Ultra-low clearance hydraulic lifting device for underground coal mines

Abstract

The present invention provides an ultra-low clearance hydraulic lifting device in a coal mine, comprising 8 load-bearing trolleys movably arranged on a monorail hanging track in a coal mine, 4 load-bearing beams hinged below the load-bearing trolleys, 2 connecting frames arranged at the same level as the 4 load-bearing beams and each rotatably connected to 2 load-bearing beams, bogies each passing through a connecting frame and rotatably connected to the connecting frame, connecting rods rotatably connected to 2 load-bearing beams located in the middle, 2 lifting arms for lifting, 2 sets of hydraulic cylinder assemblies movably arranged in each of the 2 lifting arms, 4 lifting chains for lifting, the upper ends of the 4 lifting chains are respectively fixedly connected to the bogies, and the lower ends of the 4 lifting chains are fixed to the corresponding hydraulic cylinder assemblies. Compared with the prior art, the present invention can further reduce the clearance occupied by the device, is conducive to passing through a curve when running on a monorail hanging track in a coal mine, and is more suitable for the lifting of large equipment in a lane in a coal mine.

Description

Technical Field

[0001] The invention relates to the technical field of lifting equipment, and in particular to an ultra-low clearance hydraulic lifting device in an underground coal mine. Background Art

[0002] Coal mines usually use monorail cranes and lifting beams (lifting devices) to lift and transport heavy equipment in the mine, including hydraulic supports. For example, the Chinese patent document with the authorization announcement number CN205061401U discloses a heavy-duty lifting beam for a monorail crane. Since the height of the underground tunnels in coal mines is generally about 3.2 meters, and the equipment that needs to be transported, such as hydraulic supports, is large in size, the lifting device needs to occupy as little clearance as possible on the monorail in the tunnel to facilitate the lifting of large equipment. However, due to structural limitations, the heavy-duty lifting beam of the monorail crane occupies a large space, which compresses the lifting space of heavy objects and is not conducive to the lifting of large equipment. In order to solve the problem that the lifting device occupies a large amount of clearance in the underground tunnel of the coal mine, the Chinese patent document with the authorization announcement number CN211769898U discloses a high-efficiency hydraulic cylinder lifting beam, which is mainly composed of a traveling vehicle arranged on a monorail lifting track, a connecting frame arranged on the traveling vehicle and located below the traveling vehicle, a beam body arranged on the connecting frame and located below the connecting frame, and two lifting cross plates connected to the beam body and arranged below the beam body. The cylinder body is fixed to the hydraulic cylinder on the lifting cross plate through a mounting seat, and the piston rod of the hydraulic cylinder controls the retraction and extension of the lifting chain; long holes are respectively provided at both ends of the lifting cross plate, and the two ends of the two lifting cross plates are connected by a connecting plate respectively using the long holes. Although this type of high-efficiency hydraulic cylinder lifting beam has made significant progress in reducing its own headroom compared to the heavy lifting beam of the monorail crane of CN205061401U, it still has the following problems: First, it is composed of a mobile trolley, a connecting frame, a beam body, a connecting plate, and two lifting cross plates from top to bottom, and the headroom it occupies is still relatively large, and there is still a need for improvement; second, the lifting cross plate is an integral structural member, and because of its large size, it is difficult to enter the underground tunnel of the coal mine and install it; third, the change in the spacing between the lifting points of the fixed hydraulic cylinder during the use of the tunnel when turning in the tunnel causes abnormal stress on the cylinder, affecting its use and life; fourth, its hook chain is an integrated structure, the chain is not flexible in operation, and the chain cannot be easily replaced according to the size of the workpiece being lifted. Therefore, further improving the existing underground monorail lifting beam (lifting device) of the coal mine to make it more suitable for the lifting and transportation of equipment in the underground tunnel of the coal mine is a technical problem that needs to be solved in the industry. Summary of the invention

[0003] The purpose of the present invention is to provide an ultra-low clearance hydraulic lifting device for underground coal mines in response to the problems existing in the prior art. Compared with the prior art, the device can further reduce the occupied clearance, facilitate passing curves when running on a monorail crane track, and is more suitable for lifting and transporting equipment in underground coal mine tunnels.

[0004] The technical solution of the present invention is: the ultra-low clearance hydraulic lifting device for underground coal mines of the present invention comprises 8 load-bearing trolleys which can be movably arranged on the monorail lifting track of the underground coal mine when in use, and 4 load-bearing beams hingedly connected to the bottom of the above-mentioned load-bearing trolleys, and its structural characteristics are: it also comprises 2 connecting frames which are arranged on the same layer as the above-mentioned 4 load-bearing beams and each is rotatably connected to 2 load-bearing beams, each bogie passes through one of the above-mentioned connecting frames and is rotatably connected to the connecting frames, connecting rods which are rotatably connected to the 2 load-bearing beams located in the middle, 2 lifting arms for lifting, 2 sets of hydraulic cylinder assemblies are movably arranged in each of the above-mentioned 2 lifting arms, and 4 lifting chains for lifting, the upper ends of the above-mentioned 4 lifting chains are respectively fixedly connected to the above-mentioned bogies, and the lower ends of the 4 lifting chains are fixed to the corresponding hydraulic cylinder assemblies.

[0005] A further solution is: the above-mentioned connecting frame includes a frame body and a load-bearing beam connecting member; the above-mentioned frame body is a structural member that is an overall rectangular parallelepiped, and a connecting beam clearance notch that is recessed inward is provided on each of the left and right sides of the frame body, and a front-to-rear bogie through hole and an up-and-down installation connecting hole are provided in the middle of the frame body; and one load-bearing beam connecting member is fixedly provided on the outer side of the connecting beam clearance notch on the left and right sides of the frame body.

[0006] A further solution is: a vertical connection hole is provided in the middle of the above-mentioned load-bearing beam, and a hinged connector is provided at one end of the load-bearing beam; each of the above-mentioned four load-bearing beams passes through a load-bearing beam connector of the connecting frame from the middle thereof and is rotatably connected to the load-bearing beam connector, and one end of each load-bearing beam provided with a hinged connector is arranged on the outer side of the corresponding connecting frame, and the end of each load-bearing beam not provided with a hinged connector is located in the connecting beam clearance gap of the corresponding connecting frame; each load-bearing beam is hingedly connected to the lower part of one of the above-mentioned load-bearing trolleys at the upper parts of its two sides; the two ends of the above-mentioned connecting rod are respectively hingedly connected to the hinged connectors of the load-bearing beams on the load-bearing beam connectors arranged on the opposite sides of the two connecting frames.

[0007] A further solution is that the two bogies mentioned above each pass through the bogie through hole of the frame body of one of the connecting frames in the front-rear direction and are rotatably connected to the connecting frame.

[0008] A further solution is: the above-mentioned bogie includes a frame body, a copper sleeve and a rotating shaft; an upward and downward mounting and connecting hole is provided in the middle of the above-mentioned frame body, and the copper sleeve is fixedly installed in the mounting and connecting hole of the frame body; the rotating shaft passes through the mounting and connecting hole in the middle of the frame body of the above-mentioned connecting frame and the copper sleeve to rotatably connect the bogie and the connecting frame.

[0009] A further solution is: the above-mentioned lifting boom includes two shells arranged in a mirror image, two connecting plates used to detachably fix the two shells into one body, a hook chain fixedly arranged under each shell and a hook arranged under each hook chain.

[0010] A further solution is: the lower end of the above-mentioned shell is provided with more than two hook chain mounting holes, and the upper outer end of the shell is provided with a makeshift slot hole for the above-mentioned lifting chain to pass through and shift when turning; the above-mentioned hook chain is fixed to the bottom of the shell using the hook chain mounting hole of the shell.

[0011] A further solution is: the above-mentioned hydraulic cylinder assembly includes a cylinder frame, a cylinder with a piston rod, a moving sprocket, a cylinder frame limit plate, a cylinder frame limit roller and a guide wheel; the above-mentioned cylinder frame can be movably arranged in the shell of the above-mentioned lifting boom in the left and right directions; the cylinder is fixedly arranged in the cylinder frame, and the piston rod of the cylinder extends out of the cylinder frame; the moving sprocket is fixedly installed on the outer end of the piston rod and can rotate relying on the piston rod; the cylinder frame limit plate is fixedly arranged in the shell of the lifting boom and is located on the outside of the cylinder frame, the cylinder frame limit roller is rotatably fixed in the shell of the lifting boom and more than two are arranged on the upper and lower sides of the cylinder frame, and the guide wheel is rotatably fixed on the outer upper corner of the cylinder frame; the hydraulic cylinder assembly is respectively provided with one set in each of the two shells of the two lifting booms.

[0012] A further solution is: the lower ends of the above-mentioned four lifting chains are fixed to the lower outer side of the cylinder frame after passing through the guide wheel and the movable sprocket of a corresponding set of hydraulic cylinder assemblies in sequence.

[0013] The present invention has positive effects: (1) The ultra-low clearance hydraulic lifting device for underground coal mines of the present invention is improved by arranging the load-bearing beam and the connecting frame at the same level instead of arranging them in layers, and passing the bogie through the connecting frame instead of arranging them in layers, so that the clearance occupied by the device when installed on the monorail track in the underground coal mine tunnel is smaller than that of the closest prior art, and it is more conducive to the lifting of large equipment. (2) The present invention is improved by adopting a rotatable connection between each load-bearing beam and each bogie and the connecting frame, connecting the connecting rod and the load-bearing beam in an articulated manner, and providing a clearance slot hole at the upper outer end of the shell of the lifting arm for facilitating the displacement of the lifting chain when the lifting chain passes through a bend, so that when the device encounters a curved section of the monorail track during operation, it can pass through the bend conveniently and flexibly. (3) The present invention improves the bending ability of the device by improving the structural design of the cylinder frame of the hydraulic cylinder assembly in a movable manner in the lifting boom. At the same time, the cylinder is well stressed and has no stress concentration point, thereby overcoming the problem in the prior art that the cylinder is abnormally stressed when the fixed hydraulic cylinder is used in the tunnel and the spacing between the lifting points changes when the cylinder is bent, which affects the use and life of the cylinder. (4) The present invention sets the lifting chain and the hook chain separately, which can make the lifting chain more flexible on the one hand, and can easily replace the hook chain according to the size and weight of the workpiece to be lifted on the other hand, which can solve the trouble and high cost of replacing the chain of the integral lifting chain with a direct hook in the prior art. (5) The present invention changes the lifting boom into a split detachable connection structure design, which can solve the problem in the prior art that the integral structure lifting boom is difficult to enter the underground tunnel of the coal mine, transport and install in the tunnel due to its large size. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] Figure 1 The figure is a schematic diagram of the structure of the present invention, and also schematically shows the installation and connection relationship between the present invention and the monorail hanging track in the underground tunnel of the coal mine;

[0015] Figure 2 for Figure 1 A top view of

[0016] Figure 3 for Figure 1 Left view of the image and enlarged it;

[0017] Figure 4 for Figure 2 The AA section view is enlarged;

[0018] Figure 5 for Figure 1 Schematic diagram of the external structure of some components of the hydraulic cylinder assembly and the lifting chain.

[0019] The reference numerals in the above drawings are as follows:

[0020] Carrying trolley 1; carrying beam 2; connecting frame 3, frame body 31, connecting beam clearance gap 31-1, bogie through hole 31-2, carrying beam connecting piece 32; bogie 4, frame body 41, copper sleeve 42, rotating shaft 43; connecting rod 5; lifting boom 6, shell 61, hook chain mounting hole 61-1, clearance slot hole 61-2, connecting plate 62, hook chain 63, hook 64; hydraulic cylinder assembly 7, cylinder frame 71, cylinder 72, piston rod 72-1, moving sprocket 73, cylinder frame limit plate 74, cylinder frame limit roller 75, guide wheel 76; lifting chain 8; monorail hanging track 100. DETAILED DESCRIPTION

[0021] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

[0022] (Example 1)

[0023] See Figures 1 to 5 The ultra-low clearance hydraulic lifting device for coal mines in this embodiment is mainly composed of a load-bearing trolley 1, a load-bearing beam 2, a connecting frame 3, a bogie 4, a connecting rod 5, a lifting boom 6, a hydraulic cylinder assembly 7 and a lifting chain 8.

[0024] There are 8 load-bearing trolleys 1, and when in use, the 8 load-bearing trolleys 1 are movably arranged on the monorail hanging track 100 in the underground tunnel of the coal mine. The load-bearing trolley 1 and the way it is arranged on the monorail hanging track 100 are both prior arts and will not be described in detail.

[0025] There are four load-bearing beams 2 , a vertical connection hole is provided in the middle of the load-bearing beam 2 , and a hinged connection head is provided at one end of the load-bearing beam 2 .

[0026] The connecting frame 3 is mainly composed of a frame body 31 and two load-bearing beam connectors 32. The frame body 31 is a structural member in the shape of a rectangular block as a whole. A connecting beam clearance notch 31-1 concave inward is provided on each of the left and right sides of the frame body 31. A bogie through hole 31-2 in the front and rear direction and an installation connection hole in the upper and lower direction (not marked in the figure) are provided in the middle of the frame body 31. One load-bearing beam connector 32 is fixedly provided on the outer side of the connecting beam clearance notch 31-1 on the left and right sides of the frame body 31. The connecting frame 3 is provided with two of the same structure on the left and right sides.

[0027] Each of the four load-bearing beams 2 passes through a load-bearing beam connector 32 of a connecting frame 3 from its middle part and is rotatably connected to the load-bearing beam connector 32. One end of each load-bearing beam 2 provided with a hinged connector is arranged on the outside of the corresponding connecting frame 3, and the end of each load-bearing beam 2 not provided with a hinged connector is located in the connecting beam clearance gap 31-1 of the corresponding connecting frame 3. The upper parts of both sides of each load-bearing beam 2 are respectively hingedly connected to the lower part of a load-bearing trolley 1. Different from the prior art in which the load-bearing beams and connecting frames are arranged in upper and lower layers, in this embodiment, the four load-bearing beams 2 and the two connecting frames 3 are arranged in the same layer, basically on the same plane, so that the vertical space occupied by the hydraulic lifting device of this embodiment can be reduced; the rotatable connection between each load-bearing beam 2 and the connecting frame 3 facilitates the hydraulic lifting device of this embodiment to pass through curves when running on the monorail hanging track 100 during use.

[0028] See Figure 1 , Figure 2 See also Figure 4 The bogie 4 is mainly composed of a frame body 41, a copper sleeve 42 and a rotating shaft 43. The frame body 41 is a rod-shaped structural member, and the frame body 41 is provided with an installation connection hole in the middle of the length direction, that is, the front-back direction. The copper sleeve 42 is fixedly installed in the installation connection hole of the frame body 41; the rotating shaft 43 passes through the installation connection hole in the middle of the frame body 31 of the aforementioned connecting frame 3 and the copper sleeve 42 to rotatably connect the bogie 4 with the connecting frame 3, so as to facilitate the hydraulic lifting device of this embodiment to pass the curve when the monorail hanging track 100 is running during use. There are two bogies 4 with the same structure, and the two bogies 4 are rotatably installed in each of the two connecting frames 3. Different from the prior art, in this embodiment, since the bogie 4 is arranged in the connecting frame 3, it does not occupy the upper and lower clearance, further reducing the upper and lower space occupied by the hydraulic lifting device of this embodiment; at the same time, the two bogies 4 can rotate relative to the two connecting frames 3, which can effectively improve the turning ability of the device.

[0029] The two ends of the connecting rod 5 are respectively hinged to the hinged connectors of the load beam 2 on the load beam connector 32 provided on the opposite side of the two connecting frames 3, so that the two connecting frames 3 are connected into one by the connecting rod 5 and the two load beams 2. The connecting rod 5 and the load beam 2 are connected in an articulated manner to facilitate the hydraulic lifting device of this embodiment to pass through a curve when running on the monorail hanging track 100 during use.

[0030] The lifting arm 6 is mainly composed of two housings 61 arranged in mirror images, two connecting plates 62 for detachably fixing and connecting the two housings 61 arranged in mirror images into one, a hook chain 63 and a hook 64. The lower end of the housing 61 is provided with more than two hook chain mounting holes 61-1 for mounting the hook chain 63, so that the mounting position of the hook chain 63 can be selected according to the use needs to enhance its applicability. The upper outer end of the housing 61 is provided with a clearance slot 61-2 for the lifting chain 8 to pass through and shift the lifting chain 8 when turning. The hook chain 63 adopts a mining ring chain. The hook chain 63 is fixedly set at each of the two housings 61 of the two lifting arms 6 by using the hook chain mounting holes 61-1 provided at the lower end of the housing 61, and a hook 64 is fixedly connected and set at the bottom of the hook chain 63. The lifting arm 6 of this embodiment is different from the commonly used integral structure in the prior art. It has a structure in which two shells 61 are detachably fixedly connected by a connecting plate 62, which can effectively solve the problem that the integral structure of the lifting arm in the prior art is difficult to enter the underground tunnel of the coal mine due to its large size and to be installed in the tunnel. The lifting arm 6 is provided with two identical structures.

[0031] See also Figure 1 and Figure 5 The hydraulic cylinder assembly 7 includes a cylinder frame 71, a cylinder 72 with a piston rod 72-1, a moving sprocket 73, a cylinder frame limit plate 74, a cylinder frame limit roller 75 and a guide wheel 76. The cylinder frame 71 can be movably arranged in the housing 61 of the lifting arm 6 in the left and right directions; the cylinder 72 is fixedly arranged in the cylinder frame 71, and the piston rod 72-1 of the cylinder 72 extends out of the cylinder frame 71; the moving sprocket 73 is fixedly installed on the outer end of the piston rod 72-1 and can rotate based on the piston rod 72-1; the cylinder frame limit plate 74 is fixedly arranged in the housing 61 of the lifting arm 6 and is located on the outer side of the cylinder frame 71. The cylinder frame limit plate 74 is used to adjust the oil pressure. The cylinder frame 71 is limited and stressed when it moves outward in the housing 61 of the lifting arm 6; the cylinder frame limit roller 75 is rotatably fixed in the housing 61 of the lifting arm 6 and more than two are set on the upper and lower sides of the cylinder frame 71, and the cylinder frame limit roller 75 is used to limit the cylinder frame 71 in the upper and lower directions; the guide wheel 76 is rotatably fixed at the outer upper corner of the cylinder frame 71, and the guide wheel 76 is used to guide the turning of the lifting chain 8. One set of hydraulic cylinder assembly 7 is respectively set in each of the two housings 61 of the two lifting arms 6, for a total of four sets. Different from the fixed installation method in the prior art, the cylinder frame 71 of the hydraulic cylinder assembly 7 of this embodiment is movably arranged in the lifting boom 6, which can improve the cornering ability of the device. At the same time, the cylinder 72 is well stressed and has no stress concentration point, thereby overcoming the problem of the fixed hydraulic cylinder in the prior art being in a stressed state when cornering in the tunnel during use, which affects the service life and the cornering ability.

[0032] The lifting chain 8 is a mining ring chain, and there are 4 lifting chains 8. The upper end of each lifting chain 8 is fixedly connected to the front and rear ends of a frame 41 of a bogie 4, and the lower end of each lifting chain 8 is fixed to the lower outer side of the cylinder frame 71 after passing through the guide wheel 76 and the moving sprocket 73 of a corresponding set of hydraulic cylinder assemblies 7.

[0033] Different from the structure of the lifting chain directly connected to the hook in the prior art, that is, the integral lifting chain is adopted, the lifting chain 8 and the hook chain 63 are separately arranged in the present embodiment. On the one hand, it can make the operation of the lifting chain 8 more flexible, and on the other hand, the hook chain 63 can be conveniently replaced according to the different sizes of the workpieces to be lifted, thus avoiding the trouble and high cost of replacing the lifting chain as a whole in the prior art.

[0034] The working process and principle of the ultra-low clearance hydraulic lifting device for coal mines in this embodiment are briefly described as follows:

[0035] When the ultra-low clearance hydraulic lifting device of the coal mine underground of this embodiment is in use, each hook 64 is used to hang with the workpiece to be lifted, and the cylinder 72 of each hydraulic cylinder assembly 7 is filled with oil. The piston rod 72-1 of the cylinder 72 extends outward so that the upper part of the lifting chain 8 is continuously shortened to lift the workpiece to be lifted. Since the four load-bearing beams 2 and the two connecting frames 3 are arranged on the same layer and the bogie 4 is designed to pass through the connecting frame 3, when lifting the workpiece to be lifted, the clearance h from the lower end of the monorail lifting track 100 to the upper end of the workpiece to be lifted is greatly reduced compared with the prior art, which is particularly suitable for the lifting of large equipment such as hydraulic supports. When the hydraulic lifting device of the present embodiment is running on the monorail hanging track 100 in the underground tunnel of the coal mine, the left side is located in front of the forward direction. As mentioned above, since each load-bearing beam 2 and the connecting frame 3 are connected in a rotatable manner, the bogie 4 and the connecting frame 3 are rotatably connected, the connecting rod 5 and the load-bearing beam 2 are connected in an articulated manner, the upper outer end of the shell 61 of the lifting arm 6 is provided with a makeshift slot 61-2 for the lifting chain 8 to pass through and facilitate the displacement of the lifting chain 8 when turning, the cylinder frame 71 of the hydraulic cylinder assembly 7 is movably arranged in the lifting arm 6, etc., a series of structural improvement designs enable the hydraulic lifting device of the present embodiment to pass through the curved part of the monorail hanging track 100 conveniently and flexibly when encountering it during operation.

[0036] The above embodiments are descriptions of specific implementation methods of the present invention rather than limitations of the present invention. Technical personnel in the relevant technical field can make various changes and modifications to obtain corresponding equivalent technical solutions without departing from the spirit and scope of the present invention. Therefore, all equivalent technical solutions should be included in the patent protection scope of the present invention.

Claims

1. An ultra-low clearance hydraulic lifting device for underground coal mines, comprising 8 load-bearing trolleys movably arranged on a monorail lifting track in underground coal mines when in use, and 4 load-bearing beams hingedly connected to the bottom of the load-bearing trolleys, characterized in that: It also includes two connecting frames arranged at the same level as the four load-bearing beams and each rotatably connected to two load-bearing beams, a bogie each passing through one of the connecting frames and rotatably connected to the connecting frames, connecting rods rotatably connected to two load-bearing beams located in the middle, two lifting arms for lifting, two sets of hydraulic cylinder assemblies movably arranged in each of the two lifting arms, and four lifting chains for lifting, the upper ends of the four lifting chains are respectively fixedly connected to the bogies, and the lower ends of the four lifting chains are fixed to the corresponding hydraulic cylinder assemblies; The connecting frame comprises a frame body and a load-bearing beam connecting member; the frame body is a structural member in the shape of a rectangular block as a whole, and a connecting beam clearance notch which is concave inward is provided on the left and right sides of the frame body, and a bogie through hole in the front and rear direction and an installation connection hole in the upper and lower direction are provided in the middle of the frame body; and a load-bearing beam connecting member is fixedly provided on the outer side of each connecting beam clearance notch on the left and right sides of the frame body; A vertical connection hole is provided in the middle of the load-bearing beam, and an articulated connector is provided at one end of the load-bearing beam; each of the four load-bearing beams passes through a load-bearing beam connector of the connecting frame from its middle part and is rotatably connected to the load-bearing beam connector, and one end of each load-bearing beam with an articulated connector is arranged on the outside of the corresponding connecting frame, and one end of each load-bearing beam without an articulated connector is located in the connecting beam clearance gap of the corresponding connecting frame; each load-bearing beam is articulatedly connected to the lower part of one of the load-bearing trolleys at the upper parts of both sides thereof; the two ends of the connecting rod are respectively articulated to the articulated connectors of the load-bearing beams on the load-bearing beam connectors arranged on the opposite sides of the two connecting frames; The two bogies each pass through a bogie through hole of the frame body of one of the connecting frames in a forward and backward direction and are rotatably connected to the connecting frame; The lifting arm comprises two shells arranged in mirror image, two connecting plates for detachably fixing and connecting the two shells into one, a hook chain fixedly arranged under each shell, and a hook arranged under each hook chain; The lower end of the shell is provided with more than two hook chain mounting holes, and the upper outer end of the shell is provided with a clearance slot for the lifting chain to pass through and shift when turning; the hook chain is fixed to the bottom of the shell by using the hook chain mounting hole of the shell; The hydraulic cylinder assembly comprises a cylinder frame, a cylinder with a piston rod, a moving sprocket, a cylinder frame limit plate, a cylinder frame limit roller and a guide wheel; the cylinder frame can be movably arranged in the housing of the lifting arm in the left and right directions; the cylinder is fixedly arranged in the cylinder frame, and the piston rod of the cylinder extends out of the cylinder frame; the moving sprocket is fixedly installed on the outer end of the piston rod and can rotate relying on the piston rod; the cylinder frame limit plate is fixedly arranged in the housing of the lifting arm and is located on the outside of the cylinder frame, the cylinder frame limit roller is rotatably fixed in the housing of the lifting arm and more than two are arranged on the upper and lower sides of the cylinder frame, and the guide wheel is rotatably fixed on the outer upper corner of the cylinder frame; the hydraulic cylinder assembly is respectively provided with one set in each of the two housings of the two lifting arms; The lower ends of the four lifting chains are fixed below the outer side of the oil cylinder frame after passing through the guide wheels and the moving sprocket wheels of a corresponding set of hydraulic oil cylinder assemblies in sequence.

2. The ultra-low clearance hydraulic lifting device for underground coal mines according to claim 1, characterized in that: The bogie comprises a frame body, a copper sleeve and a rotating shaft; an upper and lower mounting connection hole is provided in the middle of the frame body, and the copper sleeve is fixedly installed in the mounting connection hole of the frame body; the rotating shaft passes through the mounting connection hole in the middle of the frame body of the connecting frame and the copper sleeve to rotatably connect the bogie and the connecting frame.

Images