© 2001 MIT PSDAM AND PERG LABS NEAR KINEMATIC CONSTRAINT

© 2001 MIT PSDAM AND PERG LABS Quasi-Kinematic (QKC) alignment QKC characteristics:  Arc contact  Submicron repeatability  Stiff, sealing contact  Less expensive than KCs  Easier to make than KCs QKC Function:  Ball & groove comply  Burnish surface irregularities  Elastic recovery restores gap Groove Seat Side Reliefs Spherical Protrusion F or   initial  = 0  final Distance along Cone Face, [inches] Feature Height, mils

© 2001 MIT PSDAM AND PERG LABS PAIRS OF QKC ELEMENTS ASSEMBLED JOINTTYPE 2 GROOVE MFG. CASTFORM TOOLFINISHED += + + OR Details of QKC element geometry

© 2001 MIT PSDAM AND PERG LABS Which variation of QKC to use Design ADesign B In Design A, Peg deforms on edge -> reduced repeatability + + OR

© 2001 MIT PSDAM AND PERG LABS x y Contact Point Ball Groove Surface Peg Surface Relief Cone Seat QKC methods vs kinematic method Relief Components and Definitions Force Diagrams

© 2001 MIT PSDAM AND PERG LABS Resultant Forces [n i & Fi] Applied Loads [Fp & Mp] Deflections  ->  r Relative Error Geometry Material Modeling QKC stiffness QKC Model Geometry Material Displacements Contact Stiffness f n (  n ) Force/Torque Stiffness

© 2001 MIT PSDAM AND PERG LABS MECHANICS: Use Rotating Coordinate System Assume Sinusoidal Normal Distance of Approach Obtain Contact Stress Profile as Function of Above Integrate Stress Profile in Rotating CS thru contact Rotating CS n l s ^ ^ ^ QKC contact mechanics k n l i ^ RcRc ^ ^ ^

© 2001 MIT PSDAM AND PERG LABS 10  m 5  m 0  m Coupling + Others Process Rough Error Budget Characteristics: Ford 2.5 & 3.0 L V6 > 300,000 Units / Year Cycle Time: < 30 s Example: Duratec TM assembly

© 2001 MIT PSDAM AND PERG LABS C B Halves Block Bedplate Assembly Bolts BlockBedplate r a JRJR ee JLJL Block Bore Bedplate Bore C L C L  e MAX = 5 microns ERROR ASSEMBLY COMPONENTS Example: Assembly of Duratec TM block & bedplate

© 2001 MIT PSDAM AND PERG LABS Bedplate Main Bearing Half Block Main Bearing Half Crank Shaft Journal Block Main Bearing Halves Bedplate Crank Shaft Piston Bearing assemblies in engines

© 2001 MIT PSDAM AND PERG LABS Detail of Duratec TM QKC element placement

© 2001 MIT PSDAM AND PERG LABS MANUFACTURING: DESIGN: Results of Duratec TM QKC Research

© 2001 MIT PSDAM AND PERG LABS Bedplate 2 nd Block Fixture J L Cap Probe J R Cap Probe 1 st Block Fixture Bedplate Fixture CMM Head Axial Cap Probe Axial Sensitive 9 ( Range / 2 )| AVG = 0.65  m ( Range / 2 ) = 1.35  m Engine assembly performance