Permanent magnet motor

Abstract

The present application discloses a permanent magnet motor, which includes a housing, a stator, and a rotor. The stator includes a yoke, a plurality of first tooth portions, a plurality of second tooth portions, and a plurality of annular windings. The yoke is annular in shape, and the plurality of first tooth portions are mounted on the inner diameter surface of the yoke along the circumferential direction of the yoke and fixed to the housing; the plurality of second tooth portions are mounted on the outer diameter surface of the yoke along the circumferential direction of the yoke; each annular winding is sleeved on the yoke. The rotor includes a shaft assembly, a plurality of permanent magnets, a first sheath, and a second sheath. The rotor is rotatably connected to the housing, an annular groove is formed in the shaft assembly, and the plurality of permanent magnets are distributed in the annular groove along the circumferential direction of the shaft assembly; the first sheath is wound around the plurality of permanent magnets, and the second sheath is sleeved on the first sheath. Through the above arrangement, the stator is split into three parts, and the first sheath and the second sheath are used to wrap the permanent magnets, so as to improve the structural strength of the permanent magnet motor and reduce the loss of the permanent magnet motor during operation.

Description

Technical Field

[0001] The present application relates to the technical field of motors, and in particular to a permanent magnet motor. Background Art

[0002] Existing permanent magnet motors include a stator and a rotor. The stator includes a yoke, stator teeth, and a coil winding. For high-power density high-speed permanent magnet motors (i.e., permanent magnet motors with a rotational speed greater than or equal to 100,000 rpm and a power density greater than or equal to 15 kw / kg), the existing structure where the yoke is connected to the stator teeth makes the length of the coil winding sleeved on the yoke longer. Since the length of the permanent magnet needs to be adapted to the length of the coil winding, the length of the permanent magnet is longer, which leads to a longer length of the rotor carrying the permanent magnet, resulting in an increase in the overall length of the permanent magnet motor, and further reducing the structural strength of the permanent magnet motor. Secondly, in high-power density high-speed permanent magnet motors, there are multiple permanent magnets arranged on the rotor surface, and no reinforcement structure is provided for the permanent magnets. Therefore, during the rotation of the rotor, the permanent magnets are likely to separate from the rotor under the action of centrifugal force, further reducing the structural strength of the permanent magnet motor.

[0003] In addition, the materials used for the stator of existing permanent magnet motors are conventional and single, resulting in problems such as low magnetic permeability, high coercive force, low resistivity, and high energy loss during the operation of the permanent magnet motor, thereby affecting the efficiency and working stability of the permanent magnet motor, and further increasing the losses of the permanent magnet motor.

[0004] Therefore, how to improve the structural strength of the permanent magnet motor and reduce the losses of the permanent magnet motor is a technical problem that needs to be urgently solved by those skilled in the art. Summary of the Invention

[0005] In order to solve the deficiencies of the prior art, the purpose of the present application is to provide a permanent magnet motor that can improve the structural strength and reduce the losses.

[0006] To achieve the above purpose, the present application adopts the following technical solutions:

[0007] A permanent magnet motor, which includes a housing, a stator, and a rotor. The stator includes a yoke, a plurality of first tooth portions, a plurality of second tooth portions, and a plurality of winding groups. The yoke is made of a first material and is in a ring shape; the first tooth portions are made of the first material, and a plurality of first tooth portions are installed on the inner diameter surface of the yoke along the circumferential direction of the yoke and are fixed to the housing; the second tooth portions are made of a second material, and a plurality of second tooth portions are installed on the outer diameter surface of the yoke along the circumferential direction of the yoke, and each second tooth portion corresponds to a first tooth portion along the radial direction of the yoke, so that each second tooth portion and the corresponding first tooth portion cooperate to form a stator tooth portion; each annular winding is sleeved on the yoke, and an annular winding is arranged between two adjacent stator tooth portions. The rotor includes a rotating shaft assembly, a plurality of permanent magnets, a first sheath, and a second sheath. The rotor is surrounded by a plurality of first tooth portions, and the rotor is rotatably connected to the housing so that the rotor can rotate relative to the stator. An annular groove is formed in the rotating shaft assembly, and the opening of the annular groove is located on the outer surface of the rotating shaft assembly; a plurality of permanent magnets are in a fan-shaped ring shape, and a plurality of permanent magnets are distributed in the annular groove along the circumferential direction of the rotating shaft assembly; the first sheath is wound around a plurality of permanent magnets, and the first sheath is made of amorphous alloy; the second sheath is sleeved on the first sheath and is in interference fit with the first sheath.

[0008] Further, the second sheath is made of carbon fiber material.

[0009] Further, the rotating shaft assembly includes a first rotating shaft and a second rotating shaft. An installation groove is formed in the first rotating shaft, and an annular groove is formed in the first rotating shaft, and the opening of the annular groove is located on the outer surface of the first rotating shaft; at least a part of the second rotating shaft is located in the installation groove and is fixed to the installation groove.

[0010] Further, the length of the annular groove along the axial direction of the first rotating shaft is the same as that of the permanent magnet; the lengths of the first sheath and the second sheath along the axial direction of the first rotating shaft are greater than the length of the annular groove along the axial direction of the first rotating shaft.

[0011] Further, a plurality of weight reduction grooves are formed in the second rotating shaft, and a plurality of weight reduction grooves are evenly distributed on the outer diameter surface of the second rotating shaft along the circumferential direction of the second rotating shaft, and the openings of the plurality of weight reduction grooves face the first rotating shaft.

[0012] Further, define the two ends of the first rotating shaft along its axial direction as a first section and a second section respectively, the length of the first section along the axial direction of the first rotating shaft is the same as that of the second section along the axial direction of the first rotating shaft; the volume of the first section is greater than the volume of the second section; or an extension piece for increasing the volume of the first section is arranged on the first section, and the extension piece is fixed to the first section or is integrally formed with the first section.

[0013] Further, the first material is amorphous alloy, and the second material is soft magnetic composite material.

[0014] Further, a first stator slot is formed between two adjacent first tooth portions, and a second stator slot is formed between two adjacent second tooth portions. Each first stator slot and a second stator slot cooperate to form a winding slot for accommodating an annular winding. One end of the second tooth portion away from the yoke is the slot opening end, and both sides of the slot opening end along the circumferential direction of the yoke extend along the circumferential direction of the yoke, so that the second tooth portion has a "T" - shaped structure.

[0015] Further, both the first tooth portion and the second tooth portion extend along the radial direction of the yoke. A first protrusion structure is formed on the surface of each first tooth portion close to the yoke. A plurality of first groove structures and a plurality of second protrusion structures are respectively arranged at both ends of the yoke along its radial direction. A second groove structure is formed on the surface of each second tooth portion close to the yoke. Each first protrusion structure is clamped and fixed with a first groove structure, and each second protrusion structure is clamped and fixed with a second groove structure.

[0016] Further, a plurality of cooling holes for cooling the yoke and / or the annular winding are formed on the yoke. Each cooling hole penetrates the yoke along the axial direction of the yoke; each cooling hole corresponds to a first tooth portion and a second tooth portion along the radial direction of the yoke.

[0017] By splitting the stator tooth portion into a first tooth portion and a second tooth portion and connecting them to the yoke, the axial length of the annular winding sleeved on the yoke can be reduced, thereby reducing the length of the permanent magnet, and further reducing the overall length of the permanent magnet motor to improve the structural strength of the permanent magnet motor. In addition, by wrapping the first sheath and the second sheath outside the permanent magnet, a pre - tightening force towards the axis of the rotating shaft assembly is applied to the permanent magnet, avoiding the permanent magnet being separated from the rotating shaft assembly under the influence of centrifugal force during rotation, so as to further improve the structural strength of the permanent magnet motor. At the same time, different materials are used for the first tooth portion, the yoke and the second tooth portion, which can also reduce the loss of the permanent magnet motor during operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is an exploded view of the permanent magnet motor provided by the embodiment of the present application.

[0019] Figure 2 It is a cross - sectional view of the rotor provided by the embodiment of the present application.

[0020] Figure 3 It is a structural diagram of the installation of the stator and the rotor provided by the embodiment of the present application.

[0021] Figure 4 It is a structural diagram of the stator provided by the embodiment of the present application.

[0022] Figure 5 It is an exploded view of the stator provided by the embodiment of the present application.

[0023] Figure 6The time-varying waveform diagram of the permanent magnet loss provided by the embodiment of the present application.

[0024] Figure 7 The force analysis diagram of the carbon fiber sheath in the motor without the amorphous alloy sheath.

[0025] Figure 8 The force analysis diagram of the carbon fiber sheath in the motor with the amorphous alloy sheath provided by the embodiment of the present application.

[0026] Figure 9 The Campbell diagram of the permanent magnet motor rotor modal analysis provided by the embodiment of the present application.

[0027] Figure 10 Another Campbell diagram of the permanent magnet motor rotor modal analysis provided by the embodiment of the present application.

[0028] Figure 11 The cross-sectional view of the rotor from another perspective provided by the embodiment of the present application. Detailed implementation manners

[0029] In order to enable those skilled in the art to better understand the solution of the present application, the technical solutions in the specific implementation manners of the present application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present application.

[0030] It should be noted that the "first", "second" and similar terms used in the specification and claims of the present application do not indicate any order, quantity or importance, but are only used to distinguish different components. Similarly, terms such as "a" or "one" do not indicate a quantity limitation, but mean that there is at least one. "Multiple" or "several" means at least two. Unless otherwise specified, terms such as "front", "rear", "left", "right", "lower" and / or "upper" are only for convenience of description and are not limited to one position or a spatial orientation. The terms "including" or "comprising" and similar terms are intended to cover the elements or items listed after the "including" or "comprising" and their equivalents, and do not exclude other elements or items. The terms "connected" or "coupled" and similar terms are not limited to physical or mechanical connections, and may include electrical connections, whether direct or indirect.

[0031] The singular forms of "a", "the" and "said" used in the specification and appended claims of the present application are also intended to include the plural forms unless the context clearly dictates otherwise. It should also be understood that the term "and / or" as used herein refers to and includes any and all possible combinations of one or more of the associated listed items.

[0032] Such as Figure 1, Figure 2 and Figure 3 As shown in Figure 2 and Figure 3 , the present application provides a permanent magnet motor 100, which includes a housing 11, a stator 12, and a rotor 13. The housing 11 is the basic framework of the permanent magnet motor 100 and is used to support the stator 12 and the rotor 13. The stator 12 is fixed within the housing 11 and is used to generate a rotating magnetic field. The rotor 13 is surrounded by the stator 12 and is rotatably connected to the housing 11 so that the rotor 13 can rotate relative to the stator 12, and the rotor 13 can cooperate with the rotating magnetic field to generate an electromagnetic torque.

[0033] To clearly illustrate the technical solution of the present application, the front, rear, left, right, up, and down as shown in Figure 1 are also defined to represent the front, rear, left, right, up, and down of the permanent magnet motor 100. Figure 1

[0034] Specifically, the stator 12 includes a yoke 121, a plurality of first tooth portions 122, a plurality of second tooth portions 123, and a plurality of annular windings 125. Among them, the yoke 121 is made of a first material and is in a ring shape. The first tooth portions 122 are made of the first material, and the plurality of first tooth portions 122 are installed on the inner diameter surface of the yoke 121 along the circumferential direction of the yoke 121 and are fixed to the housing 11. The second tooth portions 123 are made of a second material, and the plurality of second tooth portions 123 are installed on the outer diameter surface of the yoke 121 along the circumferential direction of the yoke 121.

[0035] Through the above arrangement, the yoke 121 is set to be in a ring shape, so that the first tooth portions 122 provided inside the yoke 121 do not occupy extra space, thereby reducing the occupied space of the stator 12, improving the compactness of the structure of the permanent magnet motor 100, and further enhancing the structural strength of the permanent magnet motor 100.

[0036] At the same time, the windings can form annular windings 125 on the annular body. The annular windings 125 do not need to be cross-wound at the winding ends, which is beneficial to reducing the length of the annular windings 125, reducing the length of the stator 12, thereby reducing the length of the permanent magnet motor 100, further reducing the space occupancy rate of the permanent magnet motor 100, enabling the power density per unit volume of the permanent magnet motor 100 to be increased, and improving the operating power of the motor.

[0037] In addition, using the annular windings 125 can reduce the total length of the windings, reduce the resistance and losses of the windings, thereby being adaptable to the permanent magnet motor 100 with a short axial length and a small number of poles, and further improving the adaptability of the annular windings 125. Moreover, the annular windings 125 can increase the filling rate of the windings in the iron core of the stator 12, thereby improving the compactness of the structure of the permanent magnet motor 100, further enhancing the power density of the permanent magnet motor 100, and improving the performance of the permanent magnet motor 100.

[0038] ​In the present application, the yoke portion 121 is split into a plurality of arc segments to facilitate the arrangement of the annular winding 125 on the yoke portion 121.

[0039] It should be noted that the present application does not limit the number and arc length of the arc segments into which the yoke portion 121 is split, and only needs to satisfy that the annular winding 125 can be arranged on the yoke portion 121.

[0040] Meanwhile, the outer diameter of the first tooth portion 122 is substantially the same as the inner diameter of the stator 12 yoke portion 121, and the inner diameter of the second tooth portion 123 is the same as the outer diameter of the stator 12 yoke portion 121, which can enable the stator tooth portion 124 and the yoke portion 121 to be in clearance fit, thereby facilitating the assembly of the stator tooth portion 124 and the stator 12 yoke portion 121. Moreover, it can also improve the connection tightness between the stator tooth portion 124 and the stator 12 yoke portion 121, thereby facilitating the improvement of the stability of the clearance fit between the stator tooth portion 124 and the stator 12 yoke portion 121, so as to improve the overall structural strength of the permanent magnet motor 100.

[0041] More specifically, each second tooth portion 123 corresponds to a first tooth portion 122 along the radial direction of the yoke portion 121, so that each second tooth portion 123 and the corresponding first tooth portion 122 cooperate to form a stator tooth portion 124. An annular winding 125 is arranged between two adjacent stator tooth portions 124, and each annular winding 125 is sleeved on the yoke portion 121. The annular winding 125 is used to cooperate with the stator tooth portion 124 and the yoke portion 121 to generate a rotating magnetic field.

[0042] Through the above arrangement, the stator 12 is split into the first tooth portion 122, the second tooth portion 123 and the yoke portion 121, which can reduce the length of the end portion of the annular winding 125 arranged on the stator 12, thereby reducing the length of the annular winding 125 in the axial direction. Since the length of the permanent magnet 132 in the axial direction needs to be adapted to the length of the annular winding 125 in the axial direction, the length of the permanent magnet 132 can also be reduced accordingly, so that the length of the rotating shaft assembly 131 carrying the permanent magnet 132 in the axial direction can also be reduced accordingly, and further the length of the permanent magnet motor 100 in the axial direction can be reduced, so as to improve the structural strength of the permanent magnet motor 100.

[0043] In addition, the annular winding 125 can be evenly wound on the stator 12, which can avoid the over-concentration of the local magnetic field on the stator 12, make the magnetic field distribution more uniform, and thus reduce the harmonic loss. At the same time, when the annular winding 125 is arranged on the stator 12 in the above manner, the magnetic leakage of the permanent magnet motor 100 during operation can also be reduced, thereby improving the energy transmission efficiency of the permanent magnet motor 100, further reducing the harmonic loss caused by magnetic leakage, and reducing the loss of the permanent magnet motor 100 during operation.

[0044] Exemplarily, in the present application, the annular winding 125 adopts a Litz wire structure, where multiple thin wires are stranded or braided into the wires in the annular winding 125. Through the Litz wire structure, the non-uniform current distribution caused by the skin effect and proximity effect under high-frequency conditions can be effectively reduced, thereby reducing the high-frequency loss of the annular winding 125. In addition, the annular winding 125 adopting the Litz wire structure can be more tightly filled into the winding slot 128, thereby increasing the induced magnetic field density and further increasing the power density when the annular winding 125 operates.

[0045] Meanwhile, the stranding of multiple thin wires to form the wires in the annular winding 125 can increase the contact area between the wires and the external environment, thereby improving the heat dissipation of the wires. When the permanent magnet motor 100 operates, the annular winding 125 can quickly transfer the generated heat to the outside, preventing the annular winding 125 from affecting the normal operation of the permanent magnet motor 100 due to overheating, and thus improving the service life and working stability of the annular winding 125. In addition, the above-described wire formation method can also make the current evenly distributed in each thin wire, thereby preventing the current from being too concentrated in a single wire and causing local overheating of the wire, so as to improve the performance of the annular winding 125 during operation.

[0046] It should be noted that in the present application, the structure of the annular winding 125 is not limited, and it only needs to meet the requirement of reducing the loss of the annular winding 125.

[0047] In this embodiment, the rotor 13 includes a rotating shaft assembly 131, a plurality of permanent magnets 132, a first sheath 133, and a second sheath 134. Among them, the rotor 13 is surrounded by a plurality of first tooth portions 122, and the rotor 13 is rotatably connected to the housing 11 so that the rotor 13 can rotate relative to the stator 12. An annular groove 1311b is formed in the rotating shaft assembly 131, and the opening of the annular groove 1311b is located on the outer surface of the rotating shaft assembly 131. The rotating shaft assembly 131 serves as the main frame of the rotor 13 and is used to support the permanent magnets 132, the first sheath 133, and the second sheath 134. The permanent magnets 132 are in the shape of a sector ring and are used to provide a constant magnetic field in the permanent magnet motor 100 so that the magnetic field can cooperate with the rotating magnetic field generated by the stator 12 to drive the rotating shaft assembly 131 to rotate. The plurality of permanent magnets 132 are circumferentially distributed in the annular groove 1311b along the rotating shaft assembly 131. The first sheath 133 is made of amorphous alloy and is wound around the plurality of permanent magnets 132, and the second sheath 134 is sleeved on the first sheath 133 and is in interference fit with the first sheath 133.

[0048] Through the above settings, the first sheath 133 and the second sheath 134 can provide a pre-tightening force on the permanent magnet 132 towards the axis of the rotating shaft assembly 131, which can prevent the permanent magnet 132 from detaching from the rotating shaft assembly 131 due to the action of centrifugal force during the rotation of the rotating shaft assembly 131, thereby facilitating the improvement of the connection stability between the permanent magnet 132 and the rotating shaft assembly 131, so as to improve the structural strength of the permanent magnet motor 100 during rotation.

[0049] Moreover, the amorphous alloy has a relatively high magnetic permeability. The first sheath 133 is made of amorphous alloy, which can enable the first sheath 133 surrounding the permanent magnet 132 to form a pole shoe layer, and further make the magnetic field distribution generated by the permanent magnet 132 more uniform, which is beneficial to improving the operating power of the permanent magnet motor 100. Secondly, the amorphous alloy material has the characteristics of high saturation magnetic induction intensity and low energy loss, so that the first sheath 133 can centrally bear the induced eddy current caused by the armature reaction in the permanent magnet motor 100, so as to prevent the permanent magnet 132 from bearing the induced eddy current and causing the temperature of the permanent magnet 132 to be too high, and further prevent the permanent magnet 132 from losing magnetism due to high temperature caused by the too high temperature of the permanent magnet 132, so as to improve the service life of the permanent magnet 132.

[0050] In addition, an annular winding 125 is arranged on the stator 12. Since the length of the end of the annular winding 125 is shorter than that of the end of the conventional winding, the length of the annular winding 125 in the axial direction in this application is shortened. The length of the permanent magnet 132 is adapted to the length of the annular winding 125, and then the length of the permanent magnet 132 is shortened, so that the lengths of the first sheath 133 and the second sheath 134 wrapping the permanent magnet 132 are correspondingly shortened. At the same time, the rotor 13 is arranged in the first tooth part 122, and the first tooth part 122 needs to completely cover the first sheath 133 and the second sheath 134. Therefore, the length of the first tooth part 122 in the axial direction will also be correspondingly shortened, and the lengths of the first tooth part 122, the yoke part 121 and the second tooth part 123 are adapted to each other, so that the length of the stator 12 in the axial direction is shortened, and then the length of the entire permanent magnet motor 100 in the axial direction is shortened, so as to improve the structural strength of the permanent magnet motor 100.

[0051] As Figure 6 shown, as an implementation manner, the time-varying waveform of the loss of the permanent magnet 132. Among them, the abscissa is the running time of the motor, and the ordinate is the loss of the permanent magnet 132. And, the time-varying waveform of the loss of the permanent magnet 132 with a pole shoe layer is as Figure 4 shown by the green line in; the time-varying waveform of the loss of the permanent magnet 132 without a pole shoe layer is as Figure 4 shown by the red line in. As Figure 4It can be seen that during the operation of the permanent magnet motor 100, the loss of the permanent magnet 132 provided with the pole shoe layer is maintained between 8 W and 9 W; while the loss of the permanent magnet 132 without the pole shoe layer is maintained between 11 W and 12 W. Therefore, the loss of the permanent magnet 132 in this application is reduced by about 26% compared to the permanent magnet 132 without the pole shoe layer. It can be understood that by providing a pole shoe layer on the permanent magnet 132, the loss can be effectively reduced, thereby reducing the loss of the permanent magnet motor 100 during operation.

[0052] In addition, during the energized operation of the permanent magnet motor 100, armature reaction will occur, resulting in magnetic field distortion in the permanent magnet motor 100, and then inducing eddy currents in the components within the permanent magnet motor 100, causing energy loss and heat generation in these components. Utilizing the characteristic that the amorphous alloy has a higher saturation magnetic induction intensity compared to the permanent magnet 132, the induced eddy currents formed due to the armature reaction in the permanent magnet motor 100 can be concentrated on the first sheath 133. Moreover, the amorphous alloy has lower energy loss compared to the permanent magnet 132, which can avoid excessive energy loss and heat generation of the induced eddy currents on the first sheath 133, thereby reducing the heat generated during the operation of the permanent magnet motor 100, and further reducing the heat dissipation pressure of the permanent magnet motor 100 to improve the operating power of the permanent magnet motor 100.

[0053] As an implementation manner, the second sheath 134 is made of carbon fiber material. With the above arrangement, the carbon fiber material has high structural strength. The second sheath 134 made of carbon fiber material wraps the first sheath 133 and the permanent magnet 132, and can apply a pre-tightening force towards the axis of the shaft assembly 131 to the first sheath 133 and the permanent magnet 132, so that the first sheath 133 and the permanent magnet 132 will not separate from the shaft assembly 131 during the rotation of the shaft assembly 131, which is beneficial to improving the overall structural strength of the rotor 13. Secondly, the carbon fiber material has the characteristics of being basically non-magnetic and non-conductive, which can avoid eddy current loss generated on the second sheath 134 due to conductivity and magnetism, and is thus beneficial to improving the operating performance of the permanent magnet motor 100.

[0054] Secondly, by providing the first sheath 133 between the second sheath 134 and the permanent magnet 132, the shear force generated by the rotation of the shaft assembly 131 borne by the second sheath 134 can be reduced, so as to avoid the second sheath 134 falling off or breaking due to excessive shear force borne by the second sheath 134, which is beneficial to improving the installation stability of the second sheath 134 on the shaft assembly 131, and further improving the structural strength of the permanent magnet motor 100.

[0055] In addition, a first sheath 133 made of amorphous alloy is wound around the outside of the rotor, and then a second sheath 134 made of carbon fiber is wound around the outside of the first sheath 133. This can avoid the problem of large eddy current losses during the operation of the permanent magnet motor 100 when a metal alloy protective sheath is used alone, thereby extending the service life of the permanent magnet motor 100. It can also avoid the problem of restricting the critical speed of the permanent magnet motor 100 when a carbon fiber protective sheath is used alone, because the carbon fiber is arranged outside the rotor 13 and has poor shear resistance. Therefore, by arranging the first sheath 133 made of amorphous alloy inside the second sheath 134 made of carbon fiber, the influence of the shear force on the second sheath 134 can be reduced, and the critical speed of the permanent magnet motor 100 can be increased; at the same time, the first sheath 133 made of amorphous alloy can also form a magnetic steel pole shoe outside the permanent magnet 132, short-circuiting the higher-order harmonic magnetic flux, thereby effectively reducing the magnetic steel loss and further improving the performance of the permanent magnet motor 100.

[0056] As Figure 7 and Figure 8 shown, as an implementation manner, the force analysis diagram of the carbon fiber sheath is calculated at the same motor speed. Among them, Figure 5 is the force analysis diagram of the carbon fiber sheath in the permanent magnet motor 100 without the amorphous alloy sheath, Figure 6 is the force analysis diagram of the carbon fiber sheath of the permanent magnet motor 100 with the amorphous alloy sheath. It can be seen that the shear stress (the maximum value is 101.27 MPa) borne by the second sheath 134 of the permanent magnet motor 100 of the present application is less than the shear stress (106.82 MPa) borne by the carbon fiber sheath in the permanent magnet motor 100 without the amorphous alloy sheath. Moreover, the range where the shear stress borne by the second sheath 134 of the permanent magnet motor 100 of the present application is greater than 100 MPa is smaller than the range where the shear stress borne by the carbon fiber sheath in the motor without the amorphous alloy sheath is greater than 100 MPa.

[0057] Through the above settings, the shear stress borne by the second sheath 134 of the permanent magnet motor 100 of the present application is less than the shear stress borne by the carbon fiber sheath in the motor without the amorphous alloy sheath, so that the second sheath 134 in the permanent magnet motor 100 of the present application can withstand a higher motor speed, which is beneficial to increasing the critical speed of the permanent magnet motor 100 to improve the operating performance of the permanent magnet motor 100.

[0058] In addition, through the settings of the first sheath 133 and the second sheath 134, the air gap thickness in the permanent magnet motor 100 can be reduced, thereby weakening the air gap magnetic field in the permanent magnet motor 100, further reducing the air gap harmonics generated by the air gap magnetic field, which is beneficial to reducing the energy loss caused by the air gap harmonics and further improving the operating performance of the permanent magnet motor 100.

[0059] AsFigure 9 and Figure 10 As shown, the relationship between the rotational speed and frequency of the permanent magnet motor 100 in different modes. Among them, Figure 7 This is the Campbell diagram for the rotor modal analysis of the permanent magnet motor 100 in this application, Figure 7 The position of the red triangle in it is the critical speed of the permanent magnet motor 100 in this application, with a value of 44878 rpm; Figure 8 This is the Campbell diagram for the rotor modal analysis of a general permanent magnet motor 100, Figure 8 The position of the red triangle in it is the critical speed of the permanent magnet motor 100 in this application, with a value of 25269 rpm. Therefore, the critical speed of the permanent magnet motor 100 in this application is significantly increased compared to the general permanent magnet motor 100, thereby improving the operating performance of the permanent magnet motor 100.

[0060] As Figure 2 and Figure 11 shown, as an implementation manner, the rotating shaft assembly 131 includes a first rotating shaft 1311 and a second rotating shaft 1312. An installation groove 1311a is formed in the first rotating shaft 1311, and an annular groove 1311b is formed on the first rotating shaft 1311. The opening of the annular groove 1311b is located on the outer surface of the first rotating shaft 1311. The second rotating shaft 1312 is at least partially located in the installation groove 1311a and is fixed to the installation groove 1311a. Through the above settings, forming the installation groove 1311a can reduce the mass of the first rotating shaft 1311, thereby reducing the overall moment of inertia of the rotor 13, and further increasing the critical speed of the permanent magnet motor 100. Secondly, fixing the second rotating shaft 1312 in the installation groove 1311a can improve the structural strength of the first rotating shaft 1311, thereby further improving the overall structural strength of the permanent magnet motor 100.

[0061] At the same time, in this application, the second rotating shaft 1312 is a hollow shaft, so as to be able to reduce the weight of the second rotating shaft 1312, so that under the premise of meeting the strength requirements, the overall weight of the rotor 13 can be reduced, and further the overall moment of inertia of the rotor 13 can be reduced, so that the critical speed of the permanent magnet motor 100 is further increased to improve the working efficiency of the permanent magnet motor 100.

[0062] It should be noted that this application does not limit the structure of the second rotating shaft 1312, and only needs to meet the requirement of reducing the weight of the second rotating shaft 1312.

[0063] As an implementation manner, the length of the annular groove 1311b along the axial direction of the first rotating shaft 1311 is the same as that of the permanent magnet 132. Through the above arrangement, it is possible to avoid the situation that the permanent magnet 132 deflects left and right in the annular groove 1311b during the rotation of the rotor 13, thereby improving the tightness of the installation of the permanent magnet 132 in the annular groove 1311b, and further improving the structural strength of the permanent magnet 132 installed on the first rotating shaft 1311.

[0064] As an implementation manner, the length of the annular groove 1311b along the axial direction of the first rotating shaft 1311 is the same as that of the permanent magnet 132; the lengths of the first sheath 133 and the second sheath 134 along the axial direction of the first rotating shaft 1311 are greater than the length of the annular groove 1311b along the axial direction of the first rotating shaft 1311. Through the above arrangement, the first sheath 133 and the second sheath 134 can completely cover the permanent magnet 132, so as to prevent the permanent magnet 132 from being exposed in the air gap and causing the permanent magnet 132 to demagnetize due to the magnetic field distortion in the air gap, thereby being beneficial to improving the service life of the permanent magnet 132. At the same time, the first sheath 133 and the second sheath 134 can completely wrap the permanent magnet 132, so that the permanent magnet 132 is in close contact with the first rotating shaft 1311, thereby preventing the permanent magnet 132 from separating from the first rotating shaft 1311 during the rotation of the rotating shaft assembly 131, so as to improve the structural strength of the permanent magnet motor 100.

[0065] As an implementation manner, the second rotating shaft 1312 is provided with a plurality of weight-reducing grooves 1312a, and the plurality of weight-reducing grooves 1312a are uniformly distributed on the outer diameter surface of the second rotating shaft 1312 along the circumferential direction of the second rotating shaft 1312, and the openings of the plurality of weight-reducing grooves 1312a face the first rotating shaft 1311.

[0066] Through the above arrangement, the weight-reducing grooves 1312a can further reduce the weight of the second rotating shaft 1312, thereby further reducing the overall moment of inertia of the rotor 13. And the setting of the weight-reducing grooves 1312a can reduce the weight of the second rotating shaft 1312 on the premise of meeting the strength requirements of the second rotating shaft 1312, so that the overall rotor 13 can reduce the overall moment of inertia of the rotor 13 on the premise of meeting the strength requirements, which is beneficial to improving the power density of the permanent magnet motor 100 and reducing the loss during operation.

[0067] In the present application, the weight-reducing groove 1312a can be a honeycomb groove structure, so that the second rotating shaft 1312 reduces its own weight while taking into account the stiffness, thereby improving the critical speed of the permanent magnet motor 100 and enhancing the power density of the permanent magnet motor 100.

[0068] It should be noted that in the present application, the structure of the weight-reducing groove 1312a is not limited, and it only needs to meet the requirement of reducing the weight of the second rotating shaft 1312 while maintaining the stiffness of the second rotating shaft 1312.

[0069] As an implementation manner, define the two ends of the first rotating shaft 1311 along its axial direction as a first section 1311c and a second section 1311d respectively. The length of the first section 1311c along the axial direction of the first rotating shaft 1311 is the same as that of the second section 1311d along the axial direction of the first rotating shaft 1311; the volume of the first section 1311c is larger than that of the second section 1311d; or an extension member for increasing the volume of the first section 1311c is provided on the first section 1311c, and the extension member is fixed to the first section 1311c or integrally formed with the first section 1311c.

[0070] Through the above settings, the volume on the first rotating shaft 1311 can be increased. The volume difference between the first section 1311c and the second section 1311d can change the air gap thickness at the first section 1311c and the second section 1311d in the permanent magnet motor 100, and further change the flow diameter of the air in the air gap. Therefore, when the rotor 13 rotates to drive the air flow in the air gap, the air flow rate in the air gap will be reduced due to the limitation of the change in the air gap flow diameter, resulting in a low vacuum state in the air gap. Furthermore, the contact amount between the rotor 13 and the air in the air gap can be reduced, so as to reduce the wear caused by the contact between the rotor 13 and the air during rotation, and reduce the noise caused by the contact between the rotor 13 and the air during rotation. Subsequently, it is beneficial to improve the service life of the rotor 13 and reduce the operating noise of the permanent magnet motor 100.

[0071] As an implementation manner, the first material is an amorphous alloy and the second material is a soft magnetic composite material. Through the above settings, using the amorphous alloy as the manufacturing material for the yoke portion 121 and the first tooth portion 122 can reduce iron loss and increase magnetic permeability. Using the soft magnetic composite material as the manufacturing material for the second tooth portion 123, according to the characteristic of the soft magnetic composite material having a high resistivity, the eddy current loss around the toroidal winding 125 can be reduced. At the same time, the soft magnetic composite material can also be pressed into the second tooth portion 123 with different shapes to meet the structural requirements of the second tooth portion 123 in different permanent magnet motors 100, facilitating the wiring arrangement of different toroidal windings 125, thereby improving the operating efficiency of the permanent magnet motor 100 and reducing the loss during operation.

[0072] Secondly, there are still problems with the pure amorphous iron core such as being brittle in performance, having low tensile strength and poor thermal conductivity. Therefore, the yoke portion 121 and the first tooth portion 122 are made of amorphous alloy, and the second tooth portion 123 is made of soft magnetic composite material. Utilizing the characteristic of the amorphous alloy with low loss can reduce the iron loss and eddy current loss during the operation of the stator 12, thereby reducing the loss of the permanent magnet motor 100 during operation. At the same time, utilizing the characteristics of the high magnetic permeability and mechanical strength of the soft magnetic composite material, the second tooth portion 123 can optimize the air gap magnetic field distribution, thereby improving the anti-mechanical stress ability of the stator 12, enhancing the structural strength of the stator 12, and further enhancing the structural strength of the permanent magnet motor 100.

[0073] In addition, using amorphous materials and soft magnetic composite materials to make different components of the stator 12 can avoid the problem that the losses of the permanent magnet motor 100 increase with the increase of the rotational speed of the permanent magnet motor 100 when only silicon steel is used as the material to make the stator 12; it can also avoid the problem that the stator 12 is damaged due to centrifugal force and vibration during high-speed operation when only amorphous materials are used as the material to make the stator 12, thereby improving the structural strength of the permanent magnet motor 100. Moreover, the amorphous material has the problem of relatively low magnetic saturation intensity (that is, the magnetic saturation intensity of the amorphous material is greater than or equal to 1.2T and less than or equal to 1.5T). Using amorphous materials and soft magnetic composite materials to make different components of the stator 12 can also reduce the design limitations on the high magnetic flux density of the permanent magnet motor 100, thereby improving the performance of the permanent magnet motor 100.

[0074] As Figure 4 and Figure 5 shown, as an implementation manner, a first stator slot 126 is formed between two adjacent first tooth portions 122, and a second stator slot 127 is formed between two adjacent second tooth portions 123. Each first stator slot 126 and a second stator slot 127 cooperate to form a winding slot 128 for accommodating an annular winding 125. One end of the second tooth portion 123 away from the yoke portion 121 is a slot opening end 1231. Both sides of the slot opening end 1231 along the circumferential direction of the yoke portion 121 extend along the circumferential direction of the yoke portion 121, so that the second tooth portion 123 has a "T" - shaped structure. Through the above setting, the second tooth portion 123 is set to have a "T" - shaped structure, which can increase the contact area with the housing 11, thereby facilitating the excess heat in the permanent magnet motor 100 to be conducted to the outside through the housing 11; it is also beneficial to improve the firmness when the second tooth portion 123 is installed with the housing 11. At the same time, when the second tooth portion 123 has a "T" - shaped structure, it can also prevent the annular winding 125 disposed in the second stator slot 127 from directly contacting the housing 11, thereby avoiding excessive wear of the annular winding 125 and prolonging the service life of the annular winding 125.

[0075] As an implementation manner, both the first tooth portion 122 and the second tooth portion 123 extend along the radial direction of the yoke portion 121. A first convex structure 1221 is formed on the surface of each first tooth portion 122 close to the yoke portion 121. A plurality of first groove structures 1211 and a plurality of second convex structures 1212 are respectively disposed at both ends of the yoke portion 121 along its radial direction. A second groove structure 1232 is formed on the surface of each second tooth portion 123 close to the yoke portion 121. Each first convex structure 1221 is clamped and fixed with a first groove structure 1211, and each second convex structure 1212 is clamped and fixed with a second groove structure 1232.

[0076] Through the above settings, it is convenient for the first tooth part 122 and the second tooth part 123 to be clamped and positioned with the yoke part 121, thereby improving the convenience of connection between the first tooth part 122, the second tooth part 123 and the yoke part 121. At the same time, it can also increase the contact area when the first tooth part 122 and the second tooth part 123 are connected to the yoke part 121, thereby improving the fastening property when the first tooth part 122 and the second tooth part 123 are connected to the yoke part 121, so as to improve the structural strength of the permanent magnet motor 100.

[0077] As an implementation manner, a plurality of cooling holes 1213 for cooling the yoke part 121 and / or the annular winding 125 are formed in the yoke part 121, and each cooling hole 1213 penetrates through the yoke part 121 along the axial direction of the yoke part 121; each cooling hole 1213 corresponds to a first tooth part 122 and a second tooth part 123 in the radial direction of the yoke part 121. Through the above settings, after heat is generated inside the permanent magnet motor 100 during operation, the excess heat in the permanent magnet motor 100 can be transmitted to the outside through the cooling holes 1213, thereby maintaining the temperature stability of the permanent magnet motor 100 during operation, and further extending the service life of the permanent magnet motor 100.

[0078] It should be understood that for those of ordinary skill in the art, improvements or transformations can be made according to the above description, and all such improvements and transformations should fall within the protection scope of the appended claims of this application.

Claims

1. A permanent magnet motor, characterized in that: include: case; A stator, the stator comprising: A yoke, wherein the yoke is made of a first material and is in a ring shape; A plurality of first teeth, wherein the first teeth are made of the first material, and the plurality of first teeth are installed on the inner diameter surface of the yoke along the circumference of the yoke and fixed to the housing; a plurality of second tooth portions, wherein the second tooth portions are made of a second material, and the plurality of second tooth portions are mounted on the outer diameter surface of the yoke portion along the circumferential direction of the yoke portion, and each second tooth portion corresponds to one first tooth portion along the radial direction of the yoke portion, so that each second tooth portion cooperates with a corresponding first tooth portion to form a stator tooth portion; A plurality of annular windings, each of which is sleeved on the yoke, and one annular winding is arranged between two adjacent stator teeth; A rotor, the rotor being surrounded by a plurality of the first teeth, the rotor being rotatably connected to the housing so that the rotor can rotate relative to the stator, the rotor comprising: A shaft assembly, wherein an annular groove is formed on the shaft assembly, and an opening of the annular groove is located on an outer surface of the shaft assembly; A plurality of permanent magnets, wherein the plurality of permanent magnets are in a fan-shaped ring shape and are distributed in the annular groove along the circumference of the rotating shaft assembly; a first sheath, wherein the first sheath is wound around the plurality of permanent magnets, and the first sheath is made of an amorphous alloy; A second sheath is sleeved on the first sheath and is interference fit with the first sheath.

2. The permanent magnet motor according to claim 1, characterized in that: The second sheath is made of carbon fiber material.

3. The permanent magnet motor according to claim 1, characterized in that: The rotating shaft assembly comprises: A first rotating shaft, wherein a mounting groove is formed in the first rotating shaft, and the first rotating shaft is provided with the annular groove, and an opening of the annular groove is located on an outer surface of the first rotating shaft; A second rotating shaft, wherein the second rotating shaft is at least partially located in the mounting groove and fixed to the mounting groove.

4. The permanent magnet motor according to claim 3, characterized in that: The annular groove is consistent with the length of the permanent magnet along the axial direction of the first rotating shaft; The lengths of the first sleeve and the second sleeve along the axial direction of the first rotating shaft are greater than the length of the annular groove along the axial direction of the first rotating shaft.

5. The permanent magnet motor according to claim 4, characterized in that: The second rotating shaft is provided with a plurality of weight-reducing grooves, which are evenly distributed on the outer diameter surface of the second rotating shaft along the circumference of the second rotating shaft, and the openings of the plurality of weight-reducing grooves face the first rotating shaft.

6. The permanent magnet motor according to claim 4, characterized in that: The first rotating shaft is defined as having two ends along its axial direction as a first section and a second section respectively, the length of the first section along the axial direction of the first rotating shaft is consistent with the length of the second section along the axial direction of the first rotating shaft; the volume of the first section is greater than the volume of the second section; Or the first section is provided with an extension piece for increasing the volume of the first section, and the extension piece is fixed on the first section or is integrally formed with the first section.

7. The permanent magnet motor according to claim 1, characterized in that: The first material is an amorphous alloy, and the second material is a soft magnetic composite material.

8. The permanent magnet motor according to claim 7, characterized in that: A first stator slot is formed between two adjacent first tooth portions, a second stator slot is formed between two adjacent second tooth portions, and each of the first stator slots and one of the second stator slots cooperate to form a winding slot for accommodating one of the annular windings; One end of the second tooth portion away from the yoke portion is a notch end, and both sides of the notch end along the circumference of the yoke portion extend along the circumference of the yoke portion, so that the second tooth portion presents a "T"-shaped structure.

9. The permanent magnet motor according to claim 1, characterized in that: Both the first tooth portion and the second tooth portion extend radially along the yoke portion, a first protrusion structure is formed on the surface of each first tooth portion close to the yoke portion, a plurality of first groove structures and a plurality of second protrusion structures are respectively provided at both ends of the yoke portion along the radial direction, a second groove structure is formed on the surface of each second tooth portion close to the yoke portion, each first protrusion structure is clamped and fixed to one of the first groove structures, and each second protrusion structure is clamped and fixed to one of the second groove structures.

10. The permanent magnet motor according to claim 1, characterized in that: The yoke is provided with a plurality of cooling holes for cooling the yoke and / or the annular winding, and each cooling hole is arranged through the yoke along the axial direction of the yoke; Each of the cooling holes corresponds to one of the first teeth and one of the second teeth along the radial direction of the yoke.

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