Whitworth Quick Return Mechanism

INTRODUCTION

The Whitworth quick return mechanism converts rotary motion into reciprocating motion, but unlike the crank and slider, the forward reciprocating motion is slower rate than the return stroke. This is why it is called quick return mechanism.

This mechanism is made of a driving crank and of a driven slider crank. In the considered configuration, the fixed pivot of the driven crank is located on the outside of the circle on which the end of the driving crank moves. This leads to an alternated motion of the slider crank.

The angular speed of the driven crank is variable. The duration of the motion for its part corresponding to the blue arc is shorter than the one related to the red arc. This is why this device is named quick return mechanism, which was used in crank shapers, with the slow part or the stroke being used for the working time of the tool and the quick part for the non-productive time.

Theory

History

cutting machine by Sir Joseph Whitworth

Applications

Rotary engines

Power driven Saw machine

Shaping machine

Water pumping system

Slider Crank Mechanism

Whitworth (Quick return) Mechanism

Kinematic Analysis of the Whitworth Quick Return Mechanism (FIG 1)

Position Analysis

Velocity Analysis

Acceleration Analysis

Dynamic Analysis of the Whitworth Quick Return Mechanism

Forces on Each Member

Click icon to add picture

Figure3 FBD of link 2

Click icon to add picture

Figure 4 FBD of link 3

Click icon to add picture

Figure 5 FBD of link 4

SIMULATION ON SOLIDWORKS AND ADAMS

VIEW

SOLIDWORKS

SOLIDWORKS PARTS

STRESS ANALYSIS

STRAIN ANALYSIS

WORKING ON ADAMS

SIMULATION ON ADAMS (SLIDER)

SIMULATION (CRANK)

SIMULATION (MAIN)

THANK YOU

References http://www.robotee.com/LR/51029_Robotee-com-WhitWorthCQuickReturn-mechanism.pdf

http://metalab.uniten.edu.my/~kamal/documents/Machine%20Design%20Lab/Laboratory%20Manual/Whitworth's%20Quick%20Return%20Motion%20Experiment.pdf

http://www.tcsme.org/Papers/Vol33/Vol33No3Paper9.pdf

https://www.youtube.com/watch?v=XT4zt7sYPe0

http://www.mekanizmalar.com/simple_whitworth_quick_return_mechanism.html

http://jeanlouis.blanchard.pagesperso-orange.fr/english_swf/ppe_fst_quick_return.html

http://textofvideo.nptel.iitm.ac.in/112104121/lec7.pdf

http://metalab.uniten.edu.my/~kamal/documents/Machine%20Design%20Lab/Laboratory%20Manual/Whitworth's%20Quick%20Return%20Motion%20Experiment.pdf

http://library.wolfram.com/infocenter/TechNotes/5908/