Tractor Drive Train · PDF file · 2017-11-15Tractor Drive Train Dream Team Engineering Technologies ... drive system - Two differential shiftable ......

Tractor Drive Train Dream Team Engineering Technologies

Alex Mitchell Moritz Büdenbender Chloe Wiese

Mukul Aggarwal Julius Großkopf

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

Friction clutch and cardan

shaft for front axle

Selectably lockable front

axle differential

Wheel hub transmission and wheels

Selectably lockable rear

axle differential

Wheel hub transmission and wheels

Power Flow for Tractor Drivetrain

3D Concept Sketch

Engine

Rear Differential

Front Differential

Transmission

FWD Cardan Shaft Planetary Gear Hub

Front Friction Clutch

Starting Clutch PTO Cardan

Shaft

Project Plan M T W Th F M T W Th F M T W Th F M T W Th F

Creation  of  group  folder AllConsider  advantages  and  dissadvanteges  of  four  wheel  drive  concepts AllEvaluation  and  selection  of  a  four  wheel  drive  concept AllConcept  for  starting  clutch JuliusConcept  for  manual  transmission Chloe  and  MoritzConcept  for  differentials Mukul  and  AlexConcept  for  lubrication  of  the  transmission  and  differentials AllTransmission  gear  ratio  calculations AllCalculations  of  bearing  forces AllPresentation All

Mechanical  Design  4  -­‐  Project  Meeting  I  -­‐  Gantt  Chart Week  of

Responsible  Project  Milestones14.04.2014 21.04.2014 28.04.2014 05.04.2014

23.06.2014M 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

Updated  the  project  plan AllPlanned  the  implementation  of  the  CAD-­‐model AllCorrections  from  the  first  project  meeting AllDimensioning-­‐  Bearing  forces  and  fits  of  the  transimission AllDimensioning-­‐  Surface  pressure  of  starting  clutch AllTechnical  Drawing  -­‐  Starting  clutch AllTechnical  Drawing  -­‐  Manual  transmission AllCreation  of  an  abstract  skeleton  structure  (Top-­‐Down)  in  CAD AllStarting  the  implementation  of  the  manual  transmission  in  CAD  for  3rd  project  meeting AllPresentation All

Mechanical  Design  4  -­‐  Project  Meeting  II  -­‐  Gantt  Chart Week  of

Project  Milestones Responsible  12.05.2014 19.05.2014 26.05.2014 02.06.2014 09.06.2014 16.06.2014

M T W Th F M T W Th FComplete  group  folder,  review  of  project  plan AllCorrections  from  the  second  project  meeting AllTechnical  Drawing  -­‐  Manual  transmission,  clutch  and  differential AllCAD  -­‐  Complete  detailed  design  of  the  transmission AllCAD  -­‐  Deduction  of  a  technical  drawing  of  the  transmission  from  the  CAD  model AllPresentation  of  the  results  of  MD4 All

Week  of

M

Mechanical  Design  4  -­‐  Project  Meeting  III  -­‐  Gantt  Chart

Project  Milestones Responsible  23.05.2014 30.05.2014 07.07.2014

Clutch Concept Friction Disk

Flywheel

Throwout Bearing

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

Pressfitting Bearing Retaining Caps on the

ends of each shaft

Attachment Bearing Retaining Locknuts,

Snaprings, and Shaft Énd Caps

Simultaneous insertion of Output Shaft and

2nd shaft

Insertion of PTO, Power Input, and FWD shafts independently

Attachment of Main Housing Caps to

Bearing Retaining Caps via Bolts

Mounting of Transmission in

Tractor Frame Mounts

Addition of ATF via the Oil Fill Hole

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

Crown Gear

Pinion Gear

Locking Mechanism

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 •  Increased vibrations due to spur

gears •  Lack of synchronization •  Complex driver interface

Opportunities •  Expansion into underdeveloped

markets due to low cost •  Simple maintenance procedures

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!