Flow control valve, speed reducer, oil-cooled electric drive system and control method
Patent Information
- Application Number
- CN202611237795.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-08-14
- Publication Date
- 2026-11-03
AI Technical Summary
现有油冷电驱系统中，各润滑点位的流量比例固定，难以根据实际工况动态调节，导致在低负荷工况下轴承易磨损或高负荷下电耗增加，影响可靠性和整车效率。
Design a flow control valve that uses a combination of valve core and return spring to adaptively adjust the flow distribution ratio of three oil outlets by means of oil pressure. These outlets include a first oil outlet at the bottom, a second oil outlet at the top, and a third oil outlet in the valve body blocking isolation section. This enables dynamic flow distribution of the oil circuits for motor stator cooling and reducer front and rear housing bearing lubrication.
It achieves adaptive flow matching for motor stator cooling and reducer bearing lubrication, improving lubrication and heat dissipation efficiency, reducing power consumption, and enhancing the reliability and range of the entire vehicle.
Smart Images
Figure CN123028264A_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of vehicle technology, and in particular to a flow control valve, a reducer, an oil-cooled electric drive system, and a control method. Background Technology
[0002] With the continuous development of electric drive technology for new energy vehicles, electric drive systems are rapidly evolving towards higher power density and miniaturization. Oil-cooled electric drives, with their advantages of high heat exchange efficiency, high overall efficiency, and compact structure, are gradually becoming the mainstream technology. However, current oil-cooled electric drives generally use orifices to distribute flow at various lubrication points. Once the orifice size is determined, the flow ratio at each outlet remains fixed, making dynamic adjustment difficult based on actual operating conditions. Under common urban road conditions, the system load is low, heat dissipation requirements are low, and the system flow rate decreases accordingly. This leads to a reduction in bearing lubrication flow, which can easily cause bearing wear and pose reliability risks. Increasing the system flow rate to improve bearing reliability would increase power consumption, reduce overall vehicle efficiency, and consequently shorten the driving range. Summary of the Invention
[0003] The purpose of this invention is to provide a flow control valve, a speed reducer, an oil-cooled electric drive system, and a control method, solving the technical problem of low lubrication and heat dissipation efficiency in existing electric drive systems. The specific solution is as follows: A flow control valve includes: a hollow valve body housing; The valve body housing has a valve body plug fixedly installed at the top and an opening at the bottom; a U-shaped valve core is slidably installed inside the valve body housing; the valve core is arranged close to the opening of the valve body housing, and a throttling hole for oil inlet is opened at the center of the bottom of the valve core; A return spring is provided between the valve core and the valve body block; one end of the return spring extends into the valve core and abuts against the valve core, and the other end abuts against the valve body block. The valve body housing has a first oil outlet on the bottom side wall and a second oil outlet on the upper side wall; an isolation part is provided extending upward from the upper outer edge of the valve body blockage; a third oil outlet is provided on the side wall of the isolation part. The valve core is used to adjust the flow distribution ratio of the first oil outlet, the second oil outlet, and the third oil outlet according to the oil pressure.
[0004] Optionally, in the initial state, the reset spring is in the reset state, and the spring force of the reset spring abuts the valve core against the bottom of the valve body shell, thereby sealing the first oil outlet through the valve core.
[0005] Optionally, there are multiple first oil outlets, second oil outlets and third oil outlets; wherein the first oil outlets and second oil outlets are evenly spaced along the periphery of the valve body shell. The third oil outlet is evenly spaced along the periphery of the isolation section.
[0006] A speed reducer includes the flow control valve and the speed reducer housing; The reducer housing is provided with a valve body mounting groove; wherein, the valve body mounting groove is used to install a flow control valve; A first sealing ring and a second sealing ring are arranged between the valve body housing and the valve body mounting groove; in the initial state, the first sealing ring is used to seal and isolate the throttling orifice and the first oil outlet, and the second sealing ring is used to seal and isolate the first oil outlet and the second oil outlet. The valve body shell has a first sealing groove at the bottom of its outer wall for installing a first sealing ring and a second sealing groove at the middle for installing a second sealing ring.
[0007] Optionally, a gap channel is formed between the upper outer wall of the valve body housing, the outer wall of the valve body blockage and the outer wall of the isolation part and the inner wall of the valve body mounting groove; the second oil outlet and the third oil outlet are connected through the gap channel; The valve body mounting groove has a top outlet communicating with the third oil outlet at the top, and lower outlets communicating with the first oil outlet and upper outlets communicating with the second oil outlet on the inner walls of both sides, respectively. The valve body mounting groove has a bottom inlet communicating with the throttling hole of the valve core at the bottom.
[0008] An oil-cooled electric drive system includes the aforementioned reducer and heat exchanger; The oil outlet of the heat exchanger is connected to the bottom inlet; The first oil outlet is connected to the internal oil passage of the motor and is used to cool the motor stator; The second oil outlet is connected to the lubrication oil circuit of the rear housing of the reducer and is used to lubricate the rear housing assembly; wherein, the rear housing assembly includes at least: an intermediate shaft rear bearing, an input shaft rear bearing, a motor bearing, an output shaft rear bearing, and a motor rotor; The third oil outlet is connected to the lubrication oil circuit of the front housing of the reducer and is used to lubricate the front housing assembly; wherein, the front housing assembly includes at least: an intermediate shaft front bearing, an output shaft front bearing, and an input shaft front bearing.
[0009] A control method for an oil-cooled electric drive system includes the following steps: Collect the stator temperature of the motor in the electric drive system; The target lubrication output pressure is obtained by comparing the obtained motor stator temperature with the preset temperature threshold. The valve core travel is automatically adjusted according to the target lubrication output pressure.
[0010] Optionally, obtaining the target lubrication output pressure based on the comparison result between the obtained motor stator temperature and the preset temperature threshold includes: When the motor stator temperature is lower than the preset temperature threshold, the first comparison result is obtained. In response to the first comparison result, the first preset output pressure is retrieved and the lubricating oil temperature is collected; wherein, the first preset output pressure is less than the lower limit of the valve core opening pressure. If the lubricating oil temperature is greater than or equal to the first temperature value, then the target output flow rate of the electric drive system is obtained based on the first preset output pressure; wherein, the target output flow rate of the electric drive system is a preset percentage of the maximum flow rate; If the lubricating oil temperature is less than the first temperature value, then the temperature difference between the first temperature value and the lubricating oil temperature is obtained. Based on the temperature difference, the compensation pressure is obtained through the mapping relationship between the difference and the compensation pressure, and then superimposed to the first preset output pressure; The target output flow of the electric drive system is obtained based on the compensated first preset output pressure; wherein the compensated first preset output pressure is less than or equal to the lower limit of the valve core opening pressure.
[0011] Optionally, obtaining the target lubrication output pressure based on the comparison result between the obtained motor stator temperature and the preset temperature threshold includes: When the motor stator temperature is greater than or equal to the preset temperature threshold, the second comparison result is obtained; In response to the second comparison result, the target lubrication output pressure is obtained based on the motor stator temperature and the temperature-output pressure mapping relationship; wherein, the target lubrication output pressure is greater than or equal to the lower limit of the valve core opening pressure. Based on the target lubrication output pressure, the flow distribution ratio of the first, second, and third oil outlets is adjusted synchronously by automatically adjusting the movement stroke of the valve core.
[0012] Optionally, the following steps may also be included: When the motor stator temperature is greater than or equal to the preset temperature threshold and the target lubrication output pressure is greater than or equal to the valve core fully opening pressure, the second oil outlet and the third oil outlet are in a connected state.
[0013] The above solution achieves the following beneficial technical effects: This application provides a flow control valve, a reducer, an oil-cooled electric drive system, and a control method. Oil pressure is generated through a throttling orifice for oil inlet to drive the valve core to slide axially, thereby adaptively adjusting the flow area of the three oil outlets without the need for additional control signals. The axial arrangement of the bottom first oil outlet, the upper second oil outlet, and the third oil outlet on the valve body's blocking isolation section allows the valve core to move synchronously in response to oil pressure, simultaneously linking the flow areas of the first and second oil outlets. This enables adaptive adjustment of the flow distribution ratio of the first, second, and third oil outlets, ultimately achieving dynamic flow distribution between the motor stator cooling oil circuit and the reducer's front and rear bearing lubrication oil circuits. Furthermore, based on the lubricating oil temperature and the motor's electronic temperature, the corresponding lubrication output pressure is output to adaptively match the flow requirements under all operating conditions, thus improving the overall lubrication and heat dissipation efficiency of the electric drive system. Attached Figure Description
[0014] Figure 1 This is a schematic cross-sectional view of a flow control valve according to one embodiment of the present invention; Figure 2 This is a cross-sectional schematic diagram of the flow control valve mounted on a speed reducer, according to one embodiment of the invention.
[0015] In the picture: 1 Valve body housing; 2 Valve body blockage; 21 Isolation part; 3 Valve core; 4 Throttling orifice; 5 Return spring; 6 First oil outlet; 7 Second oil outlet; 8 Third oil outlet; 9 Reducer housing; 10 Valve body mounting groove; 101 Top outlet; 102 Lower outlet; 103 Upper outlet; 104 Bottom inlet; 11 First sealing ring; 12 Second sealing ring; 13 Gap channel. Detailed Implementation
[0016] To make the purpose, technical solution, and advantages of this application clearer, the following will be described in conjunction with the appendix. Figures 1 to 2 This application will be described in further detail. It is obvious that the described embodiments are merely some, not all, of the embodiments described herein. All other embodiments obtained by those skilled in the art based on the embodiments described herein without inventive effort are within the scope of protection of this application.
[0017] The terminology used in the embodiments of this application is for the purpose of describing particular embodiments only and is not intended to limit the application. The singular forms “a,” “said,” and “the” used in the embodiments of this application and the appended claims are also intended to include the plural forms, and “multiple” generally includes at least two unless the context clearly indicates otherwise.
[0018] It should be understood that the term "and / or" used in this article is merely a description of the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, and B existing alone. Additionally, the character " / " in this article generally indicates that the preceding and following related objects have an "or" relationship.
[0019] It should be understood that although the terms first, second, third, etc., may be used in the embodiments of this application, these descriptions should not be limited to these terms. These terms are only used to distinguish the descriptions. For example, first may also be referred to as second without departing from the scope of the embodiments of this application, and similarly, second may also be referred to as first.
[0020] It should also be noted that the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that an article or device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such an article or device. Without further limitation, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the article or device that includes said element.
[0021] It should be noted that any symbols and / or numbers present in the specification that are not marked in the accompanying drawings are not reference numerals.
[0022] Figure 1 The flow control valve shown includes: a hollow valve body shell 1; The valve body housing 1 has a valve body plug 2 fixedly installed at the top and an opening at the bottom; a U-shaped valve core 3 is slidably installed inside the valve body housing 1; the valve core 3 is arranged near the bottom opening of the valve body housing 1, and a throttling hole 4 for oil inlet is opened at the center of the bottom of the valve core 3; the throttling hole 4 is used to automatically adjust the movement stroke of the valve core according to the oil inlet pressure. A return spring 5 is provided between the valve core 3 and the valve body block 2; one end of the return spring 5 extends into the valve core 3 and abuts against the valve core 3, and the other end abuts against the valve body block 2; The bottom side wall of the valve body shell 1 is provided with a first oil outlet 6 and the upper side wall is provided with a second oil outlet 7; the upper outer edge of the valve body plug 2 is provided with an isolation part 21; the side wall of the isolation part 21 is provided with a third oil outlet 8. The valve core 3 is used to adjust the flow distribution ratio of the first oil outlet 6, the second oil outlet 7, and the third oil outlet 8 according to the oil pressure.
[0023] Specifically, this invention generates oil pressure through the throttling orifice 4 for oil inlet to drive the valve core 3 to slide axially, thereby adaptively adjusting the flow area of the three oil outlets without the aid of additional control signals. Through the axial arrangement of the bottom first oil outlet 6, the upper second oil outlet 7, and the valve body blockage 2 isolation part 21 third oil outlet 8, the valve core 3 can synchronously respond to the oil pressure and move in tandem with the flow area of the first oil outlet 6 and the second oil outlet 7, thereby achieving adaptive adjustment of the flow distribution ratio of the first oil outlet 6, the second oil outlet 7, and the third oil outlet 8. Ultimately, it realizes the dynamic distribution of flow in the motor stator cooling oil circuit and the lubrication oil circuit of the front and rear housing bearings of the reducer, and outputs the corresponding lubrication output pressure according to the lubricating oil temperature and the motor electronic temperature to adaptively match the flow requirements of all operating conditions, thus improving the overall lubrication and heat dissipation efficiency of the electric drive system.
[0024] In one specific embodiment, in the initial state, the reset spring 5 is in the reset state, and the spring force of the reset spring 5 abuts the valve core 3 against the bottom of the valve body housing 1, thereby sealing the first oil outlet 6 through the valve core 3.
[0025] It is understood that in the initial state, the flow control valve is in the closed state. At this time, the return spring 5 continuously pushes the valve core 3 against the bottom of the valve body shell 1 to block the first oil outlet 6, thereby achieving automatic shut-off of the motor stator cooling oil circuit. The lubricating oil can only be supplied to the lubricating oil circuits of the front and rear housings of the reducer through the second and third oil outlets 8, prioritizing the lubrication flow of the front and rear housing components. This avoids the risk of bearing wear caused by the motor stator cooling diversion occupying the lubricating oil volume of the front and rear housing components under low-speed and low-load conditions. At the same time, it can maintain the low flow operation of the lubricating oil pump, reduce the power consumption of the lubricating oil pump, and optimize the overall vehicle range performance.
[0026] In one specific embodiment, there are several of the first oil outlet 6, the second oil outlet 7 and the third oil outlet 8; wherein the first oil outlet 6 and the second oil outlet 7 are evenly spaced along the periphery of the valve body shell 1. The third oil outlet 8 is evenly spaced along the periphery of the isolation section 21.
[0027] It is understood that the present invention arranges the first oil outlet 6 and the second oil outlet 7 evenly spaced along the circumference of the valve body shell 1, and the third oil outlet 8 evenly spaced along the circumference of the isolation part 21. The advantage of the annular arrangement of the first, second and third oil outlets 8 is that it allows the oil to be evenly distributed and output along the circumference of the valve body shell 1, avoiding the problems of oil flow deviation and uneven flow distribution caused by oil outlet on one side. This ensures that the oil supply flow is consistent in all parts of the motor stator cooling oil circuit and the lubrication oil circuit of the front and rear shells of the reducer. The synchronous oil outlet of multiple openings can reduce the oil flow velocity of a single opening, reduce the local pressure loss of the oil circuit, and improve the smoothness of oil flow. At the same time, the annular arrangement of each oil outlet allows the flow area of each oil outlet to change synchronously when the valve core 3 is slidably adjusted, resulting in better linearity of flow regulation and significantly improved oil supply stability for bearing lubrication and motor stator cooling under all working conditions.
[0028] On the other hand, the present invention provides a speed reducer, including the flow control valve and the speed reducer housing 9; The reducer housing 9 is provided with a valve body mounting groove 10; wherein, the valve body mounting groove 10 is used to install a flow control valve; A first sealing ring 11 and a second sealing ring 12 are arranged between the valve body housing 1 and the valve body mounting groove 10; in the initial state, the first sealing ring 11 is used to seal and isolate the throttle hole 4 and the first oil outlet 6, and the second sealing ring 12 is used to seal and isolate the first oil outlet 6 and the second oil outlet 7. The valve body housing 1 has a first sealing groove at the bottom of its outer wall for installing a first sealing ring 11 and a second sealing groove at the middle for installing a second sealing ring 12.
[0029] Specifically, the present invention installs a flow control valve in the valve body mounting groove 10 of the reducer housing 9; wherein, the outer wall of the valve body housing 1 is provided with two sealing grooves for installing a first sealing ring 11 and a second sealing ring 12 respectively, and the two sealing rings form two sealing partitions in layers along the axial direction of the valve body housing 1; in the initial state, the first sealing ring 11 isolates the oil inlet throttling hole 4 from the first oil outlet 6 on the motor cooling side, and the second sealing ring 12 isolates the first oil outlet 6 from the second oil outlet 7; the advantage of this design is that it can avoid the interference of oil flow between the oil passage inside the motor and the lubrication oil passage of the front and rear housings of the reducer under low flow initial conditions, thus avoiding the interference of the flow distribution ratio; the flow control valve and the reducer housing 9 are integrated into one unit, requiring no additional installation space, which can adapt to the miniaturization requirements of electric drives; the two sealing grooves are precisely positioned, and the sealing ring assembly limit is reliable, which can maintain the oil flow of each oil outlet for a long time and avoid the reliability risks of insufficient bearing lubrication flow and abnormal motor cooling oil volume caused by oil passage interconnection.
[0030] In one specific embodiment, a gap channel 13 is formed between the upper outer wall of the valve body housing 1, the outer wall of the valve body plug 2 and the outer wall of the isolation part 21 and the inner wall of the valve body mounting groove 10; the second oil outlet 7 and the third oil outlet 8 are connected through the gap channel 13. The valve body mounting groove 10 has a top outlet 101 that communicates with the third oil outlet 8 at the top, and lower outlets 102 that communicate with the first oil outlet 6 and upper outlets 103 that communicate with the second oil outlet 7 on the inner walls of both sides, respectively. The valve body mounting groove 10 has a bottom inlet 104 that communicates with the throttling hole 4 of the valve core 3 at the bottom.
[0031] Specifically, this invention forms a gap channel 13 connecting the second oil outlet 7 and the third oil outlet 8 by cooperating with the upper outer wall of the valve body shell 1, the outer wall of the valve body plug 2 and the isolation part 21, and the inner wall of the valve body mounting groove 10. This allows for the interconnection of two bearing lubrication oil circuits without the need for additional independent oil passages, thereby simplifying the internal oil circuit processing structure of the valve body shell. The valve body mounting groove 10 is respectively provided with a bottom inlet 104, a lower outlet 102, an upper outlet 103, and a top outlet 101, which respectively connect to the oil inlet hole of the valve core 3, the first oil outlet 6, the second oil outlet 7, and the third oil outlet 8. The two sealing rings of the valve body shell 1 and the gap channel 13 are used to accurately divide the internal oil of the motor. The three independent fluid passages of the reducer housing, the front and rear housing lubrication circuits, and the oil circuits of the reducer allow the valve core 3 to slide in response to oil pressure, quickly adjust the flow area of each oil outlet, and continuously ensure that the second and third oil outlets 8 are supplied with bearing lubrication through the gap channel 13, always maintaining the lower limit of the basic lubrication flow of the bearings, avoiding the shortage of oil supply on one side of the bearings in the front and rear housings under high flow conditions. The entire oil circuit is integrated inside the reducer housing 9, eliminating the need for external oil pipes, resulting in a compact structure, short oil flow path, and low pressure loss. Moreover, through the passive valve body housing 1 and the cooperation of each oil circuit, the flow distribution under all working conditions can be adaptively completed, meeting the reliability of bearing lubrication and the heat dissipation requirements of the motor stator.
[0032] On the other hand, the present invention provides an oil-cooled electric drive system, including the aforementioned reducer and heat exchanger; The oil outlet of the heat exchanger is connected to the bottom inlet 104; The first oil outlet 6 is connected to the internal oil passage of the motor and is used to cool the motor stator. The second oil outlet 7 is connected to the lubrication oil circuit of the rear housing of the reducer and is used to lubricate the rear housing assembly; wherein, the rear housing assembly includes at least: an intermediate shaft rear bearing, an input shaft rear bearing, a motor bearing, an output shaft rear bearing, and a motor rotor; The third oil outlet 8 is connected to the lubrication oil circuit of the front housing of the reducer and is used to lubricate the front housing assembly; wherein, the front housing assembly includes at least: an intermediate shaft front bearing, an output shaft front bearing and an input shaft front bearing.
[0033] In this embodiment, the radiator is installed on the outside of the reducer housing 9.
[0034] Specifically, this invention achieves unified supply of cooling and lubricating oil by connecting the heat exchanger oil passage outlet to the bottom inlet 104 of the valve body mounting groove 10, and achieves precise oil diversion by configuring oil outlets in separate zones: the first oil outlet 6 connects to the internal oil passage of the motor to cool the motor stator, the second oil outlet 7 connects to the lubrication oil circuit of the rear housing of the reducer to lubricate various rear bearings and the motor rotor, and the third oil outlet 8 connects to the lubrication oil circuit of the front housing to complete the lubrication of all front bearings; the advantage of this design is that motor cooling and reducer front and rear housing assembly can be completed simultaneously by using a single oil supply. The system lubricates all bearings, eliminating the need for two independent oil pumps and cooling circuits. This greatly simplifies the oil circuit layout, reduces the space occupied by pipelines, and closely aligns with the high power density and miniaturization requirements of electric drives. Furthermore, the passive flow control valve can adaptively distribute the flow of the three oil circuits based on the oil pressure output from the radiator oil passage outlet, thereby reducing oil pressure loss. This simultaneously meets the lubrication reliability of the reducer transmission components and the heat dissipation performance of the motor under all operating conditions. It also reduces the duration of continuous high-power operation of the lubricating oil pump, lowers the energy consumption of the oil-cooled electric drive system, and improves the overall vehicle range.
[0035] On the other hand, the present invention provides a control method for the oil-cooled electric drive system, comprising the following steps: Collect the stator temperature of the motor in the electric drive system; The target lubrication output pressure is obtained by comparing the obtained motor stator temperature with the preset temperature threshold. The travel of valve core 3 is automatically adjusted according to the target lubrication output pressure.
[0036] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are specific and detailed, they should not be construed as limiting the scope of this patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this application should be determined by the appended claims.
Claims
1. A flow control valve, characterized in that, include: Hollow valve body shell; The valve body housing has a valve body plug fixedly installed at the top and an opening at the bottom; a U-shaped valve core is slidably installed inside the valve body housing; the valve core is arranged close to the opening of the valve body housing, and a throttling hole for oil inlet is opened at the center of the bottom of the valve core; A return spring is provided between the valve core and the valve body block; one end of the return spring extends into the valve core and abuts against the valve core, and the other end abuts against the valve body block. The valve body housing has a first oil outlet on the bottom side wall and a second oil outlet on the upper side wall; an isolation part is provided extending upward from the upper outer edge of the valve body blockage; a third oil outlet is provided on the side wall of the isolation part. The valve core is used to adjust the flow distribution ratio of the first oil outlet, the second oil outlet, and the third oil outlet according to the oil pressure.
2. The flow control valve according to claim 1, characterized in that, In the initial state, the reset spring is in the reset state, and the spring force of the reset spring abuts the valve core against the bottom of the valve body shell, thereby sealing the first oil outlet through the valve core.
3. The flow control valve according to claim 2, characterized in that, There are several of the first oil outlet, the second oil outlet and the third oil outlet; wherein the first oil outlet and the second oil outlet are evenly spaced along the periphery of the valve body shell. The third oil outlet is evenly spaced along the periphery of the isolation section.
4. A speed reducer, characterized in that, Includes the flow control valve and reducer housing as described in any one of claims 1-3; The reducer housing is provided with a valve body mounting groove; wherein, the valve body mounting groove is used to install a flow control valve; A first sealing ring and a second sealing ring are arranged between the valve body housing and the valve body mounting groove; in the initial state, the first sealing ring is used to seal and isolate the throttling orifice and the first oil outlet, and the second sealing ring is used to seal and isolate the first oil outlet and the second oil outlet. The valve body shell has a first sealing groove at the bottom of its outer wall for installing a first sealing ring and a second sealing groove at the middle for installing a second sealing ring.
5. The reducer according to claim 4, characterized in that, A gap channel is formed between the upper outer wall of the valve body shell, the outer wall of the valve body blockage and the outer wall of the isolation part and the inner wall of the valve body mounting groove; the second oil outlet and the third oil outlet are connected through the gap channel; The valve body mounting groove has a top outlet communicating with the third oil outlet at the top, and lower outlets communicating with the first oil outlet and upper outlets communicating with the second oil outlet on the inner walls of both sides, respectively. The valve body mounting groove has a bottom inlet communicating with the throttling hole of the valve core at the bottom.
6. An oil-cooled electric drive system, characterized in that, Includes the reducer and heat exchanger as described in claim 5; The oil outlet of the heat exchanger is connected to the bottom inlet; The first oil outlet is connected to the internal oil passage of the motor and is used to cool the motor stator; The second oil outlet is connected to the lubrication oil circuit of the rear housing of the reducer and is used to lubricate the rear housing assembly; wherein, the rear housing assembly includes at least: an intermediate shaft rear bearing, an input shaft rear bearing, a motor bearing, an output shaft rear bearing, and a motor rotor; The third oil outlet is connected to the lubrication oil circuit of the front housing of the reducer and is used to lubricate the front housing assembly; wherein, the front housing assembly includes at least: an intermediate shaft front bearing, an output shaft front bearing, and an input shaft front bearing.
7. A control method for an oil-cooled electric drive system as described in claim 6, characterized in that, Includes the following steps: Collect the stator temperature of the motor in the electric drive system; The target lubrication output pressure is obtained by comparing the obtained motor stator temperature with the preset temperature threshold. The valve core travel is automatically adjusted according to the target lubrication output pressure.
8. The control method for an oil-cooled electric drive system according to claim 7, characterized in that, The step of obtaining the target lubrication output pressure based on the comparison result between the obtained motor stator temperature and the preset temperature threshold includes: When the motor stator temperature is lower than the preset temperature threshold, the first comparison result is obtained. In response to the first comparison result, the first preset output pressure is retrieved and the lubricating oil temperature is collected; wherein, the first preset output pressure is less than the lower limit of the valve core opening pressure. If the lubricating oil temperature is greater than or equal to the first temperature value, then the target output flow rate of the electric drive system is obtained based on the first preset output pressure; wherein, the target output flow rate of the electric drive system is a preset percentage of the maximum flow rate; If the lubricating oil temperature is less than the first temperature value, then the temperature difference between the first temperature value and the lubricating oil temperature is obtained. Based on the temperature difference, the compensation pressure is obtained through the mapping relationship between the difference and the compensation pressure, and then superimposed to the first preset output pressure; The target output flow of the electric drive system is obtained based on the compensated first preset output pressure; wherein the compensated first preset output pressure is less than or equal to the lower limit of the valve core opening pressure.
9. The control method for an oil-cooled electric drive system according to claim 7, characterized in that, The step of obtaining the target lubrication output pressure based on the comparison result between the obtained motor stator temperature and the preset temperature threshold includes: When the motor stator temperature is greater than or equal to the preset temperature threshold, the second comparison result is obtained; In response to the second comparison result, the target lubrication output pressure is obtained based on the motor stator temperature and the temperature-output pressure mapping relationship; wherein, the target lubrication output pressure is greater than or equal to the lower limit of the valve core opening pressure. Based on the target lubrication output pressure, the flow distribution ratio of the first, second, and third oil outlets is adjusted synchronously by automatically adjusting the movement stroke of the valve core.
10. The control method for an oil-cooled electric drive system according to claim 9, characterized in that, It also includes the following steps: When the motor stator temperature is greater than or equal to the preset temperature threshold and the target lubrication output pressure is greater than or equal to the valve core fully opening pressure, the second oil outlet and the third oil outlet are in a connected state.