Piston Seal Test Fixture

Abstract

The U.S Environmental Protection Agency‘s (EPA) National Vehicle and Fuel Emissions Laboratory (NVFEL) is in the process of improving hydraulic hybrid technology, with specific application in improving the fuel economy of delivery trucks for the United Parcel Service (UPS). The hydraulic hybrids utilize a high and low pressure accumulator system with a pump and motor to store and transfer energy to the vehicle. A problem that the EPA is facing is the permeation of nitrogen gas from the high pressure accumulator into the hydraulic fluid. This gas eventually can build up and cause damage to various components of the hydraulic system due to cavitations. A new piston seal arrangement has been developed by a previous ME450 team to reduce the permeation of gas into the hydraulic fluid, but has yet to be validated. Our task is to create a fixture that can successfully test the new piston seal arrangement and to provide the EPA with our results.