Electric drive system and e-bike

Abstract

Provided are an electric drive system and an e-bike. The electric drive system comprises a first planetary gear train, a second planetary gear train, a first motor (04), a second motor (09), a first drive wheel (08), a chain wheel (13) and a bottom bracket shaft (14), wherein the first motor (04) is in transmission fit with a first sun wheel, and the second motor (09) is in transmission fit with a second sun wheel (12); the first drive wheel (08) is supported by means of a first bearing (21) to rotate; the end of at least one second planet shaft (10) away from a second planet wheel (07) is connected to the first drive wheel (08); and the chain wheel (13) is in transmission fit with the first drive wheel (08), and a third drive wheel (16) on the bottom bracket shaft (14) is in transmission fit with a gear ring (06) so as to drive the gear ring (06) to rotate by means of the rotation of the bottom bracket shaft (14). The system can achieve stepless variable-speed regulation, such that the e-bike does not need to be additionally provided with a speed control system any more, thereby simplifying the whole vehicle structure and thus reducing the cost.

Description

Electric drive systems and electric bicycles

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This disclosure claims priority to Chinese patent application number 202410230365.7, filed with the Chinese Patent Office on February 29, 2024, and entitled “Electric Drive System and Electric Bicycle”;

[0003] And the priority of the Chinese patent application with application number 202420401031.7 and titled “Electric Drive System and Electric Bicycle” filed with the China Patent Office on February 29, 2024, the entire contents of which are incorporated by reference into this disclosure. Technical Field

[0004] The present disclosure relates to the field of transmission technology, and in particular to an electric drive system and an electric bicycle. Background Art

[0005] Electric bicycles, also known as hybrid bicycles or ebikes, have become increasingly popular in recent years due to their combination of the leisure and effortlessness of cycling. Currently, most electric bicycles on the market use a separate electric drive system consisting of a motor and a transmission mechanism.

[0006] Such a structure can only meet the needs of electric drive, but cannot achieve convenient and fast speed change; at the same time, the separate motor and speed change mechanism make the entire electric drive system complex in structure and large in size, which brings inconvenience to loading and unloading and maintenance.

[0007] Public content

[0008] The objectives of the present disclosure include, for example, providing an electric drive system and an electric bicycle, which can simplify the electric drive system. The electric drive system can be used for stepless speed adjustment, and there is no need to install a speed change system on the bicycle, which simplifies the structure of the entire vehicle and reduces costs.

[0009] The embodiments of the present disclosure may be implemented as follows:

[0010] In a first aspect, the present disclosure provides an electric drive system, comprising:

[0011] a first planetary gear train, a second planetary gear train, a first motor, a second motor, a first transmission wheel, a sprocket, and a central shaft;

[0012] The first planetary gear train includes a ring gear, a first planet carrier, a first sun gear, a plurality of first planet gears, and a plurality of first planet shafts; the plurality of first planet gears are circumferentially arranged around the first sun gear, and each of the planet gears is meshed with the first sun gear and the ring gear; the plurality of first planet shafts are matched with the plurality of first planet gears in a one-to-one correspondence, and the first planet shafts are arranged at the centers of the corresponding first planet gears; the first planet carrier is integrated on the housing, and the plurality of first planet shafts are mounted on the first planet carrier;

[0013] The first motor cooperates with the first sun gear to drive the first sun gear to rotate;

[0014] The second planetary gear train includes a ring gear, a second sun gear, a plurality of second planet gears, and a plurality of second planet shafts; the plurality of second planet gears are circumferentially arranged around the second sun gear, and each of the planet gears is meshed with the second sun gear and the ring gear; the plurality of second planet shafts are matched with the plurality of second planet gears in a one-to-one correspondence, and the second planet shafts are arranged at the center of the corresponding second planet gears;

[0015] The second motor cooperates with the second sun gear to drive the second sun gear to rotate;

[0016] The first transmission wheel is supported by a first bearing to achieve rotation, and the axis of the first bearing, the axis of the first sun gear, and the axis of the second sun gear are all coaxially arranged; at least one of the second planetary shafts is connected to the first transmission wheel at one end away from the second planetary gear, so that the first transmission wheel can be driven to rotate when the second planetary gear revolves;

[0017] The sprocket is in transmission cooperation with the first transmission wheel so that the first transmission wheel can drive the sprocket to rotate;

[0018] A third transmission wheel is provided on the central shaft, and the third transmission wheel cooperates with the ring gear to drive the ring gear to rotate through the rotation of the central shaft.

[0019] The electric drive system of this solution includes a first planetary gear train, a second planetary gear train, a first motor, a second motor, a first transmission wheel, a sprocket, and a central shaft. The first planetary gear train and the second planetary gear train share a ring gear, and the two sun gears are coaxially arranged. When pedaling alone, the pedaling force drives the central shaft to rotate through the crank, and at the same time, the third transmission wheel on the central shaft drives the ring gear to rotate; the first motor cooperates with the first planetary gear train to drive the ring gear to rotate, and the ring gear can drive the first transmission wheel that cooperates with the second planetary gear train to rotate, and then drive the sprocket that cooperates with the first transmission wheel to rotate, thus achieving the effect of providing power for the bicycle. It should be noted that at this time, the driving force from pedaling and the power of the first motor achieve the first power confluence at the ring gear (power and torque are superimposed, and the speed matching is equal), thereby achieving the first electric power assistance and the first speed change. The second motor, in conjunction with the second planetary gear train, drives the second planetary gear to orbit, thereby rotating the first transmission wheel connected to the second planetary gear, and further rotating the sprocket in conjunction with the first transmission wheel, thus providing power assistance to the bicycle. At this point, the power that first merged at the ring gear and the power of the second motor merged a second time at the first transmission wheel (power and speed are superimposed, and torque is matched equally), thus achieving a second electric power assist and a second speed change. The transmission system increases the rider's pedaling torque and combines it with the auxiliary torque of the second motor to achieve power output from the electric drive system, thus achieving the functional innovation of the electric bicycle electric drive system that both assists power and speed.

[0020] In an optional embodiment, the first planetary gear train and the second planetary gear train share a ring gear, and the first sun gear and the second sun gear are coaxially arranged.

[0021] In an optional embodiment, along the axial direction of the ring gear, the first motor and the second motor are respectively located on both sides of the ring gear.

[0022] In an optional embodiment, along the axial direction of the ring gear, the first motor and the second motor are respectively located on the same side of the ring gear.

[0023] In an optional embodiment, the first motor has a first motor shaft, and the first sun gear is fixed on the first motor shaft; the second motor has a second motor shaft, and the second sun gear is fixed on the second motor shaft.

[0024] In an optional embodiment, the center of the first motor shaft has a mating channel extending through the first motor shaft in the axial direction, the second motor shaft passes through the mating channel, and the second motor shaft is rotatably mated with the mating channel.

[0025] Or the center of the second motor shaft has a matching channel running through it along the axial direction, the first motor shaft passes through the matching channel, and the first motor shaft is rotatably matched with the matching channel.

[0026] In an alternative embodiment, the first motor shaft and the second motor shaft are kept coaxially arranged.

[0027] In an optional embodiment, a second transmission wheel is further included;

[0028] The second transmission wheel is coaxially arranged with the sprocket; the first transmission wheel and the second transmission wheel are in transmission cooperation, so that when the first transmission wheel rotates, the sprocket is driven to rotate through the second transmission wheel.

[0029] In an optional embodiment, the second transmission wheel is coaxially arranged with the central shaft, and the sprocket is fixed on the second transmission wheel.

[0030] In an optional embodiment, one end of the second planetary shaft is rotatably disposed in the second planetary gear via a bearing, and the other end of the second planetary shaft is fixed to the first transmission gear.

[0031] In an optional embodiment, the third transmission wheel is fixed on the central shaft by a flat key, and the third transmission wheel and the outer peripheral surface of the ring gear are matched in a gear transmission manner.

[0032] In an optional embodiment, one end of the first planetary shaft is rotatably disposed in the first planetary gear via a bearing.

[0033] In an optional embodiment, the plurality of second planetary shafts are all provided on the first transmission wheel, so that the first transmission wheel can serve as a planet carrier for the plurality of second planetary wheels.

[0034] In an optional embodiment, the outer diameters of the first sun gear and the second sun gear are the same, and the outer diameters of the first planet gear and the second planet gear are the same.

[0035] In a second aspect, the present disclosure provides an electric bicycle comprising the electric drive system according to any one of the aforementioned embodiments.

[0036] In an optional embodiment, the electric bicycle further includes a frame, a front wheel and a rear wheel. The frame has a middle shaft tube, the middle shaft is rotatably disposed in the middle shaft tube, and the front wheel and the rear wheel are rotatably disposed at the front and rear ends of the frame respectively.

[0037] In an optional embodiment, the sprocket and the rear wheel are coupled via a rack and pinion transmission.

[0038] The beneficial effects of the embodiments of the present disclosure include, for example:

[0039] The electric drive system of this solution includes a first planetary gear train, a second planetary gear train, a first motor, a second motor, a first transmission wheel, a sprocket, and a central shaft. The first planetary gear train and the second planetary gear train share a ring gear, and the two sun gears are coaxially arranged. When pedaling alone, the pedaling force drives the central shaft to rotate through the crank, and at the same time, the third transmission wheel on the central shaft drives the ring gear to rotate; the first motor cooperates with the first planetary gear train to drive the ring gear to rotate, and the ring gear can drive the first transmission wheel that cooperates with the second planetary gear train to rotate, and then drive the sprocket that cooperates with the first transmission wheel to rotate, thus achieving the effect of providing power for the bicycle. It should be noted that at this time, the driving force from pedaling and the power of the first motor achieve the first power confluence at the ring gear (power and torque are superimposed, and the speed matching is equal), thereby achieving the first electric power assistance and the first speed change. The second motor, in conjunction with the second planetary gear train, drives the second planetary gear to orbit, thereby rotating the first transmission wheel connected to the second planetary gear, and further rotating the sprocket in conjunction with the first transmission wheel, thus providing power assistance to the bicycle. At this time, the power that first merged at the ring gear and the second motor power merged a second time at the first transmission wheel (power and speed are superimposed, and torque is matched equally), thus achieving a second electric power assist and a second speed change. The transmission system increases the rider's pedaling torque and combines it with the auxiliary torque of the second motor to achieve power output from the electric drive system, thus achieving the functional innovation of the electric bicycle's electric drive system, which both assists power and speed. At the same time, by eliminating the separate gear shifting mechanism, the overall vehicle structure is simplified, reducing costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present disclosure, the following briefly introduces the drawings required for use in the embodiments. It should be understood that the following drawings only illustrate certain embodiments of the present disclosure and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other relevant drawings can be obtained based on these drawings without creative work.

[0041] FIG1 is a schematic structural diagram of an electric drive system according to an embodiment of the present disclosure;

[0042] FIG2 is a schematic structural diagram of an electric drive system according to an embodiment of the present disclosure.

[0043] Icon: 01-first sun gear; 02-first motor shaft; 03-first planetary shaft; 04-first motor; 05-first planetary gear; 06-ring gear; 07-second planetary gear; 08-first transmission gear; 09-second motor; 10-second planetary shaft; 11-second motor shaft; 12-second sun gear; 13-sprocket; 14-middle shaft; 15-second transmission gear; 16-third transmission gear; 21-first bearing; 31-matching channel. DETAILED DESCRIPTION

[0044] To make the objectives, technical solutions, and advantages of the embodiments of the present disclosure more clear, the technical solutions of the embodiments of the present disclosure will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present disclosure. Obviously, the described embodiments are only some of the embodiments of the present disclosure, but not all of them. Generally, the components of the embodiments of the present disclosure described and shown in the drawings herein can be arranged and designed in various different configurations.

[0045] Therefore, the following detailed description of the embodiments of the present disclosure provided in the accompanying drawings is not intended to limit the scope of the present disclosure as claimed, but merely represents selected embodiments of the present disclosure. All other embodiments derived by persons of ordinary skill in the art based on the embodiments of the present disclosure without creative effort shall fall within the scope of protection of the present disclosure.

[0046] It should be noted that similar reference numerals and letters denote similar items in the following drawings, and therefore, once an item is defined in one drawing, it does not need to be further defined or explained in subsequent drawings.

[0047] In the description of the present disclosure, it should be noted that if the terms "upper", "lower", "inside", "outside", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the accompanying drawings, or is the orientation or position relationship in which the disclosed product is usually placed when in use. It is only for the convenience of describing the present disclosure and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it cannot be understood as a limitation on the present disclosure.

[0048] In addition, the terms “first”, “second”, etc., if used, are merely used to distinguish and describe, and should not be understood as indicating or implying relative importance.

[0049] It should be noted that, in the absence of conflict, the features in the embodiments of the present disclosure may be combined with each other.

[0050] Please refer to FIG. 1 . This embodiment provides an electric drive system, including a first planetary gear train, a second planetary gear train, a first motor 04 , a second motor 09 , a first transmission wheel 08 , a sprocket 13 , and a central shaft 14 .

[0051] The first planetary gear train includes a ring gear 06, a first planet carrier, a first sun gear 01, multiple first planet gears 05 and multiple first planet shafts 03; the multiple first planet gears 05 are circumferentially arranged around the first sun gear 01, and each planet gear is engaged with the first sun gear 01 and the ring gear 06; the multiple first planet shafts 03 are matched with the multiple first planet gears 05 in a one-to-one correspondence, and the first planet shafts 03 are arranged at the center of the corresponding first planet gears 05; the first planet carrier is integrated on the housing, and the multiple first planet shafts 03 are installed on the first planet carrier.

[0052] The first motor 04 cooperates with the first sun gear 01 to drive the first sun gear 01 to rotate.

[0053] The second planetary gear train includes a ring gear 06, a second sun gear 12, multiple second planetary gears 07 and multiple second planetary shafts 10; the multiple second planetary gears 07 are circumferentially arranged around the second sun gear 12, and each planetary gear is meshed with the second sun gear 12 and the ring gear 06; the multiple second planetary shafts 10 are matched with the multiple second planetary gears 07 in a one-to-one correspondence, and the second planetary shafts 10 are set at the center of the corresponding second planetary gears 07.

[0054] The second motor 09 cooperates with the second sun gear 12 to drive the second sun gear 12 to rotate.

[0055] The first transmission wheel 08 is supported by the first bearing 21 to achieve rotation, and the axis of the first bearing 21, the axis of the first sun gear 01 and the axis of the second sun gear 12 are all coaxially arranged; at least one second planetary shaft 10 is connected to the first transmission wheel 08 at one end away from the second planetary gear 07, so that when the second planetary gear 07 revolves, the first transmission wheel 08 can be driven to rotate.

[0056] The sprocket 13 is coupled to the first transmission wheel 08, enabling the first transmission wheel 08 to drive the sprocket 13 in rotation. It should be noted that in this embodiment, the sprocket 13 and the first transmission wheel 08 are not directly connected. Instead, the first transmission wheel 08 and the second transmission wheel 15 are coupled to each other, which in turn drives the sprocket 13. Specifically, the first transmission wheel 08 and the second transmission wheel 15 are meshed with spur gears; the sprocket 13 is directly mounted on the outside of the second transmission path. It should be noted that this arrangement is merely an example.

[0057] A third transmission wheel 16 is provided on the central shaft 14 , and the third transmission wheel 16 cooperates with the ring gear 06 to drive the ring gear 06 to rotate through the rotation of the central shaft 14 .

[0058] The first and second planetary gear trains of the electric drive system of this solution share a ring gear 06, and the first sun gear 01 and the second sun gear 12 are arranged coaxially. When pedaling alone, the pedaling force drives the central shaft 14 to rotate through the crank, and the third transmission wheel 16 on the central shaft 14 drives the ring gear 06 to rotate. The first motor 04 cooperates with the first planetary gear train to drive the ring gear 06 to rotate, and the ring gear 06 can drive the first transmission wheel 08, which is in conjunction with the second planetary gear train, to rotate, thereby driving the sprocket 13 that cooperates with the first transmission wheel 08 to rotate, thus achieving the effect of providing power for the bicycle. It should be noted that at this time, the driving force from pedaling and the power of the first motor 04 achieve the first power convergence at the ring gear 06 (power and torque are superimposed, and the speed matching is equal), thereby achieving the first electric power assistance and the first speed change.

[0059] The second motor 09, in conjunction with the second planetary gear train, drives the second planetary gears to orbit, thereby rotating the first transmission wheel 08 connected to the second planetary gears, and further rotating the sprocket 13 in conjunction with the first transmission wheel 08, thereby providing power assistance to the bicycle. The power initially combined at the ring gear 06 and the power from the second motor 09 are then combined at the first transmission wheel 08 for a second time (power and speed are superimposed, and torque is matched), thus achieving a second round of electric power assistance and a second speed change.

[0060] Specifically, the entire system has two power confluences, achieving the innovative function of both power and speed boosting:

[0061] The pedal driving force and the power of the first motor 04 realize the first power convergence at the ring gear 06 (power and torque are superimposed, and the speed matching is equal); the power converged at the ring gear 06 and the power of the second motor 09 realize the second power convergence at the first transmission wheel 08 (power and speed are superimposed, and the torque matching is equal).

[0062] The transmission system increases the rider's pedaling torque and the auxiliary torque of the second motor 09 to achieve power output of the electric drive system, thus realizing the functional innovation of the electric bicycle electric drive system in both power and speed assistance.

[0063] It should be noted that the planet carrier of the second planetary gear train is integrated into the first transmission wheel 08. In this embodiment, the second planet carrier is actually provided with a gear.

[0064] Continuing with Figure 1, it can be seen that in an optional embodiment, along the axis of the ring gear 06, the first motor 04 and the second motor 09 are located on either side of the ring gear 06. This arrangement creates a harmonious and symmetrical overall structure, enhancing the aesthetics of the product. The two motors are located on either side of the housing to facilitate heat dissipation.

[0065] In an alternative embodiment, the first motor 04 has a first motor shaft 02, with the first sun gear 01 fixedly mounted on the first motor shaft 02; the second motor 09 has a second motor shaft 11, with the second sun gear 12 fixedly mounted on the second motor shaft 11. Furthermore, the first motor shaft 02 and the second motor shaft 11 are coaxially arranged, i.e., the axis of the first motor shaft 02 and the axis of the second motor shaft 11 are coaxially aligned, thereby ensuring operational stability of the first motor 04, the second motor 09, the first planetary gear train, and the second planetary gear train.

[0066] As can also be seen from the figure, in this embodiment, the third transmission wheel 16 is fixed to the central shaft 14 via a flat key, and the third transmission wheel 16 is gear-coupled with the outer circumference of the ring gear 06. Furthermore, the third transmission wheel 16 and the ring gear 06 are spur gears, and the axis of the third transmission wheel 16 and the ring gear 06 remain parallel.

[0067] In an alternative embodiment, one end of the first planetary shaft 03 is rotatably mounted in the first planetary gear 05 via a bearing. One end of the second planetary shaft 10 is rotatably mounted in the second planetary gear 07 via a bearing, and the other end of the second planetary shaft 10 is fixed to the first transmission gear 08. This ensures that the planetary gears can freely achieve rotational and orbital motion.

[0068] Furthermore, multiple second planetary shafts 10 are mounted on the first transmission gear 08, allowing the first transmission gear 08 to serve as a planet carrier for the multiple second planetary gears 07. In other words, the first transmission gear 08 is integrated with the planet carrier of the second planetary gear train, further simplifying the overall structure. The first transmission gear 08 is mounted on the second motor shaft 11 via a bearing sleeve.

[0069] In an alternative embodiment, the first sun gear 01 and the second sun gear 12 have the same outer diameter, and the first planet gear 05 and the second planet gear 07 have the same outer diameter. This allows the dimensions of the components of the first and second planetary gear trains to be the same, increasing the versatility and interchangeability of the components of the planetary gear trains and facilitating maintenance and repair.

[0070] Optionally, the electric drive system further includes a second transmission wheel 15; the second transmission wheel 15 is coaxially arranged with the sprocket 13; the first transmission wheel 08 and the second transmission wheel 15 are in transmission engagement, such that when the first transmission wheel 08 rotates, the sprocket 13 is driven by the second transmission wheel 15. Furthermore, the second transmission wheel 15 is sleeved on the outer peripheral wall of the central axle 14 via a bearing, and the second transmission wheel 15, the third transmission wheel 16, and the central axle 14 are coaxially arranged. The sprocket 13 is fixed to the second transmission wheel 15. The sprocket 13 is sleeved on the outer periphery of the second transmission wheel 15 and is coaxially arranged with the second transmission wheel 15. The sprocket 13 here can be used directly as a chainring to directly drive the chain drive and drive the rear wheel of the bicycle to rotate.

[0071] Furthermore, a gear transmission is implemented between the second transmission wheel 15 and the first transmission wheel 08. Specifically, the first transmission wheel 08 and the second transmission wheel 15 are spur gears, and the axis of the third transmission wheel 16 and the gear ring 06 remain parallel.

[0072] It is understandable that in other embodiments of the present solution, helical gear transmission, belt transmission or chain transmission may be used between the third transmission wheel 16 and the ring gear 06, and between the first transmission wheel 08 and the second transmission wheel 15. This is merely an example and is not intended to be limiting.

[0073] Referring to Figure 2 , as another alternative embodiment of this solution, the first motor 04 and the second motor 09 are located on the same side of the ring gear 06 along the axis of the ring gear 06. This same-side arrangement can further reduce the size of the electric drive system and improve vehicle space utilization.

[0074] Optionally, the center of the first motor shaft 02 has a mating channel 31 passing through it along the axial direction, the second motor shaft 11 is provided with the mating channel 31, and the second motor shaft 11 and the mating channel 31 are rotatably mated; or the center of the second motor shaft 11 has a mating channel 31 passing through it along the axial direction, the first motor shaft 02 is provided with the mating channel 31, and the first motor shaft 02 and the mating channel 31 are rotatably mated.

[0075] Specifically, as shown in FIG. 2 , the first motor shaft 02 is provided with a matching channel 31 , and the second motor shaft 11 passes through the matching channel 31 and is fixedly connected to the second sun gear 12 .

[0076] During assembly, the third transmission gear 16 is mounted on the central shaft 14, the second transmission gear 15 is loosely mounted on the central shaft 14, and the sprocket 13 is mounted on the second transmission gear 15. The first motor shaft 02 is mounted on the rotor of the first motor 04, the first sun gear 01 is integrated with the first motor shaft 02, the second motor shaft 11 is mounted on the rotor of the second motor 09, and the second sun gear 12 is integrated with the second motor shaft 11. The first planetary shaft 03 is fixed to the housing, the first planetary gear 05 is loosely mounted on the first planetary shaft 03, the second planetary shaft 10 is mounted on the first transmission gear 08, the second planetary gear 07 is loosely mounted on the second planetary shaft 10, and the first transmission gear 08 is loosely mounted on the second motor shaft 11. The ring gear 06 is mounted on the housing via bearings.

[0077] Power transmission process:

[0078] The rider's pedaling force is converted into pedaling torque on the central shaft 14 through the crank, driving the central shaft 14 and the third transmission wheel 16 to rotate. The third transmission wheel 16 then drives the ring gear 06. Simultaneously, the driving torque of the first motor 04 drives the first sun gear 01 via the first motor shaft 02. Since the first planetary shaft 03 is stationary, the ring gear 06 rotates via the first planetary gear train. At this point, the pedaling force and the driving force of the first motor 04 achieve a first power convergence at the ring gear 06: the power and torque are superimposed on the ring gear 06, and the speeds are instantly matched.

[0079] The driving torque of the second motor 09 rotates the second sun gear 12 via the second motor shaft 11. The driving force of the second sun gear 12 and the driving force of the ring gear 06 simultaneously act on the second planetary gears 07, driving the first transmission gear 08 (planet carrier) through the second planetary gear train. At this point, the driving force acting on the ring gear 06 and the driving force of the second motor 09 combine at the first transmission gear 08, achieving a second power confluence: the power and speed are combined and acted on the ring gear 06, achieving real-time torque matching.

[0080] The first transmission wheel 08 transmits the combined driving force to the second transmission wheel 15, driving the second transmission wheel 15 and the sprocket 13 to rotate, thereby realizing power output of the electric drive system.

[0081] In a second aspect, the present disclosure provides an electric bicycle comprising the electric drive system of any of the aforementioned embodiments. Furthermore, the electric bicycle comprises a frame, a front wheel, a rear wheel, and the electric drive system of any of the aforementioned embodiments. The frame comprises a bottom bracket, in which a bottom bracket 14 is rotatably disposed. The front and rear wheels are rotatably disposed at the front and rear ends of the frame, respectively. The sprocket 13 is coupled to the rear wheel via a rack and pinion transmission.

[0082] In summary, the embodiments of the present disclosure provide an electric drive system and an electric bicycle, which have at least the following advantages:

[0083] This solution uses the second motor 09 to achieve stepless speed regulation of the output speed of the electric drive system. The bicycle no longer needs to be equipped with a speed change system, which simplifies the entire vehicle structure and reduces costs.

[0084] The transmission system increases the rider's pedaling torque and the auxiliary torque of the second motor 09 to achieve power output of the electric drive system, realizing the functional innovation of the electric bicycle electric drive system in both power and speed assistance.

[0085] The above are only specific embodiments of the present disclosure, but the scope of protection of the present disclosure is not limited thereto. Any changes or substitutions that can be easily conceived by a person skilled in the art within the technical scope disclosed in this disclosure should be included in the scope of protection of the present disclosure. Therefore, the scope of protection of the present disclosure should be based on the scope of protection of the claims. Industrial Applicability

[0086] In summary, the embodiments of the present disclosure provide an electric drive system and an electric bicycle, which can simplify the electric drive system and achieve stepless speed adjustment through the electric drive system. There is no need to install a speed change system on the bicycle, which simplifies the overall vehicle structure and reduces costs.

Claims

1. An electric drive system, characterized in that: include: A first planetary gear train, a second planetary gear train, a first motor (04), a second motor (09), a first transmission wheel (08), a sprocket (13) and a central shaft (14); The first planetary gear train comprises a ring gear (06), a first planet carrier, a first sun gear (01), a plurality of first planetary gears (05) and a plurality of first planetary shafts (03); the plurality of first planetary gears (05) are circumferentially arranged around the first sun gear (01), and each of the planetary gears is meshed with the first sun gear (01) and the ring gear (06); A plurality of the first planetary shafts (03) are matched with a plurality of the first planetary gears (05) in a one-to-one correspondence, and the first planetary shafts (03) are arranged at the center of the corresponding first planetary gears (05); the first planetary carrier is integrated on the housing, and the plurality of the first planetary shafts (03) are mounted on the first planetary carrier; the first motor (04) is matched with the first sun gear (01) in transmission so as to be able to drive the first sun gear (01) to rotate; The second planetary gear train includes a ring gear (06), a second sun gear (12), a plurality of second planetary gears (07) and a plurality of second planetary shafts (10); the plurality of second planetary gears (07) are circumferentially arranged around the second sun gear (12), and each of the planetary gears is meshed with the second sun gear (12) and the ring gear (06); the plurality of second planetary shafts (10) are matched with the plurality of second planetary gears (07) in a one-to-one correspondence, and the second planetary shafts (10) are arranged at the center of the corresponding second planetary gears (07); the second motor (09) is matched with the second sun gear (12) in transmission so as to be able to drive the second sun gear (12) to rotate; The first transmission wheel (08) is supported by a first bearing (21) to achieve rotation, and the axis of the first bearing (21), the axis of the first sun wheel (01) and the axis of the second sun wheel (12) are all coaxially arranged; at least one end of the second planetary shaft (10) away from the second planetary wheel (07) is connected to the first transmission wheel (08) to achieve the rotation of the first transmission wheel (08) when the second planetary wheel (07) revolves; The sprocket (13) is in transmission cooperation with the first transmission wheel (08), so that the first transmission wheel (08) can drive the sprocket (13) to rotate; A third transmission wheel (16) is provided on the central shaft (14), and the third transmission wheel (16) is in transmission cooperation with the ring gear (06) so as to drive the ring gear (06) to rotate by rotating the central shaft (14).

2. The electric drive system according to claim 1, characterized in that: The first planetary gear train and the second planetary gear train share a ring gear (06), and the first sun gear (01) and the second sun gear (12) are coaxially arranged.

3. The electric drive system according to claim 1 or 2, characterized in that: Along the axial direction of the gear ring (06), the first motor (04) and the second motor (09) are respectively located on both sides of the gear ring (06).

4. The electric drive system according to any one of claims 1 to 3, characterized in that: Along the axial direction of the gear ring (06), the first motor (04) and the second motor (09) are respectively located on the same side of the gear ring (06).

5. The electric drive system according to claim 4, characterized in that: The first motor (04) has a first motor shaft (02), and the first sun gear (01) is fixed on the first motor shaft (02); the second motor (09) has a second motor shaft (11), and the second sun gear (12) is fixed on the second motor shaft (11).

6. The electric drive system according to claim 5, characterized in that: The center of the first motor shaft (02) has a matching channel (31) running through it along the axial direction, the second motor shaft (11) passes through the matching channel (31), and the second motor shaft (11) and the matching channel (31) are rotatably matched; Or the center of the second motor shaft (11) has a matching channel (31) penetrating along the axial direction, the first motor shaft (02) is provided with the matching channel (31), and the first motor shaft (02) and the matching channel (31) are rotatably matched.

7. The electric drive system according to claim 5 or 6, characterized in that: The first motor shaft (02) and the second motor shaft (11) are kept coaxially arranged.

8. The electric drive system according to any one of claims 1 to 7, characterized in that: Also includes a second transmission wheel (15); The second transmission wheel (15) is coaxially arranged with the sprocket (13); the first transmission wheel (08) and the second transmission wheel (15) are in transmission cooperation, so that when the first transmission wheel (08) rotates, the sprocket (13) is driven to rotate through the second transmission wheel (15).

9. The electric drive system according to claim 8, characterized in that: The second transmission wheel (15) is coaxially arranged with the central shaft (14), and the sprocket (13) is fixed on the second transmission wheel (15).

10. The electric drive system according to any one of claims 1 to 9, characterized in that: The third transmission wheel (16) is fixed on the central shaft (14) via a flat key, and the third transmission wheel (16) and the outer peripheral surface of the gear ring (06) are gear transmission matched.

11. The electric drive system according to any one of claims 1 to 10, characterized in that: One end of the first planetary shaft (03) is rotatably arranged in the first planetary gear (05) via a bearing.

12. The electric drive system according to any one of claims 1 to 11, characterized in that: One end of the second planetary shaft (10) is rotatably arranged in the second planetary wheel (07) through a bearing, and the other end of the second planetary shaft (10) is fixed on the first transmission wheel (08).

13. The electric drive system according to any one of claims 1 to 12, characterized in that: The plurality of second planetary shafts (10) are all arranged on the first transmission wheel (08), so that the first transmission wheel (08) can serve as a planet carrier for the plurality of second planetary wheels (07).

14. The electric drive system according to any one of claims 1 to 13, characterized in that: The first sun gear (01) and the second sun gear (12) have the same outer diameter, and the first planet gear (05) and the second planet gear (07) have the same outer diameter.

15. An electric bicycle, characterized in that: The electric bicycle comprises the electric drive system according to any one of claims 1 to 14.

16. The electric bicycle according to claim 15, characterized in that: The electric bicycle further comprises a frame, a front wheel and a rear wheel. The frame is provided with a middle shaft cylinder. The middle shaft (14) is rotatably arranged in the middle shaft cylinder. The front wheel and the rear wheel are rotatably arranged at the front and rear ends of the frame respectively.

17. The electric bicycle according to claim 16, characterized in that: The sprocket (13) and the rear wheel are matched through a gear rack transmission.

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