1、 1 MIL-STD-2048 m 9999911 0502907 750 m I NOT MEASUREMENT SENS IT IVE MIL-STD-2048(SH) 11 June 1993 MILITARY STANDARD MECHANICAL VIBRATION OF NAVAL DIESEL-GENERATOR SETS AMSC N/A AREA ENVR DISTRIBUTION STATEMENT A. Approved for public release; distribution is unlimited. Provided by IHSNot for Resale
2、No reproduction or networking permitted without license from IHS-,-,-MIL-STD-2048 m 9999933 0502908 697 m DEPARTMENT OF DEFENSE Washington, DC 20362-5160 Mechanical Vibration of Naval Diesel-Generator Sets 1. the Department of Defense. This Military Standard is approved for use by all Departments an
3、d Agencies of 2. Beneficial comments (recommendations, additions, deletions) and any pertinent data which may be of use in improving this document should be addressed to: Commander, ATTN: SEA 05442, Naval Sea Systems Command, 2531 Jefferson Davis Hwy, Arlington, VA 22242-5160 by using the Standardiz
4、ation Improvement Proposal (DD Form 1426) appearing at the end of this document or by letter. ii Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-2048 9999911 0502909 523 MIL-STD-2048tSH) FOREWORD 1. This document defines the ranges of vibrati
5、on that are acceptable for proper operation of diesel-generator sets. taking measurements and where vibration measurements are to be taken. This document also provides the method for 2. This document standardizes the procedures and criteria of mechanical vibration of diesel-generator sets to avoid m
6、isinterpretation of data and costly retesting of generators. iii Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-ZOYB = 7777733 0502730 245 Paragraph - 1. 1.1 1.2 1.3 1.4 2. 2.1 2.1.1 2.1.2 2.2 2.3 3. 3.1 3.2 3.3 3.4 4. 4.1 4.1.1 4.1.2 4.2 4.
7、2.1 4.2.1.1 4.2.1.2 4.2.2 4.3 4.3.1 4.3.2 4.4 4.4.1 4.4.2 4.5 5. 5.1 5.2 5.3 5.4 CONTENTS Page SCOPE 1 Scope 1 Application 1 Purpose 1 Exceptions 1 . . . APPLICABLE DOCUMENTS . 1 Government documents 1 Specifications, standards and handbooks 1 Other Government documents, drawings and publica- tions
8、1 NonGovernment documents 2 Order of precedence 2 . . DEFINITIONS 2 Definitions . 2 Broadband 3 Vibration Severity 3 Vibration Velocity Level 3 . MEASUREMENT . Measurement Parameters Frequency Range Measurement Quantity . Instrumentation . Instrument Calibration . Transducer Calibration Electrical C
9、alibration Transducer Attachment Measurement Locations . Engine Housing . Bearing Housing Test Operating Conditions . Speed/Load Conditions Idle Speed . Measurement Records . 3 3 3 3 3 4 4 4 4 4 4 4 5 5 5 5 VIBRATION SEVERITY CRITERIA 5 Vibration Severity Limits . 5 Zone Definitions 5 Evaluation Mea
10、surements . 5 Vibration Severity Criteria . 5 iv Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-2048 rn 9999733 0502733 LB3 m CONTENTS - Continued TABLES TABLE I. Vibration Severity Ranges For Naval D-G Sets . 6 FI GURES Figure 1. Conversion
11、 Chart for Amplitude Units of Vibration 10 Figure 2. Typical Measurement Locations 11 DATA SHEETS Data Sheet 1 Vibration Measurement Record 7 Data Sheet 2 Vibration Location Diagram 8 Data Sheet 3 Summary of Vibration Measurements . 9 V Provided by IHSNot for ResaleNo reproduction or networking perm
12、itted without license from IHS-,-,-NIL-STD-2048 m 99999LL 0502912 018 m 1. SCOPE 1.1 Scope. This standard defines the measurement, evaluation, and acceptance criteria for the vibration of marine diesel-generator sets intended for naval ship- board service. 1.2 ApRliCatiOn. The vibration criteria ide
13、ntified herein apply to rigidly or resiliently mounted units in a power range of 100 kilowatts (kW) to 2500 kW within a speed range of 720 RPM to 1800 RPM. 1.3 Purpose. The purpose of this standard is to provide a consistent set of evaluation criteria which relate to both operational monitoring and
14、acceptance limits of vibration from a standpoint of mechanical suitability. 1.4 Exceptions. This standard does not apply to vibration related to airborne sound measurements (MIL-STD-740-l), structureborne vibratory acceleration measurements (MIL-STD-740-2), or torsional vibration (MIL-STD-167-2, typ
15、e III). 2. APPLICABLE DOCUMENTS 2.1 Government documents 2.1.1 Specifications, standards and handbooks. The following specifications, standards, and handbooks form a part of this document to the extent specified herein, Unless otherwise specified, the issues of these documents are those listed in th
16、e issue of the Department of Defense Index of Specifications and Standards (DODISS) and supplement thereto, cited in the solicitation. STANDARD MILITARY MIL-STD-167-1 - Mechanical Vibrations of Shipboard Equipment (Type II - Internally Excited). (Unless otherwise indicated, copies of federal and mil
17、itary specifications, standards, and handbooks are available from the Standardization Documents Order Desk, Bldg. 4D, 700 Robbins Avenue, Philadelphia, PA 19111-5094.) 2.1.2 Other Government documents, drawings and publications. The following other Government documents, drawings, and publications fo
18、rm a part of this document to the extent specified herein. Unless otherwise specified, the issues are those cited in the solicitation. NAVSEA DOCUMENT S9073-AX-SPN-OlO/MVA - Machinery Vibration Analysis. (Copies of S9073-AX-SPN-O10/MVA are available from the Standardization Documents Order Desk, Bld
19、g. 4D, 700 Robbins Avenue, Philadelphia, PA 19111-5094.) Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-2048 LL 0502933 T54 = 2.2 NonGovernment Dubiications. The following documents form a part of this document to the extent specified herein
20、. Unl.ess otherwise specified, the issues of the documents which are DOD adopted are those listed in the issue of the DODISS cited in the solicitation. Unless otherwise specified, the issues of documents not listed in the DODISS are the issues of the documents cited in the solicitation. AMERICAN NAT
21、IONAL STANDARDS INSTITUTE (ANSI) S1.l - Acoustical Terminology (Including Mechanical Shock and S2.2 S2.40 - Mechanical Vibration of Rotating and Reciprocating Machinery Vibration. - Methods for the Calibration of Shock and Vibration Pickups. - Requirements for Measuring Vibration Severity. (Applicat
22、ion for copies should be addressed to the American National Standards Institute, 1430 Broadway, New York, NY 10018-3308.) INTERNATIONAL STANDARDS ORGANIZATION (ISO) DIS 5347/3 - Methods for the Calibration of Shock and Vibration Pickups. DP 2372-Ptl- Mechanical Vibration - Evaluation of Machine Vibr
23、ation By Measurement of Nonrotating Parts. 2041 - Vibration and Shock Vocabulary. 2954 - Mechanical Vibration of Rotating and Reciprocating Machinery - Requirements for Measuring Vibration Severity. Accelerometers. 5348 - Mechanical Vibration and Shock-Mechanical Mounting of (Application for copies
24、should be addressed to the International Standards Organization, (NonGovernment standards and other publications are normally available from the organizations that prepare or distribute the documents. These documents also may be available in or through libraries or other informational services.) 2.3
25、 Order of Drecedence. In the event of a conflict between the text of this document and the references cited herein, the text of this document takes precedence. Nothing in this document, however, supersedes applicable laws and regulations unless a specific exemption has been obtained. 3. DEFINITIONS
26、3.1 Definitions. The terminology used in this standard is defined in references ANSI S1.l and IS0 2041. For ready reference, the following definitions are given: 2 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-MIL-STD-2048 = 9999911 0502914 990 3.2
27、 Broadband. The term broadband refers to the unfiltered response of the vibration measuring system over the total frequency range of concern. 3.3 Vibration severity. The term vibration severity is a simple characteristic quantity which describes the vibratory state of a machine. quantity is the root
28、-mean-square (rms) value of the vibration velocity. This 3.4 Vibration velocitv level. The velocity level of a vibration in decibels is 20 times the logarithm to the base 10 of the ratio of the rms velocity of the vibration to the reference velocity of equation: cm per second. This is expressed by t
29、he L, (dB) = 20 log, measured rms velocity (cm/sec) cm/sec rms 4. MEASUREMENT This section describes the measurements, procedures, and operating conditions for evaluating the vibration severity of diesel-generator sets. For diagnosing specific problems, additional measurements may be required. 4.1 M
30、easurement parameters. 4.1.1 Frequency range. The measurement of vibration shall be broadband so that the frequency spectrum of the diesel engine is adequately covered, In order to cover the spectrum of SSDG sets used on naval ships, the broadband measurements shall cover a range of 10 to 1000 Hertz
31、 (Hz). 4.1.2 Measurement auantitv. For purposes of this standard, the vibration severity shall be evaluated in terms of the broadband vibration velocity level in VdB. Although other parameters, such as displacement and acceleration or peak and peak-to-peak amplitudes, have been used in the past, the
32、 limit criteria set forth in 5 is specified in terms of broadband vibration velocity level in VdB. Figure 1 provides the relationship between these vibration parameters and VdB for a simple sinusoidal vibration. Note: Diesel engine forces include multifrequency synchronous and nonsynchro- nous compo
33、nents. The simple mathematical relationships between displac- ement, velocity, and acceleration do not exist except for discrete frequency measurements. Therefore, when accelerometers are used, there is no simple conversion from broadband acceleration to broadband velocity. 4.2 Instrumentation. The
34、minimal acceptable instrumentation system shall include suitable vibration transducers, signal conditioning amplifiers, and recorder device. be flat to within plus or minus 1 dB over the range of 10 to 1000 Hz. When accelerometers are used as the transducer, the signal conditioner or analysis equipm
35、ent shall utilize an integrating network to provide broadband velocity levels. The frequency response of the measuring system in rms velocity units shall 3 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,- MIL-STD-2048 = 9999911 0502915 827 4.2.1 Inst
36、rument calibration. The complete instrumentation system shall be calibrated to establish its accuracy, linearity, and frequency response. 4.2.1.1 Transducer calibration. Within 12 months prior to each use, a calibration of the transducers, traceable to the National Bureau of Standards, shall be made
37、. A secondary standard transducer, so calibrated, may be used for comparison with the transducers being used for the field measurements. ANSI S2.2 shall be used for guidance. 4.2.1.2 Electrical calibration. An electrical calibration check, exclusive of the transducer, shall be made of the complete m
38、easurement system prior to testing and when testing has been recommenced after an interruption. be introduced at selective frequencies. The output signal and the frequencies at which a plus or minus 1 dB fluctuation is attained shall be recorded. This calibration is to check the overall sensitivity
39、of the measurement system. A known voltage shall 4.2.2 Transducer attachment. Depending upon the application, the transducers shall be attached as follows: (a) For one-time or infrequent measurements, the transducer may be attached directly to the equipment being tested by a thin layer of epoxy ceme
40、nt, or by a magnetic base. shall be permanently identified by stamping or inscribing on the equipment. Specific instructions of the epoxy manufacturer shall be followed. the transducer shall be attached to blocks which, preferably, are permanently brazed or welded to the equipment. If the blocks are
41、 bonded with epoxy, their specific locations shall be permanently identified by stamping or inscribing on the equipment. The blocks shall have three mutually perpendicular faces to accom- modate triaxial arrays of transducers. The measurement locations (b) Where repeated measurements are anticipated
42、, such as for monitoring, (c) (d) Hand-held transducers or probes are not permitted. 4.3 Measurement locations. In order to establish the maximum vibration severity of the generator set, measurements shall be taken along the unit at two levels: shaft and top levels. At each location, measurements sh
43、all be made along the axial, horizontal, and vertical axes. Figure 2 provides a typical measurement location diagram. 4.3.1 Bearing housing. Vibration measurements shall be made at the forward and aft bearing housings of both the generator and the engine. be made with either single transducers suita
44、bly oriented, or with a triaxial transducer array. The measurements may 4.3.2 Engine housing. Vibration measurements shall be made at the top of the engine frame as shown on figure 2. At each location, measurements shall be made along the axial, horizontal, and vertical axes, either individually or
45、with a triaxial array. not on sheet metal panels. Caution: All measurements must be made on rigid engine framing and 4 Provided by IHSNot for ResaleNo reproduction or networking permitted without license from IHS-,-,-4.4 Test operating conditions. All vibration measurements shall be taken after the
46、unit has reached its steady-state operating conditions. 4.4.1 Speed/load conditions, Measurements shall be taken at rated speed and no load, and then repeated at rated speed with rated load, 4.4.2 Idle speed. In order to ensure safe engine operation during idle conditions, measurements shall also be
47、 taken with the engine at idle speed with no load. 4.5 Measurement records. All measured data shall be recorded together with Data essential operational data of the machine and of the measuring system used. Sheets 1, 2, and 3 identify the type of data required. 5. VIBRATION SEVERITY CRITERIA 5.1 Vib
48、ration severity limits. The vibration severity limits established herein are primarily structured to secure reliable and safe long-term operation of the unit, and to ensure that the machine vibration does not adversely affect auxiliary equipment mounted directly on the unit. 5.2 Zone definitions. In
49、 addition to establishing vibration limits for acceptable long-term operations, and consistent with practices established by ISO/DP2372, Part 1, this standard provides criteria in four zones defined as follows : (a) Zone A - New Equipment. Machines with vibration within this zone are (b) Zone B - Satisfactory for Long-Term Operation. Machines with vibra- considered as good. tion within thi
