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Correas agricolas

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Correas agricolas

  1. 1. S T A N D A R D ASABE is a professional and technical organization, of members worldwide, who are dedicated to advancement of engineering applicable to agricultural, food, and biological systems. ASABE Standards are consensus documents developed and adopted by the American Society of Agricultural and Biological Engineers to meet standardization needs within the scope of the Society; principally agricultural field equipment, farmstead equipment, structures, soil and water resource management, turf and landscape equipment, forest engineering, food and process engineering, electric power applications, plant and animal environment, and waste management. NOTE: ASABE Standards, Engineering Practices, and Data are informational and advisory only. Their use by anyone engaged in industry or trade is entirely voluntary. The ASABE assumes no responsibility for results attrib- utable to the application of ASABE Standards, Engineering Practices, and Data. Conformity does not ensure compliance with applicable ordinances, laws and regulations. Prospective users are responsible for protecting themselves against liability for infringement of patents. ASABE Standards, Engineering Practices, and Data initially approved prior to the society name change in July of 2005 are designated as ‘ASAE’, regardless of the revision approval date. Newly developed Standards, Engineering Practices and Data approved after July of 2005 are designated as ‘ASABE’. Standards designated as ‘ANSI’ are American National Standards as are all ISO adoptions published by ASABE. Adoption as an American National Standard requires verification by ANSI that the requirements for due process, consensus, and other criteria for approval have been met by ASABE. Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantial agreement has been reached by directly and materially affected interests. Substantial agreement means much more than a simple majority, but not necessarily unanimity. Consensus requires that all views and objections be considered, and that a concerted effort be made toward their resolution. CAUTION NOTICE: ASABE and ANSI standards may be revised or withdrawn at any time. Additionally, procedures of ASABE require that action be taken periodically to reaffirm, revise, or withdraw each standard. Copyright American Society of Agricultural and Biological Engineers. All rights reserved. ASABE, 2950 Niles Road, St. Joseph, MI 49085-9659, USA ph. 269-429-0300, fax 269-429-3852, hq@asabe.org ASAE S211.5 JUL1998 (R2008) V-belt and V-ribbed Belt Drives For Agricultural Machines
  2. 2. ASAE S211.5 JUL1998 (R2008) V-belt and V-ribbed Belt Drives For Agricultural Machines Adopted by ASAE June 1950; revised 1960, 1962; revision proposed by a joint committee representing the Rubber Manufacturers Association and the Farm and Industrial Equipment Institute; approved by the ASAE Power and Machinery Division Technical Committee December 1968; reconfirmed December 1973, December 1978, December 1983; revised May 1986; revised editorially February 1987, September 1988; reaffirmed December 1990, December 1995, December 1996; revised editorially March 1998; revised July 1998; reaffirmed February 2003, February 2008. Keywords: Belt, V-belt 1 Purpose 1.1 The purpose of this Standard is to provide sufficient technical data for the uniform physical application of belt drives to farm machines and mobile industrial equipment. Use of this Standard will contribute to the design of simple and economical drives. 2 Normative references The following standards contain provisions which, through reference in this text, constitute provisions of this Standard. At the time of publication, the editions indicated were valid. All standards are subject to revision, and parties to agreements based on this Standard are encouraged to investigate the possibility of applying the most recent editions of the standards indicated below. Standards organizations maintain registers of currently valid standards. ANSI/ASME B46.1-1995, Surface Texture (Surface Roughness, Waviness, and Lay) ISO 1000:1992, SI units and recommendations for the use of their multiples and of certain other units RMA/MPTA IP-20, Classical Multiple V-Belts (A, B, C, D, and E Cross Sections) RMA/MPTA IP-21, Double V-Belts (AA, BB, CC, and DD Cross Sections) RMA/MPTA IP-22, Narrow Multiple V-Belts (3V, 5V, and 8V Cross Sections) RMA/MPTA IP-26, V-Ribbed Belts (H, J, K, L, and M Cross Sections) 3 Scope 3.1 This Standard establishes acceptable manufacturing tolerances, methods of measuring, and proper application for drives using V-belts or V-ribbed belts. They may be used individually or in matched sets. 3.2 This Standard is unique to agricultural belt drives and should be used in lieu of standards for industrial drives published by the Rubber Manufacturers Association. 3.3 This Standard does not specify the load-life characteristics of belts. 3.4 This Standard does not include belts for automotive accessory drives, flat conveyor belting, flat power transmission belts, or synchronous belts. 3.5 The term belt(s) used throughout this Standard means V-belt(s) and V-ribbed belt(s). 3.6 In the interest of international standardization, metric-SI units, consistent with International Organization for Standardization Standard 1000, SI Units and Recommendations for the Use of Their Multiples and of Certain Other Units, are included in tables 1a through 15a. 4 Definitions 4.1 effective width of V-belt groove: A groove width characterizing the groove profile. It is a defined value not subject to tolerance and is usually Table 1 – Nominal dimensions of cross sections, in. Belt type Cross section bb hb hbb 1) sg 2) Classical V-belts HA 0.50 0.31 0.41 0.625 HB 0.66 0.41 0.50 0.750 HG 0.88 0.53 0.66 1.000 HD 1.25 0.75 0.84 1.438 Narrow V-belts H3V 0.38 0.31 0.38 0.406 H5V 0.62 0.53 0.62 0.688 H8V 1.00 0.91 1.00 1.125 Double-V belts HAA 0.50 0.41 HBB 0.66 0.53 HCC 0.88 0.69 Adjustable speed V-belts HI 1.00 0.50 HJ 1.25 0.59 HK 1.50 0.69 HL 1.75 0.78 HM 2.00 0.88 HN 2.25 0.94 HO 2.50 1.00 HQ 3.00 1.20 V-ribbed belts J See 0.16 0.092 L Fig. 0.38 0.185 M 1 0.66 0.370 1) Classical and narrow V-belts are also available in the joined belt configuration as illustrated in figure 1. 2) Sg is specified pulley groove spacing (see table 7). Table 1a – Nominal dimensions of cross sections, mm Belt type Cross section bb hb hbb 1) sg 2) Classical V-belts 13F 13 8 10 15 16F 16 10 13 19 22F 22 13 17 25.5 32F 32 19 21 36.5 Narrow V-belts 9FN 9 8 10 10.3 15FN 15 13 16 17.5 25FN 25 23 25 28.6 Double-V belts 13FD 13 10 16FD 16 13 22FD 22 18 Adjustable speed V-belts 25FV 25 13 32FV 32 15 38FV 38 18 44FV 44 20 51FV 51 22 57FV 57 24 63FV 63 26 76FV 76 30 V-ribbed belts FPJ See 4 2.34 FPL Fig. 10 4.70 FPM 1 17 9.40 1) Classical and narrow V-belts are also available in the joined belt configuration as illustrated in figure 1. 2) Sg is specified pulley groove spacing (see table 7). ASAE S211.5 JUL1998 „R2008…ASABE STANDARDS 2008 75
  3. 3. located at the outermost extremities of the straight side walls of the groove. For all V-belt measuring pulleys and for most machined-type pulleys, it coincides with the actual top width of the groove within reasonable tolerances. 4.2 effective diameter of V-belt pulley: The diameter of the pulley at the effective width of the pulley groove. (Formerly designated Effective outside diameter.) 4.3 effective diameter of V-ribbed pulley: The outside diameter of the pulley as a defined value at the specified pulley groove dimensions (without tolerances). 4.4 effective length: The length of a line circumscribing a belt at the level of the effective diameter of the measuring pulleys with the belt at a prescribed tension. 4.5 pitch width: The width of the belt at its neutral zone. 4.6 pitch width of groove: That width of the pulley groove which has the same dimension as the pitch width of the belt used with this pulley. 4.7 pitch diameter of pulley: The diameter of the pulley at the pitch width of pulley groove. 4.8 speed ratio and belt speed: Speed ratio is the ratio of the pitch diameter of the pulleys; generally expressed as a number equal to or greater than unity. Belt speed is the linear speed of the belt calculated using the pitch diameter of the driver pulley. 4.9 installation allowance: A design length factor permitting the unforced installation of a belt (see tables 12 through 15). 4.10 take-up allowance: A design length factor to permit sufficient tensioning over the life of the drive (see tables 12 through 15). 4.11 measuring pulleys: Pulleys used for determining the effective length of a belt (see tables 5 and 6 for dimensions). 4.12 ‘‘y’’ center distance: The center distance between measuring pulleys used to determine the effective length of a belt (see clause 7.1 for procedure). 4.13 clutching allowance: A design length factor to facilitate the belt drive systems operation as a clutch (see clause 9.5). 5 Cross sections 5.1 Nominal dimensions of belt cross sections for agricultural machines are shown in tables 1 and 2. Because of different constructions and methods of manufacture, the cross-sectional shape, dimensions, and included angle between the sidewalls may differ among manufacturers. However, all belts of a given cross section shall operate interchangeably in standard grooves of the same cross section, but belts of different manufacturers should never be mixed on the same drive (see tables 7 through 9). 6 Available lengths 6.1 The length ranges for agricultural belts are shown in tables 2 and 2a. Figure 1 – Belt types Figure 2 – Relationship between sheave or pulley outside diameter and the corresponding effective diameter ASAE S211.5 JUL1998 „R2008…76 ASABE STANDARDS 2008
  4. 4. Figure 3 – Diagram of a fixture for measured belts Figure 4 – Measuring belt ride, V-belt Table 2 – Effective length ranges, in. V-Belts V-Ribbed BeltsClassical1) Narrow1) Adjustable speed Double-V HA 25.0–130.0 H3V 25.0–140.0 HI 40.0–125.0 HAA 50.0–130.0 J 18.0–100.0 HB 30.0–300.0 H5V 50.0–355.0 HJ 50.0–160.0 HBB 50.0–300.0 L 50.0–145.0 HC 55.0–365.0 H8V 100.0–600.0 HK 60.0–180.0 HCC 85.0–365.0 M 90.0–365.0 HD120.0–365.0 HL 70.0–200.0 HM 80.0–200.0 HN 85.0–200.0 HO 90.0–200.0 HQ 90.0–200.0 1) Includes joined belts. Table 2a – Effective length ranges, mm V-Belts V-Ribbed BeltsClassical1) Narrow1) Adjustable speed Double-V 13F 635–3300 9FN 635–3560 25FV 1020–3175 13FC 1270–3300 FPJ 455–2540 16F 760–7620 15FN 1270–9020 32FV 1270–4065 22F 1400–9270 25FN 2540–15240 38FV 1525–4570 16FD 1270–7620 FPL 1270–3685 32F 3050–9270 44FV 1780–5080 51FV 2030–5080 22FD 2160–9270 FPM 2285–9270 57FV 2160–5080 63FV 2285–5080 76FV 2285–5080 1) Includes joined belts. Table 3 – Effective length tolerance, in. Effective length range Effective length tolerance Up through 51 Ϯ0.40 Over 51 to and incl. 98 Ϯ0.50 Over 98 to and incl. 124 Ϯ0.60 Over 124 to and incl. 157 Ϯ0.80 Over 157 to and incl. 197 Ϯ1.00 Over 197 to and incl. 248 Ϯ1.25 Over 248 to and incl. 315 Ϯ1.60 Over 315 to and incl. 390 Ϯ2.00 Table 3a – Effective length tolerance, mm Effective length range Effective length tolerance Up through 1300 Ϯ10 Over 1300 to and incl. 2500 Ϯ13 Over 2500 to and incl. 3150 Ϯ16 Over 3150 to and incl. 4000 Ϯ20 Over 4000 to and incl. 5000 Ϯ25 Over 5000 to and incl. 6300 Ϯ32 Over 6300 to and incl. 8000 Ϯ40 Over 8000 to and incl. 10000 Ϯ50 Table 4 – Limits of difference in effective length for matching sets, in. Effective length range Matching limits for one set Normal tensile modulus High tensile modulus1) Up through 54 0.16 0.08 Over 54 to and incl. 111 0.24 0.12 Over 111 to and incl. 236 0.39 0.20 Over 236 to and incl. 390 0.63 0.24 1) Examples of high tensile modulus belts are those containing aramid, fiberglass, or steel cable reinforcement. Table 4a – Limits of difference in effective length for matching sets, mm Effective length range Matching limits for one set Normal tensile modulus High tensile modulus1) Up through 1375 4 2 Over 1375 to and incl. 2820 6 3 Over 2820 to and incl. 6000 10 5 Over 6000 to and incl. 10.000 16 6 1) Examples of high tensile modulus belts are those containing aramid, fiberglass, or steel cable reinforcement. ASAE S211.5 JUL1998 „R2008…ASABE STANDARDS 2008 77
  5. 5. Figure 5 – Measuring belt ride, double-V belt Figure 6 – Measuring belt ride, V-ribbed belt Table 5 – Data for use in measuring belt effective length and belt ride (see figure 7) Belt cross section Pulley outside diameter Ϯ0.005 in. Pulley effective circum- ference, in. Pulley groove angle ␣ Ϯ0.25 deg Pulley groove top width bg , reference in. Diameter ball or rod dB Ϯ0.0005 in. Diameter over balls or rods Ϯ0.005 in. Groove depth hg , min. in. Total measuring force per belt, lb Maximum ride position of belt with respect to top of groove, in. Not joined Joined HA* 3.183 10.000 32 0.490 0.4375 3.499 0.490 65 0.10 0.18 HB* 4.775 15.000 32 0.630 0.5625 5.181 0.580 100 0.10 0.20 HC 7.958 25.000 34 0.879 0.7812 8.536 0.780 190 0.10 0.25 HD 11.141 35.000 34 1.259 1.1250 11.996 1.060 405 0.12 0.28 HAA 3.183 10.000 32 0.490 0.4375 3.499 0.490 65 0.03 HBB 4.775 15.000 32 0.630 0.5625 5.181 0.580 100 0.03 HCC 7.958 25.000 34 0.879 0.7812 8.536 0.780 190 0.03 H3V 3.820 12.000 38 0.350 0.3438 4.203 0.340 100 0.10 0.20 H5V 7.958 25.000 38 0.600 0.5938 8.633 0.590 225 0.12 0.25 H8V 15.916 50.000 38 1.000 1.0000 17.083 0.990 500 0.16 0.30 HI 6.366 20.000 26 1.000 0.9531 7.225 0.813 180 0.16 HJ 9.549 30.000 26 1.250 1.1875 10.601 0.938 290 0.16 HK 9.549 30.000 26 1.500 1.4375 10.879 1.000 405 0.18 HL 9.549 30.000 26 1.750 1.6875 11.158 1.125 560 0.20 HM 9.549 30.000 26 2.000 1.9062 11.266 1.188 740 0.20 HN 12.732 40.000 26 2.250 2.1250 14.558 1.339 740 0.22 HO 12.732 40.000 26 2.500 2.3750 14.836 1.456 740 0.22 HQ 12.732 40.000 30 2.8750 15.519 1.575 740 0.22 *Measuring pulley dimensions for HA and HB grooves are different than those recommended for production pulleys. The dimensions in this table reflect previous recommendations so that precision measuring pulleys will not need to be replaced and to assure correlation of length measurement. Table 5a – Data for use in measuring belt effective length and belt ride (see figure 7) Cross section Pulley outside diameter Ϯ0.10 mm Pulley effective circum- ference mm Pulley groove angle ␣ Ϯ0.25 deg Pulley groove top width bg , reference mm Diameter ball or rod dB Ϯ0.01 mm Diameter over balls or rods Ϯ0.10 mm Groove depth hg , min. mm Total measuring force per belt, N Maximum ride position of belt with respect to top of groove, mm Not joined Joined 13F 95.5 300 34 13 12.5Ϯ0.01 108.2 12 300 2.5 4.5 16F 143.2 450 34 16.5 15.5Ϯ0.02 157.7 14 450 2.5 5.0 22F 222.8 700 34 22.4 21.0Ϯ0.02 242.2 19 850 2.5 6.5 32F 318.3 1000 36 32.8 30.5Ϯ0.02 346.6 26 1800 3.0 7.0 13FD 95.5 300 34 13 12.5Ϯ0.01 108.2 12 300 0.8 16FD 143.2 450 34 16 15.5Ϯ0.02 157.7 14 450 0.8 22FD 222.8 700 36 22 21.0Ϯ0.02 242.2 19 850 0.8 9FN 95.5 300 38 8.89 8.50Ϯ0.01 104.3 8.5 445 2.5 5.1 15FN 191.0 600 38 15.24 15.00Ϯ0.02 207.8 15.0 1000 3.0 6.4 25FN 318.3 1000 38 25.40 25.00Ϯ0.02 346.3 25.1 2225 4.1 7.6 25FV 127.3 400 26 25.40 24.50Ϯ0.01 150.7 20 800 4.1 32FV 159.2 500 26 31.75 30.50Ϯ0.01 187.8 23 1300 4.1 38FV 191.0 600 26 38.10 36.50Ϯ0.01 224.8 26 1800 4.6 44FV 222.8 700 26 44.45 42.50Ϯ0.01 261.7 29 2500 5.1 51FV 254.6 800 26 50.80 48.50Ϯ0.01 298.7 32 3300 5.1 57FV 286.5 900 26 57.00 54.50Ϯ0.01 336.4 34 3300 5.6 63FV 318.3 1000 26 63.00 60.00Ϯ0.01 372.1 37 3300 5.6 76FV 318.3 1000 30 76.20 72.50Ϯ0.01 386.5 40 3300 5.6 ASAE S211.5 JUL1998 „R2008…78 ASABE STANDARDS 2008
  6. 6. Figure 7 – V-belt measuring pulley groove Figure 8 – V-ribbed belt measuring pulley groove Table 6 – Data for use in measuring effective lengths and ride of V-ribbed belts, in. (see figure 8) Cross section Pulley outside diameter, reference in. Pulley effective circumference, in. Pulley groove angle ␣ Ϯ0.25 deg Pulley groove spacing Sg , in. Diameter ball or rod dB Ϯ0.0005 in. Groove depth hg , min. in. Top radius rt ϩ0.005 Ϫ0.000 in. Maximum ride position of belt with respect to top of groove, in. Total measuring force per rib, lb J 3.183 10.000 40 0.092 0.0625 0.082 0.008 0.10 11 Ϯ0.001 L 6.366 20.000 40 0.185 0.1406 0.196 0.015 0.22 45 Ϯ0.002 M 9.549 30.000 40 0.370 0.2812 0.393 0.030 0.30 100 Ϯ0.0003 Table 6a – Data for use in measuring effective lengths and ride of V-ribbed belts, mm (see figure 8) Cross section Pulley outside diameter, reference mm Pulley effective circumference, mm Pulley groove angle ␣ Ϯ0.25 deg Pulley groove spacing Sg , mm Diameter ball or rod dB Ϯ0.01 mm Diameter over ball or rod Ϯ0.1 mm Groove depth hg , min. mm Top radius rt ϩ0.15 Ϫ0.00 mm Maximum ride position of belt with respect to top of groove mm Total measuring force per rib, newtons FPJ 95.5 300 40 2.34 1.50 97.5 2.06 0.20 2.50 50 (Ϯ0.03) FPL 159.2 500 40 4.70 4.00 163.5 4.92 0.40 5.60 200 (Ϯ0.05) FPM 254.6 800 40 9.40 7.00 259.2 10.03 0.75 7.60 450 (Ϯ0.08) Table 7a – Pitch diameter location, 2ap, mm Cross section Standard groove Deep groove 13F 6 141) 16F 8 18 22F 12 26 32F 18 36 1) Values for HA, 13F belts in RMA/MPTA combination A/B or 13C/16C grooves. Table 7 – Pitch diameter location, 2ap in. Cross section Standard groove Deep groove HA 0.25 0.531) HB 0.35 0.71 HC 0.40 1.01 HD 0.60 1.43 1) Values for HA, 13F belts in RMA/MPTA combination A/B or 13C/16C grooves. ASAE S211.5 JUL1998 „R2008…ASABE STANDARDS 2008 79
  7. 7. 7 Method of measuring belts 7.1 The effective length of an agricultural belt is determined using a measuring fixture (fig. 3), consisting of two pulleys of equal diameter having standard groove dimensions (see tables 5, 5a, 6, and 6a). One of the pulleys is fixed in position while the other is movable along a graduated scale with a specified force applied to it. The belt is rotated around the pulleys at least twice to properly seat it in the pulley grooves and to determine the midpoint of the center distance range. Effective length of the belt is determined by adding twice the average center distance measured on the fixture to the effective circumference of the measuring pulley specified in tables 5, 5a, 6, or 6a. 7.2 The belt ride dimension is checked by measuring the distance from the top of the belt to the top of the measuring pulley groove (figs. 4, 5, and 6). Belt ride shall be within the maximum limit given in tables 5, 5a, 6, and 6a. For V-belts the belt ride dimension is the only method of determining proper belt fit in the groove. 8 Specifications for pulleys used with V-belts and V- ribbed belts 8.1 Pulley groove dimensions 8.1.1 Refer to the appropriate RMA/MPTA standard for pulley groove dimensions as follows below. Please observe that the ASAE V-belt designations are prefixed with an H, indicating heavy duty construction, and the belts are not to be replaced with RMA/MPTA Standard belts even though they are dimensionally equivalent. (This terminology does not apply to V-ribbed belts). Classical Belt Drives RMA/MPTA STD IP20 Sections Sections A, B, C, D HA, HB, HC, HD 13C, 16C, 22C, 32C 13F, 16F, 22F, 32F (see clause 8.1.2) Narrow Belt Drives RMA/MPTA STD IP22 Sections H3V, H5V, H8V Sections 3V, 5V, 8V 9FN, 15FN, 25FN 9N, 15N, 25N Double V-Belt Drives RMA/MPTA STD IP21 Sections HAA, HBB, HCC Sections AA, BB, CC 13FD, 16FD, 22FD 13D, 16D, 22D V-Ribbed Belt Drives RMA/MPTA STD IP26 Sections J, L, M Sections J, L, M FPJ, FPL, FPM PJ, PL, PM Adjustable Speed Belt Drives See tables 8, 8a, 9, and 9a along with figures 9 and 10. NOTE 1: Please consult RMA or MPTA if there is uncertainty concerning the latest available standard. NOTE 2: Select deep groove pulleys for ‘‘quarter turn’’ or other situations where belts enter pulley groove at an angle. 8.1.2 Pitch diameter location (dimension 2ap in pulley groove tables) is dependent on belt construction and pitch diameter location of the belt. Refer to table 7 for recommended values of 2ap for HA, HB, HC, HD, 13F, 16F, 22F, and 32F sections. 8.2 Construction 8.2.1 Pulleys used with agricultural V-belts or V-ribbed belts shall be made of a material which is resistant to abrasion between the groove wall and the belt. The material should be sufficiently close-grained to allow the machining or forming of a smooth groove sidewall. 8.2.2 Machined pulleys shall have surface finishes equal to or smoother than the following values: Maximum surface roughness height (arithmetic average)1) Machined surface area µin. µm Pulley groove sidewall 125 3.2 Adjustable pulley sidewall 63 1.6 Flat pulley rim O.D. 250 6.3 Rim edges. rim O.D. 500 12.7 1) The measuring methods defined in ANSI/ASME B46.1 shall be used to deter- mine these values. 8.2.3 Pulleys formed from sheet metal shall be made so that the groove width and angle are uniform throughout the circumference of the pulley. The gage of the sheet metal used should be such that the groove will not deflect under the load imposed by the belt. 8.2.4 Adjustable-speed pulleys should be so designed that the movable disk is perpendicular to the axis of rotation at all times without appreciable runout or wobble. Failure to accomplish this results in a nonuniform groove width, which materially reduces belt life and may set up undesirable vibration of the machine on which it is used (see tables 8 and 8a). 9 Recommended design practices 9.1 Pulley diameters. In designing belt drives, it should be recognized that the use of larger pulley diameters will result in lower bearing loads and can result in the use of smaller and less expensive belt cross sections. Table 8 – Dimensions for pulleys using adjustable speed belts, in. Cross section Recommended minimum outside diameter Groove angle ␣Ϯ1 deg bg bgo 1) 2a 2av HI 7.60 26 1.00 1.65 0.30 2.84 HJ 9.75 26 1.25 2.11 0.37 3.73 HK 11.50 28 1.50 2.45 0.45 4.62 HL 14.00 26 1.75 3.02 0.52 5.52 HM 16.00 26 2.00 3.48 0.60 6.41 HN 17.75 26 2.25 3.94 0.68 7.36 HO 19.25 26 2.50 4.41 0.75 8.27 HQ 21.00 30 3.00 4.92 0.90 8.30 1) bgo is calculated to provide for a clearance of 0.260 in. as shown in figure 9 (dimension CL). Table 8a – Dimensions for pulleys using adjustable speed belts, mm Cross section Recommended minimum outside diameter Groove angle ␣Ϯ1 deg bg bgo 1) 2a 2av 25FV 190 26 25.40 42.0 7.6 72.0 32FV 250 26 31.75 54.7 9.4 95.5 38FV 290 26 38.10 65.1 11.4 117.0 44FV 355 26 44.45 76.9 13.2 140.5 51FV 405 26 50.80 88.7 15.2 164.0 57FV 450 26 57.00 100.2 17.2 186.9 63FV 490 26 63.00 112.0 19.0 210.0 76FV 530 30 76.20 132.9 23.0 211.7 1) bgo is calculated to provide for a clearance of 6.35 mm as shown in figure 9 (dimension CL). ASAE S211.5 JUL1998 „R2008…80 ASABE STANDARDS 2008
  8. 8. 9.2 Idlers 9.2.1 Idlers may be necessary on agricultural belt drives to provide take-up or to increase the arc of contact to obtain the required drive capacity. If an idler is needed, it should be located on the slack side of the drive. Other factors that affect the location of the idler are its effectiveness in belt take-up and its effect on arcs of contact. 9.2.2 An idler should have its axis of rotation perpendicular to the plane of the belt strand on which it runs. The idler mounting should be strong enough to maintain this relationship at all times. 9.2.3 If grooved idlers are used, the groove dimensions should be as shown in tables 9 and 9a. 9.2.4 Minimum diameters recommended for idlers are shown in tables 10 and 10a. 9.3 Length calculations 9.3.1 The approximate belt length for a two-pulley drive may be calculated using the formula: Leϭ2Cϩ1.57͑Deϩde͒ϩ ͑DeϪde͒2 4C (1) where: Le is effective length of belt; C is distance between centers of pulleys; De is effective diameter of large pulley; de is effective diameter of small pulley. (See figure 11). If pulley effective diameters (De and de) and belt effective length (Le) are known, the approximate center distance between pulleys may be calculated as follows: Figure 9 – Adjustable pulley dimensions Figure 10 – Adjustable speed companion pulley dimensions Figure 11 – Relation between center distance and belt length for drives with two pulleys Figure 12 – Belt drive with more than two pulleys Table 9 – Dimensions for adjustable speed companion or idler pulleys, in. (see figure 10) Cross section Minimum recommended effective diameter Groove angle ␣Ϯ0.5 deg bg Ϯ0.001 hg min. 2a HI 4.75 26 1.00 0.78 0.30 HJ 6.10 26 1.25 0.94 0.37 HK 7.25 26 1.50 1.05 0.45 HL 8.50 26 1.75 1.25 0.52 HM 9.50 26 2.00 1.40 0.60 HN 10.50 26 2.25 1.56 0.88 HO 11.00 26 2.50 1.69 0.75 HQ 12.00 30 3.00 1.97 0.90 Table 9a – Dimensions for adjustable speed companion or idler pulleys, mm (see figure 10) Cross section Minimum recommended effective diameter Groove angle ␣Ϯ0.5 deg bg Ϯ0.25 hg min. 2a 25FV 120 26 25.4 20 7.6 32FV 155 26 31.75 24 9.4 38FV 185 26 38.10 27 11.4 44FV 215 26 44.45 32 13.2 51FV 240 26 50.80 36 15.2 57FV 270 26 57.00 40 17.2 63FV 280 26 63.00 43 19.0 76FV 305 30 76.20 50 23.0 ASAE S211.5 JUL1998 „R2008…ASABE STANDARDS 2008 81
  9. 9. Cϭaϩͱa2 Ϫb (2) where: a ϭ Le/4Ϫ0.393͑Deϩde͒; b ϭ 0.125͑DeϪde͒2 . 9.3.2 To determine belt length when more than two pulleys are used on a drive (figure 12), lay out the pulleys in terms of their effective diameters to scale in the position desired when a new belt is applied and first brought to driving tension. The length of belt shall be the sum of the tangents and the connecting arcs around the effective diameters of the pulleys. The length of the connecting arcs can be calculated by the formula: Length of arcϭDeA/115 where: De is the effective outside diameter of the pulley; A is the angle in degrees subtended by the arc of belt contact on the pulley. Figure 13 – Installation and take-up of agricultural belts Table 10 – Minimum recommended diameters for idlers, in.1) Cross section Minimum O.D. of grooved inside idler Minimum O.D. of flat inside idler Minimum O.D. of outside idler Minimum face width of flat idler2) HA 2.75 2.25 4.25 1.00 HAA 4.25 4.25 4.25 1.00 HB 4.00 3.75 6.00 1.25 HBB 6.00 6.00 6.00 1.25 HC 6.75 5.75 8.50 1.50 HCC 8.50 8.50 8.50 1.50 HD 9.00 7.50 13.50 2.00 H3V 2.65 NR 4.25 1.13 H5V 7.10 NR 10.00 1.38 H8V 12.50 NR 17.50 1.75 J 0.80 0.65 1.25 BW L 3.00 2.63 4.50 BW M 7.00 6.25 10.50 BW HI 5.50 4.50 NR 1.75 HJ 6.75 5.63 NR 2.00 HK 8.00 6.75 NR 2.25 HL 9.25 7.75 NR 2.50 HM 10.50 8.75 NR 2.75 HN 11.75 9.88 NR 3.00 HO 13.00 11.00 NR 3.25 HQ 15.00 12.60 NR 4.00 1) NR, not recommended; BW, belt width + 0.75 in. 2) For both inside and outside idlers. Table 10a – Minimum recommended diameters for idlers, mm1) Cross section Minimum O.D. of grooved inside idler Minimum O.D. of flat inside idler Minimum O.D. of outside idler Minimum face width of flat idler2) 13F 70 57 108 25 13FD 108 108 108 25 16F 102 95 152 32 16FD 152 152 152 32 22F 172 146 216 38 22FD 216 216 216 38 32F 229 190 343 51 9FN 67 NR 108 29 15FN 180 NR 254 35 25FN 318 NR 444 44 FPJ 20 16 32 BW FPL 76 67 114 BW FPM 178 159 267 BW 25FV 140 114 NR 44 32FV 172 143 NR 51 38FV 203 172 NR 57 44FV 235 197 NR 64 51FV 267 222 NR 70 57FV 299 251 NR 76 63FV 330 279 NR 83 76FV 350 320 NR 100 1) NR, not recommended; BW, belt width + 19 mm. 2) For both inside and outside idlers. ASAE S211.5 JUL1998 „R2008…82 ASABE STANDARDS 2008
  10. 10. Table 11 – Minimum tangent lengths for 180 deg twist, in. Cross section Minimum tangent length, in. HA 18 HB 22 HC 28 HD 37 H3V 18 H5V 28 NOTE – For all other cross sections, consult belt manufacturer. Table 11a – Minimum tangent lengths for 180 deg twist, mm Cross section Minimum tangent length, mm 13F 460 16F 560 22F 710 32F 940 9FN 460 15FN 710 NOTE – For all other cross sections, consult belt manufacturer. Table 12 – Installation and take-up allowances for classical, joined classical and double-V belts, in. Effective length range Allowance for installation1) Allowance for stretch and wear2) HA HAA HA joined HB HBB HB joined HC HCC HC joined HD HD joined Normal tensile modulus High tensile modulus Up through 51.2 1.09 1.25 1.25 1.39 1.44 1.64 1.54 1.28 Over 51.2 to & incl. 98.4 1.38 1.54 1.54 1.68 1.73 1.93 2.95 2.46 Over 98.4 to & incl. 124.0 1.58 1.74 1.74 1.88 1.93 2.13 3.72 3.10 Over 124.0 to & incl. 157.5 1.92 2.07 2.07 2.22 2.26 2.47 2.51 2.75 4.73 3.94 Over 157.5 to & incl. 196.9 2.43 2.57 2.62 2.83 2.97 3.11 5.91 4.92 Over 196.9 to & incl. 248.0 2.89 3.03 3.08 3.28 3.42 3.56 7.44 6.20 Over 248.0 to & incl. 315.0 3.50 3.65 3.69 3.90 4.04 4.18 9.45 7.88 Over 315.0 to & incl. 393.7 4.41 4.61 4.75 4.89 11.81 9.84 NOTE – Refer to table 14 for footnote key. Table 12a – Installation and take-up allowances for classical, joined classical and double-V belts, mm Effective length range Allowance for installation1) Allowance for stretch and wear2) 13F 13FD 13F joined 16F 16FD 16F joined 22F 22FD 22F joined 32F 32F joined Normal tensile modulus High tensile modulus Up through 1300 28 32 32 35 37 42 39 33 Over 1300 to & incl. 2500 35 39 39 43 44 49 75 62 Over 2500 to & incl. 3150 40 44 44 48 49 54 95 79 Over 3150 to & incl. 4000 49 53 53 56 57 63 66 70 120 100 Over 4000 to & incl. 5000 62 65 67 72 75 79 150 125 Over 5000 to & incl. 6300 73 77 78 83 87 90 189 157 Over 6300 to & incl. 8000 89 93 94 99 103 106 240 200 Over 8000 to & incl. 10,000 112 117 121 124 300 250 NOTE – Refer to table 14a for footnote key. Table 13 – Installation and take-up allowances for narrow and joined narrow belts, in. Effective length range Allowance for installation1) Allowance for stretch and wear2) 3V 3V joined 5V 5V joined 8V 8V joined Normal tensile modulus High tensile modulus Up through 51.2 1.09 1.20 1.44 1.58 1.54 1.28 Over 51.2 to & incl. 98.4 1.38 1.49 1.73 1.87 2.32 2.47 2.95 2.46 Over 98.4 to & incl. 124.0 1.58 1.69 1.93 2.07 2.53 2.67 3.72 3.10 Over 124.0 to & incl. 157.5 2.26 2.40 2.86 3.00 4.73 3.94 Over 157.5 to & incl. 196.9 2.62 2.76 3.22 3.36 5.91 4.92 Over 196.9 to & incl. 248.0 3.08 3.22 3.67 3.81 7.44 6.20 Over 248.0 to & incl. 315.0 3.69 3.83 4.29 4.43 9.45 7.88 Over 315.0 to & incl. 393.7 5.00 5.15 11.81 9.84 NOTE – Refer to table 14 for footnote key. ASAE S211.5 JUL1998 „R2008…ASABE STANDARDS 2008 83
  11. 11. Table 13a – Installation and take-up allowances for narrow and joined narrow belts, mm Effective length range Allowance for installation1) Allowance for stretch and wear2) 9FN 9FN joined 15FN 15FN joined 25FN 25FN joined Normal tensile modulus High tensile modulus Up through 1300 28 30 37 40 39 33 Over 1300 to & incl. 2500 35 38 44 47 59 63 75 62 Over 2500 to & incl. 3150 40 43 49 53 64 68 95 79 Over 3150 to & incl. 4000 57 61 73 76 120 100 Over 4000 to & incl. 5000 67 70 82 85 150 125 Over 5000 to & incl. 6300 78 82 93 97 189 157 Over 6300 to & incl. 8000 94 97 109 113 240 200 Over 8000 to & incl. 10,000 127 131 300 250 NOTE – Refer to table 14a for footnote key. Table 14 – Installation and take-up allowances for V-ribbed belts, in. Effective length range Allowance for installation1) Allowance for stretch and wear2) J L M Normal tensile modulus High tensile modulus Up through 51.2 0.86 1.20 1.54 1.28 Over 51.2 to & incl. 98.4 1.15 1.49 1.93 2.95 2.46 Over 98.4 to & incl. 124.0 1.69 2.13 3.72 3.10 Over 124.0 to & incl. 157.5 2.03 2.47 4.73 3.94 Over 157.5 to & incl. 196.9 2.83 5.91 4.92 Over 196.9 to & incl. 248.0 3.28 7.44 6.20 Over 248.0 to & incl. 315.0 3.90 9.45 7.88 Over 315.0 to & incl. 393.7 4.61 11.81 9.84 1) Allowance for installation includes the minus manufacturing length tolerance from table 3, the difference between the length of belt under no tension and the length under installation tension, and an amount for installing the belts over the pulley flanges without injury. 2) Allowance for stretch and wear includes the plus manufacturing tolerance from table 3 as well as an allowance for the stretch and wear of the belt resulting from service on the drive (see tables 12, 13, 14, and 15). Installation and take-up methods are shown in figure 13. In the first sketch, the center distance of the drive can be adjusted to furnish the necessary installation and take-up allowances. In the second sketch, the center distance is fixed, and the allowance for installation and take-up is provided by the idler pulleys. Examples of the calculation of center distance, effective length, and installation and take-up allowances are shown in Annex A. Table 14a – Installation and take-up allowances for V-ribbed belts, mm Effective length range Allowance for installation1) Allowance for stretch and wear 2) FPJ FPL FPM Normal tensile modulus High tensile modulus Up through 1300 22 30 39 33 Over 1300 to & incl. 2500 29 38 49 75 62 Over 2500 to & incl. 3150 43 54 95 79 Over 3150 to & incl. 4000 52 63 120 100 Over 4000 to & incl. 5000 72 150 125 Over 5000 to & incl. 6300 83 189 157 Over 6300 to & incl. 8000 99 240 200 Over 8000 to & incl. 10,000 117 300 250 1) Allowance for installation includes the minus manufacturing length tolerance from table 3a, the difference between the length of belt under no tension and the length under installation tension, and an amount for installing the belts over the pulley flanges without injury. 2) Allowance for stretch and wear includes the plus manufacturing tolerance from table 3a as well as an allowance for the stretch and wear of the belt resulting from service on the drive (see tables 12a, 13a, 14a, and 15a). Installation and take-up methods are shown in figure 13. In the first sketch, the center distance of the drive can be adjusted to furnish the necessary installation and take-up allowances. In the second sketch, the center distance is fixed, and the allowance for installation and take-up is provided by the idler pulleys. Table 15 – Installation and take-up allowances for adjustable speed belts, in. Effective length range Allowance for installation1) Allowance for stretch and wear2) HI HJ HK HL HM HN HO HQ Normal tensile modulus High tensile modulus Up through 51.2 1.39 1.53 1.69 1.83 1.99 2.08 2.18 2.36 1.54 1.28 Over 51.2 to & incl. 98.4 1.68 1.82 1.98 2.12 2.28 2.37 2.47 2.70 2.95 2.46 Over 98.4 to & incl. 124.0 1.88 2.02 2.18 2.32 2.48 2.57 2.67 2.95 3.72 3.10 Over 124.0 to & incl. 157.5 2.22 2.36 2.51 2.66 2.81 2.91 3.00 3.15 4.73 3.94 Over 157.5 to & incl. 196.9 2.87 3.01 3.17 3.27 3.36 3.54 5.91 4.92 1) Installation allowance on a drive using two adjustable pulleys can be neglected. 2) Allowance for stretch and wear includes the plus manufacturing tolerance from table 3 as well as an allowance for the stretch and wear of the belt resulting from service on the drive (see tables 12, 13, 14, and 15). Installation and take-up methods are shown in figures 11 and 12. In the first sketch, the center distance of the drive can be adjusted to furnish the necessary installation and take-up allowances. In the second sketch, the center distance is fixed, and the allowance for installation and take-up is provided by the idler pulley. Examples of the calculation of center distance, effective length, and installation and take-up allowances are shown in Annex A. ASAE S211.5 JUL1998 „R2008…84 ASABE STANDARDS 2008
  12. 12. 9.3.3 Belt manufacturers have computer programs for calculating belt length and will provide assistance in solving complex drive geometries. 9.4 Installation and take-up (see figure 13) 9.4.1 The calculated belt length (clause 9.3) shall be the effective length of an ideal belt under operating tension. A belt drive shall be arranged so that any belt within the length tolerances given in tables 3 and 3a can be placed in the pulley groove without forcing. In addition, provision shall be made to compensate for the change in effective length caused by the seating of the belt in the pulley groove and by the stretch and wear of the belt during its life. 9.4.2 Installation and take-up allowance specified in tables 12, 12a, 13, 13a, 14, 14a, 15, and 15a shall be provided on every belt drive to ensure satisfactory operation. 9.5 Clutching belt drives. Properly designed belt drive systems can be used as a clutching mechanism. The required belt effective length is determined by adding the clutching allowance to the calculated declutched length. The clutching allowance is calculated from the formula Figure 14 – Typical two-pulley drive with one shaft movable for take-up Table 15a – Installation and take-up allowances for adjustable speed belts, mm Effective length range Allowance for installation1) Allowance for stretch and wear2) 25FV 32FV 38FV 44FV 51FV 57FV 63FV 76FV Normal tensile modulus High tensile modulus Up through 1300 35 39 43 46 51 53 55 60 39 33 Over 1300 to & incl. 2500 43 46 50 54 58 60 63 70 75 62 Over 2500 to & incl. 3150 48 51 55 59 63 65 68 75 95 79 Over 3150 to & incl. 4000 56 60 64 68 71 74 76 80 120 100 Over 4000 to & incl. 5000 73 76 81 83 85 90 150 125 1) Installation allowance on a drive using two adjustable pulleys can be neglected. 2) Allowance for stretch and wear includes the plus manufacturing tolerance from table 3a as well as an allowance for the stretch and wear of the belt resulting from service on the drive (see tables 12a, 13a, 14a, and 15a). Installation and take-up methods are shown in figures 11 and 12. In the first sketch, the center distance of the drive can be adjusted to furnish the necessary installation and take-up allowances. In the second sketch, the center distance is fixed, and the allowance for installation and take-up is provided by the idler pulley. ASAE S211.5 JUL1998 „R2008…ASABE STANDARDS 2008 85
  13. 13. Clutching allowance (min.)ϭ3.14 hbͩ ␪ 306 degͪ+(minus belt length tol.) where hb is belt thickness (see tables 1 and 1a); ␪ is arc of contact on clutching pulley, deg.; Minus belt length toleranceϭvalues from tables 3 and 3a. 9.5.1 The calculated clutching allowance should be equal to or exceed the allowance for installation given in tables 12 through 15 and 12a through 15a. 9.5.2 The drive design should provide proper belt guide(s) to permit the belt to disengage from the driving pulley. 9.6 Cross drives, mule drives, and other twisted-belt drives 9.6.1 The minimum tangent length for a 180 deg twist in a belt is shown in Tables 11 and 11a. The minimum tangent length for any amount of twist other than 180 deg can be obtained by multiplying the minimum tangent length by the fraction degrees of twist required 180 . Adjustable-speed belts are not recommended for these drives. 9.6.2 Quarter-turn drives. On quarter-turn drives, the angle of entry of the belt into the plane of the pulley grooves should not exceed 5 deg. A center distance at least 5.5 times the diameter of the large pulley is necessary to ensure this condition where one belt is used. 9.7 Specification of belt drives. In submitting a drive design problem to engineering departments of the different belt manufacturers, it is strongly recommended that complete information be given. Annex A provides examples of the data needed. Figure 15 – Two-pulley drive with centers fixed and idler used for take-up ASAE S211.5 JUL1998 „R2008…86 ASABE STANDARDS 2008
  14. 14. Annex A (informative) Examples of the calculation of belt length, center distance, installation and take-up allowances, and inspection requirements EXAMPLE 1 (Refer to figure 14) The drive consists of two pulleys; one of the shafts may be moved for installation and take-up. Effective diameters have been determined. The preferred center distance is about 20 in. Belt length and center distance 1. Substitute the effective diameters and preferred center distance in formula [1]. The effective belt length required is 79.02 in. 2. Round to the nearest tenth of an inch, or 79.0 in. 3. This length substituted in formula [2] will give a center distance of 19.97 in. Installation allowance 1. From table 12 the installation allowance will be 1.54 in. 2. Subtract this amount from the effective belt length of 79.0 in. to get a length of 77.46 in. 3. This length substituted in formula [2] will give a center distance of 19.16 in., the minimum center distance needed for installation of the belt. Take-up allowance 1. From table 12 the allowance needed for take-up is 2.95 in. 2. Add this amount to the effective belt length of 79.0 in. to get a maximum length of 81.95 in. 3. This length substituted in formula [2] will give the maximum required center distance of 21.51 in. Inspection requirement Fill in the inspection requirements for the belt required in Example 1. 1. Fill in values from table 5 as follows: Tensionϭ100 lb hgϭ0.580 in. bgϭ0.630 in. ␣ϭ32 deg. ODϭ4.775 in. Maximum ride position of belt with respect to top of groove is 0.09 in. (Note: From table 5, the effective circumference of the measuring pulley is 15.000 in.) Figure 16 – Double-V belt drive with four pulleys on fixed centers ASAE S211.5 JUL1998 „R2008…ASABE STANDARDS 2008 87
  15. 15. 2. From the effective length of 79.0 in., subtract 15.000 in. and divide the remainder by 2 to find Y, or Yϭ͑79.0Ϫ15.000͒/2ϭ32.0 in. 3. From table 3, the length tolerance is Ϯ0.50 in. The tolerance on dimension Y will be equal to these length tolerances divided by 2, or Tolerance on YϭϮ0.25 in. EXAMPLE 2 (Refer to figure 15) The effective diameters have been determined. Both shafts are fixed in position and the center distance is 26.66 in. An 8.5 in. outside diameter flat idler will be used for take-up on the drive. Belt length 1. Substitute the effective outside diameters of the pulleys and the fixed center distance of 26.66 in. in formula [1]. The resulting belt length is 80.01 in. 2. Since the centers cannot be moved for installation, the shortest possible belt must go on the drive with the idler out of the way. Consequently, the installation allowance must be added to the belt length obtained above. The installation allowance from table 12 is 1.73 in. This added to the length of 80.01 in. gives a required effective belt length of 81.74 in. Take-up allowances From table 12, the take-up allowance needed for this belt is 2.95 in. This amount added to the effective belt length of 81.74 in. gives a maximum length of 84.69 in. By one of the methods outlined above for determining belt length when more than two pulleys are used on a drive, locate the position of the idler so that it will provide take-up for this length of belt. Inspection requirements Fill in the inspection requirements for the belt required in example 2. 1. Fill in values from table 5 as follows: Tensionϭ190 lb hgϭ0.780 in. bgϭ0.879 in. ␣ϭ34 deg ODϭ7.958 in. Maximum ride position of belt with respect to top of groove is 0.09 in. (Note: From table 5, the effective circumference of the measuring pulley is 25.000 in.) 2. From the effective length of 81.74 in. subtract 25.000 in. and divide the remainder by 2 to find Y, or Yϭ(81.74Ϫ25.000)/2ϭ28.37 in. 1. From table 3, the length tolerance is Ϯ0.50 in. The tolerance on dimension Y will be equal to these length tolerances divided by 2, or Tolerance on YϭϮ0.25 in. EXAMPLE 3 (Refer to figure 16) 2. The effective diameters have been selected and shaft centers have been located approximately. All shafts will be fixed in position and belt take-up will be accomplished by means of a grooved idler pulley. Belt length 1. With the idler in its ‘‘installation position,’’ use one of the methods outlined above for determining belt length when more than two pulleys are used on a drive. 2. To find the length of belt for the drive, add to the length obtained in step 1 the allowance for installation from table 12. Take-up allowance To the length of belt for the drive, add the allowance for take-up from table 12. Check the drive with the idler in its maximum take-up position to see that this length of belt can be accommodated. Inspection requirements Fill in the inspection requirements for the belt required in example 3. 1. Fill in values from table 5 as follows: Tensionϭ190 lb hgϭ0.780 in. bgϭ0.630 in. ␣ϭ34 deg ODϭ7.958 in. Maximum ride position of belt with respect to top of groove is 0.03 in. (Note: From table 5, the effective circumference of the measuring pulley is 25.000 in.) 2. From the effective length of 176.7 in., subtract 25.000 in. and divide the remainder by 2 to find Y, or Yϭ͑176.7Ϫ25.000͒/2ϭ75.85 in. 3. From table 3, the length tolerance is Ϯ1.00 in. The tolerance on dimension Y will be equal to these length tolerances divided by 2, or Tolerance on YϭϮ0.50 in. ASAE S211.5 JUL1998 „R2008…88 ASABE STANDARDS 2008

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