The Stress Analyzing Research Of The Key Accessories Referring To EBH-132 Arm-type Roadheader

For meeting the current requirements of coal industry developedat high speed and improving an unbalance situation of excavationin coal exploitation, it is desired urgently to manufacture a type ofheavy roadheader with a much stronger cutting capability. Type EBH-132 cantilever roadheader is designed not onlyfor drivaging medium-sized section in semi-coal rock laneway, butalso for full-coal rock laneway. Therefore, this type roadheadershould be characteristics of high cutting power, good applicability,excellent stability, compact structure, spraying efficiently,manoeuvre flexibly, mounting and dismounting conveniently andoperating and maintaining easily, etc, and it could economically cutcoal rock that one-way compression strength is less than 80MPa,slope of laneway is ±16○. In allusion to the vulnerabilitycomponents of the machine model in the actual service ,we musttake effective stress analysis on it, and found the weakness of it,andsupply theoretical basis of the improvement of this machine modelin the future.At present, roadheader used by oversea and home can be sortedtwo parts: full face boring roadheader and partial sectionroadheader.Ⅰ. Full face boring roadheader is mainly used to boring rock asround section. It is more applicable to bore hydraulic culvert andrailway tunnel rather than mine coal. So there are no details in thispaper.Ⅱ. Partial section roadheader is used to bore full-coal andsemi-coal rock laneway as trapezoidal section. It is always called"coal rock" roadheader.Partial section roadheader (coal rock roadheader) is our maincharacter in this paper. We have integrated, analyzed and comparedthe main structure of common partial section roadheaders toindicate their own virtues and defects and their influence onmachine performance.Typical structures of partial section roadheader (coal rockroadheader) are: cutting mechanism, rotating mechanism, loadingmechanism, crawling mechanism and hydraulic system, electricsystem and spray system for removing dust. They will mainlycomplete these procedures as follows:crushing ore bodies, loading crushed ore bodies, carrying orebodies to transport equipment, moving whole-set roadheaderfollowing drivaging in laneway, etc.Cutting mechanism is composed of cutting head(s), cuttingreducer and cutting electromotor. Rotating system contains rotatingseat, bottom case and steady bearing and is mainly used to linkleft-and-right sides machine supports for supporting, linking andimplementing lift and rotation of cutting mechanism. Whenoperating, it can afford the weight of cutting mechanism,counterforce made by cutting and overturning moment. Loadingmechanism is made up of loading shovel board and scraper boardand conforms to loading continuously. Most coal rock roadheaderadopts track crawling mechanism that has advantages of lowground specific pressure, outstanding adaptability to bottom caseof laneway, strong traction and gradeability, flexible manoeuvre.There are two types of driven way: hydraulic and mechanical.Through analysis on the geometric space and forced anayzingresearch on the work condition, it is obvious that shovel board withpressure which makes the counterforce on track be reduced to idealrange even if it has exceeded "center of track grounding area" canimprove the stability of whole-set machine, and added a point C infront of shovel board reinforces more efficiently when operating.When cutting head(s) is/are forced to uplift with counterforce ofcoal wall (at that moment, clearance appears in front of machine,PV<0, XRa where a point of application of Rl+R2 displacesbackward to result that specific pressure in front of track shows"0"), rear stabilizer designed in machine rear is running.Rear stabilizer is the same forced analyzing methods as shovelboard.When shovel board and rear stabilizer are on the earth,cylinders for driving shovel board and rear stabilizer increasepressure simultaneously to lift roadheader up, which is convenientfor maintenance inspecting and replacing tracks and also as adesign feature of EBH-132roadheader.But it could also modify thework condition, and reduce it's functional reliability;for ensure ofthe stability of the complete appliance. We must take stressanalysis of the work condition.Traditional analyzing methods are always rough, especially tomechanical model for structure analyzing object are muchsimplified, when making the structure design by analogy, designersquote so unimaginable hypothesises according to his experiencethat causes the analyzed results too unbelievable to get a definedassess. Besides, only use manual calculation with simple tools tolist very long operations and lack of thoughtful analysis, andchoose higher safety factors for safety and credibility. All of thatlead to unfaithful size and weight of structure beyond the truth andrestrain potential of material from performing perfectly.Last 30 years, with the computer application and test methodscompleted step by step, machine design has transferred from staticlinear analysis to dynamic nonlinear analysis, form empiricalanalogy design to optimization design, from manual calculation toautomatic calculation and from approximate calculation to accuratecalculation. It tends to retain the complexity of questions, andanswer the complex and actual engineering questions in numericalmethods. In order to shorten research cycle, improve productperformance and assure product quality, we always do our best tosucceed in the first time. So we should analyze static and dynamiccharacters of product deeply during designing to find out the weaklinks and then take some measures to get accurate results.Structure and stress of rotating stand are analyzed byfinite-element analysis software that is better than traditionalmethod.Through modifying designs, the external spray system ofEBH-132 roadheader removes dust much more availably whenoperating and reduces maintenance work under mine that ensuressafety in production, raises drivaging efficiency and lessensdangers to operators' health extremely.In one word, this paper is completed under the guide of tutor,and contents as follows:1.Take analytical study of the key components assembly of theEBH-132 cantileverly development machine , which providecredibility theory digital information to the improvement anddesign of the key components assembly, and it have application inthe practice project in the future. Get reasonable structureparameters by validating parts intensity.2. Carry out finite-element analysis on key parts of EBH-132cantilever roadheader as like a pair of gear and rack to ensurereliability of designed key parts.To expend this subject, gain advanced and modern design ideasand methods and do our job with the help of modern science andtechnology, which are practiced into EBH-132 cantileverroadheader successfully.Pick up the fruits in this subject. We should study hard andcharge continuously in further actual engineering application fieldto deal with problems perfectly and scientifically. At the same time,we can put forward new tentative ideas about directions andcontents of research.1. Crawling mechanism of roadheader is driven by hydraulicmotor.The design case of crawling mechanism of EBH-132roadheader stated in this subject has defined, driven byelectromotor, and refers to correlative parts of mature productAM-50 roadheader for decreasing design work and manufactureoutfits and subsidiary tools. Driven by electromotor hascharacteristics of strong overloading capacity and gradeability andoperating and maintaining easily. It is used to mine with low-levelground water.But we should think of adopting hydraulic motor drivencrawling mechanism under mine with high-level ground water.Driven system of hydraulic motor is simple and convenient toadjust speed of crawling and also saves room.2. Rear dual-support stabilizerIt is not so ideal to adopt single-support crawling mechanismdriven by electromotor that has large volume, but under mine, thereis not enough room.After mounting motor on crawling mechanism, save a lot ofroom for set rear dual-support stabilizer that reinforce the stabilityof machine in operating.3. Hydraulic system for strengthening the function ofmachine-borne roofbolt drilling machine.Hydraulic roofbolt drilling machine driven by hydraulic motoris used to rotate and cut rock down. It always has a pump stationfor providing energy to power motor.Hydraulic system of EBH-132 roadheader stated in this subjectbrings in the whole-set technology of AM-50 roadheader.From now on, we should consider ungrading this hydraulicsystem much more, matching hydraulic roofbolt drilling machinewith roadheader together to configure build-up roofbolt excavationunit (machine-borne roofbolt drilling machine) and dismountingpump station from hydraulic roofbolt drilling machine. Come trueexcavating and supporting simultaneously, once drivaging out ofroof, support in time.