Title: Effect of transmission design on gear rattle and shiftability

Authors: T.G. Brosey, R.L. Seaman, C.E. Johnson, R.F. Hamilton

Addresses: Warner Gear Division, Borg-Warner Automotive, Inc, Muncie, Indiana, USA. ' Warner Gear Division, Borg-Warner Automotive, Inc, Muncie, Indiana, USA. ' Warner Gear Division, Borg-Warner Automotive, Inc, Muncie, Indiana, USA. ' Warner Gear Division, Borg-Warner Automotive, Inc, Muncie, Indiana, USA

Abstract: The power input to a vehicular transmission is not constant. In addition to the mean torque and speed, there is a periodic torque component, which causes a periodic angular acceleration of the transmission input shaft. A theory that shows the relationship between gear rattle and the combined effects of this angular acceleration, the effective transmission inertia, and the transmission drag is developed. The detrimental effect of high effective transmission inertia upon gear rattle and shift effort is shown. A unique test stand which can evaluate the gear rattle tendency of a transmission is described. A computer model is presented which calculates the angular acceleration at the transmission input given the spring rate, damping, and inertia of the driveline components. Finally, an optimum arrangement of the transmission geartrain is described. This arrangement lowers the effective inertia of the transmission, thereby decreasing the tendency for gear rattle and reducing shift effort.

Keywords: gear rattle; inertial approach; gear shiftability; transmission design; vehicle design; vehicle noise; angular acceleration; transmission drag; transmission inertia; shift effort.

DOI: 10.1504/IJVD.1986.061424

International Journal of Vehicle Design, 1986 Vol.7 No.1/2, pp.45 - 66

Published online: 25 May 2014 *

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