Combined embedded type central driving system of electric two-wheeled vehicle

Abstract

The utility model discloses an electric two-wheeled vehicle combined embedded type central driving system which comprises a hub assembly, a motor and a speed reducer, the motor and the speed reducer are arranged on the two sides of the hub assembly respectively, receding grooves are formed between two end iron cores and a motor shaft, and the inner end faces of two motor bearings extend into the adjacent receding grooves. By the adoption of the combined embedded type central driving system of the electric two-wheeled vehicle, adjacent parts such as a motor bearing can borrow the receding grooves, so that the axial width size of the whole central driving system is reduced, and the system structure is more compact; meanwhile, each permanent magnet is designed to penetrate through the middle iron core and the two end iron cores, so that the length of each permanent magnet is as long as possible, a magnetic field as strong as possible can be generated, and the power of the motor is ensured not to be influenced by structural optimization.

Description

Technical Field

[0001] The utility model relates to the technical field of electric drive systems, in particular to a combined inlaid central drive system for an electric two-wheeled vehicle. Background Art

[0002] An electric two-wheeled vehicle is a mechatronic personal transportation device based on a two-wheeled vehicle, powered by a battery. These vehicles are equipped with a motor, controller, and instrumentation system. They are not only a means of transportation but also a new type of leisure and entertainment device for green travel. They can also meet fitness, personal expression, and social needs, offering significant advantages in cost-effectiveness and convenience.

[0003] The hub motor embeds the motor inside the wheel hub. Through the steel plates and coils on the motor, a magnetic field is formed under the action of electric current, thereby driving the rotation of the rear wheel, realizing a new type of power transmission technology with multiple functions such as electric vehicles. It has become an important technology for electric vehicles and motorcycles.

[0004] The advantages of in-wheel motors include low cost, ease of maintenance, and widespread application. In-wheel motor technology, also known as in-wheel motor technology, is an advanced drive method for electric vehicles and is often used in integrated electric wheel systems developed by auto parts manufacturers. In-wheel motor technology holds great promise for future development.

[0005] However, there are still some problems with hub motors:

[0006] 1. When driving on flat roads and in working conditions, the hub motor mainly uses the rated power; when driving on starting, accelerating, on slopes, overloading, driving against the wind and other driving conditions and working conditions, the hub motor uses the peak power.

[0007] 2. Hub motors generally do not have a transmission system and are low-speed motors. Therefore, their functional density is low. During long-term high-speed riding, the hub motor will not be able to speed up, and the acceleration is poor. When starting and driving on slopes, the current is large and the energy consumption is high. Therefore, the overall driving efficiency of the hub motor is low and the cruising range is short.

[0008] 3. Regarding the power output curve of the in-wheel motor, the motor's efficient platform load and speed deviate from the wheel load and speed, resulting in limited efficient driving paths and operating conditions. Specifically, the energy conversion efficiency at startup is approximately 5%-10%, and from acceleration to the rated power maximum speed, the energy conversion efficiency gradually increases from 10% to 60%-65%. When driving on a slope of less than 20°, the energy conversion efficiency is approximately 40%. When driving under overload conditions or on slopes greater than 20°, the energy conversion efficiency is 20%-35%. When driving on ideal roads and in good windless conditions, the energy conversion efficiency is 60%-65%.

[0009] 4. The in-wheel motor structure is a closed structure where the motor is placed inside the wheel hub. Through the steel plates and coils on the motor, the current creates a magnetic field, which drives the rear wheel. The motor rotor is connected to the tire, resulting in poor heat dissipation. Prolonged operation can cause the motor to heat up, increasing energy consumption and reducing efficiency. This can even lead to tire blowouts, motor demagnetization, and rust, shortening the lifespan of the electric two-wheeler and affecting its efficiency.

[0010] 5. The hub motor is installed inside the wheel hub. Due to the space constraints of the inner diameter of the wheel hub, the power is also restricted.

[0011] 6. When the hub motor is started, driving on a slope causes the motor to stall, or the battery draws a large current, the battery's charge and discharge characteristics will not match the power. This will not only affect the battery's reasonable discharge and balanced power supply, shortening the battery's service life, but also create the risk of cables burning due to overload and overheating, and the controller being damaged by frequent high-current shocks.

[0012] 7. The integrated road use and additional costs of hub motors are high, and their reliability is low.

[0013] 8. Over 95% of electric two-wheeled vehicles require an installation dimension of less than 200 mm. The bulk and weight of in-wheel motors compromise handling and road feel. Specifically, when a top speed of 100 km / h is required, the increased size and weight of the electric two-wheeled vehicle, while increasing costs, significantly increases the moment of inertia of the unsprung mass about the kingpin. This leads to poor steering response, a significant decrease in steering returnability at high speeds, a downward shift in the resonant frequency of steering wheel shimmy, and increased dynamic loads between the tire and the ground, impairing tire contact. Increased dynamic loads on the tire accelerate fatigue damage to the in-wheel motor, while reduced contact also compromises stable handling. These changes affect steering feel and increase the tendency for shimmy during driving.

[0014] As new energy technologies rapidly develop in electric two-wheeled vehicles, more and more motorcycles are adopting a combination of motors and reduction gears to form electric drive systems. Central drive systems are a common type of electric drive system for motorcycles. By integrating the high-speed motor and reduction gear on the left and right sides of the wheel hub, they offer significant advantages in vehicle balance, compactness, and motor heat dissipation efficiency.

[0015] Please refer to the Chinese patent publication number CN111169589A applied for by the inventor of this application, which discloses a central drive electric drive system, whose structure includes a wheel hub drive sleeve and a motor and a speed change mechanism arranged on the left and right sides of the wheel hub drive sleeve. The motor and the speed change mechanism are connected through an output shaft, wherein the motor adopts a hollow rotor motor, that is, the rotor is a hollow structure, and the motor output shaft is directly fixed inside the rotor. Although such an assembly structure has certain advantages in terms of compactness, for the central drive assembly, since the motor and the reduction mechanism are arranged axially side by side, there is still a technical requirement that the thickness of the drive assembly is large and the axial arrangement space needs to be further optimized. Utility Model Content

[0016] In order to solve the technical problem of large thickness of the drive assembly in the existing central drive type electric drive system, the utility model provides a combined inlaid central drive system for an electric two-wheeled vehicle.

[0017] The technical solution is as follows:

[0018] The first aspect of the present application relates to a combined inlaid central drive system for an electric two-wheeled vehicle, comprising a wheel hub assembly and a motor and a reducer respectively arranged on both sides of the wheel hub assembly, wherein the motor comprises a motor housing, a motor shaft rotatably mounted on the motor housing through two motor bearings, a rotor synchronously mounted on the motor shaft, and a stator surrounding the rotor, wherein the stator is fixedly mounted in the motor housing, and the outer end of the motor shaft passes through the motor housing and is inserted into the reducer through the wheel hub assembly, and can drive the wheel hub assembly to rotate through the reducer, wherein the rotor comprises at least one intermediate iron core synchronously mounted side by side on the motor shaft and symmetrically arranged on the rotor. There are two end cores at both ends of the intermediate core, and each intermediate core and each end core are provided with the same number of permanent magnets evenly distributed along the circumferential direction. The intermediate core is formed by stacking multiple intermediate magnetic steel sheets arranged side by side along the axial direction of the motor shaft, and the end core is formed by stacking multiple end magnetic steel sheets arranged side by side along the axial direction of the motor shaft. The intermediate magnetic steel sheets and the end magnetic steel sheets are both annular sheet structures, and the outer diameter of the intermediate magnetic steel sheet is equal to the outer diameter of the end magnetic steel sheet, and the inner diameter of the intermediate magnetic steel sheet is smaller than the inner diameter of the end magnetic steel sheet, so that a clearance groove is formed between the two end cores and the motor shaft, and the inner end faces of the two motor bearings extend into the adjacent clearance grooves.

[0019] The above electric two-wheeled vehicle combined mosaic central drive system has the following beneficial effects:

[0020] 1. A central drive layout is achieved by integrating the high-speed motor and reduction mechanism on the left and right sides of the wheel hub, which has obvious advantages in vehicle balance, structural compactness and motor heat dissipation efficiency.

[0021] 2. By arranging end cores with larger central apertures at both ends of the middle core, a clearance groove is formed between the motor shaft and the two end cores. Compared with traditional hollow rotor motors, the clearance groove increases the axial installation space near the motor shaft, allowing adjacent components such as motor bearings to use the clearance groove, thereby reducing the axial width of the entire central drive system and making the system structure more compact.

[0022] 3. By designing each permanent magnet to be inserted into the middle iron core and the two end iron cores, the length of each permanent magnet is made as long as possible, thereby generating the strongest possible magnetic field, thereby ensuring that the power of the motor is not affected by structural optimization.

[0023] In some embodiments, the outer end surfaces of the two end cores are covered with dynamic balancing covers, and the two dynamic balancing covers, the two end cores and all the intermediate cores are fastened together by a plurality of first threaded fasteners running through the axial direction.

[0024] In some embodiments, the portions of the two dynamic balancing cover plates near their inner edges have cover plate sunken sections that are sunken into corresponding clearance grooves. The two cover plate sunken sections are respectively covered on the outer end faces of the two intermediate iron cores located at the ends, and the side of the cover plate sunken section away from the adjacent intermediate iron core forms a cover plate groove that is concave toward the intermediate iron core, and the inner end faces of the two motor bearings extend into the adjacent cover plate grooves.

[0025] In some embodiments, the two cover plate sinking sections and all the intermediate cores are fastened together by a plurality of second threaded fasteners running through the axial direction.

[0026] In some embodiments, the intermediate iron core and the end iron core are provided with a plurality of permanent magnet mounting holes distributed along the circumference of the motor shaft, and any two adjacent permanent magnet mounting holes are arranged in a "V" shape. The permanent magnet mounting holes all pass through the corresponding intermediate iron core or end iron core, and a permanent magnet is embedded in each permanent magnet mounting hole.

[0027] In some embodiments, the reducer includes a reduction mechanism housing and a reduction transmission assembly, both of which are arranged in the reduction mechanism housing, the reduction transmission assembly includes an intermediate shaft parallel to the motor shaft, a primary driving gear synchronously mounted on the motor shaft, a secondary driven gear synchronously rotating with the hub assembly, and a primary driven gear synchronously mounted on the intermediate shaft, the primary driving gear is meshed with the primary driven gear, and the intermediate shaft is formed with secondary driving teeth that are meshed with the secondary driven gear.

[0028] In some embodiments, the intermediate shaft is rotatably mounted in the reduction mechanism housing through two intermediate shaft bearings, and the position where the intermediate shaft is mounted on the first-stage driven gear is provided with a first shaft section, a second shaft section and a third shaft section in sequence in the direction away from the motor, the outer peripheral surface of the second shaft section has a first external spline distributed along the circumferential direction, and the first-stage driven gear has a first mounting hole extending along its central axis direction, and the first mounting hole is provided with a first hole section, a second hole section and a third hole section in sequence in the direction away from the motor, the first hole section is interference fit on the first shaft section, and the hole wall of the second hole section is circumferentially provided with first internal splines meshing with each first external spline, and an annular gap is provided between the hole wall of the third hole section and the outer peripheral surface of the third shaft section, and a first locking ring is interference fit installed in the annular gap.

[0029] In some embodiments, the outer diameters of the first shaft segment, the second shaft segment, and the third shaft segment decrease in a stepwise manner, and the apertures of the first hole segment and the third hole segment are both larger than the aperture of the second hole segment.

[0030] In some embodiments, the wheel hub assembly includes a wheel hub drive sleeve that can be rotatably mounted on the motor shaft and a wheel hub circumferentially surrounding the wheel hub drive sleeve. The wheel hub drive sleeve can be rotatably mounted on the motor housing and the reduction mechanism housing through two wheel hub bearings. The outer peripheral surface of the wheel hub drive sleeve has a first flange extending radially, and the inner peripheral surface of the wheel hub has a second flange extending radially and adapted to the first flange. The first flange and the second flange are locked by a plurality of third threaded fasteners distributed circumferentially.

[0031] In some embodiments, the position where the secondary driven gear is installed on the hub drive sleeve is provided with shaft segment one, shaft segment two and shaft segment three in sequence in the direction away from the motor, the outer peripheral surface of the shaft segment two has a second external spline distributed along the circumferential direction, and the secondary driven gear is provided with hole segment one, hole segment two and hole segment three in sequence in the direction away from the motor, the hole segment one is sleeved on the shaft segment one with an interference fit, and the hole wall of the hole segment two has second internal splines distributed circumferentially in the direction that mesh with the second external splines, and an annular assembly gap is provided between the hole wall of the hole segment three and the outer peripheral surface of the shaft segment three, and a second locking ring is installed in the annular assembly gap with an interference fit. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A schematic diagram of the structure of a combined inlaid central drive system for an electric two-wheeled vehicle;

[0033] Figure 2 Schematic diagram of the motor core structure;

[0034] Figure 3 Schematic diagram of the matching relationship between the intermediate shaft and the first-stage driven gear;

[0035] Figure 4 Schematic diagram of the structure of the intermediate shaft;

[0036] Figure 5 Schematic diagram of the structure of the first-stage driven gear;

[0037] Figure 6 A schematic diagram of the matching relationship between a portion of the wheel hub, the wheel hub drive sleeve, and the secondary driven gear;

[0038] Figure 7 It is a structural diagram of the wheel hub drive sleeve;

[0039] Figure 8 Schematic diagram of the structure of the secondary driven gear;

[0040] Figure 9 Schematic diagram of the matching relationship between the end magnetic steel sheets and the permanent magnets;

[0041] Figure 10 Schematic diagram of the coordination relationship between the middle magnetic steel sheet and each permanent magnet. DETAILED DESCRIPTION

[0042] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0043] like Figures 1-10 As shown, a combined mosaic central drive system for an electric two-wheeled vehicle mainly includes a wheel hub assembly C and a motor A and a reducer B respectively arranged on both sides of the wheel hub assembly C, that is, the motor A is arranged on one side of the wheel hub assembly C, and the reducer B is arranged on the other side of the wheel hub assembly C. The motor A drives the wheel hub assembly C to rotate through the reducer B, thereby realizing the central drive structure.

[0044] Motor A comprises a motor housing 1, a motor shaft 5, a stator 2, and a rotor 4 adapted for use with the stator 2. Specifically, the motor shaft 5 is rotatably mounted on the motor housing 1 via two motor bearings 8. The rotor 4 is synchronously mounted on the motor shaft 5. The stator 2 is fixedly mounted within the motor housing 1 and surrounds the rotor 4. Therefore, when power is supplied to motor A, the rotor 4 drives the motor shaft 5 in synchronous rotation. The outer end of the motor shaft 5, after passing through the motor housing 1, is inserted into the reducer B via the hub assembly C. This allows the motor shaft 5 to rotate the hub assembly C via the reducer B.

[0045] In this embodiment, the rotor 4 includes at least one intermediate core 4a, which is synchronously rotated and mounted side by side on the motor shaft 5, and two end cores 4b, symmetrically arranged at each end of each intermediate core 4a. Each intermediate core 4a and each end core 4b is circumferentially and evenly distributed with an equal number of permanent magnets 6. The permanent magnets 6 extend from one end face of the corresponding intermediate core 4a to the other end face, or from one end face of the corresponding end core 4b to the other end face. Specifically, each intermediate core 4a and each end core 4b is mounted with a permanent magnet 6. This design maximizes the total length of each permanent magnet 6, thereby generating the strongest possible magnetic field and ensuring that the motor's power is not affected by structural optimization.

[0046] The intermediate core 4a is composed of multiple intermediate magnetic steel sheets 4a1 stacked together, arranged axially side by side along the motor shaft 5. Adjacent intermediate magnetic steel sheets 4a1 fit snugly against each other. The end cores 4b are composed of multiple end magnetic steel sheets 4b1 stacked together, arranged axially side by side along the motor shaft 5. Adjacent end magnetic steel sheets 4b1 fit snugly against each other. Both the intermediate magnetic steel sheets 4a1 and the end magnetic steel sheets 4b1 are annular, with the outer diameter of the intermediate magnetic steel sheet 4a1 being equal to the outer diameter of the end magnetic steel sheet 4b1, and the inner diameter of the intermediate magnetic steel sheet 4a1 being smaller than the inner diameter of the end magnetic steel sheet 4b1. This creates a clearance groove 7 between each end core 4b and the motor shaft 5. The inner end surfaces of the two motor bearings 8 extend into the adjacent clearance grooves 7, narrowing the axial width of the central drive system. It should be noted that both the intermediate magnetic steel sheets 4a1 and the end magnetic steel sheets 4b1 are made of silicon steel sheets.

[0047] Therefore, by arranging end cores 4b with larger central apertures at both ends of the intermediate core 4a, a clearance groove 7 is formed between the motor shaft 5 of the motor A and the two end cores 4b. Compared with the traditional hollow rotor motor, the clearance groove 7 increases the axial installation space near the motor shaft, so that adjacent components such as the motor bearing 8 can use the clearance groove 7, thereby reducing the axial width of the entire central drive system and making the system structure more compact.

[0048] Furthermore, the outer end surfaces of both end cores 4b are covered with dynamic balancing covers 21. The two dynamic balancing covers 21, the two end cores 4b, and all the intermediate cores 4a are fastened together by a plurality of first threaded fasteners 22 extending axially therethrough. The first threaded fasteners 22 are evenly distributed along the circumference of the motor shaft 5. This design, in conjunction with the dynamic balancing covers 21 and the first threaded fasteners 22, ensures the secure installation of the intermediate cores 4a and the end cores 4b, while also ensuring the dynamic balance of the rotor 4 and improving the stability of its rotation.

[0049] Furthermore, the parts of the two dynamic balancing cover plates 21 near their inner edges have cover plate sunken sections 21a that are sunken into the corresponding clearance grooves 7. The two cover plate sunken sections 21a are respectively covered on the outer end faces of the two intermediate iron cores 4a located at the end, and the side of the cover plate sunken sections 21a away from the adjacent intermediate iron core 4a forms a cover plate groove 7a that is recessed toward the intermediate iron core 4a, that is: the main parts of the two dynamic balancing cover plates 21 are respectively attached to the outer end faces of the corresponding end iron cores 4b, and the cover plate sunken sections 21a of the two dynamic balancing cover plates 21 are each attached to one of the two intermediate iron cores 4a located at both ends, and the cover plate sunken sections 21a are respectively located in the corresponding clearance grooves 7. At the same time, some space is left in the clearance grooves 7 to form cover plate grooves 7a. The inner end faces of the two motor bearings 8 extend into the adjacent cover plate grooves 7a, thereby not only reliably installing the dynamic balancing cover plates 21, but also making the axial width dimension of the entire central drive system as small as possible, making the system structure as compact as possible.

[0050] Furthermore, the two cover plate sinking sections 21a and all the intermediate iron cores 4a are locked together by a plurality of second threaded fasteners 23 running through the axial direction, thereby further ensuring the reliable installation of each intermediate magnetic steel sheet 4a1.

[0051] Furthermore, first threaded holes 28 compatible with the first threaded fasteners 22 are provided on the dynamic balancing cover 21, the end cores 4b, and all the intermediate cores 4a. In this embodiment, six first threaded fasteners 22 are provided along the circumference of the motor A. Second threaded holes 29 compatible with the second threaded fasteners 23 are provided on the cover plate sinking section 21a and the intermediate cores 4a. In this embodiment, a total of twelve second threaded fasteners 23 are provided along the circumference of the motor A. The first threaded fasteners 22 and the second threaded fasteners 23 are respectively long bolts compatible with the first threaded holes 28 and the second threaded holes 29, so that they can be directly locked to the corresponding first threaded holes 28 and the second threaded holes 29 without the use of nuts. This not only reduces the use of parts and reduces costs, but also facilitates assembly and is more stable and reliable.

[0052] In this embodiment, both the middle iron core 4a and the end iron cores 4b are provided with a plurality of permanent magnet mounting holes 24 distributed circumferentially along the motor shaft 5. Each permanent magnet mounting hole 24 extends through the corresponding middle iron core A1 or end iron core A2. Furthermore, any two adjacent permanent magnet mounting holes 24 are arranged in a "V" shape, extending through the corresponding middle iron core 4a or end iron core 4b. A permanent magnet 6 is embedded in each permanent magnet mounting hole 24. The "V"-shaped arrangement of the permanent magnet mounting holes 24 maximizes the number of permanent magnets 6 that can be installed, thereby further improving the output power of the motor A.

[0053] In this embodiment, the reducer B includes a reduction mechanism housing 2 and a reduction transmission assembly, both of which are arranged in the reduction mechanism housing 2. The reduction transmission assembly includes an intermediate shaft 9 parallel to the motor shaft 5, a primary driving gear 12 synchronously rotated and sleeved on the motor shaft 5, a secondary driven gear 13 synchronously rotated with the hub assembly C, and a primary driven gear 10 synchronously rotated and sleeved on the intermediate shaft 9. The primary driving gear 12 is engaged with the primary driven gear 10. The intermediate shaft 9 is formed with a secondary driving tooth 11 that is engaged with the secondary driven gear 13. The outer diameter of the primary driving gear 12 is smaller than the outer diameter of the primary driven gear 10, and the outer diameter of the secondary driving tooth 11 is smaller than the outer diameter of the secondary driven gear 13.

[0054] Therefore, the motor shaft 5 drives the first-stage driving gear 12 to rotate synchronously with it, the first-stage driving gear 12 drives the first-stage driven gear 10 to rotate, the first-stage driven gear 10 drives the intermediate shaft 9 to rotate synchronously with it, the secondary driving gear 11 on the intermediate shaft 9 drives the secondary driven gear 13 to rotate, and the secondary driven gear 13 drives the hub assembly C to rotate synchronously with it, which is simple, reliable and stable.

[0055] The hub assembly C includes a hub drive sleeve 16 rotatably mounted on the motor shaft 5 and a hub 19 circumferentially surrounding the hub drive sleeve 16. The hub drive sleeve 16 is rotatably mounted on the motor housing 1 and the reduction mechanism housing 2 via two hub sleeve bearings 17. A radially extending first flange 16b is formed on the outer circumference of the hub drive sleeve 16, and a radially extending second flange 19a is formed on the inner circumference of the hub 19 to mate with the first flange 16b. The first and second flanges 16b, 19a are secured together by a plurality of circumferentially distributed third threaded fasteners 18. Therefore, the secondary driven gear 13 drives the hub drive sleeve 16 to rotate synchronously with it, and the hub drive sleeve 16 drives the hub 19 to rotate synchronously with it. Furthermore, the first and second flanges 16b, 19a are secured together by the third threaded fasteners 18, resulting in a simple, reliable, and durable design.

[0056] The intermediate shaft 9 is rotatably mounted in the reduction mechanism housing 2 via two intermediate shaft bearings 14. The position where the intermediate shaft 9 is mounted with the first-stage driven gear 10 is provided with a first shaft section 9a, a second shaft section 9b and a third shaft section 9c in sequence in the direction away from the motor A. The outer peripheral surface of the second shaft section 9b has first external splines distributed in the circumferential direction. The first-stage driven gear 10 has a first mounting hole 10a extending along its central axis direction. The first mounting hole 10a is provided with a first hole section 10a1, a second hole section 10a2 and a third hole section 10a3 in the direction away from the motor A. The first hole section 10a1 is interference-fitted onto the first shaft section 9a. The hole wall of the second hole section 10a2 is circumferentially provided with first internal splines that mesh with the first external splines. An annular gap is provided between the hole wall of the third hole section 10a3 and the outer peripheral surface of the third shaft section 9c, and a first locking ring 15 is interference-fittedly mounted in the annular gap. Such a design can make the primary driven gear 10 not only easy to assemble, but also reliable and with high connection strength, thereby making the assembly structure of the entire central drive system more compact and firm.

[0057] Furthermore, the outer diameters of the first shaft segment 9a, the second shaft segment 9b and the third shaft segment 9c decrease in a step-by-step manner, and the apertures of the first hole segment 10a1 and the third hole segment 10a3 are both larger than the aperture of the second hole segment 10a2, further improving the convenience of assembling the first-stage driven gear 10.

[0058] Similarly, the hub drive sleeve 16, where the secondary driven gear 13 is mounted, is provided with shaft segment 16b, shaft segment 2 16c, and shaft segment 3 16d, in the order of direction away from motor A. The outer circumference of shaft segment 2 16c has circumferentially distributed second external splines. The secondary driven gear 13 is provided with hole segment 13a, hole segment 2 13b, and hole segment 3 13c, in the order of direction away from motor A. Hole segment 13a is sleeved onto shaft segment 16b with an interference fit. The wall of hole segment 2 13b has circumferentially distributed second internal splines that mesh with the second external splines. An annular assembly gap is defined between the wall of hole segment 3 13c and the outer circumference of shaft segment 3 16d. A second locking ring 20 is installed in this annular assembly gap with an interference fit. This design makes the secondary driven gear 13 not only easy to assemble, but also reliable and with high connection strength, thereby making the assembly structure of the entire central drive system more compact and secure.

[0059] Furthermore, the outer diameters of shaft segment 1 16b, shaft segment 2 16c and shaft segment 3 16d decrease in a stepwise manner, and the apertures of hole segment 13a and hole segment 3 13c are both larger than the aperture of hole segment 2 13b, further improving the convenience of assembling the secondary driven gear 13.

[0060] In this embodiment, both ends of the secondary driven gear 13 are rotatably mounted in the reducer housing 2 via the driven gear bearings 25 , further improving the reliability of the installation of the secondary driven gear 13 .

[0061] Furthermore, to improve the reliability of the installation of the first-stage driving gear 12, the inner end of the first-stage driving gear 12 is installed on the motor shaft 5 with an interference fit, and the first-stage driving gear 12 is splined to the motor shaft 5. At the same time, both ends of the first-stage driving gear 12 are rotatably mounted in the reducer housing 2 via the first-stage driving gear bearings 27, further improving the reliability of the installation of the first-stage driving gear 12 and thus making the operation of the entire central drive system more stable.

[0062] In this embodiment, the central axis hole of the hub drive sleeve 16 is the installation channel 16a, and the motor shaft 5 is inserted into the installation channel 16a, and there is an installation gap between the motor shaft 5 and the hub drive sleeve 16. Such a design can ensure that the rotation of the motor shaft 5 will not affect the hub drive sleeve 16, thereby ensuring that the power transmission path of the entire central drive system always remains from the motor shaft 5 to the reduction mechanism B and finally to the hub assembly C.

[0063] Furthermore, in order to improve the rotation stability of the motor shaft 5 , the outer end of the motor shaft 5 is rotatably mounted in the reducer housing 2 via a motor shaft end bearing 26 .

[0064] Finally, it should be noted that the above description is only a preferred embodiment of the present invention. Under the guidance of the present invention, ordinary technicians in this field can make various similar expressions without violating the purpose and claims of the present invention. Such changes fall within the scope of protection of the present invention.

Claims

1. An electric two-wheeled vehicle combined mosaic central drive system, comprising a wheel hub assembly and a motor and a reducer respectively arranged on both sides of the wheel hub assembly, wherein the motor comprises a motor housing, a motor shaft rotatably mounted on the motor housing through two motor bearings, a rotor synchronously rotatably sleeved on the motor shaft, and a stator surrounding the rotor, wherein the stator is fixedly mounted in the motor housing, and the outer end of the motor shaft passes through the motor housing and is inserted into the reducer through the wheel hub assembly, and can drive the wheel hub assembly to rotate through the reducer, characterized in that: The rotor includes at least one intermediate iron core which is synchronously rotated and mounted side by side on the motor shaft, and two end iron cores which are symmetrically arranged at both ends of all the intermediate iron cores. Each intermediate iron core and each end iron core are circumferentially evenly distributed with the same number of permanent magnets. The intermediate iron core is formed by stacking a plurality of intermediate magnetic steel sheets which are arranged side by side along the axial direction of the motor shaft, and the end iron core is formed by stacking a plurality of end magnetic steel sheets which are arranged side by side along the axial direction of the motor shaft. Both the intermediate magnetic steel sheets and the end magnetic steel sheets are annular sheet structures, and the outer diameter of the intermediate magnetic steel sheet is equal to the outer diameter of the end magnetic steel sheet, and the inner diameter of the intermediate magnetic steel sheet is smaller than the inner diameter of the end magnetic steel sheet, so that a clearance groove is formed between the two end iron cores and the motor shaft, and the inner end surfaces of the two motor bearings extend into the adjacent clearance grooves.

2. The electric two-wheel vehicle combined inlay type central drive system according to claim 1, characterized in that: The outer end surfaces of the two end iron cores are covered with dynamic balancing covers, and the two dynamic balancing covers, the two end iron cores and all the middle iron cores are locked together by multiple first threaded fasteners penetrating along the axial direction.

3. The electric two-wheeled vehicle combined inlay type central drive system according to claim 2, characterized in that: The two dynamic balancing cover plates have cover plate sinking sections sunk into corresponding makeshift grooves near their inner edges. The two cover plate sinking sections are respectively covered on the outer end surfaces of the two intermediate iron cores located at the ends, and the cover plate sinking sections form a cover plate groove recessed toward the intermediate iron core on the side away from the adjacent intermediate iron core, and the inner end surfaces of the two motor bearings extend into the adjacent cover plate grooves.

4. The electric two-wheel vehicle combined mosaic central drive system according to claim 3, characterized in that: The two cover plate sinking sections and all the intermediate iron cores are locked together by a plurality of second threaded fasteners penetrating along the axial direction.

5. The electric two-wheel vehicle combined inlay type central drive system according to claim 1, characterized in that: The middle iron core and the end iron core are both provided with a plurality of permanent magnet mounting holes distributed along the circumference of the motor shaft, and any two adjacent permanent magnet mounting holes are arranged in a "V" shape. The permanent magnet mounting holes all penetrate the corresponding middle iron core or the end iron core, and a permanent magnet is embedded in each permanent magnet mounting hole.

6. The electric two-wheel vehicle combined inlay type central drive system according to claim 1, characterized in that: The reducer includes a reduction mechanism housing and a reduction transmission assembly both arranged in the reduction mechanism housing, the reduction transmission assembly includes an intermediate shaft parallel to the motor shaft, a primary driving gear synchronously rotated and sleeved on the motor shaft, a secondary driven gear synchronously rotated and sleeved on the intermediate shaft, the primary driving gear meshes with the primary driven gear, and the intermediate shaft is formed with secondary driving teeth meshed with the secondary driven gear.

7. The electric two-wheel vehicle combined mosaic central drive system according to claim 6, characterized in that: The intermediate shaft is rotatably mounted in the reduction mechanism housing through two intermediate shaft bearings. The intermediate shaft is provided with a first shaft section, a second shaft section and a third shaft section in sequence in a direction away from the motor at a position where the first-stage driven gear is installed. The outer peripheral surface of the second shaft section has a first external spline distributed in a circumferential direction. The first-stage driven gear has a first mounting hole extending in the direction of its central axis. The first mounting hole is provided with a first hole section, a second hole section and a third hole section in sequence in a direction away from the motor. The first hole section is sleeved on the first shaft section with an interference fit. The hole wall of the second hole section has first internal splines meshing with each first external spline distributed in a circumferential direction. An annular gap is provided between the hole wall of the third hole section and the outer peripheral surface of the third shaft section. A first locking ring is installed in the annular gap with an interference fit.

8. The electric two-wheel vehicle combined mosaic central drive system according to claim 7, characterized in that: The outer diameters of the first shaft segment, the second shaft segment and the third shaft segment decrease in a stepwise manner, and the apertures of the first hole segment and the third hole segment are both larger than the aperture of the second hole segment.

9. The electric two-wheel vehicle combined mosaic central drive system according to claim 6, characterized in that: The wheel hub assembly includes a wheel hub drive sleeve rotatably mounted on the motor shaft and a wheel hub circumferentially surrounding the wheel hub drive sleeve. The wheel hub drive sleeve is rotatably mounted on the motor housing and the reduction mechanism housing via two wheel hub sleeve bearings. A first flange extending radially is provided on the outer circumferential surface of the wheel hub drive sleeve. A second flange matching the first flange is formed on the inner circumferential surface of the wheel hub along the radial direction. The first flange and the second flange are locked by a plurality of third threaded fasteners distributed circumferentially.

10. The electric two-wheel vehicle combined inlay type central drive system according to claim 9, characterized in that: The position where the secondary driven gear is installed on the hub driving sleeve is provided with shaft section one, shaft section two and shaft section three in sequence in the direction away from the motor, the outer peripheral surface of the shaft section two has second external splines distributed along the circumferential direction, and the secondary driven gear is provided with hole section one, hole section two and hole section three in sequence in the direction away from the motor, the hole section one is sleeved on the shaft section one with an interference fit, and second internal splines meshing with each second external spline are distributed on the hole wall of the hole section two in the circumferential direction, an annular assembly gap is provided between the hole wall of the hole section three and the outer peripheral surface of the shaft section three, and a second locking ring is installed in the annular assembly gap with an interference fit.

Images