Srinivas Rao Gaddam
Independent Researcher
India
ABSTRACT
This study investigates how variations in crankshaft geometry—specifically journal diameter, web shape, and crankpin offset—affect engine vibration characteristics in a single-cylinder diesel test engine. Emphasis is placed on geometries and balancing techniques prevalent up to 2015. Vibration measurements were captured using accelerometers mounted on the engine block under steady-state operating conditions at four load levels (20%, 40%, 60%, 80% of full load) and five speeds (1000, 1500, 2000, 2500, 3000 rpm). Statistical analysis, including analysis of variance (ANOVA) and regression modeling, was performed to quantify the influence of each geometric parameter on amplitude and frequency of block vibration. Results reveal that increasing journal diameter lowers first-order vibration amplitude by up to 18%, while optimized web taper reduces high-frequency torsional vibrations by 12%. Recommendations for crankshaft design to minimize NVH (noise, vibration, harshness) in light-duty engines are presented.
KEYWORDS
Crankshaft geometry, engine vibration, journal diameter, web shape, NVH, diesel engine
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