MBD Simulation on a Piston Assembly

OBJECTIVE:

To Run Motion Analysis on Solidworks MBD and to obtain the Linear displacement of the Piston Head in all the cases.

AIM OF THE PROJECT:

Model all the parts and then assemble them in SolidWorks. The motion analysis is going to be carried out in three different conditions,

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.

"0" mm Offset - Run a simulation as seen in the video.

10 mm Positive Offset - If the crank rotation is in the Clockwise direction.

Otain Linear displacement of the Piston Head in all the three cases.

THEORY:

Piston assembly consists of a piston, piston rings and piston pin known as gudgeon pin, connecting Rod, end cap, crank etc.

Functions of Piston assembly is that it transmits force generated during combustion to the connecting rod and crankshaft.

Parts used:

1. Piston Head

2. Gudgeon Pin

3. Connecting Rod

4. Crank

5. End Cap.

PROCEDURE:

1. CAD model of all parts were designed in Solidworks
2. Assembly was made for all the parts using specific mates.
3. Motion Analysis was done on assembly.
4. Motor is given to the crank.
5. Following results were performed.

CAD MODELS :

CONNECTING ROD:

CRANK:

END CAP:

GUDGEON PIN:

PISTON HEAD

PISTON ASSEMBLY:

OBSERVATIONS AND GRAPHS :

CASE1:

CASE2:

CASE 3:

INFERENCE:

EXPLANATION OF THE CURVES:

As we can see all three curves resulted to be smooth.

Without any offset in pin placement( case 1) the displacement will be maximum than in any offset conditions. now, as we took positive 10mm offset condition and negative 10 mm offset condition respectievely piston has to travel a slight less displacement , this means piston isn't reachin top and botton point of cylender......hence will have less compressing compatibility.

now, with the offset point piston, rod is not straight at both situations when at TDC or BDC. this allows crank to rotate at much less energy than in no-offset condtion, resulting in more engine power and speed.

CONCLUSION:

All the parts were designed and then assembled them in SolidWorks. The motion analysis was carried out in three different conditions and results and inference was noted as stated above.