Pioneering Spirit Meets Technology

Successfully replace gear measurement center with CMMs

Maximum demands are being placed on gear wheels of all sizes as mankind looks for new ways to generate energy and optimize efficiency. For this reason, Zahnradfabrik Wittmann uses a coordinate measuring machine (CMM) from Carl Zeiss to measure its parts with micrometer accuracy.

The situation

Gear wheels have been used in their simplest form for millennia to translate forces and convert energy into motion. Today, gear wheels play a vital role in the powertrains of machines and vehicles. The quality of gearing must be ensured for it to do its job with minimal loss or wear and tear. Quality is the top priority at Zahnradfabrik Wittmann GmbH. Dr. Oliver Mager, a senior executive in the company, emphasizes that “orders from our customers are not one-way streets. We are interested in long-term partnerships.” Wittmann’s customers come from a wide range of industries: gear manufacturing, mechanical engineering, special equipment construction, railway and energy technology, and wind turbines. As a contract gear manufacturer, the company produces straight and slanted-tooth spur gears, bevel gears, chain wheels, toothed-belt gears and pinion shafts from module 1 to module 36. Ninety percent of the batches have between 10 and 100 pieces. Occasionally, the company is called on to deliver single parts, prototypes and serial orders with 1000-10,000 parts. Single parts and entire batches are inspected. The gearing is subject to extreme demands, which is reflected in the requirements of DIN accuracy class 6 and higher.

Transition to 3D coordinate measuring technology

Several events led Wittmann to replace gear measuring centers with 3D coordinate measuring technology in 2009. The most important: it is the only way to meet the constantly changing needs of the market. The seamless documentation of all features, with which liability risks can be eliminated, was the primary reason. The digital documentation of the parts is a service increasingly requested by customers. Two gear wheel measuring centers were in service before the installation of an MMZ T coordinate measuring machine from Carl Zeiss. “The decision to purchase a coordinate measuring machine was based on the fact that we were faced with increasing customer requirements for optimal quality assurance and also had to increasingly measure the form and position of geometries. This was severely limited with our existing equipment,” says Dr. Mager. The measuring range on the existing gear measuring center for gear wheels was also limited to 700 mm. MMZ T and the software packages from Carl Zeiss are exactly what are needed to meet these new challenges: inspect the gearing as well as the form and position in one setting – universal measuring. What is particularly important and something that was not possible in the past: the measuring results of large parts can be seamlessly and externally documented. Measurements are prepared offline using CALYPSO measuring software with the GEAR PRO option. The CMM is not blocked for programming. The measuring program and log are automatically backed up on the server.

The highlight is an integrated rotary table. Its special position enables it to accommodate and measure gears with a diameter of up to 1500 mm with a total weight of two tons. The new climatization concept in the form of layer ventilation for a DIN quality class 3 measuring lab must also be emphasized. Dr. Oliver Mager, who describes Wittmann as an “innovative Swabian tinkerer combined with outstanding craftsmanship,” summarizes that “all our ideas, wishes and requirements have been realized. Everyone worked together.”

About the company

Zahnradfabrik Wittmann GmbH is headquartered in Uhingen, Germany. Founded in 1955, the family-owned company specializes in the complete manufacture of high-quality, customized gearing parts. True to the company’s motto – Quality sets us apart – Zahnradfabirk Wittmann offers its customers production expertise and innovative technologies for the entire process chain.