Leakage of oil through breathers can be a serious concern in electric vehicle (EV) transaxle units, especially due to the complexities presented by small housing space and rotational components, which are running at relatively high speed compared to conventional transmission unit. Traditional methods are mostly centred on developing individual breather compartments, resulting in excess material usage, additional weight, and increased cost of manufacturing. This paper presents a novel and compact way of oil channelization that has been created for the gearbox housing and seeks to counter oil leakage along with maximizing space and efficiency.
The improved design incorporates a cover, deflector fins, and obstruction ribs together with a strategically placed oil catcher cavity that effectively keeps the breather isolated from direct exposure to oil. The larger cavity minimizes internal pressure build-up, the fins restrict oil velocity, and an exclusive return path guarantees uninterrupted drainage of any trapped oil back to the sump. Together, these features guarantee that oil cannot accumulate around the breather even under dynamic conditions and high internal pressure.
This design provides a number of benefits, such as increased gearbox reliability, minimized risk of component failure, and reduced maintenance needs, with all of these and a compact, cost-effective housing structure maintained. By eliminating the requirement for secondary compartments or elaborate assemblies, the design represents a major innovation in EV transaxle technology, aiding the industry's vision of lightweight, efficient, and robust electric drivetrains.