New High-Gear Transmissions Improve Fuel Economy, Require Advanced Sealing Solutions
With fuel economy standards increasing worldwide and growing consumer demands for more miles per gallon, the automotive industry is looking toward transmissions for the next big break in fuel savings. As OEMs and suppliers formulate new technology to increase efficiency, the National Highway Traffic Safety Administration (NHTSA) tests the effectiveness of new applications. A recent NHTSA study confirmed that driving in a higher gear helps to keep the engine operating at a higher efficiency by lowering its speed and increasing torque. Across the board, for both automatic and dual-clutch in all vehicle classes tested, eight-speed transmissions operated more efficiently and achieved a greater reduction in fuel consumption compared with five- and six-speed transmissions. The limits of efficiency from higher gear transmissions are now being tested with the introduction of eight-, nine-, and even ten-gears. These powerful transmissions are showing significantly better fuel economy than their traditional six-speed counterparts.
But improvements gained from advanced multi-speed, dual-clutch, and continuously variable transmissions can drive new requirements in other areas of the transmission and vehicle. One such example is the amplified importance of cleanliness in these high-performance transmissions, as they simply do not tolerate particles and other debris. Additionally, the possibility of increased pressure inside the valve body for newer transmissions, render the traditional single-layer bonded gaskets ineffective at sealing the transmission. Without proper sealing, efficiency gains from a higher gear number are all but canceled out by failing gaskets. Until recently, OEMs were without a solution for this problem.
Anticipating OEM Needs for Better Transmission Sealing
A strong focus on customer needs and an in-depth understanding of the industry allowed Dana to forecast an impending market challenge and pioneer an innovative solution. Knowing that loose particles and the possibility of increased operating pressures can reduce the efficiency of the transmission, Dana focused on developing a solution that addressed the need for stronger sealing while keeping particles out of the transmission. Transmission fluid is designed to lubricate gearbox components, but if dirt and other particles get in, more harm could be done than good. Traditional valve body separator plates use paper bonded gaskets with limited sealing capabilities, leading to oil leakage, paper erosion, contamination, bond failures, and an overall reduction in efficiency.
Dana’s sealing engineers looked to its industry-leading multi-layer steel (MLS) cylinder-head gasket technology, which is capable of sealing combustion at up to 200 bar, as a starting point to this impeding problem. Dana reached out to its OEM customers to introduce the possibility of this technology, helping to reinvigorate the OEM-supplier relationship by employing a strong collaborative nature from the first step. In most cases, a supplier designs and delivers parts created to precise OEM specifications, but this was a different process.
Together, Dana and leading OEMs conducted a deep investigation of transmission systems and existing solutions, and through close teamwork Dana’s MLS technology was transferred to use in transmission separator plates. The result was the new Victor Reinz® MLS transmission separator plates, which are capable of sealing the transmission at up to three times the pressure of traditional plates with single-layer, bonded gaskets. These proprietary separator plates improve sealing, efficiency, and durability for advanced multi-speed, dual-clutch, and continuously variable transmissions.
In fact, Dana was recently honored with a 2015 Automotive News PACE Innovation Partnership Award for its collaboration with Audi on this technology. The Innovation Partnership Award is presented to OEMs and shared with suppliers for exemplifying superior collaboration during the commercialization process of an innovation.
Cleanliness Has Become a Top Priority
As previously discussed, the complex nature of newly developed transmissions has led to the need for an uncontaminated transmission system completely free of debris. These systems will only tolerate a minuscule amount of particles before the risk for a blockage in the valve body becomes imminent. A blockage could damage the vehicle’s shifting ability and cause warranty issues.
Dana’s MLS separator plates substantially increase the valve body sealing of high-performance transmissions with operating pressures of up to 80 bar, which helps eliminate leak paths and increase efficiency. An integrated nylon mesh in the separator plates is an innovative feature, resulting in better, longer-lasting protection of the critical valve body from impurities and also reduces maintenance.
What sets Dana’s robust technology apart is the partial coating, which only exists in the sealing area. There is no coating where the oil flows, eliminating the chance for loose particles to form over the plate’s lifetime, which could lead to contamination. Field tests have confirmed that this unique design is the most effective on the market today. Dana is the first to develop partially coated MLS transmission separator plates and filed the first patent for this technology. Not only was Dana able to develop the technology to fulfill the industry’s unmet need for better sealing, but it also achieved exceptional cleanliness in both the performance of the transmission and the production of the plate itself.
Better Sealing Drives Further Improvements
This innovative sealing technology results in many additional benefits. As a result of better sealing, OEMs can install a smaller oil pump, reducing cost and lowering the pump’s consumption of electric power. Since mechanical oil pumps operate based on engine speed, they continuously circulate lubricants, which can lead to wasted power and energy, and use more oil than necessary. Controlled oil pumps are another option, where electronic and hydraulic controls match the required oil flow and pressure. Additionally, the valve body size can be reduced along with the number of bolts. With fewer parts to handle, lower maintenance costs, and a reduction in both size and weight, fuel economy can be further improved
The Future of Integration
The complexity of vehicle systems brings the opportunity for innovation, but also introduces great risk and new problems. To achieve maximum efficiency and deliver the level of performance drivers have come to expect requires an intricate puzzle of valves, gaskets, electronics, and other controls. It’s of utmost importance to make sure the systems operate in as pristine an environment as possible. Engineers must consider needs for short-term operation and also anticipate what could happen over the long term. The number of variables that need to be accounted for has increased exponentially, and each one plays a part in performance and efficiency.
Dana’s MLS separator plate is just the beginning. This technology is an opportune platform for future technological advancements. By studying market trends and utilizing long-term relationships with partner OEMs, Dana was able to deliver a technology to improve the sealing in transmissions. We understood the need for new technology, engineered an innovative solution, and improved the standard for our customers and the industry overall. This way of thinking makes Dana a technology and innovation leader.
We’d like to hear your thoughts.
- What will be the next technology to move the industry toward higher efficiency?
- What challenges have you faced as a result of improvements to one component causing issues in another?
- What is the largest barrier to collaboration? How do we overcome it?