Refine Your Search

Search Results

Viewing 1 to 3 of 3
Technical Paper

Predictive Calculation of Idling Rattle in Manual Transmissions -Based on Experimental Measurements of Gear Vibration Occurring in Backlashes-

2003-03-03
2003-01-0678
It is generally known that the idling rattle in manual transmissions is caused by gear tooth portions that make repeated impact-generating vibrations in the backlashes. These vibrations result from rotational fluctuations of the flywheel induced by combustion in the engine. In the study reported here, the authors constructed an experimental setup using rotary encoders and a transient torsional angle converter that allowed the long-awaited direct measurement of impact-generating vibrations in the backlashes. Using this experimental result, the following ideas that the authors must pay attention for the numerical simulation are obtained. That is, transmission drag torque is to be input and treated as the offset value in the torque value of the torsional characteristics in the clutch disc, and coefficients of attenuation have great influence upon the calculation result.
Technical Paper

Research on Idling Rattle of Manual Transmission

1985-05-15
850979
Generation mechanism and characteristics of idling rattle are systematized analytically by experiments on vehicle and digital simulation of nonlinear torsional vibration system for an inline four-cylinder four-cycle compact diesel engine. Jumping and hysteresis of the noise level are caused by both decreasing engine torque fluctuations while engine rotating velocity increases, and clutch-disc torsional characteristics of two-staged hardening spring. An improved clutch disc with a decreased noise level of 5 dB (A) was developed clarifying the optimum combination of disc characteristics, and permitting engine rotating velocity, where jumping occurs, below idling rotating velocity.
Technical Paper

Reduction of Idling Rattle in Manual Transmission

1987-02-01
870395
In SAE paper SAE850979, 1985, the authors reported on a design technique for a clutch disc with nonlinear torsional characteristics for reducing transmission idling rattle. However, when design conditions do not allow sufficiently large first stage torsional angle or the transmission is loaded with large drag torque (such as when transmission oil is cold or the transmission has a power take-off unit), clutch discs designed using the previously reported technique do not necessarily give satisfactory result. In this paper, the mechanisms generating idling rattle and their characteristics are further examined and a technique to reduce transmission idling rattle through elucidation of nonlinear torsional resonance is discussed.
X