Design of a Disconnect Clutch and Actuator for a 48V P4 Electric Drive Transmission

Sammanfattning: The vehicle industry is making great strides in electric and hybrid technologies, representing a significant step towards reducing emissions from personal vehicles. In order to make the transition to new hybrid technologies as convincing as possible, well-functioning and smooth transitions between traditional combustion engines and electric motors are required. So-called mild hybrids enable a cost-effective method to electrify existing drivetrains, as a smaller electric motor can be used separately from the combustion engine drivetrain. Due to the reduced size of the electric motor, it is not able to rotate at the high top speeds of many modern personal vehicles. This necessitates a means to disconnect the electric motor from the wheels. This disconnect device is conceptualized in this report. The aim of this thesis is to develop the disconnect system, which incorporates both the mechanical configuration and the actuator providing force transfer. A requirement is the use of a dog clutch. The product development process of the report follows the methodology produced by K. T. Ulrich and S. D. Eppinger, resulting in seven promising concepts of which two were chosen for detailed design. A total of 34 concepts were screened. Despite being removed, some concepts show additional potential and are recorded in a concept library. Placements of the disconnect system, as well as actuator technologies were evaluated. The two chosen concepts, concept WY - First Pinion and V - GenVI Hydro Sleeve, present two different methods for disconnection placed at different positions along the drivetrain. This enabled both effective work with one concept for each thesis student, and freedom of choice for BorgWarner during evaluation. The thesis continued into the phase of detailed design but further work is required before the concepts can be verified and finished.