Double-electric-drive-axle system of new energy commercial vehicle

Abstract

The invention discloses a new energy commercial vehicle double-electric-drive-axle system which comprises two independent electric drive axle units including an axle A and an axle B which are arranged on a front axle and / or a rear axle of a vehicle respectively. The unified control unit is in communication connection with the two electric drive bridge units; the unified control unit is configured as follows: a) the driving power of each electric drive bridge unit is dynamically distributed; b) coordinating the rotating speed and torque output of the two electric drive axle units; and c) switching to a redundant drive mode when a single electric drive bridge unit fails. The invention aims to optimize the improvement of the safety, the dynamic property and the practicability of the new energy commercial vehicle.

Description

Technical Field

[0001] The present invention relates to the technical field of electric vehicles, and in particular to a dual electric drive axle system for new energy commercial vehicles. Background Art

[0002] When the drive motor provides power torque to pure electric commercial vehicles, the single-drive motor is combined with the axle to form a dual-drive device. In the actual situation of providing power, the single-drive device of medium and heavy trucks will have a large load on the single-drive motor, energy consumption in power distribution, savings in transmission capacity efficiency, loss rate of transmission efficiency in multi-drive, and single-core problem of the single-drive motor (that is, when the drive motor fails, the whole vehicle will be at a standstill. If the motor failure problem is not resolved, the vehicle supported by the drive motor will have many functions unusable. The drive failure is also a core failure in a series of vehicle failures, so the drive motor also needs to be optimized). In dealing with this problem, the entire vehicle is faulty, especially when the vehicle is performing engineering operations. Drive problems will cause a series of uncontrollable events in the vehicle.

[0003] Most of the commercial vehicles in the existing technology are of a single drive module. Therefore, when a vehicle has a drive failure problem, if the drive motor fails while the vehicle is driving, it will cause uncontrollable situations in the vehicle's driving process (for example, the drive motor fails at high speed and suddenly stops working and braking. Losing power at high speed means that the accident rate increases significantly). There is a chance that the vehicle will be insufficiently powered during operation, and it is not uncommon for commercial vehicles to be overloaded and overweight during cargo operations. At this time, power is very important. Summary of the Invention

[0004] The purpose of the present invention is to provide a dual electric drive axle system for new energy commercial vehicles in order to solve the technical problems existing in the background technology.

[0005] In order to achieve the above object, the present invention adopts the following technical solutions:

[0006] A dual electric drive axle system for new energy commercial vehicles, comprising:

[0007] Two independent electric drive axle units include A-bridge and B-bridge, which are respectively configured on the front axle and / or rear axle of the vehicle;

[0008] a unified control unit, communicatively connected to the two electric drive axle units;

[0009] The unified control unit is configured to:

[0010] a) Dynamically distribute the driving power of each electric drive axle unit;

[0011] b) Coordinate the speed and torque output of the two electric drive axle units;

[0012] c) Switch to redundant drive mode when a single electric drive axle unit fails.

[0013] In some embodiments, the two electric drive axle units are both arranged on the rear axle of the vehicle to form a dual rear drive axle structure;

[0014] Each electric drive axle unit is connected to the wheels through a rigid shaft, and a mechanical differential D1 is set between the two bridges to achieve wheel speed balance.

[0015] In some embodiments, the two electric drive axle units are both arranged on the front axle of the vehicle to form a dual front drive axle structure;

[0016] The output end of each electric drive axle unit is connected to the steering hub through a universal joint.

[0017] In some embodiments, the two electric drive axle units are respectively arranged on the front axle and the rear axle of the vehicle to form an all-wheel drive structure;

[0018] The mechanical transmission shaft between the front electric drive axle unit A bridge and the rear electric drive axle unit B bridge is eliminated, and electronic coupling is achieved through the unified control unit.

[0019] In some embodiments, for light truck models, the power ratio of the front electric drive axle unit to the rear electric drive axle unit is 1:(1.2-1.5);

[0020] For medium and heavy truck models, the rear electric drive axle unit is additionally equipped with an auxiliary power coupler.

[0021] In some embodiments, the unified control unit achieves wheel speed coordination by:

[0022] A speed sensor is provided at the output end of each electric drive axle unit;

[0023] The electronic differential coefficient K between the two bridges is adjusted in real time based on sensor data, and the value of K is (0.8-1.2).

[0024] In some embodiments, the two electric drive axle units adopt a master-slave drive mode:

[0025] The main drive unit A bridge provides basic power, which is defined as ≥70% of the total power;

[0026] The auxiliary drive unit B-axle is connected to the main drive unit via a hydraulic coupler;

[0027] The unified control unit activates the auxiliary drive unit during rapid acceleration or when climbing a slope.

[0028] The beneficial effects that may be brought about by the dual electric drive axle system for new energy commercial vehicles disclosed in this application include but are not limited to:

[0029] The present invention discloses a structural arrangement of dual motors for a new energy commercial vehicle, aiming to optimize the safety, power and practicality of the new energy commercial vehicle. The dual electric drive axle means that there are two drive cores to provide power for vehicle driving, and the power of the vehicle is greatly improved. The dual electric drive axle will save a certain amount of time and cost in the arrangement and assembly of the motors, optimize the applicability of the electric drive axle, and optimize the power recovery function of the dual electric drive axle, so that the kinetic energy recovery capability of the commercial vehicle is also improved to a certain extent. The improvement of the kinetic energy recovery capability will also improve the vehicle's endurance performance. At the same time, the arrangement of the dual electric drive axle is also of reference significance and has reference value for the realization of the concept of the N electric drive axle. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 Schematic diagram of the front drive of two electric drive axle units in this embodiment;

[0031] Figure 2 This is a schematic diagram of the rear-mounted two electric drive axle units in this embodiment;

[0032] Figure 3 This is a schematic diagram of the front and rear dual placement of two electric drive axle units in this embodiment. DETAILED DESCRIPTION

[0033] In order to make the purpose, technical solutions and advantages of this application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain this application and are not intended to limit this application.

[0034] On the contrary, this application covers any alternatives, modifications, equivalents, and solutions made within the spirit and scope of this application as defined by the claims. Furthermore, to facilitate a better understanding of this application, certain specific details are described in detail below in the detailed description of this application. Those skilled in the art will be able to fully understand this application without these details.

[0035] like Figure 1-3 As shown, a new energy commercial vehicle dual electric drive axle system includes:

[0036] Two independent electric drive axle units (A-bridge and B-bridge), respectively configured on the front and / or rear axles of the vehicle;

[0037] a unified control unit (MCU), communicatively connected to the two electric drive axle units;

[0038] The unified control unit is configured to: a) dynamically distribute the driving power of each electric drive axle unit; b) coordinate the speed and torque output of the two electric drive axle units; c) switch to redundant drive mode when a single electric drive axle unit fails.

[0039] In some embodiments, the two electric drive axle units are both arranged on the rear axle of the vehicle to form a dual rear drive axle structure; each electric drive axle unit is connected to the wheels through a rigid shaft, and a mechanical differential (D1) is provided between the two axles to achieve wheel speed balance.

[0040] In some embodiments, the two electric drive axle units are both arranged on the front axle of the vehicle to form a dual front drive axle structure; the output end of each electric drive axle unit is connected to the steering hub through a universal joint (UJ).

[0041] In some embodiments, the two electric drive axle units are respectively arranged on the front axle and rear axle of the vehicle to form an all-wheel drive structure; the mechanical transmission shaft is eliminated between the front electric drive axle unit (A bridge) and the rear electric drive axle unit (B bridge), and electronic coupling is achieved through the unified control unit.

[0042] In some embodiments, for a light truck model (4×4), the power ratio of the front electric drive axle unit to the rear electric drive axle unit is 1:(1.2-1.5);

[0043] For medium and heavy truck models (6×4 / 8×4), the rear electric drive axle unit is additionally equipped with an auxiliary power coupler (CP).

[0044] In some embodiments, the unified control unit achieves wheel speed coordination by:

[0045] A speed sensor (S1, S2) is set at the output end of each electric drive axle unit;

[0046] The electronic differential coefficient between the two bridges (K=0.8~1.2) is adjusted in real time based on sensor data.

[0047] In some embodiments, the two electric drive axle units adopt a master-slave drive mode:

[0048] The main drive unit (A bridge) provides basic power (≥70% of the total power);

[0049] The auxiliary drive unit (B-axle) is connected to the main drive unit via a hydraulic coupler (HC);

[0050] The unified control unit activates the auxiliary drive unit during rapid acceleration or when climbing a slope.

[0051] The commercial vehicle with dual electric drive axles is a way to optimize the drive device of new energy commercial vehicles. It is a way to redistribute the power demand: the required power is statistically calculated (for example, what operations need to be performed, how many tons of cargo need to be transported, the power that matches the environmental conditions during vehicle operation, the power that needs to be corrected after the operation, etc.). After the correction and distribution, the power of the motors of the dual electric drive axles is distributed. There are several ways to distribute the motor power:

[0052] A. Dual electric drive axle rear

[0053] For medium and heavy trucks, the drive mode has multiple rear drive shafts (such as 6×4 and 8×4 models), so as to improve the rear axle drive dual bridge to a dual electric drive bridge. The power distribution of the dual electric drive bridge can enable each bridge to have a separate drive device, so as to achieve improved driving capacity and improve the dynamic performance. The improvement in the power of new energy commercial vehicles will enhance the competitiveness of new energy commercial vehicles with traditional fuel vehicles in terms of power, thereby providing the necessary conditions for vehicle operations under harsh working conditions, so as to achieve performance optimization of new energy commercial vehicles.

[0054] The rear-mounted dual electric drive axle structure adopts a similar structure to the dual-motor power transmission systems currently available on the market. However, the dual electric drive axle and dual motor structure differ in layout. The dual motor drive essentially concentrates the driving force of the two motors, which are then coupled through a coupler for power transmission. The driving force of the dual motors can be integrated to produce performance equal to or greater than that of a single motor, but its applicability in a wide range of applications is far superior to that of a single motor. Given the same choice, the dual electric drive axle layout offers far greater applicability than a single motor or single electric drive axle, and there are two layout options for the dual electric drive axle:

[0055] The first is that each of the dual electric drive axles is used as a separate drive device. In the drive models (such as 6×4 and 8×4 models), the two rear axles are driven by single cores respectively. The dual single-core drive devices need to coordinate the single cores to make the MCU perform the same regulation on the single-core drive of the dual electric drive axle under the driving condition, so that the working conditions required by the dual single-core drive devices during the motor control process can be kept as consistent as possible, so that the speed of the vehicle's bridge drive and the final wheel speed are consistent, so as to achieve the speed balance required for vehicle driving. However, in order to ensure that the wheel speed reaches the required speed coordination when the vehicle is operating, it is necessary to balance the wheel speed of the accessory differential.

[0056] The second type is a dual-motor configuration. In this case, the two electric drive axles need to be coupled to transmit power. This configuration requires two electric drive axles (hereinafter referred to as motors A and B), with A serving as the primary drive unit and B as the auxiliary power unit. A coupler is required between the two motors to regulate their power, and an MCU is also needed to control the motor power.

[0057] B dual electric drive axle front

[0058] This type of layout is similar to the rear-mounted dual electric drive axle layout, but for the front-mounted drive unit, it must be a front-wheel drive requirement. The range of application models is narrower (such as 8×4 models). The front-mounted dual electric drive axle layout is similar to the previous rear-mounted dual electric drive axle layout. The front-mounted dual electric drive axle layout is also divided into two cases: the first is a dual single-core electric drive axle layout, and the second is a dual-motor dual electric drive axle.

[0059] C dual electric full bridge one front and one rear arrangement

[0060] This type of layout has the widest application range and can be applied to new energy commercial vehicles, such as light trucks, medium and heavy trucks. Therefore, light trucks and medium and heavy trucks are divided into the following categories:

[0061] Light truck type: For general new energy commercial vehicles, light trucks generally adopt 4×2 models, but for the layout of dual electric drive axles, new energy will be arranged as 4×4 new energy all-wheel drive light trucks, with the dual electric drive axles arranged in front and behind. The vehicle's transmission problem will be optimized, reducing the transmission capacity consumption required by the drive shaft of front-wheel drive or rear-wheel drive vehicles. However, in the layout of light trucks, there will be coordination of the wheel speed of all-wheel drive, so the control of the motor of the dual electric drive axle is particularly important. Here, a control method is similar to the above: using an MCU to control the dual electric drive axle, so for the start of the AB motor and the control of its speed and torque, the dual electric drive axle is better for the coordination of the dual motors under the control of an MCU, but for the adjustment of the wheel speed, it is necessary to adjust the differential speed of the dual axles. After adjusting the dual axles, the four wheels are adjusted. Therefore, it is necessary to arrange the differential and adjust the differential speed of the dual axles separately to achieve the normal operating conditions of the vehicle.

[0062] Medium and heavy-duty truck types: For medium and heavy-duty truck models (generally 6×4 and 8×4 models), dual drive devices are used in a front and rear form. Similarly, the transmission method of the driving force needs to be differentiated (that is, there are two types: dual single-core drive; dual electric drive axle power main and auxiliary distribution, and east-west distribution for drive). When arranging the dual electric drive axles, the power distribution organization of the specific electric drive axles needs to be determined according to the specific needs of the vehicle model. For the control of the current dual electric drive axles, the same MCU is needed to coordinate the dual electric drive axles. In the dual single-core drive configuration, the MCU control only requires minimizing the time error of the dual-axle transmission to the wheel hub speed and the power speed error as much as possible to balance the power generated by the dual-axle drive. When controlling the main and auxiliary electric drive axles, the MCU is required to divide the dual electric drive axles into main and auxiliary, and then match the power distributed by the MCU with the auxiliary power coefficient to perform drive configuration, so as to achieve power drive coordination. For different models of vehicles, the environment in which the dual electric drive axle exists and the structural layout that needs to be configured need to be appropriately assembled according to the specific model.

[0063] This application has at least the following beneficial effects compared to the prior art:

[0064] A. Improve vehicle dynamics: When comparing the power of a single motor in a new energy commercial vehicle with a dual electric drive axle, the dual motor is superior to the single motor in terms of power and usage. In terms of power, it is more powerful than the single motor. For commercial vehicles in commercial use, it is an improvement in power level, and it meets the power capabilities of commercial vehicles for some special uses and in some specific working conditions.

[0065] B. Improve vehicle safety: Compared with the single electric drive axle, the dual electric drive axle structure can coordinate the AB motors to ensure the vehicle's driving when the vehicle drive device fails. Compared with the single motor drive device, when the vehicle can only be shut down when a failure occurs, the vehicle can only stop while driving, which does not necessarily guarantee vehicle safety. Compared with the dual electric drive axle that continues to ensure the safety of the driving road and stops driving, the safety of the single motor device is not as good as the dual electric drive axle.

[0066] C. Optimize vehicle practicality: The dual electric drive axles have improved the practicality of vehicle power. While increasing power, safety has also been improved due to the existence of dual cores. At the same time, kinetic energy recovery has also been significantly improved due to the existence of dual electric drive axles. The improvement of kinetic energy recovery capacity has also optimized the vehicle's endurance and optimized the vehicle's practicality.

[0067] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the present invention.

Claims

1. A new energy commercial vehicle dual electric drive axle system, characterized by include: Two independent electric drive axle units include A-bridge and B-bridge, which are respectively configured on the front axle and / or rear axle of the vehicle; a unified control unit, communicatively connected to the two electric drive axle units; The unified control unit is configured to: a) Dynamically distribute the driving power of each electric drive axle unit; b) Coordinate the speed and torque output of the two electric drive axle units; c) Switch to redundant drive mode when a single electric drive axle unit fails.

2. The system according to claim 1, characterized in that: The two electric drive axle units are both arranged on the rear axle of the vehicle to form a dual rear drive axle structure; Each electric drive axle unit is connected to the wheels through a rigid shaft, and a mechanical differential D1 is set between the two bridges to achieve wheel speed balance.

3. The system according to claim 1, characterized in that: The two electric drive axle units are both arranged on the front axle of the vehicle to form a dual front drive axle structure; The output end of each electric drive axle unit is connected to the steering hub through a universal joint.

4. The system according to claim 1, characterized in that: The two electric drive axle units are respectively arranged on the front axle and the rear axle of the vehicle to form an all-wheel drive structure; The mechanical transmission shaft between the front electric drive axle unit A bridge and the rear electric drive axle unit B bridge is eliminated, and electronic coupling is achieved through the unified control unit.

5. The system according to claim 4, wherein: For light trucks, the power ratio of the front electric drive axle unit to the rear electric drive axle unit is 1: (1.2-1.5); For medium and heavy truck models, the rear electric drive axle unit is additionally equipped with an auxiliary power coupler.

6. The system according to claim 1, characterized in that: The unified control unit achieves wheel speed coordination in the following ways: A speed sensor is provided at the output end of each electric drive axle unit; The electronic differential coefficient K between the two bridges is adjusted in real time based on sensor data, and the value of K is (0.8-1.2).

7. The system according to claim 1, characterized in that: The two electric drive axle units adopt the main and auxiliary drive mode: The main drive unit A bridge provides basic power, which is defined as ≥70% of the total power; The auxiliary drive unit B-axle is connected to the main drive unit via a hydraulic coupler; The unified control unit activates the auxiliary drive unit during rapid acceleration or when climbing a slope.

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