AN EXPERIMENTAL STUDY OF VEHICLE DRIVELINE VIBRATIONS

A series of road tests was made on two vehicles to investigate driveline vibrations and their influence on vehicle interior noise levels: a sports car with four-cylinder engine and manual transmission, and a sedan with six-cylinder engine and automatic transmission. Most of the peak interior noise levels were found to be associated with driveline vibrations attributable in many cases to a particular mode. Each mode is predominantly related to one system component such as the crankshaft, gearbox, axle, or a driveline rotating part. The problem is often complicated by coupling and interference between two modes or by the level of the excitation changes due to nearness of a crankshaft resonance, for example. The meshing forces at the differential pinion and wheel are significant causes of vibration at the upper end of the frequency range (400 Hz. and higher). For the sports car, the main vibration appeared to be a driveline torsional mode. The sedan had considerable vibration at the front end of a forward extension of the differential casing. Changing from standard to nonstandard tires on the sedan significantly affected vibrations, mainly at low frequencies, the most obvious change being at frequencies above 400 Hz. when differential tooth meshing frequencies become significant. Engine forcing of the driveline vibrations is strong for the in-phase torque and force harmonics, the most significant being the second order of the four-cylinder and the third order of the six-cylinder engine. A detuner-absorber fitted to the gearbox extension of the sports car was found not to meet the design specification.

• Supplemental Notes:
  • Also published in HS-029 137 (IMechE-CP-1979-10), "Noise and Vibrations of Engines and Transmissions," Bury St. Edmunds, 1979 pp 69-81. Presented at conference, Cranfield Institute of Technology, England, 10-12 July 1979. Research sponsored by Science Research Council, England.
• Corporate Authors:

  Institution of Mechanical Engineers

  1 Birdcage Walk
  London SW1H 9JJ,   England 

  Society of Automotive Engineers (SAE)

  400 Commonwealth Drive
  Warrendale, PA  United States  15096
• Authors:
  • Healy, S P
  • Heppenstall, T
  • Hodgetts, D
• Publication Date: 1979

Media Info

• Features: References;
• Pagination: 13 p.

Subject/Index Terms

• TRT Terms: Drivelines; Noise; Vehicle tests; Vibration
• Uncontrolled Terms: Causes; Interior
• Subject Areas: Environment; Safety and Human Factors; Vehicles and Equipment;

Filing Info

• Accession Number: 00386102
• Record Type: Publication
• Source Agency: National Highway Traffic Safety Administration
• Report/Paper Numbers: IMechE-C132/79, HS-029 146, SAE-MEP-109
• Files: HSL, USDOT
• Created Date: Jun 28 1984 12:00AM