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Formula SAE Motion TransferDesigned by BCD Tech FSAE3APresented by: Jrmie Beausoleil, Jean-Franois Croteau, Amir Daoud, Alexandre Tchourbassoff, December 14th 2016

uOttawa.ca

Facult de gnie | Faculty of Engineering

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Vehicle Overview0-100 km/h under 5 s57 HP engineTorque at the wheels of 308 Nm100% parametrizable2

Source: http://www.tc.umn.edu/~sae/photos/vehicles/small_2014.png

Source: https://file.kelleybluebookimages.com/kbb/vehicleimage/ evoxseo/cp/l/9800/2015-bmw-7-series-front_9800_032_640x480_ 300.png

Power to weight ratio comparable to that of a BMW 760 Li V12, which is doing a 0-60 mph in 3.7 s2

Group MandatePart of a team competing at the Formula SAEDesign of motion transfer componentsSelection of engine, rims and tiresCoordinate with chassis group3

Source: http://sae.wustl.edu/about.html

BCD Tech is part of a team responsible for the design of a Formula SAE vehicle. The Formula SAE competition is a student design competition held every year at different locations around the globe. Our mandate was to design and select motion transfer components for the Universitys race car and to integrate our components with those of the chassis group.3

4. Torsen Differential6. Wheel Assembly1. Multiplate Clutch2. Sequential Transmission3. Roller-Chain5. Tripod C.V. Joints7. Master Cylinder& Brake Pedal AssemblyGroup Mandate Designed Components4

In the following slides, we will describe and justify the design of the following components: a multiplate clutch, a sequential transmission, a roller-chain, a Torsen differential, tripod constant velocity joints, the wheel assembly and the master cylinder and brake pedal assembly.It is important to note that the components were all designed with a common objective: to win the competition4

1. Engine:BRP ACE 6003. Tires:Hoosier 18 Avon 202. Rims:Braid Sturace 10 13 Group Mandate Selected Components5

For the selected components, BCD Tech opted for a BRP ACE 600 snowmobile engine. It is selected because of its high operating speed and torque. It was preferred over motorcycle engines, because it is not equipped with a transmission. The original transmission in motorcycles engine makes it nearly impossible to design a parametrizable transmission.The selected rims are manufactured by Braid and are 10 or 13 inches in diameter, the equivalent of 25.4 or 33 cm. Finally, race tires from Hoosier and Avon are selected based on their adhesion properties and size. 5

Multiplate ClutchCompact designReliable

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Clutch handleShifting lever

The first component designed by BCD Tech is the multiplate clutch, also called a basket clutch. The main role of the clutch is to interrupt the power flow from the engine to the gearbox. Using a sequential transmission, the clutch is only disengaged when the vehicle is at rest. It is disengaged using a clutch handle which is mounted on the shift lever, as shown on the screen. This lever design insures that the driver has one hand on the steering wheel at all time.6

Multiplate Clutch7

Clutch basketClutch bossFrictional platesSteel platesClutch coverHelical compression springsRelease bearing assembly

Here is an exploded view and the name of the main components of the multiplate clutch. The most important components are the basket clutch which is mounted on the crankshaft of the engine, the clutch boss which is mounted on the input shaft of the transmission and the plates and compression springs which are responsible for transferring the engines torque without slipping.7

Sequential Transmission3-speed transmission

Easy to operate

Responsive

High performance

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Sequential Transmission

9Transmission casingOutput shaft1st gear2nd gear3rd gearShifting ratchetRatchet coverInput shaft2nd gear3rd gear1st gear

Roller-chainLightweightEfficient power transferEase of maintenanceEasily parametrizableGear ratio of 3.2

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The power is transferred from the gearbox to the Torsen differential using a roller-chain and a set of two sprockets. A roller-chain was selected over other systems because of its light weight, efficient power transfer, ease of maintenance and it is easily parametrizable by adding or removing chain elements. Finally, the sprocket and chain assembly increases the torque by a factor of 3.2.10

Torsen DifferentialTorque bias ratio of 2.97

Everlasting

Compact

Purely mechanical

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Torsen Differential

12Upright mountTorsen casingWorm gearWorm wheelFlanged bushingJournal pinThrust washerOutput sprocket

Tripod Joint

13Tripod housingTripod spider assemblyAxle shaftDust boot

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Retainer ringRetainerBearing ballCaseNeedle rollersSpacer ringSpider

Simple and effective design Lower estimated production cost

Designed to withstand high torque transfer

Tripod Joint

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Source: https://www.youtube.com/watch?v=U5TV5NC5YOg

Tripod joint operating angleBearing ball caseTripod spider & axle shaftTripod housing

Tripod joint assemblyAxle shaftTripod Joint

Wheel AssemblyFully parametrizableCompactLightweightHigh performance

16A- arm mounting pointA- arm mounting pointRotor crossed drilled holeTie rod mounting pointUpright mount

Wheel Assembly

17Upright mountCaliperRotorHubLug nutsTireWheelassemblyWheel hubbearingHub nutBearing retainerRim

Simple and effective design

Designed to withstand high operating pressures and temperatures

Low estimated production cost

18Brake padsCaliper mounting bracketCaliper pistonPiston housingSliding pinWheel Assembly Disc Brake

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Source: https://www.youtube.com/watch?v=MAuVDB-G-HQ&t=190sBrake padsCaliper mounting bracketPiston housingSliding pinPiston housingSliding PinPistonRotorCaliper mounting bracketWheel Assembly Disc Brake

Master Cylinder & Brake PedalFully parametrizableOptimal brake force distribution

20Balance bar

Master Cylinder & Brake Pedal

21Brake pedalPush rodMaster cylinderBalance barPistonCompression springBrake fluid reservoir

Team IntegrationMounting pointsTurnbucklesEngineTransmissionTorsenUpright mountsParametrizable

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Parametrization

6. Drivers weight1. Unit system3. Track selection4. Track width5. Other track width7. Rim size2. Wheelbase8. Weather9. Turbocharged23

Conclusion & Questions24

125 ms24