Thermal profiling of crankshaft torsional vibration damper for eight-cylinder automotive diesel engine

BACKGROUND: High torsional vibrations can lead to crankshaft failure. To reduce them, a damper is installed on the front crankshaft flange of high-powered inline diesel engines. The performance of torsional vibration dampers depends both on the damper design and the engine operating conditions. For a comprehensive assessment of damping performance, vibration amplitude of the crankshaft front flange is monitored. Thermal profiling of liquid dampers allows to determine their performance and characterize the changes in their thermal state based on temperature changes of the engine’s working fluid.

AIM: To study the damper thermal state and its influence on the torsional vibration damping performance.

METHODS: This study used experimental methods, conducted on an eight-cylinder automobile diesel engine. The value of the crankshaft twist angle was determined during the operation of the diesel engine by the external speed characteristic by torsiography on a special test bench. The thermal condition of the dampers was assessed by thermometry using special thermocouples, the measurement was carried out at the rated operating mode of the engine.

RESULTS: Thermal profiling of torsional vibration dampers was conducted. The authors determined the relationship between the crankshaft torsion angle, oil and damper temperature, and the warm-up time at 2,400 rpm.

CONCLUSION: The damper thermal state depends on the oil temperature in the engine pan and does not depend on the location of the measuring points on the housing. There are minor changes of the crankshaft twist angle when operating for 1 hour at 2,400 rpm.