Electric driving system and vehicle

Abstract

The invention discloses an electric driving system and a vehicle, and belongs to the technical field of vehicles. According to one specific implementation mode of the method, the electric drive system comprises an electric drive assembly and a differential mechanism installed on a wheel axle of the vehicle, the electric drive assembly comprises a plurality of motors connected in series, and the series connection direction is consistent with the axial direction of the electric drive assembly; the input end of the differential mechanism is connected with the output end of the electric drive assembly, and the output end of the differential mechanism is in drive connection with the axle. The axial direction of the electric drive assembly is perpendicular to the axle, and the axle is parallel to the ground plane. A certain included angle is formed between the plane where the axial direction of the electric drive assembly and the wheel shaft are located and the ground plane. According to the implementation mode, a gear box speed reducing mechanism can be omitted for the electric driving system, the size of the electric driving system is reduced, and therefore the technical effects of improving the system efficiency, reducing the whole vehicle weight, saving the cost and optimizing the space utilization rate are achieved.

Description

Technical Field

[0001] The present invention relates to the field of vehicle technology, and in particular to an electric drive system and a vehicle. Background Art

[0002] Traditional electric drive assemblies of vehicles usually include a gearbox reduction mechanism. The main function of the gearbox reduction mechanism is to reduce speed and increase torque. That is to say, the motor usually operates at a high speed (thousands to tens of thousands of revolutions per minute), while the wheels require a lower speed (usually hundreds to thousands of revolutions per minute). Therefore, the reducer reduces the speed and amplifies the torque so that the power output by the motor can meet the needs of vehicle starting, acceleration or climbing.

[0003] However, if the motor unit itself can output a large torque at a lower speed, the gearbox reduction mechanism can be omitted. In addition, there are many benefits to omitting the gearbox reduction mechanism, such as improving system efficiency, reducing vehicle weight, saving costs, and optimizing space utilization. Therefore, omitting the gearbox reduction mechanism has also become a focus of attention. Correspondingly, how to make the motor unit output a large enough torque under the premise of limited volume has become a key issue. Summary of the invention

[0004] In view of this, the present invention provides an electric drive system and a vehicle, which use multiple motors (preferably axial flux motors) connected in series to achieve an electric drive assembly that outputs a larger torque at a lower speed; in addition, by making the plane shared by the axial direction of the electric drive assembly and the wheel axle form a certain angle with the ground plane, it is possible to further increase the output torque of the electric drive assembly by increasing the stator outer diameter of the motor, thereby allowing the electric drive system to omit the gear box reduction mechanism, reducing the volume of the electric drive system, and achieving the technical effects of improving system efficiency, reducing the weight of the entire vehicle, saving costs, and optimizing space utilization.

[0005] In order to solve the above technical problems, the present invention provides the following technical solutions:

[0006] In a first aspect, the present invention provides an electric drive system, comprising an electric drive assembly and a differential mounted on a wheel axle of a vehicle, wherein the electric drive assembly comprises a plurality of motors connected in series, and the direction of the series connection is consistent with the axial direction of the electric drive assembly; the input end of the differential is connected to the output end of the electric drive assembly, and the output end of the differential is drivingly connected to the wheel axle; the axial direction of the electric drive assembly is perpendicular to the wheel axle, and the wheel axle is parallel to a ground plane; and a plane where the axial direction of the electric drive assembly and the wheel axle are located forms a certain angle with the ground plane.

[0007] Optionally, the electric drive assembly includes a rotor shaft, a plurality of stator disks and a plurality of rotor disks, wherein the rotor shaft connects the plurality of stator disks and the plurality of rotor disks in series to achieve series connection of the plurality of motors.

[0008] Optionally, each of the motors comprises: a stator disk and a rotor disk, wherein the stator disk and the rotor disk of each of the motors are installed on the rotor shaft alternately and in series.

[0009] Optionally, one end of the rotor shaft is connected to the input end of the differential; the end of the rotor shaft connected to the differential is lower than the other end of the rotor shaft, or is on the same horizontal plane as the other end of the rotor shaft.

[0010] Optionally, the outer diameters of the stator disk and the rotor disk are both greater than a preset threshold; the preset threshold is determined based on the outer diameters of the stator disk and the rotor disk of the electric drive assembly previously used in the vehicle; and / or, the number of motors included in the electric drive assembly is determined based on the ratio of the target output torque of the electric drive assembly to the actual output torque of each motor.

[0011] Optionally, the stator discs are mounted on the rotor shafts via bearings respectively; and the rotor discs are fixedly connected to the rotor shaft.

[0012] Optionally, the range of the angle includes 0°-180°, and the angle is preferably 90°.

[0013] Optionally, the two ends of the wheel axle are respectively connected to the two front wheels of the vehicle; or, the two ends of the wheel axle are respectively connected to the two rear wheels of the vehicle.

[0014] Optionally, the type of the plurality of motors is axial flux motor; and / or, the motor drive system is applied to an electric vehicle.

[0015] In a second aspect, an embodiment of the present invention provides a vehicle, comprising the electric drive system described in any one of the above embodiments.

[0016] The technical solution of the above invention has the following advantages or beneficial effects: multiple motors (preferably axial flux motors) are connected in series to achieve the output of a larger torque at a lower speed by the electric drive assembly; in addition, by making the plane shared by the axial direction of the electric drive assembly and the wheel axle form a certain angle with the ground plane, it is possible to further increase the output torque of the electric drive assembly by increasing the stator outer diameter of the motor, thereby enabling the electric drive system to omit the gear box reduction mechanism, reducing the volume of the electric drive system, and achieving the technical effects of improving system efficiency, reducing vehicle weight, saving costs, and optimizing space utilization. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1is a schematic structural diagram of an electric drive system according to an embodiment of the present invention;

[0018] Figure 2 is a schematic diagram of the angle between a plane common to the axial direction of an electric drive assembly and the wheel axle and a ground plane according to an embodiment of the present invention;

[0019] Figure 3 is a schematic diagram of a case where the angle between the plane shared by the axial direction of an electric drive assembly and the wheel axle and the ground plane is 90° according to an embodiment of the present invention;

[0020] Figure 4 is a schematic diagram of a case where the angle between the plane shared by the axial direction of an electric drive assembly and the wheel axle and the ground plane is 0° according to an embodiment of the present invention;

[0021] Figure 5 is a schematic diagram of a case where the angle between the plane shared by the axial direction of an electric drive assembly and the wheel axle and the ground plane is 180° according to an embodiment of the present invention;

[0022] Figure 6 is a schematic diagram of the distance of the electric drive assembly from the ground when the angle between the plane shared by the axial direction of the electric drive assembly and the wheel axle and the ground plane is 0° or 180° according to an embodiment of the present invention;

[0023] Figure 7 is a schematic structural diagram of another electric drive system according to an embodiment of the present invention. DETAILED DESCRIPTION

[0024] The following is a description of exemplary embodiments of the present invention in conjunction with the accompanying drawings, including various details of the embodiments of the present invention to facilitate understanding, which should be considered as merely exemplary. Therefore, it should be recognized by those of ordinary skill in the art that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for clarity and conciseness, the description of well-known functions and structures is omitted in the following description.

[0025] It should be pointed out that the embodiments of the present invention and the technical features therein may be combined with each other without conflict.

[0026] Figure 1 is an electric drive system according to an embodiment of the present invention, such as Figure 1As shown, it includes an electric drive assembly 1 and a differential 3 installed on the wheel axle 2 of the vehicle, wherein the electric drive assembly 1 includes a plurality of motors connected in series, and the direction of the series connection is consistent with the axial direction of the electric drive assembly 1; the input end of the differential 3 is connected to the output end of the electric drive assembly 1, and the output end of the differential 3 is drivingly connected to the wheel axle 2; the axial direction of the electric drive assembly 1 is perpendicular to the wheel axle 2, and the wheel axle 2 is parallel to the ground plane; the plane p1 where the axial direction of the electric drive assembly 1 and the wheel axle 2 are located together forms a certain angle with the ground plane p2. The angle formed by plane p1 and ground plane p2 is as shown in Figure 2 As shown, Figure 2 This is a side view of the electric drive system from the side of the wheel axle. Figure 2 The reference numeral “2” in the figure refers to the wheel axle, “p1” refers to the side view of the plane common to the axial direction of the electric drive assembly and the wheel axle, and “p2” refers to the side view of the ground plane.

[0027] Among them, the types of multiple motors belong to axial flux motors, and by connecting multiple axial flux motors in series, a larger torque can be output at a lower speed. For example, if the output torque of each motor is 500N·m, then four motors connected in series can achieve a torque output of 500N·m*4=2000N·m. Therefore, the number of motors that need to be connected in series is determined according to the target output torque of the electric drive system and the torque that each motor can actually output. Therefore, in an optional embodiment of the present invention, the number of motors included in the electric drive assembly 1 is determined according to the ratio of the target output torque of the electric drive assembly 1 to the actual output torque of each motor. In this embodiment, an electric drive assembly that outputs a larger torque at a lower speed is realized by connecting multiple axial flux motors in series, which makes it unnecessary for the electric drive system to use a gearbox reduction mechanism to achieve deceleration and torque increase, so the gearbox reduction mechanism in the traditional electric drive system can be omitted, freeing up space for the vehicle chassis and vehicle interior layout, and reducing the overall weight of the electric drive system, reducing the volume, saving space and cost, and laying the foundation for optimizing space utilization.

[0028] Furthermore, the angle range includes 0°-180°, and the angle is preferably 90°. The angle formed by the plane p1 where the axial direction of the electric drive assembly 1 and the wheel axle 2 are located and the ground plane p2 is in the range of 0°-180°, wherein Figure 3 The figure shows the case where the angle between plane p1 and the ground plane p2 is 90°, that is, the axial direction of the electric drive assembly is perpendicular to the ground plane. In this case, with the axial centerline of the electric drive assembly as the center, the volume of the electric drive assembly can be expanded in a direction parallel to the horizontal plane, such as increasing the outer diameter of the stator disc of the motor, thereby increasing the output torque of the electric drive assembly. In contrast, if the angle between p1 and p2 is 0°, as shown in FIG. Figure 4 As shown or 180° as Figure 5 As shown in FIG. 1 , the axial direction of the electric drive assembly is parallel to the ground. If the electric drive assembly is extended in a direction perpendicular to the horizontal plane with the axial centerline of the electric drive assembly as the center, the distance between the lower side of the electric drive assembly and the ground will be reduced, so that the ground clearance d of the lower side of the electric drive assembly may be less than the safe ground clearance s, as shown in FIG. Figure 6 As shown in the figure, the circle represents a schematic diagram of the electric drive assembly 1 including the stator disk and the rotor disk 103, the black dot in the middle of the circle represents the rotor shaft 101, and P2 represents the ground plane. Figure 3 The electric drive assembly shown has its axis perpendicular to the ground plane. In addition to increasing the lateral size of the motor, it can also keep the ground clearance of the lower side of the electric drive assembly within a safe distance, while making the space above the electric drive assembly more regular, allowing the space layout to be flexibly planned to optimize space utilization.

[0029] In order to further reduce the volume of the electric drive assembly, that is, to further improve the power density of the electric drive assembly, multiple motors can be connected in series more compactly. In an optional embodiment of the present invention, the electric drive assembly 1 includes a rotor shaft 101, multiple stator disks 102 and multiple rotor disks 103103, such as Figure 7 As shown, the rotor shaft 101 connects a plurality of stator disks 102 and a plurality of rotor disks 103 in series to realize the series connection of a plurality of motors. Specifically, by making a plurality of motors share the same rotor shaft 101, a plurality of stator disks and rotor disks 103 are connected in series through the same rotor shaft 101, thereby improving the compactness of the electric drive assembly structure and reducing the volume of the electric drive assembly.

[0030] In an optional embodiment of the present invention, each of the motors comprises: a stator disk 102 and a rotor disk 103, wherein the stator disk 102 and the rotor disk 103 of each motor are alternately and serially mounted on the rotor shaft 101. The specific serial connection method of multiple motors is as follows: each motor comprises one or more stator disks 102 and one or more rotor disks 103. First, the stator disk 102 and the rotor disk 103 corresponding to one motor are alternately connected in series to the rotor shaft 101, and then the stator disk 102 and the rotor disk 103 of the second motor are alternately connected in series to the rotor shaft 101, until the stator disks 102 and the rotor disks 103 of multiple motors are connected in series to the rotor shaft 101. Among them, the stator disk 102 is fixed, but the rotor shaft 101 needs to rotate. Therefore, in order to prevent the stator disk 102 from rotating with the rotation of the rotor shaft 101, each stator disk 102 is mounted on the rotor shaft 101 through a bearing. The stator disc is a circular disc with a hole in the middle, the bearing is installed in the hole, and the rotor shaft 101 passes through the circular hole in the middle of the bearing. The rotor disc 103 is fixedly connected to the rotor shaft 101 to rotate with the rotation of the rotor shaft 101.

[0031] In order to make the overall layout of the vehicle chassis and the interior space more reasonable while meeting the torque output requirements, in an optional embodiment of the present invention, one end of the rotor shaft 101 is connected to the input end of the differential 3; the end of the rotor shaft 101 connected to the differential 3 is lower than the other end of the rotor shaft 101, such as Figure 2 and Figure 3 or on the same horizontal plane as the other end of the rotor shaft 101, such as Figure 4 and Figure 5 As shown. The height of the other end of the rotor shaft 101 is equal to or higher than the height of the end of the rotor shaft 101 connected to the differential 3 .

[0032] Under the premise of ensuring that the ground clearance of the vehicle chassis is within a safe range, increasing the outer diameter of the stator disc can further increase the output torque, thereby improving the power density of the electric drive assembly. In an optional embodiment of the present invention, the outer diameters of the stator disc 102 and the rotor disc 103 are both greater than a preset threshold; the preset threshold is determined based on the outer diameters of the stator disc and the rotor disc of the electric drive assembly previously used by the vehicle. The outer diameters of the stator disc 102 and the rotor disc 103 in this embodiment are both greater than the outer diameters of the stator disc and the rotor disc 103 in the traditional electric drive system.

[0033] The electric drive system of the embodiment of the present invention can be applied to electric vehicles as a drive system for the front wheels of the electric vehicles, and can also be used as a drive system for the rear wheels. Therefore, in an optional embodiment of the present invention, the two ends of the axle 2 are respectively connected to the two front wheels of the vehicle; or, the two ends of the axle 2 are respectively connected to the two rear wheels of the vehicle.

[0034] The introduction provided in the above steps is only used to help understand the composition structure, installation location and core concept of the electric drive system of the present invention. For ordinary technicians in this technical field, without departing from the principle of the present invention, several improvements and modifications can be made to the present invention, and these improvements and modifications also fall within the scope of protection of the claims of the present invention.

[0035] According to the electric drive system of the embodiment of the present invention, a plurality of motors (preferably axial flux motors) are connected in series to achieve the output of a large torque at a relatively low speed by the electric drive assembly; in addition, by making the plane shared by the axial direction of the electric drive assembly and the wheel axle form a certain angle with the ground plane, it is possible to further increase the output torque of the electric drive assembly by increasing the stator outer diameter of the motor, thereby enabling the electric drive system to omit the gear box reduction mechanism, reducing the volume of the electric drive system, and achieving the technical effects of improving system efficiency, reducing the weight of the entire vehicle, saving costs, and optimizing space utilization.

[0036] The above specific implementations do not constitute a limitation on the protection scope of the present invention. It should be understood by those skilled in the art that various modifications, combinations, sub-combinations and substitutions may occur depending on design requirements and other factors. Any modification, equivalent substitution and improvement made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. An electric drive system, characterized in that: The invention comprises an electric drive assembly (1) and a differential (3) mounted on a wheel axle (2) of a vehicle, wherein: The electric drive assembly (1) comprises a plurality of motors connected in series, wherein the direction of the series connection is consistent with the axial direction of the electric drive assembly (1); The input end of the differential (3) is connected to the output end of the electric drive assembly (1), and the output end of the differential (3) is drivingly connected to the wheel axle (2); The axial direction of the electric drive assembly (1) is perpendicular to the wheel axle (2), and the wheel axle (2) is parallel to the ground plane; The plane (p1) on which the axial direction of the electric drive assembly (1) and the wheel axle (2) are located forms a certain angle with the ground plane (p2).

2. The system according to claim 1, characterized in that The electric drive assembly (1) comprises a rotor shaft (101), a plurality of stator discs (102) and a plurality of rotor discs (103), wherein: The rotor shaft (101) connects a plurality of the stator disks (102) and a plurality of the rotor disks (103) in series to achieve series connection of a plurality of the motors.

3. The system according to claim 2, characterized in that Each of the motors comprises: a stator disk (102) and a rotor disk (103), wherein: The stator discs (102) and rotor discs (103) of each motor are installed on the rotor shaft (101) alternately and in series.

4. The system according to claim 2 or 3, characterized in that: One end of the rotor shaft (101) is connected to the input end of the differential (3); One end of the rotor shaft (101) connected to the differential (3) is lower than the other end of the rotor shaft (101), or is on the same horizontal plane as the other end of the rotor shaft (101).

5. The system according to claim 2 or 3, characterized in that: The outer diameters of the stator disk (102) and the rotor disk (103) are both greater than a preset threshold value; the preset threshold value is determined based on the outer diameters of the stator disk and the rotor disk of the electric drive assembly previously used in the vehicle; and / or, The number of motors included in the electric drive assembly (1) is determined based on the ratio of the target output torque of the electric drive assembly (1) to the actual output torque of each motor.

6. The system according to claim 2 or 3, characterized in that: The stator discs (102) are respectively mounted on the rotor shafts (101) via bearings; The rotor disk (103) is fixedly connected to the rotor shaft (101).

7. The system according to claim 2 or 3, characterized in that: The range of the angle includes 0°-180°, and the angle is preferably 90°.

8. The system according to claim 1, characterized in that The two ends of the wheel axle (2) are respectively connected to the two front wheels of the vehicle; or, The two ends of the wheel axle (2) are respectively connected to the two rear wheels of the vehicle.

9. The system according to claim 1, characterized in that A plurality of said electric machines are of the type of axial flux electric machines; and / or, The motor drive system is applied to an electric vehicle.

10. A vehicle, characterized in that: include: An electric drive system as claimed in any one of claims 1 to 9.

Images