Influence of the buckling degree on the separation properties of clutch friction components

Armored vehicles, to accomplish missions in complex harsh conditions with high mobility, require the transmission system to achieve high energy density and high reliability. The wet multi-disc clutch becomes the perishable component under heavy load, large speed difference and frequent engagement. Due to the difficulty of maintenance in battlefield, clutch carrying post-buckling separate plate is common and the clutch working process is obstructed. Therefore, considering the post-buckling plate, the multi-physics thermodynamic model of a wet multi-disc clutch is established to describe the entire engagement and separation process. The influence of the buckling degree on the stress-strain, uniformity of gaps, torque and temperature is investigated by the numerical method and testified by bench tests. The results show that with the increasing buckling degree, the clutch engagement and separation times decrease gradually. For the separation process, the non-uniformity of gaps is increased and gaps are eventually occupied, leading to the continuous rough contact among friction pairs. Therefore, the drag torque is increased. Squeezed by the post-buckling plate, the cooling rates of separate plates are decreased. During repeated engagement-separation, temperatures of plates may reach balance points. Since continuous sliding and temperature concentration, the wear form and degree changes, especially at outer radius. Extra drag torque, heat and wear threats the friction components which increases the risk of failures of the transmission system and affect the mobility of armored vehicles.