MBD Simulation on a Piston Assembly
AIM: -
To create a 3D model of piston assembly and do its motion analysis.
OBJECTIVE: -
Our objective is to create a 3D model of piston assembly in solidwork and plot the variation of linear displacement with time for following condition:
- When right plane of piston and crank are coincident
- When right plane of piston and crank are at positive offset of 10mm
- When right plane of piston and crank are at negative offset of 10mm
Components:-
- Connecting rod
- End cap
- Crank
- Piston head
- Gudgeon pin(wrist pin)
BODY: -
Piston motion analysis is the study of the reciprocating motion of the piston in the cylinder and the motion of the assembly attached i.e. connecting rod, end cap, crankshaft & wrist pin. First of all for the assembly of a connecting rod, crankshaft, end cap, wrist pin and piston itself, we will prepare the geometric model of all the necessary components
We have to design all the different parts of the cylinder piston arrangement separately and then assembled it.
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. In an engine, its purpose is to transfer force from expanding gas in the cylinder to the crankshaft via a piston rod arid/or connecting rod
Motion Study Analysis
In the Motion study the following steps are performed.
- Select motion analysis in the drop-down menu.
- Motor is given to crank with the speed 2000 RPM.
- Frames per second are given as 12000 with precise contact.
- Contact is given between endpin and crank, crank and connecting rod, connecting rod and wrist pin and wrist pin and piston. The material selected foreach case is steel (Dry).
- Gravity in the Y direction.
Calculation is performed for the motion analysis for about 0.8 sec. Linear displacement of the piston head w.r.t time is obtained for following conditions.
- When right plane of piston and crank are coincident
- When right plane of piston and crank are at positive offset of 10mm
- When right plane of piston and crank are at negative offset of 10mm
CONCLUSION: -
From the plots obtained, we can see that Linear Displacement increases as we move from negative wrist pin offset to positive wrist pin offset i.e. the magnitude of the Linear displacement increases.