Optimization method and system of motor thermal management system, and motor

Abstract

The invention discloses an optimization method and system of a motor thermal management system and a motor, and the optimization method comprises the steps: building a one-dimensional motor thermal management system simulation model, and obtaining one-dimensional simulation data based on the one-dimensional motor thermal management system simulation model; optimizing the original motor thermal management system based on the one-dimensional simulation data to obtain an optimized first motor thermal management system; optimizing the optimized first motor thermal management system to obtain an optimized second motor thermal management system; the optimized second motor heat management system is tested, and heat transfer coefficients and targeted optimization points of all cooling channels under different flows are obtained; and performing parameter adjustment optimization on the one-dimensional motor thermal management system simulation model to obtain an optimized third motor thermal management system, and performing simulation verification on the optimized third motor thermal management system. According to the method, one-dimensional simulation is combined with three-dimensional simulation, so that the development time and computing resources can be greatly shortened on the premise of ensuring the accuracy of all working conditions.

Description

Technical Field

[0001] The present invention relates to the technical field of new energy vehicles, and more specifically, to an optimization method for a motor thermal management system and a system and a motor thereof. Background Art

[0002] In recent years, new energy vehicles have developed rapidly. As the market share of new energy vehicles continues to increase, customers continue to put forward higher requirements for vehicle performance. High speed and high torque have gradually become the mainstream performance indicators for vehicle powertrain research and development. High performance indicators have also prompted the renewal of the heat dissipation methods of electric drive products, from the initial natural cooling, forced air cooling, to water-cooled shell cooling. At present, the main heat dissipation method for high-power electric drive assemblies is oil cooling. The so-called oil cooling is to use the reducer oil in the reducer box as the cooling medium. Through the special oil channel design, the reducer oil is in direct contact with the heating device to take away the heat in time.

[0003] At present, with the continuous change of national policies, the new energy vehicle industry has put forward higher requirements for the power density, efficiency and thermal management of dual motor systems in the increasingly fierce competition in the motor industry. At present, there are two main methods for the design and selection of motor thermal management systems for new energy vehicles. One is to design based on the engineer's own experience, usually based on the existing product as the prototype, and adjust and transplant according to the actual needs of the target product. This method is quite dependent on the professional ability of the engineer and the design level of the prototype product. In addition, due to the lack of design feedback data, it is impossible to iterate and update in real time, and it is difficult to produce large optimization items; the second is to design based on the results of three-dimensional computational fluid dynamics (CFD) simulation or one-dimensional theoretical simulation. The CFD method can better optimize the flow distribution of the thermal management system and achieve targeted cooling effect on high temperature points, but the three-dimensional simulation requires high ability of engineers, and the required modeling calculation time is long. Generally speaking, it takes two days to one week to calculate a working condition (specific flow and motor speed). Therefore, it is unrealistic to perform three-dimensional simulation in the full range of working conditions in engineering. However, fewer calculation points will lead to insufficient accuracy and will also bring risks to the reliability of the motor thermal management system design. The one-dimensional simulation method has no special requirements for computing resources and its operation is fast, but the modeling of one-dimensional simulation relies on empirical equations. In the current motor thermal management system, many non-standard problems (such as spray cooling) are encountered, and conventional heat transfer equations cannot be used for one-dimensional solutions. Therefore, the prediction accuracy of conventional one-dimensional simulation methods cannot meet the needs of engineering development. Therefore, it is a technical problem that needs to be solved urgently in this field. Summary of the invention

[0004] In view of this, the present invention provides an optimization method for a motor thermal management system to solve the problem that the prediction accuracy of conventional one-dimensional simulation methods in the prior art cannot meet the needs of engineering development, while the modeling calculation time required by three-dimensional simulation software is relatively long.

[0005] In a first aspect, the present application provides a method for optimizing a motor thermal management system, comprising the following steps:

[0006] Based on the heat loss data and setting parameters of the electric drive, a one-dimensional motor thermal management system simulation model is established, and based on the one-dimensional motor thermal management system simulation model, one-dimensional simulation data is obtained;

[0007] Optimizing the original motor thermal management system based on the one-dimensional simulation data to obtain an optimized first motor thermal management system;

[0008] Optimizing the optimized first motor thermal management system using a three-dimensional simulation model to obtain an optimized second motor thermal management system;

[0009] Using a test bench to test the optimized second motor thermal management system, to obtain the heat transfer coefficient of each cooling channel at different flow rates and the targeted optimization point;

[0010] The one-dimensional motor thermal management system simulation model is optimized according to the heat transfer coefficients of the cooling passages at different flow rates, and the optimized one-dimensional thermal management system simulation model is used to obtain the optimal flow ratio. According to the optimal flow ratio and the targeted optimization point, the optimized second motor thermal management system is structurally optimized to obtain the optimized third motor thermal management system. The optimized third motor thermal management system is simulated and verified using the three-dimensional simulation model.

[0011] In a second aspect, the present application provides an optimization system for a motor thermal management system, which is applied to the optimization method for the motor thermal management system described above, including:

[0012] A simulation model building module, used to establish a one-dimensional motor thermal management system simulation model based on the heat loss data of the electric drive and the set parameters, and obtain one-dimensional simulation data based on the one-dimensional motor thermal management system simulation model;

[0013] A thermal management system optimization module is connected to the simulation model building module and is used to receive one-dimensional simulation data, optimize the original motor thermal management system based on the one-dimensional simulation data, and obtain an optimized first motor thermal management system; and optimize the optimized first motor thermal management system using a three-dimensional simulation model to obtain an optimized second motor thermal management system;

[0014] The thermal management system verification module is connected to the thermal management system optimization module, and is used to receive the optimized second motor thermal management system, test the optimized second motor thermal management system using a test bench, and obtain the heat transfer coefficient of each cooling channel at different flow rates and the targeted optimization point; optimize the one-dimensional motor thermal management system simulation model according to the heat transfer coefficient of each cooling channel at different flow rates, and use the optimized one-dimensional thermal management system simulation model to obtain the optimal flow ratio; according to the optimal flow ratio and the targeted optimization point, perform structural optimization on the optimized second motor thermal management system to obtain the optimized third motor thermal management system, and use the three-dimensional simulation model to simulate and verify the optimized third motor thermal management system.

[0015] In a third aspect, this embodiment provides a motor, including a spindle oil supply device, wherein the motor is obtained by the above-mentioned optimization method of the motor thermal management system;

[0016] The motor comprises a spindle oil supply device, the spindle oil supply device comprises a housing and a spindle sleeved on the housing, and along the axial direction of the spindle, the outer surface of the spindle is sleeved with a first seal and a second seal;

[0017] There is a gap between the first sealing member and the second sealing member, an oil guide hole is provided at a position of the core shaft corresponding to the gap, a cooling oil channel is provided at a position of the housing corresponding to the oil guide hole, and the cooling oil channel, the gap, the oil guide hole and the cavity of the core shaft are in communication;

[0018] An oil-slinging hole is provided on the core shaft, and along the radial direction of the core shaft, the orthographic projection of the oil-slinging hole does not overlap with the orthographic projection of the oil guide hole.

[0019] Compared with the prior art, the optimization method of the motor thermal management system and the system and motor provided by the present invention achieve at least the following beneficial effects:

[0020] The present invention provides an optimization method and system for a motor thermal management system. The optimization method comprises: first, based on the heat loss data and setting parameters of the electric drive, a one-dimensional motor thermal management system simulation model is established, and based on the one-dimensional motor thermal management system simulation model, one-dimensional simulation data is obtained; then, based on the one-dimensional simulation data, the original motor thermal management system is optimized to obtain an optimized first motor thermal management system; then, the optimized first motor thermal management system is optimized using a three-dimensional simulation model to obtain an optimized second motor thermal management system; secondly, the optimized second motor thermal management system is tested using a test bench to obtain the heat transfer coefficient of each cooling channel at different flow rates and a targeted optimization point; finally, the one-dimensional motor thermal management system simulation model is adjusted and optimized according to the heat transfer coefficient of each cooling channel at different flow rates, and the optimized one-dimensional thermal management system simulation model is used to obtain the optimal flow ratio, and the optimized second motor thermal management system is structurally optimized according to the optimal flow ratio and the targeted optimization point to obtain an optimized third motor thermal management system, and the optimized third motor thermal management system is simulated and verified using a three-dimensional simulation model. Compared with the prior art in which a three-dimensional thermal simulation of the motor thermal management system is directly performed, the above scheme is different from the prior art in which a three-dimensional thermal simulation is performed on the motor thermal management system. The one-dimensional simulation combined with the three-dimensional simulation can significantly shorten the development time and computing resources while ensuring the accuracy of all working conditions. It can be understood that the above scheme completes the simulation, design and optimization of the motor thermal management system without consuming a lot of computer resources and computing time, while ensuring the reliability of the results.

[0021] Of course, any product implementing the present invention does not necessarily need to achieve all of the technical effects described above at the same time.

[0022] Further features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.

[0024] Figure 1 It is a flow chart of an optimization method of a motor thermal management system provided by the present invention;

[0025] Figure 2 It is a flow chart of another method for optimizing a motor thermal management system provided by the present invention;

[0026] Figure 3 is a cross-sectional schematic diagram of the motor provided by the present invention;

[0027] Figure 4 It is a structural schematic diagram of a stator assembly provided by the present invention;

[0028] Figure 5 is a structural schematic diagram of a rotor assembly provided by the present invention;

[0029] Figure 6 It is a structural schematic diagram of the core shaft oil supply device provided by the present invention;

[0030] Figure 7 It is a simplified schematic diagram of the spindle oil supply device provided by the present invention;

[0031] Figure 8 It is a structural schematic diagram of an optimization system of a motor thermal management system provided by the present invention. DETAILED DESCRIPTION

[0032] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that the relative arrangement of components and steps, numerical expressions and numerical values ​​set forth in these embodiments do not limit the scope of the present invention unless otherwise specifically stated.

[0033] The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses.

[0034] Technologies, methods, and equipment known to ordinary technicians in the relevant art may not be discussed in detail, but where appropriate, the technologies, methods, and equipment should be considered part of the specification.

[0035] In all examples shown and discussed herein, any specific values ​​should be interpreted as merely exemplary and not limiting. Therefore, other examples of the exemplary embodiments may have different values.

[0036] It should be noted that like reference numerals and letters refer to similar items in the following figures, and therefore, once an item is defined in one figure, it need not be further discussed in subsequent figures.

[0037] See also Figure 1-Figure 5 As shown, Figure 1 It is a flow chart of an optimization method of a motor thermal management system provided by the present invention; Figure 2 It is a flow chart of another method for optimizing a motor thermal management system provided by the present invention; Figure 3 is a cross-sectional schematic diagram of the motor provided by the present invention; Figure 4 Schematic diagram of the structure of the stator assembly provided by the present invention, in which the red dots are temperature measurement points; Figure 5 : is a schematic diagram of the structure of the rotor assembly provided by the present invention, in which the red dots are temperature measurement points; this embodiment provides an optimization method for a motor thermal management system, comprising the following steps:

[0038] Step 101: Based on the heat loss data and setting parameters of the electric drive, a one-dimensional motor thermal management system simulation model is established, and based on the one-dimensional motor thermal management system simulation model, one-dimensional simulation data is obtained;

[0039] The heat loss data of the above electric drive includes motor heat loss data, battery heat loss data and electronic control component heat loss data. The motor heat loss data includes stator heat loss, rotor heat loss and magnetic steel heat loss, etc. The above stator heat loss, rotor heat loss and magnetic steel heat loss are the sources of heat generated during the operation of the motor, among which the stator heat loss mainly includes hysteresis loss and eddy current loss in the stator core, and copper loss of the stator winding 21. Hysteresis loss is the heat generated by the stator core in the alternating magnetic field, and eddy current loss is caused by eddy current in the stator core. The copper loss of the stator winding 21 is due to the Joule heat generated by the current passing through the stator winding 21; the rotor heat loss mainly includes hysteresis loss and eddy current loss of the rotor core, and copper loss of the rotor winding. When the rotor rotates at high speed, friction with the air will also generate certain mechanical losses; magnetic steel heat loss is mainly due to eddy current loss generated by the magnetic steel in the alternating magnetic field. As an important component of the motor, the heat loss of the magnetic steel will affect the efficiency and performance of the motor.

[0040] The heat loss of the battery mainly comes from the interaction between the internal resistance and the current, as well as the heat generated by the chemical reaction of the battery during the charging and discharging process. The heat loss of electronic control components includes the conduction loss and switching loss of power electronic devices. The conduction loss is the heat generated by the device when it is in the on state, while the switching loss is the heat generated during the switching process.

[0041] The heat loss data of the above motors are output based on the Maxwell electromagnetic simulation software. Maxwell is a powerful electromagnetic simulation software that can simulate the electromagnetic field distribution of the motor and evaluate the energy loss and efficiency of the motor by calculating the loss distribution of the motor. In terms of thermal simulation, Maxwell can simulate the temperature distribution of the motor, optimize the heat dissipation design by analyzing the heat flow and uneven temperature distribution of the motor, and improve the heat dissipation effect and stability of the motor.

[0042] Based on the AMEsim simulation software, the thermal loss data of batteries and electronic control components are output. AMESim (Advanced Modeling Environment for performing Simulations of engineering systems) is a multidisciplinary complex system modeling and simulation platform. AMESim also provides powerful simulation capabilities in the thermal management of battery systems and electronic control components.

[0043] Based on the set parameters required by the development plan (such as coolant temperature and coolant flow), a one-dimensional motor thermal management system simulation model is constructed in the AMEsim one-dimensional simulation software. The one-dimensional motor thermal management system simulation model includes motor thermal simulation, electronic control thermal simulation, radiator simulation, coolant heat dissipation model, etc.

[0044] Thermal simulation of the above motor:

[0045] Motors generate a lot of heat during operation, so motor thermal simulation is a key part of evaluating the performance of motor thermal management systems. Motor thermal simulation can simulate the temperature distribution and heat transfer of motors under different working conditions.

[0046] The above-mentioned electronic control thermal simulation: The electronic control system is an important part of the motor and is responsible for controlling the operation of the motor. Electronic control thermal simulation can evaluate the temperature change and heat dissipation performance of the electronic control system during operation.

[0047] Heat sink simulation:

[0048] The above radiator is a key component in the motor thermal management system, responsible for dissipating the heat generated by the motor and the electronic control system to the environment. The above radiator simulation can simulate the heat dissipation performance of the radiator, including heat dissipation efficiency, temperature distribution, etc.

[0049] The above coolant heat dissipation model:

[0050] In the motor thermal management system, coolant is used to dissipate heat more effectively. The coolant heat dissipation model can simulate the flow and heat dissipation process of the coolant in the system and evaluate its heat dissipation effect.

[0051] The combination of the above simulation models enables the one-dimensional motor thermal management system simulation model to comprehensively and accurately evaluate the performance of the motor thermal management system, providing strong support for the design and optimization of the motor.

[0052] The cooling spray system 1 is simplified into a convective heat transfer system associated with the stator winding 21 and the stator core. For example, the cooling spray system 1 mainly removes the heat generated by the stator winding 21 and the stator core by convection. During the operation of the motor, the stator winding 21 and the stator core will generate a large amount of heat due to losses. This heat needs to be dissipated through effective cooling methods to ensure the stable operation of the motor. The cooling spray system 1 sprays coolant so that the coolant undergoes convective heat exchange with the surface of the stator winding 21 and the stator core, thereby removing the heat and achieving effective cooling of the motor. This simplified model helps to focus more on studying the heat dissipation effect of the cooling spray system 1 on key components of the motor, as well as optimizing the design and performance of the cooling system.

[0053] Reference Figure 3 As shown, Figure 3The arrow in the middle represents the spray path. The cooling spray system 1 includes a stator oil spraying circuit 10 and a rotor oil throwing circuit 11. The coolant is sprayed onto the surface of the stator assembly 2 through the stator oil spraying circuit 10 to take away the heat; the coolant is thrown to the key parts of the rotor assembly 3 through the rotor oil throwing circuit 11 to achieve cooling. The stator oil spraying circuit 10 and the rotor oil throwing circuit 11 can effectively cool the key components of the motor to ensure the normal operation of the motor and extend its service life. The one-dimensional motor thermal management system simulation model is a mathematical model or calculation model used to simulate the thermal management behavior of the motor, mainly focusing on the thermal management characteristics of the motor such as heat conduction, heat convection and heat radiation in one-dimensional space. The one-dimensional motor thermal management system simulation model is used to predict the temperature distribution of the motor under different working conditions and evaluate the effectiveness of the cooling system; the one-dimensional motor thermal management system simulation model is used to calculate and obtain the thermal management related simulation results such as the temperature distribution and heat flow of the motor in one-dimensional space. The one-dimensional simulation data is presented in the form of a chart, curve or data table for analyzing and evaluating the thermal management performance of the motor.

[0054] Optionally, the setting parameters include coolant temperature and coolant flow rate, wherein the coolant temperature range is 65°C-75°C; the coolant flow rate includes stator spray coolant flow rate, rotor oil-swing coolant flow rate and bearing lubrication flow rate, wherein the oil supply ratio between the stator spray coolant flow rate, the rotor oil-swing coolant flow rate and the bearing lubrication flow rate is (0-18):(0-9):(0-2), and the above oil supply ratio is subsequently adjusted according to the temperature of the stator assembly 2, the rotor assembly 3 and the bearing. Optionally, the oil supply ratio between the stator spray coolant flow rate, the rotor oil-swing coolant flow rate and the bearing lubrication flow rate is 7:2.5:0.5.

[0055] The setting parameters are set based on the requirements of the development plan, such as the coolant temperature and the coolant flow rate. If the coolant temperature is too high, the cooling effect of the stator assembly 2 and the rotor assembly 3 will be poor; if the coolant temperature is too low, a high cooling power is required for the oil cooler (such as a coolant cooler), which is not conducive to cost control. In addition, it may have an adverse effect on the lubrication effect of the rotor assembly 3; therefore, the coolant temperature in this embodiment is designed to be 65°C-75°C, which can not only improve the cooling effect of the stator assembly 2 and the rotor assembly 3, but also reduce the cooling power requirement of the oil cooler, which is conducive to cost control while avoiding affecting the lubrication effect of the rotor assembly 3.

[0056] In the above scheme, the stator spray coolant flow rate is achieved by directly spraying the coolant onto the stator assembly 2, and the rotor oil-swinging coolant flow rate utilizes the rotation of the rotor assembly 3 to swing out the lubricating oil to cool the rotor. The bearing lubrication flow rate refers to the flow rate of the coolant (or lubricating oil) supplied to the bearing, which is used to ensure sufficient lubrication of the bearing, reduce friction and wear, and also help to take away the heat generated by the bearing.

[0057] In the above scheme, the flow rate of cooling liquid sprayed on the stator accounts for a relatively large proportion. This is because the stator is one of the main parts that generate heat in the motor. A large amount of cooling liquid flow can effectively reduce the temperature of the stator assembly 2, prevent overheating, and ensure the safe operation and performance of the motor; the rotor oil-swinging cooling liquid flow rate is second, and the rotor assembly 3 will also generate heat during the operation of the motor. The heat can be quickly taken away by the rotor oil-swinging method to maintain the normal working temperature of the rotor assembly 3; the additional lubricating oil flow rate is small, and this part of the lubricating oil is mainly used to lubricate the various components of the motor, reduce friction and wear, and also play a certain heat dissipation role.

[0058] The oil supply ratio between the stator spray coolant flow, rotor oil-swing coolant flow and bearing lubrication flow is 7:2.5:0.5, which can not only cool the stator assembly 2 on the inside and outside, but also cool the rotor assembly 3 on the inside and outside, while ensuring the lubrication of the rotor assembly 3 to prevent dry grinding. Specifically, the heat transfer coefficient is the heat transfer coefficient of the stator assembly 2 and the outside of the rotor assembly 3. This part of the heat transfer is jointly determined by the stator spray and rotor oil-swing flow, and the motor structure. Among them, the heat transfer coefficient has the greatest relationship with the stator spray coolant flow and the rotor oil-swing coolant flow. At a flow rate of 10L / min, the heat transfer coefficient of the stator assembly 2 has a preset distribution. In the actual one-dimensional simulation, in order to simplify the calculation, the average value of the three-dimensional simulation results in similar cases in the early stage is usually taken as the heat transfer coefficient. The above average value ranges from 200-2000W / (m 2 ·℃), which is an important parameter to be considered when performing one-dimensional simulation.

[0059] The heat transfer coefficient inside the rotor is automatically calculated by the built-in formula of the one-dimensional simulation software, and does not need to be filled in by engineering experience. Taking the Amesim simulation software as an example, the Amesim simulation software uses the Nusselt number and thermal conductivity to calculate the heat transfer coefficient inside the rotor. Under laminar flow, the Nusselt number calculation formula defaults to: Nu = MAX [1.86 × (Re × Pr / (leng / dh)) 1 / 3 ×(mu / mus) 0.14 ),3.66], where Nu is the Nusselt number, a dimensionless number used to quantify the heat transfer efficiency in the convective heat transfer process; Re is the Reynolds number, which indicates the flow of the fluid and is an indicator for judging whether the flow field is in laminar flow; Pr is the Prandtl number, which reflects the physical properties of the fluid, including dynamic viscosity and thermal diffusivity; length is the characteristic length, which is usually related to the geometric characteristics of the heat transfer surface; dh is the hydraulic diameter, which is related to the flow characteristics of the fluid, mu is the dynamic viscosity, and mus is the surface viscosity, which is related to the physical properties of the heat transfer surface.

[0060] Step 102: Optimize the original motor thermal management system based on the one-dimensional simulation data to obtain an optimized first motor thermal management system;

[0061] Specifically, the oil cooler and oil pump are selected for the original motor thermal management system based on the one-dimensional simulation data, wherein the heat dissipation power of the selected oil cooler is not less than 1.2 times the maximum power of the one-dimensional simulation data. Of course, according to the actual situation, the heat dissipation power of the selected oil cooler can be more than 1.5 times the maximum power of the one-dimensional simulation data, and the selected oil pump should be able to operate stably at the maximum flow required by the development plan under the condition of 1.5 times the maximum oil pressure of the one-dimensional simulation data.

[0062] The oil cooler cools the motor by cooling the oil, while the oil pump is responsible for delivering the cooling oil to the inside of the motor to achieve effective heat exchange. The working principle of the oil cooler is to absorb the heat of the motor through the circulation of the cooling oil, and then dissipate the heat into the convection cooling water or air. Driven by the oil pump, the cooling oil flows through the motor housing, absorbs the heat generated by the motor, and then returns to the oil cooler for heat dissipation, and this cycle is repeated to ensure that the motor temperature remains within a safe range.

[0063] When the cooling system is running, the coolant needs to be transported by the oil pump. The flow rate and pressure (i.e., oil pressure) of the coolant determine the operating power of the oil pump. For cost considerations, the power of the selected oil pump will not have a large margin. The maximum oil pressure condition is the maximum coolant pressure in the cooling system pipeline obtained by simulation calculation. This value can be obtained by one-dimensional simulation calculation of the cooling system pipeline transportation path. The maximum flow rate refers to the maximum coolant flow rate specified in the development plan. According to the actual heating power requirements and energy-saving and environmental protection requirements, different coolant flow outputs can be achieved through oil pump control, but usually an upper limit of the flow rate is specified, i.e., the maximum flow rate, and the various operating parameters of the motor are required to meet the design goals within the maximum flow rate limit.

[0064] The above-mentioned cooling system pipelines are pipes used to transport coolant in the cooling system. They connect various components in the system, such as radiators, oil pumps, motors and battery packs, to ensure that the coolant can circulate in the system.

[0065] One-dimensional simulation data shows that the maximum heat dissipation power of the coolant is 5kW. In order to promptly remove the motor heat absorbed by the coolant and achieve thermal balance of the cooling system, the heat dissipation power of the oil cooler is required to be no less than 5kW under this heat dissipation power and its corresponding working conditions. In order to avoid the impact of simulation errors on the test, sufficient fault tolerance margin will be given when selecting the oil cooler in the early stage of testing. Therefore, the heat dissipation power of the oil cooler is required to be no less than 7.5kW.

[0066] The optimized first motor thermal management system is briefly described as follows: based on the size, structure, connection relationship and contact area of ​​the motor, a one-dimensional thermal conduction model of the motor is constructed; based on the heat loss data of the electric drive obtained by one-dimensional electromagnetic simulation, the heat input of the motor components is used as the heat input of the motor components, and the one-dimensional thermal conduction model of the motor is optimized according to the heat input of the motor components; based on the pipeline design of the motor oil cooling spray system or the water cooling water channel, a one-dimensional fluid model is constructed, and according to the heat dissipation formula of the flow in the pipe (such as the calculation formula of the heat dissipation power in the stator component 2 and the rotor component 3), as well as the specific structure of the channel in the pipe, a heat dissipation model related to the motor is constructed. The convection heat transfer model of the tube with mechanical interaction between the motor and the machine is constructed; the cooling spray system is simplified into a convection heat transfer system associated with the stator winding and the stator core, which is connected to the one-dimensional fluid model. The heat transfer coefficient is filled in according to the previous test experience, so that the temperature of the motor under different flow rates is close to the actual result; the one-dimensional simulation model is run to obtain simulation data such as oil pressure, flow, and temperature to verify the rationality of the thermal management system (such as whether the oil pressure is too high and whether it can meet the temperature rise requirements), make a preliminary selection of the oil cooler and oil pump (such as flow, oil pressure, and temperature must meet the requirements), and complete the optimized thermal management system of the first motor.

[0067] Step 103, optimizing the optimized first motor thermal management system using a three-dimensional simulation model to obtain an optimized second motor thermal management system;

[0068] The above-mentioned three-dimensional simulation model includes a three-dimensional CFD model, which can take into account more details, intuitively give the flow state of air, and help evaluate the design feasibility of the motor cooling system.

[0069] In the three-dimensional simulation model, the optimized thermal management system of the first motor is optimized and designed. The heat dissipation effect of the cooling system is optimized by adjusting factors such as coolant flow characteristics and heat conduction. The performance of the optimized thermal management system of the first motor is verified in the three-dimensional simulation model. Through simulation operation, the temperature distribution (such as potential high-temperature risk points in actual working conditions, obtaining the location of different areas or spray points), flow rate and other parameters are observed to ensure that the optimized system meets the design requirements. After optimization design and verification, the optimized second motor thermal management system with improved performance is obtained. The optimized second motor thermal management system has better heat dissipation effect and higher reliability.

[0070] Step 104: Test the optimized second motor thermal management system using a test bench to obtain the heat transfer coefficient of each cooling channel at different flow rates and the targeted optimization point;

[0071] Specifically, in the bench test, the optimized second motor thermal management system is tested to simulate actual working conditions and obtain the heat transfer coefficient of each cooling passage at different flow rates; the bench test data is collected through the bench test, the heat transfer performance of each cooling passage is analyzed, and the points with low heat transfer efficiency or high heat generation, namely the targeted optimization points, are identified. The targeted optimization points include the high temperature points, high temperature risk points and heat dissipation power of the stator assembly 2 and the rotor assembly 3 displayed in the bench test and the three-dimensional simulation software simulation, wherein the high temperature point refers to the area with higher temperature during the operation of the optimized second motor thermal management system (such as the motor), such as 120°C-165°C, and the high temperature risk point can also be the area where the optimized second motor thermal management system (such as the motor) has high temperature risks during operation, such as poor heat dissipation or heat accumulation; the heat dissipation power is an important indicator of the performance of the optimized second motor thermal management system, reflecting the heat dissipation capacity of the optimized second motor thermal management system; the cooling spray system 1 is adjusted according to the targeted optimization points to improve the overall performance of the motor thermal management system.

[0072] Step 105, according to the heat transfer coefficient of each cooling channel with different flow rates, the one-dimensional motor thermal management system simulation model is optimized, and the optimized one-dimensional thermal management system simulation model is used to obtain the optimal flow ratio, and according to the optimal flow ratio and the targeted optimization point, the optimized second motor thermal management system is structurally optimized to obtain the optimized third motor thermal management system, and the optimized third motor thermal management system is simulated and verified using the three-dimensional simulation model.

[0073] The optimal flow ratio can be obtained by using the optimized one-dimensional thermal management system simulation model to calculate the optimal flow ratio, such as using the optimized one-dimensional thermal management system simulation model to perform DOE (Design of Experiments) calculations, comprehensively considering the cooling effect and the oil pressure load (such as the working load of the oil pump), and determining the optimal flow ratio. The above optimal flow ratio is the optimal flow ratio for each cooling pipeline, and DOE will be introduced later.

[0074] Continue to refer to Figure 2 As shown, step 1051, determine the flow rate and heat dissipation power of each cooling channel according to the bench test data, and use the corresponding relationship between the flow rate and the heat dissipation power of each cooling channel to calculate the heat transfer coefficient, compile a difference function and write it into the one-dimensional motor thermal management system simulation model to optimize the initial one-dimensional simulation model (such as using the convective heat transfer coefficient calibrated by the bench test data to replace the initially set convective heat transfer coefficient), and obtain the optimized one-dimensional motor thermal management system simulation model.

[0075] The heat transfer coefficient is calculated using the corresponding relationship between the flow rate of each cooling channel and the heat dissipation power, and is calculated using the following formula:

[0076] Q=k×ΔT×S, where Q is the heat dissipation power, k is the heat transfer coefficient (such as the corresponding heat transfer coefficient under different rotor oil throwing flow rates and stator oil spraying flow rates), ΔT is the temperature difference between the coolant and the heat generating component, and S is the contact area.

[0077] Through the previous bench test data, the corresponding heat transfer coefficients under different rotor oil-splitting flow rates and stator oil-spraying flow rates were obtained. Then, through mathematical statistics software such as MATLAB / SPSS, the flow rate and heat transfer coefficient were input, and the fitting algorithm was selected (usually a second-order polynomial fitting algorithm was used). Then, the convective heat transfer coefficient function related to the flow rate can be obtained, h=f(l1,l2), where h is the convective heat transfer coefficient and l is the flow rate. After obtaining the convective heat transfer coefficient function, the convective heat transfer coefficient function can be used to replace the convective heat transfer calculation method built into the software or set in the early stage based on engineering experience to calculate the convective heat transfer.

[0078] The above-mentioned convective heat transfer coefficient is an indicator that characterizes the strength of the convective heat transfer process. It is related to factors such as the physical properties of the fluid, flow state, temperature, layout structure of the tubes in the tube bundle, flushing method, tube diameter, tube arrangement method and tube spacing.

[0079] The above-mentioned MATLAB is used for numerical calculations and algorithm development. MATLAB has powerful matrix operations, plotting functions and data, and implementing algorithms. The above-mentioned SPSS is used for statistical analysis and data mining. SPSS has a user-friendly interface, beautiful output results, and supports a variety of statistical analysis methods, such as descriptive statistics, regression analysis, cluster analysis, etc.

[0080] Through the previous bench test data, the corresponding heat transfer coefficients under different rotor oil-slinging flow rates and stator oil-spraying flow rates were obtained. The data can be organized into a table format, such as an Excel table, in which one column is the flow rate, such as the rotor oil-slinging flow rate and the stator oil-spraying flow rate, and the other column is the corresponding heat transfer coefficient; in MATLAB, the readtable or xlsread function can be used to import the flow rate and the corresponding heat transfer coefficient. MATLAB provides a variety of fitting algorithms, such as polynomial fitting, power function fitting or exponential fitting. For example, if the fit function is used for fitting, the gof structure returned by the fit function contains a variety of goodness of fit indicators, such as R square, mean square error, etc., which are used to evaluate the quality of the fit; the fitting model is used to predict the heat transfer coefficient under new rotor oil-slinging flow rates and stator oil-spraying flow rates.

[0081] Step 1052, find the best flow distribution of each coolant, and optimize the design of the cooling pipe based on the flow distribution method in the optimized one-dimensional motor thermal management system simulation model to obtain the one-dimensional motor thermal management system simulation model of the optimized cooling pipe.

[0082] Specifically, the optimization goal is to be clear, such as reducing the maximum temperature of the motor, reducing the amount of coolant used, or improving the efficiency of the cooling system. At the same time, it is also necessary to determine the constraints, such as the flow range of the coolant and the size of the cooling pipe. According to the optimization goal and constraints, select a suitable DOE. This method can observe the changes in the output variables (such as the temperature of the motor) by systematically changing the input variables (such as the flow distribution of the coolant), so as to find the best combination of input variables; in the optimized one-dimensional motor thermal management system simulation model, perform simulation experiments according to the selected DOE. By changing the flow distribution of the coolant, observe the temperature change of the motor and record the data; analyze the data obtained from the simulation experiment to find out the relationship between the coolant flow distribution and the motor temperature. Use data analysis tools such as regression analysis and variance analysis to determine the best coolant flow distribution method. Based on the best coolant flow distribution method, optimize the cooling pipe in the optimized one-dimensional motor thermal management system simulation model, such as adjusting the cooling pipe size, layout or material to improve the cooling result and meet the constraints. Simulate and verify the optimized cooling pipe to ensure that the temperature of the motor is effectively reduced.

[0083] By using the DOE equivariant optimization method, the optimal coolant flow distribution method can be found in the optimized one-dimensional motor thermal management system simulation model, and the cooling pipeline can be optimized based on the coolant flow distribution method, thereby improving the cooling effect of the motor and meeting the design requirements.

[0084] Step 1053, input the one-dimensional motor thermal management system simulation model of the optimized cooling pipeline into the three-dimensional simulation model for thermal simulation and pressure simulation verification, and obtain the high temperature point distribution result and the three-dimensional simulation result. The high temperature point range in the high temperature point distribution result is 120°C-165°C;

[0085] Convert the thermal management system parameters and configurations (such as the layout, flow rate and temperature of the cooling pipes) obtained from the one-dimensional simulation optimization into the format required by the three-dimensional CFD model. Set the same boundary conditions and initial conditions (such as the inlet and outlet conditions of the cooling pipes, fluid properties) in the three-dimensional CFD model to ensure the accuracy of the simulation. Use the three-dimensional CFD model for thermal simulation to simulate the temperature distribution of the thermal management system in actual operation, that is, analyze the temperature distribution of the motor under different working conditions, and determine the distribution results of high-temperature points. For example, the high-temperature point range is 120℃-165℃, and then arrange the spraying sites according to the high-temperature points. Perform pressure simulation in the three-dimensional CFD model to simulate the flow of the cooling medium in the motor, reveal the heat transfer process, and provide key parameters such as flow rate and pressure distribution. Based on the three-dimensional simulation results, it is shown that there are areas with low heat transfer coefficients and poor cooling effects.

[0086] Step 1054: The optimized second motor thermal management system includes spraying points. The spraying points of the optimized second motor thermal management system are adjusted according to the high temperature point distribution result and the three-dimensional simulation result for targeted control.

[0087] The optimized second motor thermal management system includes spraying sites. The location and temperature range of the high temperature points are determined according to the temperature distribution of the motor under different working conditions. The temperature distribution and cooling effect of the motor under different spraying schemes are simulated by using three-dimensional simulation technology. The best spraying scheme is selected through comparative analysis. Based on the results of high temperature point analysis and three-dimensional simulation review, the spraying sites of the optimized second motor thermal management system are optimized and adjusted to ensure that the spraying sites of the optimized second motor thermal management system can cover all high temperature points and achieve a uniform cooling effect. The mutual coordination between step 1053 and step 1054 can effectively improve the performance of the optimized second motor thermal management system and ensure that the motor can operate stably in a high temperature environment.

[0088] Compared with the prior art, the optimization method of the motor thermal management system provided in this embodiment achieves at least the following beneficial effects:

[0089] The optimization method of the motor thermal management system provided in the present embodiment is based on the heat loss data and set parameters of the electric drive. First, a one-dimensional motor thermal management system simulation model is established, and one-dimensional simulation data is obtained based on the one-dimensional motor thermal management system simulation model; then, the original motor thermal management system is optimized based on the one-dimensional simulation data to obtain an optimized first motor thermal management system; then, the optimized first motor thermal management system is optimized using a three-dimensional simulation model to obtain an optimized second motor thermal management system; secondly, the optimized second motor thermal management system is tested using a test bench to obtain the heat transfer coefficient of each cooling channel at different flow rates and the targeted optimization point; finally, according to the heat transfer coefficient of each cooling channel at different flow rates, the one-dimensional motor thermal management system simulation model is adjusted and optimized, and the optimized one-dimensional thermal management system simulation model is used to obtain the optimal flow ratio, and according to the optimal flow ratio and the targeted optimization point, the optimized second motor thermal management system is structurally optimized to obtain an optimized third motor thermal management system, and the optimized third motor thermal management system is simulated and verified using the three-dimensional simulation model. Compared with the prior art in which the motor thermal management system is directly subjected to three-dimensional thermal simulation. The one-dimensional simulation combined with the three-dimensional simulation can significantly shorten the development time and computing resources while ensuring the accuracy of all working conditions. It can be understood that the above scheme completes the simulation, design and optimization of the motor thermal management system without consuming a lot of computer resources and computing time, while ensuring the reliability of the results.

[0090] In an optional embodiment, the original motor thermal management system includes a stator assembly 2 and a rotor assembly 3, and temperature measuring points 4 are evenly arranged on the stator assembly 2 and the rotor assembly 3;

[0091] The optimized first motor thermal management system is optimized by using a three-dimensional simulation model, and the optimized second motor thermal management system includes:

[0092] The positions of the temperature measuring points 4 on the stator assembly and the rotor assembly are adjusted based on the optimized second motor thermal management system.

[0093] Specifically, the original motor thermal management system includes a stator assembly 2 and a rotor assembly 3 , on which temperature measuring points 4 are evenly distributed.

[0094] Continue to refer to Figure 4 As shown, Figure 4 Each red dot is a temperature measuring point 4. The stator assembly 2 includes a stator winding 21 and a stator silicon steel 22. The temperature measuring points 4 can be evenly arranged on the outlet ends and welding ends of the stator winding 21 and the stator silicon steel 22. The temperature measuring points 4 can be temperature sensors. There are multiple temperature measuring points 4. The number of temperature measuring points 4 depends on the size and complexity of the motor. The more temperature measuring points 4, the higher the monitoring accuracy. The temperature measuring point 4 can be a temperature sensor. A small hole is opened on the motor housing 51. The aperture of the small hole can be 2 cm. The temperature sensor lead is tied and fixed and then led out of the motor housing 51 through the small hole, and the small hole is sealed with sealant to prevent coolant leakage.

[0095] The thermal load of the motor is derived based on the one-dimensional simulation data, and the heat dissipation capacity under different branch and flow rates is further derived. The one-dimensional simulation data can be used as a data reference for the motor thermal management simulation model and oil circuit optimization design. The positions of different temperature measuring points 4 are adjusted on the outlet and welding ends of the stator winding 21 and the stator silicon steel 22 to ensure that the temperature condition of the motor can be accurately reflected.

[0096] Continuing to refer to Figure 5, the rotor assembly 3 includes an end plate (not shown in the figure), a rotor magnet 31 and a rotor core 32. The rotor core 32 is located between the upper and lower end plates. The rotor magnet 31 is arranged around the rotor core 32. The end plate plays a role of fixed support. The rotor magnet 31 is used to generate a magnetic field, and the rotor core 32 is used to concentrate and guide the magnetic field, thereby improving the efficiency and performance of the motor. The temperature measuring points 4 are evenly arranged on the end plate, the rotor magnet 31 and the rotor core 32, which can monitor the temperature changes of key components in real time to ensure that the motor will not be damaged due to overheating during high-speed operation. The temperature measuring point 4 can be a temperature sensor. The lead of the temperature sensor extends into the interior of the rotor core 32, is glued and fixed along the wall, is led out from the opening at the end of the shaft and welded to the high-speed slip ring lead. The high-speed slip ring can collect the signal of the rotating lead and input it into the computer control device.

[0097] The above-mentioned rotor magnet 31 includes an inner ring magnet 310 and an outer ring magnet 311. The inner ring magnet 310 and the outer ring magnet 311 cooperate with each other to generate a strong magnetic field. Temperature measuring points 4 are evenly arranged on the inner ring magnet 310 and the outer ring magnet 311, which can monitor the temperature changes of the inner ring magnet 310 and the outer ring magnet 311 in real time, further ensuring that the motor will not be damaged due to overheating during high-speed operation.

[0098] Based on one-dimensional simulation data, the temperature measuring points are arranged on the stator assembly 2 and the rotor assembly 3 in areas where the temperature gradient is large, the temperature change is more significant, or high temperature is expected to occur. By optimizing the positions of the temperature measuring points on the stator assembly 2 and the rotor assembly 3, it is ensured that the temperature measuring points can capture the key temperature characteristics of the stator assembly 2 and the rotor assembly 3, while avoiding an overly dense or overly sparse layout, thereby improving the accuracy of temperature monitoring and the reliability of the system.

[0099] The temperature measuring points 4 can be arranged at risk points where the heat generation areas on the stator assembly 2 and the rotor assembly 3 are predicted to be high, so as to detect the high temperatures of the heat generation areas on the stator assembly 2 and the rotor assembly 3 using temperature sensors.

[0100] In an optional embodiment, the optimized second motor thermal management system is tested using a test bench to obtain the heat transfer coefficient of each cooling channel at different flow rates and the targeted optimization points include:

[0101] Test the maximum temperature and average temperature of the stator assembly 2 and the rotor assembly 3;

[0102] The flow rate of each cooling passage is adjusted according to the maximum temperature and average temperature of the stator assembly 2 and the rotor assembly 3 to seek the optimal flow ratio and the minimum flow rate that meets the motor heat dissipation requirements in the optimized second motor thermal management system, and obtain the heat dissipation power and heat transfer coefficient of each cooling passage at different flow rates, which are subsequently used as input data to optimize the one-dimensional motor thermal management system simulation model and the three-dimensional simulation model.

[0103] Combination Figure 3-Figure 5 As shown, in the above scheme, the maximum temperature and average temperature of the stator winding 21, the stator core, the rotor magnetic steel 31 and the rotor core 32 are tested through bench test data to ensure that the motor can still operate stably in a high temperature environment, and the working temperature of the rotor components is monitored and evaluated in real time. When testing the maximum temperature of the stator winding 21, the stator core, the rotor magnetic steel 31 and the rotor core 32, the spray points can be arranged to facilitate the arrangement or the spray points can be arranged according to the maximum temperature of the stator winding 21, the stator core, the rotor magnetic steel 31 and the rotor core 32; using the bench test, the temperature sensor is used to feedback the temperature measuring point and its surrounding area with higher temperature.

[0104] The flow rate of each cooling passage is adjusted according to the maximum temperature and average temperature of the stator assembly 2 and the rotor assembly 3. If the maximum temperature of the stator assembly 2 and the rotor assembly 3 exceeds the preset threshold, the flow rate of the corresponding cooling passage should be increased to enhance the heat dissipation effect and prevent overheating. The flow rate of each cooling passage can be the rotor oil-spinning flow rate and the stator oil-spraying flow rate.

[0105] According to the average temperature of the stator assembly 2 and the rotor assembly 3, the rotor oil-slinging flow rate and the stator oil-spraying flow rate can be adjusted, and the ratio between the two can be changed at a fixed total flow rate to analyze the heat transfer characteristics of the two, obtain the heat transfer coefficient under different rotor oil-slinging flow rates and stator oil-spraying flow rates, and provide data support for subsequent optimization. Therefore, the rotor oil-slinging flow rate and the stator oil-spraying flow rate are changed by the temperature of the stator assembly 2 and the rotor assembly 3 to ensure the effectiveness and stability of the motor thermal management system.

[0106] Use the temperature measuring point 4 to detect the maximum temperature and average temperature on the stator assembly 2 and the rotor assembly 3, and adjust the rotor oil-slinging flow rate and the stator oil-drenching flow rate according to the maximum temperature and the average temperature of the stator assembly 2 and the rotor assembly 3. If the maximum temperature of the stator assembly 2 and the rotor assembly 3 is too high, increase the rotor oil-slinging flow rate and the stator oil-drenching flow rate; if the average temperature of the stator assembly 2 and the rotor assembly 3 is too low, reduce the rotor oil-slinging flow rate and the stator oil-drenching flow rate. At different flow rates, measure the heat taken away from the rotor assembly 3 and the stator assembly 2 by the rotor oil-slinging flow rate and the stator oil-drenching flow rate, that is, the heat dissipation power. The heat transfer system is an important parameter that characterizes the heat dissipation capacity of the cooling system. It is calculated by the heat dissipation power, the temperature difference between the cooling medium and the rotor and stator, and the heat transfer area.

[0107] By adopting the above scheme, the rotor oil throwing flow rate and the stator oil pouring flow rate can be adjusted according to the maximum temperature and average temperature of the rotor assembly 3 and the stator assembly 2, and the heat dissipation power and heat transfer coefficient of each cooling path under different flow rates can be obtained, thereby ensuring that the stator assembly 2 and the rotor assembly 3 operate under optimal conditions.

[0108] Optionally, under stable working conditions, the calculation formula for the heat dissipation power in the stator assembly 2 and the rotor assembly 3 is:

[0109]

[0110] Among them, Q is the heat dissipation power, W is the heat generation, It represents the heat transfer power between the component and the surrounding components, k is the thermal conductivity, S is the contact area, and ΔT is the average temperature difference.

[0111] Except for the average temperature difference, all the data in the above formula can be obtained through one-dimensional simulation software.

[0112] The temperature sensors arranged on the stator assembly 2 and the rotor assembly 3 feedback the actual temperature of the corresponding temperature measuring point 4. The average temperature of the component (such as the stator winding 21 or the stator core) is calculated to obtain the average temperature of the component. The average temperature difference refers to the difference in average temperature between two different components in physical contact (such as the stator winding 21 and the stator core).

[0113] In an alternative embodiment, in combination Figure 6 and Figure 7 As shown, Figure 6 It is a structural schematic diagram of the core shaft oil supply device provided by the present invention; Figure 7 : is a simplified schematic diagram of the spindle oil supply device provided by the present invention; the original motor thermal management system also includes a spindle oil supply device 5, the spindle oil supply device 5 includes a spindle 52, the spindle 52 is provided with an oil-slinging hole 59 and an oil-guiding hole 56, and the orthographic projection of the oil-slinging hole 59 does not overlap with the orthographic projection of the oil-guiding hole 56;

[0114] The optimized first motor thermal management system is optimized by using a three-dimensional simulation model, and the optimized second motor thermal management system includes:

[0115] The distribution, number and aperture of the oil-slinging holes 59 and the oil-conducting holes 56 are adjusted based on the optimized thermal management system of the second motor.

[0116] The spindle oil supply device 5 comprises a housing 51 and a spindle 52 sleeved on the housing 51. Along the axial direction of the spindle 52, the outer surface of the spindle 52 is sleeved with a first seal 53 and a second seal 54.

[0117] There is a gap (not marked in the figure) between the first sealing member 53 and the second sealing member 54, an oil guide hole 56 is provided at a position corresponding to the gap in the core shaft 52, a cooling oil passage 57 is provided at a position corresponding to the oil guide hole 56 in the housing 51, the cooling oil passage 57, the gap, the oil guide hole 56 are connected with the cavity of the core shaft 52, an oil-swinging hole 59 is also provided on the core shaft 52, and along the radial direction of the core shaft 52, the orthographic projection of the oil-swinging hole 59 does not overlap with the orthographic projection of the oil guide hole 56.

[0118] The above-mentioned core shaft oil supply device 5 can be a motor rotor oil supply device. According to the distribution, number and aperture size of the oil-slinging holes 59, the oil-slinging holes 59 can maximize the use of centrifugal force to swing the oil to the targeted optimization point, thereby ensuring that the oil can evenly cover the position requiring lubrication and cooling when it is thrown out; according to the distribution, number and aperture size of the oil guide holes 56, it can be ensured that the oil quickly reaches the cavity of the core shaft 52, which is beneficial to the cooling of the targeted optimization point.

[0119] Embodiment 2

[0120] See also Figure 8 As shown, Figure 8is a structural schematic diagram of an optimization system for a motor thermal management system provided by the present invention. This embodiment provides an optimization system for a motor thermal management system, including:

[0121] The simulation model building module 100 is used to establish a one-dimensional motor thermal management system simulation model based on the heat loss data of the electric drive and the setting parameters, and obtain one-dimensional simulation data based on the one-dimensional motor thermal management system simulation model;

[0122] The thermal management system optimization module 200 is connected to the simulation model construction module 100, and is used to receive one-dimensional simulation data, optimize the original motor thermal management system based on the one-dimensional simulation data, and obtain an optimized first motor thermal management system; optimize the optimized first motor thermal management system using the three-dimensional simulation model, and obtain an optimized second motor thermal management system;

[0123] The thermal management system verification module 300 is connected to the thermal management system optimization module 200, and is used to receive the optimized first motor thermal management system, and use the test bench to test the optimized second motor thermal management system to obtain the heat transfer coefficient of each cooling channel at different flow rates and the targeted optimization point; according to the heat transfer coefficient of each cooling channel at different flow rates, the one-dimensional motor thermal management system simulation model is adjusted and optimized, and the optimized one-dimensional thermal management system simulation model is used to obtain the optimal flow ratio; according to the optimal flow ratio and the targeted optimization point, the optimized second motor thermal management system is structurally optimized to obtain the optimized third motor thermal management system, and the optimized third motor thermal management system is simulated and verified using a three-dimensional simulation model.

[0124] Embodiment 3

[0125] Continue to refer to Figure 6 and Figure 7 As shown, this embodiment provides a motor, which is obtained by the above-mentioned motor thermal management system optimization method;

[0126] The motor includes a spindle oil supply device 5, which includes a housing 51 and a spindle 52 sleeved on the housing 51. Along the axial direction of the spindle 52, the outer surface of the spindle 52 is sleeved with a first seal 53 and a second seal 54;

[0127] There is a gap (not marked in the figure) between the first sealing member 53 and the second sealing member 54, an oil guide hole 56 is opened at the position of the core shaft 52 corresponding to the gap, and a cooling oil passage 57 is opened at the position of the housing 51 corresponding to the oil guide hole 56, and the cooling oil passage 57, the gap, the oil guide hole 56 and the cavity of the core shaft 52 are connected;

[0128] An oil-slinging hole 59 is formed on the core shaft 52 . In the radial direction of the core shaft 52 , the orthographic projection of the oil-slinging hole 59 does not overlap with the orthographic projection of the oil guide hole 56 .

[0129] In the above scheme, oil guide holes 56 are opened at the positions corresponding to the core shaft 52 and the gap, and the oil guide holes 56 can be arranged along the circumference of the core shaft 52. Cooling oil channels 57 are opened at the positions corresponding to the oil guide holes 56 in the shell 51. The cooling oil channels 57, the gap, the oil guide holes 56 and the cavity of the core shaft 52 are connected.

[0130] The spindle oil supply device 5 can be a motor rotor oil supply device. One end of the spindle 52 is interference fit with the adapter flange 58, and the adapter flange 58 is used to realize the transfer between the spindle 52 and the rotor temperature measurement slip ring 50. Along the axial direction of the spindle 52, the outer surface of the spindle 52 is sleeved with a first seal 53 and a second seal 54, and the first seal 53 and the second seal 54 can be sealing rings, such as O-rings; in the radial direction of the spindle 52, the outer surface of the spindle 52 is provided with a sealing groove adapted to the first seal 53 and the second seal 54, and the sealing groove is recessed into the cavity of the spindle 52, and the first seal 53 and the second seal 54 are both embedded in the spindle 52 through the sealing groove, and have an interference fit with the housing 51.

[0131] There is a gap between the first seal 53 and the second seal 54. Along the radial direction of the core shaft 52, an oil guide hole 56 is opened at the core shaft 52 corresponding to the gap. The oil guide hole 56 is used to introduce oil. The number of oil guide holes 56 can be one, two or more. The specific number can be determined according to the length of the gap between the first seal 53 and the second seal 54. This embodiment does not make specific restrictions on this. A cooling oil channel 57 is opened at the housing 51 corresponding to the oil guide hole 56. The cooling oil channel 57 is used to circulate cooling oil to effectively reduce the heat generated by the motor rotor during operation and ensure the stable operation of the motor. The outlet of the cooling oil channel 57 leads to the space enclosed by the first seal 53, the second seal 54 and the cavity of the core shaft 52. The first seal 53 and the second seal 54 are used to prevent cooling oil leakage and play a sealing effect.

[0132] An oil-slinging hole 59 is provided on the core shaft 52. The oil-slinging hole 59 is used to swing the oil introduced through the oil guide hole 56 from one area to another area through the oil-slinging hole 59. Along the radial direction of the core shaft 52, the orthographic projection of the oil-slinging hole 59 does not overlap with the orthographic projection of the oil guide hole 56 to ensure the purpose of the oil guide hole 56 and the oil-slinging hole 59.

[0133] The cooling oil is input into the space formed by the first seal 53, the second seal 54, the oil guide hole 56 and the cavity of the core shaft 52 through the cooling oil channel 57 on the housing 51, and is pumped into the interior of the core shaft 52 through the opening on the core shaft 52 by oil pressure, thereby supplying oil to the rotor and achieving the purpose of lubrication and cooling. Specifically, the coolant through the oil guide hole 56 is pumped into the core shaft 52 under the action of oil pressure, so as to achieve internal cooling of the shaft and spraying of the rotor assembly 3, such as the rotor oil-spinning oil circuit 11 to cool the rotor assembly 3 and spray the stator assembly 2. Compared with the oil supply method of assembling an oil pan with a hole at the end of the core shaft 52, this solution can reduce production costs, avoid the risk of insulation failure caused by the contact between the oil distribution plate and the housing 51 and the stator assembly 2, and avoid potential problems between the temperature sensor on the rotor assembly 3 and the oil distribution plate.

[0134] Although some specific embodiments of the present invention have been described in detail by way of example, it will be appreciated by those skilled in the art that the above examples are for illustration only and are not intended to limit the scope of the present invention. It will be appreciated by those skilled in the art that the above embodiments may be modified without departing from the scope and spirit of the present invention. The scope of the present invention is defined by the appended claims.

Claims

1. A method for optimizing a motor thermal management system, characterized in that: The following steps are involved: Based on the heat loss data and setting parameters of the electric drive, a one-dimensional motor thermal management system simulation model is established, and based on the one-dimensional motor thermal management system simulation model, one-dimensional simulation data is obtained; Optimizing the original motor thermal management system based on the one-dimensional simulation data to obtain an optimized first motor thermal management system; Optimizing the optimized first motor thermal management system using a three-dimensional simulation model to obtain an optimized second motor thermal management system; Using a test bench to test the optimized second motor thermal management system, to obtain the heat transfer coefficient of each cooling channel at different flow rates and the targeted optimization point; The one-dimensional motor thermal management system simulation model is optimized according to the heat transfer coefficients of the cooling passages at different flow rates, and the optimized one-dimensional thermal management system simulation model is used to obtain the optimal flow ratio. According to the optimal flow ratio and the targeted optimization point, the optimized second motor thermal management system is structurally optimized to obtain the optimized third motor thermal management system. The optimized third motor thermal management system is simulated and verified using the three-dimensional simulation model.

2. The optimization method of the motor thermal management system according to claim 1, characterized in that: The original motor thermal management system includes a stator assembly and a rotor assembly, and temperature measurement points are evenly arranged on the stator assembly and the rotor assembly; The optimizing the optimized first motor thermal management system by using the three-dimensional simulation model to obtain the optimized second motor thermal management system comprises: The positions of the temperature measuring points on the stator assembly and the rotor assembly are adjusted based on the optimized second motor thermal management system.

3. The optimization method of the motor thermal management system according to claim 2, characterized in that: The method of testing the optimized second motor thermal management system using a test bench to obtain the heat transfer coefficient of each cooling channel at different flow rates and the targeted optimization points includes: Testing the maximum temperature and average temperature of the stator assembly and the rotor assembly; The flow rate of each cooling passage is adjusted according to the maximum temperature and the average temperature of the stator assembly and the rotor assembly, the optimal flow ratio and the minimum flow rate that meets the motor heat dissipation requirement in the optimized second motor thermal management system are sought, and the heat dissipation power and the heat transfer coefficient of each cooling passage under different flow rates are obtained.

4. The method for optimizing a motor thermal management system according to claim 1 or 2, characterized in that: The original motor thermal management system further includes a core shaft, on which an oil-slinging hole and an oil-conducting hole are arranged, and along the radial direction of the core shaft, the orthographic projection of the oil-slinging hole and the orthographic projection of the oil-conducting hole do not overlap; The optimizing the optimized first motor thermal management system by using the three-dimensional simulation model to obtain the optimized second motor thermal management system comprises: The distribution, quantity and aperture of the oil-slinging holes and the oil-conducting holes are adjusted based on the optimized second motor thermal management system.

5. The method for optimizing a motor thermal management system according to claim 1, characterized in that: The optimizing the original motor thermal management system based on the one-dimensional simulation data to obtain an optimized first motor thermal management system comprises: Based on the one-dimensional simulation data, an oil cooler and an oil pump are selected for the original motor thermal management system, wherein the heat dissipation power of the selected oil cooler is not less than 1.2 times the maximum power of the one-dimensional simulation data, and the selected oil pump should withstand 1.5 times the maximum oil pressure predicted in the one-dimensional simulation data.

6. The method for optimizing a motor thermal management system according to claim 1, characterized in that: The one-dimensional motor thermal management system simulation model is optimized according to the heat transfer coefficient of each cooling passage at different flow rates, and the optimized one-dimensional thermal management system simulation model is used to obtain the optimal flow ratio. According to the optimal flow ratio and the targeted optimization point, the optimized second motor thermal management system is structurally optimized to obtain the optimized third motor thermal management system, including: Determine the flow rate and heat dissipation power of each cooling system according to the bench test data, and obtain the heat transfer coefficient using the corresponding relationship between the flow rate and the heat dissipation power of each cooling system, compile a difference function and write it into the one-dimensional motor thermal management system simulation model to obtain an optimized one-dimensional motor thermal management system simulation model; Find the best coolant flow distribution in each cooling system, and optimize the design of cooling pipes based on the flow distribution method in the optimized one-dimensional motor thermal management system simulation model to obtain the one-dimensional motor thermal management system simulation model of the optimized cooling pipes.

7. The method for optimizing a motor thermal management system according to claim 6, characterized in that: The method of finding the best coolant flow distribution in each cooling system, and optimizing the cooling pipe based on the flow distribution method in the optimized one-dimensional motor thermal management system simulation model to obtain the optimized one-dimensional motor thermal management system simulation model of the cooling pipe comprises: The one-dimensional motor thermal management system simulation model of the optimized cooling pipeline is input into the three-dimensional simulation model for thermal simulation and pressure simulation verification to obtain a high temperature point distribution result and a three-dimensional simulation result, wherein the high temperature point range in the high temperature point distribution result is 120°C-165°C; The optimized second motor thermal management system includes spraying sites, and the spraying sites of the optimized second motor thermal management system are adjusted according to the high-temperature point distribution result and the three-dimensional simulation result for targeted control.

8. The method for optimizing a motor thermal management system according to claim 1, characterized in that: The setting parameters include coolant temperature and coolant flow, wherein the coolant temperature range is 65-75°C; the coolant flow includes stator spray coolant flow, rotor oil-swing coolant flow and bearing lubrication flow, wherein the oil supply ratio between the stator spray coolant flow, the rotor oil-swing coolant flow and the bearing lubrication flow is (0-18):(0-9):(0-2).

9. An optimization system for a motor thermal management system, characterized in that: The optimization method applied to the motor thermal management system according to any one of claims 1 to 8 comprises: A simulation model building module, used to establish a one-dimensional motor thermal management system simulation model based on the heat loss data of the electric drive and the set parameters, and obtain one-dimensional simulation data based on the one-dimensional motor thermal management system simulation model; A thermal management system optimization module is connected to the simulation model building module and is used to receive one-dimensional simulation data, optimize the original motor thermal management system based on the one-dimensional simulation data, and obtain an optimized first motor thermal management system; and optimize the optimized first motor thermal management system using a three-dimensional simulation model to obtain an optimized second motor thermal management system; The thermal management system verification module is connected to the thermal management system optimization module, and is used to receive the optimized second motor thermal management system, test the optimized second motor thermal management system using a test bench, and obtain the heat transfer coefficient of each cooling channel at different flow rates and the targeted optimization point; optimize the one-dimensional motor thermal management system simulation model according to the heat transfer coefficient of each cooling channel at different flow rates, and use the optimized one-dimensional thermal management system simulation model to obtain the optimal flow ratio; according to the optimal flow ratio and the targeted optimization point, perform structural optimization on the optimized second motor thermal management system to obtain the optimized third motor thermal management system, and use the three-dimensional simulation model to simulate and verify the optimized third motor thermal management system.

10. A motor, characterized in that: A motor comprising a spindle oil supply device, wherein the motor is obtained by the motor thermal management system optimization method according to claim 1 or 2; The motor comprises a spindle oil supply device, the spindle oil supply device comprises a housing and a spindle sleeved on the housing, and along the axial direction of the spindle, the outer surface of the spindle is sleeved with a first seal and a second seal; There is a gap between the first sealing member and the second sealing member, an oil guide hole is provided at a position of the core shaft corresponding to the gap, a cooling oil channel is provided at a position of the housing corresponding to the oil guide hole, and the cooling oil channel, the gap, the oil guide hole and the cavity of the core shaft are in communication; An oil-slinging hole is provided on the core shaft, and along the radial direction of the core shaft, the orthographic projection of the oil-slinging hole does not overlap with the orthographic projection of the oil guide hole.

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