Acceleration analysis of slider crank mechanism Theory Learning ...
Acceleration analysis of slider crank mechanism Theory Learning ...
Acceleration analysis of slider crank mechanism Theory Learning ...
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̇<strong>Acceleration</strong> <strong>analysis</strong> <strong>of</strong> <strong>slider</strong> <strong>crank</strong> <strong>mechanism</strong>Velocity AnalysisLet ̇ be the velocity <strong>of</strong> the <strong>slider</strong>, and ω 3 be the angular velocity <strong>of</strong> the coupler link. Then,from the data gleaned from the position <strong>analysis</strong> and the <strong>crank</strong> velocity, ω 2 , we have( )SOLVE the virtual lab@ NITK SurathkalMechanics <strong>of</strong> Machines Lab (MoM Lab)
̈<strong>Acceleration</strong> <strong>analysis</strong> <strong>of</strong> <strong>slider</strong> <strong>crank</strong> <strong>mechanism</strong><strong>Acceleration</strong> AnalysisDifferentiating the earlier equations from velocity <strong>analysis</strong>, we end up with the accelerationdata <strong>of</strong> the <strong>slider</strong> <strong>crank</strong>. With the prior knowledge <strong>of</strong> the angular acceleration <strong>of</strong> the <strong>crank</strong>, α 2 ,the parameters such as the linear acceleration <strong>of</strong> the <strong>slider</strong>, ̈, and the angular acceleration <strong>of</strong>the coupler, α 3 .( ) ( )NextSOLVE the virtual lab@ NITK SurathkalMechanics <strong>of</strong> Machines Lab (MoM Lab)
<strong>Acceleration</strong> <strong>analysis</strong> <strong>of</strong> <strong>slider</strong> <strong>crank</strong> <strong>mechanism</strong>InversionsFigure 3: InversionsDifferent <strong>mechanism</strong>s obtained by fixing different links <strong>of</strong> a kinematics chain are known as itsinversions.A <strong>slider</strong>–<strong>crank</strong> chain has the following inversions: -1. First inversion (i.e., Reciprocating engine and compressor)2. Second inversion (i.e., Whitworth quick return <strong>mechanism</strong> and Rotary engine)3. Third inversion (i.e., Oscillating cylinder engine and <strong>crank</strong> & slotted – lever <strong>mechanism</strong>)4. Fourth inversion (Hand pump)PreviousNextSOLVE the virtual lab@ NITK SurathkalMechanics <strong>of</strong> Machines Lab (MoM Lab)
<strong>Acceleration</strong> <strong>analysis</strong> <strong>of</strong> <strong>slider</strong> <strong>crank</strong> <strong>mechanism</strong>First InversionIn this type <strong>of</strong> inversion CE is held fixed and A rotates around C along a circle and B slides back andforth along CE.Figure 4: First InversionFigure 5: Reciprocating EngineThis is the most common type <strong>of</strong> inversion. It is used in reciprocating engine and compressor.PreviousNextSOLVE the virtual lab@ NITK SurathkalMechanics <strong>of</strong> Machines Lab (MoM Lab)
<strong>Acceleration</strong> <strong>analysis</strong> <strong>of</strong> <strong>slider</strong> <strong>crank</strong> <strong>mechanism</strong>Second InversionIn this type <strong>of</strong> inversion ‘C’ and ‘A’ are both held fixed and the link CE rotates in a circlearound C. The <strong>slider</strong> B slides back and forth along the rotating CE.Whitworth Quick-Return MechanismFigure 6: Second InversionIn this inversion <strong>of</strong> the <strong>slider</strong>-<strong>crank</strong> the <strong>slider</strong> guide link is made to rotate. This is called a quick-return<strong>mechanism</strong>. This linkage also converts rotary motion <strong>of</strong> the <strong>crank</strong> into oscillatory angular motion <strong>of</strong>the <strong>slider</strong> guide link. This <strong>mechanism</strong> is used in shaper machine tools for cutting metals. JosephWhitworth was a 19th century British engineer and inventor.Figure 7: Whitworth Quick-Return MechanismPreviousNextSOLVE the virtual lab@ NITK SurathkalMechanics <strong>of</strong> Machines Lab (MoM Lab)
<strong>Acceleration</strong> <strong>analysis</strong> <strong>of</strong> <strong>slider</strong> <strong>crank</strong> <strong>mechanism</strong>Third InversionIn this type <strong>of</strong> inversion A and B are both held fixed but the <strong>slider</strong> is allowed to swivel.Figure 8: Third InversionFigure 9: Oscillating CylinderThe oscillating cylinder engine is a form <strong>of</strong> a <strong>slider</strong>-<strong>crank</strong> <strong>mechanism</strong>. This <strong>mechanism</strong> is used <strong>of</strong>ten in doordamper <strong>mechanism</strong>s. In the 19th century the oscillating cylinder was used on steam locomotives.PreviousNextSOLVE the virtual lab@ NITK SurathkalMechanics <strong>of</strong> Machines Lab (MoM Lab)
<strong>Acceleration</strong> <strong>analysis</strong> <strong>of</strong> <strong>slider</strong> <strong>crank</strong> <strong>mechanism</strong>Fourth InversionIn this type <strong>of</strong> inversion the <strong>slider</strong> B is held fixed and CE slides back and forth through the <strong>slider</strong>.Figure 10: Fourth InversionExample: Hand pumpPreviousSOLVE the virtual lab@ NITK SurathkalMechanics <strong>of</strong> Machines Lab (MoM Lab)