Introduction The belt feeder breaker is a single piece machine whichis installed before the belt conveyor to receive thematerial and size it before being carried to anotherlocation for operation. The Stamler Belt Feeder is a mobile conveyor system,which incorporates a pick up breaker to reduce the sizeof the material being conveyed through the machine.
Design The design of the feeder breaker is such that thematerial is placed onto the conveyor at the intakeend of the machine, which has been built with ahopper that is adequately sized to receive theincoming material. The pick breaker breaks the material by strikingthe material with sharp pointed picks. Once thematerial is reduced to the required size, thematerial is moved through the machine and isdischarged on to a belt conveyor at the dischargeend.
Parts of Feeder Breaker Drag conveyor Pick breaker Hydraulic crawler drives Electric system Hydraulic system Programmable sensor controller
Drag ConveyorThe conveyor consists of two strands of engineeringchain with flights attached at regular intervals, tomove the material. The chain ad flights are wrappedaround and engage the sprocket attached to the headshaft located at the discharge end.The head shaft is mounted at the discharge end anddriven by a hydraulic motor and chain arrangement.A relief valve is provided in the hydraulic system toprotect theconveyor inthe eventof stall.
The tail shaft is mounted atthe intake end as an idler tomaintain the correcttension of the conveyorchains.The conveyor deck is linedwith abrasion resistantplate to resist wear.
Pick BreakerThe breaker is constructed of a solid steel shaft that hasseveral steel rings welded to it.Pick holders are welded to the rings and replaceablepicks are inserted into the holders.The breaker is suspended at each end by large rollerbearings mounted in housings.
The breaker rotates with thematerial flow allowing thepicks to strike the material asit flows towards the dischargeend of the machine. Breaker shaft is driven bychain and sprocketarrangement that isconnected to a gearbox. Ashear pin is positioned at thebreaker drive to provideprotection in case of stall.
Hydraulic Crawler DrivesCrawler drives operateindependently. Thehydraulic valves controlvalves, mounted on theside of the machinescontrol the speed anddirection of motion of thecrawlers. Hydrauliccylinders are used to levelthe machine.
Electric SystemThe electrical system is designed and built tooperate on AC supply, from the trailing cablesconnected to the power supply. The supply of 3.3KV AC supply is received from the Air CircuitBreaker (ACB) and stepped down to 1.1 KV. Theelectrical system is used to control thefollowing- Breaker Drive Conveyor Drive Hydraulics
Hydraulic System The hydraulic system consists of a pistonmotor, oil tank, several cylinders , pressuregauges and other auxiliary parts. The hydraulic system is used to control thefollowing: Conveyor Drive Crawler Drives Levelling Cylinders Auxiliary Functions (PTO, winches, cylinders,etc.)
The hydraulic system is designed withmaintenance features to provide safe andreliable operation of the feeder breakerComponent test fittingsOil level indicatorHand pump (reservoir fill) Hydraulic pressure gauges are fitted forthe visual monitoringPump operating pressuresConveyor drives system pressuresTram and levelling pressures
Programmable Sensor Controller The controller monitors signals received from thesensors and processes, and then uses the informationto ensure the feeder breaker is working within itsnormal operating requirements. If the controller unit’s programming becomes lost orcorrupted in such a way, by operator error, damage,malfunction, etc. the unit will no longer allow thefeeder breaker to operate and the controller must bere-programmed.
The controller must be programmed inaccordance to the machinery it is to be usedwith. In the feeder breaker, it is configuredfor 8 channelsWater flowWater pressureOil temperatureOil levelSequence/waterSequence/Time outStopBreaker Run
MaintenanceHead shaft assembly installation – The feeder breaker is installed with a head shaftassembly which is used to transfer power from theconveyor to the conveyor chain and flight. While the head shaft is disassembled it is a good timeto visually and mechanically inspect all of thecomponents, for excessive wear, cracks and othermechanical malfunctions.
Tail shaft assembly installation –• The same maintenance schedule is developed as thatof head shaft assembly installation.Breaker shaft assembly installation• If in the breaker shaft assembly, one of the componentbe damaged, then the whole set of the assembly is tobe repaired, monitored, or replaced if need be.
Breaker pick holderinstallation – The breaker is designedto use replaceable pickmounted in a holderthat is welded to therings on the breakershaft. Worn out picks need tobe replacedimmediately as wornout picks causesparking when strikingmaterial and causesreduction inproduction.
Shear pin replacement – The breaker has a shear hub keyed to the driven end ofthe shaft. Mounted on the hub and free to turn is thedrive shear sprocket. Shear pin is installed connecting the hub and thesprocket the breaker can now operate the pick breaker. With this design should the breaker picks strikesomething and stall causing the breaker drive tooverload, the shear pin will break causing the drive tobe disconnected from the shaft. A lubricated surfaceexists between the shear hub and the sprocket thatmust be lubricated each time the shear pin is replaced.
Conveyor chain wear –• Most of the wear causes between the inside of thebushing and the chain pin, this wear causes elongationin the chain.• The chain manufacturer has established that when theelongation reaches 3%, the chain is considered to beworn out and it needs to be replaced. The wearpercentage is found out by[(X-4.75)/7]*100where X = distance between one bushing to the nexton the outside edge.
Cone Drive(Reducer) Cone drive is a assembly of standard worm gear speedreducers and gear sets. It consists of 2 output ends in which the speedreduction ranges from 10:1 up to 70:1 is obtained.Alsoboth of the output ends are perpendicular to eachother. Range of operation is 2000-3600 R.P.M. The contact of the gear teeth and the one thread of thereducer is normally through a contact paste or grease.
In cone drive there areshims inserted between thebearing cap and housing ofbore face to properlyposition the worm and gearwithin the gear housing andto set desired bearing endplay. Shims also serve as gasketsfor the bearing caps andcarriers.