To understand the effect of speed on "Rod Load" ,we must know first what is rod load? Actually Rod load is vector sum of Gas load and inertia forces (caused by all reciprocating parts including cross head assembly) acting in the direction of piston rod.The first part i.e.Gas load is function of cylinder chamber pressures and area of piston at crank end and head end.Therefore speed will have no effect on Gas load,however it will have effect on flow rate (capacity) and power absorbed by compressor.The second part i.e. inertia forces is function of mass of reciprocating parts and its acceleration/deceleration.Obviously change in speed will have effect on magnitude of acceleration/deceleration of piston rod assembly during each revolution of the crank.
Hence compressor speed will have effect on "Piston rod load".Its absolute value may increase or decrease depending upon crank angle during each revolution.
Hence compressor speed will have effect on "Piston rod load".Its absolute value may increase or decrease depending upon crank angle during each revolution.