Thin seam coal cutter

Abstract

The invention relates to a thin seam coal mining machine, which comprises a main body shell and two swing arm shells respectively hinged at the left and right ends of the front part of the main body shell, a cutting motor is used as a hinge pin shaft between each swing arm shell and the main body shell, a cover plate is installed at the open front end of the main body shell, the swing arm shell, the main body shell, the cutting motor and the cover plate form a closed oil cylinder mounting cavity, the oil cylinders driving the left and right swing arm shells to swing are all installed in the oil cylinder mounting cavity, and the rear part of the main body shell is provided with one coal flow rear passage on the left and the right, the coal flow rear passage is a groove extending from front to back with a notch downward, and the rear end of the groove is closed. The invention can provide a larger mining range and cutting power, and is helpful to shorten the machine body and improve the coal flow loading effect.

Description

Technical Field

[0001] This invention relates to a coal mining machine, particularly a thin coal seam mining machine, which has a large mining range and a large cutting power. Background Technology

[0002] On existing thin coal seam mining machines, the cutting motor is usually located on the rocker arm and swings with the rocker arm. When the rear rocker arm of this type of thin coal seam suspended mining machine is cutting the upper cutter in the direction of travel, the problem of insufficient rear drum mining height occurs. This is because if the mining height is increased further, the cutting motor of the rear rocker arm will interfere with the upper coal platform left behind the bottom cutter of the front drum. Therefore, the overall mining height of this type of mining machine is too narrow and cannot meet the mining requirements of thin coal seam working faces with large variations in ore thickness in my country.

[0003] To address the aforementioned issues, industry experts have proposed dividing the cutting section into a swing section and a fixed section, with the main components of the cutting motor and transmission system located in the fixed section. However, this resulted in an overly complex fixed section structure, with the overhanging section of the machine being excessively long and heavy. The overall center of gravity still significantly impacts the machine's stress distribution. Furthermore, the long-bodied coal mining machine cannot execute the straight-push cutting process similar to short-wall coal mining machines, as the oblique cutting at both ends takes a considerable amount of time, thus limiting mining efficiency. Summary of the Invention

[0004] The present invention aims to provide a thin coal seam mining machine that can provide a larger mining range and a larger cutting power, and also helps to shorten the machine body and improve the coal flow loading effect.

[0005] The main technical solutions of this invention are as follows:

[0006] A thin coal seam mining machine includes a main body shell and two swing arm shells respectively hinged to the left and right ends of the front part of the main body shell. Each swing arm shell is connected to the main body shell by a cutting motor as a hinge pin, and the cutting motor is fixed relative to the main body shell.

[0007] The main body of the swing arm housing is a boom extending left and right. A cutting transmission mechanism is installed inside the boom. The input and output gears of the cutting transmission mechanism serve as the high-speed and low-speed ends of the boom, respectively. A connecting arm extends forward from the middle of the boom. A front arm and a rear arm extend left or right from the connecting arm. The front arm, rear arm, and the high-speed end of the boom are arranged alternately from front to back. The front arm and rear arm are respectively provided with a front pin mounting hole and a rear pin mounting hole, both coaxial with the input gear of the cutting transmission mechanism. The left and right ends of the front part of the main body housing are each provided with a... The device comprises a first ear seat, a second ear seat, and a third ear seat. A front groove is formed between the first and second ear seats, a middle groove is formed between the second and third ear seats, and a rear groove is formed between the third ear seat and the rear part of the main body housing. The high-speed ends of the forearm, rear arm, and boom on the same swing arm housing are correspondingly inserted into the front, middle, and rear grooves located on the same left and right sides. Each cutting motor is installed in the inner hole formed by the ear hole of the first ear seat, the front pin mounting hole, the ear hole of the second ear seat, the rear pin mounting hole, and the ear hole of the third ear seat, which are coaxial and located on the same left and right sides. The output shaft of the cutting motor is coaxially connected to the input end gear of the cutting transmission mechanism located on the same left and right sides.

[0008] Each front and rear pin mounting hole is fitted with a set of spherical bearings, and the housing of the cutting motor is rotatably supported in the corresponding front and rear pin mounting holes by means of the spherical bearings.

[0009] The connecting arm is a thin, flat structure with a width smaller than its height, and the top surface of the connecting arm is sloping. In the left-right direction, the top surface of the connecting arm is higher as it approaches the high-speed end of the boom.

[0010] The outer surface of the cantilever end of the forearm on the same swing arm housing is configured as a convex arc cylindrical surface coaxial with the corresponding front pin mounting hole. The bottom of the corresponding front groove is configured as an opening structure communicating with an inner cavity of the main body housing. The top and bottom edges of the opening are both configured as concave arc cylindrical surfaces coaxial with the ear hole of the second ear seat. The outer surface of the cantilever end of the forearm slides coaxially with the top and bottom edges.

[0011] The outer surface of the cantilever end of the rear arm and the outer surface of the high-speed end of the boom on the same swing arm housing are both configured as convex arc cylindrical surfaces coaxial with the front pin mounting hole. The bottom surfaces of the corresponding middle groove and rear groove are both configured as concave arc cylindrical surfaces coaxial with the ear hole of the second ear seat. There is a gap between the outer surface of the cantilever end of the rear arm and the outer surface of the high-speed end of the boom and the middle groove and the rear groove, respectively. The outer surfaces of the cantilever ends of the first ear seat, the second ear seat and the third ear seat are all configured as convex arc cylindrical surfaces coaxial with the ear hole of the second ear seat. The side of the connecting arm near the high-speed end of the boom is configured as a concave arc cylindrical surface. There is a gap between the outer surfaces of the cantilever ends of the first ear seat, the second ear seat and the third ear seat and the side of the corresponding connecting arm near the high-speed end of the boom.

[0012] The main body shell is a T-shaped structure that is narrow at the front and wide at the rear. The front part of the main body shell is a multi-chamber thin-walled frame structure, and the left and right parts of the rear part of the main body shell are solid structures.

[0013] A cover plate is installed at the front opening of the main body housing. The forearm, the main body housing, the cutting motor and the cover plate form a closed cylinder mounting cavity. Two cylinders are installed in the cylinder mounting cavity. One end of the two cylinders is respectively hinged to the cylinder hinge seat on the cantilever end of the left and right forearms, and the other end of the two cylinders is hinged to the main body housing.

[0014] The rear of the main body shell is provided with a coal flow rear channel on the left and right. The coal flow rear channel is a groove that extends from front to back with the groove opening facing downward. The rear end of the groove is closed. The bottom of the coal flow rear channel is higher in the front and lower in the back. The coal flow rear channels in the left and right directions are respectively located between the connecting arm and the low speed end of the boom on the same side.

[0015] Each of the left and right ends of the rear part of the main body housing is fixed with a guide shoe. The two support shoes are located behind the low-speed end of the boom of the left and right swing arm housings, respectively.

[0016] The side of the connecting arm near the low-speed end of the boom is configured as a concave arc cylindrical surface coaxial with the output gear.

[0017] The beneficial effects of this invention are:

[0018] This invention uses the cutting motor as a pivot pin connecting the swing arm housing and the main body housing, which shortens the lateral length of the main body housing, thus reducing the lateral length of the shearer's suspension section and simplifying the cutting mechanism's structure. Due to this unique hinge structure, each swing arm housing is driven by a single cutting motor. On a twin-drum shearer, the overall cutting power is greater than that of a single cutting motor, reducing the continuous power consumption of a single cutting motor when cutting hard materials during bidirectional mining. Using two cutting motors for separate main and auxiliary operations on the left and right sides improves the overall reliability of the cutting mechanism's power, especially when cutting hard materials.

[0019] This invention employs a specific structural design in which the forearm, rear arm, and high-speed end of the boom are arranged sequentially from front to back at intervals. The forearm and rear arm are the load-bearing parts, while the high-speed end of the boom is the non-load-bearing part. The separation of the load-bearing and non-load-bearing parts ensures that the transmission part located within the boom is in a good non-load-bearing state, thus helping to improve transmission accuracy.

[0020] The cutting motor is supported on the forearm and rear arm by spherical bearings, which can maintain the concentricity between the mounting holes of the front and rear pins and the housing of the cutting motor, thereby improving the transmission accuracy between the cutting motor and the cutting transmission mechanism.

[0021] The connecting arm with a special structure has virtually no impact on the coal platform above as it swings up and down with the swing arm housing, ultimately allowing the entire rocker arm to have a very large mining range.

[0022] The forearm, main body shell, cutting motor and cover plate together form a closed cavity. This closed cavity provides a clean working space for the left and right height adjustment cylinders. The overall space is compact and the machine body is short. It also ensures that the swing arm is not affected by coal and other minerals during the swinging process with the extension and retraction of the height adjustment cylinder. It also ensures that the swing arm can swing normally between the highest and lowest limit swing angle positions, and ultimately ensures that the maximum mining range is not affected.

[0023] The side of the connecting arm away from the machine body is set as a concave arc cylindrical surface coaxial with the output gear of the cutting transmission mechanism. This concave arc cylindrical surface maintains a certain gap with the drum blades, which can improve the loading effect of the drum screw conveyor.

[0024] By setting two coal flow channels on the left and right at the rear of the main body shell, the coal flow is guided into the conveying trough of the conveyor located below the rear of the main body shell, thereby improving the coal loading effect.

[0025] Furthermore, by installing two support slippers on the left and right sides, and two guide plates on the support slippers facing the left and right rear respectively, the coal thrown out by the drum is diverted to the left and right rear of the drum. The support slippers effectively separate the coal flow, reducing the impact of the coal flow outside the drum's centerline on the coal flow inside when the mining machine moves. This structure, combined with the rear coal flow channel, facilitates the entry of the inner coal flow into the conveying trough, further improving the coal loading efficiency. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of one embodiment of the thin coal seam mining machine of the present invention;

[0027] Figure 2 for Figure 1 AA section view;

[0028] Figure 3 for Figure 1 Side view;

[0029] Figure 4 for Figure 1 A partial structural diagram of the connection structure between the left-side rocker arm and the main body shell;

[0030] Figure 5 for Figure 4 BB section view;

[0031] Figure 6 for Figure 1 A schematic diagram of the main body shell.

[0032] Figure label:

[0033] 1. Rocker arm; 11. Rocker arm housing; 111. Forearm; 1111. Outer surface of the overhanging end of the forearm; 112. Rear arm; 113. Boom; 114. Connecting arm; 1141. Side near the high-speed end of the boom; 1142. Side near the low-speed end of the boom; 12. Cutting drive mechanism; 13. Roller; 14. Spherical bearing; 15. Spindle;

[0034] 2. Main body shell; 215. Outer surface of the overhanging end of the first ear seat; 216. Top and bottom edges of the opening; 217. Front groove; 218. Middle groove; 219. Rear groove; 22. Cylinder mounting cavity; 23. Cover plate; 26. Coal flow rear channel;

[0035] 3. Cut the motor;

[0036] 4. Hydraulic cylinder;

[0037] 5. Supporting skid; 51. Deflector;

[0038] 9. Conveyor; 91. Shovel plate; 95. Conveying trough. Detailed Implementation

[0039] This invention discloses a thin coal seam mining machine, such as... Figure 1-6 As shown, the system includes a main body housing 2 and two swing arm housings 11, respectively hinged to the left and right ends of the front of the main body housing. Each swing arm housing is connected to the main body housing by a cutting motor 3 as a hinge pin. The cutting motor is fixed relative to the main body housing and swings relative to the swing arm housing. By using the entire cutting motor as a pin, the lateral length of the main body housing is shortened, which is equivalent to shortening the lateral length of the shearer's suspension section, and the structure of the cutting mechanism is simplified. Due to this special hinge structure, each swing arm housing is driven by a cutting motor. On a twin-drum coal mining machine, the overall cutting power is greater than that of a single cutting motor, and the continuous power consumption of a single cutting motor when cutting hard materials can be reduced during bidirectional mining. Using two cutting motors for left and right main and auxiliary power consumption operations respectively is beneficial to improving the overall reliability of the cutting mechanism's power, especially when cutting hard materials.

[0040] The main body of the swing arm housing is a boom 113 extending left and right, and a cutting transmission mechanism 12 is installed inside the boom. The cutting transmission mechanism adopts a fixed-axis gear transmission mechanism. To facilitate the distinction between the two ends of the boom, the ends where the input gear (also the high-speed gear) and output gear (also the low-speed gear) of the cutting transmission mechanism are located are respectively referred to as the high-speed end and the low-speed end of the boom. A connecting arm 114 extending forward from the boom is provided in the middle of the boom. A front arm 111 and a rear arm 112 extending to the left or right from the connecting arm are provided on the connecting arm. The high-speed ends of the front arm, rear arm, and boom 113 are parallel to each other and arranged alternately from front to back. That is, for the right swing arm housing of the coal mining machine, the front arm and rear arm extend to the left from the connecting arm; for the left swing arm housing of the coal mining machine, the front arm and rear arm extend to the right from the connecting arm. The forearm and rear arm are respectively provided with front pin mounting holes and rear pin mounting holes, both of which are coaxial with the input gear of the cutting transmission mechanism. These holes are used to mount the cutting motor, and their coaxiality with the input gear mounting hole ensures that the installed cutting motor transmits power coaxially with the input gear. At the left and right ends of the front part of the main body housing, a first ear seat, a second ear seat, and a third ear seat are provided sequentially from front to back. A front groove 217 is formed between the first and second ear seats, a middle groove 218 is formed between the second and third ear seats, and a rear groove 219 is formed between the third ear seat and the rear part of the main body housing. The high-speed ends of the forearm, rear arm, and boom on the same swing arm housing are inserted into the front groove, middle groove, and rear groove located on the same left and right sides. Each cutting motor is installed in the inner hole formed by the combination of the ear hole of the first ear seat, the front pin mounting hole, the ear hole of the second ear seat, the rear pin mounting hole, and the ear hole of the third ear seat on the same left and right sides and coaxial. The output shaft of the cutting motor is coaxially connected to the input end gear of the cutting transmission mechanism located on the same left and right sides.

[0041] Both the coal mining machine drum 13 and the planetary reduction mechanism are installed at the low-speed end of the boom, with the planetary reduction mechanism located in the core of the drum. The planetary reduction mechanism undertakes most of the deceleration work, so the cutting transmission mechanism, as the front-stage deceleration part, can meet the deceleration requirements by using a relatively simple fixed-axis gear transmission mechanism. Consequently, the boom used to accommodate the cutting transmission mechanism has a more regular shape.

[0042] The external load on the roller is transmitted to the main body housing through the connecting arm, front arm, and rear arm. The front arm and rear arm are the load-bearing parts, while the high-speed end of the boom is the non-load-bearing part. The separation of the load-bearing and non-load-bearing parts ensures that the transmission part located within the boom is in a good non-load-bearing state, thus helping to improve transmission accuracy.

[0043] The thin coal seam mining machine is also equipped with a clutch mechanism. The output shaft of the cutting motor is a hollow shaft, and the mandrel 15 of the clutch mechanism passes through the output shaft of the cutting motor. When the clutch mechanism is in the "engaged" position (i.e., the clutch mechanism is in the position where it is in transmission action), the front spline shaft section and the rear spline shaft section of the mandrel are splinedly connected to the spline hole of the motor on the hollow shaft and the spline hole of the spline sleeve installed on the input end gear core, respectively. When the clutch mechanism is pulled backward to the disengaged position, the first spline connection is completely disengaged, and most of the second spline connection is disengaged, with some parts still maintaining the connection. The above-mentioned floating spline connection structure between the output shaft of the cutting motor and the mandrel of the clutch mechanism helps to improve the transmission accuracy between the cutting motor and the cutting transmission mechanism, maintain the concentricity of related structures, and facilitates processing and manufacturing.

[0044] Each front and rear pin mounting hole is fitted with a set of spherical plain bearings 14, which rotatably support the cutting motor housing within the corresponding front and rear pin mounting holes. These bearings are spherical plain bearings, characterized by high load capacity, impact resistance, corrosion resistance, wear resistance, and self-aligning properties. Using spherical plain bearings helps maintain the concentricity between the front and rear pin mounting holes and the cutting motor housing. The load at the hinge is largely borne by the spherical plain bearings, effectively protecting the swing arm housing, machine housing, and cutting motor from or minimizing impact, thus maintaining connection reliability.

[0045] The connecting arm is a thin, flat structure with a width smaller than its height, and its top surface is sloping. The top surface of the connecting arm is higher towards the high-speed end of the boom in the left-right direction. This connecting arm structure has virtually no impact on the upper coal platform during the up-and-down swinging motion of the boom housing, ultimately allowing for a significantly larger mining range for the entire boom.

[0046] The outer surface 1111 of the cantilever end of the forearm on the same swing arm housing is preferably configured as a convex arc-shaped cylindrical surface coaxial with the corresponding front pin mounting hole. The bottom of the corresponding front groove is configured as an opening structure communicating with an inner cavity of the main body housing. The top and bottom edges 216 of the opening are both configured as concave arc-shaped cylindrical surfaces coaxial with the ear hole of the second ear seat. The outer surface 1111 of the cantilever end of the forearm slides coaxially with the top and bottom edges. The above-described structural design of the forearm and the front groove ensures relative swinging while maintaining cleanliness between them and the inner cavity of the main body housing.

[0047] The outer surface of the cantilever end of the rear arm and the outer surface of the high-speed end of the boom on the same swing arm housing are both configured as convex arc-shaped cylindrical surfaces coaxial with the front pin mounting hole. Correspondingly, the bottom surfaces of the middle groove and the rear groove are both configured as concave arc-shaped cylindrical surfaces coaxial with the ear hole of the second ear seat. A gap is left between the outer surface of the cantilever end of the rear arm and the outer surface of the high-speed end of the boom and the middle groove and the rear groove, respectively. By controlling the gap width between the convex arc-shaped cylindrical surface and the corresponding concave arc-shaped cylindrical surface within a suitable range, the accumulation of coal and rock between the swing arm and the main body housing can be effectively controlled during the rotation of the swing arm housing relative to the main body housing.

[0048] The outer surface 215 of the overhanging end of the first ear seat, the outer surface of the overhanging end of the second ear seat, and the outer surface of the overhanging end of the third ear seat are all configured as convex arc-shaped cylindrical surfaces coaxial with the ear hole of the second ear seat. The side surface 1141 of the connecting arm near the high-speed end of the boom is configured as a concave arc-shaped cylindrical surface. There is a gap between the outer surface of the overhanging end of the first, second, and third ear seats and the side surface of the corresponding connecting arm near the high-speed end of the boom. By controlling the gap width between the concave arc-shaped cylindrical surface and the corresponding convex arc-shaped cylindrical surface within a suitable range, it is possible to effectively control the accumulation of coal and rock between the rocker arm and the main body shell during the rotation of the rocker arm 1 relative to the main body shell 2, thus preventing jamming and ensuring the free swing of the rocker arm shell.

[0049] The main body shell is a T-shaped structure that is narrow at the front and wide at the rear. The front part of the main body shell is a multi-chamber thin-walled frame structure, and the left and right parts of the rear part of the main body shell are solid structures. This allows the center of gravity of the coal mining machine to shift rearward, improving the stress stability of the entire coal mining machine.

[0050] A cover plate 23 is installed at the front opening of the main body shell. The forearm, main body shell, cutting motor, and cover plate form a closed cylinder mounting cavity 22. Two cylinders 4 are installed inside the cylinder mounting cavity. One end of each cylinder is hinged to a cylinder hinge seat on the cantilever end of the left and right forearms, and the other end is hinged to the main body shell. The extension and retraction of the cylinders causes the forearm to swing around the cutting motor, which in turn causes the swing arm shell to swing up and down. The cylinder hinge seat is a double-ear hinge seat. This closed cavity provides a clean working space for the two height-adjusting cylinders, resulting in a compact overall space, short machine length, and ensuring that the swing arm is not affected by coal or other minerals during its swinging motion with the height-adjusting cylinders. It also ensures that the swing arm can swing normally between its highest and lowest limit swing angle positions, ultimately ensuring that the maximum mining range is not affected.

[0051] The rear of the main body shell has two coal flow rear channels 26, one on each side. Each coal flow rear channel is a groove extending from front to back with its opening facing downwards. The rear end of the groove is closed, and the bottom of the coal flow rear channel is higher at the front and lower at the back. The left and right coal flow rear channels are located between the connecting arm and the low-speed end of the boom on the same side, respectively. These coal flow rear channels guide the coal flow into the conveying trough 95 of the conveyor 9 located below the rear of the main body shell, improving the coal loading efficiency.

[0052] Furthermore, the thin coal seam mining machine also includes guide slippers 5, which are supported on the conveyor's shovel plate 91. The left and right support slippers are respectively fixed to the front of the left and right ends of the rear of the main body shell. In the front-rear direction, the support slippers are located behind the low-speed end of the corresponding boom, preferably directly behind. The support slippers are equipped with two guide plates 51 inclined towards the left and right rear. The guide plates can guide the coal thrown out by the drum to the left and right rear of the drum. The support slippers serve to separate the inner and outer coal flows, reducing the impact of the coal flow outside the drum's centerline on the inner coal flow when the mining machine moves. The combination of the support slippers and guide plates with the rear coal flow channel facilitates the entry of the inner coal flow into the conveying trough, improving the coal loading effect.

[0053] The side 1142 of the connecting arm near the low-speed end of the boom is configured as a concave arc cylindrical surface coaxial with the output gear. This concave arc cylindrical surface can maintain a certain gap with the drum blades, improving the loading effect of the drum screw conveyor.

[0054] Unless otherwise specified, "before" and "after" in this article refer to directions closer to the coal face and directions farther from the coal face, respectively.

Claims

1. A thin coal seam mining machine, characterized in that: The system includes a main body housing and two swing arm housings hinged to the left and right ends of the front portion of the main body housing. Each swing arm housing is connected to the main body housing by a cutting motor as a hinge pin, and the cutting motor is fixed relative to the main body housing. The main body of each swing arm housing is a boom extending left and right. A cutting transmission mechanism is installed inside the boom. The input and output gears of the cutting transmission mechanism serve as the high-speed and low-speed ends of the boom, respectively. A connecting arm extends forward from the middle of the boom. A forearm and a rear arm extend to the left or right from the connecting arm. The forearm, rear arm, and the high-speed end of the boom are arranged alternately from front to back. The forearm and rear arm are respectively provided with a front pin mounting hole and a rear pin mounting hole, both of which are coaxial with the input gear of the cutting transmission mechanism. The left and right ends of the front portion of the main body housing are each free to extend forward. The device is subsequently provided with a first ear seat, a second ear seat, and a third ear seat. A front groove is formed between the first ear seat and the second ear seat, a middle groove is formed between the second ear seat and the third ear seat, and a rear groove is formed between the third ear seat and the rear part of the main body housing. The high-speed ends of the forearm, rear arm, and boom on the same swing arm housing are correspondingly inserted into the front groove, middle groove, and rear groove located on the same left and right sides. Each cutting motor is installed in the inner hole formed by the ear hole of the first ear seat, the front pin mounting hole, the ear hole of the second ear seat, the rear pin mounting hole, and the ear hole of the third ear seat, which are coaxial and on the same left and right sides. The output shaft of the cutting motor is coaxially connected to the input end gear of the cutting transmission mechanism located on the same left and right sides. A set of spherical bearings is installed in each front pin mounting hole and rear pin mounting hole. The housing of the cutting motor is rotatably supported in the corresponding front pin mounting hole and rear pin mounting hole through the spherical bearings.

2. The thin coal seam mining machine as described in claim 1, characterized in that: The connecting arm is a thin, flat structure with a width smaller than its height, and the top surface of the connecting arm is sloping. In the left-right direction, the top surface of the connecting arm is higher as it approaches the high-speed end of the boom.

3. The thin coal seam mining machine as described in claim 2, characterized in that: The outer surface of the cantilever end of the forearm on the same swing arm housing is configured as a convex arc cylindrical surface coaxial with the corresponding front pin mounting hole. The bottom of the corresponding front groove is configured as an opening structure communicating with an inner cavity of the main body housing. The top and bottom edges of the opening are both configured as concave arc cylindrical surfaces coaxial with the ear hole of the second ear seat. The outer surface of the cantilever end of the forearm slides coaxially with the top and bottom edges.

4. The thin coal seam mining machine as described in claim 3, characterized in that: The outer surface of the cantilever end of the rear arm and the outer surface of the high-speed end of the boom on the same swing arm housing are both configured as convex arc cylindrical surfaces coaxial with the front pin mounting hole. The bottom surfaces of the corresponding middle groove and rear groove are both configured as concave arc cylindrical surfaces coaxial with the ear hole of the second ear seat. There is a gap between the outer surface of the cantilever end of the rear arm and the outer surface of the high-speed end of the boom and the middle groove and the rear groove, respectively. The outer surfaces of the cantilever ends of the first ear seat, the second ear seat and the third ear seat are all configured as convex arc cylindrical surfaces coaxial with the ear hole of the second ear seat. The side of the connecting arm near the high-speed end of the boom is configured as a concave arc cylindrical surface. There is a gap between the outer surfaces of the cantilever ends of the first ear seat, the second ear seat and the third ear seat and the side of the corresponding connecting arm near the high-speed end of the boom.

5. The thin coal seam mining machine as described in claim 1, 2, 3 or 4, characterized in that: The main body shell is a T-shaped structure that is narrow at the front and wide at the rear. The front part of the main body shell is a multi-chamber thin-walled frame structure, and the left and right parts of the rear part of the main body shell are solid structures.

6. The thin coal seam mining machine as described in claim 5, characterized in that: A cover plate is installed at the front opening of the main body housing. The forearm, the main body housing, the cutting motor and the cover plate form a closed cylinder mounting cavity. Two cylinders are installed in the cylinder mounting cavity. One end of the two cylinders is respectively hinged to the cylinder hinge seat on the cantilever end of the left and right forearms, and the other end of the two cylinders is hinged to the main body housing.

7. The thin coal seam mining machine as described in claim 1, 2, 3 or 4, characterized in that: The rear of the main body shell is provided with a coal flow rear channel on the left and right. The coal flow rear channel is a groove that extends from front to back with the groove opening facing downward. The rear end of the groove is closed. The bottom of the coal flow rear channel is higher in the front and lower in the back. The coal flow rear channels in the left and right directions are respectively located between the connecting arm and the low speed end of the boom on the same side.

8. The thin coal seam mining machine as described in claim 7, characterized in that: Each of the left and right ends of the rear part of the main body housing is fixed with a guide shoe. The two support shoes are located behind the low-speed end of the boom of the left and right swing arm housings, respectively. The support shoes are equipped with two guide plates that are inclined to the left rear and right rear respectively.

9. The thin coal seam mining machine as described in claim 8, characterized in that: The side of the connecting arm near the low-speed end of the boom is configured as a concave arc cylindrical surface coaxial with the output gear.

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