Thin seam short span mining machine swing arm

Abstract

The present application relates to a kind of thin coal seam short span coal cutter swing arm, including swing arm shell, the main body of the swing arm shell is left and right extending arm support, cutting transmission mechanism is installed in arm support, the input end gear and output end gear of cutting transmission mechanism are respectively as the high speed end and low speed end of arm support, the connecting arm of arm support middle part is suspended from arm support forward, connecting arm is equipped with the forearm suspended from connecting arm left or right, forearm is located in the front of high speed end of arm support, front pin shaft mounting hole and rear pin shaft mounting hole for being used for the cutting motor to act as pin shaft installation therein are respectively equipped in the front of high speed end of arm support and the rear of high speed end of arm support, input end gear is installed in the rear of high speed end of arm support, and front pin shaft mounting hole and rear pin shaft mounting hole are coaxial with input end gear.The present application can provide larger mining range, larger cutting power, also can shorten machine body, improve coal cutter gravity problem.

Description

TECHNICAL FIELD

[0001] The present application relates to a kind of coal winning machine swing arms, especially suitable for thin coal seam short span coal winning machine, can provide larger mining range for coal winning machine. BACKGROUND

[0002] On the existing thin coal seam coal winning machine, cutting motor is usually located on swing arm, and swings with swing arm. When the rear swing arm of the thin coal seam suspension body coal winning machine cuts on the knife, the problem of the rear drum mining height is too small, because when the mining height increases, the rear swing arm cutting motor will interfere with the upper coal table left after the front drum cuts the bottom knife, so the overall mining height of this coal winning machine is too narrow, and it cannot adapt to the mining requirements of the large thickness variation of thin coal seam working face.

[0003] In view of the above problems, the industry has proposed that the cutting part is a swing part and a fixed part, and the cutting motor and the main part of the cutting transmission system are arranged in the fixed part, which leads to a too complex structure of the fixed part, a too long length and a too large weight of the left and right suspension sections of the machine body, and the center of gravity of the whole machine still has a great influence on the stress of the whole machine. Moreover, the long machine body structure of the coal winning machine cannot perform the straight push-in knife process similar to the shortwall coal winning machine, and the time of two-end oblique cutting is long, which has certain restriction on the mining efficiency. SUMMARY

[0004] The present application aims to provide a kind of thin coal seam short span coal winning machine swing arm, which can provide larger mining range, larger cutting power, shorten the machine body and improve the center of gravity of the coal winning machine.

[0005] The main technical scheme of the present application is as follows:

[0006] A kind of thin coal seam short span coal winning machine swing arm, including swing arm shell, the main body of the swing arm shell is left and right extending arm frame, cutting transmission mechanism is installed in the arm frame, the input end gear and the output end gear of the cutting transmission mechanism are respectively used as the high speed end and the low speed end of the arm frame, the connecting arm is suspended from the arm frame to the front, the front arm is suspended from the connecting arm to the left or to the right, the front arm is located in front of the high speed end of the arm frame, the front pin shaft mounting hole and the rear pin shaft mounting hole for the cutting motor to act as a pin shaft are installed therein, the input end gear is installed at the rear of the high speed end of the arm frame, and the front pin shaft mounting hole and the rear pin shaft mounting hole are coaxial with the input end gear.

[0007] The connecting arm is provided with an inner cavity, which is communicated with the inner cavity of the arm frame, and the inner cavity of the connecting arm is provided with a reinforced cooler.

[0008] The middle part of the arm frame can be provided with a protruding structure, and the inner cavity of the protruding structure is an auxiliary cavity, which is part of the inner cavity of the arm frame.

[0009] The cutting transmission mechanism can include an input gear, a first idler gear set, an intermediate gear, a second idler gear set and an output gear connected in sequence, and a gear pump is arranged in the inner cavity of the boom.

[0010] The outer surface of the overhanging end of the forearm, the outer surface of the front part of the high-speed end of the boom and the outer surface of the rear part of the high-speed end of the boom are all arranged as convex circular cylindrical surfaces coaxial with the front pin shaft mounting hole, and the side surface of the connecting arm near the high-speed end of the boom in the left-right direction is arranged as a concave circular cylindrical surface coaxial with the front pin shaft mounting hole.

[0011] The thin seam short span coal mining machine swing arm further comprises a drum, a drum connecting sleeve and a planetary reduction mechanism, the planetary reduction mechanism is installed at the front side of the low-speed end of the boom, the input end and the output end of the planetary reduction mechanism are a sun gear and a planet carrier respectively, the sun gear is coaxially connected with the output gear, the core of the planet carrier is provided with a spline hole, the rear shaft segment of the drum connecting sleeve is inserted into the core of the planet carrier and is spline-coupled therewith, the front flange plate structure of the drum connecting sleeve is axially fixed with the planet carrier, the radial edge of the front part of the drum connecting sleeve is preferably arranged as a polygonal convex stop structure, the drum is sleeved on the outside of the drum connecting sleeve and the planetary reduction mechanism, the drum is correspondingly provided with a polygonal concave stop structure, the drum is radially centered through the cooperation of the polygonal concave stop structure and the polygonal convex stop structure, and the drum is coaxially fixed with the drum connecting sleeve.

[0012] The side surface of the connecting arm near the low-speed end of the boom in the left-right direction is arranged as a concave circular cylindrical surface coaxial with the output gear.

[0013] The thin seam short span coal mining machine swing arm further comprises a cutting motor, the shell of the cutting motor is rotatably connected with the front pin shaft mounting hole and the rear pin shaft mounting hole, and the output shaft of the cutting motor is coaxially connected with the input gear in transmission.

[0014] The shell of the cutting motor is rotatably supported in the front pin shaft mounting hole and the rear pin shaft mounting hole through bearings.

[0015] The bearing adopts a joint bearing, an anti-friction layer is arranged between the inner ring and the outer ring of the joint bearing, one sealing seat is arranged on the radially outer side of the inner ring and the front and rear ends of the outer ring respectively, a sealing groove is arranged on the radially inner hole surface and the outer end surface of the sealing seat, and a sealing ring is arranged in the sealing groove.

[0016] The thin seam short span mining machine swing arm further comprises a clutch mechanism, the clutch mechanism comprises a mandrel and a clutch device, the clutch device is connected in front of the mandrel, the front part of the mandrel is provided with a front spline shaft section, the rear part of the mandrel is provided with a rear spline shaft section and a guide shaft section, the spline shaft section is located in front of the guide shaft section, the core of the input end gear is provided with a gear spline hole and a guide hole in front and back, the front part of the output shaft of the cutting motor is provided with a motor spline hole, when the clutch mechanism is located at the rear limit position, the front spline shaft section and the rear spline shaft section of the mandrel are respectively spline-coupled with the motor spline hole and the gear spline hole, and the front part of the guide shaft section is located in the guide hole, and a radial gap is left between the guide shaft section and the guide hole.

[0017] The present application has the following advantages:

[0018] The swing arm of the present application can be connected with the mining machine body by taking the cutting motor as a pin shaft, which shortens the left and right lengths of the front main body shell and the mining machine suspension body section, and simplifies the structure of the cutting mechanism.

[0019] The forearm, as a force-bearing part mainly for supporting, is separated from the arm support in which the cutting transmission mechanism is installed, and the front part of the high-speed end of the arm support, although being a part of the arm support, is only a secondary force-bearing part for auxiliary supporting, so that the cutting transmission mechanism can be basically ensured in a good non-force-bearing state, and the transmission precision is guaranteed.

[0020] The cutting transmission mechanism and the rear pin shaft mounting hole for auxiliary supporting the cutting motor are both arranged in the arm support, so that the structure is more compact, the power input connection point of the cutting transmission mechanism and the auxiliary supporting point are closer, the power transmission is less affected by the jumping and more stable and reliable.

[0021] The relatively compact polygon positioning and connecting structure is adopted between the drum and the drum connecting sleeve, which not only guarantees the reliability of the connection, but also greatly shortens the front and rear lengths of the planetary reduction mechanism, and is beneficial to the structure space arrangement of the high-power density thin seam mining machine swing arm.

[0022] The guide shaft section on the mandrel of the clutch mechanism and the guide hole of the input end gear core leave a larger radial gap, which increases the floating amount of the power transmission structure and improves the adaptability of the power transmission structure.

[0023] The cutting motor is supported on the swing arm shell through the joint bearing. The joint bearing helps to keep the concentricity between the front and rear pin shaft mounting holes and the shell of the cutting motor, and improves the transmission accuracy between the cutting motor and the cutting transmission mechanism. The wear-reducing layer is arranged between the inner ring and the outer ring of the joint bearing, which can reduce the wear of the sliding pair of the bearing. The wear-reducing layer is provided with a seal at both ends, which can ensure the cleanliness of the internal friction pair and keep the internal lubrication condition of the bearing, and accordingly, the transmission accuracy between the cutting motor and the cutting transmission mechanism is improved.

[0024] The height-adjusting oil cylinder is arranged below the cutting motor, which not only makes full use of the space between the roof and the floor of the coal mining face, but also greatly shortens the length of the suspension body section in the left-right direction, and for the double-drum coal mining machine, the distance between the two drums is shortened. The arrangement of the oil cylinder accommodating cavity provides a relatively clean working space for the swing and wiring of the height-adjusting oil cylinder, ensures that the swing arm shell is not affected by coal and other mining materials during the swing process, and finally ensures that the maximum mining range is not affected.

[0025] The connecting arm is also provided with an inner cavity, which is communicated with the inner cavity of the boom, and increases the oil storage volume in the swing arm shell. Moreover, the inner cavity of the connecting arm is also provided with a reinforced cooler for reinforcing the cooling of the oil cavity, so as to improve the cooling effect of the high-power-density swing arm.

[0026] Since the intermediate gear can transmit part of the power to the gear pump, the hydraulic system does not need to additionally arrange an independent power source.

[0027] The arrangement of the auxiliary cavity not only increases the oil cavity of the boom, but also increases the strength of the shell of the boom.

[0028] The side surface of the connecting arm near the low-speed end of the boom is arranged as a concave circular-arc cylindrical surface coaxial with the output gear of the cutting transmission mechanism. The concave circular-arc cylindrical surface and the drum blade maintain a certain equidistant gap, which can improve the loading effect of the drum screw conveyor. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 It is a front view of an embodiment of the swing arm;

[0030] Figure 2 It is a front view of an embodiment of the swing arm; Figure 1 It is a top view of an embodiment of the swing arm;

[0031] Figure 3 It is a structure schematic view of an embodiment of the joint bearing;

[0032] Figure 4 It is an A-A sectional view of an embodiment of the swing arm; Figure 2

[0033] It is an A-A sectional view of an embodiment of the swing arm; Figure 5 It is a partial enlarged view of the drum mounting structure;

[0034] Figure 6 C-C sectional view of Figure 5

[0035] Figure 7 B-B sectional view of Figure 2

[0036] Reference signs:

[0037] 1. swing arm; 11. swing arm housing; 111. forearm; 1111. outer surface of overhanging end of forearm; 112. front part of high speed end of arm support; 113. rear part of high speed end of arm support; 114. connecting arm; 1141. side surface close to high speed end of arm support; 1142. side surface close to low speed end of arm support; 1143. inner cavity of connecting arm; 1144. oil cylinder accommodating cavity; 1145. oil cylinder outer pin hole; 1146. concave arc cylindrical surface; 1147. top surface of oil cylinder accommodating cavity; 115. auxiliary cavity; 12. cutting transmission mechanism; 121. input end gear; 122. planetary reduction mechanism; 1221. planetary carrier; 1222. bearing; 1223. bearing seat; 1224. drum connecting sleeve; 123. intermediate gear; 13. drum; 132. polygonal concave notch structure; 14. bearing; 141. inner ring; 142. outer ring; 143. anti-friction layer; 144. sealing seat; 145. sealing ring; 148. flat key; 15. mandrel; 16. reinforced cooler; 161. water inlet; 162. cooling pipe; 17. gear pump;

[0038] 3. cutting motor;

[0039] 4. height adjustment oil cylinder. DETAILED DESCRIPTION

[0040] The application discloses a swing arm 1 (which can be simply referred to as swing arm) of a short-span coal mining machine for thin coal seams, as shown in Figures 1-7 ​​As shown, the swing arm housing 11, the main body of which is a left and right extending arm frame, has a cutting transmission mechanism 12 installed therein. The cutting transmission mechanism adopts a fixed shaft gear transmission mechanism. In order to distinguish the two ends of the arm frame, the input end gear 121 (also the high speed end gear) and the output end gear (also the low speed end gear) of the cutting transmission mechanism are respectively taken as the high speed end and the low speed end of the arm frame. The middle part of the arm frame is provided with a connecting arm 114 which is suspended forward from the arm frame, and a front arm 111 which is suspended leftward or rightward from the connecting arm, i.e. for the right swing arm housing of the coal mining machine, the front arm is suspended leftward from the connecting arm; for the left swing arm housing of the coal mining machine, the front arm is suspended rightward from the connecting arm. The front arm is located in front of the high speed end of the arm frame, and the front arm 111 and the front part 112 of the high speed end of the arm frame are respectively provided with a front pin shaft mounting hole and a rear pin shaft mounting hole for mounting the cutting motor as a pin shaft thereinto, and the input end gear 121 is mounted at the rear part 113 of the high speed end of the arm frame. The front pin shaft mounting hole and the rear pin shaft mounting hole are coaxial with the input end gear. The front pin shaft mounting hole and the rear pin shaft mounting hole are used for mounting the cutting motor 3, and they are coaxial with the input end gear to ensure that the cutting motor after being mounted is coaxial with the input end gear to transmit power. The swing arm is hinged at the front part of the high speed end of the arm frame and the front arm to the front part of the coal mining machine body. The cutting motor is fixedly connected and rotatably connected to the machine body and the swing arm housing respectively, so as to realize the hinge of the swing arm housing and the machine body with the cutting motor as a pin shaft. By taking the cutting motor as a whole pin shaft, the left and right lengths of the suspended machine body section are shortened, and the structure of the cutting mechanism is simplified. The layout of the winding and the rotor and other related structures inside the cutting motor can still adopt conventional structures.

[0041] The connecting arm is provided with an inner cavity 1143 which is communicated with the inner cavity of the arm frame, thereby increasing the oil storage volume inside the swing arm housing. The inner cavity 1143 of the connecting arm is provided with a reinforced cooler 16 for reinforcing the oil cavity to improve the cooling effect of the high power density swing arm. A plurality of cooling pipes can be arranged in the reinforced cooler, and the plurality of cooling pipes can be connected in series or in parallel. Figure 7 The reinforced cooler shown is provided with two parallel cooling pipes 162, 161 which are common water inlets of the two cooling pipes.

[0042] The middle part of the arm frame is provided with a protruding structure which protrudes rearward, and the inner cavity of the protruding structure is an auxiliary cavity 115 which is part of the inner cavity of the arm frame, thereby not only increasing the oil cavity of the arm frame, but also increasing the strength of the housing of the arm frame.

[0043] The cutting transmission mechanism comprises an input gear 121, a first idler gear set, an intermediate gear 123, a second idler gear set and an output gear which are sequentially connected in transmission. A gear pump 17 is further arranged in the inner cavity of the boom, and the intermediate gear is coaxially fixedly connected with the gear pump. The idler gears in the first and second idler gear sets can each have one or more. The first stage reduction is achieved from the input gear to the intermediate gear, and the second stage reduction is achieved from the intermediate gear to the output gear. The gear pump is the power source of the hydraulic system. Since the intermediate gear transmits part of the power to the gear pump, the hydraulic system does not need to additionally set an independent power source.

[0044] The overhanging end outer surface 1111 of the forearm, the outer surface of the front part 112 of the high-speed end of the boom and the outer surface of the rear part 113 of the high-speed end of the boom are all arranged as outer convex circular arc cylindrical surfaces coaxial with the front pin shaft mounting hole. The corresponding parts of the machine body are also provided with lug seats, and the grooves between the lug seats are arranged as inner concave circular arc cylindrical surfaces coaxial with the front pin shaft mounting hole, which correspond to the outer convex circular arc cylindrical surfaces one by one to ensure that the swing arm can swing freely without interference.

[0045] The side surface 1141 of the connecting arm close to the high-speed end of the boom is arranged as an inner concave circular arc cylindrical surface coaxial with the front pin shaft mounting hole. Correspondingly, the overhanging end outer surface of the lug seat on the machine body is arranged as an outer convex circular arc cylindrical surface coaxial with the front pin shaft mounting hole. They correspond to each other and also provide a guarantee for the swing arm to swing freely without interference.

[0046] The thin seam short span mining machine swing arm further comprises a drum 13, a drum connecting sleeve 1224 and a planetary reduction mechanism 122 installed on the front side of the low-speed end of the boom. The input end and the output end of the planetary reduction mechanism are a sun gear and a planet carrier 1221 respectively. The bearing seat 1223 is fixedly installed relative to the boom, the bearing 1222 is installed in the bearing seat, and the planet carrier is supported on the bearing 1222. The sun gear is coaxially connected with the output gear. The planetary reduction mechanism undertakes most of the reduction work, so the cutting transmission mechanism as the front stage reduction part adopts a relatively simple fixed shaft gear transmission mechanism to meet the reduction requirement, and correspondingly, the outer shape of the boom for accommodating the cutting transmission mechanism is more regular.

[0047] The external load force received by the drum is transmitted to the machine body through the connecting arm, the forearm and the front part of the high-speed end of the boom. The forearm, as the main supporting force part, is separated from the boom on which the cutting transmission mechanism is installed, and the front part of the high-speed end of the boom, although being a part of the boom, only serves as a secondary force part for auxiliary support. Therefore, the cutting transmission mechanism can be basically ensured in a good non-force state, so that the transmission precision is guaranteed.

[0048] The cutting transmission mechanism and the rear pin shaft mounting hole for assisting in supporting the cutting motor are arranged in the boom, which not only has a more compact structure, but also makes the power input connection point of the cutting transmission mechanism and the assisting support point closer, so that the power transmission is less affected by the runout and more stable and reliable.

[0049] The core of the planet carrier is provided with a spline hole. The rear shaft segment of the drum connecting sleeve is inserted into the core of the planet carrier and is spline-coupled therewith. The front flange structure of the drum connecting sleeve is axially fixed with the planet carrier. The radial edge of the front of the drum connecting sleeve is provided in a polygonal convex stop structure. The drum is sleeved on the drum connecting sleeve and the planetary reduction mechanism. The drum is provided with a polygonal concave stop structure 132. The drum is radially centered by the cooperation of the polygonal concave stop structure and the polygonal convex stop structure. The drum is coaxially fixed with the drum connecting sleeve. In the embodiment shown in the drawings, the planetary reduction mechanism is a two-stage planetary reduction mechanism. The input end and the output end thereof are respectively the input end of the first-stage planetary reduction mechanism and the output end of the second-stage planetary reduction mechanism.

[0050] The connecting arm is provided with an inner concave circular arc cylindrical surface coaxial with the output end gear on the side 1142 close to the low-speed end of the boom in the left-right direction. The inner concave circular arc cylindrical surface can keep a certain gap with the drum blade, thereby improving the loading effect of the drum in conveying the material.

[0051] The thin seam short-span mining machine swing arm further comprises a cutting motor 3. The shell of the cutting motor is rotatably connected with the front pin shaft mounting hole and the rear pin shaft mounting hole. The output shaft of the cutting motor is coaxially and drivingly connected with the input end gear.

[0052] The shell of the cutting motor is rotatably supported in the front pin shaft mounting hole and the rear pin shaft mounting hole by bearings 14. Most of the load at the hinge is borne by the bearings, which can well protect the swing arm shell, the machine body shell and the cutting motor from being affected or less affected, and maintain the connection reliability.

[0053] The bearing adopts a joint bearing, which has large load capacity, impact resistance, corrosion resistance, wear resistance and self-centering. The adoption of the joint bearing helps to maintain the concentricity between the front and rear pin shaft mounting holes and the shell of the cutting motor.

[0054] A wear-reducing layer 143 is further arranged between the inner ring 141 and the outer ring 142 of the joint bearing to reduce the wear of the sliding pair of the bearing. A sealing seat 144 is arranged on the radially outer side of the inner ring and on the front and rear ends of the outer ring. A sealing groove is arranged on the radially inner hole surface and the outer end surface of the sealing seat, and a sealing ring 145 is arranged in the sealing groove. The inner ring is circumferentially fixed with the shell of the cutting motor by means of a flat key 148. The adoption of the joint bearing can improve the service life of the sliding pair and help to improve the transmission accuracy between the cutting motor and the cutting transmission mechanism.

[0055] The lower part of the connecting arm is provided with an oil cylinder accommodating cavity 1144 extending left and right and opening downward, which is located below the front arm in the front-rear direction. The oil cylinder accommodating cavity is used to install the height-adjusting oil cylinder 4, and the height-adjusting oil cylinder is located in the oil cylinder accommodating cavity during installation, one end of the height-adjusting oil cylinder is hinged to the connecting arm, and the other end is hinged to the machine body, and the two hinge axes extend horizontally in the front-rear direction. The height-adjusting oil cylinder can drive the swing arm housing to swing up and down around the machine body. The oil cylinder accommodating cavity provides a relatively clean working space for the height-adjusting oil cylinder, ensures that the swing arm housing is not affected by coal and other mining materials during swinging, and ultimately ensures that the maximum mining range is not affected. Since the height-adjusting oil cylinder can be arranged below the front arm, not only the space between the roof and the floor of the coal mining face is fully utilized, but also the length of the suspended machine body section in the left-right direction is greatly shortened, and for a double-drum coal mining machine, the distance between the two drums is shortened.

[0056] The front and rear cavity walls of the oil cylinder accommodating cavity near the low-speed end of the boom are provided with an oil cylinder outer pin hole 1145, and the hinge shaft of the height-adjusting oil cylinder hinged to the connecting arm is installed in the oil cylinder outer pin hole. The front and rear widths of the oil cylinder accommodating cavity are slightly wider than the cylinder diameter of the height-adjusting oil cylinder. The space above the cylinder of the height-adjusting oil cylinder and below the top surface 1147 of the oil cylinder accommodating cavity is relatively closed, and can be used for the layout of the oil cylinder pipeline. The upper part of the oil cylinder outer pin hole can be provided as a concave circular cylindrical surface 1146 coaxial with the oil cylinder outer pin hole, and the end of the height-adjusting oil cylinder hinged to the swing arm housing can smoothly rotate below the concave circular cylindrical surface 1146. As long as the gap width between the two is properly controlled, coal and rock can be prevented from entering.

[0057] The thin-seam short-span coal mining machine swing arm further comprises a clutch mechanism, the clutch mechanism comprises a mandrel 15 and a clutch device, and the clutch device is connected in front of the mandrel. The front part of the mandrel is provided with a front spline shaft section, the rear part of the mandrel is provided with a rear spline shaft section and a guide shaft section, and the spline shaft section is located in front of the guide shaft section. The core of the input end gear is provided with a gear spline hole and a guide hole in front and back, and the front part of the output shaft of the cutting motor is provided with a motor spline hole. When the clutch mechanism is in the rear limit position (i.e. the "engaged" position), the front and rear spline shaft sections of the mandrel are respectively spline-coupled with the motor spline hole and the gear spline hole, and the front part of the guide shaft section is located in the guide hole, and a radial gap is left between the guide shaft section and the guide hole. When the clutch device is pulled forward, the rear spline shaft section of the mandrel is disconnected from the gear spline hole, the rear part of the guide shaft section is located in the guide hole, and the front spline shaft section of the mandrel is partially disconnected from the motor spline hole. A radial gap is left between the guide shaft section and the guide hole, which increases the floating amount of the power transmission structure and improves the adaptability of the power transmission structure.

[0058] The left and right width of the middle and upper part of the connecting arm in the height direction is the narrowest, and the nearer to the upper and lower ends, the wider, especially the lower part is wider, for setting the oil cylinder accommodating cavity. The whole connecting arm forms a flat and thin structure. The left and right width of the narrowest part is preferably the same height as the front pin shaft mounting hole. The top surface of the connecting arm is inclined, and the nearer to the high speed end of the arm support in the left and right direction, the higher. The flat and thin structure and the special inclined surface structure of the connecting arm make the upper coal table basically not affected when the swing arm shell swings up and down, so that a large mining range can be ensured.

[0059] Unless specifically specified, the front and back mentioned herein refer to the direction close to the coal wall and away from the coal wall respectively.

Claims

1. A swing arm for a short-span coal mining machine in thin coal seams, characterized in that: The device includes a swing arm housing, the main body of which 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 boom in the middle of the boom. A forearm extends left or right from the connecting arm on the connecting arm. The forearm is located in front of the high-speed end of the boom. The front of the forearm and the high-speed end of the boom are respectively provided with a front pin mounting hole and a rear pin mounting hole for the cutting motor to be installed as a pin. The input gear is installed at the rear of the high-speed end of the boom. The front and rear pin mounting holes are coaxial with the input gear. The housing of the cutting motor is rotatably supported in the front and rear pin mounting holes by bearings. The connecting arm extends downward beyond the bottom surface of the middle of the boom. The lower part of the connecting arm is provided with a hydraulic cylinder receiving cavity that extends left and right and opens downward.

2. The swing arm of the thin coal seam short span coal mining machine as described in claim 1, characterized in that: The connecting arm has an inner cavity that communicates with the inner cavity of the boom, and an enhanced cooler is provided in the inner cavity of the connecting arm.

3. The swing arm of the thin coal seam short span coal mining machine as described in claim 1, characterized in that: The boom has a rearward protruding ridge structure in the middle, and the cavity inside the ridge structure is an auxiliary cavity, which is part of the inner cavity of the boom.

4. The swing arm of the thin coal seam short span coal mining machine as described in claim 1, characterized in that: The cutting transmission mechanism includes an input gear, a first idler gear set, an intermediate gear, a second idler gear set, and an output gear connected in sequence. A gear pump is also provided in the inner cavity of the boom, and the intermediate gear is coaxially and fixedly connected to the gear pump.

5. The swing arm of the thin coal seam short span coal mining machine as described in claim 1, characterized in that: The outer surface of the cantilever end of the forearm, the outer surface of the front part of the high-speed end of the boom, and the outer surface of the rear part of the high-speed end of the boom are all configured as convex arc cylindrical surfaces coaxial with the front pin mounting hole. The side of the connecting arm near the high-speed end of the boom in the left-right direction is configured as a concave arc cylindrical surface coaxial with the front pin mounting hole.

6. The swing arm of a short-span coal mining machine for thin coal seams as described in claims 1, 2, 3, 4, or 5, characterized in that: It also includes a roller, a roller connecting sleeve, and a planetary reduction mechanism. The planetary reduction mechanism is installed on the front side of the low-speed end of the boom. The input end and output end of the planetary reduction mechanism are the sun gear and the planet carrier, respectively. The sun gear and the output gear are coaxially connected. The core of the planet carrier is provided with a spline hole. The rear shaft section of the roller connecting sleeve is inserted into the core of the planet carrier and splinedly connected to it. The front flange structure of the roller connecting sleeve is axially fixed to the planet carrier. The radial edge of the front part of the roller connecting sleeve is set as a polygonal convex stop structure. The roller is sleeved outside the roller connecting sleeve and the planetary reduction mechanism. The roller is provided with a polygonal concave stop structure. The roller is radially centered by the cooperation of the polygonal concave stop structure and the polygonal convex stop structure. The roller and the roller connecting sleeve are coaxially fixed.

7. The swing arm of the thin coal seam short span coal mining machine as described in claim 6, characterized in that: The side of the connecting arm near the low-speed end of the boom in the left-right direction is configured as a concave arc cylindrical surface coaxial with the output gear.

8. The swing arm of a short-span coal mining machine for thin coal seams as described in claims 1, 2, 3, 4 or 5, characterized in that: It also includes a cutting motor, the housing of which is rotatably connected to both the front and rear pin mounting holes, and the output shaft of the cutting motor is coaxially connected to the input gear.

9. The swing arm of the thin coal seam short span coal mining machine as described in claim 6, characterized in that: It also includes a cutting motor, the housing of which is rotatably connected to both the front and rear pin mounting holes, and the output shaft of the cutting motor is coaxially connected to the input gear.

10. The swing arm of the short-span coal mining machine in thin coal seams as described in claim 7, characterized in that: It also includes a cutting motor, the housing of which is rotatably connected to both the front and rear pin mounting holes, and the output shaft of the cutting motor is coaxially connected to the input gear.

11. The swing arm of the thin coal seam short span coal mining machine as described in claim 8, characterized in that: The bearing is a spherical plain bearing. A friction-reducing layer is provided between the inner ring and the outer ring of the spherical plain bearing. A sealing seat is provided on the radial outer side of the inner ring and at both the front and rear ends of the outer ring. A sealing groove is provided on the radial inner hole surface and the outer end face of the sealing seat, and a sealing ring is installed in the sealing groove.

12. The swing arm of the short-span coal mining machine in thin coal seams as described in claim 11, characterized in that: It also includes a clutch mechanism, which includes a spindle and a clutch device. The clutch device is connected to the front of the spindle. The front part of the spindle is provided with a front spline shaft section, and the rear part of the spindle is provided with a rear spline shaft section and a guide shaft section. The spline shaft section is located in front of the guide shaft section. The core of the input end gear is provided with a gear spline hole and a guide hole at intervals. The front part of the output shaft of the cutting motor is provided with a motor spline hole. When the clutch mechanism is in the rear extreme position, the front spline shaft section and the rear spline shaft section of the spindle are splinedly connected to the motor spline hole and the gear spline hole, respectively. The front part of the guide shaft section is located in the guide hole, and a radial clearance is left between the guide shaft section and the guide hole.

Images