ANSI EP389.2-1993 Auger Flighting Design Considerations.pdf

1、 ANSI/ASAE EP389.2 JUN1993 (R2015) Auger Flighting Design Considerations American Society of Agricultural and Biological Engineers ASABE is a professional and technical organization, of members worldwide, who are dedicated to advancement of engineering applicable to agricultural, food, and biologica

2、l 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

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6、nd 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 oth

7、er 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 necessari

8、ly 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 CAUTION NOTICE: ASABE and ANSI standards may be revised or withdrawn at any time.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

9、reaffirm, revise, or withdraw each standard. Copyright American Society of Agricultural and Biological Engineers. All rights reserved. ASABE, 2950 Niles Road, St. Joseph, Ml 49085-9659, USA, phone 269-429-0300, fax 269-429-3852, hqasabe.org ANSI/ASAE EP389.2 JUN1993 (R2015) Copyright American Societ

10、y of Agricultural and Biological Engineers 1 ANSI/ASAE EP389.2 JUN1993 (R2015) Approved January 1994; reaffirmed January 2015 as an American National Standard Auger Flighting Design Considerations Developed by the Auger Flight Subcommittee of the ASAE Power and Machinery Division Standards Committee

11、; approved by the Power and Machinery Division Standards Committee; adopted by ASAE December 1977; revised editorially December 1980, January 1982; reconfirmed December 1982; revised March 1988; reaffirmed December 1992; revised June 1993; approved as an American National Standard January 1994; revi

12、sed editorially by ASAE May 1997; reaffirmed by ASAE December 1998, December 1999; reaffirmed by ANSI June 2000; reaffirmed by ASAE January 2001, February 2005; reaffirmed by ANSI March 2005; reaffirmed by ASABE and ANSI January 2010, January 2015. Keywords: Auger, Conveyors, Flighting 1 Purpose and

13、 Scope This Engineering Practice is a guide for designing conveyor augers using steel helicoid flighting and for specifying helicoid flighting as generally used in agricultural equipment. 2 Normative Reference The following standard contains provisions which, through reference in this text, constitu

14、te provisions of this Engineering Practice. At the time of publication, the edition indicated was valid. All standards are subject to revision, and parties to agreements based on this Engineering Practice are encouraged to investigate the possibility of applying the most recent edition of the standa

15、rd indicated below. Standards organizations maintain registers of currently valid standards. ANSI B32.3, Preferred Metric Sizes for Flat Metal Products 3 Flighting Material 3.1 Physical properties generally limit the number of materials that can be formed into helicoid flighting. 3.2 Present day hel

16、icoid manufacturing machines are designed for ferrous metals that are ductile and are therefore generally not used in manufacture of auger flighting from non-ferrous and plastic materials. Other means, such as molding, extruding, forming, and casting, must be developed for these materials. The heavy

17、 deformation of the material as it goes through the forming rolls of the flighting machine demands a material that is very ductile and which will stand large amounts of elongation and bending without fracture and wrinkling. 3.3 Hot rolled and cold rolled carbon steels with specifications in the area

18、 of AISI (American Iron and Steel Institute) 1006, 1008, 1010, and 1012 and hardnesses of no more than 115 to 140 BHN (Brinell Hardness Number) may be used satisfactorily. The more difficult the flighting is to make, the lower the carbon content must be in the strip. In many cases, it is necessary t

19、o use fully killed, fine grained steel. Stainless steel requires special consideration. Consult manufacturer before designing. ANSI/ASAE EP389.2 JUN1993 (R2015) Copyright American Society of Agricultural and Biological Engineers 2 4 Flighting Dimensions 4.1 Illustrations and standard tolerances for

20、appropriate dimensions are shown in Figure 1 and Table 1. Table 1 Flighting tolerances mm (in.) Inside diameter 0 to 40 (1.6) +3.0 (0.12) 0.0 40 (1.6) to 70 (2.8) +5.0 (0.20) 0.0 70 (2.8) and over +7.0 (0.28) 0.0 Strip width 20 (0.8) to 50 (2.0) +0.8 (0.03)* 0.8 (0.03)* 50 (2.0) to 120 (5.0) +1.2 (0

21、.05)* 1.2 (0.05)* 120 (5.0) to 250 (10.0) +1.5 (0.06)* 1.5 (0.06)* 250 (10.0) to 300 (12.0) +2.4 (0.09)* 2.4 (0.09)* Pitch 0 to 149 (6.0) +15.0 (0.59) 15.0 (0.59) 150 (6.0) to 249 (10.0) +20.0 (0.79) 20.0 (0.79) 250 (10.0) to 349 (14.0) +25.0 (1.00) 25.0 (1.00) 350 (14.0) and over +40.0 (1.57) 40.0

22、(1.57) Outside diameter (welded assembly) 0 to 200 (8.0) +3.0 (0.12) 3.0 (0.12) 200 (8.0) to 350 (14.0) +5.0 (0.20) 5.0 (0.20) 350 (14.0) and over +7.0 (0.28) 7.0 (0.28) Length 0 to 1500 (60.0) +0.0 13.0 (0.51) 1500 (60.0) and over +0.0 20.0 (0.79) Strip thickness Standard mill tolerance for thickne

23、ss specified. *Mill edge tolerance. If tighter tolerances are required, they should be specified on the print and have the concurrence of the supplier. ANSI/ASAE EP389.2 JUN1993 (R2015) Copyright American Society of Agricultural and Biological Engineers 3 Figure 1 Standard auger flighting features 4

24、.2 Inside diameter, I.D. The selection of the nominal inside diameter will depend on the type of fit desired. Inside diameters less than 1/5 of the outside diameter should be avoided. Tolerance of shaft diameter used must be considered in determining the inside diameter. 4.3 Outside diameter, O.D. T

25、he outside diameter is determined by adding 2 times the strip width to the I.D. The O.D. is not specified except as a reference dimension for the loose helicoid flighting. O.D. tolerances on the completed welded assembly are given in Table 1. 4.4 Pitch of flighting. The most economical pitch is equa

26、l to the flighting outside diameter. Pitches shorter than 0.9 O.D. and longer than 1.5 O.D. are generally not recommended. Pitches shorter than 0.9 O.D. or longer than 1.5 O.D. should only be used after verifying that the supplier has the capability of making the part. 4.5 Strip thickness. The strip

27、 thickness may be determined from the outer edge thickness desired. The outer edge thickness is approximately one half the strip thickness, but if greater accuracy is required, it may be calculated. In rolling flighting the material is stretched and thinned along the outer edge and compressed and th

28、ickened slightly on the inner edge. The neutral axis is out about 1/5 the strip width from the I.D. (see Figure 2). Calculate the edge and strip thicknesses as follows: D = O.D. d = I.D. P = pitch W = strip width= (D d)/2 C = O.D. circumference = D N = neutral axis diameter = d + 2W/5 A = neutral ax

29、is circumference = N H = length of helix at N in one pitch = 22PA + ANSI/ASAE EP389.2 JUN1993 (R2015) Copyright American Society of Agricultural and Biological Engineers 4 L = length of helix at O.D. in one pitch = 22PC +T = strip thickness = (LE)/H E = outer edge thickness = (HT)/L Strip thickness

30、tolerance should be standard mill tolerance for strip thickness specified. Figure 2 Flighting dimension definitions 4.6 Cup or lean of flighting. In most cases, the radial centerline of the flighting material should be perpendicular to the auger axis within the tolerances shown in Figure 1. There ar

31、e situations where deliberate cupping or leaning of the flighting toward the material flow will improve performance. The maximum degree or amount of lean is dependent on the capabilities of the supplier but, generally should be less than 15 deg. Angular tolerances with the auger axis should be the s

32、ame as with perpendicular flighting. 4.7 End shearing. Flighting should be sheared on a radial line passing through the centerline of the auger flighting. Allowable cut variations are given in Figure 1. 5 Hand of Flighting Flighting may be rolled with either a right hand or left hand helix as shown

33、in Figure 3. Figure 3 Flow ANSI/ASAE EP389.2 JUN1993 (R2015) Copyright American Society of Agricultural and Biological Engineers 5 6 Flighting Sizes 6.1 Flighting is specified by the I.D., strip width, strip thickness, pitch, and length. O.D. and outer edge thickness are reference only.1 6.2 Strip w

34、idth should be specified in multiples of 10 mm; for example: 40 mm, 50 mm, 60 mm, etc. Where these increments are too large, even multiples of 5 mm should be used. If used, inch dimensions should be specified in even multiples of 1/4 in.; for example: 1 in., 1 1/4 in., 1 1/2 in., etc. 6.3 Strip thic

35、kness should be specified in accordance with ANSI B32.3. Sizes of whole 1 mm increments are preferred; for example, 4 mm, 5 mm, 6 mm, etc. If used, inch dimensioned parts should specify the decimal equivalents of the Manufacturers Standard Gauge sizes; for example: 0.1196 in. (11 ga.), .1345 in. (10

36、 ga.), etc. NOTE: Decimal equivalents used should be in accordance with local steel purchasing conventions. 6.4 The strip width should not exceed 25 times the strip thickness; for example: 4 mm thick100 mm maximum width. 1Specifying flighting by the I.D., O.D., strip thickness, pitch, and length is

37、not recommended. If that method is used, the strip width will be half the difference between the O.D. and I.D. by default and might result in an odd and/or unique strip size. This unique size would present no problem to the strip supplier, who must slit the strip in most cases and can slit to any si

38、ze. It could, however, cause additional inventory within the company where the flighting is formed or used if it is different from other strips currently in inventory. Specifying the strip width in the increments shown in this Engineering Practice (or common with an existing auger) and adjusting the O.D. slightly can help reduce parts proliferation and inventory levels without affecting auger performance.