Lesson 1: Basic concepts on Mechanisms# Lesson contents: Definitions Machines vs Mechanisms Parts of a mechanism Parts of a link Kinematic pairs (Joints) Kinematic chain Topological and abstract analysis of mechanisms Open and closed kinematic chains Mobility and degrees of freedom Equivalent mechanisms Kinematic inversion Dyads Links and joints: detailed classification Types of closure in kinematic pairs Classification of links Classification of pairs by degree of freedom Four-bar linkage Bar names Grashof’s law Try it yourself! Motorbike swingarm Six-bar linkage Stephenson mechanism Watt mechanism Pallet pusher Other well-known mechanisms Slider-crank mechanism Quick-return mechanism Geneva wheel Determining the d.o.f. count Grübler’s formula for planar mechanisms Kutzbach’s general formula Practical application of the formula Numbering options Joints with more than two links Exceptions and problematic cases Numerical methods criterion DOF solved problems Example 1 Example 2 Example 3 Example 4 Example 5 Example 6 Example 7 Problems: Determine the kinematic chain Blind slats Feeder 1 Translation without rotation Car trunk Scissor lift Elliptical trainer Motorbike suspension Stacked joints
