Drive assembly, control method of a drive assembly, electronic device, and transport vehicle

Abstract

The application relates to the technical field of power driving, in particular to a driving assembly, a control method of the driving assembly, electronic equipment and a transport carrier. The driving assembly comprises a driving device, a differential device, a transmission device and a hydraulic retarder. The driving device has an output shaft, and an input end of the differential device is connected to the output shaft. The transmission device is drivingly connected to an output end of the differential device, and the hydraulic retarder comprises a retarder stator and a retarder rotor. The retarder stator is fixedly arranged, and the retarder rotor is drivingly connected to the transmission device. In the power transmission path of the driving assembly, the hydraulic retarder is located on the output side of the differential device. The structure of the above-mentioned driving assembly is relatively compact.

Description

Technical Field

[0001] This application relates to the field of power drive technology, and more specifically, to a drive assembly, a control method for the drive assembly, electronic equipment, and a transport vehicle. Background Technology

[0002] Existing new energy vehicles, especially electric vehicles and hybrid vehicles, usually prioritize regenerative braking to recover energy when the vehicle is decelerating or going downhill, and use mechanical friction braking in conjunction with regenerative braking when regenerative braking is insufficient to achieve vehicle deceleration.

[0003] However, regenerative braking capability is easily limited under conditions such as long-distance, high-load downhill driving, full-load driving, or frequent braking. For example, when the battery is at a high state of charge and cannot continue to recharge, or when the motor or electronic control system reaches its temperature or power limits, or even malfunctions, regenerative braking may not be able to continuously provide sufficient braking torque. In such cases, the vehicle often needs to rely more on mechanical friction brakes to provide braking force. Mechanical friction brakes are prone to problems such as overheating, wear, and thermal fade when operating under continuous high loads, which in turn affects braking stability and driving safety.

[0004] Against this backdrop, related technologies have also explored the use of auxiliary braking structures to share the braking load of mechanical friction brakes, thereby improving the braking performance of vehicles under continuous deceleration conditions. Auxiliary braking structures can, to some extent, alleviate the thermal load on mechanical friction brakes and improve the vehicle's continuous braking capability under specific operating conditions.

[0005] However, currently, auxiliary braking structures are usually located outside the powertrain output end and are set up relatively independently from the drive system. This results in a long transmission link and a more complex transmission structure between the vehicle's power transmission structure and the auxiliary braking structure, which is not conducive to the integration and compact arrangement of the powertrain and the auxiliary braking structure. Summary of the Invention

[0006] This application provides a drive assembly, a control method for the drive assembly, an electronic device, and a transport vehicle.

[0007] According to a first aspect of this application, an embodiment of this application provides a drive assembly, including a drive unit, a differential unit, a transmission unit, and a hydraulic retarder. The drive unit has an output shaft, and the input end of the differential unit is connected to the output shaft. The transmission unit is drivenly connected to the output end of the differential unit. The hydraulic retarder includes a retarding stator and a retarding rotor. The retarding stator is fixedly disposed, and the retarding rotor is drivenly connected to the transmission unit. In the power transmission path of the drive assembly, the hydraulic retarder is located on the output side of the differential unit.

[0008] According to a second aspect of this application, embodiments of this application also provide a control method for a drive assembly, applied to the aforementioned drive assembly. The method includes: acquiring a braking torque demand; acquiring the maximum regenerative braking torque and the maximum braking torque of the hydraulic retarder; determining a braking strategy based on the braking torque demand, the maximum regenerative braking torque, and the maximum braking torque of the hydraulic retarder, according to a preset braking execution priority, wherein the braking execution priority is used to characterize the order in which the braking torque demand is sequentially allocated to the regenerative braking device, the hydraulic retarder, and the mechanical braking device; and controlling at least one of the regenerative braking device, the hydraulic retarder, and the mechanical braking device to execute the braking strategy according to the determined braking strategy.

[0009] According to a third aspect of this application, embodiments of this application also provide an electronic device, including a memory and a processor, wherein the memory is used to store a computer program; the processor is used to execute the computer program stored in the memory, and the computer program is configured to perform the above-described method.

[0010] According to a fourth aspect of this application, embodiments of this application also provide a transport vehicle, including the aforementioned electronic equipment and / or the aforementioned drive assembly.

[0011] In the embodiments provided in this application, the power output by the drive unit is transmitted to the differential unit via the output shaft. After the differential unit performs differential power distribution, the power is then transmitted again by the transmission unit. The hydraulic retarder is connected to the transmission unit and is located on the output side of the differential unit in the power transmission path of the drive assembly. Therefore, the hydraulic retarder is integrated into the power transmission path of the drive assembly, rather than being independently located outside the drive assembly. This improves the integration between the drive assembly and the auxiliary retarding structure, making the arrangement between the drive structure and the auxiliary retarding structure more compact and simplifying the transmission relationship between them.

[0012] Furthermore, since the input end of the differential is connected to the output shaft, and the transmission is connected to the output end of the differential, while the hydraulic retarder is connected to the transmission, the power output by the drive unit can first achieve differential distribution through the differential, then be transmitted to the hydraulic retarder via the transmission, and finally to the driving system. Thus, the hydraulic retarder is positioned downstream of the differential after the differential has achieved differential distribution, allowing it to slow down the output power after differential without affecting the differential's basic differential function. This enables the drive assembly to perform auxiliary slowing functions while simultaneously achieving power output and differential transmission.

[0013] Furthermore, since the hydraulic retarder is located on the output side of the differential, and the retarding rotor can be connected to the wheel axle or half-axle in the driving system, the retarding effect generated by the hydraulic retarder can be applied to the output power path leading to the driving system. Compared to the decentralized arrangement of auxiliary retarding structures and powertrain, the above structural relationship makes the power transmission path more concentrated, which is beneficial to improving the integration between the drivetrain and the auxiliary retarding structure, and making the overall structure of the drivetrain more compact. Attached Figure Description

[0014] To more clearly illustrate the technical solution of this application, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0015] Figure 1 A schematic diagram of the structure of a transport vehicle provided in some embodiments of this application is shown.

[0016] Figure 2 It shows Figure 1 A schematic diagram of one possible structure of the drive assembly of the transport vehicle shown.

[0017] Figure 3 It shows Figure 2 A magnified schematic diagram of a portion of the drive assembly shown.

[0018] Figure 4 It shows Figure 2 Another structural schematic diagram of the drive assembly shown.

[0019] Figure 5 It shows Figure 2 This is another structural schematic diagram of the drive assembly shown.

[0020] Figure 6 A flowchart illustrating a control method for a drive assembly provided in some embodiments of this application is shown.

[0021] Figure 7 This paper illustrates another flowchart of a control method for a drive assembly provided in some embodiments of this application.

[0022] Figure 8 This illustration shows a process diagram of a hydraulic retarder performing a braking strategy according to some embodiments of this application.

[0023] Figure 9 This illustration shows another process diagram of a hydraulic retarder performing a braking strategy according to some embodiments of this application.

[0024] Figure 10This illustration shows a process diagram of a mechanical braking device according to some embodiments of the present application executing a braking strategy.

[0025] Figure 11 This illustration shows a process diagram of a regenerative braking device according to some embodiments of the present application executing a braking strategy.

[0026] Figure 12 A functional block diagram of a drive assembly control device provided in some embodiments of this application is shown.

[0027] Figure 13 A block diagram of an electronic device provided in some embodiments of this application is shown. Detailed Implementation

[0028] To enable those skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are merely some embodiments of the present application, and not all embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present application without creative effort are within the scope of protection of the present application.

[0029] If certain terms are used in the specification and claims to refer to specific components, those skilled in the art will understand that hardware manufacturers may use different names to refer to the same component. The specification and claims do not distinguish components based on differences in name, but rather on differences in function. For example, the term "comprising" used throughout the specification and claims is an open-ended term and should be interpreted as "including but not limited to"; "generally" means that those skilled in the art can solve the technical problem and basically achieve the technical effect within a certain margin of error.

[0030] In this application, unless otherwise expressly specified or limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or merely surface contact. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0031] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0032] The drive assembly and transport vehicle proposed in this application will be further described below with reference to specific embodiments and accompanying drawings.

[0033] Please see Figure 1 This application provides a drive assembly 100 and a transport vehicle 400 configured with the drive assembly 100.

[0034] The transport vehicle 400 may include a body 401 and the aforementioned drive assembly 100. The body 401 is provided with a passenger compartment for providing seating space, and the drive assembly 100 is disposed within the body 401. The specific structure of the transport vehicle 400 is not limited to this application specification; it may be a land vehicle, a water vehicle, an air vehicle, or an amphibious or triphibious vehicle, etc. In these cases, the drive assembly 100 provides the power for the transport vehicle 400 to move. Specifically, the transport vehicle 400 may also include a driving system 405, which is connected to the drive assembly 100. The driving system 405 may include at least one mechanism such as wheels, a flight propeller, or a marine propeller to enable the transport vehicle 400 to move. Specifically, in this application specification, the transport vehicle 400 is described using a car as an example, which can be an electric vehicle. In this case, the driving system 405 includes multiple wheels.

[0035] In some embodiments, the transport vehicle 400 may further include a power battery pack 407, which is electrically connected to the drive assembly 100, for example, via a high-voltage cable. The drive assembly 100 is used to convert the electrical energy input from the power battery pack 407 into mechanical energy, thereby inputting drive motion into the driving system 405.

[0036] Please see Figure 2 In some embodiments, the drive assembly 100 may include a drive unit 20, a differential unit 30, a transmission unit 40, and a hydraulic retarder 50. A power transmission path is formed between the drive assembly 100 and the driving system 405, in which the drive unit 20, the differential unit 30, the transmission unit 40, and the hydraulic retarder 50 are sequentially connected.

[0037] The drive unit 20 provides the initial driving force to the drive assembly 100. The drive unit 20 has an output shaft 2231 for outputting power. The drive unit 20 can be an electric drive device, such as an electric motor, or other drive mechanisms capable of outputting rotational power. In an embodiment using a new energy vehicle as an example, the drive unit 20 can convert the electrical energy output from the power battery pack 407 into mechanical energy and output driving torque to downstream components (such as the differential device 30) via the output shaft 2231. The output shaft 2231 can be the motor shaft of the drive unit 20, a transmission shaft fixedly connected to the drive unit 20, or other rotating output components connected to the output end of the drive unit 20.

[0038] The input end of the differential device 30 is connected to the output shaft 2231 to receive the power output from the output shaft 2231 and distribute the power to at least two output sides to adapt to the differential requirements of the transport vehicle under conditions such as turning, changes in adhesion conditions, or uneven loads on both sides. In this specification, "the input end of the differential device 30 is connected to the output shaft 2231" means that the differential device 30 can receive the power transmitted from the output shaft 2231 through its input portion. This connection can be a direct connection, such as a spline connection, key connection, interference fit connection, flange connection, or integral molding connection, or an indirect connection, such as a power transmission connection achieved through an intermediate shaft, coupling, gear pair, etc. As long as the power output from the output shaft 2231 can be transmitted to the input end of the differential device 30, it can be understood as a "connection" as referred to in this specification. In some embodiments, the differential device 30 can be a bevel gear differential, planetary gear differential, or double sun gear differential, etc., that can achieve differential distribution. Taking a dual sun gear differential as an example, the input end of the differential device 30 is connected to the output shaft 2231 to receive the power output by the drive device 20; the output end of the differential device 30 may include two output sides arranged opposite to each other, and the two output sides are respectively connected to the two power input sides of the transmission device 40 to transmit the differential power to the corresponding transmission device 40.

[0039] The transmission device 40 is connected to the output end of the differential device 30 to receive the power distributed by the differential device 30 and further transmit this power to the driving system 405 of the transport vehicle 400, such as wheel axles, wheel shafts, or output components associated with wheel axles. In this embodiment, the transmission device 40 can be a gear transmission mechanism, a planetary gear transmission mechanism, a reduction mechanism, or other mechanisms capable of receiving the output power of the differential device 30 and continuing to transmit power. In some embodiments, the transmission device 40 can also have the function of reducing speed and increasing torque, so that the high-speed, low-torque power output by the drive device 20 is converted into low-speed, high-torque power more suitable for vehicle driving. The term "transmission connection" as used in this specification is not limited to direct contact connections and can also include indirect power transmission relationships achieved through intermediate components.

[0040] The hydraulic retarder 50 is connected to the transmission device 40. The hydraulic retarder 50 is used to provide auxiliary retardation during deceleration, downhill driving, or continuous braking of the transport vehicle 400. The hydraulic retarder 50 includes a retarder stator 52 and a retarder rotor 54. The retarder stator 52 is fixedly installed, and the retarder rotor 54 can rotate relative to the retarder stator 52.

[0041] In this embodiment, "fixed setting of the decelerating stator 52" means that the decelerating stator 52 remains stationary or substantially stationary relative to the fixed reference component of the drive assembly 100 during operation. This fixed reference component can be the housing, mounting base, support frame, or other non-rotating component of the drive assembly 100. For example, in some embodiments, the decelerating stator 52 can be fixedly connected to the housing of the drive assembly 100; in other embodiments, the decelerating stator 52 can also be mounted on a fixed structure that does not rotate with power output via brackets, flanges, or fasteners.

[0042] The retarder rotor 54 is driven by the transmission device 40 so that the power output from the transmission device 40 can drive the retarder rotor 54 to rotate and transmit the power to the driving system 405. The retarder rotor 54 and the transmission device 40 can be directly connected, for example, through splines, key connections, pin connections, interference fits, or integral molding; or indirectly connected, for example, through an intermediate shaft, connecting disc, sleeve, or other rotary transmission components. Furthermore, the retarder rotor 54 is driven by the driving system 405 of the transport vehicle 400. Taking a car as an example, the driving system 405 includes wheels and wheel axles or wheel half-axles connected to the wheels. The retarder rotor 54 can be connected to the wheel axles or wheel half-axles to transmit power or braking force to the driving system 405.

[0043] In this embodiment, the hydraulic retarder 50 is located on the output side of the differential device 30 in the power transmission path of the drive assembly 100. Taking this embodiment as an example, in this power transmission path, the power passes at least sequentially through the drive device 20, the differential device 30, the transmission device 40, and the output components related to the transmission device 40, and is finally transmitted to the driving system 405. The phrase "located on the output side of the differential device 30" in this specification means that, in the power flow direction, the hydraulic retarder 50 is positioned on the side receiving the output power of the differential device 30, that is, after the differential device 30, rather than before the differential device 30 or in an upstream position parallel to the input end of the differential device 30. Therefore, the hydraulic retarder 50 is arranged on the downstream power path after the differential device 30 has completed differential distribution. This arrangement allows the hydraulic retarder 50 to apply a slowing effect to the power output by the differential device 30, thereby achieving auxiliary braking without changing the basic differential function of the differential device 30.

[0044] In some embodiments, the hydraulic retarder 50 can be in a non-operating state when the drive assembly 100 is driving normally. In this state, the power output by the drive unit 20 is transmitted to the driving system via the differential device 30 and the transmission device 40 to drive the transport vehicle 400. When the transport vehicle 400 is in a deceleration, downhill, or other condition requiring auxiliary braking, the hydraulic retarder 50 enters the operating state. The retarding rotor 54 rotates under the drive of the transmission device 40 and cooperates with the retarding stator 52 to form a hydraulic retarding effect, thereby creating a braking effect on the driving system 405 located at the output end to provide auxiliary braking torque.

[0045] It should be noted that, Figure 2 The number, specific structural form, and interconnection method of the drive unit 20, differential unit 30, transmission unit 40, and hydraulic retarder 50 shown are merely examples. In other embodiments, the transmission unit 40 can be a single-stage transmission structure or a multi-stage transmission structure; the hydraulic retarder 50 can be one or multiple depending on the needs of the left and right output branches; the differential unit 30 can also adopt different differential mechanism forms. As long as the basic concept of "drive unit 20 outputs power, differential unit 30 receives power and performs differential distribution, and hydraulic retarder 50 is located on the output side of differential unit 30" is met, it can fall within the protection scope of this application.

[0046] Therefore, in the drive assembly 100 of this embodiment, the power output by the drive device 20 is transmitted to the differential device 30 via the output shaft 2231. After the differential device 30 performs differential power distribution, the power is then transmitted again by the transmission device 40. The hydraulic retarder 50 is connected to the transmission device 40 and is located on the output side of the differential device 30 in the power transmission path of the drive assembly 100. Thus, the hydraulic retarder 50 is integrated into the power transmission path of the drive assembly 100, rather than being set independently outside the drive assembly 100. This helps to improve the integration between the drive assembly 100 and the auxiliary retarding structure, making the arrangement between the drive structure and the auxiliary retarding structure more compact, and simplifying the transmission relationship between the two.

[0047] Furthermore, since the input end of the differential device 30 is connected to the output shaft 2231, and the transmission device 40 is driven to the output end of the differential device 30, and the hydraulic retarder 50 is driven to the transmission device 40, the power output by the drive device 20 can first complete the differential distribution through the differential device 30, then be transmitted to the hydraulic retarder 50 through the transmission device 40, and finally be transmitted to the driving system 405. Thus, the hydraulic retarder 50 is positioned downstream of the differential device 30 after the differential distribution, enabling it to slow down the output power after differential without affecting the basic differential function of the differential device 30. This allows the drive assembly 100 to simultaneously achieve power output and differential transmission while also providing auxiliary slowing functionality.

[0048] Furthermore, since the hydraulic retarder 50 is located on the output side of the differential device 30, and the retarding rotor 54 can be connected to the wheel axle or wheel half-axle in the driving system 405, the retarding effect generated by the hydraulic retarder 50 can be applied to the output power path leading to the driving system 405. Compared to the distributed arrangement of the auxiliary retarding structure and the powertrain, the above structural relationship makes the power transmission path more concentrated, which is beneficial to improving the integration between the drive assembly 100 and the auxiliary retarding structure, and making the overall structure of the drive assembly 100 more compact.

[0049] The following will describe in detail the drive assembly 100 and its various components provided in the embodiments of this application, with reference to specific accompanying drawings and embodiments.

[0050] In some embodiments of this application, the drive device 20 is used to provide initial driving force to the drive assembly 100. The drive device 20 can be a power device capable of outputting rotational power. For example, the drive device 20 may include an electric motor, an engine, or a range-extended engine, etc. When the drive device 20 is an electric motor, it can convert electrical energy into mechanical energy and output driving torque to the differential device 30 via the output shaft 2231; when the drive device 20 is an engine or a range-extended engine, it can output mechanical energy through fuel combustion and output rotational power to the differential device 30 via the output shaft 2231. In the embodiments of this application, the specific type of drive device 20 is not limited.

[0051] Specifically, in this embodiment, the drive device 20 can be an electric motor. The electric motor can be a permanent magnet synchronous motor, an induction motor, a switched reluctance motor, or other motors suitable as a drive source for the transport vehicle 400. For example, the drive device 20 can be an axial flux motor. Using an axial flux motor as the drive device 20 ensures that its axial dimension is relatively small and its torque density is high, which is beneficial for the integrated arrangement of the drive assembly 100 on the transport vehicle 400. At the same time, the rotor inner diameter of the drive device 20 is relatively large, which facilitates the arrangement of components such as the differential device 30 in the structure that cooperates with it.

[0052] Please see Figure 3 Specifically, the drive unit 20 may include a motor stator 221 and a motor rotor 223, which are arranged axially along the drive unit 20. The motor stator 221 is used to generate a magnetic field after being energized. The motor rotor 223 cooperates with the motor stator 221 to rotate relative to the motor stator 221 under the action of the magnetic field, thereby outputting rotational power. The output shaft 2231 is connected to the motor rotor 223. For example, the output shaft 2231 may be fixedly connected to the motor rotor 223, or the output shaft 2231 may be connected to the motor rotor 223 through splines, key connections, interference fits, or other transmission connection methods, so that when the motor rotor 223 rotates, it can drive the output shaft 2231 to rotate synchronously, and the output shaft 2231 outputs power to the differential device 30.

[0053] Furthermore, the motor rotor 223 is disposed at the end of the motor stator 221 along its axial direction. Specifically, the motor rotor 223 is located at one axial end of the motor stator 221 and is substantially opposite to the motor stator 221 along its axial direction. Therefore, the motor stator 221 and the motor rotor 223 can be substantially coaxially arranged, wherein the motor stator 221 is relatively fixed, and the motor rotor 223 is rotatable relative to the motor stator 221. In this embodiment, by arranging the motor rotor 223 at the axial end of the motor stator 221, the drive device 20 can form a magnetic flux path along its axial direction to output rotational driving force.

[0054] It should be noted that the above description of "motor rotor 223 being disposed at the end of motor stator 221 along the axial direction" is merely an illustrative description of the basic axial flux structure of the drive device 20. In other embodiments, the drive device 20 may also include multiple motor rotors 223. For example, the drive device 20 may include one motor stator 221 and two motor rotors 223, with the two motor rotors 223 respectively located at the two axial ends of the motor stator 221, thereby forming a dual-rotor single-stator structure. The output shaft 2231 may pass through the motor stator 221, and the two motor rotors 223 are respectively disposed at both ends of the output shaft 2231. In this embodiment, the two motor rotors 223 constitute a dual-rotor single-stator motor structure. The yoke of the motor stator 221 is relatively short and does not require a large cooling space, which helps to reduce slot leakage flux, improve motor efficiency, and further contributes to a more compact overall structure of the drive device 20.

[0055] In some embodiments, the output shaft 2231 serves as the motor shaft of the drive device 20. One end of the output shaft 2231 or its corresponding axial position is connected to the motor rotor 223, and the other end or its downstream output side is connected to the input end of the differential device 30, so that the power output by the drive device 20 can be directly transmitted to the differential device 30. In some embodiments, the output shaft 2231 has a mounting cavity 2233, and the differential device 30 is disposed within the mounting cavity 2233, so that the drive device 20 and the differential device 30 are spatially integrated, thereby reducing the space occupied by the drive assembly 100 in the radial or axial direction and improving the overall structural compactness. It should be noted that the drive device 20 is not limited to an axial flux motor. In other embodiments, the drive device 20 can also be a radial flux motor. When using a radial flux motor, the differential device 30 can also be internally arranged by reasonably setting the output shaft 2231 and the mounting cavity 2233.

[0056] The mounting cavity 2233 can be formed inside the output shaft 2231. For example, the output shaft 2231 can be a hollow shaft structure, and the mounting cavity 2233 is located inside the output shaft 2231 and extends axially along the output shaft 2231. The differential device 30 is at least partially located within the mounting cavity 2233. For example, the main body of the differential device 30 is disposed within the mounting cavity 2233 so that the power output from the output shaft 2231 can be transmitted to the differential device 30 within the area where the mounting cavity 2233 is located. Since the motor rotor 223 is disposed at the end of the motor stator 221 in the axial direction, and the output shaft 2231 is connected to the motor rotor 223, the mounting cavity 2233 can be located within the corresponding area of ​​the space enclosed by the motor rotor 223, or within the radially inner area of ​​the motor rotor 223. Thus, the structure of the drive device 20 outputting power and the mounting structure of the differential device 30 can spatially cooperate with each other, thereby facilitating the compact integration of the drive device 20 and the differential device 30.

[0057] It should be noted that the differential device 30 is disposed within the mounting cavity 2233, but this does not mean that the differential device 30 must be completely housed within the mounting cavity 2233. In some embodiments, the differential device 30 may be entirely disposed within the mounting cavity 2233; in other embodiments, only a portion of the differential device 30 may be disposed within the mounting cavity 2233, while the remaining portion may be located at the end of the output shaft 2231 or in the mounting space adjacent to the output shaft 2231. The specific shape and size of the mounting cavity 2233 are not limited by this specification or the accompanying drawings. For example, the mounting cavity 2233 may be a cylindrical cavity, a stepped cavity, or an irregularly shaped cavity adapted to the shape of the differential device 30. The arrangement of the mounting cavity 2233 is also not limited; it may be formed by removing material from the output shaft 2231, or it may be formed by combining multiple shaft components.

[0058] In some embodiments, the differential device 30 includes two differential mechanisms 32, which are respectively drivenly connected to two motor rotors 223. Correspondingly, the transmission device 40 may include two transmission mechanisms 42, which are respectively drivenly connected to two differential mechanisms 32. The power output from the drive device 20 can be transmitted to the two differential mechanisms 32 via the two motor rotors 223. After the two differential mechanisms 32 transmit and differentially distribute the power on the corresponding paths, they are then transmitted to the two transmission mechanisms 42 to form two relatively independent power transmission branches.

[0059] Two differential mechanisms 32 can be respectively disposed in the mounting cavities 2233 at both ends of the output shaft 2231. Each differential mechanism 32 may include a center wheel 321 and a transmission wheel 323 that mesh with each other. The transmission wheel 323 is used to drively connect with the corresponding motor rotor 223 to receive the power output by the motor rotor 223. The center wheel 321 meshes with the transmission wheel 323 to receive the power transmitted by the transmission wheel 323 and output the power to the corresponding transmission mechanism 42. In each differential mechanism 32, the transmission wheel 323 can serve as a power input side component connected to the motor rotor 223, and the center wheel 321 can serve as a power output side component connected to the transmission device 40. Therefore, in this embodiment, the differential device 30 is a dual sun gear planetary differential device, which is beneficial to integrate the differential device 30 into the output shaft 2231, thereby improving the integration of the drive device 20 and the differential device 30, making the overall structure of the drive assembly 100 more compact, and also facilitating the output of power to the transmission devices 40 on both sides, providing a basis for the arrangement of the rear two-way transmission and auxiliary retarder structure.

[0060] Therefore, in this embodiment, the differential device 30 is arranged at the output shaft 2231, that is, on the power input side, which helps to reduce the torque load borne by the differential device 30. As an example, in a conventional scheme where the differential is arranged at the output end, the differential often needs to withstand a large output torque, for example, up to about 5000 Nm, while the differential speed is relatively low, for example, about 100 rpm; in this case, the differential gear, planetary gear, and differential housing usually need to be set to be large. In contrast, when the differential device 30 is arranged at the output shaft 2231, the torque it bears can be significantly reduced, for example, reduced to about 400 Nm, while the differential speed can be correspondingly increased, for example, reaching about 1300 rpm. As a result, the size of the gear components and housing structure in the differential device 30 can be correspondingly reduced, which is beneficial to integrate the differential device 30 into the mounting cavity 2233 of the output shaft 2231, thereby saving the structural size and arrangement space of the drive assembly 100. Accordingly, in this embodiment, the dimensions of the gear components and housing of the differential device 30 can be reduced, thereby reducing the overall size of the differential device 30 and further facilitating its integration within the mounting cavity 2233 of the output shaft 2231, thus saving space in the drive assembly 100. Furthermore, when the differential device 30 is positioned at the output shaft 2231, the area where the output shaft 2231 is located has good lubrication conditions, ensuring sufficient lubrication for the differential device 30 to meet operational requirements, thus preventing a significant increase in lubrication risk due to the relatively high differential speed. Therefore, by arranging the differential device 30 within the mounting cavity 2233 of the output shaft 2231, the torque borne by the differential device 30 can be reduced, making the related gear components and housing structure in the differential device 30 easier to miniaturize. This also facilitates the integrated arrangement of the differential device 30 and the drive device 20, thereby improving the compactness of the drive assembly 100.

[0061] In this embodiment, each transmission mechanism 42 may include a sun gear 421, an input planetary gear 423, an output planetary gear 425, a ring gear 427, and a planet carrier 429. The sun gear 421 is coaxially connected to the corresponding center gear 321 to receive the power output by the center gear 321. The input planetary gear 423 meshes with the sun gear 421, the output planetary gear 425 is coaxially connected with the input planetary gear 423, and the ring gear 427 meshes with and is fixedly disposed with the output planetary gear 425. Therefore, the power output by the center gear 321 is first transmitted to the sun gear 421, and then transmitted from the sun gear 421 to the input planetary gear 423. The input planetary gear 423 then drives the output planetary gear 425, which is coaxially connected with it, to rotate. The output planetary gear 425 engages with the fixedly disposed ring gear 427 to achieve further transmission and transformation of power.

[0062] In some embodiments, the input planetary gear 423 and the output planetary gear 425 can together form a composite planetary gear structure, wherein the input planetary gear 423 and the output planetary gear 425 are arranged along a common axis and rotate synchronously. The planet carrier 429 is rotatably connected to the output planetary gear 425. Specifically, the planet carrier 429 may be provided with a support for mounting the input planetary gear 423 and the output planetary gear 425, so that the input planetary gear 423 and the output planetary gear 425 can be rotatably arranged relative to the planet carrier 429. The planet carrier 429, as the output component of the transmission mechanism 42, is connected to the decelerating rotor 54 to output power to the wheel axle connected to the transport vehicle 400 via the decelerating rotor 54. That is, the power output by the center wheel 321 is finally output by the planet carrier 429 after meshing between the sun gear 421, the input planetary gear 423, the output planetary gear 425 and the ring gear 427. As can be seen, in this embodiment, each transmission mechanism 42 adopts an NW-type double planetary gear transmission structure, which can reduce speed and increase torque on the output path of the later stage, thereby improving the torque output capability of the drive assembly 100. Specifically, two hydraulic retarders 50 are respectively located at the rear end of the output branches on both sides of the differential device 30, and respectively correspond to the wheel half-shafts on both sides of the same axle. Under the premise of meeting the auxiliary retardation performance requirements, the two hydraulic retarders 50 can respectively form a retardation effect on the output branches on both sides, thereby making the braking load of the left and right output branches more balanced and reducing the risk of yaw caused by differential torque. Furthermore, by distributing the retardation requirements to two hydraulic retarders, it is also beneficial to reduce the requirements of a single hydraulic retarder in terms of capacity, volume and size, thereby facilitating the miniaturization and compact layout of the drive assembly. In addition, using two transmission mechanisms 42 to realize the separate transmission of power to the dual output branches is also beneficial to improve the vibration and noise problems when the single path has a large torque output, thereby improving the running stability of the drive assembly 100.

[0063] Furthermore, since the planetary carrier 429 is connected to the retarder rotor 54, and the retarder rotor 54 is also connected to the wheel axle or wheel half-axle in the driving system 405, the power output from each transmission mechanism 42 can be transmitted to the corresponding wheel axle of the driving system 405 of the transport vehicle 400 via the corresponding retarder rotor 54. Accordingly, when the hydraulic retarder 50 is in operation, the retarder rotor 54, while rotating along the power path, can also cooperate with the retarder stator 52 to form a hydraulic retarding effect, thereby providing an auxiliary retarding effect on the power output via the corresponding transmission mechanism 42.

[0064] It should be noted that the above-described structural forms of the differential mechanism 32 and the transmission mechanism 42 are merely examples. In other embodiments, the specific tooth profiles of the center wheel 321 and the transmission wheel 323, the specific number of input planetary gears 423 and output planetary gears 425, the fixing method of the gear ring 427, and the specific connection method between the planet carrier 429 and the decelerating rotor 54 can all be set according to actual needs. As long as the power output from the two motor rotors 223 can be transmitted to the corresponding decelerating rotors 54 via the two differential mechanisms 32 and the two transmission mechanisms 42, and further output to the wheel axles of the transport vehicle 400, it can be understood that it falls within the protection scope of this application.

[0065] In some embodiments, the hydraulic retarder 50 may further include a retarding housing 56, within which a working chamber 561 is provided. A retarding stator 52 and a retarding rotor 54 are disposed within the retarding housing 56. The retarding stator 52 and the retarding rotor 54 together define the working chamber 561, which is used to contain the working medium. The retarding housing 56 may be provided with an inlet 563 and an outlet 565. The inlet 563 is used to input the working medium into the working chamber 561, and the outlet 565 is used to discharge the working medium from the working chamber 561. When the hydraulic retarder 50 is in operation, the working medium enters the working chamber 561 through the inlet 563. As the retarding rotor 54 rotates along the power transmission path, it cooperates with the retarding stator 52 to form a hydraulic retardation effect, thereby creating a retardation effect on the rotating components in the power transmission path to provide an auxiliary retardation effect. When the hydraulic retarder 50 is in a non-working state, the working medium in the working chamber 561 is reduced or does not participate in the retarding effect, thereby reducing or eliminating the retarding effect of the hydraulic retarder 50.

[0066] In some embodiments, the drive assembly 100 may further include a control device 10 for controlling the drive device 20. Specifically, the control device 10 may be a controller corresponding to the drive device 20, such as a motor controller. The control device 10 is electrically connected to the drive device 20 to achieve drive control, state adjustment, or operation management of the drive device 20. In this embodiment, the control device 10 is provided with a heat dissipation channel 121, which may be formed inside the housing of the control device 10, inside the base plate, or in a heat exchange structure fixedly connected to the control device 10. The heat dissipation channel 121 allows a cooling medium to flow through the heat-generating area of ​​the control device 10 to remove the heat generated by the control device 10 during operation.

[0067] Please see Figure 4In some embodiments, the drive assembly 100 may further include a cooling device 70, which provides a cooling medium for heat-generating components and / or liquid-using components in the drive assembly 100. The cooling device 70 is provided with a cooling circuit 702, which may communicate with a heat dissipation channel 121, thereby providing a cooling medium to the heat dissipation channel 121, allowing the cooling medium flowing through the cooling circuit 702 to dissipate heat from the control device 10. Specifically, the cooling circuit 702 may be a liquid circulation circuit, and the heat dissipation channel 121 is disposed on the cooling circuit 702, allowing the cooling medium in the cooling circuit 702 to flow through the heat dissipation channel 121 during its flow. In some embodiments, the cooling device 70 may further include structures such as a liquid pump, radiator, heat exchanger, or liquid storage component communicating with the cooling circuit 702 to drive the cooling medium to circulate and exchange heat.

[0068] As an example, the cooling device 70 includes a control valve 76 connected in series with the cooling circuit 702, which controls the conduction state of the cooling circuit 702. The cooling device 70 may also include a cooling pipe 78, which may include a first pipe 781 and a second pipe 783. The first pipe 781, the control valve 76, and the second pipe 783 are connected in series to form the cooling circuit 702.

[0069] Furthermore, the cooling device 70 may also include an expansion tank 71, a heat dissipation mechanism 72, a liquid pump 74, and a heat exchanger 75. A cooling pipe 78 connects the expansion tank 71, the heat dissipation mechanism 72, the liquid pump 74, the heat exchanger 75, and the control valve 76 to form a cooling circuit 702. Specifically, one end of the first pipe 781 is connected to the expansion tank 71, and the heat dissipation mechanism 72, the liquid pump 74, the heat exchanger 75, and the control valve 76 are connected in series. A heat dissipation channel 121 for the control device 10 is provided on the first pipe 781 so that the cooling medium flowing through the first pipe 781 can dissipate heat from the control device 10. One end of the second pipe 783 is connected to the control valve 76, and the other end is connected to the expansion tank 71, thereby forming a return path between the control valve 76 and the expansion tank 71 through the second pipe 783. The heat dissipation mechanism 72 may include a cooling fan and / or cooling fins, or a heat dissipation element such as an oil-cooled heat exchanger; the heat exchanger 75 may include a cooling fan and / or cooling fins, or a heat exchange element such as an oil-cooled heat exchanger.

[0070] Thus, the expansion tank 71, heat dissipation mechanism 72, liquid pump 74, heat exchanger 75, control valve 76, first pipeline 781, and second pipeline 783 together constitute the aforementioned cooling circuit 702. In some embodiments, the cooling medium can circulate along the cooling circuit 702 under the drive of the liquid pump 74, and flow sequentially through the heat dissipation mechanism 72, heat dissipation channel 121, heat exchanger 75, and control valve 76, thereby achieving cooling or heat exchange for the control device 10 and other components requiring heat exchange.

[0071] In some embodiments, the working chamber 561 of the hydraulic retarder 50 can also establish a communication relationship with the cooling circuit 702 under certain operating conditions. Based on this, the drive assembly 100 may further include a connecting device 80, which connects the working chamber 561 of the hydraulic retarder 50 to the cooling circuit 702, allowing the working chamber 561 to be selectively connected to the cooling circuit 702. Through the connecting device 80 and the control valve 76, the cooling medium in the cooling circuit 702 can be guided into the working chamber 561.

[0072] Specifically, when the hydraulic retarder 50 needs to provide a retardation function, the control valve 76 can connect the working chamber 561 to the cooling circuit 702 through the connecting device 80, thereby allowing the working medium in the cooling circuit 702 to enter the working chamber 561. When the hydraulic retarder 50 does not need to provide a retardation function, the control valve 76 can disconnect the working chamber 561 from the cooling circuit 702, thereby reducing or preventing the cooling medium from entering the working chamber 561. Thus, the cooling device 70 can not only dissipate heat from the control device 10 through the heat dissipation channel 121, but also provide or cut off the working medium supply to the hydraulic retarder 50, and remove the heat generated during the operation of the hydraulic retarder 50. By adopting the above-mentioned shared cooling circuit structure, it is beneficial to integrate the working fluid circulation of the hydraulic retarder 50 with the cooling and heat dissipation system of the drive assembly 100, thereby eliminating the need to set up an independent control pump source and heat dissipation equipment for the hydraulic retarder 50, which helps to simplify the overall structure of the drive assembly 100 and reduce the overall layout space.

[0073] In this embodiment, the working chamber 561 of the hydraulic retarder 50 has an inlet 563 and an outlet 565. The connecting device 80 may include an input pipe 81 and an output pipe 82. The input pipe 81 is connected between the control valve 76 and the inlet 563, and the output pipe 82 is connected between the control valve 76 and the outlet 565. The input pipe 81 is used to introduce the cooling medium distributed via the control valve 76 into the working chamber 561, and the output pipe 82 is used to export the working medium flowing out of the working chamber 561 and return it to the cooling circuit 702. This allows the cooling medium in the cooling circuit 702 to selectively enter the working chamber 561 or bypass the working chamber 561 and circulate within the cooling circuit 702 when the control valve 76 is in different connected states.

[0074] To control the connection between the cooling circuit 702 and the working chamber 561, the control valve 76 may be provided with an inlet 761, a first outlet 763, and a second outlet 765. A first pipe 781 is connected to the inlet 761, a second pipe 783 is connected to the first outlet 763, an output pipe 82 is connected to the second pipe 783, and an input pipe 81 is connected to the second outlet 765. The control valve 76 can selectively connect between the inlet 761 and the first outlet 763, and between the inlet 761 and the second outlet 765, thereby controlling whether the working chamber 561 is connected to the cooling circuit 702. As an example, the control valve 76 can be a three-way valve, such as a two-position three-way solenoid directional valve. Of course, in other embodiments, the control valve 76 can also be other valve body structures capable of realizing the above-mentioned flow path switching function.

[0075] In some embodiments, when the control valve 76 connects the inlet 761 to the first outlet 763, the cooling medium flowing through the first pipe 781 can enter the second pipe 783 via the control valve 76, instead of entering the working chamber 561 via the input pipe 81. At this time, the working chamber 561 is disconnected from the cooling circuit 702, and the cooling medium mainly circulates within the cooling circuit 702. Correspondingly, when the control valve 76 connects the inlet 761 to the second outlet 765, the cooling medium flowing through the first pipe 781 can enter the working chamber 561 via the input pipe 81, and after flowing through the working chamber 561, it flows from the outlet 565 to the output pipe 82, and then returns to the cooling circuit 702 via the second pipe 783. Based on this, the working chamber 561 is connected to the cooling circuit 702, and the hydraulic retarder 50 can utilize the working medium entering the working chamber 561 to form a hydraulic retarding effect.

[0076] In some further embodiments, the connecting device 80 may also include a one-way valve 84 and a throttle valve 85 disposed on the output pipe 82. The throttle valve 85 is located between the one-way valve 84 and the outlet 565, wherein the throttle valve 85 is located on the input side of the one-way valve 84. Along the direction in which the working medium flows out of the working chamber 561, the throttle valve 85 is located on the side closer to the outlet 565, and the one-way valve 84 is located on the side of the throttle valve 85 away from the outlet 565. This allows the throttle valve 85 to be used to throttle and regulate the working medium flowing out of the working chamber 561, thereby regulating the fluid state and pressure state within the working chamber 561. The one-way valve 84 is used to prevent the working medium from flowing back into the working chamber 561 in the reverse direction, thereby reducing the impact of backflow on the working state of the working chamber 561. As some specific examples, the throttle valve 85 may be a valve body structure with an adjustable flow area, used to regulate the flow rate of the working medium in the output pipe 82, thereby changing the pressure level within the working chamber 561. The check valve 84 can be a check valve, which allows the working medium to flow away from the working chamber 561, while restricting the working medium to flow in the opposite direction towards the working chamber 561. By sequentially arranging the throttle valve 85 and the check valve 84 on the output pipe 82, it is beneficial to improve the stability and controllability of the fluid state within the working chamber 561.

[0077] In some embodiments, the connecting device 80 may further include a first pressure sensor 86 and a second pressure sensor 87 disposed on the output pipe 82. The first pressure sensor 86 is located between the throttle valve 85 and the outlet 565, that is, on the side closer to the working chamber 561, and is used to detect the pressure information on the outlet side of the working chamber 561. The second pressure sensor 87 is located on the output side of the one-way valve 84, that is, on the side of the one-way valve 84 away from the throttle valve 85, and is used to detect the pressure information on the downstream side of the output pipe 82 or the connecting area of ​​the second pipeline 783. This embodiment uses the first pressure sensor 86 and the second pressure sensor 87, which can respectively detect the pressure state at different positions upstream and downstream of the output pipe 82, thereby providing pressure parameters for monitoring the working state of the working chamber 561, controlling the fluid state, and implementing the control strategy of the hydraulic retarder 50. In a specific application example, the pressure detected by the first pressure sensor 86 can characterize the actual working pressure on one side of the working chamber 561, and the pressure detected by the second pressure sensor 87 can characterize the backflow pressure or pipeline pressure on the side of the output pipe 82 away from the working chamber 561. By comparing the pressure information corresponding to the first pressure sensor 86 and the second pressure sensor 87, the flow state of the working medium in the working chamber 561 can be further determined, thereby providing a basis for subsequent control of the liquid pump 74 or other control actions.

[0078] In some embodiments, the drive assembly 100 further includes a switching device 60, which is configured in conjunction with the hydraulic retarder 50 and is used to switch the hydraulic retarder 50 between an operating state and an inactive state. Specifically, in the operating state, the hydraulic retarder 50 has a slowing braking capability to slow down the power output from the transmission device 40; in the inactive state, the slowing braking capability of the hydraulic retarder 50 is less than that in the operating state. Based on this, the switching device 60 is used to change the participation state of the hydraulic retarder 50 according to the actual operating conditions, so that the hydraulic retarder 50 can provide a greater slowing effect when auxiliary slowing is needed, and reduce the impact on the power transmission path when auxiliary slowing is not needed. The term "operating state" as used in this specification can be understood as the state in which the hydraulic retarder 50 exerts a hydraulic retardation effect on the power transmission path; for example, there is a working medium in the working chamber 561 sufficient to exert a hydraulic effect, and the retarding rotor 54 can cooperate with the retarding stator 52 under the drive of the transmission device 40 to exert a hydraulic retardation effect. Correspondingly, the term "non-operating state" as used in this specification can be understood as the state in which the retardation effect of the hydraulic retarder 50 is reduced or eliminated; for example, the working medium in the working chamber 561 is discharged, or the power transmission relationship between the retarding rotor 54 and the transmission device 40 is cut off; in this case, the additional resistance effect of the hydraulic retarder 50 on the power transmission path is reduced, thereby helping to reduce additional losses under non-braking conditions.

[0079] In some embodiments, the switching device 60 can be implemented in various structural forms. For example, the switching device 60 can adopt a clutch structure to switch the hydraulic retarder 50 between the working state and the non-working state by switching the mechanical transmission connection; the switching device 60 can also adopt a drainage structure to switch the hydraulic retarder 50 between the working state and the non-working state by changing the state (present or absent) of the working medium in the working chamber 561. Of course, in other embodiments, the switching device 60 can also adopt other structures that can achieve the above-mentioned switching function, and this specification does not limit it.

[0080] Please see Figure 5In some embodiments, the switching device 60 may include a clutch 62, which is used to selectively engage or disengage the retarder rotor 54 with the transmission device 40 and / or the wheel axle, thereby switching the hydraulic retarder 50 between an operating state and an inactive state. Specifically, the clutch 62 may be disposed between the transmission device 40 and the retarder rotor 54, and connected to both the transmission device 40 and the retarder rotor 54 respectively. The clutch 62 may be a friction clutch, an electromagnetic clutch, a jaw clutch, or other clutch structure capable of selective engagement and disengagement. When the clutch 62 is engaged, the power output from the transmission device 40 can be transmitted to the retarder rotor 54 via the clutch 62. The retarder rotor 54 then transmits the power or braking force to the wheel axle or wheel half-shaft connected to it, thereby putting the hydraulic retarder 50 into a working state or providing the basis for entering a working state. When the clutch 62 is disengaged, the power transmission relationship between the transmission device 40 and the retarder rotor 54 is cut off, thereby putting the hydraulic retarder 50 into a non-working state. In this case, the transmission device 40 can be directly connected to the wheel axle or wheel half-shaft.

[0081] Please refer to it again. Figure 4 In some embodiments, the switching device 60 may include an air pump 641 and a gas pipeline 642. The air pump 641 is connected to the working chamber 561 of the hydraulic retarder 50 through the gas pipeline 642 and is used to input gas into the working chamber 561 to discharge the working fluid in the working chamber 561, thereby putting the hydraulic retarder 50 into a non-working state. Specifically, the hydraulic retarder 50 may also be provided with an air port 567 connected to the working chamber 561, and the gas pipeline 642 is connected to the air port 567. When the air pump 641 is working, gas enters the working chamber 561 through the gas pipeline 642 and the air port 567, and pushes the working fluid in the working chamber 561 to be discharged through the liquid outlet 565, thereby reducing or emptying the working medium in the working chamber 561 used to form the hydraulic retarding effect, thereby reducing or even eliminating the retarding braking capability of the hydraulic retarder 50, and switching the hydraulic retarder 50 from the working state to the non-working state.

[0082] In some examples, the switching device 60 may further include a reversing valve 643 connected in series with the gas pipeline 642. The reversing valve 643 is located between the air pump 641 and the working chamber 561, and is used to control the conduction state of the gas pipeline 642, thereby controlling the communication relationship between the air pump 641 and the working chamber 561. In specific examples, the reversing valve 643 may be a valve body structure capable of switching the conduction state of the gas pipeline 642. For example, the reversing valve 643 may be a two-position, two-way solenoid valve. The reversing valve 643 is connected in series with the gas pipeline 642 and located between the air pump 641 and the working chamber 561, used to control the gas path communication relationship between the air pump 641 and the working chamber 561. Specifically, when the reversing valve 643 is in the first working position, the gas pipeline 642 is open, and the air pump 641 can deliver gas to the working chamber 561 through the gas pipeline 642 to push the working fluid in the working chamber 561 out. When the reversing valve 643 switches to the second working position, it can cooperate with the air pump 641 to reverse, so that the air pump 641 can extract gas from the working chamber 561 through the gas pipeline 642, thereby reducing the gas pressure in the working chamber 561. Thus, the reversing valve 643 can not only control the connection and disconnection between the air pump 641 and the working chamber 561, but also cooperate with the air pump 641 to switch the gas state in the working chamber 561 under different working conditions of forward gas supply and reverse gas extraction.

[0083] In some examples, the switching device 60 may also include an air filter 645, which is connected to the air pump 641 and located on the air inlet side of the air pump 641. External air can be filtered by the air filter 645 before entering the air pump 641, and then transported by the air pump 641 to the working chamber 561 via the gas pipe 642. This helps reduce the risk of external impurities entering the working chamber 561 with the air, thereby helping to maintain the operational reliability of the switching device 60 and the hydraulic retarder 50.

[0084] In some embodiments, there can be two hydraulic retarders 50, located on the output branches on both sides of the differential device 30. After the differential device 30 completes the differential distribution, it forms two output power paths. These two output power paths are transmitted to the corresponding hydraulic retarders 50 via corresponding transmission mechanisms 42, and further transmitted to the driving system 405. Taking a car as an example, the two hydraulic retarders 50 can be respectively connected to the wheel half-shafts or wheel axles on both sides of the same axle, thereby acting on the output power paths on both sides of the same axle. By adopting the above arrangement, the two hydraulic retarders 50 can respectively slow down the power output from both sides of the differential device 30. Specifically, the two hydraulic retarders 50 can be respectively set one-to-one with the two transmission mechanisms 42. Each transmission mechanism 42 has a corresponding hydraulic retarder 50 connected to its output side. The retarder rotor 54 in each hydraulic retarder 50 is connected to the corresponding transmission mechanism 42 and to the corresponding wheel axle or wheel half axle to transmit power or braking force to the driving system 405.

[0085] In some embodiments, the two hydraulic retarders 50 can be controlled independently. For example, the two hydraulic retarders 50 can each be provided with an independent control loop, an independent connecting device 80, and / or an independent switching device 60, thereby controlling the operating and non-operating states of the two hydraulic retarders 50 respectively. Thus, the operating states of the two hydraulic retarders 50 can be adjusted according to the actual needs of the power paths on both sides.

[0086] In other embodiments, the two hydraulic retarders 50 may also share the same control loop. As an example, the inlets 563 of the two hydraulic retarders 50 can be connected in parallel to the corresponding branches of the same control valve 76, so that the cooling medium distributed by the control valve 76 can enter the working chambers 561 of the two hydraulic retarders 50 respectively; the outlets 565 of the two hydraulic retarders 50 can be connected in parallel to the same throttle valve 85, and then connected to the output pipe 82 and the cooling loop 702. By adopting the above parallel arrangement, the two hydraulic retarders 50 can share the same working medium supply and return structure, thereby simplifying the piping layout.

[0087] Furthermore, regarding the switching structure, the two hydraulic retarders 50 can either employ different switching devices 60, or share at least a portion of the structure of the same switching device 60. For example, when using a mechanical switching scheme, the two hydraulic retarders 50 can each be equipped with two clutches 62, which are respectively located between the corresponding transmission device 40 and the corresponding retarding rotor 54, to control the engagement and disengagement of the corresponding hydraulic retarders 50, allowing the two hydraulic retarders 50 to switch between operating and non-operating states.

[0088] In other embodiments, when using a gas supply structure as the switching scheme, the two hydraulic retarders 50 can share the same pneumatic control branch. Specifically, the air port 567 of each hydraulic retarder 50 can be connected in parallel to the same gas pipeline 642, which is then connected to the air pump 641 via a reversing valve 643. In this case, the gas output from the air pump 641 can simultaneously or synchronously enter the working chambers 561 of the two hydraulic retarders 50 via the gas pipeline 642 to drive the working fluid in the two working chambers 561 out, or simultaneously or synchronously extract the gas in the opposite direction. By adopting the above-mentioned shared pneumatic control branch method, it is beneficial to reduce the number of gas circuit components and simplify the gas circuit structure.

[0089] In some embodiments, the drive assembly 100 may further include a housing 90, within which the hydraulic retarder 50, differential 30, drive unit 20, and transmission unit 40 are respectively disposed. The housing 90 provides mounting space and support structure for the hydraulic retarder 50, differential 30, drive unit 20, and transmission unit 40, and defines the relative positional relationships between the components within the drive assembly 100. Integrating these components within the housing 90 improves the overall integration of the drive assembly 100 and makes the power transmission path more concentrated. Further, in some embodiments, when there are two hydraulic retarder 50s, the two hydraulic retarder 50s can be symmetrically distributed on both sides of the drive unit 20. For example, the two hydraulic retarder 50s are located on both sides of the drive unit 20 in the width direction, and respectively correspond to the output branches on both sides of the differential 30. Correspondingly, the two transmission devices 40 can also be located on both sides of the drive device 20 and connected to the hydraulic retarder 50 on the corresponding side, so as to transmit the power distributed by the differential device 30 to the corresponding hydraulic retarder 50.

[0090] In the embodiments provided in this application, by arranging the drive unit 20, differential unit 30, transmission unit 40, and hydraulic retarder 50 sequentially on the power transmission path of the drive assembly 100, and by placing the hydraulic retarder 50 on the output side of the differential unit 30, the drive assembly 100 can provide auxiliary retardation on the output power path while simultaneously achieving power output and differential transmission. This facilitates the integration of drive function and auxiliary retardation function into the same assembly. Furthermore, by placing the differential unit 30 within the mounting cavity 2233 of the output shaft 2231, and preferably arranging it on the power input side, it is beneficial to reduce the torque requirement borne by the differential unit 30, thereby reducing the structural size of the differential unit 30 and improving the integration between the drive unit 20 and the differential unit 30, resulting in a more compact overall structure of the drive assembly 100.

[0091] Please see Figure 6 This application also provides a control method for a drive assembly 100. In practical applications, the control method for the drive assembly 100 is applied to the drive assembly 100 provided in any of the above embodiments, or to a transport vehicle 400 equipped with the drive assembly 100. Specifically, the control method for the drive assembly 100 in this embodiment may include the following steps S110 to S140. In some embodiments, the control device 10 in the drive assembly 100 is configured to perform the following control process S110 to S140 during the operation of the transport vehicle 400, especially during deceleration, downhill, or braking conditions, to determine a corresponding braking strategy based on the braking torque requirement, regenerative braking capability, and the slowing braking capability of the hydraulic retarder 50, and to control at least one of the regenerative braking device, the hydraulic retarder 50, and the mechanical braking device to execute the braking strategy, thereby improving the braking adaptability and operational stability of the transport vehicle 400 under different operating conditions.

[0092] It should be understood that in the following embodiments, the drive assembly 100 includes a hydraulic retarder 50, a cooling device 70, and a connecting device 80, and the working chamber 561 of the hydraulic retarder 50 can be selectively connected to the cooling circuit 702 as an example for specific description. In this case, the control device 10 can not only control the operation of the regenerative braking device and the mechanical braking device, but also control the hydraulic retarder 50 to form an auxiliary retardation effect through the working medium in the working chamber 561. It should be understood that in other embodiments, if the drive assembly 100 uses a switching device 60 to switch the hydraulic retarder 50 between the working state and the non-working state, for example, using a clutch 62 for mechanical switching, or using an air pump 641, a gas pipeline 642, and a reversing valve 643 for air supply and liquid discharge switching, then its specific control steps can be adjusted according to the corresponding structure. However, the basic principle of coordinating regenerative braking, hydraulic retarder 50, and mechanical braking device based on braking demand is roughly the same, so this specification will not describe them one by one.

[0093] Step S110: Obtain the braking torque requirement.

[0094] In this embodiment, braking torque requirement refers to the total braking torque required for the transport vehicle to achieve target deceleration, target coasting control, target speed maintenance, or stop under the current operating conditions. The braking torque requirement characterizes the total deceleration torque that needs to be applied to the transport vehicle at the current moment. The braking distribution of the subsequent regenerative braking device, hydraulic retarder, and mechanical braking device is determined based on the braking torque requirement.

[0095] In some embodiments, the braking torque requirement can originate from different operating states of the transport vehicle. For example, the braking torque requirement can be the torque requirement when the transport vehicle is in coasting mode (D gear) or the torque requirement when the driver depresses the brake pedal. In other words, the braking torque requirement can originate from both the deceleration requirement during coasting and the braking requirement during active braking.

[0096] Specifically, in some embodiments, when the transport vehicle is in coasting mode (D), for example, when the driver releases the accelerator pedal and does not depress the brake pedal, the control device can obtain the braking torque requirement based on the current coasting condition of the transport vehicle. In this case, the braking torque requirement can be the total braking torque required to maintain the transport vehicle in the desired coasting state or limit the increase in vehicle speed. For example, the control device can determine the braking torque requirement in coasting mode (D) based on at least one of the following: the current gear information of the transport vehicle, the accelerator pedal status, the current vehicle speed, road gradient information, and longitudinal acceleration information. Thus, even when the driver does not actively depress the brake pedal, the control device can still obtain the corresponding braking torque requirement based on the coasting operation requirements of the transport vehicle.

[0097] In other embodiments, the braking torque demand when the driver depresses the brake pedal may originate from the driver's active braking intention. Specifically, the control device can acquire an input signal corresponding to the brake pedal and analyze the braking intensity required by the driver based on the input signal to determine the braking torque demand. As an example, the input signal may include at least one of the following: brake pedal travel signal, brake pedal opening signal, brake pedal displacement signal, brake pedal force signal, or brake master cylinder pressure signal. The control device can determine the braking torque demand corresponding to the current moment based on the above input signal and in conjunction with at least one of the following: the current vehicle speed, load status, gradient information, wheel speed information, and longitudinal acceleration information.

[0098] In some embodiments, the braking torque requirement may include either directly acquiring the target braking torque already calculated by the host controller, or calculating the braking torque by the control device based on the collected operating status parameters and operation input parameters. Therefore, the braking torque requirement can be generated by the vehicle controller, domain controller, or other host controller in the transport vehicle and sent to the control device, or it can be obtained by the control device itself based on relevant sensor signals and control parameters through conversion or parsing. This specification does not limit this.

[0099] It should be noted that the aforementioned coasting in D gear and braking with the brake pedal depressed are merely exemplary operating conditions for obtaining braking torque requirements. In other embodiments, any control quantity that can characterize the current deceleration requirement of the transport vehicle can be used as the source of braking torque requirements. For example, braking torque requirements can also originate from autonomous driving control commands, cruise deceleration commands, or collision avoidance deceleration commands.

[0100] Furthermore, in some embodiments, the braking torque demand can be characterized as the total braking torque demand and used as an input for determining the subsequent braking strategy. After obtaining the braking torque demand in step S110, the control device can further allocate the braking torque demand based on the maximum regenerative braking torque and the maximum retarder braking torque corresponding to the hydraulic retarder, in order to determine a braking strategy that is jointly or individually executed by at least one of the regenerative braking device, the hydraulic retarder, and the mechanical braking device.

[0101] Step S120: Obtain the maximum regenerative braking torque and the maximum braking torque of the hydraulic retarder.

[0102] In some embodiments, the transport vehicle may also include regenerative braking and mechanical braking.

[0103] A regenerative braking device is used to provide regenerative braking torque during deceleration or coasting of a transport vehicle and to convert at least a portion of the kinetic energy of the transport vehicle into electrical energy. As an example, when the drive unit is an electric motor, the regenerative braking device may include a drive unit and a control unit electrically connected to the drive unit, the control unit controlling the drive unit to operate in a regenerative braking condition to induce regenerative braking on the driving system.

[0104] Mechanical braking devices are used to provide mechanical braking force during the deceleration or braking of a transport vehicle. As an example, a mechanical braking device can be located in the running system and corresponding to a wheel, wheel axle, or wheel half-axle. The mechanical braking device can include at least one of the following structures: brake disc, brake caliper, brake pad, brake drum, and brake shoes, to apply braking force to the running system through friction braking. Therefore, in subsequent control processes, the braking torque demand can be distributed among the regenerative braking device, the hydraulic retarder, and the mechanical braking device to achieve braking control of the transport vehicle.

[0105] In this embodiment, the maximum regenerative braking torque refers to the maximum braking torque that the regenerative braking device can provide under the current operating conditions. The maximum regenerative braking torque characterizes the maximum regenerative braking force that the regenerative braking device can output to the transport vehicle at the current moment, in the current operating state, and under the current energy recovery conditions.

[0106] In this embodiment, the maximum braking torque of the hydraulic retarder refers to the maximum auxiliary braking torque that the hydraulic retarder can provide under the current operating conditions. The maximum braking torque of the hydraulic retarder characterizes the maximum deceleration braking torque that the hydraulic retarder can output to the transport vehicle at the current moment, under the current operating state and the current thermal conditions.

[0107] In some embodiments, the control device may acquire the maximum regenerative braking torque and the maximum braking torque of the hydraulic retarder respectively, and use both as constraints for subsequently determining the braking strategy.

[0108] Specifically, in some embodiments, the maximum regenerative braking torque can be obtained by the control device based on the current operating parameters of the regenerative braking device. As an example, when the regenerative braking device includes a drive unit and a control unit, the control device can determine the regenerative braking capability under the current operating condition and obtain the corresponding maximum regenerative braking torque based on at least one of the following: current vehicle speed, drive unit rotation speed, battery pack state of charge, battery pack allowable charging power, voltage state, reserved charging power, and the temperature state of the drive unit and control unit. For example, the control device can identify the acceptable charging power of the battery pack under the current state of charge and, in conjunction with the current vehicle speed and drive unit rotation speed, convert this acceptable power into a corresponding upper limit for regenerative braking torque; simultaneously, the control device can also limit the upper limit of regenerative braking torque by combining the maximum regenerative torque of the drive unit at the corresponding rotation speed, thereby obtaining the maximum regenerative braking torque.

[0109] In some embodiments, when the state of charge of the power battery pack does not meet the conditions for continued charging, or when the drive device or control device experiences a temperature exceeding a threshold, a malfunction, or a condition that restricts regeneration, the control device can determine that the regenerative braking device cannot effectively provide regenerative braking at present, and thus set the maximum regenerative braking torque to zero or a low value. Therefore, in this embodiment, the maximum regenerative braking torque can dynamically reflect the actual usability of the regenerative braking device under the current operating conditions.

[0110] Furthermore, in some embodiments, the maximum braking torque of the hydraulic retarder can be obtained by the control device based on the current operating state of the hydraulic retarder. As an example, the control device can obtain the maximum braking torque of the hydraulic retarder under the current operating condition based on at least one of the following: the current vehicle speed, the rotational speed of the retarding rotor, the temperature state of the hydraulic retarder, and the fluid state of the working chamber. For instance, the torque parameters of the hydraulic retarder can be pre-stored in the control device as a retarder characteristic relationship. This retarder characteristic relationship characterizes the correspondence between vehicle speed, temperature, and retarding braking torque. The control device can retrieve the corresponding maximum output braking torque according to the current vehicle speed and current temperature based on the preset retarder characteristic relationship, thereby determining this torque as the maximum braking torque of the hydraulic retarder.

[0111] In some embodiments, the maximum braking torque of the hydraulic retarder can also be correlated with the pressure state within the working chamber. That is, under the current rotational speed and temperature conditions, the control device can determine the maximum auxiliary braking torque that the hydraulic retarder can output, taking into account the pressure level that can be established within the working chamber. Therefore, the maximum braking torque of the hydraulic retarder not only characterizes its maximum retardation capability under current operating conditions but also provides a basis for subsequent control of the hydraulic retarder's output braking torque based on the working chamber pressure.

[0112] In some embodiments, the maximum regenerative braking torque and / or the maximum braking torque of the hydraulic retarder may include parameters calculated or obtained by the control device directly based on current sensor signals, state parameters, and preset characteristic data, or they may include parameters already calculated received from a host controller, domain controller, or other functional control module. This specification does not limit this. As long as the control device can obtain parameters characterizing the current maximum braking capacity of the regenerative braking device and the hydraulic retarder, and use them to determine subsequent braking strategies, they can be understood as the maximum regenerative braking torque and / or the maximum braking torque of the hydraulic retarder referred to in this embodiment.

[0113] Step S130: Based on the braking torque demand, the maximum regenerative braking torque, and the maximum braking torque of the hydraulic retarder, determine the braking strategy according to the preset braking execution priority.

[0114] In this embodiment, the braking strategy refers to the control arrangement made regarding the participation mode, sequence, and degree of participation of the regenerative braking device, hydraulic retarder, and mechanical braking device under the current operating conditions in order to meet the braking torque requirement obtained in step S110. Therefore, the braking strategy is used to determine which one or more of the regenerative braking device, hydraulic retarder, and mechanical braking device will participate in braking at the current moment, and the range of braking demand undertaken by each.

[0115] Furthermore, in this embodiment, the braking execution priority is used to characterize the order in which the braking torque demand is sequentially allocated to the regenerative braking device, the hydraulic retarder, and the mechanical braking device. Based on this, in determining the braking strategy, the control device prioritizes having the regenerative braking device handle the braking demand; when the braking capacity provided by the regenerative braking device is insufficient to meet the braking torque demand, the hydraulic retarder then handles at least a portion of the remaining braking demand; when the braking force provided by the regenerative braking device and the hydraulic retarder together is still insufficient to meet the braking torque demand, the mechanical braking device then handles the remaining braking demand. Thus, the control device can determine a braking strategy adapted to the current demand based on the available capacity of each braking execution component under the current operating condition.

[0116] As an example, when the current braking torque required by the transport vehicle is relatively low, and the regenerative braking device can provide sufficient regenerative braking force under the current operating conditions, the control device can determine that the braking strategy should prioritize braking by the regenerative braking device. In this case, the hydraulic retarder and mechanical braking device may not participate in the current braking or may remain in standby mode.

[0117] As another example, when the current braking torque demand of the transport vehicle exceeds the maximum braking force that the regenerative braking device can provide under the current operating conditions, but does not exceed the braking force that the regenerative braking device and the hydraulic retarder can provide together, the control device can determine that the braking strategy is for the regenerative braking device and the hydraulic retarder to jointly perform braking. In this case, the regenerative braking device takes priority in undertaking the braking portion it can provide, and the remaining braking demand is supplemented by the hydraulic retarder.

[0118] As another example, when the current braking torque demand of the transport vehicle increases further, such that the braking force provided by the regenerative braking system and the hydraulic retarder is still insufficient to meet the current braking demand, the control device can determine a braking strategy where the regenerative braking system, the hydraulic retarder, and the mechanical braking system jointly perform braking. In this case, the mechanical braking system is used to handle the remaining braking demand not covered by the regenerative braking system and the hydraulic retarder. Therefore, the transport vehicle can still obtain sufficient total braking force under conditions of high braking demand.

[0119] In some embodiments, the determination of the braking strategy can also be based on the current operating state of the transport vehicle. For example, in coasting mode in D gear, the control device can prioritize the braking strategy involving regenerative braking and / or hydraulic retarder based on the braking torque demand under coasting conditions; when the driver depresses the brake pedal, the control device can further determine whether it is necessary to introduce mechanical braking to participate in braking based on the braking torque demand under active braking conditions.

[0120] Step S140: According to the determined braking strategy, control at least one of the regenerative braking device, hydraulic retarder, and mechanical braking device to execute the braking strategy.

[0121] In this embodiment, "execute braking strategy" means that the control device outputs a corresponding control command to at least one of the regenerative braking device, hydraulic retarder and mechanical braking device according to the braking strategy determined in step S130, so that the corresponding execution component participates in braking according to the braking strategy.

[0122] Specifically, in some embodiments, when the braking strategy indicates that braking should be performed by the regenerative braking device, the control device can control the regenerative braking device to enter a regenerative braking state so that the regenerative braking device can provide the corresponding braking torque. At this time, the hydraulic retarder and mechanical braking device may not participate in the current braking or may remain in a standby state. Therefore, when the braking demand is low, the regenerative braking device can be given priority in performing braking.

[0123] In some embodiments, when the braking strategy is characterized by braking being performed jointly by a regenerative braking device and a hydraulic retarder, the control device can simultaneously control the regenerative braking device to provide regenerative braking torque and control the hydraulic retarder to enter a working state, so that the hydraulic retarder provides auxiliary retardation braking force. Therefore, when the regenerative braking device is insufficient to meet the braking torque requirement alone, a hydraulic retarder can be further introduced to participate in braking.

[0124] In some embodiments, when the braking strategy is characterized by braking being performed jointly by a regenerative braking device, a hydraulic retarder, and a mechanical braking device, the control device can further control the mechanical braking device to perform mechanical braking, based on controlling the regenerative braking device and the hydraulic retarder to participate in braking, thereby enabling the transport vehicle to obtain greater total braking force.

[0125] In some embodiments, controlling at least one of the regenerative braking device, hydraulic retarder, and mechanical braking device to execute a braking strategy may further include determining a target control quantity corresponding to each actuator based on the allocation result in the braking strategy, and controlling the operation of the corresponding actuator based on the target control quantity. For example, the control device may determine the target regenerative braking torque of the regenerative braking device, the target retardation torque of the hydraulic retarder, and the target mechanical braking torque of the mechanical braking device according to the braking strategy, and output control commands to the corresponding actuators respectively.

[0126] In some embodiments, in step S140, the transport vehicle or drive assembly can also dynamically adjust the execution process according to the operating state of the transport vehicle. For example, during the braking process of the transport vehicle, if the availability of the regenerative braking device, the hydraulic retarder, or the mechanical braking device changes, the control device can readjust the control of each actuator based on the updated braking strategy so that the transport vehicle continuously obtains a braking effect that matches the current operating conditions.

[0127] Based on the control method of the drive assembly provided in this embodiment, the transport vehicle or drive assembly can obtain the braking torque demand, the maximum regenerative braking torque, and the maximum braking torque of the hydraulic retarder, and determine the braking strategy according to the preset braking execution priority. This enables the transport vehicle to adaptively select at least one of regenerative braking, hydraulic retarder, and mechanical braking to participate in braking under different operating conditions, which is beneficial for prioritizing the use of regenerative braking to achieve energy recovery. When the regenerative braking capacity is insufficient, the hydraulic retarder can be introduced in time to participate in braking, thereby reducing the dependence on mechanical braking; when the braking demand further increases, mechanical braking can then participate to supplement the braking force, thereby improving the braking adaptability and operational stability of the transport vehicle under conditions such as coasting, deceleration, downhill, and active braking.

[0128] Please see Figure 7 This application also provides a control method for a drive assembly. In practical applications, the control method for the drive assembly is applied to the drive assembly provided in any of the above embodiments, or to a transport vehicle equipped with a drive assembly. Specifically, the control method for the drive assembly in this embodiment may include the following steps S210 to S240. In some embodiments, the control device in the drive assembly is configured to execute the control process of steps S210 to S240 during the operation of the transport vehicle, especially under deceleration, downhill, coasting, or braking conditions, to further refine the braking strategy based on the braking torque requirement, the maximum regenerative braking torque, and the maximum braking torque of the hydraulic retarder, and to control at least one of the regenerative braking device, the hydraulic retarder, and the mechanical braking device to perform corresponding braking control, thereby improving the braking coordination, braking accuracy, and operational stability of the transport vehicle under different operating conditions.

[0129] Step S210: Obtain the braking torque requirement.

[0130] For a detailed description of the implementation of step S210, please refer to the specific description of step S110 in the above embodiments of the specification, which will not be repeated here.

[0131] Step S220: Obtain the maximum regenerative braking torque and the maximum braking torque of the hydraulic retarder; For details on the specific implementation of step S220, please refer to the specific description of step S120 in the above embodiments of the specification, which will not be repeated here.

[0132] Step S230: Based on the braking torque demand, the maximum regenerative braking torque, and the maximum braking torque of the hydraulic retarder, a braking strategy is determined according to a preset braking execution priority. The braking execution priority is used to characterize the order in which the braking torque demand is allocated to the regenerative braking device, the hydraulic retarder, and the mechanical braking device.

[0133] Specifically, for some specific implementations of step S230 in this embodiment, please refer to the detailed description of step S130 in the above embodiment of the specification, which will not be repeated here.

[0134] In summary, the main purpose of step S230 is to allocate the total braking demand under the current operating condition according to a preset braking execution priority, based on the obtained braking torque requirement, regenerative braking maximum torque, and hydraulic retarder maximum braking torque. In this embodiment, when determining the braking strategy, the regenerative braking device is given priority in meeting the braking demand; when the braking force provided by the regenerative braking device is insufficient, the hydraulic retarder will then meet at least a portion of the remaining braking demand; when the braking force provided by the regenerative braking device and the hydraulic retarder is still insufficient to meet the braking demand, the mechanical braking device will then meet the remaining braking demand. This approach can meet the current braking demand of the transport vehicle while also taking into account energy recovery and auxiliary retardation requirements.

[0135] In some embodiments, step S230 may further include the following sub-steps S231, S233, and S235. Sub-steps S231, S233, and S235 correspond to different braking demand allocation scenarios under different magnitude relationships, namely, the scenarios where braking is performed only by the regenerative braking device, braking is performed jointly by the regenerative braking device and the hydraulic retarder, and braking is performed jointly by the regenerative braking device, the hydraulic retarder, and the mechanical braking device.

[0136] In sub-step S231, if the braking torque demand is less than the maximum regenerative braking torque, the braking strategy is determined as follows: the braking torque demand is allocated to the regenerative braking device, and the regenerative braking device performs the braking.

[0137] In this scenario, it indicates that the regenerative braking system is already capable of meeting the total braking demand of the transport vehicle under the current operating conditions, thus eliminating the need for a hydraulic retarder or mechanical brake to participate in the current braking. As an example, when the transport vehicle is coasting in Drive (D) gear, or when the driver lightly applies the brake pedal, resulting in a lower braking torque demand, if the maximum regenerative braking torque is not less than the braking torque demand, it can be prioritized that only the regenerative braking system performs the braking. For instance, if the current braking torque demand is 80 Nm, and the current maximum regenerative braking torque is 120 Nm, the control device can determine that the regenerative braking system will handle the entire 80 Nm braking demand, while the hydraulic retarder and mechanical brake will not participate in the current braking.

[0138] In sub-step S233, when the braking torque demand is greater than the maximum regenerative braking torque, and the difference between the braking torque demand and the maximum regenerative braking torque is less than or equal to the maximum braking torque of the hydraulic retarder, the braking strategy is determined as follows: the braking torque demand is sequentially distributed to the regenerative braking device and the hydraulic retarder, and the regenerative braking device and the hydraulic retarder jointly perform braking.

[0139] In this scenario, the regenerative braking device alone provides insufficient braking force to meet the total braking demand under the current operating conditions. However, the shortfall can be supplemented by the hydraulic retarder, thus eliminating the need for a mechanical braking device to participate in the current braking. Specifically, the regenerative braking device can first handle the maximum braking force it can provide under the current operating conditions, and then the hydraulic retarder can handle the remaining difference. As an example, if the current braking torque demand is 180 Nm, the current maximum regenerative braking torque is 120 Nm, and the maximum braking torque of the hydraulic retarder is 100 Nm, then the difference between the braking torque demand and the maximum regenerative braking torque is 60 Nm. This difference is less than the maximum braking torque of the hydraulic retarder, so it can be determined that the regenerative braking device will handle 120 Nm, the hydraulic retarder will handle the remaining 60 Nm, and the mechanical braking device will not participate in the current braking. In this embodiment, since the regenerative braking device cannot completely cover the braking demand, the hydraulic retarder can be further utilized to handle the remaining demand, thereby reducing the use of the mechanical braking device, reducing brake pad wear and noise, and minimizing the environmental pollution caused by brake pad wear.

[0140] In sub-step S235, when the braking torque demand is greater than the sum of the maximum regenerative braking torque and the maximum braking torque of the hydraulic retarder, the braking strategy is determined as follows: the braking torque demand is sequentially distributed to the regenerative braking device, the hydraulic retarder, and the mechanical braking device, and the braking is jointly performed by the regenerative braking device, the hydraulic retarder, and the mechanical braking device.

[0141] In this scenario, it indicates that the combined braking force provided by the regenerative braking device and the hydraulic retarder under the current operating conditions is insufficient to meet the total braking demand of the transport vehicle. Therefore, a mechanical braking device is needed to handle the remaining portion. Specifically, the regenerative braking device can first handle the maximum braking force it can provide under the current operating conditions, then the hydraulic retarder can handle the maximum retardant braking force it can provide under the current operating conditions, and finally the mechanical braking device can handle the remaining unmet braking demand. As an example, if the current braking torque demand is 260 Nm, the current maximum regenerative braking torque is 120 Nm, and the maximum braking torque of the hydraulic retarder is 100 Nm, the sum of which is 220 Nm, which is still less than the current braking torque demand of 260 Nm. Therefore, the remaining 40 Nm of braking demand can be handled by the mechanical braking device. In this embodiment, under conditions of high braking demand, the transport vehicle can obtain sufficient total braking force through the coordinated operation of the regenerative braking device, the hydraulic retarder, and the mechanical braking device.

[0142] Step S240: Based on the determined braking strategy, control at least one of the regenerative braking device, hydraulic retarder, and mechanical braking device to execute the braking strategy.

[0143] Specifically, for some specific implementations of step S240 in this embodiment, please refer to the detailed description of step S240 in the above embodiment of the specification, which will not be repeated here.

[0144] Further in this embodiment, the drive assembly may include a cooling circuit. The working chamber of the hydraulic retarder can be selectively connected to the cooling circuit via a control valve, which is used to change the connection state between the working chamber and the cooling circuit. When the hydraulic retarder participates in executing the braking strategy, the control valve can change the fluid inlet state of the working chamber and adjust the state of the working medium entering the working chamber, and the cooling circuit can control the hydraulic retarder to output the corresponding retarding braking torque. The specific structure of the cooling circuit can be referred to the embodiment provided above, and will not be repeated here.

[0145] Specifically, in this embodiment, the process of controlling the hydraulic retarder to execute the braking strategy may include the following steps: Step S241, determining the target retarding torque of the hydraulic retarder based on the maximum regenerative braking torque and the braking torque requirement; Step S243, controlling the connection between the working chamber and the cooling circuit based on the control valve; Step S245, determining the target working pressure of the working chamber based on the target retarding torque, and controlling the operation of the liquid pump in the cooling circuit according to the target working pressure. Therefore, when the regenerative braking device is insufficient to meet the current braking demand alone, the hydraulic retarder can undertake at least part of the remaining braking demand, and further convert this part of the demand into a working chamber pressure control demand, and then adjust the flow state of the working medium through the liquid pump so that the hydraulic retarder outputs a retarding braking torque that matches the current braking strategy. Please also refer to... Figure 8 and Figure 9 The following will provide a more detailed description of some possible embodiments of steps S241, S243, and S245.

[0146] Step S241: Determine the target retarding torque of the hydraulic retarder based on the maximum regenerative braking torque and the braking torque requirement.

[0147] In some embodiments, the target retarding torque can be determined based on the relationship between the current total braking demand and the regenerative braking capacity. As an example, when the determined braking strategy indicates that the hydraulic retarder needs to participate in braking, the vehicle and / or drive assembly can further acquire the current vehicle speed and control the operating state of the hydraulic retarder based on the current vehicle speed, thereby determining the target retarding torque of the hydraulic retarder. Specifically, when the current vehicle speed is greater than or equal to a preset trigger speed, the vehicle and / or drive assembly can determine the target retarding torque of the hydraulic retarder based on the maximum regenerative braking torque and the braking torque demand; when the current vehicle speed is less than the preset trigger speed, the vehicle and / or drive assembly can determine that the hydraulic retarder will not participate in the current braking and control the hydraulic retarder to enter a standby state. This is beneficial for ensuring that the hydraulic retarder mainly participates in braking within the speed range most suitable for providing auxiliary retarding, thereby improving the rationality of braking distribution.

[0148] For example, when the vehicle is in D-mode braking mode and the current vehicle speed is greater than or equal to the braking trigger speed of the hydraulic retarder, such as greater than or equal to 10 km / h, at least a portion of the braking demand not covered by regenerative braking can be determined as the target retardation torque of the hydraulic retarder. Furthermore, this target retardation torque can be compared with the maximum braking torque that the hydraulic retarder can provide under the current speed and temperature conditions, and the smaller of the two values ​​can be used to determine the target retardation torque of the hydraulic retarder. Thus, the braking demand undertaken by the hydraulic retarder can both supplement the insufficient regenerative braking and will not exceed the available capacity of the hydraulic retarder under the current operating conditions. As another example, when the vehicle is in D-mode braking mode and the current vehicle speed is less than the braking trigger speed of the hydraulic retarder, such as less than 10 km / h, the target retardation torque of the hydraulic retarder can be disregarded, and the hydraulic retarder can be controlled to enter a standby state.

[0149] Step S243: Based on the control valve, control the connection between the working chamber and the cooling circuit.

[0150] In some embodiments, after acquiring the target retarding torque, the drive assembly and / or transport vehicle can further control the connection between the working chamber and the cooling circuit based on a control valve. Specifically, the control valve can be controlled to switch to a connected state that allows the cooling medium to enter the working chamber. For example, based on the structure of the control valve having an inlet, a first outlet, and a second outlet in the above embodiments, the control valve can be controlled to connect the inlet and the second outlet, thereby connecting the cooling circuit to the working chamber of the hydraulic retarder via an input pipe, so that the cooling medium enters the working chamber.

[0151] In some embodiments, the hydraulic retarder is provided with a gas supply mechanism connected to the working chamber. Accordingly, after the aforementioned connection between the working chamber and the cooling circuit is controlled by the control valve, the connection between the gas supply mechanism and the working chamber can be cut off. Simultaneously, the reversing valve located on the gas pipeline can be controlled to be in a closed state, thereby preventing gas from entering the working chamber via the gas pipeline when the hydraulic retarder enters the retardation braking condition, thus avoiding any impact on the establishment process of the working medium within the working chamber. Therefore, in this embodiment, when the hydraulic retarder participates in the current braking, a liquid connection path can be established by controlling the control valve, resulting in a relatively stable hydraulic retardation condition with the liquid path established and the gas path closed.

[0152] Furthermore, in some embodiments, after the drive assembly or transport vehicle issues a control request to switch the control valve to connect the inlet and the second outlet, and issues a control request to close the directional valve on the gas pipeline, the drive assembly and / or transport vehicle can also detect the execution result. Specifically, it can detect whether the control valve is actually in the state of connecting the inlet and the second outlet, and whether the directional valve on the gas pipeline is actually in the closed state. If the detection result indicates that the control valve is not in the state of connecting the inlet and the second outlet, and / or the directional valve on the gas pipeline is not in the closed state, it can be determined that the current hydraulic retarder does not meet the basic conditions for entering the retarding braking condition. In this case, the drive assembly and / or transport vehicle can report fault information and control the hydraulic retarder to enter the standby state. The "standby state" referred to in this specification can be understood as the hydraulic retarder temporarily not participating in the current braking torque output, or its actual output retarding torque being regarded as zero or a low value, in order to avoid incorrectly establishing the working medium passage when the valve body state is abnormal, thereby affecting braking stability. Similarly, the drive assembly or transport vehicle can further detect that the reversing valve on the gas pipeline is closed. If so, it confirms that the gas passage has been cut off; otherwise, it can report a fault and control the hydraulic retarder to enter a standby state. Accordingly, if the detection result indicates that the control valve is already connected between the inlet and the second outlet, and the reversing valve on the gas pipeline is closed, it can be considered that the liquid passage of the hydraulic retarder is established normally, and the gas passage has been cut off. Based on this, the drive assembly and / or transport vehicle can further enter the subsequent control process, for example, continuing to calculate the target working pressure of the working chamber based on the target retarding torque, and controlling the liquid pump in the cooling circuit to operate according to the target working pressure, so that the hydraulic retarder outputs a retarding braking torque adapted to the current braking demand. Accordingly, in some examples, when the hydraulic retarder is not participating in the current braking strategy, the control valve can also switch to a state that disconnects or bypasses the working chamber from the cooling circuit, thereby preventing the cooling medium from entering the working chamber. For example, based on the above embodiment, the inlet and the first outlet of the control valve are connected.

[0153] Step S245: Based on the target slow torque, determine the target working pressure of the working chamber, and control the operation of the liquid pump in the cooling circuit according to the target working pressure.

[0154] In some embodiments, the target operating pressure can be determined based on the operating characteristic data of the hydraulic retarder. As an example, the target operating pressure can be obtained by querying the current target retarding torque, current rotor speed, and current temperature within the working chamber, according to a preset "braking torque-rotor speed-temperature-pressure" correspondence. Therefore, in this embodiment, the target retarding torque of the hydraulic retarder can be converted into a target control quantity related to the working chamber pressure, thereby facilitating the control of the actual braking output of the hydraulic retarder through fluid pressure. The pressure of the working chamber in this embodiment can be measured by the first pressure sensor described in the previous embodiment.

[0155] In some embodiments, after obtaining the target working pressure, the transport vehicle or drive assembly is further used to determine the target working state of the liquid pump based on the target working pressure, and control the liquid pump to operate according to the corresponding state. Specifically, for example, the transport vehicle or drive assembly determines the target working state of the liquid pump according to a preset correspondence between "liquid pump speed - working fluid temperature - working chamber pressure", and controls the operation of the liquid pump through pressure feedback in the pipeline.

[0156] Furthermore, the transport vehicle or drive assembly can also acquire the actual working pressure of the working chamber in real time, and adjust the speed of the hydraulic pump based on the target working pressure and the actual working pressure, so that the difference between the actual working pressure and the target working pressure is maintained within a preset range, thereby making the actual output retarding torque of the hydraulic retarder closer to the target retarding torque. In some embodiments, the actual working pressure can be acquired by a first pressure sensor located on the outlet side of the working chamber. Thus, the pressure detected by the first pressure sensor can not only serve as the basis for the feedback adjustment of the hydraulic pump speed, but also as a representation of the current output torque of the hydraulic retarder. As an example, the actual retarding torque of the hydraulic retarder can be obtained by reverse lookup based on the currently detected actual working pressure of the working chamber and a preset hydraulic retarder operating characteristic relationship, and this actual retarding torque can be provided as a feedback quantity to the upper control module for subsequent compensation calculations for mechanical braking requirements.

[0157] In some embodiments, if a control valve or a switching valve associated with the hydraulic retarder malfunctions, causing the working medium to fail to enter the working chamber as expected or to fail to maintain the expected pressure state, the actual retardation torque of the hydraulic retarder can be considered zero or a low value, and the braking strategy can be readjusted accordingly. In this embodiment, the hydraulic retarder uses the coolant from the cooling device as the working medium. The hydraulic retarder removes the heat generated during operation through the circulation of the working medium, thus maintaining relatively stable retardation performance during long-term continuous operation, reducing the risk of thermal fade problems associated with mechanical friction brakes, and providing a large auxiliary braking torque even at high vehicle speeds. Therefore, during braking control, the non-contact, low-wear hydraulic retarder can handle at least part of the braking demand, thereby reducing the intervention frequency of mechanical braking devices, reducing brake pad wear, and minimizing braking noise.

[0158] In some embodiments, the control method for the drive assembly may further include the following step S247.

[0159] Step S247: When the hydraulic retarder does not participate in the current braking strategy, control the control valve to switch to a state that disconnects or bypasses the working chamber from the cooling circuit.

[0160] When the hydraulic retarder is not participating in the current braking strategy, the control valve can be switched to a state that disconnects or bypasses the working chamber from the cooling circuit, thereby preventing the cooling medium from entering the working chamber. For example, based on the control valve structure in the previous embodiment, the inlet of the control valve can be connected to the first outlet, keeping the hydraulic retarder in a non-operating state. It should be understood that "the hydraulic retarder is not participating in the current braking strategy" as stated in this specification means that under the current operating conditions, the braking torque demand is not allocated to the hydraulic retarder, and the hydraulic retarder does not bear the current braking torque output. At this time, the hydraulic retarder can be in a standby state or a non-operating state, and its output retarding torque is zero or less than the output retarding torque when participating in braking. For example, when the regenerative braking device is sufficient to meet the current braking demand, or the current vehicle speed is lower than the braking trigger speed of the hydraulic retarder, or the hydraulic retarder does not meet the conditions for participating in braking, it can be considered that the hydraulic retarder is not participating in the current braking strategy.

[0161] In some embodiments, the control method for the drive assembly may further include the following step S249.

[0162] Step S249: After the hydraulic retarder exits the working state, the liquid discharge control is executed to discharge the liquid in the working chamber.

[0163] In some embodiments, when the transport vehicle exits the braking mode and enters the driving or coasting mode, the control method of this embodiment may further include drainage control after the hydraulic retarder exits the working state. Based on this, the control method of this embodiment may further include: when the actual working pressure of the working chamber is greater than or equal to a first preset pressure, cutting off the connection between the liquid inlet of the working chamber and the cooling circuit; controlling the gas supply mechanism to supply gas to the working chamber, so that the liquid in the working chamber is output to the cooling circuit through the liquid outlet of the working chamber. Specifically, the transport vehicle or drive assembly controls the control valve to switch to the state of bypassing the cooling circuit, so that the working medium no longer enters the working chamber; on this basis, the gas supply mechanism is then restored to the working chamber to create conditions for subsequent gas input to the working chamber. Thus, the hydraulic retarder switches from the slow braking mode to the drainage mode.

[0164] In a specific embodiment, when the pressure in the working chamber reaches a preset trigger condition and the current vehicle speed meets the preset condition, the drain control can be activated. As an example, when the pressure detected by the first pressure sensor is greater than or equal to 1.5 bar and the current vehicle speed is greater than or equal to 10 km / h, the switch valve on the gas passage can be opened, and the air pump can be activated to input gas into the working chamber. Thus, after the gas enters the working chamber, it can push the residual working fluid in the working chamber out through the drain passage, thereby reducing the drag loss of the hydraulic retarder under non-braking conditions.

[0165] In some embodiments, during the drainage control process, the speed and direction of the air pump can be adjusted based on the pressure difference between the first pressure sensor and the second pressure sensor. Therefore, the control method of this embodiment may further include: controlling the air supply mechanism to draw gas from the working chamber when the difference between the actual working pressure of the working chamber and the pressure of the cooling circuit is less than or equal to a preset difference; and cutting off the connection between the air supply mechanism and the working chamber when the actual working pressure of the working chamber is less than or equal to a second preset pressure, wherein the second preset pressure is less than the first preset pressure. As an example, the working state of the air pump can be controlled so that the pressure corresponding to the first pressure sensor is slightly greater than the pressure corresponding to the second pressure sensor, for example, the pressure difference is approximately 0.1 bar, thereby using the pressure difference to push the residual liquid in the working chamber outwards, achieving process control of air intake and drainage.

[0166] Furthermore, as the liquid is discharged, the pressure difference between the first and second sensors decreases. For example, when the pressure difference is less than 0.1 bar, it indicates that the liquid is almost completely drained. At this point, the gas supply mechanism can be controlled to extract gas from the working chamber. As an example, the duration of gas extraction from the working chamber can be determined by the actual pressure of the working chamber. When the actual working pressure of the working chamber is less than or equal to a second preset pressure (e.g., less than 0.05 bar), the gas extraction is considered complete, and the extraction process ends. As another example, the duration of gas extraction from the working chamber can be determined by a preset working time and the dynamic pressure of the working chamber. For example, after maintaining the gas supply and liquid discharge preset time (e.g., about 3 seconds), the air pump can be controlled to reverse for a preset time, such as about 3 seconds, to extract gas from the working chamber, thereby reducing the residual gas in the working chamber. Through the above-mentioned reverse extraction process, it is beneficial to further reduce the no-load drag loss of the hydraulic retarder in the non-working state. Furthermore, in some embodiments, after controlling the air pump to reverse for a preset time, the pressure data of the working chamber can be acquired again. If it is determined that the pressure of the working chamber falls within a preset pressure range, such as 0.1 to 0.3 bar, the air pump is controlled to stop running and the switching valve on the gas passage is closed; otherwise, the air pump continues to run in reverse until the pressure of the working chamber falls within the preset pressure range. This helps to further reduce the no-load drag loss of the hydraulic retarder in the non-working state.

[0167] Furthermore, in some embodiments, after the hydraulic retarder exits the braking mode and completes drainage and evacuation, the transport vehicle enters the driving state. During driving, the transport vehicle or drive assembly can also acquire pressure data and vehicle speed of the working chamber in real time or intermittently, and determine whether the liquid has been completely drained based on the working chamber pressure and vehicle speed. If it is determined that there is still residual liquid in the working chamber, the above-mentioned process of air intake, drainage, and reverse evacuation can be repeated. This helps to maintain the low drag state of the hydraulic retarder after the transport vehicle enters normal driving conditions. When the transport vehicle is in driving and the pressure of the working chamber is detected to be less than or equal to a preset pressure value, for example, less than or equal to 1.5 bar, it can be further judged in conjunction with the current vehicle speed. Specifically, if the current vehicle speed is less than or equal to a preset vehicle speed, for example, less than or equal to 10 km / h, it can be determined that the liquid in the working chamber has not been completely drained or that there is still residual liquid. In this situation, the reversing valve on the gas passage can be kept open, and the air pump can be controlled to deliver gas into the working chamber, thereby repeating the aforementioned air intake and liquid drainage process. After completing the air intake and liquid drainage, the aforementioned air pump reversal process can be continued to further reduce the residual liquid and residual gas in the working chamber. It should be noted that the trigger pressure, vehicle speed conditions, pressure difference, and maintenance time for liquid drainage control in this application specification are only examples. In other embodiments, the relevant thresholds and control duration can be adjusted according to the structure of the hydraulic retarder, the operating requirements of the transport vehicle, and the control requirements.

[0168] In some embodiments, when the hydraulic retarder is in a non-operating state, for example, when the vehicle exits braking mode and enters D-mode drive mode (such as when the driver depresses the accelerator pedal to enter normal driving mode), the vehicle can set the torque of the hydraulic retarder to 0 and maintain the cooling circuit in a bypass state, connecting the inlet of the control valve to the first outlet. Subsequently, it can be detected whether the inlet and first outlet of the control valve are connected. If not, a fault message is reported, and the maximum speed of the current vehicle is limited. If yes, the reversing valve on the gas passage is further connected, and it is detected whether the reversing valve is in the expected state. If not, a fault message is reported. If yes, the air pump is further controlled to operate and deliver gas to the working chamber, and the aforementioned air intake, liquid discharge, and reverse air extraction control process is initiated. During this process, the operating status of the air pump can also be acquired in real time or intermittently. If the air pump is not operating normally, a fault message is reported. Meanwhile, when the transport vehicle is in D-mode drive, the control device can also confirm the torque demand of the drive unit based on the accelerator pedal, and control the drive unit to respond to the torque request based on the bus voltage, drive unit temperature and corresponding calibration data; and control the hydraulic pump speed and radiator fan speed based on the temperature of the drive unit and the electronic control unit. The hydraulic pump speed control demand no longer includes the braking demand of the hydraulic retarder.

[0169] In some embodiments, the drive assembly further includes a clutch connected between the hydraulic retarder and the transmission device, used to disconnect or maintain the transmission relationship between the hydraulic retarder and the transmission device. When the transport vehicle exits the braking mode and enters the driving or coasting condition, the control method of this embodiment may further include clutch disengagement control after the hydraulic retarder exits the working state, using the clutch to disconnect the hydraulic retarder from the transmission device and / or wheel axle. Based on this, the control method of this embodiment may further include: cutting off the connection between the liquid inlet of the working chamber and the cooling circuit when the actual working pressure of the working chamber is greater than or equal to a first preset pressure; and disconnecting the transmission connection between the retarder's retarder rotor and the power output end via the clutch. In some embodiments, the clutch may be a friction clutch, an electromagnetic clutch, or other clutch structures capable of selective engagement and disengagement. When the clutch is in the disengaged state, the rotational motion of the power output end is no longer transmitted to the retarder rotor of the hydraulic retarder, thereby helping to reduce the drag loss of the hydraulic retarder in non-braking conditions. Accordingly, when it is necessary to re-engage the hydraulic retarder with braking, the transmission connection between the retarder rotor and the power output end can be re-established via the clutch. The specific implementation schemes for draining out the hydraulic retarder and disengaging the hydraulic retarder via clutch can be used as two alternative implementation schemes, or in combination as needed.

[0170] Please see Figure 10 In some embodiments, the braking strategy characterizes the situation where the mechanical braking device needs to participate in braking. Controlling the mechanical braking device to execute the braking strategy may include: determining the mechanical braking target torque of the mechanical braking device based on the maximum regenerative braking torque, the maximum retarding torque of the hydraulic retarder, and the braking torque requirement, and controlling the mechanical braking device to operate according to the mechanical braking target torque. After the regenerative braking device and the hydraulic retarder jointly participate in braking, if the braking force they can provide is still insufficient to meet the current total braking demand, the mechanical braking device will undertake the remaining braking demand, thereby ensuring that the transport vehicle obtains sufficient total braking force under the current operating conditions.

[0171] In some embodiments, the mechanical braking target torque can be determined based on the current braking torque demand, the actual braking output of the regenerative braking device, and the actual retardation output of the hydraulic retarder. Specifically, when the transport vehicle is in braking condition and the braking torque demand is greater than the sum of the maximum regenerative braking torque and the maximum retardation torque of the hydraulic retarder, the remaining uncovered portion can be determined as the mechanical braking target torque of the mechanical braking device after the regenerative braking device and the hydraulic retarder have each undertaken their respective braking demands.

[0172] Furthermore, in some embodiments, the target mechanical braking torque can be determined according to the following formula: the target mechanical braking torque is equal to the braking torque requirement minus the actual braking torque of the regenerative braking device and the actual retardation torque of the hydraulic retarder, and is compared with the maximum mechanical braking torque that the mechanical braking device can provide under the current operating conditions, and the smaller of the two is taken as the target mechanical braking torque. In some examples, the target mechanical braking torque can be expressed as: Tmbrkreq=min(Tbrkreq-Te-Tret,Tmbmax), where, Tbrkreq represents the current braking torque requirement; Te represents the actual braking torque of the regenerative braking device; Tret represents the actual retarding torque of the hydraulic retarder; Tmbmax ​​represents the maximum mechanical braking torque that the mechanical braking device can provide under the current speed and temperature conditions.

[0173] By limiting the specific torque of mechanical braking, it is possible to avoid the mechanical braking device undertaking braking demands beyond its current available capacity. As an example, if the current braking torque demand of the transport vehicle is 260 Nm, the actual braking torque of the regenerative braking device is 120 Nm, the actual retardation torque of the hydraulic retarder is 100 Nm, and the maximum mechanical braking torque that the mechanical braking device can provide under the current operating conditions is greater than or equal to 40 Nm, then the target mechanical braking torque can be determined as 40 Nm, and the mechanical braking device is controlled to operate at 40 Nm. Alternatively, if the remaining value after subtracting the actual braking torque of the regenerative braking device and the actual retardation torque of the hydraulic retarder from the braking torque demand is greater than the maximum mechanical braking torque that the mechanical braking device can provide under the current operating conditions, then the maximum mechanical braking torque of the mechanical braking device under the current operating conditions is determined as the target mechanical braking torque.

[0174] In some embodiments, after determining the target mechanical braking torque, a corresponding control command can be further output to the mechanical braking device to cause the mechanical braking device to perform braking according to the target mechanical braking torque. As an example, the mechanical braking device may include a friction braking mechanism corresponding to the driving system. The control command can be used to control braking pressure, clamping force, or other execution parameters related to mechanical braking force, thereby causing the mechanical braking device to output a mechanical braking force corresponding to the target mechanical braking torque. Thus, the regenerative braking device, the hydraulic retarder, and the mechanical braking device can coordinate under the same braking strategy.

[0175] In some embodiments, if the regenerative braking device or the hydraulic retarder fails to output the expected braking force under the current operating conditions, for example, if the regenerative braking device cannot provide effective regenerative braking due to battery status, electric drive failure, or temperature limitations, or if the hydraulic retarder cannot provide effective retarding braking due to valve body failure, abnormal fluid supply, or abnormal pressure, the actual output of the corresponding actuator can be regarded as zero or a lower value, and the mechanical braking target torque can be re-determined based on the updated actual output. This helps to ensure that the mechanical braking device can promptly make up for the remaining braking demand, thereby improving the reliability and safety of the transport vehicle during the braking process.

[0176] Please see Figure 11 In some embodiments, the braking strategy characterizes the situation where the regenerative braking device needs to participate in braking. Controlling the regenerative braking device to execute the braking strategy may include: determining the target regenerative braking torque of the regenerative braking device based on the maximum regenerative braking torque and the braking torque requirement, and controlling the regenerative braking device to operate according to the target regenerative braking torque. Under the current braking condition, the transport vehicle can prioritize using the regenerative braking device to provide braking force, and when the available capacity of the regenerative braking device is insufficient, the hydraulic retarder and mechanical braking device can supplement the remaining braking demand.

[0177] In some embodiments, the transport vehicle may include a vehicle domain controller, a motor controller, and a battery management system. The vehicle domain controller receives accelerator pedal and brake pedal signals and estimates the braking torque demand or regenerative braking torque demand under the current operating conditions. The battery management system sends the state of charge information of the power battery to the vehicle domain controller. The motor controller is communicatively connected to the drive unit and controls the drive unit to perform regenerative braking based on the torque request sent by the vehicle domain controller. The motor domain controller can be implemented by the aforementioned control device. Further, the vehicle domain controller can, according to a preset regenerative braking strategy, sequentially allocate the total braking torque demand to the regenerative braking device, the hydraulic retarder, and the mechanical braking device, wherein the regenerative braking device participates in braking first, the hydraulic retarder second, and the mechanical braking device last.

[0178] In some embodiments, determining the regenerative braking target torque of the regenerative braking device may include: determining the regenerative braking target torque of the regenerative braking device when the current vehicle speed meets the regenerative braking trigger speed and the power battery meets the recovery charging conditions; and determining the maximum regenerative braking torque as zero when the current vehicle speed does not meet the regenerative braking trigger speed or the power battery does not meet the recovery charging conditions. Specifically, the vehicle domain controller can determine whether the power battery meets the recovery charging conditions based on the current vehicle speed and the power battery state of charge sent by the battery management system. If the current vehicle speed is not greater than a preset speed, such as not greater than 10 km / h, or the power battery does not meet the recovery charging conditions, the maximum regenerative braking torque can be fed back as zero; if the current vehicle speed meets the preset conditions and the power battery meets the recovery charging conditions, the vehicle domain controller can further generate a motor recovery torque request.

[0179] In some embodiments, controlling the regenerative braking device to operate according to the regenerative braking target torque may include: the vehicle domain controller sending a motor recovery torque request, and the motor controller controlling the drive unit to respond to the motor recovery torque request based on the current operating state. Specifically, the vehicle domain controller can identify the rechargeable power of the power battery based on the current battery state of charge and vehicle speed, and determine the required regenerative braking torque by combining the accessory power consumption and reserved power; furthermore, the required regenerative braking torque can be compared with the maximum recovery torque that the drive unit can provide at the corresponding speed, and the smaller value between the two can be taken as the motor recovery torque request.

[0180] In some embodiments, after receiving a motor regenerative torque request, the motor controller can further determine whether the regenerative braking conditions are met based on the temperature status of the drive unit, the temperature status of the electronic control unit, and the current regenerative conditions. If the regenerative conditions are not met, for example, due to overheating of the drive unit or electronic control unit, or a fault in the electric drive system or the power battery management system, the maximum regenerative braking torque can be set to zero. If the regenerative conditions are met, the motor controller can control the drive unit to respond to the motor regenerative torque request based on the bus voltage and temperature, and output the actual regenerative braking torque. As an example, the actual regenerative braking torque Te can be determined based on the following formula: Te = min[(battery rechargeable power + accessory loss power - reserved power), motor regenerative power Pmax] / motor speed.

[0181] Therefore, the drive unit can prioritize regenerative braking within the limits allowed by the current electrical and thermal conditions.

[0182] In some embodiments, controlling the regenerative braking device to operate according to the regenerative braking target torque may further include: sending a cooling flow demand based on the temperature status of the drive unit and the electronic control unit, and controlling the speed of the liquid pump and the speed of the radiator fan. Specifically, when the motor controller controls the drive unit to perform regenerative braking, it may also synchronously send a cooling demand corresponding to the drive unit and the electronic control unit, and control the speed of the liquid pump and the speed of the radiator fan based on the temperature of the drive unit and the temperature of the electronic control unit, thereby ensuring that the drive unit and the electronic control unit are within a suitable operating temperature range under regenerative braking conditions.

[0183] In some embodiments, the vehicle domain controller can also receive the actual regenerative braking torque fed back by the motor controller, or receive the corresponding maximum regenerative braking torque, and use it as the basic parameter for the subsequent allocation of braking demand by the hydraulic retarder and mechanical braking device. Thus, when the regenerative braking device fails to cover all braking demand, the hydraulic retarder and mechanical braking device can further supplement the remaining braking torque demand, thereby enabling the transport vehicle to meet braking requirements while prioritizing the use of regenerative braking to achieve energy recovery as much as possible.

[0184] In summary, the drive assembly control method provided in this embodiment, by acquiring the braking torque demand, the maximum regenerative braking torque, and the maximum braking torque of the hydraulic retarder, and determining the braking strategy according to a preset braking execution priority, enables the transport vehicle to adaptively select at least one of regenerative braking, hydraulic retarder, and mechanical braking to participate in braking under different operating conditions. This improves the rationality of braking distribution and the adaptability of the braking process. Furthermore, by prioritizing the use of regenerative braking, energy recovery can be maximized while meeting braking requirements. When regenerative braking capacity is insufficient, the hydraulic retarder can then handle at least a portion of the remaining braking demand, with mechanical braking supplementing the remaining capacity when necessary. This reduces the frequency of mechanical braking usage and minimizes mechanical wear.

[0185] Please see Figure 12 Based on the drive assembly control method provided in the above embodiments, this application provides a drive assembly control device 300. Figure 12 A structural block diagram of the drive assembly control unit 300 is shown. The drive assembly control unit 300 operates as follows: Figure 2 The drive assembly 100 shown is used to execute the drive assembly control method described above. In this embodiment, the drive assembly control device 300 is stored in the memory of the drive assembly 100 and configured to be executed by one or more processors of the drive assembly 100.

[0186] In this embodiment, the drive assembly control device 300 includes a torque demand determination module 310, a maximum braking torque determination module 330, a strategy formulation module 350, and a control module 370. The torque demand determination module 310 is used to acquire the braking torque demand; the maximum braking torque determination module 330 is used to acquire the maximum regenerative braking torque and the maximum braking torque of the hydraulic retarder; the strategy formulation module 350 is used to determine a braking strategy based on the braking torque demand, the maximum regenerative braking torque, and the maximum braking torque of the hydraulic retarder, according to a preset braking execution priority, wherein the braking execution priority is used to characterize the order in which the braking torque demand is sequentially allocated to the regenerative braking device, the hydraulic retarder, and the mechanical braking device; the control module 370 is used to control at least one of the regenerative braking device, the hydraulic retarder, and the mechanical braking device to execute the braking strategy according to the determined braking strategy.

[0187] In some embodiments, the strategy formulation module 350 is specifically configured to: when the maximum regenerative braking torque is greater than or equal to the braking torque demand, determine the braking strategy as follows: allocate the braking torque demand to the regenerative braking device, and have the regenerative braking device perform braking; when the braking torque demand is greater than the maximum regenerative braking torque, and the difference between the braking torque demand and the maximum regenerative braking torque is less than or equal to the maximum braking torque of the hydraulic retarder, determine the braking strategy as follows: allocate the braking torque demand sequentially to the regenerative braking device and the hydraulic retarder, and have the regenerative braking device and the hydraulic retarder jointly perform braking; when the braking torque demand is greater than the sum of the maximum regenerative braking torque and the maximum braking torque of the hydraulic retarder, determine the braking strategy as follows: allocate the braking torque demand sequentially to the regenerative braking device, the hydraulic retarder, and the mechanical braking device, and have the regenerative braking device, the hydraulic retarder, and the mechanical braking device jointly perform braking.

[0188] The working chamber of the hydraulic retarder is connected in parallel to the cooling circuit via a control valve, which is used to change the connection state between the working chamber and the cooling circuit. During the process of the control module 370 controlling the hydraulic retarder to execute the braking strategy, specifically, it is used to: determine the target retarding torque of the hydraulic retarder based on the maximum regenerative braking torque and the braking torque requirement; control the connection between the working chamber and the cooling circuit based on the control valve; determine the target working pressure of the working chamber based on the target retarding torque; and control the operation of the liquid pump in the cooling circuit according to the target working pressure. Specifically, when the control module 370 controls the operation of the liquid pump in the cooling circuit according to the target working pressure, it is used to: acquire the actual working pressure of the working chamber in real time; and control the operation of the liquid pump in the cooling circuit based on the target working pressure and the actual working pressure, so that the difference between the actual working pressure and the target working pressure is maintained within a preset range. In some embodiments, after controlling the connection between the working chamber and the cooling circuit based on the control valve, the control module 370 is also used to disconnect the connection between the air supply mechanism and the working chamber.

[0189] In some embodiments, after the hydraulic retarder stops braking, the control module 370 is further configured to, when the actual working pressure of the working chamber is greater than or equal to a first preset pressure, disconnect the connection between the liquid inlet of the working chamber and the cooling circuit; control the gas supply mechanism to supply gas to the working chamber, so that the liquid in the working chamber is output to the cooling circuit through the liquid outlet of the working chamber. Alternatively, after the hydraulic retarder stops braking, the control module 370 is further configured to, when the actual working pressure of the working chamber is greater than or equal to a first preset pressure, disconnect the connection between the liquid inlet of the working chamber and the cooling circuit; and disconnect the transmission connection between the retarder's retarding rotor and the power output end via a clutch.

[0190] In some embodiments, the control module 370 is further configured to control the gas supply mechanism to extract gas from the working chamber when the difference between the actual working pressure of the working chamber and the pressure of the cooling circuit is less than or equal to a preset difference; and to cut off the connection between the gas supply mechanism and the working chamber when the actual working pressure of the working chamber is less than or equal to a second preset pressure, wherein the second preset pressure is less than the first preset pressure.

[0191] Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working process of the above-described device and module can be referred to the corresponding process in the foregoing method embodiments, and will not be repeated here.

[0192] In the several embodiments provided in this application, the coupling or direct coupling or communication connection between the modules shown or discussed may be an indirect coupling or communication connection through some interface, device or module, and may be electrical, mechanical or other forms.

[0193] Furthermore, the functional modules in the various embodiments of this application can be integrated into one processing module, or each module can exist physically separately, or two or more modules can be integrated into one module. The integrated modules described above can be implemented in hardware or as software functional modules. Please refer to... Figure 13 Based on the aforementioned drive assembly control device 300 and drive assembly control method, this application embodiment also provides an electronic device 500, which may include a processor 510 and a memory 520. The memory 520 is used to store computer programs; the processor 510 is used to execute the computer programs stored in the memory 520. One or more computer programs are stored in the memory 520 and configured to be executed by one or more processors 510, and the one or more computer programs are configured to perform the methods described in the above embodiments.

[0194] The processor 510 may include one or more processing cores. The processor 510 connects to various parts of the entire battery management system using various interfaces and lines, and performs various functions and processes data of the battery management system by running or executing instructions, programs, code sets, or instruction sets stored in the memory 520, and by calling data stored in the memory 520. Optionally, the processor 510 may be implemented using at least one hardware form of Digital Signal Processing (DSP), Field-Programmable Gate Array (FPGA), or Programmable Logic Array (PLA). The processor 510 may integrate one or more of the following: a Central Processing Unit (CPU), a Graphics Processing Unit (GPU), and a modem. The CPU primarily handles the operating system, user interface, and computer programs; the GPU is responsible for rendering and drawing the displayed content; and the modem handles wireless communication. It is understood that the modem may also not be integrated into the processor 510 and may be implemented separately using a communication chip.

[0195] The memory 520 may include random access memory (RAM) or read-only memory (ROM). The memory 520 can be used to store instructions, programs, code, code sets, or instruction sets. The memory 520 may include a program storage area and a data storage area. The program storage area may store instructions for implementing an operating system, instructions for implementing at least one function (e.g., touch functionality, sound playback functionality, image playback functionality, etc.), and instructions for implementing the various method embodiments described above. The data storage area may also store data created during use of the drive assembly diagram (e.g., phonebook, audio / video data, chat log data, etc.).

[0196] This application also provides a transport vehicle, which includes the aforementioned electronic device 500 and / or the drive assembly 100 provided in any of the above embodiments. The transport vehicle may also include hardware such as a vehicle body, chassis, and driving system. The electronic device 500 is disposed within the vehicle body and may be the vehicle's central controller.

[0197] This application also provides a computer-readable storage medium storing computer program instructions that can be invoked by a processor to execute the methods described in the above embodiments.

[0198] Computer-readable storage media can be, for example, flash memory, electrically erasable programmable read-only memory (EEPROM), electrically programmable read-only memory (EPROM), hard disk, or read-only memory (ROM). Optionally, computer-readable storage media includes non-transitory computer-readable storage medium. The computer-readable storage medium has storage space for computer program instructions that perform any of the method steps described above. These computer program instructions can be read from or written to one or more computer program products.

[0199] In this application, "multiple" refers to two or more.

[0200] Those skilled in the art will understand that all or part of the steps of the methods described in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium. When executed, the program includes one or a combination of the steps of the method embodiments. Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0201] The storage medium mentioned above can be a read-only memory, a disk, or an optical disk, etc. Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions, and variations to the above embodiments within the scope of this application.

[0202] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0203] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

Claims

1. A drive assembly, characterized in that, include: A drive device having an output shaft; A differential device, wherein the input end of the differential device is connected to the output shaft; The transmission device is connected to the output end of the differential device. as well as A hydraulic retarder, comprising a retarding stator and a retarding rotor, wherein the retarding stator is fixedly disposed and the retarding rotor is tractively connected to the transmission device, wherein the hydraulic retarder is located on the output side of the differential device in the power transmission path of the drive assembly.

2. The drive assembly as described in claim 1, characterized in that, The drive assembly also includes a switching device, which is configured in conjunction with the hydraulic retarder and is used to drive the hydraulic retarder to switch between an operating state and an inactive state; in the operating state, the hydraulic retarder has a slowing braking capability to slow down the power output by the transmission device. In the non-operating state, the slowing and braking capacity of the hydraulic retarder is less than that in the operating state.

3. The drive assembly as described in claim 2, characterized in that, The switching device includes a clutch for selectively engaging or disengaging the retarder rotor from the transmission device, thereby switching the hydraulic retarder between the operating state and the non-operating state.

4. The drive assembly as described in claim 2, characterized in that, The switching device includes an air pump and a gas pipeline. The air pump is connected to the working chamber of the hydraulic retarder through the gas pipeline and is used to input gas into the working chamber to discharge the working fluid in the working chamber, thereby putting the hydraulic retarder in the non-working state. The switching device also includes a reversing valve connected in series on the gas pipeline.

5. The drive assembly as described in claim 1, characterized in that, The drive assembly also includes: A control device is electrically connected to the drive device, and the control device is provided with a heat dissipation channel; A cooling device, wherein the cooling device is provided with a cooling circuit, and the heat dissipation channel is disposed on the cooling circuit; and A connecting device is provided between the working chamber of the hydraulic retarder and the cooling circuit, so that the working chamber can be selectively connected to the cooling circuit.

6. The drive assembly as described in claim 5, characterized in that, The working chamber has a liquid inlet and a liquid outlet. The cooling device includes a control valve connected in series in the cooling circuit. The connecting device includes an input pipe and an output pipe. The input pipe is connected between the control valve and the liquid inlet. The output pipe is connected between the control valve and the liquid outlet. The working chamber can be selectively connected to the cooling circuit via the input pipe, the output pipe, and the control valve.

7. The drive assembly as described in claim 6, characterized in that, The connecting device further includes a one-way valve and a throttle valve disposed on the output pipe, wherein the throttle valve is located between the one-way valve and the liquid outlet, and the throttle valve is located on the input side of the one-way valve.

8. The drive assembly as described in claim 7, characterized in that, The communication device further includes a first pressure sensor and a second pressure sensor disposed in the output pipe. The first pressure sensor is located between the throttle valve and the liquid outlet, and the second pressure sensor is located on the output side of the one-way valve.

9. The drive assembly as described in claim 6, characterized in that, The cooling device further includes a first pipe and a second pipe, the first pipe, the control valve, and the second pipe are connected in series to form the cooling circuit, and the control device is located in the first pipe; The control valve has an inlet, a first outlet, and a second outlet. The first pipeline is connected to the inlet, the second pipeline is connected to the first outlet, and the output pipeline is connected to the second pipeline. The input pipe is connected to the second outlet, and the control valve is used to selectively connect the inlet to either the first outlet or the second outlet.

10. The drive assembly as described in claim 9, characterized in that, The cooling device further includes a liquid pump, a heat dissipation mechanism, and a heat exchanger installed in the first pipeline, wherein the heat dissipation mechanism, the liquid pump, the heat dissipation channel, and the heat exchanger are connected in series.

11. The drive assembly as claimed in claim 1, characterized in that, The drive device includes an electric motor, which includes a motor stator and a motor rotor. The motor rotor is located at the end of the motor stator along its axial direction, and the output shaft is connected to the motor rotor.

12. The drive assembly as described in claim 11, characterized in that, The output shaft has a mounting cavity, and the differential device is disposed within the mounting cavity.

13. The drive assembly as described in claim 11, characterized in that, The motor has two rotors, which are located at both ends of the motor stator and are coaxially arranged with the motor stator. The differential device includes two differential mechanisms, each of which includes a central wheel and a transmission wheel that mesh with each other, and the transmission wheels of the two differential mechanisms are respectively connected to the two motor rotors for transmission. The transmission device includes two transmission mechanisms, which are respectively connected to the center wheels of the two differential mechanisms.

14. The drive assembly as described in claim 13, characterized in that, The hydraulic retarder is of two types, and the two hydraulic retarders are respectively connected to the output side of the two transmission mechanisms. The two hydraulic retarders are respectively used to connect the wheel half-axles on both sides of the same axle of the transport vehicle.

15. The drive assembly as described in claim 14, characterized in that, The drive assembly further includes a housing, in which the hydraulic retarder, the differential device, the drive device, and the transmission device are respectively disposed; the two hydraulic retarders are symmetrically distributed on both sides of the drive device.

16. The drive assembly as claimed in claim 13, characterized in that, The transmission mechanism includes: The sun gear is coaxially connected to the corresponding central gear. The planetary gears are fed in and engage with the sun gear. The output planetary gear is coaxially connected to the input planetary gear. The gear ring meshes with and is fixedly disposed with the output planetary gear; A planetary carrier, rotatably connected to the output planetary gears and to the decelerating rotor, is used to output power through the decelerating rotor to the wheel axles connected to the transport vehicle.

17. A control method for a drive assembly, characterized in that, Applied to the drive assembly as described in claim 1, the method includes: Obtain braking torque requirements; Obtain the maximum torque of regenerative braking and the maximum braking torque of the hydraulic retarder; Based on the braking torque demand, the maximum regenerative braking torque, and the maximum braking torque of the hydraulic retarder, a braking strategy is determined according to a preset braking execution priority. The braking execution priority is used to characterize the order in which the braking torque demand is allocated to the regenerative braking device, the hydraulic retarder, and the mechanical braking device. According to the determined braking strategy, at least one of the regenerative braking device, the hydraulic retarder, and the mechanical braking device is controlled to execute the braking strategy.

18. The method as described in claim 17, characterized in that, The braking strategy determined based on the braking torque demand, the maximum regenerative braking torque, and the maximum braking torque of the hydraulic retarder, according to a preset braking execution priority, includes: When the maximum regenerative braking torque is greater than or equal to the braking torque requirement, the braking strategy is determined to be: to allocate the braking torque requirement to the regenerative braking device, and to have the regenerative braking device perform braking. When the braking torque demand is greater than the maximum regenerative braking torque, and the difference between the braking torque demand and the maximum regenerative braking torque is less than or equal to the maximum braking torque of the hydraulic retarder, the braking strategy is determined as follows: the braking torque demand is sequentially distributed to the regenerative braking device and the hydraulic retarder, and the regenerative braking device and the hydraulic retarder jointly perform braking. When the braking torque demand is greater than the sum of the maximum regenerative braking torque and the maximum braking torque of the hydraulic retarder, the braking strategy is determined as follows: the braking torque demand is sequentially distributed to the regenerative braking device, the hydraulic retarder, and the mechanical braking device, and the braking is jointly performed by the regenerative braking device, the hydraulic retarder, and the mechanical braking device.

19. The method as described in claim 17, characterized in that, The drive assembly includes a cooling circuit, and the working chamber of the hydraulic retarder is connected in parallel to the cooling circuit via a control valve. The control valve is used to change the connection state between the working chamber and the cooling circuit. The process of controlling the hydraulic retarder to execute the braking strategy includes: Based on the maximum regenerative braking torque and the braking torque requirement, the target retarding torque of the hydraulic retarder is determined. Based on the control valve, the working chamber is connected to the cooling circuit; Based on the target slowing torque, the target working pressure of the working chamber is determined; The operation of the liquid pump in the cooling circuit is controlled according to the target working pressure.

20. The method as described in claim 19, characterized in that, The step of controlling the operation of the liquid pump in the cooling circuit according to the target working pressure includes: The actual working pressure of the working chamber is obtained in real time; Based on the target working pressure and the actual working pressure, the liquid pump in the cooling circuit is controlled to maintain the difference between the actual working pressure and the target working pressure within a preset range.

21. The method as described in claim 19, characterized in that, The hydraulic retarder is equipped with an air supply mechanism connected to the working chamber; After the working chamber is connected to the cooling circuit based on the control valve, the connection between the air supply mechanism and the working chamber is cut off.

22. The method as described in claim 21, characterized in that, The method further includes: If the actual working pressure of the working chamber is greater than or equal to the first preset pressure, the connection between the liquid inlet of the working chamber and the cooling circuit is cut off. The gas supply mechanism is controlled to deliver gas to the working chamber, so that the liquid in the working chamber is output to the cooling circuit through the liquid outlet of the working chamber.

23. The method as described in claim 22, characterized in that, The method further includes: When the difference between the actual working pressure of the working chamber and the pressure of the cooling circuit is less than or equal to a preset difference, the gas supply mechanism is controlled to extract gas from the working chamber. When the actual working pressure of the working chamber is less than or equal to the second preset pressure, the connection between the gas supply mechanism and the working chamber is cut off, wherein the second preset pressure is less than the first preset pressure.

24. The method as described in claim 19, characterized in that, The drive assembly further includes a clutch; the method further includes: If the actual working pressure of the working chamber is greater than or equal to the first preset pressure, the connection between the liquid inlet of the working chamber and the cooling circuit is cut off. The clutch disconnects the transmission connection between the retarding rotor of the hydraulic retarder and the power output end.

25. An electronic device, characterized in that, include: Memory, used to store computer programs; A processor for executing a computer program stored in memory, the computer program being configured to perform the method as described in any one of claims 17 to 24.

26. A transport vehicle, characterized in that, Includes the electronic device of claim 25 and / or includes the drive assembly of any one of claims 1 to 16.

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