Method for preventing air suction of gear oil cooling circulating pump of hydraulic rocker arm of coal mining machine and coal mining machine

Abstract

The invention relates to the technical field of design of an air suction prevention scheme for a hydraulic rocker gear oil cooling circulating pump of a coal mining machine, in particular to an air suction prevention method for the hydraulic rocker gear oil cooling circulating pump of the coal mining machine and the coal mining machine. Aiming at the problem of air suction damage of a circulating pump caused by change of the inclination angle of the rocker arm, oil suction ports are formed in the lowest liquid level positions of the positive and negative inclination angles of the rocker arm respectively, the inclination angles are monitored in real time through an angle sensor, and an electric control box controls an electric proportional reversing valve to act according to inclination angle signals and drives a hydraulic control reversing valve to be switched to a corresponding working position. And the gear oil circulating pump is always communicated with the current lowest liquid level oil suction port. According to the scheme, the pumping air corrosion risk is thoroughly eliminated, the service life of the pump body and the gear set is prolonged, and meanwhile system energy consumption is reduced. According to the preferable scheme, the filter and the cooler are integrated to form a closed-loop purification cooling loop, and the cleanliness and the thermal stability of the oil are further guaranteed. According to the invention, the adaptability defect of the fixed oil suction port under the dynamic dip angle working condition is overcome, and reliable guarantee is provided for high-load continuous operation of the coal mining machine.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of a coal mining machine hydraulic rocker gear oil cooling circulating pump anti-vacuum scheme, in particular to a coal mining machine hydraulic rocker gear oil cooling circulating pump anti-vacuum method and a coal mining machine. BACKGROUND

[0002] The rocker of the coal mining machine is a key transmission component, and the internal gear set needs to be lubricated and cooled through forced circulation of gear oil. Due to the undulating changes of the coal seam of the coal mining face, the rocker needs to continuously swing in the positive and negative inclination angle range (typical working condition is ± 25° to ± 45°), which causes the liquid level in the gear oil tank to dynamically deviate with the inclination angle. The traditional technology adopts a single fixed oil suction port design. When the rocker switches from the positive inclination angle to the negative inclination angle, the original lowest liquid level point will change to a relatively high position, and the new lowest liquid level point is far away from the oil suction port, causing the gear oil circulating pump to be intermittently vacuumed. The vacuum phenomenon causes pump body cavitation, volume efficiency drops and abnormal vibration, not only causing early wear and failure of the circulating pump (average service life is less than 1500 hours), but also causing the planetary gear set in the rocker to be burned and stuck due to interrupted lubrication. The existing improvement scheme includes increasing the oil tank volume or adding an auxiliary oil supplement pump, but the former cannot be implemented due to the limitation of the internal space of the rocker, and the latter increases the energy consumption by more than 15% and cannot fundamentally solve the instantaneous vacuuming when the inclination angle suddenly changes. In addition, although some technologies attempt to arrange double oil suction ports at both ends of the rocker, they still cannot track the lowest liquid level point in real time due to the lack of an effective dynamic switching mechanism. Therefore, an anti-vacuum scheme that can adapt to the inclination angle change of the rocker, accurately locate the lowest liquid level and intelligently switch the oil circuit is needed to ensure the continuous and efficient operation of the coal mining machine.

[0003] Therefore, the prior art still needs further development. SUMMARY

[0004] The purpose of the present application is to overcome the above technical deficiencies and provide a coal mining machine hydraulic rocker gear oil cooling circulating pump anti-vacuum method to solve the problems existing in the prior art.

[0005] To achieve the above technical purpose, according to the first aspect of the present application, the present application provides a coal mining machine hydraulic rocker gear oil cooling circulating pump anti-vacuum method, comprising: S100, monitoring the real-time inclination angle of the coal mining machine rocker; S200, based on the real-time inclination angle, determining the target oil suction port corresponding to the lowest place of the rocker internal gear oil liquid level; S300, controlling the oil circuit switching device to communicate the oil inlet of the gear oil circulating pump (3) with the target oil suction port, so that the circulating pump (3) sucks oil from the lowest place.

[0006] Specifically, the real-time inclination angle of the coal mining machine rocker is realized by an angle sensor.

[0007] Specifically, the step of determining the target oil suction port based on the real-time inclination angle is performed by an electric control box, and the electric control box receives signals of the angle sensor.

[0008] Specifically, the step of controlling the oil path switching device includes that the electric control box sends an instruction to an electric proportional reversing valve (6) to control the flow direction of pressure oil, and then drives a hydraulic control reversing valve (4) to act to switch the oil path.

[0009] Specifically, the target oil suction port is a first oil suction port or a second oil suction port, the first oil suction port (5) is arranged at a lowest liquid level when the rocker arm is at a positive inclination angle, and the second oil suction port is arranged at a lowest liquid level when the rocker arm is at a negative inclination angle.

[0010] Specifically, the hydraulic control reversing valve (4) is a multi-position valve, an inlet thereof is connected with the first oil suction port (5) and the second oil suction port, and an outlet thereof is connected with an inlet of the circulating pump (3).

[0011] Specifically, the gear oil discharged by the circulating pump (3) returns to the rocker arm in sequence through a filter (2) and a cooler (1).

[0012] Specifically, the method is continuously operated in a working process of the coal mining machine, and real-time response to changes in the inclination angle of the rocker arm.

[0013] Specifically, a working oil port (P) of the electric proportional reversing valve (6) receives pressure oil from a hydraulic system of the coal mining machine, and a return oil port (T) thereof is connected to an oil tank.

[0014] To achieve the above technical purpose, according to a second aspect of the present application, the present application provides a coal mining machine adopting the above-mentioned method for preventing air suction of a hydraulic rocker arm gear oil cooling circulating pump.

[0015] Beneficial effects: The present application realizes the following breakthroughs through the closed-loop control of inclination angle sensing, decision-making and execution: 1. Completely eliminate air suction damage: the angle sensor monitors the change in the inclination angle of the rocker arm in real time, the electric control system dynamically determines the lowest liquid level position, and accurately switches to the corresponding oil suction port through the hydraulic control reversing valve, so as to ensure that the circulating pump is always immersed in the oil, completely avoids the risk of cavitation, and prolongs the service life of the pump body by more than 2 times.

[0016] 2. Improve the reliability of the transmission system: stable oil supply significantly enhances the continuity of the oil film of the gear box, and the occurrence rate of pitting corrosion of the planetary gear train is reduced by 60%, which avoids the vicious accidents such as gear collapse and sintering caused by lubrication failure, and reduces the probability of equipment failure.

[0017] 3. Optimizing system energy efficiency: Compared with the auxiliary pump scheme, the additional power consumption is reduced, the pressure loss of the hydraulic control circuit is reduced by 40% compared with the electromagnetic valve direct drive scheme, and the whole machine oil consumption is reduced by 10%-15%, which meets the green trend of mine equipment.

[0018] 4. Enhancing working condition adaptability: The double suction oil port cooperates with the intelligent switching mechanism to effectively cope with the complex actions such as the pitch cutting of the coal mining machine, and can still maintain the stability of the oil circuit under the mutation working condition of the inclination rate reaching 8° / s, breaking through the adaptability limit of 5° / s of the traditional system.

[0019] 5. Reducing maintenance cost: The life of the circulating pump and the gear set is improved, the replacement frequency of spare parts and maintenance time is reduced, and the improvement of oil cleanliness and cooling efficiency prolongs the oil change cycle by 30%, which significantly reduces the maintenance cost per ton of coal. BRIEF DESCRIPTION OF DRAWINGS

[0020] Figure 1 is the principle diagram involved in the method for preventing air suction of the circulating pump of the inner gear oil of the rocker arm of the coal mining machine provided in the embodiments of the present application; In the above drawings, there are the following reference signs: 1, cooler; 2, filter; 3, circulating pump; 4, hydraulic control reversing valve; 5, first suction oil port; 6, electric proportional reversing valve; P, working oil port; T, oil return port; a, first working position; b, second working position. DETAILED DESCRIPTION

[0021] In order for those skilled in the art to better understand the technical solutions of the present application, the technical solutions of the present application will be described clearly and completely below in combination with the drawings of the present application. Based on the embodiments in the present application, other similar embodiments obtained by those skilled in the art without creative labor should belong to the scope of protection of the present application. In addition, the direction words mentioned in the following embodiments, such as "up", "down", "left", "right", etc. are only the directions of the drawings, therefore, the direction words used are used to illustrate but not to limit the present application.

[0022] First of all, it needs to be pointed out that the gear oil inside the rocker arm of the coal mining machine needs to be circulated and cooled to improve the working life and efficiency of the transmission gear set inside the rocker arm. However, the rocker arm of the coal mining machine swings up and down during work. If the rocker arm of the gear oil runs from a positive inclination angle to a negative inclination angle, the lowest part of the positive inclination angle will become the highest part of the negative inclination angle. In this process, the gear oil circulating pump will be in an air suction working state at a certain time, which will damage the structure inside the pump. To a certain extent, it will affect the working efficiency of the pump and even damage the pump. The present scheme is to prevent the gear oil circulating pump from being damaged, so that the rocker arm can ensure that the lowest part of the gear oil inside the rocker arm can be sucked and circulated to cool and filter under the working conditions of positive inclination angle and negative inclination angle.

[0023] It can be understood that, Figure 1 The oil suction port of the left hydraulic control reversing valve is located at the lowest position of the oil when the rocker arm is in a negative inclination state, and the oil suction port of the right hydraulic control reversing valve is located at the lowest position of the oil when the rocker arm is in a positive inclination state. During the working process of the coal mining machine rocker arm, the lowest liquid level of the positive inclination will become the highest liquid level of the negative inclination. The angle sensor monitors the inclination change and transmits instructions to the electric control box. The electric control box always supplies power to the electromagnetic reversing valve of the oil suction port with the lowest liquid level. In this way, the gear oil circulating pump can suck oil at the lowest position in the rocker arm, effectively preventing air suction and preventing damage to the gear pump and even the gear set in the rocker arm of the coal mining machine.

[0024] 1. The angle sensor is installed at the center of the rocker arm rotation, and the signal line shielding layer is double-ended grounded to resist interference; 2. The electric control box uses PLC program to process the inclination signal (sampling period 50ms), and outputs the relay contact to control the proportional valve; 3. The hydraulic pipeline uses SAE100R16 type steel wire braided rubber pipe (bursting pressure ≥80MPa).

[0025] Actual measurement data: no air suction alarm for 600 hours of continuous operation, gear oil temperature drop reduced by 18℃, pump noise reduced from 98dB(A) to 82dB(A).

[0026] The present application will be further described below in conjunction with the drawings and preferred embodiments.

[0027] Please refer to Figure 1 , the present application provides a coal mining machine hydraulic rocker arm gear oil cooling circulating pump anti-suction method, comprising: S100, monitoring the real-time inclination of the coal mining machine rocker arm; S200, based on the real-time inclination, determining the target oil suction port corresponding to the lowest gear oil liquid level in the rocker arm; S300, controlling the oil circuit switching device to communicate the oil inlet of the gear oil circulating pump 3 with the target oil suction port, so that the circulating pump 3 sucks oil from the lowest liquid level.

[0028] It needs to be further explained that, as Figure 1 shown, one oil suction port is arranged at each end of the coal mining machine rocker arm: The first oil suction port 5: located at 380mm below the rocker arm shaft center line when the rocker arm is horizontal, corresponding to the positive inclination +α lowest liquid level point; The second oil suction port is not shown in the figure: located at 420mm above the rocker arm shaft center line when the rocker arm is horizontal, corresponding to the negative inclination -β lowest liquid level point.

[0029] Further, the implementation steps include: 1. Inclination monitoring: MTS magnetostrictive angle sensor is used to collect the real-time inclination θ of the rocker arm, with a range of ±50° and an accuracy of 0.1°. 2. Target oil suction port decision: When θ>+5°, the positive inclination state is determined, and the first oil suction port is selected; when θ<-5°, the negative inclination state is determined, and the second oil suction port is selected. The ±5° threshold value can avoid frequent switching at the critical point. 3. Oil circuit switching execution: The a / b working position of the hydraulic control reversing valve 4 is controlled by the electric proportional reversing valve 6 to connect the target oil suction port and the circulating pump 3 oil inlet pipeline.

[0030] It can be understood that the beneficial effects of the above scheme include: completely eliminating the air suction phenomenon, and the actual pump life is improved from 1200 hours to more than 3000 hours.

[0031] Specifically, the real-time inclination of the monitoring coal mining machine rocker arm is realized by an angle sensor.

[0032] Specifically, the step of determining the target oil suction port based on the real-time inclination is executed by an electric control box, which receives the signal of the angle sensor.

[0033] Specifically, the step of controlling the oil circuit switching device includes: the electric control box sends an instruction to the electric proportional reversing valve 6 to control the flow direction of the pressure oil, and then drives the hydraulic control reversing valve 4 to act to switch the oil circuit.

[0034] It needs to be further explained that the electric proportional reversing valve 6 is a 4WE6E type, the P port is connected to the coal mining machine main hydraulic system pressure of 20 MPa, and the T port is connected to the oil tank. When the electric control box outputs +24VDC signal to the proportional solenoid A, the valve core moves to the a position, the pressure oil drives the hydraulic control reversing valve 4 to switch to the first working position a, so that the first oil suction port is connected to the pump; when the output signal is sent to the solenoid B, the valve core moves to the b position, and switches to the second working position b.

[0035] It can be understood that the 20 MPa system pressure can ensure that the response time of the hydraulic control reversing valve is less than 0.2 seconds, avoiding the delay of oil circuit switching caused by sudden inclination change, which causes instantaneous air suction.

[0036] Specifically, the target oil suction port is the first oil suction port or the second oil suction port, the first oil suction port 5 is arranged at the lowest liquid level when the rocker arm is in positive inclination, and the second oil suction port is arranged at the lowest liquid level when the rocker arm is in negative inclination.

[0037] It needs to be further explained that the inclination judgment threshold is optimized to ±8° instead of ±5° in embodiment 1, which is suitable for working conditions with an inclination change rate of >5° / s. It can be understood that: when the rocker arm rapidly reverses, such as when the traction speed is >8 m / min, increasing the switching threshold can reduce oil circuit shaking, the actual switching frequency is reduced from 35 times / min to 12 times / min, and the valve life is extended by 2 times.

[0038] Specifically, the hydraulic control reversing valve 4 is a multi-position valve, the oil inlet of which is connected with the first oil suction port 5 and the second oil suction port respectively, and the oil outlet of which is connected with the oil inlet of the circulating pump 3.

[0039] It should be further explained that the hydraulic control reversing valve 4 adopts a 4WH type hydraulic slide valve, the spool stroke of which is set to 15 mm. When working in a position, the spool moves left to make the first oil suction port oil passage conduct with the pump inlet and the second oil suction port is closed; when working in b position, the spool moves right to switch to the second oil suction port to conduct.

[0040] It can be understood that the key parameters include: the gap between the spool and the valve body is 8-10 μm, preferably 9 μm, which can ensure the sealing and avoid jamming.

[0041] Specifically, the gear oil discharged by the circulating pump 3 returns to the rocker arm in sequence through the filter 2 and the cooler 1.

[0042] It should be further explained that the circulating pump 3 discharge line is connected in sequence: Filter 2: PLF-H100 type double-cylinder filter with a filtering precision of 10 μm, and a parallel differential pressure transmitter alarm threshold of 0.3 MPa; Cooler 2: GLCA type plate heat exchanger with an oil side pressure drop of <0.15 MPa, and a cooling water flow rate of ≥15 m³ / h to maintain an oil temperature of ≤65℃.

[0043] It can be understood that the beneficial effects of the above scheme include: The oil cleanliness NAS7 level is improved to NAS5 level, and the gear set wear is reduced by 60%.

[0044] Specifically, the method is continuously operated in the working process of the coal mining machine, and real-time response to the change of the rocker arm inclination angle.

[0045] Specifically, the working oil port P of the electric proportional reversing valve 6 receives pressure oil from the hydraulic system of the coal mining machine, and the return oil port T is connected to the oil tank.

[0046] In the preferred embodiment, the application further provides a coal mining machine, which comprises: The computer device can be a server, a terminal, or any other electronic device having necessary computing and / or processing capabilities. In one embodiment, the computer device can include a processor, a memory, a network interface, a communication interface, and the like connected by a system bus. The processor of the computer device can be configured to provide necessary computing, processing, and / or control capabilities. The memory of the computer device can include a non-volatile storage medium and an internal memory. The non-volatile storage medium can store an operating system, a computer program, and the like therein or thereon. The internal memory can provide an environment for running the operating system and the computer program in the non-volatile storage medium. The network interface and the communication interface of the computer device can be configured to connect and communicate with external devices through a network. The computer program, when executed by the processor, performs the steps of the method of the present application.

[0047] The present application can be implemented as a computer readable storage medium having a computer program stored thereon, which, when executed by a processor, causes the steps of the method of the embodiments of the present application to be performed. In one embodiment, the computer program is distributed over a plurality of computer devices or processors coupled by a network, such that the computer program is stored, accessed, and executed by one or more computer devices or processors in a distributed manner. A single method step / operation, or two or more method steps / operations, can be performed by a single computer device or processor, or by two or more computer devices or processors. One or more method steps / operations can be performed by one or more computer devices or processors, and one or more other method steps / operations can be performed by one or more other computer devices or processors. One or more computer devices or processors can perform a single method step / operation, or perform two or more method steps / operations.

[0048] It will be appreciated by those skilled in the art that the method steps of the present application can be instructed by a computer program to relevant hardware such as a computer device or a processor, which can be stored in a non-transitory computer readable storage medium, and which, when executed, causes the steps of the present application to be performed. Depending on the circumstances, any reference herein to a memory, storage, database, or other medium can include non-volatile and / or volatile memory. Examples of non-volatile memory include read-only memory (ROM), programmable ROM (PROM), electrically programmable ROM (EPROM), electrically erasable programmable ROM (EEPROM), flash memory, magnetic tapes, floppy disks, magneto-optical data storage devices, optical data storage devices, hard disks, solid-state disks, and the like. Examples of volatile memory include random access memory (RAM), external cache memory, and the like.

[0049] The technical features described above can be combined arbitrarily. Although all possible combinations of the technical features are not described, any combination of the technical features should be considered to be covered by the present specification, as long as there is no contradiction in such a combination.

[0050] The specific embodiments of the application described above are not to be construed as limiting the scope of the present application. Any other corresponding changes and modifications of the technical concept according to the present application should be included in the scope of the protection of the present application.

Claims

1. A method for preventing air suction in the hydraulic rocker arm gear oil cooling circulation pump of a coal mining machine, characterized in that, Includes the following steps: S100, monitors the real-time tilt angle of the coal mining machine's rocker arm; S200. Based on the real-time tilt angle, determine the target oil suction port corresponding to the lowest point of the gear oil level in the rocker arm; S300, control the oil circuit switching device to connect the oil inlet of the gear oil circulation pump (3) with the target oil suction port so that the circulation pump (3) can draw oil from the lowest liquid level.

2. The method according to claim 1, characterized in that, The real-time tilt angle of the coal mining machine's rocker arm is monitored using an angle sensor.

3. The method according to claim 2, characterized in that, The step of determining the target oil intake port based on the real-time tilt angle is executed by the electrical control box, which receives the signal from the angle sensor.

4. The method according to claim 3, characterized in that, The steps of the control oil circuit switching device include: the electrical control box sends a command to the electro-proportional directional valve (6) to control the flow direction of the pressure oil, thereby driving the hydraulic directional valve (4) to switch the oil circuit.

5. The method according to claim 4, characterized in that, The target oil suction port is either the first oil suction port or the second oil suction port. The first oil suction port (5) is located at the lowest liquid level when the rocker arm is at a positive tilt angle, and the second oil suction port is located at the lowest liquid level when the rocker arm is at a negative tilt angle.

6. The method according to claim 5, characterized in that, The hydraulic control directional valve (4) is a multi-position valve, with its inlet connected to the first suction port (5) and the second suction port respectively, and its outlet connected to the inlet of the circulating pump (3).

7. The method according to any one of claims 1 to 6, characterized in that, The gear oil discharged by the circulating pump (3) passes through the filter (2) and cooler (1) in sequence before returning to the rocker arm.

8. The method according to claim 7, characterized in that, The method operates continuously during the operation of the coal mining machine, responding in real time to changes in the rocker arm tilt angle.

9. The method according to claim 4, characterized in that, The working port (P) of the electro-proportional directional valve (6) receives pressure oil from the hydraulic system of the coal mining machine, and its return port (T) is connected to the oil tank.

10. A coal mining machine, characterized in that, The coal mining machine employs the anti-air suction method as described in any one of claims 1-9 to cool and circulate the gear oil inside the rocker arm.

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