An off-line electric drive cleanliness control method

Abstract

The present invention provides an offline electric drive cleanliness control method, including an electric drive cooling and lubricating system and the following steps: setting an offline cycle of a filter press in the electric drive cooling and lubricating system; in the offline cycle, the electronic pump in the electric drive cooling and lubricating system directly sends the oil filtered by the suction filter to the oil cooler, and the oil output by the oil cooler is directly sent to the drive motor or the reduction box; when the offline cycle requirements are met, the electronic pump directly sends the oil filtered by the suction filter to the filter press, and the oil output by the filter press is sent to the drive motor or the reduction box, or sent to the oil tank of the electric drive cooling and lubricating system, and the drive motor and the reduction box are in a closed state. The filter press of the electric drive cooling and lubricating system is independent and does not work with the operation of the cooling and lubricating system. The oil of the electric drive system is filtered in an "offline" working mode, which avoids the problems of reduced flow, overheating of the motor, ablation, etc. caused by filter element blockage in the traditional solution, and reduces the cost of components.

Description

Technical Field

[0001] The present invention relates to the technical field of electric drive cooling and lubrication for new energy vehicles, and in particular to an offline electric drive cleanliness control method. Background Art

[0002] At present, the electric drive cooling and lubrication system of new energy vehicles is mainly composed of hardware such as suction filter, electronic pump, filter press, oil cooler, etc. These hardware are indispensable for the oil-cooled electric drive system of new energy vehicles. When working, such as the electric drive cooling and lubrication system in the self-test method of the electric drive cooling and lubrication system in the authorization announcement number CN117704260B, and Fig.11 As shown, the electronic pump is running, drawing oil from the suction filter (coarse filter), and pumping the oil into the filter press for fine filtration, and then entering the oil cooler for heat exchange. One channel of oil is sent to the drive motor for lubrication and cooling, and the other channel of oil is sent to the reduction gearbox for lubrication and cooling. Among them, the resistance of the filter press accounts for 1 / 2 of the back pressure of the electronic pump, and a larger power electronic pump is required to ensure the target flow, which increases the cost of parts. At the same time, since the filter press continuously captures pollutants during the operation of the system, as the filter element continues to be blocked, the resistance of the filter element increases, which can easily lead to a reduction in the system flow, and then cause problems such as overheating and abnormal wear of the system. Summary of the invention

[0003] In view of the problems in the prior art, the present invention provides an off-line electric drive cleanliness control method, which aims to achieve off-line filtration of the filter press without affecting the normal operation of the electric drive.

[0004] An off-line electric drive cleanliness control method includes an electric drive cooling and lubrication system and the following steps:

[0005] Step 1: Set the offline period of the filter press in the electric drive cooling and lubrication system;

[0006] Step 2: During the offline period, the electronic pump in the electric drive cooling and lubrication system directly sends the oil filtered by the suction filter to the oil cooler, and the oil output by the oil cooler is directly sent to the drive motor or the reduction box;

[0007] Step 3: When the offline cycle requirements are met, the electronic pump sends the oil filtered by the suction filter directly to the filter press, and the oil output by the filter press is sent to the drive motor or the reduction box, or to the oil tank of the electric drive cooling and lubrication system and the drive motor and the reduction box are turned off.

[0008] Furthermore: by monitoring the curve of the change of electric drive oil cleanliness with vehicle mileage in the vehicle durability test, it is obtained that when the vehicle runs to A kilometers, the oil cleanliness exceeds the preset upper limit value, and the vehicle mileage less than A kilometers is selected as the offline period.

[0009] Further, a first one-way valve is arranged between the suction filter and the electronic pump, and the conducting direction of the first one-way valve is from the suction filter to the electronic pump; a second one-way valve is arranged between the electronic pump and the oil cooler, and the conducting direction of the second one-way valve is from the electronic pump to the oil cooler; a third one-way valve is arranged between the common end of the first one-way valve and the suction filter and the common end of the second one-way valve and the electronic pump, and the conducting direction of the third one-way valve is from the suction filter to the electronic pump, and the electronic pump is a bidirectional electronic pump; a fourth one-way valve and a pressure filter are arranged in sequence between the common end of the first one-way valve and the electronic pump and the oil tank, and the conducting direction of the fourth one-way valve is from the electronic pump to the pressure filter;

[0010] In step 2, the electronic pump rotates forward, and the oil is sent to the oil cooler after passing through the suction filter, the first one-way valve, the electronic pump, and the second one-way valve in sequence; in step 3, the electronic pump rotates reversely, and the oil is sent back to the oil tank after passing through the suction filter, the third one-way valve, the electronic pump, the fourth one-way valve, and the filter press in sequence.

[0011] Further, a first connection node is provided on the pipeline between the fourth one-way valve and the filter press, and a second connection node is provided on the pipeline between the filter press and the oil tank;

[0012] In step 2, the filter press is not connected to the first connection node and the second connection node; in step 3, after the filter press is connected to the first connection node and the second connection node, the electronic pump is started, and the filter press is removed after the oil cleaning of the electric drive cooling and lubrication system is completed.

[0013] Further, a solenoid valve is provided between the electronic pump and the oil cooler, a first branch is provided at a common end of the solenoid valve and the oil cooler, a second branch is provided at a common end of the solenoid valve and the electronic pump, and both the first branch and the second branch are connected to the filter press through an interface;

[0014] In step 2, the filter press is not connected to the first branch and the second branch; in step 3, after the filter press is connected to the first branch and the second branch, the electronic pump is started, and the filter press is removed after the oil of the electric drive cooling and lubrication system is cleaned.

[0015] Further: the filter press is an industrial filter.

[0016] Further, a three-way electric control switch is arranged between the electronic pump and the oil cooler, the oil inlet of the three-way electric control switch is connected to the electronic pump, and the first oil outlet of the three-way electric control switch is connected to the oil inlet of the oil cooler; the second oil outlet of the three-way electric control switch is connected to the oil tank after passing through the filter press;

[0017] In step 2, the oil is sent to the oil cooler after passing through the suction filter, the electronic pump, and the three-way electric control switch in sequence; in step 3, the oil is sent back to the oil tank after passing through the suction filter, the electronic pump, the three-way electric control switch, and the filter press in sequence.

[0018] Further, a three-way electric control switch is arranged between the electronic pump and the oil cooler, the oil inlet of the three-way electric control switch is connected to the electronic pump, and the first oil outlet of the three-way electric control switch is connected to the oil inlet of the oil cooler; the second oil outlet is connected to the oil inlet of the oil cooler after passing through the pressure filter and the fifth one-way valve in sequence, and the conduction direction of the fifth one-way valve is from the pressure filter to the oil cooler;

[0019] In step 2, the oil is sent to the oil cooler after passing through the suction filter, the electronic pump, and the three-way electric control switch in sequence; in step 3, the oil is sent to the drive motor or the reduction box after passing through the suction filter, the electronic pump, the three-way electric control switch, the pressure filter, the fifth one-way valve, and the oil cooler in sequence, and the drive motor and the reduction box are in the closed state.

[0020] The beneficial effects of the present invention are as follows: the filter press (fine filter) of the cooling and lubrication system is separated out and does not work with the operation of the cooling and lubrication system, and the oil of the electric drive system is filtered in an "offline" working mode to control the cleanliness of the electric drive oil; after the filter press is arranged offline, whether it is blocked or not does not affect the flow of the cooling and lubrication system, thereby avoiding the problems of reduced flow, overheating of the motor, and ablation due to blockage of the filter element in the traditional solution; during the normal operation of the cooling and lubrication system, the filter press does not generate resistance, and only the oil cooler behind the electronic pump generates resistance, so its load is greatly reduced, the power of the electronic pump can be greatly reduced, and the cost of parts is reduced; when the system is running in an offline oil cleaning condition, the flow of the electronic pump is only provided to the filter press for filtration, and the reduction in system flow caused by blockage of the filter press will not affect the electric drive, so the filter element of the filter press can be allowed to be more seriously blocked than when used online, thereby increasing the service life of the filter press when offline and the reliability of the system. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a flow chart of the present invention;

[0022] Figure 2 It is a schematic structural diagram of the electric drive cooling and lubrication system in the first embodiment of the present invention;

[0023] Figure 3 is the oil cleanliness curve of the electric drive system without a pressure filter in the present invention;

[0024] Figure 4 The oil cleanliness curve of the electric drive system with online filtration by the filter press;

[0025] Figure 5 is a target cleanliness curve of the first embodiment of the present invention;

[0026] Figure 6 is a comparison curve of oil cleanliness control in the present invention;

[0027] Figure 7It is a schematic structural diagram of an electric drive cooling and lubrication system in a second embodiment of the present invention;

[0028] Figure 8 It is a schematic structural diagram of an electric drive cooling and lubrication system in a third embodiment of the present invention;

[0029] Fig. 9 It is a schematic structural diagram of an electric drive cooling and lubrication system in a fourth embodiment of the present invention;

[0030] Fig.10 It is a structural schematic diagram of an electric drive cooling and lubrication system in a fifth embodiment of the present invention;

[0031] Fig.11 It is a schematic diagram of the structure of the electric drive cooling and lubrication system in the prior art. DETAILED DESCRIPTION

[0032] The present invention is described in detail below in conjunction with the accompanying drawings. The embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements with the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be interpreted as limiting the present invention. The directional terms such as left, middle, right, top, and bottom in the embodiments of the present invention are only relative concepts or are based on the normal use state of the product, and should not be considered as restrictive.

[0033] An offline electric drive cleanliness control method, combined with Figure 1 and Figure 2 As shown, it includes an electric drive cooling and lubrication system and the following steps:

[0034] Step 1: Setting the offline cycle of the filter press 5 in the electric drive cooling and lubrication system; by monitoring the curve of the electric drive oil cleanliness changing with the vehicle mileage in the vehicle endurance test, it is obtained that when the vehicle runs to A kilometers, the oil cleanliness exceeds the preset upper limit value, and the vehicle mileage less than A kilometers is selected as the offline cycle, where A is a positive number;

[0035] Step 2: During the offline period, the electronic pump 4 in the electric drive cooling and lubrication system directly sends the oil filtered by the suction filter 7 to the oil cooler 2, and the oil output by the oil cooler 2 is directly sent to the drive motor 3 or the reduction box 1, that is, the filter press 5 does not participate in the filtering of the oil;

[0036] Step 3: When the offline cycle requirements are met, the electronic pump 4 directly sends the oil filtered by the suction filter 7 to the filter press 5, and the oil output by the filter press 5 is sent to the drive motor 3 or the reduction box 1, or sent to the oil tank 6 of the electric drive cooling and lubrication system and the drive motor 3 and the reduction box 1 are turned off.

[0037] Among them, Figure 1 As shown, a first one-way valve 81 is provided between the suction filter 7 and the electronic pump 4, and the conducting direction of the first one-way valve 81 is from the suction filter 7 to the electronic pump 4; a second one-way valve 82 is provided between the electronic pump 4 and the oil cooler 2, and the conducting direction of the second one-way valve 82 is from the electronic pump 4 to the oil cooler 2; a third one-way valve 83 is provided between the common end of the first one-way valve 81 and the suction filter 7 and the common end of the second one-way valve 82 and the electronic pump 4, and the conducting direction of the third one-way valve 83 is The direction is from the suction filter 7 to the electronic pump 4, and the electronic pump 4 is a bidirectional electronic pump; a fourth one-way valve 84 and a pressure filter 5 are sequentially arranged between the common end of the first one-way valve 81 and the electronic pump 4 and the oil tank 6, and the conduction direction of the fourth one-way valve 84 is from the electronic pump 4 to the pressure filter 5; since the pressure filter does not participate in the work when the assembly is working, the resistance is reduced, and the power of the electronic pump can be greatly reduced. In this embodiment, the cost of reducing the power of the electronic pump is much greater than that of adding three one-way valves;

[0038] In step 2, the electronic pump 4 rotates forward, and the oil is sent to the oil cooler 2 after passing through the suction filter 7, the first one-way valve 81, the electronic pump 4, and the second one-way valve 82 in sequence; in step 3, the electronic pump 4 rotates reversely, and the oil is sent back to the oil tank after passing through the suction filter 7, the third one-way valve 83, the electronic pump 4, the fourth one-way valve 84, and the filter press 5 in sequence.

[0039] In addition, the oil cleanliness of the electric drive system is mainly purified by the filter press, and the oil cleanliness can be rated according to the ISO-16232 standard; the oil cleanliness of the vehicle electric drive system is statistically analyzed, and the statistical content is the cleanliness level of 15μm particles in the oil. The higher the level, the more corresponding particles there are, and the dirtier the oil is. The statistical cycle is 20,000 kilometers. Figure 3 As shown in the figure, when the electric drive system of the vehicle does not have a filter press, it can be seen that the cleanliness of the electric drive oil starts from 0 kilometers after leaving the factory. As the mileage of the vehicle increases, the cleanliness level also increases rapidly. When the vehicle travels to 15,000 kilometers, the cleanliness of the oil in the electric drive system has exceeded the upper limit of the cleanliness level, and the oil can no longer be used, otherwise it will aggravate the wear of the assembly; Figure 4 As shown in the figure, when the vehicle's electric drive system has a filter press and the filter press is filtered online, it can be seen that the oil cleanliness of the assembly has been controlled at a good cleanliness level within 20,000 kilometers; combined with Figure 5 and Figure 6 As shown, according to the present invention, when the vehicle is running, the oil cleanliness of the assembly increases in the state without a pressure filter, and the oil is cleaned offline several times to reduce the cleanliness of the oil to a lower level in a short time. The overall oil cleanliness curve fluctuates in a sawtooth shape with the increase of mileage, thereby achieving control of the oil cleanliness.

[0040] Second embodiment:

[0041] An offline electric drive cleanliness control method, combined with Figure 1 and Figure 2 As shown, it includes an electric drive cooling and lubrication system and the following steps:

[0042] Step 1: Setting the offline cycle of the filter press 5 in the electric drive cooling and lubrication system; by monitoring the curve of the electric drive oil cleanliness changing with the vehicle mileage in the vehicle endurance test, it is obtained that when the vehicle runs to A kilometers, the oil cleanliness exceeds the preset upper limit value, and the vehicle mileage less than A kilometers is selected as the offline cycle, where A is a positive number;

[0043] Step 2: During the offline period, the electronic pump 4 in the electric drive cooling and lubrication system directly sends the oil filtered by the suction filter 7 to the oil cooler 2, and the oil output by the oil cooler 2 is directly sent to the drive motor 3 or the reduction box 1, that is, the filter press 5 does not participate in the filtering of the oil;

[0044] Step 3: When the offline cycle requirements are met, the electronic pump 4 directly sends the oil filtered by the suction filter 7 to the filter press 5, and the oil output by the filter press 5 is sent to the drive motor 3 or the reduction box 1, or sent to the oil tank 6 of the electric drive cooling and lubrication system and the drive motor 3 and the reduction box 1 are turned off.

[0045] Among them, combined Figure 7 As shown, a first connection node 91 is provided on the pipeline between the fourth one-way valve 84 and the filter press 5, and a second connection node 91 is provided on the pipeline between the filter press 5 and the oil tank 6;

[0046] In step 2, the filter press 5 is not connected to the first connection node 91 and the second connection node 92, that is, the filter press 5 is not installed on the vehicle; in step 3, after the filter press 5 is connected to the first connection node 91 and the second connection node 92, the electronic pump 4 is started, and after the oil cleaning of the electric drive cooling and lubrication system is completed, the filter press 5 is removed so that the filter press 5 no longer runs with the vehicle.

[0047] Third embodiment:

[0048] An offline electric drive cleanliness control method, combined with Figure 1 and Figure 2 As shown, it includes an electric drive cooling and lubrication system and the following steps:

[0049] Step 1: Setting the offline cycle of the filter press 5 in the electric drive cooling and lubrication system; by monitoring the curve of the electric drive oil cleanliness changing with the vehicle mileage in the vehicle endurance test, it is obtained that when the vehicle runs to A kilometers, the oil cleanliness exceeds the preset upper limit value, and the vehicle mileage less than A kilometers is selected as the offline cycle, where A is a positive number;

[0050] Step 2: During the offline period, the electronic pump 4 in the electric drive cooling and lubrication system directly sends the oil filtered by the suction filter 7 to the oil cooler 2, and the oil output by the oil cooler 2 is directly sent to the drive motor 3 or the reduction box 1, that is, the filter press 5 does not participate in the filtering of the oil;

[0051] Step 3: When the offline cycle requirements are met, the electronic pump 4 directly sends the oil filtered by the suction filter 7 to the filter press 5, and the oil output by the filter press 5 is sent to the drive motor 3 or the reduction box 1, or sent to the oil tank 6 of the electric drive cooling and lubrication system and the drive motor 3 and the reduction box 1 are turned off.

[0052] Among them, combined Figure 8 As shown, a solenoid valve 101 is provided between the electronic pump 4 and the oil cooler 2, a first branch 93 is provided at the common end of the solenoid valve 101 and the oil cooler 2, and a second branch 94 is provided at the common end of the solenoid valve 101 and the electronic pump 4, and the first branch 93 and the second branch 94 are both connected to the filter press 5 through an interface; in step 2, the filter press 5 is not connected to the first branch 93 and the second branch 94, that is, the filter press 5 is not installed on the vehicle; in step 3, after the filter press 5 is connected to the first branch 93 and the second branch 94, the electronic pump 4 is started, and after the oil cleaning of the electric drive cooling and lubrication system is completed, the filter press 5 is removed so that the filter press 5 no longer runs with the vehicle.

[0053] The filter press 5 may be an industrial filter, and offline filtration may be included in the vehicle maintenance scope. The oil may be filtered using the industrial filter at a service station, thereby further reducing vehicle use costs.

[0054] Fourth embodiment:

[0055] An offline electric drive cleanliness control method, combined with Figure 1 and Figure 2 As shown, it includes an electric drive cooling and lubrication system and the following steps:

[0056] Step 1: Setting the offline cycle of the filter press 5 in the electric drive cooling and lubrication system; by monitoring the curve of the electric drive oil cleanliness changing with the vehicle mileage in the vehicle endurance test, it is obtained that when the vehicle runs to A kilometers, the oil cleanliness exceeds the preset upper limit value, and the vehicle mileage less than A kilometers is selected as the offline cycle, where A is a positive number;

[0057] Step 2: During the offline period, the electronic pump 4 in the electric drive cooling and lubrication system directly sends the oil filtered by the suction filter 7 to the oil cooler 2, and the oil output by the oil cooler 2 is directly sent to the drive motor 3 or the reduction box 1, that is, the filter press 5 does not participate in the filtering of the oil;

[0058] Step 3: When the offline cycle requirements are met, the electronic pump 4 directly sends the oil filtered by the suction filter 7 to the filter press 5, and the oil output by the filter press 5 is sent to the drive motor 3 or the reduction box 1, or sent to the oil tank 6 of the electric drive cooling and lubrication system and the drive motor 3 and the reduction box 1 are turned off.

[0059] Among them, combined Fig. 9 As shown, a three-way electric control switch 102 is arranged between the electronic pump 4 and the oil cooler 2, the oil inlet of the three-way electric control switch 102 is connected to the electronic pump 4, and the first oil outlet of the three-way electric control switch 102 is connected to the oil inlet of the oil cooler 2; the second oil outlet of the three-way electric control switch 102 is connected to the oil tank 6 after passing through the filter press 5; in step 2, the oil is sent to the oil cooler 2 after passing through the suction filter 7, the electronic pump 4, and the three-way electric control switch 102 in sequence; in step 3, the oil is sent back to the oil tank 6 after passing through the suction filter 7, the electronic pump 4, the three-way electric control switch 102, and the filter press 5 in sequence.

[0060] Fifth embodiment:

[0061] An offline electric drive cleanliness control method, combined with Figure 1 and Figure 2 As shown, it includes an electric drive cooling and lubrication system and the following steps:

[0062] Step 1: Setting the offline cycle of the filter press 5 in the electric drive cooling and lubrication system; by monitoring the curve of the electric drive oil cleanliness changing with the vehicle mileage in the vehicle endurance test, it is obtained that when the vehicle runs to A kilometers, the oil cleanliness exceeds the preset upper limit value, and the vehicle mileage less than A kilometers is selected as the offline cycle, where A is a positive number;

[0063] Step 2: During the offline period, the electronic pump 4 in the electric drive cooling and lubrication system directly sends the oil filtered by the suction filter 7 to the oil cooler 2, and the oil output by the oil cooler 2 is directly sent to the drive motor 3 or the reduction box 1, that is, the filter press 5 does not participate in the filtering of the oil;

[0064] Step 3: When the offline cycle requirements are met, the electronic pump 4 directly sends the oil filtered by the suction filter 7 to the filter press 5, and the oil output by the filter press 5 is sent to the drive motor 3 or the reduction box 1, or sent to the oil tank 6 of the electric drive cooling and lubrication system and the drive motor 3 and the reduction box 1 are turned off.

[0065] Among them, combined Fig.10As shown, a three-way electric control switch 102 is arranged between the electronic pump 4 and the oil cooler 2, the oil inlet of the three-way electric control switch 102 is connected to the electronic pump 4, and the first oil outlet of the three-way electric control switch 102 is connected to the oil inlet of the oil cooler 2; the second oil outlet is connected to the oil inlet of the oil cooler 2 after passing through the pressure filter 5 and the fifth one-way valve 85 in sequence, and the conducting direction of the fifth one-way valve 85 is from the pressure filter 5 to the oil cooler 2; in step 2, the oil is sent to the oil cooler 2 after passing through the suction filter 7, the electronic pump 4, and the three-way electric control switch 102 in sequence; in step 3, the oil is sent to the drive motor 3 or the reduction box 1 after passing through the suction filter 7, the electronic pump 4, the three-way electric control switch 102, the pressure filter 5, the fifth one-way valve 85, and the oil cooler 2 in sequence, and the drive motor 3 and the reduction box 1 are closed.

[0066] In the present invention, in some implementations, a solenoid valve or an electric control switch is used to control the on and off of the oil circuit, and in some embodiments, a one-way valve is used in conjunction with a two-way electronic pump to select the on and off of the oil circuit; the cost of the solenoid valve and the electric control switch is much higher than that of the one-way valve, and the cost of an independent one-way valve is about one or two yuan; but the cost of the solenoid valve or the electric control switch is tens of yuan, especially the cost of a two-position three-way solenoid valve is higher. In addition, the sealing gap of the solenoid valve is relatively small. If the filter press does not participate in the work during normal operation of the vehicle, the cleanliness of the oil is not good, and impurities are easily retained in the gap of the solenoid valve and cause the solenoid valve to get stuck; the sealing gap of the one-way valve is larger and the maximum opening is larger, so it is not easy to get stuck; therefore, a one-way valve is used in conjunction with a two-way electronic pump to realize the offline operation of the filter press in the electric drive cooling and lubrication system, which has the lowest cost and stable performance.

[0067] The above shows and describes the basic principles, main features and advantages of the present invention. It should be understood by those skilled in the art that the present invention is not limited to the above embodiments. The above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, which fall within the scope of the present invention. The scope of protection of the present invention is defined by the attached claims and their equivalents.

Claims

1. An off-line electric drive cleanliness control method, characterized in that: Including the electric drive cooling and lubrication system and the following steps: Step 1: Set the offline period of the filter press in the electric drive cooling and lubrication system; Step 2: During the offline period, the electronic pump in the electric drive cooling and lubrication system directly sends the oil filtered by the suction filter to the oil cooler, and the oil output by the oil cooler is directly sent to the drive motor or the reduction box; Step 3: When the offline cycle requirements are met, the electronic pump directly sends the oil filtered by the suction filter into the filter press, and the oil output by the filter press is sent to the oil tank of the electric drive cooling and lubrication system, and the drive motor and the reduction box are turned off; Among them, a first one-way valve is arranged between the suction filter and the electronic pump, and the conducting direction of the first one-way valve is from the suction filter to the electronic pump; a second one-way valve is arranged between the electronic pump and the oil cooler, and the conducting direction of the second one-way valve is from the electronic pump to the oil cooler; a third one-way valve is arranged between the common end of the first one-way valve and the suction filter and the common end of the second one-way valve and the electronic pump, and the conducting direction of the third one-way valve is from the suction filter to the electronic pump, and the electronic pump is a bidirectional electronic pump; a fourth one-way valve and a pressure filter are arranged in sequence between the common end of the first one-way valve and the electronic pump and the oil tank, and the conducting direction of the fourth one-way valve is from the electronic pump to the pressure filter; in step 2, the electronic pump rotates in the forward direction, and the oil is sent to the oil cooler after passing through the suction filter, the first one-way valve, the electronic pump, and the second one-way valve in sequence; in step 3, the electronic pump rotates in the reverse direction, and the oil is sent back to the oil tank after passing through the suction filter, the third one-way valve, the electronic pump, the fourth one-way valve, and the pressure filter in sequence.

2. The off-line electric drive cleanliness control method according to claim 1, characterized in that: By monitoring the curve of electric drive oil cleanliness changing with vehicle mileage in the vehicle durability test, it is found that when the vehicle runs to A kilometers, the oil cleanliness exceeds the preset upper limit value, and the vehicle mileage less than A kilometers is selected as the offline cycle.

3. The off-line electric drive cleanliness control method according to claim 1, characterized in that: A first connection node is provided on the pipeline between the fourth one-way valve and the filter press, and a second connection node is provided on the pipeline between the filter press and the oil tank; In step 2, the filter press is not connected to the first connection node and the second connection node; in step 3, after the filter press is connected to the first connection node and the second connection node, the electronic pump is started, and the filter press is removed after the oil cleaning of the electric drive cooling and lubrication system is completed.

Images