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  • 8/10/2019 Beltweigher Mechanical Manual

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    FH 5180 SPI

    Schenck Process India Limited

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    1 Check of Shipment upon Receipt

    Check packing for possible transport damages.

    Claim damages immediately and in written form to forwarding agent.

    Back to ContentFH 5180 E/1

    .

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    2 Suggestions for Storage

    Check to see whether the permissible limit temperatures of -25C and +55

    C may be

    exceeded.

    - If not,

    store the shipment in original packing in dry and clean room where the

    relative humidity will not exceed 75 %.

    - If so,

    remove

    Load cell,

    Speed transducer and

    Terminal box

    (see also Section 3.2.1, Completeness of Items) from packages.

    These electronic components require storage in a room where limit

    temperatures and humidity mentioned above will not be exceeded.

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    3 Installation of Mechanical Equipment

    General comments:

    The following instructions for installation, summarized into 10 rules, are essential if the belt weigheris to achieve the required weighing accuracy. Strict adherence to these rules will minimize the

    influence of external factors affecting the functioning and measuring accuracy of the unit.

    Observe the special relation :

    weigher accuracy and feed rate - number of idlers in weigher's influential zone

    requires two idlers in front of and two behind ofmeasuring station

    requires three idlers in front of and threebehind of measuring station

    According of the weigher type one or more idlers are installed on the measuring station

    Integrate the belt weigher into the conveyor belt in accordance with the 10 rules

    given below.

    1. Install Belt Weigher in a Straight Belt Section

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    Feed rate -

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    Unloaded belt must rest on all idlers of carrying idler sets, i.e.:In the weigher influential zone and On two further idler sets upstream anddownstream of influential zone.

    Catenary rollers are unsuitable.

    Here below typical locations of belt weigher are indicated, ranked:

    Back to ContentFH 5180 E/4

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    Back to Content

    FH 5180 E/5

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    2 Rise or slope of belt conveyor must only be such that the material handled does not

    exert relative movements to the conveyor belt

    Maximum possible angle of rise: 20

    o

    Note:Relative movements may occur also below 20

    o:

    - If material is fine and of uniform grain size- If belt speed is very high- Immediately after belt feeder(s)- If there are gaps in feeding

    In the case of conveyors with adjustable inclination, any changes therein will entermeasurements as an error.

    Talk to SCHENCK PROCESS for possibility of correction.

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    The entire influential zone must be away from the point(s) of feed,

    The required distance depends on:

    - Belt speed- Belt inclination- Type of material feed- Material properties

    (*) The minimum distance must correspond to the distance the belt covers in onesecond but must not be less than 2 m.

    Skirt boards must not extend into weigh length or should be attached such thatweighing accuracy is not affected.

    Back to ContentFH 5180 E/8

    3. Install belt weigher so far removed from point(s) of feed that material stream cansettle and will exert no relative movement

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    4. Observe minimum distance between belt weigher and belt pulley

    Measuring station

    Ensure that the belt is in contact with the idlers at all times.

    This is assisted by

    - light troughing

    - Flexible belt.

    Ensure high belt loads.

    V-shaped troughing has an adverse effect on accuracy . Use only for low accuracy requirements.

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    5. Idler troughing influences accuracy

    Upto 20 GOOD

    Upto 30 ADEQUATE

    Upto 45 Deep troughing has an adverseeffect on accuracy. Use only for lowaccuracy requirements

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    6. In the influential zone of the weigher full and constant belt troughing must exist

    Belt conveyors with pulleys arranged at a higher level than the carrying idlers are not suitable.

    If necessary, select a larger distance of pulley from influential zone.

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    7. Align idlers in influential zone of weigher accurately

    Idler sets with offset idlers (as viewed from above) may have an adverse effect on accuracy

    Arrange carrying idlers in influential zone elevated by 10 mm.

    Secure aligned idler sets against displacement and settling.

    Average idler out-of-round when aligning.

    Maximum permissible out-of-round is 0.2 mm. Mark position of average out-of-round on roller

    shell on both sides.

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    Ensure that the axes of weighed and limiting idler are perfectly level and aligned(as viewed from above).

    Weighed and limiting idler sets with offset spindles will result in an incorrect weigh length.

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    8 Ensure that in the weigher influential zone belt stringers are rigid and that the foundation is

    solid and safe from settling

    In the influential zone, belt stringer joints must be welded.

    Belt stringers and substructure must ensure permanent alignment of idlers (see Rule 6). Ifnecessary, reinforce belt stringers, or support additionally.

    measuring station

    Wire-rope-suspended belt conveyors are not suitable for installation of belt weighers,

    Keep vibrations from influential zone.

    Belt tracking idlers for correcting belt tracking should not be installed in the influential zone of

    the belt weigher.

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    The larger the variations in belt tension the larger the possible error in measurement.

    10 Take precautionary measures to protect belt from the effects of wind, weather, and extreme

    temperature changes

    Wind falsifies measurements.

    Direct sun radiation can cause an impermissibly high temperature to occur at load cell.

    Moisture, ice, and snow support material build-up and thus produce misalignment in influential

    zone.

    Solar radiation on one side of the belt weigher may cause twisting and possible temperature

    drifts.

    Back to ContentFH 5180 E/14

    9 Provide gravity take-up unit

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    3.1.1 Mounting of Measuring Station

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    Measuring station is suitablefor installation in belt conveyorsto DIN 22 107 with belt widths500 1400mm, withoutmodification to belt stringers.

    Installation into other types ofconveyor is possible by adaptingbelt stringers accordingly.

    Mounting of measuring station isvia two supplied cross-members

    Weight of measuring station isDetermined according to beltwidth :

    500mm = approx. 160 Kg 650mm = approx. 170 Kg 800mm = approx. 185 Kg1000mm = approx. 200 Kg1200mm = approx. 210 Kg1400mm = approx. 265 Kg

    Example of adaptation to other types of conveyor

    Add additional longitudinal beamsin influential zone and cut outexisting support frame in measuringstation area.

    Tubular framework should be stiffened by two (2) longitudinal channels of minimum section IMC 125 to

    accommodate the two cross-members.

    Back to ContentFH 5180 E/16

    Travel

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    3.1.2 Mounting of Speed Transducer

    Pick-up of belt speed takes place at the inside of lower belt strand.

    If at all possible, locate transducer directly at weighed idler set. If not, do not exceed a 5-mdistance. Holes are provided in mounting yoke of measuring station for attachment of transducer.

    Keep vibrations from return belt in transducer area. Therefore, install transducer next to a returnroller in direction of travel of lower belt strand (as shown).

    Maximum out-of-round tolerance of return roller 1 mm.

    Remove material build-ups from roller, or avoid them by using a rubber-coated roller.

    Slippage between friction wheel and belt causes errors in measurement. Therefore, keep beltinside clean by installing a suitable device.

    Back to ContentFH 5180 E/17

    200

    ROCKER

    MEASURING STATION

    ARTICULATION

    14

    55

    200-300 490

    113

    M

    IN.17

    MAX.100

    DIRECTION OF TRAVEL RETURN BELT

    MOUNTING YOKE

    65

    FRICTION WHEEL

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    3.2 Installation

    3.2.1 Completeness of items

    Mechanical scope of supply:

    Measuring station

    Two side parts

    Two receptors for user's weighed idler sets

    Two cross-members

    One set of bolts

    Load cellSpeed transducer with friction wheel

    Rocker for mounting speed transducer

    Terminal box for connection of load cell and transducer cables to evaluation system.

    .

    Back to ContentFH 5180 E/18

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    3.2.2 Preparation or Installation

    Mark envisaged location of belt weigher in accordance with criteria given in Section 3-1.1, and ensure that criteria are observed with the aid of the check list below:

    Keyword Rules according to 3.1.1

    Placement in conveyor 1 2 3 5 8 1 0

    Stability 7

    Belt Tension 9

    Idler set requirements 4 5 6(profile, out-of-round)

    If conveyor belt is already placed, tension may have to be released and for the belt to belifted from carrying idlers in the influential zone by means of suitable lifting tackle suchthat later the measuring station with its cross-members can be inserted from the side.

    Further Preparations- Provide, if required, the items described in Section 3.1.2: additional supportsand/or longitudinal beams.

    - Note Section 3.1.3 for installation of speed transducer.- Debur idler set ties at points of support.

    Back to ContentFH 5180 E/19

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    Recess measuring stations at both ends.

    To shim idler sets in the influential zone as well as for subsequent alignment and fixingof sets are required:

    Fit hoist (100 kg) above weigher location.

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    FH 5180 E/20

    min 15

    min 15

    3 5 24 limiting blocks

    12 shims

    6 packing plates 1.0mm6 packing plates 0.5mm12 packing plates 0.2mm

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    3.2.3 Installation of Measuring Station

    First install load cell: Loosen the red painted transit

    restraint angle, but bolt it back in place

    upside down (as shown in drawing) sothat it cannot be lost.

    Insert compression screw (SW 17) with counter nut (SW 24) such that theinstallation dimension of the load cell complete with boot is approximatelyreached.

    Raise weighing yoke carefully by approx 5 mm against the force of the platesprings to insert the load cell complete with boot and screw it in place withfixing screw complete with spring washer centered to compression screw.Clean carefully contact surfaces of compression screw and load button ofload cell with a soft cloth (do not grease), before letting weighing yokecarefully down.

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    FH 5180 E/21

    Weighing yokeLeaf Springs

    A B

    Fixing screw

    Compression screw

    with counter nut

    Load cell with boot

    Straight edge

    Air duct forpressure compensation

    With spring washer

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    Place a straightedge alongside one of the plate springs and adjust the

    difference in height of surface areas A to B 0.5 mm by means of thecompression screw resting on the load button.

    Then secure compression screw by its counter nut.

    NOTE: From now on, for protection of the load cell, the minus pole must be applieddirectly to the welding point during welding work on measuring station.

    Now install measuring station, at first bolted loosely outside of belt stringers.

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    FH 5180 E/22

    Cross - members

    Side parts

    Weighed idler set receptors

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    Lift measuring station onto belt stringers with correct side in direction of belt travel

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    FH 5180 E/23

    4

    5

    3 1 2 1 3

    Travel

    D C1

    DC2

    3

    H

    3

    H

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    Align measuring station at its place of installation in a rectangular way to beltstringers and weld the 4 bolt heads in place on belt stringers.

    Set straightedges on measuring positions 1 and 2.

    Level areas C to D using set nuts 4 and 5, however, without twisting the measuringstation, i.e. distance H has to be about equal at all 4 corner points.

    Then tighten bolts 1, 2, and 3 have to be screwed in place, compensating for apossibly resulting displacement in height of areas C to D within the hole play of bolts1 and 2. Then set distance H once more.

    3.2.4 Installation of Speed Transducer

    Screw transducer to rocker. The four (4) screws can be turned one after the otherinto the transducer tap holes via the enlarged recess in the friction wheel if you setrecess to an angle of 45 by turning the friction wheel accordingly.

    Note : Cable connection of transducer must not show up.

    Bolt speed transducer with its articulation at envisaged location to belt stringers ormeasuring station.

    See to it that transducer with its friction wheel is in positive contact with lower belt.

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    FH 5180 E/24

    DIRECTION OF TRAVEL RETURN BELT

    ROCKER ARM ARTICULATION

    MEASURING STATIONBELT STRINGERS

    SUPPORT ROLLER

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    3.2.5

    Cabling

    For detailed description, see INTECONT Manual FHa 116, Section "Connections",but also note the following suggestions:

    Run load cell and speed transducer cables to cable junction boxsupplied and installed at a protected place.NOTE: Watch cable lengths:

    Load cell 5 mTransducer 6 m

    Do not shorten cables. If necessary, arrange in a loop.

    Connect white wire of speed transducer cable for 1270 pulses perrevolution in terminal box.

    Core Colours RD RED WH WHITE BL BLUE BK - BLACK

    Attach cables by means of clamps to stationary structural parts immediately ahead ofand after connections. In between, attach cables with clamps, or place in a conduit ifrequired.

    Ensure that cable connection of speed transducer will not affect positive contactbetween friction wheel and lower belt.

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    FH 5180 E/25

    Interconnecting Cable 6M Long

    BK

    BL

    WH

    RD

    1270 Pulses/Rev

    + Supply

    OV

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    3.2.6 Installation of Carrying Idler Sets

    Arrange carrying idlers in influential weigher zone at a level higher by 3 to5 mm above remaining idlers.

    For this purpose, place prepared carrying idler sets (troughing profile, out-of-round tolerance) via prefabricated shims on belt stringers.

    Place weighed idler set on height-adjustable receptor plates of measuringstation, and protect from tilting.

    Align all idler sets in influential zone in accordance with criteria mentionedbelow and include in alignment the carrying idlers next to the influentialzone but not elevated.

    - Correct angle to belt stringers.- Alignment of idler sets relative to one another- Maintenance of twice the idler spacing between the carrying idlersets next to the measuring station.- PARTICULARLY IMPORTANT: Parallelity of the two carrying idler

    sets next to the measuring idler set.

    Bolt idler sets temporarily to belt stringers.

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    FH 5180 E/26

    Weigher influential zone

    Weigher idlersCarrying idlers Carrying idlers

    3 - 5mm

    3 - 5mm

    L L L

    L

    3 x L 5mm

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    3.3 Alignment and Ascertainment of Effective Platform Length

    Align the weighed and carrying idler sets arranged in the influential zoneraised by 3 to 5 mm to a tolerance of max. 0.2 mm.

    - For this purpose, remove all idlers from the carrying idler sets 1 & 2 and fromthe weighed idler set.

    - String six (6) (*) steel wires, 0.5mm thick. (See figure on the next page.)- Set the measuring station with nuts 4 and 5 to distance measure = H + X withthe aid of which the weighed idler sets are coarsely aligned to the carrying idlersets no. 3.

    - Remove all idlers from weighed idler sets.- Place first idler into one of the carrying idler sets 2, and align this idler as

    described below. Align each single idler this way, completing the sequence ofwork with the weighed idler set.

    Align each idler side with averaged out-of-round tolerance (marked point onidler shell turned towards steel wires) :

    - Refile the idler spindle seat at the respective end of the idler to lower theidler on the particular side.

    - Raise the idler end, for instance, by deposit welding followed by filing to raisethe idler on the particular side.

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    FH 5180 E/27

    1 1

    x x

    L L L

    3 x L 5 mm

    H H

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    (*) Note: Flat belt conveyors can be aligned with two (2) steel wires only.

    In parallel to alignment, ensure that:- The two carrying idler sets next to the weighed idler are parallel.- All carrying idler sets in the influential zone fit square to belt stringers.- Idler spacing = 3 x L 5mm.

    Fix carrying idler sets on belt stringers by welding on the limiting blocks andshims.

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    FH 5180 E/28

    Weld on limiting blocksand shims.

    L L L

    2 x L

    3 x L 5 mm

    3/5

    0.2

    influential zone comprising three (3)approach and three (3) retreat idler sets.

    Alignment tolerancemax 0.2 mm

    Out-of-round tolerancemax. 0.2 mm

    40 kgFix wire here Fix wire here

    Steel wire 0.5

    Mark position of averaged out-of-round tolerance on idler shell

    Positions of six (6)strung steel wires

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    Fix measuring idler set by welding to the receptor plates of the measuringstation (weighed idler set).

    Check idler alignment once more ensuring fixed seat of all bolted

    connections, and then remove steel wires.

    To complete installation, determine effective platform length (Ing):- Measure idler spindle spacing on both sides of the conveyor andcalculate as average value

    a =2

    21 aSideaSidespacingSpindle +=

    b =2

    21 bSidebSidespacingSpindle +=

    c =2

    21 cSidecSidespacingSpindle +=

    Effective platform lng :

    lng = LLLL=++

    cba

    2Enter this value into the measuring system with the

    units stated in the electrical manual.

    .

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    FH 5180 E/29

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    4 Operating Hints

    4.1 Measuring Station

    NOTE: During welding work on the measuring station, apply the minus pole direct tothe point of welding for protection of the load cell.

    4.1.1 Construction and Principle of Operation

    The measuring station is constructed on the principle of leaf spring parallel guides.

    At three points, a rigid carrying frame is bolted to the two cross-members provided byuser. The carrying frame is designed to receive load cell and leaf spring parallelguides staying the weighing yoke. Mounted on the load cell, the weighing yokecarries the two weighed idler sets.

    The Load cell, Series RT / Series S make SPIL is hermetically sealed andmaintenance free.For the exact type designation, see load cell type plate. For essential data, seebelow :Rated capacity : In accordance with type plate.Maximum load : Max. load at rated capacity of

    1.5 t = 0.15 - 0.22 t2.0 t = 0.33 t2.5 t = 0.47 - 0.68 t

    Protection mode : IP 67Nominal temperature : - 10 to + 40CService temperature : - 30 to + 80CCable:

    Length : 5 mService temperature : - 30 to + 150C

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    FH 5180 E/30

    Belt Stringers

    Cross MembersWeighing Yoke

    Load Cell

    Carrying Frame

    Weighed Idler Receptors

    Weighed Idler Sets

    Travel

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    4.1.2 Maintenance

    If there are any doubts as to the accuracy of the weighing results, by all means firstcheck the alignment of the idler sets :

    Lift conveyor belt in weigher influential zone.

    String six (6) steel wires (0.5 mm thick) over the clean idlers.

    Align each idler in accordance with Section 3.3 "Alignment", and

    Replace idlers with an out-of-round tolerance exceeding 0.2 mm.

    Keep air duct for pressure compensation of load cell open. Suck off dust deposits.

    (Compressed air could damage load cell by its pressure burden.)

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    FH 5180 E/31

    L L L

    2 x L3 x L 5 mm

    3/5

    0.2

    influential zone comprising three (3)approach and three (3) retreat idler sets.

    Alignment tolerancemax 0.2 mm

    Out-of-round tolerancemax. 0.2 mm

    40 kgFix wire here Fix wire here

    Steel wire 0.5

    Mark position of averaged out-of-round tolerance on idler shell

    Positions of six (6)strung steel wires

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    In the weigher influential zone, keep weigher free of material build-ups.

    Ensure full troughing of unloaded conveyor belt on carrying idlers:- In the weigher influential zone and

    - at another two idler sets upstream and downstream of the influential zone.

    Ensure correct tracking of the belt, and avoid off-middle loading, leading to belt drift

    and incorrect weighing results.

    Back to Content

    FH 5180 E/32

    Load button

    Load cell

    Air duct for pressurecompensation

    Weigher influential zone

    Weigher idlersCarrying idlers Carrying idlers

    3 - 5mm

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    4-1-3 Inspection and Repair

    First, proceed in accordance with Section 4.1.2 "Maintenance".However, if you have to replace the load cell

    Pinch off load cell cable and disconnect from fixing points. Lift weighing yoke by approx. 5 mm and prop up. Unscrew fixing screw from load cell boot, and remove load cell from

    measuring station from below. Handle new load cell in accordance with instructions packed with

    load cell. If in doubt, also replace compression screw before installing new load

    cell.

    NOTE! For exchange of compression screw, the following is required in any

    case:- Set the height of the weighing yoke in accordance with

    Section 3.2.3 "Installation of Measuring Station"

    and

    - Align the weighed idler sets in accordance with Section3.3 "Alignment".

    Back to ContentFH 5180 E/33

    Leaf Springs

    A B

    Fixing screw

    Compression screwwith counter nut

    Load cell with boot

    Straight edge

    Air duct for pressure compensation

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    Do not grease load button, as greasing as indicated in brochureconcerning load cell applies exclusively for sealed load applicationdevices, but clean compression surfaces using a soft cloth.

    Push load cell, complete with boot attached, fully in place such thatthe air duct for pressure compensation is turned by 90 as comparedto representation, and screw in place after careful centring to loadbutton.

    Carefully let weighing yoke down.

    If necessary, align weighed idler set with carrying idler sets ininfluential zone as described in Section 3.3 "Alignment".

    Lay and connect load cell cable.

    If you have to replace leaf springs :

    Always replace all four (4) leaf springs.

    Take care for metallically clean and burfree connecting surfaces onparts to be bolted together.

    Align weighing yoke before tightening all screws in steps:- centrically to load cell load button,- vertically to load cell load button, and

    - with axis parallel to measuring station carrying frame or crossmembers.

    Align weighed idler with remaining idler sets in influential zone asdescribed in Section 3.3 "Alignment".

    4.2 Speed Transducer

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    FH 5180 E/34

    FRICTION WHEEL

    ROCKER ARMPROXIMITY SWITCH

    ROCKER ARM

    ARTICULATION

    BELT STRINGER

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    4.2.1 Construction and principle of operationThe speed transducer is fixed to the weighed idler set or a neighbouring structure bymeans of a retainer.A friction wheel, rolling off the inside of the lower belt, drives the speed transducer.

    The speed transducer outputs pulses proportional to belt speed which, as speedsignal multiplied by the load cell signal, result in the belt weigher flow rate.

    Technical data of speed transducer:Type : JGA - 20Supply : S.P.I.L.Output : 20 Pulse / Rev. of Friction WheelDiagram of Friction Wheel : 200 mmProtection Class : IP 65 (for Proximity Switch)Service temperature : - 25 to +100C

    4.2.2 Maintenance The speed transducer itself is maintenance-free, its bearings are

    lubricated for life. Ensure good mobility of rocker arm articulation. Replace rubber running ring of friction wheel as soon as wear is

    recognized. Ensure good friction connection to lower belt.

    4.2.3 Inspection and Repair

    Repair of the speed transducer is not possible. Replace the device if defective:

    Unscrew the four (4) screws fixing the transducer to the rocker arm byturning the friction wheel until the respective screw can be accessedthrough the enlarged recess within a 45 angle.

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    FH 5180 E/35

    Bearing Cover

    Washer

    Split Pin

    Circlips

    Screws

    Extractor

    Transmission to third parties and reproduction of this documentation are not permitted;Schenck Process reserves all rights of ownership and copyrights.

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    Pull friction wheel from spindle by means of an extractor

    Place friction wheel on spindle of new transducer, also by means of adevice.

    If necessary, first check spindle fitting.

    NOTE: It must be possible to pushing friction wheel almost by hand.- Never clamp transducer in a vise, and- Never force on friction wheel by means of a hammer.

    Carefully secure friction wheelwith end plate and countersunk screw.

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    FH 5180 E/36

    Bearing Cover

    Washer

    Split Pin

    Circlips

    Screws