Multibody Lubrication Dynamics of Mechanical Transmission System

In a transmission multibody system, it consists of several lubricated frictional pairs which transmit motions and forces among components. Under lubrication conditions, the effective fluid lubricating oil films are formed in these frictional motion pairs due to the geometric wedge gap effect, which separates the two surfaces of contacting body to avoid direct contact, and thus reduce wear, friction, and energy consumption. However, due to geometric constraints of components, the presence of the oil film can affect the forces on the components, and also change the stiffness and damping between the contact bodies, thereby affecting the dynamic characteristics of the multibody system. What’s more, the value of film thickness is related to the lubricant properties, forces and velocity, and these factors interact with each other. Therefore, it is necessary to model the multibody system from the perspective of multibody lubrication in order to more accurately predict its dynamics characteristics. In this study, a multibody lubrication dynamics model for a multibody system of cylindrical roller bearings is developed, and such an advanced model is applied to explore the mechanical, lubrication and dynamic performance of cylindrical roller bearing under high conditions. It is demonstrated that the formation of film thickness not only changes the loads between rollers and raceways, bearing cage motion, and vibration of the entire bearing, but also introduces the additional forces inside the bearing under certain conditions.