Powertrain Differentials

David Ng

Objectives

• Familiarize with the essential elements of Powertrain

• Provide an oversight of torque and speed transfer to differentials

http://www.simcreator.com/product_sheets/powertrain_ps.pdf

Powertrain Components

• Engine• Torque Converter• Gear Box• Transfer Case (depending on drive

type)• Rear/Front Differentials

Engine

• Creates torque• Torque is defined by torque map• Summed with additional torque from

any accessories and downstream components

Torque Converter

• Based on the input speed ratio

Downstream Angular Velocity: Upstream Angular Velocity

• Smoothes torque transfer from Upstream and Downstream

• Predicts transient behavior

Gear Box

• Manual Transmission is user-defined• Automatic Transmission

– Current Speed is estimated– Accelerator pedal angle and calculates

speed for gear-shift– If current speed is greater then speed

for gear-shift then gear is changed.

Transfer Case

• Applies upstream torque to the wheels

• AWD divides torque equally among the front and rear wheels

• Transfers torque to wheels via Driveshaft

• Upstream Angular velocity is propagated down to torque components

Conclusion

• Introduction to Powertrain Components

• Function of the Powertrain• Transfer of Torque and Speed

through components

References

1. Realtime Technologies: http://www.simcreator.com/product_sheets/powertrain_ps.pdf

2. Engineering Fundamentals:3. http://www.efunda.com/DesignStan

dards/gears/gears_auto_diff.cfm4. Wikipedia:

http://en.wikipedia.org/wiki/Differential_gear