Challenge

MBD Simulation on a Piston Assembly

AAnant Kumar Singh21 Jun 2020

Objective

To design 3D model of all parts of piston use to parform the motion analysis include piston, wrist pin, connecting rod, end cap, and crank.

Parform the motion analysis for following diffrent condition.

Sl.No	Wrist Pin Offset `	Crank Speed (Rpm)
1	"0" mm	2000
2	10 mm Positive	2000
3	10 mm Negative	2000

Wrist Pin Offset - The position of the wrist pin is going to be varied as followed. But the center of the axis of the piston head and the crank are coincident to each other (i.e) They are on the same plane in all the three cases.

Design of 3D part

piston

A piston is a component of reciprocating engines, reciprocating pumps, gas compressors and pneumatic cylinders, among other similar mechanisms. It is the moving component that is contained by a cylinder and is made gas-tight by piston rings.

Wrist pin

In internal combustion engines, the gudgeon pin (UK, wrist pin or piston pin US) connects the piston to the connecting rod, and provides a bearing for the connecting rod to pivot upon as the piston moves.

Connecting rod

A connecting rod, also called a con rod, is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciptocting motion of the piston into the rotation of the crankshaft.

End cap

The big end of the connecting rod connects to the crankpin journal to provide a pivot point on the crankshaft. Connecting rods are produces as one piece or two-piece components. A rod cap is the removable section of a two-piece connecting rod that provides a bearing surface for the crankpin journal.

Crank

A crank is an arm attached at a right angle to a rotating shaft by which circular motion is imparted to or received from the shaft. When combined with a connecting rod, it can be used to convert circular motion into reciprocating motion.

Final asssembaly

Assembal the all part to parform motion analysis

Setup for motion study

Give the rotatry motion to the axis of crank
set the solid contact between end cap and conn. rod
set the solid contact between conn. rod and crank
set the solid contact between conn. rod and wrist pin
set the solid contact between wrist pin and crank
use material steel(dry)
set precise contact 7200(fps)

run the study

Result

Sl.No	Wrist Pin Offset `	Crank Speed (Rpm)
1	"0" mm	2000
2	10 mm Positive	2000
3	10 mm Negative	2000

Plot 1 at '0' mm wrist pin offset

plot show the displacement of piston when wrist pin is not offset.

Plot 2 at '10' mm positive wrist pin offset

plot show the displacement when wrist pin 10mm positive offset.

Plot 3 at '10' mm negative wrist pin offset

plot show the displacement when wrist pin 10mm negative offset.

Superimpose of all the three graphs into a single graph

superimpose the graph show how the linear displacement of change according to change the position of the piston.

Conclusion

Graph is smooth that show the movement of piston is uniform.
change in position does not affect the speed of crank.
In superimpose graph we see clearly the devition of piston in three cases due to change the position of piston.

MBD Simulation on a Piston Assembly

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Ship work like thisin your own course.

Talk to a career counsellor

Ship work like this
in your own course.