DESIGN & MODIFICATION OF ROLLERS IN TRACKS OF SURFACE DRILLING MACHINES

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1 DESIGN & ODIFICATION OF ROLLERS IN TRACKS OF SURFACE DRILLING ACHINES r. S.N. Shinde P.D.V.V.P.C.O.E.Ahmednagar Prof. R.R. Navthar Aociate Profeor Dept. of ech Engg. P.D.V.V.P.C.O.E.Ahmednagar ABSTRACT Surface Drilling achine are large crawler mounted mining machine which have variou component aemblie like boom, Feed aembly and rotation aembly, Track Aembly etc. While working in mine, machine need to take variou poition of drilling for making a hole. Hence machine need to move from one hole poition to another by tramming operation. Tramming i the proce for moving the machine from one place to another.roller wheel mounted to the crawler frame to tranfer machine weight to the track. The wheel, acting a contact point, help ditribute machine weight evenly acro the ground through the track.roller wheel alo help in guiding the track. Roller wheel are a wear item and need to be replaced periodically or after wear. Currently weight of rig i: 15.5 ton. According to report and their pre tudy it i required to take ome improvement action on crawler. INTRODUCTION Surface Drilling achine are large crawler mounted mining machine which have variou component aemblie like boom, Feed aembly, Rotation aembly and Track aembly etc. While working in mine, machine need to take variou poition of drilling for making a hole. Hence machine need to move from one hole poition to another by tramming. Tramming i the proce for moving the machine from one place to another. Drilling i the proce of making a hole into a hard urface where the length of the hole i very large compared to the diameter. In the context of mining engineering drilling refer to making hole into a rock ma. Surface mining require drilling for different purpoe that include: 1. Production drilling i.e. for making hole for placement of exploive for blating. The objective of drilling and blating i to prepare well-fragmented looe rock amenable to excavation with better productivity from the excavation machinery. The hole drilled for thi purpoe are defined a blat hole.. Exploration drilling for ample collection to etimate the quality and quantity of a mineral reerve. The ample are collected a core and the drilling for uch purpoe are referred a Core drilling. A diamond bit are ued for uch drilling, core drilling i often called diamond drilling. 3. Technical drilling during development of a mine for drainage, lope tability and foundation teting purpoe. Opencat mining involve removal of wate rock and ubequent winning of the mineral. In cae of depoit underlying hard and compact wate rock called over burden looening of the rock ma i eential prior to excavation. Thu drilling and blating i the important ground preparation job. Unle the rock ma i highly weathered and very much unconolidated drilling of hole for placement of exploive and detonating them for blating i required for any mining operation. odern machine like continuou urface miner can however eliminate the need of drilling and blating in certain urface mining operation. Succeful drilling under pecific ite condition require blending many technologie and ervice into a coherent efficient team, particularly if it i for deep exploration drilling. Blat hole drilling i comparatively impler. However, to minimize cot and optimize the performance and pot drilling operation technical manager and deciion manager mut undertand the language and technology of drilling operation. The modern hydraulically operated drill have number of advantage over pneumatic drill. Thee are: 1. The elf-contained dieel powered hydraulic percuive drill do not require auxiliary compreor for drill operation.. Energy delivered per troke being higher, hydraulic percuive drill offer higher penetration rate compared to the pneumatic drill. 3. Le noiy 4. any hydraulic drill claim energy aving a high a 66% than pneumatic drilling. Vertical blat hole are mot common. However, to avoid formation of hard toe and to obtain better fragmentation and reduced vibration level inclined blat hole are more ueful in many ituation. A hard trata occurring at depth in the lower horizon of a high bench i better blated by horizontal blat hole. However, horizontal drilling i not normally carried out in opencat mining due to the difficultie aociated with drilling and charging. 1 P a g e

2 PROBLE IDENTIFICATION The up gradation of roller in exiting track i required to maintain the ground preure a per Drilling Rig afety tandard. Exiting machine conit of 6 No of roller per track Hence total No. of roller become 1 no including both track. A per Atla Copco field report analyi there wa wear in roller after few working of hour of machine. There are everal drawback they found during the inpection. Out of draw bag it i uggeted to change the roller ize including No of Roller pre track ytem. Load ditribution i not equal in procket mechanim of track vehicle due to le number of roller. Hence more chance of failure due to uneven load. ore wear and tear of roller. Le life of roller. The purpoe of up gradation of roller for track frame wa to overcome the failure problem at variou wort load condition and to develop a univeral track aembly that would utain the maximum weight with higher capacity. So the need of project i to upgrade the roller for track frame to utain the increaed weight of new upgraded technologie on the machine. And by maintaining minimum cot of manufacturing of machine o making it compatible to all urface drilling machine. Thu to validate the part a per pecification ome deign modification need to be done. INTRODUCTION TO UNDERCARRIAGEAND ROLLER Fig 1 Roller part UNDERCARRIAGE ASSEBLY-The total undercarriage aembly of a dreer crawler i made up of component that tranfer tractive effort from the tractor to create forward or revere motion. Front Idler-It i baically ued for making chain in tenion. A large wheel at the front of the track frame that guide the track chain and aborb hock load. It i adjutable for proper track chain tenion. Fig Undercarriage Aembly Roller wheel mounted to the crawler frame to tranfer machine weight to the track. The wheel, acting a contact point, help ditribute machine weight evenly acro the ground through the track. Roller wheel alo help guide the track. Roller wheel are contructed of a high-denity platic core with rubber bonded to the circumference. The rubber act a a cuhion. Roller wheel are wear item and need to be replaced periodically. the three key function of undercarriage roller wheel are: 1. Ditribute weight of machine from the frame to the track.. Guide the track. 3. Provide a cuhion between the track P a g e

3 EXISTING TRACKFRAE AND ROLLER Novateur Publication PRELIINARY CHANGES SUGGESTED: Increae no. of roller from 6 no to 7 no. Increae the diameter of roller according to ize available in market and feaible to machine. odify the track frame accordingly. Increae in roller ize will alo help to improve the ground clearance of machine. ETHODOLOGY Theoretical calculation over roller Selection of roller baed on calculation Creation of 3D model and drawing uing Pro Engineer oftware Verification of propoed deign by FEA analyi uing analyi oftware ANSYS. Correction of Deign odel on the bai of FEA Analyi. Updating and Releae the Drawing for Fabrication. Fabrication of odel & Radiography for Fabricated Track frame. Aembly of roller and track on machine. Tet and validation of actual component on ite. THEORETICAL CALCULATION STATIC LOAD CASE One of the track i prevented from moving relative to the ground while the other track pull at maximum traction force,. The non-moving track i ubjected to a bending moment and the hear force at the haft and the force couple R1 & R form a couple at haft of mainframe from the ground. Lr1 Lr R1 mg R F 3 P a g e

4 The bending moment on the haft pivot (at the ide of the locked track) become = = (5000X.4) =14800Nm (gear box torque=15490nm, procket R=0.3m hence =5000N) The ize of the force couple become R 1 = =14800/1.5=99840N Lr1 R = =14800/1.35= N Lr Contact urface area of idler for R1 reaction i Ai = mm. And ame time 1 t three roller will may have contact with track chain, then total urface area of roller contact i Ar = 550 mm Lr R1 R σ b = = and τ = = Wb Atotal A ALr = 99840/ = 5.64 N/mm = kg/mm. aterial i SAE 1541, Yield tre value i 50 pa= 50 N/mm. FATIGUE LOAD CASE ON SHAFT AND ROLLER. In thi cae the non-moving track i not locked to the ground. Intead the track i aumed to rotate relative to ground with friction force developed. The maximum traction force available may not be needed to overcome friction. L w F t f Q m g L t F t f The normal force acting on each track equal half of the rig total weight mg N = = (15500X9.81)/=7607.5N Ditributed friction force amplitude under the liding track N Q = µ = (0.5X7607.5)/3= N/m L t Required moment on the track haft pivot to overcome friction force Lt / Lt / N µ N Lt µ m g Lt = l Q dl = µ l dl = = = (0.5X15500X9.81X3)/8= Nm L t Deign moment range, when drill rig move back and forth µ m g Lt r = ± f = f = = = (0.5X15500X9.81X3)/4=5700.6Nm 4 Note that f (traction force needed to overcome friction moment) can be maller than (maximum traction force) if the friction under the liding track i ufficiently low: Deign hear force that act on haft pivot together with torque above F = ± F = F = 5000X=104000N r tf tf The friction coefficient i difficult to etimate theoretically, the highet bending moment on the track pivot axle, about 57kNm. When the complete load pectrum from all kind of uage i normalied to a contant amplitude load at 4 P a g e

5 1,000,000 load cycle, an equivalent bending moment range of 8.5kNm i obtained. With rig ma 15,500kg, track length.4m and a afety factor of 1.5 on the meaured reult, the following equivalent friction coefficient i obtained 3 3 µ = µ equivalent = load cycle 4 We have Ditributed friction force amplitude under the liding track i Q= N/m Auming track frame tructure i rigid body, Hence all force will tranmit to idler wheel, procket & roller of one track during turning. Total area = idler wheel contact area+ all roller chain contact area+ procket contact area. = mm+5100 mm mm = mm Conidering force generated by both track during turning in oppoite ide (force generated by gear box) = N Stre = / = 3.46 N/mm aterial of roller i SAE 1541, Yield tre value i 50 pa= 50 N/mm. Hence roller, idler i afe under turning. CONCLUSION Cot effective olution for the highly under treed Track Solution for the Weaket part of the machine which mut be very trong Trac frame deign & election of roller to utain the load without fracture and wear at it extreme downward poition of drilling. Newly deign track will alo be applicable for the machine which will going to ue for 6 drilling Hole Application. NOENCLATURE m Total ma of the drill rig [kg] g Gravity contant 9.8 [m/] Width between track [m] Lt Track length [m] aximum traction force of one track [N] f Needed traction force for fatigue load [N] Coefficient of friction [-] N Normal force on one track [N] REFERENCES 1. ohamed A Omar; odular ultibody Formulation for Simulating Off-Road Tracked Vehicle ; Studie in Engineering and Technology, vol no. 1 (014).. Abdelmotalab Fadlelmola Kheiralla; Conceptual Deign of a Rubber Tracked ini-vehicle for Small Holder Uing Off-Road Vehicle Engineering Technique ; International Conference on Trend in Indutrial and echanical Engineering (ICTIE'01) arch 4-5, 01 Dubai. 3. D. Rubintein a, R. Hitron, A detailed multi-body model for dynamic imulation of off-road tracked vehicle ; Journal of Terramechanic 41 (004) E. Ruińki*, J. Czmochowki, P. oczko; Failure reaon invetigation of dumping conveyor breakdown ; Journal of Achievement in aterial and anufacturing Engineering; VOLUE 3, ISSUE 1 July Arindam Pal, Sumit Sharma, Abhinav Jain, C.D.Naiju ; Optimized Supenion Deign of an Off-Road Vehicle ; The International Journal Of Engineering And Science (IJES), vol no. Iue 6 (006) pp B J Robinon & A J Scarlett; Development of technical requirement / performance pecification for a) track and b) exterior and acceorie of agricultural and foretry vehicle ; Tranport Reearch Laboratory, (013). 7. Z. -D. a; A Track-Wheel-Terrain Interaction odel for Dynamic Simulation of Tracked Vehicle, VEHICLE SYSTE DYNAICS AUGUST Kenjiro Tadakuma, Riichiro Tadakuma, Hiroaki Kinohita; echanical Deign Of Cylindrical Track for Sideway otion ; Proceeding of 008 IEEE International Conference on echatronic and Automation,. 5 P a g e