Method for providing supplementary lubrication for directional lubrication system through oil cooling system

Abstract

The invention discloses a method for providing supplementary lubrication for a directional lubrication system by using an oil cooling system, which is characterized in that a communicating pipeline is arranged between the front section of an oil return pipeline of a cooling oil duct of the oil cooling system and an oil conveying pipeline of a directional oil duct of the directional lubrication system; when the directional lubricating system cannot timely and sufficiently supply lubricating oil to all directional lubricating components, the oil cooling system conveys the lubricating oil to the oil conveying pipeline of the directional lubricating system through the communicating pipeline, and the communicating pipeline is closed when the directional lubricating system can normally supply oil. The directional lubrication system has the advantages that when the directional lubrication system does not supply oil to a part needing directional lubrication in time and is not sufficient, the oil cooling system originally independent of the directional lubrication system can be used for temporarily replacing the directional lubrication system to supply required lubricating oil to the part needing directional lubrication in time; dry grinding of related parts which start to rotate due to no oil and little oil is avoided; the cooling effect of the oil cooling system on the gearbox is not influenced at all; and combination and separation of functions of the two systems can be automatically switched.

Description

Technical Field

[0001] The invention relates to a method for providing supplementary lubrication for a directional lubrication system by utilizing an oil cooling system, and belongs to the technical field of gearbox lubrication. Background Art

[0002] In the electric drive project of mining trucks, in order to solve the lubrication and cooling problems of the electric drive gearbox, we adopted the solution of using a mechanical pump to lubricate the parts that need directional lubrication. The parts that need directional lubrication here refer to bearings, gears, synchronizers, etc. that are not easily covered by splashing lubricating oil (the large gear immersed in the lubricating oil at the bottom of the gearbox stirs up splashing lubricating oil when rotating at high speed). Then an electronic oil pump is used to suck oil from the bottom of the inner cavity of the electric drive gearbox of the mining truck, and the pumped lubricating oil enters the heat exchanger through the oil holes designed on the shell for cooling, and then transported back to the inner cavity of the gearbox to cool the gearbox. The mechanical pump is used to lubricate specific parts in a specific area, and the electronic oil pump plus the heat exchanger is used to cool the lubricating oil in the inner cavity. Lubrication and cooling were originally two independent systems.

[0003] The advantage of a mechanical pump is that it has a large driving torque and is not prone to jamming. However, on the one hand, the drive shaft can only rotate when the wheels and shafts inside the gearbox are running. The drive shaft is connected to the mechanical pump, and the speed of the drive shaft's rotation directly affects the displacement of the mechanical pump. Especially during the startup phase, due to the low shaft speed driving the mechanical pump and the small displacement of the mechanical pump, there is a risk of insufficient lubrication for parts that require directional lubrication. On the other hand, it takes a certain amount of time for the lubricating oil to reach each part that requires directional lubrication through the oil channel. Before the lubricating oil reaches each part that requires directional lubrication through the oil channel, there is also a risk of poor dry lubrication. Summary of the invention

[0004] The technical problem to be solved by the present invention is: how to use the oil cooling system to implement supplementary oil supply when the directional lubrication system does not supply oil to the components requiring directional lubrication in a timely and insufficient manner.

[0005] In view of the above problems, the technical solution proposed by the present invention is: A method for providing supplementary lubrication for a directional lubrication system using an oil cooling system comprises setting a connecting pipeline between the front section of the return oil pipeline of the cooling oil channel of the oil cooling system and the oil delivery pipeline of the directional oil channel of the directional lubrication system; when the directional lubrication system cannot supply lubricating oil to each directional lubrication component in a timely and sufficient manner, the oil cooling system delivers lubricating oil to the oil delivery pipeline of the directional lubrication system through the connecting pipeline, and the connecting pipeline is closed when the directional lubrication system can supply oil normally.

[0006] When the front section of the return oil pipeline of the cooling oil channel transports lubricating oil to the oil delivery pipeline of the directional lubrication system through the connecting pipeline, the rear section of the return oil pipeline is closed. When the connecting pipeline is closed, the rear section of the return oil pipeline of the oil cooling system is opened.

[0007] To achieve alternate closing and opening of the connecting pipeline and the oil return pipeline, the measures taken include setting up a joint control mechanism between the oil cooling system and the directional lubrication system.

[0008] The measures taken also include setting the oil pressure of the cooling oil channel return line to be lower than the oil pressure of the directional oil channel delivery line under normal operating conditions. Under abnormal operating conditions where the mechanical pump speed of the directional lubrication system is low, the oil pressure of the return line is higher than the oil pressure of the delivery line.

[0009] The joint control mechanism includes setting a one-way valve controlled by the upper and lower pressure differences on the connecting pipeline so as to only allow the oil to flow to the oil pipeline, and setting a pressure control device for opening and closing the rear section of the return oil pipeline between the rear section of the return oil pipeline and the oil pipeline; when the oil pressure of the oil pipeline is lower than the oil pressure of the return oil pipeline 5, the one-way valve automatically opens the connecting pipeline, and the pressure control device automatically closes the rear section of the return oil pipeline of the oil cooling system; when the oil pipeline has the oil pressure under normal working conditions, the one-way valve automatically closes the connecting pipeline, and the pressure control device automatically opens the rear section of the return oil pipeline.

[0010] The pressure control device includes a cylinder sleeve body with a cylinder cavity, a piston valve is arranged in the cylinder cavity, and the cylinder cavity is divided into an upper cylinder cavity and a lower cylinder cavity. The upper cylinder cavity is connected with the oil delivery pipeline, and a compression spring pre-compressed by the piston valve is arranged in the lower cylinder cavity. The piston valve is provided with a valve hole that passes through the left and right sides, and an oil inlet hole connected to the front section of the return oil pipeline and an oil outlet hole connected to the rear section of the return oil pipeline are respectively arranged on the left and right cylinder walls of the cylinder cavity. When the piston valve is lifted by the compression spring so that the valve hole is higher than the oil inlet hole and the oil outlet hole on both sides, the rear section of the return oil pipeline is closed, and when the valve hole of the piston valve is connected to the oil inlet hole and the oil outlet hole on both sides at the same height, the rear section of the return oil pipeline is opened.

[0011] The piston valve is limited upward so that the piston valve pre-compresses the compression spring. When the oil pressure in the oil pipeline is lower than the oil pressure in the oil return pipeline, the pressure of the oil pressure in the upper cylinder chamber on the piston valve is insufficient to overcome the pre-compression force of the compression spring and prevent the piston valve from moving downward, thereby keeping the rear section of the return oil pipeline closed. The piston valve is limited downward so that when the oil pressure in the oil pipeline is higher than the oil pressure in the return oil pipeline, the pressure of the oil pressure in the upper cylinder chamber on the piston valve is able to overcome the pre-compression force of the compression spring and cause the piston valve to move downward and stop at the downward limit, thereby ensuring that the valve hole of the piston valve is connected at the same height with the oil inlet and outlet holes on both sides, thereby opening the rear section of the return oil pipeline of the oil cooling system.

[0012] The upward limiting of the piston valve is implemented by arranging an upper limiting column capable of supporting the top wall of the upper cylinder cavity at the top of the piston valve, and the downward limiting of the piston valve is implemented by arranging a lower limiting column capable of supporting the bottom end of the piston valve at the bottom of the lower cylinder cavity.

[0013] The joint control mechanism includes setting a control system, setting a solenoid valve 1 on the connecting pipeline, setting a solenoid valve 2 on the return oil pipeline, and setting an oil pressure sensor 1 and an oil pressure sensor 2 in the directional oil channel and the cooling oil channel respectively. The control system controls the solenoid valve 1 to open or close the connecting pipeline, and controls the solenoid valve 2 to open or close the return oil pipeline.

[0014] The above method: Applied to the initial stage of mining truck startup, it includes the following steps: S1. Turn on the electronic oil pump of the oil cooling system. The lubricating oil pumped out by the electronic oil pump first enters the oil delivery pipeline of the directional oil channel of the directional lubrication system through the connecting pipeline, and reaches each directional lubrication component in a timely and sufficient manner along the oil delivery pipeline. During this process, the rear section of the oil return pipeline of the oil cooling system is closed; S2, start the mining truck, the axle in the gearbox rotates, and the mechanical pump of the directional lubrication system starts synchronously. The speed does not reach the point where the oil pressure of the oil delivery pipeline is greater than the oil pressure of the oil return pipeline. The directional lubrication components still rely on the lubricating oil pumped out by the electronic oil pump for lubrication; S3. The axle in the gearbox reaches the operating condition, the speed of the mechanical pump reaches a level that allows the oil pressure in the oil delivery pipeline to be greater than the oil pressure in the oil return pipeline, the one-way valve closes the connecting pipeline, the pressure control device opens the rear section of the oil return pipeline, and the directional lubrication system and the oil cooling system perform their respective functions. Beneficial Effects

[0015] 1. When the directional lubrication system fails to supply oil to the parts that need directional lubrication in a timely and sufficient manner, the oil cooling system that is originally independent of the directional lubrication system can be used to temporarily replace the directional lubrication system to provide the required lubricating oil to the parts that need directional lubrication in a timely manner, so as to avoid dry grinding of the related parts that have started to rotate due to lack of oil or insufficient oil; 2. It does not affect the cooling effect of the oil cooling system on the gearbox at all; 3. The directional lubrication system and oil cooling system can be automatically switched between combination and separation; 4. Simple structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the layout of some external components of the oil cooling system and the directional lubrication system at one end of the gearbox described in Example 1; Figure 2 It is a structural stereoscopic schematic diagram of the main components of the gearbox oil cooling system and the directional lubrication system according to the first embodiment; Figure 3 This is a three-dimensional schematic diagram of the flow path of the gearbox oil cooling system and the directional lubrication system according to the first embodiment, in which the main branch of the oil pipeline is cut away; Figure 4This is a schematic diagram of the flow channel joint control structure of the gearbox oil cooling system and the directional lubrication system according to the first embodiment, in which the oil cooling system replenishes lubricating oil to the directional lubrication system, and arrow A indicates the flow direction of the box bottom lubricating oil from the oil cooling system to the directional lubrication system; Figure 5 for Figure 4 A partial schematic diagram of Figure 6 This is a schematic diagram of the flow channel joint control structure of the gearbox oil cooling system and the directional lubrication system according to the first embodiment. The figure shows that the oil cooling system and the directional lubrication system are functionally separated and work independently. Arrow A indicates that the bottom lubricating oil of the gearbox is directly returned to the bottom of the gearbox after being cooled by the oil cooling system, and arrow B indicates that the bottom lubricating oil of the gearbox is transported by the directional lubrication system to the components that require directional lubrication; Figure 7 A one-way valve that can be used in embodiment 1; Figure 8 This is a joint control structure described in Example 2.

[0017] In the figure: 1, cooling oil channel; 101, oil suction pipeline 1; 102, oil return pipeline; 2, electronic oil pump; 3, heat exchanger; 4, directional oil channel; 401, oil suction pipeline 2; 402, oil delivery pipeline; 4020, oil collection and distribution chamber; 4021, branch 1; 4022, branch 2; 5, mechanical pump; 6, connecting pipeline; 7, one-way valve; 701, valve chamber; 702, valve ball; 703, tapered hole; 8, pressure control device; 801 , cylinder liner; 8011, cylinder chamber; 80111, upper cylinder chamber; 80112, lower cylinder chamber; 8012, oil inlet hole; 8013, oil outlet hole; 8014, exhaust hole; 802, piston valve; 8021, valve hole; 803, compression spring; 804, upper limit column; 805, lower limit column; 806, bolt body; 9, hydraulic pipe; 10, right first and second gear shaft; 11, lubricating oil at the bottom of the box; 12, solenoid valve one; 13, solenoid valve two. DETAILED DESCRIPTION

[0018] like Figure 1 —3, as shown in the figure, the present invention relates to a lubricating oil cooling system (hereinafter referred to as the oil cooling system) and a directional active lubrication system (hereinafter referred to as the directional lubrication system) of a mining truck gearbox. The oil cooling system includes a cooling oil channel 1 composed of an oil suction line 101 and an oil return line 102, an electronic oil pump 2 arranged between the oil suction line 101 and the oil return line 102, and a heat exchanger 3 arranged on the oil return line 102. The directional lubrication system includes a directional oil channel 4 composed of an oil suction line 2 401 and an oil delivery line 402, and a mechanical pump 5 arranged between the oil suction line 2 401 and the oil delivery line 402.

[0019] In the prior art, the electronic oil pump 2 of the oil cooling system sucks the lubricating oil 11 from the bottom of the gearbox through the oil suction line 101, and then flows back to the bottom of the gearbox after being cooled by the heat exchanger 3 arranged on the return oil line 102, thereby achieving moderate cooling of all components in the gearbox.

[0020] The directional lubrication system oil pipeline 402 can be bifurcated into multiple branches as needed, such as Figure 3 , 4 The oil delivery pipeline 402 shown has been bifurcated into branch 1 4021 and branch 2 4022. Branch 1 4021 mainly runs along the axis of the right first and second gear shaft 10 and the right third and fourth gear shaft, and branch 2 4022 mainly runs along the axis of the left first and second gear shaft and the left third and fourth gear shaft. Branch 1 4021 and branch 2 4022 can be further bifurcated to the parts that need directional lubrication. Under working conditions, the right first and second gear shaft 10 drives the mechanical pump 5 to rotate, and the oil suction pipeline 2 401 sucks the bottom lubricating oil 11 from the bottom of the gearbox, and then delivers it to various parts that need directional lubrication through the oil delivery pipeline 402.

[0021] The present invention will be further described below in conjunction with embodiments and drawings: Embodiment 1

[0022] like Figure 1 As shown in FIG. 6 , a method for using an oil cooling system to provide supplementary lubrication for a directional lubrication system is to set a connecting pipeline 6 between the front section of the return oil pipeline 102 of the cooling oil channel 1 of the oil cooling system (preferably after the heat exchanger 3) and the oil delivery pipeline 402 of the directional oil channel 4 of the directional lubrication system. When the directional lubrication system cannot supply lubricating oil to each directional lubrication component in a timely and sufficient manner, the oil cooling system delivers lubricating oil to the oil delivery pipeline 402 of the directional lubrication system through the connecting pipeline 6, and closes the connecting pipeline 6 when the directional lubrication system can supply oil normally. In this way, when the directional lubrication system does not supply lubricating oil to the components that need directional lubrication in a timely and sufficient manner, the oil cooling system that is originally independent of the directional lubrication system is used to temporarily replace the directional lubrication system to provide the required lubricating oil to the components that need directional lubrication in a timely manner, thereby avoiding dry grinding and damage of the related parts that have already started to rotate due to lack of oil or insufficient oil. The connecting pipeline is set after the heat exchanger 3, and all the lubricating oil supplied to the oil delivery pipeline of the directional lubrication system is cooled by the heat exchanger. Therefore, the cooling effect of the gearbox is not affected at all during the process of the oil cooling system serving the directional lubrication system. Here, the failure to supply lubricating oil to each directional lubrication component in a timely and sufficient manner generally refers to the initial stage of starting a mining truck, when the axle in the gearbox begins to rotate, but due to the low speed in the initial stage, the mechanical pump does not pump enough oil and the oil circuit is too long.

[0023] Furthermore, when the front section of the return oil pipeline 102 of the cooling oil channel 1 delivers lubricating oil to the oil delivery pipeline 402 of the directional lubrication system through the connecting pipeline 6, the rear section of the return oil pipeline 102 is closed. When the connecting pipeline 6 is closed, the rear section of the return oil pipeline 102 of the oil cooling system is opened, and the cooled lubricating oil flows back to the bottom of the gearbox through the return oil pipeline 102. In this way, when necessary, all the lubricating oil that jumps out of the electronic oil pump 2 can be supplied to the oil delivery pipeline 402, and after the oil delivery pipeline 402 is supplied with oil, the oil cooling system and the directional lubrication system can perform their own functions independently.

[0024] To achieve the alternate closing and opening of the connecting pipeline 6 and the oil return pipeline 102, the measures taken include setting a joint control mechanism between the oil cooling system and the directional lubrication system.

[0025] In this embodiment, the measures taken also include setting the oil pressure of the return oil pipeline 102 of the cooling oil channel 1 to be lower than the oil pressure of the oil delivery pipeline 402 of the directional oil channel 4 under normal operating conditions. Under abnormal operating conditions where the speed of the mechanical pump 5 of the directional lubrication system is low, the oil pressure of the return oil pipeline 102 is higher than the oil pressure of the oil delivery pipeline 402.

[0026] The joint control mechanism includes setting a one-way valve 7 on the connecting pipeline 6 that can only flow to the oil pipeline 402 and is controlled by the upper and lower pressure differences, and setting a pressure control device 8 for opening and closing the rear section of the return oil pipeline 102 between the rear section of the return oil pipeline 102 and the oil pipeline 402; when the oil pressure of the oil pipeline 402 is lower than the oil pressure of the return oil pipeline 5, the one-way valve 7 automatically opens the connecting pipeline 6, and the pressure control device 8 automatically closes the rear section of the return oil pipeline 102 of the oil cooling system; when the oil pipeline 402 has the oil pressure under normal working conditions, the one-way valve 7 automatically closes the connecting pipeline 6, and the pressure control device 8 automatically opens the rear section of the return oil pipeline 102. This embodiment provides a one-way valve 7 as described below: like Figure 7 As shown, the one-way valve 7 has a valve cavity 701, and a valve ball 702 is arranged in the valve cavity 701. The valve cavity 701 is a cylindrical cavity, and its diameter is larger than the diameter of the valve ball 702. The bottom of the valve cavity 701 is a tapered hole 703. The valve ball 702 falls into the tapered hole 703 to block the tapered hole 703. The upper part of the valve cavity 701 is connected with the upper section of the connecting pipeline 6, and the lower end of the tapered hole 703 is connected with the lower section of the connecting pipeline 6. When the oil pressure of the return oil pipeline 102 is greater than the oil pressure of the oil delivery pipeline 402, the lubricating oil in the lower section of the connecting pipeline 6 lifts the valve ball 702, and the lubricating oil flows upward from the tapered hole 703 through the gap between the valve ball 702 and the inner wall of the valve cavity 701, so that the one-way valve 7 is in an open state. When the oil pressure of the oil return pipeline 102 is lower than the oil pressure of the oil delivery pipeline 402, the valve ball 702 falls back, the tapered hole 703 is blocked, and the one-way valve 7 is in a closed state.

[0027] like Figure 4As shown in FIG. 6 , the pressure control device 8 comprises a cylinder sleeve body 801 having a cylinder cavity 8011, wherein a piston valve 802 is arranged in the cylinder cavity 8011, dividing the cylinder cavity 8011 into an upper cylinder cavity 80111 and a lower cylinder cavity 80112, wherein the upper cylinder cavity 80111 is connected to the oil delivery pipeline 402, a compression spring 803 pressed by the piston valve 802 is arranged in the lower cylinder cavity 80112, a valve hole 8021 extending through the piston valve 802 is arranged on the piston valve 802, and an oil inlet hole 8012 connected to the front section of the return oil pipeline and an oil outlet hole 8013 connected to the rear section of the return oil pipeline 102 are respectively arranged on the left and right cylinder walls of the cylinder cavity 8011. In this way, when the piston valve 802 is lifted by the compression spring 803 so that the valve hole 8021 is higher than the oil inlet hole 8012 and the oil outlet hole 8013 on both sides, the rear section of the return oil pipeline 102 is closed; when the valve hole 8021 of the piston valve 802 is connected at the same height with the oil inlet hole 8012 and the oil outlet hole 8013 on both sides, the rear section of the return oil pipeline 102 is opened.

[0028] A threaded hole with a diameter greater than or equal to the diameter of the cylinder cavity 8011 is provided at the bottom of the cylinder sleeve 801. A bolt body 806 is screwed into the threaded hole from bottom to top at the bottom of the cylinder cavity 8011. The lower limit column is fixed on the bolt body 806, which makes it easy to install the piston valve 802 from the threaded hole.

[0029] In addition, an exhaust hole 8014 is provided in the lower cylinder chamber 80112.

[0030] Furthermore, the piston valve 802 is limited upwardly so that the piston valve 802 pre-compresses the compression spring 803. When the oil pressure in the oil supply pipeline 402 is lower than the oil pressure in the oil return pipeline 102, the pressure of the oil pressure in the upper cylinder chamber 80111 on the piston valve 802 is insufficient to overcome the pre-compression force of the compression spring 803 and prevent the piston valve 802 from moving downward, so as to keep the rear section of the oil return pipeline 102 closed; the piston valve 802 is limited downwardly so that when the oil pressure in the oil supply pipeline 402 is higher than the oil pressure in the oil return pipeline 102, the pressure of the oil pressure in the upper cylinder chamber 80111 on the piston valve 802 can overcome the pre-compression force of the compression spring 803 and cause the piston valve 802 to move downward and stop at the downward limit, so as to ensure that the valve hole 8021 of the piston valve 802 is connected at the same height with the oil inlet hole 8012 and the oil outlet hole 8013 on both sides, thereby opening the rear section of the oil return pipeline 102 of the oil cooling system.

[0031] The above-mentioned upward limiting of the piston valve 802 is specifically implemented by providing an upper limiting column 804 capable of supporting the top wall of the upper cylinder chamber 80111 at the top of the piston valve 802; the above-mentioned downward limiting of the piston valve 802 is specifically implemented by providing a lower limiting column 805 capable of supporting the bottom end of the piston valve 802 at the bottom of the lower cylinder chamber 80112.

[0032] Setting up the joint control mechanism also includes setting up an oil collecting and distributing chamber 4020 on the oil pipeline 402, so that the connecting pipeline 6 is connected to the oil collecting and distributing chamber 4020, and the upper cylinder chamber 80111 is connected to the oil collecting and distributing chamber 4020 through the oil pressure pipe 9, and all branches of the oil pipeline 402 are branched from the oil collecting and distributing chamber 4020.

[0033] The above method, when applied to the initial stage of mining card startup, includes the following steps: S1, the electronic oil pump 2 of the oil cooling system is turned on, and the lubricating oil pumped by the electronic oil pump 2 first enters the oil delivery pipeline 402 of the directional oil channel 4 of the directional lubrication system through the connecting pipeline 6, and is delivered to each directional lubrication component in a timely and sufficient manner along the oil delivery pipeline 402. During this process, the rear section of the oil return pipeline 102 of the oil cooling system is closed; S2, start the mining truck, the axle in the gearbox rotates, and the mechanical pump 5 of the directional lubrication system starts synchronously. The rotation speed does not reach a level that can make the oil pressure of the oil delivery pipeline 402 greater than the oil pressure of the oil return pipeline 102. The directional lubrication components still rely on the lubricating oil pumped by the electronic oil pump 2 for lubrication; S3. The axle in the gearbox operates at normal conditions, the speed of the mechanical pump 5 reaches a level that allows the oil pressure in the oil delivery pipeline 402 to be greater than the oil pressure in the oil return pipeline 102, the one-way valve 7 closes the connecting pipeline 6, the pressure control device 8 opens the rear section of the oil return pipeline, and the directional lubrication system and the oil cooling system each perform their respective functions. Embodiment 2

[0034] like Figure 8 As shown, the difference between the embodiment 1 and the embodiment 1 is that the joint control mechanism includes setting a control system, setting a solenoid valve 12 on the connecting pipeline 6, setting a solenoid valve 2 13 on the oil return pipeline 102, and setting an oil pressure sensor 1 (not shown in the figure) and an oil pressure sensor 2 (not shown in the figure) on the directional oil channel 4 and the cooling oil channel 1 respectively, and the control system controls the solenoid valve 12 to open or close the connecting pipeline 6, and controls the solenoid valve 2 13 to open or close the oil return pipeline 102.

[0035] The above embodiments are only used to more clearly describe the present invention and cannot be regarded as limiting the protection scope of the present invention. Any modifications in equivalent forms should be regarded as falling within the protection scope of the present invention.

Claims

1. A method for providing supplementary lubrication for a directional lubrication system using an oil cooling system, characterized in that: A connecting pipeline (6) is provided between the front section of the oil return pipeline (102) of the cooling oil channel (1) of the oil cooling system and the oil delivery pipeline (402) of the directional oil channel (4) of the directional lubrication system. When the directional lubrication system cannot supply lubricating oil to each directional lubrication component in a timely and sufficient manner, the oil cooling system delivers lubricating oil to the oil delivery pipeline (402) of the directional lubrication system through the connecting pipeline (6). The connecting pipeline (6) is closed when the directional lubrication system can supply oil normally.

2. The method for providing supplementary lubrication for a directional lubrication system using an oil cooling system according to claim 1, characterized in that: When the front section of the oil return pipeline (102) of the cooling oil channel (1) delivers lubricating oil to the oil delivery pipeline (402) of the directional lubrication system through the connecting pipeline (6), the rear section of the oil return pipeline (102) is closed; when the connecting pipeline (6) is closed, the rear section of the oil return pipeline (102) of the oil cooling system is opened.

3. The method for providing supplementary lubrication for a directional lubrication system using an oil cooling system according to claim 2, characterized in that: To achieve the alternate closing and opening of the connecting pipeline (6) and the oil return pipeline (102), the measures taken include setting a joint control mechanism between the oil cooling system and the directional lubrication system.

4. The method for providing supplementary lubrication for a directional lubrication system using an oil cooling system as claimed in claim 3, characterized in that: The measures taken also include setting the oil pressure of the return oil pipeline (102) of the cooling oil channel (1) to be lower than the oil pressure of the oil delivery pipeline (402) of the directional oil channel (4) under normal operating conditions, and under abnormal operating conditions where the speed of the mechanical pump (5) of the directional lubrication system is low, the oil pressure of the return oil pipeline (102) is higher than the oil pressure of the oil delivery pipeline (402).

5. The method for providing supplementary lubrication for a directional lubrication system using an oil cooling system according to claim 4, characterized in that: The joint control mechanism comprises a one-way valve (7) controlled by the upper and lower pressure differences and capable of only flowing to the oil delivery pipeline (402) and a pressure control device (8) for opening and closing the rear section of the return oil pipeline (102) between the rear section of the return oil pipeline (102) and the oil delivery pipeline (402); when the oil pressure of the oil delivery pipeline (402) is lower than the oil pressure of the return oil pipeline 5, the one-way valve (7) automatically opens the connecting pipeline (6) and the pressure control device (8) automatically closes the rear section of the return oil pipeline (102) of the oil cooling system; when the oil delivery pipeline (402) has the oil pressure under normal working conditions, the one-way valve (7) automatically closes the connecting pipeline (6) and the pressure control device (8) automatically opens the rear section of the return oil pipeline (102).

6. The method for providing supplementary lubrication for a directional lubrication system using an oil cooling system according to claim 5, characterized in that: The pressure control device (8) comprises a cylinder sleeve (801) having a cylinder cavity (8011), wherein a piston valve (802) is provided in the cylinder cavity (8011), dividing the cylinder cavity (8011) into an upper cylinder cavity (80111) and a lower cylinder cavity (80112), wherein the upper cylinder cavity (80111) is connected to an oil delivery pipeline (402), wherein a compression spring (803) pre-compressed by the piston valve (802) is provided in the lower cylinder cavity (80112), wherein a valve hole (8021) extending from left to right is provided on the piston valve (802), and wherein a piston hole (8021) extending from left to right is provided in the cylinder cavity (8011) An oil inlet hole (8012) connected to the front section of the oil return pipeline and an oil outlet hole (8013) connected to the rear section of the oil return pipeline (102) are respectively provided on the left and right cylinder walls. When the piston valve (802) is lifted by the compression spring (803) so that the valve hole (8021) is higher than the oil inlet hole (8012) and the oil outlet hole (8013) on both sides, the rear section of the oil return pipeline (102) is closed. When the valve hole (8021) of the piston valve (802) is connected to the oil inlet hole (8012) and the oil outlet hole (8013) on both sides at the same height, the rear section of the oil return pipeline (102) is opened.

7. The method for providing supplementary lubrication for a directional lubrication system using an oil cooling system according to claim 6, characterized in that: The piston valve (802) is limited upwardly so that the piston valve (802) pre-compresses the compression spring (803). When the oil pressure of the oil delivery pipeline (402) is lower than the oil pressure of the oil return pipeline (102), the oil pressure in the upper cylinder chamber (80111) on the piston valve (802) is insufficient to overcome the pre-compression force of the compression spring (803) and prevent the piston valve (802) from moving downward, thereby keeping the rear section of the oil return pipeline (102) closed. The piston valve (802) is limited downwardly. When the oil pressure of the oil delivery pipeline (402) is higher than the oil pressure of the oil return pipeline (102), the pressure of the oil pressure in the upper cylinder chamber (80111) on the piston valve (802) can overcome the pre-compression force of the compression spring (803), causing the piston valve (802) to move downward and stop at the downward limit position, thereby ensuring that the valve hole (8021) of the piston valve (802) is connected to the oil inlet hole (8012) and the oil outlet hole (8013) on both sides at the same height, so that the rear section of the oil return pipeline (102) of the oil cooling system is opened.

8. The method for providing supplementary lubrication for a directional lubrication system using an oil cooling system according to claim 7, characterized in that: The upward limit positioning of the piston valve (802) is implemented by arranging an upper limit column (804) on the top of the piston valve (802) capable of supporting the top wall of the upper cylinder chamber (80111), and the downward limit positioning of the piston valve (802) is implemented by arranging a lower limit column (805) on the bottom of the lower cylinder chamber (80112) capable of supporting the bottom end of the piston valve (802).

9. The method for providing supplementary lubrication for a directional lubrication system using an oil cooling system according to claim 4, characterized in that: The joint control mechanism comprises providing a control system, providing a solenoid valve 1 (12) on the connecting pipeline (6), providing a solenoid valve 2 (13) on the oil return pipeline (102), and providing an oil pressure sensor 1 and an oil pressure sensor 2 on the directional oil passage (4) and the cooling oil passage (1), respectively. The control system controls the solenoid valve 1 (12) to open or close the connecting pipeline (6), and controls the solenoid valve 2 (13) to open or close the oil return pipeline (102).

10. The method for providing supplementary lubrication for a directional lubrication system using an oil cooling system according to any one of claims 5 to 9, characterized in that: The initial stage of starting a mining truck includes the following steps: S1, turning on the electronic oil pump (2) of the oil cooling system, the lubricating oil pumped out by the electronic oil pump (2) first enters the oil delivery pipeline (402) of the directional oil passage (4) of the directional lubrication system through the connecting pipeline (6), and reaches each directional lubrication component in a timely and sufficient manner along the oil delivery pipeline (402). During this process, the rear section of the oil return pipeline (102) of the oil cooling system is closed; S2, the mining truck is started, the axle in the gearbox rotates, and the mechanical pump (5) of the directional lubrication system is started synchronously. The rotation speed does not reach a level that enables the oil pressure in the oil delivery pipeline (402) to be greater than the oil pressure in the oil return pipeline (102). The directional lubrication components still rely on the lubricating oil pumped out by the electronic oil pump (2) for lubrication; S3. The axle in the gearbox reaches the operating condition, the rotation speed of the mechanical pump (5) reaches a level that enables the oil pressure in the oil delivery pipeline (402) to be greater than the oil pressure in the oil return pipeline (102), the one-way valve (7) closes the connecting pipeline (6), the pressure control device (8) opens the rear section of the oil return pipeline, and the directional lubrication system and the oil cooling system each perform their respective functions.

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