Whether it be a classic automotive transmission design or the latest in electric vehicle technology, there is always a need to move high-pressure fluid through different operational systems.
Cooling systems are required for the battery storage compartment in both hybrid and fully electric vehicles. Whether the system is water or oil cooled, these fluids need to be pushed around and through various components to dissipate the unwanted heat.
Space limitations allow no room for leak paths
Automatic transmissions have an elaborate series of fluid circuits, or passages, required to feed the oil necessary to engage the hydraulic clutches. This is especially true with the newer eight, nine, and ten-speed transmissions. This increase in the components within the transmission also reduces the amount of available space for each clutch requiring that all space within the transmission case be used with the utmost efficiency.
Movement of fluid from the pump to the main control, to the appropriate clutch, sometimes requires the most direct route. This can require cutting through and/or across different components opening up potential leak paths in the circuit. In other applications, the circuit may need to be manipulated around components or systems that cannot be moved. A large leak can cause only partial engagement of the clutch piston resulting in a burnt clutch and very costly repair or even rebuild of the transmission. Even a small fluid leak results in a loss of system overall efficiency.
In the past, many of these joints were sealed utilizing an O-ring placed in a shallow counterbore and compressed axially against the mating component. These seals were prone to becoming dislodged before the mating component could be assembled resulting in cut seals or even the seals missing altogether. In addition, having different sized ports in close proximity to each other often resulted in the O-rings being mixed up into the wrong locations.
Customizable fluid transfer sealing reduces warranty costs
Parker engineers have developed multiple fluid transfer sealing technologies that can be customized for different applications. Designed with a metal insert to provide resistance to seal extrusion into the gap between components under fluid pressure, the boot type sealing lip configuration can accommodate wider axial tolerance stack conditions without losing sealing performance. In addition, the ribbed outer diameter provides a low assembly force interference fit into the bore. Secure positioning of the seal in the bore is ensured until the mating component is secured into place. Mis-builds are eliminated, thus improving first time through capability and reducing warranty costs.
Custom multi-port configurations can be designed to meet specific application needs. The positioning of the different seals in the carrier reduces complexity by providing a single component solution. Mixed seal locations are also eliminated.
Many different elastomers are also available to meet specific application requirements. Our Parker chemists have compounds available to ensure performance for chemical compatibility to the media being sealed, as well as solutions for very high or even very low-temperature applications. Custom materials can also be developed to satisfy unique requirements.
Please contact one of Parker O-Ring & Engineered Seals Division applications engineers who can assist you in solving your fluid transfer sealing system needs.
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Article contributed by Scott A. Van Luvender, automotive applications engineering manager, Engineered Materials Group.
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