The shearer is one of the main equipment of the complete set of fully mechanized mining equipment[1]。The shearer is evolved from the coal interceptor.The shearer is a collection ofMechanics, electrical and hydraulic systems, and the working environment is harshfaultIt will lead to the interruption of the whole coal mining work and huge economic losses.
Shearer is one of the important equipment to realize mechanization and modernization of coal mine production.Mechanized coal mining can reduce physical labor, improve safety, and achieve the purpose of high output, high efficiency and low consumption.
In the longwall mining face, the working mechanism is used to break the coal from the coal body (coal breaking) and load it into the face conveyor (coal loading).The shearer moves (pulls) at the set traction speed, so that the coal breaking and loading processes can be carried out continuously[2]。
Chinese name
Shearer
Foreign name
coal winning machine
Application
Coal mine production mechanization and modern equipment
characteristic
Reduce labor force, good safety and high efficiency
The shearer is generally composed of cutting part, loading part, walking part (traction part), motor, operation control system, auxiliary device, etc[2]。
Cutting part
The general term of working mechanism and its mechanical transmission or driving device.When the cutting part is driven by a special motor, the cutting part also includes a cutting motor.The working mechanism is a component that directly realizes the main functions of cutting and crushing.It is equipped with a pick, which will break the coal from the coal body.In order to form the required cutting section shape, the working mechanism of some shearers has one or several auxiliary working mechanisms in addition to one main working mechanism.The working mechanism often has the function of loading the broken coal into the conveyor at the working face. The shearer using this kind of working mechanism no longer needs a separate loading part.The mechanical transmission device is used to transmit power to the working mechanism to meet the requirements of its motion mode, motion direction and cutting speed.The mechanical transmission device usually adopts gear transmission, which cannot change speed during use. However, a special speed change gear pair is available for replacement during installation to meet the requirements of cutting speed.The mechanical transmission device can be composed of one or more boxes according to the structural requirements[2]。
Loading unit
Load the broken coal from the working mechanism into the parts of the conveyor at the working face.If the working mechanism cannot have the coal loading function at the same time, an independent loading part shall be set.The loading part generally includes a loading mechanism and a mechanical transmission device.When the loading part has a special motor, it also includes the loading motor.The loader can also be driven by the mechanical transmission device of the cutting part[2]。
Walking part
Also called traction part, the general name of walking (traction) mechanism and its driving device.The traveling mechanism, also called traction mechanism, is the executive mechanism of the traveling part.Its structural forms mainly include steel wire rope reel, steel wire rope friction drum, traction chain sprocket and chainless traction walking rail walking wheel.The first two types of shearers used in the early stage have small traction, low traction speed, short service life and poor safety.Modern shearers all adopt chainless traction.The traveling drive device includes a speed regulating system and a mechanical transmission device.The speed control system is used to adjust the traction speed and change the traction direction, including mechanical speed control, hydraulic speed control and electrical speed control.Mechanical speed regulation is realized by mechanical means, such as ratchet claw drive, friction plate pulsation drive, etc.It is often combined with the mechanical transmission device, and the speed of its output shaft is often uneven. This speed regulation mode was only used on early shearers.Hydraulic speed regulation is realized by hydraulic transmission, such as variable pump, certain motor, variable pump variable motor transmission, etc.Electric speed regulation is realized by electric speed regulation drive, such as DC speed regulation drive and AC frequency conversion speed regulation drive.Hydraulic speed regulation and electrical speed regulation are stepless speed regulation, and the speed regulation system is generally independent.Modern shearers all adopt electric speed regulating system[2]。
Motor
When several main parts of the whole shearer share a motor drive, the motor becomes the main independent part of the shearer, which is often called the main motor.The main motor usually has an output shaft at both ends. One end drives the cutting part, and the other end drives the walking part. The shape is box shaped. The body of the shearer is connected with adjacent parts by fastening bolts.The motor must be explosion-proof.The motors of modern shearers are water-cooled, and most of them are stator water-cooled[2]。
Operation control system
The system that operates and controls the power supply (power source) and working condition of the shearer.It can be divided into mechanical controlhydraulic control And electrical control.According to the control mode, it can be divided into local control, direct vision remote control and roadway control[2]。
Auxiliary device
Shearers of different structural types need to be equipped with various corresponding auxiliary devices.Common auxiliary devices include: dust fall (collection) system;Streaming device of power supply cable and water supply pipe;Various safety protection devices, etc[2]。
performance parameter
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Motor power:It refers to the rated power of a single cutting motor (main motor).When multiple motors drive, the sum of the rated power of each motor is called the total installed power.
Cutting height:The height of the space formed above the floor of the working face when the working mechanism of the shearer is working.The limit height allowed to be reached in structure is called the maximum cutting height, which is an important parameter determining the mining height of the coal face.
Machine surface height:The height from the upper surface of the shearer body below the support top beam to the floor of the working face.It determines the minimum mining height of the coal mining face.
Depth of cut:The depth at which the working mechanism of the shearer cuts into the coal body each time.
Cutting speed:Linear speed of pick tip movement (without considering the influence of traction speed and swing speed of working mechanism).The cutting speed affects the cutting depth of each pick, the rate of broken coal, the heat and wear of the pick, the generation and flying of dust, and the generation of sparks when cutting hard rocks.
Traction speed:It is also called walking speed.Linear speed of the whole shearer moving along the traction (walking) direction of the longwall mining face.In the process of coal mining, it is necessary to adjust the traction speed frequently according to the cutting resistance of the broken coal (the cutting resistance corresponding to the unit cutting depth when the standard pick is used to cut the coal according to the specified method) and the change of working conditions.The shearer often needs to move its position in the working face at a higher speed without cutting coal. This speed is called transfer traction speed.The rated values of working traction speed and regulating traction speed of various shearers are often referred to as traction speed and regulating speed for short.
Traction:Also called walking force, it is the force that drives the shearer to walk.It is necessary to overcome various resistances in the traction (walking) direction.The tractive force during coal mining is relatively large, while the tractive force during mobilization is relatively small.The rated value of traction force of various shearers is often referred to as traction force for short.
Undercut depth:The working mechanism of the shearer is structurally allowed to cut down to the maximum depth below the floor of the working face.When the floor of the working face is uneven or the treads at both ends of the working face are raised, the shearer must have sufficient cutting depth to avoid continuous upward drift.
Coal passing height:Lower part and matching of trough mounted shearerScraper conveyorThe maximum space height between plates in the middle groove.It marks the capacity of passing coal and large pieces of coal (rock) under the fuselage[2]。
classification
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There are many classification methods for shearers, which are generally classified according to the working principle and structural form of the working mechanism, the applicable thickness of the coal seam, and the dip angle of the coal seam[2]。
Classification according to the working principle and structural form of working mechanism
According to the working principle and structural form of the working mechanism, it can be divided into four types: cutting frame type, roller type, vertical roller type and drilling type.At present, the narrow sense of shearer only refers to the most widely usedDrum shearer。MainlyFrame shearer, drum shearer, vertical drum shearer and drilling shearer, etc[2]。
Classification according to applicable coal seam thickness
According to the applicable coal seam thickness classification, it can be divided into four types: extremely thin, thin, medium thick and thick coal seam shearers.Extremely thin coal seam shearers are suitable for mining coal seams with a minimum thickness of 0.8m or less. Due to the difficulty in design and low production capacity, there are few varieties and quantities;The thin seam shearer is suitable for mining coal seams with a minimum thickness of 1.3m or less;Medium thick coal seam shearers are suitable for mining coal seams with a thickness of 1.3~3.5m, which is the mainstream of shearers with many varieties and wide use;The thick coal seam shearer is applicable to mining the coal seam with the maximum thickness of more than 3.5m. It is basically a model derived from the medium thick coal seam shearer. At present, the maximum cutting height can reach 4.5~5m[2]。
Classification according to applicable dip angle of coal seam
According to the applicable coal seam dip angle, it can be divided into three types: gently inclined, moderately inclined and steeply inclined shearers.
Slightly inclined coal seam shearer.It is applicable to coal seams with dip angle below 25 °, and most shearers belong to this category.The modern developed shearer is generally applicable to the dip angle of 35 ° in strike longwall mining face, while the dip angle is smaller in inclined longwall mining face.
Shearer for medium inclined coal seam.It is applicable to coal seams with dip angles of 25 °~45 °.This kind of shearer is generally modified on the basis of the shearer in gently inclined seam.The modern developed medium inclined seam shearer can often be used in the strike longwall mining face at the seam dip angle of about 35 °~55 °, also known as the large inclined seam shearer.
Steep seam shearer.It is applicable to coal seams with an inclination greater than 45 °.Due to the bad conditions in steep coal seams, the coal mined will roll down at high speed and injure people;The falling roof will roll downward and slide, which will cause insufficient filling in the goaf and cause roof accidents;The normal pressure between the shearer and the bottom plate is too small, and the shearer cannot use the middle trough of the working face conveyor as the walking guide, which makes the operation of the shearer difficult to maintain stability;In addition to overcoming the resistance of the working mechanism in the traveling direction, the shearer also needs to overcome the larger component of the machine's own weight when it goes up, so it requires sufficient traction. When it goes down, the shearer must take measures to control its downward speed, and also consider the possibility of serious accidents caused by the uncontrolled falling of the machine due to the damage of the traveling mechanism. Therefore,Although all countries in the world have successively developed various types of steep seam shearers, they have not been able to be popularized and used for a long time[2]。
Detailed introduction
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Frame shearer
Frame shearerShearer with frame cutting disc as the main working mechanism.The frame shearer is divided into thin coal seam and medium thick coal seam, which are suitable for mining 0.6~0.9m and 0.8~2.8m gently inclined coal seams respectively.
Basic structure: The frame shearer is composed of motor, traction part, cutting part, coal loading part and auxiliary devices.The cutting part comprises a working mechanism and a transmission device.The traction part includes traction mechanism and traction drive device.The shaft at both ends of the motor drives the cutting part and the traction part respectively.The coal loading department includes the coal loading mechanism, coal loading reduction gearbox and coal loading motor.
The tooth seat and the chain plate are connected with horizontal hinge pins to form a closed chain cut.It circulates on the frame shaped guide frame to form a frame shaped cutting disc.The pick is installed on the tooth holder with different inclination angles in a sector shape, so that the cutting groove has the necessary width.When the chain is moving, the pick will cut a frame shaped slot on the coal body, and the cutting depth is generally 1.6~2m.The height of the cutting frame is determined by the thickness of the coal seam to be mined, which is generally 0.7~1.4m, the minimum is 0.5m, and the maximum is 2m.When the height of the cutting frame is high and the coal quality is hard, and the coal in the frame shaped cutting chute cannot be crushed by itself, the crushing rod and crushing plate must be added.The crushing rod is equipped with crushing teeth, the crushing disc is sleeved on the crushing rod, and the periphery is equipped with picks.The cutting transmission device transmits the power of the motor according to the moving speed and direction of the frame shaped cutting disc and the crushing rod, and the cutting speed is fixed.Used for driving frame cutting disccylindrical gearThe transmission of the crushing rod requires a primary bevel gear.The transmission device is divided into two stages. The first stage reduction gearbox is fixed, and the second stage reduction gearbox can rotate around the first stage reduction gearbox. There is a clutch connection between the two stages.When the shearer is in working state, the frame shaped cutting disc is perpendicular to the body, and the clutch is closed.When the shearer is to be lowered, the clutch must be disengaged first, and then the frame shaped cutting disc, together with the second stage reduction box, shall be turned to the position in line with the body.The traction mechanism is composed of steel wire rope and drum.The drum is installed at the bottom or top of the traction reducer.One end of the wire rope is fixed on the drum, led out by the pulley, and the other end is fixed on the bottom of the strut between the top plate and the bottom plate.When the drum rotates, the wire rope is recovered, so that the shearer moves along the coal wall of the working face.The capacity of the drum is 25~50m. After the drum is fully wound, make it rotate in reverse quickly. Pull out the wire rope manually, and then continue to pull it after it is re fixed in the front.The traction drive device transmits the power of the motor to the drum, and the drive device also requires speed regulation during operation, so it is set in the transmission systemcrank shaft ratchetOr friction plate pulsator, or hydraulic transmission.The traction unit also provides a higher drum speed, which is used to release the rope and adjust (lower) the shearer.The coal loading mechanism is a scraper ejection type, and the vertical closed chain is equipped with a cantilever scraper. The lower chain runs from the coal wall to the gob from the bottom plate to the slope near the conveyor of the working face, so that the coal can be ejected into the conveyor at a high speed.The coal loading section is assembled into separate parts, which are dragged behind the frame shaped cutting disc with connecting plates and steel wire ropes. When it is lowered, the connecting pieces are disconnected, and it is also turned into a position in a straight line with the fuselage.The coal powder generated by chain cutting is taken out of the cutting groove by the pick and the tooth seat.The pulverized coal remover pushes away the accumulated pulverized coal to prevent it from being brought back to the cutting groove again and blocking the chain cutting operation.
Frame shearerIs characterized by:A large number of picks are used to cut coal in the cutting slot with small cutting parameters, so that the pulverized coal (≤ 6mm) extracted in the cutting slot can reach 80%, so the specific energy consumption is large and the efficiency is low[3]。
Sawing shearer
Also called coal interceptor, it cuts coal in the coal wall by the pick installed on the circulating chain.
The mechanized cutting machine is used to increase the free surface of blasting and improve the blasting efficiency. There are three types: disc type, cut rod type and cut chain type.a wire ropeThe two ends are respectively fixed on the anchor pillar and the rope drum of the coal cutter.When working, the rope drum rotates to pull the coal cutter forward at a speed of 0.25~1.1m/min.The length of the traction wire rope is 25m, and the anchor column needs to be moved every 20~25m.The coal interceptor cannot directly drop coal, and the process of blasting coal dropping needs to be added on the working faceDrum shearerReplace.
Planer shearer
I.ecoal ploughThe coal is broken by the reciprocating motion of the planer.
There are two types of coal ploughs: ① power coal plough, which uses the planer blade to break coal by impact, and there are many problems, which are still under research; ②Static plough is used to break coal under static pressure by planer blade, which can be divided into tow hook type, scraper type and sliding type.At present, China's multi-purpose drag hook coal plough, commonly known as coal plough, consists of a planer body with a knife rest and left and right supporting plates. The planer knives are symmetrically distributed on the planer body.In order to ensure the stability of coal ploughing during coal ploughing, the chassis of coal ploughing shall be pressed under the conveyor chute.The coal plough shall be pulled by anchor chain, and the coal shall fall down in a reciprocating motion along the working face, with a depth of 50-125mm.The coal plough whose plow speed is greater than the conveyor chain speed is called fast plow.The plough is suitable for thin and medium thick coal seams with stable roof and floor, soft coal and simple geological structure.
Drilling shearer
Drilling shearerThe coal body is drilled by the cutter teeth at the edge of the drill bit, and the coal body in the middle is broken by the coal breaking cutter teeth in the middle of the drill bit.
Drilling shearer A shearer whose main working mechanism is the drilling head.It is used for mining gently inclined long wall thin coal seams and is suitable for cutting hard coal. It has the advantages of large coal yield and less dust, but it is long, complex in structure, small in height adjustment range and cannot cut by itself.
Basic structure: It is composed of cutting part, walking part, motor and auxiliary device.The cutting part comprises a working mechanism and a mechanical transmission device.The walking part comprises a walking mechanism, a speed regulating system and a mechanical transmission device.
The drilling head is the main working mechanism, which is divided into single ring and multi ring.The end of the annular body of the single annular drilling head is welded with a tooth seat with different inclination angles, and is equipped with a pick. When the drilling head rotates, the pick cuts a certain width of annular cutting groove on the coal body.When the cutting chute reaches a certain depth, the picks installed on the inner wall and bottom of the ring will crush the columnar coal in the ring cutting chute into blocks, and the coal blocks will be thrown from the coal loading ports on both sides of the ring to the working face conveyor.Because the diameter of the drilling head is fixed and cannot adapt to the change of mining height, and the arc coal at the four corners needs to be removed, it is often supplemented by auxiliary working mechanisms such as top cutting disc, bottom cutting disc and vertical cutting disc.The top cutting disc can be lifted and the vertical cutting disc can swing to adapt to the change of mining height.There are two kinds of multi ring drilling heads: concentric multi ring and non concentric multi ring.The structure of concentric multi ring drilling head is similar to that of single ring, except that the cylindrical coal formed by the outer ring is broken through the pick of the inner ring.The pick of the non concentric multi ring drilling head is arranged radially on the drilling head.A part of the working area of two adjacent drilling heads is overlapped, and the upper and lower arc coal is leveled by the auxiliary working mechanism.The coal loading mechanism is a closed articulated chain with a coal loading scraper, which generally has the function of auxiliary working mechanism.The mechanical transmission device transmits the power of the motor according to the cutting speed and movement direction required by the drilling head and auxiliary working mechanism. Generally, gear transmission is adopted, and speed change is not allowed.In the past, the traveling mechanism used to use chain traction, but now it uses chainless traction.The speed governing system is generally hydraulic transmission, so that the traction speed can be adjusted during the working process.The mechanical transmission device transmits power according to the required traction speed and movement direction, and generally adopts gear transmission.The motor is of box structure, with shafts at both ends, driving the cutting part and walking part respectively, and fixing the three parts into one with connecting bolts.The motor power of modern single ring drilling shearer is 200kW, the maximum traction speed is 7.3m/min, and the traction force is 300kN.
brief history: Single ringDrilling shearerIt appeared in the UK in the early 1950s and has not been popularized in large areas due to its own shortcomings.The multi ring drilling shearer has been developed and used in the United States and the former Soviet Union, and is now obsolete[4]。
Impact shearer
According to the stress characteristics and mechanical characteristics of the coal wall, and taking full advantage of the mechanical characteristics of the weakest tensile strength of coal and rock, the cutting tool of the coal wall of the parallel working face is used to punch the coal body, so that the cutting tool contacts and rushes into the coal body to generate the punching tensile stress in the coal body, which makes the coal body crack and fall.
Drum shearer
Drum shearerSuitable forCoal seam thicknessIt is used under the conditions of small change, no rock inclusion, simple geological structure, coal seam dip angle below 15 °, and easy roof management.When the inclination angle is large, anti-skid device shall be installed.Drum shearer riding on bendable scraperConveyorWorking up and running back and forth along the working face.The helical drum is equipped with picks arranged in a certain rule.When the drum rotates, the pick successively cuts out many grooves on the coal body in a certain order, so that the coal body between the grooves is broken, and the coal is loaded into the conveyor through the rotary vane of the drum and the arc coal baffle.The drum diameter is the cutting diameter measured to the pick tip. Each manufacturer has different series, which are selected according to the mining height.The drum width is equivalent to the section depth, and there are 0.6, 0.8, 1.0, 1.2m and other specifications.
Drum shearerIt is a shearer with a cutting drum equipped with cutting tools and rotating around the horizontal axis as the working mechanism.When the drum shearer is working, the drum moves along the coal wall randomly, the cutting cutter cuts into the coal body under the traction of the machine, and uses the torque generated by the drum rotation to break the coal from the coal body.The early drum shearers used drum drum as the working mechanism, and the broken coal needed to be loaded into the working face conveyor with the help of special coal loading mechanisms such as coal plough boards.Modern drum shearers all use the spiral drum as the working mechanism. When the drum breaks down the coal, it usesHelical bladeLoad coal into the face conveyor.
The drum shearer is used for mechanized coal mining in the long wall coal mining face, and can also be used for mining other minerals such as potash or oil shale.At present, the cutting height of drum shearer is 0.65~5.0m, which can cut various coal seams with cutting impedance[5]。
Drum shearerIt is the main mechanical equipment for coal production. With the development of comprehensive mechanization of coal mining, the structure and performance of drum shearers are still being improved and perfected, mainly including: ① further expand the application scope of drum shearers, and develop high-efficiency drum shearers suitable for thin, thick and inclined coal seams; ②Improve the production capacity of drum shearer; ③Improve the reliability and safety of machine operation[5]。
According to the number of rollers, there are single rollers andDouble drum shearerAmong them, the double drum shearer is the most widely used.
Single drum shearer: There are three ways of feed: ① advanced cutter moves the head backward, generally oblique cutting feed is used, which is simple and easy, but the feed time is long; ②Move the machine head first and then feed the cutter, which can make full use of the working hours, but the workload of notching is large; ③The machine head is moved at the same time when feeding, which is simple to feed and short in time, but requires strong pushing of the conveyor.
There are two ways of coal cutting: ① one-way coal mining, one knife cutting on the shearer and downward loading.The advantage is that the machine can be fully used to load coal with high efficiency, but the working face takes a long time to cut, and the roof overhang time is long, which is generally applicable to coal seams with stable roof, large mining height, and large amount of surplus coal. ②Two way coal mining, one knife for each round trip.The advantage is that it can improve the utilization rate of working hours, the production capacity of the working face is large, the roof support is timely, the process is compact, but when the mining height is largeFloatation cleaningCoal workload is large.
Double drum shearer: One time full height mining, with a drum at both ends of the shearer.The front drum cuts the top coal and the rear drum cuts the bottom coal.The two rollers generally rotate opposite each other. The left roller of the driver uses the left spiral, and the right roller of the driver uses the right spiral.It can also rotate in opposite directions. The driver's left cylinder uses the right screw, and the driver's right cylinder uses the left screw.Generally, two-way coal mining is adopted, and the advanced cutter moves the head behind the oblique cutting feed mode;The tangent feed mode of moving the machine head at the same time can also be used.
Drum shearerOther classifications: according to the form of traveling mechanism, there are three types of drum shearers: wire rope traction, chain traction and chainless traction.There are three types of drum shearers (usually referred to as mechanical haulage, hydraulic haulage and electric haulage shearers) according to the speed regulation transmission mode of the walking drive device.There are two types of drum shearers, internal traction and external traction, according to the arrangement position of the walking parts.There are two types of drum shearers, namely, trough riding type and floor climbing type, according to the matching guide mode of the body and the conveyor at the working face.According to the general structural arrangement, the shearer can be divided into two types: longitudinal and transverse arrangement of the cutting motor[5]。
Troubleshooting
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The shearer is a large and complex system integrating machinery, electricity and hydraulic pressure. The working environment is harsh. If a fault occurs, the whole coal mining work will be interrupted, causing huge economic losses.
Repairing Shearer Wear on the Spot with Polymer Materials
As the shearer breaks coal by rotating working mechanism, the operating environment is relatively harsh and the force is relatively large, so the mechanical wear of parts and components at the transmission part often occurs, such as the telescopic cylinder of the shearerBearing positionWear, inner hole of shearer reducer boxBearing chamberWear, hinge pin hole of shearerImpact abrasionThe inner hole of the coal pick seat of the shearer drum is worn.
After the above problems occur, the traditional solution for enterprises isRepair weldingorBrush platingPost machining repair, but both of them have certain disadvantages: the thermal stress caused by the high temperature of repair welding cannot be completely eliminated, which is easy to cause material damage, resulting in bending or fracture of parts;However, brush plating is subject to the coating thickness, which is easy to peel off, and the above two methods are both metal repair methods, which cannot change the "hard to hard" coordination relationship.
Brief History and Trends
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The shearer is evolved from the coal interceptor.The coal interceptor can only cut a deep cutting groove in the coal body (generally close to the floor), then drill and blast, and manually load the coal, which is low in efficiency and high in labor intensity.So it appeared to use multiple cutting discs (including curved cutting discs) on the basis of the coal cutter, and if necessary, add a crushing rod or a crushing disc to break down all the coal at the full mining height, and then drag the loading part on the back, so that the coal breaking and loading can be completed at the same time. This is the prototype of the coal cutter.By the end of 1940s, the Soviet Union had developedFrame shearerIn the early 1950s, drum shearers and drilling shearers appeared in Britain.After the 1960s, the frame shearer was gradually eliminated,Drum shearerContinuously improve and update the technology and structure, and become the most widely used model in the world.
China began to develop it in the early 1960s. During this period, it experienced from introduction, digestion, imitation to independent developmentSingle drum shearerTo the serial development of double drum shearer;The power of shearer cutting motor is increased from 60kW to 1000kW, and the total installed power is increased from 60kW to 2550kW;The overall structure of the shearer is from single motor to multiple motors, from longitudinal layout to horizontal layout;The form of traction has changed from wire rope traction to ring chain traction, to chainless traction;Traction speed regulation has developed from mechanical traction speed regulation to hydraulic stepless speed regulation, to DC speed regulation and AC frequency conversion speed regulation;System protection is from simple to perfect;The operation is from simple manual on machine operation to both terminal station operation and wireless ionizer operation;The mechanization degree of the working face is from general mining to high-grade general mining, and then to comprehensive mining;Development process from thin coal seam to extra thick coal seam[1]。
Development trend
Explore new coal breaking working principle and new working mechanism to improve the block size composition of product coal and increase the proportion of large coal;Make full use of the characteristics that the tensile strength and shear strength of coal are much lower than the compressive strength to reduce the specific energy consumption of coal breaking.Expand the scope of application, develop extremely thin coal seam and thin coal seam shearers with high output and good performance, and steep coal seam shearers.Improve the degree of automation, together with other supporting equipment, form automatic coal mining face equipment and realize unmanned coal mining face[2]。The shearer is used to cut the bottom of the working face of gently inclined thin coal seam and extremely thin composite coal seam under the general medium and small mines, so as to achieve the function of cutting and coal falling.Small size, light weight, low noise, good dust prevention effect, safe and reliable use.The electrical part has certain explosion-proof performance, and the motorCooling modeIt is water cooled.Compared with manual coal mining, it can improve the coal lump rate and save mining time. It is an equipment for mining extremely thin composite coal seams instead of manual cutting.
Develop enterprises
In recent years, China's coal mining machinery industry has developed rapidly. By 2010, there were 24 coal mining machinery production enterprises in China, with production and sales volume of about 800 sets and production capacity of about 1500 sets.From the perspective of the competition situation of domestic coal machinery, China's coal machinery manufacturing enterprises have developed slowly under the influence of the planned economy era, not only with a low level of technology, but also with a single product.Although the technology has improved rapidly in recent years, compared with foreign coal machinery giants, the reliability and stability of China's coal machinery equipment is still not strong, and the industry's top brands are lacking. There is still a gap between China's capital strength and technology research and development ability and the international advanced levelopencut coal mineThere is a big gap between the production of mining equipment and that of foreign countries, which is a true portrayal of the current coal machinery industry in China.
Industrial competition optimization
At present, the overall situation of overcapacity of coal machinery in China has been formed. The product competition will inevitably turn to brand competition, promoting the merger and reorganization of the domestic coal machinery industry, so as to strengthen the brand is an inevitable move for China's coal machinery enterprises to achieve breakthrough.For this reason, the country needs to strengthen guidance in policy and other aspects, so as to promote China to eliminate backward production capacity as soon as possible and realize the healthy development of coal machinery industry.The resource integration and big group strategy implemented by China's coal industry, especially the construction of 13 coal bases, will play a huge role in promoting the brand building and product upgrading of the coal machinery industry.These measures will not only provide huge market opportunities, but also promote the reshuffle of the whole coal machinery industry market.At present, the mechanization rate of the coal industry is about 70%, but the comprehensive mining rate is relatively low, about 44%, while the comprehensive mining rate of coal in countries around the world is more than 80%, or even 100%, so there is still much room for the comprehensive mining of the coal industry.
