Airflex® Product Application by Industry
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Airflex® Product Application by Industry Section X Engine Clutches ........................................................................................................................................................................ 299 Grinding Mills ........................................................................................................................................................................... 303 Marine Drives ............................................................................................................................................................................ 307 Paper Machine Drives .............................................................................................................................................................. 314 Power Presses, Brakes, and Shears ........................................................................................................................................ 317 Tensioning, Winding, and Unwinding .................................................................................................................................... 322 Well Drilling ............................................................................................................................................................................... 326 298 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 Airflex® Engine Clutches Section X General Selections for Engines Without Torque Converters Power rating capability is determined by engine design. Combined capability and durability of all engine components determine how much power can be produced in a particular application. Clutch selection is based upon the power transmitted, clutch rpm, the appropriate service factor, 110 psi (7,6 bar) actuating air pressure and clutch engagement at engine idle. The power output of a basic engine model can be varied within its design ranges by changing the engine fuel setting or speed setting. Both of these settings affect the engine's maximum fuel rate and the power output capability. Recommended Engine Clutch Service Factors Some of the application conditions considered by an engine manufacturer in determining a rating for an application are: Drive SF Compound -Drilling Rig 1.8 Generator1.5 Metal Shredder 2.2 Rotary Table -Drilling Rig 1.5 •• Load factor •• Duty cycle •• Operating hours •• Historical experience Torque loss due to centrifugal effect must be taken into account. Follow procedure given in Section B. The peripheral speed of our spiders and drums should not exceed the limits shown in the below table. The same basic engine model can have different ratings for different industries and applications. Usually, they are grouped into the following categories: Standard Cast spiders, Drums and Hubs (MTL 1-4): 8500 fpm •• Industrial High Speed Cast Drums and Hubs (MTL 1-5): 11,000 fpm High Speed Cast spiders (MTL 1-6): 12,100 fpm •• Truck •• Off-highway •• Power generation •• Petroleum •• Marine Also, within these groupings, are ratings for continuous and intermittent service. Continuous ratings are for continuous use without interruption or load cycling. Intermittent ratings apply to about one hour operation followed by one hour operation at or below the continuous rating. Engine Clutches The CB element is usually recommended for engine clutch applications. Selections are based on the horsepower transmitted by the clutch. In some cases, it may be much lower than the engine's horsepower rating due to other engine driven auxiliary loads. Extra loads imposed by a cooling fan, alternator, air compressor or hydraulic pumps may represent a significant proportion of total engine power available. The use of ductile iron components allows for the higher speed limits. If speed exceeds above limits, a dual element should be considered. Single elements are preferred because of smaller overhung loads and ease of alignment. Selections for Engines With Torque Converters The selection procedure for engines with torque converters is the same as that discussed above for direct drives, but with one other major consideration. Under the stall conditions, i.e. converter output shaft at zero speed, the clutch must be able to transmit the torque multiplication of the converter. The Power Capacity Table can be used to make a selection for single CB clutch elements having a 1.8 service factor and an operating pressure of 110 psi (7,6 bar). Find the horsepower value that is equal or greater than that which must be transmitted in the appropriate rpm line and read the clutch size in the column heading. For dual elements, double the power values in the table. EATON Airflex® Clutches & Brakes 10M1297GP November 2012 299 Airflex® Engine Clutches Section X rpm HP Capacity Table (110 psi and 1.8 SF) for Clutch Sizes: 1000 1050 1100 1150 1200 1250 1300 1350 1400 1450 1500 1550 1600 1650 1700 1750 1800 1850 1900 1950 2000 2050 2100 2150 12CB350 147 153 158 163 167 171 175 179 182 185 187 189 191 192 193 193 193 192 191 189 187 184 181 177 14CB400 216 223 229 235 241 245 249 253 256 258 259 259 259 258 256 253 249 245 239 232 225 216 206 195 16CB500 362 371 379 385 390 394 395 395 394 390 385 378 369 358 345 329 312 18CB500 440 449 456 462 465 466 465 462 456 448 437 423 407 388 20CB500 520 529 536 539 540 538 533 525 514 499 481 459 22CB500 587 595 599 600 597 591 581 567 549 527 rpm kW Capacity Table (7,6 bar and 1,8 SF) for Clutch Sizes: 1000 1050 1100 1150 1200 1250 1300 1350 1400 1450 1500 1550 1600 1650 1700 1750 1800 1850 1900 1950 2000 2050 2100 2150 12CB350 110 114 118 121 125 128 131 133 136 138 139 141 142 143 143 144 144 143 142 141 139 137 135 132 300 14CB400 161 166 171 175 179 183 186 188 190 192 193 193 193 192 191 189 186 182 178 173 167 161 154 146 16CB500 270 277 283 287 291 293 295 295 293 291 287 282 275 267 257 245 232 18CB500 328 335 340 344 346 347 347 344 340 334 326 315 303 289 20CB500 388 394 399 402 402 401 397 391 383 372 358 342 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 22CB500 438 443 446 447 445 441 433 423 409 392 24CB500 688 693 695 693 685 674 657 635 607 26CB525 803 804 798 787 769 744 28CB525 884 879 866 846 30CB525 32CB525 967 1054 954 1033 932 24CB500 512 517 518 516 511 502 489 473 452 26CB525 599 599 595 586 573 555 28CB525 659 655 645 630 30CB525 32CB525 721 786 711 770 695 Airflex® Engine Clutches Section X Engine Clutch Arrangements Typical Spider Engine-Mounted Application For direct engine drive applications, the standard arrangement (Forms CB408 and CB427) uses an external flange drum mounted to the engine flywheel. The clutch element and its spider are fastened to a separate bearing supported jackshaft as shown in the figure. When the clutch mounts on an engine stub shaft or on the output shaft of a torque converter, then the standard gap mounting arrangements (Forms CB406 and CB407) are used. Clutch Engagement Speed The recommended clutch engagement speed is 4500 fpm (22.8 mps) at the friction couple. If the speed at engine idle exceeds this value, then the idle speed should be changed. Engine Clutch Control To ensure clutch engagement at engine idle, the control shown below is recommended. Relay Valve snap acting sequencing A B Ports passes air only when pilot pressure exceeds a set pressure (100 PSI) Pneumatically Controlled Engine Governor/Throttle Port B Supply Pressure (110 PSI) Pilot Pilot connection should be located as close to the clutch as possible Port A Control Valve 2 port compound Port A: instant on/off Port B: modulated pressure with lever position This control system prevents the engine speed from increasing before the pressure in the clutch reaches a preset value. CB Clutch EATON Airflex® Clutches & Brakes 10M1297GP November 2012 301 Airflex® Engine Clutches Section X Example Example A 200 HP, 1200 rpm engine is required to drive a generator. A torque converter is being considered for the application in second example. The converter will have a torque multiplication factor of 3. Operating within its efficiency range, the maximum horsepower output is 332 and the maximum output speed is 1000 rpm. What size clutch is required? A clutch is required to connect the engine to the generator. Mc = = HP.63025 ⋅S F n 200 ⋅ 63025 1200 = 15750 l b ⋅ i n Try 12CB350 rated 13300 lb·in at 75 psi. Me = p 0 - pp - p c 75 ⋅ Mr PP=2 psi (Page B-92) PC=CS.N2=17 psi Stall torque at converter output shaft 332.63025 1200 ⋅ 3 = 52300 l b ⋅ i n = A 16CB500 element at 110 psi is capable of: (110 - 2) X 35200 = 50,688 lb.in 75 The 16CB500 torque is light, therefore, try an 18CB500. Referring to the Engine Selection Guide, the 18CB500 element at 1000 rpm is capable of 445 HP. The clutch selection would be an 18CB500 = 110 - 2 - 17 ⋅ 13300 75 = 16140 l b ⋅ i n Spider peripheral speed v = 0.262 ⋅ N ⋅ D = 0.262 ⋅ 1200 ⋅ 18 5660 fpm < 8500 fpm...OK = 5660fpm Engagement Speed V = 0.262.N.D = 0.262.1200.12 = 3772.8 fpm < 4500 fpm...Good Therefore, the 12CB350 selection is suitable. Example A 332 HP, 1200 rpm engine is used as a direct drive in a compound. What size clutch is required? For the Power Capacity Table, running across the 1200 rpm line, a 16CB500 clutch is selected. 302 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 Airflex® Grinding Mills Section X General Mill Motor Current Demand Grinding mills are classified by the media used for grinding. The more common types of mills are: Ball mills - These mills use forged steel balls up to 5 inches (127 mm) in diameter to crush and grind the material. Mill length is two or more times its diameter. A: Standard torque motor start B: Clutch egagement C: Time to start mill with either drive D: High torque motor start Amperage The function of a grinding mill is to reduce the particle size of a material to a size necessary for a given process. The grinding is accomplished by rotating a large cylinder that is partially filled with the material to be ground and grinding media. As the cylinder rotates, its contents is lifted until it falls or tumbles over itself back down to the bottom of the cylinder. The impact of the grinding media and the tumbling action crush and grind the material down to the desired particle size. B to D: 6 to 10 seconds Rod mills - Steel rods up to 4.5 inches (114 mm) in diameter and slightly shorter then the mill length are used for the grinding process. Mill length is two or more times its diameter. Pebble mills - These mills use small cylinders, balls, or other chunks of silica, porcelain, aluminum or zirconium oxides for grinding. This type of mill is used when the product must be free of metallic contamination. Autogenous mills - These mills use coarse ore particles of the material to grind itself. Grinding is by attrition. An autogenous mill's diameter is larger compared to its length. Semi-Autogenous mills - Forged steel balls in addition to the coarse ore perform the grinding. Mill diameter is larger compared to mill length. Use of a clutch permits the mill motor or motor and reducer to be started in the unloaded condition, keeping current demand and power factor within limits agreed upon with local utilities. The result is a substantial savings on power costs. The following amperage curves compare peak current demands of high torque - direct drive systems and drive systems using standard torque motors with Airflex clutches which replaced them. Time A type VC clutch element or use an Airflex auxiliary hydraulic inching drive is selected using the procedure outlined in Section B. For good friction lining life, it is desirable to limit the maximum clutch engagement speed to 4500 fpm (22,8 mps). If the clutch is used for inching of the mill, engagement speed should not exceed 3500 fpm (17,8 mps). Gap mounted arrangements, Forms VC506 thru VC510, are recommended. A preliminary clutch selection guide is given on the following pages. The selections are valid for the operating parameters stated on the guide. Because of the large thermal loads associated with mill startup, the use of VC clutches are recommended. Clutch Selection The required clutch torque is calculated from the power rating of the mill motor, clutch shaft rpm and an appropriate service factor. P p ⋅ 63025 ⋅ S F(l b ⋅ i n) n P p ⋅ 9550 Mc = ⋅ S F(N ⋅ m) n Mc = Type of Mill SF Ball and Rod Pebble and Semi-Autogenous Autogenous 2 2.5 3.0 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 303 Airflex® Grinding Mills Section X For motor ratings up to 3000 HP (2240 kW) and clutch shaft speeds up to 277 rpm, the clutch element selected should have sufficient thermal capacity and in most cases can be used for inching or spotting of the mill. For larger power motors and higher clutch shaft speeds a more thorough analysis of the mill is required. Various mill starts can be simulated by computer modeling to determine the proper clutch size and starting time. The various starts are obtained by changing the rate of pressure build-up, and hence the rate of torque build-up in the clutch. For a given clutch size, the mill starting times are plotted against the resulting clutch thermal load. A typical overview of the starts are shown below. The preferred starting time is when the peak loading is at a minimum. For any given starting time, the entire clutch profile can be projected for the complete start. By comparing the profile to the rated capacity, the clutch's suitability for the drive can be determined. The information required for simulation must include: •• Type of mill •• Mill inertia •• Mill rpm Clutch Thermal Loading •• Inside diameter of shell liners Clutch Control Normal mill starting procedure is to bring the motor up to operating speed and then engage the clutch to accelerate the mill. Airflex offers several types of reliable systems for clutch control. The systems consists of two parts: the pneumatic and electrical portions. Refer to Airflex catalog A-191 or Section B of this catalog for more information. The pneumatic portion is basically that shown in Section Y, with the addition of a three-way normally closed solenoid valve, a manually adjusted flow control valve and pressure switch, all plumbed in the air line to the clutch. The pressure switch in the clutch air line prevents motor starting if the clutch is pressurized. The pressure switch on the air tank insures that sufficient air volume and pressure is available before a start can be made. Rate of clutch torque build-up and mill acceleration is determined by the flow control valve setting. The pressure switches are tied in electrically to the motor and clutch control circuits. The electrical clutch control furnished by Airflex regulates the electrical signal to the solenoid valve. The standard control permits starting, stopping and where applicable, inching of the mill. Clutch Starting Profile HP/in2 •• Total weight or mass of charge including grinding media Clutch Torque •• Normal percent mill fill •• Material cascade angle •• Method of material discharge (overflow, grate or batch) •• Motor power ratingMill Starting Time (seconds) •• Motor pullout torque Clutch Thermal Load •• Clutch shaft rpm •• Maximum air pressure available •• Mounting style - FWD/ REV Mill rpm •• Hydraulic lifters - YES/NO HP/in2 Clutch Thermal Loading Clutch Starting Profile Clutch Torque Time (seconds) Mill Starting Time (seconds) Clutch Thermal Load 304 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 Airflex® Grinding Mills Preliminary Clutch Selection Guide Section X Motor Horse Power 100 125 150 175 200 250 400 450 500 600 n l 129 M 800 900 1000 1250 1500 1650 1750 2000 2200 2250 2500 2750 FF P UU h s TT EE 133 D n F 144 h FF T M 150 R E 157 n l 164 P RR h T F 180 ss s EE 172 n FF P 190 l 200 212 C h n F D 225 l 240 F F E s h F n M C 360 F l B D 450 E 514 600 C 720 A BB X T P M l 327 RR EE h n 277 900 T P 257 400 P M 300 T FF R n PP T PP T P n M s FF F P l F EE n P CC l M EE FF K CC l M ll K KK PP R PP gg MM AA 1200 Selection Guide Parameters: Minimum Torque Service Factor - 2 Minimum Operating Air Pressure - 100 psig Maximum Contact Velocity - 4,500 fpm Inching with clutch permitted at 3500 FPM or less (unshaded area). Consult factory for applications which exceed these specifications. 41 700 PP E 124 Clutch shaft RPM (60 Hz. Synchronous speeds) 350 F 120 138 300 For motor ratings up to 3000 hp (2250 kW) and clutch shaft speeds up to 277 rpm, the clutch element selected from this chart should have sufficient thermal capacity and in most cases can be used for inching and spotting of the mill. For larger power motors and higher clutch shaft speeds a more thorough analysis of the mill is required. Various mill starts can be simulated by computer modeling EATON VC Clutches for Grinding Mills April 2012 to determine the proper clutch size and starting time. The various starts are obtained by changing the rate of pressure build-up, hence the rate of torque build-up in the clutch. EATON Airflex® Clutches & Brakes 10M1297GP November 2012 305 Airflex® Grinding Mills Section X 3000 3500 4000 4400 4800 5000 5500 6000 6500 7000 7500 8000 8500 9000 9500 10000 10500 11000 11500 12000 12500 13000 13500 120 124 UU WW ZZ QQ 129 133 VV 138 144 YY QQ 150 157 WW 164 172 UU 180 190 TT VV QQ 200 212 ss TT 225 WW 240 YY 257 RR 277 VV TT Clutch shaft RPM (60 Hz. Synchronous speeds) TT 300 UU 327 360 RR ss 400 PP 450 514 600 720 900 J 42VC650 T 46VC1200 A 11.5VC500 X 14VC1000 U 52VC1200 B 14VC500 K 16VC1000 V 51VC1600 C 16VC600 L 20VC1000 W 60VC1600 D 20VC600 M 24VC1000 Y 66VC1600 E 24VC650 N 28VC1000 Z 76VC1600 F 28VC650 P 32VC1000 Q 76VC2000 G 33VC650 R 38VC1200 H 37VC650 S 42VC1200 Double letters indicate dual elements This guide is based on minimum data only. Final clutch selection must be approved by the Airflex Division’s Application Engr. Dept. in Cleveland, Ohio. EATON VC Clutches for Grinding Mills April 2012 306 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 ® 42 Airflex® Marine Drives Section X General Selection Procedure Airflex marine clutches are readily adaptable to the wide variety of drive arrangements found in the marine industry. They have been used for main propulsion, bow thrusters, reversereduction gears and Z-drives. Clutch selection is based upon the torque requirement calculated from the maximum power to be transmitted, clutch shaft rpm and an appropriate service factor. For drives utilizing a controllable pitch propeller, the service factor is 1.5; for a fixed pitch propeller 1.7. The type VC element can be easily combined with a torsional coupling for the main propulsion drive or it can be furnished in quill shaft mountings required for reverse-reduction gear drives. The more common VC marine clutch arrangements appear on the following pages. Type CM elements are used primarily for connecting the engine to in-line reverse reduction gears. Maximum recommended operating air pressure for reversing clutch application is 125 psi (8,6 bar). For reversing applications employing a propeller shaft brake or disconnect applications having a controllable pitch propeller, maximum operating air pressure is 150 psi (10,3 bar). Follow the selection procedure outlined in Section B for VC and CM elements. Horsepower capacities for VC elements at various speeds appear on the following pages. The elements shown have sufficient thermal capacity to handle crash stops. For maneuvering (slipping the clutch to obtain propeller speeds below engine idle), contact the factory. Clutch Power Capacities — Reversing Applications — 125 psi (8,6 bar) Fixed-Pitch Propeller Clutch Shaft rpm 11.5VC500 14VC500 16VC500 20VC600 24VC650 28VC650 33VC650 37VC650 42VC650 200 250 300 350 400 450 515 550 600 650 720 750 810 850 900 950 1000 1050 1100 1225 1300 1400 1500 1600 1700 1800 HP 91 114 136 158 179 199 225 239 258 275 299 309 327 338 351 363 373 382 390 403 407 405 396 378 353 316 HP 133 165 197 228 258 287 323 342 368 392 424 436 460 474 489 503 514 523 530 535 530 512 481 436 377 HP 220 273 326 377 427 475 535 566 608 648 699 720 757 780 805 826 843 857 866 870 HP kW 313 234 389 290 462 345 533 398 601 449 666 497 746 556 786 586 839 626 888 662 947 706 969 723 1007 751 1027 766 1046 780 1058 789 1062 793 1059 790 1047 781 HP kW 453 338 561 419 666 497 766 572 862 643 952 710 1059 790 1112 829 1181 881 1241 926 1311 978 1334 995 1370 1022 1385 1033 1393 1039 1389 1036 1371 1023 1339 999 HP kW 609 455 753 562 892 665 1023 763 1147 856 1262 941 1396 1042 1461 1090 1542 1150 1610 1201 1681 1254 1701 1269 1725 1287 1726 1287 1710 1276 1674 1249 1617 1206 HP kW 849 633 1046 781 1234 920 1409 1051 1570 1171 1716 1280 1878 1401 1951 1455 2036 1519 2098 1565 2140 1596 2141 1597 2111 1574 2065 1540 1976 1474 HP kW 1060 791 1302 971 1529 1140 1737 1296 1924 1436 2087 1557 2258 1684 2328 1736 2399 1790 2434 1816 2416 1802 2382 1777 2265 1689 2147 1602 HP kW 1256 937 1542 1150 1808 1349 2051 1530 2268 1692 2454 1831 2644 1973 2720 2029 2791 2082 2817 2101 2769 2065 2716 2026 2547 1900 2385 1779 kW 68 85 101 118 133 149 168 178 192 205 223 230 244 252 262 271 278 285 291 301 303 302 295 282 263 236 kW 99 123 147 170 192 214 241 255 274 293 316 326 343 353 365 375 384 390 395 399 395 382 359 325 281 kW 164 204 243 281 318 354 399 422 454 483 522 537 565 582 600 616 629 639 646 649 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 307 Airflex® Marine Drives Section X Clutch Power Capacities — Reversing Applications — 125 psi (8,6 bar) Fixed-Pitch Propeller Clutch Shaft rpm 14VC1000 16VC1000 20VC1000 24VC1000 28VC1000 32VC1000 200 250 300 350 400 450 515 550 600 650 720 750 810 850 900 950 1000 1050 1100 1225 1300 1400 1500 1600 1700 1800 HP 286 356 424 492 559 623 705 747 806 863 937 968 1025 1061 1102 1141 1175 1205 1231 1277 1291 1290 1268 1221 1150 1051 HP 382 476 567 657 744 829 935 990 1066 1137 1230 1267 1336 1378 1426 1468 1503 1533 1555 1580 1572 1532 1456 HP 538 668 795 918 1036 1149 1288 1359 1453 1540 1647 1688 1759 1799 1838 1866 1882 1886 1876 1789 1691 HP 730 904 1073 1236 1391 1538 1714 1801 1916 2017 2136 2178 2244 2274 2296 2298 2279 2240 2178 1917 HP 984 1217 1441 1655 1857 2045 2266 2373 2510 2626 2750 2789 2838 2848 2835 2791 2714 2602 2455 HP 1375 1698 2007 2299 2572 2823 3111 3247 3414 3548 3674 3705 3720 3695 3620 3496 3319 KW 213 265 317 367 417 465 526 557 601 643 699 722 764 791 822 851 876 899 918 953 963 962 945 911 857 784 KW 285 355 423 490 555 618 698 738 795 848 917 945 997 1028 1063 1094 1121 1143 1160 1178 1172 1142 1086 KW 401 498 593 684 773 857 961 1013 1083 1148 1229 1259 1312 1341 1371 1392 1404 1406 1399 1334 1261 KW 544 674 800 922 1037 1147 1278 1343 1429 1504 1593 1624 1673 1696 1712 1713 1700 1670 1624 1430 KW 733 907 1074 1234 1385 1525 1690 1770 1872 1958 2051 2079 2116 2124 2114 2081 2024 1940 1830 KW 1025 1266 1497 1715 1918 2105 2320 2421 2546 2646 2740 2763 2774 2755 2700 2607 2475 Clutch Power Capacities — Reversing Applications With Propeller Shaft Brake, and Disconnect Applications with Controllable Pitch Propeller — 150 psi (10,3 bar) Clutch Shaft rpm 14VC1000 16VC1000 20VC1000 24VC1000 28VC1000 32VC1000 200 250 300 350 400 450 515 550 600 650 720 750 810 850 900 950 1000 1050 1100 HP 346 430 514 597 678 758 859 912 986 1057 1153 1192 1268 1316 1372 1425 1475 1520 1561 HP 463 576 688 798 905 1010 1142 1211 1307 1398 1520 1569 1662 1720 1788 1849 1905 1955 1997 HP 652 810 965 1116 1263 1405 1581 1671 1794 1909 2056 2114 2219 2281 2349 2406 2450 2482 2500 HP 884 1097 1305 1506 1700 1885 2112 2226 2379 2519 2692 2757 2869 2930 2991 3031 3052 3051 3027 HP 1192 1477 1754 2020 2274 2515 2804 2947 3136 3304 3501 3571 3683 3735 3774 3782 3757 3698 3603 HP 1668 2064 2446 2812 3158 3482 3865 4051 4292 4499 4728 4802 4905 4939 4937 4886 4782 308 KW 258 321 384 445 506 565 641 680 735 789 860 889 945 981 1023 1063 1100 1133 1164 KW 345 430 513 595 675 753 852 903 974 1043 1133 1170 1239 1283 1333 1379 1421 1458 1489 KW 486 604 720 832 942 1048 1179 1246 1337 1423 1533 1576 1655 1701 1752 1794 1827 1851 1865 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 KW 659 818 973 1123 1268 1406 1575 1660 1774 1879 2007 2056 2140 2185 2230 2260 2276 2275 2257 KW 889 1102 1308 1507 1696 1875 2091 2198 2339 2464 2611 2663 2746 2785 2814 2820 2802 2758 2686 KW 1244 1539 1824 2097 2355 2596 2882 3021 3201 3355 3526 3581 3658 3683 3682 3644 3566 Airflex® Marine Drives Section X Clutch Shaft rpm 14VC1000 16VC1000 20VC1000 24VC1000 28VC1000 32VC1000 1225 1300 1400 1500 1600 1700 1800 HP 1645 1680 1710 1717 1701 1676 1609 HP 2073 2095 2095 2059 HP KW 2485 1853 2429 1812 HP KW 2863 2135 HP HP KW 1226 1253 1275 1281 1268 1250 1200 KW 1546 1562 1562 1535 KW KW Clutch Power Capacities — Fixed Pitch Propeller — 125 psi (8,6 bar) Clutch Shaft rpm 38VC1200 42VC1200 46VC1200 52VC1200 51VC1600 60VC1600 66VC1600 80 100 120 180 200 250 300 350 400 450 515 550 600 650 HP 816 1017 1217 1803 1992 2451 2884 3286 3652 3975 4325 4477 4645 4750 HP 982 1224 1465 2169 2396 2946 3463 3941 4372 4751 5154 5324 5506 5609 HP 1138 1418 1695 2500 2759 3377 3947 4459 4905 5274 5623 5743 5825 HP 1454 1810 2162 3181 3505 4274 4970 5580 6089 6483 6799 6868 HP 1927 2399 2866 4218 4648 5669 6597 7411 8094 8627 9064 HP kW 2610 1947 3248 2423 3876 2892 5687 4243 6259 4669 7602 5671 8798 6563 9816 7323 10627 7928 11203 8357 HP kW 3340 2491 4151 3097 4947 3691 7211 5380 7914 5904 9528 7108 10899 8130 11978 8936 12717 9487 kW 608 759 908 1345 1486 1829 2152 2452 2724 2966 3227 3340 3465 3543 kW 733 913 1093 1618 1788 2198 2583 2940 3261 3544 3845 3972 4108 4184 kW 849 1058 1264 1865 2058 2519 2944 3327 3659 3934 4195 4285 4345 kW 1085 1351 1613 2373 2615 3188 3708 4163 4543 4836 5072 5123 kW 1437 1790 2138 3146 3468 4229 4921 5529 6038 6436 6762 Clutch Shaft rpm Dual 32VC1000 Dual 38VC1200 Dual 42VC1200 Dual 46VC1200 Dual 52VC1200 Dual 51VC1600 Dual 60VC1600 Dual 66VC1600 80 100 120 180 200 250 300 350 400 450 515 550 600 650 720 750 800 900 950 HP 997 1243 1489 2212 2448 3023 3574 4095 4583 5031 5548 5791 6093 6337 6570 6628 6667 6504 6294 HP 1631 2034 2433 3605 3985 4903 5769 6573 7303 7951 8651 8954 9290 9500 9565 HP kW 1964 1465 2449 1827 2929 2185 4337 3236 4793 3575 5892 4396 6926 5167 7881 5879 8744 6523 9502 7088 10308 7690 10649 7944 11012 8215 11218 8368 HP kW 2276 1698 2835 2115 3389 2528 5001 3731 5518 4116 6753 5038 7893 5889 8919 6653 9810 7318 10547 7868 11246 8390 11487 8569 11650 8691 HP kW 2908 2169 3621 2701 4324 3226 6362 4746 7011 5230 8548 6376 9940 7415 11160 8325 12178 9085 12966 9673 13598 10144 13735 10246 HP kW 3853 2875 4799 3580 5732 4276 8435 6293 9297 6935 11339 8459 13193 9842 14823 11058 16189 12077 17254 12872 18129 13524 HP kW 5219 3893 6495 4846 7753 5784 11374 8485 12518 9339 15205 11343 17596 13126 19632 14646 21255 15856 22405 16714 HP kW 6680 4983 8303 6194 9895 7382 14422 10759 15828 11808 19056 14215 21797 16261 23956 17871 25434 18974 kW 743 927 1110 1650 1826 2255 2666 3055 3419 3753 4139 4320 4546 4727 4901 4945 4973 4852 4695 kW 1217 1517 1815 2689 2973 3658 4304 4903 5448 5931 6454 6680 6930 7087 7135 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 309 Airflex® Marine Drives Section X Clutch Power Capacities — Controllable Pitch Propeller — 125 psi (8,6 bar) Clutch Shaft rpm 38VC1200 42VC1200 46VC1200 52VC1200 51VC1600 60VC1600 66VC1600 80 100 120 180 200 250 300 350 400 450 515 550 600 650 HP 924 1153 1379 2043 2258 2778 3269 3724 4139 4505 4902 5074 5264 5383 HP 1113 1388 1660 2458 2716 3339 3925 4466 4955 5384 5841 6034 6240 6357 HP 1290 1607 1920 2834 3127 3827 4473 5054 5559 5977 6373 6509 6602 HP 1648 2052 2451 3605 3973 4844 5633 6324 6901 7347 7706 7783 HP kW 2184 1629 2719 2028 3248 2423 4780 3566 5268 3930 6425 4793 7476 5577 8399 6266 9174 6844 9778 7294 10273 7664 HP kW 2957 2206 3681 2746 4393 3277 6445 4808 7094 5292 8616 6428 9971 7438 11125 8299 12044 8985 12696 9471 HP kW 3785 2824 4705 3510 5607 4183 8173 6097 8969 6691 10798 8055 12352 9214 13575 10127 14412 10752 kW 690 860 1029 1524 1684 2073 2439 2778 3087 3361 3657 3785 3927 4016 kW 830 1035 1238 1834 2026 2491 2928 3332 3696 4017 4357 4502 4655 4742 kW 962 1199 1433 2114 2333 2855 3337 3770 4147 4459 4754 4856 4925 kW 1229 1531 1828 2690 2964 3613 4202 4718 5148 5481 5748 5806 Clutch Shaft rpm Dual 32VC1000 Dual 38VC1200 Dual 42VC1200 Dual 46VC1200 Dual 52VC1200 Dual 51VC1600 Dual 60VC1600 Dual 66VC1600 80 100 120 180 200 250 300 350 400 450 515 550 600 650 720 750 800 900 950 HP 1129 1409 1687 2507 2774 3426 4050 4641 5194 5702 6287 6563 6906 7182 7446 7512 7556 7372 7133 HP kW 1849 1379 2305 1720 2758 2057 4086 3048 4516 3369 5557 4145 6538 4877 7449 5557 8277 6175 9011 6722 9804 7314 10148 7571 10528 7854 10766 8032 10840 8087 HP kW 2226 1661 2775 2070 3320 2477 4916 3667 5432 4052 6678 4982 7850 5856 8932 6663 9910 7393 10769 8033 11682 8715 12069 9003 12481 9311 12714 9484 HP kW 2579 1924 3214 2397 3841 2865 5668 4228 6253 4665 7654 5710 8946 6674 10108 7540 11118 8294 11954 8918 12746 9508 13018 9712 13203 9850 HP kW 3295 2458 4103 3061 4901 3656 7211 5379 7946 5927 9687 7227 11266 8404 12648 9435 13802 10296 14695 10962 15411 11497 15567 11613 HP kW 4367 3258 5438 4057 6496 4846 9560 7132 10536 7860 12851 9587 14953 11155 16799 12532 18347 13687 19555 14588 20546 15327 HP kW 5915 4413 7362 5492 8787 6555 12891 9616 14187 10584 17232 12855 19942 14877 22250 16598 24089 17970 25392 18943 HP kW 7570 5647 9410 7020 11214 8366 16345 12194 17938 13382 21596 16111 24704 18429 27150 20254 28825 21503 310 kW 843 1051 1258 1870 2069 2556 3021 3462 3875 4254 4690 4896 5152 5357 5555 5604 5636 5499 5321 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 Airflex® Marine Drives Section X 3.75 95 D2 D Single Element H H Capacities to 4900 HP (3680 kW) Size 14VC1000 16VC1000 20VC1000 24VC1000 28VC1000 32VC1000 DD Dual Element Dimensions in inches D 14.69 14.44 14.81 14.81 14.94 15.88 H 24.00 26.00 30.00 34.50 38.50 44.25 Capacities to 29000 HP (21600 kW) Dimensions in millimeters English Dimensions in inches D 373 368 376 376 379 403 38VC1200 42VC1200 46VC1200 52VC1200 51VC1600 60VC1600 66VC1600 19.75 19.75 20.25 20.75 24.25 24.25 24.25 33.50 33.50 34.00 35.00 42.50 43.00 43.00 17.00 17.00 17.00 18.00 18.00 18.00 18.00 49.88 54.13 60.75 67.50 67.50 76.50 83.50 Size Single or Dual 38VC1200 42VC1200 46VC1200 52VC1200 51VC1600 60VC1600 66VC1600 D 502 502 514 527 616 616 616 DD 851 851 863 889 1080 1092 1092 D2 432 432 432 457 457 457 457 H 1267 1375 1543 1715 1715 1943 2120 H 610 660 762 876 978 1124 SI Dimensions in millimeters EATON Airflex® Clutches & Brakes 10M1297GP November 2012 311 Airflex® Marine Drives Section X Dual Element DD D D Single Element H H Capacities to 29000 HP (21600 kW) Capacities to 2820 HP (2100 kW) Size Single or Dual Dimensions in inches Dimensions in millimeters Size Dimensions in inches Dimensions in millimeters 38VC1200 42VC1200 46VC1200 52VC1200 51VC1600 60VC1600 66VC1600 D 432 495 508 533 648 699 756 11.5VC500 14VC500 16VC600 20VC600 24VC650 28VC650 33VC650 37VC650 42VC650 D 12.25 12.25 14.75 14.75 15.38 15.38 15.38 15.38 15.38 D 311 311 375 375 391 391 391 391 391 D 17.00 19.50 20.00 21.00 25.50 27.50 29.75 DD 34.50 34.50 37.75 38.75 40.75 45.75 48.00 H 49.88 54.13 60.75 67.50 67.50 76.50 83.50 DD 876 876 959 984 1035 1162 1219 H 1267 1375 1543 1715 1715 1943 2121 H 19.63 23.50 25.50 29.50 34.50 38.00 44.63 48.63 53.63 H 498 597 648 749 876 965 1134 1235 1362 General dimension of typical VC clutches for marine application are shown in the above drawings. Construction details vary slightly in clutches of different sizes. For example, clutch design may include a one-piece or two-piece drum and hub. 312 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 Airflex® Marine Drives Section X Brake Torque as a Percentage of Full Propulsive Power Propeller shaft brakes are used to improve vessel maneuverability by stopping the propeller shaft as fast as possible, to prevent engine stalling during hard reversing maneuvers and to reduce the thermal load on the reversing clutch. In addition, the brake reduces the shock loads on the major components of the propulsion system and prevents freewheeling of the propeller in heavy currents. The chart below compares the thermal load imposed on a reversing clutch through a "crash astern maneuver" and a brake and reverse clutch through the same maneuver. Clutch thermal load is much less when the brake/clutch combination is used, prolonging clutch life. Airflex element types VC, CH and calipers are recommended for use as propeller shaft brakes. A: Full ahead C: thermal Full astern B: Peak loadclutch only Thermal Load Towing Barge, Tug & Fishing Boats High Performance Hulls & Twin propellers All other vessels Full 3/4 1/2 1/4 100 50 25 20 100 100 50 45 100 70 35 25 Full Ahead Full Ahead Ahead Ahead Astern Astern Propellor stopped Maximum Braking Torque B: Peak thermal loadclutch only A: Full ahead Thermal Load Ship Speed Maximum Braking Torque Braking Torque Braking Torque General Driving Torque Driving Torque Propeller Shaft Brakes Propellor stopped Full Astern Full Astern After the propeller is stopped, the reversing clutch is engaged and the propeller speed increased in the astern direction to stop the vessel. C: Full astern A tentative brake selection is made using the torque calculated from the percentage of full propulsive power. The selected brake's thermal capacity is then compared to the stopping thermal load. The thermal load is calculated from the component inertias to be stopped and the wind milling propeller torque resulting from water flow through the propeller. Time Brake Selection Procedure A characteristic propeller shaft Time reversing torque curve at maximum speed ahead is shown below. This generally is the operating speed requiring the greatest stopping torque. The characteristic curve is dependent upon ship design and varies somewhat with the type of vessel. The propeller shaft brake must have sufficient torque to reduce propeller speed to the maximum brake torque point. This torque rarely exceeds 70% of full power torque except for vessels with high performance hulls and/or twin propellers. Use 100% of full power torque for these vessels. (Full power torque does not include service factor). Brake torque at various speeds for different types of vessels are given in the following table: EATON Airflex® Clutches & Brakes 10M1297GP November 2012 313 Airflex® Paper Machine Drives Section X General L: width of web (in) Selections for all paper machine sections are based upon TAPPI NRL* power requirements, the clutch shaft speed and a service factor. Because of the large inertia associated with dryer sections, additional calculations are required to determine if the selected clutch has sufficient thermal capacity and breakaway and acceleration torque. Use N=1 for other sections TAPPI NRL Power Constants The normal running load (NRL) constants given in the table are indicative of the power required to run the section under normal conditions. The units used are horsepower per inch of width per 100 feet per minute (HP/in width/100 fpm). The power is calculated from: N ⋅ NRL ⋅ L ⋅ v PT = 100 PT: TAPPI HP N: Number of dryers Power Requirements of Fourdrinier Machines Machine Section NRL Fourdrinier (total power) A. Toweling and light wrapping 0.043 B. Glassine and bond 0.064 C. News, kraft, and book under 0.064 1200 fpm with Millspaugh rolls D. News, kraft, and 0.086 book 1200-2000 fpm E. News, kraft and 0.086 book above 2000 fpm F. Kraft board 0.09 Fourdrinier Driven Rolls Wire return 0.0012 Lumpbreaker 0.001 Calender Stacks (eight and nine Rolls) Up to 70 lb paper 0.035 70 to 90 lb paper 0.056 90 to 130 lb paper 0.056 130 lb and above 0.056 Reel Up to 125 lb -except kraft 0.008 Above 125 lb -except kraft 0.008 All kraft paper 0.008 Presses Main press: (plain or suction) 0.024 pair of main rolls Clutch Torque The torque requirement of the clutch is determined from: Mc = Pt·63025 ·SF n Mc: clutch torque (lb·in) n: clutch shaft speed (rpm) SF: service factor from following table Clutch selections are made by choosing a size which provides a torque greater than or equal to the required torque. Clutch types CB and VC are recommended for all but the dryer sections. Because of the thermal load, only type VC is recommended for the dryer. Follow the selection procedure given in Section B to determine the clutch size to use. Limit the maximum friction couple velocity to 4500 fpm (22 mps). Power Requirements of Fourdrinier Machines Machine Section NRL Dual press Side rolls only -each 0.020 Side rolls only -each 0.024 Suction pickup 0.010 Suction wringer 0.015 Suction wringer 0.018 Suction felt 0.010 Transfer 0.030 Smoothing press – marking 0.007 press pair of rolls Size press – pair of rolls 0.020 Dryers: Paper and Felt 60 inch diam. rolls -each 0.0018 48 inch diam. rolls -each 0.0014 42 inch diam. rolls -each 0.0013 36 inch diam. rolls -each 0.0011 Yankee Dryer 0.05 Doctors (each) Metal 0.001 Laminated plastic 0.0015 Fiberglass 0.0017 *TAPPI NRL = Technical Association of the Pulp and Paper Industry Normal Running Load. Reprinted from TAPPI, Vol. 45, No. 2, February 1962 Copyright, 1962, by Technical Association of the Pulp and Paper Industry, and reprinted by permission of the copyright owner. 314 v: paper web speed (fpm) EATON Airflex® Clutches & Brakes 10M1297GP November 2012 Machine Section SF Fourdrinier Couch w/plain bearings 2.2 Couch w/anti-friction bearings 1.8 Press Sections Suction press w/plain bearings 2.2 Suction press w/anti-friction bearings 1.8 1.8 Plain press w/plain bearings Plain press w/anti-friction bearings 1.5 Smoothing press w/plain bearings 1.8 Smoothing press w/anti-friction 1.5 bearings Breaker press w/plain bearings 1.8 Breaker press w/anti-friction bearings 1.5 Size press w/plain bearings 1.8 Size press w/anti-friction bearings 1.5 Transfer press w/anti-friction bearings 1.8 Dryer w/plain bearings and helper drive see w/plain bearings and no helper drive text w/anti-friction bearings and 2 helper drive w/anti-friction bearings and 2 no helper drive Yankee Dryer 2.5 Calendar w/plain bearings 4.5 w/anti-friction bearings 3.5 Notes: Recommended Drive Constant For machines of 90 inch minimum width. For nip pressures up to 100 lb/in. For nip pressures over 100 lb/in. Airflex® Paper Machine Drives Section X Dryer Sections Normally dryer clutch sizing is determined by thermal capacity and the resulting clutch selection will have torque capacities that exceed those indicated by the above calculations. Energy capacities are primarily a function of friction area. The recommended clutch friction area is determined from: W k2 ⋅ v2 A= 2 D ⋅ 1.21E + 0 6 A: clutch friction area (in2) Wk2: inertia of dryer section (lb·ft2) D: dryer roll diameter (in) For dryer sections having plain journal bearings, the clutch must be capable of overcoming the breakaway torque of the bearings. This torque can be estimated from: Wt ⋅ d ⋅ v Mf = 0.48 ⋅ D ⋅ n Mf: breakaway torque (lb·in) Wt: total weight of dryers, gears and one-half of felt and feeney dryers* d: journal bearing diameter (in) SF: service factor from following table: Service Factors for dryers equipped with journal bearings If the Wk of the section is not known, it can be estimated from: 2 Wk2 = N·L·K Wk2: estimated Wk2 of section (lb·ft2) N: number of dryer rolls K: factor from dryer constants table For sections having a large number of dryer rolls and the paper speed is high, an air cooled clutch may not be suitable. A special VC water- cooled unit, having a different friction couple, can be furnished. The friction area required for watercooling is 1/6 of that required for an air-cooled clutch; however, the clutch torque rating must be reduced by 40%. The clutch must also be capable of accelerating the dryer in a reasonable time. The acceleration torque can be calculated from: W k2 ⋅ v Ma = 0.74 ⋅ 2 D ⋅n Ma: acceleration torque (lb·in) Z: acceleration rate (fpm/sec) Use 50 to 60 fpm/sec if the acceleration rate is not specified. Paper Speed fpm 0 to 500 500 to 750 750 to 1000 1000 to 1500 1500 to 1800 Without Helper Drive 3.0 3.5 4.0 4.5 5.0 With Helper Drive 1.5 2.0 2.5 3.0 3.5 *If total weight is not known, it can be estimated from: Wt = N·[K1· L+K2] K1 & K2 : factors from dryer constant table In general, a clutch selection for a dryer section is usually based upon the required friction area A. The selection is then checked to determine if its torque capacity is capable of torques Mc, Ma and Mf with the available applied air pressures. If not specified, selections should be based on 40 psi. Dryer Constants Dryer Roll Dia. in 24 36 42 48 48 60 60 60 72 72 Shell Thickness in 0.50 0.63 0.75 0.81 1.00 1.00 1.25 1.38 1.44 1.50 K 12 51 97 157 197 378 467 518 936 966 K1 16.5 24 29 34 40 48 60 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 K2 1000 1600 2150 2500 2500 6000 6000 315 Airflex® Paper Machine Drives Section X Example Example A clutch is required for the third dryer section of a paper machine which operates under the following conditions: Determine the clutch torque required for the transfer press for the paper machine given in the first example. Web L: 188 inch NRL = 0.030 Speed v: 2500 fpm PT = Dryer diameter D: 36 inch No. of dryers N: 5 Anti-friction bearings PT = 100 = 5.0.0011.188.2500 100 Mc = n . SF = 26.63025 1000 = 3260 lb·in Wk = N·L·K = 5 · 188 · 51=48000 lb·ft2 W k2 ⋅ v M a = 0.74 ⋅ 2 ⋅Z D ⋅n 48000 ⋅ 2500 = 0.74 ⋅ ⋅5 0 2 3 6 ⋅n = 3430 lb·in = W k2 ⋅ v2 D ⋅ 1.21E + 0 6 2 48000 ⋅ 25002 3 62 ⋅ 1.21E + 0 6 = 191 in2 Clutch selection is made from friction area required. Select 14VC500. Friction couple velocity = 14·1000·0.262 = 3670 fpm. The 14VC500 element meets all the requirements. Operating pressure would be approximately 40 psi. 316 PT.63025.v n 141.63025 1000 = 16000 lb·in .2 2 A= Mc = = PT = 26 HP PT.63025 100 = 0.030.188.2500 = 141HP Clutch speed n: 1000 N.NRL.L.v N.NRL.L.v EATON Airflex® Clutches & Brakes 10M1297GP November 2012 . SF . 1.8 100 Airflex® Power Presses, Brakes and Shears Section X General Single geared, single drive clutch mounted on bullgear Power presses are used for punching or stamping, forming or drawing and embossing operations. Press brakes are used for bending operations. Shears are used to cut material to size. In most cases, the material being worked is steel. Motor Flywheel Drive Pinion These machines usually utilize a slider-crank linkage to transfer kinetic energy from a rotating flywheel to a reciprocating ram. They are rated by the force Fr, the ram can exert at a given distance d above the bottom of the stroke. This distance is called the drive capacity. The product of the drive capacity and rated force determines the maximum energy which should be removed from the flywheel to perform the necessary work. Clutch As energy is removed from the flywheel, and work is performed, the flywheel slows down. The machine's motor replaces the expended flywheel energy before the next work stroke by bringing the flywheel back up to its operating speed. Bullgear Crankshaft Single geared, single drive clutch mounted on flywheel Motor A clutch and brake is usually required for one or all of the following reasons: •• For die or blade setup. •• For feeding and removing work pieces from the machine. Flywheel Drive Pinion •• For emergency stopping. Clutch Because these machines are inherently dangerous, the brakes are spring-set, pressure released types. Crankshaft mounted flywheel Motor Crankshaft Bullgear Double geared, single drive Flywheel Motor Flywheel shaft pinion Clutch Intermediate gear Flywheel Drive Pinion Clutch Second gear train Crankshaft First gear train Bullgear Crankshaft EATON Airflex® Clutches & Brakes 10M1297GP November 2012 317 Airflex® Power Presses, Brakes and Shears Section X Double geared, twin gear Motor Flywheel Shaft Pinion Flywheel First gear train Intermediate gear Eccentric, two point Clutch Drive pinion Second gear train First Gear Train Crankshaf Bullgear Eccentric, single point Main Gear Eccentric CL Gear Main Pin CL Eccentric Eccentric, four point 318 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 Airflex® Power Presses, Brakes and Shears Section X Drive Capacities Power presses Mechanically, the drive capacity is dependent upon the drive train between the crank and flywheel shafts. Commonly used drive trains are illustrated on the preceding pages. The distance is a minimum for crankshaft mounted flywheels and a maximum for twin geared drives. If not specifically stated, the values given in the following table may be used. Drive Capacities d for Open Back Inclinable (OBI) and Horn Presses Rated Tonnage c/s Flywheel Drive 32 and less 0.03 in (0,8 mm) over 32 to 110 0.06 in (1,5 mm) over 110 Geared Drive 0.13 in (3,3 mm) 0.25 in (6,4 mm) 0.25 in (6,4 mm) For Single-Action, Single and Multiple Point Geared Presses Single drive Eccentric drive Twin drive 0.25 in (6,4 mm) 0.50 in (13 mm) 0.50 in (13 mm) Press brakes The drive capacity for short stroke machines, if not specified, can be approximated from the width V of the vee die opening. Use the following approximations: For stroke less than 3 in (76 mm) d = 0.28V For larger strokes d = 1 in (25 mm) Raked Blade r Shears The tonnage and drive capacity needed to cut a given material depends upon the type of blade used. The diagrams illustrate the differences between straight, raked and bow tie blades and gives the drive capacities. Usually, the shear blade is allowed to over travel the work piece thickness tm by a small distance e to provide a clean cut. tm Bow Tie Blade r tm Straight Blade tm EATON Airflex® Clutches & Brakes 10M1297GP November 2012 319 Airflex® Power Presses, Brakes and Shears Section X Crankshaft Torque The slider-crank linkage is shown below. The torque lever arm L varies throughout the stroke of the machine. At any point in the stroke, the lever arm can be calculated from: L = c·sin Ø Crankshaft throw The force Fp which the pitman must transmit can be calculated from: Fp = Fr /cos Ø Fr = 2000 · Rated Tonnage of Press The crankshaft torque M is: Pitman M = Fp· L = Fr · c · tan Ø The torque required at the machine's drive capacity is used in the clutch selection procedure. Clutch Torque Clutch torque Mc calculations can be simplified by the use of the effective lever arm Le graphs and the following formula. The graphs assume the pitman length is twice the stroke. Longer pitmans will slightly reduce the effective lever arm. L t c p Mc= Fr .Le R ·SF R: reduction between clutch shaft and crankshaft. SF: service factor from following table. φ Brake Capacity d The crank link t length is equal to the crankshaft throw (onehalf of the stroke distance) or in the case of an eccentric drive, the eccentric offset. The link p connecting the crankshaft throw to the ram is called the pitman. Knowing the lengths of the throw and pitman, the pitman angle Ø can be calculated at any point in the stroke from: cos o = p2 +c2 - t2 2.p.c c=p+t-d 320 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 Type of Drive SF Crankshaft mounted flywheel Single drive, single reduction Single drive, double reduction, single throw Single drive, double reduction, double throw Twin drive, single reduction Twin drive, double reduction 0.8 1.0 1.1 1.2 1.3 1.5 Airflex® Power Presses, Brakes and Shears Section X The selected brake must satisfy the following conditions: Select FSPA109 (20CB500 clutch and 15CS300 brake): It must have sufficient torque to stop the ram within a given crankshaft angle. clutch torque = 53600 lb·in It must have sufficient torque to hold the ram and die on the back stroke. reverse brake torque = 3500 lb·in It must have sufficient thermal capacity to handle the single stroke rate of the machine. Formulas are given in Section Y which allow calculation of brake torque Mb knowing the stopping angle, inertia to be stopped and the brake shaft speed n. A brake selection is made using Mb. Holding torque Mh is calculated from: forward brake torque = 22000 lb·in flywheel Wk2 = 942 lb·ft2 Wk2 drum and hub = 61 lb·ft2 Total Wk2 to be stopped = 10 + 61 = 71 lb·ft2 Stopping Time: td = Wk 2 ⋅ n 71.100 = 25.58 ⋅ Mb 25.58 ⋅ 22000 Mh = F· t/R F: total weight or mass of ram including attached tooling. Stopping Angle: The reverse torque of the brake selected is compared to Mh to determine if it has sufficient capacity. fd =3 · n · td = 3 · 100 · 0.012 Cyclic thermal power Pc is calculated from formula 23, Section Y. The allowable thermal loading on the friction area of Airflex types CS, CTE and DB brakes is 0.012 HP/in2 (0.0014 kW/cm2). Mh= F·t Example Press rating - 60 tons Type of drive - crankshaft mounting Drive capacity d - 0.06 in Stroke - 3 in Pitman length p - 8 in Crankshaft speed - 100 rpm Single stroke rate - 30 cpm = 0.012 sec = 3.60 = 200·1.5 = 300 lb·in Wr= Wk 2 ⋅ n 71.100 2 = = 121ft ⋅ l b 5873 5873 Pc = Wr ⋅ cpm 121.30 = = 0.11HP 33000 33000 P c 0.11 = = 0.0012 H P 2 in A 89 Both thermal capacity and holding torque requirements are within the 15CS300 parameters. Ram and die weight F - 200 pounds Wk2 less clutch and brake - 10 lb·ft2 Stopping angle od - 150 Flywheel Wk2 - 900 lb·ft2 Calculations c = t+p-d = 0.5·3 + 8 - 0.06 = 9.44 in cos f= p2 + c2 − t 2 82 + 9.44 2 − 1.52 = 2⋅p ⋅c 2 ⋅ 8 ⋅ 9.44 = 0.9988 Ø = 2.780 L = 9.44·sin Ø = 0.46 in M =Fr · c · tan Ø = 60 · 2000 · 9.44 · tan 2.78 = 55000 lb·in Mc= 55000 ·0.8 = 44000 lb·in EATON Airflex® Clutches & Brakes 10M1297GP November 2012 321 Airflex® Tensioning, Winding and Unwinding Section X General Metal Tension Guide Winding is the process of taking up a web or a strand of a long length of material onto a beam, a cone, a core, a drum or a spool; primarily for handling convenience for end use or reprocessing. Depending upon the industry, the process is also called coiling or spooling. Examples are a roll of paper toweling and a coil of steel providing material in a stamping operation. Depending upon material, multiply the graph tension by the following factors: Unwinding is the process of controlled payoff of material which has previously been wound, coiled or spooled. In both processes it is important to maintain a constant tension or pull on the material. Improper tensioning during winding results in roll dishing or telescoping and improper roll density. Improper tensioning during unwinding can cause web distortion and flutter, affecting the reprocessing operation. Material tension can be controlled electrically, hydraulically or mechanically. Airflex products recommended for mechanical (friction) control include the types E, EB, WCB and caliper elements. See selection guide, below. Aluminum, full hardness 1.00 Aluminum, half hardness 0.75 Brass, full hardness 1.00 Brass, half hardness 0.75 Steel: Carbon, full hardness 2.25 Mild 1.00 Nickel 2.50 Silicon 1.20 Stainless, cold drawn 4.25 As indicated, correct tension is important; however, most users are unaware of the material tension required. Tension values may vary considerably from plant to plant and from machine to machine; operator preference as to tightness of web and desired roll densities are also factors. To assist in this matter, the tension charts shown are intended to serve only as a guide. Material thickness (inches) Material Tension Selection Guide Material thickness (millimeters) Tension (lb/in) Tension (N/cm) 322 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 Airflex® Tensioning, Winding and Unwinding Section X Paper and Board Tension Guide Slip Clutches and Tension Brakes The paper and board chart is for 3000 ft (279 m ) of material which is the equivalent of 500 sheets (Ream) 24 in x 36 in (0.62 x 0.91 m). Various papers and board stocks with different basic weight and size designations should be adjusted to 3000 ft2 for direct reading from the chart. For example, if a board is designated 120 lbs per 1000 ft2, multiply 120 by 3 to bring it to 3000 ft2. If board weight is in points, multiply by 10 (i.e., 50 point board x 10 = 500 lbs per 3000 ft2). For chip board multiply the point designation by 8.5. 2 2 In most winding and unwinding applications, in addition to a constant tension, the material processing procedure requires a constant web speed that is usually controlled by the processing machine's main drive. During unwinding, as the roll diameter decreases, the roll rpm increases and the tension or drag brake torque requirement decreases. When winding, as the roll diameter increases, the roll rpm decreases and the slip clutch torque requirement increases. Both clutch and brake torque is adjusted by regulation of the applied pressure during the winding and unwinding procedure. Selection Procedure Material Tension (lb/in) In many cases, the winding and unwinding machines are required to handle different types of materials and/or operate under different parameters. It is important to determine the maximum and minimum operating ranges The following parameters are necessary to determine proper clutch and brake sizes (see Section Y for units): Material Tmax: maximum material tension Tmin: minimum material tension or Fmax: maximum material pull Fmin: minimum material pull Paper Weight (lb/3000 ft 2 ) D: maximum roll diameter d: minimum roll or core diameter wmax: maximum web width wmin: minimum web width vmax: maximum web speed Material Tension (N/cm) vmin: minimum web speed R: reduction between clutch or brake shaft and roll shaft Paper Mass (gram/m 2 ) EATON Airflex® Clutches & Brakes 10M1297GP November 2012 323 Airflex® Tensioning, Winding and Unwinding Section X Using the parameters, the following calculations are made: F = T .w The calculated torques, thermal power and speeds must fall within the capacities given in the appropriate product catalog section. Fmin = Tmin.wmin Mmax = Fmax·0.5 D/R Type E slip clutch arrangements are shown in Section C on catalog Forms E605 through E607. Air-cooled tension brake arrangements are shown on catalog Forms E608 and E609; water-cooled arrangement on Form E610. Mmin = Fmin.0.5 d/R The caliper tension brake arrangement is shown in Section H, Form CA1003. max Nmax = max max Vmax ⋅ R 0.262 ⋅ d Nmin = Vmin ⋅ R 0.262 ⋅ D nmax = Vmax ⋅ R 5,236 E - 0 5 ⋅ d nmin = Vmin ⋅ R 5,236 E - 0 5 ⋅ D Water-cooled WCB tension brakes are shown in Section I. English Units SI Units For a tension or drag brake on an unwind stand, the thermal power to be dissipated Ptb is Ptb = Fmax ⋅ Vmax (H P ) 33000 Ptb = Fmax ⋅ Vmax (k W ) 60000 For a slip clutch on a winding stand, it is desirable to have the driving side of the clutch rotating at a slightly faster speed than the driven side to prevent clutch lockup and a slip-grab situation. The recommended driving speed is 10% greater than the driven speed for speeds under 100 rpm and 5% greater for speeds over 100 rpm. Slip clutch thermal power to be dissipated Ptc is: Ptc = Mmax ⋅ ns (H P ) 63025 Ptc = Mmax ⋅ ns (k W ) 9550 ns: slip rpm = (1.10 or 1.05).nmax - nmin 324 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 Application examples appear on the following page. Airflex® Tensioning, Winding and Unwinding Section X Example Example A slip clutch is required for a rewind stand operating under the following conditions: A tension brake is required to handle the following requirement: Material pull Fmax: 125 lb Material tension Tmax: 18 lb/in Maximum coil diameter D: 20 in Material tension Tmin: 18 lb/in Minimum core diameter d: 12 in Maximum roll diameter D: 108 in Web speed vmax: 1000 fpm Core diameter d: 16 in Reduction R: 1:1 M = F .0.5 · D = 125.0.5· 20 Maximum web width wmax: 216 in = 1250 lb·in Mmin= Fmax. 0.5 . d = 125 .0.5 · 12 Maximum web speed vmax: 4100 fpm Reduction R: 1:1 max Minimum web width wmin: 216 in max Minimum web speed vmin: 4100 fpm = 750 lb·in v max 1000 = 318 rpm 318rpm = nmax= 0.262 ⋅ d 0.262 ⋅ 12 recommended driving speed=1.05 · 318=334 rpm nmin= ns v min 1000 = = 190rpm 0.262 ⋅ D 0.262 ⋅ 2 0 = 334 - 190 = 144 rpm Pt= v max ⋅ ns 1250 ⋅ 144 = 2.9HP = 2.9 HP 63025 63025 Fmax = Fmin = Tmax·Wmax = 18·216 = 3890 lb Mmax= Fmax.0.5·D = 3890.0.5.108 = 210000 lb·in Mmin = Fmin.0.5.d = 3890·0.5.16 = 31100 lb·in nmax = Vmax 4100 = = 978 rpm 0.262 ⋅ d 0.262 ⋅ 16 nmin= Vmin 4100 = = 145 rpm 0.262 ⋅ D 0.262 ⋅ 108 Ptb= Fmax ⋅ v max 3890 ⋅ 4100 = = 483 H P 33000 33000 From Pt curves for 3 HP @ 334 rpm select 14E475 Approximate operating pressure = 1250 ·75~6 psi 16000 Select 324 WCB Operating pressure: Mmax Pmax= = Mr 210000 300000 x Pr + Pp (Page I-13, Pp) x 80 + 5 = 61 psi Pmin = = Mmin Mr 31100 300000 x Pr + Pp (Page I-13, Pp) x 80 + 5 = 13 psi EATON Airflex® Clutches & Brakes 10M1297GP November 2012 325 Airflex® Well Drilling Section X General A rotary well drilling rig is a piece of equipment designed to bore a hole into the earth. For oil exploration, the hole can be anywhere from 4.5 to 20 inches (114 to 508 mm) in diameter and 30000 feet (9140 meters) in depth. Clutches are required for the rig's prime movers and to control the drawworks and rotary table functions. Engine Clutch Pump Pump Pump Clutch Engine Engine Clutch Pump Clutch Engine Engine Clutch Inertia Brake Engine Master Clutch Rotary Clutch Sand Reel Drum Sand Reel Clutch Main Cable Drum Drum Clutch Rotary Table 326 EATON Airflex® Clutches & Brakes 10M1297GP November 2012 Airflex® Well Drilling Line Diameter Section X Engine Clutches Low speed clutch On the majority of rigs, three or more diesel engines supply power to run all the machinery necessary to bore the hole. The engines are arranged so that they may be put in operation as the need arises. For instance, at the start of drilling, one engine may provide all the power necessary. As the hole becomes deeper, the second and then the third engine can be brought on-line. This arrangement is called a compound and CB clutches are used to engage and disengage the engines. The low speed drum clutch torque requirement ML is deterDrumdrum radius r. mined by the single line pull F and the working Radius Usually, the maximum hook load H is given instead of single line pull. Single line pull is calculated from: During the drilling operation, pumps are used to circulate a mud slurry to clean the bottom of the hole, to cool and lubricate the tools and to maintain the walls of the well. Hereto, CB elements are used to connect and disconnect the pumps as required. E: Tackle efficiency A selection procedure for engine clutches is given in Section X. Use the procedure for clutch sizing. Drawworks Clutches Sections of pipe are used to connect the drilling bit to the rotary table. After the bit has bored a pipe length depth, the operation is stopped and a new pipe section added. The drilling bits wear and must be replaced several times when drilling a well. This means the drill string (the bit and all the pipe sections) must be withdrawn from the hole, the bit replaced and the drill string re-assembled. Raising and lowering of the string is the function of the drawworks. Tackle Efficiency F= Working Radius H N.E N: number of lines strung Good design practice limits the line pull to one-half of the line breaking strength. N Number of lines strung E Tackle Efficiency 4 6 8 10 12 14 16 18 0.908 0.874 0.842 0.811 0.782 0.755 0.728 0.703 The following figure illustrates the working drum radius. Usually, the drawworks is rated on the second line wrap on the drum. The working radius can be calculated from: r = 0.5 D + 0.866.d.w - 0.366.d D: drum diameter d: line or wire rope diameter w: number of wraps Single Line Pull No. of Lines Strung Working Radius Line Diameter Hook Load A drawworks is basically a hoist which raises or lowers heavy loads by means of wire rope (line) wound on a drum. The drawwork's transmission allows a number of drum speeds. The deeper drilling rigs have a low and high speed drum clutch which further increases the number of possible drum speeds. The drill string weight (hook load) determines which clutch is used. Working Radius Drum Radius EATON Airflex® Clutches & Brakes 10M1297GP November 2012 327 Airflex® Well Drilling Section X Low speed clutch torque can then be calculated from: Example ML = F·r Determine the low and high speed drum clutch torques required for the following conditions: No service factor is used because this is the maximum torque required and only occurs at the maximum hole depth. Applying a service factor results in too large a clutch torque for the range of speeds and a overstressed line. Using the calculated low drum torque and the lowest drum rpm NL, the power required for hoisting Ph is calculated from: M ⋅n Ph = L L (H P ) 63025 Ph = Lines strung N: 8 Line dia. d: 1.125 in Rated wrap W: 3 High speed range: 108 to 254 rpm ML ⋅ nL (k W ) 9550 F = High speed clutch torque MH is calculated from the hoist power and the lowest high speed drum rpm NH. A service factor is applied because of abuse from higher engagement speeds and shock loading due to breaking the drill string free of the rotary table slips. PPhh⋅⋅63025 63025 ⋅⋅1.5 1.5((llbb⋅⋅iinn)) nnHH PP ⋅⋅9550 9550 MH = hh 1,5((N N⋅⋅m m)) ⋅⋅1,5 nnHH In many cases, the same size clutch is used for both the high and low speed clutches to keep the number of clutch sizes on a rig to a minimum. Because of the large torque requirement, VC elements are used. Follow the selection procedure given in Section B. Inertia Brake This brake is used to stop the rotating transmission components of the drawworks. Its selection is based upon the rotating inertia, the brake shaft speed and the desired stopping time. Other Drawworks Clutches All other clutch selections with the exception of the sand reel are based upon the maximum power which the clutch must transmit, the clutch shaft speed and the appropriate service factor from the following table. The sand reel clutch torque depends upon its line pull and drum working radius Clutch SF Master Rotary Pump Sand Reel 1.5 1.5 1.8 1.25 328 Hoist drum dia. D: 20 in Low speed range: 34 to 77 rpm High speed clutch MH = Maximum hook load H: 500000 lb EATON Airflex® Clutches & Brakes 10M1297GP November 2012 H 500000 500000 H 74228lb == ==74228lb N⋅⋅EE 88⋅⋅0.842 0.842 N r = 0.5 · D + 0.866 · d · w - 0.366 · d = (0.5 · 20) + (0.866 ·1.125 · 3) - (0.366 · 1.125) = 12.51 in ML = F·r = 74228·12.51 = 928593 lb·in Ph = M MLL ⋅⋅nnLL 928593 928593⋅⋅33 44 == == 501HP 501HP 63025 63025 63025 63025 MH = Ph ⋅ 63025 501⋅ 63025 ⋅ 1.5 = ⋅ 1.5 nH 108 = 438550 lb·in Airflex® Well Drilling Section X Drawworks Auxiliary Brake The information required for a selection includes; This brake is used for fine and precise control of drilling speed of all hook loads at all depths. Airflex WCBD & WCSB units are selected for 100% of maximum rated loads. They will function as retarding and stopping the loads. 1. Empty hook load WCSB is a combination brake that provides dynamic (tensioning) braking, parking (static holding) and spring applied e-stop braking. The WCSB (combo) is designed for direct mounting and to be used as the sole brake (only mechanical brake) on a drawworks application. (AC, DC or Mechanical).The water cooled portion of the brake offers energy absorption (HP) capacity, while the spring set function accommodates “fail safe” braking (for parking & e-stop). WCSB must be sized with 2 aspects; plenty of torque (spring set) for heaviest loads at “worn condition” and then also plenty of HP (for dynamic braking). However on AC drawworks, the brake may not see full HP, as the motors are doing most of the energy dissipation. 4. Available air pressure A WCBD is primarily an “auxiliary” brake for all types of drawworks, as it can be coupled, chain driven or direct mounted. HP sizing is the primary concern. If used on an AC drawworks, a fail-safe mechanical brake must be present (spring set bands, spring set calipers, spring set plate brake, etc…) 14. Hook speed (Full load) 2. Maximum full load 3. Number of lines strung 5. Wire rope diameter 6. Hoist drum diameter (Bare) 7. Rated wrap 8. Motor power 9. Number of motors 10. Gear box inertia at brake 11. Cable drum inertia at brake 12. Total number of brakes 13. Hook speed (Empty) Airflex has a selection tool for a thorough analysis of the torque and the thermal loading encountered in a drilling operation. EATON Airflex® Clutches & Brakes 10M1297GP November 2012 329
