In industry it is always desirable to increase the productivity or reduce the time loss. A beautiful mechanism in which, for the constant input rotation, the forward stroke takes larger time(cutting stroke) than the return stroke(idle stroke).

1. PROJECT SEMINAR
PROJECT GUIDE: D.SRINIVAS RAO
(ASSOCIATE PROFESSOR)
BY : MD NASEERUDDIN SHAH 1604-11-736-072
IBRAHIM MD AMEENUDDIN 1604-11-736-075
MOHD JALEELUDDIN 1604-11-736-105
MD SOHAIL KURANI 1604-11-736-135

3.  Introduction
 Defining the Problem
 Design
 ANSYS Validation
 Analysis
 Manufacturing and Fabrication
 Future Scope
 Application
 Conclusion
 Bibliography

4. Quick return mechanism, (QRM), is used in
machines like Shaper, Planar, Slotter.

5. Whitworth Quick Return Mechanism

6. Crank and Slotted Lever Quick Return Mechanism

7. Lower Quick Return Ratio
Vibrations due to non linear velocity
Defining Problem
Rigid structure
Selection of material
Changing the slider height
Overcoming the problem

8. 1.Link lengths
2.Forces acting on each link
3.Selecting materials
4.Suitable cross section
5.Power Calculations
 Factors To Be Considered In Design
Design

9. Specifications
Stroke length = 270mm
Quick return ratio = 5/3
No. of strokes/min = 100 strokes/min
Crank Length = 75mm
Length of Coupler =100 mm

10. Link Lengths
Length of AC =r/cos(90-α/2)
= 75/cos(68)
= 200 mm
Length of slotted lever (AP)=P1Q/sin(90-α/2)
= 135/sin(22)
= 360 mm
Length of AR= AQ + QR
= AP cos (90-α/2) + PR sin(90-α/2)
= 360 cos(22) + 100 sin(22)
= 375 mm

11.  Calculation of Forces
 F6 = τAl *d* w
 F6 = 50*2*5
 F6 = 500N
 F5 = F6 /cos(90-α/2)
 F5 = 500 /68
 F5 = 539N
 F4 =F5 = 539 N

12.  Mean Cutting Velocity = L*S* (360/α)
= 270*100*(360/136)
= 71.47 m/min
 Cutting Power = F6 * Vmean = 596 W
 Power required at Crank Pin = Power / η
= 596/0.8
= 745 W
L = length of stroke
S = number of strokes / minute
η= mechanical efficiency

13. Design of Crank Pin
Torque at Crank Pin (Tcr) = (P*60)/(2*π*N)
= (745*60) /(2*π*100)
= 71.14 N-m
Force at Crank Pin (Fcr) = Torque / crank radius
= (71.14*1000) / 75
= 948 N
Max Force at Crank Pin (Fcrm) = Fcr * I.F
= 948*2
= 1896 N
Diameter of Crank Pin = sqrt(4F/πτ)
=sqrt(4*1896 / π*50)
=7 mm
=8 mm (standard size pin)

14. Design of Shaft
Torque acting on shaft =(P*60)/(2*π*N)
=(745*60)/(2*π*100)
= 142 N-m
Diameter of the shaft (d)=cube root(16T/ πτ)
=cube root(16*142*1000 /π*75)
= 20 mm

15. Design Of Slotted Bar
Maximum Force acting on Slotted Bar = 539 * Impact Load Factor
= 539*3 = 1617N
Cross-sectional Area Of Crank = Max Load / Permissible Stress
= 1617/30 = 54 mm2 ………..1

16. ANSYS
•ANSYS is a general purpose software, used to
simulate interactions of all disciplines of physics,
structural, vibration, fluid dynamics, heat transfer
and electromagnetic for engineers.
•To validate the design QRM structural analysis
where used.
•Static Analysis-Used to determine displacements,
stresses, etc. under static loading conditions. Both
linear and nonlinear static analyses.

17. View of the model after
Applying loads
Meshed model
SLOTTED LEVER

18. Deformed + Undeformed
shape
Displacement Vector Sum

19. Von Mises Stresses Principle Stresses

20. COUPLER LINK
View of the model after
Applying loads
Meshed Model

21. Displacement Vector Sum Von Mises Stresses

22. RAM
View of the model after applying
loads
Meshed Model

23. Meshed Model after applying Loads Displacement Vector Sum

24.  Graphical Method
 Analytical Method
 Software Method
 Experimental Method
Analysis of Mechanism

25. Graphical Method
Graphical method starts with position analysis by
simply drawing the linkage mechanism to scale. Then
the velocity analysis is performed which requires the
angular position of the links to be determined
beforehand. Similarly it is necessary to know angular
velocities of links for acceleration analysis. Thus, the
sequence for kinematic analysis of mechanisms is -
position analysis, then velocity analysis and then
acceleration analysis.

26. Ground length = 25mm
 When crank radius
tends to ground length
, QRR tends to infinite
Crank radius = 10mm
 When ground length
tends to crank radius
length , QRR tends to
infinite
QRR Vs Crank Radius , QRR Vs Ground length

27. MATLAB ANALYSIS
Graph: Instantaneous slider velocity Vs Crank angle

28. Variation in cutting force with variation in crank angle for different
slider heights

29. EXPERIMENTAL SETUP

30. Crank Angle Slider
Position
0 10
20 15
40 20
60 40
80 65
100 100
120 140
Crank Angle Slider
Position
220 260
240 240
260 220
280 175
320 70
340 35
360 0
Crank Angle Slider Position
140 180
180 230
200 245
EXPERIMENTAL OBSERVATIONS

31. SAMPLE CALCULATION OF VELOCITY
At 100 rpm time required for 20 degrees= 20/(100*360)
= 1/30 s
Velocity of the slider at beginning = d/t
of the stroke
= 5 / (1/30)
= 0,15 m/s
Velocity of the slider at middle of the = 50 / (1/30)
stroke
= 1.5 m/s
Velocity of the slider at the end of = 35 / (1/30)
the stroke
= 1.05 m/s

32. Manufacturing and Fabrication
Fabrication is an industrial term refers to building metal
structures by cutting, machining and drilling.
For construction of mechanism in these project billets standard
of sizes were taken.
Some of the machine tools used where centre lathe machine,
radial drilling machine, tapping, vertical milling machine,
grinding machine, files, hydraulic press machine.

33. Shaft
Machine tools used:
Lathe
Operations performed:
Facing
Turning
Circlip groves
Chamfering

34. Bull Gear
Machine tools used
Lathe
AC Arc Welding Machine
Radial Drilling Machine
Vertical Milling Machine
Operations performed:
Facing
Turning
Welding
Drilling
Milling
Chamfering

35. Slotted Lever
Machine tools used
Radial Drilling Machine
Vertical Milling Machine
Bench Grinder
Operations performed:
Drilling
Milling
Grinding

36. Coupler Link
Machine tools used
Radial Drilling Machine
Bench Grinder
Operations performed:
Drilling
Grinding

37. Guide ways
Machine Tools Used
Hydraulic Press Machine
Radial Drilling Machine
Operations
Pressing to required shape
Drilling
Filing

38. Ram
Machine Tools Used
Hydraulic Press Machine
Radial Drilling Machine
Tapping equipments
Operations
Pressing to required shape
Drilling
Tapping
Filing

39. Frame
Machine Tools Used
Band Saw Machine
Drilling Machine
Operations
Cutting
Slotting
Drilling

40. Future Scope
• Accurate instantaneous velocity measurement can be done by
using precise instruments.
• Comparison can be made with Whitworth Quick Return Mechanism.
• Vibration analysis can be performed.
• Model can be made to achieve higher quick return ratio.
• Kinematic and dynamic analysis can be performed.

41.  Machine tools
 Shaping machines
 Power-driven saws
 Slotter machines
Applications

42. Conclusion
• Quick return ratio is limited to strength of the material. By
incorporating stronger materials QRR can be increased.
• Backlash can be minimized by choosing close tolerances
and proper assembly techniques.
• With increase in slider height, QRR increases.
• Friction at the interface of guide ways and ram can be
minimized by using turcite tape.
• Ram velocity varies from zero at beginning, maximum at
middle of the stroke and zero at the end.

43. BIBLIOGRAPHY
• R.S Khurmi & J.K Gupta
• Joseph E. Shigley
• S S Rattan
• Thomas Bevan
•http://engineering.myindialist.com/2013/kinematic-inversions-
of-four-bar-chain-slider-crank-and-double-slider-crank-
mechanism/
•https://www.wisc-online.com/learn/career-
clusters/stem/eng20704/quick-return-mechanism-velocity-
calculations
•http://theengineeringdiary.blogspot.in/2011/06/crank-and-
slotted-lever-quick-return.htmlhttp://www.quora.com/What-are-
differences-between-crank-and-slotted-lever-mechanisms-and-
a-Whitworth-quick-return-mechanism