Lubrication control device, control method and vehicle for multi-speed dual-motor electric drive box

Abstract

This application relates to a lubrication control device, control method, and vehicle for a multi-speed dual-motor electric drive unit. The control device includes: an oil supply drive component for providing flow power to lubricating oil; an oil circuit; and a control component, which includes a data acquisition unit, a calculation unit, and an output unit. The data acquisition unit acquires motion data of the parts to be lubricated and the motor's gear position data. The calculation unit calculates the required flow rate based on the motion data and the gear position data. The output unit sends a control signal to the oil supply drive component based on the required flow rate, so that the oil supply drive component supplies the required flow rate of lubricating oil. This invention achieves precise matching between cooling and lubrication flow rate demand and supply by accurately calculating the required flow rate of the electric drive unit under different operating conditions and utilizing an electric pump for precise supply; it improves the reliability guarantee capability of the lubrication system for the electric drive unit system, ensuring sufficient lubrication under various operating conditions.

Description

Technical Field

[0001] This application relates to the field of vehicle lubrication technology, and in particular to a lubrication control device, control method, and vehicle for a multi-speed dual-motor electric drive unit. Background Technology

[0002] In modern electric drive systems, lubrication and cooling of the drive assembly are crucial factors in ensuring its efficient and stable operation. As a core component of the powertrain in new energy vehicles, the electric drive unit experiences high input speeds and rapid power changes, placing higher demands on the lubrication and cooling system. Under these high-speed, high-power conditions, traditional lubrication and cooling methods often fall short, easily leading to insufficient lubrication, high-temperature thermal damage, and failure, severely impacting the lifespan and reliability of the electric drive unit.

[0003] Currently, the cooling and lubrication systems of electric drive units mainly employ splash lubrication or mechanical pump forced lubrication. Splash lubrication relies on gear rotation to splash oil onto the surfaces of each friction pair, forming an oil film. However, it suffers from significant oil churning losses, and its lubrication effect is poor at low speeds or low oil levels. While mechanical pump forced lubrication can provide more adequate lubrication, it typically requires limit boundary calculations to determine the required flow rate. To ensure reliable lubrication and cooling, the selected pump flow rate is often too high. This not only wastes energy but also requires adding more lubricating oil to prevent cavitation during oil suction, further increasing oil churning losses. Summary of the Invention

[0004] To address these issues, this invention proposes a precision lubrication device and method for a multi-speed dual-motor electric drive unit. This device precisely controls the flow rate and pressure of the lubricating oil, dynamically adjusting the lubrication strategy according to the actual operating requirements of the electric drive unit to achieve more efficient and economical lubrication and cooling. This precision lubrication device reduces oil churning losses and energy consumption, while ensuring sufficient lubrication under various operating conditions, effectively preventing high-temperature thermal failure caused by insufficient lubrication.

[0005] In a first aspect, a lubrication control device for a multi-speed dual-motor electric drive box is provided, the control device comprising:

[0006] Oil supply drive components are used to provide the power to flow lubricating oil.

[0007] An oil passage is provided between the oil supply drive component and the parts to be lubricated in the electric drive box; and

[0008] The control component includes a data acquisition unit, a calculation unit, and an output unit. The data acquisition unit is used to acquire motion data of the parts to be lubricated and gear data of the motor. The calculation unit is used to calculate the required flow rate based on the motion data and the gear data. The output unit is used to send a control signal to the oil supply drive component based on the required flow rate, so that the oil supply drive component supplies the required flow rate of lubricating oil.

[0009] In one embodiment, there are two oil supply drive units and two sets of oil circuits. Each set of oil circuits includes a housing oil circuit located inside the electric drive box and a pipeline oil circuit located between the oil supply drive unit and the housing oil circuit.

[0010] In one embodiment, the acquisition unit further includes a temperature sensor for acquiring the temperature of the electric drive box, and the calculation unit is used to calculate the required flow rate based on the temperature of the electric drive box.

[0011] Secondly, a lubrication control method for a multi-speed dual-motor electric drive box is provided, based on the aforementioned control device, including the following steps:

[0012] Obtain motion data of the parts to be lubricated and motor gear data;

[0013] Calculate the required flow rate based on the motion data and the gear data;

[0014] A control signal is sent to the oil supply drive according to the required flow rate, so that the oil supply drive supplies the required flow rate of lubricating oil.

[0015] In one embodiment, the motion data includes the rotational speed and torque of the part to be lubricated;

[0016] In one embodiment, the parts to be lubricated include gears and bearings, and the step of calculating the required flow rate based on the motion data and the gear position data includes: calculating the wear of the parts to be lubricated.

[0017] The meshing power loss P of the gear is calculated using the following formula. Mi :

[0018] ,

[0019] Where fm is the meshing friction coefficient, T1 is the torque of the small wheel, n1 is the speed of the small wheel, and βw is the helix angle;

[0020] The power loss P of the bearing is calculated using the following formula. Bi :

[0021] ,

[0022] Where M1 is the torque loss of the first bearing, M2 is the torque loss of the second bearing, and n is the rotational speed.

[0023] In one embodiment, the first bearing is a radial load bearing, and the second bearing is an axial cylindrical roller bearing;

[0024] The radial load bearing loss torque M1 is calculated using the following formula:

[0025] ,

[0026] Where f1 is the friction coefficient of the radial load bearing, p1 is the equivalent dynamic load of the bearing, and d m is the average diameter of the bearing, and a and b are correction factors;

[0027] The axial cylindrical roller bearing loss torque M2 is calculated using the following formula:

[0028] ,

[0029] Where f2 is the friction coefficient of the cylindrical roller bearing, F a For axial load, d m This represents the average diameter of the bearing.

[0030] In one embodiment, the step of calculating the required flow rate based on the motion data and the gear data includes:

[0031] The power loss of the parts to be lubricated is calculated based on the motion data and the gear data.

[0032] The required flow rate q is calculated based on the power loss of the part to be lubricated using the following formula:

[0033]

[0034] Among them, P G For the power loss of the parts to be lubricated, C p ρ is the specific heat capacity of the lubricating oil, ρ is the density of the lubricating oil, and Δt is the temperature difference between the inlet and outlet of the radiator.

[0035] Establish a matrix statistical table of demand flow and parts to be lubricated.

[0036] In one embodiment, after establishing the matrix statistical table of demand flow and parts to be lubricated, the method further includes the following steps:

[0037] Establish k standard operating conditions, each corresponding to a different demand flow range;

[0038] Based on the location of the parts to be lubricated, the oil circuit and the parts to be lubricated on the oil circuit are divided into zones, and lubricating oil is supplied to each zone at a corresponding preset flow rate.

[0039] Thirdly, a vehicle is provided that uses the aforementioned lubrication control method for a multi-speed dual-motor electric drive box for lubrication.

[0040] This application has the following technical advantages:

[0041] (1) Precise matching of lubrication and cooling requirements: This invention achieves precise matching between the required flow rate of the electric drive unit under different operating conditions by accurately calculating the required flow rate and using an electric pump for precise supply. This method can not only adapt to the lubrication requirements of the electric drive unit under different speeds, torques and gears, but also effectively reduce the risk of high-temperature thermal damage failure caused by insufficient lubrication.

[0042] (2) Operating condition identification and oil temperature monitoring: This invention uses algorithms to identify the operating conditions of the electric drive unit, including factors such as speed, torque, and gear position, and monitors the assembly's operating oil temperature to achieve self-adjustment. This intelligent monitoring and adjustment mechanism improves the lubrication system's ability to guarantee the reliability of the electric drive unit system, ensuring sufficient lubrication under various operating conditions.

[0043] (3) Intelligent control strategy: The present invention may also include intelligent control strategies, such as adopting an initial timing flow control strategy under low operating conditions to solve the problem of insufficient lubrication of the remote bearing; and adopting a directional adjustment control strategy under high operating conditions to make precise flow adjustment to take into account both cooling and lubrication requirements. Attached Figure Description

[0044] Figure 1 This is a schematic diagram of the lubrication control device for an electric drive unit according to an embodiment of this application.

[0045] Figure 2 This is a matrix table of required flow rates for gears and bearings under different operating conditions, according to an embodiment of the present invention.

[0046] Figure 3 This is a standard operating condition diagram of an embodiment of the present invention.

[0047] Figure 4 This is a schematic diagram of regional layering according to an embodiment of the present invention.

[0048] Figure 5 This is a traffic comparison confirmation table according to an embodiment of the present invention. Detailed Implementation

[0049] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0050] In the description of this application, it should be understood that if terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" appear, these terms indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0051] Furthermore, where the terms "first" and "second" appear, these terms are 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 with "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, where the term "multiple" appears, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0052] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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 the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0053] In this application, unless otherwise expressly specified and limited, the use of descriptions such as "above" or "below" the second feature indicates that the first and second features are in direct contact or indirect contact via an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. Similarly, "below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0054] It should be noted that if an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. If an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. If so, the terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used in this application are for illustrative purposes only and do not represent the only possible implementation.

[0055] like Figure 1 As shown in the figure, an embodiment of the electric drive unit provided in this application includes an oil supply drive component, an oil circuit, and a control component. The oil supply drive component is used to provide flow power to lubricating oil. The oil circuit is located between the oil supply drive component and the parts to be lubricated in the electric drive unit. The control component includes a data acquisition unit, a calculation unit, and an output unit. The data acquisition unit is used to acquire motion data of the parts to be lubricated and motor gear data. The calculation unit is used to calculate the required flow rate based on the motion data and the gear data. The output unit is used to send a control signal to the oil supply drive component based on the required flow rate, so that the oil supply drive component supplies the required flow rate of lubricating oil.

[0056] The aforementioned lubrication control device can accurately calculate the required flow rate of the electric drive unit under different operating conditions and precisely supply it using an electric pump, achieving a precise match between cooling and lubrication flow requirements and supply. This method not only adapts to the lubrication needs of the electric drive unit under different speeds, torques, and gears, but also effectively reduces the risk of high-temperature thermal damage failure due to insufficient lubrication. The calculation unit identifies the operating conditions of the electric drive unit, including factors such as speed, torque, and gear, and monitors the assembly's operating oil temperature, enabling self-adjustment. This intelligent monitoring and adjustment mechanism improves the lubrication system's reliability guarantee for the electric drive unit system, ensuring sufficient lubrication under various operating conditions. The device facilitates the implementation of oil quantity control strategies, such as using an initial timed flow control strategy under low operating conditions to address insufficient lubrication in remote bearings; and using a directional adjustment control strategy under high operating conditions for precise flow adjustment, balancing cooling and lubrication needs.

[0057] In one embodiment, there are two oil supply drive units and two sets of oil circuits. Each set of oil circuits includes a housing oil circuit located inside the electric drive box and a pipeline oil circuit located between the oil supply drive unit and the housing oil circuit.

[0058] The electric drive unit of this application is based on a dual-motor vehicle configuration, with each motor corresponding to a fuel supply drive component and a set of oil circuits. The electric drive unit also includes a housing, an oil tank, and a filter, etc. The housing forms a cavity to accommodate the fuel supply drive component, motor, and other components. Oil circuits are formed on the housing, connecting the filter and the pipeline oil circuits. The filter is located between the oil tank and the filter, and is used to filter the lubricating oil.

[0059] The system features two oil supply drives, filters, and oil circuits, with each set forming a group. These groups are symmetrically arranged to ensure proper lubrication of the multi-speed dual intermediate shaft structure. The layout is simple, assembly is convenient, and parts are highly interchangeable. Lubricating oil passes through the filter, housing oil circuit, and pipeline oil circuit to precisely lubricate the required gear and bearing positions. The dual oil supply drives provide accurate flow rates to the oil circuits.

[0060] To ensure low oil churning in the largest gear, an arc-shaped oil shield can be placed on the underside of the parts to be lubricated to minimize oil churning loss at different angles and under different working conditions.

[0061] In one embodiment, the acquisition unit further includes a temperature sensor for acquiring the temperature of the electric drive box, and the calculation unit is used to calculate the required flow rate based on the temperature of the electric drive box.

[0062] Specifically, the calculation unit has built-in specialized software that can calculate the required flow rate based on the motion data and gear position data. This required flow rate serves as a baseline value. After the temperature of the electric drive housing is input as a parameter into the calculation unit, the required flow rate is optimized to obtain the final value of the required flow rate. For example, if the temperature sensor detects that the temperature exceeds the warning temperature of 120°C, it will self-adjust by controlling the oil supply drive to increase the oil supply range. This mainly ensures the normal operation of the shaft gear system at the boundary of high-heat or extremely poor heat dissipation conditions. This is a special strategy and is generally not activated.

[0063] This application also provides a lubrication control method for a multi-speed dual-motor electric drive box, based on the above-mentioned control device, including the following steps:

[0064] S100: Obtain motion data of the parts to be lubricated and motor gear data;

[0065] S200: Calculate the required flow rate based on the motion data and the gear data;

[0066] S300: Send a control signal to the oil supply drive according to the required flow rate, so that the oil supply drive supplies the required flow rate of lubricating oil.

[0067] In one embodiment, the motion data includes the rotational speed and torque of the part to be lubricated.

[0068] Step S200 can build a power loss calculation model based on formulas or professional software. The calculated power loss includes gear loss, bearing loss, oil seal loss, friction pair loss, etc. The following uses gear and bearing loss as an example to introduce the calculation model.

[0069] In one embodiment, the part to be lubricated includes gears and / or bearings, and the step of calculating the required flow rate based on the motion data and the gear position data includes: S210, calculating the wear of the part to be lubricated:

[0070] The power loss in gear meshing is a function of gear meshing action and friction coefficient. Gear meshing action includes some sliding of the meshing gears separated by an oil film. Meshing efficiency is a function of sliding ratio and meshing friction coefficient. The power loss P of the gear meshing is calculated using the following formula (1). Mi :

[0071] (1),

[0072] Among them, f m Let T1 be the meshing friction coefficient, T1 be the torque of the small wheel, n1 be the speed of the small wheel, and β be the meshing friction coefficient. w The helix angle;

[0073] The power loss P of the bearing is calculated using the following formula (2). Bi :

[0074] (2),

[0075] M1 is the torque loss of the first bearing, M2 is the torque loss of the second bearing, and n is the rotational speed.

[0076] In one embodiment, the first bearing is a radial load bearing, and the second bearing is a cylindrical roller bearing;

[0077] The calculation methods for different types of bearings also differ. For radial load bearings, the loss torque is the equation of bearing friction coefficient f1 and calculation load P1. The loss torque M1 of radial load bearings is calculated using the following formula (3):

[0078] (3),

[0079] Where f1 is the friction coefficient of the radial load bearing, p1 is the equivalent dynamic load of the bearing, and dm is the average diameter of the bearing, and a and b are correction factors;

[0080] For cylindrical roller bearings subjected to axial loads, the total frictional torque needs to be increased by adding torque M2. M2 depends on the axial load. The loss torque M2 of the cylindrical roller bearing is calculated by the following formula (4):

[0081] (4),

[0082] Where f2 is the friction coefficient of the cylindrical roller bearing, F a For axial load, d m This represents the average diameter of the bearing.

[0083] In one embodiment, step S200 of calculating the required flow rate based on the motion data and the gear data further includes:

[0084] S211. Calculate the power loss of the part to be lubricated based on the motion data and the gear data;

[0085] S220. Based on different operating conditions, including speed, torque, gear, etc., the system power loss is calculated, and the corresponding required flow rate q is calculated. The required flow rate q is calculated according to the power loss of the parts to be lubricated by the following formula (5):

[0086] (5),

[0087] Among them, P G For the power loss of the parts to be lubricated, C p ρ is the specific heat capacity of the lubricating oil, ρ is the density of the lubricating oil, and Δt is the temperature difference between the inlet and outlet of the radiator.

[0088] S230. Based on the results calculated in step S220, establish a matrix statistical table of required flow rate and parts to be lubricated. For example, with a speed interval of 1000 r / min and a torque interval of 50 Nm, obtain the required flow rate matrix for different speed settings, such as... Figure 2 As shown.

[0089] In one embodiment, after establishing the matrix statistical table of demand flow and parts to be lubricated, the method further includes step S400:

[0090] S410. Establish k standard operating conditions, each standard operating condition corresponding to a different demand flow range;

[0091] S420. Based on the location of the parts to be lubricated, the oil circuit and the parts to be lubricated on the oil circuit are divided into zones, and lubricating oil is supplied to each zone at a corresponding preset flow rate.

[0092] Step S300 can be executed according to the rules defined in S400. Specifically, based on the demand flow matrix, electric pump performance, and system control capabilities, an electric pump control strategy is formulated, ultimately determining the oil supply conditions to have eight spans to ensure the total oil supply, i.e., the k value in S410 is set to 8, establishing a system as follows: Figure 3 The eight standard operating conditions shown correspond to a q value and a speed and torque range, thus enabling the division of the matrix statistical table.

[0093] In step S420, in order to ensure that the supply at each position in the demand flow matrix meets the demand, the system's total lubrication oil circuit is optimized by hierarchical grouping. According to the position of the parts to be lubricated, the oil circuit and the parts to be lubricated on the oil circuit are divided into regions. Each region module includes at least one part to be lubricated and the oil circuits before and after it. One or more region modules are divided into an oil supply layer. The oil supply layer and the region module are the region layering scheme.

[0094] Furthermore, the specific characteristic of the layered approach is that after the optimization of the previous layer is completed, changes in design variables during the optimization of the next layer will not cause significant changes in the traffic already allocated in the previous layer. For example... Figure 4 The example shown illustrates a layered region structure, where each branch is a supply layer. For instance, the oil circuit where the output gear is located also includes a multi-layered structure, where the upper output gear and the lower reduction gear do not interfere with each other, and each node of each branch constitutes a region.

[0095] The hierarchical grouping optimization was experimentally verified based on software 1D-3D coupled simulation. The simulation results of the supply flow were compared with the target demand flow matrix table, and the minimum difference was greater than 0. Figure 5 As shown, the supply flow rate was ultimately confirmed to meet the design requirements, ensuring the reliability of the lubrication system.

[0096] This application also provides a vehicle that uses the above-described lubrication control method for a multi-speed dual-motor electric drive box, and the vehicle is equipped with dual-motor drive and multi-speed control.

[0097] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0098] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A lubrication control device for a multi-speed dual-motor electric drive box, characterized in that, The control device includes: Oil supply drive components are used to provide the power for the flow of lubricating oil; An oil passage is provided between the oil supply drive component and the parts to be lubricated in the electric drive box; The control component includes a data acquisition unit, a calculation unit, and an output unit. The data acquisition unit is used to acquire motion data of the parts to be lubricated and gear data of the motor. The calculation unit is used to calculate the required flow rate based on the motion data and the gear data. The output unit is used to send a control signal to the oil supply drive component based on the required flow rate, so that the oil supply drive component supplies the required flow rate of lubricating oil. The acquisition unit further includes a temperature sensor for acquiring the temperature of the electric drive box, and the calculation unit is used to calculate the required flow rate based on the temperature of the electric drive box; The parts to be lubricated include gears and bearings. The step of calculating the required flow rate based on the motion data and the gear position data includes: calculating the wear of the parts to be lubricated. The meshing power loss P of the gear is calculated using the following formula. Mi : ， Among them, f m Let T1 be the meshing friction coefficient, T1 be the torque of the small wheel, n1 be the speed of the small wheel, and β be the meshing friction coefficient. w The helix angle; The power loss P of the bearing is calculated using the following formula. Bi : ， Where M1 is the torque loss of the first bearing, M2 is the torque loss of the second bearing, and n is the rotational speed; The step of calculating the required flow rate based on the motion data and the gear data further includes: The power loss of the parts to be lubricated is calculated based on the motion data and the gear data. The required flow rate q is calculated based on the power loss of the part to be lubricated using the following formula: ； Among them, P G For the power loss of the parts to be lubricated, C p ρ is the specific heat capacity of the lubricating oil, ρ is the density of the lubricating oil, and Δt is the temperature difference between the inlet and outlet of the radiator. Establish a matrix statistical table of demand flow and parts to be lubricated.

2. The lubrication control device for the multi-speed dual-motor electric drive box according to claim 1, characterized in that, The oil supply drive unit is provided in two parts, and the oil circuit is provided in two sets. Each set of oil circuits includes a housing oil circuit located in the electric drive box and a pipeline oil circuit located between the oil supply drive unit and the housing oil circuit.

3. A lubrication control method for a multi-speed dual-motor electric drive box, characterized in that, The control device according to any one of claims 1-2 includes the following steps: Obtain motion data of the parts to be lubricated and gear position data of the electric drive unit; Calculate the required flow rate based on the motion data and the gear data; A control signal is sent to the oil supply drive according to the required flow rate, so that the oil supply drive supplies the required flow rate of lubricating oil.

4. The lubrication control method for a multi-speed dual-motor electric drive box according to claim 3, characterized in that, The motion data includes the rotational speed and torque of the part to be lubricated.

5. The lubrication control method for a multi-speed dual-motor electric drive box according to claim 3, characterized in that, The first bearing is a radial load bearing, and the second bearing is an axial cylindrical roller bearing; The radial load bearing loss torque M1 is calculated using the following formula: ， Where f1 is the friction coefficient of the radial load bearing, p1 is the equivalent dynamic load of the bearing, and d m is the average diameter of the bearing, and a and b are correction factors; The axial cylindrical roller bearing loss torque M2 is calculated using the following formula: ， Where f2 is the friction coefficient of the cylindrical roller bearing, F a For axial load, d m This represents the average diameter of the bearing.

6. The lubrication control method for a multi-speed dual-motor electric drive box according to claim 3, characterized in that, After establishing the matrix statistical table of demand flow and parts to be lubricated, the following steps are also included: Establish k standard operating conditions, each corresponding to a different demand flow range; Based on the location of the parts to be lubricated, the oil circuit and the parts to be lubricated on the oil circuit are divided into zones, and lubricating oil is supplied to each zone at a corresponding preset flow rate.

7. A vehicle, characterized in that, Lubrication is performed using the lubrication control method for the multi-speed dual-motor electric drive box as described in any one of claims 3-6.

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