Driveline components for electrified powertrains

Purpose and goal

The purpose has been to develop transmission components for electrified drivelines that provide lightweight, compact, quiet, and efficient drivelines. A test rig has been built and demonstrated to evaluate noice and losses of gears at 14,000 rpm and 120 Nm. Simulation concepts for gear contact have been developed. The impact of surface topography, heat treatment, and steel on fatigue properties has been evaluated. A rig to study the mechanism of unsynchronized couplings has been developed, and testing has been conducted and analyzed.

Expected results and effects

The gear test rig is in operation. Noice and losses are measured using an accelerometer in three directions, a microphone, Laser Doppler Vibrometer, and input power. Speeds up to 14,000 rpm and torque up to 120 Nm can be applied. Drop lubrication is used, and lubricants can be varied. Further work is needed to study the impact of both macro- and micro-geometry of gears on noise and vibrations. The rig and work on steel, surfaces, and heat treatment enable methodologies for further research on transmissions for high-speed electrified drivelines.

Planned approach and implementation

We have worked in four work packages where the test rigs have had an overarching purpose. Both companies and R&D partners have been involved in the rig design as it encompasses several areas of expertise. The impact of surface topography, steel, and heat treatment has been tested through fatigue testing in rotating-bend, gear, and contact fatigue rigs. The influence of lubrication and surfaces is being evaluated in a full-roll contact rig. A thesis on this topic will be conducted in the spring of 2024. Gears and test components have been developed with parallel test series for rig testing.