Multi-motor drive systems, control methods for multi-motor drive systems, and vehicles

Abstract

This invention discloses a multi-motor drive system, a control method for the multi-motor drive system, and a vehicle. The multi-motor drive system includes a drive motor, a planetary transmission structure, a first input shaft, a second input shaft, a third input shaft, an output shaft, and a locking structure. The first motor and the second motor are respectively connected to the planetary transmission structure via the first and second input shafts, and the planetary transmission structure is connected to the output shaft. The third motor is connected to the output shaft via the third input shaft. The locking structure controls the transmission ratio of the drive motors. The first motor, the second motor, and the third motor are coaxially arranged. This invention provides a compact multi-motor drive system.

Description

Technical Field

[0001] This invention relates to the field of vehicle drive technology, and in particular to a multi-motor drive system, a control method for the multi-motor drive system, and a vehicle. Background Technology

[0002] With the introduction of my country's dual-carbon goals, the development of pure electric vehicles has been rapidly promoted.

[0003] For existing commercial vehicle electric drive system solutions, most electric drive systems use a combination of a single motor and an AMT (Automated Manual Transmission). However, it is difficult for a single motor drive system to simultaneously meet the requirements of low speed and high torque and high speed driving conditions. Moreover, the system efficiency is low when it is in the low speed and high torque or high speed driving conditions.

[0004] With technological innovation, multi-motor drive systems have emerged one after another. These multi-motor drive assemblies mostly adopt a motor matrix layout. Due to the limitation of the overall vehicle layout space, the matrix layout scheme of multi-motor drive assemblies is difficult to arrange and install in the vehicle. Summary of the Invention

[0005] The main objective of this invention is to provide a multi-motor drive system, specifically a compact multi-motor drive system.

[0006] To achieve the above objectives, the present invention proposes a multi-motor drive system, which includes a drive motor, a planetary transmission structure, a first input shaft, a second input shaft, a third input shaft, an output shaft, and a locking structure.

[0007] The first motor is connected to the planetary gear transmission structure via the first input shaft, the second motor is connected to the planetary gear transmission structure via the second input shaft, and the planetary gear transmission structure is connected to the output shaft.

[0008] The third motor is connected to the output shaft via the third input shaft;

[0009] The locking structure can control the transmission ratio of the drive motor;

[0010] The first motor, the second motor, and the third motor are coaxially arranged.

[0011] Optionally, the first input shaft is coaxially arranged with the output shaft, the second input shaft is sleeved on the first input shaft or the output shaft, and the third input shaft is arranged on the output shaft, so that the first motor, the second motor and the third motor are coaxially arranged.

[0012] Optionally, the planetary transmission structure includes a sun gear, planet gears, a ring gear, and a planet carrier. The sun gear meshes with the planet gears, the planet gears mesh with the ring gear, and the planet gears are mounted on the planet carrier. The first input shaft is connected to the sun gear, and the planet carrier is connected to the output shaft.

[0013] Optionally, the locking structure includes a first locking component, which includes a first intermediate shaft, a first gear sleeve, and a first sliding sleeve. The first intermediate shaft is fixed to the first input shaft, the first sliding sleeve meshes with the gear hub of the first intermediate shaft, the first gear sleeve is fixedly connected to the housing of the multi-motor drive system, and the first sliding sleeve can selectively mesh with the first gear sleeve to enable the first locking component to control the power on / off of the first motor.

[0014] Optionally, the second input shaft is fixedly connected to the gear ring.

[0015] Optionally, the locking structure includes a second locking component, which includes a second toothed sleeve and a second sliding sleeve. The second toothed sleeve is fixedly connected to the housing of the multi-motor drive system, and the second sliding sleeve engages with the gear ring. The second sliding sleeve can selectively engage with the second toothed sleeve to allow the second locking component to control the power supply of the second motor.

[0016] Optionally, the locking structure includes a third locking component, which includes a third sliding sleeve that meshes with the gear hub of the planetary carrier and can selectively mesh with the sun gear to control the transmission ratio of the first motor and the second motor.

[0017] Optionally, the multi-motor drive system further includes a gear transmission structure, through which the third motor is connected to the output shaft via the gear transmission structure.

[0018] Optionally, the planetary transmission structure and the gear transmission structure are located in the same housing.

[0019] Optionally, the gear transmission structure is a two-gear pair structure.

[0020] Optionally, the locking structure includes a fourth locking component. The two gear pairs include a first gear pair and a second gear pair that are connected in a transmission manner. The first gear pair is connected in a transmission manner to the third motor, and both the first gear pair and the second gear pair are located on the output shaft. The fourth locking component includes a fourth sliding sleeve, which is located on the output shaft and between the first gear pair and the second gear pair. The fourth sliding sleeve can selectively mesh with the first gear pair and the second gear pair so that the fourth locking component controls the transmission ratio of the third motor.

[0021] Optionally, the gear transmission structure is a three-gear pair structure. The locking structure includes a fourth locking component and a fifth locking component. The two gear pairs include a first-gear pair, a second-gear pair, and a third-gear pair connected in sequence. The first-gear pair is connected to the third motor, and the first, second, and third gear pairs are all located on the output shaft. The fourth locking component includes a fourth sliding sleeve located on the output shaft between the first and second gear pairs, and the fourth sliding sleeve can selectively mesh with the first and second gear pairs. The fifth locking component includes a fifth sliding sleeve located on the output shaft between the second and third gear pairs, and the fifth sliding sleeve can selectively mesh with the second and third gear pairs, so that the fourth and fifth locking components cooperate to control the transmission ratio of the third motor and the planetary transmission structure.

[0022] Optionally, the multi-motor drive system further includes a control unit, which includes a PMS, a TCU, and an MCU. The PMS is electrically connected to and controls the TCU and the MCU. The TCU is electrically connected to the locking structure and controls the movement of the locking structure. The MCU is electrically connected to the first motor, the second motor, and the third motor and controls the driving of the first motor, the second motor, and the third motor.

[0023] This invention also proposes a control method for a multi-motor drive system, applied to the aforementioned multi-motor drive system, the method comprising:

[0024] Obtain the vehicle's load and speed;

[0025] Based on the load and the driving speed, determine the target operating mode of the vehicle and generate a switching request for the target operating mode;

[0026] In response to the switching request, the operating mode of the vehicle is switched to the target operating mode;

[0027] The target operating mode of the vehicle is determined based on the load and the driving speed, specifically including at least one of the following:

[0028] When the load is less than or equal to the first load calibration value, the target operating mode of the vehicle is determined to be a single motor drive mode.

[0029] When the load is greater than the first load calibration value and less than the second load calibration value, or when the load is greater than or equal to the second load calibration value and the driving speed is less than or equal to the first speed calibration value, the target operating mode of the vehicle is determined to be the dual-motor drive mode.

[0030] When the load is greater than or equal to the second load calibration value and the driving speed is greater than the first speed calibration value, the target operating mode of the vehicle is determined to be the three-motor drive mode.

[0031] The present invention also proposes a vehicle including the aforementioned multi-motor drive system.

[0032] One technical solution of this invention involves setting up a multi-motor drive system including a first motor, a second motor, and a third motor. The first and second motors are respectively connected to a planetary transmission structure via a first input shaft and a second input shaft, and the planetary transmission structure outputs power through an output shaft. The third motor outputs power through a third input shaft and an output shaft. The multi-motor drive system also includes a locking structure that controls the transmission ratio of the drive motors, thereby adjusting the transmission ratios of the first, second, and third motors to ensure that the motors operate at high efficiency speeds under different vehicle speeds. Furthermore, the first, second, and third motors are coaxially arranged. Compared to the matrix arrangement of multi-motor systems in the prior art, the coaxial arrangement of the first, second, and third motors along the length of the vehicle results in a smaller radial dimension of the multi-motor drive system, occupying less space in the width direction of the vehicle. This improves the structural compactness of the multi-motor drive system, facilitates the overall vehicle space layout, and expands the applicability of the multi-motor drive system. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without creative effort.

[0034] Figure 1This is a schematic diagram of the structure of the first embodiment of the multi-motor drive system of the present invention;

[0035] Figure 2 This is a schematic diagram of the structure of a second embodiment of a multi-motor drive system;

[0036] Figure 3 This is a schematic diagram of the structure of the third embodiment of the multi-motor drive system;

[0037] Figure 4 This is a schematic diagram of the structure of the fourth embodiment of the multi-motor drive system;

[0038] Figure 5 This is a schematic diagram of the structure of the fifth embodiment of the multi-motor drive system;

[0039] Figure 6 for Figure 1 Power transmission path diagram of EV1 in the first embodiment of the multi-motor drive system in gear;

[0040] Figure 7 for Figure 1 Power transmission path diagram of EV2 gear in the first embodiment of the multi-motor drive system;

[0041] Figure 8 for Figure 1 Power transmission path diagram of EV3 gear in the first embodiment of the multi-motor drive system;

[0042] Figure 9 for Figure 1 Power transmission path diagram of EV4 gear in the first embodiment of the multi-motor drive system;

[0043] Figure 10 for Figure 1 Power transmission path diagram of EV5 gear in the first embodiment of the multi-motor drive system;

[0044] Figure 11 for Figure 1 Power transmission path diagram of EV6 gear in the first embodiment of the multi-motor drive system;

[0045] Figure 12 for Figure 1 Power transmission path diagram of EV7 in gear mode in the first embodiment of the multi-motor drive system;

[0046] Figure 13 for Figure 1 Power transmission path diagram of EV8 in gear mode in the first embodiment of the multi-motor drive system;

[0047] Figure 14 for Figure 1 Power transmission path diagram of EV9 in gear in the first embodiment of the multi-motor drive system;

[0048] Figure 15 for Figure 1 Power transmission path diagram of EV10 in gear in the first embodiment of the multi-motor drive system;

[0049] Figure 16 for Figure 1 Power transmission path diagram of EV11 in gear mode in the first embodiment of the multi-motor drive system;

[0050] Figure 17 This is a shift control logic diagram for a multi-motor drive system.

[0051] Figure 18 The shifting process from EV1 to EV2 in the first embodiment of the multi-motor drive system is described below.

[0052] Figure 19 The second shifting process from EV1 to EV2 in the first embodiment of the multi-motor drive system;

[0053] Figure 20 The third step in the shifting process from EV1 to EV2 in the first embodiment of the multi-motor drive system;

[0054] Figure 21 The shifting process from EV1 to EV2 in the first embodiment of the multi-motor drive system is described in section four.

[0055] Figure 22 The shifting process from EV5 to EV6 in the first embodiment of the multi-motor drive system;

[0056] Figure 23 The second shift process for switching from EV5 to EV6 in the first embodiment of the multi-motor drive system;

[0057] Figure 24 The third step in the shifting process from EV5 to EV6 in the first embodiment of the multi-motor drive system;

[0058] Figure 25 The shifting process from EV5 to EV6 in the first embodiment of the multi-motor drive system is described in section four.

[0059] Figure 26 Partial power transmission path of the fifth embodiment of the multi-motor drive system Figure 1 ;

[0060] Figure 27 Partial power transmission path of the fifth embodiment of the multi-motor drive system Figure 2 ;

[0061] Figure 28 Partial power transmission path of the fifth embodiment of the multi-motor drive system Figure 3 .

[0062] Explanation of icon numbers:

[0063]

[0064]

[0065] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0066] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0067] It should be noted that all directional indications (such as up, down, left, right, front, back, etc.) in the embodiments of the present invention are only used to explain the relative positional relationship and movement of each component in a certain specific posture (as shown in the figure). If the specific posture changes, the directional indication will also change accordingly.

[0068] Furthermore, the use of terms such as "first" and "second" in this invention is for descriptive purposes only and should not be construed as indicating or implying their relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined with "first" or "second" may explicitly or implicitly include at least one of those features. Additionally, the term "and / or" throughout the text includes three solutions; taking A and / or B as an example, it includes technical solution A, technical solution B, and a technical solution that simultaneously satisfies A and B. Furthermore, the technical solutions of various embodiments can be combined with each other, but this must be based on the ability of a person skilled in the art to implement them. When the combination of technical solutions is contradictory or impossible to implement, it should be considered that such a combination of technical solutions does not exist and is not within the scope of protection claimed by this invention.

[0069] With the introduction of my country's dual-carbon goals, the development of pure electric vehicles has been rapidly promoted. Especially in the market for pure electric medium and heavy-duty trucks, electric drive systems have become a key focus of research and development for various companies.

[0070] For existing commercial vehicle electric drive system solutions, most electric drive systems use a combination of a single motor and an automated manual transmission (AMT). However, a single-motor drive system struggles to simultaneously meet the demands of low-speed, high-torque and high-speed driving conditions. Furthermore, the system efficiency is low during low-speed, high-torque or high-speed driving. Additionally, a single-motor AMT experiences power interruption during gear shifts. Moreover, if the single motor fails, the vehicle will be unable to operate normally.

[0071] With technological innovation, multi-motor drive systems have emerged. These multi-motor drive assemblies often adopt a motor matrix arrangement, meaning multiple motors are arranged along the width of the vehicle. Due to space constraints, the matrix arrangement of multi-motor drive assemblies presents challenges in vehicle layout and installation. Furthermore, due to space limitations, individual motors have relatively low power output. Therefore, during gear shifts, only one or a portion of the motors can maintain power output, resulting in significant power loss during gear changes.

[0072] In view of this, the present invention proposes a multi-motor drive system.

[0073] Please refer to Figures 1 to 5 In this embodiment of the invention, the multi-motor drive system includes a drive motor, a planetary gear transmission structure 30, a first input shaft 21, a second input shaft 22, a third input shaft 23, an output shaft 24, and a locking structure 40.

[0074] Specifically, the drive motor is the power source in the multi-motor drive system. The drive motor includes a first motor 11, a second motor 12, and a third motor 13, meaning all three motors can serve as power sources to drive the vehicle. Thus, compared to the single-motor drive system in the prior art, this invention uses three motors as power sources, thereby avoiding the problem of poor power performance caused by the maximum power limitation of a single-motor drive; avoiding the problem of torque drop and poor high-speed driving ability of a single-motor drive system when the motor is running at high speed; avoiding the problem of low efficiency due to the small efficient range of a single-motor drive system, which cannot cover a wide range of vehicle operating conditions; and avoiding the problem of the vehicle being unable to continue driving if a single motor fails, thus improving the vehicle's safety and reliability. In one embodiment, all three motors can be conventional permanent magnet synchronous motors.

[0075] The first motor 11 is connected to the planetary gear transmission structure 30 via the first input shaft 21; the second motor 12 is connected to the planetary gear transmission structure 30 via the second input shaft 22; the planetary gear transmission structure 30 is connected to the output shaft 24; and the third motor 13 is connected to the output shaft 24 via the third input shaft 23.

[0076] Specifically, the power of the first motor 11 is transmitted to the planetary transmission structure 30 via the first input shaft 21. After being reduced in speed and increased in torque by the planetary transmission structure 30, the power is transmitted to the output shaft 24, and then to the wheels of the vehicle, thereby enabling the first motor 11 to drive the vehicle. The first input shaft 21 can be the rotor shaft of the first motor 11, that is, the first motor 11 is connected to the planetary transmission structure 30 through its rotor shaft. In another embodiment, the first input shaft 21 can also be a high-speed shaft, which is fixedly connected to the rotor shaft of the first motor 11 via a spline or other means, and the first motor 11 is connected to the planetary transmission structure 30 through the high-speed shaft.

[0077] The power of the second motor 12 is transmitted to the planetary transmission structure 30 via the second input shaft 22. After being reduced in speed and increased in torque by the planetary transmission structure 30, the power is transmitted to the output shaft 24, and then to the wheels of the vehicle, thereby enabling the second motor 12 to drive the vehicle. The second input shaft 22 can be the rotor shaft of the second motor 12, that is, the second motor 12 is connected to the planetary transmission structure 30 through its rotor shaft. In another embodiment, the second input shaft 22 can also be a high-speed shaft, which is fixedly connected to the rotor shaft of the second motor 12 by means of splines or the like, and the second motor 12 is connected to the planetary transmission structure 30 through the high-speed shaft.

[0078] The power of the third motor 13 is transmitted to the output shaft 24 via the third input shaft 23, and then to the wheels of the vehicle via the output shaft 24, thereby enabling the third motor 13 to drive the vehicle. The third input shaft 23 can be the rotor shaft of the third motor 13, that is, the third motor 13 is connected to the output shaft 24 through its rotor shaft. In another embodiment, the third input shaft 23 can also be a high-speed shaft, which is fixedly connected to the rotor shaft of the third motor 13 via a spline or other means, and the third motor 13 is connected to the output shaft 24 through the high-speed shaft.

[0079] In this way, the three motors transmit power through their respective input shafts. That is, each power source has a corresponding input shaft. Compared with the single input shaft structure design, the three input shafts avoid the problem of power interruption during gear shifting. Especially in uphill conditions, the interruption of power during gear shifting may cause the vehicle to roll downhill, thereby improving the safety of vehicle use.

[0080] The locking structure 40 can control the transmission ratio of the drive motor. Specifically, the locking structure 40 can selectively engage or disengage between the planetary transmission structure 30 and the first motor 11 and the second motor 12. That is, the locking structure 40 can engage or disengage the planetary transmission structure 30 and the first motor 11, thereby controlling the transmission ratio of the first motor 11; the locking structure 40 can also engage or disengage the planetary transmission structure 30 and the second motor 12, thereby controlling the transmission ratio of the second motor 12. In another embodiment, the locking structure 40 can also engage or disengage the third motor 13 and the output shaft 24, thereby controlling the transmission ratio of the third motor 13. Thus, through the selective engagement of the locking structure 40, the transmission ratios of the first motor 11, the second motor 12, and the third motor 13 can be controlled, thereby controlling the overall driving force of the entire multi-motor drive system and ensuring that the motors operate at high-efficiency speeds under different driving speeds.

[0081] The first motor 11, the second motor 12, and the third motor 13 are coaxially arranged. Specifically, the first motor 11, the second motor 12, and the third motor 13 are coaxially arranged along the length of the vehicle. Compared to the matrix arrangement of multiple motors in the prior art, the coaxial arrangement of the first motor 11, the second motor 12, and the third motor 13 along the length of the vehicle in this invention results in a smaller radial dimension of the multi-motor drive system, occupying less space in the width direction of the vehicle, improving the structural compactness of the multi-motor drive system, which is beneficial to the spatial layout of the entire vehicle and expands the applicability of the multi-motor drive system. At the same time, compared to the problem of large space occupation when using high-speed, high-power motors in the matrix arrangement of multiple motors in the prior art, the power selection of a single motor in this invention is not limited by the arrangement space. In one embodiment, all three motors can be conventional permanent magnet synchronous motors.

[0082] One technical solution of the present invention involves setting up a multi-motor drive system including a first motor 11, a second motor 12, and a third motor 13. The first motor 11 and the second motor 12 are respectively connected to a planetary transmission structure 30 via a first input shaft 21 and a second input shaft 22, and the planetary transmission structure 30 outputs power via an output shaft 24. The third motor 13 outputs power via a third input shaft 23 and an output shaft 24. The multi-motor drive system also includes a locking structure 40, which can control the transmission ratio of the drive motors, thereby adjusting the transmission ratios of the first motor 11, the second motor 12, and the third motor 13 to ensure that the motors operate at high efficiency speeds under different vehicle speeds. Meanwhile, the first motor 11, the second motor 12, and the third motor 13 are arranged coaxially. Compared with the matrix arrangement of multiple motors in the prior art, the first motor 11, the second motor 12, and the third motor 13 are arranged coaxially along the length of the vehicle in this invention, which makes the radial dimension of the multi-motor drive system smaller and occupies less space in the width direction of the vehicle. This improves the structural compactness of the multi-motor drive system, is beneficial to the spatial arrangement of the whole vehicle, and expands the applicability of the multi-motor drive system.

[0083] Furthermore, the first input shaft 21 is coaxially arranged with the output shaft 24, the second input shaft 22 is sleeved on the first input shaft 21 or the output shaft 24, and the third input shaft 23 is arranged on the output shaft 24, so that the first motor 11, the second motor 12 and the third motor 13 are coaxially arranged.

[0084] Specifically, the first input shaft 21 and the output shaft 24 are coaxial, meaning their axes coincide. The first input shaft 21 and the output shaft 24 are arranged along the front-rear direction of the vehicle, with a certain gap between them. Both the first input shaft 21 and the output shaft 24 are solid shafts. The second input shaft 22 is a hollow shaft, sleeved outside the first input shaft 21 or the output shaft 24, and can rotate relative to it. The third input shaft 23 is located on the output shaft 24. In some embodiments, the third input shaft 23 can be fixed to the output shaft 24; that is, the third input shaft 23 is a solid shaft, and the third input shaft 23 and the output shaft 24 are fixedly connected by splines or welding. In other embodiments, the third input shaft 23 is sleeved on the output shaft 24; that is, the third input shaft 23 is a hollow shaft, sleeved outside the output shaft 24, and the third input shaft 23 and the output shaft 24 can rotate relative to each other. This allows the first motor 11, the second motor 12, and the third motor 13 to be coaxially arranged. Compared to the matrix arrangement of multiple motors in the prior art, the first motor 11, the second motor 12, and the third motor 13 in this invention are arranged coaxially along the length of the vehicle, resulting in a smaller radial dimension of the multi-motor drive system, occupying less space in the width direction of the vehicle, improving the structural compactness of the multi-motor drive system, facilitating the overall vehicle space layout, and expanding the applicability of the multi-motor drive system. Furthermore, compared to the problem of large space occupation caused by high-speed, high-power motors in the matrix arrangement of multiple motors in the prior art, the power selection of a single motor in this invention is not limited by the arrangement space. In one embodiment, all three motors can be conventional permanent magnet synchronous motors.

[0085] Furthermore, the planetary transmission structure 30 includes a sun gear 31, planet gears 32, a ring gear 33, and a planet carrier 34. The sun gear 31 meshes with the planet gears 32, the planet gears 32 mesh with the ring gear 33, and the planet gears 32 are mounted on the planet carrier 34. The first input shaft 21 is connected to the sun gear 31, and the planet carrier 34 is connected to the output shaft 24.

[0086] Specifically, the sun gear 31 is located at the center of the planetary gear transmission structure 30. The planet gears 32 mesh with the outer ring of the sun gear 31. Multiple sets of planet gears 32 can be arranged in the circumferential direction of the sun gear 31; the number of sets of planet gears 32 is not limited here. Each planet gear 32 is fixed to the planet carrier 34 by a bearing, and the planet carrier 34 provides fixed support for the planet gear 32. At the same time, the planet gears 32 also mesh with the inner ring of the gear ring 33, that is, the planet gears 32 and the adjacent sun gear 31 and gear ring 33 are in a constant meshing state, thereby realizing the transmission between the three. The first input shaft 21 is connected to the sun gear 31. In one embodiment, the two are fixedly connected by a spline or a flat key, thereby realizing the transmission of power from the first motor 11 to the planetary gear transmission structure 30. The planetary carrier 34 is connected to the output shaft 24. In one embodiment, the two are fixedly connected by a spline or a flat key, thereby realizing the transmission connection between the planetary gear transmission structure 30 and the output shaft 24. This enables the power of the first motor 11 to be output through the planetary gear transmission structure 30 and then through the output shaft 24.

[0087] Furthermore, the locking structure 40 includes a first locking assembly, which includes a first intermediate shaft 41, a first gear sleeve 42, and a first sliding sleeve 43. The first intermediate shaft 41 is fixedly mounted on the first input shaft 21. The first sliding sleeve 43 meshes with the gear hub of the first intermediate shaft 41. The first gear sleeve 42 is fixedly connected to the housing of the multi-motor drive system. The first sliding sleeve 43 can selectively mesh with the first gear sleeve 42 so that the first locking assembly controls the power on / off of the first motor 11.

[0088] Specifically, the first intermediate shaft 41 is fixed to the first input shaft 21 by means of splines, flat keys, or welding. The first input shaft 21 is also fixedly connected to the sun gear 31, thus the first intermediate shaft 41 and the sun gear 31 are also fixedly connected. Both ends of the first intermediate shaft 41 are provided with gear hubs. The first sliding sleeve 43 has splined holes, and the first sliding sleeve 43 is constantly meshed with the gear hubs of the first intermediate shaft 41; that is, the splined holes of the first sliding sleeve 43 mesh with the gear hubs of the first intermediate shaft 41. The first gear sleeve 42 is fixedly connected to the housing of the multi-motor drive system. The first gear sleeve 42 has engaging teeth that can mesh with the splined holes of the first sliding sleeve 43 to achieve meshing between the first gear sleeve 42 and the first sliding sleeve 43.

[0089] The first sliding sleeve 43 can slide left and right along the axial direction of the first input shaft 21. When the first sliding sleeve 43 approaches the first gear sleeve 42 along the axial direction of the first input shaft 21, and the spline hole of the first sliding sleeve 43 meshes with the engaging teeth of the first gear sleeve 42, the first locking assembly locks the first input shaft 21, that is, locks the first motor 11. At this time, the power of the first motor 11 cannot be transmitted downward through the planetary gear transmission structure 30, the first motor 11 does not participate in driving, and the transmission ratio of the first motor 11 is 0. In addition, when the first motor 11 is in the locked state, the sun gear 31 is also locked. At this time, the power of the second motor 12 achieves a fixed reduction ratio through the planetary gear transmission structure 30 to output power.

[0090] When the first motor 11 is required to participate in driving, the first sliding sleeve 43 moves away from the first gear sleeve 42 along the axial direction of the first input shaft 21, causing the first sliding sleeve 43 to disengage from the first gear sleeve 42. At this time, the first motor 11 is in the unlocked state, and the power of the first motor 11 can be transmitted downward through the planetary transmission structure 30 to participate in driving. Through the cooperation of the first locking component, the power of the first motor 11 can be controlled to be connected or interrupted.

[0091] Furthermore, the second input shaft 22 is fixedly connected to the gear ring 33. Specifically, in one embodiment, the second input shaft 22 and the gear ring 33 are fixedly connected via a spline or a flat key, thereby realizing the transmission of power from the second motor 12 to the planetary gear transmission structure 30. Simultaneously, the planet carrier 34 in the planetary gear transmission structure 30 is connected to the output shaft 24, thereby realizing the transmission connection between the planetary gear transmission structure 30 and the output shaft 24. Thus, the power of the second motor 12 is transmitted through the planetary gear transmission structure 30 and then output through the output shaft 24.

[0092] Furthermore, the locking structure 40 includes a second locking assembly, which includes a second toothed sleeve 44 and a second sliding sleeve 45. The second toothed sleeve 44 is fixedly connected to the housing of the multi-motor drive system, and the second sliding sleeve 45 engages with the toothed ring 33. The second sliding sleeve 45 can selectively engage with the second toothed sleeve 44 so that the second locking assembly controls the power on / off of the second motor 12.

[0093] Specifically, the second locking assembly includes a second toothed sleeve 44 and a second sliding sleeve 45. The second sliding sleeve 45 has a splined hole and is constantly engaged with the gear ring 33, that is, the splined hole of the second sliding sleeve 45 is constantly engaged with the gear ring 33. The second toothed sleeve 44 is fixedly connected to the housing of the multi-motor drive system. The second toothed sleeve 44 has engaging teeth that can engage with the splined hole of the second sliding sleeve 45 to achieve engagement between the second toothed sleeve 44 and the second sliding sleeve 45.

[0094] The second sliding sleeve 45 can slide left and right along the axial direction of the first input shaft 21. When the second sliding sleeve 45 approaches the second gear sleeve 44 along the axial direction of the first input shaft 21, and the spline hole of the second sliding sleeve 45 meshes with the engaging teeth of the second gear sleeve 44, the second locking assembly locks the second input shaft 22, that is, locks the second motor 12. At this time, the power of the second motor 12 cannot be transmitted downward through the planetary transmission structure 30, the second motor 12 does not participate in driving, and the transmission ratio of the second motor 12 is 0. In addition, when the second motor 12 is in the locked state, the gear ring 33 is also locked. At this time, the power of the first motor 11 achieves a fixed reduction ratio through the planetary transmission structure 30 to output power.

[0095] When the second motor 12 is required to participate in driving, the second sliding sleeve 45 moves away from the second gear sleeve 44 along the axial direction of the first input shaft 21, causing the second sliding sleeve 45 to disengage from the second gear sleeve 44. At this time, the second motor 12 is in the unlocked state, and the power of the second motor 12 can be transmitted downward through the planetary transmission structure 30 to participate in driving. Through the cooperation of the second locking component, the power of the second motor 12 can be controlled to be connected or interrupted.

[0096] Furthermore, the locking structure 40 includes a third locking assembly, which includes a third sliding sleeve 46 that meshes with the gear hub of the planetary carrier 34 and can selectively mesh with the sun gear 31 to enable the third locking assembly to control the transmission ratio of the first motor 11 and the second motor 12.

[0097] Specifically, the third locking assembly includes a third sliding sleeve 46, which has a splined hole, and a planetary carrier 34, which has a gear hub. The splined hole of the third sliding sleeve 46 is constantly engaged with the gear hub of the planetary carrier 34, meaning that the third sliding sleeve 46 and the planetary carrier 34 are in a constantly engaged state. The sun gear 31 also has engagement teeth, which can engage with the splined hole of the third sliding sleeve 46 to achieve engagement between the third sliding sleeve 46 and the sun gear 31.

[0098] The third sliding sleeve 46 can slide left and right along the axial direction of the first input shaft 21. When the third sliding sleeve 46 approaches the sun gear 31 along the axial direction of the first input shaft 21, and the spline hole of the third sliding sleeve 46 meshes with the engagement teeth of the sun gear 31, the third locking assembly locks the sun gear 31 and the planet carrier 34. At this time, the sun gear 31, planet gears 32, and ring gear 33 within the planetary transmission structure 30 no longer rotate relative to each other, and the planetary transmission structure 30 rotates as a whole. That is, the planetary transmission structure 30 is locked. At this time, the first motor 11 and the second motor 12 can simultaneously achieve direct drive mode, that is, the transmission ratio of the first motor 11 and the second motor 12 is both 1. Thus, through the setting of the third locking assembly, the adjustment and control of the transmission ratio of the first motor 11 and the second motor 12 are realized.

[0099] Furthermore, the multi-motor drive system also includes a gear transmission structure 50, through which the third motor 13 is connected to the output shaft 24 via the gear transmission structure 50.

[0100] Specifically, in one embodiment, the third motor 13 is connected to the output shaft 24 via a gear transmission structure 50. The gear transmission structure 50 can adjust the transmission ratio of the third motor 13, such as... Figure 1 , Figures 3 to 5 As shown, the power of the third motor 13 can be reduced and amplified by the gear transmission structure 50 before being output through the output shaft 24, thus meeting the different speed ratio requirements of the multi-motor drive system. In this way, the first motor 11 and the second motor 12 are driven by the planetary transmission structure 30, and the third motor 13 is driven by the gear transmission structure 50. This means that the multi-motor drive system has two relatively independent transmission routes: the planetary transmission structure 30 and the gear transmission structure 50. This allows for uninterrupted power shifting during gear changes, thereby improving vehicle stability and comfort.

[0101] Of course, in some embodiments, the power of the third motor 13 can also be output directly through the output shaft 24 without going through the gear transmission structure 50, such as... Figure 2 As shown. Thus, the third motor 13 adopts a direct drive mode, which makes the overall system structure simpler and the axial dimension smaller, which is beneficial to the structural compactness of the multi-motor drive system.

[0102] Furthermore, the planetary transmission structure 30 and the gear transmission structure 50 are located within the same housing. Specifically, both the planetary transmission structure 30 and the gear transmission structure 50 are integrated inside a single transmission housing, which results in a high degree of integration for the multi-motor drive system and further contributes to the structural compactness of the multi-motor drive system.

[0103] Furthermore, the gear transmission structure 50 consists of two sets of gear pairs. Specifically, as shown... Figure 1, 3 As shown in Figure 4, when a two-gear pair structure is adopted, the power of the third motor 13 is output by selecting different paths in the two gear pairs, thereby realizing different transmission ratios for the third motor 13.

[0104] Furthermore, the gear transmission structure 50 consists of two sets of gear pairs, and the locking structure 40 includes a fourth locking component. The two sets of gear pairs include a first-gear pair and a second-gear pair that are connected in transmission. The first-gear pair is connected in transmission to the third motor 13, and both the first-gear pair and the second-gear pair are located on the output shaft 24. The fourth locking component includes a fourth sliding sleeve 47, which is located on the output shaft 24 and between the first-gear pair and the second-gear pair. The fourth sliding sleeve 47 can selectively mesh with the first-gear pair and the second-gear pair so that the fourth locking component controls the transmission ratio of the third motor 13.

[0105] Specifically, in one embodiment, the gear transmission structure 50 consists of two sets of gear pairs, and the locking structure 40 further includes a fourth locking component, such as... Figure 1 , 4 As shown. The two gear pairs include a first-gear pair and a second-gear pair. The first-gear pair includes a meshing first-gear drive gear 51 and a first-gear driven gear 52. The second-gear pair includes a meshing second-gear drive gear 53 and a second-gear driven gear 54. The first-gear drive gear 51 is driven by the third input shaft 23, and the second-gear drive gear 53 is driven by the first-gear driven gear 52. Both the first-gear drive gear 51 and the second-gear driven gear 54 are loosely fitted onto the output shaft 24 via bearings. The fourth locking assembly includes a fourth sliding sleeve 47, which is fixedly connected to the output shaft 24. In one embodiment, the hub of the fourth sliding sleeve 47 is fixedly connected to the output shaft 24 via a spline or a flat key. The fourth sliding sleeve 47 is also located between the first-gear drive gear 51 and the second-gear driven gear 54.

[0106] The fourth sliding sleeve 47 can move left and right along the axial direction of the first input shaft 21. When the fourth sliding sleeve 47 moves towards the first gear drive gear 51 and meshes with the first gear drive gear 51, the power of the third motor 13 is directly transmitted to the output shaft 24 through the first gear drive gear 51 and the fourth sliding sleeve 47. This is the direct drive mode of the third motor 13, that is, the power of the third motor 13 is directly output without deceleration.

[0107] When the fourth sliding sleeve 47 moves towards the second-gear driven gear 54 and engages with it, the power of the third motor 13 is transmitted to the output shaft 24 via the first-gear driving gear 51, the first-gear driven gear 52, the second-gear driving gear 53, and the second-gear driven gear 54. At this time, the power of the third motor 13 is output after being reduced in speed and increased in torque by the second-gear. Thus, by setting the fourth locking component, the transmission ratio of the third motor 13 can be adjusted and controlled.

[0108] In arranging the first motor 11, the second motor 12, the third motor 13, the planetary gear transmission structure 30, and the gear transmission structure 50, in one embodiment, the first motor 11, the second motor 12, the planetary gear transmission structure 30, the gear transmission structure 50, and the third motor 13 are arranged sequentially along the axial direction of the first input shaft 21, as follows: Figure 1 As shown. In another embodiment, the first motor 11, planetary transmission structure 30, second motor 12, third motor 13, and gear transmission structure 50 can be arranged sequentially along the axial direction of the first input shaft 21, as shown. Figure 4 As shown.

[0109] Furthermore, the gear transmission structure 50 is a three-gear pair structure. Specifically, as shown... Figure 5 As shown, when a three-gear pair structure is used, two of the three gear pairs are used for the power output of the third motor 13, and one of the three gear pairs is used for the power output of the first motor 11 and / or the second motor 12, that is, for transmission connection with the planet carrier 34 in the planetary transmission structure 30, thereby adjusting the transmission ratio at the output end of the planet carrier 34. Compared with the two-gear pair structure, the three-gear pair structure adds one gear set, realizing the reduction and torque increase at the output end of the planet carrier 34, making the speed ratio adjustment range wider and the actual applicability better. Thus, by selecting a two-gear pair structure or a three-gear pair structure, the output ends of the third motor 13 and the planet carrier 34 can have different transmission ratios, thereby meeting the different speed ratio requirements of the multi-motor drive system. Of course, the gear transmission structure 50 can also be a four- or five-gear pair structure. The number of gear pairs in the gear transmission structure 50 can be adjusted according to the speed ratio requirements of the multi-motor drive system.

[0110] Furthermore, the gear transmission structure 50 is a three-gear pair structure, and the locking structure 40 includes a fourth locking component and a fifth locking component. The three gear pairs include a first-gear pair, a second-gear pair, and a third-gear pair connected in sequence. The first-gear pair is connected to the third motor 13, and the first-gear pair, second-gear pair, and third-gear pair are all located on the output shaft 24. The fourth locking component includes a fourth sliding sleeve 47, which is located on the output shaft 24 and between the first-gear pair and the second-gear pair. The fourth sliding sleeve 47 can selectively mesh with the first-gear pair and the second-gear pair. The fifth locking component includes a fifth sliding sleeve 48, which is located on the output shaft 24 and between the second-gear pair and the third-gear pair. The fifth sliding sleeve 48 can selectively mesh with the second-gear pair and the third-gear pair, so that the fourth locking component and the fifth locking component cooperate to control the transmission ratio of the third motor 13 and the planetary transmission structure 30.

[0111] Specifically, compared to the embodiment described above where the gear transmission structure 50 has two sets of gear pairs and the locking structure 40 includes a fourth locking component, this embodiment adds a third gear pair to the gear transmission structure 50 and adds a fifth locking component to the locking structure 40 that cooperates with the second or third gear pair, such as... Figure 5 As shown.

[0112] like Figure 5 As shown, in this embodiment, the output shaft 24 includes a first output shaft and a second output shaft. The first output shaft is connected to the planet carrier 34 of the planetary transmission structure 30, and the second output shaft is used to connect to the vehicle's wheels. One end of the second output shaft is sleeved outside the first output shaft, allowing them to rotate relative to each other but not to transmit power. The three-speed gear pair includes a meshing third-speed drive gear 55 and a third-speed driven gear 56. The third-speed drive gear 55 is connected to the second-speed drive gear 53, and the third-speed driven gear 56 is sleeved outside the first output shaft. A fifth sliding sleeve 48 is located on the first output shaft, between the third-speed driven gear 56 and the second-speed driven gear 54. The second driven gear, the fourth sliding sleeve 47, and the first drive gear are located on the second output shaft.

[0113] Please refer to Figure 26 When the fourth sliding sleeve 47 meshes with the first gear drive gear 51, and the fifth sliding sleeve 48 meshes with the third gear driven gear 56, the power of the first motor 11 and / or the second motor 12 is output through the planetary carrier 34 - first output shaft - fifth sliding sleeve 48 - third gear driven gear 56 - third gear drive gear 55 - second gear drive gear 53 - second gear driven gear 54 - second output shaft. The power of the third motor 13 is output through the third input shaft 23 - fourth sliding sleeve 47 - first gear drive gear 51 - first gear driven gear 52 - second gear drive gear 53 - second gear driven gear 54 - second output shaft.

[0114] Please refer to Figure 27 When the fourth sliding sleeve 47 meshes with the first gear drive gear 51 and the fifth sliding sleeve 48 meshes with the second gear driven gear 54, the power of the first motor 11 and / or the second motor 12 is output through the planetary carrier 34-first output shaft-fifth sliding sleeve 48-second gear driven gear 54-second output shaft. The power of the third motor 13 is output through the third input shaft 23-fourth sliding sleeve 47-first gear drive gear 51-first gear driven gear 52-second gear drive gear 53-second gear driven gear 54-second output shaft.

[0115] Please refer to Figure 28 When the fourth sliding sleeve 47 meshes with the second-gear driven gear 54, and the fifth sliding sleeve 48 meshes with the second-gear driven gear 54, the power of the first motor 11 and / or the second motor 12 is output through the planetary carrier 34-first output shaft-fifth sliding sleeve 48-second-gear driven gear 54-second output shaft. The power of the third motor 13 is output through the third input shaft 23-fourth sliding sleeve 47-second-gear driven gear 54-second output shaft.

[0116] Thus, the three-gear pair structure adds one more gear pair compared to the two-gear pair structure, thereby achieving speed reduction and torque increase at the output end of the planet carrier 34 in the planetary transmission structure 30, making the speed ratio adjustment range of the multi-motor drive system wider and its actual applicability better.

[0117] Of course, in some embodiments, the multi-motor drive system includes a gear transmission structure 50, but does not include a locking structure 40 that cooperates with the gear transmission structure 50, such as... Figure 3 As shown. The third motor 13 has a fixed reduction ratio output, a simple structure, and a small axial dimension.

[0118] Furthermore, the multi-motor drive system also includes a control unit 60, which includes a PMS 61, a TCU 62, and an MCU 63. The PMS 61 is electrically connected to and controls the TCU 62 and MCU 63. The TCU 62 is electrically connected to the locking structure 40 and controls the movement of the locking structure 40. The MCU 63 is electrically connected to and controls the driving of the first motor 11, the second motor 12, and the third motor 13.

[0119] The following explanation will focus on an example where the power of the third motor 13 is output through two sets of gear pairs, and the multi-motor drive system is equipped with a fourth locking component that cooperates with the two sets of gear pairs. Figure 1The first embodiment of the multi-motor drive system will be described in detail. Specifically, the multi-motor drive system also includes a control unit 60, which includes a power generation management system (PMS) 61, a transmission control unit (TCU) 62, and an MCU 63. PMS 61 refers to the power generation management system, TCU 62 refers to the transmission control unit 60, and MCU 63 refers to the motor control unit 60. PMS 61 determines the output torque based on the vehicle load, mode signal, throttle signal, and current vehicle speed. TCU 62 determines the control mode, torque, and speed of each drive motor based on torque requirements and sends this information to MCU 63 via CAN communication. MCU 63 controls the corresponding motor to participate in vehicle drive based on power requirements. TCU 62 also determines the current gear of the multi-motor drive system and achieves the target gear by controlling the first sliding sleeve 43, the second sliding sleeve 45, the third sliding sleeve 46, and the fourth sliding sleeve 47 of the multi-motor drive system.

[0120] This invention also proposes a control method for a multi-motor drive system. This method is applied to the aforementioned multi-motor drive system, and under the control of this method, the multi-motor drive system has multiple operating modes. In this invention, the controller is the main execution entity. More specifically, the control unit 60 is the main execution entity, and the control unit 60 includes a PMS 61, a TCU 62, and an MCU 63.

[0121] S101. Obtain the vehicle's load and speed.

[0122] In this embodiment, the PMS 61 in the control unit 60 can obtain the vehicle's speed through a speed sensor installed in the vehicle. This speed is the vehicle's speed at the current moment. The PMS 61 can also obtain the vehicle's load through a load sensor installed in the vehicle. This load is the vehicle's load at the current moment.

[0123] In one example, the PMS61 can periodically acquire the load and speed after the vehicle starts. This period can be set empirically, for example, every 10 minutes or every 30 minutes.

[0124] S102. Based on the load and the driving speed, determine the target operating mode of the vehicle and generate a switching request for the target operating mode.

[0125] In this embodiment, the vehicle's operating modes include single-motor drive mode, dual-motor drive mode, and tri-motor drive mode. The control unit 60 can determine the operating mode the vehicle will execute at the current moment based on the load and driving speed. This upcoming operating mode is the target operating mode. The control unit 60 can generate a switching request based on the target operating mode. This switching request is used to switch the vehicle's operating mode.

[0126] In one example, when the vehicle is running, the control unit 60 can periodically acquire the load data. When the load data acquired by the control unit 60 is low, the control unit 60 determines the target operating mode of the vehicle. This target operating mode is a single-motor drive mode. At this time, a switching request is used to control the vehicle to switch to the single-motor drive mode.

[0127] In another example, when the vehicle is running, the control unit 60 can periodically acquire load and speed data. When the load acquired by the control unit 60 is moderate, or when the load is high and the speed is low, the single-motor drive mode cannot meet the vehicle's driving requirements. In this case, the control unit 60 determines that the target operating mode for the vehicle is dual-motor drive mode. A switching request is then used to control the vehicle to switch from single-motor drive mode to dual-motor drive mode.

[0128] In another example, when the vehicle is running, the control unit 60 can periodically acquire the load and driving speed. When the load acquired by the control unit 60 is high and the driving speed is moderate or high, the dual-motor drive mode cannot meet the vehicle's driving needs. At this time, the control unit 60 determines that the target operating mode of the vehicle is the tri-motor drive mode. A switching request is then used to control the vehicle to switch from the dual-motor drive mode to the tri-motor drive mode.

[0129] In one example, the specific steps for determining the target operating mode of a vehicle may include:

[0130] S1021. When the load is less than or equal to the first load calibration value, the target working mode of the vehicle is determined to be the single motor drive mode.

[0131] In this step, the control unit 60 can periodically acquire the vehicle's load and speed after the vehicle starts. The first load calibration value can be 30%. This first load calibration value can be determined empirically. When the vehicle is in motion, if the control unit 60 detects that the load is less than or equal to the first load calibration value, the control unit 60 determines that the vehicle is in a low-load condition. At this time, regardless of whether the vehicle's speed is low, medium, or high, single-motor drive can meet the vehicle's driving needs. The control unit 60 can then determine that the target operating mode is single-motor drive mode. The vehicle is switched to this single-motor drive mode.

[0132] S1022. When the load is greater than the first load calibration value and less than the second load calibration value, or when the load is greater than or equal to the second load calibration value and the driving speed is less than or equal to the first speed calibration value, the target operating mode of the vehicle is determined to be the dual-motor drive mode.

[0133] In this step, the control unit 60 can periodically acquire the vehicle's load and speed after the vehicle starts. The second load calibration value can be 50%. This second load calibration value can be determined empirically. The first speed calibration value can be 20 km / h. This first speed calibration value can be determined empirically. When the vehicle is in motion, if the control unit 60 detects that the load is greater than the first load calibration value but less than the second load calibration value, the control unit 60 determines that the vehicle is in a medium-load condition. Alternatively, if the control unit 60 detects that the load is greater than or equal to the second load calibration value and the speed is less than or equal to the first speed calibration value, the control unit 60 determines that the vehicle is in a heavy-load, low-speed condition. At this time, single-motor drive cannot meet the vehicle's driving requirements. Therefore, the control unit 60 can determine that the target operating mode is a dual-motor drive mode. The vehicle will then be switched from single-motor drive mode to dual-motor drive mode.

[0134] S1023. When the load is greater than or equal to the second load calibration value and the driving speed is greater than the first speed calibration value, the target working mode of the vehicle is determined to be the three-motor drive mode.

[0135] In this step, the control unit 60 can periodically acquire the vehicle's load and speed after the vehicle starts. When the vehicle is in motion, if the control unit 60 detects that the load is greater than or equal to the second load calibration value and the speed is greater than the first speed calibration value, the control unit 60 determines that the vehicle is in a heavy-load medium-speed or heavy-load high-speed condition. At this time, the dual-motor drive cannot meet the vehicle's driving requirements. The control unit 60 can then determine that the target operating mode is a three-motor drive mode. The vehicle will then be switched from the dual-motor drive mode to the three-motor drive mode.

[0136] S103. In response to the switching request, the operating mode of the vehicle is switched to the target operating mode.

[0137] In this embodiment, when the control unit 60 receives a switching request, it can respond to the switching request and switch the vehicle's operating mode. When the vehicle is in power-on mode, the switching request is used to control the vehicle to start and enter the target operating mode. When the vehicle is in the start-up state, the switching request is used to control the vehicle to switch from the current operating mode to the target operating mode.

[0138] More specifically, the multi-motor drive system has one or more of the following operating modes: single-motor drive mode, dual-motor drive mode, and tri-motor drive mode.

[0139] Single motor drive mode: One of the three motors 11, 12 and 13 is engaged in operation, while the other two are not engaged in operation. The locking structure 40 controls the power connection of the engaged motor and controls the power interruption of the non-engaged motor.

[0140] Dual-motor drive mode: Two of the three motors 11, 12 and 13 are engaged in operation, while the third motor is not engaged in operation. The locking structure 40 controls the power connection of the engaged motor and controls the power interruption of the non-engaged motor.

[0141] Three-motor drive mode: all three motors, namely the first motor 11, the second motor 12 and the third motor 13, are engaged in operation, and the locking structure 40 controls the transmission ratio of the three motors.

[0142] The following explanation will focus on an example where the power of the third motor 13 is output through two sets of gear pairs, and the multi-motor drive system is equipped with a fourth locking component that cooperates with the two sets of gear pairs. Figure 1 The first embodiment of the multi-motor drive system is used as an example for specific explanation. Its working status table is shown in Table 1. In Table 1, "-" indicates that it does not participate in the operation, "●" indicates that it participates in the operation, "0" indicates that the gear transmission structure 50 does not transmit power, "1" indicates that the gear transmission structure 50 transmits power through the first gear, and "2" indicates that the gear transmission structure 50 transmits power through the second gear.

[0143] Table 1 - Operating Status Table of an Embodiment of a Multi-Motor Drive System

[0144]

[0145]

[0146] Figures 6 to 16 The diagrams correspond to the power paths of EV1 through EV11, with the bold lines representing the power paths.

[0147] Please refer to Figure 6 In this embodiment, in single-motor drive mode, in EV1 gear, the fourth sliding sleeve 47 meshes with the second-gear driven gear 54, while the first sliding sleeve 43, second sliding sleeve 45, and third sliding sleeve 46 are all in a disengaged state. At this time, the first motor 11 does not participate in driving, the second motor 12 does not participate in driving, and the third motor 13 participates in driving. The gear transmission structure 50 transmits power through the first gear. This gear is suitable for light-load start-up and low-speed driving conditions.

[0148] The power transmission path of the third motor 13 is as follows: third motor 13 - third input shaft 23 - first gear drive gear 51 - first gear driven gear 52 - second gear drive gear 53 - second gear driven gear 54 - fourth sliding sleeve 47 - output shaft 24.

[0149] Please refer to Figure 7 In this embodiment, in single-motor drive mode, at EV2 gear, the second sliding sleeve 45 engages with the second gear sleeve 44, and the gear ring 33 is locked. The first sliding sleeve 43, the third sliding sleeve 46, and the fourth sliding sleeve 47 are all in a disengaged state. At this time, the first motor 11 participates in driving, while the second motor 12 and the third motor 13 do not participate in driving. This gear is suitable for light-load, low-to-medium-speed driving conditions.

[0150] The power transmission path of the first motor 11 is: first motor 11 - first input shaft 21 - sun gear 31 - planet gear 32 - planet carrier 34 - output shaft 24.

[0151] Please refer to Figure 8 In this embodiment, in single-motor drive mode, at EV3 gear, the first sliding sleeve 43 engages with the first gear sleeve 42, and the sun gear 31 is locked. The second sliding sleeve 45, the third sliding sleeve 46, and the fourth sliding sleeve 47 are all in a disengaged state. At this time, the first motor 11 does not participate in driving, the second motor 12 participates in driving, and the third motor 13 does not participate in driving. This gear is suitable for light-load, medium-speed driving and other operating conditions.

[0152] The power transmission path of the second motor 12 is: second motor 12 - second input shaft 22 - gear ring 33 - planetary gear 32 - planetary carrier 34 - output shaft 24.

[0153] Please refer to Figure 9 In this embodiment, in single-motor drive mode, at EV4 gear, the fourth sliding sleeve 47 meshes with the first gear drive gear 51, while the first sliding sleeve 43, second sliding sleeve 45, and third sliding sleeve 46 are all in a disengaged state. At this time, the first motor 11 and second motor 12 do not participate in driving, while the third motor 13 participates in driving, and the gear transmission structure 50 transmits power through the second gear. This gear is a separate direct-drive mode for the third motor 13, suitable for light-load, high-speed driving and other operating conditions.

[0154] The power transmission path of the third motor 13 is: third motor 13 - third input shaft 23 - first gear drive gear 51 - fourth sliding sleeve 47 - output shaft 24.

[0155] Please refer to Figure 10 In this embodiment, under dual-motor drive mode, in EV5 gear, the second sliding sleeve 45 meshes with the second gear sleeve 44, at which time the gear ring 33 is locked, the fourth sliding sleeve 47 meshes with the second-gear driven gear 54, and the first sliding sleeve 43 and the third sliding sleeve 46 are both in a disengaged state. At this time, the first motor 11 participates in driving, the second motor 12 does not participate in driving, and the third motor 13 participates in driving. The gear transmission structure 50 transmits power through the first gear. This gear is suitable for medium and heavy load low-speed driving conditions.

[0156] The power transmission path of the first motor 11 is: first motor 11 - first input shaft 21 - sun gear 31 - planet gear 32 - planet carrier 34 - output shaft 24.

[0157] The power transmission path of the third motor 13 is as follows: third motor 13 - third input shaft 23 - first gear drive gear 51 - first gear driven gear 52 - second gear drive gear 53 - second gear driven gear 54 - fourth sliding sleeve 47 - output shaft 24.

[0158] Please refer to Figure 11 In this embodiment, under dual-motor drive mode, in EV6 gear, the first sliding sleeve 43 meshes with the first gear sleeve 42, at which time the sun gear 31 is locked, the fourth sliding sleeve 47 meshes with the second-gear driven gear 54, and the second sliding sleeve 45 and the third sliding sleeve 46 are both in a disengaged state. At this time, the first motor 11 does not participate in driving, the second motor 12 participates in driving, and the third motor 13 participates in driving. The gear transmission structure 50 transmits power through the first gear. This gear is suitable for medium and low speed driving conditions under half load.

[0159] The power transmission path of the second motor 12 is: second motor 12 - second input shaft 22 - gear ring 33 - planetary gear 32 - planetary carrier 34 - output shaft 24.

[0160] The power transmission path of the third motor 13 is as follows: third motor 13 - third input shaft 23 - first gear drive gear 51 - first gear driven gear 52 - second gear drive gear 53 - second gear driven gear 54 - fourth sliding sleeve 47 - output shaft 24.

[0161] Please refer to Figure 12 In this embodiment, under dual-motor drive mode, in EV7 gear, the first sliding sleeve 43 meshes with the first gear sleeve 42, at which time the sun gear 31 is locked, the fourth sliding sleeve 47 meshes with the first gear drive gear 51, and the second sliding sleeve 45 and the third sliding sleeve 46 are both in a disengaged state. At this time, the first motor 11 does not participate in driving, the second motor 12 participates in driving, and the third motor 13 participates in driving. The gear transmission structure 50 transmits power through the second gear. This gear is suitable for medium and low speed driving conditions under half load.

[0162] The power transmission path of the second motor 12 is: second motor 12 - second input shaft 22 - gear ring 33 - planetary gear 32 - planetary carrier 34 - output shaft 24.

[0163] The power transmission path of the third motor 13 is: third motor 13 - third input shaft 23 - first gear drive gear 51 - fourth sliding sleeve 47 - output shaft 24.

[0164] Please refer to Figure 13In this embodiment, in the dual-motor drive mode, at EV8 gear, the third sliding sleeve 46 engages with the sun gear 31, locking both the sun gear 31 and the planetary carrier 34. The fourth sliding sleeve 47 engages with the first-gear drive gear 51, while the first sliding sleeve 43 and the second sliding sleeve 45 are disengaged. At this time, the first motor 11 does not participate in driving, while the second motor 12 and the third motor 13 participate in driving. The gear transmission structure 50 transmits power through the second gear. This gear is a direct-drive mode for the second motor 12 and the third motor 13, suitable for medium- and high-speed driving conditions under half-load conditions.

[0165] The power transmission path of the second motor 12 is: second motor 12 - second input shaft 22 - gear ring 33 - planetary gear 32 - third sliding sleeve 46 - planetary carrier 34 - output shaft 24.

[0166] The power transmission path of the third motor 13 is: third motor 13 - third input shaft 23 - first gear drive gear 51 - fourth sliding sleeve 47 - output shaft 24.

[0167] Please refer to Figure 14 In this embodiment, under dual-motor drive mode, in EV9 gear, the third sliding sleeve 46 engages with the sun gear 31. At this time, both the sun gear 31 and the planetary carrier 34 are locked, and the first sliding sleeve 43, the second sliding sleeve 45, and the fourth sliding sleeve 47 are all in a disengaged state. In this mode, the first motor 11 and the second motor 12 participate in driving, while the third motor 13 does not. This gear is a direct drive mode for the first motor 11 and the second motor 12, suitable for medium- and high-speed driving conditions under half-load conditions.

[0168] The power transmission path of the first motor 11 is: first motor 11 - first input shaft 21 - sun gear 31 - third sliding sleeve 46 - planetary carrier 34 - output shaft 24.

[0169] The power transmission path of the second motor 12 is: second motor 12 - second input shaft 22 - gear ring 33 - planetary gear 32 - third sliding sleeve 46 - planetary carrier 34 - output shaft 24.

[0170] Please refer to Figure 15 In this embodiment, in the three-motor drive mode, at EV10 gear, the fourth sliding sleeve 47 meshes with the second-gear driven gear 54, while the first sliding sleeve 43, the second sliding sleeve 45, and the third sliding sleeve 46 are all in a disengaged state. At this time, the first motor 11, the second motor 12, and the third motor 13 all participate in the drive, and the gear transmission structure 50 transmits power through the first gear. This gear is suitable for heavy-load, low-speed driving conditions.

[0171] The power transmission path of the first motor 11 is: first motor 11 - first input shaft 21 - sun gear 31 - planet gear 32 - planet carrier 34 - output shaft 24.

[0172] The power transmission path of the second motor 12 is: second motor 12 - second input shaft 22 - gear ring 33 - planetary gear 32 - planetary carrier 34 - output shaft 24.

[0173] The power transmission path of the third motor 13 is as follows: third motor 13 - third input shaft 23 - first gear drive gear 51 - first gear driven gear 52 - second gear drive gear 53 - second gear driven gear 54 - fourth sliding sleeve 47 - output shaft 24.

[0174] Please refer to Figure 16 In this embodiment, in the dual-motor drive mode, at EV11 gear, the third sliding sleeve 46 meshes with the sun gear 31, at which time both the sun gear 31 and the planetary carrier 34 are locked. The fourth sliding sleeve 47 meshes with the first gear drive gear 51, while the first sliding sleeve 43 and the second sliding sleeve 45 are disengaged. At this time, the first motor 11, the second motor 12, and the third motor 13 all participate in the drive, and the gear transmission structure 50 transmits power through the second gear. This gear is suitable for heavy-load, medium- and high-speed driving conditions.

[0175] The power transmission path of the first motor 11 is: first motor 11 - first input shaft 21 - sun gear 31 - third sliding sleeve 46 - planetary carrier 34 - output shaft 24.

[0176] The power transmission path of the second motor 12 is: second motor 12 - second input shaft 22 - gear ring 33 - planetary gear 32 - third sliding sleeve 46 - planetary carrier 34 - output shaft 24.

[0177] The power transmission path of the third motor 13 is: third motor 13 - third input shaft 23 - first gear drive gear 51 - fourth sliding sleeve 47 - output shaft 24.

[0178] In this invention, the power transmission routes of each drive motor are different, and different transmission ratios can be designed according to power requirements. Power transmission remains uninterrupted when switching between different modes. The shift control logic of the multi-motor drive system is detailed below. Figure 17 .

[0179] According to the shift logic, during the shift process, the TCU62 determines the appropriate drive mode and shift point based on signals such as current vehicle speed, required torque, load and working mode. The following uses single motor drive mode switching and dual motor mode switching as examples to illustrate the shift process without power interruption.

[0180] Please refer to Figures 18 to 21 In single-motor drive mode, the example of switching from EV1 mode to EV2 mode will be used for explanation.

[0181] First, in EV1 drive mode, before shifting gears, the third motor 13 drives the entire vehicle independently, and transmits power to the output shaft 24 through the gear transmission structure 50. The first motor 11 and the second motor 12 do not participate in driving, and the first sliding sleeve 43, the second sliding sleeve 45 and the third sliding sleeve 46 are all in a separated state.

[0182] Second, when TCU62 determines that it is close to the shift point, it sends a shift request signal to PMS61. PMS61 sends a shift permission signal back. After receiving the feedback, TCU62 sends control mode signals and speed signals for the first motor 11 and the second motor 12 to make them reach the appropriate speed. After the speed adjustment is completed, TCU62 controls the second sliding sleeve 45 to move to the right. At this time, the speed of the first motor 11 and the speed of the output shaft 24 are in a fixed speed ratio relationship.

[0183] Third, the torque of the first motor 11 is increased, while the torque of the third motor 13 decreases. During the torque adjustment process, the power output of the electric drive assembly is maintained to meet the power requirements of the whole vehicle.

[0184] Fourth, after the torque adjustment process is completed, the first motor 11 drives the entire vehicle alone, and the third motor 13 has no power output. The fourth sliding sleeve 47 of the gear transmission structure 50 is disengaged. After disengagement, the third motor 13 is in the free deceleration process and its enable is turned off.

[0185] After completing the above process, the multi-motor drive system has switched from EV1 mode to EV2 mode.

[0186] Please refer to Figures 22 to 25 In the dual-motor drive mode, the example of switching from EV5 mode to EV6 mode will be used for explanation.

[0187] First, in EV5 drive mode, before shifting gears, the first motor 11 and the third motor 13 jointly drive the whole vehicle. The power is transmitted to the output shaft 24 through the gear transmission structure 50 and the planetary transmission structure 30. The second motor 12 does not participate in the drive. The second sliding sleeve 45 meshes with the second gear sleeve 44, that is, the second sliding sleeve 45 is in a locked state.

[0188] Second, when TCU62 determines that it is close to the shift point, it sends a shift request signal to PMS61. PMS61 sends a shift permission signal. After receiving the feedback, TCU62 sends a control mode signal and a torque reduction signal to the first motor 11. After completing the torque reduction, TCU62 controls the second sliding sleeve 45 in the planetary transmission structure 30 to move to the left and unlock the gear ring 33. At this time, the third motor 13 continues to output power to ensure that the driving force of the whole vehicle is not interrupted.

[0189] Third, the TCU62 controls the first motor 11 and the second motor 12 to adjust their speeds, so that the speed of the first motor 11 is close to 0 rpm. After the speed adjustment is completed, the first sliding sleeve 43 is controlled to mesh with the first gear sleeve 42, locking the first input shaft 21 and turning off the first motor 11. During the above control process, the third motor 13 continues to output power to ensure that the driving force of the whole vehicle is not interrupted.

[0190] Fourth, the TCU62 controls the torque of the second motor 12 to increase. At this time, the second motor 12 and the third motor 13 output power simultaneously, entering the EV6 drive mode.

[0191] After completing the above process, the multi-motor drive system has switched from EV5 mode to EV6 mode.

[0192] Thus, in this invention, on the one hand, a three-motor coaxial arrangement is adopted, allowing all three motors to achieve direct drive mode at high speeds, ensuring the power requirements of the vehicle at high speeds are met; on the other hand, the three-motor coaxial arrangement is more compact than a matrix arrangement, facilitating layout and installation, and the power selection of a single motor is not limited by the layout space; furthermore, the planetary transmission structure 30 allows the control unit 60 to adjust the motor speed to achieve the gear ratio, ensuring that the motor operates at high-efficiency speeds under different driving conditions; furthermore, the planetary transmission structure 30 achieves speed reduction and torque increase, as well as power coupling. Planetary gears, due to their light weight, small size, large transmission ratio, and strong load-bearing capacity, provide strong high-speed driving capabilities, making them particularly suitable for medium and heavy-duty vehicles; and finally, single-motor, dual-motor, and three-motor drive modes can be selected according to the actual usage requirements of the vehicle. During gear shifting, the motors can work alternately, ensuring uninterrupted power during shifting while maintaining the high-efficiency speed range of all working motors, thus improving system efficiency.

[0193] The present invention also proposes a vehicle including a multi-motor drive system. The specific structure of the multi-motor drive system is as described in the above embodiments. Since the vehicle adopts all the technical solutions of all the above embodiments, it has at least all the beneficial effects brought about by the technical solutions of the above embodiments, which will not be described in detail here.

[0194] The above description is merely an optional embodiment of the present invention and does not limit the patent scope of the present invention. All equivalent structural transformations made using the contents of the present invention's specification and drawings under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A multi-motor drive system, characterized in that, It includes a drive motor, a planetary gear transmission structure, a first input shaft, a second input shaft, a third input shaft, an output shaft, and a locking structure; The drive motor includes a first motor, a second motor, and a third motor; The planetary transmission structure includes a sun gear, planet gears, a ring gear, and a planet carrier. The sun gear meshes with the planet gears, the planet gears mesh with the ring gear, and the planet gears are mounted on the planet carrier. The first motor is driven to the sun gear via the first input shaft, the second motor is driven to the ring gear via the second input shaft, and the planet carrier is driven to the output shaft; The third motor is connected to the output shaft via the third input shaft; The locking structure can control the transmission ratio of the drive motor; The first motor, the second motor, and the third motor are coaxially arranged. The locking structure includes a third locking component, which includes a third sliding sleeve that meshes with the gear hub of the planetary carrier and can selectively mesh with the sun gear to control the transmission ratio of the first motor and the second motor.

2. The multi-motor drive system as described in claim 1, characterized in that, The first input shaft is coaxially arranged with the output shaft, the second input shaft is sleeved on the first input shaft or the output shaft, and the third input shaft is arranged on the output shaft, so that the first motor, the second motor and the third motor are coaxially arranged.

3. The multi-motor drive system as described in claim 1, characterized in that, The locking structure includes a first locking component, which includes a first intermediate shaft, a first gear sleeve, and a first sliding sleeve. The first intermediate shaft is fixed to the first input shaft. The first sliding sleeve meshes with the gear hub of the first intermediate shaft. The first gear sleeve is fixedly connected to the housing of the multi-motor drive system. The first sliding sleeve can selectively mesh with the first gear sleeve so that the first locking component controls the power on / off of the first motor.

4. The multi-motor drive system as described in claim 1, characterized in that, The second input shaft is fixedly connected to the gear ring.

5. The multi-motor drive system as described in claim 4, characterized in that, The locking structure includes a second locking component, which includes a second toothed sleeve and a second sliding sleeve. The second toothed sleeve is fixedly connected to the housing of the multi-motor drive system. The second sliding sleeve engages with the toothed ring, and the second sliding sleeve can selectively engage with the second toothed sleeve to allow the second locking component to control the power supply of the second motor.

6. The multi-motor drive system as described in claim 1, characterized in that, The multi-motor drive system also includes a gear transmission structure, through which the third motor is connected to the output shaft via the gear transmission structure.

7. The multi-motor drive system as described in claim 6, characterized in that, The planetary transmission structure and the gear transmission structure are located in the same housing.

8. The multi-motor drive system as described in claim 6, characterized in that, The gear transmission structure consists of two sets of gear pairs.

9. The multi-motor drive system as described in claim 8, characterized in that, The locking structure includes a fourth locking component. The two gear pairs include a first-gear pair and a second-gear pair that are connected in a transmission manner. The first-gear pair is connected in a transmission manner to the third motor, and both the first-gear pair and the second-gear pair are located on the output shaft. The fourth locking component includes a fourth sliding sleeve, which is located on the output shaft and between the first-gear pair and the second-gear pair. The fourth sliding sleeve can selectively mesh with the first-gear pair and the second-gear pair to control the transmission ratio of the third motor.

10. The multi-motor drive system as described in claim 9, characterized in that, The gear transmission structure comprises three sets of gear pairs. The locking structure includes a fourth locking component and a fifth locking component. The three sets of gear pairs include a first-gear pair, a second-gear pair, and a third-gear pair connected in sequence. The first-gear pair is connected to the third motor, and all three gear pairs are located on the output shaft. The fourth locking component includes a fourth sliding sleeve located on the output shaft between the first-gear pair and the second-gear pair, and can selectively mesh with both gear pairs. The fifth locking component includes a fifth sliding sleeve located on the output shaft between the second-gear pair and the third-gear pair, and can selectively mesh with both gear pairs. This allows the fourth and fifth locking components to cooperate in controlling the transmission ratio of the third motor and the planetary transmission structure.

11. The multi-motor drive system according to any one of claims 1 to 10, characterized in that, The multi-motor drive system also includes a control unit, which includes a PMS, a TCU, and an MCU. The PMS is electrically connected to and controls the TCU and the MCU. The TCU is electrically connected to and controls the movement of the locking structure. The MCU is electrically connected to and controls the driving of the first motor, the second motor, and the third motor.

12. A control method for a multi-motor drive system, applied to the multi-motor drive system as described in any one of claims 1 to 11, characterized in that, The method includes: Obtain the vehicle's load and speed; Based on the load and the driving speed, determine the target operating mode of the vehicle and generate a switching request for the target operating mode; In response to the switching request, the operating mode of the vehicle is switched to the target operating mode; The target operating mode of the vehicle is determined based on the load and the driving speed, specifically including at least one of the following: When the load is less than or equal to the first load calibration value, the target operating mode of the vehicle is determined to be a single motor drive mode. When the load is greater than the first load calibration value and less than the second load calibration value, or when the load is greater than or equal to the second load calibration value and the driving speed is less than or equal to the first speed calibration value, the target operating mode of the vehicle is determined to be the dual-motor drive mode. When the load is greater than or equal to the second load calibration value and the driving speed is greater than the first speed calibration value, the target operating mode of the vehicle is determined to be the three-motor drive mode.

13. A vehicle, characterized in that, Including the multi-motor drive system as described in any one of claims 1 to 11.

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