Presentation on theme: "IRS POINT MACHINE IRS POINT MACHINE is rotary locking type point machine and designed to comply with IRS specification S-24/2000 and RDSO Dr.No.S10.800."— Presentation transcript:
1IRS POINT MACHINEIRS POINT MACHINE is rotary locking type point machine and designed to comply with IRS specification S-24/2000 and RDSO Dr.No.Sit is designed operate all type of points /switches.It is available in two model low stroke (143mm) and high stroke (220mm)It is non-trailable type point machine
2Important feature Sr Nob Description remark 1 Type D.C. high thrust (stroke 143mm)2Other modelHigh stroke 220mm3Type of LockingRotary type4Locking of switchesIndependent (two lock slides)5Arrangement for Locking of switchesIndirect through ground connections (rods) in side machine6Thrust700 Kg7Over load protectionFriction clutch self adjustable8SnubbingMechanical9Locking of throwAvailable10Number of control contact2+211Number of detection contact12Greasing nipple13weight220 Kg14packingWooden skeleton15Number of ground connectionsFive (02 lock+ 02 detection + 01 through)
3General Features of point machine The basic design of point machine generally comprises ofCast iron casing and cover with locking arrangementMotorReduction gearCrank handle mechanismFriction clutchContact assembly with spring loaded rollers and Detection slidesRotary to linear conversion mechanismLocking and throw assembly
5Cast iron case accommodates all the parts of point machine is made of cast iron and designed to fix all parts at required place.provide access to/ slots for different lock and detection slidesfacilitate fixing of machine on sleepersProvides an arrangement to drain out water/ oil in bottom of casting.Provides cable entry.
7COVER OF POINT MACHINEMade up of thick iron sheet and fixed on cast iron casting (case)Contain lock ( S&T maintainer's lock) on inner side surface to lock it with cast iron casting (case).Secure all the parts of machine in weather proof environment and prevents un-authorosed interference.Provides access only to nominated (ward &feather) crank handle insertion.All the apertures for keys and crank handle are secured by flapsAll flaps has a locking arrangement
8COVER OF POINT MACHINE Cover top view Cover inner view Flap for crank handle keylockFlapForCoverkeyFlapFor CrankhandleCover top viewCover inner view
9MOTORDC motor IRS: S 37 Motors for Electric Point Machine.shall comply with the requirements of IRS: S 37 'Motor for Electric Point machine.Motor comprises ofcrank handle cutout contact assembly,DC motorreduction gear
10CRANK HANDLE AND CRANK HANDLE MECHANISM It allows Manual operation (without power) of pointIt require in case of failures of point/ point machine OR for the purpose of maintenance of point machine.It containCRANK HANDLE AND KEYCRANK HANDLE CUTOUT CONTACT ASSEMBLY
11CRANK HANDLEThis apparatus is used for manual operation of point machineIt is a “Z” shape structure made of steel pipe and has wooden handle on one end to have better gripe.Wards &feathers are welded on other end of pipefacilitates coding (insertion of only to nominated crank handle).A stud is intrude in the pipe, it get engage in forked shaft of motorWoodenhandleWard &featherCrank handle
12CRANK HANDLE CUTOUT CONTACT ASSEMBLY It disallows simultaneous power and manual operation of point machine to protect staff performing crank handling.Ordinarily crank handle can not be inserted in machineTuring of crank handle key permits/ allows insertion of crank handle in the machine.Turning of crank handle key isolates the negative power path of motor.It comprise ofCrank handle cutout contactsflap cover plateCrank handle key
13Crank handle cutout contacts 11There are two sets of contactThese contacts are wired in negative path of power supply to motor.Contacts break / open with insertion and turning of crank handle keyMakes when crank handle key is taken out.2Crank handle contact closed & Flap in front of shaftCrank handle contact open &Flap displaced & shaft visible
14Flap cover plate & keycontrols the entry of crank handle in the machine for manual operationmetal flaps attached to a lockhangs/ placed in front of motor shaft at the entry point of crank handle.flap cover plate is displaced by means of a crank handle keyThe insertion and turning of crank handle keydisplace the flap cover plate to allow insertion of crank handleopen crank handle cutout contacts.Removal of the crank handle keyreplaces flap cover in front of motor shaftmakes the crank handle contact.Crank handle key
15Flap cover plate and crank handle key Flap cover plate in front of crank handle Entry& shaft of motorCrank handle insertionInsertion & turning of key displaces flap Cover plate
16DC motor is a series split field DC motor Is design to work on 110volt DCIs a series motor to meet high initial torque requirementIs split field so that motor can be rotated in both directioncontains four field windings and two windings are connected in series to form a set of winding.Use carbon brushes
17Technical parameters of motor SrNobDescriptionRemarks1TypeD.C. Series split field2Operating voltage110 Volt DC (60 volt mini)3current2 to 2.5 Amps4Thrust700 Kg5Power0.48KWt6Reduction ratio (in side motor)20.8 :17AC immunity160 , 300, 400 volts8Power supply terminals039Insulation grade of windingsMore than 10 M Ohms
18DC MOTOR main parts Armature and commutator Field winding Carbon brushesMotor bodyGroove for crank handle
20Armature and commutator Function of armatureTo carry current crossing the field thus creating shaft toqueTo generate an electromotive forceFunction of CommutatorReverse the current in moving coil of motor’s armature and generate a steady rotating force (torque)
21Field windingThe function of the field winding create magnetic field for armaturemotor contains four field windingstwo windings are connected in series to form a set of winding.one set of winding rotate motor clockwise and other set of winding rotate motor anticlockwise direction
22Carbon brushesBrush is rectangular carbon block and spring loaded in holderBrush provides the electric connectivity between field windings and rotating commutatorthe holders should be mounted a maximum of .125" above the contact surface.Proper functioning of the holder depend upon,Inside holder dimensionsequally Holder spacingHolder angle (20 to 30 deg.)Holder heightSpring force ( PSI)Electrical connectionsCarbon brush
23Reduction gearIt is trail of gears which provides reduction ratio 20.8:1Number of teeth on driverReduction Ratio =Number of teeth on driveReduction ratio provides a torque-speed conversion from a higher speed motor to a slower but more forceful output.Motor rotate at very high speed and Load can not be directly placed on motor shaft.Appropriate reduction gear ratio is usedto get require mechanical advantage/ thrustto syncronised various functionsto change direction of rotationto get desire power as
25Friction ClutchFriction clutch is an assembly of spring loaded Gear, shaft and disks which are placed between motor and Load (point throw / transmission assembly).Functions of friction clutch areTo protect the motor from overloadTo achieve mechanical (dynamic) snubbingTo follow the sequence of point operation.
27Feature of friction clutch The friction clutch designed toextend stroke (force) from motor to load (point) if load is within Specified limit (700 Kg)de-clutch (separate) motor and Load (point) if load is more Specified limit (700 Kg).De-clutching of friction clutch can be adjusted to suite Specified limit of load (700 Kg) by loosening Or tightening spring.Friction clutch require / needs an adjustment ifslipping current /obstruction current shall not be more than 1.6 to 2 times of normal working currentdifference between normal working current and slipping current /obstruction current is less than 0.5 Amps.The friction clutch shall adjusted in workshop only (not at site).
28Parts of friction clutch Friction clutch comprises ofControl discLift out discDrive discGear rim and slip rimShoe expansion (locking plate)Helical spring
29Sequence of rotation of gear &disc How different gear and disc rotate in side friction clutchPinion of motor rotatesGear rim, then Gear rim rotatesslip rim then slip rim rotatesshoe expansion, then shoe rotateslift out disc anddrive disc, then d.disc rotatecontrol disc andshaft with pinion & lock pawl
30Control disc It is a circular disc with notch on outer periphery Notch for top rollerIt is a circular disc with notch on outer peripheryEdges of notch are verticalFunction of control disc areAllow the top roller (roller A) to fall in side respective notch at end friction clutch rotationPrevent upward movement of top roller (lock the top roller)Control disc outer viewStuds for non trail ableblockControl disc inner view
31Lift out disc It is circular disc with notch on outer periphery. It has notch on inner periphery also which engages with shoe expansion.It has two grooves which are fill with grease & fitted with two grease nipples.It is first disc to rotate in friction clutch.FunctionTo lift the top roller (roller A) to open detection contacts at beginning of point operationNotch on innerperipheryInner viewGreaseNippleOuter view
32Drive Disc Drive disc is a Thick circular disc & has Two projections on outer and inner periphery.A shaft keyed in the centerLock pawl and pinion fixed on one end of shaftLock pawl and pinion fixed at180 degree oppositeA circular offset on outer periphery on which gear rim restsTwo studs which engaged with non trailable block.A Small window to have access to friction clutch adjustment nut.
34Functions of Drive Disc Extend movement to shaft hence rotate pinion and lock pawl.Restrict rotary movement to 270° and provide subbingHold gear rim on outer peripheryConvert rotary movement in to linear movement
35Gear rim & spring loaded slip rim It is main part of friction clutch whererotary movement of motor is extended to other parts of machineOverload protection to motor achievedSnubbing is achievedThe main parts areGear rimSlip rimShoe expansion with helical spring
36GEAR RIM & SPRING LOADED SLIP RIM Shoe expansiongear rimHelical spring
37Gear Rim A circular gear having 92 teeth on it’s outer periphery It engages with pinion of the MotorIt Accommodate slip rim and spring loaded shoe expansion.When rotated by motor It transmits rotary motion to shoe expansion through slip rim
38Slip rim It is semicircular rim with grips on it’s outer surface. It’s width is less than the width of gear rimRotate freely within gear rim when not loaded by spring.When spring loaded it rotate with gear rim
39Shoe expansion (locking plate right & left) and helical spring Two rectangular steel strips hold by a clamp at one end.Other end butted against slip rim ends.Shoe expansion extends rotary movement of gear rim to lift out & drive disc.Helical spring placed between shoe expansion in compressed condition.Compressed spring compel gear rim and slip rim to act as one piece
40Sequence of rotation of gear &disc How different gear and disc rotate in side friction clutchPinion of motor rotatesGear rim, then Gear rim rotatesslip rim then slip rim rotatesshoe expansion, then shoe rotateslift out disc anddrive disc, then d.disc rotatecontrol disc andshaft with pinion & lock pawl
41How friction clutch performs? During normal course of operationDuring obstructionAt end of operation
42Friction clutch during normal course of operation Pinion operates gear rimslip rim & shoe expansion rotates along with gear rim as these are spring loaded in side gear rimthe edge of one shoe expansion engages in the notch on inner periphery of lift out disc & lift out disc rotatesthe same edge of one shoe expansion engages with projection on drive disc also & drive disc rotatesshaft rotates along with drive disc & stroke of 143mm generated
43Friction clutch during normal course of operation Gear RimProjectionon InnerperipheryOf drive diskSlip RimShoe expansion
44During obstructionThe drive disc cannot rotate, as throw bar/gear rack is stationaryHence shoe expansion engages with projection on drive disc also cannot rotate.But pinion of motor forced to rotate gear rimHence rotary force will appear on other shoe expansionThe helical spring get compressed & slip rim collapse to reduce circumference of slip rimThe gear rim alone rotates with slight friction between gear rim& slip rim.
45During obstruction Gear Rim Projection on Inner periphery s Of drive diskSlip RimShoe expansion
46Friction clutch at end of operation At end of operation projection on outer periphery buts with bottom rodObstruction is generated inside the machineFriction clutch slips & snubbing is achieved.
47Friction clutch at end of operation Drive discBottom bar
48CONTACT ASSEMBLY WITH SPRING LOADED ROLLERS Contact assembly comprises of two spring loaded contact groups which are fixed inside the casting.Function of the contact assembly: - make and break the sets of contact.One group Contains two sets of contact fixed side by sideContact controls feed (Power) to motor and point indication relay
49CONTACT ASSEMBLY WITH SPRING LOADED ROLLERS Each Contact group comprises ofEight terminals in two sets for wires terminationterminals sets fixed opposite to each other on the castingEight high tensile contact (metal strips) in two sets.Two sets of contact are fixed back to back on spring loaded bracket / crank.Two sets of roller are fixed on same spring loaded bracket / crank.Bottom roller and top rollerA transparent cover protects all sets of contact and terminalsThe transparent cover has sealing arrangement also.ControlcontactsControlcontactsBottom rollerTop Roller
50CONTACT ASSEMBLY WITH SPRING LOADED ROLLERS Terminal and finger contacts are insulated from metal part of point machine.Two Finger contacts are shorted at one endCarbon tip is fixed on other end of Finger.Outer side two sets of contact are known as Control contact and inner side two sets of contact are known as Detection contact.These contacts are self wiping, they clean themselves during the process of making and opening.
52Making of contactsMaking of contact depend upon position of top and bottom roller on the periphery of control disc and detection slid respectively.Detection contact in one group & control contact in other group makes whentop roller fall in nominated notch on friction clutchbottom roller fall in nominated notch on periphery detection slidFalling of top roller in notch proves correct locking of pointFalling of bottom roller in notch on proves correct setting of switches / points.BottomRollerInsidenotchtopRollerInsidenotchtopRolleroutsidenotch
53Detection contactsMaking of Detection contacts proves correct setting and locking of switches.Detection contacts are classified as Normal detection contact (ND) and reverse detection (RD) contact.ND contact make when point correctly set and lock in Normal.RD contact make when point correctly set and lock in Reverse.if point is not set correctly and/ or not correctly locked then both ND contact and RD contact are remain in open condition.ND contact and RD contact are used circuit of point indication relay NWKR and RWKR respectively.
54Check for Correct setting and locking of point The notches on detection slides and friction clutch can be make available for bottom and top roller by moving lock slides and detection slides.Dose it Mean that ND & RD contacts can make even though point is not lock and set?proving of correct setting and locking of point by ND & RD contact is subject to condition that length of ground connections between point slides are accurately adjusted.This is prime check to be done at site during installation & Maintenance
55Control contact Feed to motor is control through these contacts Control contact controls feed to motor in normal course of working Types of Control contactsNormal Control contact (NC)Reverse Control contact (RC).When points set and lock in Normal then RC contact makes.When points set and lock in Reverse then NC contact makes.When point is not correctly set and/ or not correctly locked position than both NC contact &RC contact are remain in make condition.NC contact controls feed for reveres to normal operation of pointRC contact controls feed for normal to reveres operation of point.NC and RC opens as soon as point correctly set and lock in required position.
56Detection slides D Type detection slid Threaded Stud Small notch Brass stripeThreaded StudSmall notchWide notchC Type Detection slid
57Detection slidesThese are two rectangular strong metal strips and two threaded rods are welded at one end.Each slid have a small and a wide notch on its one of surface.These slides are connected to switches of point and used to prove correct setting of switches.Bottom Rollers of switching unit are mounted on surface of these slides.Threaded studs welded sideways to avoid interchanging position of slidesRectangular Brass strips are riveted on inner surfaceBrass strips avoids transfer of movement to other slid which is supposed to be stationary in case of rod breakage
59Lock slidesThese are two rectangular strong metal strips and two threaded rods are welded at on end.Each slid have a small and a wide semicircular notch ,These slides are connected to switches of point and used to lock the switches.Lock segment on drive disc engages in these notchesThreaded studs welded sideways to avoid interchanging position of slidesRectangular Brass strips are riveted on inner surfaceBrass strips avoids transfer of movement to other slid supposed to be stationary in case of rod breakage
60Position of point/ Switches Position of Notches onLock slidPosition oftop RollerND For RHS mountingRDRHS mountingNC RHS mountingRC RHS mountingControl/lift out discBottom rollerLHS mountingWhen switching unit is not fixed on machineMakeOpenopenSet in normal but not lockedAvailableOn periphery of control disc & lift disc1,1a5,5a2,2a6,6aNot AvailableHanging on notch of detection slidesSet and locked in normalIn the notch of control disc & lift disc3,3a7,7aIn the notch of detection slides4 ,4a8 ,8a5 ,5aSet in reverse but not lockedSet and locked in reverse