1、 Guidance Notes on Propulsion Shafting Alignment GUIDANCE NOTES ON PROPULSION SHAFTING ALIGNMENT APRIL 2006 (Updated February 2014 see next page) American Bureau of Shipping Incorporated by Act of Legislature of the State of New York 1862 Copyright 2006 American Bureau of Shipping ABS Plaza 16855 No
2、rthchase Drive Houston, TX 77060 USA Updates February 2014 consolidation includes: April 2006 version plus Corrigenda/Editorials ABSGUIDANCE NOTES ON PROPULSION SHAFTING ALIGNMENT .2006 iii Foreword Foreword The mission of the American Bureau of Shipping (ABS) is to serve the public interest, as wel
3、l as the needs of its clients, by promoting the security of life, property and the natural environment primarily through the development and verification of standards for the design, construction and operational maintenance of marine-related facilities. The Rules and Guides on which classification i
4、s predicated are established from theoretical and empirical principles of naval architecture, marine engineering and other engineering principles that have proven satisfactory by service experience and systematic analysis. The classification Rules are not intended to address every single aspect of t
5、he vessel design, but rather to indicate the minimum set of criteria which will ensure safety and functionality of all vital components of the vessel, and at the same time provide sufficient space to the industry to accommodate their practices and technologies with minimum constraints from regulator
6、y bodies. However, in situations where the complexity of the problem results in conflicting interpretation of regulations and when the consequence of this disparity results in damage to the equipment and affects vessels safety, additional regulation clarification and guidance may be necessary. The c
7、ase of shaft alignment is an example of where ABS has noticed the need to provide a more detailed explanation on alignment design and practices, which has resulted in the development of the subject Guidance Notes. These Guidance Notes have been developed primarily to clarify the subject matter for A
8、BS field inspectors and design review engineers to ensure consistency of the survey and plan approval process. Moreover, the subject guidelines may help the industry to improve its approach towards shaft alignment analyses and procedures. Additionally, ABS has developed state of the art analytical t
9、ools primarily for the purpose of engineering analysis and design. The ABS shaft alignment program, combined with alignment optimization software, is capable of analyzing complex propulsion installations and, when used as design tool, may provide an optimal solution to the alignment problem. We welc
10、ome your feedback. Comments or suggestions can be sent electronically to rsdeagle.org. iv ABSGUIDANCE NOTES ON PROPULSION SHAFTING ALIGNMENT .2006 Table of Contents GUIDANCE NOTES ON PROPULSION SHAFTING ALIGNMENT CONTENTS SECTION 1 Introduction 1 1 Propulsion Shaft Alignment . 1 2 Objective . 2 3 Th
11、e Alignment Problem 3 3.1 Solution to Alignment Problem 4 3.2 Analytical Support 4 4 Modern Vessel Design 5 5 Rule Requirements . 5 SECTION 2 Shaft Alignment Design and Review 7 1 General . 7 2 Review vs. Design 7 3 Review 8 3.1 Plans and Particulars Required . 8 3.2 Shaft Alignment Model . 9 3.3 Sc
12、ope of Calculation 9 3.4 Results Verification 10 3.5 Documenting the Review . 17 4 Design . 18 4.1 General 18 4.2 Stern Tube Bearing 18 4.3 Stern Tube Bearing Contact Modeling . 22 4.4 Crankshaft Modeling 27 4.5 Applying a Partial Equivalent Model of the Crankshaft 31 4.6 Engine Bearing Misalignment
13、 33 4.7 Bearing Clearance . 33 4.8 Bearing Elasticity . 34 4.9 Bearing Wear Down . 35 4.10 Gear Meshes . 36 TABLE 1 Influence Coefficient Matrix . 13 FIGURE 1 Directly Coupled Propulsion Shafting Example . 8 FIGURE 2 Bearing Reactions . 14 FIGURE 3 Nodal Slope and Deflection Curve 15 ABSGUIDANCE NOT
14、ES ON PROPULSION SHAFTING ALIGNMENT .2006 v FIGURE 4 Diesel Engine Output Flange Allowable Shear Force and Bending Moment . 16 FIGURE 5 Tail Shaft Bearing Evaluation Program . 17 FIGURE 6 Ideal Contact Area on the Bearing Exerted by Shaft (Misalignment Angle Zero) 19 FIGURE 7 Tail Shaft Bearing Cont
15、act as a Function of Alignment Design . 21 FIGURE 8 Crankshaft Outline 27 FIGURE 9 Crankshaft Equivalent Model for Shaft Alignment . 28 FIGURE 10 FE Model of Half of the Crank . 29 FIGURE 11 Defining Equivalent Model 30 FIGURE 12 Reduced Crankshaft Model 2 M/E Bearings Only . 32 FIGURE 13 Reduced Cr
16、ankshaft Model 4 M/E Bearings 32 FIGURE 14 ABS Bearing Evaluation Interface. 35 FIGURE 15 Gear Driven Propulsion Equal Gear Shaft Bearing Reactions 0.21 mrad Gear Misalignment Angle . 36 FIGURE 16 Gear Driven Propulsion Uneven Gear Shaft Bearing Reactions Zero Misalignment Angle at Gear Wheel . 37 S
17、ECTION 3 Shaft Alignment Procedure . 38 1 General . 38 2 Shaft Alignment Procedure . 38 3 Sighting Through (Boresighting) . 39 3.1 Piano Wire Application 41 4 Slope Boring Bearing Inclination 42 5 Engine Bedplate Pre-sagging . 45 6 Sag and Gap . 46 6.1 Theoretical Background. 46 7 Reactions Measurem
18、ent . 48 8 Bearing-Shaft Misalignment Measurement . 48 9 Shaft Eccentricity 49 10 Intermediate Bearing Offset Adjustment . 50 10.1 System with Forward S/T Bearing . 51 10.2 System with No Forward S/T Bearing . 53 10.3 Which Solution to Adopt 55 11 Diesel Engine Alignment . 55 11.1 Crankshaft Deflect
19、ions 56 12 FAQ Problems and Solution 58 TABLE 1 Influence Coefficient Matrix System with Forward Stern Tube Bearing . 52 TABLE 2 Influence Coefficient Matrix System without Forward Stern Tube Bearing . 54 FIGURE 1 Example of Optical/Laser Sighting Through . 40 FIGURE 2 Piano Wire Application 41 vi A
20、BSGUIDANCE NOTES ON PROPULSION SHAFTING ALIGNMENT .2006 FIGURE 3 Slope Boring Arrangement 43 FIGURE 4 Slope Boring Machine . 43 FIGURE 5 Bearing Inclination . 44 FIGURE 6 Bedplate Sagging Measurement Using Piano Wire 45 FIGURE 7 Flange Arrangement in Sag and Gap Analysis . 47 FIGURE 8 Stern Tube Bea
21、ring Contact Condition Evaluation Sample Analysis . 49 FIGURE 9 System Sensitivity to Intermediate Shaft Bearing Offset Change with Forward Stern Tube Bearing . 52 FIGURE 10 Bearing Reactions for Design Offset with Forward Stern Tube Bearing . 53 FIGURE 11 System Sensitivity to Intermediate Shaft Be
22、aring Offset Change without Forward Stern Tube Bearing 54 FIGURE 12 Bearing Reactions for Design Offset without Forward Stern Tube Bearing . 55 FIGURE 13 Crankshaft Installation in the Engine 57 FIGURE 14 Diesel Engine Bearing Damage due to Edge Loading . 58 FIGURE 15 Bearing Reactions for a Dry Doc
23、k Alignment with Intentionally Unloaded Second Main Engine Bearing . 59 FIGURE 16 Deflection Curve and Bearing Offset for Dry Dock Condition, which Resulted in Intentionally Unloaded Second Main Engine Bearing . 59 FIGURE 17 Bearing Reactions for a Waterborne Vessel Rectified by Hull Deflections and
24、 Bedplate Sag. 60 FIGURE 18 Total Vertical Offset at the Bearings Including Prescribed Displacements, Hull Deflection Estimate and Bedplate Sag 60 FIGURE 19 Vessel in Dry Dock 62 FIGURE 20 Vessel Waterborne Hull Deflections Affect the Propulsion . 62 FIGURE 21 Vessel Waterborne Engine Sag Applied 63
25、 SECTION 4 Shaft Alignment Survey . 65 1 General . 65 2 Alignment Acceptance Criteria 65 2.1 Attendance 66 2.2 Required Information . 66 2.3 Measurement Procedure . 66 2.4 S/T Bearing Wear Down 66 2.5 Dry Dock Alignment . 67 2.6 Noncompliance with Construction Completion Requirements . 67 2.7 Sag an
26、d Gap Acceptability 67 2.8 Number of Bearings to be Verified . 67 2.9 Reaction Measurement Acceptability . 67 2.10 Slope Boring 68 2.11 Dry Dock Alignment . 68 2.12 Shaft Runout 68 2.13 Construction Practices . 68 ABSGUIDANCE NOTES ON PROPULSION SHAFTING ALIGNMENT .2006 vii SECTION 5 Alignment Measu
27、rements 69 1 General . 69 2 Bearing Reaction Measurements . 69 2.1 Jack-up Method . 69 2.2 Strain Gauge Method 75 3 Bearing Vertical Offset Measurements . 79 3.1 Reverse Shafting Alignment Calculation of the Bearing Offsets . 80 4 Bearing Misalignment Measurements 84 5 Crankshaft Deflection Measurem
28、ent 84 6 Gear Contact Misalignment Measurement . 85 7 Sag and Gap Measurement 86 8 Eccentricity (Runout) Measurement of the Shaft 89 8.1 Dial Gauge Runout Measurements . 89 8.2 Runout Measurement in Lathe 89 9 Stress Measurements . 90 9.1 Stress in the Shafting 90 9.2 Stress in the Bearing . 90 TABL
29、E 1 Sample Influence Coefficient Matrix . 72 TABLE 2 Offset Vector Spectrum . 83 FIGURE 1 Hydraulic Jack with Load Cell . 70 FIGURE 2 Digital Dial Gauge . 71 FIGURE 3 Reaction Measurement at Intermediate Shaft Bearing . 71 FIGURE 4 Jack-up Measurement of the Bearing Reactions Inside Diesel Engine 72
30、 FIGURE 5 Jack-up Curve . 73 FIGURE 6 Jack-up Curve for Unloaded Bearing 75 FIGURE 7 Strain Gauge Installation . 76 FIGURE 8 Pair of Uniaxial Gauges 77 FIGURE 9 Wheatstone Bridge . 77 FIGURE 10 Bending Moments Measured at Nine Different Locations Along the Shaft Line 78 FIGURE 11 Reverse Analysis I/
31、O Interface . 81 FIGURE 12 Dry Dock Bearing Offset Reverse Analysis vs. As-designed Offset Comparison . 82 FIGURE 13 Ballast Bearing Offset Reverse Analysis vs. As-designed Offset Comparison . 82 FIGURE 14 Full Load Bearing Offset Reverse Analysis vs. As-designed Offset Comparison . 83 FIGURE 15 Int
32、ermediate Shaft Bottom Clearance and Runout Measurement 84 FIGURE 16 Crankshaft Deflection Measurements . 85 FIGURE 17 Gear Contact . 86 FIGURE 18 Sag and Gap Measurement 87 viii ABSGUIDANCE NOTES ON PROPULSION SHAFTING ALIGNMENT .2006 FIGURE 19 Assembled Shafting Condition Desired After Sag and Gap
33、 is Verified . 88 FIGURE 20 Preassembly Shafting Setup for Sag and Gap Measurement 88 SECTION 6 Hull Girder Deflections . 91 1 General . 91 2 Analytical Approach 92 3 Hull Girder Deflection Measurements . 92 3.1 Bending Moment Measurements . 93 3.2 Bearing Reaction Measurements. 95 3.3 Crankshaft De
34、flection Measurements 96 4 Example 96 4.1 Analytical Approach . 96 4.2 Example - Hull Girder Deflection Measurements . 100 5 Hull Deflection Application 101 FIGURE 1 Hull Girder Deflections Influence on Propulsion System 92 FIGURE 2 Strain Gauge Measurement 94 FIGURE 3 Hydraulic Jack Locations for R
35、eaction Measurements on the Shafting and M/E Bearings . 95 FIGURE 4 Bearing Reactions are Measurements Using Hydraulic Jacks . 95 FIGURE 5 Vessel Deflections Change with Loading Condition . 97 FIGURE 6 Large Container Vessel Shafting for Shaft Alignment Analysis Purpose 97 FIGURE 7 Shaft Alignment D
36、esign with No Hull Deflections Considered 98 FIGURE 8 Still-water Deflections of the Vessel 98 FIGURE 9 Containership Diesel Engine Bearing Reactions as a Function of Hull Deflections and Bedplate Sag 98 FIGURE 10 Still-water Hull Deflections Ballast . 99 FIGURE 11 Still-water Hull Deflections Laden
37、 99 SECTION 7 Alignment Optimization . 102 1 General . 102 2 Optimization Example . 102 3 Optimization 105 TABLE 1 Estimated Hull Girder Deflections . 104 TABLE 2 Optimal Solution 107 TABLE 3 Dry Dock Bearing Reactions for Prescribed Offset 108 TABLE 4 Ballast Vessel Hull Deflections Bearing Reactio
38、ns and Total Bearing Offset 108 TABLE 5 Laden Vessel Hull Deflections Bearing Reactions and Total Bearing Offset 109 ABSGUIDANCE NOTES ON PROPULSION SHAFTING ALIGNMENT .2006 ix FIGURE 1 Discrete Model of the Shafting 103 FIGURE 2 Bearing Offset; Shaft Deflection Curve; Nodal Slopes . 103 FIGURE 3 Be
39、aring Reactions; Bending Moment; Shear Forces 103 FIGURE 4 Laden Bearing Offset Disturbed by Hull Deflections; Bearing Reactions Unloaded M/E Bearing #2 . 104 FIGURE 5 Ballast Bearing Offset Disturbed by Hull Deflections; Bearing Reactions Unloaded M/E Bearing #2 . 104 FIGURE 6 GA Input Data and Out
40、put Showing Two of Ten Desired Solutions . 105 SECTION 8 Glossary 111 1 Abbreviations 111 2 Definitions . 111 This Page Intentionally Left Blank ABSGUIDANCE NOTES ON PROPULSION SHAFTING ALIGNMENT .2006 1 Section 1: Introduction SECTION 1 Introduction 1 Propulsion Shaft Alignment The propulsion shaft
41、ing alignment is a process which consists of two parts: The design and analysis The alignment procedure and measurements The definition of the shaft alignment process and the practices in performing the alignment are not consistent in the industry. The terminology and requirements for the shaft alig
42、nment will vary depending on the machinery application, the propulsion systems size, as well as on the perception of the alignment process itself1. In order to avoid misunderstandings in interpretation and definition of the terms in these Guidance Notes, a definition of the propulsion shafting and t
43、he propulsion shafting alignment is provided below. The definitions adopted here and the references made throughout these Guidance Notes, whether mentioned explicitly or not, are considered valid for the alignment of the ship propulsion machinery. Propulsion shafting is a system of revolving rods th
44、at transmit power and motion from the main drive to the propeller. The shafting is supported by an appropriate number of bearings. Propulsion shaft alignment is a static condition observed at the bearings supporting the propulsion shafts. In order for the propulsion shafting alignment to be properly
45、 defined, the following minimum set of parameters (whichever may be applicable) need to be confirmed as acceptable: Bearing vertical offset Bearing reactions Misalignment angles Crankshafts web deflections Gear misalignment Shaft and bearings strength Coupling bolts strength The alignment is conside
46、red to be satisfactory when it is possible to control the above parameters, and maintain them within the required limits under all operating conditions of the vessel. By “all operating conditions of the vessel”, the intent is that the alignment remains acceptable for: Vessel loading variation from b
47、allast to laden Temperature variation affecting the propulsion shafting system The change in loading of the vessel will result in variation of hull girder deflections, thus disturbing offset of the shaft-supporting bearings. Hull deflections will affect all bearings in the system simultaneously. Mak
48、ing the alignment satisfactory for all loading conditions will require several analyses to be conducted to verify alignment acceptability for all different vessel loadings. 1The approaches to the alignment presently seen throughout the industry vary from defining the alignment as pure static and a c
49、ombination of static and dynamic, with a variety of methods in modeling and analyzing the alignment. Section 1 Introduction 2 ABSGUIDANCE NOTES ON PROPULSION SHAFTING ALIGNMENT .2006 The temperature rise or drop will also affect the bearing offset. However, unlike the hull deflections, the effect of temperature change may be local to the particular bearing or to the set of bearings (e.g., main engine, gear-box). Basic propulsion shafting alignment criteria, requirements and limits are us
