Search Results

It is common that angular velocities can be different from time to time between an engine output and transmission input, because both are connected by a damper in torque converter with flexible elements in it. When this difference occurs abruptly for some reasons, an internal impact could start between the engine-attached members (also known as driving members) and the transmission-attached members (or driven members). The resulting impact load could be several times the torque an engine’s combustion force can generate, depending on the impact energy. An impact load can be very devastating to a torque converter and other power-train members, just as to all other mechanical systems. This work presents a comprehensive and interesting study to help understand the rotational impact behavior for a system where none of bodies is stationary at the onset of impact.

Determining an amount of clutch clearance for the lockup device in a torque converter is important for its being operating precisely in the intended mode. Challenges may exist for the torque converters whose nominal clearances are on purpose very small. Any potential changes in the clutch lockup system (e.g., due to the deformation of components) may make such a small clearance instantaneously diminish during the mode of open-clutch, thus leading to unwanted drag in the clutch and unnecessary loss of energy. In the open-clutch mode, the actual clutch clearance may be different from the nominal clearance anticipated, primarily because of deformation caused by the internal load acting on clutch members. It has been found that the pressure distribution in a clutch chamber also depends on the very clutch gap through which the fluid flows. This interdependence between the fluid pressure load and structural deformation is typical of two-way coupling in simulation.

Metal fatigue has been a topic interesting to engineers for long, because it has had a profound impact on making the design of virtually all products more reliable. As the research in this area evolved, the understanding of fatigue has been gained so tremendously that it has been become possible to conduct more and more complicated fatigue analysis or simulation without having to undergo lengthy fatigue tests for a product under design. In this work is a numerical model to predict the fatigue life of a power train component, whose metal material essentially behaves as being inhomogeneous due to a thin and hard surface layer on the top of the base material. As a typical case in the power train of automobiles, the clutch component is subject to the inertial load arising from an angular velocity as well as the torque loads, varying cyclically with time in a form other than what is called constant-amplitude.