Single point grinding of skiving tools
On the Haas Schleifmaschinen stand at the EMO exhibition in Milan, 4th – 9th October 2021, the grinding machine manufacturer demonstrated on one of its Multigrind machine platforms the single point grinding of a skiving tool to such close tolerances that it can produce gears to quality 2 to 3. The accuracy class when skiving gears is traditionally 4 to 6.
“Today, dimensional tolerances of two microns are not uncommon. The production of such accurate profiles requires highly complex calculations. If we want to have that under control, we have to do the math ourselves.”Wolfram Hermle, software department manager at Haas Schleifmaschinen
Two years ago, when the project to develop the required software was initiated, there was no satisfactory method on the market for determining machining cycles to achieve the ever-increasing gear precision being demanded by the industry. The goal was to create a system for calculating cycles for machining the wide variety of gears that need to be produced.
Though the finer details of the newly developed calculation model in Haas Schleifmaschinen’s Multigrind Horizon software have not been divulged, Mr Hermle confirms that gears of accuracy class 2 to 3 can be achieved. However, he pointed out that it is only one element of the process, the other being the high precision the grinding machine must be capable of achieving. The alignment of the grinding wheel must be accurate to 0.0001 degrees.
Crucial to achieving the desired grinding performance is continuous dressing of the grinding wheel and high-level measuring technology, with constant automatic workpiece measurement and closed-loop compensation of errors.
“As far as I know, this accuracy is achieved exclusively using Haas Schleifmaschinen production solutions. Only when software and hardware are perfectly matched can a skiving tool be created for manufacturing a perfect gear.”Mr Hermle