With fuel costs continuing to rise, and with regulations seeking to lower overall fuel emissions, improved fuel economy has become indispensible for today's gasoline engine designer. Reducing engine friction is an effective means of improving fuel economy and specific engine components have been developed towards this objective. Chain drive system components are no exception to this trend. In an attempt to decrease friction loss in the timing chain system and thereby improving fuel economy, the following three topics were studied: 1) defining sources of friction loss; 2) investigating the effect(s) of each loss factor using friction simulation; and, 3) evaluating methods to minimize friction losses.
Chain system friction loss can occur when the chain slides on the Arm & Guide face. Friction loss can also occur between the chain link and pin joint, and during chain engagement with the sprocket.
The low friction chain drive system under development is designed for future 2.4L 4-cylinder gasoline engine production.