USING CONSTRAINTS IN MECHANISM DESIGN 2001 MIT PSDAM

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USING CONSTRAINTS IN MECHANISM DESIGN © 2001 MIT PSDAM AND PERG LABS

USING CONSTRAINTS IN MECHANISM DESIGN © 2001 MIT PSDAM AND PERG LABS

Alternatives to motion with physical contact Problems you can not avoid with contact: ¤

Alternatives to motion with physical contact Problems you can not avoid with contact: ¤ ¤ Surface topology (finish) Wear and Fretting Friction Limited resolution, at best on order of microns…. Wear on Groove Next generation applications require nanometer level fixtures, i. e. : ¤ ¤ Fiber optics Photolithography Compliant mechanisms: ¤ ¤ Mechanical reduction to interface with larger scale actuators Motion through strain Small and moderately sized motions in comparison to mechanism size Can be made to emulate machines © 2001 MIT PSDAM AND PERG LABS

Compliant mechanism examples University of Michigan: Prof. Sridhar Kota ¤ http: //www. engin. umich.

Compliant mechanism examples University of Michigan: Prof. Sridhar Kota ¤ http: //www. engin. umich. edu/labs/csdl/index. htm Why compliant mechanisms in precision fixtures ¤ ¤ ¤ Repeatable/low hysteresis No assembly No contact © 2001 MIT PSDAM AND PERG LABS

From kinematic couplings to compliant stages y x A 1 qz A 3 ©

From kinematic couplings to compliant stages y x A 1 qz A 3 © 2001 MIT PSDAM AND PERG LABS A 2 Patent Pending, Culpepper

Constraint based compliant mechanisms High volume, low cost, multi-degree of freedom alignment Example 3

Constraint based compliant mechanisms High volume, low cost, multi-degree of freedom alignment Example 3 DOF flexure system: Target applications: Opto-electronic packaging/alignment © 2001 MIT PSDAM AND PERG LABS Video x and qz Video x Video y y qz

Constraint based compliant mechanisms cont. y x qz © 2001 MIT PSDAM AND PERG

Constraint based compliant mechanisms cont. y x qz © 2001 MIT PSDAM AND PERG LABS y

Constraint based compliant mechanisms cont. Example 6 DOF alignment capability Target app. : Micro

Constraint based compliant mechanisms cont. Example 6 DOF alignment capability Target app. : Micro and meso scale positioning (I. e. opto-electronics) Video Permanent set due to plastic deformation Have option to rely on elastic deformation z , qx , qy © 2001 MIT PSDAM AND PERG LABS x and qz Patent Pending, Culpepper

Constraint based compliant mechanisms cont. Example 6 DOF alignment capability Target app. : Micro/meso

Constraint based compliant mechanisms cont. Example 6 DOF alignment capability Target app. : Micro/meso scale positioning (I. e. opto-electronics) Video © 2001 MIT PSDAM AND PERG LABS Video z , qx , qy z qz

Constraint based compliant mechanisms cont. 3 DOF active alignment [ x, y, z ]

Constraint based compliant mechanisms cont. 3 DOF active alignment [ x, y, z ] & 2 DOF passive alignment [ z, qy ] Good fit for wire-EDM (stacked sheets) ~ order of $ 1 - 10 Video Dx & Dqz x Video Dy Video © 2001 MIT PSDAM AND PERG LABS y Dqz Video Dx & Dy Dqy Patent Pending, Culpepper

Constraint based compliant mechanisms cont. Plastic deformation can be utilized for position keeping Fy

Constraint based compliant mechanisms cont. Plastic deformation can be utilized for position keeping Fy 2 Fy 1 Device should be potted in place to avoid stress relief Fx y x Initial position © 2001 MIT PSDAM AND PERG LABS Plastically flexed

Constraint based compliant mechanisms cont. Static or flexible kinematic coupling Components biased toward each

Constraint based compliant mechanisms cont. Static or flexible kinematic coupling Components biased toward each other Flexure takes up bias, provides mating force in z direction © 2001 MIT PSDAM AND PERG LABS

ADJUSTABLE GEOMETRIC CONSTRAINTS 2001 MIT PSDAM AND PERGADJUSTABLE GEOMETRIC CONSTRAINTS 2001 MIT PSDAM AND PERG
DESIGN OF CONSTRAINT LECTURE 2001 MIT PSDAM ANDDESIGN OF CONSTRAINT LECTURE 2001 MIT PSDAM AND
NEAR KINEMATIC CONSTRAINT 2001 MIT PSDAM AND PERGNEAR KINEMATIC CONSTRAINT 2001 MIT PSDAM AND PERG
Lecture 03 Constraints Example Schema CONSTRAINTS Constraints ConstraintsLecture 03 Constraints Example Schema CONSTRAINTS Constraints Constraints
WHAT IS ENGINEERING 2002 MIT PSDAM LAB rootWHAT IS ENGINEERING 2002 MIT PSDAM LAB root
Social Constraints Breaking social constraints Carnival Social ConstraintsSocial Constraints Breaking social constraints Carnival Social Constraints
Constraints Constraints in Inventor Constraints Defined Constraint TheConstraints Constraints in Inventor Constraints Defined Constraint The
Constraints on Organisations Statutory constraints Statutory constraints areConstraints on Organisations Statutory constraints Statutory constraints are
Species Constraints Unconstrained Learning Timing Constraints Domain ConstraintsSpecies Constraints Unconstrained Learning Timing Constraints Domain Constraints
Database Constraints Database Constraints Database constraints are restrictionsDatabase Constraints Database Constraints Database constraints are restrictions