Tandem type axial magnetic flux motor for new energy automobile power assembly

Abstract

The invention discloses a series axial magnetic flux motor for a new energy automobile power assembly, which comprises a casing, two spindles are symmetrically mounted at two ends in the casing, one ends of the two spindles are connected with the casing, and the other ends of the two spindles respectively extend out of two axial ends of the casing. The two main shafts are both provided with axial magnetic flux assemblies, the two axial magnetic flux assemblies are symmetrically arranged, each axial magnetic flux assembly comprises a rotor assembly connected with the corresponding main shaft, a first stator iron core and a second stator iron core, the first stator iron core and the second stator iron core are located on the two axial sides of the rotor assembly respectively, and the first stator iron core and the second stator iron core are of an asymmetric structure; wherein a winding is wound on the first stator iron core, and the second stator iron core is a first yoke iron core or a first magnetic steel assembly. The problem that a speed reducer and a differential mechanism need to be used for power transmission of existing automobile double motors can be solved, and the problem that axial force borne by a rotor in an existing asymmetric axial magnetic flux motor is large can also be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of axial flux motors, and in particular to the design and implementation of a dual-output axial flux motor, and more specifically to a series axial flux motor for a new energy vehicle powertrain. Background Art

[0002] At present, the powertrain transmission system of new energy vehicles is mainly composed of electric motors, speed reducers, differentials and other components. In order to simplify the structure and remove the differential, two motors are generally used to drive independently, and differential steering is achieved by controlling the speed difference between the two. However, due to the limitation of the torque density of permanent magnet synchronous motors or asynchronous motors, the existing powertrain transmission system with independent control of dual motors still needs to use a speed reducer. Therefore, how to remove the speed reducer and differential and realize the powertrain transmission system directly driven by the motor is also a problem that needs to be solved in the field of new energy vehicles.

[0003] Axial flux motors have been valued in new energy vehicle applications in recent years due to their small size, light weight, and high power density. Usually, there are three structures of axial flux motors. The first structure is a rotor in the middle and stators on both sides, such as Chinese patents CN109217597A, CN109104059A, and CN109194082A. This layout structure is adopted; the second structure is a stator in the middle and rotors on both sides, such as Chinese patents CN208623519U and CN109660097A. The third structure is a stator on one side and a rotor on the other side, that is, a single stator and single rotor structure arranged axially, such as Chinese patents CN107408875B and CN109274240A. For axial flux motors with one end cover as the mounting surface, the first and second structures are symmetrical balanced electromagnetic structures, with small rotor axial force and small mechanical friction resistance, which is conducive to improving the motor output torque. However, since there are windings on both sides, the three-phase windings must be led out from the motor housing, which will occupy the radial space of the motor housing, which is not conducive to fully exerting the role of the outer ring of the core to generate greater torque, and reduces the electromagnetic torque of the motor. The third structure is an asymmetric electromagnetic structure. The three-phase winding can be led out from the inner ring of the end cover on one side, which will not occupy the radial space of the motor housing. The other side is used for motor installation. Although it simplifies the installation and improves the electromagnetic torque density of the motor, because the rotor is subjected to axial force on one side, the rotor is subjected to relatively large axial force, which will cause greater mechanical friction resistance, reduce the effective output torque and operating efficiency of the motor, and is not conducive to its application in new energy vehicles, which have relatively high requirements for endurance.

[0004] Therefore, how to give full play to the advantages of axial flux motors, overcome their disadvantages, and realize high-efficiency and high-torque-density axial flux motor direct drive as the power of new energy vehicles is a technical problem that needs to be solved urgently in this field. Summary of the invention

[0005] The present invention provides a series axial flux motor for a new energy vehicle powertrain, which can solve the problem that a reducer and a differential are needed in the existing dual-motor power transmission of an automobile, and can also solve the problem that the axial force on the rotor in the existing asymmetric axial flux motor is relatively large.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a series axial flux motor for a new energy vehicle powertrain, comprising a casing, wherein two main shafts are symmetrically installed at both ends of the casing, one end of the two main shafts is connected to the casing, and the other ends of the two main shafts extend from the axial ends of the casing respectively, and axial flux components are installed on the two main shafts and the two axial flux components are symmetrically arranged, the axial flux component comprises a rotor component connected to the main shaft, a first stator core and a second stator core respectively located on both axial sides of the rotor component, the first stator core and the second stator core are asymmetric structures, wherein the first stator core is wound with a winding, and the second stator core is a first yoke core or a first magnetic steel component, and by arranging two main shafts and axial flux components, a motor with dual-axis independent power output is realized, and compared with a traditional motor with two independent output shafts, the number of stators and windings required is less, the output power and speed control are accurate, and flexible control of the vehicle can be achieved without a reducer and a differential. At the same time, by designing the first stator core and the second stator core as an asymmetric structure, the axial force of the stator cores on both sides on the rotor assembly is balanced, which is beneficial to reduce the mechanical wear of the bearing, extend the bearing life, and improve the motor operation efficiency and output torque.

[0007] Preferably, the first stator core is installed near the middle of the casing, and the rotor assembly and the second stator core are installed near the end of the casing.

[0008] Preferably, the first stator core is installed near an end of the casing, and the rotor assembly and the second stator core are installed near a middle of the casing.

[0009] Preferably, the first stator core includes a second yoke core and a tooth core arranged on the second yoke core, and the winding is wound on the tooth core. By setting the tooth core, the radial space of the casing can be utilized as much as possible to set the winding, thereby improving the electromagnetic torque.

[0010] Preferably, the rotor assembly includes a fixed disk located in the middle and a second magnetic steel assembly installed on the side of the fixed disk facing the first stator core. When the second stator core is the first yoke core, the first magnetic steel assembly is installed on the other side of the fixed disk. When the second stator core is the first magnetic steel assembly, the first yoke core is installed on the other side of the fixed disk. The positions of the first yoke core and the first magnetic steel assembly can be flexibly replaced, making the structural setting of the rotor assembly more flexible.

[0011] Preferably, the winding adopts a flat copper wire winding, which can greatly improve the slot filling rate, and is beneficial to reducing the size of the motor and improving the torque density of the motor.

[0012] Preferably, the winding adopts a winding structure with a first pitch y of , a second pitch y of , and a combined pitch y of , which is beneficial to reducing the length of the winding end, reducing the motor manufacturing cost, reducing the winding resistance, and improving the motor operating efficiency.

[0013] Preferably, the lead wires of the winding are led out from the axial end of the casing, which facilitates the wiring of the motor and does not occupy the radial space of the casing to set the wiring terminal.

[0014] Preferably, the casing comprises an outer shell and end covers arranged at both axial ends of the outer shell, and the end covers are provided with threading holes for the lead wires to pass through, which facilitates the installation and maintenance of internal components of the casing and also facilitates the lead wires of the windings to be led out.

[0015] Preferably, a support wall is centrally disposed inside the housing, and the main shaft is connected to the support wall and the end cover via a bearing, which can effectively and stably support the two main shafts so that the main shafts can rotate flexibly.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] (1) The overall volume is small, the installation is flexible, it has an axial flux component, and the internal structure is compact. The axial flux component can be used to drive the main shaft for output. Compared with the radial flux motor, the torque density is higher. It can realize the direct drive of the power of new energy vehicles without the need for a reducer. It is also smaller in size and has good economic benefits.

[0018] (2) With two symmetrically arranged axial flux components and main shafts, the motor has two independent output shafts and independent magnetic fields on both sides. Compared with the traditional motor with two independent output shafts, it requires fewer stators and windings. The speed of the two independent motor output shafts can be controlled separately, which improves the flexibility and controllability of the motor. When realizing functions such as automobile steering, the differential can be optimized in the transmission system;

[0019] (3) By designing the first stator core and the second stator core as an asymmetric structure, the axial force of the stator cores on both sides on the rotor assembly is balanced, which is beneficial to reducing the mechanical wear of the bearing, extending the bearing life, and improving the motor operation efficiency and output torque; compared with the symmetrical structure of the stator core, the asymmetric structure has only one set of three-phase windings, which can be directly led out from one side of the end cover and installed and fixed on the other side. The structure is simpler, easy to install and connect, and the internal space of the core is fully utilized to give full play to the advantage of the outer ring generating a large torque;

[0020] (4) The winding adopts flat copper wire, which greatly improves the slot fill rate. It is beneficial to reduce the size of the motor and improve the torque density of the motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a front view cross-sectional structural diagram of a first embodiment of the overall layout of the present invention;

[0022] Figure 2 It is a front cross-sectional structural diagram of a second embodiment of the overall layout of the present invention;

[0023] Figure 3 It is a perspective view of an exploded state of a first embodiment of an axial flux assembly of the present invention;

[0024] Figure 4 It is a perspective view of an exploded state of a second embodiment of the axial flux assembly of the present invention;

[0025] Figure 5 It is a schematic diagram of the winding method of the winding of the present invention.

[0026] Reference numerals:

[0027] 1. First stator core, 11. Casing, 14. First magnetic steel assembly, 15. First yoke core, 16. Tooth core, 17. Second yoke core, 2. Winding, 3. Second magnetic steel assembly, 4. Threading hole, 5. Fixed plate, 6. Second stator core, 7. Bearing, 8. Main shaft, 9. End cover, 10. Casing, A. Axial magnetic flux assembly; B. Rotor assembly. DETAILED DESCRIPTION

[0028] The technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention.

[0029] like Figure 1-5As shown, the present invention is to solve the problem that the existing dual-motor power transmission of automobiles requires a reducer and a differential, and also to solve the problem that the axial force on the rotor in the existing asymmetric axial flux motor is relatively large. The present invention provides the following technical solutions: A series axial flux motor for a new energy vehicle powertrain, comprising a casing 11, wherein two main shafts 8 are symmetrically installed at both ends of the casing 11, one end of the two main shafts 8 is connected to the casing 11, and the other ends of the two main shafts 8 extend from the axial ends of the casing 11 respectively, and an axial flux assembly A is installed on the two main shafts 8 and the two axial flux assemblies A are symmetrically arranged, and the axial flux assembly A includes a main shaft 8 and a main shaft 8. The rotor assembly B connected to the shaft 8, the first stator core 1 and the second stator core 6 respectively located on the axial sides of the rotor assembly B, the first stator core 1 and the second stator core 6 are asymmetric structures, wherein the first stator core 1 is wound with a winding 2, and the second stator core 6 is a first yoke core 15 or a first magnetic steel assembly 14. By setting two main shafts 8 and an axial flux assembly A, a motor with dual-axis independent power output is realized. Compared with a traditional motor with two independent output shafts, the number of stators and windings required is less, the output power and speed control are accurate, and the flexible control of the car can be achieved without a reducer and a differential. At the same time, by designing the first stator core 1 and the second stator core 6 as an asymmetric structure, the axial force of the stator cores on both sides on the rotor assembly B is balanced, which is conducive to reducing the mechanical wear of the bearing, extending the bearing life, and improving the motor operation efficiency and output torque.

[0030] Specifically, the axial magnetic flux components A are all controlled individually, and the internal magnetic field is also independent, so the output of each main shaft 8 can be accurately controlled. For example, two main shafts 8 are connected to two wheels through transmission shafts, so that the axial magnetic flux components A can be controlled to drive the main shafts 8 to output different speeds to achieve the steering of the vehicle. A support wall is centrally arranged inside the housing 11, and the main shaft 8 is connected to the support wall and the end cover 9 through the bearing 7.

[0031] During installation, the positions of the first stator core 1 and the second stator core 6 relative to the rotor assembly B can be swapped, such as Figure 1 As shown, as an embodiment of the first installation mode, the first stator core 1 is installed at a position close to the middle of the housing 11, and the rotor assembly B and the second stator core 6 are installed at a position close to the end of the housing 11. At this time, a threading hole 4 can be provided in the middle of the housing 11, and the lead wire of the winding 2 on the first stator core 1 can extend from the threading hole 4 in the middle of the housing 11 to the outer wall of the housing 11 and be led out, so that the radial space of the housing 11 is not actually occupied, because the threading hole 4 is provided on the supporting wall in the middle of the housing 11, and the internal space of the supporting wall is utilized, and the space utilization is reasonable.

[0032] The second installation method can also be used. Figure 2 As shown, the first stator core 1 is installed near the end of the housing 11, and the rotor assembly B and the second stator core 6 are installed near the middle of the housing 11. In order to better utilize the axial space of the housing 11, the lead wires of the winding 2 are led out from the axial end of the housing 11, which is convenient for the wiring of the motor and does not occupy the radial space of the housing 2 to set the wiring terminals. At the same time, in order to facilitate installation, the housing 11 includes an outer shell 10 and end covers 9 arranged at both axial ends of the outer shell 10. The end covers 9 are provided with threading holes 4 for the lead wires to pass through, which is convenient for the installation and maintenance of the internal components of the housing 11 and also convenient for the lead wires of the winding 2 to be led out. During installation, the first stator core 1 or the second stator core 6 can be fixed on the end cover 9, so that when the end cover 9 is disassembled, the first stator core 1 or the second stator core 6 can be disassembled together.

[0033] The first stator core 1, the second stator core 6 and the rotor assembly B are all closely arranged along the axial direction of the main shaft 8, so that the volume of the entire housing 11 is very small, which can greatly save installation space compared to the traditional radial flux motor, and the two axial flux assemblies A are installed in the same housing 11, and the structure is very compact. At the same time, the first stator core 1 and the winding 2 can generate a relatively large output torque on the rotor assembly B, which is more suitable for use as a power component of new energy vehicles.

[0034] When it is working, the first stator core 1 and the winding 2 apply a relatively large output torque to the rotor assembly B while also generating a relatively large axial thrust to the rotor assembly B. Therefore, after the rotor assembly B is connected to the main shaft 8, the main shaft 8 is also subjected to a relatively large axial force, which will cause a large mechanical friction resistance, reducing the effective output torque and operating efficiency of the motor. For example, a bearing 7 will be installed between the main shaft 8 and the housing 11. The axial force of the main shaft 8 acting on the bearing 7 will increase the burden on the bearing 7, reduce the life of the bearing, and increase mechanical loss.

[0035] Therefore, in this embodiment, the interaction force between the second stator core 6 and the rotor assembly B is used to balance the axial force of the first stator core 1 on the rotor assembly B. This can greatly reduce the unilateral axial force on the main shaft 8, reduce the mechanical wear of the bearings, extend the life of the bearings, and improve the operating efficiency and output torque of the motor.

[0036] In this embodiment, if Figure 3-4As shown, the first stator core 1 includes a second yoke core 17 and a tooth core 16 arranged on the second yoke core 17, the winding 2 is wound on the tooth core 16, the outer edge of the second yoke core 17 is as close to the inner wall of the housing 11 as possible, the tooth core 16 is composed of a plurality of teeth arranged around the center of the circle, and the winding 2 is wound on each tooth. By setting the tooth core 16, the radial space of the housing 11 can be used as much as possible to set the winding 2, thereby improving the electromagnetic torque.

[0037] As embodiment 1 of rotor assembly B:

[0038] like Figure 3 As shown, the rotor assembly B includes a fixed disk 10 located in the middle and a second magnetic steel assembly 3 installed on the side of the fixed disk 5 facing the first stator core 1. When the second stator core 6 is the first yoke core 15, the first magnetic steel assembly 14 is installed on the other side of the fixed disk 5. The second magnetic steel assembly 3 and the first magnetic steel assembly 14 here have the same structure, both of which are annular structures composed of fan-shaped magnetic steels around the circumference, and their areas match the fixed disk 5. The second magnetic steel assembly 3 and the first magnetic steel assembly 14 can both interact with the winding 2 to rotate the rotor assembly B, and the first magnetic steel assembly 14 simultaneously interacts with the first yoke core 15 to generate axial force, so that the rotor assembly B can be subjected to axial forces on both sides.

[0039] As embodiment 2 of rotor assembly B:

[0040] like Figure 4 As shown, when the second stator core 6 is the first magnetic steel component 14, the first yoke core 15 is installed on the other side of the fixed disk 5, and the positions of the first yoke core 15 and the first magnetic steel component 14 can be flexibly replaced, so that the structural setting of the rotor component B is more flexible. Compared with Example 1, the positions of the first yoke core 15 and the first magnetic steel component 14 are replaced, which can produce the same technical effect.

[0041] like Figure 5 As shown, the winding 2 adopts a flat copper wire winding, which can greatly improve the slot fill rate. It is beneficial to reduce the size of the motor and improve the torque density of the motor. At the same time, the winding 2 adopts a winding structure in which the first pitch y1 is 1, the second pitch y2 is 0, and the combined pitch y is 1. Figure 5 The figure shows the schematic diagram of the A-phase winding. Since the B and C phases are consistent with the A-phase winding, only the A-phase winding type is drawn. This winding structure is beneficial to reducing the length of the winding end, reducing the motor manufacturing cost, reducing the winding resistance, and improving the motor operating efficiency.

[0042] It should be noted that all directional indications in the embodiments of the present invention (such as up, down, left, right, front, back, etc.) are only used to explain the relative position relationship, movement status, etc. between the components under a certain specific posture (as shown in the accompanying drawings). If the specific posture changes, the directional indication will also change accordingly.

[0043] In addition, in the present invention, descriptions such as "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or implying their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" or "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0044] In the present invention, unless otherwise clearly specified and limited, the terms "connection", "fixation", etc. should be understood in a broad sense. For example, "fixation" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] 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 fact that ordinary technicians in the field can implement it. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such combination of technical solutions does not exist and is not within the scope of protection required by the present invention.

Claims

1. A series axial flux motor for a new energy vehicle powertrain, comprising a housing (11), characterized in that: Two main shafts (8) are symmetrically mounted at both ends of the casing (11), one end of the two main shafts (8) is connected to the casing (11), and the other ends of the two main shafts (8) extend from both axial ends of the casing (11), and an axial magnetic flux assembly (A) is mounted on each of the two main shafts (8), and the two axial magnetic flux assemblies (A) are symmetrically arranged, and the axial magnetic flux assembly (A) comprises a rotor assembly (B) connected to the main shaft (8), a first stator core (1) and a second stator core (6) respectively located on both axial sides of the rotor assembly (B), and the first stator core (1) and the second stator core (6) are asymmetric structures, wherein a winding (2) is wound around the first stator core (1), and the second stator core (6) is a first yoke core (15) or a first magnetic steel assembly (14).

2. The series axial flux motor for the new energy vehicle powertrain according to claim 1 is characterized in that: The first stator core (1) is installed near the middle of the casing (11), and the rotor assembly (B) and the second stator core (6) are installed near the end of the casing (11).

3. The series axial flux motor for the new energy vehicle powertrain according to claim 1 is characterized in that: The first stator core (1) is installed at a position close to the end of the casing (11), and the rotor assembly (B) and the second stator core (6) are installed at a position close to the middle of the casing (11).

4. The series axial flux motor for a new energy vehicle powertrain according to any one of claims 1 to 3, characterized in that: The first stator core (1) comprises a second yoke core (17) and a tooth core (16) arranged on the second yoke core (17), and the winding (2) is wound around the tooth core (16).

5. The series axial flux motor for the new energy vehicle powertrain according to claim 4 is characterized in that: The rotor assembly (B) comprises a fixed disk (5) located in the middle and a second magnetic steel assembly (3) installed on the side of the fixed disk (5) facing the first stator core (1); when the second stator core (6) is the first yoke core (15), the other side of the fixed disk (5) is installed with the first magnetic steel assembly (14); when the second stator core (6) is the first magnetic steel assembly (14), the other side of the fixed disk (5) is installed with the first yoke core (15).

6. The series axial flux motor for the new energy vehicle powertrain according to claim 1 is characterized in that: The winding (2) is a flat copper wire winding.

7. The series axial flux motor for the new energy vehicle powertrain according to claim 6 is characterized in that: The winding (2) adopts a winding structure in which the first pitch y1 is 1, the second pitch y2 is 0, and the combined pitch y is 1.

8. The series axial flux motor for a new energy vehicle powertrain according to claim 1, characterized in that: The lead wire of the winding (2) is led out from the axial end of the casing (11).

9. The series axial flux motor for the new energy vehicle powertrain according to claim 8 is characterized in that: The housing (11) comprises an outer shell (10) and end covers (9) arranged at two axial ends of the outer shell (10), and the end covers (9) are provided with threading holes (4) for lead wires to pass through.

10. The series axial flux motor for the new energy vehicle powertrain according to claim 9, characterized in that: A support wall is centrally arranged inside the housing (11), and the main shaft (8) is connected to the support wall and the end cover (9) via a bearing (7).

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