A special machine builder in Detroit, who has specialized in custom machining centers for automation lines since the 1940’s approached Motion Index Drives for a precision rotary solution. The machining center was developed for Catepillar to automate the machining of an axle for a heavy earth moving construction vehicle. The precision rotary table had to be completely sealed, to eliminate any containments from entering the internal components of the indexer during the machining process. The indexer had to be capable of working with a Fanuc machining center and have the ability to communicate with the other servo motors utilized in the machining center. Stiffness of the bearing assembly on the rotary table was critical to handle the forces of machining and keeping the axle from tilting during the machining process. An accuracy of 12 arc seconds was requested by the machine builder to hold the tolerances of the machining specifications of the axle. The machine builder wanted a bearing system that could withstand high radial, tilting and axial forces. Lastly the customer asked if Motion Index Drives could accommodate them with a customer hole pattern on the top dial to allow them to mount their fixtures directly to the indexer.
SOLUTION
Motion Index Drives barrel cam programmable rotary index drive TMF5000 (custom) fit the end customer’s specification. Our TMF5000 is equipped with a programmable barrel cam and was able to achieve 9 arc seconds or accuracy, exceeding the customers’ expectations. Our four‐point contact bearing in diameter of 1350 mm is capable of achieving a bearing stiffness of 1,500,000 Nm/rad for this particular application. We equipped the TMF5000 index drive with a BSF802 SEW Eurodrive reducer with a special servo adapter that we used to mount the customer provided FANUC BETA servo motor. To eliminate machining coolant fluid and metal particulates we engineered a custom flange with special sealing to mount to the standard TMF5000 rotary dial surface. This was also machined to the customers specified hole patterns to accommodate them in quick installation of their tooling fixtures.
