Hydraulic-electric mixed transmission system of coal mining machine and transmission control method thereof

Abstract

This invention discloses an electro-hydraulic hybrid transmission system for coal mining machines and its transmission control method. The system includes a pure electric motor drive mechanism and a hydraulic auxiliary mechanism, both of which are installed on the cutting section of the coal mining machine body. This invention utilizes a dual-height-adjustment pump station as an auxiliary power source and designs a torque-coupled electro-hydraulic hybrid transmission system for the coal mining machine's cutting section. This fully utilizes the existing hydraulic power of the coal mining machine, saves layout space, and further couples the power of the height-adjustment pump station with the cutting motor. This provides sufficient auxiliary power to the cutting section of the coal mining machine under non-steady operating conditions, effectively solving the problem that the cutting torque of the coal mining machine cannot be adjusted with load fluctuations, and providing greater cutting power to cope with high-load conditions. It fully utilizes the output characteristics of the dual power sources to timely supplement the kinetic energy of the coal mining machine drum under non-steady operating conditions, avoiding overload and stall problems of the cutting motor and reducing the risk of cutting motor failure.

Description

Technical Field

[0001] This invention relates to the field of transmission technology for the cutting section of a coal mining machine, and in particular to a hybrid electro-hydraulic cutting transmission system for a coal mining machine and its transmission control method. Background Technology

[0002] Although my country has abundant coal reserves, the thickness of coal seams varies across the country, and a significant portion consists of complex geological seams with intricate geological conditions, making mining extremely difficult. Mining complex coal seams presents various challenges, such as complex geological structures like faults and interbedded rock, the need to accelerate the mining of thinner seams, and the frequent occurrence of insufficient power in mining machinery due to limitations in cutting processes.

[0003] The cutting section of a coal mining machine is a key component for coal cutting, experiencing high cutting loads that fluctuate dramatically depending on the characteristics and distribution of the coal and rock at the working face. Existing cutting sections are designed for maximum power demand, and due to space constraints, a variable frequency speed control system cannot be installed. This results in the cutting section being unable to adjust torque and speed, making it difficult to operate efficiently under unstable conditions with drastic load changes, and prone to problems such as cutting motor overload or stalling. Because my country's coal resources are characterized by complex geological conditions and high mining difficulty, the cutting load of coal mining machines is characterized by high load, large fluctuations, and unevenness. When encountering hard rock layers, interbedded gangue layers, or during rapid cutting, the coal mining machine may encounter sudden changes in coal seam hardness or coal-rock distribution, leading to drastic load fluctuations. Furthermore, due to the influence of the cutting process, the left and right cutting drums of the coal mining machine operate at different vertical positions, resulting in uneven cutting loads between the left and right drums.

[0004] To address the issues of insufficient cutting torque and inability to adjust torque in coal mining machines under non-steady operating conditions, this paper proposes an electro-hydraulic hybrid transmission system and its transmission control method. Utilizing the coal mining machine's elevation pump station as an auxiliary power source, an electro-hydraulic hybrid transmission structure for the cutting section is designed to cope with drastic load changes, thereby improving the cutting efficiency of the coal mining machine under non-steady operating conditions and providing a feasible solution for adjusting the cutting torque of the coal mining machine's cutting section. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a hybrid electro-hydraulic cutting transmission system for coal mining machines and its transmission control method, which makes full use of the output characteristics of dual power sources, improves energy utilization, avoids overload of the cutting motor of the coal mining machine, and achieves the goals of maximizing cutting efficiency and optimizing the overall performance of coal mining.

[0006] To solve the above-mentioned technical problems, the technical solution adopted by the present invention is as follows:

[0007] The coal mining machine electro-hydraulic cutting hybrid transmission system includes a pure electric drive mechanism and a hydraulic auxiliary mechanism. Both the pure electric drive mechanism and the hydraulic auxiliary mechanism are installed on the cutting section of the coal mining machine body. There are two sets of cutting sections on the coal mining machine body, and each set of cutting sections is equipped with a pure electric drive mechanism and a hydraulic auxiliary mechanism. The pure electric drive mechanism operates independently in pure electric working mode, and the pure electric drive mechanism and the hydraulic auxiliary mechanism operate simultaneously in electro-hydraulic hybrid drive cooperation.

[0008] The pure electric drive mechanism includes a cutting motor, a rocker arm gear reduction mechanism, a planetary reducer, and a coal mining machine drum. The cutting motor is fixed on the inner wall of the cutting part housing, and the output shaft of the cutting motor is connected to the input end of the rocker arm gear reduction mechanism. The output end of the rocker arm gear reduction mechanism is connected to the sun gear of the planetary reducer. The output end of the secondary planetary reducer of the planetary reducer is connected to the coal mining machine drum.

[0009] The hydraulic auxiliary mechanism includes a hydraulic motor, an accumulator, an electro-hydraulic proportional directional valve, a low-pressure relief valve, a height adjustment motor, and a height adjustment pump station. The output end of the height adjustment pump station, one output port of the electro-hydraulic proportional directional valve, and the input end of the hydraulic motor cooperate to form a booster circuit, which drives the output shaft of the hydraulic motor. The accumulator is installed on the booster circuit. The height adjustment motor acts on the input end of the height adjustment pump station to adjust the oil delivery rate of the height adjustment pump station. A pressure relay is installed inside the input end of the accumulator, and the connection end of the pressure relay is electrically connected to a controller. The accumulator is installed in the transmission system between the hydraulic motor and the height adjustment pump station to store hydraulic oil and complete energy storage. The height adjustment pump station, the other output port of the electro-hydraulic proportional directional valve, and the accumulator cooperate to form a hydraulic oil circulation circuit.

[0010] A torque coupling mechanism is installed on the idler wheel of the rocker arm gear reducer. The output end of the hydraulic motor transmits power to the coal mining machine drum through the torque coupling mechanism, thereby enhancing the power of the coal mining machine drum.

[0011] Two parallel oil pipelines are connected between the booster circuits of the two cutting sections. Check valve groups and proportional valve groups are installed on the oil pipelines. The oil pipelines, check valve groups and proportional valve groups work together to enable the hydraulic oil of the two height adjustment pump stations to be transmitted to each other and to dynamically distribute power.

[0012] Preferably, the two sets of height adjustment pump stations are the left height adjustment pump station and the right height adjustment pump station.

[0013] Preferably, the one-way valve assembly includes one-way valve one and one-way valve two, and the proportional valve assembly includes proportional valve one and proportional valve two.

[0014] One-way valve 1 and proportional valve 1 are connected in series on one of the oil pipelines, and one-way valve 2 and proportional valve 2 are connected in series on the other oil pipeline.

[0015] Preferably, the pure electric operating mode operates as follows:

[0016] When the cutting motor starts, the output power is transmitted to the planetary reducer through the rocker arm gear reduction mechanism. The output end of the secondary planetary reducer drives the coal mining machine drum to rotate, and the planet carrier of the primary planetary gear drives the torque coupling mechanism to rotate. The torque coupling mechanism is connected to the idler wheel of the rocker arm gear reduction mechanism at the rear end. At this time, the hydraulic motor is in a follow-up state, and the speed of the hydraulic motor is set at 1450 r / min.

[0017] Preferably, the electro-hydraulic hybrid drive coordination mode includes:

[0018] The hybrid drive single-pump single-side working mode operates as follows:

[0019] When the cutting motor starts, its output power is transmitted to the sun gear of the first-stage planetary gear train of the planetary reducer via the rocker arm gear reduction mechanism. When the left-side height adjustment pump station starts, its power is transmitted to the hydraulic motor via the left position of the electro-hydraulic proportional directional valve. When there is a pressure difference between the output pressure of the hydraulic motor and the low-pressure relief valve, the torque of the auxiliary power source is transmitted to the idler gear of the rocker arm gear reduction mechanism via the torque coupling mechanism. The torque of the auxiliary power source is then transmitted to the planet carrier of the first-stage planetary gear train of the planetary reducer via the torque coupling mechanism, and together with the power of the cutting motor, it is transmitted to the second-stage planetary gear train in the first-stage planetary gear train of the planetary reducer, and finally output to the coal mining machine drum.

[0020] The hybrid drive single-pump dual-side working mode operates as follows:

[0021] When the left and right cutting motors start, the output power is transmitted to the sun gear of the first-stage planetary gear train of the planetary reducer via the rocker arm gear reduction mechanism. When the left or right height adjustment pump station starts, the power is transmitted to the hydraulic motor via the proportional valve port and the left position of the electro-hydraulic proportional directional valve. When there is a pressure difference between the output pressure of the hydraulic motor and the low-pressure relief valve, the torque of the auxiliary power source is transmitted to the idler gear of the rocker arm gear reduction mechanism via the torque coupling mechanism. The power of the cutting motor is then transmitted to the second-stage planetary gear train in the first-stage planetary gear train of the planetary reducer, and finally output to the coal mining machine drum.

[0022] The hybrid dual-pump single-side operating mode operates as follows:

[0023] When the cutting motor starts, its output power is transmitted to the sun gear of the first-stage planetary gear train of the planetary reducer via the rocker arm gear reduction mechanism. When the left-adjustable pump station starts, its power is transmitted to the hydraulic motor via the left position of the electro-hydraulic proportional directional valve. When there is a pressure difference between the output pressure of the hydraulic motor and the low-pressure relief valve, the torque of the auxiliary power source is transmitted to the idler gear of the rocker arm gear reduction mechanism via the torque coupling mechanism. The power from the cutting motor is then transmitted to the second-stage planetary gear train in the first-stage planetary gear train of the planetary reducer, and finally output to the coal mining machine drum.

[0024] The hybrid drive single-pump dual-side working mode operates as follows:

[0025] When the left and right cutting motors start, the output power is transmitted to the sun gear of the first-stage planetary gear train of the planetary reducer via the rocker arm gear reduction mechanism. When the left or right height adjustment pump station starts, the power is transmitted to the left position of the electro-hydraulic proportional directional valve through one of the oil pipelines, and then to the hydraulic motor. When there is a pressure difference between the output pressure of the hydraulic motor and the low-pressure relief valve, the torque of the auxiliary power source is transmitted to the idler gear of the rocker arm gear reduction mechanism through the torque coupling mechanism, and then, together with the power of the cutting motor, is transmitted to the second-stage planetary gear train of the first-stage planetary gear train of the planetary reducer, and finally output to the coal mining machine drum.

[0026] The hybrid dual-pump single-side operating mode operates as follows:

[0027] When the cutting motor starts, its output power is transmitted through the rocker arm gear reduction mechanism to the sun gear of the first-stage planetary gear train of the planetary reducer. The left and right height adjustment pump stations start simultaneously. The power of the right height adjustment pump station is transmitted through the proportional valve and the check valve to the left height adjustment pump station and then through the electro-hydraulic proportional directional valve to the hydraulic motor. When there is a pressure difference between the output pressure of the hydraulic motor and the low-pressure relief valve, the torque of the auxiliary power source is transmitted through the torque coupling mechanism to the idler gear of the rocker arm gear reduction mechanism. It is then transmitted through the first-stage planetary gear train of the planetary reducer to the second-stage planetary gear train and finally output to the coal mining machine drum.

[0028] The hybrid dual-pump independent operating mode operates as follows:

[0029] When the left and right cutting motors start, the output power is transmitted to the sun gear of the first-stage planetary gear train of the planetary reducer through the rocker arm gear reduction mechanism. The left and right height adjustment pump stations start simultaneously. At this time, proportional valve one and proportional valve two are closed. The power of the left and right height adjustment pump stations is transmitted to the hydraulic motor through the left position of two sets of electro-hydraulic proportional directional valves. When there is a pressure difference between the output pressure of the hydraulic motor and the low-pressure relief valve, the torque of the auxiliary power source is transmitted to the idler gear of the rocker arm gear reduction mechanism through the torque coupling mechanism. It is then combined with the power of the cutting motor in the first-stage planetary gear train of the planetary reducer and transmitted to the second-stage planetary gear train, and finally output to the coal mining machine drum.

[0030] The hybrid dual-pump coordinated operating mode operates as follows:

[0031] When the left and right cutting motors start, their output power is transmitted through the rocker arm gear reduction mechanism to the sun gear of the first-stage planetary gear train of the planetary reducer. The left and right height adjustment pump stations start simultaneously. At this time, proportional valve one and proportional valve two remain open. The power from the left and right height adjustment pump stations is transmitted to the hydraulic motor through the left position of two sets of electro-hydraulic proportional directional valves. When there is a pressure difference between the output pressure of the hydraulic motor and the low-pressure relief valve, the torque of the auxiliary power source is transmitted through the torque coupling mechanism to the idler gear of the rocker arm gear reduction mechanism. It is then combined with the power of the cutting motor in the first-stage planetary gear train of the planetary reducer and transmitted to the second-stage planetary gear train, and finally output to the coal mining machine drum.

[0032] The transmission control method for the electro-hydraulic cutting hybrid transmission system of a coal mining machine includes the following steps:

[0033] S1. The cutting section operates in pure electric mode. The coal mining machine body is turned on, and the cutting motors of the two cutting sections and the two height adjustment motors are powered on, which drives the coal mining machine drum to rotate and mine the coal seam.

[0034] S2. The load status of the two sets of coal mining machine drums is determined by monitoring the rotational speed of the drums using speed sensors. A threshold speed for the drums under stable operating conditions is set and compared with the real-time monitored rotational speed during operation. The method also includes observing whether the drum speed decreases and falls below the threshold.

[0035] The working stability of the coal mining machine drum is monitored. When the coal mining machine drum vibrates due to resistance, it is automatically determined that the load is too large, i.e., an overload state.

[0036] By combining the feedback images from infrared cameras and lidar, continuous frames of images are captured, and the displacement speed and structural deformation of the coal mining machine drum are analyzed by comparing the images. When the displacement speed of the coal mining machine drum slows down or there is a shaking deformation in the structure of the coal mining machine drum, it indicates that the cutting resistance is large, that is, the coal mining machine drum is overloaded.

[0037] Based on the judgment result, perform the following operations:

[0038] S2-1, if yes, it means that the two sets of coal mining machine drums are in an overload state;

[0039] S2-2. Otherwise, it indicates that the two sets of coal mining machine drums are in a stable state:

[0040] The load status determination process also includes the following steps:

[0041] S2.1 The coal mining machine drum is working in a stable state, that is, both sets of coal mining machine drums are stable, and the pure electric working mode is maintained at this time.

[0042] S2.2 When the coal mining machine drum is operating under overload conditions, it is necessary to further determine whether the traction rocker arms connected to both sets of coal mining machine drums are being adjusted, that is, whether there is swing arm movement in the coal mining machine drum. The following situations apply:

[0043] If S2.2-1 is true, it means that the swing arm movement increases the load. At this time, the traction speed of the coal mining machine body is reduced, and the pure electric working mode is maintained to make the coal mining machine drum tend to a stable state.

[0044] S2.2-2 If not, it means that the working load of the coal mining machine drum itself is too large. At this time, it is necessary to further judge the working status of the two sets of height adjustment pump stations.

[0045] S3. Determination and Processing of Pump Station Operating Status: Based on a hydraulic monitoring system composed of an accumulator, pressure relay, electro-hydraulic proportional directional valve, and controller, the pressure relay senses the internal pressure of the accumulator, the torque sensor senses the output torque and overload status of the cutting motor, and the controller receives and analyzes the pressure signal to determine the pump station status. Furthermore, it determines the additional output torque and hydraulic coupling system pressure required by the pump station for the cutting motor, i.e., the pressure adjustment value at the hydraulic motor input end.

[0046] To determine whether both sets of height-adjusting pump stations are idle, based on the load status at the input of the cutting motor, the following conditions must be met:

[0047] S3-1, If ​​so, control the two sets of height adjustment pump stations to start and make them work;

[0048] S3-2. Otherwise, control one of the elevated pump stations to start and operate;

[0049] S4. Determine whether both sets of coal mining machine drums are under overload. The following conditions must be met:

[0050] S4-1. When only one set of height adjustment pump station is working, if both sets of coal mining machine drums are in an overload state, the pure electric working mode will be switched to the hybrid drive single pump double-sided working mode, and one height adjustment pump station will be used to provide auxiliary power to the two sets of coal mining machine drums.

[0051] S4-2. When only one set of height adjustment pump stations is working, if only one set of coal mining machine drums is in an overloaded state, the pure electric working mode will be switched to the hybrid drive single pump single-side working mode, and one height adjustment pump station will be used to provide auxiliary power to the coal mining machine drums in an overloaded state.

[0052] S4-3. When both sets of height adjustment pump stations are working, if both sets of coal mining machine drums are in an overloaded state, it is necessary to further determine whether the load of at least one set of coal mining machine drums exceeds the power supply limit of a single height adjustment pump station. The following situations apply:

[0053] S4-3-1. At least one set of coal mining machine drums is overloaded beyond the power supply limit of a single height adjustment pump station. The pure electric working mode is switched to the hybrid drive dual pump dual-side coordinated working mode. Two sets of height adjustment pump stations are used to provide auxiliary power to the two sets of coal mining machine drums, and the auxiliary power is coordinated and distributed to the two sets of coal mining machine drums.

[0054] S4-3-2. The loads of the two sets of coal mining machine drums did not exceed the power supply limit of the corresponding single height adjustment pump station. The pure electric working mode was switched to the hybrid drive dual pump dual-side independent working mode, and the two sets of height adjustment pump stations were used to provide auxiliary power to the two sets of coal mining machine drums respectively.

[0055] S4-4. When the two sets of height adjustment pump stations are working, if at least one of the coal mining machine drums is not in an overloaded state, the pure electric working mode is switched to the hybrid drive dual pump single-side working mode, and the two sets of height adjustment pump stations are used to provide auxiliary power to the coal mining machine drum in an overloaded state.

[0056] S5. Determine whether the provided auxiliary power meets the load requirements of the two sets of coal mining machine drums, under the following conditions:

[0057] S5-1. If so, maintain the original working mode, pull the coal mining machine body at a constant speed, continue the cutting operation, and start the judgment process of S2.

[0058] S5-2. Otherwise, reduce the traction speed of the coal mining machine body to make the coal mining machine drum tend to a stable state.

[0059] S7. During the operation of S5-1 and S5-2, the two sets of coal mining machine drums end the overload state and can stably mine the coal seam. When the load of the two sets of coal mining machine drums no longer needs to rely on auxiliary power, switch back to pure electric working mode, and then repeat the judgment process of S2.

[0060] S7. Cutting operation completed, stop the machine.

[0061] The present invention has the following beneficial effects:

[0062] 1. This invention utilizes the existing dual height adjustment pump station on the coal mining machine as an auxiliary power source, and designs a torque-coupled electro-hydraulic hybrid transmission system for the coal mining machine's cutting section. This fully utilizes the existing hydraulic power of the coal mining machine, saves layout space, and further couples the power of the coal mining machine's height adjustment pump station with the cutting motor. This provides sufficient auxiliary power to the coal mining machine's cutting section under non-steady working conditions, effectively solving the problem that the coal mining machine's cutting torque cannot be adjusted with load fluctuations, and providing greater cutting power to cope with high load conditions. It fully utilizes the output characteristics of the dual power sources to replenish the kinetic energy of the coal mining machine's drum in a timely manner under non-steady working conditions, avoiding the problems of overload and stall of the coal mining machine's cutting motor, and reducing the risk of cutting motor failure.

[0063] 2. This invention utilizes a torque coupling mechanism to achieve torque coupling between power sources, which can fully leverage the torque-increasing effect of auxiliary power sources and achieve the goal of optimal torque distribution in the coal cutting section. Through the torque coupling mechanism on the idler wheel, combined with a special cross arrangement, the problem of difficult installation due to limited space can be avoided, reducing the difficulty of processing and installation, and achieving the goal of maximizing cutting efficiency and optimizing the overall performance of coal mining. Attached Figure Description

[0064] Figure 1 A simplified diagram of the hybrid transmission system for the coal mining machine cutting electro-hydraulic hybrid transmission system provided by the present invention;

[0065] Figure 2 This is a diagram illustrating the transmission effect of the electro-hydraulic hybrid transmission system of the present invention in a hybrid drive single-pump single-side working mode;

[0066] Figure 3 This is a diagram illustrating the transmission effect of the electro-hydraulic hybrid transmission system of the present invention in a hybrid drive single-pump dual-sided working mode.

[0067] Figure 4 This is a diagram illustrating the transmission effect of the electro-hydraulic hybrid transmission system of the present invention in a hybrid dual-pump single-side operating mode.

[0068] Figure 5 This is a diagram illustrating the transmission effect of the electro-hydraulic hybrid transmission system of the present invention in a hybrid dual-pump independent operating mode.

[0069] Figure 6 This is a diagram illustrating the transmission effect of the electro-hydraulic hybrid transmission system of the present invention in a hybrid dual-pump coordinated working mode.

[0070] Figure 7 This is a schematic diagram of the assembly structure of the electro-hydraulic hybrid transmission system of the present invention.

[0071] Figure 8 For the present invention Figure 7 Sectional view of section AA;

[0072] Figure 9 For the present invention Figure 7 Mid-longitudinal sectional view;

[0073] Figure 10 The flowchart of the transmission control strategy of the electro-hydraulic cutting hybrid transmission system for coal mining machines provided by the present invention.

[0074] These include: 1. Coal mining machine cutting section housing; 2. Cutting motor; 3. Rocker arm gear reduction mechanism; 4. Planetary reducer; 5. Coal mining machine drum; 6. Torque coupling mechanism; 7. Hydraulic motor; 8. Accumulator; 9. Pressure relay; 10. Electro-hydraulic proportional directional valve; 11. Low-pressure relief valve; 12. Height adjustment pump station; 13. Height adjustment motor;

[0075] 12-1, Left elevation pump station; 12-2, Right elevation pump station; 12-3, Proportional valve one; 12-4, Proportional valve two; 12-5, Check valve one; 12-7, Check valve two. Detailed Implementation

[0076] The present invention will now be described in further detail with reference to the accompanying drawings and specific preferred embodiments.

[0077] In the description of this invention, it should be understood that the terms "left side," "right side," "upper part," "lower part," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. "First," "second," etc., do not indicate the importance of the components, and therefore should not be construed as a limitation of this invention. The specific dimensions used in this embodiment are only for illustrating the technical solution and do not limit the scope of protection of this invention.

[0078] like Figure 1 As shown, the electro-hydraulic cutting hybrid transmission system of the coal mining machine includes a pure electric drive mechanism and a hydraulic auxiliary mechanism. Both the pure electric drive mechanism and the hydraulic auxiliary mechanism are installed on the cutting section of the coal mining machine body. There are two sets of cutting sections on the coal mining machine body, and both sets of cutting sections are equipped with a pure electric drive mechanism and a hydraulic auxiliary mechanism. The pure electric drive mechanism operates independently in pure electric working mode, and the pure electric drive mechanism and the hydraulic auxiliary mechanism operate simultaneously under the electro-hydraulic hybrid drive.

[0079] The pure electric motor drive mechanism includes a cutting motor 2, a rocker arm gear reduction mechanism 3, a planetary reducer 4, and a coal mining machine drum 5. The cutting motor 2 is fixed on the inner wall of the outer shell 1 of the cutting part, and the output shaft of the cutting motor 2 is connected to the input end of the rocker arm gear reduction mechanism 3. The output end of the rocker arm gear reduction mechanism 3 is connected to the sun gear of the planetary reducer 4. The output end of the second-stage planetary reducer of the planetary reducer 4 is connected to the coal mining machine drum 5.

[0080] The hydraulic auxiliary mechanism includes a hydraulic motor 7, an accumulator 8, an electro-hydraulic proportional directional valve 10, a low-pressure relief valve 11, and an elevation pump station 12. The output end of the elevation pump station 12, one output port of the electro-hydraulic proportional directional valve 10, and the input end of the hydraulic motor 7 cooperate to form a booster circuit, which drives the output shaft of the hydraulic motor 78. The accumulator 8 is installed on the booster circuit. The elevation motor 13 acts on the input end of the elevation pump station 12 to adjust the oil delivery rate of the elevation pump station 12. A pressure relay 9 is installed at the input end of the accumulator 8, and the connection end of the pressure relay 9 is electrically connected to a controller. The accumulator 8 is installed in the transmission system between the hydraulic motor 7 and the elevation pump station 12 to store hydraulic oil and complete energy storage. The elevation pump station 12, another output port of the electro-hydraulic proportional directional valve 10, and the accumulator 8 cooperate to form a hydraulic oil circulation circuit.

[0081] A torque coupling mechanism 6 is installed on the idler wheel of the rocker gear reduction mechanism 3. The output end of the hydraulic motor 7 transmits power to the coal mining machine drum 5 through the torque coupling mechanism 6, thereby enhancing the power of the coal mining machine drum 5.

[0082] Two parallel oil pipelines are connected between the booster circuits of the two cutting sections. Check valve groups and proportional valve groups are installed on the oil pipelines. The oil pipelines, check valve groups and proportional valve groups work together to enable the hydraulic oil of the two sets of height adjustment pump stations 12 to be transmitted to each other and to dynamically distribute power.

[0083] Specifically, the two sets of height adjustment pump stations 12 are the left height adjustment pump station 12-1 and the right height adjustment pump station 12-2.

[0084] Specifically, the check valve assembly includes check valve one 12-5 and check valve two 12-7, and the proportional valve assembly includes proportional valve one 12-3 and proportional valve two 12-4.

[0085] One-way valve 12-5 and proportional valve 12-3 are connected in series on one of the oil pipelines, and one-way valve 22-7 and proportional valve 22-4 are connected in series on the other oil pipeline.

[0086] Specifically, the operating mode in pure electric mode is as follows:

[0087] When the cutting motor 2 starts, the output power is transmitted to the planetary reducer 4 through the rocker arm gear reduction mechanism 3. The output end of the secondary planetary reducer drives the coal mining machine drum 5 to rotate, and the planet carrier of the primary planetary gear drives the torque coupling mechanism 6 to rotate. The hydraulic motor 7 is in a follow-up state at this time, and the speed of the hydraulic motor 7 is set at 1450 r / min. At this time, the hydraulic oil circulation loop formed by the pump station 12, the other output port of the electro-hydraulic proportional reversing valve 10, and the accumulator 8 is adjusted to circulate the hydraulic oil. The system pressure is the pressure set by the low pressure relief valve 11, specifically about 1.5 MPa.

[0088] When the load on the coal mining machine drum 5 is stable and the two sets of cutting motors 2 can work normally, the pure electric working mode is adopted. Alternatively, when the load on the coal mining machine drum 5 is large and the pump station 12 is working, the load on the coal mining machine drum 5 is reduced by lowering the traction speed of the coal mining machine body, and the pure electric working mode is also adopted.

[0089] The electro-hydraulic hybrid drive coordination modes include hybrid drive single pump single-side working mode, hybrid drive single pump double-side working mode, hybrid dual pump single-side working mode, hybrid dual pump independent working mode, and hybrid dual pump coordinated working mode.

[0090] like Figure 2 As shown, the hybrid drive single-pump single-side working mode operates as follows:

[0091] When the cutting motor 2 starts, the output power is transmitted to the sun gear of the first-stage planetary gear train of the planetary reducer 4 via the rocker arm gear reduction mechanism 3. When the left-adjusting pump station 12-1 starts, the power is transmitted to the hydraulic motor 7 via the left position of the electro-hydraulic proportional reversing valve 10. When there is a pressure difference between the output pressure of the hydraulic motor and the low-pressure relief valve 11, the torque of the auxiliary power source is transmitted to the idler gear of the rocker arm gear reduction mechanism via the torque coupling mechanism 6. The power of the cutting motor 2 is transmitted to the second-stage planetary gear train in the first-stage planetary gear train of the planetary reducer 4 and finally output to the coal mining machine drum 5.

[0092] like Figure 3 As shown, the hybrid drive single pump dual-side working mode operates as follows:

[0093] When the left and right cutting motors 2 start, the output power is transmitted through the rocker arm gear reduction mechanism 3 to the sun gear of the first-stage planetary gear system of the planetary reducer 4. When the left height adjustment pump station 12-1 or the right height adjustment pump station 12-2 starts, the power is transmitted through the oil pipeline of one of the passages to the left position of the electro-hydraulic proportional reversing valve 10 and then to the hydraulic motor 7. When there is a pressure difference between the output pressure of the hydraulic motor and the low-pressure relief valve 11, the torque of the auxiliary power source is transmitted through the torque coupling mechanism 6 to the idler gear of the rocker arm gear reduction mechanism, and then, together with the power of the cutting motor 2, it is transmitted through the first-stage planetary gear system of the planetary reducer 4 to the second-stage planetary gear system, and finally output to the coal mining machine drum 5.

[0094] like Figure 4 As shown, the hybrid dual-pump single-side operating mode operates as follows:

[0095] When the cutting motor 2 starts, the output power is transmitted through the rocker arm gear reduction mechanism 3 to the sun gear of the first-stage planetary gear system of the planetary reducer 4. The left height adjustment pump station 12-1 and the right height adjustment pump station 12-2 start simultaneously. The power of the right height adjustment pump station 12-2 is transmitted through the proportional valve 12-3 and the check valve 12-5 together with the power of the left height adjustment pump station 12-1 through the left position of the electro-hydraulic proportional reversing valve 10 to the hydraulic motor 7. When there is a pressure difference between the output pressure of the hydraulic motor and the low pressure relief valve 11, the torque of the auxiliary power source is transmitted through the torque coupling mechanism 6 to the idler gear of the rocker arm gear reduction mechanism, and is transmitted with the power of the cutting motor 2 through the first-stage planetary gear system of the planetary reducer 4 to the second-stage planetary gear system, and finally output to the coal mining machine drum 5.

[0096] like Figure 5 As shown, the hybrid dual-pump independent operating mode operates as follows:

[0097] When the left and right cutting motors 2 start, the output power is transmitted to the sun gear of the first-stage planetary gear system of the planetary reducer 4 through the rocker arm gear reduction mechanism 3. The left height adjustment pump station 12-1 and the right height adjustment pump station 12-2 start at the same time. At this time, the proportional valve 12-3 and the proportional valve 212-4 are closed. The power of the left height adjustment pump station 12-1 and the right height adjustment pump station 12-2 is transmitted to the hydraulic motor 7 through the left position of the two sets of electro-hydraulic proportional reversing valves 10. When there is a pressure difference between the output pressure of the hydraulic motor and the low pressure relief valve 11, the torque of the auxiliary power source is transmitted to the idler gear of the rocker arm gear reduction mechanism through the torque coupling mechanism 6. The power of the cutting motor 2 is transmitted to the second-stage planetary gear system in the first-stage planetary gear system of the planetary reducer 4 and finally output to the coal mining machine drum 5.

[0098] like Figure 6 As shown, the hybrid dual-pump coordinated working mode operates as follows:

[0099] When the left and right cutting motors 2 start, the output power is transmitted through the rocker arm gear reduction mechanism 3 to the sun gear of the first-stage planetary gear train of the planetary reducer 4. The left height adjustment pump station 12-1 and the right height adjustment pump station 12-2 start simultaneously. At this time, the proportional valve 12-3 and the proportional valve 22-4 remain open. The power of the left height adjustment pump station 12-1 and the right height adjustment pump station 12-2 is transmitted to the hydraulic motor 7 through the left position of the two sets of electro-hydraulic proportional directional valves 10. When there is a pressure difference between the output pressure of the hydraulic motor and the low-pressure relief valve 11, the torque of the auxiliary power source is transmitted through the torque coupling mechanism 6 to the idler gear of the rocker arm gear reduction mechanism. It is then combined with the power of the cutting motor 2 in the first-stage planetary gear train of the planetary reducer 4 and transmitted to the second-stage planetary gear train, and finally output to the coal mining machine drum 5.

[0100] In all the above working modes, the output power distribution of the two sets of height-adjusting pump stations 12 can be dynamically controlled by controlling the displacement of the height-adjusting pump station 12, the displacement of the hydraulic motor 7, the opening size of proportional valve 12-3, proportional valve 2-4, and the electro-hydraulic proportional directional valve 10.

[0101] like Figure 1-10 As shown, the transmission control method of the electro-hydraulic cutting hybrid transmission system of a coal mining machine includes the following steps:

[0102] S1. The cutting section operates in pure electric mode. The coal mining machine body is turned on, and the cutting motors 2 and the height adjustment motors 13 of the two cutting sections are powered on, which drives the coal mining machine drum 5 to rotate and mine the coal seam.

[0103] S2. Load status judgment of the two sets of coal mining machine drums 5: The rotational speed of the coal mining machine drums 5 is monitored using speed sensors. A speed threshold for the coal mining machine drums 5 under stable operating conditions is set and compared with the real-time monitored rotational speed of the coal mining machine drums 5 during operation. It is observed whether the rotational speed of the coal mining machine drums 5 decreases and falls below the threshold. The judgment method also includes:

[0104] The working stability of the coal mining machine drum 5 is monitored. When the coal mining machine drum 5 vibrates due to resistance, it is automatically determined that the load is too large, i.e., overload state.

[0105] The images are captured in a continuous frame by combining the feedback images from infrared cameras and lidar. The displacement speed and structural deformation of the coal mining machine drum 5 are analyzed by comparing the images. When the displacement speed of the coal mining machine drum 5 slows down or there is a shaking deformation in the structure of the coal mining machine drum 5, it indicates that the cutting resistance is large, that is, the coal mining machine drum 5 is overloaded.

[0106] Based on the judgment result, perform the following operations:

[0107] S2-1, if so, it means that the two sets of coal mining machine drums 5 are in an overload state;

[0108] S2-2, Otherwise, it indicates that the two sets of coal mining machine drums 5 are in a stable state:

[0109] The load status determination process also includes the following steps:

[0110] S2.1 The coal mining machine drum 5 is working in a stable state, that is, both sets of coal mining machine drums 5 are stable, and the pure electric working mode is maintained at this time.

[0111] S2.2 When the coal mining machine drum 5 is operating under overload conditions, it is necessary to further determine whether the traction rocker arms connected to both sets of coal mining machine drums 5 are being adjusted, i.e., whether the coal mining machine drum 5 is experiencing swing arm movement. Swing arm movement specifically refers to the rocker arm connected to the coal mining machine drum 5 moving along an arc-shaped trajectory similar to erasing a blackboard, under the cooperation of the hydraulic cylinder and the drive mechanism, in order to change the digging position. During this process, since the coal mining machine drum 5 is subjected to both vertical and horizontal forces, the stability of the coal mining machine drum 5 is very likely to be compromised. To determine whether swing arm movement exists, the following operations are performed:

[0112] If S2.2-1 is true, it means that the swing arm movement increases the load. At this time, the traction speed of the coal mining machine body is reduced and the pure electric working mode is maintained, so that the coal mining machine drum 5 tends to a stable state. This not only makes the coal mining operation more stable and safe, but also reduces the wear and tear on the coal mining machine drum 5 and extends the service life of the equipment.

[0113] S2.2-2 Otherwise, it indicates that the working load of the coal mining machine drum 5 is too large. At this time, it is necessary to further judge the working status of the two sets of height adjustment pump stations 12.

[0114] S3. Determination and processing of the working status of the height-adjusting pump station 12: Based on the hydraulic monitoring system composed of accumulator 8, pressure relay 9, electro-hydraulic proportional directional valve 10, and controller, pressure relay 9 senses the internal pressure of accumulator 8. A torque sensor is installed at the output end of the cutting motor 2 (not shown in the structural diagram). The torque sensor senses the output torque and overload of the cutting motor 2, and the controller receives the pressure signal and identifies and analyzes it to determine the pump station status. It further determines the additional output torque and hydraulic coupling system pressure required by the height-adjusting pump station 12 for the cutting motor 2, i.e., the pressure adjustment value at the input end of the hydraulic motor 7. If the sensing value of pressure relay 9 is higher than 25MPa, the accumulator 8 is closed. The accumulator 8 completes energy storage in pure electric mode and releases energy in any hybrid drive mode to improve the response speed during load changes. When the system switches to any hybrid drive mode, the accumulator 8 opens and releases energy to improve the response speed of the hydraulic system during load changes and provide auxiliary power more quickly.

[0115] Regarding the pressurization status of the input terminal of the cutting motor 2, it is determined whether both sets of height adjustment pump stations 12 are idle. If the height adjustment pump station 12 does not pressurize the input terminal of the hydraulic motor 7 or the detected increase in pressure is less than the set threshold, it indicates that the height adjustment pump station 12 is in an idle state; otherwise, it is in a working state. Based on the judgment result, the following operations are performed:

[0116] S3-1, If ​​so, control the two sets of height adjustment pump stations 12 to start and make them work;

[0117] S3-2, Otherwise, control one of the sets of height-adjusting pump stations 12 to start and make it work;

[0118] S4. Determine whether both sets of coal mining machine drums 5 are in an overload state. The following conditions apply:

[0119] S4-1. When only one set of height adjustment pump station 12 is working, if both sets of coal mining machine drums 5 are in an overload state, the pure electric working mode will be switched to the hybrid drive single pump double-sided working mode, and one height adjustment pump station 12 will be used to provide auxiliary power to the two sets of coal mining machine drums 5.

[0120] S4-2. When only one set of height adjustment pump station 12 is working, if only one set of coal mining machine drum 5 is in an overload state, the pure electric working mode is switched to the hybrid drive single pump single-side working mode, and one height adjustment pump station 12 is used to provide auxiliary power to the coal mining machine drum 5 in the overload state.

[0121] S4-3. When both sets of height adjustment pump stations 12 are working, if both sets of coal mining machine drums 5 are in an overloaded state, it is necessary to further determine whether the load of at least one set of coal mining machine drums 5 exceeds the power supply limit of a single height adjustment pump station 12, and the following situations apply:

[0122] S4-3-1. At least one set of coal mining machine drums 5 has a load that exceeds the power supply limit of a single height adjustment pump station 12. The pure electric working mode is switched to the hybrid drive dual pump dual-side coordinated working mode. Two sets of height adjustment pump stations 12 are used to provide auxiliary power to the two sets of coal mining machine drums 5, and the auxiliary power is coordinated and distributed to the two sets of coal mining machine drums 5.

[0123] S4-3-2, The load of both sets of coal mining machine drums 5 did not exceed the power supply limit of the corresponding single height adjustment pump station 12. The pure electric working mode was switched to the hybrid drive dual pump dual-side independent working mode, and the two sets of height adjustment pump stations 12 were used to provide auxiliary power to the two sets of coal mining machine drums 5 respectively.

[0124] S4-4. When the two sets of height adjustment pump stations 12 are working, if at least one of the coal mining machine drums 5 is not in an overload state, the pure electric working mode is switched to the hybrid drive dual pump single-side working mode, and the two sets of height adjustment pump stations 12 are used to provide auxiliary power to the coal mining machine drum 5 in an overload state.

[0125] The above-mentioned mode switching can be achieved manually or through intelligent switching by programs and control machines to maintain the uniformity of coal seam mining efficiency, improve the controllability and predictability of the construction period, maximize cutting efficiency and optimize the overall performance of coal mining, and reduce energy consumption.

[0126] S5. Determine whether the provided auxiliary power meets the load requirements of the two sets of coal mining machine drums 5, and consider the following situations:

[0127] S5-1. If so, maintain the original working mode, pull the coal mining machine body at a constant speed, continue the cutting operation, and start the judgment process of S2.

[0128] S5-2. Otherwise, reduce the traction speed of the coal mining machine body to make the coal mining machine drum 5 tend to a stable state.

[0129] S6. During the operation of S5-1 and S5-2, the two sets of coal mining machine drums 5 end the overload state and can stably mine the coal seam. When the load of the two sets of coal mining machine drums 5 no longer needs to rely on auxiliary power, switch back to pure electric working mode, and then repeat the judgment process of S2.

[0130] S7. Cutting operation completed, stop the machine.

[0131] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various equivalent transformations can be made to the technical solutions of the present invention, and these equivalent transformations all fall within the protection scope of the present invention.

Claims

1. A mixed electro-hydraulic cutting transmission system for a coal winning machine, characterised in that: The pure motor driving mechanism and the hydraulic auxiliary mechanism are installed on the cutting part of the coal mining machine body, the number of the cutting part on the coal mining machine body is two groups, and the pure motor driving mechanism and the hydraulic auxiliary mechanism are installed in the two groups of cutting parts, the pure motor driving mechanism operates independently in the pure electric working mode, and the pure motor driving mechanism and the hydraulic auxiliary mechanism operate simultaneously in the electro-hydraulic hybrid driving cooperation; The pure motor driving mechanism includes a cutting motor (2), a rocker arm gear reduction mechanism (3), a planetary reducer (4) and a coal mining machine drum (5), the cutting motor (2) is fixed on the inner wall of the cutting part shell (1), and the output shaft of the cutting motor (2) is in transmission connection with the input end of the rocker arm gear reduction mechanism (3), the output end of the rocker arm gear reduction mechanism (3) is in transmission connection with the sun gear of the planetary reducer (4), and the output end of the two-stage planetary reducer of the planetary reducer (4) is in transmission connection with the coal mining machine drum (5); The hydraulic auxiliary mechanism includes a hydraulic motor (7), an accumulator (8), an electro-hydraulic proportional directional valve (10), a low-pressure overflow valve (11) and a height-adjusting pump station (12), the output end of the height-adjusting pump station (12) and the input end of the hydraulic motor (7) are connected to form a flow pressure circuit, the output shaft of the hydraulic motor (7) is in transmission connection, the accumulator (8) is installed on the pressure increasing circuit, the height-adjusting motor (13) acts on the input end of the height-adjusting pump station (12), and is used for adjusting the oil delivery rate of the height-adjusting pump station (12), the pressure relay (9) is installed on the input end of the accumulator (8), and the connection end of the pressure relay (9) is electrically connected with a control machine, and the height-adjusting pump station (12) and the other output port of the electro-hydraulic proportional directional valve (10) and the accumulator (8) form a hydraulic oil circulation circuit; The idler of the rocker arm gear reduction mechanism (3) is provided with a torque coupling mechanism (6), and the output end of the hydraulic motor (7) transmits power to the coal mining machine drum (5) through the torque coupling mechanism (6), so that the power of the coal mining machine drum (5) is enhanced; Two parallel oil delivery pipelines are connected between the pressure increasing circuits of the two groups of cutting parts, a one-way valve group and a proportional valve group are installed on the oil delivery pipelines, and the oil delivery pipelines, the one-way valve group and the proportional valve group cooperate to enable the hydraulic oil of the two groups of height-adjusting pump stations (12) to be transmitted to each other and dynamically allocate power; The electro-hydraulic hybrid driving cooperation mode includes: The mixed driving single pump single side working mode has the following working mode: The cutting motor (2) starts, the output power is transmitted to the sun gear of the first planetary gear train of the planetary reducer (4) through the rocker arm gear reduction mechanism (3), the left height adjustment pump station (12-1) starts, the power is transmitted to the hydraulic motor (7) through the left position of the electro-hydraulic proportional reversing valve (10), when there is a pressure difference between the output pressure of the hydraulic motor (7) and the low-pressure overflow valve (11), at this time, the torque of the auxiliary power source is transmitted to the idler gear of the rocker arm gear reduction mechanism (3) through the torque coupling mechanism (6), and the power of the cutting motor (2) is transmitted to the second planetary gear train through the first planetary gear train of the planetary reducer (4), and finally output to the shearer drum (5); The mixed drive single-pump double-side working mode has the following working mode: The left and right cutting motors (2) start, the output power is transmitted to the sun gear of the first planetary gear train of the planetary reducer (4) through the rocker arm gear reduction mechanism (3), the left height adjustment pump station (12-1) or the right height adjustment pump station (12-2) starts, the power is transmitted to the hydraulic motor (7) through the oil pipeline of one of the passages and the left position of the electro-hydraulic proportional reversing valve (10), when there is a pressure difference between the output pressure of the hydraulic motor (7) and the low-pressure overflow valve (11), at this time, the torque of the auxiliary power source is transmitted to the idler gear of the rocker arm gear reduction mechanism (3) through the torque coupling mechanism (6), and the power of the cutting motor (2) is transmitted to the second planetary gear train through the first planetary gear train of the planetary reducer (4), and finally output to the shearer drum (5); The mixed power double-pump single-side working mode has the following working mode: The cutting motor (2) starts, the output power is transmitted to the sun gear of the first planetary gear train of the planetary reducer (4) through the rocker arm gear reduction mechanism (3), the left height adjustment pump station (12-1) and the right height adjustment pump station (12-2) start at the same time, the power of the right height adjustment pump station (12-2) is transmitted to the hydraulic motor (7) through the proportional valve (12-3) and the one-way valve (12-5) and the left height adjustment pump station (12-1) through the left position of the electro-hydraulic proportional reversing valve (10), when there is a pressure difference between the output pressure of the hydraulic motor (7) and the low-pressure overflow valve (11), at this time, the torque of the auxiliary power source is transmitted to the idler gear of the rocker arm gear reduction mechanism (3) through the torque coupling mechanism (6), and the power of the cutting motor (2) is transmitted to the second planetary gear train through the first planetary gear train of the planetary reducer (4), and finally output to the shearer drum (5); The mixed power double-pump independent working mode has the following working mode: When the left and right cutting motors (2) are started, the output power is transmitted to the sun gear of the first planetary gear train of the planetary reducer (4) through the rocker arm gear reduction mechanism (3), the left and right height adjustment pump stations (12-1 and 12-2) are started at the same time, at this time, the proportional valve one (12-3) and the proportional valve two (12-4) are closed, the power of the left and right height adjustment pump stations (12-1 and 12-2) is transmitted to the hydraulic motor (7) through the left position of the two groups of electro-hydraulic proportional directional valves (10), when there is a pressure difference between the output pressure of the hydraulic motor (7) and the low-pressure overflow valve (11), at this time, the torque of the auxiliary power source is transmitted to the idler gear of the rocker arm gear reduction mechanism (3) through the torque coupling mechanism (6), and the power of the cutting motor (2) is transmitted to the second planetary gear train through the first planetary gear train of the planetary reducer (4), and finally output to the shearer drum (5); The working mode of the hybrid power double-pump coordination is as follows: When the left and right cutting motors (2) are started, the output power is transmitted to the sun gear of the first planetary gear train of the planetary reducer (4) through the rocker arm gear reduction mechanism (3), the left and right height adjustment pump stations (12-1 and 12-2) are started at the same time, at this time, the proportional valve one (12-3) and the proportional valve two (12-4) are closed, the power of the left and right height adjustment pump stations (12-1 and 12-2) is transmitted to the hydraulic motor (7) through the left position of the two groups of electro-hydraulic proportional directional valves (10), when there is a pressure difference between the output pressure of the hydraulic motor (7) and the low-pressure overflow valve (11), at this time, the torque of the auxiliary power source is transmitted to the idler gear of the rocker arm gear reduction mechanism (3) through the torque coupling mechanism (6), and the power of the cutting motor (2) is transmitted to the second planetary gear train through the first planetary gear train of the planetary reducer (4), and finally output to the shearer drum (5).

2. The electro-hydraulic cutting hybrid drive system of a coal winning machine as claimed in claim 1 wherein: The two groups of height adjustment pump stations (12) are respectively left height adjustment pump station (12-1) and right height adjustment pump station (12-2).

3. The electro-hydraulic cutting hybrid drive system of a coal mining machine of claim 1, wherein: The one-way valve group includes one-way valve one (12-5) and one-way valve two (12-7), and the proportional valve group includes proportional valve one (12-3) and proportional valve two (12-4); The one-way valve one (12-5) and the proportional valve one (12-3) are installed in series on one of the oil supply pipelines, and the one-way valve two (12-7) and the proportional valve two (12-4) are installed in series on the other oil supply pipeline.

4. The electro-hydraulic cutting hybrid drive system of a shearer as claimed in claim 1, characterized in that: The working mode of the pure electric working mode is as follows: When the cutting motor (2) is started, the output power is transmitted to the planetary reducer (4) through the rocker arm gear reduction mechanism (3), the shearer drum (5) is driven to rotate by the output end of the second planetary reducer, and the torque coupling mechanism (6) is driven to rotate by the planetary carrier of the first planetary gear, and the torque coupling mechanism (6) is connected to the idler gear of the rocker arm gear reduction mechanism (3) through the rear end, at this time, the hydraulic motor (7) is in a follow-up state, and the rotating speed of the hydraulic motor (7) is set to 1450r / min.

5. The method according to any one of claims 1 to 4, characterized in that: The method comprises the following steps: S1, the cutting part pure electric operation mode runs, the coal winning machine body is started, the two groups of cutting part cutting motor (2) and two groups of height adjustment motor (13) are powered on, drive the coal winning machine drum (5) rotation, the coal seam is exploited; S2, two groups of coal winning machine drum (5) load state judgment, with the help of speed sensor, the speed of coal winning machine drum (5) is monitored, set the speed threshold of coal winning machine drum (5) in stable working condition, and compare with the speed of coal winning machine drum (5) in real-time monitoring, observe whether the speed of coal winning machine drum (5) is reduced and below the threshold, have the following conditions: S2-1, if yes, two groups of coal winning machine drum (5) are in overload state; S2-2, if no, two groups of coal winning machine drum (5) are in stable state: In load state judgment, the following steps are also included: S2.1, the coal winning machine drum (5) works in stable state, that is, two groups of coal winning machine drum (5) are stable, at this time, the pure electric operation mode is maintained; S2.2, the coal winning machine drum (5) works in overload state, at this time, it is further judged whether the two groups of coal winning machine drum (5) connected to the traction rocker arm are adjusting, that is, whether the coal winning machine drum (5) has swing arm movement, which has the following conditions: S2.2-1 if yes, the swing arm movement increases the load, at this time, the traction speed of the coal winning machine body is reduced, and the pure electric operation mode is maintained, so that the coal winning machine drum (5) tends to be stable; S2.2-2 if no, the working load of the coal winning machine drum (5) itself is too large, at this time, it is further judged whether the working state of the two groups of height adjustment pump stations (12) is; S3, height adjustment pump station (12) working state determination and processing, based on the hydraulic monitoring system composed of accumulator (8), pressure relay (9), electro-hydraulic proportional reversing valve (10) and control machine, pressure relay (9) senses the pressure inside accumulator (8), when reaching the maximum pressure of accumulator (8), the energy storage device opening is closed, the output torque and overload of cutting motor (2) are sensed by torque sensor, and the pressure electric signal is received by control machine, and then it is identified and analyzed, so as to judge the pump station state, and further obtain the output torque and hydraulic coupling system pressure required by height adjustment pump station (12) for cutting motor (2), that is, the pressure regulation value of input end of hydraulic motor (7); For the state of cutting motor (2) input end load / overload, it is judged whether the two groups of height adjustment pump stations (12) are idle, which has the following conditions: S3-1, if yes, control two groups of height adjustment pump stations (12) to start and work; S3-2, if no, control one group of height adjustment pump station (12) to start and work; S4, it is judged whether two groups of coal winning machine drum (5) are in overload state, which has the following conditions: S4-1, when only one group of height adjustment pump station (12) works, if two groups of coal winning machine drum (5) are in overload state, the pure electric operation mode is switched to the mixed drive single pump double side working mode, and one height adjustment pump station (12) is used to provide auxiliary power for two groups of coal winning machine drum (5); S4-2, only one set of height adjustment pump station (12) is working, if only one set of shearer drum (5) is in an overload state, switch from pure electric working mode to hybrid drive single pump single side working mode, use one height adjustment pump station (12) to provide auxiliary power for the shearer drum (5) in the overload state; S4-3, two sets of height adjustment pump stations (12) are working, if both sets of shearer drums (5) are in an overload state, further judge whether the load of at least one set of shearer drum (5) exceeds the energy supply limit of a single height adjustment pump station (12), which has the following situations: S4-3-1, the load of at least one set of shearer drum (5) exceeds the energy supply limit of a single height adjustment pump station (12), switch from pure electric working mode to hybrid drive double pump double side coordinated working mode, use two sets of height adjustment pump stations (12) to provide auxiliary power for two sets of shearer drums (5), and the auxiliary power is coordinated and distributed to two sets of shearer drums (5); S4-3-2, the load of two sets of shearer drums (5) does not exceed the energy supply limit of the corresponding single height adjustment pump station (12), switch from pure electric working mode to hybrid drive double pump double side independent working mode, use two sets of height adjustment pump stations (12) to provide auxiliary power for two sets of shearer drums (5) respectively; S4-4, two sets of height adjustment pump stations (12) are working, if at least one shearer drum (5) is not in an overload state, switch from pure electric working mode to hybrid drive double pump single side working mode, use two sets of height adjustment pump stations (12) to provide auxiliary power for the shearer drum (5) in the overload state; S5, judge whether the provided auxiliary power meets the needs of the load of two sets of shearer drums (5), which has the following situations: S5-1, if yes, maintain the original working mode, pull the shearer body at a constant speed, continue the cutting operation, and start the discrimination procedure of S2; S5-2, if no, reduce the pulling speed of the shearer body, so that the shearer drum (5) tends to be stable; S7, during the working process of S5-1 and S5-2, two sets of shearer drums (5) end the overload state and can stably mine the coal seam, when the load of two sets of shearer drums (5) does not need to rely on auxiliary power, switch back to pure electric working mode, and then cycle the discrimination procedure of S2; S7, the cutting operation is completed, and the machine is stopped.

6. The method of transmission control of the electro-hydraulic cutting hybrid transmission system of the coal mining machine according to claim 5, characterized in that: The method for judging the load state of the shearer drum (5) in S2 further includes monitoring the working stability of the shearer drum (5), and automatically determining that the load is too large, i.e. the overload state, when the shearer drum (5) shakes due to resistance.

7. The method of claim 5, wherein: When judging the working stability of the shearer drum (5) in S2, the images of continuous frames are intercepted through the images fed back by the infrared camera and the laser radar, and the displacement speed and the deformation amount of the structure of the shearer drum (5) are analyzed according to the image comparison, when the displacement speed of the shearer drum (5) slows down or the shearer drum (5) has a shaking type deformation on the structure, it indicates that the cutting resistance is large, i.e. the shearer drum (5) is overloaded.

8. The method of claim 5, wherein: In the S3, when determining the working state of the height-adjusting pump station (12), if the height-adjusting pump station (12) does not increase the pressure at the input end of the hydraulic motor (7) or the increased pressure value is less than the set threshold value, it indicates that the height-adjusting pump station (12) is in an idle state, otherwise it is in a working state.

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