Parallel dual electric drive axle assembly, driving method, and vehicle

Abstract

The present invention relates to the technical field of electric drive for commercial vehicles, and provides a parallel dual electric drive axle system, a driving method, and a vehicle. The parallel dual electric drive axle system comprises a middle electric drive axle and a rear electric drive axle; the middle electric drive axle comprises a first speed reduction mechanism and a second speed reduction mechanism arranged on a middle-axle wheel shaft; the first speed reduction mechanism is connected to a first motor, and the second speed reduction mechanism is connected to a second motor; the second speed reduction mechanism comprises a unidirectional driving device; the rear electric drive axle comprises a third speed reduction mechanism and a fourth speed reduction mechanism arranged on a rear-axle wheel shaft; the third speed reduction mechanism is connected to a third motor, and the fourth speed reduction mechanism is connected to a fourth motor; and the fourth speed reduction mechanism comprises a disconnection device. In the present invention, on the basis of the middle electric drive axle provided with a speed reduction mechanism having a unidirectional driving function and the rear electric drive axle having a disconnection function, by configuring the speed ratios of the speed reduction mechanisms and the external characteristics of the motors, driving functions for the vehicle under multiple operating conditions and scenarios, including low speed / high speed and heavy load / light load, can be achieved.

Description

Dual electric drive axle, driving method and vehicle TECHNICAL FIELD

[0001] The present application belongs to the technical field of electric drive of commercial vehicles, and particularly relates to a dual electric drive axle, a driving method and a vehicle. BACKGROUND

[0002] The electric drive axle is one of the feasible routes to realize the electrification of vehicles, and helps to achieve the goals of integration, high efficiency and light weight of vehicles. The transmission configuration and driving method of the electric drive axle are the structural basis and technical support for realizing the high efficiency of vehicles. For the electric drive axle of commercial vehicles, especially the electric drive axle of heavy commercial vehicles, since it generally adopts a dual electric drive axle to realize the high load bearing requirement of the vehicle, it provides more possibilities and greater difficulty for the configuration and driving method of the electric drive axle.

[0003] At present, the dual electric drive axle is generally composed of the same configuration of the electric drive axle of the middle axle and the electric drive axle of the rear axle, and the same torque is evenly output during driving. Such configuration and driving method cannot guarantee that the electric drive axle works in the high efficiency zone, and has the characteristics of low system efficiency and large vehicle power consumption. For example, a dual electric drive axle driving mechanism with the publication number CN11605024A adopts a single-speed electric drive axle for the electric drive axle of the middle axle and a multi-gear electric drive axle for the electric drive axle of the rear axle, aiming to improve the scene adaptability and the large overall power consumption caused by the parallel arrangement of the dual electric drive axle. For another example, a dual axle electric drive axle cooperative control method with the publication number CN116587880A obtains the optimal torque distribution ratio of the dual axle electric drive axle through experiments, and then realizes the economy of the dual axle electric drive axle through the torque distribution between the dual axle electric drive axle. Both of the above-mentioned schemes take the difference configuration between the two electric drive axles and the torque distribution between the two electric drive axles as the control object to realize, without configuring the electric drive axle from the global perspective, and the optimization degree of the dual electric drive axle configuration is low, and the overall optimization of the power performance and the economy of the electric drive axle cannot be realized.

[0004] Therefore, it is necessary to provide a dual electric drive axle, a driving method and a vehicle in view of the above-mentioned defects in the prior art. SUMMARY

[0005] In view of the above-mentioned high load bearing requirement of the electric drive axle of the commercial vehicle, the present application provides a dual electric drive axle, a driving method and a vehicle to solve the above-mentioned technical problems.

[0006] In a first aspect, the present application provides a dual electric drive axle, comprising an electric drive axle of a middle axle and an electric drive axle of a rear axle.

[0007] The middle electric drive axle comprises a first reduction mechanism and a second reduction mechanism arranged on the middle axle wheel shaft;

[0008] The first reduction mechanism is connected with a first motor, and the second reduction mechanism is connected with a second motor;

[0009] The second reduction mechanism comprises a one-way drive device;

[0010] The rear electric drive axle comprises a third reduction mechanism and a fourth reduction mechanism arranged on the rear axle wheel shaft;

[0011] The third reduction mechanism is connected with a third motor, and the fourth reduction mechanism is connected with a fourth motor;

[0012] The fourth reduction mechanism comprises a cut-off connection device.

[0013] Further, the middle electric drive axle further comprises a first differential lock and a first differential;

[0014] The first differential lock, the first differential, the second reduction mechanism and the first reduction mechanism are sequentially arranged on the middle axle wheel shaft along the direction from the left middle axle wheel to the right middle axle wheel;

[0015] The rear electric drive axle further comprises a second differential lock and a second differential;

[0016] The second differential lock, the second differential, the fourth reduction mechanism and the third reduction mechanism are sequentially arranged on the rear axle wheel shaft along the direction from the left rear axle wheel to the right rear axle wheel.

[0017] Further, the second reduction mechanism further comprises a second gear set;

[0018] The second reduction mechanism is arranged on the middle axle wheel shaft through the second gear set and is connected with the first differential through the second gear set;

[0019] The one-way drive device is coaxially arranged with the output shaft of the second motor. The present application realizes the installation of the one-way drive device in a smaller space range and guarantees sufficient torque transmission capacity.

[0020] Further, the fourth reduction mechanism further comprises a fourth gear set;

[0021] The fourth reduction mechanism is arranged on the rear axle wheel shaft through the fourth gear set;

[0022] The cut-off connection device is coaxially arranged with the rear axle wheel shaft and is arranged between the second differential and the fourth gear set. The present application disconnects more gear transmission mechanisms to reduce more drag losses by disconnecting the fourth motor connection through the cut-off connection device when the vehicle speed increases.

[0023] Further, the disconnecting device adopts a dog clutch.

[0024] The speed ratio of the first, second and third reduction mechanisms is greater than 10 and less than 30.

[0025] The speed ratio of the fourth reduction mechanism is greater than 40 and less than 80. The dog clutch realizes reliable power connection and disconnection function at a low cost.

[0026] The first and third reduction mechanisms realize the cruise driving function of the vehicle, the second reduction mechanism realizes the acceleration function of the vehicle during the cruise process, and the fourth motor realizes the starting, large-angle climbing and other low-speed heavy-load driving functions of the vehicle.

[0027] In the second aspect, the application provides a driving method of a double electric drive axle, which is used for the double electric drive axle of the first aspect and includes the following steps:

[0028] S1. Obtain vehicle speed information and vehicle demand torque information;

[0029] S2. Determine the start-stop state of the disconnecting device in the fourth reduction mechanism and the driving state of the fourth motor according to the vehicle speed information;

[0030] S3. Determine the driving state of the second motor according to the vehicle demand torque information;

[0031] S4. Control the double electric drive axle according to the determined start-stop state of the disconnecting device, the driving state of the fourth motor and the driving state of the second motor.

[0032] Further, the step S2 includes the following steps:

[0033] S21. Determine the relationship between the vehicle speed and the vehicle speed threshold;

[0034] When the vehicle speed is less than or equal to the vehicle speed threshold, step S22 is entered;

[0035] When the vehicle speed is greater than the vehicle speed threshold, step S23 is entered;

[0036] S22. Determine that the disconnecting device in the fourth reduction mechanism of the vehicle does not work, and the fourth motor is in the driving state, and step S3 is entered;

[0037] S23. Determine that the disconnection device in the fourth deceleration mechanism of the vehicle needs to be activated, and the fourth motor is in a stopped state.

[0038] Further, the step S3 comprises the following steps:

[0039] S31. Determine the relationship between the vehicle demand torque and the torque threshold value;

[0040] When the vehicle demand torque is greater than the torque threshold value, proceed to step S32;

[0041] When the vehicle demand torque is less than or equal to the torque threshold value, proceed to step S33;

[0042] S32. Determine that the vehicle needs to be provided with driving torque, and the second motor is operated, and proceed to step S4;

[0043] S33. Determine that the vehicle does not need to be provided with driving torque, and the second motor is not operated.

[0044] Further, the vehicle speed threshold value is greater than 20 km / h and less than 30 km / h;

[0045] The torque threshold value is the output torque of the electric drive axle when the first motor and the third motor are operated at the current vehicle speed.

[0046] In a third aspect, the application provides a vehicle adopting the double electric drive axle of the first aspect.

[0047] The application has the following beneficial effects:

[0048] The double electric drive axle, the driving method and the vehicle provided by the application each have two motors and two deceleration mechanisms, each deceleration mechanism and the corresponding motor have their own functions, and the division of labor is clear, which has high efficiency and high power potential. Specifically, the middle axle electric drive axle and the rear axle electric drive axle are respectively configured with one deceleration mechanism in a long meshing state, which is used for normal driving of the vehicle such as cruising; the middle axle is further configured with one deceleration mechanism with one-way driving function, which is used for accelerating driving of the vehicle such as overtaking; and the rear axle is further configured with one deceleration mechanism with a disconnection function, which is used for low-speed heavy-load driving of the vehicle such as starting and climbing. Based on the above structure, by configuring the speed ratio of the deceleration mechanism and the motor external characteristic, the driving function of the vehicle in multiple working conditions and multiple scenes such as low speed / high speed and heavy load / light load can be realized, which is especially suitable for heavy commercial vehicles with complex application scenes and large load changes.

[0049] In addition, the design principle of the application is reliable, the structure is simple, and it has very wide application prospects.

[0050] As can be seen, compared with the prior art, the application has outstanding substantial characteristics and significant progress, and the beneficial effects of its implementation are also obvious. BRIEF DESCRIPTION OF DRAWINGS

[0051] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the accompanying drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows. Obviously, for those of ordinary skill in the art, other drawings can also be obtained based on these drawings without any creative effort.

[0052] Fig. 1 is a schematic diagram of one embodiment of the double electric drive axle of the present application.

[0053] Fig. 2 is a schematic diagram of another embodiment of the double electric drive axle of the present application.

[0054] Fig. 3 is a flowchart of one embodiment of the driving method of the double electric drive axle of the present application.

[0055] Fig. 4 is a flowchart of another embodiment of the driving method of the double electric drive axle of the present application.

[0056] Main reference sign explanation

[0057] A1 - middle axle electric drive axle, 1 - first motor, 2 - first reduction mechanism, 3 - second reduction mechanism, 3-1 - one-way drive device, 3-2 - second gear set, 4 - second motor, 5 - first differential, 6 - first differential lock, 7-1 - middle axle left wheel, 7-2 - middle axle right wheel, 8 - first reducer, 9 - second reducer; A2 - rear axle electric drive axle, 10 - third motor, 20 - third reduction mechanism, 30 - fourth reduction mechanism, 30-1 - fourth gear set, 30-2 - disconnecting device, 40 - fourth motor, 50 - second differential, 60 - second differential lock, 70-1 - rear axle left wheel, 70-2 - rear axle right wheel, 80 - third reducer, 90 - fourth reducer. DETAILED DESCRIPTION

[0058] The technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those of ordinary skill in the art without any creative effort should belong to the scope of protection of the present application.

[0059] The double electric drive axle, driving method and vehicle provided by the present application improve the system power, driving efficiency and reduce the energy consumption of the whole vehicle by configuring the speed ratio, gear position and disconnecting device of the reduction mechanism corresponding to each motor of the double electric drive axle on the basis of meeting the driving demand of the vehicle.

[0060] The double electric drive axle and the driving method can be applied to a vehicle, and the vehicle can be a commercial vehicle, such as a heavy commercial vehicle with a complex application scene and a large load variation, such as a 6x4, 8x4, etc.

[0061] Referring to FIG. 1, a double electric drive axle in an embodiment is shown, including a middle axle electric drive axle A1 and a rear axle electric drive axle A2;

[0062] The middle axle electric drive axle A1 includes a first reduction mechanism 2 and a second reduction mechanism 3 arranged on a middle axle wheel shaft;

[0063] The first reduction mechanism 2 is connected with a first motor 1, and the second reduction mechanism 3 is connected with a second motor 4;

[0064] The second reduction mechanism 3 includes a one-way drive device 3-1;

[0065] The rear axle electric drive axle A2 includes a third reduction mechanism 20 and a fourth reduction mechanism 30 arranged on a rear axle wheel shaft;

[0066] The third reduction mechanism 20 is connected with a third motor 10, and the fourth reduction mechanism 30 is connected with a fourth motor 40;

[0067] The fourth reduction mechanism 30 includes a cut-off connection device 30-2;

[0068] The middle axle electric drive axle further includes a first differential lock 6 and a first differential 5;

[0069] The first differential lock 6, the first differential 5, the second reduction mechanism 3, and the first reduction mechanism 2 are sequentially arranged on the middle axle wheel shaft along a direction from a middle axle left wheel 7-1 to a middle axle right wheel 7-2;

[0070] The rear axle electric drive axle further includes a second differential lock 60 and a second differential 50;

[0071] The second differential lock 60, the second differential 50, the fourth reduction mechanism 30, and the third reduction mechanism 20 are sequentially arranged on the rear axle wheel shaft along a direction from a rear axle left wheel 70-1 to a rear axle right wheel 70-2;

[0072] The second reduction mechanism 3 further includes a second gear set 3-2;

[0073] The second reduction mechanism 3 is arranged on the middle axle wheel shaft through the second gear set 3-2 and connected with the first differential 5 through the second gear set 3-2;

[0074] The one-way drive device 3-1 is coaxially arranged with an output shaft of the second motor 4;

[0075] The fourth reduction mechanism 30 further includes a fourth gear set 30-1;

[0076] The fourth reduction mechanism 30 is arranged on the rear axle through a fourth gear set 30-1;

[0077] The cut-off connection device 30-2 is arranged coaxially with the rear axle and between the second differential 50 and the fourth gear set 30-1.

[0078] The double electric drive axle of the present application can realize the normal driving function of the vehicle through the first reduction mechanism 2 and the third reduction mechanism 20; the second reduction mechanism 3 with one-way driving can realize the driving torque increase of the vehicle without the shifting process, and can realize the fast and non-impact torque increase, and is automatically disconnected when the second motor 4 is not working, thereby reducing the drag loss; the fourth reduction mechanism 30 has two states of being in gear and being in neutral, and is switched to the neutral state when the fourth motor 40 is not working, thereby reducing the drag loss. The present application lays a structural foundation for realizing the high power and economy of the vehicle based on the speed ratio, gear position and disconnection mechanism of the double electric drive axle reduction mechanism.

[0079] Different from the above embodiments, as shown in FIG. 2, the output shaft of the first motor 1 is further provided with a first reducer 8, the output shaft of the second motor 4 is further provided with a second reducer 9, the output shaft of the third motor 10 is further provided with a third reducer 80, and the output shaft of the fourth motor 40 is further provided with a fourth reducer 90.

[0080] In some embodiments, the cut-off connection device 30-2 adopts a dog clutch;

[0081] The speed ratio of the first reduction mechanism 2, the second reduction mechanism 3 and the third reduction mechanism 20 is greater than 10 and less than 30;

[0082] The speed ratio of the fourth reduction mechanism 30 is greater than 40 and less than 80. The fourth reduction mechanism has the largest speed ratio, and is suitable for the large torque output scene such as starting and climbing; the first reduction mechanism and the second reduction mechanism have smaller speed ratios, and are suitable for the cruising scene; the third reduction mechanism also has a smaller speed ratio, and is suitable for the overtaking and accelerating scene in the cruising process.

[0083] It should be understood that the size of the serial number of each step in the above embodiments does not mean the execution order of the processes, and the execution order should be determined according to the function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0084] The following is an embodiment of a driving method of the double electric drive axle provided by the present disclosure. The driving method belongs to the same inventive concept as the double electric drive axle of each of the above embodiments. Details not described in the embodiment of the driving method of the double electric drive axle can be referred to the above embodiments of the double electric drive axle.

[0085] As shown in FIG. 3, the method comprises the following steps:

[0086] S1. obtaining vehicle speed information and vehicle demand torque information;

[0087] S2. determining the start-stop state of the disconnecting device in the fourth reduction mechanism of the vehicle and the driving state of the fourth motor according to the vehicle speed information;

[0088] S3. determining the driving state of the second motor according to the vehicle demand torque information;

[0089] S4. controlling the dual-motor electric drive axle according to the determined start-stop state of the disconnecting device, the driving state of the fourth motor and the driving state of the second motor.

[0090] In the embodiment, as shown in FIG. 4, the specific steps of step S2 are as follows:

[0091] S21. judging the relationship between the vehicle speed and the vehicle speed threshold value;

[0092] When the vehicle speed ≤ the vehicle speed threshold value, step S22 is entered;

[0093] When the vehicle speed > the vehicle speed threshold value, step S23 is entered;

[0094] S22. determining that the disconnecting device in the fourth reduction mechanism of the vehicle needs to be inoperative, and the fourth motor needs to be in the driving state, and then entering step S3;

[0095] S23. determining that the disconnecting device in the fourth reduction mechanism of the vehicle needs to be in operation, and the fourth motor needs to be in the stop state;

[0096] The specific steps of step S3 are as follows:

[0097] S31. judging the relationship between the vehicle demand torque and the torque threshold value;

[0098] When the vehicle demand torque > the torque threshold value, step S32 is entered;

[0099] When the vehicle demand torque ≤ the torque threshold value, step S33 is entered;

[0100] S32. determining that the driving torque needs to be provided for the vehicle, and the second motor needs to be in operation, and then entering step S4;

[0101] S33. determining that the driving torque does not need to be provided for the vehicle, and the second motor does not need to be in operation.

[0102] In some embodiments, the vehicle speed threshold value is greater than 20 km / h and less than 30 km / h;

[0103] The torque threshold value is the output torque of the electric drive axle when the first motor and the third motor are in operation at the current vehicle speed.

[0104] The driving method of the double electric drive axle of the application realizes basic control of four motors of the double electric drive axle based on vehicle speed information and vehicle demand torque information.

[0105] Although the present application has been described in detail with reference to the preferred embodiments, it should be understood that the application is not limited to those preferred embodiments. Without departing from the spirit and essential characteristics of the application, one of ordinary skill can make other variations and modifications after having studied the disclosure. Any variations and modifications based on the technical concept disclosed in the present application should be considered as falling within the scope of the application.

Claims

1. A twin electric drive axle characterized in that, The middle axle electric drive axle and the rear axle electric drive axle are included; The middle axle electric drive axle includes a first reduction mechanism and a second reduction mechanism arranged on the middle axle wheel shaft; The first reduction mechanism is connected with a first motor, and the second reduction mechanism is connected with a second motor; The second reduction mechanism includes a one-way drive device; The rear axle electric drive axle includes a third reduction mechanism and a fourth reduction mechanism arranged on the rear axle wheel shaft; The third reduction mechanism is connected with a third motor, and the fourth reduction mechanism is connected with a fourth motor; The fourth reduction mechanism includes a cut-off connection device.

2. The twin electric drive axle of claim 1, wherein, The middle axle electric drive axle further includes a first differential lock and a first differential; The first differential lock, the first differential, the second reduction mechanism, and the first reduction mechanism are sequentially arranged on the middle axle wheel shaft along a direction from the middle axle left wheel to the middle axle right wheel; The rear axle electric drive axle further includes a second differential lock and a second differential; The second differential lock, the second differential, the fourth reduction mechanism, and the third reduction mechanism are sequentially arranged on the rear axle wheel shaft along a direction from the rear axle left wheel to the rear axle right wheel.

3. The twin electric drive axle of claim 2, wherein, The second reduction mechanism further includes a second gear set; The second reduction mechanism is arranged on the middle axle wheel shaft through the second gear set and is connected with the first differential through the second gear set; The one-way drive device is coaxially arranged with the output shaft of the second motor.

4. The twin electric drive axle of claim 2, wherein, The fourth reduction mechanism further includes a fourth gear set; The fourth reduction mechanism is arranged on the rear axle wheel shaft through the fourth gear set; The cut-off connection device is coaxially arranged with the rear axle wheel shaft and is arranged between the second differential and the fourth gear set.

5. The twin electric drive axle of claim 1, wherein, The output shaft of the first motor is further provided with a first reducer, the output shaft of the second motor is further provided with a second reducer, the output shaft of the third motor is further provided with a third reducer, and the output shaft of the fourth motor is further provided with a fourth reducer.

6. A method of driving a twin electric drive axle, characterized in that The double electric drive axle according to any one of claims 1-5, comprising the following steps: S1. obtaining vehicle speed information and vehicle demand torque information; S2. determining the start-stop state of the cut-off connection device in the fourth reduction mechanism of the vehicle and the driving state of the fourth motor according to the vehicle speed information; S3. determining the driving state of the second motor according to the vehicle demand torque information; S4. controlling the double electric drive axle according to the determined start-stop state of the cut-off connection device, the driving state of the fourth motor, and the driving state of the second motor.

7. The driving method of a twin axle electric drive axle according to claim 6, characterized in that, The specific steps of step S2 are as follows: S21. judging the relationship between the vehicle speed and the vehicle speed threshold value; When the vehicle speed ≤ the vehicle speed threshold value, step S22 is entered; When the vehicle speed > the vehicle speed threshold value, step S23 is entered; S22. determining that the cut-off connection device in the fourth reduction mechanism of the vehicle needs to be disabled, and the fourth motor is in a driving state, and entering step S3; S23. determining that the cut-off connection device in the fourth reduction mechanism of the vehicle needs to be enabled, and the fourth motor is in a stop state.

8. The driving method of a twin axle electric drive axle according to claim 7, characterized in that, The specific steps of step S3 are as follows: S31. judging the relationship between the vehicle demand torque and the torque threshold value; When the vehicle demand torque > the torque threshold value, step S32 is entered; When the vehicle demand torque ≤ the torque threshold value, step S33 is entered; S32. determining that driving torque needs to be provided for the vehicle, and the second motor is working, and entering step S4; S33. determining that driving torque does not need to be provided for the vehicle, and the second motor is not working.

9. The driving method of a twin axle electric drive axle according to claim 8, characterized in that, the vehicle speed threshold is greater than 20 km / h and less than 30 km / h; the torque threshold is the output torque of the electric drive axle when the first electric machine and the third electric machine are working at a constant torque at the current vehicle speed.

10. A vehicle characterized by comprising: The double electric drive axle of any of claims 1-5.

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