Ford Revo Knucle

1Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

IntroductionThe simple answer to torque steer:

“Revo” Suspension

• Dipl. – Ing. Michael Frantzen

• Dipl. – Ing. Jasper Bouma

• Dr. – Ing. Wolfgang David

• Dipl. – Ing. Marc Simon

• Dipl. – Ing. Lauri Ohra-aho

Ford Forschungszentrum Aachen

2Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

Index

• „Torque Steer“

• RevoKnuckle

• Results

3Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

Wheel Forces and Moments

4Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

Wheel Forces and Moments

5Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

Wheel Forces and Moments

Focus or Mondeo Knuckle

King pin axis

Wheel center

50 –75 mm

6Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

Disturbing Forces and Moments• No „Torque Steer“ on symmetric conditions

7Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

Technology Description & Scope

„Torque steer“ on asymmetric conditions

Torque Steer Feedback

8Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

Tire Conicity

9Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

Torque Steer Contributors

• Road Conditions(friction and surface)

• Vehicle State(cornering,roll., acc.)

• Weight Distribution (loading)

• Suspension Geometry(kingpin offset, camber,caster, tolerances)

• Tire Quality(Conicity, wear, profile)

• Wheel Geometry (size, uniformity, wheel offset)

• Engine (torque, alignment)

• Differential(friction, self locking effect, Torsen differential)

• Drive Shafts (alignment, length, symmetry)

10Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

Index

• „Torque Steer“

• RevoKnuckle

• Results

11Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

RevoKnuckle vs. McPhersonRevoKnuckle MacPherson Strut

Tire Contact Patch

King Pin Axis

Wheel Centre Line

Scrub Radius

King Pin Offset

Wheel Centre

Balljoint

New Bearings

Sleeve Joint

12Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

RevoKnuckle – RevoKnuckle Joint Concepts

Ball Joint

New FFA / ZF Patent Application

Roller Bearing

13Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

Advantages concept• Improved Vehicle Dynamics Performance

- Torque Steer- Wheelfight- Steering Nibble- Brake Judder

• Reduced torquesteer sensitivity to changes in tire size (low aspect ratio) and tire conicity

• Fits to McPherson package, no body changes

• Less expensive than Double Wishbone suspension

• Lighter than Double Wishbone suspension

• Smaller Kingpin offset vs. Double Wishbone suspension : 20-30 vs. 40 mm

14Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

Index

• „Torque Steer“

• RevoKnuckle

• Results

15Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

Kinematics Results

16Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

FEA Results

17Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

Driving Results

Results from Driving Evaluation:

• Significant reduction of “torque steer effect”

• Improved vehicle dynamics performance

• No additional error state

• Promising Concept for front driven highperformance vehicles

18Suspension Projects - The RevoKnuckle

Research & Advanced Engineering Vehicle DynamicsCopyright © Ford Motor Company 2004

End

Questions