LIGHT POWER & PRECISION DRIVE DESIGN MANUAL Table of Contents NOTE: Click on the desired item or page number to jump directly to that page. Introduction to Gates Products ........................................................................................................................................................ 1 - 7 Drive Comparison Graphs ....................................................................................................................................................................... 8 Synchronous Drive Comparisons ....................................................................................................................................................9 - 11 PowerGrip® GT®3, HTD®, and Timing Belt Drive Selection Procedure - Single Sided ....................................................................... 12 PowerGrip® GT®3 Belt Drives - Single Sided .................................................................................................................................13 - 21 Belt Lengths and Widths ..........................................................................................................................................................15 - 16 Pitch Selection Guide ...................................................................................................................................................................... 17 Belt Width Selection / Torque and Power Ratings .....................................................................................................................18 - 21 PowerGrip® GT®2 Belt Drives - Twin Power ................................................................................................................................. 22 - 28 Belt Lengths and Widths ................................................................................................................................................................. 23 Drive Selection Procedure ............................................................................................................................................................... 24 Pitch Selection Guide ...................................................................................................................................................................... 25 Belt Width Selection / Torque and Power Ratings .................................................................................................................... 26 - 28 5M PowerGrip® GT®2 Sprocket Information ................................................................................................................................. 29 - 37 PowerGrip® HTD® Belt Drives ........................................................................................................................................................ 38 - 49 Belt Lengths and Widths - Single Sided .................................................................................................................................. 39 - 40 Pitch Selection Guide ...................................................................................................................................................................... 41 Belt Width Selection / Torque Ratings - Single Sided & Twin Power ........................................................................................ 42 - 43 Twin Power Belt Drives ....................................................................................................................................................................44 Belt Lengths and Widths - Twin Power ............................................................................................................................................45 Sprocket Information ............................................................................................................................................................... 46 - 49 PowerGrip® Timing Belt Drives ..................................................................................................................................................... 50 - 58 Belt Lengths and Widths - Single Sided .................................................................................................................................. 51 - 52 Pitch Selection Guide ......................................................................................................................................................................53 Belt Width Selection / Torque Ratings - Single Sided & Twin Power ................................................................................................54 Twin Power Belt Drives .................................................................................................................................................................... 55 Belt Lengths and Widths - Twin Power ............................................................................................................................................56 Pulley Information .................................................................................................................................................................... 57 - 58 PowerGrip® Long Length Belting .......................................................................................................................................................... 59 Synchronous Belt Drive Engineering ............................................................................................................................................ 60 - 79 Belt Tensioning ........................................................................................................................................................................ 64 - 66 Synchronous Belt Specifications ..................................................................................................................................................... 72 Synchronous Sprocket Specifications ...................................................................................................................................... 73 - 79 Polyflex® JB® Belt Drives ............................................................................................................................................................... 80 - 82 Micro-V® Belt Drives ...................................................................................................................................................................... 83 - 84 Polyflex® and Micro-V® Drive Selection Procedures ................................................................................................................... 85 - 90 Polyflex® JB® Power Ratings ................................................................................................................................................... 88 - 89 Micro-V® Power Ratings ..................................................................................................................................................................90 Polyflex® and Micro-V® Belt Drive Engineering ......................................................................................................................... 91 - 102 Belt Tensioning ........................................................................................................................................................................ 93 - 94 Polyflex® Sheave Groove Specifications ........................................................................................................................................... 98 Micro-V® Pulley Groove Specifications .............................................................................................................................................99 Belt Pull and Bearing Loads .................................................................................................................................................100 - 101 Belt Storage and Handling ............................................................................................................................................................. 102 Useful Formulas and Calculations .............................................................................................................................................103 - 108 ® www.gates.com/drivedesign ® Introduction Gates belt drive systems offer more Gates continually makes strides in specialized research, product development, testing and Continuous engineering support is available advantages at lower cost than other overnight availability of products. The team of your for complex drive layouts including hardware design engineers and Gates application engineers design and specifications. methods of motion transfer or assures an efficient, low-cost and quality drive system. power transmission. MADE-TO-ORDER METALS (800) 709-6001 Total quality support The popularity of Gates drive systems Gates offers professional support from conceptual CUSTOMER SERVICE can be attributed to our commitment design to delivery of the finished product. We make (877) 782-3587 sure you… to customer satisfaction and quality. • u se the best product for the application PRODUCT APPLICATION ENGINEERING • m inimize drive package size and cost (303) 744-5800 • minimize testing time using our experience (303) 744-4600 fax ® ® Introduction – PowerGrip GT 3 Belt Drives PowerGrip® GT®3 Belts are an HTD was developed for high torque drive advanced design of Gates HTD® applications, but is not acceptable for most system and feature: precision indexing or registration applications. The HTD design requires substantial belt tooth to • a modified curvilinear belt tooth profile with sprocket groove clearance (backlash) to perform. mating sprocket groove. As smaller diameter sprockets are used, the • r egistration and indexing accuracy equivalent to clearance required to operate properly is increased. the conventional PowerGrip Timing Belt System. HTD drive clearance, using small diameter PowerGrip® GT® 3 Belt • a higher load-carrying capacity and longer belt sprockets, is approximately four times greater than Tooth/Groove Contact life than either PowerGrip HTD or Timing belts. an equivalent timing belt drive. It’s difficult to make a true quantitative comparison between the backlash of a trapezoidal tooth The PowerGrip® GT®3 deep tooth profile drive and PowerGrip® GT®3 tooth drive due to provides… the difference in “sprocket to belt tooth” fit. (See • i ncreased contact area and improves resistance illustrations at left). Trapezoidal belts contact the to ratcheting. sprocket in the root radius — upper flank area only, while the PowerGrip® GT®3 system permits • e asy, clean entering and exiting the sprocket full flank contact. grooves…resulting in reduced vibration. • p arallel contact with the groove and eliminates PowerGrip® HTD® Belt stress concentrations and tooth deformation The main stress line in a trapezoidal tooth timing Tooth/Groove Contact under load. belt is at the tooth base. During operation stress greatly reduces belt life. The PowerGrip® GT®3 • i mproved registration characteristics and system overcomes this with complete tooth flank maintains high torque carrying capability. contact…which eliminates the tooth stress line area. This greatly increases belt life and prevents tooth distortion caused by drive torque. In addition, the conventional timing belt has a chordal effect as it wraps small sprockets. This is significantly reduced in the PowerGrip® GT®3 system due to full tooth support along the sprocket. Full support PowerGrip® Timing Belt improves meshing, reduces vibration and minimizes Tooth/Groove Contact tooth deformation. On drives using a low installation tension, small pulleys, and light loads, the backlash of the PowerGrip® GT®3 system will be slightly better than the trapezoidal timing belt system. However, with increased tension and/or loads and/or sprocket sizes, the performance of the PowerGrip® GT®3 system becomes significantly better than the trapezoidal timing belt system. 2 ® www.gates.comd/ rivedesign ® ® ® Introduction – PowerGrip GT 3 Belt Drives This PowerGrip® GT®3 synchronous belt When precision is critical, depend on fits in tight, hard to fit applications with PowerGrip®GT®3 belts room to spare. PowerGrip® GT®3 belts are designed for precision 2MGT applications. Custom-built constructions are Lasts longer than competitive belts available for applications requiring maximum 3MGT performance. Worldwide manufacturing PowerGrip® GT®3 belts outlast the competition in capabilities assure you of prompt service for these ways: important markets. 5MGT • D eep tooth profile provides superior load- PowerGrip® GT® 3 belts are available in 2mm, carrying strength and reduces ratcheting 3mm and 5mm pitches. Larger 8mm and 14mm when using Gates sprockets. pitch belts are also available. See Catalog 17195 - PowerGrip® GT®3 Belt • A durable nylon fabric tooth covering PowerGrip® GT® 3 Belt Drive Design Manual. Profiles/Pitches increases tooth strength and provides wear and abrasion resistance. Here are some of the many PowerGrip® • F iberglass tensile cords wrapped in a durable GT®3 belt applications: neoprene body provide flexibility and increase • data storage equipment service life. • machine tools • hand power tools Precision registration PowerGrip® GT®3 belts provide timing and • postage handling equipment synchronization accuracy for flawless registration, • DC stepper/servo applications with no loss of torque carrying capability. • food processors • centrifuges Increases load-carrying capacity • printers Load capacities exceed HTD and trapezoidal • floor care equipment belt capabilities…making PowerGrip® GT®3 the • money handling equipment choice for accurate registration, heavy loads and small sprockets. Smaller and tougher than HTD • medical diagnostic equipment or trapezoidal belts, PowerGrip® GT®3 belts give • sewing machines engineers more space-saving flexibility for micro-technology. • automated teller machines • ticket dispensers Sounds this quiet … • ploters PowerGrip® GT®3 belt’s specially engineered teeth • copiers reduce noise and vibration. Clean meshing and • robotics equipment reduced belt width results in noise reduction when • vending equipment compared to PowerGrip Timing and HTD belts. • v acuum cleaners • office equipment PowerGrip® GT®3 Belt Drives Pages 13-35 ® www.gates.comd/ rivedesign 3 ® ® ® Introduction – PowerGrip HTD Belt Drives Good torque carrying capability and Some PowerGrip HTD Belt design versatility Applications are: PowerGrip HTD drives provide advantages over • f loor polishers conventional gear and chain type drives… 3mm • v acuum cleaners • run quiet • s ewing machines • do not need lubricating • require virtually zero maintenance • s anders • high reliability and low operating costs • o ffice equipment 5mm Gates 3mm and 5mm pitch HTD belts are capable • p laners of operating at both low and high speeds while • c entrifuges carrying heavy loads. They can provide higher speed ratios than comparable XL and L pitch timing • d iagnostic equipment PowerGrip® HTD® Belt Profiles/Pitches belts in the same space. Compared to conventional • p ower tools timing belts, they transmit the same power in a • v ending machines more compact drive package. • j uicers HTD belts have the same characteristics as larger 8mm and 14mm pitch belts, but are designed for smaller horsepower and higher speed PowerGrip HTD Drives ............... Pages 36-45 requirements. 3mm and 5mm pitch HTD belts provide positive non-slip power transmission with many advantages over conventional drive systems. They can handle tough applications, even those subject to sudden shock and overloading. ® PowerGrip Timing Belt Drives Provide positive, non-slip power PowerGrip Timing Belts MXL transmission Application Types: PowerGrip Timing Belts are a good standard line • office equipment XL product with a history of reliability. Around for • m oney handling equipment PowerGrip® Timing Belt ovf esry n6c0h ryoenaorsu,s t hpiosw perro dtruacnts lminies swioans pthrieo rf ltaog Gshaitpe s • f ood processors Profiles/Pitches introduction of PowerGrip HTD and GT Belts. • medical equipment Gates timing belts are made with a true design • r obotics pitch, a standard of the Rubber Manufacturers • d ata processing equipment Association and the International Standards Organization. • m iniaturized applications • m ailing equipment • p rinters/plotters PowerGrip Timing Drives Pages .......... 46-50 4 ® www.gates.comd/ rivedesign ® ® ® Introduction – PowerGrip Twin Power Belt Drives Dual driving surfaces allow for unique, NOTE: Twin Power Belts are available in GT2, HTD problem solving drive designs and Timing Belt configurations, so designers can use them in a wide variety of applications. 0.200’’ (1/5’’) pitch extra light (XL) Gates Twin Power Belts have teeth on both sides to provide synchronization from both driving surfaces. PowerGrip Twin Power Timing Belt This feature makes possible drive designs such as Some typical PowerGrip Twin Power Profile/Pitch multi-point drives, rotation reversal with one belt, applications are: serpentine drives, etc. Twin Power belts provide • c opiers solutions to difficult design problems. • s erpentine drives Twin Power Belts are similar in construction 3mm to regular synchronous belts, including nylon- • r eversing rotations faced teeth on both sides. This construction uses essentially the same design parameters as standard synchronous belts. They are rated at PowerGrip GT2 Twin Power Belts ....Pages 22-23 5mm the same horsepower capacity as conventional PowerGrip HTD Twin Power Belts ....Pages 42-43 PowerGrip Belts of identical pitch and width on PowerGrip Twin Power Belts ............Pages 51-52 PowerGrip Twin Power HTD Timing Belt either side of the belt. Profile/Pitch 3mm 5mm PowerGrip Twin Power GT2 Timing Belt Profile/Pitch ® PowerGrip Long Length Belting For drives that require belt lengths longer Typical PowerGrip Long Length Belting than can be produced in the conventional uses are: endless form • r eciprocating carriage drives PowerGrip Long-length Belting has the same basic • r ack and pinion drives construction as conventional Gates timing belts. Gates can make continuous belting in spiral cut • l arge plotters form on a made-to-order basis. For information or assistance on any long length PowerGrip Long Length Belting .........Page 54 belt problem, contact Gates Product Application Clamp Plate Specifications ................Page 55 Engineering. ® www.gates.comd/ rivedesign 5 ® ® ® Introduction – Polyflex JB Belt Drives Gates Polyflex® JB® is a joined Typical Polyflex JB applications are: 1/8” belt with a different angle • c omputer peripherals “High Power Density” is what you get from this 3mm • b ench-type milling machines high-precision belt. Developed by Gates and 3mm produced using patented manufacturing processes, • g lass blowing lathes Polyflex JB belts provide load-carrying capacity at • v alve grinding machines 3/16” higher speeds on precision applications. Polyflex JB • c rankshaft grinding machines 5mm belts can operate at shaft speeds well in excess of 5mm 10,000 rpm. • w oodworking spindle drives Polyflex JB features joined belt construction for • h orizontal milling machines Standard Polyflex® Polyflex® JB Belt stability. Backside ribs relieve bending stress on • d ental grinders Belt Profile Profile small sheaves and provide lateral rigidity. The 60° • f loor care equipment angle provides more undercord support to the tensile section and distributes the load evenly. • m icrofiche readers The small cross-section allows belts to be used • d rilling machines on short centers and small diameter sheaves for • l athe drives “cleaner” machine designs. It virtually eliminates the need for double-reduction drives and lets you • k nife grinders use more cost-effective single-reduction drives. • s cissor sharpeners Gates Polyflex JB belts are a homogenous • c entrifuges product. State-of-the-art manufacturing • b lowers processes assure uniformity of construction, resulting in minimal vibration and smooth • w heelchairs operation on precision applications. • o ptical lens grinders Gates special high modulus polyurethane • f ans compound has a high coefficient of friction that • m etalworking spindle drives resists fatigue, wear, ozone and most adverse environmental conditions. Cost Savings — PLUS! Polyflex JB belts bring Polyflex JB Drives Pages ....................... 77-81 V-belt economy and simplicity to applications For additional Polyflex belt data refer to Gates where conventional V-belts are not feasible, Heavy Duty V-Belt Drive Design Manual #14995-A resulting in cost savings and design freedom never before possible. 6 ® www.gates.comd/ rivedesign ® ® Introduction – Micro-V Belt Drives For the best ribs around, look no Just some of the applications for Micro-V further than Gates Micro-V® Belts Belts are: H section • h igh speed machine tools Truncated tooth profile increases flexibility and reduces heat • m illing lathes J section Gates Micro-V Belts outperform other V-ribbed • w ashing machines belts because the Vees are shorter. The truncated • p recision surface grinders Micro-V Belt Profiles (shortened) profile of the Vees give Gates Micro-V Belts increased flexibility, reduced heat buildup and • f loor polishers lets them perform at extra high speeds on smaller • t ool grinders diameter sheaves. • h igh-speed printing presses Gates exclusive truncated design • c entrifuges gives you… • a gitators • 8 0% higher horsepower capacity than RMA • p recision center lathes standards. • p umps • e xtra load-carrying capacity for extra long life. • h igh-speed atomizers • Truncated belt ribs for improved wedging in the pulley grooves and greater load capacity. • t rash compactors • p laners and molders Micro-V Belts are smooth running and resistant • d ryers to oil, heat and other adverse conditions. Plus, undercords are static conductive. • f ood slicers • e lectric massagers • l awn mowers • j uice mixers • i ndustrial vacuum cleaners • microwave ovens • b akery equipment • c ompressors • f ans Micro-V Drives Pages ............................ 82-83 For additional Micro-V belt data refer to Gates Heavy Duty V-Belt Drive Design Manual 14995-A. ® www.gates.comd/ rivedesign 7 ® Drive Comparison Graphs The following graph contains a representation of horsepower ratings, over a wide speed range, of the belt types represented in this catalog. The sprocket/pulley/sheave diameters and belt widths are all comparable for a realistic comparison of product capability. The following graph provides a comparison of the rated torque carrying capabilities of synchronous belts, on small diameter sprockets/pulleys at low speeds. The sprocket/ pulley diameters and belt widths are all comparable for a realistic comparison. L o w S p e e d D r i v e R a t i n g G r a p h C o m p a r a b l e D i a m e t e r s & W i d t h s 06.0 35.0 54.0 83.0 03.0 32.0 51.0 80.0 0.0 01 02 04 06 01 02 03 04 05 06 08 01 S p e e d ( R P M ) 8 ® www.gates.comd/ rivedesign ® R a t e d H o r s e p o w e r