Dual-motor electric drive system

Abstract

The present application relates to the technical field of transmission, and in particular to a dual-motor electric drive system, specifically comprising a housing, a first planetary gear train, a second planetary gear train, a first motor, a first motor shaft, a second motor, a second motor shaft, a fifth transmission wheel, a first transmission wheel, and a pedal shaft. At least one second planetary shaft is connected to the fifth transmission wheel; the first transmission wheel is in transmission engagement with the fifth transmission wheel by means of a second transmission wheel; a third transmission wheel on the pedal shaft is in transmission engagement with a ring gear. In the dual-motor electric drive system, power confluence is achieved at two positions: at a first position, human pedaling power inputted by the pedal shaft and input power from a first motor achieve first power confluence at the ring gear, and at a second position, power transmitted by the ring gear and input power from a second motor achieve second power confluence at the fifth transmission wheel. In this way, stepless speed adjustment can be achieved by means of dual-motor control, and the overall structure is simple and the cost is reduced.

Description

Dual-motor electric drive system

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411634972.6, entitled "Dual Motor Electric Drive System", filed on November 15, 2024, the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to the field of transmission technology, and more specifically, to a dual-motor electric drive system. Background Technology

[0004] Most existing e-bikes feature electric drive systems that only provide assistance, with speed adjustment achieved through the bicycle's gear system. A few manufacturers, such as MGU and Valeo, offer geared products, using traditional gear shifting technology to achieve stepped speed regulation. Furthermore, all existing e-bikes are equipped with torque and cadence sensors, which are fundamental for intelligent control.

[0005] In other words, most electric bicycles on the market have electric drive systems consisting of a separate motor and a gear shifting mechanism. This structure can only meet the requirements of electric drive, but cannot achieve convenient and quick gear shifting; at the same time, the separate motor and gear shifting mechanism make the entire electric drive system complex and bulky, resulting in inconvenience in installation, disassembly and maintenance. Summary of the Invention

[0006] The purpose of this disclosure includes, for example, providing a dual-motor electric drive system that can achieve stepless speed regulation through dual-motor control, and has a simple overall structure and lower cost.

[0007] The embodiments of this disclosure can be implemented as follows:

[0008] In a first aspect, this disclosure provides a dual-motor electric drive system, comprising:

[0009] Housing, first planetary gear train, second planetary gear train, first motor, first motor shaft, second motor, second motor shaft, fifth transmission wheel, first transmission wheel, foot pedal shaft;

[0010] The first planetary gear system includes a gear ring, a first planet carrier, a first sun gear, a first planet gear, and a first planet shaft that cooperate with each other; the first planet carrier is integrated on the housing, and the first motor is connected to the first sun gear through the first motor shaft so as to drive the first sun gear to rotate;

[0011] The second planetary gear system includes a meshing ring gear, a second sun gear, a second planet gear, and a second planet shaft; the second motor is connected to the second sun gear via a second motor shaft so as to drive the second sun gear to rotate.

[0012] The fifth transmission wheel is rotatably mounted in the housing via bearings; at least one second planetary shaft is connected to the fifth transmission wheel so that the fifth transmission wheel can rotate when the second planetary gear revolves.

[0013] The first transmission wheel is connected to the fifth transmission wheel via the second transmission wheel, so that the fifth transmission wheel can drive the first transmission wheel to rotate.

[0014] A third transmission wheel is provided on the foot pedal axle, and the third transmission wheel is in transmission cooperation with the gear ring so that the gear ring can be driven to rotate by the rotation of the foot pedal axle;

[0015] The dual-motor electric drive system achieves power convergence at two points: the first is through the human pedaling power P input via the foot pedal axle. 脚踏 With the input power P of the first motor M1 The first power convergence is achieved at the gear ring, and the analytical expression for the power combining relationship at this time is:

[0016] Power: P 齿圈 =P M1 +P 脚踏 ;

[0017] Torque: T 齿圈 =k1T M1 +k2T 脚踏 ;

[0018] Rotational speed: n 齿圈 =k1n 脚踏 =k2n M1 ;

[0019] Among them, P 齿圈 P is the power of the gear ring. M1 P is the input power of the first motor. 脚踏 T represents the power of manually pedaling the pedal axle. 齿圈 T is the torque of the gear ring. M1 T is the torque of the first motor. 脚踏 n is the torque of the pedal axle. 齿圈 Let n be the rotational speed of the gear ring. 脚踏 n is the rotational speed of the pedal axle. M1 k1 is the speed of the first motor, k2 is the transmission ratio from the pedal shaft to the gear ring, and k2 is the transmission ratio from the first motor to the gear ring.

[0020] The second point concerns the power transmitted by the gear ring and the input power P of the second motor.M2 The second power convergence occurs at the fifth drive wheel, and the analytical expression for the power combining relationship at this point is:

[0021] Power: P 行星架 =P 齿圈 +P M2 ;

[0022] Torque: T 行星架 =k3T 齿圈 =k4T M2 ;

[0023] Rotational speed: n 行星架 =k3n 齿圈 +k4n M2 ;

[0024] P 行星架 P is the power of the fifth transmission wheel. M2 T is the input power of the second motor. 行星架 T is the torque of the fifth transmission wheel. M2 Let n be the torque of the first motor. 行星架 n is the rotational speed of the fifth transmission wheel. M2 K is the rotational speed of the second motor, k3 is the transmission ratio from the gear ring to the fifth transmission wheel, and k4 is the transmission ratio from the second motor to the fifth transmission wheel.

[0025] In an optional embodiment, the second planetary gear is rotatably mounted on one end of the second planetary shaft via a bearing, and the other end of the second planetary shaft is fixed to the fifth transmission gear.

[0026] In an optional embodiment, the second planetary shaft is disposed on the fifth transmission wheel so that the fifth transmission wheel can serve as a planet carrier for the second planetary gear.

[0027] In an optional embodiment, the first planetary gear is rotatably mounted on one end of the first planetary shaft via a bearing, and the other end of the first planetary shaft is fixed to the housing.

[0028] In an optional embodiment, the axis of the fifth transmission wheel, the axis of the first sun wheel, and the axis of the second sun wheel are all arranged coaxially.

[0029] In an optional embodiment, the second and fifth drive wheels may be driven by gears, belts, or chains.

[0030] In an optional implementation, the third drive wheel and the gear ring can be driven by gears, belts, or chains.

[0031] In an alternative implementation, the first drive wheel may be designed as a gear, pulley, or sprocket.

[0032] In an optional embodiment, the second transmission wheel is arranged coaxially with the first transmission wheel; the fifth transmission wheel is in transmission cooperation with the second transmission wheel so that when the fifth transmission wheel rotates, it drives the first transmission wheel to rotate through the second transmission wheel.

[0033] In an optional embodiment, the second drive wheel is arranged coaxially with the pedal shaft, and the first drive wheel is fixed on the second drive wheel.

[0034] In an optional embodiment, the first motor and the second motor are located on opposite sides of the gear ring along the axial direction of the gear ring.

[0035] In an optional embodiment, the gear ring is mounted on the housing via a bearing, and the gear ring is provided with an outer tooth, a first inner tooth, and a second inner tooth; the first inner tooth meshes with the outer tooth of the first planetary gear, the second inner tooth meshes with the outer tooth of the second planetary gear, and the outer tooth meshes with the outer tooth of the third transmission gear.

[0036] The beneficial effects of the embodiments disclosed herein include, for example:

[0037] This solution provides a dual-motor electric drive system comprising a housing, a first planetary gear system, a second planetary gear system, a first motor, a second motor, a fifth transmission wheel, a first transmission wheel, and a pedal axle. In operation, the pedaling force sequentially drives the pedal axle and the third transmission wheel to rotate, which in turn drives the gear ring to rotate. Simultaneously, the first motor operates and engages with the first planetary gear system to drive the gear ring to rotate, thus achieving a first power convergence at the gear ring due to the driving force from the pedal and the power from the first motor. Further, the second motor operates and engages with the second planetary gear system to sequentially drive the fifth transmission wheel and the first transmission wheel to rotate, thus achieving a second power convergence at the fifth transmission wheel due to the combined power from the first power convergence at the gear ring and the power from the second motor. Additionally, by collecting the real-time rotational speed of the first motor, the rider's real-time pedaling frequency can be sensed, enabling the first motor to function as a pedal frequency sensor. By separately collecting the real-time torque of the first and second motors and understanding the coupling relationship of the power convergence, the rider's real-time pedaling torque can be sensed, thus enabling the second motor to function as a torque sensor. In summary, this dual-motor electric drive system achieves torque regulation with the first motor and speed regulation with the second motor, thus realizing the innovative function of both assisting and accelerating. At the same time, by eliminating the separate gear transmission mechanism, the overall vehicle structure is simplified and the cost is reduced. Attached Figure Description

[0038] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings used in the embodiments will be briefly described below. It should be understood that the following drawings only show some embodiments of this disclosure and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0039] Figure 1 is a schematic diagram of the structure of a dual-motor electric drive system according to an embodiment of the present disclosure.

[0040] Icons: A01 - First transmission wheel; A02 - Second transmission wheel; A03 - Third transmission wheel; A05 - Foot pedal shaft; B01 - First motor; B02 - First motor shaft; B03 - Second motor; B04 - Second motor shaft; C01 - Housing; D01 - First sun gear; D02 - First planetary shaft; D03 - First planetary gear; D04 - Ring gear; D05 - Second planetary gear; D06 - Fifth transmission wheel; D07 - Second planetary shaft; D08 - Second sun gear. Detailed Implementation

[0041] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. The components of the embodiments of this disclosure described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0042] Therefore, the following detailed description of the embodiments of this disclosure provided in the accompanying drawings is not intended to limit the scope of the claimed disclosure, but merely to illustrate selected embodiments of the disclosure. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without inventive effort are within the scope of protection of this disclosure.

[0043] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0044] In the description of this disclosure, it should be noted that if terms such as "upper," "lower," "inner," or "outer" are used to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed during use, they are only for the convenience of describing this disclosure and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this disclosure.

[0045] Furthermore, the terms "first" and "second" are used only to distinguish descriptions and should not be interpreted as indicating or implying relative importance.

[0046] It should be noted that, where there is no conflict, the features in the embodiments of this disclosure can be combined with each other.

[0047] Please refer to Figure 1. This embodiment provides a dual-motor electric drive system, including:

[0048] Box C01, first planetary gear system, second planetary gear system, first motor B01, first motor shaft B02, second motor B03, second motor shaft B04, fifth transmission wheel D06, first transmission wheel A01, foot pedal shaft A05;

[0049] The first planetary gear system includes a gear ring D04, a first planet carrier, a first sun gear D01, a first planet gear D03, and a first planet shaft D02 that cooperate with each other; the first planet carrier is integrated on the housing C01, and the first motor B01 is connected to the first sun gear D01 through the first motor shaft B02 so as to drive the first sun gear D01 to rotate.

[0050] The second planetary gear system includes a gear ring D04, a second sun gear D08, a second planet gear D05, and a second planet shaft D07 that cooperate with each other; the second motor B03 is connected to the second sun gear D08 through the second motor shaft B04 so as to drive the second sun gear D08 to rotate.

[0051] The fifth transmission wheel D06 is rotatably mounted in the housing C01 via a bearing; at least one second planetary shaft D07 is connected to the fifth transmission wheel D06 so that the fifth transmission wheel D06 can rotate when the second planetary gear D05 revolves.

[0052] The first transmission wheel A01 is connected to the fifth transmission wheel D06 via the second transmission wheel A02, so that the fifth transmission wheel D06 can drive the first transmission wheel A01 to rotate.

[0053] A third transmission wheel A03 is provided on the foot pedal axle A05. The third transmission wheel A03 is in transmission cooperation with the gear ring D04 so that the rotation of the foot pedal axle A05 drives the gear ring D04 to rotate.

[0054] The dual-motor electric drive system achieves power convergence at two points: the first is through the human pedaling power P input via the foot pedal axle A05. 脚踏 With the input power P of the first motor B01 M1 The first power combination occurs at point D04 of the gear ring, and the analytical expression for the power combination relationship at this point is:

[0055] Power: P 齿圈 =P M1 +P脚踏 ;

[0056] Torque: T 齿圈 =k1T M1 +k2T 脚踏 ;

[0057] Rotational speed: n 齿圈 =k1n 脚踏 =k2n M1 ;

[0058] Among them, P 齿圈 For the power of gear ring D04, P M1 P is the input power of the first motor B01. 脚踏 For the power of manually pedaling the A05 axle, T 齿圈 T is the torque of gear ring D04. M1 T represents the torque of the first motor B01. 脚踏 For the torque of pedal shaft A05, n 齿圈 Let n be the rotational speed of gear ring D04. 脚踏 n is the rotational speed of pedal shaft A05. M1 k1 is the rotational speed of the first motor B01, k2 is the transmission ratio from the foot pedal shaft A05 to the gear ring D04, and k2 is the transmission ratio from the first motor B01 to the gear ring D04.

[0059] The second point is the power transmitted by the gear ring D04 and the input power P of the second motor B03. M2 The second power convergence occurs at the fifth drive wheel D06, and the analytical expression for the power combining relationship at this time is:

[0060] Power: P 行星架 =P 齿圈 +P M2 ;

[0061] Torque: T 行星架 =k3T 齿圈 =k4T M2 ;

[0062] Rotational speed: n 行星架 =k3n 齿圈 +k4n M2 ;

[0063] P 行星架 For the power of the fifth transmission wheel D06, P M2 T is the input power of the second motor B03. 行星架 T represents the torque of the fifth transmission wheel D06. M2 Let n be the torque of the first motor B01. 行星架 n is the rotational speed of the fifth transmission wheel D06. M2k3 is the rotational speed of the second motor B03, k4 is the transmission ratio from the gear ring D04 to the fifth transmission wheel D06, and k5 is the transmission ratio from the second motor B03 to the fifth transmission wheel D06.

[0064] The dual-motor electric drive system is that the pedal force of a single pedal drives the pedal shaft A05 and the third transmission wheel A03 to rotate and drive the gear ring D04 to rotate. At the same time, the first motor B01 works and cooperates with the first planetary gear system to drive the gear ring D04 to rotate. In this way, the driving force from the pedal and the power of the first motor B01 achieve the first power convergence at the gear ring D04.

[0065] Furthermore, the second motor B03 operates and engages with the second planetary gear system to sequentially drive the fifth transmission wheel D06 and the first transmission wheel A01 to rotate. Thus, the power that first merges at the gear ring D04 and the power of the second motor B03 merge for the second time at the fifth transmission wheel D06.

[0066] Furthermore, by collecting the real-time rotational speed of the first motor B01, the real-time pedaling frequency of the rider can be sensed, thus enabling the first motor B01 to function as a pedaling frequency sensor. Simultaneously, by separately collecting the real-time torque of the first motor B01 and the second motor B03, the real-time pedaling torque of the rider can be sensed through the coupling relationship of power convergence, thereby enabling the second motor B03 to function as a torque sensor. This system's first motor can adjust torque, and the second motor can adjust rotational speed, thus achieving an innovative function that provides both power assist and speed boost. At the same time, by eliminating the need for a separate gear transmission mechanism, the overall bicycle structure is simplified, reducing costs.

[0067] Optionally, both the first motor B01 and the second motor B03 adopt a vector control strategy and are controlled using a spatial vector modulation algorithm.

[0068] The first motor B01 is in torque control mode. Under the control strategy, the speed of the first motor B01 is automatically matched with the speed of the first sun gear D01 in real time. Since the first sun gear D01 has a fixed transmission ratio with the gear ring D04 and the third transmission wheel A03, it is also matched with the speed of the pedal shaft A05 in real time.

[0069] The second motor B03 is in speed control mode. Under the control strategy, the torque of the second motor B03 is automatically matched with the pedal torque and the coupling torque of the first motor B01 acting on the fifth transmission wheel D06 in real time. Since the pedal torque, the power of the first motor B01 and the second motor B03 are transmitted to the fifth transmission wheel D06 with fixed transmission ratios, the real-time pedal torque can be analytically calculated through the torque balance relationship of the three.

[0070] The first motor B01 functions as a pedal frequency sensor, which can detect the rider's real-time pedaling frequency by collecting the real-time rotation speed of the first motor B01.

[0071] The second motor B03 acts as a torque sensor. By collecting the real-time torque of the first motor B01 and the second motor B03 respectively, the real-time pedaling torque of the rider can be sensed through the coupling relationship of power convergence.

[0072] In an optional embodiment, the second planetary gear D05 is rotatably mounted on one end of the second planetary shaft D07 via a bearing, and the other end of the second planetary shaft D07 is fixed on the fifth transmission gear D06.

[0073] In an optional embodiment, the second planetary shaft D07 is disposed on the fifth transmission wheel D06 so that the fifth transmission wheel D06 can serve as the planet carrier for the second planetary wheel D05.

[0074] In an optional embodiment, the first planetary gear D03 is rotatably mounted on one end of the first planetary shaft D02 via a bearing, and the other end of the first planetary shaft D02 is fixed to the housing C01.

[0075] One end of the pedal shaft A05 is mounted on the housing C01 via a bearing, and the other end is mounted in the hole of the second drive wheel A02 via a bearing. The second drive wheel A02 is mounted on the housing C01 via a bearing. The third drive wheel A03 is mounted on the pedal shaft A05 via the first bearing A04. Both ends of the pedal shaft A05 extend outside the housing C01 and are externally connected to the crank.

[0076] As can also be seen from Figure 1, in the optional embodiment, the axis of the fifth transmission wheel D06, the axis of the first sun gear D01, and the axis of the second sun gear D08 are all arranged coaxially. This ensures stability during power transmission and also reduces the overall volume of the housing C01.

[0077] In an optional implementation, the second drive wheel A02 and the fifth drive wheel D06 can be driven by gears, belts, or chains.

[0078] In an optional implementation, the third drive wheel A03 and the gear ring D04 can be driven by gears, belts, or chains.

[0079] In this embodiment, the second transmission wheel A02 and the fifth transmission wheel D06 are coupled through gear transmission.

[0080] As can also be seen from the figure, the gear ring D04 is mounted on the housing C01 via a bearing, and the gear ring D04 is provided with an external tooth D042, a first internal tooth D041, and a second internal tooth D043.

[0081] The first internal tooth D041 meshes with the external teeth of the first planetary gear D03, the second internal tooth D043 meshes with the external teeth of the second planetary gear D05, and the external tooth D042 meshes with the external teeth of the third transmission gear A03, so that the gear ring D04 and the third transmission gear A03 are engaged in gear transmission.

[0082] In an optional embodiment, the first drive wheel A01 can be designed as a gear, pulley, or sprocket. When the first drive wheel A01 is a sprocket, it can also function as a standard chainring bicycle. In an optional embodiment, the second drive wheel A02 is coaxially arranged with the first drive wheel A01; the fifth drive wheel D06 is driven by the second drive wheel A02, so that when the fifth drive wheel D06 rotates, it drives the first drive wheel A01 to rotate via the second drive wheel A02. This shortens the power transmission path.

[0083] In an optional embodiment, the second drive wheel A02 is coaxially arranged with the pedal axle A05, and the first drive wheel A01 is fixed on the second drive wheel A02. In this embodiment, the second drive wheel A02 is sleeved on the pedal axle A05.

[0084] In an optional embodiment, along the axial direction of the gear ring D04, the first motor B01 and the second motor B03 are located on both sides of the gear ring D04, respectively. This arrangement makes the overall structure harmonious and symmetrical, improving the aesthetics of the product. The two motors are arranged on both sides of the housing C01, which facilitates heat dissipation for the motors.

[0085] The rotor of the first motor B01 is mounted on the first motor shaft B02. The first sun gear D01 is integrated into or mounted on the first motor shaft B02. The first planetary shaft D02 is mounted on the housing C01. The first planetary gear D03 is loosely fitted on the first planetary shaft D02. The first planetary gear D03 meshes with the internal teeth D401 of both the first sun gear D01 and the ring gear D04. When more than one of the first planetary shaft D02 and the first planetary gear D03 is arranged circumferentially, the first sun gear D01, the first planetary gear D03, the ring gear D04, and the housing C01 (i.e., the planet carrier of the first planetary system) constitute the first planetary gear system PG1.

[0086] The rotor of the second motor B03 is mounted on the second motor shaft B04. The second sun gear D08 is integrated into or mounted on the second motor shaft B04. The second planetary shaft D07 is mounted on the fifth transmission gear D06. The second planetary gear D05 is loosely fitted on the second planetary shaft D07. The second planetary gear D05 meshes with the internal teeth D403 of both the second sun gear D08 and the ring gear D04. When the second planetary shaft D07 and the second planetary gear D05 are arranged circumferentially on the fifth transmission gear D06, the second sun gear D08, the second planetary gear D05, the second planetary shaft D07, the ring gear D04, and the fifth transmission gear D06 (i.e., the planet carrier of the second planetary system) constitute another second planetary gear system PG2.

[0087] The gear ring D04, the second sun gear D08, and the fifth transmission gear D06 are three power application points. Power is input at any two of these power application points according to the set requirements, and the other power application point outputs power according to the set requirements.

[0088] In summary, the embodiments of this disclosure provide a dual-motor electric drive system, which has at least the following advantages:

[0089] This solution utilizes two motors to achieve the functions of two sensors, eliminating the need for dedicated cadence and torque sensors to collect pedal torque and cadence information.

[0090] This solution is equipped with dual motors and designed with three power input points. Structurally, power is combined at two locations to achieve both power assistance and speed adjustment. The overall speed of the vehicle is determined by the coupling of the pedal frequency and the speed of the assist motor, rather than by a single power coupling. A single power coupling means that the motor torque and pedaling torque are superimposed, and the speed automatically matches the pedal frequency in real time, so the overall speed is determined by the pedal frequency.

[0091] The above are merely specific embodiments of this disclosure, but the scope of protection of this disclosure is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this disclosure should be included within the scope of protection of this disclosure. Therefore, the scope of protection of this disclosure should be determined by the scope of the claims. Industrial applicability

[0092] The first motor of the dual-motor electric drive system disclosed herein can adjust the torque, and the second motor can adjust the speed, thus achieving the innovative function of both assisting and accelerating; at the same time, by eliminating the separate gear transmission mechanism, the overall vehicle structure is simplified and the cost is reduced.

Claims

1. A dual-motor electric drive system, characterized by, include: Housing (C01), first planetary gear system, second planetary gear system, first motor (B01), first motor shaft (B02), second motor (B03), second motor shaft (B04), fifth transmission wheel (D06), first transmission wheel (A01), foot pedal shaft (A05); The first planetary gear system includes a gear ring (D04), a first planet carrier, a first sun gear (D01), a first planet gear (D03), and a first planet shaft (D02) that cooperate with each other; the first planet carrier is integrated on the housing (C01), and the first motor (B01) is connected to the first sun gear (D01) through the first motor shaft (B02) so as to drive the first sun gear (D01) to rotate; The second planetary gear system includes a meshing gear ring (D04), a second sun gear (D08), a second planet gear (D05), and a second planet shaft (D07); the second motor (B03) is connected to the second sun gear (D08) via the second motor shaft (B04) so ​​as to drive the second sun gear (D08) to rotate. The fifth transmission wheel (D06) is rotatably mounted in the housing (C01) via a bearing; at least one second planetary shaft (D07) is connected to the fifth transmission wheel (D06) so that the fifth transmission wheel (D06) can rotate when the second planetary gear (D05) revolves. The first transmission wheel (A01) is connected to the fifth transmission wheel (D06) via the second transmission wheel (A02) so that the fifth transmission wheel (D06) can drive the first transmission wheel (A01) to rotate. The foot pedal axle (A05) is provided with a third transmission wheel (A03), which is in transmission cooperation with the gear ring (D04) so ​​that the gear ring (D04) is driven to rotate by the rotation of the foot pedal axle (A05); The dual-motor electric drive system achieves power convergence at two points: the first point is where the human pedaling power P input through the pedal shaft (A05) and the power PM1 input from the first motor (B01) converge at the gear ring (D04). The analytical expression for the power combining relationship at this point is: Power: P gear ring = PM1 + P pedal; Torque: T gear ring = k1TM1 + k2T pedal; Rotational speed: n gear ring = k1n pedal = k2nM1; Wherein, P gear ring is the power of gear ring (D04), PM1 is the input power of the first motor (B01), P foot pedal is the power of the human-powered pedal shaft (A05), T gear ring is the torque of gear ring (D04), TM1 is the torque of the first motor (B01), T foot pedal is the torque of the pedal shaft (A05), n gear ring is the speed of gear ring (D04), n foot pedal is the speed of pedal shaft (A05), nM1 is the speed of the first motor (B01), k1 is the transmission ratio from pedal shaft (A05) to gear ring (D04), and k2 is the transmission ratio from the first motor (B01) to gear ring (D04). The second point is where the power transmitted by the gear ring (D04) and the input power PM2 of the second motor (B03) combine for the second time at the fifth transmission wheel (D06). The analytical expression for the power combination relationship at this point is: Power: P planetary carrier = P gear ring + PM2; Torque: T planetary carrier = k3T gear ring = k4TM2; Rotational speed: n planetary carrier = k3n gear ring + k4nM2; P planetary carrier represents the power of the fifth transmission wheel (D06), PM2 represents the input power of the second motor (B03), T planetary carrier represents the torque of the fifth transmission wheel (D06), TM2 represents the torque of the first motor (B01), n ​​planetary carrier represents the speed of the fifth transmission wheel (D06), nM2 represents the speed of the second motor (B03), k3 represents the transmission ratio from the gear ring (D04) to the fifth transmission wheel (D06), and k4 represents the transmission ratio from the second motor (B03) to the fifth transmission wheel (D06).

2. The dual-motor electric drive system according to claim 1, characterized in that: The second planetary gear (D05) is rotatably mounted on one end of the second planetary shaft (D07) via a bearing, and the other end of the second planetary shaft (D07) is fixed on the fifth transmission gear (D06).

3. The dual-motor electric drive system according to claim 2, characterized in that: The second planetary shaft (D07) is disposed on the fifth transmission wheel (D06) so that the fifth transmission wheel (D06) can serve as the planet carrier of the second planetary gear (D05).

4. The dual-motor electric drive system according to claim 2, characterized in that: The first planetary gear (D03) is rotatably mounted on one end of the first planetary shaft (D02) via a bearing, and the other end of the first planetary shaft (D02) is fixed to the housing (C01).

5. The dual-motor electric drive system according to any one of claims 1-4, characterized in that: The axis of the fifth transmission wheel (D06), the axis of the first sun wheel (D01), and the axis of the second sun wheel (D08) are all arranged coaxially.

6. The dual-motor electric drive system according to any one of claims 1-4, characterized in that: The second drive wheel (A02) and the fifth drive wheel (D06) are driven by gears, belts, or chains.

7. The dual-motor electric drive system of any one of claims 1-4, characterized by: The third drive wheel (A03) and the gear ring (D04) are connected by gear drive, belt drive or chain drive.

8. The dual-motor electric drive system according to any one of claims 1-7, characterized in that: The first transmission wheel (A01) is configured as a gear, pulley or sprocket.

9. The dual-motor electric drive system according to any one of claims 1-8, characterized in that: The second transmission wheel (A02) is arranged coaxially with the first transmission wheel (A01); the fifth transmission wheel (D06) is in transmission cooperation with the second transmission wheel (A02) so that when the fifth transmission wheel (D06) rotates, it drives the first transmission wheel (A01) to rotate through the second transmission wheel (A02).

10. The dual-motor electric drive system according to claim 9, characterized in that: The second transmission wheel (A02) is coaxially arranged with the foot pedal shaft (A05), and the first transmission wheel (A01) is fixed on the second transmission wheel (A02).

11. The dual-motor electric drive system according to any one of claims 1-10, characterized in that: Along the axial direction of the gear ring (D04), the first motor (B01) and the second motor (B03) are located on both sides of the gear ring (D04).

12. The dual-motor electric drive system according to any one of claims 1-11, characterized in that: The gear ring (D04) is mounted on the housing (C01) via bearings. The gear ring (D04) is provided with external teeth (D042), a first internal tooth (D041), and a second internal tooth (D043). The first internal tooth (D041) meshes with the external teeth of the first planetary gear (D03), the second internal tooth (D043) meshes with the external teeth of the second planetary gear (D05), and the external tooth (D042) meshes with the external teeth of the third transmission wheel (A03).

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