Dynamic control and lubricating oil circulation shared hydraulic system of shearer height adjusting oil cylinder

Abstract

The present application belongs to the technical field of hydraulic control of coal mining machine, and solves the problem that the dynamic control of height-adjusting cylinder and the lubricating oil circulation of reducer cannot be shared. A hydraulic system for dynamic control of height-adjusting cylinder and lubricating oil circulation of coal mining machine is provided. High-pressure lubricating oil enters the lubricating oil cavity of oil power conversion device through a three-position four-way valve. The inner cavity of the oil power conversion device is divided into a lubricating oil cavity and a hydraulic oil cavity, and shares a piston rod with a piston at both ends. The oil power conversion device completes the conversion from lubricating oil power to hydraulic oil power through the common movement of the lubricating oil side piston and the hydraulic oil side piston. The squeezed hydraulic oil on the hydraulic oil side enters the height-adjusting cylinder, and pushes the cutting drum to rise or fall. The present application realizes the sharing of a set of hydraulic control system for the dynamic control of height-adjusting cylinder and the lubricating oil circulation of reducer, meets the requirements of compact design of coal mining machine, and realizes the mechanized mining of thin coal seams.

Description

Technical Field

[0001] This invention belongs to the field of hydraulic control technology for coal mining machines, specifically relating to a hydraulic system that combines dynamic control of the height adjustment cylinder and lubricating oil circulation in a coal mining machine. Background Technology

[0002] The cutting drum of a coal mining machine rotates via a motor and reducer to achieve the purpose of coal mining. Depending on the height of the coal face, the cutting drum needs to be adjusted in height, which is achieved by a hydraulic cylinder. The operation of the drum height adjustment cylinder requires hydraulic power, therefore a hydraulic system is needed, including a hydraulic tank, motor, hydraulic pump, control valves, filters, and hydraulic pipelines.

[0003] The gear oil in a drum reducer lubricates and cools the gears and bearings. To ensure effective cooling, an external circulation cooling system is typically designed. This system pumps the lubricating oil out of the reducer for cooling before returning it to the reducer cavity. This lubricating oil circulation system also requires corresponding pumps, valves, filters, coolers, and other components. Coal mining machines, especially those used in thin coal seams, have limited working space, necessitating a low overall height and compact structure.

[0004] In current technology, the components of the two hydraulic systems are redundant, resulting in wasted power sources. Moreover, according to the structural characteristics of coal mining machines, the components are often scattered, and power is transmitted between the components through a large number of pipelines, which occupies a lot of space and has many potential failure points, failing to meet the requirement of a high power-to-volume ratio for coal mining machines.

[0005] Meanwhile, in current technology, the working medium of the hydraulic system is hydraulic oil, and the working pressure is generally higher, above 16MPa, depending on the load requirements of the hydraulic cylinder; the working medium of the lubrication system is lubricating oil, and the circulation pressure requirement is lower, generally below 2MPa. The two systems cannot be unified or shared. Summary of the Invention

[0006] In order to solve at least one of the above-mentioned technical problems in the prior art, the present invention provides a hydraulic system for dynamic control of the height adjustment cylinder of a coal mining machine and shared lubricating oil circulation.

[0007] This invention is achieved using the following technical solution: a shared hydraulic system for dynamic control of the height adjustment cylinder and lubricating oil circulation in a coal mining machine, comprising a lubrication pump assembly, a filter, a first control valve group, an oil-hydraulic power conversion device, a height adjustment cylinder, and a hydraulic lock; the high-pressure gear pump of the lubrication pump assembly draws oil from the reducer cavity of the coal mining machine into the lubrication pump assembly and converts it into high-pressure lubricating oil. The high-pressure lubricating oil passes through the filter and enters the solenoid pilot valve and the three-position four-way directional valve of the first control valve group. The voltage of the solenoid pilot valve is controlled by the controller to switch the working position of the valve core of the solenoid pilot valve. The working port of the solenoid pilot valve is connected to the hydraulic control port of the three-position four-way valve. This system switches the working position of the three-position four-way valve core, thereby controlling the direction of the high-pressure lubricating oil. The high-pressure lubricating oil enters the lubricating oil chamber of the hydraulic power conversion device through the three-position four-way valve. The inner chamber of the hydraulic power conversion device is divided into a lubricating oil chamber and a hydraulic oil chamber, which share a piston rod with pistons at both ends. The hydraulic power conversion device completes the conversion from lubricating oil power to hydraulic oil power through the joint movement of the piston on the lubricating oil side and the piston on the hydraulic oil side. The hydraulic oil on the hydraulic oil side, after being squeezed, enters the height adjustment cylinder, realizing the extension or retraction of the piston rod of the height adjustment cylinder, thereby pushing the cutting drum to rise or fall, and is locked and fixed by a hydraulic lock.

[0008] Preferably, the first control valve assembly includes a solenoid pilot valve, a three-position four-way directional valve, a relief valve, an adjustable flow valve, and a first valve body. The oil inlet P1 of the first valve body is connected to the oil inlets P2 and P3 of the solenoid pilot valve and the three-position four-way directional valve via an internal oil passage within the valve body. The oil return port T1 of the first valve body is connected to the oil return ports T2 and T3 of the solenoid pilot valve and the three-position four-way directional valve, as well as the oil inlet P4 of the relief valve. The adjustable flow valve is installed at the oil return port T2 of the solenoid pilot valve and the three-position four-way directional valve. In the oil circuit between the return port T3, the working port A1 of the solenoid pilot valve is connected to the control port K1 of the three-position four-way directional valve, the working port B1 of the solenoid pilot valve is connected to the control port K2 of the three-position four-way directional valve, and the return port T4 of the first valve body is connected to the return port T5 of the relief valve. The high-pressure lubricating oil discharged from the return port T1 of the first valve body flows back to the reducer cavity through the cooler, and the high-pressure lubricating oil discharged from the return port T4 of the first valve body flows directly back to the reducer cavity.

[0009] Preferably, a second control valve group is provided at the hydraulic power conversion device. The second control valve group includes a shuttle valve, a first check valve, a second check valve, a first safety valve, a second safety valve, a first two-position two-way valve, a second two-position two-way valve, and a second valve body. The working ports A2 and B2 of the three-position four-way directional valve are respectively connected to the working ports A3 and B3 of the second valve body. The working ports A3 and B3 of the second valve body are respectively connected to the working ports A4 and B4 of the hydraulic power conversion device. The working ports A4 and B4 are located in the rodless chamber and rod chamber of the lubricating oil chamber, respectively. The working ports A5 and B5 of the second valve body are respectively connected to the working ports A6 and B6 of the hydraulic power conversion device. The working ports A6 and B6 are located in the rodless chamber and rod chamber of the hydraulic oil chamber, respectively. The shuttle valve is inserted into the second valve body. The two inlets A7 and B7 of the shuttle valve are respectively connected to the working ports A3 and B3 of the second valve body. The inlets of the first check valve and the second check valve are connected to the working ports of the second valve body. Port A8 is connected. The oil outlets of the first and second check valves are connected to the working oil ports A5 and B5 of the second valve body, respectively. The oil inlets of the first and second safety valves are connected to the working oil ports A5 and B5 of the second valve body, respectively. The oil outlets of the first and second safety valves are connected to the working oil port A8 of the second valve body. The working oil ports A9 and A10 of the first and second two-position two-way valves are both connected to the working oil port A8 of the second valve body. The working oil ports B9 and B10 of the first and second two-position two-way valves are connected to the working oil ports A5 and B5 of the second valve body, respectively. The control oil ports K3 and K4 of the first and second two-position two-way valves are both connected to the oil outlet K5 of the shuttle valve. The working oil port A8 of the second valve body is connected to a replenishing oil tank through a pipeline. The working oil ports A5 and B5 of the second valve body are connected to the rodless chamber and rod chamber of the height adjustment cylinder through pipelines, respectively. The hydraulic lock is installed on the pipeline between the second valve body and the height adjustment cylinder.

[0010] Preferably, the lubrication pump assembly includes a high-pressure gear pump, a third safety valve, an air filter, a temperature sensor, a pressure sensor, and a pump housing; the oil inlet of the high-pressure gear pump is connected to the oil inlet on the pump housing through an internal oil passage, the pressure port of the high-pressure gear pump is connected to the oil outlet of the pump housing through an internal oil passage, the oil inlet of the third safety valve is connected to the oil outlet of the pump housing through an internal oil passage, and the oil outlet of the third safety valve is connected to the reducer cavity through an internal oil passage; the air filter interface is connected to the reducer cavity through an internal oil passage, and the oil ports of the temperature sensor and pressure sensor are connected to the oil outlet of the pump housing through internal oil passages.

[0011] Preferably, the area ratio of the rod chamber to the rodless chamber of the height adjustment cylinder is the same as the area ratio of the rod chamber to the rodless chamber of the hydraulic oil chamber in the power conversion device.

[0012] Preferably, the lubrication pump assembly is installed on the housing of the coal mining machine reducer, the first control valve group, filter, cooler, oil-hydraulic power conversion device, and oil replenishment tank are distributed in the gaps of the main structure of the coal mining machine, the second control valve group is installed on the oil port end face of the oil-hydraulic power conversion device, the hydraulic lock is installed on the end of the height adjustment cylinder, one end of the height adjustment cylinder is hinged to the cutting mechanism, and the other end of the height adjustment cylinder is hinged to the main structure of the coal mining machine.

[0013] Compared with the prior art, the beneficial effects of the present invention are:

[0014] The hydraulic control system of the height adjustment cylinder of the coal mining machine and the lubrication system of the reducer share a single power mechanism. When the cutting drum needs to be adjusted in height, the power of the lubrication system is switched to the hydraulic system by changing the control signal of the electromagnetic pilot valve. This dynamically and continuously controls the movement of the height adjustment cylinder, allowing the hydraulic system to utilize the power of the lubrication system. The hydraulic system's operation and the lubrication system's cooling cycle occur simultaneously. After the adjustment is completed, the electromagnetic pilot valve signal is controlled to disconnect the hydraulic system from the lubrication system, allowing the lubrication system to perform normal cooling and lubrication of the reducer during the coal cutting process. The integrated valve group, including the first control valve group, the second control valve group, and the lubrication pump assembly, maximizes the integration of various pumps, valves, and sensor valves, eliminating a large number of connecting pipelines, saving space, reducing failure points, facilitating operation and maintenance, and improving the overall reliability and service life of the machine. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0016] Figure 1 This is a schematic diagram of the hydraulic system according to an embodiment of the present invention;

[0017] Figure 2 This is a hydraulic schematic diagram of the first control valve group according to an embodiment of the present invention;

[0018] Figure 3 This is a schematic diagram of the first control valve group according to an embodiment of the present invention;

[0019] Figure 4 This is a hydraulic schematic diagram of the second control valve group and the hydraulic power conversion device according to an embodiment of the present invention;

[0020] Figure 5 This is a schematic diagram of the second control valve group and the hydraulic power conversion device according to an embodiment of the present invention;

[0021] Figure 6 This is a schematic diagram of a lubrication pump assembly according to an embodiment of the present invention.

[0022] In the diagram: 1.1-High-pressure gear pump; 1.2-Third safety valve; 1.3-Air filter; 1.4-Temperature sensor; 1.5-Pressure sensor; 1.6-Pump housing; 2-Filter; 3.1-Solenoid pilot valve; 3.2-Three-position four-way directional valve; 3.3-Relief valve; 3.4-Adjustable flow valve; 3.5-First valve body; 4-Hydraulic power conversion device; 5.1-Shuttle valve; 5.2-First check valve; 5.3-Second check valve; 5.4-First safety valve; 5.5-Second safety valve; 5.6-First two-position three-way valve; 5.7-Second two-position three-way valve; 5.8-Second valve body; 6-Height adjustment cylinder; 7-Hydraulic lock; 8-Cooler; 9-Maintenance oil tank; 10-Reducer oil sump. Detailed Implementation

[0023] The technical solutions of the embodiments of the present invention will be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other implementation methods obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0024] It should be noted that the structures, proportions, sizes, etc., shown in the accompanying drawings of this specification are only for the purpose of assisting those skilled in the art in understanding and reading the content disclosed in the specification, and are not intended to limit the conditions under which the present invention can be implemented. Therefore, they have no substantial technical significance. Any modifications to the structure, changes in the proportional relationships, or adjustments to the size, without affecting the effects and objectives that the present invention can produce, should fall within the scope of the technical content disclosed in the present invention. It should be noted that in this specification, relational terms such as "first" and "second" are only used to distinguish one entity from several other entities, and do not necessarily require or imply any actual relationship or order between these entities.

[0025] This invention provides an embodiment:

[0026] like Figures 1 to 6As shown, a hydraulic system for dynamic control of the height adjustment cylinder and shared lubricating oil circulation in a coal mining machine includes a lubrication pump assembly, a filter 2, a first control valve group, an oil-hydraulic power conversion device 4, a height adjustment cylinder 6, and a hydraulic lock 7. The high-pressure gear pump 1.1 of the lubrication pump assembly draws oil from the reducer cavity of the coal mining machine into the lubrication pump assembly and converts it into high-pressure lubricating oil. The high-pressure lubricating oil enters the solenoid pilot valve 3.1 and the three-position four-way directional valve 3.2 of the first control valve group through the filter 2. The voltage of the solenoid pilot valve 3.1 is dynamically controlled by the controller to achieve dynamic switching of the working position of the valve core of the solenoid pilot valve 3.1. The working oil port of the solenoid pilot valve 3.1 is connected to the hydraulic control port of the three-position four-way valve 3.2 to achieve dynamic switching of the working position of the valve core of the three-position four-way valve, thereby achieving dynamic control of the direction of the high-pressure lubricating oil.

[0027] High-pressure lubricating oil enters the lubricating oil chamber of the hydraulic power conversion device 4 through the three-position four-way valve 3.2. The inner cavity of the hydraulic power conversion device 4 is divided into a lubricating oil chamber and a hydraulic oil chamber, and they share a piston rod with pistons at both ends. The hydraulic power conversion device 4 completes the dynamic conversion from lubricating oil power to hydraulic oil power through the joint movement of the lubricating oil side piston and the hydraulic oil side piston.

[0028] The hydraulic oil, after being compressed, enters the height adjustment cylinder 6, enabling the piston rod of the height adjustment cylinder 6 to dynamically and continuously extend or retract, thereby driving the cutting drum to dynamically and continuously rise or fall, and is locked in place by the hydraulic lock 7. The coal mining machine includes a cutting drum, motor, reducer, coupling, hydraulic system, and water cooling system.

[0029] In this embodiment, the lubrication pump assembly is installed on the housing of the coal mining machine reducer. The first control valve group, filter 2, cooler 8, oil-hydraulic power conversion device 4, and oil replenishment tank 9 can be installed separately according to the space size of the gap in the main structure of the coal mining machine to save space. The second control valve group is installed on the oil port end face of the oil-hydraulic power conversion device 4. The hydraulic lock 7 is installed on the end of the height adjustment cylinder 6. One end of the height adjustment cylinder 6 is hinged to the cutting mechanism, and the other end of the height adjustment cylinder 6 is hinged to the main structure of the coal mining machine.

[0030] In this embodiment, the lubrication pump assembly includes a high-pressure gear pump 1.1, a third safety valve 1.2, an air filter 1.3, a temperature sensor 1.4, a pressure sensor 1.5, and a pump housing 1.6. The oil inlet of the high-pressure gear pump 1.1 is connected to the oil inlet on the pump housing 1.6 through an internal oil passage. The pressure port of the high-pressure gear pump 1.1 is connected to the oil outlet of the pump housing 1.6 through an internal oil passage. The oil inlet of the third safety valve 1.2 is connected to the oil outlet of the pump housing 1.6 through an internal oil passage. The oil outlet of the third safety valve 1.2 is connected to the reducer cavity through an internal oil passage. The interface of the air filter 1.3 is connected to the reducer cavity through an internal oil passage. The oil ports of the temperature sensor 1.4 and the pressure sensor 1.5 are connected to the oil outlet of the pump housing 1.6 through internal oil passages.

[0031] The first control valve assembly includes a solenoid pilot valve 3.1, a three-position four-way directional valve 3.2, a relief valve 3.3, an adjustable flow valve 3.4, and a first valve body 3.5. The oil inlet P1 of the first valve body 3.5 is connected to the oil inlets P2 and P3 of the solenoid pilot valve 3.1 and the three-position four-way directional valve 3.2 via an internal oil passage. The oil return port T1 of the first valve body 3.5 is connected to the oil return ports T2 and T3 of the solenoid pilot valve 3.1 and the three-position four-way directional valve 3.2, as well as the oil inlet P4 of the relief valve 3.3. The adjustable flow valve 3.4 is installed at the oil return port T2 and the three-position four-way directional valve 3.1. In the oil line between the return port T3 of the four-way directional valve 3.2, the working port A1 of the solenoid pilot valve 3.1 is connected to the control port K1 of the three-position four-way directional valve 3.2, the working port B1 of the solenoid pilot valve 3.1 is connected to the control port K2 of the three-position four-way directional valve 3.2, and the return port T4 of the first valve body 3.5 is connected to the return port T5 of the relief valve 3.3; the high-pressure lubricating oil discharged from the return port T1 of the first valve body 3.5 flows back to the reducer cavity through the cooler 8, and the high-pressure lubricating oil discharged from the return port T4 of the first valve body 3.5 flows directly back to the reducer cavity.

[0032] A second control valve group is installed at the hydraulic power conversion device 4. The second control valve group includes a shuttle valve 5.1, a first check valve 5.2, a second check valve 5.3, a first safety valve 5.4, a second safety valve 5.5, a first two-position two-way valve 5.6, a second two-position two-way valve 5.7, and a second valve body 5.8. The working ports A2 and B2 of the three-position four-way directional valve 3.2 are connected to the working ports A3 and B3 of the second valve body 5.8 via the working ports A11 and B11 of the first valve body 3.5, respectively. The working ports A3 and B3 of the second valve body 5.8 are connected to the working ports A4 and B4 of the hydraulic power conversion device 4, respectively. The working ports A4 and B4 are located in the rodless chamber and rod chamber of the lubricating oil chamber, respectively. The working ports A5 and B5 of the second valve body 5.8 are connected to the working ports A6 and B6 of the hydraulic power conversion device 4, respectively. The working ports A6 and B6 are located in the rodless chamber and rod chamber of the hydraulic oil chamber, respectively.

[0033] A shuttle valve 5.1 is inserted into the second valve body 5.8. The two inlets A7 and B7 of the shuttle valve 5.1 are connected to the working ports A3 and B3 of the second valve body 5.8, respectively. The inlets of the first check valve 5.2 and the second check valve 5.3 are connected to the working port A8 of the second valve body 5.8. The outlets of the first check valve 5.2 and the second check valve 5.3 are connected to the working ports A5 and B5 of the second valve body 5.8, respectively. The inlets of the first safety valve 5.4 and the second safety valve 5.5 are connected to the working ports A5 and B5 of the second valve body 5.8, respectively. The outlets of the first safety valve 5.4 and the second safety valve 5.5 are connected to the working port A8 of the second valve body 5.8. The first two-position two-way valve 5.6... The working ports A9 and A10 of the two-position two-way valve 5.7 are connected to the working port A8 of the second valve body 5.8. The working ports B9 and B10 of the first two-position two-way valve 5.6 and the second two-position two-way valve 5.7 are connected to the working ports A5 and B5 of the second valve body 5.8, respectively. The control ports K3 and K4 of the first two-position two-way valve 5.6 and the second two-position two-way valve 5.7 are connected to the outlet port K5 of the shuttle valve. The working port A8 of the second valve body 5.8 is connected to the replenishing oil tank 9 through a pipeline. The working ports A5 and B5 of the second valve body 5.8 are connected to the rodless chamber and the rod chamber of the height adjustment cylinder 6 through pipelines, respectively. The hydraulic lock 7 is installed on the pipeline between the second valve body 5.8 and the height adjustment cylinder 6.

[0034] Working principle:

[0035] The high-pressure gear pump 1.1 of the lubrication pump assembly is connected to the gear inside the reducer via a coupling. After the coal mining machine starts, the motor drives the reducer gear to rotate, and the gear drives the high-pressure gear pump 1.1 to rotate, drawing the oil in the reducer cavity into the lubrication pump assembly through the oil passage of the housing. The high-pressure gear pump 1.1 converts the static pressure lubricating oil in the reducer cavity into high-pressure lubricating oil. The high-pressure oil further enters the filter 2 through the pipeline to filter impurities in the oil and enters the first control valve group.

[0036] The voltage of the solenoid pilot valve 3.1 is dynamically controlled by the controller to achieve dynamic switching of the working position of the valve core of the solenoid pilot valve 3.1. The oil of the working port of the solenoid pilot valve 3.1 controls the hydraulic control port of the three-position four-way valve 3.2, thereby achieving dynamic switching of the working position of the valve core of the three-position four-way valve 3.2, and thus achieving dynamic control of the direction of the pressure oil.

[0037] When the solenoid pilot valve 3.1 does not receive control voltage, both the solenoid pilot valve 3.1 and the three-position four-way valve 3.2 are in the neutral position. The high-pressure lubricating oil enters the cooler 8 directly through the first control valve group. After cooling, it returns to the reducer cavity through the oil passage on the reducer housing, thus only completing the cooling of the lubricating oil.

[0038] When the solenoid pilot valve 3.1 receives the first voltage value, the valve core of the solenoid pilot valve 3.1 is in the left position. After the pressure oil passes through the solenoid pilot valve 3.1, it controls the valve core of the three-position four-way valve 3.2 to be in the right position. The pressure oil passes through the three-position four-way valve 3.2 to the working port A11 of the first valve body 3.5. After being transmitted through the pipeline, it enters the working port A3 of the second valve body 5.8. Inside the second valve body 5.8, it passes through the oil passage and the working port A4 of the hydraulic power conversion device 4 to enter the rodless lubricating oil chamber of the power conversion device. Under the action of the high-pressure lubricating oil, the piston of the hydraulic power conversion device 4 moves downward, and the excess lubricating oil in the rod chamber of the lubricating oil chamber is discharged. It returns to the three-position four-way valve 3.2 through the working port B4 of the hydraulic power conversion device 4, the working port B3 of the second valve body 5.8, and the working port B11 of the first valve body 3.5. After passing through the three-position four-way valve 3.2, it enters the cooler 8 through the internal oil passage and external pipeline of the first valve body 3.5. After being cooled, it returns to the reducer cavity.

[0039] Due to the continuous action of high-pressure lubricating oil, the piston in the hydraulic power conversion device 4 moves downwards, reducing the volume of the rodless chamber and increasing the volume of the rod chamber. The hydraulic oil in the rodless chamber is compressed into high-pressure hydraulic oil, which is then discharged and enters the rodless chamber of the height-adjusting cylinder 6 through oil passages and pipelines. This high-pressure hydraulic oil pushes the piston rod of the height-adjusting cylinder 6 to extend, thus raising the cutting drum. The hydraulic oil discharged from the rod chamber of the height-adjusting cylinder 6 returns to the rod chamber of the lubricating oil chamber in the hydraulic power conversion device 4 through pipelines and the oil passages of the second valve body, achieving a balance between the oil output and inflow of the hydraulic oil in the hydraulic power conversion device 4.

[0040] When the solenoid pilot valve 3.1 receives the second voltage value, the valve core of the solenoid pilot valve 3.1 is in the right position. After passing through the solenoid pilot valve 3.1, the pressure oil controls the valve core of the three-position four-way valve 3.2 to be in the left position. After passing through the three-position four-way valve 3.2, the pressure oil reaches the working port B11 of the first valve body 3.5, and after being transmitted through the pipeline, enters the working port B3 of the second valve body 5.8. Inside the second valve body 5.8, it follows the oil passage through the working port B4 of the hydraulic power conversion device 4 and enters the hydraulic power conversion device 4. Under the action of pressurized lubricating oil, the piston of the oil-hydraulic power conversion device 4 moves upward in the rod chamber of the lubricating oil chamber, and the excess lubricating oil in the rodless chamber of the lubricating oil chamber is discharged. It returns to the three-position four-way valve 3.2 through the working oil port A4 of the oil-hydraulic power conversion device 4, the working oil port A3 of the second valve body 5.8 and the working oil port A11 of the first valve body 3.5. After passing through the three-position four-way valve 3.2, it enters the cooler 8 through the internal oil passage and external pipeline of the first valve body 3.5. After cooling, it returns to the reducer chamber.

[0041] Due to the continuous action of high-pressure lubricating oil, the piston of the hydraulic power conversion device 4 moves upward continuously. The volume of the rod chamber of the hydraulic oil chamber decreases, while the volume of the rodless chamber increases. The hydraulic oil in the rod chamber is squeezed to form high-pressure hydraulic oil, which is discharged and enters the rod chamber of the height adjustment cylinder 6 through oil passages and pipelines. The high-pressure hydraulic oil pushes the piston rod of the height adjustment cylinder 6 to retract, pushing the cutting drum downward. The hydraulic oil discharged from the rodless chamber of the height adjustment cylinder 6 returns to the rodless chamber of the hydraulic oil chamber of the hydraulic power conversion device 4 through pipelines and the oil passages of the second valve body 5.8, achieving a balance between the oil output and inflow of the hydraulic oil in the hydraulic power conversion device 4.

[0042] By repeatedly and dynamically controlling the pilot solenoid valve 3.1 between the first and second voltage values, the dynamic continuous extension or retraction control of the piston rod of the height adjustment cylinder 6 is realized, thereby realizing the dynamic continuous rise or fall control of the cutting drum.

[0043] In this embodiment, the air filter 1.3 of the lubrication pump assembly ensures that atmospheric pressure is maintained within the reducer cavity, ensuring smooth oil intake by the high-pressure gear pump 1.1. Simultaneously, it filters dust and impurities from the external air, preventing them from entering the reducer. The third safety valve 1.2 is set to a relatively high pressure value. When the pressure at the outlet of the high-pressure gear pump 1.1 exceeds this set value, oil will overflow from the safety valve, ensuring that the system pressure does not exceed this value and protecting components from damage. Temperature sensor 1.4 and pressure sensor 1.5 draw oil from the lubrication pump's outlet line, enabling real-time monitoring of system temperature and pressure.

[0044] Filter 2 is a high-pressure filter that filters out metal, particulate impurities, and other contaminants from the reducer lubricating oil.

[0045] The heat exchange between the lubricating oil and the cooling water is completed inside the cooler 8, thereby cooling the lubricating oil.

[0046] The overflow valve 3.3 is set to a lower pressure value. When the return oil pressure of the lubricating oil exceeds this set value, the lubricating oil overflows from the overflow valve 3.3, ensuring that the return oil pressure does not exceed this pressure value and protecting the cooler 8 from damage. The adjustable flow valve 3.4 is set to a certain flow rate value to provide a certain back pressure to the return oil system, so that the cutting drum is not impacted when it descends.

[0047] The hydraulic power conversion device completes the conversion from lubricating oil power to hydraulic oil power through the joint movement of the piston in the lubricating oil chamber and the piston in the hydraulic oil chamber, while the lubricating oil and hydraulic oil do not permeate each other under the action of the sealing ring.

[0048] Shuttle valve 5.1 provides control oil regardless of whether there is pressure at either port A3 or B3 of the second valve body 5.8, switching the two two-position two-way valves from the on position to the off position. Two check valves, during the operation of the lifting cylinder 6, allow hydraulic oil to be replenished from the replenishment tank into the hydraulic chamber of the hydraulic power conversion device 4, preventing reverse flow and pressure loss, thus compensating for oil losses caused by leakage in the closed hydraulic system. The first and second safety valves are both set with a pressure value slightly higher than the working pressure of the lifting cylinder 6, ensuring that the hydraulic oil level does not exceed this set value during the operation of the lifting cylinder, protecting the cylinder and mechanical structure from damage. When there is no pressure at ports A3 and B3 of the second valve body 5.8 (i.e., when the lifting cylinder is not operating), the two two-position two-way valves are in the on position, connecting the hydraulic chamber of the power conversion device to the replenishment tank, thus depressurizing the entire hydraulic system and ensuring safety. When there is pressurized oil at the working ports A3 and B3 of the second valve body 5.8, that is, when the lifting cylinder is activated, the two-position two-way valve is switched to the closed position through the control oil of the shuttle valve, and the hydraulic high-pressure oil circuit is connected to the replenishing oil tank to ensure normal working pressure.

[0049] The replenishing oil tank 9 contains hydraulic oil and has a small capacity of approximately 3-5L, which can replenish leaked oil in the closed hydraulic system. The height adjustment cylinder 6 is a single-rod cylinder with an integrated hydraulic lock at the end to ensure reliable locking after the cutting drum is adjusted to the appropriate position. The area ratio of the rod-side chamber to the rodless chamber of the height adjustment cylinder 6 should be the same as the area ratio of the hydraulic rod-side chamber and the hydraulic rodless chamber of the power conversion device, and the total volume of the rod-side chamber and the total volume of the rodless chamber should be equal to achieve a balance in the inflow and outflow of hydraulic oil.

[0050] The above description is merely a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A hydraulic system for dynamic control of the height adjustment cylinder and shared lubricating oil circulation in a coal mining machine, characterized in that: It includes a lubrication pump assembly, a filter (2), a first control valve group, an oil power conversion device (4), a height adjustment cylinder (6), and a hydraulic lock (7); The high-pressure gear pump (1.1) of the lubrication pump assembly draws the oil in the reducer chamber of the coal mining machine into the lubrication pump assembly and converts it into high-pressure lubricating oil. The high-pressure lubricating oil enters the solenoid pilot valve (3.1) and the three-position four-way directional valve (3.2) of the first control valve group through the filter (2). The voltage of the solenoid pilot valve (3.1) is dynamically controlled by the controller to realize the switching of the working position of the valve core of the solenoid pilot valve (3.1). The working oil port of the solenoid pilot valve (3.1) is connected to the hydraulic control port of the three-position four-way directional valve (3.2) to realize the switching of the working position of the valve core of the three-position four-way directional valve, thereby realizing the dynamic control of the direction of the high-pressure lubricating oil. High-pressure lubricating oil enters the lubricating oil chamber of the oil power conversion device (4) through the three-position four-way reversing valve (3.2). The inner cavity of the oil power conversion device (4) is divided into a lubricating oil chamber and a hydraulic oil chamber, and they share a piston rod with pistons at both ends. The oil power conversion device (4) completes the conversion from lubricating oil power to hydraulic oil power by the joint movement of the piston in the lubricating oil chamber and the piston in the hydraulic oil chamber. After being squeezed, the hydraulic oil in the hydraulic oil chamber enters the height adjustment cylinder (6), which realizes the dynamic extension or retraction of the piston rod of the height adjustment cylinder (6), thereby driving the cutting drum to rise or fall continuously and lock it in place by the hydraulic lock (7). A second control valve group is provided at the hydraulic power conversion device (4). The second control valve group includes a shuttle valve (5.1), a first two-position two-way valve (5.6), a second two-position two-way valve (5.7), and a second valve body (5.8). The shuttle valve (5.1) is inserted into the second valve body (5.8). The oil inlet A7 of the shuttle valve (5.1) is connected to the working oil port A3 of the second valve body (5.8), and the oil inlet B7 of the shuttle valve (5.1) is connected to the working oil port B3 of the second valve body (5.8). The working port A9 of the first two-position two-way valve (5.6) and the working port A10 of the second two-position two-way valve (5.7) are both connected to the working port A8 of the second valve body (5.8). The working port B9 of the first two-position two-way valve (5.6) is connected to the working port A5 of the second valve body (5.8). The working port B10 of the second two-position two-way valve (5.7) is connected to the working port B5 of the second valve body (5.8). The control port K3 of the first two-position two-way valve (5.6) and the control port K4 of the second two-position two-way valve (5.7) are both connected to the outlet port K5 of the shuttle valve. The working port A8 of the second valve body (5.8) is connected to a replenishing oil tank (9) through a pipeline.

2. The hydraulic system for dynamic control of the coal mining machine height adjustment cylinder and shared lubricating oil circulation as described in claim 1, characterized in that: The first control valve assembly includes a solenoid pilot valve (3.1), a three-position four-way directional valve (3.2), a relief valve (3.3), an adjustable flow valve (3.4), and a first valve body (3.5). The inlet P1 of the first valve body (3.5) is connected to the inlet P2 of the solenoid pilot valve (3.1) and the inlet P3 of the three-position four-way directional valve (3.2) via an internal oil passage. The return port T1 of the first valve body (3.5) is connected to the return port T2 of the solenoid pilot valve (3.1), the return port T3 of the three-position four-way directional valve (3.2), and the relief valve. 3.3) The oil inlet P4 is connected, and the adjustable flow valve (3.4) is installed in the oil line between the oil return port T2 of the solenoid pilot valve (3.1) and the oil return port T3 of the three-position four-way directional valve (3.2). The working oil port A1 of the solenoid pilot valve (3.1) is connected to the control oil port K1 of the three-position four-way directional valve (3.2). The working oil port B1 of the solenoid pilot valve (3.1) is connected to the control oil port K2 of the three-position four-way directional valve (3.2). The oil return port T4 of the first valve body (3.5) is connected to the oil return port T5 of the relief valve (3.3). The high-pressure lubricating oil discharged from the oil return port T1 of the first valve body (3.5) flows back to the reducer cavity through the cooler (8), and the high-pressure lubricating oil discharged from the oil return port T4 of the first valve body (3.5) flows directly back to the reducer cavity.

3. The hydraulic system for dynamic control of the coal mining machine height adjustment cylinder and shared lubricating oil circulation as described in claim 2, characterized in that: The second control valve group also includes a first check valve (5.2), a second check valve (5.3), a first safety valve (5.4), and a second safety valve (5.5); the working port A2 of the three-position four-way directional valve (3.2) is connected to the working port A3 of the second valve body (5.8) via the working port A11 of the first valve body (3.5); the working port B2 of the three-position four-way directional valve (3.2) is connected to the working port B3 of the second valve body (5.8) via the working port B11 of the first valve body (3.5); and the working port A3 of the second valve body (5.8) is connected to the hydraulic power conversion device (4). The working port A4 is connected, the working port B3 of the second valve body (5.8) is connected to the working port B4 of the hydraulic power conversion device (4), the working port A4 is located in the rodless chamber of the lubricating oil chamber, the working port B4 is located in the rod chamber of the lubricating oil chamber, the working port A5 of the second valve body (5.8) is connected to the working port A6 of the hydraulic power conversion device (4), the working port B5 of the second valve body (5.8) is connected to the working port B6 of the hydraulic power conversion device (4), the working port A6 is located in the rodless chamber of the hydraulic oil chamber, and the working port B6 is located in the rod chamber of the hydraulic oil chamber; The oil inlets of the first check valve (5.2) and the second check valve (5.3) are both connected to the working oil port A8 of the second valve body (5.8). The oil outlet of the first check valve (5.2) is connected to the working oil port A5 of the second valve body (5.8). The oil outlet of the second check valve (5.3) is connected to the working oil port B5 of the second valve body (5.8). The oil inlet of the first safety valve (5.4) is connected to the working oil port A5 of the second valve body (5.8). The oil inlet of the second safety valve (5.5) is connected to the working oil port B5 of the second valve body (5.8). The oil outlets of the first safety valve (5.4) and the second safety valve (5.5) are both connected to the working oil port A8 of the second valve body (5.8). The working port A5 of the second valve body (5.8) is connected to the rodless chamber of the height adjustment cylinder (6) through a pipeline, and the working port B5 of the second valve body (5.8) is connected to the rod chamber of the height adjustment cylinder (6) through a pipeline. The hydraulic lock (7) is installed on the pipeline between the second valve body (5.8) and the height adjustment cylinder (6).

4. The hydraulic system for dynamic control of the coal mining machine height adjustment cylinder and shared lubricating oil circulation as described in claim 3, characterized in that: The lubrication pump assembly includes a high-pressure gear pump (1.1), a third safety valve (1.2), an air filter (1.3), a temperature sensor (1.4), a pressure sensor (1.5), and a pump housing (1.6). The oil inlet of the high-pressure gear pump (1.1) is connected to the oil inlet on the pump housing (1.6) through an internal oil passage. The pressure port of the high-pressure gear pump (1.1) is connected to the oil outlet of the pump housing (1.6) through an internal oil passage. The third safety valve... The oil inlet of (1.2) is connected to the oil outlet of the pump housing (1.6) through the internal oil passage of the pump housing (1.6); the oil outlet of the third safety valve (1.2) is connected to the reducer cavity through the internal oil passage of the pump housing (1.6); the interface of the air filter (1.3) is connected to the reducer cavity through the internal oil passage of the pump housing (1.6); and the oil ports of the temperature sensor (1.4) and pressure sensor (1.5) are connected to the oil outlet of the pump housing (1.6) through the internal oil passage of the pump housing (1.6).

5. The hydraulic system for dynamic control of the coal mining machine height adjustment cylinder and shared lubricating oil circulation as described in claim 4, characterized in that: The area ratio of the rod chamber and rodless chamber of the height adjustment cylinder (6) is the same as the area ratio of the rod chamber and rodless chamber of the hydraulic oil chamber in the power conversion device (4).

6. The hydraulic system for dynamic control of the coal mining machine height adjustment cylinder and shared lubricating oil circulation as described in claim 5, characterized in that: The lubrication pump assembly is installed on the housing of the coal mining machine reducer. The first control valve group, filter (2), cooler (8), oil power conversion device (4), and oil replenishment tank (9) are distributed in the gaps of the main structure of the coal mining machine. The second control valve group is installed on the oil port end face of the oil power conversion device (4). The hydraulic lock (7) is installed at the end of the height adjustment cylinder (6). One end of the height adjustment cylinder (6) is hinged to the cutting mechanism, and the other end of the height adjustment cylinder (6) is hinged to the main structure of the coal mining machine.

7. The hydraulic system for dynamic control of the coal mining machine height adjustment cylinder and shared lubricating oil circulation as described in claim 6, characterized in that: By dynamically controlling the control voltage value of the electromagnetic pilot valve (3.1), the piston rod of the lifting cylinder (6) can be dynamically extended or retracted, thereby realizing the dynamic and continuous adjustment of the cutting drum lifting. The number of lifting cylinders (6) is one or more.

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