Cross-head guide forces 1

[Thomasmac]

I'm trying to calculate the crosshead guide forces on a recip compressor but are struggling to find any literiture on it. Are there standard equations to calculate these forces?

 

[iainuts]

By "crosshead guide forces" I assume you mean the force perpendicular to the direction to motion. That force is calculated from basic principals.

Your piston load is simply piston area times pressure, call that force F. Your rod is pinned at each end and has some length (call it RL), and makes some angle depending on it's length and cranshaft dimensions. If your crank throw (half the stroke) is CT, you can derive the force perpendicular to the direction of piston motion from
Fr = F * CT / RL
Where F = Piston Area * Pressure
CT = 0.5 * stroke length
RL = distance from center of rod at crank to center of rod at wrist pin.

 

[iainuts]

Note: the above calculation is for when the crank shaft center to rod center is perpendicular to the rod center to wrist pin center. Although this may be the maximum or close to maximum side load, you should check your particular case to determine the maximum side loading using basic principals.