Dual-motor drive system and electric power-assisted vehicle

Abstract

A dual-motor drive system, comprising a central shaft (11), a first transmission wheel (100), a planetary gear set (500), a first motor (410), a second motor (420), a second transmission wheel (200), and a third transmission wheel (300). The planetary gear set (500) comprises a sun gear (510), a planetary gear mechanism (520), and a ring gear (530), and the planetary gear mechanism (520) is separately meshed with the sun gear (510) and inner teeth of the ring gear (530). The planetary gear mechanism (520) is sleeved on a planetary shaft (540), and the planetary shaft (540) is fixedly arranged on the second transmission wheel (200), so that the second transmission wheel (200) forms a planetary carrier. The first transmission wheel (100) is fixedly arranged on the central shaft (11), and the first transmission wheel (100) is transmittingly connected to the ring gear (530). A first motor shaft (411) of the first motor (410) is transmittingly connected to the ring gear (530). A second motor shaft (422) of the second motor (420) is connected to the sun gear (510) to drive the sun gear (510) to rotate. The second transmission wheel (200) is transmittingly connected to the third transmission wheel (300) to output power to a wheel. Also disclosed is an electric power-assisted vehicle, comprising the dual-motor drive system. In this way, the entire dual-motor drive system has power combination at two points, so that continuously variable adjustment can be realized more simply and more efficiently.

Description

Dual-motor drive system and electric-assisted vehicle

[0001] Cross-reference to related applications

[0002] This disclosure claims priority to Chinese Patent Application No. 202411006361.7, filed on July 25, 2024, entitled "Dual Motor Drive System and Electric Assisted Vehicle"; the entire contents of which are incorporated herein by reference. Technical Field

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

[0004] Electric bicycles, also known as hybrid bicycles or e-bikes, combine the sporty and recreational features of cycling with ease and comfort, and have become increasingly popular in the market in recent years. Currently, most electric bicycles on the market have an electric drive system consisting of a separate motor and a gear mechanism.

[0005] Most existing electric-assist bicycles use a single motor for their electric drive system, providing only assistance. Speed ​​adjustment is achieved through the bicycle's gear system. The most common method is to use traditional gear shifting to achieve stepped gear regulation. However, this method is complex and inconvenient to assemble and maintain.

[0006] Public content

[0007] The purpose of this disclosure includes, for example, providing a dual-motor drive system and an electric-assisted vehicle that can achieve continuously variable transmission (CVT) more simply and efficiently.

[0008] The embodiments of this disclosure can be implemented as follows:

[0009] In a first aspect, embodiments of this disclosure provide a dual-motor drive system, including:

[0010] Central shaft, first transmission wheel, planetary gear set, first motor, second motor, second transmission wheel, and third transmission wheel;

[0011] The planetary gear set includes a sun gear, a planetary gear mechanism, and a ring gear. The planetary gear mechanism meshes with the internal teeth of the sun gear and the ring gear. The planetary gear mechanism is sleeved on a planetary shaft, and the planetary shaft is fixed to the second transmission wheel so that the second transmission wheel forms a planet carrier.

[0012] The first transmission wheel is fixed on the central shaft, and the first transmission wheel is connected to the gear ring in a transmission connection.

[0013] The first motor shaft of the first motor is connected to the gear ring; the second motor shaft of the second motor is connected to the sun gear to drive the sun gear to rotate; the second transmission wheel is connected to the third transmission wheel to output power to the wheels.

[0014] In an optional embodiment, the centerline of the central shaft and the centerline of the second motor shaft are parallel to each other; the centerline of the second motor shaft and the centerline of the first motor shaft form an angle.

[0015] In an optional embodiment, it further includes a first mating wheel and a second mating wheel; the second mating wheel is disposed on the outer wall of the gear ring, and the first mating wheel is disposed at the end of the first motor shaft;

[0016] The first mating wheel and the second mating wheel are fitted with bevel gears.

[0017] In an optional embodiment, a speed-changing mechanism is also included; the first motor shaft is connected to the first mating wheel through the speed-changing mechanism to adjust the torque and speed output by the first motor to the first mating wheel.

[0018] In an optional implementation, a speed-changing mechanism is also included, which is integrated into the first motor shaft.

[0019] In an optional embodiment, the third drive wheel is further provided with an output wheel, which can be connected to the wheel for transmission.

[0020] In an alternative embodiment, the output wheel is configured to output power to the wheel via gears, belts, or chains.

[0021] In an optional embodiment, the planetary gear set is an NW type or NGW type gear system.

[0022] In an optional implementation, the planetary gear mechanism includes a first gear and a second gear;

[0023] The first wheel is fitted onto the planetary shaft, and the second wheel is fixed to the outside of the first wheel;

[0024] The first wheel meshes with the internal teeth of the gear ring, and the second wheel meshes with the sun gear.

[0025] In an optional embodiment, the outer teeth of the gear ring mesh with the first drive wheel.

[0026] In an optional embodiment, the second drive wheel is configured to be connected to the third drive wheel via gear drive, belt drive, or chain drive;

[0027] And / or, the first drive wheel is configured to be connected to the gear ring via gear drive, belt drive, or chain drive.

[0028] In an optional embodiment, the third drive wheel is loosely fitted onto the central shaft via a bearing.

[0029] In an optional embodiment, the third drive wheel, the gear ring, and the second drive wheel are mounted on the housing via bearings.

[0030] In an optional embodiment, the third drive wheel meshes with the second drive wheel.

[0031] In an optional embodiment, the second mating wheel and the first mating wheel mesh, and both are bevel gears.

[0032] Secondly, embodiments of this disclosure provide an electrically assisted vehicle, the electrically assisted vehicle including the aforementioned dual-motor drive system.

[0033] The beneficial effects of the embodiments disclosed herein include, for example:

[0034] This dual-motor drive system includes a bottom bracket, a first drive wheel, a planetary gear set, a first motor, a second motor, a second drive wheel, and a third drive wheel. The pedaling force drives the bottom bracket to rotate, and the first drive wheel is configured to transmit this force to the ring gear. The first motor drives the ring gear, thus achieving a first power convergence at the ring gear, combining the rider's pedaling torque and the first motor's power, resulting in power and torque superposition and equal speed matching. Furthermore, because the second motor is connected to the sun gear, it sequentially drives the sun gear, planetary gears, and then the second drive wheel. This causes a second power convergence at the second drive wheel, where the power from the first convergence at the ring gear and the second motor's power converge again, before being transmitted to the third drive wheel and finally outputting power to the wheels. In summary, the entire dual-motor drive system has two points of power convergence, achieving the innovative function of both assisting and accelerating the vehicle. Attached Figure Description

[0035] 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.

[0036] Figure 1 is a schematic diagram of the structure of the dual-motor drive system according to an embodiment of the present disclosure;

[0037] Figure 2 is a schematic diagram of the dual-motor drive system according to an embodiment of this disclosure;

[0038] Figure 3 is a schematic diagram of the structure of the dual-motor drive system according to an embodiment of the present disclosure;

[0039] Figure 4 is a schematic diagram of the dual-motor drive system according to an embodiment of this disclosure.

[0040] Icons: 11-Central shaft; 100-First transmission wheel; 200-Second transmission wheel; 300-Third transmission wheel; 333-Output wheel; 410-First motor; 411-First motor shaft; 420-Second motor; 422-Second motor shaft; 500-Planetary gear set; 510-Sun gear; 520-Planetary gear mechanism; 521-First gear; 522-Second gear; 530-Ring gear; 540-Planetary shaft; 610-First mating gear; 620-Second mating gear; 700-Speed ​​change mechanism. 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 disclosed product is usually placed, 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 configured 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 Figures 1 and 2. This embodiment provides a dual-motor drive system, including a central shaft 11, a first transmission wheel 100, a planetary gear set 500, a first motor 410, a second motor 420, a second transmission wheel 200, and a third transmission wheel 300.

[0048] The planetary gear set 500 includes a sun gear 510, a planetary gear mechanism 520, and a ring gear 530. The planetary gear mechanism 520 meshes with the internal teeth of the sun gear 510 and the ring gear 530, respectively. The planetary gear mechanism 520 is sleeved on the planetary shaft 540, and the planetary shaft 540 is fixed to the second transmission wheel 200 so that the second transmission wheel 200 forms a planet carrier.

[0049] The first transmission wheel 100 is fixed on the central shaft 11 and is connected to the gear ring 530; the first motor shaft 411 of the first motor 410 is connected to the gear ring 530; the second motor shaft 422 of the second motor 420 is connected to the sun gear 510 to drive the sun gear 510 to rotate; the second transmission wheel 200 is connected to the third transmission wheel 300 to output power to the wheels.

[0050] The two ends of the central shaft 11 along its length can be connected to crank pedals, allowing the central shaft 11 to rotate by pedaling. The pedaling force drives the central shaft 11 to rotate, and the first transmission wheel 100 is configured to transmit this force to the gear ring 530; the first motor 410 then drives the gear ring 530 to rotate. In this way, the rider's pedaling torque and the power of the first motor 410 achieve initial power convergence at the gear ring 530, resulting in power and torque superposition and equal speed matching.

[0051] Furthermore, because the second motor 420 is connected to the sun gear 510, it sequentially drives the sun gear 510, the planetary gear mechanism 520, and the second transmission wheel 200 to rotate. This causes the power from the first power convergence at the gear ring 530 to merge with the power from the second motor 420 at the second transmission wheel 200, and then transmits this power to the third transmission wheel 300, ultimately outputting power to the wheels. In summary, the entire dual-motor drive system has two points of power convergence, achieving the innovative function of both assisting and accelerating.

[0052] Please refer to Figures 1 and 2 for more structural details of the dual-motor drive system.

[0053] As shown in the figure, the centerline of the central shaft 11 and the centerline of the second motor shaft 422 are parallel to each other; the centerline of the second motor shaft 422 and the centerline of the first motor shaft 411 form an angle. This allows the first motor 410 and the second motor 420 to be arranged at an angle as needed, effectively reducing the overall thickness of the electric drive system and facilitating its placement on the vehicle. Furthermore, the first motor 410 can be concealed within the bicycle frame.

[0054] In this embodiment of the present disclosure, the dual-motor drive system further includes a first mating wheel 610 and a second mating wheel 620; the second mating wheel 620 is disposed on the outer wall of the gear ring 530, and the first mating wheel 610 is disposed at the end of the first motor shaft 411; the first mating wheel 610 and the second mating wheel 620 are engaged by bevel gears.

[0055] Specifically, the second mating wheel 620 is fixed to the outer wall of the gear ring 530. Both the first mating wheel 610 and the second mating wheel 620 are bevel gears, so that the first motor shaft 411 and the second motor shaft 422 are perpendicular to each other.

[0056] In an optional embodiment, the first mating wheel 610 and the second mating wheel 620 may also be configured as gears of other shapes, which are not limited here.

[0057] Optionally, the planetary gear set 500 can be an NW type or NGW type gear system. It is easy to understand that by adjusting the configuration of the planetary gear set 500, different power output effects can be achieved. This is just an example and is not a limitation.

[0058] Optionally, the dual-motor drive system also includes a speed change mechanism 700; the first motor shaft 411 is connected to the first mating wheel 610 through the speed change mechanism 700 to adjust the torque and speed output from the first motor 410 to the first mating wheel 610; thus, the output torque after merging can be further adjusted.

[0059] It should be noted that the transmission mechanism 700 can also be integrated into the first motor 410, thereby further reducing the volume of the first motor 410 and improving the space utilization within the frame.

[0060] In this embodiment of the present disclosure, the third transmission wheel 300 is further provided with an output wheel 333, which can be connected to the wheel for transmission. Optionally, the output wheel 333 can output power to the wheel through a transmission method such as gears, belts, or chains. For example, the output wheel 333 can be a chainring or pulley.

[0061] Optionally, the second drive wheel 200 is configured to be connected to the third drive wheel 300 via gear drive, belt drive, or chain drive; and / or, the first drive wheel 100 is configured to be connected to the gear ring 530 via gear drive, belt drive, or chain drive. Specifically, in this embodiment, the external teeth of the second drive wheel 200 mesh with the external teeth of the second drive wheel 200; the external teeth of the first drive wheel 100 mesh with the external teeth of the gear ring 530.

[0062] Optionally, the planetary gear mechanism 520 includes a first gear 521 and a second gear 522; the first gear 521 is sleeved on the planetary shaft 540, and the second gear 522 is fixed to the outside of the first gear 521; the first gear 521 meshes with the internal teeth of the gear ring 530, and the second gear 522 meshes with the sun gear 510. Understandably, the planetary gear mechanism 520 here is a double-gear structure, and the first gear 521 and the second gear 522 respectively mesh with the gear ring 530 and the sun gear 510.

[0063] As shown in Figures 1 and 2, the specific connection method of the dual-motor drive system is as follows:

[0064] The first transmission wheel 100 is fixedly connected to the central shaft 11, the third transmission wheel 300 is loosely fitted onto the central shaft 11 through a bearing, the output wheel 333 is fixedly connected to the third transmission wheel 300, and the second mating wheel 620 is fixedly connected to the gear ring 530.

[0065] The first motor shaft 411 is mounted on the rotor of the first motor 410, and the first mating wheel 610 is fixedly connected to the first motor shaft 411. The second motor shaft 422 is mounted on the rotor of the second motor 420, and the sun gear 510 is fixedly connected to the second motor shaft 422. It should be noted that the centerline of the sun gear 510 is collinear with the centerline of the second motor shaft 422.

[0066] Planetary shaft 540 is fixedly connected to the second transmission wheel 200, and the second wheel 522 is fixedly connected to the first wheel 521. The first wheel 521 is loosely fitted onto planetary shaft 540 via bearings. The third transmission wheel 300, the gear ring 530, and the second transmission wheel 200 are mounted on the housing via bearings.

[0067] The third transmission wheel 300 is constantly meshed with the second transmission wheel 200, the second mating wheel 620 and the first mating wheel 610 are bevel gears and are constantly meshed, and the sun gear 510 is constantly meshed with the second wheel 522.

[0068] The gear ring 530 has internal and external teeth integrated on it. Its external teeth are constantly meshed with the first transmission wheel 100, and its internal teeth are constantly meshed with the first wheel 521.

[0069] The sun gear 510, second gear 522, first gear 521, planetary shaft 540, second transmission gear 200, and ring gear 530 constitute a planetary gear system. This planetary gear system is of type NW, but it can also be designed as other types of planetary gear systems. The second transmission gear 200 is the planet carrier of the planetary gear system. The third transmission gear 300, ring gear 533, output gear 333, and second transmission gear 200 can be connected by gear drive, belt drive, or chain drive. The output gear 333 is the power output gear 333 of the entire drive system, which outputs power through gears, belts, or chains.

[0070] The axes of the central shaft 11 and the second motor shaft 422 are arranged parallel in space. The axes of the second motor shaft 422 and the first motor shaft 411 are arranged intersecting in space, allowing the first motor shaft 411 to be arranged at any desired angle within the cross-section of the second motor shaft 422. A speed-changing mechanism 700 can be added between the first motor shaft 411 and the first mating wheel 610 as needed to adjust the output torque and speed of the first motor 410.

[0071] Power transmission process:

[0072] The rider's pedaling force is converted into pedaling torque through the crank on the bottom bracket 11, driving the bottom bracket 11 and the first drive wheel 100 to rotate. The first drive wheel 100 then drives the gear ring 530 to rotate. Simultaneously, the driving torque of the first motor 410 drives the first mating wheel 610 to rotate through the first motor shaft 411, which in turn drives the gear ring 530 to rotate. At this point, the pedaling force and the driving force of the first motor 410 achieve the first power convergence at the gear ring 530: power and torque are superimposed on the gear ring 530, and the rotational speeds are matched and equal in real time.

[0073] The driving torque of the second motor 420 drives the sun gear 510 to rotate through the second motor shaft 422. The driving force of the sun gear 510 and the driving force of the ring gear 530 act simultaneously on the planetary gears of the first gear 521 and the second gear 522, driving the second transmission gear 200 (planet carrier) to rotate through the planetary gear system. At this time, the driving force acting on the ring gear 530 and the driving force of the second motor 420 achieve a second power convergence at the second transmission gear 200: power and speed are superimposed on the ring gear 530, and the torque is matched and equal in real time.

[0074] The second drive wheel 200 transmits the combined driving force to the third drive wheel 300, which in turn drives the third drive wheel 300 and the output wheel 333 to rotate, thereby realizing the power output of the electric drive system.

[0075] Referring to Figures 3 and 4, as an optional implementation, the dual-motor drive system may exclude the transmission mechanism 700, with the first mating wheel 610 directly mounted on the end of the first motor shaft 411. Furthermore, the planetary gear mechanism 520 consists of single-wheel planetary gears, which mesh with the internal teeth of the ring gear 530 and the sun gear 510, respectively. This arrangement results in a simpler structure and better stability.

[0076] Secondly, embodiments of this disclosure provide an electric-assisted vehicle, which includes the aforementioned dual-motor drive system. It should be noted that the electric-assisted vehicle can be an electric-assisted bicycle, an electric scooter, or an electric motorcycle, etc., and is not limited thereto.

[0077] In summary, the embodiments of this disclosure provide a dual-motor drive system and an electrically assisted vehicle, which have at least the following advantages:

[0078] The two motor shafts are arranged to intersect, which can effectively reduce the overall thickness of the electric drive system, making it easier to arrange the system on the vehicle. Moreover, the first motor 410 can be hidden inside the vehicle frame.

[0079] This transmission system couples the rider's pedaling torque with the driving torque of the dual motors, achieving an innovative function of both assisting and speed regulation in the electric drive system.

[0080] This patented technology enables stepless speed regulation of the electric drive system's output speed, eliminating the need for a gear system on the bicycle, simplifying the overall structure and reducing costs.

[0081] 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

[0082] In summary, the embodiments of this disclosure provide a dual-motor drive system and an electric-assisted vehicle, which can achieve stepless speed regulation more simply and efficiently.

Claims

1. A dual electric motor drive system, characterized by, Comprising: a middle shaft (11), a first transmission wheel (100), a planetary gear set (500), a first motor (410), a second motor (420), a second transmission wheel (200) and a third transmission wheel (300); the planetary gear set (500) comprises a sun gear (510), a planetary gear mechanism (520) and a ring gear (530), the planetary gear mechanism (520) is respectively engaged with the sun gear (510) and the inner teeth of the ring gear (530); the planetary gear mechanism (520) is sleeved on a planetary shaft (540), and the planetary shaft (540) is fixedly arranged on the second transmission wheel (200), so that the second transmission wheel (200) constitutes a planet carrier; the first transmission wheel (100) is fixedly arranged on the middle shaft (11), and the first transmission wheel (100) is in transmission connection with the ring gear (530); the first motor shaft (411) of the first motor (410) is in transmission connection with the ring gear (530); the second motor shaft (422) of the second motor (420) is connected with the sun gear (510) to drive the sun gear (510) to rotate; the second transmission wheel (200) is in transmission connection with the third transmission wheel (300) to output power to the wheels.

2. The dual-motor drive system according to claim 1, wherein: the axis of the middle shaft (11) and the axis of the second motor shaft (422) are parallel to each other; the axis of the second motor shaft (422) and the axis of the first motor shaft (411) form an included angle.

3. The dual-motor drive system according to claim 2, wherein: further comprising a first matching wheel (610) and a second matching wheel (620); the second matching wheel (620) is arranged on the outer wall of the ring gear (530), and the first matching wheel (610) is arranged on the end of the first motor shaft (411); the first matching wheel (610) and the second matching wheel (620) are in bevel gear matching.

4. The dual-motor drive system according to claim 3, wherein: further comprising a transmission mechanism (700); the first motor shaft (411) is connected with the first matching wheel (610) through the transmission mechanism (700) to adjust the torque and speed of the first motor (410) output to the first matching wheel (610).

5. The dual-motor drive system according to claim 4, wherein: further comprising a transmission mechanism (700), and the transmission mechanism (700) is integrated on the first motor shaft (411).

6. The dual-motor drive system according to any one of claims 1-5, wherein: the third transmission wheel (300) is further provided with an output wheel (333), and the output wheel (333) can be in transmission connection with the wheels.

7. The dual-motor drive system according to claim 6, wherein: the output wheel (333) is configured to output power to the wheels through gears, belts or chains.

8. The dual-motor drive system of any one of claims 1-7, wherein: the planetary gear set (500) is a NW or NGW type gear train.

9. The dual-motor drive system of any one of claims 1-8, wherein: the planetary gear mechanism (520) comprises a first wheel (521) and a second wheel (522); the first wheel (521) is sleeved on the planetary shaft (540), and the second wheel (522) is fixed on the outside of the first wheel (521); the first wheel (521) is engaged with the inner teeth of the ring gear (530), and the second wheel (522) is engaged with the sun gear (510).

10. The dual-motor drive system of any one of claims 1-9, wherein: the outer teeth of the ring gear (530) are engaged with the first transmission wheel (100).

11. The dual-motor drive system of any one of claims 1-10, wherein: the second transmission wheel (200) is configured to be connected with the third transmission wheel (300) through gear transmission, belt transmission or chain transmission; and / or, the first transmission wheel (100) is configured to be connected with the ring gear (530) through gear transmission, belt transmission or chain transmission.

12. The dual-motor drive system of any one of claims 1-11, wherein: the third transmission wheel (300) is loosely sleeved on the central shaft (11) through a bearing.

13. The dual-motor drive system of any one of claims 1-12, wherein: the third transmission wheel (300), the ring gear (530) and the second transmission wheel (200) are mounted on a box through bearings.

14. The dual-motor drive system of any one of claims 1-13, wherein: the third transmission wheel (300) is engaged with the second transmission wheel (200).

15. The dual-motor drive system of any one of claims 1-14, wherein: the second mating wheel (620) and the first mating wheel (610) are engaged, and both are bevel gears.

16. An electrically assisted vehicle, comprising the dual-motor drive system of any one of claims 1-15. ​

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