Robust Tolerance Design at Volvo Aero Corporation - Chalmers

44 Pages·2011·1.23 MB·English

Robust Tolerance Design at
Volvo Aero Corporation
Master of Science Thesis in the Master’s program Product Development
ANDREAS STENLUND

Department of Product and Production Development
Division of Product Development
CHALMERS UNIVERSITY OF TECHNOLOGY
Göteborg, Sweden 2010

MASTER OF SCIENCE THESIS

Robust Tolerance Design at
Volvo Aero Corporation
Master of Science Thesis in the Master’s program Product Development
ANDREAS STENLUND

Department of Product and Production Development
Division of Product Development
CHALMERS UNIVERSITY OF TECHNOLOGY
Göteborg, Sweden 2010
Robust Tolerance Design at Volvo Aero Corporation
Master of Science Thesis in the Master’s program Product Development
ANDREAS STENLUND
© ANDREAS STENLUND, 2010

Examensarbete / Institutionen för Produkt och Produktionsutveckling,
Chalmers tekniska högskola

Department of Product and Production Development
Division of Product Development
Chalmers University of Technology
SE-412 96 Göteborg
Sweden
Telephone: + 46 (0)31-772 1000

Reproservice / Department of Product and Production Development
Göteborg, Sweden 2010
Robust Tolerance Design at Volvo Aero Corporation
Master of Science Thesis in the Master’s program Product Development
ANDREAS STENLUND
Department of Product and Production Development
Division of Product Development
Chalmers University of Technology

ABSTRACT
Volvo Aero Corporation develops and produces advanced components for aircraft
engines. To fulfil the demands for lighter engines, their new product development is
based on Volvo Aero’s capability for light weight design, through fabrication.
Fabrication, as opposed to traditional production methods of a one-piece casting,
consists of smaller cast, forged and sheet metal worked parts, which are welded
together. Simultaneously with this new design follows problems that need to be
solved in order to stay competitive and to be able to produce their products. By
working with robust tolerance design and geometry assurance, variation related
problems can be avoided and thereby improve the quality of produced products.
Robust tolerance design is also required in order to, avoid manual adjustments in
production and thereby make it possible to increase the level of automation.
In the thesis work, several case studies have been conducted in order to investigate
Volvo Aero’s potential to adapt to robust tolerance design methods. These studies
show improvement potential for the parts tested and have been used in order to
describe important work procedures and tasks. A “geometry system developer” role
has been tested in a project in concept phase, were the robust tolerance design tasks
and questions have been handled.
Key words: Robust tolerance design, Fabrication, Variation, Geometry assurance.

I
Robust Tolerans Konstruktion på Volvo Aero Corporation
Examensarbete inom Product Development
ANDREAS STENLUND
Institutionen för Produkt och Produktionsutveckling
Avdelningen för Produktutveckling
Chalmers tekniska högskola

SAMMANFATTNING
Volvo Aero Corporation utvecklar och tillverkar avancerade komponenter till
flygmotorer. För att uppfylla kraven för lättare motorer, är deras utveckling av nya
produkter baserade på Volvo Aeros lättvikts konstruktion, genom fabrikation.
Fabrikation, i jämförelse med traditionella framställningsmetoder genom ett gjutet
stycke, består av mindre gjutna eller smidda delar samt plåtar, som svetsas samman.
Tillsammans med denna nya design följer problem som måste lösas för att förbli
konkurrenskraftiga och för att kunna producera sina produkter. Genom att arbeta med
geometrisk robust konstruktion och geometrisäkring kan variationsrelaterade problem
undvikas och därigenom förbättra kvaliteten på producerade produkter. Geometrisk
robust konstruktion är också nödvändigt för att undvika manuella justeringar i
produktionen och därmed göra det möjligt att öka graden av automatisering.
I examensarbetet har flera fallstudier genomförts för att undersöka Volvo Aeros
potential att anpassa sina metoder till geometrisk robust konstruktion. Dessa studier
visar förbättringspotential för de testade komponenterna och har använts för att
beskriva viktiga arbetssätt och arbetsuppgifter. En "Geometri System Utvecklar" roll
har testats i konceptfasen av ett projekt, genom att ta hand om arbetsuppgifter och
frågor relaterade till geometrisk robust konstruktion.
Nyckelord: Robust konstruktion, Fabrikation, Variation, Geometrisäkring.

II
CONTENTS
ABSTRACT I 
SAMMANFATTNING II 
CONTENTS III 
PREFACE V 
1  INTRODUCTION 1 
1.1  Background 1 
1.2  Purpose 1 
1.3  Objective 1 
1.4  Research questions 2 
1.5  Scope 2 
2  FRAME OF REFERENCE 3 
2.1  Tolerances 3 
2.1.1  Worst case tolerancing 3 
2.1.2  Statistical tolerancing 4 
2.1.3  Process capability indices 4 
2.2  Locating scheme 5 
2.3  Geometrical robust design 5 
2.3.1  Wingquist Laboratory and RD&T 7 
2.4  Measurements 8 
2.5  Geometry System Developer role 8 
3  RESEARCH APPROACH 9 
3.1  Case study research 9 
3.2  Research process 10 
4  RESEARCH FINDINGS 11 
4.1  Case studies 11 
4.1.1  Product X 12 
4.1.2  Product Y 14 
4.1.3  Product Z 16 
4.2  GSU role 17 
5  DISCUSSION 19 
5.1  Discussion about research questions 19 
5.2  Discussion about research approach 21 
5.3  Discussion about case studies 22 

III
6  CONCLUSION 23 
6.1  Recommendations 23 
7  REFERENCES 25 
8  APPENDIX A. CASE STUDY OF PRODUCT X 27 
9  APPENDIX B. CASE STUDY OF PRODUCT Y 29 
10  APPENDIX C. CASE STUDY OF PRODUCT Z 31 
11  APPENDIX D. INTERVIEW 33 

IV
Preface
This Master of Science, thesis report, describes a study about how Volvo Aero
Corporation can implement robust tolerance design into their Global Development
Process (GDP). The research has been carried out between March 2010 and
November 2010, at Volvo Aero Trollhättan, Sweden. The thesis work is the final part
of the master’s program Product Development at Chalmers University of Technology.
It comprises 30 units of credits.
The work has been carried out by Andreas Stenlund and the progress has been
supervised by Prof. Rikard Söderberg at Product development, Chalmers University
of Technology. At Volvo Aero Corporation, mentoring and supervising have been
performed by PhD Johan Lööf.
I would like to thank Rikard for being my mentor and Volvo Aero Corporation for
being able to perform this thesis. Special thanks to Johan who has been the company
supervisor. I want to thank him for all his mentoring and support during the whole
process. I am also thankful to Alejandro Vega Galvez, Tor Wendel, Jesper Larsson,
and all other persons who have helped me at Volvo Aero Trollhättan.

Because of company secrecy policy, all important figures, manufacturing methods
and delicate information have been moved to classified appendixes and can be viewed
in Volvo Aero Corporation’s internal system. With these appendixes available the
reader is advised to ignore Section 4.1 and instead read the appendixes.

Göteborg, Mars 2011
Andreas Stenlund

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