Dual Speed Motorcycle Hub
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Dual Speed Motorcycle Hub A thesis submitted to the Faculty of the Mechanical Engineering Technology Program of the University of Cincinnati in partial fulfillment of the requirements for the degree of Bachelor of Science in Mechanical Engineering Technology at the College of Engineering & Applied Science by TRAVIS PIERCE Bachelor of Science University of Cincinnati May 2011 Faculty Advisor: Professor Laura Caldwell TABLE OF CONTENTS DUAL SPEED MOTORCYCLE HUB .................................................................................... 1 TABLE OF CONTENTS .......................................................................................................... II LIST OF FIGURES ................................................................................................................ III LIST OF TABLES .................................................................................................................. III ABSTRACT ............................................................................................................................ III INTRODUCTION .................................................................................................................... 1 BACKGROUND .................................................................................................................................................... 1 CURRENT DESIGN ............................................................................................................................................... 1 EXISTING SOLUTIONS ......................................................................................................................................... 2 CUSTOMER FEEDBACK, FEATURES, AND OBJECTIVES ............................................. 3 SURVEY ANALYSIS .............................................................................................................................................. 3 PRODUCT OBJECTIVES ........................................................................................................................................ 4 ENGINEERING CHARACTERISTICS ........................................................................................................................ 5 ALTERNATIVE DESIGNS ..................................................................................................... 6 SLIDING GEAR DESIGN ....................................................................................................................................... 6 SELECTOR RING DESIGN .................................................................................................................................... 6 CALCULATIONS .................................................................................................................... 9 DOWEL PINS ....................................................................................................................................................... 9 DRAWINGS ........................................................................................................................... 10 MODIFICATIONS ................................................................................................................. 12 SCHEDULE ............................................................................................................................ 13 BUDGET ................................................................................................................................ 14 REFERENCES ....................................................................................................................... 14 APPENDIX A – RESEARCH ............................................................................................... A1 APPENDIX B - SURVEY ...................................................................................................... B1 APPENDIX C – QFD ............................................................................................................. C1 APPENDIX D – PRODUCT OBJECTIVES ......................................................................... D1 APPENDIX E – BUDGET ..................................................................................................... E1 APPENDIX F – SCHEDULE ................................................................................................. F1 APPENDIX G- CALCULATIONS ....................................................................................... G1 APPENDIX H-DRAWING ................................................................................................... H1 ii LIST OF FIGURES Figure 1-Suzuki DR650 Chain/Sprocket Setup ........................................................................ 1 Figure 2- U.S. Patent 4,083,421 ................................................................................................ 2 Figure 3-Sturmey-Archer 3-speed geared bicycle hub ............................................................. 3 Figure 4-Sliding Gear Design Drawing .................................................................................... 6 Figure 5- Selector Ring Design................................................................................................. 7 Figure 6- Outer Hub Assembly ............................................................................................... 10 Figure 7- Side Cover ............................................................................................................... 10 Figure 8- Locking rings Locked ............................................................................................. 11 Figure 9- Locking Rings Unlocked......................................................................................... 11 Figure 10- Modified and Stock Planetary Assemblies ........................................................... 12 LIST OF TABLES Table 1-Survey with Results ..................................................................................................... 4 Table 2-Engineering Characteristics ......................................................................................... 5 Table 3- Weighted Objective Method Table ............................................................................ 7 Table 4-Schedule .................................................................................................................... 13 Table 5-Budget........................................................................................................................ 14 ABSTRACT Motorcycles are used as enjoyable and economic modes of transportation. Due to this, many different types and classifications of motorcycles are manufactured. A narrow niche of motorcycles is grouped as dual-sports. These motorcycles look very similar to off-road only dirt bikes, but are completely road legal with lights and mirrors. The advantage of these motorcycles is that they offer great mobility on-road as well as off-road, allowing the riders to “choose their own path”. Due to being used on-road as well as off-road, comfort is important. Many riders will travel hundreds of miles in a day on their bikes and they want to be able to do it without being discomforted. Likewise, durability and reliability of their machines is always a topic of conversation. No rider wants to lose faith in their machine they trust their life with. With these thoughts in mind, the problem statement and the eventual solution to that problem statement were decided in this project. iii Dual Speed Motorcycle Hub Travis Pierce INTRODUCTION BACKGROUND Dual sport motorcycles have gained much popularity around the world in the past 20 years. They allow economic and fun cruising while allowing go-anywhere capability. The problem lies in the methods manufacturers use to choose the gear ratios of the motorcycles. The manufacturer is able to choose the ratios as well as the number of ratios in the gearbox (most have 5 or 6 gear ratios), as well as the final drive ratio, dictated by the two sprockets connected by a chain. The motorcycle this project concentrates on is a 2001 Suzuki DR650. That same basic motorcycle has been in production since 1996 until now, only the colors of the plastics have changed. A common complaint from dual sport motorcycle riders is the lack of gearing for off- road use. From the manufacturer, these motorcycles are geared towards on-road use allowing them to cruise at 65-70mph in the middle range speed range of the motor while maintaining 45-55 miles per gallon fuel efficiency. The lack of low end gearing causes the rider to slip the clutch more than usual causing excess heat and wear in the engine. CURRENT DESIGN Front Sprocket Drive Chain Rear Sprocket Figure 1-Suzuki DR650 Chain/Sprocket Setup 1 Dual Speed Motorcycle Hub Travis Pierce The chain and sprocket setup of the 1995+ Suzuki DR650 is very similar to that on most dual sport motorcycles. A front sprocket, attached to the output shaft of the transmission, is connected a rear sprocket, attached to the rear wheel, via a chain. This is shown above in figure 1 on page 1 (1). The sizes of the two sprockets determine the final drive ratio. The slack of the chain is adjusted by the stationary rear axle with a built in adjuster. EXISTING SOLUTIONS By far the most common solution used by riders today is to change the sprocket sizes. Many different sprocket sizes are available through retail stores for nearly every chain driven motorcycle. The advantages the changing the sprockets are that the rider can get the