CONTENTS
CONTENTS
Contents 1 - Abstract
5
2 - Acknowledgments
6
3 - Introduction
7
3.1
ERASMUS Placements Program . . . . . . . . . . . . . . . . . . . . . . . . . . . .
7
3.2
Application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
3.3
Company . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
3.3.1
Background and Present . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
3.3.2
Business areas facts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9
3.3.3
Expansion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.3.4
Achievements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.3.5
Wind Gears Key numbers . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.3.6
Industrial Gears key numbers . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.3.7
Moventas Briefly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.4
Allocation and daily procedures . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4 - Placement Tasks
15
4.1
Initial steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
4.2
Practical Tasks / Simulations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 4.2.1
Housing Simplification
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16 Procedures and Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19 4.2.2
Internship Webpage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Web page Structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4.2.3
Inspection Covers
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Initial approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21 Initial results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22 Validation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25 4.2.4
Bearing cover
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
3
CONTENTS
CONTENTS Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 4.2.5
Gear Testing Layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 Modified components seeking optimization . . . . . . . . . . . . . . . . . . . 29 Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 Load Steps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 Comparison of Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 Frame results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 Welded bases results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 41 Screws results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 Contact tool results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 44 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 47
4.2.6
Planet Carrier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 Results . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54 Comments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
4.3
Trainings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 4.3.1
Femfat . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
4.3.2
SKF . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69
4.3.3
Ansys . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Tampere . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Jyv¨ askyl¨ a . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 69 Copenhagen . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 70
5 - Conclusions and future work
71
5.1
Main achievements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71
5.2
Improvements . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
5.3
Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72
4
1 - ABSTRACT
1 - Abstract A practical placement taking part in a European Company, integrated in the studies plan, with full recognition before graduating, is nowadays possible through the New ERASMUS Programme - LLP (Lifelong Learning Programme) Placements.
This report focuses on the activities and achievements during the period of the placement. This placement corresponds to the final project equivalence in MIEM (Integrated Master in Mechanical Engineering) Degree, specialization in Structural Engineering and Machine Design, contributing 30 ECTS (European Credits Transfer System), provided at UP (University of Porto).
5
2 - ACKNOWLEDGMENTS
2 - Acknowledgments The author would like to thank Petri Lahtinen, Group Manager in Technical analysis of Structural components, from Moventas, in the role of a coordinator to this placement for providing timely inputs based on his experience in the domain of wind gears.
Further more, the author would like to acknowledge Paulo Tavares de Castro and Jorge Seabra, from FEUP - Engineering Faculty of Porto University, for enabling this placement and for providing constant support and follow-up.
In addition, the author would like to acknowledge the team spirit shown by the colleagues at Moventas namely Petri, Teemu and Ismo for their valuable time and contributions.
The author would to mention the importance of European ERASMUS programme, which has provided a remarkable change in the European educational scenario.
I would like also to thank my family and friends for their understanding and comradeship throughout this placement period.
Finally, special thanks to Merie Joseph for the report review.
6
3 - INTRODUCTION
3 - Introduction 3.1
ERASMUS Placements Program
The framework of ERASMUS (European Community Action Scheme for the Mobility of University Students ) was established in 1987 and is a major part of the European Union Lifelong Learning Programme (LLP) period from 2007 to 2013. It is the operational framework for the European Commission’s initiatives in higher education. The recently created ERASMUS placements, differs from the ERASMUS Studies in that it is a type of placement combined with a specified time period in an enterprise or organization in European, EFTA/EEE and Turkey countries, with a view to help individuals to adapt to the requirements of the European labor market, acquiring specific skills and improve understanding of the economic and social culture of the country concerned while acquiring the work experience. The period may be supported, as appropriate, by preparatory or refresher courses in the host language or working language. Host organizations for student placements may be enterprizes, training centers, research centers or other organizations. The characteristics of the individual placements are: • Full recognition is provided by the home higher education institution for the period spent abroad. • It is necessary to have a Training Agreement for the student, regarding the programme of the placement period; this agreement must be endorsed by the home higher education institution and the host organization. • The period of placement is covered by a placement contract endorsed by the higher education institution sending the student, the consortium sending the student (if applicable), the host organization and the beneficiary. In a company environment, this program provides work experience, enabling the use of knowledge, tools, procedures, that in this specific situation, were acquired trough the MIEM subjects,projects,work-groups,professors at FEUP. It also allows to achieve maturity and personal growth,in a different environment as a result of applied work experience.
7
3 - INTRODUCTION
3.2
3.2. APPLICATION
Application
The author had experience of undertaking ERASMUS studies in Hungary in Spring semester 2007. After receiving the confirmation from the department of cooperation at FEUP about the eligibility of the placement program, in November 2007, several countries were considered for the placement program.
The country of placement was finalized as Finland because of previously established network relationships. After many applications, to companies like Outokumpu, W¨artsil¨a, Aker Yards, Ruukki, response to take part in this challenging Programme, was sent by Moventas . The placement works as a Final Project Equivalence in MIEM ( Integrated Master in Mechanical Engineering) Degree, the final part of the studies plan, summing 30 ECTS ( European Credits Transfer System). The report states the practical work placement, structured by date, performed at Moventas Wind Oy, Jyv¨ askyl¨ a , FINLAND in the framework of ERASMUS LLP - Placements programme.
3.3 3.3.1
Company Background and Present
Moventas, earlier Metso Drives, is one of the leading experts in mechanical power transmission. The company designs, manufactures and markets power transmission solutions and services for process and energy industries. Moventas operates in a rapidly growing market. The company’s e 207 million sales revenue grew by 25 % in 2006, and grew by more than a third in 2007, Figure 3.1. Moventas aims to double its sales by 2010 through organic growth.
Figure 3.1: Numbers of 2007 - MOVENTAS
8
3 - INTRODUCTION
3.3.2 Business areas facts
With its headquarters in Jyv¨ askyl¨ a, Finland, the company has more than a century of engineering experience. Well-known company names namely, Metso Drives, Santasalo and Valmet are among the predecessors of Moventas, Figure 3.2. Having this solid background, the company nowadays deals with both Wind (WG) and Industrial gears (IG). Today the company has nine locations globally, in Finland, Sweden, Germany, Canada, the United States and Singapore. With its dedicated 24/7 service commitment, the company intends to further strengthen its global reach to bring it closer to its customers.
Figure 3.2: Moventas History
3.3.2
Business areas facts
Wind Gears After-market sales is a growing area. Wind-power generation is growing rapidly at an annual growth rate of over 20 %. As one of the global leaders in the manufacture of windturbine gears, Moventas is benefiting from the increased need for energy, the need to reduce carbon-dioxide emissions, and the improved competitiveness of wind power as a result of technological advances. The wind-turbine gear business is also enjoying a widening of customer demand both in existing markets and in new regions, as even more customers seek to rely on renewable energy resources, like India, China and Italy. After-market sales for wind-turbines is one of the fastest-growing areas for Moventas and clearly one of its business advantages. Turbines are often sited offshore or in remote locations, so minimizing unscheduled maintenance is important.
9
3 - INTRODUCTION
3.3.2 Business areas facts
Monitoring Monitoring the performance and condition of key components, such as the mechanical power-transmission systems, which are at the heart of a wind turbine, is vital to ensure that wind-turbines maintain high levels of reliability. Moventas has launched a sophisticated condition-management system, that not only monitors the turbine’s operation, but also provides the operator with an early warning of potential risk factors before actual damage is done. The system can be integrated into new turbine designs or fitted to machines already in operation. Proactive lifecycle approach The gears Life Cycle takes in account all aspects and consequences, Figure 3.3.
Figure 3.3: Proactive lifecycle
Industrial Gears Moventas has a strong position in the process industry also. It is the leading supplier of mechanical drives for the pulp and paper industry and one of the leading players in the growing mining and minerals sector. The most promising growth prospects in Moventas industrial-gear business are in service and maintenance programmes covering the entire lifespan of equipment. Moventas has been keen to adopt a life-cycle approach which plays an important role in creating top-class customer satisfaction. First-time installations in the mining and minerals sector are also growing strongly. In particular, demand for servicing and renewal of machinery is on the increase in the wood-processing industry
10
3 - INTRODUCTION 3.3.3
3.3.3 Expansion
Expansion
In response to growing market demand, the company has begun a substantial investment programme totalling e100 million. Part of the visionary growth strategy is to expand production capacity in Finland which will create approximately 100 new jobs this year and roughly the same number again over the next few years with an extensive investment programme . Presently Moventas employs about 1200 individuals, Figure 3.4. The first project in the investment programme has now been completed, with the opening of an expanded facility for wind-turbine production in Jyv¨ askyl¨ a, Finland in March. A new construction project aimed at further increasing production capacity for wind-turbine gears in Jyv¨ askyl¨ a has already started. The Karkkila plant in Southern Finland, which concentrates on industrial gears, will increase its large gear-manufacturing and assembly capacity. The full additional capacity will come on stream in 2009.
Figure 3.4: Company Worldwide
3.3.4
Achievements
• Installed base for more than 8,000 units • First wind turbine gears delivered in 1980 • Wind turbine main gears for the major wind turbine manufacturers • Innovative technology for wind turbine gears up to multi MW class • Uncompromising reliability • Life cycle gear service support , Figure 3.3.
11
3 - INTRODUCTION 3.3.5
3.3.5 Wind Gears Key numbers
Wind Gears Key numbers
The section of Wind Gears, represents nowadays more than 50 % of the business, Figures 3.5 and 3.6.
Figure 3.5: Wind gears 2007 facts
Figure 3.6: Wind gears Sales/employes
3.3.6
Industrial Gears key numbers
The section of Industrial Gears, represented worldwide, offers solutions for all high demand industries, Figures 3.7,3.8.
Figure 3.7: Industrial gears 2007 facts
12
3 - INTRODUCTION
3.3.7 Moventas Briefly
Figure 3.8: Industrial gears Sales/employes 3.3.7
Moventas Briefly
Figure 3.9: Moventas Key facts
13
3 - INTRODUCTION
3.4
3.4. ALLOCATION AND DAILY PROCEDURES
Allocation and daily procedures
The department where the placement took place is the department of Research and Design, integrated part of Moventas Wind Oy division. It is organized in different sub-sections; Structural (Fatigue [2], Eigen frequencies, Classification, . . . ), Modeling, Lubrication, Gears [8], , Documentation , with respective responsibilities. The placement specifically was held in the Structural analysis subsection, which is responsible for research, analysis and certification of all Wind Energy products. At the Structural section, the work-tools consist of a Cluster - Fujitsu Celsius 2 processor Books, Internet, Applications and respective Help [1], [3], manuals [2], [10], [13]; and guidelines, [11]. Software licenses are limited. The working schedule is flexible, consisting of average 37,5 hours a week. For security and practical reasons, for crossing the doors, magnetic keys are used, and this is the also the support to store data such as working hours and vacations period. Periodical meetings are held at the department. Archive and backup of information is an important issue, existing a network drive and Tape support ( 20-50 Gb). The organization of the space is open, easing contacts , suggestions and permanent follow-up. There is a help desk for all kinds of software and hardware problems.
The main aspects concerning this section are : • Team of Structural Analysis included in the Research and Design division.Stress and dynamic analysis performed • Usage of numerous compulsory softwares, Table 3.1, and procedures for full structural analysis. • Frequent training, meetings and dynamic environment.
Table 3.1: Some Compulsory Software for simulation/structural analysis Software CatiaV5
Solidworks
Miktex
Linux(CentOS)
14
Ansys(Classic/Workbench)
FEMFat
4 - PLACEMENT TASKS
4 - Placement Tasks 4.1
Initial steps
The initial step was integration which involved understanding all processes, departments, factory layout and internal activities, organization, guidelines, personnel. The tools for work, mainly the workstation, software, literature and objectives were made available in the first weeks by installing all the software required and by providing hardware and cables. Meanwhile, some individual personal training with the support of the software help [1], [3], [13], internet, colleagues and books, in softwares like Ansys Classic ( developing the basics previously done during the MIEM course in subjects namely Mecˆ anica das Estruturas II , Mecˆ anica da Fractura), Catia V5 tutorials , Network configurations and data exchange between computers and Cluster ( 8 processors, for Heavy FEM calculations). All internal section reports are made using LaTex2ε, [4], [5], [6], [7], [9],. Also the usage of tools for e-mail, software for bills like SAP, reservations, internal mail between departments, and others, were acquired.
15
4 - PLACEMENT TASKS
4.2. PRACTICAL TASKS / SIMULATIONS
Table 4.1: Sequential Tasks Plan
4.2
Practical Tasks / Simulations
The software required to perform all sort of different tasks, was not fully available initially. When new tasks were required, new software was sequently added as soon as possible, so that the tasks were naturally performed. After gaining experience and confidence, through both personal and interpersonal ways, the tasks could be developed more easily, more confidently and autonomously. A brief review of the activities and tasks that took place during placement period, can be seen in Table 4.1.
4.2.1
Housing Simplification
Description The housing of a 2MW power wind turbine (Figure 4.1), that was modeled in Catia V5, needed simplification and preparation for modal analysis in Ansys Workbench. The steps are to deactivate, hide or even change sketches in Catia V5, so that the global model is suitable, incorporating good sense, for eliminating possible problems of elements size and shape when meshing. The materials and constraints of the structure need to be carefully assigned for the future Modal analysis.
16
4 - PLACEMENT TASKS
4.2.1 Housing Simplification
Table 4.3: Cast Iron GJS250 Proprieties
Table 4.4: Cast Iron GJL400 Proprieties
Figure 4.2: Fixed supports applied in the moment-arm holes
18
4 - PLACEMENT TASKS
4.2.1 Housing Simplification
Comments This task allowed the author contact with parts of gear and allowed to realize and see the functional components, size and geometry of Wind Turbines. The Softwares Catia V5 and Ansys Workbench , were initially explored ( March 2008 ). Later on, the Ansys capabilities in Eigen frequencies, allowed to study the behavior of the structure for further considerations.
(a) 1st
(b) 2nd
Figure 4.3: Housing Eigen Frequencies - 1st and 2nd Natural Modes
19
4 - PLACEMENT TASKS 4.2.2
4.2.2 Internship Webpage
Internship Webpage
Description The webpage concerning the Internship was created in April 2008 with TextoHtml and also basic HTML Language. This webpage was continuously reanalyzed and modified structurally. Improvements were also made later, adding suitable information and also correcting some errors. (http://paginas.fe.up.pt/˜em03078/).
Figure 4.4: Aspects of Internship webpage
Web page Structure The most suitable Webpage structure was found to be: • Placement Info • Updated Workplan • Downloads of Documents Comments The Webpage creation, maintenance and design, gives an idea of the structure, data storage and procedures in order to provide essential information with direct and clear basis on the Internet.
20
4 - PLACEMENT TASKS
4.2.3 Inspection Covers
(a) Inspection cover in present production
(b) Initial geometry attempt leading to improvements
Figure 4.6: Inspection Covers - Geometry changes Initial results The initial results, trial attempt, leading to the right direction of objectives, observed the change in the vibration mode from axial to bending, and the removal of the ribs,Figure 4.7. The obtained values for 1st /fundamental Frequency can be seen on Table 4.5.
Table 4.5: Inspection covers initial improvement aiming a higher fundamental frequency Inspection covers assembly details
Weight (Kg)
1st Frequency - Fundamental (Hz) MODAL
Original
55
1703
Modified
55,9
2057
22
4 - PLACEMENT TASKS
4.2.3 Inspection Covers
(a) Present Production Inspection Covers - Axial Vibration mode
(b) Initial geometry attempt - bending vibration mode
Figure 4.7: Inspection covers improvement aiming higher 1st /fundamental frequency
23
4 - PLACEMENT TASKS
4.2.3 Inspection Covers
Figure 4.9: 1st /fundamental frequency - Results for Final optimum solution
Table 4.6: Results of the production-ready inspection covers Part
Fundamental Freq (Hz)
Inspection cover ready for casting
1979
Comments The inspection cover resolution, led the author to deal closely with a practical application using the knowledge and tool of frequency analysis. It shows the sort of problems, encountered when the gears (multi-body drive-train) are under run. The experience gained in modeling provided a necessary skill in a practical work environment for a mechanical engineer.
25
4 - PLACEMENT TASKS
4.2.4 Bearing cover
Approach The modeling performed in Catia V5, allowed various options for changing the geometry. The main design changes was the addition of ribs/stiffners due to limitation in the functional areas (ex. bearings, shaft ,. . . ). After importing this CATParts to Ansys Workbench, the boundary conditions were maintained and solved towards the solution sequentially. The mesh and fixed support boundaries are displayed in Figure 4.12
(a) Bearing cover - Mesh
(b) Bearing cover - Fixed support
Figure 4.12: Geometry and Constrains of bearing cover : Final solution
27
4 - PLACEMENT TASKS
4.2.4 Bearing cover
Figure 4.13: 4th Natural Vibration Mode Results The values achieved for this purpose are presented in Table 4.7. The Mode shape for the 4th Natural frequency is displayed in Figure 4.13. Table 4.7: Bearing cover modifications achieving a higher 4th frequency Cover details
Weight (Kg)
4th Mesh Frequency (Hz)
Original
57.6
1502,8
Modified
65.2
1743
Comments The best result was obtained when adding stiffeners in the exterior face. This was considered because of the location and functionality, which did not allow a wide area of maneuverability, resulting in adding stiffeners in the exterior face instead of interior face for solving the eigen frequency resonance problem. Functional details, such as forced lubrication pointing out the flow proprieties were also taken in account.
28
4 - PLACEMENT TASKS
4.2.5 Gear Testing Layout
Figure 4.15: Original Model
Figure 4.16: Modified Model
Figure 4.17: New concept model Procedure The Original cut section submodel/structure, constructed from the whole gear testing structure, was analyzed first,so that reference results could be obtained for the most important parts like: welded frame, welded bases and housing. The material is considered as structural steel for all components, Table 4.8.
30
4 - PLACEMENT TASKS
4.2.5 Gear Testing Layout
Table 4.10: Description of screws/bolts for Original and Modified Screws Size
Number screws
Pretension (N)
Details
M30
6
3e5
Housing to Platform
M16
4
3000
Spacers to Keljo VB dock-lock ( LONG )
M16
8
3000
Frame to Keljo VB dock-lock ( SHORT )
NEW CONCEPT Since is New concept version is substantially different, the analysis was done with some different aspects. In the New concept. cut structure, some components were completely removed and there were changes in several components. The welded plates are different, the screws are only 6xM16, the holes housing, frame, spacers and welded plates are 17,5 mm diameter The screws pre-tension and fixed support are repeated and also the contacts definition. The contacts are kept the same, as others parameters moment, preload, and so on. The housing and the weld frame holes were changed according to the screw’s size. The location of screws is different Figure4.21 and Table 4.11.
Figure 4.21: Moment and Pre-tensions - New Concept
Table 4.11: Description of M16 screws/bolts for New concept Screws Size
Number screws
Pretension (N)
Details
M16
6
3e5
Housing to cylinder
33
4 - PLACEMENT TASKS
4.2.5 Gear Testing Layout
Comparison of Results Stress and Strain Analysis for Housing
The Ansys Workbench results are displayed in 2x
Auto (380x real). The deformations, Figure 4.24, and Figure 4.25, for Original and Modified respectively, highlight the maximum deformation in the housing and the much higher deformation in the screws caused by the pre-tension. The tension values, for this Original and Modified retrieve unrealistic results, reason why they are not shown, thus the maximum stress is at the screws, 10X bigger than in the frame.
Figure 4.24: Total deformation Original For the New concept, the Von Mises stresses, Figure 4.26, are very low, displaying the places where the direct effect of the moment applied is visible.
The deformation of the elements can be noticed on the screw because of the magnification and element characteristics.
In addiction, for the housing, the stress/strain values, due to screws elements distortion, are not reliable and should not be taken in the analysis. However, the housing stresses are low and acceptable.
35
4 - PLACEMENT TASKS
4.2.5 Gear Testing Layout
Figure 4.25: Total deformation Modified
Figure 4.26: Von Mises - New concept
36
4 - PLACEMENT TASKS
4.2.5 Gear Testing Layout
Figure 4.27: ORIGINAL - Frame stress (Von Mises)- maximum near bolt head Frame results Stress Analysis Original : The welding locations in the frame (top and bottom faces) were simulated with bonded contact. The pretension inflicts stresses on this weldings. However, the high pretension of the screws leads to maximum stress in a very localized area around the holes. The frame verifies almost no changes when moment is applied, Figure 4.27.
Modified : In the modified structure, the behavior is the same, so that from the Original to the Modified structure we jump from 20 MPa to 30 MPa in surface areas near holes, which is still a reasonable value, Figure 4.28.
New concept: In this substantially changed structure, the behavior is the same, but from the Original or Modified to this one, the realistic results come to surface. There is a reduction of stresses, because the pretension of M16 screws is 10x smaller (leads from 20/30 MPa originally to 5 MPa ) in surface areas near holes, Figure 4.29.
37
4 - PLACEMENT TASKS
4.2.5 Gear Testing Layout
Figure 4.28: MODIFIED - Frame stress (Von Mises)- maximum near bolt head
Figure 4.29: NEW CONCEPT - Frame stress (Von Mises)- maximum near bolt head
38
4 - PLACEMENT TASKS
4.2.5 Gear Testing Layout
Deformation Analysis The deformation results of the frame behavior, Original and Modified, inflicted by the bolts pre-tension, followed by a moment, retrieve the expected traction side/compression side, which effectively brings notice to the bigger displacements, Figures 4.30, 4.31. The main differences occur in the holes location and edges.
Figure 4.30: Original Total deformation of frame
For the New Concept, the loads are in a different level with lower magnitude, resulting in deformations which are three times smaller.
39
4 - PLACEMENT TASKS
4.2.5 Gear Testing Layout
Figure 4.31: Modified Total deformation of frame
Figure 4.32: New concept Total deformation of frame
40
4 - PLACEMENT TASKS
4.2.5 Gear Testing Layout
Welded bases results Since there were high pre-tensions, stresses were analyzed in parts with direct connections with the bolts. The welding locations between the frame and weld bases, simulated with bonded contact, have to be taken in account that are not very close to reality, as said before, because in real welding situation only the edges are welded while in simulation the entire surface on the plane is selected and by consequence simulated as welded. The pretension of the screws inflict the maximum stress in the opening located below the part. The contact areas of pressure in this component caused by the M30 Screw, are located here, Figures 4.33, 4.34. Furthermore, for different geometries of holes (opposing original/Modified versus New Concept), the stresses are much smaller in the New concept, Figure 4.35
Figure 4.33: ORIGINAL - welded region stresses
41
4 - PLACEMENT TASKS
4.2.5 Gear Testing Layout
Figure 4.34: MODIFIED - welded region stresses
Figure 4.35: NEW CONCEPT - welded region stresses
42
4 - PLACEMENT TASKS
4.2.5 Gear Testing Layout
Screws results The results for the screws are provided in the tables given below, without any important differences between the original, modified and New concept sub structures, concerning the adjustment and variation of working load, Tables 4.14, 4.15 and 4.16.
Table 4.14: Original bolts pretension results
Original bolts results Behavior/Location
Traction
Compression
Center
Bolt
M30
M16 (Long)
M16 (Short)
M30
M16 (Long)
M16 (Short)
M30
Adjustment (mm)
0,8099
0,2202
0,0827
0,8084
0,2204
0,0827
0,8017
Max Work Load (N)
3e5
3,012e4
3,014e4
2,997e5
2,989e4
2,99e4
3,00e5
Table 4.15: Modified bolts pretension results
Modified bolts results Behavior/Location
Traction
Compression
Center
Bolt
M30
M16 (Long)
M16 (Short)
M30
M16 (Long)
M16 (Short)
M30
Adjustment (mm)
0,8120
0,2161
0,0812
0,8015
0,2167
0,0811
0,801
Max Work Load (N)
3e5
3,013e4
3,012e4
2,997e5
2,989e4
2,986e4
3,00e5
Table 4.16: New concept bolts pretension results
New concept - M16 bolts Location
Pretension(N)
Working Load(N)
Difference(%)
Adjustment(mm)
Traction
30000
30128
0,43
0,26996
Center
30000
30029
0,1
0,26888
Compression
30000
29866
0,45
0,26974
43
4 - PLACEMENT TASKS
4.2.5 Gear Testing Layout
Contact tool results The contact tool was used to visualize the properties of the frictional contacts present, only for original, modified . These are between the spacers/housing and cylinder/weld base , Figures 4.36 and 4.37, respectively. The sliding exists practically only due to the pretension of screws. Note also the gap created by the parallel screws pretension (M30 and long M16), Figure 4.36. Analyzing the sequence in the contact, through the animation, because of the moment and bonded contact simulating the welding, it is observed that there is penetration in the elements, caused initially by the pre-tension, but afterwards by the pure moment applied.
44
4 - PLACEMENT TASKS
4.2.5 Gear Testing Layout
(a) Gap Original structure
(b) Gap Modified structure
Figure 4.36: Contact tool results for the frictional contacts-GAP
45
4 - PLACEMENT TASKS
4.2.5 Gear Testing Layout
(a) Status original structure
(b) Status modified structure
Figure 4.37: Contact tool results for the frictional contacts - STATUS
46
4 - PLACEMENT TASKS
4.2.5 Gear Testing Layout
Comments The model evaluated, does not consider the bonded/welded regions properly, since the whole welded area is bonded and it should only be evaluating the edges with proper geometry and thickness of the type of welding.The moment applied would be more realistic if the whole housing with bearing loads was available. Switching from Original to Modified, there is an effect of 50 % higher stresses in the frame which is still low and acceptable (30 Mpa). By removing components and/or material for saving weight, results show a direction to modify the actual parts. Ansys results demonstrate that the moment applied, together with boundary conditions and screws pretension, result in reasonably acceptable results for the New concept structure, having almost no visible effect on stresses (5 MPa). The proposed changes, made for saving weight, show some components can be removed. The usage of only M16 screws is suitable, analyzing the details of the holes. The implementation of this New concept solution is strongly recommended.
47
4 - PLACEMENT TASKS 4.2.6
4.2.6 Planet Carrier
Planet Carrier
Description A Planetary gears carrier, Figure 4.38 has to be optimized to achieve the reduction of weight. It consists of a housing integrating four planetary gears which are in contact with an external ring gear, Figure 4.39. The functional regions must be kept and the reduction must be done in regions which will be highlighted in the FEM analysis in Ansys and Ansys Workbench. Subsequent decisions will be made based on these results by the modeling team professionals.
Figure 4.38: Planetary Gearbox Assembly
Figure 4.39: Planet Carrier detail
48
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Procedure Initially, 6 revisions were available, all with modifications to achieve mass reduction. The list of revisions can be seen in Figure 4.40, pointing out that Revision 3 was not studied due to numerous similarities comparing to Revision 4. The mesh has to be resized to achieve good accuracy near fillets and areas with sudden geometry changes . The simulation is done by analyzing the Planet Carrier as having the applied moment and four supports, simulating the presence of the gear teeth contacts with ring gear.
(a) Revision 1
(b) Revision 2
(c) Revision 4
(d) Revision 5
(e) Revision 6
(f) Revision 7
Figure 4.40: Revisions for study
49
4 - PLACEMENT TASKS Materials
4.2.6 Planet Carrier
The supports for simulation have 10 % of Young Modulus (E) of the carrier’s cast
iron GJS-700. The structural steel material proprieties are applied for the pins which in reality will hold 2 bearings each for each planetary gear. The materials are described in Tables 4.18 4.19 4.17. Table 4.17: GJS-700 Cast iron material proprieties GJS−700 Proprieties
Value
Young’s Modulus
1,76e+005 Mpa
Poisson’s Ratio
0,275
Density
7, 2e − 0064kg/mm3
Thermal Expansion
1, 25e − 0051/◦ C
Table 4.18: Structural steel material proprieties Structural steel Proprieties
Value
Young’s Modulus
2,e+005 MPa
Poisson’s Ratio
0,3
Density
7, 85e − 006kg/mm3
Thermal Expansion
1, 2e − 0051/◦ C
Tensile Yield Strength
250 MPa
Compressive Yield Strength
250, MPa
Tensile Ultimate Strength
460, MPa
Table 4.19: Supports material proprieties Joustava Proprieties
Value
Young’s Modulus
17600 MPa
Poisson’s Ratio
0,3
Density
7, 2e − 006kg/mm3
Thermal Expansion
1, 25e − 0051/◦ C
50
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Figure 4.43: Planet carrier constraints and moment load Boundary conditions and Loads It is required to add displacement constraints because of numerical errors. Even the smallest error would translate the model. The ”compression only” supports are applied because bending must be allowed and translation along the moment axis ( yy axis , 2525 KNm). The fix support simulates the planetary gears. Contacts The contacts must be set as frictional between carrier and the pins, Figure 4.44, because it’s the most important contact for the load, and more close to reality. Since there are bearings in the planetary gears, the contact here is considered frictionless, Figure 4.45.
52
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Figure 4.44: Frictional Contacts
Figure 4.45: Frictionless contacts
53
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Results The results were obtained using structural analysis, obeying the same constraints, mesh sizes and contacts. The revisions are listed sequentially. Revision 1
The Revision 1 can be admitted as reference to others. It gathers the main ideas and functionalities required for the function in the wind gear train, that is, the model to modify. There are secondary maximums in the ribs edges. The maximum occurs, as always, inside the pin hole.
Figure 4.46: Minimum Principal Stress - revision 7
54
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Figure 4.47: Maximum Principal Stress - CUT - revision 1
Figure 4.48: Pin cut - stresses - Revision 1
55
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Revision 2
The changes in this revision are mainly for the inside and outside fillets, attempting a new concept and direction. There are secondary maximums on the edges of the ribs. The maximum occurs, as always, inside the pin hole.
Figure 4.49: Minimum Principal Stress - revision 7
56
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Figure 4.50: Maximum Principal Stress - CUT - revision 2
Figure 4.51: Pin cut - stresses - Revision 2
57
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Revision 4
There is a change in the thickness of the housing in this case, so that the pin has to be modified (shortened) the same amount of length 15 mm. The external area is substantially changed in order to save weight. There are secondary maximums on the edges of the ribs. The maximum occurs, as always, inside the pin hole.
Figure 4.52: Minimum Principal Stress - revision 7
58
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Figure 4.53: Maximum Principal Stress - CUT - revision 4
Figure 4.54: Pin cut - stresses - Revision 4
59
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Revision 5
In this revision, a new approach was utilized, keeping edges and modeling a deep gap, keeping structural stiffness and removing some material at the same time. There are secondary maximums on the edges of the ribs. The maximum occurs, as always, inside the pin hole.
Figure 4.55: Minimum Principal Stress - revision 7
60
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Figure 4.56: Maximum Principal Stress - CUT - revision 5
Figure 4.57: Pin cut - stresses - Revision 5
61
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Revision 6
The main modifications are the added chamfer in front and holes crossing the hole carrier. There are secondary maximums on the edges of the ribs. The maximum occurs, as always, inside the pin hole.
Figure 4.58: Minimum Principal Stress - revision 7
62
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Figure 4.59: Maximum Principal Stress - CUT - revision 6
Figure 4.60: Pin cut - stresses - Revision 6
63
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Revision 7
The final revision tries to achieve the maximum advantage of an external rib between gears. The minimum stress is in this case with reversed color scale and the elements are visible. The maximum occurs, as always, inside the pin hole.
Figure 4.61: Minimum Principal Stress - revision 7
64
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Figure 4.62: Maximum Principal Stress - CUT - revision 7
Figure 4.63: Pin cut - stresses - Revision 7
65
4 - PLACEMENT TASKS Shape optimization
4.2.6 Planet Carrier The availability of shape finder module in Workbench, confirmed the
initial assumption, about where are the locations for material removal or modifications, Figure 4.64. The main visible area to remove is easy to understand analyzing the low material stresses. The advantage is that some details like near the pin hole or outer surface, can be seen more easily and action can be taken to remove material in those locations.
Figure 4.64: Shape optimization for Revision 1
Tangential deformation
While observing the functionality of the gears, the deflection has to
be analyzed., Figure 4.65. Probes for displacement are positioned in the front and the back, with the suitable coordinate system, Figures 4.66 and 4.67, measuring the tangential displacement, in order to have an approximation.
66
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Figure 4.65: Deformation probes
Figure 4.66: Deformation probe 1
Figure 4.67: Deformation probe 2
67
4 - PLACEMENT TASKS
4.2.6 Planet Carrier
Table 4.20: Results for the Planet carrier
Comments The results show an optimum achievable mass reduction of about 500 Kg. The maximum stress value occurs, as always, inside the pin hole. Design modifications need to be done for lowering the stresses in this spot. Different designs can now be taken into consideration. It is possible to conclude that the recommended way of achieving this goal was correct. The achievement of higher safety factors can be considered as a future research area.. The deformation achieves the best result for Revision 7, concerning the weight goal, among new revisions. On the other side, the deformation is much higher than the original planet carrier , Table 4.20 . Future work will be done to solve this problem.
68
4 - PLACEMENT TASKS
4.3
4.3. TRAININGS
Trainings
Various trainings were attended during this placement. These trainings allowed the author to learn and understand interaction of companies, formal procedures, control and selection of information, importance of IT (Information§Technology) and HPC (High Performance Computing). 1. FEMFAT 2. SKF 3. ANSYS 4. Ricardo 5. MEDESO CAE User conference - Ansys 4.3.1
Femfat
A trainer from Austria was provided to Moventas facilities, in order to assure all the contents for the training, transmitting theoretical background and practical utilization of the FEMFat Software. 4.3.2
SKF
In this training, done in Lapland, the main topics were : • Basic rating life • ISO 281 • SKF AFC • Galaxy • SKF Bearing Beacon • SKF ECS 4.3.3
Ansys
Tampere A presentation and discussion were arranged at the facilities of a new licences supplier company - Process Flow, showcasing problems and requirements. Jyv¨ askyl¨ a Medeso Conference/Seminar was conducted for performing training and showcasing new products, clearing doubts, new softwares, meeting other colleagues from the sector.
69
4 - PLACEMENT TASKS
4.3.3 Ansys
Copenhagen MEDESO CAE User conference: 26, 27 May 2008 Conference, with companies from all over Scandinavia, sharing experience and applications, representing and establishing contacts. This conference provided the author with the opportunity to have more theoretical background and to absorb case studies in other companies namely: • AlfaLaval • Kanthal AB • Grundfos • SwereaSicomp • XDIN • Scania • Siemens • BAE Systems Bofors • Validus Engineering
70
5 - CONCLUSIONS AND FUTURE WORK
5 - Conclusions and future work 5.1
Main achievements
This placement provided the author with an enriching personal and professional experience. Since it was held in a company of extremely good environment, reputation, know-how and results through all existence, based on professionalism and excellence, numerous achievements and experiences were possible.
The tasks performed allowed the author in understanding the problems that are faced in practice, exploring softwares used in mechanical applications, learning new engineering contents, such as contact analysis, mesh creation efficiency, developing problem questioning and method of resolution, maturing skills and knowledge acquired previously. From an engineering perspective, the usage of tools such as Ansys for FEM and Vibrations, Femfat, for Fatigue, Catia V5 for Modeling were found to be extremely powerful and fast, while analyzing huge amount of data, load cases and different geometries. The tasks were performed as the primary present needs were discussed and settled in the structural analysis section. The optimization of components, structures is always an objective in mind.
It was sequently enjoyed the variety of challenges through out the placement in this organization. During the strong personal growth period the whole company has been able to improve operations and utilize new capacity effectively, bringing even more challenges to future operations. From a management perspective, the whole process of adapting to a new corporate environment, working in teams, cooperating between departments, and exposure to practical aspects of running an enterprise helped in providing a sense of satisfaction for the author. From a personal perspective, the author was glad to acquire the ability to adjust, accept and adapt to a different culture in a new country, having a different language. In short,this challenging role helped the author to develop soft and hard skills which are essential for an international career. Highlighting achievements from the placement, those can be summarized as follows: 1. The starting procedures were easily performed, and the integration was easy owing to the cooperation and help of colleagues at Moventas. 2. The tasks performed required multiple skills in modeling and FEM based on discussion with team members. The learning process was a step by step process,helping the author to evolve professionally, socially and personally.
71
5 - CONCLUSIONS AND FUTURE WORK
5.2. IMPROVEMENTS
3. The tasks performed depended wholly on the dialogues between team elements and sections. The specific areas dealt by the author did not have a resolution in advance and required several trials and changes, experience and good sense in order to obtain results. This provided the author with the unique opportunity of interaction with others to obtain best results. 4. The placement made the author understand the importance of the role played by software, information system and computational power in an enterprise. Tasks were performed as per the current needs of the enterprise. The solutions provided by the author were discussed and settled in the structural analysis section. The author has observed that the optimization of components and structures is always an objective in the minds of Moventas employees.
The main strengths in the organizational climate of the company can be described as follows: • Moventas’s values and objectives are seen as worth aiming for • Awareness of the objectives and values of the company • Decisions concerning one’s own work can be made independently enough
5.2
Improvements
Computer administration plays a major role in the efficiency of an enterprise. The lack of proper computer administration in a company leads rise to delay in effective problem resolutions and difficulty in information sharing and access. In Moventas, efforts are being done to improve the situation along with the growth of the company.
The main areas in need of development on the whole company level: • Organization of work. • Work in departments as well as decision-making are not regarded having the optimum efficiency. • Information flow (information flow between and inside the departments, high amount of rumors). • Induction into new tasks.
5.3
Future Work
The author was still under the placement at the date of report submission. Present task is to study the 2D interaction between the pin and hole of planet carrier, as described in section 4.2.6 , Page 48.
72
LIST OF FIGURES
LIST OF FIGURES
List of Figures
3.1
Numbers of 2007 - MOVENTAS . . . . . . . . . . . . . . . . . . . . . . . . . . . .
8
3.2
Moventas History . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
9
3.3
Proactive lifecycle . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.4
Company Worldwide . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11
3.5
Wind gears 2007 facts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.6
Wind gears Sales/employes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.7
Industrial gears 2007 facts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12
3.8
Industrial gears Sales/employes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
3.9
Moventas Key facts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4.1
Gears Housing after simplification . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.2
Fixed supports applied in the moment-arm holes . . . . . . . . . . . . . . . . . . . 18
4.3
Housing Eigen Frequencies - 1st and 2nd Natural Modes . . . . . . . . . . . . . . . 19
4.4
Aspects of Internship webpage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 20
4.5
Wind turbine gear Assembly - Meshed - Inspection cover Location . . . . . . . . . 21
4.6
Inspection Covers - Geometry changes . . . . . . . . . . . . . . . . . . . . . . . . . 22
4.7
Inspection covers improvement aiming higher 1st /fundamental frequency . . . . . . 23
4.8
Mesh and contact for production-ready inspection covers . . . . . . . . . . . . . . . 24
4.9
1st /fundamental frequency - Results for Final optimum solution . . . . . . . . . . . 25
4.10 Wind turbine gear Assembly - Meshed - Bearing cover location . . . . . . . . . . . 26 4.11 Bearing cover in present production . . . . . . . . . . . . . . . . . . . . . . . . . . 26 4.12 Geometry and Constrains of bearing cover : Final solution
. . . . . . . . . . . . . 27
4.13 4th Natural Vibration Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28 4.14 Gears testing structure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29 4.15 Original Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 4.16 Modified Model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 4.17 New concept model . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 4.18 Gears testing ground support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31 4.19 Location of the Bolts/screws analyzed for Original and Modified . . . . . . . . . 32 4.20 Moment and Pre-tensions - Original and Modified . . . . . . . . . . . . . . . . . . 32 4.21 Moment and Pre-tensions - New Concept . . . . . . . . . . . . . . . . . . . . . . . 33 4.22 Bolts pretension step . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4.23 Moment step graphic . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4.24 Total deformation Original . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 35 4.25 Total deformation Modified . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36 4.26 Von Mises - New concept . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
73
LIST OF FIGURES
LIST OF FIGURES
4.27 ORIGINAL - Frame stress (Von Mises)- maximum near bolt head . . . . . . . . . 37 4.28 MODIFIED - Frame stress (Von Mises)- maximum near bolt head . . . . . . . . . 38 4.29 NEW CONCEPT - Frame stress (Von Mises)- maximum near bolt head . . . . . . 38 4.30 Original Total deformation of frame . . . . . . . . . . . . . . . . . . . . . . . . . . 39 4.31 Modified Total deformation of frame . . . . . . . . . . . . . . . . . . . . . . . . . . 40 4.32 New concept Total deformation of frame
. . . . . . . . . . . . . . . . . . . . . . . 40
4.33 ORIGINAL - welded region stresses . . . . . . . . . . . . . . . . . . . . . . . . . . 41 4.34 MODIFIED - welded region stresses . . . . . . . . . . . . . . . . . . . . . . . . . . 42 4.35 NEW CONCEPT - welded region stresses . . . . . . . . . . . . . . . . . . . . . . . 42 4.36 Contact tool results for the frictional contacts-GAP
. . . . . . . . . . . . . . . . . 45
4.37 Contact tool results for the frictional contacts - STATUS
. . . . . . . . . . . . . . 46
4.38 Planetary Gearbox Assembly . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 4.39 Planet Carrier detail . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48 4.40 Revisions for study . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 49 4.41 Planet Carrier - Mesh . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 4.42 Mesh - refinement locations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 4.43 Planet carrier constraints and moment load . . . . . . . . . . . . . . . . . . . . . . 52 4.44 Frictional Contacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 4.45 Frictionless contacts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 53 4.46 Minimum Principal Stress - revision 7 . . . . . . . . . . . . . . . . . . . . . . . . . 54 4.47 Maximum Principal Stress - CUT - revision 1 . . . . . . . . . . . . . . . . . . . . . 55 4.48 Pin cut - stresses - Revision 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 4.49 Minimum Principal Stress - revision 7 . . . . . . . . . . . . . . . . . . . . . . . . . 56 4.50 Maximum Principal Stress - CUT - revision 2 . . . . . . . . . . . . . . . . . . . . . 57 4.51 Pin cut - stresses - Revision 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 57 4.52 Minimum Principal Stress - revision 7 . . . . . . . . . . . . . . . . . . . . . . . . . 58 4.53 Maximum Principal Stress - CUT - revision 4 . . . . . . . . . . . . . . . . . . . . . 59 4.54 Pin cut - stresses - Revision 4 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 4.55 Minimum Principal Stress - revision 7 . . . . . . . . . . . . . . . . . . . . . . . . . 60 4.56 Maximum Principal Stress - CUT - revision 5 . . . . . . . . . . . . . . . . . . . . . 61 4.57 Pin cut - stresses - Revision 5 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 61 4.58 Minimum Principal Stress - revision 7 . . . . . . . . . . . . . . . . . . . . . . . . . 62 4.59 Maximum Principal Stress - CUT - revision 6 . . . . . . . . . . . . . . . . . . . . . 63 4.60 Pin cut - stresses - Revision 6 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 63 4.61 Minimum Principal Stress - revision 7 . . . . . . . . . . . . . . . . . . . . . . . . . 64 4.62 Maximum Principal Stress - CUT - revision 7 . . . . . . . . . . . . . . . . . . . . . 65 4.63 Pin cut - stresses - Revision 7 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 65 4.64 Shape optimization for Revision 1 4.65 Deformation probes
. . . . . . . . . . . . . . . . . . . . . . . . . . . 66
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
74
LIST OF FIGURES
LIST OF FIGURES
4.66 Deformation probe 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67 4.67 Deformation probe 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
75
LIST OF TABLES
LIST OF TABLES
List of Tables
3.1
Some Compulsory Software for simulation/structural analysis . . . . . . . . . . . . 14
4.1
Sequential Tasks Plan . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.2
Structural Steel Proprieties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
4.3
Cast Iron GJS250 Proprieties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.4
Cast Iron GJL400 Proprieties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
4.5
Inspection covers initial improvement aiming a higher fundamental frequency . . . 22
4.6
Results of the production-ready inspection covers . . . . . . . . . . . . . . . . . . . 25
4.7
Bearing cover modifications achieving a higher 4th frequency . . . . . . . . . . . . 28
4.8
Structural Steel Proprieties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.9
Friction proprieties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
4.10 Description of screws/bolts for Original and Modified
. . . . . . . . . . . . . . . . 33
4.11 Description of M16 screws/bolts for New concept . . . . . . . . . . . . . . . . . . . 33 4.12 Bolts pretension step table
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34
4.13 Moment step table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 4.14 Original bolts pretension results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 4.15 Modified bolts pretension results . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43 4.16 New concept bolts pretension results . . . . . . . . . . . . . . . . . . . . . . . . . . 43 4.17 GJS-700 Cast iron material proprieties . . . . . . . . . . . . . . . . . . . . . . . . . 50 4.18 Structural steel material proprieties . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 4.19 Supports material proprieties . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50 4.20 Results for the Planet carrier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
76
REFERENCES
REFERENCES
References [1] ANSYS. Ansys CLASSIC and Ansys WORKBENCH - HTML Help. [2] Dr. Joachim Bergmann. Synthetische f¨ ur Eisenverkstoffe, 1999. Software SWL1999. [3] CATIAV5Help. CATIA V5 HTML Help. [4] TeX Community. TeX Help, How-to, Guides, Macros, Packages, Webpages. [5] Victor Eijkhout. Tex by Topic. Addison-Wesley, 2nd edition, March 1992. [6] Michel; Rahtz Sebastian Goossens. The LaTeX Web Companion. Addison-Wesley, 2nd edition, December 1999. [7] Donald Ervin Knuth. The Texbook. Addison-Wesley, 3rd edition, October 1990. [8] S. Butterfield McNiff B., W.Musial. Improving wind turbine gearbox reliability. National Renewable Energy Lab. 1617 Cole Blv. Golden, CO 80401-3393, May 2007. NREL. [9] Tobias Oetiker. The not so short Introduction to LaTeX 2ε. 4.22 edition, June 2007. c FEUP, Porto[10] Jos´e Dias Rodrigues. Apontamentos de Vibra¸c˜ oes de Sistemas Mecˆ anicos . Portugal, 2nd edition, September 2007. c Finland, December 2005. [11] SFS. SFS Standards . c [12] PAKARINEN; Mauno; KUKKOLA; Teemu. Vibration Resonances in GE Wind Turbine . ¨ ¨ , FINMOVENTAS WIND OY, MARTINKATU, P.O. BOX 158, FIN-40101 JYVASKYL A LAND, April 2008. c Medeso, Germany, 1st edition, [13] Mr. Erke Wang. Efficient Contact Analysis with Ansys . September 2006.
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