[Technical Data] Selection of Transmission Timing Belts 2

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Edward Whitehead
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1 Selection of Transmission ming Belts 2 Selection is easy with ming Pulleys and Belts automatic calculation tool available at: [Step 2-c] For 2GT/GT Series Design Power (Pd) =Transmission Power (Pt) Overload Coefficient (Ks) [Step 2-d] For EV5GT/EV8YU Series Design Power (Pd) =Transmission Power (Pt) x Overload Factor (Ks) Calculate the Transmission Power (Pt) from the motor rated power (Originally, it is ideal to calculate from the actual load applied to the belt) Normal Motor Load Factor (Ks)=Ko+Ki+Kr+Kh Ko : Load Correction Factor (Table 8) Ki : Idler Correction Factor (Table 9) Kr : Speed Increase Correction Factor (Table ) Kh : Operation me Correction Factor (Table ) <For Servo Motor Applications> In the process of designing, apply Ko=2.5 for the rated torque and Ko=0.5 for the max. torque. * If the max. torque is generated each time the belt system is started up or stopped, choose an applicable load correction factor Ko from the Table 8., "Load Correction Factors based on Frequency of Start/Stop (Ko) operation," and apply it to the above expression. <For Spindle Motor Applications> In the process of designing, apply Ko=2.2 for the rated output and the basic rotation speed. Table 8. Load Correction Factor (Ko) of Motor Peak Output/Basic Output 50% or Less Over 50%~0% or Less Over 250% Single-Phase All s AC Motor Squirrel Cage Wound Field 2 Phase All s 4 Phase 7Kw or More 0Kw or Less 6 Phase 8 Phase All s 4 Phase 5Kw or Less 6 Phase Kw or Less 8 Phase 5.5Kw or Less Synchronous Motor Standard Torque High Torque DC Motor Shunt Wound Field Series Hydraulic Motor All s Office Machinery Printer Fax Machine Copy Machine.2.4 Home Appliance Juicer.4.6 Vacuum Cleaner.2.4 Finance Equipment Money Exchanger cket Machine cket Gates Bank Teller Machine..4.5 Food Medicine Medical Equipment Machine Tool Bakery Equipment Mixer Granulator Centrifuge Medical Machinery Measurement Equipment.2.4 Drill Press Lathe Milling Machine..5.7 Wood Lather Printing Book Making Printer Book Making Machine Cutter Textile Machine Textile Knitting Machinery..5.7 Sawing Machine Sawing Machine Home Use.2.4 Sawing Machine Industrial.6.8 Belt Conveyor Packaging Machine Film Wire Making Machine Belt Conveyor Light Objects...5 Packaging Machine Calender Extruder Wire Making Machinery Table 9. Idler Correction Factor (Ki) Idler Position Inside Outside Loose Side of the Belt Tense Side of the Belt Table. Operation me Correction Factor (Kh) Operation me Correction Factor Less than hours (Everyday) 0 ~6 Hours Continuous (Everyday) ~24 Hours Continuous (Everyday) Hours/Year or Less (Seasonal operations etc.) 0.2 Table. Load Correction Factor based on Frequency of Start/Stop (Ko) operation When the frequency of Start/Stop is less than 0 times per day Ko=.5 When the frequency of Start/Stop is 0 times or more but less than,000 times per day Ko=2.0 When the frequency of Start/Stop is more than,000 times per day Ko=2.5 Table. Speed Multiplication Correction Factor (Kr) Speed Increase Ratio Correction Factor or More Less than or More Less than or More Less than or More Less than or More Table 2. Special Motor Correction Factor (Kp) Motor Load Correction Factor Servo Motor Spindle Motor Design as Kp=2.5 for Rated Output, and Kp=0.5 for Peak Output (Rational speed as applied speed) Design as Kp=2.2 for Rated Output and Base Rotational Speed Calculate Transmission Power at Motor Rated Power Output. (It is ideal to calculate from the actual load applied to the belt.) Overload Factor (Ks)=Ko+Ki+Kr+Kh+Km Ko : Load Correction Factor (Table 4) Ki : Idler Correction Factor (Table 5) Kr : Speed Multiplication Correction Factor (Table 6) Kh : Operation me Correction Factor (Table 7) Km : Start/Stop Correction Factor (Table 8) When converting the torque (Tq) into transmission power (Pd), calculate the applicable values by using the following expressions. Torque (Tq)=tqxKs Transmitting Power (Pd)=Tqxn/9550 Table 4. Load Correction Factor (Ko) Prime Motor Induction Servo Motor (Peak Output/Rated Output) Spindle Motor Motor 0% or Less ~299% 00% or More Robot Scara Injection Mold Machine Mold Fastening Ball Screw Drive Machine Tool Lathe Drill Press Machine Tool Milling Machine Conveyor Medical Machinery Measurement Equipment Packaging Machine Agitator Mixer Liquid Viscous Material Drilling Machine Granulator Centrifuge Mills Ball Rods Printing Machine Book Making Machine Paper Making Machine Calender Dryer Textile Machine Wire Related Wire Drawing & Twisting Machine Woodworking Machine Pump Compressor Reciprocating Rotating Fan Blower Axial Flow Roots Generator Exciter Rubber Industry Machinery Lumber Mill Machinery Table 5. Idler Correction Factor (Ki) No Idler 0 Inside Idler 0. (Qty-) Outside Idler 0. (Qty-) Table 7. Operation me Correction Factor (Kh) Operation Duration (Hours/Day) Correction Factor < Tq : Design Torque (N m) tq : Transmission Torque Ks : Overload Factor Pd : Design Power (kw) n : Speed (rpm) Table 6. Speed Multiplication Correction Factor (Kr) Operation Duration (Hours/Day) Correction Factor or More Less than or More Less than or More Less than or More Less than or More 0.4 Table 8. Start/Stop Correction Factor (Km) Start/Stop Frequency (mes/day) Correction Factor 0. <0 0.2 < <

2 Selection of Transmission ming Belts Selection is easy with ming Pulleys and Belts automatic calculation tool available at: [Step ] Temporarily Selecting the of Belt from Selection Guide Table Table 9. Selection Guide Table (MXL,XL,L,H,T5,T) Table 24. Selection Guide Table (2GT GT series) 50,000 40,000 0,000,000,000 5,000,450 2,500,750,500, ,000, MXL XL T5 L T H 2GT GT Design Power(kW) Design Power (kw) Table 2. Selection Guide Table (P_M series) Design Power kw toothed 0 toothed 40 toothed 0kW 00kW 0kW.0.40 teeth 0 Applicable Pulley Tooth Number 0.40 teeth kW W 0.kW 50 70W 0.kW W W W W T 0 T 40 T Pitch Width No. of Teeth of Small Pulley (mm) (mm) P8M600 P8M400 P8M250 P8M0 P8M50 PM50 PM0 PM060 P5M250 P5M0 P5M50 P5M0 00 P2M0 P2M060 P2M040 Rotational Pulley (rpm) Table 2. Selection Guide Table 5 (UP_M series) Design Power kw UP8M UP5M Rotational Table 25. Selection Guide Table (EV5GT EV8YU series) 4,000,000,000 0 Table. Selection Guide Table 2 (S_M series) Table 22. Selection Guide Table 4 (MT) S2M 0. SM EV5GT EV8YU 0. 0,000 Design Power(kW) Design Power (kw) MT S4M Design Power (kw) [Step 4] Determining Number of Teeth of Large and Small Pulley, Belt Length, Inter-Shaft Distance () Select the number of teeth of large and small pulley from P.226~227, which can satisfy the predeterminated speed ratio. (However, select the small pulley with number of teeth more than Min. Number of Teeth on Table 26.) Number of Teeth of Large Pulley Speed Ratio= Number of Teeth of Small Pulley Table 26. Allowable min. number of teeth Rotary Small of Belt, Minimum Number of Teeth Pulley (rpm) MXL XL L H S2M SM S4M P2M PM P5M P8M UP5M UP8M MT T5 T 2GT GT EV5GT EV8YU 900 or Less Over or Less Over or Less Over or Less Over or Less Over or Less (2) Determine approx. belt circum. length (Lp') in terms of temporary inter-shaft distance (C'), diameter of large pulley (Dp) and diameter of small pulley (dp). (Calculate pulley diameter with P.D. dimensions.) π(dp+dp) (Dpdp) 2 Lp'=2C' C' C ' : Temporary Inter-shaft Distance dp : Pitch Diameter of Small Pulley (mm) Dp : Pitch Diameter of Large Pulley (mm) Lp' : Approx. Belt Circum. Length (mm) () Determine a belt circum. length (Lp') that is the nearest value to approx. belt circum. length referring to P.459~470, and then calculate the correct inter-shaft distance using the following formula. b+ b 2 8(Dpdp) 2 Dp : Pitch Diameter of Large Pulley (mm) dp : Pitch Diameter of Small Pulley (mm) Lp : Belt Circum. Length (mm) C : Inter-shaft Distance EV8YU Belt Length(mm) 600 or less 60~900 90~250 25~ or less C= 8 b=2lpπ(dp+dp) [Step 5] Determining ()Calculate an approx. belt width using the following formula, and then select a belt width (Bw':mm) that is the nearest value to the approximated value. Pd: Design Power Pd Bw'= Wp Ps: Reference Transmission Capacity Use the Reference Transmission Capacity Table on P.226~227. Ps Km Km: Engagement Correction Coefficient (Table 27) Wp: Reference (Table 28) Table 27. Engagement Correction Coefficient (Km) Table 28. Reference (Wp) No. of Teeth Engaged Zm More than Km *Km No. of Teeth Engaged (Zm)= Zd 60 =80 57.(Dpdp) C Zd: No.of Teeth of Small Pulley Dp: Pitch Diameter of Large Pulley (mm) C:Inter-shaft Distance (mm) : Contact Angle ( ) dp: Pitch Diameter of Small Pulley (mm) (2)Check if Design Power (Pd) satisfies the following formula. (If not, select the belt width of one size larger again.) VFor belt types PiM and UPiM, substitute *Km for meshing compensation factor Pd<Ps Km Kb Z2GT GT EV5GT EV8YU Pd<Ps Km Kb KL Table 29. Width Correction Coefficient (Kb) of Width Correction Coefficient of Width Correction Coefficient MXL S2M XL L H SM MT S4M Table 0. Length Correction Coefficient(KL) Pd : Design Power Ps : Reference Transmission Capacity Length Correction Coefficient(KL) GT Belt Length(mm) 0 or less ~82 8~280 28~49 4 or less GT Belt Length(mm) 90 or less 9~260 26~400 40~ or less EV5GT Belt Length(mm) 440 or less 44~550 55~800 80~0 0 or less of Belt MXL XL L H S2M SM S4M MT Reference of Belt P2M PM P5M P8M T5 T Reference Km : Engagement Correction Coefficient Kb : Width Correction Coefficient (Table 29) of Width Correction Coefficient P2M PM P5M P8M T T KL : Length Correction Coefficient (Table 0) of Width Correction Coefficient GT GT EV5GT EV8YU

3 Selection of Transmission ming Belts 4 -Transmission Capacity Table- Selection is easy with ming Pulleys and Belts automatic calculation tool available at: [Step 6] Check if Inter-Shaft Distance Adjustment Range is Larger than that in Table 0 QPrecautions on Operation. Be careful to avoid the ingress of foreign particles. When solid foreign particles enter during operation, it can scratch the belt and adversely affect the engagement of the belt and the pulley. In some cases, the pulley may disengage, land on the teeth of the pulley, and be cut. 2. Avoid Adhesion of oil. Oil on the rubber timing belt may wet and expand it, drastically shortening its service life. (a)take special care when using solvent type oil. (b)a small amount of lubricant or grease, however, rarely causes a trouble.. Do not use the belt in a humid atmosphere. 4. Please use a well-ventilated safety cover. 5. The service life of the belt, when used at a high temperature (80 C or more), can be drastically shortened. Reference Tolerance (Unit: mm) Belt Length 5 or Less 5 to to or More or Less to to Ci (Min. Adjustment Range, Inside) CS (Min. Adjustment Range, Outside) C (Inter-shaft Distance) Table Minimum Inter-Axial Distance Adjustment Range Belt Length Inter-Shaft Length Distance Tolerance Tolerance Belt Length Length Inter-Shaft Distance Tolerance Tolerance 50 or Less ± 0.40 ± MXL XL L H GT GT EV5GT EV8YU Ci Cs Ci Cs Ci Cs Ci Cs Over or Less ± 0.60 ± Over or Less ± 0.66 ± S2M SM Over or Less ± 0.40 ± 0. Over or Less ± 0.46 ± 0.2 Over or Less ± 0.50 ± 0.25 Over or Less ± 0.76 ± 0.8 Over or Less ± 0.82 ± 0.4 Over or Less ± 0.86 ± 0.4 Over or Less ± 0.92 ± 0.46 S4M MT P2M PM P5M P8M T5 T Ci Cs Ci Cs Ci Cs Ci Cs Ci Cs Ci Cs Ci Cs Ci Cs Ci Cs Ci Cs Ci Cs 50 or Less ±0.5 ± to 250 ±0.4 ± to 80 ±0.46 ± to 500 ±0.5 ± to 750 ±0.60 ± to 00 ±0.66 ± to 250 ±0.76 ± to 500 ±0.82 ± to 750 ±0.86 ± to 00 ±0.92 ± Cautions on Use of Belt QHow to Extend Belt When the belt is too taut, its service life can be shortened, while when it is not taut enough, the belt may (jump off) the groove of the pulley due to an activating torque or shock load. Keep the belt stationary and optimize its tautness. The warp load necessary to provide the optimum tautness can be calculated from values representing the belt, its width and the span in equation A below. Apply deflection load between max. value and recommended value. t Y + Lp Td= Equation A 6 A Td t B Ø Td : Load N Needed for Deflection d at the Center of Span t : Initial Tension N From Table Lp : Length of the Belt (mm) Y : Correction Coefficient From Table C : Inter-shaft Distance (mm) C (Inter-shaft Distance) t : Span Length (mm) (Dpdp) 2 t= C 2 4 Table 2. Initial Tension () and Correction Coefficient (Y) MXL XL L H S2M SM MT S4M 2GT GT EV5GT EV8YU Y Y Y mm Coefficient Y Coefficient Y Coefficient Y : Deflection (mm) =0.06t dp : Pitch Circle of the Small Pulley (mm) Coefficient Y mm Coefficient Y Coefficient Y Coefficient Y Coefficient Y Coefficient Y mm Coefficient Y Coefficient Y Coefficient Y Coefficient Y T5 T Y P2M PM P5M P8M Y Dp : Pitch Circle of the Large Pulley (mm) mm Coefficient Y Coefficient Y Coefficient Y Coefficient Y mm Coefficient Y Coefficient Y

4 Selection of Transmission ming Belts 9 -Transmission Capacity Table- Selection is easy with ming Pulleys and Belts automatic calculation tool available at: Table 49. Reference Transmission Capacity of T5 Ps - mm- Rotary No. of Teeth of Small Pulley Pitch Circle(mm) * Endurance time will be reduced in marked area. Please avoid if possible. * The above table shows values for the nominal width (mm). Multiply a value in the table by correction coefficient Kb in the table 29 for other widths. Table 50. Reference Transmission Capacity of T Ps - mm- Rotary No. of Teeth of Small Pulley Pitch Circle(mm) * Endurance time will be reduced in marked area. Please avoid if possible. * Balance the traveling speed as wind velocity of pulley in the marked range reaches more than (m/s) * The above table shows values for the nominal width (mm). Multiply a value in the table by correction coefficient Kb in the table 29 for other widths. Table 5. Reference Transmission Capacity of 2GT Ps - 4mm- Rotary No. of Teeth of Small Pulley Pitch Circle(mm) * Endurance time will be reduced in marked area. Please avoid if possible. If the belt width changes, multiply the compensation factors Kb from Table 29. Table 52. Reference Transmission Capacity of GT Ps - 6mm- Rotary No. of Teeth of Small Pulley Pitch Circle(mm) * Endurance time will be reduced in marked area. Please avoid if possible. If the belt width changes, multiply the compensation factors Kb from Table

5 Selection of Transmission ming Belts -Allowable Tension Table- Selection is easy with ming Pulleys and Belts automatic calculation tool available at: Table 6. 2GT Allowable Tension Table: Per 4.0mm of (Unit: N) Number of Small Pulley Teeth (mm) * The above table is for 4.0mm of belt width. When the desired belt has the other width, multiply the value on the above table by the relevant width correction factor Kb provided on the Table 29. Table 6. EV5GT Allowable Tension Table: Per 5.0mm of (Unit: N) Number of Small Pulley Teeth (mm) * The above table is for 5.0mm of belt width. When the desired belt has the other width, multiply the value on the above table by the relevant width correction factor Kb provided on the Table 29. Table 62. GT Allowable Tension Table: Per 6.0mm of (Unit: N) Number of Small Pulley Teeth (mm) * The above table is for 6.0mm of belt width. When the desired belt has the other width, multiply the value on the above table by the relevant width correction factor Kb provided on the Table 29. Table 64. EV8YU Allowable Tension Table: Per.0mm of (Unit: N) Number of Small Pulley Teeth (mm) * The above table is for.0mm of belt width. When the desired belt has the other width, multiply the value on the above table by the relevant width correction factor Kb provided on the Table 29.

Synchronous Belt Reference Information Synchronous Belt Replacement Signs Z Early failures and countermeasures Abnormal Phenomena Cause Measures Abnormal Wear of Belt Side Faces Tooth Contact

Pulley Teeth Pulley Circumference Wear Pulley misalignment Pulley shafts misalignments Bent pulley flanges Belt tension too high, too low Pulley tooth shape incorrect Belt tension too high Pulley

Pulley diameter too small Realign Correct shaft misalignments Correct bent pulley flanges with a wide belt or use larger belt pitch Try to recreate belt systems by taking note of tooth tip radius

6 Synchronous Belt Reference Information Synchronous Belt Replacement Signs Z Early failures and countermeasures Abnormal Phenomena Cause Measures Abnormal Wear of Belt Side Faces Tooth Contact Pressure Surface Abnormal Wear Belt abnormal wear on pulley contacting area Broken/missing tooth Severed Core Wire Cracks on Backing Rubber Heat Degradation of Rubber Rubber Swelling Abnormal Wear of Pulley Teeth Pulley Circumference Wear Pulley misalignment Pulley shafts misalignments Bent pulley flanges Belt tension too high, too low Pulley tooth shape incorrect Belt tension too high Pulley diameter too small Small pulley meshing 6 teeth or less Shock loading exists Core wire decreased elasticity or corrosion Induction of foreign matter Excessive temperature Usage in low temperature Pulley diameter too small Realign Correct shaft misalignments Correct bent pulley flanges with a wide belt or use larger belt pitch Try to recreate belt systems by taking note of tooth tip radius Increase small pulley tooth mesh or redesign Avoid shock loading on belt Increase belt width Check belt storage and shipping history/condision Avoid shocks Provide a belt cover Lower environment temperature Raise environment temp. Increase pulley diameter Rubber degradation due to high enviroment temperature Lower environment temperature Contact with oils Contact with water Belt tension too high Pulley material too soft Pulley service life has been reached Belt tension too high (core wire visible on belt back side) Avoid oil from contacting Avoid water from contacting Apply surface hardening treatment on pulley or change pulley material Replace with a new pulley Replace with new pulley and belt, and use lower belt tension Z Names of Belt Components Tooth Body Rubber Tooth p Z Examples of Belt Replacement Signs Examples Tooth Lining (Reinforcement). When belt tooth reinforcement fabric is worn and rubber/core wire are exposed When tooth surface/grooves are worn and rubber/core wire are exposed 2. When the backing rubber shows cracks due to hardening Valley of teeth Tooth Surface Condition Core Wire Abnormal Sound Belt tension too high Pulley diameter too small Pulley tooth shape incorrect Realign Correct pulley tooth geometry. When cracks reaching the rubber are seen at tooth base Apparent Belt Stretch Shaft center distance too small Loose machine base Adjust to correct shaft distance Reinforce machine base Z About Pulley Alignments Misaligned pulleys may cause early belt failure and flange damages. Align as show below 4. Belt side faces are damaged due to wear θ θ 5. When missing tooth can be seen MXL/XL/L/H/S_M/MTS_M/T Series Belt width (mm) 0 tan 5/00 /00 2/00 P_M/UP_M Belt width (mm) 0 tan 5/00 _GT/EV5GT/EV8YU Belt width (mm) 40 tan 6/00 /00 6. When excessive wear can be seen on belt back side 7. When belt or core wire are broken VThese are belt replacement timing guides. Early or periodical replacements are recommended even the signs shown above are not yet visible

[Technical Data] Selection of Transmission Timing Belts 1

[Technical Data] Selection of Transmission Timing Belts 1 Selection of Transmission ming Belts Selection is easy with ming Pulleys and Belts automatic calculation tool available at: http://fawos.misumi.jp/fa_web/pulley_sea/ [Step ] Setting the Required Design