Pin-guided Clutch With S-Type Three Flyweights

S-TypePin-guided clutch withthree fly weightsConstruction and mode of operation25343112564c d e HubFlyweightsCylindrical pinf g h Low noise level by guided pinsPerformance factor of 1.5Compact design18Tension springLiningClutch drum / Cover disc

S-TypePerformance data and dimensionsd max. [mm]M at nE 750 andnB 1500 [Nm]recommendedmotor power[kW] 3M at nE 1250 andnB 2500 [Nm]recommendedmotor power[kW] 3M at nE 1500 andnB 3000 [Nm]recommendedmotor power[kW] 3highB [mm] 1normalD [mm]lowType Numberstandard borediameterd [mm] (inch) 2Standard rotational speedS0480252415 (3/4; 7/8)4.30.3121.617.52.8S0590253014; 30 (3/4; 1)7.50.62122.8314.9S06100252420; 24; 28 (3/4; 7/8)110.8304.0437.0S07110253028; 30 (1)151.2456.06410.0øDS08125254020; 30 (1; 1/2)302.48511.012420.0ødS09138253017; 30 (1; 1 1/8)403.011215.016025.0S10150354038; (1 1/8)786.021628.031049.0d max. M nE nB max. bore dia.torqueengagement speedoperating speed1)2)3)BThe transmitted power increases as the width B is increased.Tapered bores and special dimensions can be manufactured on request.Motor power is calculated using a safety factor of 2.Final selection of the clutch should be accomplished by SUCO!d bore dia.D inside dia. of drumB flyweight width19

P-TypePerformance data and dimensionsøDStandard rotational speedD [mm]B [mm]1M at nE 750 andnB 1500 [Nm]recommendedmotor power[kW] 2M at nE 1500 andnB 3000 [Nm]recommendedmotor power[kW] 2highType NumberlowP11187301751346060P12193301801450070Other sizes are available on request.MnEnB torqueengagement speedoperating speed1)2)F08Quantity(depending on model drivenside)K, G, E, A, S: Number ofrows of flyweightsR: Number of groovesD inside dia. of drumB flyweight widthThe transmitted power increases as the width B is increased.Motor power is calculated using a safety factor of 2.Final selection of the clutch should be accomplished by SUCO!Key to model codesType designation:F – TypeS – TypeW – TypeP – TypeBSize:See table"Performance dataand dimensions" onpages 17, 19, 21, 23E1Models driven side:K – CoreG – Core with drumE – Unit version with bearingR – Belt pulley versionA – Axial output with flexiblecouplingS – Customer special1 –Bore, Input Side,1 – Cylindrical hole2 – Tapered hole (core side)3 – Tapered hole (bearing side)4 – Gear teeth5 – Thread6 – Flange9 – Special formXXXXConsecutive number23

General technical information oncentrifugal clutches and brakesHow do centrifugal clutches orbrakes work?Centrifugal clutches and brakes use centrifugal forces to transmit power (clutch) orto limit speed (brake).As the brakes are based on a physicalprinciple, centrifugal clutches or brakesdo not require any additional externalpower supply, which makes them aperfect solution for safety applications.Centrifugal clutches and brakes consistof a driving shaft c. Around the drivingshaft, there are flyweights d mounted,which are kept on the shaft by springse. On the outer side of the flyweightsthere are friction pads f.101. When the driving shaft starts turning, theflyweights and the friction pads are kept together by the retaining forces of the springs.2. At a predefined speed (engagementspeed), the centrifugal forces overcomethe retaining forces of the springs and thefriction pads do contact the outer drum g.3. The friction pads begin to transmitpower to the drum, but will show a slipping effect until the speed is furtherincreased to the operating speed, whichmeans a non-slip torque transmission.Based on long experience and knowhow, SUCO designs the clutches witha safety factor, which guarantees thatthe transmissible torque at the operating speed is higher than necessary. Thisensures a slip free application and thus,reduces wear and service requirements.Differences between a centrifugalclutch and a centrifugal brake:The main difference between a centrifugal clutch and a centrifugal brake is in thedrum:At a centrifugal clutch the drum is notfixed and will begin to turn when theengagement speed / operating speed isreached.At a centrifugal brake the outer drum isfix and cannot turn. This causes a brakingforce when the friction pads touch thedrum.When designing and operating centrifugal brakes, there must be a specialfocus on braking time and maximum heat.Please refer to page 13 for further information.

cdefg Driving shaft FlyweightsTension spring Friction pads Outer drum31524Construction of a centrifugal clutch /brakeTypical applications for centrifugalclutches:Centrifugal clutches are mainly used as astart up clutch. A centrifugal clutch allowsthe usage of a smaller motor, becausethe motor can start loadfree until it hasreached its optimum operating speed, atwhich the load is smoothly added by thecentrifugal clutch.Typical applications for centrifugalbrakes:What are the key criteria whenselecting and designing acentrifugal clutch / brake:Performance data:tThe power which needs to betransmitted (kW)tttEngagement speed [rpm]The main application for centrifugal brakesis limiting the speed of e.g.tt tdescending weight or personssafety- and fire doors –industrial applicationswto a safe level.Operating speed [rpm]The max. allowable sizeBy knowing the max. size and power,the most suitable clutch model canbe chosen, as all models do have adifferent performance factorDesign and dimensions:Input design:t Shaft diameterOutput design:There are different output designspossible. So we need to know if you useOnly core versionFlex couplingBelt Pulley designBall bearings or nott ttt Please refer to pages 14-15 for furtherinformation.Additional required information forcentrifugal brakes:ttLoad in kgMax. braking time and braking frequency11

Calculating the torque:CriteriaF-TypeW-TypeP-TypeS-TypeGeneral technical information oncentrifugal clutches and brakesM torque [Nm]Page6812142.51.01.75 1.251.5n speed of rotation [rpm]P power [kW or hp]Compact designNoisefree operationPM 9550 · –n [kW]Easy replaceable partsPM 7121 · –n [hp]Performance factorSelection matrix of SUCO centrifugal clutchesPerformance factorEngagement speed:The performance factor is a measureto compare the power transmission ofclutches. The W-Type clutch has a performance factor of 1.0. The F-type at thesame size and the same flyweight masscan transmit 2.5x more torque.The engagement speed of centrifugalclutches indicates the speed at whichthe centrifugal forces overcome theretaining forces of the spring and thefriction pads touch the outer drum.From the first engagement until theoperating speed the friction pads willslip, what will cause wear of the pads.To minimise wear of the friction pads,the target is to pass quickly through theengagement speed band to the operating speed.Operating speed:ClutchMotorExample of engagement behaviourClutch not engagedClutch slippingAt the operating speed the friction padsare in full contact with the drum andtransfer the torque without slipping.Clutch engagedTorque transmissionVariances in the motor speed must beconsidered when determining the operating speed. Therefore SUCO uses asafety factor which ensures a non-slipping application.1008060All SUCO clutches are dry-operated.20Speed of rotation [rpm]nE engagement speed, nB operating 09000800Torque [Nm]40

Centrifugal brakes:Standard centrifugal brakes are usedto limit speed – they cannot bring asystem to standstill. The basic principleis to keep a balance between the load ofthe driving side and the braking torque.During the operation there is a constantfriction which generates heat.The amount of generated heat dependson various factors:t Transmitted braking torquet Brake speedt Duration of the braking operationt Size of the friction surfacet The mass of the brake drum that hasto be heatedOver the braking time the temperaturecurve rises very steeply at the start andthen gradually approaches a maximum.The temperature at the friction surface(T 2) is substantially higher than the temperature (T1) at the outer surface of thebrake drum.Nevertheless, the brake drum can becomevery hot during operation and is a sourceof danger. The authority responsible foroperation of the machine is solely responsible for ensuring that suitable protectivemeasures are taken.The maximum temperature must notexceed the manufacturer's maximumpermitted temperature for the frictionmaterial, otherwise the linings maybe damaged. This can lead to a loss ofeffectiveness of the brake and, in the worstcase, to destruction of the brake.To prevent this, detailed data about theapplication is required when designingcentrifugal brakes:tt ttttOperating speed of the system tobe brakedEngagement speed of thecentrifugal brakeBraking torque required at thebraking speedChanges in the braking torqueBraking times and frequencyField of applicationCentrifugal brakes are speed limitingdevices and are finding increased use inlowering equipment. In such cases, thespeed of lowering corresponds to thebalanced condition between the speedgoverned by load torque and the speedgoverned by braking torque.Friction produces heatCentrifugal brakes convert mechanicalenergy into heat, which is generatedbetween the linings and the brake drum,and mostly heats up the latter.The temperature distribution illustratedabove on a sectioned brake drum clearlyshows the higher heating of the drum inthe region over the flyweights.13

Dif ferent solutions,driven-sideTo accommodate the variety of transmission requirements, SUCO offers a wide and flexible productrange. Both axial and radial drives can be supplied.All centrifugal brakes and clutches must only be used in conjunction with a suitable drumor belt pulley. The operation of a clutch or brake without a suitable drum or belt pulley isforbidden. Non-compliance can result in injury to persons.Model KCore version -KThis version without a drum is supplied whena clutch or brake drum already exists in thecustomer's set up, or a suitable component forthis purpose is available on the output side.The drum must be accurately centredand securely mounted.For higher torque transmission a clutchcan be equipped with several rows offlyweights.The shaft diameter can be varied andtapered mountings are possible.Figure 1Figure 2Model GCore version with drum -GThis version can be used to connect two shaftends.The installation must have the lowestpossible misalignment in both radial andangular directions.Excessive misalignment can result inrapid wear of the linings orcomplete failure of the clutch.14Figure 3

Model EUnit version -EWhere it is not practical to align both shaftends or one shaft end and the drum, a bearingcan be used between hub and drum.As shown in Figure 4, the output drive can bedirected through a tolerance ring on to whicha belt pulley, a timing-belt pulley, or a mounting flange can be pressed.Figure 5 shows a go kart clutch with a driveflange for a chain sprocket.Figure 4Figure 5Model AUnit version with flexible coupling -AThe easiest way of compensating radial andangular misalignments between two shafts isto use a flexible shaft coupling.The flexible coupling can be installed andlocated either radially or axially.Figure 6Model RBelt-pulley version -RWhere torque is transmitted through a V-Belt,the belt groove(s) can be machined in thedrum. Single, duplex or multiple groove pulleyscan be produced in this way.Depending on the clutch size, effective pulleydiameters from ca. 80 to 270 mm can be incorporated.Figure 7Figure 8Figure 9Figure 10Common groove forms are: SPA, SPB, SPZ,and Poly-V according to DIN/EN.Figure 7 to 10 show different belt-driveclutch versions.The clutch shown in Figure 9 with a split pulley allows elimination of a tensioning pulley. The V-Belt is tensioned by changing thespacer shims between the two pulley halves.15

How do centrifugal clutches or brakes work? Centrifugal clutches and brakes use centri-fugal forces to transmit power (clutch) or to limit speed (brake). As the brakes are based on a physical principle, centrifugal clutches or brakes do not require any additional external power supply, which makes them a perfect solution for safety applications .