Mining dumper
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This document discusses different types of dumpers classified by their dumping method (rear, side, bottom discharge), frame type (rigid, articulated), and capacity (small, medium, large, giant). It provides details on the key components of dumpers including the chassis, body, powertrain, hydraulic and braking systems. The rear discharge dumper and its variants are described in more depth. Key aspects covered include the dump body, suspension, wheels, tyres, cab, and causes of tire damage.
Mining dumper
- 1. Dumper
- 2. Classification • On the basis of dumping 1. Rear discharge dumper • Rear end tractor trailer • Rear end truck type dumper 1. Side discharge dumper 2. Bottom discharge dumper • On the basis of frame 1. Rigid frame dumper 2. Articulated dumper • On the basis of capacity 1. Small capacity dumper;- up to 50 tonnes 2. Medium capacity dumper;- 50- 100 tonnes 3. Large capacity dumper;- 100-250 tonnes 4. Giant dumper; more than 250 tonnes
- 4. • In this type the main body, which accept the material from excavator is placed on the rear part of operators cabin and discharges material through the rear portion of the equipment • Rear end body is tilted on the rear side by means of telescopic types hydraulic jacks, • upper end of which are fitted to the bottom of the body while lower ends are attached to the chasis of the equipment • The rear end after discharging material returns to its original position on retracting telescopic jacks Rear discharge dumper
- 5. • Rear end tractor trailer;- a trailer body mounted on two wheels is usually attached at the rear side of the tractor • Rear end truck type dumper Rear discharge dumper
- 7. Side discharge dumper • They deliver material over the drive tires • Discharging of material is achieved by hoisting system by 1. Integral hydraulic system 2. By external sky hook arrangement
- 9. Bottom discharge dumper • the bottom dump dumper consist of a diesel powered prime mover fitted with a large trailer at the rear end mounted on two large wheels , the trailer unit has drop bottom or clame shell type doors, the are actuated by double acting single hydraulic cylinder
- 10. construction
- 11. (1) DUMP BODY TAILGATE. A panel, at the rear of the dump body, which can be opened from the top or bottom .(2) DUMP BODY DEBRIS COVER. A cover used to prevent loose cargo (sand, gravel,etc.) from being blown out of the dump body. (3) DUMP BODY CAB PROTECTOR. Protects the cab from damage caused by shifting loads. (4) DUMP BODY LIFT CYLINDER. A hydraulic cylinder which is used to raise and lower the dump body
- 14. CONSTRUCTION • The main assemblies are 1. The chassis;- includes frame, suspension system, wheels and tyres 2. Body assembly 3. The power train ;- engine, clutch, transmission drive shaft and differential 4. hydraulic system for steering and body hoisting, braking and air system
- 15. Wheel • The wheel mainly consist of brake shoe assembly. • Tyres are fitted to these assembly • Brake shoes assembly are two types 1. Expanded shoe type 2. Disk brake type
- 16. Expanded shoe type brake • This consist of two semicircular shoes held in position by a piston cylinder arrangements • The piston cylinder are actuated by pressurised hydraulic fluid • Liners are secured on the outer periphery of the brake shoes • Brake shoes are held in retracted position by return spring • as the brake pedal is pressed , the pistons along with the shoes expands outwards and stop rotating drum of the wheels. When the effort is withdrawal , the shoes are retracted to their previous original position their by releasing the brake
- 17. The chassis;- includes frame, suspension system, wheels and tyres • Frame ;- are made from channels and braced. the are made of special alloy steel with integral front dumper. the length of the channel section and other dimensions , the no of braced members and their profile depends on individual design
- 18. suspension system • To save the frame body suspension system are used • Types of suspension system 1. Semi elliptical leaf spring 2. Suspension cylinder system Semi elliptical leaf spring • Springs in the form of thin leaves are placed one on the top of another and are bolted by means of U- bolt. One end of the spring is rigidly connected to the chassis by means of a shaknle pin. • During deflection the spring extends towards the shankle pin side , where by adjustment of the load and deflection are made • These are mostly used in small dumper up to 25 tonnes capacity
- 19. Suspension cylinder system • These consist two pars 1. A stationary cylinder;- is secured to the dumper frame or chassis at the top or at the side and a piston is attached to the spindle which is connected to wheel mounting s • The piston plays inside the cylinder , which divides the cylinder into two parts 1. The chamber above the piston head ;- is the upper chamber , which consist a layer of oil for lubricating as well as to maintain a gas tight sealing of piston head. The rest of the chamber is fitted with nitrogen gas Lower chamber;- contains air only at atmospheric conditions. The piston used is is hollow one and contains specified amount of oil As the loads comes on the dumper the piston tends to move upward. The compressed nitrogen gas forces oil from the piston top through drilled holes in the piston wall and out of the outer lower chamber surrounding the piton When piston moves downwards due to withdrawal or discharging of material , oil in the oputer chamber is drawn back to the top of the piston. Compressed nitrogen prevents extreme prevents extreme downward movement
- 20. tyres • There are two types of tyre 1. Tubeless tyre 2. tubes tyre
- 21. tyres • Tubeless tyres This consist of a tyre body and a special inner liner. This is designed to hold air instead of an inflated rubber tube. The body is made of an air-tight cord fabric to retain air. Tubeless tyres are light in weight and do not get heated as fast or as much as tubed tyres. Periodic inspection is necessary, specially to check for nails, etc. that could damage or puncture the tyre. • Tubed tyre this design provides for an inner tube that retain air inflates the tyre. The tube is an endless ruber tube with a valve. Compressed air is introduced through the valve and is retained inside tube under pressure. In some cases a flap is used between the tube and the rim
- 22. • All tyres in heavy earth moving machinery consist of the following • Beads:- they are bundles of strong steel wire placed at the inner circle of the tyre. They prevent any changes in tyre shape that would interfere during fitting on the rim • Core body:- this is the fabric body of the tyre that provides the strength to hold the internal pressure which supports the load. • Piles:-Piles are the individual fabric layer in the cord body. They are usually looped around the beads. • Tread:- this is thick rubber layer surrounding the core body. It is designed to provide tracton. Cushioning qualities and cut resistance. • Side walls:- the side of the tyre, that is between tread and beads. This is mainly used as protection coating on the sides.
- 23. CAB • Operator’s cabin are usually rubber mounted, fully enclosed chamber. Wind shield of tough glass is fitted at the front and a window vent and door is placed at the side. It is usually placed at the front left hand side of the vehicle
- 24. Body assembly. • The dump bodies used in dumpers are of two types, 1. the rectangular section body, and 2. the deep V-shaped body. • RECTANGULAR SECTION BODY • The shape of this type of body is rectangular box pattern, the cab shield is welded at the front, which protects the operator’s cab during the loading of the dumper. This is provided with a tailgate at its rear end. Which is mounted on the rear top portion of the body by hinge joints. There is a locking arrangement of the gate at the rear bottom end of the body. The tailgate carries two locking pins at the two sides of the bottom portion of the gate. • Locking of the door is achieved by inserting the pins in between the locking arms with the help of locking lever. When the body is tilted on its back the gate is opened by operating the lever and the material is discharged
- 25. • The shape of body resembles to letter V . The cab shield is welded at the front . There is no tail gate and desined for heavy duty • Made of high tensile steel • The bottom plate thickness is approximately 16 mm and side and front wall 10mm thickness
- 26. POWER TRAIN • All the dumpers are rear wheel drive • Power transmission are three types 1. Transmission with gear system 2. Transmission with hydraulic system 3. Transmission with electrical drive
- 27. Transmission with gear system • The engine delivers the power to the gear box through mechanical clutch or torque convertor • The output shaft of the gear box connected to the universal joint propeller shaft and again with another universal joint which is connected to the differential • The differential finally drive delivers power to the wheel through final drive • It has 6 forward gear and one reverse gear
- 28. Transmission with hydraulic system • Used for all types of dumper up to 100 tonnes capacity • The engine delivers the power to the torque convertor and hydraulic transmission system • The output shaft of the torque convertor connected to the universal joint propeller shaft and again with another universal joint which is connected to the differential • The differential finally drive delivers power to the wheel through final drive • It has 6 forward gear and one reverse gear • Due to presence of Torque convertor The vehicle can accelerate and decelerated • automatic shifting gear • Trans mission subjected to less shift Shock there by increase life of engine
- 29. Transmission with electrical drive • This type of transmission is used in high capacity Dumpers • Engine drive a generator , which supplies power to two or four wheel motors eliminating use of clutches, gear box, convertor, differential • The motor are driven by DC power and sped is controlled by means of stepping resister in the rotor circuits • The Dc motor is cooled by a mechanically driven fan • The drive gear and reduction gear are assembled and installed as a single unit • High transmission efficiency and less noise in the system • This machine is less expensive and less maintenance • The breaking system is disc type which is provided with electro dynamic retarding system
- 30. Differential • The main function of differential is to adjust the speed and torque of wheel depending on situation • When a vehicle travel around a corner , the distance travel by outer wheel is greater than inner wheels. • If the wheel are mounted on dead axel , so that they turn independely of each other like front wheel , they will turn in different speed to compensate for the difference in travel • If however the wheels are driven positively by the engine , a device is necessary which will permit them to revolve at different speeds without interfering with propulsion of the vehicle • to accomplish this purpose a system of gears called the differential is provided
- 31. Differential
- 37. Dumper air system • The air system consist of the following air circuits 1. Main air circuit 2. Hydraulic tank air circuits 3. Parking brake air circuits 4. Dynamic brake air circuits 5. Air over hydraulic brake circuits
- 38. Main air circuit • The air circuit provides air pressure for the operation and control of the air system as a whole • The component used in the circuit are 1. Engine air cleaner and service indicator 2. Air compressor 3. Auto drain valve 4. Un loader valve 5. Mai air tank 6. Shut off cock 7. Safety valve
- 39. Main air circuit • Air sucked through the air cleaner is allow to pass through the auto drain valve. this valve separates the moisture from the air and fairly dry air passes in the forward direction. • Air is now allowed to pass through an uploader valve to relive the compressor pumping load when normal operating air pressure has been attainted in the system and to reestablish compression when the reservoir air pressure falls below the minimum pressure • The main tank is provided with a safety valve and a shutt off valve. The pressure setting of the safety valve is 9.2 Kg/ cm2
- 40. Hydraulic tank air circuits • The purpose of this circuit is to provide air pressure over the hydraulic tank thereby helping in the flow of the hydraulic fluid from the tank. • The circuit consist of pressure reducer valve a hand control valve , a hydraulic tank , pressure relief valve • air from the main tank is allowed to pass through the pressure reduce valve ,when air pressure is reduced to between 0.56-0.7 Kg/cm2. this air passes through the hand control valve in the hydraulic tank • During the hoisting of the main body air pressure help in discharging the fluid from the tank to the hoist cylinder . When the body is lowered the fluid reenters the tank, causing air to compressed and then escape through relief valve within tanks thus preventing the buildup of pressure
- 42. Parking brake air circuits • This circuit consist of 1. Parking brake valve 2. Quick relief valve 3. Parking brake chamber 4. Low pressure warning switch This operates parking brake chamber ,which in turn operate the brake shoe. •The chamber is a spring loaded air cylinder . With no air pressure applied to the cylinder , the spring retract the piston assembly and applies the brake. •With the application of air pressure to the cylinder the spring pressure overcome and the piston assembly extends and release the parking brake •When the control valve is operated to apply the brake the value allows all the air to be expelled into the atmosphere from the brake chamber , there by allowing the pinion to move forward by spring force , which in turn moves the push rod and the brake is applied
- 44. Dynamic brake air circuits • When the brake pedal is depressed air pressure is directed to the top of the piston held against a spring force in the brake valve. • As the piston travels downwards the combined inletexaust valve is shifted off its seat and air enters directly to actuate the roto chamber • This air pressure entering the roto chamber act against a piston forcing its to move against a return spring pressure to actuate the hydro retardar valve on the transmission. • As the air pressure reduces the piston is forced back and the retarder returns to the designated state
- 46. Air over hydraulic brake circuits • This circuits consist of the following components 1. Two reservoir 2. Dual tradel valve 3. Two emergency relay valves 4. six slave servo and master cylinder brake assemblies for the wheel 5. Two limiting and quick release valves 6. Dry and slippery road control valve( hand operated) 7. brake lock control valve
- 48. Air over hydraulic brake circuits operation • The two emergency relay valves maintain proper air pressure of each reservoir during the use of brake. When the brake pedal is depressed, air from one of the reservoirs passes through the emergency relay valve to the primary section of the brake valve. Air from the other reservoir also flows through another emergency valve to the secondary section of the brake valve. Air pressure entering the emergency relay valve causes air to flow out from the reservoir to the slave servo of the brake circuit. Air pressure in the servo operates the master cylinder. Hydraulic pressure from the master cylinder actuates the wheel cylinder of the brake assemblies. One air circuit controls the operation of the hydraulic circuit for activation the brake shoes at the rear of each brake assembly, while the other circuit operates the hydraulic circuit made for the front of each brake assembly.
- 52. Causes of tire damage • Under or Over Inflation Tyres that are under inflated or over inflated can affect your tyre life, driving comfort, traction and braking. Under inflation generates excessive flexing of the tyre casing, which results in overheating, increase of rolling resistance and premature wear. In extreme cases, under inflation can cause tyre damage. Likewise, over inflation can reduce tyre life, reduce grip and create irregular wear. Driving at Speed • Driving at high speeds has a greater chance of causing tyre damage than at low speeds. If contact is made with a road hazard, it has a greater chance of causing tyre damage. • Driving at speed will cause the tyre a greater build up of heat, which can cause tyre damage. • Overloading • To ensure that your tyres are not overloaded, read the load index of your tyres, which is found on the tyre sidewall. Do not exceed the load capacity relative to this load index. Tyres that are loaded beyond their maximum loads can build up excessive heat that may result in sudden tyre destruction.