Manufacturing

Case Study:

Slicker PLM for GFT

3 April 2008

To gain faster and more cost-efficient product planning Getrag Ford Transmissions (GFT) implemented a Siemens PLM Software solution.

Getrag Ford Transmissions was founded in 2001 as a joint venture between the automobile manufacturer, Ford, and the transmissions specialist, Getrag. The company develops and manufactures manual and automated manual transmissions as well as dual-clutch transmissions for all Ford brands as well as for other OEMs.

GFT was planning to launch a new generation of dual-clutch transmissions that allow automatic gear shifting without any loss of power flow. The biggest problem in the development of a dual-clutch transmission is how to place two clutches together with all the associated hydraulic and electronic components in a space no larger than that required for a conventional transmission box. “To transfer maximum torque using a clutch that is only half the normal size, we use wet clutch systems that operate in an oil bath for high-performance engines,” says head of CAD product development at GFT, Rüdiger Muth. “This means that oil circulation through the complex internal mechanism must be guaranteed under all operating conditions.”

In the past, engineers used a graduated breaker to fill prototypes with a given quantity of oil. There was a certain amount of spillage, but even more expensive and time-consuming were examinations of the oil level under driving conditions. This not only required a tilting test rig but also the production of a transparent housing − a cost item of about 100,000 euros.

Since no commercial software could be found to determine oil levels digitally, GFT’s PLM partner, Siemens PLM Software, offered to develop a solution. The solution, based on the NX digital product development system, allows the calculation of volumes enclosed by multiple individual parts using a type of mathematical filling simulation, and is now commercially available as the SpaceFinder function in NX.

The fill simulation provides the user with a model of the ‘frozen’ oil, which is then used as a basis for further analyses. “For example, I can specify an oil level that I need for optimal transmission operation and the software determines the corresponding volume,” says Ronald Engel, technical specialist for pump and lubricant technology in dual-clutch transmissions at GFT. “This optimisation takes into account a minimum level for lubrication and a maximum amount that is dictated by price and efficiency considerations.”

Engel predicts that the new CAE tool will make many measurements in physical transmission systems unnecessary, saving time and effort, as well as the long lead times for the production of a physical prototype. “To perform a basic transmission measurement, we need at least a week in the lab,” he explains. “I can imagine that in the future we will be able to establish all of this faster and more efficiently in the CAD system prior to producing the prototypes.”

This article first appeared in the Spring 2008 issue of Prime magazine.