Laying the foundation for virtual product optimization
Sauer-Danfoss develops programs in NX that determine performance characteristics of future products
Optimizing hydraulic systems is a huge computational challenge.
Meeting a design challenge
Sauer-Danfoss is a comprehensive supplier of mobile hydraulic and electronic solutions. The company supplies markets throughout the world with hydrostatic transmissions, open circuit products, orbital motors, steering, valves and electrohydraulic controls as either components or integrated systems. Its products are used on a wide range of mobile equipment in agriculture, construction, material handling and road building, as well as specialty vehicles in forestry and on-highway.
With the goal of creating highly optimized hydraulic solutions, Sauer-Danfoss engineers apply advanced design technology to new product development throughout its various facilities in the United States, Denmark and Germany. This case study is about the engineers’ use of NX™ software at the Neumünster, Germany site.
Handling critical calculations
In designing hydraulic solutions, a critical aspect is the optimization of the axial reciprocating engine, and in particular the controller. The controller has the task of connecting the circulating cylinder drillings at every half rotation with one of the pressure terminals. Pressure causes the oscillating pistons to suck in oil from one terminal and transport it to the other terminal. For simulation calculations, it is important to know the size of the passage opening on both the high- and low-pressure sides, depending on the angle of rotation. This passage opening affects the operating characteristic of the pumps in the rerouting area. In single-step mode, the passage area can be displayed for every angular step. In this way the problematic cross-section contours can be detected.
Sauer-Danfoss has been working with the Technische Universität, Hamburg-Harburg, to create simulation programs capable of ascertaining hydraulic characteristics of products under development. These programs are being developed in NX using the system’s open application programming interface – NX Open. By providing a direct programming interface to NX, custom applications can be created.
One NX-based program, for example, developed in cooperation with Conmatrix Engineering Solutions, precisely measures the passage areas in every angular position of the cylinder block. It takes the user through a number of menus, and adapts to recognize and measure different types of controls. Here, the user gets the information needed, beginning with the alignment phase, to avoid possible problems since every passage area can be visualized in the single-step mode.
Another program allows designers to analyze the effect of the cross-sectional flow on the finished product even while it is in the design stage. These two applications are just the beginning. The next step may be a recursive change of cross-sectional contours, which independently sends optimized suggestions based on the gathered data. Sven-Kelana Christiansen, CAE consultant with Conmatrix, says “The source code can be expanded and adapted as required through object-oriented program building.”
These applications establish the foundation for virtual product optimization at Sauer-Danfoss. By walking engineers through complex simulation processes, they provide ready access to the information needed to design superior hydraulic products.