In the Pole Position
Optical Measuring System Determines Geometry of a Differential Gear Casing
- The user operates the measuring device by means of the Nexiv VMR Automeasure user interface
- The steel structure of the differential gear casing is replaced by aluminum, thereby reducing the weight of the racing car
- The differential casing is measured by the optical measuring system Nexiv VMR-3020, with the objective of substituting a different material for the casing
Students of the Vienna Technical University autonomously developed a prototype of a formula racing car. The TU's Institute of Production Engineering assisted the team in measuring a rear-axle differential gear casing. A Nikon optical measuring system determined the geometry.
The "TUW Racing" team, students of the Vienna Technical University, has been participating in the "Formula Student" racing season since 2008. The teams taking part in the competition are developing prototypes of a formula racing car, destined for the production of a thousand vehicles per year. At the end, the jury not only assesses the speed of the racing car but also features like acceleration, aerodynamics and the power-to-weight ratio. Also, the students have to present a cost plan and sales arguments.
The students of the Vienna Technical University focused their development activities on optimizing the weight. The rear-axle differential gear casing is made of steel. The team's idea was to substitute this with a lighter material like aluminum for the casing. In order to produce the differential, it had to be geometrically measured, so that the geometrically given gears could be used in the lighter differential, too. The Institute of Production assisted the team by recording the dimensions of the bores with the aid of a Nikon optical measuring system.
The measuring system (Nexiv VMR-3020) has a wide work space, so that even large components like the differential can be measured. The device uses transmitted light and allows very fine increments in adding incident light. An outer and an inner ring light will give the user optimally adjustable lighting conditions. Operation of the device during measuring is carried out via the Nexiv VMR Automeasure software. A teach-in method was used to establish the sequence of measuring: The coordinate zero was positioned in the central bore, the seat of the rear axle. The diameter of the differential and the position of the five circumferential bores were determined by the Profil Pitch Vector software, the scanning of the profile being done with a distance-between-points of 0.5 mm.
Differential Casing Race-tested
The data from the software were finally exported into an Excel spreadsheet and the measuring report was established.
With this, the students of the TUW Racing Team were able to produce the casing from aluminum. During the 2008 season, the component already saw its employment in three races, in Silverstone, England, on the German Hockenheimring and in Fiorano, Italy. And the weight optimization attained found its reward: In the first year of participation, already, the team was awarded a cup in the category of "Best Engineered Car".