Pressure Equalization Element Protects Transmissions During Water Crossings
Volker Buchmann, Business Development Manager, Konzelmann
In a world where extreme weather conditions and waterrelated challenges have become commonplace, the automotive industry faces a pivotal question: How can we equip vehicles for water crossings efficiently while saving time and resources? The answer lies in a groundbreaking innovation that is poised to revolutionize how we approach water crossings and offers OEMs and Tier 1 suppliers a transformative advantage.
Safeguarding against the elements
Throughout this past summer, extreme weather conditions occurred all over the world, with extraordinarily strong rainfalls accompanied by heavy thunderstorms and an increased risk of flash floods. When tunnels or underpasses are flooded due to continuous rain, there are often only two options: detour or wade through. Vehicle drivers tend to overestimate their vehicle‘s ability to cross water. In these situations, water or mud can quickly infiltrate the transmission resulting in a failure that only a towing service and costly repairs can resolve.
While vehicles usually are equipped with a hose construction to manage water crossings, there was no simple technical solution for wading through water. Until now. The newly designed Pressure Equalization Element (PEE), directly integrated into the transmission, prevents both positive as well as negative pressure within closed housings in electric axes and differentials, promising new perspectives for reducing product costs and time to market.
Hose construction: elaborate and costly
As mentioned, to prevent water from entering, a hose is connected directly to the transmission, providing ventilation during pressure variations. Although the hose construction is suitable for water crossings and is installed as standard, it is considered elaborate in design, resulting in time and cost-intensive assembly. Currently, there is a lack of a simple technical solution for water crossings.
The solution to this challenge is the Pressure Equalization Element (PEE), a pioneering innovation designed to fit directly into the transmission housing. The PEE houses an internal pressure-regulating valve that swiftly balances pressure differentials, safeguarding the ventilation space against contamination and the intrusion of liquids. Operating at 70 mbar, equaling a water column of 70 cm, the valve withstands exposure to gearbox oil aerosols, typical vehicle substances, and environmental materials.
Konzelmann’s Pressure Equalization Element protects the system seals from damage due to positive or negative pressure. Source: Konzelmann GmbH
A membrane that defies liquids and contaminants
In contrast to a conventional hose system, the PEE is securely integrated within the electric axle housing.The pressure equalization valve, designed to prevent positive pressure, allows escaping gas to exit through a lateral opening in the housing while permitting air to flow in during a negative pressure situation in the housing. This air passes through an air-permeable yet waterproof Ventikon membrane. This membrane is capable of withstanding a water column of 30 meters, effectively blocking liquids as well as contaminants, safeguarding the electric axle against foreign objects.
At a defined negative pressure, the valve opens, enabling air to flow in to equalize the pressure difference. The PEE‘s membrane is thoughtfully shielded, preventing it from being coated with spray oil. Furthermore, a labyrinth-like oil separator, positioned between the valve and the electric axle‘s interior, shields the valve from direct contact with splashing oil.
Simulating real-world performance
Konzelmann, in collaboration with an OEM and a Tier 1 supplier deeply involved in transmission and differential development, has conducted in-depth analysis and established testing parameters for a dedicated testing environment. This in-house testing platform enables accurate simulation of transmission behaviour, allowing precise customization of the pressure equalization valve to meet the unique requirements of each manufacturer.
The testing setup mirrors the oil and air volumes within a transmission housing, ensuring a comprehensive evaluation of the system‘s performance throughout its lifespan. Information from the transmission manufacturer regarding residual air content in the transmission guides the testing process. The artificial transmission is then filled with the manufacturer‘s original transmission oil and subjected to controlled heating, creating positive pressure and pressure equalization. When the oil and air cool, a vacuum or negative pressure forms, drawing in outside air through the membrane. This testing approach has already successfully simulated 8,000 kilometers of test drives.
The Konzelmann endurance test stand for load spectra of oil temperatures of up to 120 °Celsius
A consultative approach
Thus, for the first time, a valve has been developed that optimally functions during the critical phase of water crossings, ensuring that the membrane remains unclogged with oil. All gearboxes available on the market can be tested in advance and manufacturers can be advised optimally.
This groundbreaking product innovation is adaptable to all vehicle types and drivetrains, even within mobile systems. It is characterized by its minimal installation requirements and space-efficient design. The precisely defined ventilation and exhaust mechanism guarantees optimal pressure management within transmissions and other systems. Additionally, the Pressure Equalization Element offers a distinct production advantage over conventional hose constructions: It enables vehicle rotation on the production line even after the transmission/e-axle unit has been filled with oil.
Currently, the product is already undergoing testing with an OEM, with production scheduled for 2024.
About Konzelmann
Konzelmann GmbH, headquartered in Löchgau between Stuttgart and Heilbronn in south-western Germany, develops and produces high-quality plastic injection molding products. For more than 60 years now, Konzelmann has planned, developed, and manufactured high-precision components and complex assemblies made of polymeric materials for the medical, automotive and industrial sectors. Their extensive experience has made them a market leader in the fields of highly specialized technical applications. Furthermore, Konzelmann has a global presence, with representatives in Detroit/USA, Seoul/Korea and New Delhi/India.
More information: https://www.konzelmann.com/en/expertise
