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This paper presents the propshaft liner development that is expanded from previously published SAE technical paper and US patents. The new developments will expand in two facets: liner tuning adjustment and refinement, along with the implications to and solutions for broadband attenuation. Methods for developing a liner with higher tuning adjustment capability will be discussed, along with the results for a design-of-experiments study. In addition, concerns are explored and addressed of broadband attenuation in balancing the tuning effectiveness for particularly targeted frequency range. A particular application of the newly developed liner, trade-marked as Sylent liner, was illustrated and discussed in detail.

The installation of various liners into the propeller shaft tube is a traditional driveline NVH treatment to attenuate driveline vibration. The most commonly used liners include rolled paper, C-cut cardboard, corrugated cardboard, etc. These traditional liner treatments are expected to provide damping to the driveline system to reduce the vibration levels. However their added level of damping and effectiveness to the driveline system are limited, particularly when dealing with driveline gear mesh vibration and noise. This paper presents a novel type of liner treatment - tunable liners. The liner is designed such that it functions as a tuned dynamic vibration absorber. Through proper design of the liner, it can be tuned for bending and torsion modes at the same time. The liner design parameters and their impact on the frequency tuning are analyzed and studied through both physical testing and FEA analysis.

Ideally, the calculation of driveline component imbalance sensitivity is a straightforward operation of normalizing the changes in dynamic responses that occur when a known imbalance is added to a rotating component. In practice, however, overlapping driveline component orders (and wheel order harmonics) often prohibit the measurement repeatability required to distinguish these changes. A solution to the measurement repeatability issue is presented for chassis dynamometer testing, based on prescribing minor adjustments to the roll speeds for different wheels in order to separate the orders of various rotating components.