BODIE ELECTRIC COMPAY BODIE ELECTRIC COMPAY Small Mots Geamots Motion Contols MOTOR & GEARMOTOR 1. SELECTIO 2. GUIDE. IT S AS EASY AS 3.
Ceated by the Bodine Electic Company, this Mot and Geamot Selection Guide is designed to help you specify the best mot geamot f you application. By consideing thee key design citeia, you can quickly select a dive system that allows f poductive follow-up with the mot manufactue s sales enginees, saving you consideable time and expense. The thee design citeia ae: 1. Detemine speed and tque. 2. Select the appopiate mot type. 3. Select gea educe, if needed. Enclosed is an easyto-complete wksheet that seves as the companion to this guide. When you ae eady, just fill in the blanks and etun it to Bodine Electic Company. Thee s easie way to detemine the best mot f you application. BODIE ELECTRIC COMPAY 1. Detemine speed and tque F assistance with calculations in Step 1, see DEFIITIO OF TERMS on facing page. The desied output speed of the mot geamot is usually kwn. The load tque might be measued, calculated, estimated, aived at using a combination of methods, depending on the type of mechanical system. Fou common systems ae: Diect dive Lead scew Belt dive ack & pinion Gea dive, chain & spocket, belt & pulley Identify which type of mechanical system is simila to yous and poceed to one of the following sections to detemine what tque and speed ae equied f you application. ote that many applications involve a combination of the basic mechanical systems. DIRECT DRIVE F a Diect Dive application, acceleation tque, (T ACCEL ), and fiction tque, (T FRICTIO ), must be detemined. The following equations assume that the diven load is a hollow cylinde. F a solid cylinde, 1 = 0. T ACCEL (oz-in) = [ ρl( 2 4-1 4) + JMOTOR R 2 E ] 246 9.55t a Assume that J MOTOR = 0, solve the equation, choose a mot based on you esult, and then come back and ecalculate T ACCEL using J MOTOR of the mot you selected. T FRICTIO (oz-in) can eithe be estimated measued using one of the methods descibed in Figue 1 (See inside). Afte solving f T ACCEL and T FRICTIO, select a mot geamot that meets the following citeia: HP COT = T FRICTIO 1,008,400 at a speed of T COT (oz-in) = T FRICTIO at a speed of Make sue the mot geamot has a stating tque capability equal to T ACCEL + T FRICTIO. Then poceed to Step 2 (See inside). LEAD SCREW F a Lead Scew application, acceleation tque, (T ACCEL ), fiction tque, (T FRICTIO ), beakaway tque, (T BREAKAWAY ), and gavity tque, (T GRAVITY ), must be detemined. T ACCEL may be iged unless acceleation time is citical. T ACCEL (oz-in) = [ d 2 W L&C + ρl 4 + J MOTOR R 2 E ] 60V LOAD 15239e 246 9.55d t a Assume that J MOTOR = 0, solve the equation, choose a mot based on you esult, and then come back and ecalculate T ACCEL using J MOTOR of the mot you selected. T FRICTIO can eithe be measued, using one of the methods in Figue 1 (See inside), calculated using the equation: T FRICTIO (oz-in) = dw L&Cµ 6.28e T BREAKAWAY is only a fact duing stating and can eithe be estimated measued using one of the methods in Figue 1 (See inside). T GRAVITY only needs to be consideed when the lead scew is t mounted hizontally. It is a positive numbe when the load is moved upwad, and a negative numbe when the load is moved downwad. It can be calculated using the equation: T GRAVITY (oz-in) = d W L&Csin ϕ 6.28e Afte solving f T ACCEL, T FRICTIO, T BREAKAWAY, and T GRAVITY, select a mot geamot that meets the following citeia: HP COT = (T FRICTIO + T GRAVITY )60V LOAD at a speed of 60V LOAD 1,008,400d d T COT (oz-in) = T FRICTIO + T GRAVITY at a speed of 60V LOAD d Diect Dive Make sue the mot geamot has a stating tque capability equal to T ACCEL + T FRICTIO +T BREAKAWAY + T GRAVITY. Then poceed to Step 2 (See inside). ϕ Lead Scew 2 1 V LOAD
Definition of tems BELT DRIVE RACK & PIIO F a Belt Dive Rack & Pinion application, acceleation tque, (T ACCEL ), fiction tque,(t FRICTIO ), beakaway tque,(t BREAKAWAY ), and gavity tque,(t GRAVITY ) must be detemined. T ACCEL may be iged unless acceleation time is citical. The following equations assume a belt dive system. F a ack & pinion system, substitute the wd pinion in place of olle, and ack in place of belt. Assume that J MOTOR = 0, solve the equation, choose a mot based on you esult, and then come back and ecalculate T ACCEL using J MOTOR of the mot you selected. T FRICTIO can be estimated measued using one of the methods in Figue 1 (See inside). T BREAKAWAY is only a fact duing stating and can eithe be estimated measued using one of the methods in Figue 1 (See inside). T GRAVITY only needs to be consideed when the belt is t mounted hizontally. It is a positive numbe when the load is moved upwad, and a negative numbe when the load is moved downwad. It can be calculated using the equation: Afte solving f T ACCEL, T FRICTIO, T BREAKAWAY, and T GRAVITY, select a mot geamot that meets the following citeia: T ACCEL (oz-in) = [ W LOAD 2 + nw ROLLER 2 + W BELT 2 +J MOTOR R 2 E ] V LOAD 386 772 386 t a T GRAVITY (oz-in) = W LOAD sin ϕ HP COT = (T FRICTIO +T GRAVITY )V LOAD at a speed of 9.55V LOAD 105,592 T COT (oz-in) = T FRICTIO + T GRAVITY at a speed of 9.55V LOAD Make sue the mot geamot has a stating tque capability equal to T ACCEL + T FRICTIO + T BREAKAWAY + T GRAVITY. Then poceed to Step 2 (See inside). GEAR DRIVE, CHAI & SPROCKET, BELT & PULLEY F a Gea Dive application, acceleation tque, (T ACCEL ), beakaway tque, (T BREAKAWAY ), and eflected load tque, (T REFLECTED ), must be detemined. T ACCEL may be iged unless acceleation time is citical. The same equations can be used f chain & spocket belt & pulley systems. Just eplace the wd gea with spocket pulley. T ACCEL (oz-in) =[ J LOAD + W GEAR1 1 2 The value f J LOAD depends on what is connected to the output of GEAR 1. Refe to the equations f the othe types of mechanical systems to solve f J LOAD. T FRICTIO can be estimated measued using one of the methods in Figue 1 (See inside). T BREAKAWAY is only a fact duing stating and can eithe be estimated measued using one of the methods in Figue 1 (See inside). T REFLECTED (oz-in) = T LOAD e (G) + W 2 GEAR2 2 +J MOTOR R 2 E ] 1 G eg 2 772G 2 772 9.55t a T LOAD depends on what is connected to the output gea. Refe to the equations f the othe mechanical systems to solve f T LOAD. Afte solving f T ACCEL, T BREAKAWAY, and T REFLECTED, select a mot geamot that meets the following citeia: V LOAD Belt Dive Rack & Pinion 2 1 2 Gea Dive V LOAD 1 ϕ ϕ d = lead of scew (inch/ev) E = geamot geaing efficiency (see Table 3) e = mechanism efficiency (see Table 3) G = atio of input speed to output speed J LOAD = inetia of diven load (oz-in-sec 2 ) J MOTOR = mot inetia (oz-in-sec 2 ) L = length of cylinde lead scew (inches) = angula velocity of load (RPM) n = numbe of olles ϕ = angle of scew belt fom hizontal (degees) ρ = density of cylinde lead scew (oz/in 3 ) (see Table 1) R = geamot gea atio = adius of olle, scew, gea, pulley (inches) t a = time to acceleate (seconds) T LOAD = load tque (oz-in) µ = coefficient of fiction (see Table 2) V LOAD = linea velocity of load (inch/sec) W BELT = weight of belt olle (ounces) HP COT = T REFLECTED 1 G at a speed of 1 G 1,008,400 T COT (oz-in) = T REFLECTED at a speed of 1 G Make sue the mot geamot has a stating tque capability equal to T ACCEL + T BREAKAWAY + T LOAD. Then poceed to Step 2 (See inside). 1 2 1 Belt & Pulley 2 W GEAR 1 = weight of gea 1 (ounces) W GEAR 2 = weight of gea 2 (ounces) W L&C = weight of load & caiage (ounces) The equations used in this selection guide have been deived fom fundamental motion contol fmulas. F me application-specific infmation, please contact the Bodine Electic Company. W LOAD = weight of load (ounces) W ROLLER = weight of olle (ounces)
FIGURE 1 METHODS FOR MEASURIG THE BREAKAWAY AD FRICTIO TORQUE OF A MACHIE. The Sting and Pulley Method Affix a pulley to the shaft of the machine to be diven (see Figue A). Secue one end of a cd to the oute suface of the pulley and wap the cd aound it. Tie the othe end of the cd to a sping scale. Pull on the scale until the shaft tuns. The fce, in pounds indicated on the scale, multiplied by the adius of the pulley (in inches) gives the beakaway tque in pound-inches. machine shaft Test With An AC Dive Use a tque wench sting and pulley to find the appoximate size of the test mot geamot needed. An AC mot geamot whose ated output speed is close to the desied final speed of the machine should be obtained. ext, hook up the AC dive, along with a vaiable autotansfme to the load (See Figue B). With a voltmete connected to the line, incease the voltage supplied by the autotansfme until it stats and acceleates the load up to speed (to check speed use a tachomete stoboscope). Recd the stating voltage at all possible stating locations of the device. This is poptional to the T BREAKAWAY. ext, back off slowly until the mot stalls. Read the voltage. This is poptional to the T FRICTIO. V AC mot geamot line convesion tables table 1 MATERIAL oz lb gm DESITIES in 3 in 3 cm 3 Aluminum 1.57.098 2.72 Bass 4.96.31 8.6 Coppe 5.15.322 8.91 Plastic.64.04 1.11 Steel 4.48.28 7.75 table 2 FRICTIO COEFFICIETS (SLIDIG) µ Steel on Steel.58 Steel on Steel(Geased).15 Aluminum on Steel.45 Coppe on Steel.36 Bass on Steel.44 Plastic on Steel.2 Line Beaings.001 Figue A Simple sting and pulley method of tque measuement (Tque = Fce eading on sping scale x adius of the pulley) Tque Wench Method A simple tque wench can be applied to the shaft of the machine to be diven. Tun the wench as you would an dinay pipe wench, and when the shaft begins to otate, ead the value f T BREAKAWAY (in ounce-inches pound-inches) on the tque wench gauge. Test Mot method Both AC and DC test mots geamots can be used to measue beakaway tque, (T BREAKAWAY ), and fiction tque, (T FRICTIO ). This method equies me time and instumentation, but can be well wth the expense in the long un. It is the best way to optimally match machine and dive unit, and is populaly used f all high volume OEM (iginal equipment manufactue) applications. Afte using these methods, contact the mot manufactues sales enginee f help in intepeting the data. voltmete Figue B AC mot geamot with adjustable autotansfme, and voltmete connected f load measuement. Test With A DC Dive The DC method equies that both voltage and ampeage eadings be taken fom the amatue cicuit (See Figue C). Speed of the DC mot is poptional to the voltage while T FRICTIO is poptional to the amatue ampeage. DC mot geamot ARM S V Voltmete A Ampmete DC Figue C PM DC mot geamot with voltmete and ampmete connected f load measuement. table 3 MECHAISM EFFICIECIES % Acme Scew (Bass ut) 35-65 Acme Scew (Plastic ut) 5-85 Ball-Scew 85-95 Peloaded Ball-Scew 75-85 Spu Bevel Geas 92 pe stage Timing Belt 96-98 Chain and Spocket 95-98 Wm Geas 80 -.6G (G=gea atio) F maximum accuacy, the actual test mot should be sent to the manufactue with the voltage, ampeage and speed infmation f bench ( dynamomete) testing. The minimum stating tque should also be supplied.
2. Select a mot type appopiate f the application By answeing a few key questions, you can select a suitable mot type as a sample in you application. You can then discuss the application in detail with the mot manufactue s sales enginees. Actual testing of the sample will confim you selection. 3-phase Does application equie an adjustable output speed? What type of powe supply is available? AC Does application equie an output speed >3600 RPM? Does mot un continuously will it be cycled on and off epeatedly? Will mot be poweed in continuous stall? single-phase Does application equie an adjustable output speed? Does application have constant load and an accuacy equiement that would make an open-loop system acceptable? Is powe supply AC DC? Does application equie point-to-point positioning? Does application equie contolled acceleation and deceleation, even when an ovehauling load is pesent? Does application have constant load and an accuacy equiement that would make an open-loop system acceptable? Does application equie point-to-point positioning? DC Does application equie an adjustable output speed? Does application equie contolled acceleation and deceleation, even when an ovehauling load is pesent? Does application equie an output speed >5000 RPM?
BODIE ELECTRIC COMPAY To what degee can speed vay fom load to full load? less than 1% geate than 1% SYCHROOUS POLYPHASE MOTOR WITH VARIABLE FREQUECY DRIVE O-SYCHROOUS POLYPHASE MOTOR WITH VARIABLE FREQUECY DRIVE To what degee can speed vay fom load to full load? less than 1% geate than 1% SYCHROOUS POLYPHASE MOTOR O-SYCHROOUS POLYPHASE MOTOR SERIES WOUD MOTOR continuous cycling How does stating tque equiement compae to unning tque? Is mot equied to emain stalled at a specified tque at a specified position? position tque geate than 150% To what degee can speed vay fom load to full load? less than 150% To what degee can speed vay fom load to full load? less than 1% geate than 1% geate than 1% less than 1% Do you want a low output speed (72 RPM) without a geabox? SYCHROOUS SPLIT PHASE MOTOR O-SYCHROOUS SPLIT PHASE MOTOR O-SYCHROOUS PERMAET SPLIT CAPACITOR MOTOR SYCHROOUS PERMAAT SPLIT CAPACITOR MOTOR HY-SYC MOTOR HIGH SLIP PERMAET SPLIT CAPACITOR MOTOR STEPPER MOTOR WITH AC-POWERED DRIVER mechanical ise, electical ise, maintenance needs? BRUSHLESS DC MOTOR WITH AC-POWERED 4-QUADRAT AMPLIFIER. ECODER & MOTIO COTROLLER PERMAET MAGET MOTOR WITH AC POWERED 4-QUADRAT AMPLIFIER, ECODER & MOTIO COTROLLER mechanical ise, electical ise, maintenance needs? BRUSHLESS DC MOTOR WITH AC-POWERED 4-QUADRAT AMPLIFIER PERMAET MAGET MOTOR WITH AC-POWERED 4-QUADRAT AMPLIFIER mechanical ise, electical ise, maintenance needs? BRUSHLESS DC MOTOR WITH AC-POWERED SPEED COTROL PERMAET MAGET MOTOR WITH AC-POWERED SPEED COTROL STEPPER MOTOR WITH DC-POWERED DRIVER mechanical ise, electical ise, maintenance needs? BRUSHLESS DC MOTOR WITH DC-POWERED 4-QUADRAT AMPLIFIER, ECODER & MOTIO COTROLLER PERMAET MAGET MOTOR WITH DC POWERED 4-QUADRAT AMPLIFIER, ECODER & MOTIO COTROLLER mechanical ise, electical ise, maintenance needs? BRUSHLESS DC MOTOR WITH DC-POWERED SPEED COTROL 4-QUADRAT AMPLIFIER PERMAET MAGET MOTOR WITH DC-POWERED 4-QUADRAT AMPLIFIER mechanical ise, electical ise, maintenance needs? BRUSHLESS DC MOTOR WITH DC-POWERED SPEED COTROL PERMAET MAGET MOTOR WITH DC-POWERED SPEED COTROL PERMAET MAGET MOTOR SERIES WOUD MOTOR
3. select gea educe, if needed Afte the speed and tque ae detemined in Step 1 and the mot type is selected in Step 2, the next step is to detemine if a gea educe is needed and, if so, select the best type and atio. How to select the best gea atio Some easons f using a gea educe ae speed eduction, tque multiplication, and inetia matching. The amount of speed eduction needed depends on the mot type that was selected in Step 2. Some mots can opeate at low speeds (i.e. less than 1000 RPM) without a gea educe; othes can t. If speed eduction is the only concen, then the gea atio can be calculated as: G = MOTOR LOAD Gea educes multiply the output tque of a mot. This might be desied because a small mot with a gea educe could be less expensive and smalle in oveall size than a lage mot without a gea educe. If tque multiplication is the only concen, then the gea atio can be calculated as: T LOAD G = T MOTOR e GEARS Gea educes educe the load inetia eflected to the mot by a fact of the squae of the gea atio. In high pefmance motion contol applications, it is ideal f the eflected load inetia to equal the mot inetia. If inetia matching is the only concen, then the gea atio can be calculated as: G = J LOAD J MOTOR How to select the best type of gea educe Thee ae two basic classes of gea educes with seveal diffeent types within each class. The two classes ae the ight angle and the paallel shaft gea educes. Diffeent types of ight angle gea educes include wm, bevel (staight and spial), and hypoid. Diffeent types of paallel shaft gea educes include spu (intenal and extenal), helical, planetay, and hamonic. A single gea educe package may be made up of multiple stages that combine me than one type of gea educe. Space estictions usually detemine whethe to use a ight angle a paallel shaft gea educe. Howeve, thee ae othe chaacteistics to conside. Wm geas with atios 20:1 highe ae typically self-locking. This might be desiable in applications that equie the load to stay in place afte the mot is tuned off. Unftunately, wm geas ae much less efficient than othe gea types and so equie a lage mot to get the same continuous output tque. The effect of gea efficiency on mot hsepowe can be seen in the equation: HP MOTOR = T LOAD MOTOR 1,008,400Ge F example, a 50% efficient wm gea educe would equie a mot with a hsepowe ating 1.6 times that of an 80% efficient spu gea educe with the same gea atio. Spu, helical, and bevel geas ae much me efficient, but they tend to poduce me ise than wm geas, which may may t be objectionable. High pecision positioning applications may t toleate the inheent backlash of spu, helical, wm, and bevel geas. Those applications often equie low-backlash planetay hamonic gea educes. Right Angle Paallel Shaft
The 3-step pocedue that we ve just pesented should help you to select an acceptable mot geamot f you application. If you want the optimum mot geamot, then thee ae many othe details that should be discussed with the mot manufactue s sales enginee. Some of these ae: AMBIET TEMPERATURE Mot atings ae based on a cetain ambient tempeatue, usually 40 C. Continuous duty applications with a highe ambient tempeatue may equie a mot with a highe tque ating than calculated with this selection guide. DUTY CYCLE Duty cycle influences the tempeatue ise of mots and the wea ate of geas. Intemittent duty applications might be able to use a mot with a lowe tque ating than calculated with this guide. On the othe hand, fequent stats and stops would educe the expected life of geas. This is elated to the sevice facts that many gea manufactues publish in thei catalogs. FORM FACTOR When using DC mot speed contols, the fm fact of the output DC voltage fom the contol can influence the mot size and the gea atio, if a educe is needed. Unfilteed contols esult in a highe tempeatue ise in the mot, so a lage mot might be needed than calculated with this guide, especially if the duty cycle is continuous. Unfilteed contols also have a lowe output voltage than filteed contols, so the mot speed would be slowe. Be sue to use the cect mot speed when calculating the gea atio. RADIAL & AXIAL LOADS Diffeent types and diffeent sizes of mot beaings have diffeent adial and axial loading capacities. Applications that have a high adial load, such as pinch olles and belt dives, that have a high axial load, such as lead scews, may equie a lage mot than calculated with this guide. In this case, a mot geamot is needed that is stonge in tems of physical obustness, athe than in tems of output powe. COVERSIO OF MOMET OF IERTIA A B kg-m 2 kg-cm-s 2 oz-in-s 2 lb-in-s 2 oz-in 2 lb-in 2 lb-ft 2 kg-m 2 1 10.2 141.6 8.85 5.27x10 4 3.42x10 3 23.73 kg-cm-s 2.098 1 13.88.868 5.36x10 3 3.35x10 2 2.32 oz-ins 2 7.06x10 3 7.19x10 2 1 6.25x10-2 386.09 24.13.1676 lb-in-s 2.113 1.152 16 1 6.18x10 3 386.09 2.681 oz-in 2 1.83x10-5 1.87x10-4 2.59x10-3 1.62x10-4 1.0625 4.34x10-4 lb-in 2 2.93x10-4 2.985x10-3 4.14x10-2 2.59x10-3 16 1 6.94x10-3 lb-ft 2 4.21x10-2.429 5.968.373 2304 144 1 in ft m To convet fom A to B, multiply A by enty in table. Gavity constant = g = 386 = 32.2 = 9.8 s 2 s 2 s 2 BODIE ELECTRIC COMPAY 2500 W. Badley Place Chicago, Illiis 60618 U.S.A. Phone: (312) 478-3515 Fax: (312) 478-3232 Pinted in U.S.A. F location and contact infmation of neaest Distict Repesentative Authized Distibut, phone 1-800-7BODIE P/ 074 81011A (WQ)