Electric two-wheeler gapless adaptive compensation central drive system

Abstract

The utility model discloses a kind of electric two-wheeled vehicle gapless self-adaptive compensation central drive system, including wheel hub assembly and respectively arranged motor assembly and speed reducer assembly in the both sides of wheel hub assembly, motor shaft is provided with gapless self-adaptive compensation washer, and the bearing self-adaptive compensation disc spring group is elastically supported between this gapless self-adaptive compensation washer and the inner ring of motor box bearing.Using the above structure, not only have the overall advantages of central drive arrangement form, and by adding gapless self-adaptive compensation washer and bearing self-adaptive compensation disc spring group between motor shaft and the motor box bearing located in the inner end of motor shaft, equivalent to eliminating the axial gap of motor shaft, using bearing self-adaptive compensation disc spring group, when small axial displacement and jitter of motor shaft occur, the energy of small axial displacement and jitter can be absorbed, so that it can not only play very effective damping and noise reduction effect, but also delay the wear of motor shaft and tool, prolong the service life of motor.

Description

Technical Field

[0001] This utility model relates to the field of electric drive system technology, specifically to a gapless adaptive compensation central drive system for an electric two-wheeled vehicle. Background Technology

[0002] Electric two-wheelers are mechatronic personal transportation vehicles that use batteries as auxiliary power and are based on two-wheeled vehicles, equipped with components such as motors, controllers, and display instrument systems. They are not only a means of transportation but have also evolved into new tools for leisure, entertainment, and green travel. They can also meet needs such as fitness, expressing individuality, and social interaction, offering significant advantages in terms of economy and convenience.

[0003] In-wheel motors are a new type of power transmission technology that embeds a motor inside the wheel hub. Through steel plates and coils on the motor, a magnetic field is generated under the influence of an electric current, thereby driving the rotation of the rear wheel. This enables various functions in electric vehicles and has become an important technology for electric cars and motorcycles. The advantages of in-wheel motors are: low cost, ease of maintenance, and wide application. In-wheel motor technology, also known as in-wheel motor technology, is an advanced drive method applied to electric vehicles and is frequently used in integrated electric wheel systems developed by automotive component manufacturers. In-wheel motor technology has great development potential.

[0004] However, hub motors still have some problems:

[0005] 1. Under smooth road conditions and working conditions, the hub motor mainly uses the rated power; under driving conditions and working conditions such as starting, acceleration, slope, overload, and headwind, the hub motor uses the peak power.

[0006] 2. Hub motors generally do not have a transmission system and are low-speed motors. Therefore, their energy density is low. During long-term high-speed riding, hub motors may fail to accelerate, resulting in poor acceleration. They also have high current and energy consumption during starting and hill riding. Consequently, hub motors have low overall driving efficiency and short range.

[0007] 3. Regarding the power output curve of the hub motor, the high-efficiency platform load and speed of the motor deviate from the wheel load and speed, indicating limited efficient driving conditions. Specifically, the energy conversion efficiency at startup is approximately 5%-10%, gradually increasing from 10% to 60%-65% from initial acceleration to the rated power maximum speed; the energy conversion efficiency is approximately 40% when driving on a slope of less than 20°; the energy conversion efficiency is 20%-35% when driving under overload conditions or on slopes greater than 20°; and the energy conversion efficiency is 60%-65% when driving on ideal roads and in windless, favorable conditions.

[0008] 4. The hub motor structure places the motor inside the wheel hub. Through steel plates and coils on the motor, a magnetic field is generated under the influence of current, thus driving the rotation of the rear wheel in a closed structure. The motor rotor is connected to the tire, resulting in extremely poor heat dissipation. Prolonged operation causes the motor temperature to rise, leading to increased energy consumption and reduced efficiency. It can even cause tire blowouts, motor demagnetization, and rust, shortening the lifespan of the electric two-wheeler and impacting its overall efficiency.

[0009] 5. The hub motor is installed inside the hub, and its power is also limited due to the space constraints of the hub's inner diameter.

[0010] 6. When the hub motor starts or is driven on a slope, causing the motor to be unable to rotate and the battery to draw a large current, the battery's charging and discharging characteristics and power may become mismatched. This will not only affect the proper discharge and balanced power supply of the battery and affect its lifespan, but also cause the cables to burn due to overload and overheating, and the controller to be damaged by frequent high current surges.

[0011] 7. Hub motors have high overall road operating and additional costs, and low reliability.

[0012] 8. Over 95% of electric two-wheelers require an installation size of less than 200 mm. Larger and heavier hub motors negatively impact handling and road feel. Specifically, when electric two-wheelers are required to reach speeds exceeding 100 km / h, the increased size and weight not only increase costs but also significantly increase the rotational inertia of the unsprung mass around the kingpin. This leads to poorer directional force response, a significant decrease in steering self-centering at high speeds, a lower resonant frequency of steering wheel shimmy, and increased dynamic load between the tire and the ground, resulting in poorer tire contact with the road. This increased dynamic load accelerates fatigue failure of the hub motor, and the poorer contact with the road also hinders stable handling. These changes affect steering feel and increase the tendency for shimmy during driving.

[0013] Therefore, with the rapid development of new energy technologies, more and more motorcycles are adopting electric drive systems that combine motors and reduction gears. Among these, the central drive system is a common type of electric drive system for motorcycles. By integrating the high-speed motor and reduction gear on both sides of the wheel hub, it offers significant advantages in terms of vehicle balance, structural compactness, and motor heat dissipation efficiency.

[0014] Please refer to Chinese invention patent with announcement number CN111169589A and Chinese utility model patent with announcement number CN222347245U. The inventor of this application designed a central drive electric drive system, the structure of which includes a hub assembly and a motor assembly and a reducer assembly respectively disposed on both sides of the hub assembly. The motor shaft of the motor assembly passes through the hub assembly and is connected to the reducer assembly, and then drives the hub assembly to rotate through the reducer assembly. However, the applicant discovered through long-term motor testing and application that a certain amount of clearance is necessary between the motor shaft, bearings, and housing for normal and reasonable rotation. Under conditions such as startup and large changes in speed / torque, this clearance forces the motor shaft to reciprocate or vibrate axially at high frequency within a small distance (usually around 0.01-0.09 mm). This also causes the gear meshing to experience alternating loads and impacts, resulting not only in impact loads but also in gear fatigue, tooth surface wear, vibration, and noise. Over time, this will inevitably exacerbate rotor vibration and uneven operation, causing wear on bearings and other components, thus affecting efficiency and service life.

[0015] Solving these problems is now a top priority. Utility Model Content

[0016] To address the technical problem of vibration, noise, and wear caused by frequent small high-frequency axial displacement of the motor shaft in existing central drive systems under operating conditions, this invention provides a backlash-free adaptive compensation central drive system for electric two-wheeled vehicles.

[0017] The technical solution is as follows:

[0018] The first aspect of this application relates to a backlash-free adaptive compensation central drive system for an electric two-wheeled vehicle, comprising a hub assembly and a motor assembly and a reducer assembly respectively disposed on both sides of the hub assembly. The motor assembly includes a motor housing, a motor shaft, a rotor, and a stator. The rotor is synchronously rotatably mounted on the portion of the motor shaft located within the motor housing. The stator is fixedly mounted within the motor housing and surrounds the rotor. The reducer assembly includes a reducer housing and a reduction assembly mounted within the reducer housing. The portion of the motor shaft located within the reducer housing is rotatably mounted within the reducer housing via at least one reducer housing bearing and can drive the hub assembly to rotate via the reduction assembly. The portion of the motor shaft located within the motor housing is rotatably mounted within the motor housing via at least one motor housing bearing. A backlash-free adaptive compensation washer mounted on the motor shaft is provided between the rotor and the motor housing bearing located at the end of the motor shaft. A bearing adaptive compensation disc spring assembly mounted on the motor shaft elastically supports the inner ring of the motor housing bearing located at the end of the motor shaft.

[0019] The above-mentioned backlash-free adaptive compensation central drive system for electric two-wheelers not only achieves a central drive layout, integrating the high-speed motor and reduction mechanism on both sides of the wheel hub, but also offers significant advantages in vehicle balance, structural compactness, and motor heat dissipation efficiency. Furthermore, by adding backlash-free adaptive compensation washers and bearing adaptive compensation disc spring assemblies between the motor shaft and the motor housing bearing located at the inner end of the motor shaft, the axial backlash of the motor shaft is effectively eliminated. The bearing adaptive compensation disc spring assemblies can absorb the energy of minute axial displacement and vibration when the motor shaft experiences minor axial displacement and vibration, thereby effectively reducing vibration and noise, delaying wear on the motor shaft and related components, and extending the motor's service life. Attached Figure Description

[0020] Figure 1 A schematic diagram of the gapless adaptive compensation central drive system for an electric two-wheeler;

[0021] Figure 2 A cross-sectional view of the main structure of the gapless adaptive compensation central drive system for an electric two-wheeler;

[0022] Figure 3 This is a structural schematic diagram of the motor assembly;

[0023] Figure 4 This is a structural schematic diagram of the motor housing;

[0024] Figure 5 This is a schematic diagram of the motor shaft.

[0025] Figure 6 This is a schematic diagram of the internal dynamic balancing clamp of the rotor. Detailed Implementation

[0026] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0027] like Figures 1-3 As shown, an electric two-wheeled vehicle's gapless adaptive compensation central drive system mainly includes a wheel hub assembly and a motor assembly and a reducer assembly respectively disposed on both sides of the wheel hub assembly. That is, the motor assembly is disposed on one side of the wheel hub assembly, and the reducer assembly is disposed on the other side of the wheel hub assembly. The motor assembly drives the wheel hub assembly to rotate through the reducer assembly, thereby realizing the central drive structure.

[0028] The motor assembly includes a motor housing 1, a motor shaft 3, a rotor 4, and a stator 5 adapted to the rotor 4. The rotor 4 is synchronously mounted on the portion of the motor shaft 3 located within the motor housing 1. The stator 5 is fixedly installed within the motor housing 1 and surrounds the rotor 4. The reducer assembly includes a reducer housing 12 and a reduction gear assembly installed within the reducer housing 12. Therefore, when energized, the rotor 4 drives the motor shaft 3 to rotate synchronously with it. After the outer end of the motor shaft 3 exits the motor housing 1, it is inserted into the reducer housing 12 via the hub assembly, thus enabling the motor shaft 3 to drive the hub assembly to rotate via the reduction gear assembly.

[0029] In this embodiment, the portion of the motor shaft 5 located in the reducer housing 12 is rotatably mounted in the reducer housing 12 via at least one reducer housing bearing 13. Simultaneously, the portion of the motor shaft 5 located in the motor housing 1 is rotatably mounted in the motor housing 1 via at least one motor housing bearing 2. A backlash-free adaptive compensation washer 6 is fitted onto the motor shaft 3. This backlash-free adaptive compensation washer 6 is located between the rotor 4 and the motor housing bearing 2 located at the inner end of the motor shaft 3 (i.e., one end of the motor shaft 3 located in the motor housing 1). Additionally, a bearing adaptive compensation disc spring assembly 7 is fitted onto the motor shaft 3. The two ends of the bearing adaptive compensation disc spring assembly 7 are elastically supported on the backlash-free adaptive compensation washer 6 and the inner ring of the motor housing bearing 2 located at the inner end of the motor shaft 3, respectively.

[0030] A gapless adaptive compensation washer 6 is provided between the rotor 4 and the motor housing bearing 2 located at the end of the motor shaft 3. The gapless adaptive compensation washer 6 and the inner ring of the motor housing bearing 2 located at the end of the motor shaft 3 elastically support the bearing adaptive compensation disc spring assembly 7, which is also mounted on the motor shaft 3.

[0031] Therefore, by adding a backlash-free adaptive compensation washer 6 and a bearing adaptive compensation disc spring assembly 7 between the motor shaft 3 and the motor housing bearing 2 located at the inner end of the motor shaft 3, the axial backlash of the motor shaft is effectively eliminated. When the motor shaft experiences slight axial displacement and vibration, the bearing adaptive compensation disc spring assembly 7 can absorb the energy of the slight axial displacement and vibration. This not only provides extremely effective vibration reduction and noise reduction, but also slows down the wear of the motor shaft 3 and the hand parts, extending the service life of the motor.

[0032] In this embodiment, the bearing adaptive compensation disc spring assembly 7 can consist of one or more disc springs, arranged according to actual needs. Correspondingly, the thickness and material of the gapless adaptive compensation washer 6 can be arranged according to actual needs; it can be a metal washer, or a rubber or silicone washer.

[0033] Please see Figure 2 , Figure 3 and Figure 6The rotor 4 includes a rotor support connecting ring 4a synchronously mounted on the motor shaft 3, several sets of rotor cores 4b surrounding the rotor support connecting ring 4a, and an inner rotor dynamic balancing clamp 4c and an outer rotor dynamic balancing clamp 4d for locking the sets of rotor cores 4b together. The inner rotor dynamic balancing clamp 4c and the outer rotor dynamic balancing clamp 4d are locked to both sides of the rotor support connecting ring 4a by several bolts (short bolts), and the sets of rotor cores 4b are locked between the inner rotor dynamic balancing clamp 4c and the outer rotor dynamic balancing clamp 4d by several bolts (long bolts). Specifically, each set of rotor cores 4b is defined by the inner rotor dynamic balancing clamp 4c and the outer rotor dynamic balancing clamp 4d. The rotor support connecting ring 4a, the inner rotor dynamic balancing clamp 4c, the outer rotor dynamic balancing clamp 4d, and each set of rotor cores 4b are locked together by multiple long bolts and short bolts to form the rotor 4, which is simple, reliable, and easy to assemble.

[0034] In this embodiment, the portion of the rotor core 4b mounted on the inner rotor dynamic balancing clamp 4c protrudes away from the outer rotor dynamic balancing clamp 4d, forming a sizing groove 4c1 for mounting the rotor core 4b. This allows for the installation of more rotor cores 4b between the inner rotor dynamic balancing clamp 4c and the outer rotor dynamic balancing clamp 4d, increasing the output power of the motor assembly. Correspondingly, by adding the sizing groove 4c1, a recessed clearance groove 4c2 is formed at the center of the inner rotor dynamic balancing clamp 4c, providing assembly space for the backlash-free adaptive compensation washer 6 and the bearing adaptive compensation disc spring assembly 7. Both the backlash-free adaptive compensation washer 6 and the bearing adaptive compensation disc spring assembly 7 are located within the clearance groove 4c2.

[0035] Please see 2. Figure 3 and Figure 5 The portion of the motor shaft 3 located within the motor housing 1 protrudes to form an external spline 3a. Two dynamic balancing clamp mounting grooves 3a1, with a spacing matching the width of the rotor support connecting ring 4a, are formed on this external spline 3a. The inner wall of the rotor support connecting ring 4a is an internal spline 4a1 that mates with the external spline 3a, thereby enabling the rotor 4 to drive the motor shaft 3 to rotate synchronously with it. Dynamic balancing clamps 8 are installed in both dynamic balancing clamp mounting grooves 3a1, locking the rotor support connecting ring 4a between them, thus reliably locking the rotor 4 onto the motor shaft 3.

[0036] Correspondingly, the gapless adaptive compensation washer 6 is supported on one end face of the external spline 3a near the bearing adaptive compensation disc spring assembly 7. That is, one side of the gapless adaptive compensation washer 6 is supported on the end face of the external spline 3a, and the other side is supported on one end of the bearing adaptive compensation disc spring assembly 7, which ensures the stability and reliability of the gapless adaptive compensation washer 6 installation.

[0037] In this embodiment, the inner end of the motor shaft 3 is preferably rotatably mounted in the motor housing 1 via two motor housing bearings 2, which ensures reliable installation of the motor shaft 3 and minimizes the use of motor housing bearings 2, effectively controlling costs.

[0038] For the two motor housing bearings 2, the axial direction of one motor housing bearing 2 is defined by the motor housing 1 and the bearing adaptive compensation disc spring group 7, and the radial direction is defined by the motor shaft 3 and the motor housing 1; the inner ring of the other motor housing bearing 2 is supported on the end face of the outer spline 3a away from the bearing adaptive compensation disc spring group 7, that is: the axial direction of the motor housing bearing 2 is defined by the motor housing 1 and the outer spline 3a, and the radial direction is defined by the motor shaft 3 and the motor housing 1.

[0039] Please see Figures 2-5 The motor housing 1 includes a main body 1a with a mounting groove 1a3 and an end cover 1b that covers the opening of the mounting groove 1a3. A motor shaft through hole 1a1 adapted to the motor shaft 3 is provided at the center of the bottom of the mounting groove 1a3. A first bearing seat 1a2 adapted to the motor housing bearing 2 is integrally formed around the motor shaft through hole 1a1. A second bearing seat 1b1 adapted to the motor housing bearing 2 is integrally formed on the inner side of the end cover 1b. The inner end of the motor shaft 3 is mounted on the second bearing seat 1b1 through a motor housing bearing 2, and the middle part of the motor shaft 3 is mounted on the first bearing seat 1a2 through a motor housing bearing 2, which ensures the reliable installation of the motor shaft 3 and the two motor housing bearings 2. The stator 5 is fixedly installed on the groove wall of the mounting groove 1a3, which is simple and reliable.

[0040] In this embodiment, the encoder 9 is mounted on the end cover 1b, and the encoder magnet 10, which is compatible with the encoder 9, is fitted onto the inner end of the motor shaft 3. Meanwhile, in order to facilitate the maintenance of the encoder 9, an operation port 1b2 is provided at the center of the end cover 1b, and an encoder cover 11 is detachably mounted on the operation port 1b2.

[0041] Please see Figure 1 and Figure 2 The hub assembly includes a hub drive sleeve 23 rotatably mounted on the motor shaft 3 and a hub 14 mounted outside the hub drive sleeve 23. Specifically, the motor shaft 3 passes through the hub drive sleeve 23, and the hub 14 is fixedly mounted on the hub drive sleeve 23 by multiple circumferentially distributed bolts, forming a flange-type mounting structure that is stable and reliable. Meanwhile, the hub drive sleeve 23 is rotatably mounted on the motor housing 1 and the reducer housing 12 via two hub sleeve bearings 15, ensuring that the rotation of the hub drive sleeve 23 does not affect the motor housing 1 and the reducer housing 12.

[0042] Please see Figure 1The motor housing 1 and the reducer housing 12 are respectively fixedly connected to the two flat fork arms of the flat fork 24, so that they can be connected to the frame of the two-wheeled vehicle through the flat fork 24.

[0043] Please see Figure 2 Two oil seals 16 are fitted on the hub drive sleeve 23. The two oil seals 16 are located on the sides of the two hub sleeve bearings 15 that are close to each other, and respectively seal the gaps between the hub drive sleeve 23 and the motor housing 1 and the reducer housing 12, thereby preventing oil leakage. At the same time, the annular gap between the hub drive sleeve 23 and the motor shaft 3 forms an oil passage 17 connecting the motor housing 1 and the reducer housing 12, so that the oil in the motor housing 1 and the reducer housing 12 can flow through the oil passage 17, balancing the oil pressure in the motor housing 1 and the reducer housing 12, and effectively cooling the components in the motor housing 1 and the reducer housing 12.

[0044] Furthermore, a weight-reducing groove 23a is formed on the circumferential inner wall of the wheel hub drive sleeve 23, which can effectively reduce the weight of the wheel hub drive sleeve 23 and achieve lightweight design, and can also serve as a temporary oil storage space to better balance the oil pressure in the motor housing 1 and the reducer housing 12.

[0045] Furthermore, the motor housing 1 has a motor shaft through hole 1a1 adapted to the motor shaft 3. A magnetic ring 18 is installed on the motor shaft through hole 1a1, and the magnetic ring 18 surrounds the motor shaft 3, leaving an annular gap between it and the motor shaft 3 for oil to pass through. By adding the magnetic ring 18, iron filings and impurities in the lubricating and cooling oil can be effectively adsorbed by magnetic attraction, which not only provides better protection for the motor assembly and reduction gear components, but also extends the service life of the lubricating and cooling oil and reduces maintenance costs.

[0046] The preferred lubricating and cooling oils are motor housing oils with excellent cooling capabilities, such as Castrol E-Enable and Great Wall ERO E1 transmission fluid. Castrol E-Enable, with its low-viscosity formula, is specifically developed for low conductivity and enhanced system protection. It helps the motor cooler operate efficiently, enhances transmission cooling, improves motor performance, and has lower conductivity than traditional transmission fluids, preventing arcing and extending the lifespan of the transmission system. Great Wall ERO E1 transmission fluid provides reliable insulation protection, excellent motor cooling performance, high efficiency and long-lasting stability, good compatibility with motor insulation and sealing materials, and excellent gear shaft lubrication protection.

[0047] Please see Figure 2The reduction assembly includes a primary drive gear 19 synchronously mounted on the motor shaft 3, a reduction shaft 20 parallel to the motor shaft 3, a primary driven gear 21 synchronously mounted on the reduction shaft 20, and a secondary driven gear 22 synchronously mounted on the hub drive sleeve 23. The primary drive gear 19 meshes with the primary driven gear 21. The reduction shaft 20 has an integrally formed secondary drive gear 20a that meshes with the secondary driven gear 22. The outer diameter of the primary drive gear 19 is smaller than the outer diameter of the primary driven gear 21, and the outer diameter of the secondary drive gear 20a is smaller than the outer diameter of the secondary driven gear 22.

[0048] Therefore, the motor shaft 3 drives the first-stage driving gear 19 to rotate synchronously with it, the first-stage driving gear 19 drives the first-stage driven gear 21 to rotate, the first-stage driven gear 21 drives the reduction shaft 20 to rotate synchronously with it, the second-stage driving gear 20a on the reduction shaft 20 drives the second-stage driven gear 22 to rotate, and the second-stage driven gear 22 drives the hub drive sleeve 23 of the hub assembly to rotate synchronously with it. This not only realizes the function of two-stage reduction and torque increase transmission, but is also simple, reliable, and has good stability.

[0049] Finally, it should be noted that the above description is merely a preferred embodiment of the present utility model. Those skilled in the art, under the guidance of the present utility model, can make various similar representations without departing from the spirit and claims of the present utility model, and such modifications all fall within the protection scope of the present utility model.

Claims

1. A backlash-free adaptive compensation central drive system for an electric two-wheeled vehicle, comprising a hub assembly and a motor assembly and a reducer assembly respectively disposed on both sides of the hub assembly, wherein the motor assembly includes a motor housing, a motor shaft, a rotor, and a stator, the rotor being synchronously rotatably mounted on the portion of the motor shaft located within the motor housing, the stator being fixedly installed within the motor housing and surrounding the rotor, and the reducer assembly including a reducer housing and a reduction assembly installed within the reducer housing, characterized in that: The portion of the motor shaft located in the reducer housing is rotatably mounted in the reducer housing via at least one reducer housing bearing, and can drive the hub assembly to rotate via the reduction assembly; the portion of the motor shaft located in the motor housing is rotatably mounted in the motor housing via at least one motor housing bearing, and a backlash-free adaptive compensation washer is provided between the rotor and the motor housing bearing located at the end of the motor shaft, which is fitted on the motor shaft. The backlash-free adaptive compensation washer and the inner ring of the motor housing bearing located at the end of the motor shaft elastically support a bearing adaptive compensation disc spring assembly fitted on the motor shaft.

2. The backlash-free adaptive compensation central drive system for electric two-wheeled vehicles according to claim 1, characterized in that: The hub assembly includes a hub drive sleeve rotatably mounted on the motor shaft and a hub mounted outside the hub drive sleeve. The hub drive sleeve is rotatably mounted on the motor housing and the reducer housing via two hub sleeve bearings. The motor shaft can drive the hub drive sleeve to rotate via a reduction assembly.

3. The backlash-free adaptive compensation central drive system for electric two-wheeled vehicles according to claim 2, characterized in that: The hub drive sleeve is fitted with two oil seals. The two oil seals are located on the sides of the two hub sleeve bearings that are close to each other, and respectively seal the gaps between the hub drive sleeve and the motor housing and the reducer housing. The annular gap between the hub drive sleeve and the motor shaft forms an oil passage connecting the motor housing and the reducer housing.

4. The backlash-free adaptive compensation central drive system for electric two-wheeled vehicles according to claim 3, characterized in that: The motor housing has a motor shaft through hole that is adapted to the motor shaft. A magnetic ring with magnetism is installed on the motor shaft through hole. The magnetic ring surrounds the motor shaft and leaves an annular gap between it and the motor shaft for oil to pass through.

5. The backlash-free adaptive compensation central drive system for electric two-wheeled vehicles according to claim 2, characterized in that: The reduction assembly includes a primary drive gear synchronously mounted on the motor shaft, a reduction shaft parallel to the motor shaft, a primary driven gear synchronously mounted on the reduction shaft, and a secondary driven gear synchronously mounted on the hub drive sleeve. The primary drive gear meshes with the primary driven gear, and the reduction shaft has a secondary drive gear integrally formed thereon that meshes with the secondary driven gear.

6. The backlash-free adaptive compensation central drive system for electric two-wheeled vehicles according to claim 1, characterized in that: The rotor includes a rotor support connecting ring that is synchronously mounted on the motor shaft, several sets of rotor cores surrounding the rotor support connecting ring, and an inner rotor dynamic balancing clamp and an outer rotor dynamic balancing clamp for locking the sets of rotor cores together. The inner rotor dynamic balancing clamp and the outer rotor dynamic balancing clamp are locked to both sides of the rotor support connecting ring by several bolts, and the sets of rotor cores are locked between the inner rotor dynamic balancing clamp and the outer rotor dynamic balancing clamp by several bolts.

7. The backlash-free adaptive compensation central drive system for electric two-wheeled vehicles according to claim 6, characterized in that: The part of the rotor core installed in the inner dynamic balancing clamp protrudes away from the outer dynamic balancing clamp to form a relief groove for installing the rotor core, thereby creating a recessed relief groove at the center of the inner dynamic balancing clamp. The gapless adaptive compensation washer and the bearing adaptive compensation disc spring assembly are both located in the relief groove.

8. The backlash-free adaptive compensation central drive system for electric two-wheeled vehicles according to claim 6 or 7, characterized in that: The portion of the motor shaft located within the motor housing protrudes to form an external spline. Two dynamic balancing clamp mounting slots with a spacing adapted to the width of the rotor support connecting ring are provided on the external spline. The inner wall of the rotor support connecting ring is an internal spline that mates with the external spline. Dynamic balancing clamps are installed in both dynamic balancing clamp mounting slots, and the two dynamic balancing clamps lock the rotor support connecting ring between them. The gapless adaptive compensation washer is supported on the end face of the external spline near the bearing adaptive compensation disc spring assembly.

9. The backlash-free adaptive compensation central drive system for electric two-wheeled vehicles according to claim 8, characterized in that: The motor shaft is rotatably mounted in the motor housing via two motor housing bearings, with the inner ring of one of the motor housing bearings, away from the bearing adaptive compensation disc spring assembly, supported on the end face of the outer spline away from the bearing adaptive compensation disc spring assembly.

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