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transcript
29-09-2015
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ME 311: Dynamics of Machines and
Mechanisms
Lecture 22: Engine Dynamics: Part 4
By
Suril Shah
Mechanical Department
IIT Jodhpur
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Outline
• Pin Forces
• Balancing the Single-cylinder Engine
• Design Trade-offs And Ratios
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Simplified Kinematics
3
Gas Torque
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Approximate Model
Approximate Model
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Inertia Force
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Shaking Force
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Inertia and
Shaking Torques
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Total torque
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Flywheel (3400 rpm)
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Pin Forces in the
Single-cylinder
Engine
• Design of the pins and the bearings at the joints
• We will calculate the effect of
– Gas force (Fg)
– Inertia force due to the piston mass (Fip)
– Inertia force due to the mass of the conrod at the wrist pin (Fiw)
– Inertia force due to the mass of the conrod at the crank pin (Fic)
– Inertia force due to the mass of the crank at the crank pin (Fir)
• Superpose them to obtain the complete pin force at each joint.
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Gas force (Fg)
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Inertia force due to the piston mass (Fip)
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Inertia force due to the mass of the conrod
at the wrist pin (Fiw)
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Inertia force due to the mass of the
conrod at the crank pin (Fic)
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Inertia force due to the mass of the
crank at the crank pin (Fir)
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800 rpm 3400 rpm
6000 rpm
Speed Vs Pin
Forces
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Pin forces in
LRCS
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Balancing Single Cylinder Engine
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Crank Over balalnced
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Exact Balance Vs Over Balance
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Effect of balancing on Pin
Forces
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THANK YOU
Next Class: Multicylinder Engine
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