Vibration Control of a Diesel Auto-Riksha using Low-cost Passive Engine-Mounts

High idling vibrations of a single cylinder Diesel engine proved to be a cause of discomfort for passengers of an Auto-Riksha (3-wheeler). Extensive vibration measurements identified rolling resonance of the engine-mount system.

This paper presents mathematical and experimental work to seek directions of the vibration control with low cost passive engine mounts. The work covered study of

1. 1)
   use of softer rubber mounts at the engine-base
2. 2)
   placing stiff rubber mounts closer to the Principal Roll-Axis of the engine
3. 3)
   separate use of a Tie-Rod and Hydraulic Dampers between the engine and chassis
4. 4)
   limitations of a Decoupled engine-mount configuration.

Overall assessment of these methods was carried out by Eigen Analysis of a Lumped Mass Model of the engine-mount system as well as by measurement of the vehicle vibrations over a wide speed range. It was revealed that requirements of the vibration isolation in both low & high frequency range and that of fatigue life of the rubber isolators imposed a limit on the performance extracted from the passive engine-mounts.