1、 ANSI/ASA S2.75-2017/Part 2 AMERICAN NATIONAL STANDARD Shaft Alignment Methodology, Part 2: Vocabulary Accredited Standards Committee S2, Mechanical Vibration and Shock Standards Secretariat Acoustical Society of America 300 Walt Whitman Road, Suite 300 Melville, NY 11747ANSI/ASAS2.75-2017/Part2 The
2、 American National Standards Institute, Inc. (ANSI) is the national coordinator of voluntary standards development and the clearinghouse in the U.S.A. for information on national and international standards. The Acoustical Society of America (ASA) is an organization of scientists and engineers forme
3、d in 1929 to increase and diffuse the knowledge of acoustics and to promote its practical applications. ANSI/ASA S2.75-2017/Part 2 AMERICAN NATIONAL STANDARD Shaft Alignment Methodology, Part 2: Vocabulary Secretariat: Acoustical Society of America Approved on June 6, 2017, by: American National Sta
4、ndards Institute, Inc. Abstract The purpose of this standard is to define terminology unique to the alignment of machinery that has been in common use among engineers and technicians working in the field. Words and phrases are presented in alphabetical order. This vocabulary is intended to be used w
5、ith the ANSI/ASA S2.75 series Shaft Alignment Methodology. AMERICAN NATIONAL STANDARDS ON ACOUSTICS The Acoustical Society of America (ASA) provides the Secretariat for Accredited Standards Committees S1 on Acoustics, S2 on Mechanical Vibration and Shock, S3 on Bioacoustics, S3/SC 1 on Animal Bioaco
6、ustics, and S12 on Noise. These committees have wide representation from the technical community (manufacturers, consumers, trade associations, organizations with a general interest, and government representatives). The standards are published by the Acoustical Society of America through the America
7、n Institute of Physics as American National Standards after approval by their respective Standards Committees and the American National Standards Institute (ANSI). These standards are developed and published as a public service to provide standards useful to the public, industry, and consumers, and
8、to Federal, State, and local governments. Each of the accredited Standards Committees (operating in accordance with procedures approved by ANSI) is responsible for developing, voting upon, and maintaining or revising its own Standards. The ASA Standards Secretariat administers Committee organization
9、 and activity and provides liaison between the Accredited Standards Committees and ANSI. After the Standards have been produced and adopted by the Accredited Standards Committees, and approved as American National Standards by ANSI, the ASA Standards Secretariat arranges for their publication and di
10、stribution. An American National Standard implies a consensus of those substantially concerned with its scope and provisions. 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. Su
11、bstantial 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 towards their resolution. The use of an American National Standard is completely voluntary. Their existence do
12、es not in any respect preclude anyone, whether he or she has approved the Standards or not, from manufacturing, marketing, purchasing, or using products, processes, or procedures not conforming to the Standards. NOTICE: This American National Standard may be revised or withdrawn at any time. The pro
13、cedures of the American National Standards Institute require that action be taken periodically to reaffirm, revise, or withdraw this Standard. Acoustical Society of America Standards Secretariat 1305 Walt Whitman Road, Suite 300 Melville, New York 11747 Telephone: 1 (631) 390-0215 Fax: 1 (631) 923-2
14、875 E-mail: asastdsacousticalsociety.org 2017 by Acoustical Society of America. This standard may not be reproduced in whole or in part in any form for sale, promotion, or any commercial purpose, or any purpose not falling within the provisions of the U.S. Copyright Act of 1976, without prior writte
15、n permission of the publisher. For permission, address a request to the Standards Secretariat of the Acoustical Society of America. 2017 Acoustical Society of America All rights reserved i Contents 1 Scope 1 2 Terms and definitions 1 Bibliography . 16 2017 Acoustical Society of America All rights re
16、served iiForeword This Foreword is for information only, and is not a part of ANSI/ASA S2.75-2017/Part 2 American National Standard Shaft Alignment Methodology, Part 2: Vocabulary. As such, this Foreword may contain material that has not been subjected to public review or a consensus process. In add
17、ition, it does not contain requirements necessary for conformance to the standard. This standard comprises a part of a group of definitions, standards, and specifications for use in mechanical vibration and shock. It was developed and approved by Accredited Standards Committee S2 Mechanical Vibratio
18、n and Shock, under its approved operating procedures. Those procedures have been accredited by the American National Standards Institute (ANSI). The Scope of Accredited Standards Committee S2 is as follows: Standards, specification, methods of measurement and test, and terminology in the field of me
19、chanical vibration and shock, and condition monitoring and diagnostics of machines, including the effects of exposure to mechanical vibration and shock on humans, including those aspects which pertain to biological safety, tolerance and comfort. This standard is not comparable to any existing ISO St
20、andard. This proposed standard was compiled to provide a common understanding of words and phrases used in machinery alignment. This standard is intended to be used by persons engaged in the installation, commissioning, and repair of machines. This is a new standard that does not duplicate definitio
21、ns provided in other vocabulary standards. At the time this Standard was submitted to Accredited Standards Committee S2, Mechanical Vibration and Shock for approval, the membership was as follows: C.F. Gaumond, Chair J.T. Nelson, Vice-Chair N.B. Stremmel, Secretary Acoustical Society of America . C.
22、F. Gaumond . J.T. Nelson American Industrial Hygiene Association . D. Driscoll Association of American Railroads . J. Moller . N. Cooperrider (Alt.) Bose Corporation . J. Parison Calnetix L.A. Hawkins . P. McMullen (Alt.) Caterpillar, Inc. D.G. Roley Duke University Dept. of Biomedical Engineering C
23、.R. Bass Eckardt Johanning, MD, P.C. . E. Johanning Emerson Electric Copeland Corporation . A.T. Herfat Engineering Dynamics, Inc. S. McGregor FLIR Systems . G.L. Orlove 2017 Acoustical Society of America All rights reserved iiiFokus Reliability . .G. Hakansson G.E. Energy R. Bankert John Deere L. D
24、eVries Logan Mullinix Consulting L. Mullinix Mechanical Solutions, Inc. W.D. Marscher . M. Onari (Alt.) National Institute for Occupational Safety and Health (NIOSH) R. Dong . T.W. McDowell (Alt.) National Institute of Standards FAX: 631-923-2875; E-mail: asastdsacousticalsociety.org. AMERICAN NATIO
25、NAL STANDARD ANSI/ASA S2.75-2017/Part 2 2017 Acoustical Society of America All rights reserved 1 American National Standard Shaft Alignment Methodology, Part 2: Vocabulary 1 Scope The words and phrases provided here are descriptive of the instruments and methods in common use for shaft alignment of
26、industrial and utility machines. The machines have rotating shafts at speeds of several hundred revolutions per minute and higher. The machines are typically stationary, being attached to a fixed location on a structure, but could also be on a vehicle, such as a watercraft. The definitions are inten
27、ded to be used in other standards for shaft alignment and general machinery servicing. 2 Terms and definitions For the purposes of this document, the following terms and definitions apply. 2.1 air gap the internal open space in an electrical machine between the stationary and movable components that
28、 transmits energy via the magnetic field NOTE In a motor or generator, this is the radial space between the rotor and stator. 2.2 alignment, machinery the relative orientation of components which results in the least amount of vibration or wear NOTE See “shaft alignment.” 2.3 alignment tolerance the
29、 maximum allowable deviation, plus or minus, from desired values NOTE In machinery, perfect alignment is not achievable. This tolerance provides a range that is economically achievable within a reasonable time and will not cause premature wear or excessive vibration. 2.4 anchor bolts fasteners embed
30、ded in concrete used to secure a machine to a foundation NOTE 1 Also known as a “J-bolt.” NOTE 2 The fasteners could be male or female threaded. NOTE 3 See “base” and “foundation.” ANSI/ASA S2.75-2017/Part 2 2017 Acoustical Society of America All rights reserved 2 2.5 angularity the amount of deviat
31、ion of two lines from a straight line coaxial orientation expressed as an angle from the intersection point in mils per inch, millimeters per meter, or milliradians NOTE For two shaft centerlines, this is the rate at which the offset changes as one travels along the axes of the shafts. See “offset.”
32、 2.6 axial gap the spacing in the longitudinal direction set at the time of installation NOTE 1 For shaft ends, this spacing allows for replacing coupling parts without moving the machines, thereby not disturbing the alignment. NOTE 2 For coupling halves, this dimension is specified by the coupling
33、manufacturer for proper operation. NOTE 3 For all machines, this parameter controls thrust forces on the bearings. NOTE 4 For large electric motors with plain bearings, this spacing between couplings is set with the rotor at its magnetic center. 2.7 axial play the longitudinal freedom of movement in
34、 the direction of the shafts NOTE 1 Sometimes called “end play.” NOTE 2 This is a measure of thrust bearing wear as it relates to the clearance between physical stops. 2.8 axial runout the measured total indicator reading (T.I.R.) when traversing a circle in a plane perpendicular to the shaft axis N
35、OTE This is typically used to measure how “square” a coupling half, bearing, or other component is mounted to the axis of rotation. 2.9 back feet the machines hold-down location farthest from the coupling 2.10 bar sag the downward vertical deflection of a measuring rod caused by the overhung weight
36、of the rod and the dial indicator or other device NOTE Synonymous with “bracket sag.” 2.11 base a structural assembly to which two or more machines are connected, whose purpose is to maintain alignment ANSI/ASA S2.75-2017/Part 2 2017 Acoustical Society of America All rights reserved 3NOTE 1 The base
37、 is usually metal and relatively rigid. It could be machined, rolled, welded, or otherwise fabricated. Plastic or composite bases exist. NOTE 2 See “base plate” and “sole plate.” 2.12 base bound a condition where a machine needs to be lowered but cannot be because there are no shims remaining NOTE T
38、here are several methods to deal with this to accomplish a satisfactory alignment. They are addressed in ANSI/ASA S2.75/Part 1. 2.13 base plate a heavy and thick metal plate onto which machine components are mounted for the purpose of maintaining alignment and to spread the load over the substratum
39、NOTE Sometimes called “sole plate.” 2.14 body fit bolt a fastener with zero clearance between the shank and the bore NOTE Used on high-speed and high-power rotating machines with rigid couplings to avoid placing the bolts in shear. 2.15 bolt bound a condition where lateral movement is restricted bec
40、ause the clearance hole in the machine is too small and the bolt threads press against the side of the hole NOTE There are several methods to deal with this to accomplish a satisfactory alignment; they are addressed in ANSI/ASA S2.75/Part 1. 2.16 bore alignment measurement and adjustment of two or m
41、ore cylindrical openings where a shaft will be later placed NOTE The openings could be bearing pockets, diaphragm seats, or seal surfaces. 2.17 bucking in a process of measuring geometric features, like a bore train or a surface, with several iterations using an optical instrument with the purpose o
42、f finding the average so that the sensor will not be out of range at the extremes NOTE This process finds the farthest and nearest points, and how all the other points relate to them. 2.18 calibration the process of comparing a measuring instrument to a reference NOTE 1 This process also checks func
43、tionality and determines the proper correction factors. ANSI/ASA S2.75-2017/Part 2 2017 Acoustical Society of America All rights reserved 4 NOTE 2 There are no known absolute references for shaft alignment instruments. All calibration methods are a comparison of accuracy to other measuring instrumen
44、ts. See “traceability.” 2.19 cardan shaft a drive shaft with two universal joints NOTE See “universal joint.” 2.20 catenary sag the shape of a shaft or machine system assumed by a cord of uniform density and cross section that is perfectly flexible but not capable of being stretched and that hangs f
45、reely from two fixed points NOTE 1 This is the shape of a hanging chain. NOTE 2 Synonymous with “shaft bow” and “shaft sag.” NOTE 3 A significant factor for aligning heavy machines and long machine trains. 2.21 clock face a method of indicating angular location around a circle by referencing 12 ordi
46、nal positions spaced at 30 degree angles, 12 oclock being vertically upward NOTE 1 Also known as “orientation” or “view point” as viewed from one end of a machine system. NOTE 2 In this context, left side is defined as 9 oclock and right side as 3 oclock. 2.22 colinear in shaft alignment, two or mor
47、e rotating centerlines that lay on the same straight line NOTE 1 Rotating centerlines are defined by the bearings and have no relation to the shape of the shaft. See “rotating centerline.” NOTE 2 Machine component centerlines are colinear when they share two common three-dimensional points. NOTE 3 P
48、erfect colinearity with zero offset and zero angularity is an ideal and not achievable. 2.23 coupling backlash freedom of movement, or clearance between physical stops, in the circumferential direction in a coupling NOTE 1 This is akin to looseness in a coupling. NOTE 2 This looseness is troublesome
49、 for repeatable measurements with dial indicators and some laser systems. 2.24 coupling, clearance a device connecting two machine shafts that accommodates some misalignment with open space between internal elements that allows for articulation during rotation without encountering a hard physical stop NOTE Examples are gear-type toothed couplings, roller chain, and jaw-type couplings. ANSI/ASA S2.75-2017/Part 2 2017 Acoustical Society of America All rights reserved 52.25 coupling, flexible a device connecting two machine shafts that employs an elasti
