Effect of Housing Design on oil Splash Lubrication in an E-Drive Unit through Computational Fluid Dynamics Simulation

Effective lubrication of gears and bearings is essential for optimal performance of electric vehicle (EV) e-drive units, particularly under high-speed and high-torque conditions. Rather than relying on costly and time-consuming physical prototypes with transparent casings to study lubrication, we employed Simerics-MP+ software to create a virtual testing environment. Computational Fluid Dynamics (CFD) modeling serves as a valuable alternative by enabling rapid design assessments and shortening product development cycles. This research utilizes CFD to evaluate a housing design aimed at improving lubrication in the rear and front drive units (RDU/FDU) of EVs. Multiphase flow simulations were performed using the volume of fluid (VOF) method within Simerics-MP+, which utilizes an unstructured Cartesian mesh and handles complex mesh dynamics via volume remeshing techniques. Results demonstrated that an oil collection feature enhanced lubrication by guiding oil splash towards the bearings. Furthermore, the gearbox’s rotational direction influenced oil splash collection, leading to superior bearing lubrication in the RDU at low speeds, while the FDU exhibited relatively better lubrication at higher speeds. This computational study highlights the capabilities of CFD in analyzing oil splash lubrication and optimizing e-drive unit designs.