Downhill mountain bike gearbox
Download
1 / 38

Downhill Mountain Bike Gearbox - PowerPoint PPT Presentation


  • 144 Views
  • Uploaded on

Downhill Mountain Bike Gearbox. Josh Filgate, Jesse Kuhn, Morgan Misek Jay Seiter, Michael Witonis. Problem Statement. Problem Statement:

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about ' Downhill Mountain Bike Gearbox ' - idra


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
Downhill mountain bike gearbox

Downhill Mountain Bike Gearbox

Josh Filgate, Jesse Kuhn, Morgan Misek

Jay Seiter, Michael Witonis


Problem statement
Problem Statement

Problem Statement:

When subjected to the abusive environment of downhill mountain biking, current drive train designs perform unreliably, require constant maintenance, and are easily damaged by a wide variety of external factors.

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Proposed solution
Proposed Solution

Proposed Solution:

To remedy these problems, it is our intention to design and construct an internal gearbox transmission.

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Design goals
Design Goals

The final design will take into account:

  • Max rider input of 115 N-m at 90 RPMs

  • Existing gear ratios of current drive trains (2.1-3.3)

  • High impacts resulting from crashing

  • G-CON 2.0 mounting standards

  • Sealing against mud, snow, and dust

  • Industry standard shifters, cranks, and bottom brackets

  • Targeting racers accustomed to spending between $4000 and $7000 for a complete bike

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Gearbox vs current drive system
Gearbox vs. Current Drive System

UPDATE ME

Gearboxes offer:

  • Ingress Protection

    • Separate sensitive surfaces from exposure to elements

    • Contain lubrication within a controlled environment

  • Impact Protection

    • Encloses potentially fragile components within a protective case

  • Low Maintenance

    • Less frequent lubrication and tuning required

    • Less repairs due to impacts

  • Improved Center of Gravity

    • Mass of shifting mechanisms (chain guide, derailleur, and cassette) moved to a lower and more central point in the frame

    • Improved handling

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


What is downhill mountain biking
What is Downhill Mountain Biking?

Downhill Races Involve:

  • High Speeds:

    • Up to 50+ mph

  • Natural Obstacles:

    • rock gardens

    • boulders

    • roots

    • steep terrain

  • Stunts:

    • drop-offs over 10 vertical ft

    • gap jumps of over 35 feet

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Downhill mountain biking
Downhill Mountain Biking

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Downhill mountain biking1
Downhill Mountain Biking

HIGH SPEEDS

TRAIL DEBRIS

LARGE OBSTACLES

ROOTS & VEGETATION

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Examples of harsh environments
Examples of Harsh Environments

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Current drive train is fragile
Current Drive Train is Fragile

IRREPAIRABLE FRAME AND COMPONENT DAMAGE

EXPOSED DRIVE TRAIN COMPONENT FAILURE

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


State of the industry market research
State of the Industry: Market Research

  • Online Study: “How many Derailleurs did you break in 2007?”

    • 192 responses via forums on www.bustedspoke.com and www.ridemonkey.com

    • 47% of riders broke at least one derailleur in 2007

    • 2 Pro riders broke more than 10 derailleurs

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


State of the industry early prototypes
State of the Industry: Early Prototypes

  • First internal tranmission mountain bike prototypes introduced in the late 1990s

  • First bikes used existing technologies modified into centralized locations

  • Multi-speed hubs

  • Derailleur-in-a-box

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


State of the industry future growth

Frame weldment

Crank Input

Bolt pattern

State of the Industry: Future Growth

  • Creation of G-CON 2.0 standard

  • Growing number of frame manufacturers designing gearbox compatible frames

  • Interfacing between gearboxes and frames becoming more standardized

Three current prototype designs that conform to the G-CON standards

G-CON 2.0 Gearbox Interface

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Design process

Brainstorming and Initial Concept Modeling

Design Criteria Decision Matrix

Proof of Concept Prototype

Detailed System Design

Design Process

Phase 1: Shifting Mechanism

Phase 2: Gear Assembly

Phase 3: Case and Interfacing

Concept Chosen for Design

Step 1: Geometric Driven Modeling

Step 2: Calculations performed on simplified geometries

Step 3: Detailed Modeling

Step 4: FEA with COSMOSWorks

Iterative Analytical Design

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Decision matrix
Decision Matrix

High Score

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Design process1

Brainstorming and Initial Concept Modeling

Design Criteria Decision Matrix

Proof of Concept Prototype

Detailed System Design

Design Process

Phase 1: Shifting Mechanism

Phase 2: Gear Assembly

Phase 3: Case and Interfacing

Concept Chosen for Design

Step 1: Geometric Driven Modeling

Step 2: Calculations performed on simplified geometries

Step 3: Detailed Modeling

Step 4: FEA with COSMOSWorks

Iterative Analytical Design

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Design phase i shifting mechanism

PAWLS

SHIFT BULB RETURN SPRING

SHIFTING BULB

PAWL RETURN SPRINGS

SHIFT PULL CABLE

Design Phase I: Shifting Mechanism

Model of Current Shifting System Configuration

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Design phase i shifting mechanism1
Design Phase I: Shifting Mechanism

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Design phase i shifting mechanism2

Max Stress: 370 MPa

Max Stress: 261 MPa

Design Phase I: Shifting Mechanism

Governing Equations:

Cosmos FEA of Shaft and Pawl:

τ = Tc

ΣF = Σ ma = 0

J

Assumptions:

2:1 Torque reduction from cranks to gearbox input

Torque distributed evenly over the three pawls

F.O.S. = 2

Simplified Geometry Calculations:

Max stress calculated at outside diameter of shaft:

21.7 MPa

Materials Selected:

Shaft: 4130 Steel Q&T

Pawl: 4130 Steel Normalized

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Design phase ii gear assembly

Planetary Barrel

Support Plate

Barrel Bearing

Hollow Drive Shaft

Output Gear

Sun Bearing

Design Phase II: Gear Assembly

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Design phase ii gear assembly1

AGMA Bending Stress

Buckingham Wear Load

Fw = K Q b Dp

Design Phase II: Gear Assembly

  • Three types of gear analysis performed

    • AGMA bending stress

    • Buckingham gear wear

    • Fatigue

  • Givens

    • Max rider input: 115 N-m at 90 RPMS

    • 2:1 Gear reduction from cranks to gearbox input

    • Product lifetime of 3 years

  • Independent Variables

    • Tooth width

    • Module

    • Pitch diameter

    • Material

Governing Equations:

Assumptions:

K0 = 1.25

Kv = 1

Ks = 1

Km = 1.2

J = 0.35

F.O.S. = 1.25

Available Gear Materials:

  • 303 Stainless Steel

  • 416 Stainless Steel

  • l7-4 PH Stainless Steel

  • 2024 T4 Aluminum

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Design phase ii gear assembly2
Design Phase II: Gear Assembly

Ring Gear

Material Selected: 2024 T4 Aluminum

Module: 1 Gear width: 5.6 mm

Fatigue Stress Limit: 324 MPa

Yield Strength: 325 Mpa

AGMA Stress x F.O.S: 266 MPa

Wear Stress: 19.9 MPa

Sun Gear

Material Selected: 416 Stainless Steel

Module: 1 Gear width: 5.6 mm

Endurance Limit: 277 Mpa

Yield Strength: 277 MPa

AGMA Stress x F.O.S: 266 MPa

Wear Stress: 22.5 MPa

Planet Gear

Material Selected: 416 Stainless Steel

Module: 1 Gear width: 5.6 mm

Endurance Limit: 277 MPa

Yield Strength: 277 MPa

AGMA Stress x F.O.S: 266 MPa

Wear Stress: 31.8 MPa

Example of Gear Analysis: Gear Set 4

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Design phase ii gear assembly3
Design Phase II: Gear Assembly

Gear material was selected by optimizing AGMA bending stress and fatigue

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Design phase iii case and interfacing

.2*Fd

.2*Fd

.2*Fd

Max Left Leg Loading

Max Right Leg Loading

.2*Fd

Fd

.2*Fd

Design Phase III: Case and Interfacing

Drive Shaft Bearing Support

Support Flanges

G-CON 2.0 Mounting Feature

Barrel Bearing Support

Output Shaft Bearing Support

Threaded Bottom Bracket Shell

  • Mounts to G-CON 2.0 standard frames

  • Supports gears and shafts

  • Structural member of frame

Free body diagram

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Design phase iii

Max Stress: 7 MPa

Design Phase III

Loading Conditions:

Rider transmits 100% of load from vertical impact to pedals via legs

0% absorption with bike suspension

Maximum force rider’s legs can transmit = 500 lb

COSMOS FEA of Case:

Material Selected:

6061 T6 Aluminum

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Design phase iii case and interfacing1

Input Sprocket

Shifting Cable Scalar

Output Sprocket

Gasket

Industry Standard Bottom Bracket and Cranks

Impact Resistant Bash Guard

Design Phase III: Case and Interfacing

Industry Standard Component Compatibility:

  • Shifting cable scalar interfaces with indexed shifters

  • Case sized and threaded for integration with standards bottom brackets and cranks

  • Standard mountain bike sprockets used for input and output

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Final design
Final Design

Weight:7.5 lbs

Estimated Cost:$4000

Gear Ratios:2.1, 2.3, 2.5, 2.7, 2.9, 3.1, 3.3

Materials:416 Stainless Steel, 303 Stainless Steel, 17-4 PH Stainless Steel, 4130 Steel, 1045 Steel, 2024 Aluminum, 6061 Aluminum

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Proof of concept prototype
Proof of Concept Prototype

Weight: 8 lbs

Cost:$1500

Gear Range:2.1, 2.5, 3.3

Materials:SLA, 303 Stainless Steel, 6061 Aluminum, 1045 Steel, Carbon Steel, Nylon

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Concluding thoughts
Concluding Thoughts

  • Proof of concept testing

    • Shifting mechanism functions

    • Gear configuration provides three distinct ratios

    • Case supports internal systems and interfaces with industry standard components

    • Sub systems mechanically integrate

  • Further development

    • Build and test final design prototype

    • Reduce weight

    • Extend lifetime

    • Improve manufacturability

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Questions
Questions?

Special thanks to the following individuals for their technical and moral support:

Randy Moore, Brian Weinberg, Jim Forte

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Extra slides
Extra Slides

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Images
Images

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Images1
Images

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


- Face Width

- Module

- Material Yield Strength

- Size Factor = 1

- Mounting Factor = 1.3

- Life Factor

- Overload Factor = 1.5 (1 - 2.25)

- Temperature Factor

- Velocity Factor (precision, pitch velocity)

- Reliability Factor

- Transmitted tangential load

- Geometry Factor: .45

AGMA

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Different suspensions with g con 2 0
Different Suspensions with G-CON 2.0

ONLINE VIDEO OF MORE PIVOT DESIGNS

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Slide graveyard
Slide Graveyard

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Proof of concept prototype1
Proof of Concept Prototype

Final Design Prototype

Weight:7.5 lbs

Cost:$4000

Gear Ratios:2.1, 2.3, 2.5, 2.7, 2.9, 3.1, 3.3

Materials:416 Stainless Steel, 303 Stainless Steel, 17-4 PH Stainless Steel, 4130 Steel, 1045 Steel, 2024 Aluminum, 6061 Aluminum

Proof of Concept Prototype

Weight: 8 lbs

Cost:$1500

Gear Range:2.1, 2.5, 3.3

Materials:SLA, 303 Stainless Steel, 6061 Aluminum, 1045 Steel, Carbon Steel, Nylon

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


Final design1
Final Design

PLANETARY STACK

SHIFTING CABLE SCALER

INPUT SPROCKET

OUTPUT SPROCKET

STANDARD MOUNTAIN BIKE CRANKSET, BOTTOM BRACKET. AND BASHGUARD

Design Team: Joshua Filgate, Jesse Kuhn, Morgan Misek, Jay Seiter, Michael Witonis


ad