Tractor Drive Train Dream Team Engineering Technologies Alex Mitchell Mukul Aggarwal Moritz Büdenbender Julius Großkopf Chloe Wiese

Problem Definition •  Summary -  Develop a drivetrain for an agricultural tractor with given technical specifications

•  Possible Approaches -  Three differential all wheel drive system -  Two differential shiftable four wheel drive system http://www.deere.com

Our Solution •  Concept - Shiftable FWD system with two selectably lockable differentials - FWD actuated via friction clutch Combustion engine

Single plate friction starting clutch

Mechanical manual transmission

Selectably lockable rear axle differential

Friction clutch and cardan shaft for front axle

Wheel hub transmission and wheels

Power Flow for Tractor Drivetrain

Selectably lockable front axle differential

Wheel hub transmission and wheels

3D Concept Sketch Starting Clutch Engine

PTO Cardan Shaft

Transmission

Front Differential

Front Friction Clutch

FWD Cardan Shaft

Rear Differential Planetary Gear Hub

Project Plan Mechanical  Design  4  -­‐  Project  Meeting  I  -­‐  Gantt  Chart Project  Milestones

Responsible  

Week  of 14.04.2014 21.04.2014 28.04.2014 05.04.2014 M T W Th F M T W Th F M T W Th F M T W Th F

Creation  of  group  folder All Consider  advantages  and  dissadvanteges  of  four  wheel  drive  concepts All Evaluation  and  selection  of  a  four  wheel  drive  concept All Concept  for  starting  clutch Julius Concept  for  manual  transmission Chloe  and  Moritz Concept  for  differentials Mukul  and  Alex Concept  for  lubrication  of  the  transmission  and  differentials All Transmission  gear  ratio  calculations All Calculations  of  bearing  forces All Presentation All Mechanical  Design  4  -­‐  Project  Meeting  II  -­‐  Gantt  Chart Project  Milestones

Responsible  

Updated  the  project  plan Planned  the  implementation  of  the  CAD-­‐model Corrections  from  the  first  project  meeting Dimensioning-­‐  Bearing  forces  and  fits  of  the  transimission Dimensioning-­‐  Surface  pressure  of  starting  clutch Technical  Drawing  -­‐  Starting  clutch Technical  Drawing  -­‐  Manual  transmission Creation  of  an  abstract  skeleton  structure  (Top-­‐Down)  in  CAD Starting  the  implementation  of  the  manual  transmission  in  CAD  for   3rd  project  meeting Presentation

Week  of 12.05.2014 19.05.2014 26.05.2014 02.06.2014 09.06.2014 16.06.2014 23.06.2014 M T W Th F M T W Th F M T W Th F M T W Th F M T W Th F M T W Th F M

All All All All All All All All All All

Mechanical  Design  4  -­‐  Project  Meeting  III  -­‐  Gantt  Chart Project  Milestones Complete  group  folder,  review  of  project  plan Corrections  from  the  second  project  meeting Technical  Drawing  -­‐  Manual  transmission,  clutch  and  differential CAD  -­‐  Complete  detailed  design  of  the  transmission CAD  -­‐  Deduction  of  a  technical  drawing  of  the  transmission  from  the  CAD  model

Presentation  of  the  results  of  MD4

Responsible   All All All All All All

Week  of 23.05.2014 30.05.2014 M T W Th F M T W Th F

07.07.2014 M

Clutch Concept Friction Disk

Throwout Bearing

Flywheel

Shaft 1

Spring Disk

Transmission Concept Shaft 2

Shaft 1

Shaft 3

Front Wheel Drive

Transmission Concept •  Components of transmission –  Five shafts –  Working and driving gears –  First, second and reverse gears •  Useable with both working and driving ratios

–  Front Wheel Drive (FWD) •  Useable with any gear selection

–  Power Take Off (PTO) •  Useable with both working and driving ratios

Transmission Assembly Assembly of Shafts with Gears and Selectors via Pressfits and Snaprings

Attachment of Main Housing Caps to Bearing Retaining Caps via Bolts

Mounting of Transmission in Tractor Frame Mounts

Pressfitting Bearing Retaining Caps on the ends of each shaft

Insertion of PTO, Power Input, and FWD shafts independently

Addition of ATF via the Oil Fill Hole

Attachment Bearing Retaining Locknuts, Snaprings, and Shaft Énd Caps

Simultaneous insertion of Output Shaft and 2nd shaft

Transmission Calculations •  Shaft Calculations –  Based on material properties of 42CrMo4 –  Static and dynamic calculations –  Included a safety factor of 1.4

Transmission Calculations •  Bearing Calculations –  Basic lifetime calculation •  Bearing selection (SKF)

–  Extended lifetime calculation •  Ensuring lifetime functionality

–  Static load check •  Static safety

Transmission Calculations •  Gear Calculations –  Ratios from engine rpm and desired speeds for different gear selections –  Used material properties to determine necessary dimensions –  Module and number of teeth

Selectably Lockable Differentials Locking Mechanism

Pinion Gear

Crown Gear

Technical Advantages •  Low manufacturing cost •  FWD-shiftable under load •  Two differentials •  Use of selectably lockable differentials •  Use of friction clutch (FWD) •  Simple lubrication

SWOT Analysis Strengths •  •  •  • 

Low-cost Durable Minimal complexity Proven technology

Weaknesses •  •  • 

Opportunities •  • 

Expansion into underdeveloped markets due to low cost Simple maintenance procedures

Increased vibrations due to spur gears Lack of synchronization Complex driver interface

Threats •  • 

Changing of the market landscape to high-tech products Low profit margin per part

Conclusion •  Designed a durable, low cost drivetrain - Simple approach to a complex problem - Selectable FWD - Integrated inexpensive parts •  Spur gears •  Chains •  Simple housing •  Elimination of synchronization

Thank you!