Gearbox cooling and lubricating system and method

Abstract

The invention provides a gearbox cooling and lubricating system and method, and belongs to the technical field of commercial vehicles, the system is characterized in that the input end of a first filter communicates with a lubricating oil bottom shell, the output end of the first filter communicates with the input end of an electronic pump, and the output end of the electronic pump communicates with the input ends of a thermolator and a cooler; the output end of the thermolator connected with the cooler in parallel is communicated with the input end of the second filter; the temperature sensor collects the temperature of lubricating oil in the oil pan; the MTCU controller controls the thermolator channel to be opened and the cooler channel to be closed under the condition that the temperature is smaller than a first temperature threshold value, controls the thermolator channel and the cooler channel to be partially opened under the condition that the temperature is larger than or equal to the first temperature threshold value and smaller than a second temperature threshold value, and controls the cooler channel to be partially closed under the condition that the temperature is larger than or equal to the second temperature threshold value. The thermolator channel is controlled to be closed; and the cooler channel is controlled to be completely opened. The gearbox can solve the problem that an existing gearbox of a hybrid power or electric commercial vehicle is low in efficiency.

Description

Technical Field

[0001] This invention relates to the field of commercial vehicle technology, specifically to a transmission cooling and lubrication system and method. Background Technology

[0002] Heavy-duty transmissions are typically equipped with coolers, and the coolant temperature entering these coolers is generally above 90°C. When the transmission oil temperature is lower than the coolant temperature, the cooler heats the transmission, improving overall vehicle efficiency; when the transmission oil temperature is higher than the coolant temperature, the cooler cools the transmission, ensuring reliable operation. However, hybrid or electric vehicles require coolant to supply both the electric motor and the transmission. The coolant temperature is often below 70°C. When the transmission oil temperature is lower than the coolant temperature, the cooler continuously cools the transmission, leading to reduced transmission efficiency.

[0003] Meanwhile, heavy-duty transmissions used in traditional commercial vehicles often employ active lubrication, which typically uses a mechanical pump design. As the speed of the mechanical pump increases, the flow rate also increases, and it is impossible to adjust the flow rate according to the operating conditions (oil temperature), resulting in reduced transmission efficiency. Summary of the Invention

[0004] In view of this, it is necessary to provide a transmission cooling and lubrication system and method to solve the technical problem of low efficiency in existing commercial vehicle transmissions.

[0005] To address the aforementioned problems, in a first aspect, the present invention provides a gearbox cooling and lubrication system, comprising: a first filter, an electronic pump, a thermostat, a cooler, a second filter, a temperature sensor, and an MTCU controller; The input end of the first filter is connected to the lubricating oil pan, the output end of the first filter is connected to the input end of the electronic pump, the output end of the electronic pump is connected to the input ends of the temperature controller and the cooler, and the output end of the temperature controller and the cooler connected in parallel is connected to the input end of the second filter. The temperature sensor is used to collect the temperature of the lubricating oil in the oil pan; The MTCU controller is configured to control the thermostat channel to open and the cooler channel to close when the temperature is less than a first temperature threshold; control the thermostat channel and the cooler channel to partially open when the temperature is greater than or equal to the first temperature threshold and less than a second temperature threshold; and control the thermostat channel to close and the cooler channel to fully open when the temperature is greater than or equal to the second temperature threshold.

[0006] In one possible implementation, the gearbox cooling and lubrication system further includes: a bypass valve connected in parallel with the second filter.

[0007] In one possible implementation, the output of the second filter is connected to the main oil passage of the transmission.

[0008] In one possible implementation, the transmission cooling and lubrication system further includes: a pressure sensor; The pressure sensor is used to collect the lubricating oil pressure at the main oil passage of the transmission; The MTCU controller is communicatively connected to the pressure sensor and is also used to control the electronic pump to stop working when the lubricating oil pressure is greater than a preset maximum pressure threshold.

[0009] In one possible implementation, the MTCU controller is further configured to control the electronic pump to stop working and issue an alarm via the CAN bus when the lubricating oil pressure is greater than a preset maximum pressure threshold and the difference between two adjacent detected lubricating oil pressures is greater than or equal to zero.

[0010] In one possible implementation, the MTCU controller is further configured to issue an alarm via the CAN bus when the lubricating oil pressure is less than a preset minimum pressure threshold, the gearbox speed signal is not zero, and the temperature is greater than a preset maximum temperature threshold.

[0011] In one possible implementation, the MTCU controller is further configured to control the electronic pump to operate at a first speed when the lubricating oil pressure is greater than or equal to a preset minimum pressure threshold and less than or equal to a preset maximum pressure threshold, the temperature is less than or equal to a preset maximum temperature threshold, the transmission input speed signal is not zero, and the transmission gear ratio is zero; or, when the lubricating oil pressure is less than the preset minimum pressure threshold, the transmission input speed signal is not zero, and the temperature is less than or equal to a preset maximum temperature threshold, the electronic pump is controlled to operate at a first speed.

[0012] In one possible implementation, the MTCU controller is further configured to control the electronic pump to operate at a second speed when the lubricating oil pressure is greater than or equal to a preset minimum pressure threshold and less than or equal to a preset maximum pressure threshold, the temperature is less than or equal to a preset maximum temperature threshold, the transmission input speed signal is not zero, and the transmission gear ratio is between the intermediate gear ratio and the maximum gear ratio.

[0013] In one possible implementation, the MTCU controller is further configured to control the electronic pump to operate at a third speed when the lubricating oil pressure is greater than or equal to a preset minimum pressure threshold and less than or equal to a preset maximum pressure threshold, the temperature is less than or equal to a preset maximum temperature threshold, the transmission input speed signal is not zero, and the transmission gear ratio is between the first gear ratio and the intermediate gear ratio; or when the lubricating oil pressure is less than the preset minimum pressure threshold, the transmission speed signal is not zero, and the temperature is greater than the preset maximum temperature threshold.

[0014] In a second aspect, the present invention provides a method for cooling and lubricating a transmission, the method being applied to the system described in any of the above claims, the method comprising: When the temperature of the lubricating oil in the oil pan is lower than the first temperature threshold, the MTCU controller controls the thermostat channel to open and the cooler channel to close. When the temperature is greater than or equal to a first temperature threshold and lower than a second temperature threshold, the MTCU controller controls the thermostat channel and partially controls the cooler channel to open. When the temperature is greater than or equal to the second temperature threshold, the MTCU controller controls the thermostat channel to close and the cooler channel to open completely.

[0015] The beneficial effects of the above implementation are as follows: The transmission cooling and lubrication system and method provided by this invention can collect the temperature of the lubricating oil in the oil pan through a temperature sensor and transmit the temperature data to the MTCU controller. The MTCU controller controls the cooler to be closed, partially open, or fully open based on the temperature collected by the temperature sensor. This allows the lubricating oil to be controlled to pass through the cooler or not, depending on different operating conditions. For example, when the transmission lubricating oil temperature is low and the cooler inlet water temperature is also low, the lubricating oil does not pass through the cooler, thereby improving transmission efficiency. When the transmission lubricating oil temperature is high and the cooler inlet water temperature is low, the cooler starts working, thereby improving the reliability of transmission operation. Therefore, this invention can solve the technical problem of low efficiency in existing commercial vehicle transmissions. Attached Figure Description

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 A schematic diagram of a structure of an embodiment of the gearbox cooling and lubrication system provided by the present invention; Figure 2 A flowchart of one embodiment of the EMT gearbox cooling and lubrication method provided by the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0019] In the description of the embodiments of this application, unless otherwise stated, "a plurality of" means two or more.

[0020] In this embodiment of the invention, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, apparatus, product or device that includes a series of steps or modules is not necessarily limited to those steps or modules that are explicitly listed, but may include other steps or modules that are not explicitly listed or that are inherent to such process, method, product or device.

[0021] The naming or numbering of steps in the embodiments of the present invention does not mean that the steps in the method flow must be executed in the time / logical order indicated by the naming or numbering. The execution order of the named or numbered process steps can be changed according to the technical purpose to be achieved, as long as the same or similar technical effect can be achieved.

[0022] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of the invention. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0023] This invention provides a gearbox cooling and lubrication system and method, which will be described below.

[0024] This invention provides a gearbox cooling and lubrication system, such as Figure 1 As shown, the system includes: a first filter 102, an electronic pump 103, a thermostat 104, a cooler 105, a second filter 106, a temperature sensor 110, and an MTCU controller 108.

[0025] The input end of the first filter 102 is connected to the lubricating oil pan 101, the output end of the first filter 102 is connected to the input end of the electronic pump 103, the output end of the electronic pump 103 is connected to the input ends of the thermostat 104 and the cooler 105, and the output end of the thermostat 104 and the cooler 105 connected in parallel is connected to the input end of the second filter 106. The temperature sensor 110 is used to collect the temperature of the lubricating oil in the oil pan 101; The MTCU controller 108 is configured to control the thermostat 104 channel to open and the cooler 105 channel to close when the temperature is less than a first temperature threshold; control the thermostat 104 channel and the cooler 105 channel to partially open when the temperature is greater than or equal to the first temperature threshold and less than a second temperature threshold; and control the thermostat 104 channel to close and the cooler 105 channel to fully open when the temperature is greater than or equal to the second temperature threshold.

[0026] It is understood that this invention discloses a gearbox lubrication system such as Figure 1 As shown, the transmission in this invention can be an EMT transmission. It includes an oil pan 101, two filters, an electronic pump 103 (electronic oil pump, also simply an oil pump, which can be a variable displacement electronic pump), a cooler 105, a thermostat 104, a bypass valve 107, a temperature sensor 110, a pressure sensor 111, and an MTCU control unit 108. The thermostat 104 channel is connected in series in the oil circuit and in parallel with the cooler 105 channel. The opening temperature T1 of the thermostat 104 is set to 90°C. The first filter 102 can be a coarse filter, and the second filter 106 can be a fine filter.

[0027] When the temperature collected by temperature sensor 110 is less than T1 (i.e., the first temperature threshold), the thermostat 104 channel is opened, and the lubricating oil flows through this channel to the second filter 106. At this time, the cooler 105 channel is closed. When the temperature collected by temperature sensor 110 rises to between T1 and T2 (i.e., the second temperature threshold), the thermostat 104 channel and the cooler 105 channel are partially opened, and some of the lubricating oil enters the cooler 105 through the cooler 105 channel. At this time, the cooler 105 channel is partially open. When the temperature collected by temperature sensor 110 continues to rise above T2, the thermostat 104 channel is closed, and all the lubricating oil enters the filter through the cooler 105 channel. At this time, the cooler 105 channel is fully open.

[0028] In some embodiments, the gearbox cooling and lubrication system further includes: a bypass valve 107 connected in parallel with the second filter 106.

[0029] Understandably, when the oil pressure in the main oil passage 113 is less than the opening pressure of the bypass valve 107, lubricating oil flows into the main oil passage through the second filter 106 channel, and the bypass valve 107 channel closes. When the oil pressure in the main oil passage 113 is greater than the opening pressure of the bypass valve 107, lubricating oil flows into the main oil passage 113 through the bypass valve 107 channel and begins to depressurize.

[0030] In some embodiments, the output of the second filter 106 is connected to the main oil passage 113 of the transmission.

[0031] Understandably, the output end of the second filter 106 is connected to the main oil passage 113, which is connected to the oil passage of the gearbox gear spray device, the oil passage into the gearbox bearing, and the oil passage into the gearbox planetary gear system. It is used to output filtered lubricating oil to the gearbox gears, gearbox bearings, and gearbox planetary gears for lubrication.

[0032] In some embodiments, the gearbox cooling and lubrication system further includes: a pressure sensor 111; The pressure sensor 111 is used to collect the lubricating oil pressure at the main oil passage 113; The MTCU controller 108 is communicatively connected to the pressure sensor 111 and is also used to control the electronic pump 103 to stop working when the lubricating oil pressure is greater than the preset maximum pressure threshold.

[0033] It is understood that the preset maximum pressure threshold can be the maximum working pressure allowed by the transmission. If the lubricating oil pressure is greater than the preset maximum pressure threshold, the electronic pump 103 can be controlled to stop working.

[0034] In some embodiments, the MTCU controller 108 is further configured to control the electronic pump 103 to stop working and issue an alarm via the CAN bus when the lubricating oil pressure is greater than a preset maximum pressure threshold and the difference between two adjacent detected lubricating oil pressures is greater than or equal to zero.

[0035] It is understandable that when the lubricating oil pressure is greater than the preset maximum pressure threshold and the difference between two adjacent detected lubricating oil pressures is greater than or equal to zero, it indicates that the output lubricating oil circuit is blocked. At this time, the lubrication system may be faulty, and it is necessary to control the electronic pump 103 to stop working, issue an alarm, and notify personnel to carry out maintenance.

[0036] In some embodiments, the MTCU controller 108 is further configured to issue an alarm via the CAN bus when the lubricating oil pressure is less than a preset minimum pressure threshold, the gearbox input speed signal is not zero, and the temperature is greater than a preset maximum temperature threshold.

[0037] Understandably, the preset minimum pressure threshold can be the minimum allowable operating pressure of the transmission, and the preset maximum temperature threshold can be the maximum allowable operating temperature of the transmission. When the lubricating oil pressure is lower than the preset minimum pressure threshold and the temperature collected by the temperature sensor is higher than the preset maximum temperature threshold, it indicates that there may be a fault in the system, requiring an alarm to be triggered and personnel to be notified for maintenance.

[0038] In some embodiments, the MTCU controller 108 is further configured to control the electronic pump 103 to operate at a first speed when the lubricating oil pressure is greater than or equal to a preset minimum pressure threshold and less than or equal to a preset maximum pressure threshold, the temperature is less than or equal to a preset maximum temperature threshold, the transmission input speed signal is not zero, and the transmission gear ratio is zero; or, when the lubricating oil pressure is less than a preset minimum pressure threshold, the transmission input speed signal is not zero, and the temperature is less than or equal to a preset maximum temperature threshold, the electronic pump 103 is configured to operate at a first speed.

[0039] Understandably, the minimum pressure threshold can be the minimum working pressure allowed by the transmission, the maximum pressure threshold can be the maximum working pressure allowed by the transmission, the preset maximum temperature threshold can be the maximum working temperature allowed by the transmission, and the first speed can be the speed of the basic lubricating oil volume.

[0040] The gear ratio of a transmission is the ratio of the input speed to the output speed of the transmission.

[0041] In some embodiments, the MTCU controller 108 is further configured to control the electronic pump 103 to operate at a second speed when the lubricating oil pressure is greater than or equal to a preset minimum pressure threshold and less than or equal to a preset maximum pressure threshold, the temperature is less than or equal to a preset maximum temperature threshold, the transmission speed signal is not zero, and the transmission gear ratio is between the intermediate gear ratio and the maximum gear ratio.

[0042] Understandably, the second speed can be the speed at which the planetary gear system requires less lubrication, and the preset maximum temperature threshold can be the maximum operating temperature allowed by the gearbox.

[0043] The intermediate gear ratio is the gear ratio of the transmission when it is in the middle gear, and the maximum gear ratio is the gear ratio of the transmission when it is in the maximum gear.

[0044] In some embodiments, the MTCU controller 108 is further configured to control the electronic pump 103 to operate at a third speed when the lubricating oil pressure is greater than or equal to a preset minimum pressure threshold and less than or equal to a preset maximum pressure threshold, the temperature is less than or equal to a preset maximum temperature threshold, the transmission speed signal is not zero, and the transmission gear ratio is between the first gear ratio and the intermediate gear ratio; or when the lubricating oil pressure is less than a preset minimum pressure threshold, the transmission input speed signal is not zero, and the temperature is greater than a preset maximum temperature threshold.

[0045] Understandably, the third speed can be the speed at which the planetary gear system requires a large amount of lubricating oil, and the preset maximum temperature threshold can be the maximum operating temperature allowed by the gearbox.

[0046] The first gear ratio is the gear ratio of the transmission when it is in first gear.

[0047] In some embodiments, the gearbox lubrication system provided by the present invention, such as Figure 1 As shown, the sensor signals collected by the electric commercial vehicle are used to transmit the signals to the MTCU control unit via the CAN bus, and then the control unit controls the flow of the electronic pump 103.

[0048] The control method is as follows: Step 1: Enter the electronic pump 103 oil quantity calibration value into the MTCU. a. Based on simulation data, give the speed V1 (i.e., the first speed) required to maintain the basic lubricating oil volume of the transmission at idle speed, and the peak speed Vmax (i.e., the preset maximum speed threshold) when the oil pump has the maximum flow rate. b. Based on actual calibration data, provide the engine speeds V2 (second speed) and V3 (third speed) for the target oil volume of the oil pump under different operating conditions. For example, if the transmission is operating in the high gear range, the engine speed V2 is the speed at which the planetary gear system requires less lubricating oil. 2， And the speed V3 when the gearbox is operating in the low gear range, at which point the planetary gear system requires a large amount of lubricating oil.

[0049] C. Input the gear position signal of the transmission. If the transmission has n gears, then the transmission speed ratio i is i1, i2, ..., i... n The gear ratio of a transmission is the ratio of its input speed to its output speed. In a transmission with a main gearbox and planetary gear train auxiliary gearbox structure, the low-gear positions are i1, i2…i… n / 2 The gear ratio in the high-gear zone is i n / 2+1 ...i n .

[0050] D. Enter the maximum permissible operating temperature T of the transmission. max (i.e., the preset maximum temperature threshold).

[0051] E. Enter the minimum permissible working pressure P of the gearbox. min (i.e., preset minimum pressure threshold) and maximum permissible working pressure P max (i.e., the preset maximum pressure threshold).

[0052] Step 2: Establish the control logic of MTCU. MTCU is controlled by CAN bus.

[0053] Power-on pre-lubrication control strategy. Before the vehicle starts, the transmission needs to be pre-lubricated. Referring to Table 1, based on the signal collected by temperature sensor 110 and the preset lubrication time, the speed V1 of the oil pump (i.e., electronic pump 103) is given. At this time, the transmission input speed collected by speed sensor 109 is 0.

[0054] Table 1: Correspondence between temperature and lubrication time

[0055] Signal judgment and processing of speed sensor 109. When the transmission input speed V measured by speed sensor 109 is 0, the electronic pump 103 does not work. At this time, the speed of electronic pump 103 is V. 泵 =0; When the transmission input speed V measured by the speed sensor 109 is not equal to 0, the electronic pump 103 enters the working state.

[0056] Pressure sensor 111 signal judgment and handling: The lubrication system oil pressure (i.e., lubricating oil pressure) P is measured at regular intervals. If P > Pmax (i.e., the preset maximum pressure threshold) and the transmission input speed (i.e., the transmission input signal) n input speed ≠ 0, the oil pump stops working. This is repeated three times to eliminate measurement errors, and the oil pressure P is then monitored. If P... i+1 If -P≥0, an alarm is triggered via the CAN bus, the oil pump stops working, and the pump speed V=0. Pmax is set as a fault feedback signal to prevent blockage in the lubrication system's oil circuit. If P<Pmin (i.e., the preset minimum pressure threshold), the input speed signal ninput speed ≠ 0, and the temperature signal θ≤Tmax (i.e., the preset maximum temperature threshold), then the oil pump's input speed is set to V1. If P<Pmin, the input transmission speed signal ninput speed ≠ 0, and the temperature signal θ>Tmax, then the oil pump's input speed is set to V3, and an alarm is triggered via the CAN bus. Pmin is set as a fault feedback signal to prevent oil leakage in the lubrication system's oil circuit. Pmin and Pmax need to be set in conjunction with calibration data.

[0057] Gear position sensor 112 signal judgment and handling: The position sensor measures the gearbox gear position and transmits the gear ratio signal i to the MTCU.

[0058] Temperature sensor 110 signal judgment and handling: As the temperature rises, when the temperature sensor 110 measures a temperature θ ≤ Tmax, the oil pump's operating state is controlled based on the data measured by the speed sensor 109. As the temperature rises further, when it exceeds T1, an oil temperature signal θ is fed back every 30 seconds. i Measure 3-5 times consecutively to eliminate measurement error. If the temperature θ is within the range of 5 measurements, then the next measurement should be taken after 5 measurements. i+1 -θ i If the temperature is >0, the oil pump speed will continue to rise. For every 1°C increase, the oil pump speed will increase by 300 rpm until the oil pump reaches its set peak speed Vmax. The pump must not operate at the peak speed for more than 1 hour. At the same time, an alarm will be sent to the entire vehicle via the CAN bus.

[0059] For the specific speeds of the electronic pump 103 corresponding to different signals, please refer to Table 2: Table 2: Correspondence of Oil Pump Operating Speeds

[0060] Step 3: The electronic pump 103 operates according to the speed signal output by the MTCU, thereby achieving the purpose of flow adjustment.

[0061] In summary, this invention addresses the problem of low cooling water temperature in electric or hybrid commercial vehicles by installing a thermostat 104 in the main oil circuit 113, with a cooler 105 connected in parallel. When both the transmission lubricating oil temperature and the cooler 105 inlet water temperature are low, the lubricating oil does not pass through the cooler 105 passage, thereby improving transmission efficiency. When the transmission lubricating oil temperature is high and the cooler 105 inlet water temperature is low, the cooler 105 begins to operate, thereby improving transmission reliability. Therefore, this invention can significantly improve the efficiency of EMT transmissions in electric commercial vehicles.

[0062] Simultaneously, this invention also utilizes signals collected by existing sensors in electric commercial vehicles to feed back to the MTCU. The MTCU control unit compares these signals with preset values ​​and controls the rotational speed of the electronic pump 103 according to different operating conditions, thereby adjusting the oil pump flow rate. This adjustment of the oil pump flow rate improves the transmission efficiency. By using the MTCU to adjust the oil pump (electronic pump 103) flow rate, the transmission efficiency is improved. The structure is simple, utilizing existing sensor signals from electric commercial vehicles simplifies the layout space, simplifies the oil circuit, and reduces manufacturing costs. Furthermore, the MTCU's placement is less affected by environmental factors (dust, rain), improving system reliability.

[0063] The present invention also provides a cooling and lubrication method for an EMT transmission, wherein the method is applied to any of the systems described above, such as... Figure 2 As shown, the method includes: S201, MTCU controller 108 controls the thermostat 104 channel to open and the cooler 105 channel to close when the temperature collected by the temperature sensor is less than the first temperature threshold. S202, When the temperature is greater than or equal to the first temperature threshold and lower than the second temperature threshold, the MTCU controller 108 controls the thermostat 104 channel and the cooler 105 channel to be partially turned on. S203, when the temperature is greater than or equal to the second temperature threshold, the MTCU controller 108 controls the thermostat 104 channel to close and the cooler 105 channel to open completely.

[0064] Those skilled in the art will understand that all or part of the processes of the methods described in the above embodiments can be implemented by a computer program instructing related hardware, and the program can be stored in a computer-readable storage medium. The computer-readable storage medium may be a disk, optical disk, read-only memory, or random access memory, etc.

[0065] The gearbox cooling and lubrication system and method provided by the present invention have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A gearbox cooling and lubrication system, characterized in that, include: First filter, electric pump, thermostat, cooler, second filter, temperature sensor and MTCU controller; The input end of the first filter is connected to the lubricating oil pan, the output end of the first filter is connected to the input end of the electronic pump, the output end of the electronic pump is connected to the input ends of the temperature controller and the cooler, and the output end of the temperature controller and the cooler connected in parallel is connected to the input end of the second filter. The temperature sensor is used to collect the temperature of the lubricating oil in the oil pan; The MTCU controller is configured to control the thermostat channel to open and the cooler channel to close when the temperature is less than a first temperature threshold; control the thermostat channel and the cooler channel to partially open when the temperature is greater than or equal to the first temperature threshold and less than a second temperature threshold; and control the thermostat channel to close and the cooler to fully open when the temperature is greater than or equal to the second temperature threshold.

2. The gearbox cooling and lubrication system according to claim 1, characterized in that, It also includes: a bypass valve, which is connected in parallel with the second filter.

3. The gearbox cooling and lubrication system according to claim 1, characterized in that, The output end of the second filter is connected to the main oil circuit of the transmission.

4. The gearbox cooling and lubrication system according to any one of claims 1-3, characterized in that, Also includes: Pressure sensor; The pressure sensor is used to collect the lubricating oil pressure at the main oil circuit of the transmission. The MTCU controller is communicatively connected to the pressure sensor and is also used to control the electronic pump to stop working when the lubricating oil pressure is greater than a preset maximum pressure threshold.

5. The gearbox cooling and lubrication system according to claim 4, characterized in that, The MTCU controller is also used to control the electronic pump to stop working and to issue an alarm via the CAN bus when the lubricating oil pressure is greater than the preset maximum pressure threshold and the difference between two adjacent detected lubricating oil pressures is greater than or equal to zero.

6. The gearbox cooling and lubrication system according to claim 4, characterized in that, The MTCU controller is also used to issue an alarm via the CAN bus when the lubricating oil pressure is less than a preset minimum pressure threshold, the gearbox input speed signal is not zero, and the temperature is greater than a preset maximum temperature threshold.

7. The gearbox cooling and lubrication system according to claim 4, characterized in that, The MTCU controller is further configured to control the electronic pump to operate at a first speed when the lubricating oil pressure is greater than or equal to a preset minimum pressure threshold and less than or equal to a preset maximum pressure threshold, the temperature is less than or equal to a preset maximum temperature threshold, the transmission input speed signal is not zero, and the transmission gear ratio is zero; or, when the lubricating oil pressure is less than a preset minimum pressure threshold, the transmission input speed signal is not zero, and the temperature is less than or equal to a preset maximum temperature threshold, the electronic pump is also configured to operate at a first speed.

8. The gearbox cooling and lubrication system according to claim 4, characterized in that, The MTCU controller is further configured to control the electronic pump to operate at a second speed when the lubricating oil pressure is greater than or equal to a preset minimum pressure threshold and less than or equal to a preset maximum pressure threshold, the temperature is less than or equal to a preset maximum temperature threshold, the transmission input speed signal is not zero, and the transmission gear ratio is between the intermediate gear ratio and the maximum gear ratio.

9. The gearbox cooling and lubrication system according to claim 4, characterized in that, The MTCU controller is further configured to control the electronic pump to operate at a third speed when the lubricating oil pressure is greater than or equal to a preset minimum pressure threshold and less than or equal to a preset maximum pressure threshold, the temperature is less than or equal to a preset maximum temperature threshold, the transmission speed signal is not zero, and the transmission gear ratio is between the first gear ratio and the intermediate gear ratio; or when the lubricating oil pressure is less than a preset minimum pressure threshold, the transmission input speed signal is not zero, and the temperature is greater than a preset maximum temperature threshold.

10. A method for cooling and lubricating a gearbox, characterized in that, The method is applied to the system according to any one of claims 1-9, and the method includes: When the temperature of the lubricating oil in the oil pan is lower than the first temperature threshold, the MTCU controller controls the opening of the thermostat channel and the closing of the cooler channel. When the temperature is greater than or equal to a first temperature threshold and lower than a second temperature threshold, the MTCU controller controls the thermostat channel and partially controls the cooler channel to open. When the temperature is greater than or equal to the second temperature threshold, the MTCU controller controls the thermostat channel to close and the cooler channel to open completely.

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