Electric drive axle integrating flywheel energy storage and working mode of electric drive axle

Abstract

The invention discloses an electric drive axle integrating flywheel energy storage and a working mode of the electric drive axle, and belongs to the technical field of new energy automobiles, the electric drive axle comprises a flywheel, a double-rotor motor and a transmission device, and the double-rotor motor and the transmission device are an assembly of a double-rotor motor, a planetary gear mechanism, four clutches, two brakes, a main speed reducer, a differential mechanism, a half shaft, a bearing and a shell. An output shaft of the flywheel is connected with an input shaft of the double-rotor motor and transmission device through a first clutch and a first brake, a sun gear of the planetary gear mechanism is connected with the input shaft, a gear ring is connected with the inner rotor through a second brake and a second clutch, and a planet carrier and the outer rotor are connected with the output shaft through a third clutch and a fourth clutch respectively through a planet carrier connecting shaft. Output shaft power is transmitted to wheels through the main speed reducer, the differential mechanism and the half shafts in sequence. Braking energy can be efficiently recycled and utilized, impact in the flywheel energy storage process is reduced, eight working modes such as motor outer rotor driving are achieved, and the beneficial effects of being compact in structure and high in power are achieved.

Description

Technical Field

[0001] The present invention belongs to the technical field of new energy vehicles, and more specifically, relates to an electric drive axle integrating flywheel energy storage and an operating mode thereof. Background Art

[0002] As an important power supply and transmission method, electric drive axles have become a key research and development target in the field of new energy vehicles. Their performance directly affects the vehicle's power, economy, and safety. Traditional electric drive axles mostly use a single motor drive combined with a power battery energy storage model. First, the vehicle's driving range is affected by indicators such as battery specific energy, specific power, and vehicle mass. Second, when the vehicle requires strong power for acceleration or climbing, it often suffers from insufficient power. Third, during the energy transfer process during energy recovery and utilization, the energy is converted from mechanical energy to electrical energy, and then from electrical energy to mechanical energy. The conversion of different energy types will result in significant energy losses.

[0003] Flywheel energy storage technology, with its advantages of high power density, rapid charge and discharge response, and long cycle life, holds enormous potential for vehicle energy recovery and auxiliary drive applications. Therefore, developing a flywheel energy storage electric drive axle system with a compact structure, flexible power output, efficient energy recovery, and high safety is a key approach to addressing existing technical challenges and promoting technological advancements in new energy vehicles.

[0004] A search revealed that ① Chinese patent publication number: CN 112757886 B, publication date: May 7, 2021, discloses a dual-clutch electric vehicle motor-flywheel hybrid transmission device, comprising a motor, a dual-clutch structure, and a power output structure. The device also includes a planetary gear structure, wherein the sun gear shaft of the planetary gear structure is transmission-connected to the low-speed clutch of the dual-clutch structure, the ring gear is transmission-connected to the high-speed clutch of the dual-clutch structure, and the planetary carrier is transmission-connected to the final reducer of the power output mechanism. The device also includes a continuously variable transmission mechanism, wherein the ring gear of the planetary gear mechanism is transmission-connected to the continuously variable transmission mechanism via a first transmission mechanism, and the sun gear shaft is transmission-connected to the continuously variable transmission mechanism via a second transmission mechanism. The device also includes a flywheel mechanism transmission-connected to the continuously variable transmission mechanism via a third transmission mechanism, and further includes a ring gear brake and a sun gear brake. This device minimizes impact on transmission system components during gear shifting, effectively recovers braking energy, and fully utilizes the energy stored in the flywheel. ② Chinese Patent Publication No.: CN 110365158 B, published on October 22, 2019, discloses a flywheel-motor magnetic coupling transmission hybrid system; it includes a flywheel energy storage magnetic coupling transmission device, an electromagnetic clutch, and a dual-rotor motor. One end of the motor's inner rotor shaft is movably connected to the active portion of the electromagnetic clutch via a bearing, and the other end of the motor's inner rotor shaft is movably connected to a connector via a bearing. The motor's permanent magnet inner rotor is connected to the motor's inner rotor shaft; the motor's stator is connected to the main housing; one end of the motor's magnetically adjustable outer rotor is movably connected to the motor's main housing via a bearing, and the other end of the motor's magnetically adjustable outer rotor is fixedly connected to one end of the connector; the other end of the connector extends out of the cavity structure and is connected to an external load. The flywheel energy storage magnetic coupling transmission device, magnetic coupling transmission mechanism, and dual-rotor motor of the present invention work together to achieve normal uniform speed operation of the vehicle, brake energy recovery during vehicle braking and downhill descents, and conversion of flywheel kinetic energy into vehicle kinetic energy during vehicle acceleration and uphill descents. The above two cases improve energy utilization efficiency to a certain extent, but still have limitations. Specifically, Case 1 (CN112757886 B) has a complex system structure and leaves room for improvement in energy efficiency, while Case 2 (CN110365158 B) also has room for further improvement. Furthermore, neither case fully considers the overall layout and integrated design of the electric drive axle. Summary of the Invention

[0005] In order to solve at least one technical problem in the prior art, the present invention provides an electric drive bridge with integrated flywheel energy storage and its working mode, including a flywheel, a dual-rotor motor and a transmission device, with eight working modes: motor outer rotor drive, motor inner and outer rotor drive, flywheel drive, hybrid drive, flywheel recovery of braking energy, power battery recovery of braking energy, hybrid recovery of braking energy, and power battery recovery of flywheel energy. It can efficiently recover and utilize braking energy, reduce the impact of the flywheel energy storage process, and has the characteristics of high integration, compact structure and strong power.

[0006] The purpose of the present invention is achieved through the following technical solutions:

[0007] An electric drive axle with integrated flywheel energy storage and its working mode, comprising a flywheel, a dual-rotor motor and a transmission device;

[0008] The flywheel includes a flywheel rotor, a flywheel bearing, a vacuum housing, and a flywheel output shaft. The vacuum housing encloses the flywheel rotor and the flywheel bearing. The flywheel output shaft supports the flywheel rotor through the flywheel bearing, and the right end extends out of the vacuum housing.

[0009] The dual-rotor motor and transmission device includes a dual-rotor motor, a planetary gear mechanism, four clutches, two brakes, a final reducer, a differential, a half shaft, nine sets of bearings and a housing;

[0010] The dual-rotor motor includes a stator, an inner rotor, and an outer rotor. The stator is composed of an iron core and a coil and is fixed to the housing. The inner rotor and the outer rotor are respectively inlaid with permanent magnets. The inner rotor connecting ring is connected to the inner rotor.

[0011] The planetary gear mechanism includes a sun gear, planet gears, a planet carrier and a ring gear. The sun gear is connected to the input shaft. The planet gears are arranged between the sun gear and the ring gear and mesh with the sun gear and the ring gear respectively. The planet gear shafts are fixed to the planet carrier, and the planet carrier is connected to the planet carrier connecting shaft.

[0012] The four clutches include clutch one, clutch two, clutch three and clutch four, wherein the left end of clutch one is connected to the flywheel output shaft and the right end is connected to the input shaft, the left end of clutch two is connected to the ring gear and the right end is connected to the inner rotor connecting ring, the left end of clutch three is connected to the planetary carrier connecting shaft and the right end is connected to the output shaft, and the left end of clutch four is connected to the outer rotor and the right end is connected to the output shaft;

[0013] The two brakes include brake 1 and brake 2, wherein brake 1 is used for braking the input shaft and brake 2 is used for braking the ring gear;

[0014] The main reducer includes a pinion and a gear, wherein the pinion is connected to the output shaft, the gear meshes with the pinion for transmission, and the gear is connected to the differential housing;

[0015] The differential includes a differential case and differential planetary gears, and the power of the differential planetary gears is transmitted to the wheels via the half shafts;

[0016] The half shafts include a first half shaft and a second half shaft, the first half shaft and the second half shaft are coaxially arranged and driven by the differential planetary gear respectively;

[0017] The nine groups of bearings include bearing 1, bearing 2, bearing 3, bearing 4, bearing 5, bearing 6, bearing 7, bearing 8, and bearing 9. Bearing 1 and bearing 2 are used to support the output shaft, bearing 3 and bearing 6 are used to support the outer rotor, bearing 4, bearing 5, and bearing 7 are used to support the inner rotor and the ring gear, and bearing 8 and bearing 9 are used to support the input shaft.

[0018] The housing encloses the dual-rotor motor, planetary gear mechanism, four clutches, two brakes, the final reducer, and the differential. The housing is a closed structure composed of three parts. The first part encloses the planetary gear mechanism, clutch one, brake one, clutch two, and brake two, and together with bearings seven, eight, and nine, supports the input shaft and the planetary gear mechanism. The second part encloses the dual-rotor motor, clutch three, clutch four, part of the final reducer, and part of the differential, and together with bearings one, two, three, four, five, and six, supports the output shaft and the dual-rotor motor. The third part encloses part of the final reducer and part of the differential. The three parts of the housing are all connected by bolts. The three-part housing structure is adapted to the internal enclosing structure.

[0019] The flywheel cooperates with the dual-rotor motor and the transmission device to realize motor outer rotor drive, motor inner and outer rotor drive, flywheel drive, hybrid drive, flywheel recovery braking energy, power battery recovery braking energy, hybrid recovery braking energy, and power battery recovery flywheel energy mode;

[0020] In the motor outer rotor driving mode, the clutch 4 is engaged, and the power of the motor outer rotor is transmitted through the clutch 4, from the output shaft to the main reducer, the differential, and the half shaft to the wheels in sequence;

[0021] In the motor inner and outer rotor drive mode, the brake 1, clutch 2, clutch 3, and clutch 4 are engaged, and the power of the motor inner rotor is transmitted through the clutch 2, the ring gear, the planetary gear, the planetary carrier, the planetary carrier connecting shaft, and clutch 3, and the power of the motor outer rotor is transmitted through the clutch 4, and then transmitted to the wheels by the output shaft in sequence through the main reducer, the differential, and the half shaft;

[0022] In the flywheel drive mode, the clutch 1, brake 2, and clutch 3 are engaged, and the flywheel power is transmitted through the clutch 1, input shaft, sun gear, planetary gear, planetary carrier, planetary carrier connecting shaft, clutch 3, and then from the output shaft to the wheels through the final reducer, differential, and half shafts in sequence;

[0023] In the hybrid drive mode, clutches 1, 2, 3, and 4 are engaged, and the flywheel power is transmitted through clutch 1, the input shaft, and the sun gear, and then through clutch 2 and the ring gear, and then through the planetary gears, the planetary carrier, the planetary carrier connecting shaft, and clutch 3, and then through the motor's outer rotor power through the fourth clutch. Together, the power is transmitted by the output shaft to the wheels in sequence through the final reducer, the differential, and the half shafts.

[0024] In the flywheel braking energy recovery mode, clutch 1, clutch 2, and clutch 3 are engaged, and the wheel braking force is transmitted to the flywheel in sequence through the half shaft, differential, final reducer, output shaft, clutch 3, planetary carrier connecting shaft, planetary carrier, planetary gear, sun gear, input shaft, and clutch 1; at the same time, the impact on the motor's inner rotor during flywheel energy recovery is coordinated through clutch 2, ring gear, and planetary gear;

[0025] In the power battery recovery braking energy mode, the fourth clutch is engaged, and the wheel braking force is transmitted to the motor outer rotor in sequence through the half shaft, differential, final reducer, output shaft, and fourth clutch, thereby realizing power battery energy recovery;

[0026] In the hybrid braking energy recovery mode, clutch 1, clutch 2, clutch 3, and clutch 4 are engaged, and the wheel braking force is transmitted to the outer rotor in sequence through the half-shafts, differential, final reducer, output shaft, and clutch 4, thereby realizing power battery energy recovery. At the same time, the wheel braking force is transmitted to the flywheel through clutch 3, planetary carrier connecting shaft, planetary carrier, planetary gear, sun gear, input shaft, and clutch 1 after passing through the half-shafts, differential, final reducer, output shaft, and then to the flywheel. The impact on the inner rotor of the motor during flywheel energy recovery is coordinated through clutch 2, ring gear, and planetary gear.

[0027] In the power battery flywheel energy recovery mode, when the vehicle is in the parking state, the clutch 1, clutch 2, and clutch 3 are engaged, and the flywheel power drives the inner rotor of the motor in sequence through the clutch 1, input shaft, sun gear, planetary gear, ring gear, and clutch 2 to charge the battery; the clutch 3 connects the output shaft with the planetary carrier connecting shaft and the planetary carrier, and uses the entire vehicle as a large inertia resistance to realize the braking effect of the planetary carrier.

[0028] To further achieve the purpose of the present invention, preferably, the flywheel rotor is made of a high-strength alloy material, the flywheel bearing is a magnetic bearing, and the inner wall of the vacuum housing is provided with a heat insulation layer;

[0029] Preferably, the clutch 1 and the brake 1 have an interlocking function in structure, that is, the two are not engaged at the same time;

[0030] Preferably, the second clutch and the second brake have an interlocking function in structure, that is, the two are not engaged at the same time;

[0031] Preferably, the four clutches and two brakes all adopt a hydraulic drive system;

[0032] Preferably, the dual-rotor motor is a permanent magnet synchronous motor.

[0033] Beneficial effects

[0034] Those skilled in the art will appreciate that, compared to the prior art, the electric drive axle with integrated flywheel energy storage and its working mode of the present invention have at least the following beneficial effects: First, compared with ① China Patent Publication No.: CN112757886B and ② China Patent Publication No.: CN110365158B, the present invention integrates a dual-rotor motor and a transmission device into the electric drive axle housing and divides it into three parts to form a closed structure with high integration and compact structure, thus avoiding the problem of large space occupation and complex transmission path caused by the dispersed arrangement of multiple systems in the prior art; second, the present invention has multiple modes such as motor outer rotor drive, motor inner and outer rotor drive, flywheel drive, and hybrid drive, with flexible and powerful power output, adapting to various driving conditions, and solving the problem of insufficient power caused by the traditional electric drive axle relying on a single motor; third, the present invention has the function of flywheel recovery of braking energy and power battery recovery. Various energy recovery modes, such as braking energy, hybrid recovery braking energy, and power battery recovery flywheel energy mode, can efficiently recover braking energy according to different vehicle operating conditions, flywheel energy storage status and battery charge. At the same time, the flywheel directly stores braking energy in the form of mechanical energy, reducing the energy loss in the traditional mechanical energy to electrical energy and then to mechanical energy conversion process. The present invention significantly improves the recovery efficiency of braking energy and reduces energy loss; Fourth, in the flywheel recovery braking energy mode, the present invention utilizes the dynamic adjustment of the inner rotor to reduce the impact of the flywheel energy storage process and improve the stability of the system; Fifth, the present invention has an interlocking safety mechanism, and clutch one and brake one, clutch two and brake two respectively have interlocking functions, which solves the safety problem when multiple actuators work together in the existing technology, ensures the stability and reliability of switching between various working modes, and simplifies the complexity of control.

[0035] Other features and advantages of the present invention will be described in detail in the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] The accompanying drawings are used to provide a further understanding of the present invention and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the present invention but do not constitute a limitation of the present invention. In the accompanying drawings:

[0037] Figure 1 The overall composition and structure of the electric drive axle with integrated flywheel energy storage of the present invention are illustrated;

[0038] Figure 2 The diagram illustrates the interlocking structure and working principle of the brake 2 and clutch 2 of the present invention;

[0039] Reference numerals:

[0040] 1. Flywheel; 2. Clutch 1; 3. Housing; 301. Internal spline 1; 4. Input shaft; 5. Brake 1; 6. Sun gear; 7. Ring gear; 701. External spline 1; 702. External spline 2; 8. Planetary gear; 9. Brake 2; 901. First oil circuit; 902. Circlip 1; 903. First piston; 904. First steel plate group; 905. First friction plate group; 906. Seal ring 1; 907. First piston chamber; 908. Seal ring 2; 909. First return spring; 10. Planetary carrier; 11. Clutch 2; 1101. Second oil circuit; 1102. Circlip 2; 1103. Second piston; 1104. Second steel plate group; 1105. Second friction plate group; 1106, sealing ring three; 1107, second piston chamber; 1108, sealing ring four; 1109, second return spring; 1110, bolt; 12, outer rotor; 13, stator; 14, inner rotor; 1401, inner rotor connecting ring; 1402, inner spline two; 15, clutch three; 16, clutch four; 17, bearing one; 18, bearing two; 19, output shaft; 20, pinion; 21, gear; 22, half shaft one; 23, differential; 24, bearing three; 25, bearing four; 26, bearing five; 27, bearing six; 28, planetary carrier connecting shaft; 29, bearing seven; 30, bearing eight; 31, bearing nine; 32, half shaft two; 33, wheel. DETAILED DESCRIPTION

[0041] It should be understood by those skilled in the art that the embodiments described below are only some embodiments of the present invention, rather than all embodiments of the present invention, and that these embodiments are intended to explain the technical principles of the present invention and are not intended to limit the scope of protection of the present invention. Based on the embodiments provided by the present invention, all other embodiments obtained by those skilled in the art without creative effort should still fall within the scope of protection of the present invention.

[0042] It should be noted that in the description of the present invention, terms such as "left," "right," "inner," and "outer" indicating directions or positional relationships are based on the directions or positional relationships shown in the accompanying drawings. These terms are used solely for ease of description and are not intended to indicate or imply that the device or component described must have, be constructed, or operate in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Furthermore, the terms "one," "two," and "three," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0043] Furthermore, it should be noted that, in the description of the present invention, unless otherwise expressly specified or limited, the terms "mounted," "connected," and "connected" should be understood in a broad sense. For example, they may refer to fixed connections, detachable connections, or integral connections; mechanical connections, electrical connections; direct connections, indirect connections through an intermediate medium, or internal communication between two components. Those skilled in the art will understand the specific meanings of the above terms in the present invention based on specific circumstances.

[0044] The present invention provides an electric drive bridge integrating flywheel energy storage and its working mode, comprising a flywheel, a dual-rotor motor and a transmission device; the flywheel comprises a flywheel rotor, a flywheel bearing, a vacuum shell, and a flywheel output shaft, the vacuum shell wraps the flywheel rotor and the flywheel bearing, the flywheel output shaft supports the flywheel rotor through the flywheel bearing, and the right end extends out of the vacuum shell; the dual-rotor motor and the transmission device comprise a dual-rotor motor, a planetary gear mechanism, 4 clutches, 2 brakes, a main reducer, a differential, a half shaft, 9 sets of bearings and a housing, the left end of clutch one is connected to the flywheel output shaft, and the right end is connected to the input shaft, the sun gear of the planetary gear mechanism is connected to the input shaft, the left end of clutch two is connected to the ring gear, and the right end is connected to the inner rotor connecting ring, and the left end of clutch three is connected to the planetary carrier connecting The connecting shaft and the right end are connected to the output shaft, the left end of clutch four is connected to the outer rotor, and the right end is connected to the output shaft; brake one is used for braking the input shaft, and brake two is used for braking the ring gear; the main reducer includes a pinion and a large gear, the pinion is connected to the output shaft, and the large gear is connected to the differential housing; the differential includes a differential housing and differential planetary gears, and the power of the differential planetary gears is transmitted to the wheels through the half-shafts; the half-shafts include half-shaft one and half-shaft two, and half-shaft one and half-shaft two are coaxially arranged and driven by the differential planetary gears respectively; the housing wraps the dual-rotor motor, planetary gear mechanism, 4 clutches, 2 brakes, main reducer, and differential. The housing is a closed structure composed of three parts and jointly supports the dual-rotor motor and planetary gear mechanism with 9 sets of bearings.

[0045] The present invention cooperates with a flywheel, a dual-rotor motor and a transmission device to realize eight operating modes, including motor outer rotor drive, motor inner and outer rotor drive, flywheel drive, hybrid drive, flywheel recovery of braking energy, power battery recovery of braking energy, hybrid recovery of braking energy, and power battery recovery of flywheel energy, according to different vehicle operating conditions, flywheel energy storage status and battery charge status. It can efficiently recover and utilize braking energy, reduce the impact of the flywheel energy storage process, and has the characteristics of high integration, compact structure and strong power.

[0046] The specific structure and working process of the electric drive axle with integrated flywheel energy storage and its working mode of the present invention are described below with reference to the accompanying drawings and specific embodiments.

[0047] Embodiment 1 of the present invention

[0048] like Figure 1 As shown, the electric drive axle with integrated flywheel energy storage in this embodiment includes a flywheel 1, a dual-rotor motor and transmission device consisting of a dual-rotor motor, a planetary gear mechanism, four clutches, two brakes, a final reducer, a differential 23, half shafts, nine sets of bearings, and a housing 3. The dual-rotor motor includes an outer rotor 12, a stator 13, and an inner rotor 14; the planetary gear mechanism includes a sun gear 6, planetary gears 8, a planetary carrier 10, and a ring gear 7; the four clutches include clutch 1 2, clutch 2 11, clutch 3 15, and clutch 4 16; the two brakes include brake 1 5 and brake 2 9; the final reducer includes a pinion 20 and a gear 21; the half shafts include half shaft 1 22 and half shaft 2 32; and the nine sets of bearings include bearing 1 17, bearing 2 18, bearing 3 24, bearing 4 25, bearing 5 26, bearing 6 27, bearing 7 29, bearing 8 30, and bearing 9 31.

[0049] Continue to refer to Figure 1As shown, flywheel 1 is used to store or release braking energy. The output shaft of flywheel 1 is connected to input shaft 4 via clutch 1-2 and brake 1-5. Clutch 1-2 is used to engage and disengage flywheel 1 from input shaft 4, while brake 1 is used to brake input shaft 4. The sun gear 6 of the planetary gear mechanism is connected to input shaft 4. Planet carrier 10 is connected to planet carrier connecting shaft 28. Planet carrier connecting shaft 28 is connected to output shaft 19 via clutch 3-15. Clutch 3-15 is used to engage and disengage planet carrier connecting shaft 28 from output shaft 19. Ring gear 7 is connected to inner rotor connecting ring 1401 via brake 2-9 and clutch 2-11. Brake 2-19 is used to brake ring gear 7, while clutch 2-11 is used to engage and disengage ring gear 7 from inner rotor connecting ring 1401. The outer rotor 12 of the dual-rotor motor is connected to the output shaft 19 via clutch 4 16, which engages and disengages the outer rotor 12 and output shaft 19. The stator 13 is fixed to the housing 3, located inside the outer rotor. The inner rotor 14 is connected to the inner rotor connecting ring 1401, located inside the stator 13. The output shaft 19 supports and transmits power to the pinion 20. The final drive, consisting of the pinion 20 and the gear 21, primarily reduces speed and increases torque. The gear 21 is connected to the housing of the differential 23, which comprises the differential housing and differential planetary gears. The power from the differential planetary gears is transmitted coaxially to the wheels 33 on both sides via axle shafts 1 22 and 32. Bearing 1 17 and bearing 2 18 are used to support the output shaft 19 , bearing 3 24 and bearing 6 27 are used to support the outer rotor 12 , bearing 4 25 , bearing 5 26 , and bearing 7 29 are used to support the inner rotor 14 and the ring gear 7 , and bearing 8 30 and bearing 9 31 are used to support the input shaft 4 . Housing 3 encloses the dual-rotor motor, planetary gear mechanism, four clutches, two brakes, the final reducer, and differential 23. Housing 3 comprises a three-part closed structure. The first part encloses the planetary gear mechanism, clutch 1 2, brake 1 5, clutch 2 11, and brake 2 9, and together with bearings 7 29, 8 30, and 9 31, supports the input shaft 4 and the planetary gear mechanism. The second part encloses the dual-rotor motor, clutch 3 15, clutch 4 16, part of the final reducer, and part of the differential 23, and together with bearings 1 17, 2 18, 3 24, 4 25, 5 26, and 6 27, supports the output shaft 19 and the dual-rotor motor. The third part encloses part of the final reducer and part of the differential 23. All three parts of housing 3 are connected by bolts, and the three-part structure of housing 3 is compatible with the internal packaging structure. The components within housing 3 of this embodiment are rationally positioned, resulting in a compact structure that effectively and fully utilizes the internal space of housing 3.

[0050] Embodiment 2 of the present invention

[0051] This embodiment shows eight working modes of the electric drive axle with integrated flywheel energy storage of the present invention, including motor outer rotor drive, motor inner and outer rotor drive, flywheel drive, hybrid drive, flywheel recovery of braking energy, power battery recovery of braking energy, hybrid recovery of braking energy, and power battery recovery of flywheel energy. When the vehicle is in different operating conditions, the working mode of the electric drive axle with integrated flywheel energy storage is selected according to the flywheel energy storage state and the battery charge.

[0052] 1. Motor outer rotor drive mode

[0053] When the vehicle is traveling at low or medium speeds and requires moderate or low power, the motor outer rotor drive mode is used. In this mode, clutch four 16 is engaged, and the power of the motor outer rotor 12 is transmitted through clutch four 16, via output shaft 19, through the final reducer consisting of pinion 20 and gear 21, differential 23, half shaft 1 22, and half shaft 2 32 to wheels 33.

[0054] 2. Motor Inner and Outer Rotor Drive Mode

[0055] When the vehicle is experiencing high power requirements, such as during continuous acceleration, high-speed driving, or climbing a hill, the motor inner and outer rotor drive mode is used. In this mode, clutch 2 11, clutch 3 15, clutch 4 16, and brake 1 5 are engaged. Both the motor outer rotor 12 and the motor inner rotor 14 are in the drive state. The power of the motor outer rotor 12 is coupled via clutch 4 16 and the power of the motor inner rotor 14 via clutch 2 11, ring gear 7, planetary gear 8, planetary carrier 10, planetary carrier connecting shaft 28, and clutch 3 15. After this, the power is transmitted from the output shaft 19 through the final reducer consisting of the pinion 20 and gear 21, the differential 23, and the axle shafts 1 and 2, respectively, to the wheels 33.

[0056] 3. Flywheel drive mode

[0057] When a vehicle is traveling on congested roads and requires frequent braking and starting, or when the vehicle is in a starting condition requiring this, or when the vehicle is temporarily stopped and needs to be started, and flywheel 1 has a high level of stored energy, the flywheel drive mode is used. In this mode, clutch 1 2, clutch 3 15, and brake 2 9 are engaged. Flywheel 1 power is transmitted through clutch 1 2, input shaft 4, sun gear 6, planetary gears 8, planetary carrier 10, planetary carrier connecting shaft 28, clutch 3 15, and output shaft 19, sequentially through the final drive consisting of pinion 20 and gear 21, differential 23, half-shaft 1 22, and half-shaft 2 32 to wheels 33. Brake 2 9 is locked, braking ring gear 7.

[0058] 4. Hybrid Drive Mode

[0059] When the vehicle requires high power for a short period of time, such as during instantaneous acceleration or short-term hill climbing acceleration, hybrid drive mode is used. In this mode, clutch 1 2, clutch 2 11, clutch 3 15, and clutch 4 16 are engaged. Both the motor outer rotor 12 and the motor inner rotor 14 are in the drive state. The flywheel 1's power is coupled via clutch 1 2, input shaft 4, and sun gear 6, and then to the motor inner rotor 14 via clutch 2 11 and ring gear 7. Furthermore, it is coupled via planetary gears 8, planetary carrier 10, planetary carrier connecting shaft 28, clutch 3 15, and to the motor outer rotor 12 via clutch 4 16. After this, it is transmitted from the output shaft 19 through the final reducer consisting of pinion 20 and gear 21, differential 23, half-shaft 1 22, and half-shaft 2 32 to wheels 33.

[0060] 5. Flywheel recovery braking energy mode

[0061] Flywheel regenerative braking mode is used when a vehicle is in a congested area requiring frequent braking and starting, or when braking smoothly downhill and decelerating smoothly, and flywheel 1's stored energy allows for further recharge. In this mode, clutch 1 2, clutch 2 11, and clutch 3 15 are engaged. The braking force of wheel 33 is transmitted sequentially through the final drive consisting of half-shafts 1 22 and 32, differential 23, gear 21 and pinion 20, output shaft 19, clutch 3 15, planetary carrier connecting shaft 28, planetary carrier 10, planetary gears 8, sun gear 6, input shaft 4, and clutch 1 2 to flywheel 1, where it begins accelerating to store energy. However, during flywheel regenerative braking, speed fluctuations can cause shock, requiring adjustment by the motor's inner rotor 14. The inner rotor 14 motor operates in electric mode. The power of the inner rotor 14 of the motor is transmitted through the clutch 2 11, the ring gear 7, and the planetary gear 6 to buffer the power fluctuation from the braking force of the wheel 33 to the planetary carrier, making the energy recovery process smoother and avoiding impact damage to components and affecting the driving experience.

[0062] 6. Power battery recovery braking energy mode

[0063] When the vehicle is in a braking condition requiring frequent braking and starting on congested roads, or braking on a long downhill slope, or undergoing smooth deceleration, the flywheel 1 has a high stored energy level, preventing further charging, and the power battery's state of charge is less than or equal to 95%. The power battery regenerative braking energy mode is used. In this mode, clutch four 16 is engaged. The motor's outer rotor 12 operates in a generating mode. The braking force of the wheels 33 is transmitted sequentially through the final reducer consisting of half-shafts 1 and 32, differential 23, gear 21, and pinion 20, output shaft 19, and clutch four 16 to the outer rotor 12. Under the braking force of the wheels 33, the motor's outer rotor 12 generates electricity, which is converted into electrical energy and stored in the power battery.

[0064] 7. Hybrid Regenerative Braking Energy Mode

[0065] When the vehicle is in emergency braking, requiring a high amount of regenerative braking energy, the flywheel 1 energy storage state allows further charging, and the power battery state of charge is less than or equal to 95%, hybrid regenerative braking energy mode is used. In this mode, clutch 1 2, clutch 2 11, clutch 3 15, and clutch 4 16 are engaged. The outer rotor 12 of the motor works in the generating state, and the inner rotor 14 of the motor works in the driving state. The braking force of the wheel 33 is transmitted to the outer rotor 12 in sequence through the main reducer composed of half-shaft 1 22 and half-shaft 2 32, differential 23, large gear 21 and pinion 20, output shaft 19, and clutch 4 16 to realize power battery energy recovery. At the same time, the braking force of the wheel 33 is transmitted to the flywheel 1 through the main reducer composed of half-shaft 1 22 and half-shaft 2 32, differential 23, large gear 21 and pinion 20, output shaft 19, clutch 3 15, planetary carrier connecting shaft 28, planetary carrier 10, planetary gear 8, sun gear 6, input shaft 4, and clutch 1 2. The inner rotor 14 serves as a regulating motor. The power of the inner rotor 14 is coordinated with the impact suffered during flywheel energy recovery through clutch 2 11, ring gear 7, and planetary gear 6, thereby ensuring the safety of flywheel energy storage and a good driving experience.

[0066] 8. Power battery flywheel energy recovery mode

[0067] When the vehicle is parked for an extended period, flywheel 1 stores a large amount of mechanical energy, and the power battery's state of charge is less than or equal to 95%, the power battery recovery flywheel energy mode is used. The energy stored in flywheel 1 is consumed relatively quickly by the power battery due to various friction factors. To improve energy efficiency, the power battery recovery flywheel energy mode is used when the vehicle is parked for extended periods. In this mode, clutch 1 2, clutch 2 11, and clutch 3 15 are engaged. The motor's inner rotor 14 operates in a generating state. The flywheel 1's power sequentially drives the motor's inner rotor 14 through clutch 1 2, input shaft 4, sun gear 6, planetary gears 8, ring gear 7, and clutch 2 11 to charge the power battery. The vehicle acts as a large inertial resistance, and the engagement of clutch 3 15 achieves a braking effect on the planetary carrier connecting shaft 28 and the planetary carrier 10.

[0068] This embodiment, through the combination of four clutches and two brakes, illustrates the operating modes under different vehicle operating conditions, adapting to various driving conditions. Under different driving conditions, it can meet both the vehicle's power requirements and the need for efficient braking energy recovery.

[0069] Embodiment 3 of the present invention

[0070] Combine Figures 1 to 2As shown, this embodiment shows the highly integrated structure of the electric drive axle with integrated flywheel energy storage of the present invention, which is used to illustrate the interlocking function of the clutch 1 2 and the brake 1 5, and the clutch 2 11 and the brake 2 9 structures, that is, the two are not engaged at the same time. The structure and working principle of the clutch 2 11 and the brake 2 9 are explained as follows:

[0071] Brake 2 (9) includes a first steel plate group (904), a first circlip (902), a first piston (903), a first friction plate group (905), a first seal (906), a second seal (908), and a first return spring (909). To facilitate the operation of Brake 2 (9), the housing (3) and the ring gear (7) are machined with internal splines (301) and external splines (701), respectively. Clutch 2 (11) includes a second circlip (1102), a second piston (1103), a second steel plate group (1104), a second friction plate group (1105), a third seal (1106), a fourth seal (1108), and a second return spring (1109). To facilitate the operation of Clutch 2 (11), internal splines (1402) and external splines (702) are machined on the inner rotor connecting ring (1401) and the ring gear (7), respectively. To functionally interlock Brake 2 (9) and Clutch 2 (11), bolts (1110) connect the first piston (903) and the second piston (1103). To accommodate the operation of brake 2 (9) and clutch 2 (11), the housing is provided with a first oil passage (901) and a second oil passage (1101). These passages, together with the first piston (903) and the second piston (110), form a first piston chamber (907) and a second piston chamber (1107). Seal rings 1 (906) and 2 (908) seal the first piston chamber (907), while seal rings 3 (1106) and 4 (1108) seal the second piston chamber (1107).

[0072] Continue to refer to Figure 1 and Figure 2 As shown, the first steel plate group 904 and the first friction plate group 905 are installed between the inner spline 301 and the outer spline 701. A retaining spring 902 is installed in a retaining spring groove machined on the housing 3 next to the inner spline 301, providing axial positioning for the first steel plate group 904 and the first friction plate group 905. A first return spring 909 is installed axially between the ring gear 7 and the first piston 903, ensuring the return of the first piston 903. The second steel plate group 1104 and the second friction plate group 1105 are installed between the inner spline 1402 and the outer spline 702. A retaining spring 1102 is installed in a retaining spring groove machined on the inner rotor connecting ring 1401 next to the inner spline 1402, ensuring the axial positioning of the second steel plate group 1104 and the second friction plate group 1105. A second return spring 1109 is installed axially between the inner rotor connecting ring 1401 and the second piston 1103, ensuring the return of the second piston 1103.

[0073] Continue to refer to Figure 1 and Figure 2As shown, when hydraulic oil at a certain pressure enters the first piston chamber 907 through the first oil passage 901, it pushes the first piston 903 leftward, overcoming the pressure of the first return spring 909 and compressing the first steel plate group 904 and the first friction plate group 905 to generate friction, thereby engaging the second brake 9. At this time, the ring gear 7 is braked relative to the housing 3. When hydraulic oil at a certain pressure enters the first piston chamber 1107 through the second oil passage 1101, it pushes the second piston 1103 rightward, overcoming the pressure of the second return spring 1109 and compressing the second steel plate group 1104 and the second friction plate group 1105 to generate friction, thereby engaging the second clutch 11. At this time, the ring gear 7 engages with the inner rotor connecting ring 1401. When the first piston 903 drives the second piston 1103 to move leftward together, or the second piston 1103 drives the first piston 903 to move rightward together, the structure achieves an interlocking function between the second brake 9 and the second clutch 11, i.e., they cannot be engaged simultaneously. When the first oil circuit 901 is depleted of oil, the first piston 903 returns to its original position under the pressure of the first return spring 909, releasing the brake relationship between the ring gear 7 and the housing 3. When the second oil circuit 1101 is depleted of oil, the second piston 1103 returns to its original position under the pressure of the second return spring 1109, releasing the connection between the ring gear 7 and the inner rotor connecting ring 1401. When both the first oil circuit 901 and the second oil circuit 1101 are depleted of oil pressure, the first and second pistons 903 and 1103 are in an intermediate position under the action of the first and second return springs 909 and 1109.

[0074] So far, the technical solutions of the present invention have been described in conjunction with the above multiple embodiments. However, it is easy for those skilled in the art to understand that the scope of protection of the present invention is not limited to these specific embodiments. Without departing from the technical principles of the present invention, those skilled in the art may split and combine the technical solutions in the above various embodiments, and may also make equivalent changes or replacements to the relevant technical features. Any changes, equivalent replacements, improvements, etc. made within the technical concept and / or technical principles of the present invention will fall within the scope of protection of the present invention.

Claims

1. An electric drive axle with integrated flywheel energy storage and its operating mode, characterized by: It includes a flywheel, a dual-rotor motor and a transmission device; The flywheel includes a flywheel rotor, a flywheel bearing, a vacuum housing, and a flywheel output shaft. The vacuum housing encloses the flywheel rotor and the flywheel bearing. The flywheel output shaft supports the flywheel rotor through the flywheel bearing, and the right end extends out of the vacuum housing. The dual-rotor motor and transmission device includes a dual-rotor motor, a planetary gear mechanism, four clutches, two brakes, a final reducer, a differential, a half shaft, nine sets of bearings and a housing, and is characterized by: The dual-rotor motor includes a stator, an inner rotor, and an outer rotor. The stator is composed of an iron core and a coil and is fixed to the housing. The inner rotor and the outer rotor are respectively inlaid with permanent magnets. The inner rotor connecting ring is connected to the inner rotor. The planetary gear mechanism includes a sun gear, planet gears, a planet carrier and a ring gear. The sun gear is connected to the input shaft. The planet gears are arranged between the sun gear and the ring gear and mesh with the sun gear and the ring gear respectively. The planet gear shafts are fixed to the planet carrier, and the planet carrier is connected to the planet carrier connecting shaft. The four clutches include clutch one, clutch two, clutch three and clutch four, wherein the left end of clutch one is connected to the flywheel output shaft and the right end is connected to the input shaft, the left end of clutch two is connected to the ring gear and the right end is connected to the inner rotor connecting ring, the left end of clutch three is connected to the planetary carrier connecting shaft and the right end is connected to the output shaft, and the left end of clutch four is connected to the outer rotor and the right end is connected to the output shaft; The two brakes include brake 1 and brake 2, wherein brake 1 is used for braking the input shaft and brake 2 is used for braking the ring gear; The main reducer includes a pinion and a gear, wherein the pinion is connected to the output shaft, the gear meshes with the pinion for transmission, and the gear is connected to the differential housing; The differential includes a differential case and differential planetary gears, and the power of the differential planetary gears is transmitted to the wheels via the half shafts; The half shafts include a first half shaft and a second half shaft, the first half shaft and the second half shaft are coaxially arranged and driven by the differential planetary gear respectively; The nine groups of bearings include bearing 1, bearing 2, bearing 3, bearing 4, bearing 5, bearing 6, bearing 7, bearing 8, and bearing 9. Bearing 1 and bearing 2 are used to support the output shaft, bearing 3 and bearing 6 are used to support the outer rotor, bearing 4, bearing 5, and bearing 7 are used to support the inner rotor and the ring gear, and bearing 8 and bearing 9 are used to support the input shaft. The housing encloses the dual-rotor motor, planetary gear mechanism, four clutches, two brakes, the final reducer, and the differential. The housing is a closed structure composed of three parts. The first part encloses the planetary gear mechanism, clutch one, brake one, clutch two, and brake two, and together with bearings seven, eight, and nine, supports the input shaft and the planetary gear mechanism. The second part encloses the dual-rotor motor, clutch three, clutch four, part of the final reducer, and part of the differential, and together with bearings one, two, three, four, five, and six, supports the output shaft and the dual-rotor motor. The third part encloses part of the final reducer and part of the differential. The three parts of the housing are all connected by bolts. The three-part housing structure is adapted to the internal enclosing structure. The flywheel cooperates with the dual-rotor motor and the transmission device to realize motor outer rotor drive, motor inner and outer rotor drive, flywheel drive, hybrid drive, flywheel recovery braking energy, power battery recovery braking energy, hybrid recovery braking energy, and power battery recovery flywheel energy mode; in the motor outer rotor drive mode, the clutch four is engaged, and the power of the motor outer rotor passes through the clutch four and is transmitted from the output shaft to the wheels in sequence through the main reducer, the differential, and the half shaft; In the motor inner and outer rotor drive mode, the brake 1, clutch 2, clutch 3, and clutch 4 are engaged, and the power of the motor inner rotor is transmitted through the clutch 2, the ring gear, the planetary gear, the planetary carrier, the planetary carrier connecting shaft, and clutch 3, and the power of the motor outer rotor is transmitted through the clutch 4, and then transmitted to the wheels by the output shaft in sequence through the main reducer, the differential, and the half shaft; In the flywheel drive mode, the clutch 1, brake 2, and clutch 3 are engaged, and the flywheel power is transmitted through the clutch 1, input shaft, sun gear, planetary gear, planetary carrier, planetary carrier connecting shaft, clutch 3, and then from the output shaft to the wheels through the final reducer, differential, and half shafts in sequence; In the hybrid drive mode, clutches 1, 2, 3, and 4 are engaged, and the flywheel power is transmitted through clutch 1, the input shaft, and the sun gear, and then through clutch 2 and the ring gear, and then through the planetary gears, the planetary carrier, the planetary carrier connecting shaft, and clutch 3, and then through the motor's outer rotor power through the fourth clutch. Together, the power is transmitted by the output shaft to the wheels in sequence through the final reducer, the differential, and the half shafts. In the flywheel braking energy recovery mode, clutch 1, clutch 2, and clutch 3 are engaged, and the wheel braking force is transmitted to the flywheel in sequence through the half shaft, differential, final reducer, output shaft, clutch 3, planetary carrier connecting shaft, planetary carrier, planetary gear, sun gear, input shaft, and clutch 1; at the same time, the impact on the motor's inner rotor during flywheel energy recovery is coordinated through clutch 2, ring gear, and planetary gear; In the power battery recovery braking energy mode, the fourth clutch is engaged, and the wheel braking force is transmitted to the motor outer rotor in sequence through the half shaft, differential, final reducer, output shaft, and fourth clutch, thereby realizing power battery energy recovery; In the hybrid braking energy recovery mode, clutch 1, clutch 2, clutch 3, and clutch 4 are engaged, and the wheel braking force is transmitted to the outer rotor in sequence through the half-shafts, differential, final reducer, output shaft, and clutch 4, thereby realizing power battery energy recovery. At the same time, the wheel braking force is transmitted to the flywheel through clutch 3, planetary carrier connecting shaft, planetary carrier, planetary gear, sun gear, input shaft, and clutch 1 after passing through the half-shafts, differential, final reducer, output shaft, and then to the flywheel. The impact on the inner rotor of the motor during flywheel energy recovery is coordinated through clutch 2, ring gear, and planetary gear. In the power battery flywheel energy recovery mode, when the vehicle is in the parking state, the clutch 1, clutch 2, and clutch 3 are engaged, and the flywheel power drives the inner rotor of the motor in sequence through the clutch 1, input shaft, sun gear, planetary gear, ring gear, and clutch 2 to charge the battery; the clutch 3 connects the output shaft with the planetary carrier connecting shaft and the planetary carrier, and uses the entire vehicle as a large inertia resistance to realize the braking effect of the planetary carrier.

2. The electric drive axle with integrated flywheel energy storage and its operating mode according to claim 1, characterized in that: The clutch and brake have an interlocking structure.

3. The electric drive axle with integrated flywheel energy storage and its operating mode according to claim 1, characterized in that: The second clutch and the second brake have an interlocking function in structure.

4. The electric drive axle with integrated flywheel energy storage and its operating mode according to claim 1, characterized in that: The 4 clutches and 2 brakes can be driven by hydraulic, electromagnetic or other means.

5. The electric drive axle with integrated flywheel energy storage and its operating mode according to claim 1, characterized in that: The dual-rotor motor is a permanent magnet synchronous motor.

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