Sedler, Stephen Joseph2012-12-052012-12-052012-09https://hdl.handle.net/11299/140148University of Minnesota M.S. thesis. September 2012. Major: Mechanical Engineering Advisors: Thomas R. Chase, Perry Y. Li. 1 computer file (PDF); viii, 187 pages, appendices A-E.The design of a four-mode, input-coupled, power-split hydromechanical transmission with energy storage is presented. The focus of this thesis is on the design process of the transmission utilizing Lagrange multiplier optimization and machine design principles to construct the prototype transmission for use on a Polaris Ranger chassis. The four-mode design presented facilitates vehicle operation in hydromechanical power-split mode, parallel mode, and two series modes. An optimal mode of operation map is determined and a maximum fuel economy of 78.5 mpg is calculated.en-USMechanical EngineeringThesis or Dissertation