The Dudes ltd.

DMTB EngineeringPresentation 1: Research and Concept SelectionMini Baja GearboxFebruary 6, 2014

AgendaProblem Definition;Design Constraints;Research;Conclusions; andProject Plan for Next Steps.Problem DefinitionCreate a simple mechanical gearbox for use in a Mini Baja off-road vehicle.

Objectives Include:Must have forward and reverse gears;Must be robust yet relatively lightweight;Must be cost effective; andMust produce a suitable final drive reduction ratio.Design ConstraintsSize/Weight

Motor & Transmission10 HP Briggs & Stratton engineContinuously Variable Transmission

Budget

Source: Memorial BajaResearchGEARS

Parallel Axis GearsSpur Helical

Gear Materials

SHAFTS

Three types of shafts we are concerned with when talking about gearboxes:

Input ShaftCountershaftOutput Shaft

Shaft Materials

GEAR ATTACHMENTThere are various ways we can attach the gears to the shafts:

SetscrewKeywayCirclipShear PinsLocking Assembly

GEARBOX HOUSINGFluid Tight Container to Hold LubricantProvides Support For Internal ComponentsSupports External Forces on the ShaftProvides Convenient Access to Internal Components For Inspections

Potential MaterialsCast AluminumUnique Shapes

Billet AluminumMore Precise (CNC)

Composite MaterialHigh PerformanceCombination of Durability & Lightweight

ConclusionsDMTB GearboxGears will be steel spur gears;Shafts will be steel alloy;Housing will be milled from billet aluminum; andFinal output will be an internally splined female connection.

Proposed Output Design

Source: Pure PolarisBenefit of a splined joint as opposed to key way;Narrow mating surface decreases the amount of plunge needed in CV joints; andPre-made half shafts mean easy replacement in the event of failure.Project Plan

Gear Layout;CAD Model;Force Analysis; andDrawing Package.Questions?www.dmtbeng.weebly.com