A method for calibrating oil pump rotating speed and lubricating oil supplement of an electric drive assembly

Abstract

A kind of oil pump rotating speed and calibration method of lubricating oil compensation of electric drive assembly, comprising the following steps: 1) in electric drive assembly oil channel, select a place in oil channel and set oil outlet, set the amount cup below the oil outlet;2) record the initial liquid level of oil pool, lubricating oil temperature, start motor, record motor speed, until the specified amount of lubricating oil is collected in the amount cup, stop motor, record time;3) compare actual lubricating oil flow and total lubricating oil flow, if less than then enter step 4), if greater than or equal to then electronic oil pump rotating speed is 0;4) add lubricating oil to initial liquid level, start motor, electronic oil pump, record electronic oil pump rotating speed, until the specified amount of lubricating oil is collected in the amount cup, stop motor and electronic oil pump, record time;5) compare actual lubricating oil flow and total lubricating oil flow, if less than return to step 4), change electronic oil pump rotating speed, if greater than or equal to then record electronic oil pump rotating speed;6) change lubricating oil temperature and motor speed, make calibration table.

Description

Technical Field

[0001] This invention relates to the field of electric drive assemblies for new energy vehicles, and specifically to a method for calibrating the oil pump speed and lubricating oil replenishment amount of an electric drive assembly. Background Technology

[0002] Planetary gearboxes are increasingly being chosen by OEMs as reducers for electric drive assemblies due to their compact structure, light weight, and wide transmission ratio range. To ensure proper operation, planetary gearboxes require lubrication and cooling through the injection of a certain amount of lubricating oil. Current technology typically uses a drive motor to agitate the gears, combined with an electronic oil pump for compensation, to lubricate the planetary gearbox. However, since the entire lubrication process occurs within the electric drive assembly, the amount of splashed oil from the gear agitation is immeasurable, and the required compensation oil volume for the electronic oil pump lacks a clear basis, making it impossible to confirm whether the planetary gearbox receives sufficient lubricating oil. To avoid the risk of inadequate lubrication, current technology resorts to increasing the electronic oil pump speed to pump out excess lubricating oil for planetary gearbox lubrication. This method not only increases the energy consumption of the electric drive assembly but also accelerates the aging of the lubricating oil. Furthermore, excess oil increases the operating resistance of components, resulting in resource waste. Summary of the Invention

[0003] To address the aforementioned problems, this invention provides a calibration method for the oil pump speed and lubricating oil replenishment amount of an electric drive assembly. This method involves measuring the actual amount of lubricating oil flowing through a selected oil passage at a certain drive motor speed, and using the difference between the required lubricating oil amount for that oil passage and the actual amount of lubricating oil flowing through it as the lubricating oil replenishment amount. The lubricating oil replenishment amount is then made up by an electronic oil pump to compensate for the excess oil flow, ensuring sufficient lubrication for that oil passage.

[0004] To achieve the above objectives, the technical solution of the present invention is: a method for calibrating the oil pump speed and lubricating oil replenishment amount of an electric drive assembly, comprising the following steps: 1) In the oil passage of the electric drive assembly, select one oil passage and set an oil outlet to export the lubricating oil at that point. A measuring cup is set below the oil outlet to collect the exported lubricating oil. 2) Record the current oil level in the electric drive assembly as the initial oil level, record the current lubricating oil temperature, start the drive motor, record the drive motor speed, drive the gears to stir the oil until the specified amount of lubricating oil is collected in the measuring cup, stop the drive motor, and record the time taken for this process. 3) Calculate the actual lubricating oil flow rate through the oil outlet per unit time and compare it with the total lubricating oil flow rate required for the oil passage at that point. If the actual lubricating oil flow rate is less than the total lubricating oil flow rate, proceed to step 4). If the actual lubricating oil flow rate is greater than or equal to the total lubricating oil flow rate, record the speed of the electronic oil pump as 0. 4) Clean the measuring cup, let the electric drive assembly stand until the other lubricating oil in the housing flows back to the oil sump, add lubricating oil until the oil level in the oil sump is the initial level, start the drive motor at the same speed, and at the same time turn on the electronic oil pump. Record the speed of the electronic oil pump until the specified amount of lubricating oil is collected in the measuring cup, stop the drive motor and the electronic oil pump, and record the time taken for this process. 5) Calculate the actual lubricating oil flow rate through the oil outlet per unit time and compare it with the total lubricating oil flow rate required for the oil passage at that point. If the actual lubricating oil flow rate is less than the total lubricating oil flow rate, return to step 4) and change the speed of the electronic oil pump. If the actual lubricating oil flow rate is greater than or equal to the total lubricating oil flow rate, record the speed of the electronic oil pump. 6) Change the lubricating oil temperature and the drive motor speed, and repeat steps 2) to 6) to finally make a calibration table.

[0005] Preferably, a heat exchanger is provided on the electric drive assembly, and the heat exchanger is connected to an external temperature control system for changing the lubricating oil temperature.

[0006] Preferably, the planetary gear housing of the electric drive assembly is replaced with a transparent planetary gear housing for observing the liquid level in the oil sump of the electric drive assembly.

[0007] Preferably, in step 1), the oil passage at the outer bearing of the planetary gear set is selected as the oil outlet.

[0008] Preferably, an oil baffle is installed between the outer bearing of the planetary gear set and the planetary gear set housing of the electric drive assembly to prevent the lubricating oil flowing through the outer bearing of the planetary gear set from returning to the oil sump inside the electric drive assembly. The oil baffle is provided with an oil passage to guide the lubricating oil flowing through the outer bearing of the planetary gear set to the outside of the planetary gear set housing. A measuring cup is provided below the oil outlet of the oil passage of the oil baffle.

[0009] Preferably, the contact surface between the oil baffle and the planetary gear housing is sealed.

[0010] The beneficial effects of this invention are as follows: 1. This invention achieves precise measurement of the actual lubricating oil flow generated by gear churning by setting an oil outlet in the oil passage of the electric drive assembly, along with an oil baffle and a measuring cup. This breaks the "black box" state of the traditional internal lubrication process of the electric drive assembly, provides a clear and scientific basis for the amount of oil replenished by the electronic oil pump, achieves precise oil replenishment, reduces energy consumption, and avoids resource waste.

[0011] 2. Based on actual measured flow data, this invention calibrates and determines the optimal speed of the electronic oil pump under different operating conditions (motor speed, lubricating oil temperature), ensuring that the oil replenishment amount precisely compensates for the insufficient oil churning by the gears, thus avoiding the problem of excessive oil pumping in traditional technologies. This not only reduces the operating energy consumption of the electronic oil pump but also reduces unnecessary consumption and aging of the lubricating oil, while avoiding the component operating resistance caused by excessive oil, thereby improving the overall operating efficiency of the electric drive assembly. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the oil flow in the oil pump of the present invention. Figure 2 This is a schematic diagram of the lubricating oil flow according to the present invention; Figure 3 This is a schematic diagram of the installation of the oil baffle plate of the present invention. Detailed Implementation

[0013] See Figures 1 to 3 A method for calibrating the oil pump speed and lubricating oil replenishment amount of an electric drive assembly, comprising the following steps: 1) In the oil passages of the electric drive assembly, an oil outlet is selected at one oil passage to discharge the lubricating oil. A measuring cup 5 is installed below the oil outlet to collect the discharged lubricating oil. In this embodiment, the oil passage of the outer bearing 4 of the planetary gear set 3 is selected as the oil outlet. Specifically, an oil baffle 6 is installed between the outer bearing 4 of the planetary gear set 3 and the planetary gear set housing of the electric drive assembly to prevent the lubricating oil flowing through the outer bearing 4 of the planetary gear set 3 from returning to the oil sump inside the electric drive assembly. The contact surface between the oil baffle 6 and the planetary gear set housing is sealed to prevent the lubricating oil from flowing back into the oil sump inside the electric drive assembly through the gap between the oil baffle 6 and the planetary gear set housing. An oil passage is provided on the oil baffle 6 to discharge the lubricating oil flowing through the outer bearing 4 of the planetary gear set 3 to the outside of the transparent planetary gear set housing. A measuring cup 5 is installed below the oil outlet of the oil passage of the oil baffle 6. The reason for selecting the oil passage at the outer bearing of the planetary gear set is that this oil passage is isolated from the outside world only by an oil seal. After removing the oil seal, the lubricating oil in this oil passage can be discharged to the outside, making oil access convenient. Furthermore, since there is a bearing, the required amount of lubricating oil for that bearing (provided by the bearing manufacturer) can be used as a standard for calibration. The planetary gear set housing of the electric drive assembly is replaced with a transparent planetary gear set housing, which is consistent with the actual planetary gear set housing and is used to observe the liquid level in the oil sump of the electric drive assembly.

[0014] 2) Record the current oil level in the electric drive assembly as the initial oil level, record the current lubricating oil temperature, start the drive motor, record the drive motor speed, and use the drive motor to drive the gears to agitate the oil until a specified amount of lubricating oil is collected in the measuring cup. In this invention, the specified amount of lubricating oil can be set according to the selected oil passage location. If the oil flow rate at that location is large, the specified amount of lubricating oil can be set to a larger value; if the oil flow rate at that location is small, the specified amount of lubricating oil can be set to a smaller value. Stop the drive motor and record the time taken for this process. 3) Calculate the actual lubricating oil flow rate through the oil outlet per unit time. The actual lubricating oil flow rate is calculated by dividing the amount of lubricating oil collected in the measuring cup by the time taken for this process. This is the actual lubricating oil flow rate. Compare this with the total lubricating oil flow rate required for the oil passage at that location. In this embodiment, the total lubricating oil flow rate is the amount of lubricating oil required by the bearing (provided by the bearing manufacturer). If the actual lubricating oil flow rate is less than the total lubricating oil flow rate, proceed to step 4). If the actual lubricating oil flow rate is greater than or equal to the total lubricating oil flow rate, record the rotational speed of the electronic oil pump as 0. 4) Clean the measuring cup, let the electric drive assembly stand until the other lubricating oil in the housing flows back to the oil sump, add lubricating oil until the oil level in the oil sump is the initial level, start the drive motor at the same speed, and at the same time turn on the electronic oil pump 1, record the speed of the electronic oil pump 1, until the specified amount of lubricating oil is collected in the measuring cup, stop the drive motor and the electronic oil pump 1, and record the time taken for this process. 5) Calculate the actual lubricating oil flow rate through the oil outlet per unit time. The calculation method is the same as in step 3), and compare it with the total lubricating oil flow rate required by the oil passage at that point. If the actual lubricating oil flow rate is less than the total lubricating oil flow rate, return to step 4) and change the speed of the electronic oil pump. In this invention, the speed of the electronic oil pump is changed according to the difference between the total lubricating oil flow rate and the actual lubricating oil flow rate (i.e., lubricating oil replenishment). The larger the lubricating oil replenishment, the greater the oil pumping demand of the electronic oil pump, and the more the speed of the electronic oil pump increases. The smaller the lubricating oil replenishment, the smaller the oil pumping demand of the electronic oil pump, and the less the speed of the electronic oil pump increases. If the actual lubricating oil flow rate is greater than or equal to the total lubricating oil flow rate, when comparing the actual lubricating oil flow rate and the total lubricating oil flow rate, the actual lubricating oil flow rate can only be slightly greater than the total lubricating oil flow rate, and cannot be much greater than the total lubricating oil flow rate. If the actual lubricating oil flow rate is much greater than the total lubricating oil flow rate, it means that the pumping oil volume of the electronic oil pump is much greater than the required lubricating oil replenishment, which will also increase the energy consumption of the electric drive assembly and cause resource waste. When the actual lubricating oil flow rate is much greater than the total lubricating oil flow rate during the test, the speed of the electronic oil pump is reduced and the measurement is repeated until the actual lubricating oil flow rate is slightly greater than the total lubricating oil flow rate, and then the speed of the electronic oil pump is recorded. 6) Change the lubricating oil temperature and the drive motor speed, and repeat steps 2) to 6) to finally make a calibration table.

[0015] In this invention, a heat exchanger 2 is installed on the electric drive assembly, and the heat exchanger is connected to an external temperature control system for changing the lubricating oil temperature. Since the electric drive assembly in this invention is not connected to a load, the temperature of the lubricating oil will hardly change during this test, so an external temperature control system is needed to change the lubricating oil temperature.

[0016] Using the above steps, in this embodiment, the total lubricating oil flow rate required for the outer bearing of the planetary gear set is 0.3 L / min, and the specified amount of lubricating oil collected in the measuring cup is set to 3 mL. The table below shows partial data of the drive motor speed K, electronic oil pump speed P, and actual lubrication flow rate of the outer bearing of the planetary gear set from the calibration table. This embodiment will be further explained using lubricating oil temperatures T (°C) of 30°C and 60°C:

[0017] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications made to the present invention by those skilled in the art without departing from the spirit of the present invention shall fall within the protection scope of the present invention.

Claims

1. A method for calibrating the oil pump speed and lubricating oil replenishment quantity of an electric drive assembly, characterized in that: Includes the following steps: 1) In the oil passage of the electric drive assembly, select one oil passage and set an oil outlet to export the lubricating oil at that point. A measuring cup is set below the oil outlet to collect the exported lubricating oil. 2) Record the current oil level in the electric drive assembly as the initial oil level, record the current lubricating oil temperature, start the drive motor, record the drive motor speed, drive the gears to stir the oil until the specified amount of lubricating oil is collected in the measuring cup, stop the drive motor, and record the time taken for this process. 3) Calculate the actual lubricating oil flow rate through the oil outlet per unit time and compare it with the total lubricating oil flow rate required for the oil passage at that point. If the actual lubricating oil flow rate is less than the total lubricating oil flow rate, proceed to step 4). If the actual lubricating oil flow rate is greater than or equal to the total lubricating oil flow rate, record the speed of the electronic oil pump as 0. 4) Clean the measuring cup, let the electric drive assembly stand until the other lubricating oil in the housing flows back to the oil sump, add lubricating oil until the oil level in the oil sump is the initial level, start the drive motor at the same speed, and at the same time turn on the electronic oil pump. Record the speed of the electronic oil pump until the specified amount of lubricating oil is collected in the measuring cup, stop the drive motor and the electronic oil pump, and record the time taken for this process. 5) Calculate the actual lubricating oil flow rate through the oil outlet per unit time and compare it with the total lubricating oil flow rate required for the oil passage at that point. If the actual lubricating oil flow rate is less than the total lubricating oil flow rate, return to step 4) and change the speed of the electronic oil pump. If the actual lubricating oil flow rate is greater than or equal to the total lubricating oil flow rate, record the speed of the electronic oil pump. 6) Change the lubricating oil temperature and the drive motor speed, and repeat steps 2) to 6) to finally make a calibration table.

2. The method for calibrating the oil pump speed and lubricating oil replenishment quantity of an electric drive assembly according to claim 1, characterized in that: A heat exchanger is installed on the electric drive assembly, and the heat exchanger is connected to an external temperature control system for changing the temperature of the lubricating oil.

3. The method for calibrating the oil pump speed and lubricating oil replenishment of an electric drive assembly according to claim 1, characterized in that: The planetary gear housing of the electric drive assembly has been replaced with a transparent planetary gear housing for observing the oil level in the oil sump of the electric drive assembly.

4. The method for calibrating the oil pump speed and lubricating oil replenishment quantity of an electric drive assembly according to claim 1, characterized in that: In step 1), the oil passage at the outer bearing of the planetary gear set is selected as the oil outlet.

5. The method for calibrating the oil pump speed and lubricating oil replenishment of an electric drive assembly according to claim 4, characterized in that: An oil baffle is installed between the outer bearing of the planetary gear set and the planetary gear set housing of the electric drive assembly to prevent the lubricating oil flowing through the outer bearing of the planetary gear set from returning to the oil sump inside the electric drive assembly. An oil passage is provided on the oil baffle to guide the lubricating oil flowing through the outer bearing of the planetary gear set to the outside of the planetary gear set housing. A measuring cup is provided below the oil outlet of the oil passage of the oil baffle.

6. The method for calibrating the oil pump speed and lubricating oil replenishment quantity of an electric drive assembly according to claim 5, characterized in that: The oil baffle plate and the planetary gear housing are sealed together.

Images