MBD Simulation on a Piston Assembly
Aim :- To develop MBD Parts siualtion and carry out the motion anlaysis in various conditions.
Piston motion analysis is tudy of reciprocating motion of the piston in the cylinder and the motion of the assembly attached i.e connecting rod, end cap crank shaft & gudgeon pin.
Design different parts of the piston and cylinder.
The Parts to be developed are as follows:-
1) Piston
2) Connecting Rod
3) Gudgeon Pin
4) Crank
5) End Cap
1) Piston is a component of reciprocating engines, reciprocating pumps, gas compressors, hydraulic cylinders and pneumatic cylinders, among other similar mechanisms.
2) Connecting Rod is the part of a piston engine which connects the piston to the crankshaft. Together with the crank, the connecting rod converts the reciprocating motion of the piston into the rotation of the crankshaft.
3) Gudgeon Pin in Internal combustion engines the gudgeon pin connects the piston to the connecting rod and provides a bearing for the connecting rod to pivot upon as the piston moves.
4) Crank is a mechanical part to convert the reciprocating motion from the piston into rotational motion.
5) End Cap it is connected to the end of the connecting rod which is assembled crank.
Assembly
After completing the Assembly
Motion Study Parameters
1) Select the motion study slect crank as motor with the speed of 2000 RPM.
2) Frames per second as 7200 with precise contact.
3) Providing the contact pair between them also Gravity.
Calculate Linear displacement and w.r.t time
The Above conditions as :-
| 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.
Results Plot
1) "0" mm Offset -
2) 10 mm Positive Offset - crank rotation in Clockwise direction.
3) 10 mm Negative Offset - crank rotation in Clockwise direction.
Comparing
Observation :-- The linear displacement graphy is smooth in all 3 cases
There is only time difference between the piston reached tdc nd bdc when positive or negative offset is given to the piston.
The positive offset reaches TDCand BDC faster than the other two with the negative offset behind the other two.