, an axial configuration and a radial configuration.

[0033] Figure 2 An exploded cross-sectional view of an electric motor is shown, comprising: a permanent magnet support (4), a stator (2) in a rotor (1), an iron core (5), a channel (6) in the iron core for allowing coolant to flow, a three-phase winding (7) spirally wound on the iron core, the side (8) and the bottom (9) being the wall of the motor housing, a transmission shaft (10) fixed inside the motor via bearings (11) and (12), and the rotational motion of the transmission shaft is transmitted by the rotor (1).

[0034] Figure 3 A longitudinal cross-sectional exploded view of the permanent magnet assembly (3) and the permanent magnet support (4) is shown.

[0035] Figure 4 A longitudinal cross-section of a Halbach permanent magnet assembly (3) arrangement is shown, wherein the arrows indicate the polarity of the magnets in the permanent magnet assembly (3). All permanent magnets have the same shape, but have 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, and the other side of the permanent magnet assembly is suppressed. The use of ferromagnetic material is unnecessary for the magnetic circuit in the permanent magnet holder (4). The minimum number of permanent magnets in the Halbach permanent magnet assembly arrangement is 4, and the maximum number is not limited.

[0036] Figure 5 A longitudinal cross-section of a standard arrangement type magnet assembly (3) is shown, wherein the arrows indicate the polarity of the magnets in the permanent magnet assembly (3). In the case of a standard permanent magnet assembly (3), only two opposite radial polarities (17) and (18) are used. In this case, the permanent magnet holder (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.

[0037] Figure 6 An exploded view of the stator is shown, comprising an iron core (5), firstly, a three-phase winding (7) forming a rigid frame, secondly, a channel for the flow of coolant in the iron core (not shown in this figure), a channel for the flow of circulating coolant formed therein (not shown in the figure), and thirdly, a permanent magnet having a circular magnetic field. Figure 6 It is also shown that the element (19) includes channels for input (20) and output (21) for the flow of coolant, which are connected to the core (5) and arranged along the periphery of the stator connecting pins (22) to fix the stator in the motor housing.

[0038] Figure 7 A view of a three-phase winding spirally wound (23) is shown, wherein each coil (23) is connected to a controller (not shown) which in turn energizes the phase windings, thereby causing the rotor to rotate relative to the stator. The number of turns per spiral on each coil (23) is equal to the number of poles in the rotor permanent magnets. Theoretically, the minimum number is 2, and the maximum is limited only by the motor design.

[0039] The cross-section of the coil in each phase is generally circular ( Figure 8 ). and square ( Fig. 9). In order to reduce the losses caused by eddy currents inside the conductor, Litz-type conductors are used, which consist of many conducting wires (24). The helical shape of the three-phase windings on the core makes it possible to achieve a high space factor and use it entirely for torque generation.

[0040] Fig.10a , 10b , 10c and 10d show views of an exemplary configuration of slots (25) for laying a three-phase winding on a core, wherein their height can vary smoothly from 0% to 100% of the conductive portion of the insulated three-phase winding.

[0041] Fig.11 A general view showing the structure of a monopole permanent magnet.

[0042] The motor operates as follows:.

[0043] The present invention relates to electric motors, and in particular to slotted and slotless electric motors and generators. The working principle of such electric 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 in a three-phase winding (7), which is spirally wound on an iron core (5) in a stator. The number of permanent magnets is an even number, and they are placed in pairs and kept at 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 winding (7) of the stator (2) includes three coils (23), each of which is provided with a sinusoidal or trapezoidal AC voltage with a phase difference of 120°. The current of the coils (23) of the stator (2) generates a tangential Lorentz force from the alternating voltage in the magnetic field of the rotor (1), causing the rotor to rotate. During the current change, the rotor (1) rotates according to the two magnetic poles of the magnet. To operate the motor, a standard controller of a PMSM (permanent magnet synchronous motor) can be used.

[0044] Up to 95% of the coils, except for their upper part, are in the magnetic field and participate in the generation of torque. The recommended design of the motor has the largest possible ratio of active and stationary working winding parts for all existing motors. By varying the height of the slots from 0 to the diameter of the winding wire, a wide range of motor models can be created. Slotless motors can achieve high power density due to the low losses in the core, while slotted motors can achieve high torque at low speeds.

[0045] Thus, the present invention is an electric machine whose structural design will provide an opportunity to achieve a technical result including optimizing the rotor and stator unit design which will increase the torque density of the electric machine.

Claims

1. A motor, comprising a rotor, the rotor being composed of at least two permanent magnet assemblies with different polarities, and a stator, the stator being located inside the rotor, the stator having an iron core and a three-phase winding helically wound on the iron core, characterized in that: The permanent magnet forms a spiral around the stator, the three-phase winding covers the entire core surface, the ratio of the number of spirally arranged permanent magnets to the number of spiral windings is 2:6, when the permanent magnet assembly is a Halbach permanent magnet assembly, the ratio of the number of spirally arranged permanent magnets to the number of spiral windings is 4:6, the number of permanent magnets on the rotor is an even number, the three-phase winding is composed of three independent coils per phase, each coil can provide a sinusoidal or trapezoidal AC voltage with a phase difference of 120°, each phase includes at least one wire, the configuration of the wire can reduce eddy currents, a slot is provided on the core, the height of the slot is 0% to 100% of the height of the conductive part of each phase in the insulated three-phase winding, and the coil of the three-phase winding is at least partially located in the slot.

2. The motor according to claim 1, characterized in that The permanent magnet assembly is supported by a permanent magnet bracket.

3. The motor according to claim 2, characterized in that The permanent magnet bracket is made of ferromagnetic steel.

4. The motor according to claim 2, characterized in that The material of the permanent magnet bracket includes: aluminum alloy, magnesium alloy, titanium alloy, carbon fiber, or plastic.

5. The motor according to claim 1, characterized in that The cross section of the coil of each phase is circular or square.

6. The motor according to claim 1, characterized in that A channel for the flow of coolant is formed inside the core.

7. The motor according to claim 1, characterized in that The permanent magnets in the permanent magnet assembly are connected to each other through an adhesive and bonded to the permanent magnet bracket.

8. The motor according to claim 1, characterized in that The iron core is made of anisotropic silicon steel sheets, or isotropic silicon steel sheets, or amorphous layered foil, or high magnetic permeability material, or insulating powdered soft magnetic composite material.

9. The motor according to claim 1, characterized in that The coil material of the three-phase winding is epoxy resin, or reinforced epoxy resin, or polyimide.

10. The motor according to claim 1, characterized in that The conductive part of the three-phase winding is made of copper, silver, aluminum, carbon nanotubes, nickel, or steel.

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

12. The motor according to claim 1, characterized in that The permanent magnet assembly includes at least one pole pair.

13. The motor according to claim 1, characterized in that The motor is manufactured in the form of a ring.

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